linux/net/bridge/br_forward.c

315 lines
7.1 KiB
C
Raw Normal View History

/*
* Forwarding decision
* Linux ethernet bridge
*
* Authors:
* Lennert Buytenhek <buytenh@gnu.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/err.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 09:04:11 +01:00
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/netpoll.h>
#include <linux/skbuff.h>
#include <linux/if_vlan.h>
#include <linux/netfilter_bridge.h>
#include "br_private.h"
static int deliver_clone(const struct net_bridge_port *prev,
struct sk_buff *skb,
void (*__packet_hook)(const struct net_bridge_port *p,
struct sk_buff *skb));
/* Don't forward packets to originating port or forwarding disabled */
static inline int should_deliver(const struct net_bridge_port *p,
const struct sk_buff *skb)
{
bridge: vlan: add per-vlan struct and move to rhashtables This patch changes the bridge vlan implementation to use rhashtables instead of bitmaps. The main motivation behind this change is that we need extensible per-vlan structures (both per-port and global) so more advanced features can be introduced and the vlan support can be extended. I've tried to break this up but the moment net_port_vlans is changed and the whole API goes away, thus this is a larger patch. A few short goals of this patch are: - Extensible per-vlan structs stored in rhashtables and a sorted list - Keep user-visible behaviour (compressed vlans etc) - Keep fastpath ingress/egress logic the same (optimizations to come later) Here's a brief list of some of the new features we'd like to introduce: - per-vlan counters - vlan ingress/egress mapping - per-vlan igmp configuration - vlan priorities - avoid fdb entries replication (e.g. local fdb scaling issues) The structure is kept single for both global and per-port entries so to avoid code duplication where possible and also because we'll soon introduce "port0 / aka bridge as port" which should simplify things further (thanks to Vlad for the suggestion!). Now we have per-vlan global rhashtable (bridge-wide) and per-vlan port rhashtable, if an entry is added to a port it'll get a pointer to its global context so it can be quickly accessed later. There's also a sorted vlan list which is used for stable walks and some user-visible behaviour such as the vlan ranges, also for error paths. VLANs are stored in a "vlan group" which currently contains the rhashtable, sorted vlan list and the number of "real" vlan entries. A good side-effect of this change is that it resembles how hw keeps per-vlan data. One important note after this change is that if a VLAN is being looked up in the bridge's rhashtable for filtering purposes (or to check if it's an existing usable entry, not just a global context) then the new helper br_vlan_should_use() needs to be used if the vlan is found. In case the lookup is done only with a port's vlan group, then this check can be skipped. Things tested so far: - basic vlan ingress/egress - pvids - untagged vlans - undef CONFIG_BRIDGE_VLAN_FILTERING - adding/deleting vlans in different scenarios (with/without global ctx, while transmitting traffic, in ranges etc) - loading/removing the module while having/adding/deleting vlans - extracting bridge vlan information (user ABI), compressed requests - adding/deleting fdbs on vlans - bridge mac change, promisc mode - default pvid change - kmemleak ON during the whole time Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-25 19:00:11 +02:00
struct net_bridge_vlan_group *vg;
vg = nbp_vlan_group_rcu(p);
return ((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) &&
bridge: vlan: add per-vlan struct and move to rhashtables This patch changes the bridge vlan implementation to use rhashtables instead of bitmaps. The main motivation behind this change is that we need extensible per-vlan structures (both per-port and global) so more advanced features can be introduced and the vlan support can be extended. I've tried to break this up but the moment net_port_vlans is changed and the whole API goes away, thus this is a larger patch. A few short goals of this patch are: - Extensible per-vlan structs stored in rhashtables and a sorted list - Keep user-visible behaviour (compressed vlans etc) - Keep fastpath ingress/egress logic the same (optimizations to come later) Here's a brief list of some of the new features we'd like to introduce: - per-vlan counters - vlan ingress/egress mapping - per-vlan igmp configuration - vlan priorities - avoid fdb entries replication (e.g. local fdb scaling issues) The structure is kept single for both global and per-port entries so to avoid code duplication where possible and also because we'll soon introduce "port0 / aka bridge as port" which should simplify things further (thanks to Vlad for the suggestion!). Now we have per-vlan global rhashtable (bridge-wide) and per-vlan port rhashtable, if an entry is added to a port it'll get a pointer to its global context so it can be quickly accessed later. There's also a sorted vlan list which is used for stable walks and some user-visible behaviour such as the vlan ranges, also for error paths. VLANs are stored in a "vlan group" which currently contains the rhashtable, sorted vlan list and the number of "real" vlan entries. A good side-effect of this change is that it resembles how hw keeps per-vlan data. One important note after this change is that if a VLAN is being looked up in the bridge's rhashtable for filtering purposes (or to check if it's an existing usable entry, not just a global context) then the new helper br_vlan_should_use() needs to be used if the vlan is found. In case the lookup is done only with a port's vlan group, then this check can be skipped. Things tested so far: - basic vlan ingress/egress - pvids - untagged vlans - undef CONFIG_BRIDGE_VLAN_FILTERING - adding/deleting vlans in different scenarios (with/without global ctx, while transmitting traffic, in ranges etc) - loading/removing the module while having/adding/deleting vlans - extracting bridge vlan information (user ABI), compressed requests - adding/deleting fdbs on vlans - bridge mac change, promisc mode - default pvid change - kmemleak ON during the whole time Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-25 19:00:11 +02:00
br_allowed_egress(vg, skb) && p->state == BR_STATE_FORWARDING;
}
int br_dev_queue_push_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
{
if (!is_skb_forwardable(skb->dev, skb))
goto drop;
skb_push(skb, ETH_HLEN);
br_drop_fake_rtable(skb);
if (skb->ip_summed == CHECKSUM_PARTIAL &&
(skb->protocol == htons(ETH_P_8021Q) ||
skb->protocol == htons(ETH_P_8021AD))) {
int depth;
if (!__vlan_get_protocol(skb, skb->protocol, &depth))
goto drop;
skb_set_network_header(skb, depth);
}
dev_queue_xmit(skb);
return 0;
drop:
kfree_skb(skb);
return 0;
}
EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit);
int br_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
{
2015-09-16 03:04:16 +02:00
return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING,
net, sk, skb, NULL, skb->dev,
br_dev_queue_push_xmit);
}
EXPORT_SYMBOL_GPL(br_forward_finish);
static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
{
bridge: vlan: add per-vlan struct and move to rhashtables This patch changes the bridge vlan implementation to use rhashtables instead of bitmaps. The main motivation behind this change is that we need extensible per-vlan structures (both per-port and global) so more advanced features can be introduced and the vlan support can be extended. I've tried to break this up but the moment net_port_vlans is changed and the whole API goes away, thus this is a larger patch. A few short goals of this patch are: - Extensible per-vlan structs stored in rhashtables and a sorted list - Keep user-visible behaviour (compressed vlans etc) - Keep fastpath ingress/egress logic the same (optimizations to come later) Here's a brief list of some of the new features we'd like to introduce: - per-vlan counters - vlan ingress/egress mapping - per-vlan igmp configuration - vlan priorities - avoid fdb entries replication (e.g. local fdb scaling issues) The structure is kept single for both global and per-port entries so to avoid code duplication where possible and also because we'll soon introduce "port0 / aka bridge as port" which should simplify things further (thanks to Vlad for the suggestion!). Now we have per-vlan global rhashtable (bridge-wide) and per-vlan port rhashtable, if an entry is added to a port it'll get a pointer to its global context so it can be quickly accessed later. There's also a sorted vlan list which is used for stable walks and some user-visible behaviour such as the vlan ranges, also for error paths. VLANs are stored in a "vlan group" which currently contains the rhashtable, sorted vlan list and the number of "real" vlan entries. A good side-effect of this change is that it resembles how hw keeps per-vlan data. One important note after this change is that if a VLAN is being looked up in the bridge's rhashtable for filtering purposes (or to check if it's an existing usable entry, not just a global context) then the new helper br_vlan_should_use() needs to be used if the vlan is found. In case the lookup is done only with a port's vlan group, then this check can be skipped. Things tested so far: - basic vlan ingress/egress - pvids - untagged vlans - undef CONFIG_BRIDGE_VLAN_FILTERING - adding/deleting vlans in different scenarios (with/without global ctx, while transmitting traffic, in ranges etc) - loading/removing the module while having/adding/deleting vlans - extracting bridge vlan information (user ABI), compressed requests - adding/deleting fdbs on vlans - bridge mac change, promisc mode - default pvid change - kmemleak ON during the whole time Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-25 19:00:11 +02:00
struct net_bridge_vlan_group *vg;
vg = nbp_vlan_group_rcu(to);
bridge: vlan: add per-vlan struct and move to rhashtables This patch changes the bridge vlan implementation to use rhashtables instead of bitmaps. The main motivation behind this change is that we need extensible per-vlan structures (both per-port and global) so more advanced features can be introduced and the vlan support can be extended. I've tried to break this up but the moment net_port_vlans is changed and the whole API goes away, thus this is a larger patch. A few short goals of this patch are: - Extensible per-vlan structs stored in rhashtables and a sorted list - Keep user-visible behaviour (compressed vlans etc) - Keep fastpath ingress/egress logic the same (optimizations to come later) Here's a brief list of some of the new features we'd like to introduce: - per-vlan counters - vlan ingress/egress mapping - per-vlan igmp configuration - vlan priorities - avoid fdb entries replication (e.g. local fdb scaling issues) The structure is kept single for both global and per-port entries so to avoid code duplication where possible and also because we'll soon introduce "port0 / aka bridge as port" which should simplify things further (thanks to Vlad for the suggestion!). Now we have per-vlan global rhashtable (bridge-wide) and per-vlan port rhashtable, if an entry is added to a port it'll get a pointer to its global context so it can be quickly accessed later. There's also a sorted vlan list which is used for stable walks and some user-visible behaviour such as the vlan ranges, also for error paths. VLANs are stored in a "vlan group" which currently contains the rhashtable, sorted vlan list and the number of "real" vlan entries. A good side-effect of this change is that it resembles how hw keeps per-vlan data. One important note after this change is that if a VLAN is being looked up in the bridge's rhashtable for filtering purposes (or to check if it's an existing usable entry, not just a global context) then the new helper br_vlan_should_use() needs to be used if the vlan is found. In case the lookup is done only with a port's vlan group, then this check can be skipped. Things tested so far: - basic vlan ingress/egress - pvids - untagged vlans - undef CONFIG_BRIDGE_VLAN_FILTERING - adding/deleting vlans in different scenarios (with/without global ctx, while transmitting traffic, in ranges etc) - loading/removing the module while having/adding/deleting vlans - extracting bridge vlan information (user ABI), compressed requests - adding/deleting fdbs on vlans - bridge mac change, promisc mode - default pvid change - kmemleak ON during the whole time Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-25 19:00:11 +02:00
skb = br_handle_vlan(to->br, vg, skb);
if (!skb)
return;
skb->dev = to->dev;
if (unlikely(netpoll_tx_running(to->br->dev))) {
if (!is_skb_forwardable(skb->dev, skb))
kfree_skb(skb);
else {
skb_push(skb, ETH_HLEN);
br_netpoll_send_skb(to, skb);
}
return;
}
2015-09-16 03:04:16 +02:00
NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT,
dev_net(skb->dev), NULL, skb,NULL, skb->dev,
br_forward_finish);
}
static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
{
bridge: vlan: add per-vlan struct and move to rhashtables This patch changes the bridge vlan implementation to use rhashtables instead of bitmaps. The main motivation behind this change is that we need extensible per-vlan structures (both per-port and global) so more advanced features can be introduced and the vlan support can be extended. I've tried to break this up but the moment net_port_vlans is changed and the whole API goes away, thus this is a larger patch. A few short goals of this patch are: - Extensible per-vlan structs stored in rhashtables and a sorted list - Keep user-visible behaviour (compressed vlans etc) - Keep fastpath ingress/egress logic the same (optimizations to come later) Here's a brief list of some of the new features we'd like to introduce: - per-vlan counters - vlan ingress/egress mapping - per-vlan igmp configuration - vlan priorities - avoid fdb entries replication (e.g. local fdb scaling issues) The structure is kept single for both global and per-port entries so to avoid code duplication where possible and also because we'll soon introduce "port0 / aka bridge as port" which should simplify things further (thanks to Vlad for the suggestion!). Now we have per-vlan global rhashtable (bridge-wide) and per-vlan port rhashtable, if an entry is added to a port it'll get a pointer to its global context so it can be quickly accessed later. There's also a sorted vlan list which is used for stable walks and some user-visible behaviour such as the vlan ranges, also for error paths. VLANs are stored in a "vlan group" which currently contains the rhashtable, sorted vlan list and the number of "real" vlan entries. A good side-effect of this change is that it resembles how hw keeps per-vlan data. One important note after this change is that if a VLAN is being looked up in the bridge's rhashtable for filtering purposes (or to check if it's an existing usable entry, not just a global context) then the new helper br_vlan_should_use() needs to be used if the vlan is found. In case the lookup is done only with a port's vlan group, then this check can be skipped. Things tested so far: - basic vlan ingress/egress - pvids - untagged vlans - undef CONFIG_BRIDGE_VLAN_FILTERING - adding/deleting vlans in different scenarios (with/without global ctx, while transmitting traffic, in ranges etc) - loading/removing the module while having/adding/deleting vlans - extracting bridge vlan information (user ABI), compressed requests - adding/deleting fdbs on vlans - bridge mac change, promisc mode - default pvid change - kmemleak ON during the whole time Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-25 19:00:11 +02:00
struct net_bridge_vlan_group *vg;
struct net_device *indev;
bridge: Fix LRO crash with tun > Kernel BUG at drivers/net/tun.c:444 > invalid opcode: 0000 [1] SMP > last sysfs file: /class/net/lo/ifindex > CPU 0 > Modules linked in: tun ipt_MASQUERADE iptable_nat ip_nat xt_state ip_conntrack > nfnetlink ipt_REJECT xt_tcpudp iptable_filter d > Pid: 6912, comm: qemu-kvm Tainted: G 2.6.18-128.el5 #1 > RIP: 0010:[<ffffffff886f57b0>] [<ffffffff886f57b0>] > :tun:tun_chr_readv+0x2b1/0x3a6 > RSP: 0018:ffff8102202c5e48 EFLAGS: 00010246 > RAX: 0000000000000000 RBX: ffff8102202c5e98 RCX: 0000000004010000 > RDX: ffff810227063680 RSI: ffff8102202c5e9e RDI: ffff8102202c5e92 > RBP: 0000000000010ff6 R08: 0000000000000000 R09: 0000000000000001 > R10: ffff8102202c5e94 R11: 0000000000000202 R12: ffff8102275357c0 > R13: ffff81022755e500 R14: 0000000000000000 R15: ffff8102202c5ef8 > FS: 00002ae4398db980(0000) GS:ffffffff803ac000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > CR2: 00002ae4ab514000 CR3: 0000000221344000 CR4: 00000000000026e0 > Process qemu-kvm (pid: 6912, threadinfo ffff8102202c4000, task > ffff81022e58d820) > Stack: 00000000498735cb ffff810229d1a3c0 0000000000000000 ffff81022e58d820 > ffffffff8008a461 ffff81022755e528 ffff81022755e528 ffffffff8009f925 > 000005ea05ea0000 ffff8102209d0000 00001051143e1600 ffffffff8003c00e > Call Trace: > [<ffffffff8008a461>] default_wake_function+0x0/0xe > [<ffffffff8009f925>] enqueue_hrtimer+0x55/0x70 > [<ffffffff8003c00e>] hrtimer_start+0xbc/0xce > [<ffffffff886f58bf>] :tun:tun_chr_read+0x1a/0x1f > [<ffffffff8000b3f3>] vfs_read+0xcb/0x171 > [<ffffffff800117d4>] sys_read+0x45/0x6e > [<ffffffff8005d116>] system_call+0x7e/0x83 > > > Code: 0f 0b 68 40 62 6f 88 c2 bc 01 f6 42 0a 08 74 0c 80 4c 24 41 > RIP [<ffffffff886f57b0>] :tun:tun_chr_readv+0x2b1/0x3a6 > RSP <ffff8102202c5e48> > <0>Kernel panic - not syncing: Fatal exception This crashed when an LRO packet generated by bnx2x reached a tun device through the bridge. We're supposed to drop it at the bridge. However, because the check was placed in br_forward instead of __br_forward, it's only effective if we are sending the packet through a single port. This patch fixes it by moving the check into __br_forward. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-10 00:07:18 +01:00
if (skb_warn_if_lro(skb)) {
kfree_skb(skb);
return;
}
vg = nbp_vlan_group_rcu(to);
bridge: vlan: add per-vlan struct and move to rhashtables This patch changes the bridge vlan implementation to use rhashtables instead of bitmaps. The main motivation behind this change is that we need extensible per-vlan structures (both per-port and global) so more advanced features can be introduced and the vlan support can be extended. I've tried to break this up but the moment net_port_vlans is changed and the whole API goes away, thus this is a larger patch. A few short goals of this patch are: - Extensible per-vlan structs stored in rhashtables and a sorted list - Keep user-visible behaviour (compressed vlans etc) - Keep fastpath ingress/egress logic the same (optimizations to come later) Here's a brief list of some of the new features we'd like to introduce: - per-vlan counters - vlan ingress/egress mapping - per-vlan igmp configuration - vlan priorities - avoid fdb entries replication (e.g. local fdb scaling issues) The structure is kept single for both global and per-port entries so to avoid code duplication where possible and also because we'll soon introduce "port0 / aka bridge as port" which should simplify things further (thanks to Vlad for the suggestion!). Now we have per-vlan global rhashtable (bridge-wide) and per-vlan port rhashtable, if an entry is added to a port it'll get a pointer to its global context so it can be quickly accessed later. There's also a sorted vlan list which is used for stable walks and some user-visible behaviour such as the vlan ranges, also for error paths. VLANs are stored in a "vlan group" which currently contains the rhashtable, sorted vlan list and the number of "real" vlan entries. A good side-effect of this change is that it resembles how hw keeps per-vlan data. One important note after this change is that if a VLAN is being looked up in the bridge's rhashtable for filtering purposes (or to check if it's an existing usable entry, not just a global context) then the new helper br_vlan_should_use() needs to be used if the vlan is found. In case the lookup is done only with a port's vlan group, then this check can be skipped. Things tested so far: - basic vlan ingress/egress - pvids - untagged vlans - undef CONFIG_BRIDGE_VLAN_FILTERING - adding/deleting vlans in different scenarios (with/without global ctx, while transmitting traffic, in ranges etc) - loading/removing the module while having/adding/deleting vlans - extracting bridge vlan information (user ABI), compressed requests - adding/deleting fdbs on vlans - bridge mac change, promisc mode - default pvid change - kmemleak ON during the whole time Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-25 19:00:11 +02:00
skb = br_handle_vlan(to->br, vg, skb);
if (!skb)
return;
indev = skb->dev;
skb->dev = to->dev;
skb_forward_csum(skb);
2015-09-16 03:04:16 +02:00
NF_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD,
dev_net(indev), NULL, skb, indev, skb->dev,
br_forward_finish);
}
/* called with rcu_read_lock */
void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
{
if (to && should_deliver(to, skb)) {
__br_deliver(to, skb);
return;
}
kfree_skb(skb);
}
EXPORT_SYMBOL_GPL(br_deliver);
/* called with rcu_read_lock */
void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, struct sk_buff *skb0)
{
bridge: set is_local and is_static before fdb entry is added to the fdb hashtable Problem Description: We can add fdbs pointing to the bridge with NULL ->dst but that has a few race conditions because br_fdb_insert() is used which first creates the fdb and then, after the fdb has been published/linked, sets "is_local" to 1 and in that time frame if a packet arrives for that fdb it may see it as non-local and either do a NULL ptr dereference in br_forward() or attach the fdb to the port where it arrived, and later br_fdb_insert() will make it local thus getting a wrong fdb entry. Call chain br_handle_frame_finish() -> br_forward(): But in br_handle_frame_finish() in order to call br_forward() the dst should not be local i.e. skb != NULL, whenever the dst is found to be local skb is set to NULL so we can't forward it, and here comes the problem since it's running only with RCU when forwarding packets it can see the entry before "is_local" is set to 1 and actually try to dereference NULL. The main issue is that if someone sends a packet to the switch while it's adding the entry which points to the bridge device, it may dereference NULL ptr. This is needed now after we can add fdbs pointing to the bridge. This poses a problem for br_fdb_update() as well, while someone's adding a bridge fdb, but before it has is_local == 1, it might get moved to a port if it comes as a source mac and then it may get its "is_local" set to 1 This patch changes fdb_create to take is_local and is_static as arguments to set these values in the fdb entry before it is added to the hash. Also adds null check for port in br_forward. Fixes: 3741873b4f73 ("bridge: allow adding of fdb entries pointing to the bridge device") Reported-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-27 15:52:56 +01:00
if (to && should_deliver(to, skb)) {
if (skb0)
deliver_clone(to, skb, __br_forward);
else
__br_forward(to, skb);
return;
}
if (!skb0)
kfree_skb(skb);
}
static int deliver_clone(const struct net_bridge_port *prev,
struct sk_buff *skb,
void (*__packet_hook)(const struct net_bridge_port *p,
struct sk_buff *skb))
{
struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
skb = skb_clone(skb, GFP_ATOMIC);
if (!skb) {
dev->stats.tx_dropped++;
return -ENOMEM;
}
__packet_hook(prev, skb);
return 0;
}
static struct net_bridge_port *maybe_deliver(
struct net_bridge_port *prev, struct net_bridge_port *p,
struct sk_buff *skb,
void (*__packet_hook)(const struct net_bridge_port *p,
struct sk_buff *skb))
{
int err;
if (!should_deliver(p, skb))
return prev;
if (!prev)
goto out;
err = deliver_clone(prev, skb, __packet_hook);
if (err)
return ERR_PTR(err);
out:
return p;
}
/* called under bridge lock */
static void br_flood(struct net_bridge *br, struct sk_buff *skb,
struct sk_buff *skb0,
void (*__packet_hook)(const struct net_bridge_port *p,
struct sk_buff *skb),
bool unicast)
{
struct net_bridge_port *p;
struct net_bridge_port *prev;
prev = NULL;
list_for_each_entry_rcu(p, &br->port_list, list) {
/* Do not flood unicast traffic to ports that turn it off */
if (unicast && !(p->flags & BR_FLOOD))
continue;
/* Do not flood to ports that enable proxy ARP */
if (p->flags & BR_PROXYARP)
continue;
if ((p->flags & BR_PROXYARP_WIFI) &&
BR_INPUT_SKB_CB(skb)->proxyarp_replied)
continue;
prev = maybe_deliver(prev, p, skb, __packet_hook);
if (IS_ERR(prev))
goto out;
}
if (!prev)
goto out;
if (skb0)
deliver_clone(prev, skb, __packet_hook);
else
__packet_hook(prev, skb);
return;
out:
if (!skb0)
kfree_skb(skb);
}
/* called with rcu_read_lock */
void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb, bool unicast)
{
br_flood(br, skb, NULL, __br_deliver, unicast);
}
/* called under bridge lock */
void br_flood_forward(struct net_bridge *br, struct sk_buff *skb,
struct sk_buff *skb2, bool unicast)
{
br_flood(br, skb, skb2, __br_forward, unicast);
}
#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
/* called with rcu_read_lock */
static void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
struct sk_buff *skb, struct sk_buff *skb0,
void (*__packet_hook)(
const struct net_bridge_port *p,
struct sk_buff *skb))
{
struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
struct net_bridge *br = netdev_priv(dev);
struct net_bridge_port *prev = NULL;
struct net_bridge_port_group *p;
struct hlist_node *rp;
rp = rcu_dereference(hlist_first_rcu(&br->router_list));
p = mdst ? rcu_dereference(mdst->ports) : NULL;
while (p || rp) {
struct net_bridge_port *port, *lport, *rport;
lport = p ? p->port : NULL;
rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) :
NULL;
port = (unsigned long)lport > (unsigned long)rport ?
lport : rport;
prev = maybe_deliver(prev, port, skb, __packet_hook);
if (IS_ERR(prev))
goto out;
if ((unsigned long)lport >= (unsigned long)port)
p = rcu_dereference(p->next);
if ((unsigned long)rport >= (unsigned long)port)
rp = rcu_dereference(hlist_next_rcu(rp));
}
if (!prev)
goto out;
if (skb0)
deliver_clone(prev, skb, __packet_hook);
else
__packet_hook(prev, skb);
return;
out:
if (!skb0)
kfree_skb(skb);
}
/* called with rcu_read_lock */
void br_multicast_deliver(struct net_bridge_mdb_entry *mdst,
struct sk_buff *skb)
{
br_multicast_flood(mdst, skb, NULL, __br_deliver);
}
/* called with rcu_read_lock */
void br_multicast_forward(struct net_bridge_mdb_entry *mdst,
struct sk_buff *skb, struct sk_buff *skb2)
{
br_multicast_flood(mdst, skb, skb2, __br_forward);
}
#endif