2e31396fa1
When transmit timestamping is enabled at the socket level, record a timestamp on packets written to a PACKET_TX_RING. Tx timestamps are always looped to the application over the socket error queue. Software timestamps are also written back into the packet frame header in the packet ring. Reported-by: Paul Chavent <paul.chavent@onera.fr> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
3502 lines
87 KiB
C
3502 lines
87 KiB
C
/*
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* Routines having to do with the 'struct sk_buff' memory handlers.
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*
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* Authors: Alan Cox <alan@lxorguk.ukuu.org.uk>
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* Florian La Roche <rzsfl@rz.uni-sb.de>
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*
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* Fixes:
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* Alan Cox : Fixed the worst of the load
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* balancer bugs.
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* Dave Platt : Interrupt stacking fix.
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* Richard Kooijman : Timestamp fixes.
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* Alan Cox : Changed buffer format.
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* Alan Cox : destructor hook for AF_UNIX etc.
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* Linus Torvalds : Better skb_clone.
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* Alan Cox : Added skb_copy.
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* Alan Cox : Added all the changed routines Linus
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* only put in the headers
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* Ray VanTassle : Fixed --skb->lock in free
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* Alan Cox : skb_copy copy arp field
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* Andi Kleen : slabified it.
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* Robert Olsson : Removed skb_head_pool
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*
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* NOTE:
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* The __skb_ routines should be called with interrupts
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* disabled, or you better be *real* sure that the operation is atomic
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* with respect to whatever list is being frobbed (e.g. via lock_sock()
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* or via disabling bottom half handlers, etc).
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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/*
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* The functions in this file will not compile correctly with gcc 2.4.x
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/kmemcheck.h>
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#include <linux/mm.h>
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#include <linux/interrupt.h>
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#include <linux/in.h>
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#include <linux/inet.h>
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#include <linux/slab.h>
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#include <linux/netdevice.h>
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#ifdef CONFIG_NET_CLS_ACT
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#include <net/pkt_sched.h>
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#endif
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#include <linux/string.h>
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#include <linux/skbuff.h>
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#include <linux/splice.h>
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#include <linux/cache.h>
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#include <linux/rtnetlink.h>
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#include <linux/init.h>
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#include <linux/scatterlist.h>
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#include <linux/errqueue.h>
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#include <linux/prefetch.h>
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#include <net/protocol.h>
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#include <net/dst.h>
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#include <net/sock.h>
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#include <net/checksum.h>
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#include <net/xfrm.h>
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#include <asm/uaccess.h>
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#include <trace/events/skb.h>
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#include <linux/highmem.h>
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struct kmem_cache *skbuff_head_cache __read_mostly;
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static struct kmem_cache *skbuff_fclone_cache __read_mostly;
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static void sock_pipe_buf_release(struct pipe_inode_info *pipe,
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struct pipe_buffer *buf)
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{
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put_page(buf->page);
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}
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static void sock_pipe_buf_get(struct pipe_inode_info *pipe,
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struct pipe_buffer *buf)
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{
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get_page(buf->page);
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}
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static int sock_pipe_buf_steal(struct pipe_inode_info *pipe,
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struct pipe_buffer *buf)
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{
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return 1;
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}
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/* Pipe buffer operations for a socket. */
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static const struct pipe_buf_operations sock_pipe_buf_ops = {
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.can_merge = 0,
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.map = generic_pipe_buf_map,
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.unmap = generic_pipe_buf_unmap,
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.confirm = generic_pipe_buf_confirm,
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.release = sock_pipe_buf_release,
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.steal = sock_pipe_buf_steal,
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.get = sock_pipe_buf_get,
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};
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/**
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* skb_panic - private function for out-of-line support
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* @skb: buffer
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* @sz: size
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* @addr: address
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* @msg: skb_over_panic or skb_under_panic
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*
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* Out-of-line support for skb_put() and skb_push().
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* Called via the wrapper skb_over_panic() or skb_under_panic().
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* Keep out of line to prevent kernel bloat.
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* __builtin_return_address is not used because it is not always reliable.
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*/
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static void skb_panic(struct sk_buff *skb, unsigned int sz, void *addr,
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const char msg[])
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{
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pr_emerg("%s: text:%p len:%d put:%d head:%p data:%p tail:%#lx end:%#lx dev:%s\n",
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msg, addr, skb->len, sz, skb->head, skb->data,
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(unsigned long)skb->tail, (unsigned long)skb->end,
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skb->dev ? skb->dev->name : "<NULL>");
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BUG();
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}
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static void skb_over_panic(struct sk_buff *skb, unsigned int sz, void *addr)
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{
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skb_panic(skb, sz, addr, __func__);
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}
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static void skb_under_panic(struct sk_buff *skb, unsigned int sz, void *addr)
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{
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skb_panic(skb, sz, addr, __func__);
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}
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/*
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* kmalloc_reserve is a wrapper around kmalloc_node_track_caller that tells
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* the caller if emergency pfmemalloc reserves are being used. If it is and
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* the socket is later found to be SOCK_MEMALLOC then PFMEMALLOC reserves
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* may be used. Otherwise, the packet data may be discarded until enough
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* memory is free
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*/
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#define kmalloc_reserve(size, gfp, node, pfmemalloc) \
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__kmalloc_reserve(size, gfp, node, _RET_IP_, pfmemalloc)
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static void *__kmalloc_reserve(size_t size, gfp_t flags, int node,
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unsigned long ip, bool *pfmemalloc)
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{
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void *obj;
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bool ret_pfmemalloc = false;
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/*
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* Try a regular allocation, when that fails and we're not entitled
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* to the reserves, fail.
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*/
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obj = kmalloc_node_track_caller(size,
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flags | __GFP_NOMEMALLOC | __GFP_NOWARN,
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node);
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if (obj || !(gfp_pfmemalloc_allowed(flags)))
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goto out;
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/* Try again but now we are using pfmemalloc reserves */
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ret_pfmemalloc = true;
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obj = kmalloc_node_track_caller(size, flags, node);
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out:
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if (pfmemalloc)
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*pfmemalloc = ret_pfmemalloc;
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return obj;
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}
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/* Allocate a new skbuff. We do this ourselves so we can fill in a few
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* 'private' fields and also do memory statistics to find all the
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* [BEEP] leaks.
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*
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*/
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struct sk_buff *__alloc_skb_head(gfp_t gfp_mask, int node)
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{
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struct sk_buff *skb;
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/* Get the HEAD */
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skb = kmem_cache_alloc_node(skbuff_head_cache,
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gfp_mask & ~__GFP_DMA, node);
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if (!skb)
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goto out;
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/*
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* Only clear those fields we need to clear, not those that we will
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* actually initialise below. Hence, don't put any more fields after
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* the tail pointer in struct sk_buff!
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*/
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memset(skb, 0, offsetof(struct sk_buff, tail));
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skb->data = NULL;
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skb->truesize = sizeof(struct sk_buff);
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atomic_set(&skb->users, 1);
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#ifdef NET_SKBUFF_DATA_USES_OFFSET
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skb->mac_header = ~0U;
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#endif
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out:
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return skb;
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}
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/**
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* __alloc_skb - allocate a network buffer
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* @size: size to allocate
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* @gfp_mask: allocation mask
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* @flags: If SKB_ALLOC_FCLONE is set, allocate from fclone cache
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* instead of head cache and allocate a cloned (child) skb.
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* If SKB_ALLOC_RX is set, __GFP_MEMALLOC will be used for
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* allocations in case the data is required for writeback
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* @node: numa node to allocate memory on
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*
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* Allocate a new &sk_buff. The returned buffer has no headroom and a
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* tail room of at least size bytes. The object has a reference count
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* of one. The return is the buffer. On a failure the return is %NULL.
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*
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* Buffers may only be allocated from interrupts using a @gfp_mask of
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* %GFP_ATOMIC.
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*/
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struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
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int flags, int node)
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{
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struct kmem_cache *cache;
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struct skb_shared_info *shinfo;
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struct sk_buff *skb;
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u8 *data;
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bool pfmemalloc;
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cache = (flags & SKB_ALLOC_FCLONE)
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? skbuff_fclone_cache : skbuff_head_cache;
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if (sk_memalloc_socks() && (flags & SKB_ALLOC_RX))
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gfp_mask |= __GFP_MEMALLOC;
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/* Get the HEAD */
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skb = kmem_cache_alloc_node(cache, gfp_mask & ~__GFP_DMA, node);
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if (!skb)
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goto out;
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prefetchw(skb);
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/* We do our best to align skb_shared_info on a separate cache
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* line. It usually works because kmalloc(X > SMP_CACHE_BYTES) gives
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* aligned memory blocks, unless SLUB/SLAB debug is enabled.
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* Both skb->head and skb_shared_info are cache line aligned.
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*/
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size = SKB_DATA_ALIGN(size);
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size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
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data = kmalloc_reserve(size, gfp_mask, node, &pfmemalloc);
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if (!data)
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goto nodata;
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/* kmalloc(size) might give us more room than requested.
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* Put skb_shared_info exactly at the end of allocated zone,
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* to allow max possible filling before reallocation.
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*/
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size = SKB_WITH_OVERHEAD(ksize(data));
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prefetchw(data + size);
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/*
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* Only clear those fields we need to clear, not those that we will
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* actually initialise below. Hence, don't put any more fields after
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* the tail pointer in struct sk_buff!
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*/
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memset(skb, 0, offsetof(struct sk_buff, tail));
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/* Account for allocated memory : skb + skb->head */
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skb->truesize = SKB_TRUESIZE(size);
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skb->pfmemalloc = pfmemalloc;
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atomic_set(&skb->users, 1);
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skb->head = data;
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skb->data = data;
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skb_reset_tail_pointer(skb);
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skb->end = skb->tail + size;
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#ifdef NET_SKBUFF_DATA_USES_OFFSET
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skb->mac_header = ~0U;
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skb->transport_header = ~0U;
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#endif
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/* make sure we initialize shinfo sequentially */
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shinfo = skb_shinfo(skb);
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memset(shinfo, 0, offsetof(struct skb_shared_info, dataref));
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atomic_set(&shinfo->dataref, 1);
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kmemcheck_annotate_variable(shinfo->destructor_arg);
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if (flags & SKB_ALLOC_FCLONE) {
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struct sk_buff *child = skb + 1;
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atomic_t *fclone_ref = (atomic_t *) (child + 1);
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kmemcheck_annotate_bitfield(child, flags1);
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kmemcheck_annotate_bitfield(child, flags2);
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skb->fclone = SKB_FCLONE_ORIG;
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atomic_set(fclone_ref, 1);
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child->fclone = SKB_FCLONE_UNAVAILABLE;
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child->pfmemalloc = pfmemalloc;
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}
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out:
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return skb;
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nodata:
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kmem_cache_free(cache, skb);
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skb = NULL;
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goto out;
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}
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EXPORT_SYMBOL(__alloc_skb);
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/**
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* build_skb - build a network buffer
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* @data: data buffer provided by caller
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* @frag_size: size of fragment, or 0 if head was kmalloced
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*
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* Allocate a new &sk_buff. Caller provides space holding head and
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* skb_shared_info. @data must have been allocated by kmalloc()
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* The return is the new skb buffer.
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* On a failure the return is %NULL, and @data is not freed.
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* Notes :
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* Before IO, driver allocates only data buffer where NIC put incoming frame
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* Driver should add room at head (NET_SKB_PAD) and
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* MUST add room at tail (SKB_DATA_ALIGN(skb_shared_info))
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* After IO, driver calls build_skb(), to allocate sk_buff and populate it
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* before giving packet to stack.
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* RX rings only contains data buffers, not full skbs.
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*/
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struct sk_buff *build_skb(void *data, unsigned int frag_size)
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{
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struct skb_shared_info *shinfo;
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struct sk_buff *skb;
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unsigned int size = frag_size ? : ksize(data);
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|
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skb = kmem_cache_alloc(skbuff_head_cache, GFP_ATOMIC);
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if (!skb)
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return NULL;
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|
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size -= SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
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|
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memset(skb, 0, offsetof(struct sk_buff, tail));
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skb->truesize = SKB_TRUESIZE(size);
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skb->head_frag = frag_size != 0;
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atomic_set(&skb->users, 1);
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skb->head = data;
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skb->data = data;
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skb_reset_tail_pointer(skb);
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skb->end = skb->tail + size;
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#ifdef NET_SKBUFF_DATA_USES_OFFSET
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skb->mac_header = ~0U;
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skb->transport_header = ~0U;
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#endif
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|
|
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/* make sure we initialize shinfo sequentially */
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shinfo = skb_shinfo(skb);
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memset(shinfo, 0, offsetof(struct skb_shared_info, dataref));
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atomic_set(&shinfo->dataref, 1);
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kmemcheck_annotate_variable(shinfo->destructor_arg);
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|
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return skb;
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}
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EXPORT_SYMBOL(build_skb);
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|
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struct netdev_alloc_cache {
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struct page_frag frag;
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/* we maintain a pagecount bias, so that we dont dirty cache line
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* containing page->_count every time we allocate a fragment.
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*/
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unsigned int pagecnt_bias;
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};
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static DEFINE_PER_CPU(struct netdev_alloc_cache, netdev_alloc_cache);
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|
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static void *__netdev_alloc_frag(unsigned int fragsz, gfp_t gfp_mask)
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{
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struct netdev_alloc_cache *nc;
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void *data = NULL;
|
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int order;
|
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unsigned long flags;
|
|
|
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local_irq_save(flags);
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nc = &__get_cpu_var(netdev_alloc_cache);
|
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if (unlikely(!nc->frag.page)) {
|
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refill:
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for (order = NETDEV_FRAG_PAGE_MAX_ORDER; ;) {
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gfp_t gfp = gfp_mask;
|
|
|
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if (order)
|
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gfp |= __GFP_COMP | __GFP_NOWARN;
|
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nc->frag.page = alloc_pages(gfp, order);
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if (likely(nc->frag.page))
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break;
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if (--order < 0)
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goto end;
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}
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nc->frag.size = PAGE_SIZE << order;
|
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recycle:
|
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atomic_set(&nc->frag.page->_count, NETDEV_PAGECNT_MAX_BIAS);
|
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nc->pagecnt_bias = NETDEV_PAGECNT_MAX_BIAS;
|
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nc->frag.offset = 0;
|
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}
|
|
|
|
if (nc->frag.offset + fragsz > nc->frag.size) {
|
|
/* avoid unnecessary locked operations if possible */
|
|
if ((atomic_read(&nc->frag.page->_count) == nc->pagecnt_bias) ||
|
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atomic_sub_and_test(nc->pagecnt_bias, &nc->frag.page->_count))
|
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goto recycle;
|
|
goto refill;
|
|
}
|
|
|
|
data = page_address(nc->frag.page) + nc->frag.offset;
|
|
nc->frag.offset += fragsz;
|
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nc->pagecnt_bias--;
|
|
end:
|
|
local_irq_restore(flags);
|
|
return data;
|
|
}
|
|
|
|
/**
|
|
* netdev_alloc_frag - allocate a page fragment
|
|
* @fragsz: fragment size
|
|
*
|
|
* Allocates a frag from a page for receive buffer.
|
|
* Uses GFP_ATOMIC allocations.
|
|
*/
|
|
void *netdev_alloc_frag(unsigned int fragsz)
|
|
{
|
|
return __netdev_alloc_frag(fragsz, GFP_ATOMIC | __GFP_COLD);
|
|
}
|
|
EXPORT_SYMBOL(netdev_alloc_frag);
|
|
|
|
/**
|
|
* __netdev_alloc_skb - allocate an skbuff for rx on a specific device
|
|
* @dev: network device to receive on
|
|
* @length: length to allocate
|
|
* @gfp_mask: get_free_pages mask, passed to alloc_skb
|
|
*
|
|
* Allocate a new &sk_buff and assign it a usage count of one. The
|
|
* buffer has unspecified headroom built in. Users should allocate
|
|
* the headroom they think they need without accounting for the
|
|
* built in space. The built in space is used for optimisations.
|
|
*
|
|
* %NULL is returned if there is no free memory.
|
|
*/
|
|
struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
|
|
unsigned int length, gfp_t gfp_mask)
|
|
{
|
|
struct sk_buff *skb = NULL;
|
|
unsigned int fragsz = SKB_DATA_ALIGN(length + NET_SKB_PAD) +
|
|
SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
|
|
|
|
if (fragsz <= PAGE_SIZE && !(gfp_mask & (__GFP_WAIT | GFP_DMA))) {
|
|
void *data;
|
|
|
|
if (sk_memalloc_socks())
|
|
gfp_mask |= __GFP_MEMALLOC;
|
|
|
|
data = __netdev_alloc_frag(fragsz, gfp_mask);
|
|
|
|
if (likely(data)) {
|
|
skb = build_skb(data, fragsz);
|
|
if (unlikely(!skb))
|
|
put_page(virt_to_head_page(data));
|
|
}
|
|
} else {
|
|
skb = __alloc_skb(length + NET_SKB_PAD, gfp_mask,
|
|
SKB_ALLOC_RX, NUMA_NO_NODE);
|
|
}
|
|
if (likely(skb)) {
|
|
skb_reserve(skb, NET_SKB_PAD);
|
|
skb->dev = dev;
|
|
}
|
|
return skb;
|
|
}
|
|
EXPORT_SYMBOL(__netdev_alloc_skb);
|
|
|
|
void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off,
|
|
int size, unsigned int truesize)
|
|
{
|
|
skb_fill_page_desc(skb, i, page, off, size);
|
|
skb->len += size;
|
|
skb->data_len += size;
|
|
skb->truesize += truesize;
|
|
}
|
|
EXPORT_SYMBOL(skb_add_rx_frag);
|
|
|
|
static void skb_drop_list(struct sk_buff **listp)
|
|
{
|
|
struct sk_buff *list = *listp;
|
|
|
|
*listp = NULL;
|
|
|
|
do {
|
|
struct sk_buff *this = list;
|
|
list = list->next;
|
|
kfree_skb(this);
|
|
} while (list);
|
|
}
|
|
|
|
static inline void skb_drop_fraglist(struct sk_buff *skb)
|
|
{
|
|
skb_drop_list(&skb_shinfo(skb)->frag_list);
|
|
}
|
|
|
|
static void skb_clone_fraglist(struct sk_buff *skb)
|
|
{
|
|
struct sk_buff *list;
|
|
|
|
skb_walk_frags(skb, list)
|
|
skb_get(list);
|
|
}
|
|
|
|
static void skb_free_head(struct sk_buff *skb)
|
|
{
|
|
if (skb->head_frag)
|
|
put_page(virt_to_head_page(skb->head));
|
|
else
|
|
kfree(skb->head);
|
|
}
|
|
|
|
static void skb_release_data(struct sk_buff *skb)
|
|
{
|
|
if (!skb->cloned ||
|
|
!atomic_sub_return(skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1,
|
|
&skb_shinfo(skb)->dataref)) {
|
|
if (skb_shinfo(skb)->nr_frags) {
|
|
int i;
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
|
|
skb_frag_unref(skb, i);
|
|
}
|
|
|
|
/*
|
|
* If skb buf is from userspace, we need to notify the caller
|
|
* the lower device DMA has done;
|
|
*/
|
|
if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) {
|
|
struct ubuf_info *uarg;
|
|
|
|
uarg = skb_shinfo(skb)->destructor_arg;
|
|
if (uarg->callback)
|
|
uarg->callback(uarg, true);
|
|
}
|
|
|
|
if (skb_has_frag_list(skb))
|
|
skb_drop_fraglist(skb);
|
|
|
|
skb_free_head(skb);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Free an skbuff by memory without cleaning the state.
|
|
*/
|
|
static void kfree_skbmem(struct sk_buff *skb)
|
|
{
|
|
struct sk_buff *other;
|
|
atomic_t *fclone_ref;
|
|
|
|
switch (skb->fclone) {
|
|
case SKB_FCLONE_UNAVAILABLE:
|
|
kmem_cache_free(skbuff_head_cache, skb);
|
|
break;
|
|
|
|
case SKB_FCLONE_ORIG:
|
|
fclone_ref = (atomic_t *) (skb + 2);
|
|
if (atomic_dec_and_test(fclone_ref))
|
|
kmem_cache_free(skbuff_fclone_cache, skb);
|
|
break;
|
|
|
|
case SKB_FCLONE_CLONE:
|
|
fclone_ref = (atomic_t *) (skb + 1);
|
|
other = skb - 1;
|
|
|
|
/* The clone portion is available for
|
|
* fast-cloning again.
|
|
*/
|
|
skb->fclone = SKB_FCLONE_UNAVAILABLE;
|
|
|
|
if (atomic_dec_and_test(fclone_ref))
|
|
kmem_cache_free(skbuff_fclone_cache, other);
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void skb_release_head_state(struct sk_buff *skb)
|
|
{
|
|
skb_dst_drop(skb);
|
|
#ifdef CONFIG_XFRM
|
|
secpath_put(skb->sp);
|
|
#endif
|
|
if (skb->destructor) {
|
|
WARN_ON(in_irq());
|
|
skb->destructor(skb);
|
|
}
|
|
#if IS_ENABLED(CONFIG_NF_CONNTRACK)
|
|
nf_conntrack_put(skb->nfct);
|
|
#endif
|
|
#ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
|
|
nf_conntrack_put_reasm(skb->nfct_reasm);
|
|
#endif
|
|
#ifdef CONFIG_BRIDGE_NETFILTER
|
|
nf_bridge_put(skb->nf_bridge);
|
|
#endif
|
|
/* XXX: IS this still necessary? - JHS */
|
|
#ifdef CONFIG_NET_SCHED
|
|
skb->tc_index = 0;
|
|
#ifdef CONFIG_NET_CLS_ACT
|
|
skb->tc_verd = 0;
|
|
#endif
|
|
#endif
|
|
}
|
|
|
|
/* Free everything but the sk_buff shell. */
|
|
static void skb_release_all(struct sk_buff *skb)
|
|
{
|
|
skb_release_head_state(skb);
|
|
if (likely(skb->data))
|
|
skb_release_data(skb);
|
|
}
|
|
|
|
/**
|
|
* __kfree_skb - private function
|
|
* @skb: buffer
|
|
*
|
|
* Free an sk_buff. Release anything attached to the buffer.
|
|
* Clean the state. This is an internal helper function. Users should
|
|
* always call kfree_skb
|
|
*/
|
|
|
|
void __kfree_skb(struct sk_buff *skb)
|
|
{
|
|
skb_release_all(skb);
|
|
kfree_skbmem(skb);
|
|
}
|
|
EXPORT_SYMBOL(__kfree_skb);
|
|
|
|
/**
|
|
* kfree_skb - free an sk_buff
|
|
* @skb: buffer to free
|
|
*
|
|
* Drop a reference to the buffer and free it if the usage count has
|
|
* hit zero.
|
|
*/
|
|
void kfree_skb(struct sk_buff *skb)
|
|
{
|
|
if (unlikely(!skb))
|
|
return;
|
|
if (likely(atomic_read(&skb->users) == 1))
|
|
smp_rmb();
|
|
else if (likely(!atomic_dec_and_test(&skb->users)))
|
|
return;
|
|
trace_kfree_skb(skb, __builtin_return_address(0));
|
|
__kfree_skb(skb);
|
|
}
|
|
EXPORT_SYMBOL(kfree_skb);
|
|
|
|
/**
|
|
* skb_tx_error - report an sk_buff xmit error
|
|
* @skb: buffer that triggered an error
|
|
*
|
|
* Report xmit error if a device callback is tracking this skb.
|
|
* skb must be freed afterwards.
|
|
*/
|
|
void skb_tx_error(struct sk_buff *skb)
|
|
{
|
|
if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) {
|
|
struct ubuf_info *uarg;
|
|
|
|
uarg = skb_shinfo(skb)->destructor_arg;
|
|
if (uarg->callback)
|
|
uarg->callback(uarg, false);
|
|
skb_shinfo(skb)->tx_flags &= ~SKBTX_DEV_ZEROCOPY;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(skb_tx_error);
|
|
|
|
/**
|
|
* consume_skb - free an skbuff
|
|
* @skb: buffer to free
|
|
*
|
|
* Drop a ref to the buffer and free it if the usage count has hit zero
|
|
* Functions identically to kfree_skb, but kfree_skb assumes that the frame
|
|
* is being dropped after a failure and notes that
|
|
*/
|
|
void consume_skb(struct sk_buff *skb)
|
|
{
|
|
if (unlikely(!skb))
|
|
return;
|
|
if (likely(atomic_read(&skb->users) == 1))
|
|
smp_rmb();
|
|
else if (likely(!atomic_dec_and_test(&skb->users)))
|
|
return;
|
|
trace_consume_skb(skb);
|
|
__kfree_skb(skb);
|
|
}
|
|
EXPORT_SYMBOL(consume_skb);
|
|
|
|
static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
|
|
{
|
|
new->tstamp = old->tstamp;
|
|
new->dev = old->dev;
|
|
new->transport_header = old->transport_header;
|
|
new->network_header = old->network_header;
|
|
new->mac_header = old->mac_header;
|
|
new->inner_transport_header = old->inner_transport_header;
|
|
new->inner_network_header = old->inner_network_header;
|
|
new->inner_mac_header = old->inner_mac_header;
|
|
skb_dst_copy(new, old);
|
|
new->rxhash = old->rxhash;
|
|
new->ooo_okay = old->ooo_okay;
|
|
new->l4_rxhash = old->l4_rxhash;
|
|
new->no_fcs = old->no_fcs;
|
|
new->encapsulation = old->encapsulation;
|
|
#ifdef CONFIG_XFRM
|
|
new->sp = secpath_get(old->sp);
|
|
#endif
|
|
memcpy(new->cb, old->cb, sizeof(old->cb));
|
|
new->csum = old->csum;
|
|
new->local_df = old->local_df;
|
|
new->pkt_type = old->pkt_type;
|
|
new->ip_summed = old->ip_summed;
|
|
skb_copy_queue_mapping(new, old);
|
|
new->priority = old->priority;
|
|
#if IS_ENABLED(CONFIG_IP_VS)
|
|
new->ipvs_property = old->ipvs_property;
|
|
#endif
|
|
new->pfmemalloc = old->pfmemalloc;
|
|
new->protocol = old->protocol;
|
|
new->mark = old->mark;
|
|
new->skb_iif = old->skb_iif;
|
|
__nf_copy(new, old);
|
|
#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
|
|
new->nf_trace = old->nf_trace;
|
|
#endif
|
|
#ifdef CONFIG_NET_SCHED
|
|
new->tc_index = old->tc_index;
|
|
#ifdef CONFIG_NET_CLS_ACT
|
|
new->tc_verd = old->tc_verd;
|
|
#endif
|
|
#endif
|
|
new->vlan_proto = old->vlan_proto;
|
|
new->vlan_tci = old->vlan_tci;
|
|
|
|
skb_copy_secmark(new, old);
|
|
}
|
|
|
|
/*
|
|
* You should not add any new code to this function. Add it to
|
|
* __copy_skb_header above instead.
|
|
*/
|
|
static struct sk_buff *__skb_clone(struct sk_buff *n, struct sk_buff *skb)
|
|
{
|
|
#define C(x) n->x = skb->x
|
|
|
|
n->next = n->prev = NULL;
|
|
n->sk = NULL;
|
|
__copy_skb_header(n, skb);
|
|
|
|
C(len);
|
|
C(data_len);
|
|
C(mac_len);
|
|
n->hdr_len = skb->nohdr ? skb_headroom(skb) : skb->hdr_len;
|
|
n->cloned = 1;
|
|
n->nohdr = 0;
|
|
n->destructor = NULL;
|
|
C(tail);
|
|
C(end);
|
|
C(head);
|
|
C(head_frag);
|
|
C(data);
|
|
C(truesize);
|
|
atomic_set(&n->users, 1);
|
|
|
|
atomic_inc(&(skb_shinfo(skb)->dataref));
|
|
skb->cloned = 1;
|
|
|
|
return n;
|
|
#undef C
|
|
}
|
|
|
|
/**
|
|
* skb_morph - morph one skb into another
|
|
* @dst: the skb to receive the contents
|
|
* @src: the skb to supply the contents
|
|
*
|
|
* This is identical to skb_clone except that the target skb is
|
|
* supplied by the user.
|
|
*
|
|
* The target skb is returned upon exit.
|
|
*/
|
|
struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src)
|
|
{
|
|
skb_release_all(dst);
|
|
return __skb_clone(dst, src);
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_morph);
|
|
|
|
/**
|
|
* skb_copy_ubufs - copy userspace skb frags buffers to kernel
|
|
* @skb: the skb to modify
|
|
* @gfp_mask: allocation priority
|
|
*
|
|
* This must be called on SKBTX_DEV_ZEROCOPY skb.
|
|
* It will copy all frags into kernel and drop the reference
|
|
* to userspace pages.
|
|
*
|
|
* If this function is called from an interrupt gfp_mask() must be
|
|
* %GFP_ATOMIC.
|
|
*
|
|
* Returns 0 on success or a negative error code on failure
|
|
* to allocate kernel memory to copy to.
|
|
*/
|
|
int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask)
|
|
{
|
|
int i;
|
|
int num_frags = skb_shinfo(skb)->nr_frags;
|
|
struct page *page, *head = NULL;
|
|
struct ubuf_info *uarg = skb_shinfo(skb)->destructor_arg;
|
|
|
|
for (i = 0; i < num_frags; i++) {
|
|
u8 *vaddr;
|
|
skb_frag_t *f = &skb_shinfo(skb)->frags[i];
|
|
|
|
page = alloc_page(gfp_mask);
|
|
if (!page) {
|
|
while (head) {
|
|
struct page *next = (struct page *)head->private;
|
|
put_page(head);
|
|
head = next;
|
|
}
|
|
return -ENOMEM;
|
|
}
|
|
vaddr = kmap_atomic(skb_frag_page(f));
|
|
memcpy(page_address(page),
|
|
vaddr + f->page_offset, skb_frag_size(f));
|
|
kunmap_atomic(vaddr);
|
|
page->private = (unsigned long)head;
|
|
head = page;
|
|
}
|
|
|
|
/* skb frags release userspace buffers */
|
|
for (i = 0; i < num_frags; i++)
|
|
skb_frag_unref(skb, i);
|
|
|
|
uarg->callback(uarg, false);
|
|
|
|
/* skb frags point to kernel buffers */
|
|
for (i = num_frags - 1; i >= 0; i--) {
|
|
__skb_fill_page_desc(skb, i, head, 0,
|
|
skb_shinfo(skb)->frags[i].size);
|
|
head = (struct page *)head->private;
|
|
}
|
|
|
|
skb_shinfo(skb)->tx_flags &= ~SKBTX_DEV_ZEROCOPY;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_copy_ubufs);
|
|
|
|
/**
|
|
* skb_clone - duplicate an sk_buff
|
|
* @skb: buffer to clone
|
|
* @gfp_mask: allocation priority
|
|
*
|
|
* Duplicate an &sk_buff. The new one is not owned by a socket. Both
|
|
* copies share the same packet data but not structure. The new
|
|
* buffer has a reference count of 1. If the allocation fails the
|
|
* function returns %NULL otherwise the new buffer is returned.
|
|
*
|
|
* If this function is called from an interrupt gfp_mask() must be
|
|
* %GFP_ATOMIC.
|
|
*/
|
|
|
|
struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
|
|
{
|
|
struct sk_buff *n;
|
|
|
|
if (skb_orphan_frags(skb, gfp_mask))
|
|
return NULL;
|
|
|
|
n = skb + 1;
|
|
if (skb->fclone == SKB_FCLONE_ORIG &&
|
|
n->fclone == SKB_FCLONE_UNAVAILABLE) {
|
|
atomic_t *fclone_ref = (atomic_t *) (n + 1);
|
|
n->fclone = SKB_FCLONE_CLONE;
|
|
atomic_inc(fclone_ref);
|
|
} else {
|
|
if (skb_pfmemalloc(skb))
|
|
gfp_mask |= __GFP_MEMALLOC;
|
|
|
|
n = kmem_cache_alloc(skbuff_head_cache, gfp_mask);
|
|
if (!n)
|
|
return NULL;
|
|
|
|
kmemcheck_annotate_bitfield(n, flags1);
|
|
kmemcheck_annotate_bitfield(n, flags2);
|
|
n->fclone = SKB_FCLONE_UNAVAILABLE;
|
|
}
|
|
|
|
return __skb_clone(n, skb);
|
|
}
|
|
EXPORT_SYMBOL(skb_clone);
|
|
|
|
static void skb_headers_offset_update(struct sk_buff *skb, int off)
|
|
{
|
|
/* {transport,network,mac}_header and tail are relative to skb->head */
|
|
skb->transport_header += off;
|
|
skb->network_header += off;
|
|
if (skb_mac_header_was_set(skb))
|
|
skb->mac_header += off;
|
|
skb->inner_transport_header += off;
|
|
skb->inner_network_header += off;
|
|
skb->inner_mac_header += off;
|
|
}
|
|
|
|
static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
|
|
{
|
|
#ifndef NET_SKBUFF_DATA_USES_OFFSET
|
|
/*
|
|
* Shift between the two data areas in bytes
|
|
*/
|
|
unsigned long offset = new->data - old->data;
|
|
#endif
|
|
|
|
__copy_skb_header(new, old);
|
|
|
|
#ifndef NET_SKBUFF_DATA_USES_OFFSET
|
|
skb_headers_offset_update(new, offset);
|
|
#endif
|
|
skb_shinfo(new)->gso_size = skb_shinfo(old)->gso_size;
|
|
skb_shinfo(new)->gso_segs = skb_shinfo(old)->gso_segs;
|
|
skb_shinfo(new)->gso_type = skb_shinfo(old)->gso_type;
|
|
}
|
|
|
|
static inline int skb_alloc_rx_flag(const struct sk_buff *skb)
|
|
{
|
|
if (skb_pfmemalloc(skb))
|
|
return SKB_ALLOC_RX;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* skb_copy - create private copy of an sk_buff
|
|
* @skb: buffer to copy
|
|
* @gfp_mask: allocation priority
|
|
*
|
|
* Make a copy of both an &sk_buff and its data. This is used when the
|
|
* caller wishes to modify the data and needs a private copy of the
|
|
* data to alter. Returns %NULL on failure or the pointer to the buffer
|
|
* on success. The returned buffer has a reference count of 1.
|
|
*
|
|
* As by-product this function converts non-linear &sk_buff to linear
|
|
* one, so that &sk_buff becomes completely private and caller is allowed
|
|
* to modify all the data of returned buffer. This means that this
|
|
* function is not recommended for use in circumstances when only
|
|
* header is going to be modified. Use pskb_copy() instead.
|
|
*/
|
|
|
|
struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t gfp_mask)
|
|
{
|
|
int headerlen = skb_headroom(skb);
|
|
unsigned int size = skb_end_offset(skb) + skb->data_len;
|
|
struct sk_buff *n = __alloc_skb(size, gfp_mask,
|
|
skb_alloc_rx_flag(skb), NUMA_NO_NODE);
|
|
|
|
if (!n)
|
|
return NULL;
|
|
|
|
/* Set the data pointer */
|
|
skb_reserve(n, headerlen);
|
|
/* Set the tail pointer and length */
|
|
skb_put(n, skb->len);
|
|
|
|
if (skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len))
|
|
BUG();
|
|
|
|
copy_skb_header(n, skb);
|
|
return n;
|
|
}
|
|
EXPORT_SYMBOL(skb_copy);
|
|
|
|
/**
|
|
* __pskb_copy - create copy of an sk_buff with private head.
|
|
* @skb: buffer to copy
|
|
* @headroom: headroom of new skb
|
|
* @gfp_mask: allocation priority
|
|
*
|
|
* Make a copy of both an &sk_buff and part of its data, located
|
|
* in header. Fragmented data remain shared. This is used when
|
|
* the caller wishes to modify only header of &sk_buff and needs
|
|
* private copy of the header to alter. Returns %NULL on failure
|
|
* or the pointer to the buffer on success.
|
|
* The returned buffer has a reference count of 1.
|
|
*/
|
|
|
|
struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom, gfp_t gfp_mask)
|
|
{
|
|
unsigned int size = skb_headlen(skb) + headroom;
|
|
struct sk_buff *n = __alloc_skb(size, gfp_mask,
|
|
skb_alloc_rx_flag(skb), NUMA_NO_NODE);
|
|
|
|
if (!n)
|
|
goto out;
|
|
|
|
/* Set the data pointer */
|
|
skb_reserve(n, headroom);
|
|
/* Set the tail pointer and length */
|
|
skb_put(n, skb_headlen(skb));
|
|
/* Copy the bytes */
|
|
skb_copy_from_linear_data(skb, n->data, n->len);
|
|
|
|
n->truesize += skb->data_len;
|
|
n->data_len = skb->data_len;
|
|
n->len = skb->len;
|
|
|
|
if (skb_shinfo(skb)->nr_frags) {
|
|
int i;
|
|
|
|
if (skb_orphan_frags(skb, gfp_mask)) {
|
|
kfree_skb(n);
|
|
n = NULL;
|
|
goto out;
|
|
}
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
skb_shinfo(n)->frags[i] = skb_shinfo(skb)->frags[i];
|
|
skb_frag_ref(skb, i);
|
|
}
|
|
skb_shinfo(n)->nr_frags = i;
|
|
}
|
|
|
|
if (skb_has_frag_list(skb)) {
|
|
skb_shinfo(n)->frag_list = skb_shinfo(skb)->frag_list;
|
|
skb_clone_fraglist(n);
|
|
}
|
|
|
|
copy_skb_header(n, skb);
|
|
out:
|
|
return n;
|
|
}
|
|
EXPORT_SYMBOL(__pskb_copy);
|
|
|
|
/**
|
|
* pskb_expand_head - reallocate header of &sk_buff
|
|
* @skb: buffer to reallocate
|
|
* @nhead: room to add at head
|
|
* @ntail: room to add at tail
|
|
* @gfp_mask: allocation priority
|
|
*
|
|
* Expands (or creates identical copy, if &nhead and &ntail are zero)
|
|
* header of skb. &sk_buff itself is not changed. &sk_buff MUST have
|
|
* reference count of 1. Returns zero in the case of success or error,
|
|
* if expansion failed. In the last case, &sk_buff is not changed.
|
|
*
|
|
* All the pointers pointing into skb header may change and must be
|
|
* reloaded after call to this function.
|
|
*/
|
|
|
|
int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
|
|
gfp_t gfp_mask)
|
|
{
|
|
int i;
|
|
u8 *data;
|
|
int size = nhead + skb_end_offset(skb) + ntail;
|
|
long off;
|
|
|
|
BUG_ON(nhead < 0);
|
|
|
|
if (skb_shared(skb))
|
|
BUG();
|
|
|
|
size = SKB_DATA_ALIGN(size);
|
|
|
|
if (skb_pfmemalloc(skb))
|
|
gfp_mask |= __GFP_MEMALLOC;
|
|
data = kmalloc_reserve(size + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)),
|
|
gfp_mask, NUMA_NO_NODE, NULL);
|
|
if (!data)
|
|
goto nodata;
|
|
size = SKB_WITH_OVERHEAD(ksize(data));
|
|
|
|
/* Copy only real data... and, alas, header. This should be
|
|
* optimized for the cases when header is void.
|
|
*/
|
|
memcpy(data + nhead, skb->head, skb_tail_pointer(skb) - skb->head);
|
|
|
|
memcpy((struct skb_shared_info *)(data + size),
|
|
skb_shinfo(skb),
|
|
offsetof(struct skb_shared_info, frags[skb_shinfo(skb)->nr_frags]));
|
|
|
|
/*
|
|
* if shinfo is shared we must drop the old head gracefully, but if it
|
|
* is not we can just drop the old head and let the existing refcount
|
|
* be since all we did is relocate the values
|
|
*/
|
|
if (skb_cloned(skb)) {
|
|
/* copy this zero copy skb frags */
|
|
if (skb_orphan_frags(skb, gfp_mask))
|
|
goto nofrags;
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
|
|
skb_frag_ref(skb, i);
|
|
|
|
if (skb_has_frag_list(skb))
|
|
skb_clone_fraglist(skb);
|
|
|
|
skb_release_data(skb);
|
|
} else {
|
|
skb_free_head(skb);
|
|
}
|
|
off = (data + nhead) - skb->head;
|
|
|
|
skb->head = data;
|
|
skb->head_frag = 0;
|
|
skb->data += off;
|
|
#ifdef NET_SKBUFF_DATA_USES_OFFSET
|
|
skb->end = size;
|
|
off = nhead;
|
|
#else
|
|
skb->end = skb->head + size;
|
|
#endif
|
|
skb->tail += off;
|
|
skb_headers_offset_update(skb, off);
|
|
/* Only adjust this if it actually is csum_start rather than csum */
|
|
if (skb->ip_summed == CHECKSUM_PARTIAL)
|
|
skb->csum_start += nhead;
|
|
skb->cloned = 0;
|
|
skb->hdr_len = 0;
|
|
skb->nohdr = 0;
|
|
atomic_set(&skb_shinfo(skb)->dataref, 1);
|
|
return 0;
|
|
|
|
nofrags:
|
|
kfree(data);
|
|
nodata:
|
|
return -ENOMEM;
|
|
}
|
|
EXPORT_SYMBOL(pskb_expand_head);
|
|
|
|
/* Make private copy of skb with writable head and some headroom */
|
|
|
|
struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, unsigned int headroom)
|
|
{
|
|
struct sk_buff *skb2;
|
|
int delta = headroom - skb_headroom(skb);
|
|
|
|
if (delta <= 0)
|
|
skb2 = pskb_copy(skb, GFP_ATOMIC);
|
|
else {
|
|
skb2 = skb_clone(skb, GFP_ATOMIC);
|
|
if (skb2 && pskb_expand_head(skb2, SKB_DATA_ALIGN(delta), 0,
|
|
GFP_ATOMIC)) {
|
|
kfree_skb(skb2);
|
|
skb2 = NULL;
|
|
}
|
|
}
|
|
return skb2;
|
|
}
|
|
EXPORT_SYMBOL(skb_realloc_headroom);
|
|
|
|
/**
|
|
* skb_copy_expand - copy and expand sk_buff
|
|
* @skb: buffer to copy
|
|
* @newheadroom: new free bytes at head
|
|
* @newtailroom: new free bytes at tail
|
|
* @gfp_mask: allocation priority
|
|
*
|
|
* Make a copy of both an &sk_buff and its data and while doing so
|
|
* allocate additional space.
|
|
*
|
|
* This is used when the caller wishes to modify the data and needs a
|
|
* private copy of the data to alter as well as more space for new fields.
|
|
* Returns %NULL on failure or the pointer to the buffer
|
|
* on success. The returned buffer has a reference count of 1.
|
|
*
|
|
* You must pass %GFP_ATOMIC as the allocation priority if this function
|
|
* is called from an interrupt.
|
|
*/
|
|
struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
|
|
int newheadroom, int newtailroom,
|
|
gfp_t gfp_mask)
|
|
{
|
|
/*
|
|
* Allocate the copy buffer
|
|
*/
|
|
struct sk_buff *n = __alloc_skb(newheadroom + skb->len + newtailroom,
|
|
gfp_mask, skb_alloc_rx_flag(skb),
|
|
NUMA_NO_NODE);
|
|
int oldheadroom = skb_headroom(skb);
|
|
int head_copy_len, head_copy_off;
|
|
int off;
|
|
|
|
if (!n)
|
|
return NULL;
|
|
|
|
skb_reserve(n, newheadroom);
|
|
|
|
/* Set the tail pointer and length */
|
|
skb_put(n, skb->len);
|
|
|
|
head_copy_len = oldheadroom;
|
|
head_copy_off = 0;
|
|
if (newheadroom <= head_copy_len)
|
|
head_copy_len = newheadroom;
|
|
else
|
|
head_copy_off = newheadroom - head_copy_len;
|
|
|
|
/* Copy the linear header and data. */
|
|
if (skb_copy_bits(skb, -head_copy_len, n->head + head_copy_off,
|
|
skb->len + head_copy_len))
|
|
BUG();
|
|
|
|
copy_skb_header(n, skb);
|
|
|
|
off = newheadroom - oldheadroom;
|
|
if (n->ip_summed == CHECKSUM_PARTIAL)
|
|
n->csum_start += off;
|
|
#ifdef NET_SKBUFF_DATA_USES_OFFSET
|
|
skb_headers_offset_update(n, off);
|
|
#endif
|
|
|
|
return n;
|
|
}
|
|
EXPORT_SYMBOL(skb_copy_expand);
|
|
|
|
/**
|
|
* skb_pad - zero pad the tail of an skb
|
|
* @skb: buffer to pad
|
|
* @pad: space to pad
|
|
*
|
|
* Ensure that a buffer is followed by a padding area that is zero
|
|
* filled. Used by network drivers which may DMA or transfer data
|
|
* beyond the buffer end onto the wire.
|
|
*
|
|
* May return error in out of memory cases. The skb is freed on error.
|
|
*/
|
|
|
|
int skb_pad(struct sk_buff *skb, int pad)
|
|
{
|
|
int err;
|
|
int ntail;
|
|
|
|
/* If the skbuff is non linear tailroom is always zero.. */
|
|
if (!skb_cloned(skb) && skb_tailroom(skb) >= pad) {
|
|
memset(skb->data+skb->len, 0, pad);
|
|
return 0;
|
|
}
|
|
|
|
ntail = skb->data_len + pad - (skb->end - skb->tail);
|
|
if (likely(skb_cloned(skb) || ntail > 0)) {
|
|
err = pskb_expand_head(skb, 0, ntail, GFP_ATOMIC);
|
|
if (unlikely(err))
|
|
goto free_skb;
|
|
}
|
|
|
|
/* FIXME: The use of this function with non-linear skb's really needs
|
|
* to be audited.
|
|
*/
|
|
err = skb_linearize(skb);
|
|
if (unlikely(err))
|
|
goto free_skb;
|
|
|
|
memset(skb->data + skb->len, 0, pad);
|
|
return 0;
|
|
|
|
free_skb:
|
|
kfree_skb(skb);
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(skb_pad);
|
|
|
|
/**
|
|
* skb_put - add data to a buffer
|
|
* @skb: buffer to use
|
|
* @len: amount of data to add
|
|
*
|
|
* This function extends the used data area of the buffer. If this would
|
|
* exceed the total buffer size the kernel will panic. A pointer to the
|
|
* first byte of the extra data is returned.
|
|
*/
|
|
unsigned char *skb_put(struct sk_buff *skb, unsigned int len)
|
|
{
|
|
unsigned char *tmp = skb_tail_pointer(skb);
|
|
SKB_LINEAR_ASSERT(skb);
|
|
skb->tail += len;
|
|
skb->len += len;
|
|
if (unlikely(skb->tail > skb->end))
|
|
skb_over_panic(skb, len, __builtin_return_address(0));
|
|
return tmp;
|
|
}
|
|
EXPORT_SYMBOL(skb_put);
|
|
|
|
/**
|
|
* skb_push - add data to the start of a buffer
|
|
* @skb: buffer to use
|
|
* @len: amount of data to add
|
|
*
|
|
* This function extends the used data area of the buffer at the buffer
|
|
* start. If this would exceed the total buffer headroom the kernel will
|
|
* panic. A pointer to the first byte of the extra data is returned.
|
|
*/
|
|
unsigned char *skb_push(struct sk_buff *skb, unsigned int len)
|
|
{
|
|
skb->data -= len;
|
|
skb->len += len;
|
|
if (unlikely(skb->data<skb->head))
|
|
skb_under_panic(skb, len, __builtin_return_address(0));
|
|
return skb->data;
|
|
}
|
|
EXPORT_SYMBOL(skb_push);
|
|
|
|
/**
|
|
* skb_pull - remove data from the start of a buffer
|
|
* @skb: buffer to use
|
|
* @len: amount of data to remove
|
|
*
|
|
* This function removes data from the start of a buffer, returning
|
|
* the memory to the headroom. A pointer to the next data in the buffer
|
|
* is returned. Once the data has been pulled future pushes will overwrite
|
|
* the old data.
|
|
*/
|
|
unsigned char *skb_pull(struct sk_buff *skb, unsigned int len)
|
|
{
|
|
return skb_pull_inline(skb, len);
|
|
}
|
|
EXPORT_SYMBOL(skb_pull);
|
|
|
|
/**
|
|
* skb_trim - remove end from a buffer
|
|
* @skb: buffer to alter
|
|
* @len: new length
|
|
*
|
|
* Cut the length of a buffer down by removing data from the tail. If
|
|
* the buffer is already under the length specified it is not modified.
|
|
* The skb must be linear.
|
|
*/
|
|
void skb_trim(struct sk_buff *skb, unsigned int len)
|
|
{
|
|
if (skb->len > len)
|
|
__skb_trim(skb, len);
|
|
}
|
|
EXPORT_SYMBOL(skb_trim);
|
|
|
|
/* Trims skb to length len. It can change skb pointers.
|
|
*/
|
|
|
|
int ___pskb_trim(struct sk_buff *skb, unsigned int len)
|
|
{
|
|
struct sk_buff **fragp;
|
|
struct sk_buff *frag;
|
|
int offset = skb_headlen(skb);
|
|
int nfrags = skb_shinfo(skb)->nr_frags;
|
|
int i;
|
|
int err;
|
|
|
|
if (skb_cloned(skb) &&
|
|
unlikely((err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC))))
|
|
return err;
|
|
|
|
i = 0;
|
|
if (offset >= len)
|
|
goto drop_pages;
|
|
|
|
for (; i < nfrags; i++) {
|
|
int end = offset + skb_frag_size(&skb_shinfo(skb)->frags[i]);
|
|
|
|
if (end < len) {
|
|
offset = end;
|
|
continue;
|
|
}
|
|
|
|
skb_frag_size_set(&skb_shinfo(skb)->frags[i++], len - offset);
|
|
|
|
drop_pages:
|
|
skb_shinfo(skb)->nr_frags = i;
|
|
|
|
for (; i < nfrags; i++)
|
|
skb_frag_unref(skb, i);
|
|
|
|
if (skb_has_frag_list(skb))
|
|
skb_drop_fraglist(skb);
|
|
goto done;
|
|
}
|
|
|
|
for (fragp = &skb_shinfo(skb)->frag_list; (frag = *fragp);
|
|
fragp = &frag->next) {
|
|
int end = offset + frag->len;
|
|
|
|
if (skb_shared(frag)) {
|
|
struct sk_buff *nfrag;
|
|
|
|
nfrag = skb_clone(frag, GFP_ATOMIC);
|
|
if (unlikely(!nfrag))
|
|
return -ENOMEM;
|
|
|
|
nfrag->next = frag->next;
|
|
consume_skb(frag);
|
|
frag = nfrag;
|
|
*fragp = frag;
|
|
}
|
|
|
|
if (end < len) {
|
|
offset = end;
|
|
continue;
|
|
}
|
|
|
|
if (end > len &&
|
|
unlikely((err = pskb_trim(frag, len - offset))))
|
|
return err;
|
|
|
|
if (frag->next)
|
|
skb_drop_list(&frag->next);
|
|
break;
|
|
}
|
|
|
|
done:
|
|
if (len > skb_headlen(skb)) {
|
|
skb->data_len -= skb->len - len;
|
|
skb->len = len;
|
|
} else {
|
|
skb->len = len;
|
|
skb->data_len = 0;
|
|
skb_set_tail_pointer(skb, len);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(___pskb_trim);
|
|
|
|
/**
|
|
* __pskb_pull_tail - advance tail of skb header
|
|
* @skb: buffer to reallocate
|
|
* @delta: number of bytes to advance tail
|
|
*
|
|
* The function makes a sense only on a fragmented &sk_buff,
|
|
* it expands header moving its tail forward and copying necessary
|
|
* data from fragmented part.
|
|
*
|
|
* &sk_buff MUST have reference count of 1.
|
|
*
|
|
* Returns %NULL (and &sk_buff does not change) if pull failed
|
|
* or value of new tail of skb in the case of success.
|
|
*
|
|
* All the pointers pointing into skb header may change and must be
|
|
* reloaded after call to this function.
|
|
*/
|
|
|
|
/* Moves tail of skb head forward, copying data from fragmented part,
|
|
* when it is necessary.
|
|
* 1. It may fail due to malloc failure.
|
|
* 2. It may change skb pointers.
|
|
*
|
|
* It is pretty complicated. Luckily, it is called only in exceptional cases.
|
|
*/
|
|
unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta)
|
|
{
|
|
/* If skb has not enough free space at tail, get new one
|
|
* plus 128 bytes for future expansions. If we have enough
|
|
* room at tail, reallocate without expansion only if skb is cloned.
|
|
*/
|
|
int i, k, eat = (skb->tail + delta) - skb->end;
|
|
|
|
if (eat > 0 || skb_cloned(skb)) {
|
|
if (pskb_expand_head(skb, 0, eat > 0 ? eat + 128 : 0,
|
|
GFP_ATOMIC))
|
|
return NULL;
|
|
}
|
|
|
|
if (skb_copy_bits(skb, skb_headlen(skb), skb_tail_pointer(skb), delta))
|
|
BUG();
|
|
|
|
/* Optimization: no fragments, no reasons to preestimate
|
|
* size of pulled pages. Superb.
|
|
*/
|
|
if (!skb_has_frag_list(skb))
|
|
goto pull_pages;
|
|
|
|
/* Estimate size of pulled pages. */
|
|
eat = delta;
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
int size = skb_frag_size(&skb_shinfo(skb)->frags[i]);
|
|
|
|
if (size >= eat)
|
|
goto pull_pages;
|
|
eat -= size;
|
|
}
|
|
|
|
/* If we need update frag list, we are in troubles.
|
|
* Certainly, it possible to add an offset to skb data,
|
|
* but taking into account that pulling is expected to
|
|
* be very rare operation, it is worth to fight against
|
|
* further bloating skb head and crucify ourselves here instead.
|
|
* Pure masohism, indeed. 8)8)
|
|
*/
|
|
if (eat) {
|
|
struct sk_buff *list = skb_shinfo(skb)->frag_list;
|
|
struct sk_buff *clone = NULL;
|
|
struct sk_buff *insp = NULL;
|
|
|
|
do {
|
|
BUG_ON(!list);
|
|
|
|
if (list->len <= eat) {
|
|
/* Eaten as whole. */
|
|
eat -= list->len;
|
|
list = list->next;
|
|
insp = list;
|
|
} else {
|
|
/* Eaten partially. */
|
|
|
|
if (skb_shared(list)) {
|
|
/* Sucks! We need to fork list. :-( */
|
|
clone = skb_clone(list, GFP_ATOMIC);
|
|
if (!clone)
|
|
return NULL;
|
|
insp = list->next;
|
|
list = clone;
|
|
} else {
|
|
/* This may be pulled without
|
|
* problems. */
|
|
insp = list;
|
|
}
|
|
if (!pskb_pull(list, eat)) {
|
|
kfree_skb(clone);
|
|
return NULL;
|
|
}
|
|
break;
|
|
}
|
|
} while (eat);
|
|
|
|
/* Free pulled out fragments. */
|
|
while ((list = skb_shinfo(skb)->frag_list) != insp) {
|
|
skb_shinfo(skb)->frag_list = list->next;
|
|
kfree_skb(list);
|
|
}
|
|
/* And insert new clone at head. */
|
|
if (clone) {
|
|
clone->next = list;
|
|
skb_shinfo(skb)->frag_list = clone;
|
|
}
|
|
}
|
|
/* Success! Now we may commit changes to skb data. */
|
|
|
|
pull_pages:
|
|
eat = delta;
|
|
k = 0;
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
int size = skb_frag_size(&skb_shinfo(skb)->frags[i]);
|
|
|
|
if (size <= eat) {
|
|
skb_frag_unref(skb, i);
|
|
eat -= size;
|
|
} else {
|
|
skb_shinfo(skb)->frags[k] = skb_shinfo(skb)->frags[i];
|
|
if (eat) {
|
|
skb_shinfo(skb)->frags[k].page_offset += eat;
|
|
skb_frag_size_sub(&skb_shinfo(skb)->frags[k], eat);
|
|
eat = 0;
|
|
}
|
|
k++;
|
|
}
|
|
}
|
|
skb_shinfo(skb)->nr_frags = k;
|
|
|
|
skb->tail += delta;
|
|
skb->data_len -= delta;
|
|
|
|
return skb_tail_pointer(skb);
|
|
}
|
|
EXPORT_SYMBOL(__pskb_pull_tail);
|
|
|
|
/**
|
|
* skb_copy_bits - copy bits from skb to kernel buffer
|
|
* @skb: source skb
|
|
* @offset: offset in source
|
|
* @to: destination buffer
|
|
* @len: number of bytes to copy
|
|
*
|
|
* Copy the specified number of bytes from the source skb to the
|
|
* destination buffer.
|
|
*
|
|
* CAUTION ! :
|
|
* If its prototype is ever changed,
|
|
* check arch/{*}/net/{*}.S files,
|
|
* since it is called from BPF assembly code.
|
|
*/
|
|
int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len)
|
|
{
|
|
int start = skb_headlen(skb);
|
|
struct sk_buff *frag_iter;
|
|
int i, copy;
|
|
|
|
if (offset > (int)skb->len - len)
|
|
goto fault;
|
|
|
|
/* Copy header. */
|
|
if ((copy = start - offset) > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
skb_copy_from_linear_data_offset(skb, offset, to, copy);
|
|
if ((len -= copy) == 0)
|
|
return 0;
|
|
offset += copy;
|
|
to += copy;
|
|
}
|
|
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
int end;
|
|
skb_frag_t *f = &skb_shinfo(skb)->frags[i];
|
|
|
|
WARN_ON(start > offset + len);
|
|
|
|
end = start + skb_frag_size(f);
|
|
if ((copy = end - offset) > 0) {
|
|
u8 *vaddr;
|
|
|
|
if (copy > len)
|
|
copy = len;
|
|
|
|
vaddr = kmap_atomic(skb_frag_page(f));
|
|
memcpy(to,
|
|
vaddr + f->page_offset + offset - start,
|
|
copy);
|
|
kunmap_atomic(vaddr);
|
|
|
|
if ((len -= copy) == 0)
|
|
return 0;
|
|
offset += copy;
|
|
to += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
|
|
skb_walk_frags(skb, frag_iter) {
|
|
int end;
|
|
|
|
WARN_ON(start > offset + len);
|
|
|
|
end = start + frag_iter->len;
|
|
if ((copy = end - offset) > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
if (skb_copy_bits(frag_iter, offset - start, to, copy))
|
|
goto fault;
|
|
if ((len -= copy) == 0)
|
|
return 0;
|
|
offset += copy;
|
|
to += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
|
|
if (!len)
|
|
return 0;
|
|
|
|
fault:
|
|
return -EFAULT;
|
|
}
|
|
EXPORT_SYMBOL(skb_copy_bits);
|
|
|
|
/*
|
|
* Callback from splice_to_pipe(), if we need to release some pages
|
|
* at the end of the spd in case we error'ed out in filling the pipe.
|
|
*/
|
|
static void sock_spd_release(struct splice_pipe_desc *spd, unsigned int i)
|
|
{
|
|
put_page(spd->pages[i]);
|
|
}
|
|
|
|
static struct page *linear_to_page(struct page *page, unsigned int *len,
|
|
unsigned int *offset,
|
|
struct sock *sk)
|
|
{
|
|
struct page_frag *pfrag = sk_page_frag(sk);
|
|
|
|
if (!sk_page_frag_refill(sk, pfrag))
|
|
return NULL;
|
|
|
|
*len = min_t(unsigned int, *len, pfrag->size - pfrag->offset);
|
|
|
|
memcpy(page_address(pfrag->page) + pfrag->offset,
|
|
page_address(page) + *offset, *len);
|
|
*offset = pfrag->offset;
|
|
pfrag->offset += *len;
|
|
|
|
return pfrag->page;
|
|
}
|
|
|
|
static bool spd_can_coalesce(const struct splice_pipe_desc *spd,
|
|
struct page *page,
|
|
unsigned int offset)
|
|
{
|
|
return spd->nr_pages &&
|
|
spd->pages[spd->nr_pages - 1] == page &&
|
|
(spd->partial[spd->nr_pages - 1].offset +
|
|
spd->partial[spd->nr_pages - 1].len == offset);
|
|
}
|
|
|
|
/*
|
|
* Fill page/offset/length into spd, if it can hold more pages.
|
|
*/
|
|
static bool spd_fill_page(struct splice_pipe_desc *spd,
|
|
struct pipe_inode_info *pipe, struct page *page,
|
|
unsigned int *len, unsigned int offset,
|
|
bool linear,
|
|
struct sock *sk)
|
|
{
|
|
if (unlikely(spd->nr_pages == MAX_SKB_FRAGS))
|
|
return true;
|
|
|
|
if (linear) {
|
|
page = linear_to_page(page, len, &offset, sk);
|
|
if (!page)
|
|
return true;
|
|
}
|
|
if (spd_can_coalesce(spd, page, offset)) {
|
|
spd->partial[spd->nr_pages - 1].len += *len;
|
|
return false;
|
|
}
|
|
get_page(page);
|
|
spd->pages[spd->nr_pages] = page;
|
|
spd->partial[spd->nr_pages].len = *len;
|
|
spd->partial[spd->nr_pages].offset = offset;
|
|
spd->nr_pages++;
|
|
|
|
return false;
|
|
}
|
|
|
|
static bool __splice_segment(struct page *page, unsigned int poff,
|
|
unsigned int plen, unsigned int *off,
|
|
unsigned int *len,
|
|
struct splice_pipe_desc *spd, bool linear,
|
|
struct sock *sk,
|
|
struct pipe_inode_info *pipe)
|
|
{
|
|
if (!*len)
|
|
return true;
|
|
|
|
/* skip this segment if already processed */
|
|
if (*off >= plen) {
|
|
*off -= plen;
|
|
return false;
|
|
}
|
|
|
|
/* ignore any bits we already processed */
|
|
poff += *off;
|
|
plen -= *off;
|
|
*off = 0;
|
|
|
|
do {
|
|
unsigned int flen = min(*len, plen);
|
|
|
|
if (spd_fill_page(spd, pipe, page, &flen, poff,
|
|
linear, sk))
|
|
return true;
|
|
poff += flen;
|
|
plen -= flen;
|
|
*len -= flen;
|
|
} while (*len && plen);
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Map linear and fragment data from the skb to spd. It reports true if the
|
|
* pipe is full or if we already spliced the requested length.
|
|
*/
|
|
static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe,
|
|
unsigned int *offset, unsigned int *len,
|
|
struct splice_pipe_desc *spd, struct sock *sk)
|
|
{
|
|
int seg;
|
|
|
|
/* map the linear part :
|
|
* If skb->head_frag is set, this 'linear' part is backed by a
|
|
* fragment, and if the head is not shared with any clones then
|
|
* we can avoid a copy since we own the head portion of this page.
|
|
*/
|
|
if (__splice_segment(virt_to_page(skb->data),
|
|
(unsigned long) skb->data & (PAGE_SIZE - 1),
|
|
skb_headlen(skb),
|
|
offset, len, spd,
|
|
skb_head_is_locked(skb),
|
|
sk, pipe))
|
|
return true;
|
|
|
|
/*
|
|
* then map the fragments
|
|
*/
|
|
for (seg = 0; seg < skb_shinfo(skb)->nr_frags; seg++) {
|
|
const skb_frag_t *f = &skb_shinfo(skb)->frags[seg];
|
|
|
|
if (__splice_segment(skb_frag_page(f),
|
|
f->page_offset, skb_frag_size(f),
|
|
offset, len, spd, false, sk, pipe))
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Map data from the skb to a pipe. Should handle both the linear part,
|
|
* the fragments, and the frag list. It does NOT handle frag lists within
|
|
* the frag list, if such a thing exists. We'd probably need to recurse to
|
|
* handle that cleanly.
|
|
*/
|
|
int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
|
|
struct pipe_inode_info *pipe, unsigned int tlen,
|
|
unsigned int flags)
|
|
{
|
|
struct partial_page partial[MAX_SKB_FRAGS];
|
|
struct page *pages[MAX_SKB_FRAGS];
|
|
struct splice_pipe_desc spd = {
|
|
.pages = pages,
|
|
.partial = partial,
|
|
.nr_pages_max = MAX_SKB_FRAGS,
|
|
.flags = flags,
|
|
.ops = &sock_pipe_buf_ops,
|
|
.spd_release = sock_spd_release,
|
|
};
|
|
struct sk_buff *frag_iter;
|
|
struct sock *sk = skb->sk;
|
|
int ret = 0;
|
|
|
|
/*
|
|
* __skb_splice_bits() only fails if the output has no room left,
|
|
* so no point in going over the frag_list for the error case.
|
|
*/
|
|
if (__skb_splice_bits(skb, pipe, &offset, &tlen, &spd, sk))
|
|
goto done;
|
|
else if (!tlen)
|
|
goto done;
|
|
|
|
/*
|
|
* now see if we have a frag_list to map
|
|
*/
|
|
skb_walk_frags(skb, frag_iter) {
|
|
if (!tlen)
|
|
break;
|
|
if (__skb_splice_bits(frag_iter, pipe, &offset, &tlen, &spd, sk))
|
|
break;
|
|
}
|
|
|
|
done:
|
|
if (spd.nr_pages) {
|
|
/*
|
|
* Drop the socket lock, otherwise we have reverse
|
|
* locking dependencies between sk_lock and i_mutex
|
|
* here as compared to sendfile(). We enter here
|
|
* with the socket lock held, and splice_to_pipe() will
|
|
* grab the pipe inode lock. For sendfile() emulation,
|
|
* we call into ->sendpage() with the i_mutex lock held
|
|
* and networking will grab the socket lock.
|
|
*/
|
|
release_sock(sk);
|
|
ret = splice_to_pipe(pipe, &spd);
|
|
lock_sock(sk);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* skb_store_bits - store bits from kernel buffer to skb
|
|
* @skb: destination buffer
|
|
* @offset: offset in destination
|
|
* @from: source buffer
|
|
* @len: number of bytes to copy
|
|
*
|
|
* Copy the specified number of bytes from the source buffer to the
|
|
* destination skb. This function handles all the messy bits of
|
|
* traversing fragment lists and such.
|
|
*/
|
|
|
|
int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len)
|
|
{
|
|
int start = skb_headlen(skb);
|
|
struct sk_buff *frag_iter;
|
|
int i, copy;
|
|
|
|
if (offset > (int)skb->len - len)
|
|
goto fault;
|
|
|
|
if ((copy = start - offset) > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
skb_copy_to_linear_data_offset(skb, offset, from, copy);
|
|
if ((len -= copy) == 0)
|
|
return 0;
|
|
offset += copy;
|
|
from += copy;
|
|
}
|
|
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
|
|
int end;
|
|
|
|
WARN_ON(start > offset + len);
|
|
|
|
end = start + skb_frag_size(frag);
|
|
if ((copy = end - offset) > 0) {
|
|
u8 *vaddr;
|
|
|
|
if (copy > len)
|
|
copy = len;
|
|
|
|
vaddr = kmap_atomic(skb_frag_page(frag));
|
|
memcpy(vaddr + frag->page_offset + offset - start,
|
|
from, copy);
|
|
kunmap_atomic(vaddr);
|
|
|
|
if ((len -= copy) == 0)
|
|
return 0;
|
|
offset += copy;
|
|
from += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
|
|
skb_walk_frags(skb, frag_iter) {
|
|
int end;
|
|
|
|
WARN_ON(start > offset + len);
|
|
|
|
end = start + frag_iter->len;
|
|
if ((copy = end - offset) > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
if (skb_store_bits(frag_iter, offset - start,
|
|
from, copy))
|
|
goto fault;
|
|
if ((len -= copy) == 0)
|
|
return 0;
|
|
offset += copy;
|
|
from += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
if (!len)
|
|
return 0;
|
|
|
|
fault:
|
|
return -EFAULT;
|
|
}
|
|
EXPORT_SYMBOL(skb_store_bits);
|
|
|
|
/* Checksum skb data. */
|
|
|
|
__wsum skb_checksum(const struct sk_buff *skb, int offset,
|
|
int len, __wsum csum)
|
|
{
|
|
int start = skb_headlen(skb);
|
|
int i, copy = start - offset;
|
|
struct sk_buff *frag_iter;
|
|
int pos = 0;
|
|
|
|
/* Checksum header. */
|
|
if (copy > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
csum = csum_partial(skb->data + offset, copy, csum);
|
|
if ((len -= copy) == 0)
|
|
return csum;
|
|
offset += copy;
|
|
pos = copy;
|
|
}
|
|
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
int end;
|
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
|
|
|
|
WARN_ON(start > offset + len);
|
|
|
|
end = start + skb_frag_size(frag);
|
|
if ((copy = end - offset) > 0) {
|
|
__wsum csum2;
|
|
u8 *vaddr;
|
|
|
|
if (copy > len)
|
|
copy = len;
|
|
vaddr = kmap_atomic(skb_frag_page(frag));
|
|
csum2 = csum_partial(vaddr + frag->page_offset +
|
|
offset - start, copy, 0);
|
|
kunmap_atomic(vaddr);
|
|
csum = csum_block_add(csum, csum2, pos);
|
|
if (!(len -= copy))
|
|
return csum;
|
|
offset += copy;
|
|
pos += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
|
|
skb_walk_frags(skb, frag_iter) {
|
|
int end;
|
|
|
|
WARN_ON(start > offset + len);
|
|
|
|
end = start + frag_iter->len;
|
|
if ((copy = end - offset) > 0) {
|
|
__wsum csum2;
|
|
if (copy > len)
|
|
copy = len;
|
|
csum2 = skb_checksum(frag_iter, offset - start,
|
|
copy, 0);
|
|
csum = csum_block_add(csum, csum2, pos);
|
|
if ((len -= copy) == 0)
|
|
return csum;
|
|
offset += copy;
|
|
pos += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
BUG_ON(len);
|
|
|
|
return csum;
|
|
}
|
|
EXPORT_SYMBOL(skb_checksum);
|
|
|
|
/* Both of above in one bottle. */
|
|
|
|
__wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset,
|
|
u8 *to, int len, __wsum csum)
|
|
{
|
|
int start = skb_headlen(skb);
|
|
int i, copy = start - offset;
|
|
struct sk_buff *frag_iter;
|
|
int pos = 0;
|
|
|
|
/* Copy header. */
|
|
if (copy > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
csum = csum_partial_copy_nocheck(skb->data + offset, to,
|
|
copy, csum);
|
|
if ((len -= copy) == 0)
|
|
return csum;
|
|
offset += copy;
|
|
to += copy;
|
|
pos = copy;
|
|
}
|
|
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
int end;
|
|
|
|
WARN_ON(start > offset + len);
|
|
|
|
end = start + skb_frag_size(&skb_shinfo(skb)->frags[i]);
|
|
if ((copy = end - offset) > 0) {
|
|
__wsum csum2;
|
|
u8 *vaddr;
|
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
|
|
|
|
if (copy > len)
|
|
copy = len;
|
|
vaddr = kmap_atomic(skb_frag_page(frag));
|
|
csum2 = csum_partial_copy_nocheck(vaddr +
|
|
frag->page_offset +
|
|
offset - start, to,
|
|
copy, 0);
|
|
kunmap_atomic(vaddr);
|
|
csum = csum_block_add(csum, csum2, pos);
|
|
if (!(len -= copy))
|
|
return csum;
|
|
offset += copy;
|
|
to += copy;
|
|
pos += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
|
|
skb_walk_frags(skb, frag_iter) {
|
|
__wsum csum2;
|
|
int end;
|
|
|
|
WARN_ON(start > offset + len);
|
|
|
|
end = start + frag_iter->len;
|
|
if ((copy = end - offset) > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
csum2 = skb_copy_and_csum_bits(frag_iter,
|
|
offset - start,
|
|
to, copy, 0);
|
|
csum = csum_block_add(csum, csum2, pos);
|
|
if ((len -= copy) == 0)
|
|
return csum;
|
|
offset += copy;
|
|
to += copy;
|
|
pos += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
BUG_ON(len);
|
|
return csum;
|
|
}
|
|
EXPORT_SYMBOL(skb_copy_and_csum_bits);
|
|
|
|
void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to)
|
|
{
|
|
__wsum csum;
|
|
long csstart;
|
|
|
|
if (skb->ip_summed == CHECKSUM_PARTIAL)
|
|
csstart = skb_checksum_start_offset(skb);
|
|
else
|
|
csstart = skb_headlen(skb);
|
|
|
|
BUG_ON(csstart > skb_headlen(skb));
|
|
|
|
skb_copy_from_linear_data(skb, to, csstart);
|
|
|
|
csum = 0;
|
|
if (csstart != skb->len)
|
|
csum = skb_copy_and_csum_bits(skb, csstart, to + csstart,
|
|
skb->len - csstart, 0);
|
|
|
|
if (skb->ip_summed == CHECKSUM_PARTIAL) {
|
|
long csstuff = csstart + skb->csum_offset;
|
|
|
|
*((__sum16 *)(to + csstuff)) = csum_fold(csum);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(skb_copy_and_csum_dev);
|
|
|
|
/**
|
|
* skb_dequeue - remove from the head of the queue
|
|
* @list: list to dequeue from
|
|
*
|
|
* Remove the head of the list. The list lock is taken so the function
|
|
* may be used safely with other locking list functions. The head item is
|
|
* returned or %NULL if the list is empty.
|
|
*/
|
|
|
|
struct sk_buff *skb_dequeue(struct sk_buff_head *list)
|
|
{
|
|
unsigned long flags;
|
|
struct sk_buff *result;
|
|
|
|
spin_lock_irqsave(&list->lock, flags);
|
|
result = __skb_dequeue(list);
|
|
spin_unlock_irqrestore(&list->lock, flags);
|
|
return result;
|
|
}
|
|
EXPORT_SYMBOL(skb_dequeue);
|
|
|
|
/**
|
|
* skb_dequeue_tail - remove from the tail of the queue
|
|
* @list: list to dequeue from
|
|
*
|
|
* Remove the tail of the list. The list lock is taken so the function
|
|
* may be used safely with other locking list functions. The tail item is
|
|
* returned or %NULL if the list is empty.
|
|
*/
|
|
struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list)
|
|
{
|
|
unsigned long flags;
|
|
struct sk_buff *result;
|
|
|
|
spin_lock_irqsave(&list->lock, flags);
|
|
result = __skb_dequeue_tail(list);
|
|
spin_unlock_irqrestore(&list->lock, flags);
|
|
return result;
|
|
}
|
|
EXPORT_SYMBOL(skb_dequeue_tail);
|
|
|
|
/**
|
|
* skb_queue_purge - empty a list
|
|
* @list: list to empty
|
|
*
|
|
* Delete all buffers on an &sk_buff list. Each buffer is removed from
|
|
* the list and one reference dropped. This function takes the list
|
|
* lock and is atomic with respect to other list locking functions.
|
|
*/
|
|
void skb_queue_purge(struct sk_buff_head *list)
|
|
{
|
|
struct sk_buff *skb;
|
|
while ((skb = skb_dequeue(list)) != NULL)
|
|
kfree_skb(skb);
|
|
}
|
|
EXPORT_SYMBOL(skb_queue_purge);
|
|
|
|
/**
|
|
* skb_queue_head - queue a buffer at the list head
|
|
* @list: list to use
|
|
* @newsk: buffer to queue
|
|
*
|
|
* Queue a buffer at the start of the list. This function takes the
|
|
* list lock and can be used safely with other locking &sk_buff functions
|
|
* safely.
|
|
*
|
|
* A buffer cannot be placed on two lists at the same time.
|
|
*/
|
|
void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&list->lock, flags);
|
|
__skb_queue_head(list, newsk);
|
|
spin_unlock_irqrestore(&list->lock, flags);
|
|
}
|
|
EXPORT_SYMBOL(skb_queue_head);
|
|
|
|
/**
|
|
* skb_queue_tail - queue a buffer at the list tail
|
|
* @list: list to use
|
|
* @newsk: buffer to queue
|
|
*
|
|
* Queue a buffer at the tail of the list. This function takes the
|
|
* list lock and can be used safely with other locking &sk_buff functions
|
|
* safely.
|
|
*
|
|
* A buffer cannot be placed on two lists at the same time.
|
|
*/
|
|
void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&list->lock, flags);
|
|
__skb_queue_tail(list, newsk);
|
|
spin_unlock_irqrestore(&list->lock, flags);
|
|
}
|
|
EXPORT_SYMBOL(skb_queue_tail);
|
|
|
|
/**
|
|
* skb_unlink - remove a buffer from a list
|
|
* @skb: buffer to remove
|
|
* @list: list to use
|
|
*
|
|
* Remove a packet from a list. The list locks are taken and this
|
|
* function is atomic with respect to other list locked calls
|
|
*
|
|
* You must know what list the SKB is on.
|
|
*/
|
|
void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&list->lock, flags);
|
|
__skb_unlink(skb, list);
|
|
spin_unlock_irqrestore(&list->lock, flags);
|
|
}
|
|
EXPORT_SYMBOL(skb_unlink);
|
|
|
|
/**
|
|
* skb_append - append a buffer
|
|
* @old: buffer to insert after
|
|
* @newsk: buffer to insert
|
|
* @list: list to use
|
|
*
|
|
* Place a packet after a given packet in a list. The list locks are taken
|
|
* and this function is atomic with respect to other list locked calls.
|
|
* A buffer cannot be placed on two lists at the same time.
|
|
*/
|
|
void skb_append(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&list->lock, flags);
|
|
__skb_queue_after(list, old, newsk);
|
|
spin_unlock_irqrestore(&list->lock, flags);
|
|
}
|
|
EXPORT_SYMBOL(skb_append);
|
|
|
|
/**
|
|
* skb_insert - insert a buffer
|
|
* @old: buffer to insert before
|
|
* @newsk: buffer to insert
|
|
* @list: list to use
|
|
*
|
|
* Place a packet before a given packet in a list. The list locks are
|
|
* taken and this function is atomic with respect to other list locked
|
|
* calls.
|
|
*
|
|
* A buffer cannot be placed on two lists at the same time.
|
|
*/
|
|
void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&list->lock, flags);
|
|
__skb_insert(newsk, old->prev, old, list);
|
|
spin_unlock_irqrestore(&list->lock, flags);
|
|
}
|
|
EXPORT_SYMBOL(skb_insert);
|
|
|
|
static inline void skb_split_inside_header(struct sk_buff *skb,
|
|
struct sk_buff* skb1,
|
|
const u32 len, const int pos)
|
|
{
|
|
int i;
|
|
|
|
skb_copy_from_linear_data_offset(skb, len, skb_put(skb1, pos - len),
|
|
pos - len);
|
|
/* And move data appendix as is. */
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
|
|
skb_shinfo(skb1)->frags[i] = skb_shinfo(skb)->frags[i];
|
|
|
|
skb_shinfo(skb1)->nr_frags = skb_shinfo(skb)->nr_frags;
|
|
skb_shinfo(skb)->nr_frags = 0;
|
|
skb1->data_len = skb->data_len;
|
|
skb1->len += skb1->data_len;
|
|
skb->data_len = 0;
|
|
skb->len = len;
|
|
skb_set_tail_pointer(skb, len);
|
|
}
|
|
|
|
static inline void skb_split_no_header(struct sk_buff *skb,
|
|
struct sk_buff* skb1,
|
|
const u32 len, int pos)
|
|
{
|
|
int i, k = 0;
|
|
const int nfrags = skb_shinfo(skb)->nr_frags;
|
|
|
|
skb_shinfo(skb)->nr_frags = 0;
|
|
skb1->len = skb1->data_len = skb->len - len;
|
|
skb->len = len;
|
|
skb->data_len = len - pos;
|
|
|
|
for (i = 0; i < nfrags; i++) {
|
|
int size = skb_frag_size(&skb_shinfo(skb)->frags[i]);
|
|
|
|
if (pos + size > len) {
|
|
skb_shinfo(skb1)->frags[k] = skb_shinfo(skb)->frags[i];
|
|
|
|
if (pos < len) {
|
|
/* Split frag.
|
|
* We have two variants in this case:
|
|
* 1. Move all the frag to the second
|
|
* part, if it is possible. F.e.
|
|
* this approach is mandatory for TUX,
|
|
* where splitting is expensive.
|
|
* 2. Split is accurately. We make this.
|
|
*/
|
|
skb_frag_ref(skb, i);
|
|
skb_shinfo(skb1)->frags[0].page_offset += len - pos;
|
|
skb_frag_size_sub(&skb_shinfo(skb1)->frags[0], len - pos);
|
|
skb_frag_size_set(&skb_shinfo(skb)->frags[i], len - pos);
|
|
skb_shinfo(skb)->nr_frags++;
|
|
}
|
|
k++;
|
|
} else
|
|
skb_shinfo(skb)->nr_frags++;
|
|
pos += size;
|
|
}
|
|
skb_shinfo(skb1)->nr_frags = k;
|
|
}
|
|
|
|
/**
|
|
* skb_split - Split fragmented skb to two parts at length len.
|
|
* @skb: the buffer to split
|
|
* @skb1: the buffer to receive the second part
|
|
* @len: new length for skb
|
|
*/
|
|
void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len)
|
|
{
|
|
int pos = skb_headlen(skb);
|
|
|
|
skb_shinfo(skb1)->tx_flags = skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG;
|
|
if (len < pos) /* Split line is inside header. */
|
|
skb_split_inside_header(skb, skb1, len, pos);
|
|
else /* Second chunk has no header, nothing to copy. */
|
|
skb_split_no_header(skb, skb1, len, pos);
|
|
}
|
|
EXPORT_SYMBOL(skb_split);
|
|
|
|
/* Shifting from/to a cloned skb is a no-go.
|
|
*
|
|
* Caller cannot keep skb_shinfo related pointers past calling here!
|
|
*/
|
|
static int skb_prepare_for_shift(struct sk_buff *skb)
|
|
{
|
|
return skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
|
|
}
|
|
|
|
/**
|
|
* skb_shift - Shifts paged data partially from skb to another
|
|
* @tgt: buffer into which tail data gets added
|
|
* @skb: buffer from which the paged data comes from
|
|
* @shiftlen: shift up to this many bytes
|
|
*
|
|
* Attempts to shift up to shiftlen worth of bytes, which may be less than
|
|
* the length of the skb, from skb to tgt. Returns number bytes shifted.
|
|
* It's up to caller to free skb if everything was shifted.
|
|
*
|
|
* If @tgt runs out of frags, the whole operation is aborted.
|
|
*
|
|
* Skb cannot include anything else but paged data while tgt is allowed
|
|
* to have non-paged data as well.
|
|
*
|
|
* TODO: full sized shift could be optimized but that would need
|
|
* specialized skb free'er to handle frags without up-to-date nr_frags.
|
|
*/
|
|
int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen)
|
|
{
|
|
int from, to, merge, todo;
|
|
struct skb_frag_struct *fragfrom, *fragto;
|
|
|
|
BUG_ON(shiftlen > skb->len);
|
|
BUG_ON(skb_headlen(skb)); /* Would corrupt stream */
|
|
|
|
todo = shiftlen;
|
|
from = 0;
|
|
to = skb_shinfo(tgt)->nr_frags;
|
|
fragfrom = &skb_shinfo(skb)->frags[from];
|
|
|
|
/* Actual merge is delayed until the point when we know we can
|
|
* commit all, so that we don't have to undo partial changes
|
|
*/
|
|
if (!to ||
|
|
!skb_can_coalesce(tgt, to, skb_frag_page(fragfrom),
|
|
fragfrom->page_offset)) {
|
|
merge = -1;
|
|
} else {
|
|
merge = to - 1;
|
|
|
|
todo -= skb_frag_size(fragfrom);
|
|
if (todo < 0) {
|
|
if (skb_prepare_for_shift(skb) ||
|
|
skb_prepare_for_shift(tgt))
|
|
return 0;
|
|
|
|
/* All previous frag pointers might be stale! */
|
|
fragfrom = &skb_shinfo(skb)->frags[from];
|
|
fragto = &skb_shinfo(tgt)->frags[merge];
|
|
|
|
skb_frag_size_add(fragto, shiftlen);
|
|
skb_frag_size_sub(fragfrom, shiftlen);
|
|
fragfrom->page_offset += shiftlen;
|
|
|
|
goto onlymerged;
|
|
}
|
|
|
|
from++;
|
|
}
|
|
|
|
/* Skip full, not-fitting skb to avoid expensive operations */
|
|
if ((shiftlen == skb->len) &&
|
|
(skb_shinfo(skb)->nr_frags - from) > (MAX_SKB_FRAGS - to))
|
|
return 0;
|
|
|
|
if (skb_prepare_for_shift(skb) || skb_prepare_for_shift(tgt))
|
|
return 0;
|
|
|
|
while ((todo > 0) && (from < skb_shinfo(skb)->nr_frags)) {
|
|
if (to == MAX_SKB_FRAGS)
|
|
return 0;
|
|
|
|
fragfrom = &skb_shinfo(skb)->frags[from];
|
|
fragto = &skb_shinfo(tgt)->frags[to];
|
|
|
|
if (todo >= skb_frag_size(fragfrom)) {
|
|
*fragto = *fragfrom;
|
|
todo -= skb_frag_size(fragfrom);
|
|
from++;
|
|
to++;
|
|
|
|
} else {
|
|
__skb_frag_ref(fragfrom);
|
|
fragto->page = fragfrom->page;
|
|
fragto->page_offset = fragfrom->page_offset;
|
|
skb_frag_size_set(fragto, todo);
|
|
|
|
fragfrom->page_offset += todo;
|
|
skb_frag_size_sub(fragfrom, todo);
|
|
todo = 0;
|
|
|
|
to++;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Ready to "commit" this state change to tgt */
|
|
skb_shinfo(tgt)->nr_frags = to;
|
|
|
|
if (merge >= 0) {
|
|
fragfrom = &skb_shinfo(skb)->frags[0];
|
|
fragto = &skb_shinfo(tgt)->frags[merge];
|
|
|
|
skb_frag_size_add(fragto, skb_frag_size(fragfrom));
|
|
__skb_frag_unref(fragfrom);
|
|
}
|
|
|
|
/* Reposition in the original skb */
|
|
to = 0;
|
|
while (from < skb_shinfo(skb)->nr_frags)
|
|
skb_shinfo(skb)->frags[to++] = skb_shinfo(skb)->frags[from++];
|
|
skb_shinfo(skb)->nr_frags = to;
|
|
|
|
BUG_ON(todo > 0 && !skb_shinfo(skb)->nr_frags);
|
|
|
|
onlymerged:
|
|
/* Most likely the tgt won't ever need its checksum anymore, skb on
|
|
* the other hand might need it if it needs to be resent
|
|
*/
|
|
tgt->ip_summed = CHECKSUM_PARTIAL;
|
|
skb->ip_summed = CHECKSUM_PARTIAL;
|
|
|
|
/* Yak, is it really working this way? Some helper please? */
|
|
skb->len -= shiftlen;
|
|
skb->data_len -= shiftlen;
|
|
skb->truesize -= shiftlen;
|
|
tgt->len += shiftlen;
|
|
tgt->data_len += shiftlen;
|
|
tgt->truesize += shiftlen;
|
|
|
|
return shiftlen;
|
|
}
|
|
|
|
/**
|
|
* skb_prepare_seq_read - Prepare a sequential read of skb data
|
|
* @skb: the buffer to read
|
|
* @from: lower offset of data to be read
|
|
* @to: upper offset of data to be read
|
|
* @st: state variable
|
|
*
|
|
* Initializes the specified state variable. Must be called before
|
|
* invoking skb_seq_read() for the first time.
|
|
*/
|
|
void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from,
|
|
unsigned int to, struct skb_seq_state *st)
|
|
{
|
|
st->lower_offset = from;
|
|
st->upper_offset = to;
|
|
st->root_skb = st->cur_skb = skb;
|
|
st->frag_idx = st->stepped_offset = 0;
|
|
st->frag_data = NULL;
|
|
}
|
|
EXPORT_SYMBOL(skb_prepare_seq_read);
|
|
|
|
/**
|
|
* skb_seq_read - Sequentially read skb data
|
|
* @consumed: number of bytes consumed by the caller so far
|
|
* @data: destination pointer for data to be returned
|
|
* @st: state variable
|
|
*
|
|
* Reads a block of skb data at &consumed relative to the
|
|
* lower offset specified to skb_prepare_seq_read(). Assigns
|
|
* the head of the data block to &data and returns the length
|
|
* of the block or 0 if the end of the skb data or the upper
|
|
* offset has been reached.
|
|
*
|
|
* The caller is not required to consume all of the data
|
|
* returned, i.e. &consumed is typically set to the number
|
|
* of bytes already consumed and the next call to
|
|
* skb_seq_read() will return the remaining part of the block.
|
|
*
|
|
* Note 1: The size of each block of data returned can be arbitrary,
|
|
* this limitation is the cost for zerocopy seqeuental
|
|
* reads of potentially non linear data.
|
|
*
|
|
* Note 2: Fragment lists within fragments are not implemented
|
|
* at the moment, state->root_skb could be replaced with
|
|
* a stack for this purpose.
|
|
*/
|
|
unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
|
|
struct skb_seq_state *st)
|
|
{
|
|
unsigned int block_limit, abs_offset = consumed + st->lower_offset;
|
|
skb_frag_t *frag;
|
|
|
|
if (unlikely(abs_offset >= st->upper_offset))
|
|
return 0;
|
|
|
|
next_skb:
|
|
block_limit = skb_headlen(st->cur_skb) + st->stepped_offset;
|
|
|
|
if (abs_offset < block_limit && !st->frag_data) {
|
|
*data = st->cur_skb->data + (abs_offset - st->stepped_offset);
|
|
return block_limit - abs_offset;
|
|
}
|
|
|
|
if (st->frag_idx == 0 && !st->frag_data)
|
|
st->stepped_offset += skb_headlen(st->cur_skb);
|
|
|
|
while (st->frag_idx < skb_shinfo(st->cur_skb)->nr_frags) {
|
|
frag = &skb_shinfo(st->cur_skb)->frags[st->frag_idx];
|
|
block_limit = skb_frag_size(frag) + st->stepped_offset;
|
|
|
|
if (abs_offset < block_limit) {
|
|
if (!st->frag_data)
|
|
st->frag_data = kmap_atomic(skb_frag_page(frag));
|
|
|
|
*data = (u8 *) st->frag_data + frag->page_offset +
|
|
(abs_offset - st->stepped_offset);
|
|
|
|
return block_limit - abs_offset;
|
|
}
|
|
|
|
if (st->frag_data) {
|
|
kunmap_atomic(st->frag_data);
|
|
st->frag_data = NULL;
|
|
}
|
|
|
|
st->frag_idx++;
|
|
st->stepped_offset += skb_frag_size(frag);
|
|
}
|
|
|
|
if (st->frag_data) {
|
|
kunmap_atomic(st->frag_data);
|
|
st->frag_data = NULL;
|
|
}
|
|
|
|
if (st->root_skb == st->cur_skb && skb_has_frag_list(st->root_skb)) {
|
|
st->cur_skb = skb_shinfo(st->root_skb)->frag_list;
|
|
st->frag_idx = 0;
|
|
goto next_skb;
|
|
} else if (st->cur_skb->next) {
|
|
st->cur_skb = st->cur_skb->next;
|
|
st->frag_idx = 0;
|
|
goto next_skb;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(skb_seq_read);
|
|
|
|
/**
|
|
* skb_abort_seq_read - Abort a sequential read of skb data
|
|
* @st: state variable
|
|
*
|
|
* Must be called if skb_seq_read() was not called until it
|
|
* returned 0.
|
|
*/
|
|
void skb_abort_seq_read(struct skb_seq_state *st)
|
|
{
|
|
if (st->frag_data)
|
|
kunmap_atomic(st->frag_data);
|
|
}
|
|
EXPORT_SYMBOL(skb_abort_seq_read);
|
|
|
|
#define TS_SKB_CB(state) ((struct skb_seq_state *) &((state)->cb))
|
|
|
|
static unsigned int skb_ts_get_next_block(unsigned int offset, const u8 **text,
|
|
struct ts_config *conf,
|
|
struct ts_state *state)
|
|
{
|
|
return skb_seq_read(offset, text, TS_SKB_CB(state));
|
|
}
|
|
|
|
static void skb_ts_finish(struct ts_config *conf, struct ts_state *state)
|
|
{
|
|
skb_abort_seq_read(TS_SKB_CB(state));
|
|
}
|
|
|
|
/**
|
|
* skb_find_text - Find a text pattern in skb data
|
|
* @skb: the buffer to look in
|
|
* @from: search offset
|
|
* @to: search limit
|
|
* @config: textsearch configuration
|
|
* @state: uninitialized textsearch state variable
|
|
*
|
|
* Finds a pattern in the skb data according to the specified
|
|
* textsearch configuration. Use textsearch_next() to retrieve
|
|
* subsequent occurrences of the pattern. Returns the offset
|
|
* to the first occurrence or UINT_MAX if no match was found.
|
|
*/
|
|
unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
|
|
unsigned int to, struct ts_config *config,
|
|
struct ts_state *state)
|
|
{
|
|
unsigned int ret;
|
|
|
|
config->get_next_block = skb_ts_get_next_block;
|
|
config->finish = skb_ts_finish;
|
|
|
|
skb_prepare_seq_read(skb, from, to, TS_SKB_CB(state));
|
|
|
|
ret = textsearch_find(config, state);
|
|
return (ret <= to - from ? ret : UINT_MAX);
|
|
}
|
|
EXPORT_SYMBOL(skb_find_text);
|
|
|
|
/**
|
|
* skb_append_datato_frags - append the user data to a skb
|
|
* @sk: sock structure
|
|
* @skb: skb structure to be appened with user data.
|
|
* @getfrag: call back function to be used for getting the user data
|
|
* @from: pointer to user message iov
|
|
* @length: length of the iov message
|
|
*
|
|
* Description: This procedure append the user data in the fragment part
|
|
* of the skb if any page alloc fails user this procedure returns -ENOMEM
|
|
*/
|
|
int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
|
|
int (*getfrag)(void *from, char *to, int offset,
|
|
int len, int odd, struct sk_buff *skb),
|
|
void *from, int length)
|
|
{
|
|
int frg_cnt = skb_shinfo(skb)->nr_frags;
|
|
int copy;
|
|
int offset = 0;
|
|
int ret;
|
|
struct page_frag *pfrag = ¤t->task_frag;
|
|
|
|
do {
|
|
/* Return error if we don't have space for new frag */
|
|
if (frg_cnt >= MAX_SKB_FRAGS)
|
|
return -EMSGSIZE;
|
|
|
|
if (!sk_page_frag_refill(sk, pfrag))
|
|
return -ENOMEM;
|
|
|
|
/* copy the user data to page */
|
|
copy = min_t(int, length, pfrag->size - pfrag->offset);
|
|
|
|
ret = getfrag(from, page_address(pfrag->page) + pfrag->offset,
|
|
offset, copy, 0, skb);
|
|
if (ret < 0)
|
|
return -EFAULT;
|
|
|
|
/* copy was successful so update the size parameters */
|
|
skb_fill_page_desc(skb, frg_cnt, pfrag->page, pfrag->offset,
|
|
copy);
|
|
frg_cnt++;
|
|
pfrag->offset += copy;
|
|
get_page(pfrag->page);
|
|
|
|
skb->truesize += copy;
|
|
atomic_add(copy, &sk->sk_wmem_alloc);
|
|
skb->len += copy;
|
|
skb->data_len += copy;
|
|
offset += copy;
|
|
length -= copy;
|
|
|
|
} while (length > 0);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(skb_append_datato_frags);
|
|
|
|
/**
|
|
* skb_pull_rcsum - pull skb and update receive checksum
|
|
* @skb: buffer to update
|
|
* @len: length of data pulled
|
|
*
|
|
* This function performs an skb_pull on the packet and updates
|
|
* the CHECKSUM_COMPLETE checksum. It should be used on
|
|
* receive path processing instead of skb_pull unless you know
|
|
* that the checksum difference is zero (e.g., a valid IP header)
|
|
* or you are setting ip_summed to CHECKSUM_NONE.
|
|
*/
|
|
unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len)
|
|
{
|
|
BUG_ON(len > skb->len);
|
|
skb->len -= len;
|
|
BUG_ON(skb->len < skb->data_len);
|
|
skb_postpull_rcsum(skb, skb->data, len);
|
|
return skb->data += len;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_pull_rcsum);
|
|
|
|
/**
|
|
* skb_segment - Perform protocol segmentation on skb.
|
|
* @skb: buffer to segment
|
|
* @features: features for the output path (see dev->features)
|
|
*
|
|
* This function performs segmentation on the given skb. It returns
|
|
* a pointer to the first in a list of new skbs for the segments.
|
|
* In case of error it returns ERR_PTR(err).
|
|
*/
|
|
struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features)
|
|
{
|
|
struct sk_buff *segs = NULL;
|
|
struct sk_buff *tail = NULL;
|
|
struct sk_buff *fskb = skb_shinfo(skb)->frag_list;
|
|
unsigned int mss = skb_shinfo(skb)->gso_size;
|
|
unsigned int doffset = skb->data - skb_mac_header(skb);
|
|
unsigned int offset = doffset;
|
|
unsigned int tnl_hlen = skb_tnl_header_len(skb);
|
|
unsigned int headroom;
|
|
unsigned int len;
|
|
__be16 proto;
|
|
bool csum;
|
|
int sg = !!(features & NETIF_F_SG);
|
|
int nfrags = skb_shinfo(skb)->nr_frags;
|
|
int err = -ENOMEM;
|
|
int i = 0;
|
|
int pos;
|
|
|
|
proto = skb_network_protocol(skb);
|
|
if (unlikely(!proto))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
csum = !!can_checksum_protocol(features, proto);
|
|
__skb_push(skb, doffset);
|
|
headroom = skb_headroom(skb);
|
|
pos = skb_headlen(skb);
|
|
|
|
do {
|
|
struct sk_buff *nskb;
|
|
skb_frag_t *frag;
|
|
int hsize;
|
|
int size;
|
|
|
|
len = skb->len - offset;
|
|
if (len > mss)
|
|
len = mss;
|
|
|
|
hsize = skb_headlen(skb) - offset;
|
|
if (hsize < 0)
|
|
hsize = 0;
|
|
if (hsize > len || !sg)
|
|
hsize = len;
|
|
|
|
if (!hsize && i >= nfrags) {
|
|
BUG_ON(fskb->len != len);
|
|
|
|
pos += len;
|
|
nskb = skb_clone(fskb, GFP_ATOMIC);
|
|
fskb = fskb->next;
|
|
|
|
if (unlikely(!nskb))
|
|
goto err;
|
|
|
|
hsize = skb_end_offset(nskb);
|
|
if (skb_cow_head(nskb, doffset + headroom)) {
|
|
kfree_skb(nskb);
|
|
goto err;
|
|
}
|
|
|
|
nskb->truesize += skb_end_offset(nskb) - hsize;
|
|
skb_release_head_state(nskb);
|
|
__skb_push(nskb, doffset);
|
|
} else {
|
|
nskb = __alloc_skb(hsize + doffset + headroom,
|
|
GFP_ATOMIC, skb_alloc_rx_flag(skb),
|
|
NUMA_NO_NODE);
|
|
|
|
if (unlikely(!nskb))
|
|
goto err;
|
|
|
|
skb_reserve(nskb, headroom);
|
|
__skb_put(nskb, doffset);
|
|
}
|
|
|
|
if (segs)
|
|
tail->next = nskb;
|
|
else
|
|
segs = nskb;
|
|
tail = nskb;
|
|
|
|
__copy_skb_header(nskb, skb);
|
|
nskb->mac_len = skb->mac_len;
|
|
|
|
/* nskb and skb might have different headroom */
|
|
if (nskb->ip_summed == CHECKSUM_PARTIAL)
|
|
nskb->csum_start += skb_headroom(nskb) - headroom;
|
|
|
|
skb_reset_mac_header(nskb);
|
|
skb_set_network_header(nskb, skb->mac_len);
|
|
nskb->transport_header = (nskb->network_header +
|
|
skb_network_header_len(skb));
|
|
|
|
skb_copy_from_linear_data_offset(skb, -tnl_hlen,
|
|
nskb->data - tnl_hlen,
|
|
doffset + tnl_hlen);
|
|
|
|
if (fskb != skb_shinfo(skb)->frag_list)
|
|
continue;
|
|
|
|
if (!sg) {
|
|
nskb->ip_summed = CHECKSUM_NONE;
|
|
nskb->csum = skb_copy_and_csum_bits(skb, offset,
|
|
skb_put(nskb, len),
|
|
len, 0);
|
|
continue;
|
|
}
|
|
|
|
frag = skb_shinfo(nskb)->frags;
|
|
|
|
skb_copy_from_linear_data_offset(skb, offset,
|
|
skb_put(nskb, hsize), hsize);
|
|
|
|
skb_shinfo(nskb)->tx_flags = skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG;
|
|
|
|
while (pos < offset + len && i < nfrags) {
|
|
*frag = skb_shinfo(skb)->frags[i];
|
|
__skb_frag_ref(frag);
|
|
size = skb_frag_size(frag);
|
|
|
|
if (pos < offset) {
|
|
frag->page_offset += offset - pos;
|
|
skb_frag_size_sub(frag, offset - pos);
|
|
}
|
|
|
|
skb_shinfo(nskb)->nr_frags++;
|
|
|
|
if (pos + size <= offset + len) {
|
|
i++;
|
|
pos += size;
|
|
} else {
|
|
skb_frag_size_sub(frag, pos + size - (offset + len));
|
|
goto skip_fraglist;
|
|
}
|
|
|
|
frag++;
|
|
}
|
|
|
|
if (pos < offset + len) {
|
|
struct sk_buff *fskb2 = fskb;
|
|
|
|
BUG_ON(pos + fskb->len != offset + len);
|
|
|
|
pos += fskb->len;
|
|
fskb = fskb->next;
|
|
|
|
if (fskb2->next) {
|
|
fskb2 = skb_clone(fskb2, GFP_ATOMIC);
|
|
if (!fskb2)
|
|
goto err;
|
|
} else
|
|
skb_get(fskb2);
|
|
|
|
SKB_FRAG_ASSERT(nskb);
|
|
skb_shinfo(nskb)->frag_list = fskb2;
|
|
}
|
|
|
|
skip_fraglist:
|
|
nskb->data_len = len - hsize;
|
|
nskb->len += nskb->data_len;
|
|
nskb->truesize += nskb->data_len;
|
|
|
|
if (!csum) {
|
|
nskb->csum = skb_checksum(nskb, doffset,
|
|
nskb->len - doffset, 0);
|
|
nskb->ip_summed = CHECKSUM_NONE;
|
|
}
|
|
} while ((offset += len) < skb->len);
|
|
|
|
return segs;
|
|
|
|
err:
|
|
while ((skb = segs)) {
|
|
segs = skb->next;
|
|
kfree_skb(skb);
|
|
}
|
|
return ERR_PTR(err);
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_segment);
|
|
|
|
int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb)
|
|
{
|
|
struct sk_buff *p = *head;
|
|
struct sk_buff *nskb;
|
|
struct skb_shared_info *skbinfo = skb_shinfo(skb);
|
|
struct skb_shared_info *pinfo = skb_shinfo(p);
|
|
unsigned int headroom;
|
|
unsigned int len = skb_gro_len(skb);
|
|
unsigned int offset = skb_gro_offset(skb);
|
|
unsigned int headlen = skb_headlen(skb);
|
|
unsigned int delta_truesize;
|
|
|
|
if (p->len + len >= 65536)
|
|
return -E2BIG;
|
|
|
|
if (pinfo->frag_list)
|
|
goto merge;
|
|
else if (headlen <= offset) {
|
|
skb_frag_t *frag;
|
|
skb_frag_t *frag2;
|
|
int i = skbinfo->nr_frags;
|
|
int nr_frags = pinfo->nr_frags + i;
|
|
|
|
offset -= headlen;
|
|
|
|
if (nr_frags > MAX_SKB_FRAGS)
|
|
return -E2BIG;
|
|
|
|
pinfo->nr_frags = nr_frags;
|
|
skbinfo->nr_frags = 0;
|
|
|
|
frag = pinfo->frags + nr_frags;
|
|
frag2 = skbinfo->frags + i;
|
|
do {
|
|
*--frag = *--frag2;
|
|
} while (--i);
|
|
|
|
frag->page_offset += offset;
|
|
skb_frag_size_sub(frag, offset);
|
|
|
|
/* all fragments truesize : remove (head size + sk_buff) */
|
|
delta_truesize = skb->truesize -
|
|
SKB_TRUESIZE(skb_end_offset(skb));
|
|
|
|
skb->truesize -= skb->data_len;
|
|
skb->len -= skb->data_len;
|
|
skb->data_len = 0;
|
|
|
|
NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE;
|
|
goto done;
|
|
} else if (skb->head_frag) {
|
|
int nr_frags = pinfo->nr_frags;
|
|
skb_frag_t *frag = pinfo->frags + nr_frags;
|
|
struct page *page = virt_to_head_page(skb->head);
|
|
unsigned int first_size = headlen - offset;
|
|
unsigned int first_offset;
|
|
|
|
if (nr_frags + 1 + skbinfo->nr_frags > MAX_SKB_FRAGS)
|
|
return -E2BIG;
|
|
|
|
first_offset = skb->data -
|
|
(unsigned char *)page_address(page) +
|
|
offset;
|
|
|
|
pinfo->nr_frags = nr_frags + 1 + skbinfo->nr_frags;
|
|
|
|
frag->page.p = page;
|
|
frag->page_offset = first_offset;
|
|
skb_frag_size_set(frag, first_size);
|
|
|
|
memcpy(frag + 1, skbinfo->frags, sizeof(*frag) * skbinfo->nr_frags);
|
|
/* We dont need to clear skbinfo->nr_frags here */
|
|
|
|
delta_truesize = skb->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff));
|
|
NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE_STOLEN_HEAD;
|
|
goto done;
|
|
} else if (skb_gro_len(p) != pinfo->gso_size)
|
|
return -E2BIG;
|
|
|
|
headroom = skb_headroom(p);
|
|
nskb = alloc_skb(headroom + skb_gro_offset(p), GFP_ATOMIC);
|
|
if (unlikely(!nskb))
|
|
return -ENOMEM;
|
|
|
|
__copy_skb_header(nskb, p);
|
|
nskb->mac_len = p->mac_len;
|
|
|
|
skb_reserve(nskb, headroom);
|
|
__skb_put(nskb, skb_gro_offset(p));
|
|
|
|
skb_set_mac_header(nskb, skb_mac_header(p) - p->data);
|
|
skb_set_network_header(nskb, skb_network_offset(p));
|
|
skb_set_transport_header(nskb, skb_transport_offset(p));
|
|
|
|
__skb_pull(p, skb_gro_offset(p));
|
|
memcpy(skb_mac_header(nskb), skb_mac_header(p),
|
|
p->data - skb_mac_header(p));
|
|
|
|
skb_shinfo(nskb)->frag_list = p;
|
|
skb_shinfo(nskb)->gso_size = pinfo->gso_size;
|
|
pinfo->gso_size = 0;
|
|
skb_header_release(p);
|
|
NAPI_GRO_CB(nskb)->last = p;
|
|
|
|
nskb->data_len += p->len;
|
|
nskb->truesize += p->truesize;
|
|
nskb->len += p->len;
|
|
|
|
*head = nskb;
|
|
nskb->next = p->next;
|
|
p->next = NULL;
|
|
|
|
p = nskb;
|
|
|
|
merge:
|
|
delta_truesize = skb->truesize;
|
|
if (offset > headlen) {
|
|
unsigned int eat = offset - headlen;
|
|
|
|
skbinfo->frags[0].page_offset += eat;
|
|
skb_frag_size_sub(&skbinfo->frags[0], eat);
|
|
skb->data_len -= eat;
|
|
skb->len -= eat;
|
|
offset = headlen;
|
|
}
|
|
|
|
__skb_pull(skb, offset);
|
|
|
|
NAPI_GRO_CB(p)->last->next = skb;
|
|
NAPI_GRO_CB(p)->last = skb;
|
|
skb_header_release(skb);
|
|
|
|
done:
|
|
NAPI_GRO_CB(p)->count++;
|
|
p->data_len += len;
|
|
p->truesize += delta_truesize;
|
|
p->len += len;
|
|
|
|
NAPI_GRO_CB(skb)->same_flow = 1;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_gro_receive);
|
|
|
|
void __init skb_init(void)
|
|
{
|
|
skbuff_head_cache = kmem_cache_create("skbuff_head_cache",
|
|
sizeof(struct sk_buff),
|
|
0,
|
|
SLAB_HWCACHE_ALIGN|SLAB_PANIC,
|
|
NULL);
|
|
skbuff_fclone_cache = kmem_cache_create("skbuff_fclone_cache",
|
|
(2*sizeof(struct sk_buff)) +
|
|
sizeof(atomic_t),
|
|
0,
|
|
SLAB_HWCACHE_ALIGN|SLAB_PANIC,
|
|
NULL);
|
|
}
|
|
|
|
/**
|
|
* skb_to_sgvec - Fill a scatter-gather list from a socket buffer
|
|
* @skb: Socket buffer containing the buffers to be mapped
|
|
* @sg: The scatter-gather list to map into
|
|
* @offset: The offset into the buffer's contents to start mapping
|
|
* @len: Length of buffer space to be mapped
|
|
*
|
|
* Fill the specified scatter-gather list with mappings/pointers into a
|
|
* region of the buffer space attached to a socket buffer.
|
|
*/
|
|
static int
|
|
__skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len)
|
|
{
|
|
int start = skb_headlen(skb);
|
|
int i, copy = start - offset;
|
|
struct sk_buff *frag_iter;
|
|
int elt = 0;
|
|
|
|
if (copy > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
sg_set_buf(sg, skb->data + offset, copy);
|
|
elt++;
|
|
if ((len -= copy) == 0)
|
|
return elt;
|
|
offset += copy;
|
|
}
|
|
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
int end;
|
|
|
|
WARN_ON(start > offset + len);
|
|
|
|
end = start + skb_frag_size(&skb_shinfo(skb)->frags[i]);
|
|
if ((copy = end - offset) > 0) {
|
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
|
|
|
|
if (copy > len)
|
|
copy = len;
|
|
sg_set_page(&sg[elt], skb_frag_page(frag), copy,
|
|
frag->page_offset+offset-start);
|
|
elt++;
|
|
if (!(len -= copy))
|
|
return elt;
|
|
offset += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
|
|
skb_walk_frags(skb, frag_iter) {
|
|
int end;
|
|
|
|
WARN_ON(start > offset + len);
|
|
|
|
end = start + frag_iter->len;
|
|
if ((copy = end - offset) > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
elt += __skb_to_sgvec(frag_iter, sg+elt, offset - start,
|
|
copy);
|
|
if ((len -= copy) == 0)
|
|
return elt;
|
|
offset += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
BUG_ON(len);
|
|
return elt;
|
|
}
|
|
|
|
int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len)
|
|
{
|
|
int nsg = __skb_to_sgvec(skb, sg, offset, len);
|
|
|
|
sg_mark_end(&sg[nsg - 1]);
|
|
|
|
return nsg;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_to_sgvec);
|
|
|
|
/**
|
|
* skb_cow_data - Check that a socket buffer's data buffers are writable
|
|
* @skb: The socket buffer to check.
|
|
* @tailbits: Amount of trailing space to be added
|
|
* @trailer: Returned pointer to the skb where the @tailbits space begins
|
|
*
|
|
* Make sure that the data buffers attached to a socket buffer are
|
|
* writable. If they are not, private copies are made of the data buffers
|
|
* and the socket buffer is set to use these instead.
|
|
*
|
|
* If @tailbits is given, make sure that there is space to write @tailbits
|
|
* bytes of data beyond current end of socket buffer. @trailer will be
|
|
* set to point to the skb in which this space begins.
|
|
*
|
|
* The number of scatterlist elements required to completely map the
|
|
* COW'd and extended socket buffer will be returned.
|
|
*/
|
|
int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer)
|
|
{
|
|
int copyflag;
|
|
int elt;
|
|
struct sk_buff *skb1, **skb_p;
|
|
|
|
/* If skb is cloned or its head is paged, reallocate
|
|
* head pulling out all the pages (pages are considered not writable
|
|
* at the moment even if they are anonymous).
|
|
*/
|
|
if ((skb_cloned(skb) || skb_shinfo(skb)->nr_frags) &&
|
|
__pskb_pull_tail(skb, skb_pagelen(skb)-skb_headlen(skb)) == NULL)
|
|
return -ENOMEM;
|
|
|
|
/* Easy case. Most of packets will go this way. */
|
|
if (!skb_has_frag_list(skb)) {
|
|
/* A little of trouble, not enough of space for trailer.
|
|
* This should not happen, when stack is tuned to generate
|
|
* good frames. OK, on miss we reallocate and reserve even more
|
|
* space, 128 bytes is fair. */
|
|
|
|
if (skb_tailroom(skb) < tailbits &&
|
|
pskb_expand_head(skb, 0, tailbits-skb_tailroom(skb)+128, GFP_ATOMIC))
|
|
return -ENOMEM;
|
|
|
|
/* Voila! */
|
|
*trailer = skb;
|
|
return 1;
|
|
}
|
|
|
|
/* Misery. We are in troubles, going to mincer fragments... */
|
|
|
|
elt = 1;
|
|
skb_p = &skb_shinfo(skb)->frag_list;
|
|
copyflag = 0;
|
|
|
|
while ((skb1 = *skb_p) != NULL) {
|
|
int ntail = 0;
|
|
|
|
/* The fragment is partially pulled by someone,
|
|
* this can happen on input. Copy it and everything
|
|
* after it. */
|
|
|
|
if (skb_shared(skb1))
|
|
copyflag = 1;
|
|
|
|
/* If the skb is the last, worry about trailer. */
|
|
|
|
if (skb1->next == NULL && tailbits) {
|
|
if (skb_shinfo(skb1)->nr_frags ||
|
|
skb_has_frag_list(skb1) ||
|
|
skb_tailroom(skb1) < tailbits)
|
|
ntail = tailbits + 128;
|
|
}
|
|
|
|
if (copyflag ||
|
|
skb_cloned(skb1) ||
|
|
ntail ||
|
|
skb_shinfo(skb1)->nr_frags ||
|
|
skb_has_frag_list(skb1)) {
|
|
struct sk_buff *skb2;
|
|
|
|
/* Fuck, we are miserable poor guys... */
|
|
if (ntail == 0)
|
|
skb2 = skb_copy(skb1, GFP_ATOMIC);
|
|
else
|
|
skb2 = skb_copy_expand(skb1,
|
|
skb_headroom(skb1),
|
|
ntail,
|
|
GFP_ATOMIC);
|
|
if (unlikely(skb2 == NULL))
|
|
return -ENOMEM;
|
|
|
|
if (skb1->sk)
|
|
skb_set_owner_w(skb2, skb1->sk);
|
|
|
|
/* Looking around. Are we still alive?
|
|
* OK, link new skb, drop old one */
|
|
|
|
skb2->next = skb1->next;
|
|
*skb_p = skb2;
|
|
kfree_skb(skb1);
|
|
skb1 = skb2;
|
|
}
|
|
elt++;
|
|
*trailer = skb1;
|
|
skb_p = &skb1->next;
|
|
}
|
|
|
|
return elt;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_cow_data);
|
|
|
|
static void sock_rmem_free(struct sk_buff *skb)
|
|
{
|
|
struct sock *sk = skb->sk;
|
|
|
|
atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
|
|
}
|
|
|
|
/*
|
|
* Note: We dont mem charge error packets (no sk_forward_alloc changes)
|
|
*/
|
|
int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
int len = skb->len;
|
|
|
|
if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
|
|
(unsigned int)sk->sk_rcvbuf)
|
|
return -ENOMEM;
|
|
|
|
skb_orphan(skb);
|
|
skb->sk = sk;
|
|
skb->destructor = sock_rmem_free;
|
|
atomic_add(skb->truesize, &sk->sk_rmem_alloc);
|
|
|
|
/* before exiting rcu section, make sure dst is refcounted */
|
|
skb_dst_force(skb);
|
|
|
|
skb_queue_tail(&sk->sk_error_queue, skb);
|
|
if (!sock_flag(sk, SOCK_DEAD))
|
|
sk->sk_data_ready(sk, len);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(sock_queue_err_skb);
|
|
|
|
void skb_tstamp_tx(struct sk_buff *orig_skb,
|
|
struct skb_shared_hwtstamps *hwtstamps)
|
|
{
|
|
struct sock *sk = orig_skb->sk;
|
|
struct sock_exterr_skb *serr;
|
|
struct sk_buff *skb;
|
|
int err;
|
|
|
|
if (!sk)
|
|
return;
|
|
|
|
if (hwtstamps) {
|
|
*skb_hwtstamps(orig_skb) =
|
|
*hwtstamps;
|
|
} else {
|
|
/*
|
|
* no hardware time stamps available,
|
|
* so keep the shared tx_flags and only
|
|
* store software time stamp
|
|
*/
|
|
orig_skb->tstamp = ktime_get_real();
|
|
}
|
|
|
|
skb = skb_clone(orig_skb, GFP_ATOMIC);
|
|
if (!skb)
|
|
return;
|
|
|
|
serr = SKB_EXT_ERR(skb);
|
|
memset(serr, 0, sizeof(*serr));
|
|
serr->ee.ee_errno = ENOMSG;
|
|
serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
|
|
|
|
err = sock_queue_err_skb(sk, skb);
|
|
|
|
if (err)
|
|
kfree_skb(skb);
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_tstamp_tx);
|
|
|
|
void skb_complete_wifi_ack(struct sk_buff *skb, bool acked)
|
|
{
|
|
struct sock *sk = skb->sk;
|
|
struct sock_exterr_skb *serr;
|
|
int err;
|
|
|
|
skb->wifi_acked_valid = 1;
|
|
skb->wifi_acked = acked;
|
|
|
|
serr = SKB_EXT_ERR(skb);
|
|
memset(serr, 0, sizeof(*serr));
|
|
serr->ee.ee_errno = ENOMSG;
|
|
serr->ee.ee_origin = SO_EE_ORIGIN_TXSTATUS;
|
|
|
|
err = sock_queue_err_skb(sk, skb);
|
|
if (err)
|
|
kfree_skb(skb);
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_complete_wifi_ack);
|
|
|
|
|
|
/**
|
|
* skb_partial_csum_set - set up and verify partial csum values for packet
|
|
* @skb: the skb to set
|
|
* @start: the number of bytes after skb->data to start checksumming.
|
|
* @off: the offset from start to place the checksum.
|
|
*
|
|
* For untrusted partially-checksummed packets, we need to make sure the values
|
|
* for skb->csum_start and skb->csum_offset are valid so we don't oops.
|
|
*
|
|
* This function checks and sets those values and skb->ip_summed: if this
|
|
* returns false you should drop the packet.
|
|
*/
|
|
bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off)
|
|
{
|
|
if (unlikely(start > skb_headlen(skb)) ||
|
|
unlikely((int)start + off > skb_headlen(skb) - 2)) {
|
|
net_warn_ratelimited("bad partial csum: csum=%u/%u len=%u\n",
|
|
start, off, skb_headlen(skb));
|
|
return false;
|
|
}
|
|
skb->ip_summed = CHECKSUM_PARTIAL;
|
|
skb->csum_start = skb_headroom(skb) + start;
|
|
skb->csum_offset = off;
|
|
skb_set_transport_header(skb, start);
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_partial_csum_set);
|
|
|
|
void __skb_warn_lro_forwarding(const struct sk_buff *skb)
|
|
{
|
|
net_warn_ratelimited("%s: received packets cannot be forwarded while LRO is enabled\n",
|
|
skb->dev->name);
|
|
}
|
|
EXPORT_SYMBOL(__skb_warn_lro_forwarding);
|
|
|
|
void kfree_skb_partial(struct sk_buff *skb, bool head_stolen)
|
|
{
|
|
if (head_stolen) {
|
|
skb_release_head_state(skb);
|
|
kmem_cache_free(skbuff_head_cache, skb);
|
|
} else {
|
|
__kfree_skb(skb);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(kfree_skb_partial);
|
|
|
|
/**
|
|
* skb_try_coalesce - try to merge skb to prior one
|
|
* @to: prior buffer
|
|
* @from: buffer to add
|
|
* @fragstolen: pointer to boolean
|
|
* @delta_truesize: how much more was allocated than was requested
|
|
*/
|
|
bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
|
|
bool *fragstolen, int *delta_truesize)
|
|
{
|
|
int i, delta, len = from->len;
|
|
|
|
*fragstolen = false;
|
|
|
|
if (skb_cloned(to))
|
|
return false;
|
|
|
|
if (len <= skb_tailroom(to)) {
|
|
BUG_ON(skb_copy_bits(from, 0, skb_put(to, len), len));
|
|
*delta_truesize = 0;
|
|
return true;
|
|
}
|
|
|
|
if (skb_has_frag_list(to) || skb_has_frag_list(from))
|
|
return false;
|
|
|
|
if (skb_headlen(from) != 0) {
|
|
struct page *page;
|
|
unsigned int offset;
|
|
|
|
if (skb_shinfo(to)->nr_frags +
|
|
skb_shinfo(from)->nr_frags >= MAX_SKB_FRAGS)
|
|
return false;
|
|
|
|
if (skb_head_is_locked(from))
|
|
return false;
|
|
|
|
delta = from->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff));
|
|
|
|
page = virt_to_head_page(from->head);
|
|
offset = from->data - (unsigned char *)page_address(page);
|
|
|
|
skb_fill_page_desc(to, skb_shinfo(to)->nr_frags,
|
|
page, offset, skb_headlen(from));
|
|
*fragstolen = true;
|
|
} else {
|
|
if (skb_shinfo(to)->nr_frags +
|
|
skb_shinfo(from)->nr_frags > MAX_SKB_FRAGS)
|
|
return false;
|
|
|
|
delta = from->truesize - SKB_TRUESIZE(skb_end_offset(from));
|
|
}
|
|
|
|
WARN_ON_ONCE(delta < len);
|
|
|
|
memcpy(skb_shinfo(to)->frags + skb_shinfo(to)->nr_frags,
|
|
skb_shinfo(from)->frags,
|
|
skb_shinfo(from)->nr_frags * sizeof(skb_frag_t));
|
|
skb_shinfo(to)->nr_frags += skb_shinfo(from)->nr_frags;
|
|
|
|
if (!skb_cloned(from))
|
|
skb_shinfo(from)->nr_frags = 0;
|
|
|
|
/* if the skb is not cloned this does nothing
|
|
* since we set nr_frags to 0.
|
|
*/
|
|
for (i = 0; i < skb_shinfo(from)->nr_frags; i++)
|
|
skb_frag_ref(from, i);
|
|
|
|
to->truesize += delta;
|
|
to->len += len;
|
|
to->data_len += len;
|
|
|
|
*delta_truesize = delta;
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL(skb_try_coalesce);
|