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linux/samples/bpf/tcbpf2_kern.c
Daniel Borkmann 96a8eb1eee bpf: fix samples to add fake KBUILD_MODNAME 
Some of the sample files are causing issues when they are loaded with tc
and cls_bpf, meaning tc bails out while trying to parse the resulting ELF
file as program/map/etc sections are not present, which can be easily
spotted with readelf(1).

Currently, BPF samples are including some of the kernel headers and mid
term we should change them to refrain from this, really. When dynamic
debugging is enabled, we bail out due to undeclared KBUILD_MODNAME, which
is easily overlooked in the build as clang spills this along with other
noisy warnings from various header includes, and llc still generates an
ELF file with mentioned characteristics. For just playing around with BPF
examples, this can be a bit of a hurdle to take.

Just add a fake KBUILD_MODNAME as a band-aid to fix the issue, same is
done in xdp*_kern samples already.

Fixes: 65d472fb00 ("samples/bpf: add 'pointer to packet' tests")
Fixes: 6afb1e28b8 ("samples/bpf: Add tunnel set/get tests.")
Fixes: a3f7461734 ("cgroup: bpf: Add an example to do cgroup checking in BPF")
Reported-by: Chandrasekar Kannan <ckannan@console.to>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-29 14:46:12 -04:00

383 lines
8.1 KiB
C
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/* Copyright (c) 2016 VMware
* Copyright (c) 2016 Facebook
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*/
#define KBUILD_MODNAME "foo"
#include <uapi/linux/bpf.h>
#include <uapi/linux/if_ether.h>
#include <uapi/linux/if_packet.h>
#include <uapi/linux/ip.h>
#include <uapi/linux/ipv6.h>
#include <uapi/linux/in.h>
#include <uapi/linux/tcp.h>
#include <uapi/linux/filter.h>
#include <uapi/linux/pkt_cls.h>
#include <net/ipv6.h>
#include "bpf_helpers.h"
#define _htonl __builtin_bswap32
#define ERROR(ret) do {\
char fmt[] = "ERROR line:%d ret:%d\n";\
bpf_trace_printk(fmt, sizeof(fmt), __LINE__, ret); \
} while(0)
struct geneve_opt {
__be16 opt_class;
u8 type;
u8 length:5;
u8 r3:1;
u8 r2:1;
u8 r1:1;
u8 opt_data[8]; /* hard-coded to 8 byte */
};
struct vxlan_metadata {
u32 gbp;
};
SEC("gre_set_tunnel")
int _gre_set_tunnel(struct __sk_buff *skb)
{
int ret;
struct bpf_tunnel_key key;
__builtin_memset(&key, 0x0, sizeof(key));
key.remote_ipv4 = 0xac100164; /* 172.16.1.100 */
key.tunnel_id = 2;
key.tunnel_tos = 0;
key.tunnel_ttl = 64;
ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key), BPF_F_ZERO_CSUM_TX);
if (ret < 0) {
ERROR(ret);
return TC_ACT_SHOT;
}
return TC_ACT_OK;
}
SEC("gre_get_tunnel")
int _gre_get_tunnel(struct __sk_buff *skb)
{
int ret;
struct bpf_tunnel_key key;
char fmt[] = "key %d remote ip 0x%x\n";
ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
if (ret < 0) {
ERROR(ret);
return TC_ACT_SHOT;
}
bpf_trace_printk(fmt, sizeof(fmt), key.tunnel_id, key.remote_ipv4);
return TC_ACT_OK;
}
SEC("vxlan_set_tunnel")
int _vxlan_set_tunnel(struct __sk_buff *skb)
{
int ret;
struct bpf_tunnel_key key;
struct vxlan_metadata md;
__builtin_memset(&key, 0x0, sizeof(key));
key.remote_ipv4 = 0xac100164; /* 172.16.1.100 */
key.tunnel_id = 2;
key.tunnel_tos = 0;
key.tunnel_ttl = 64;
ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key), BPF_F_ZERO_CSUM_TX);
if (ret < 0) {
ERROR(ret);
return TC_ACT_SHOT;
}
md.gbp = 0x800FF; /* Set VXLAN Group Policy extension */
ret = bpf_skb_set_tunnel_opt(skb, &md, sizeof(md));
if (ret < 0) {
ERROR(ret);
return TC_ACT_SHOT;
}
return TC_ACT_OK;
}
SEC("vxlan_get_tunnel")
int _vxlan_get_tunnel(struct __sk_buff *skb)
{
int ret;
struct bpf_tunnel_key key;
struct vxlan_metadata md;
char fmt[] = "key %d remote ip 0x%x vxlan gbp 0x%x\n";
ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
if (ret < 0) {
ERROR(ret);
return TC_ACT_SHOT;
}
ret = bpf_skb_get_tunnel_opt(skb, &md, sizeof(md));
if (ret < 0) {
ERROR(ret);
return TC_ACT_SHOT;
}
bpf_trace_printk(fmt, sizeof(fmt),
key.tunnel_id, key.remote_ipv4, md.gbp);
return TC_ACT_OK;
}
SEC("geneve_set_tunnel")
int _geneve_set_tunnel(struct __sk_buff *skb)
{
int ret, ret2;
struct bpf_tunnel_key key;
struct geneve_opt gopt;
__builtin_memset(&key, 0x0, sizeof(key));
key.remote_ipv4 = 0xac100164; /* 172.16.1.100 */
key.tunnel_id = 2;
key.tunnel_tos = 0;
key.tunnel_ttl = 64;
__builtin_memset(&gopt, 0x0, sizeof(gopt));
gopt.opt_class = 0x102; /* Open Virtual Networking (OVN) */
gopt.type = 0x08;
gopt.r1 = 1;
gopt.r2 = 0;
gopt.r3 = 1;
gopt.length = 2; /* 4-byte multiple */
*(int *) &gopt.opt_data = 0xdeadbeef;
ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key), BPF_F_ZERO_CSUM_TX);
if (ret < 0) {
ERROR(ret);
return TC_ACT_SHOT;
}
ret = bpf_skb_set_tunnel_opt(skb, &gopt, sizeof(gopt));
if (ret < 0) {
ERROR(ret);
return TC_ACT_SHOT;
}
return TC_ACT_OK;
}
SEC("geneve_get_tunnel")
int _geneve_get_tunnel(struct __sk_buff *skb)
{
int ret;
struct bpf_tunnel_key key;
struct geneve_opt gopt;
char fmt[] = "key %d remote ip 0x%x geneve class 0x%x\n";
ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
if (ret < 0) {
ERROR(ret);
return TC_ACT_SHOT;
}
ret = bpf_skb_get_tunnel_opt(skb, &gopt, sizeof(gopt));
if (ret < 0) {
ERROR(ret);
return TC_ACT_SHOT;
}
bpf_trace_printk(fmt, sizeof(fmt),
key.tunnel_id, key.remote_ipv4, gopt.opt_class);
return TC_ACT_OK;
}
SEC("ipip_set_tunnel")
int _ipip_set_tunnel(struct __sk_buff *skb)
{
struct bpf_tunnel_key key = {};
void *data = (void *)(long)skb->data;
struct iphdr *iph = data;
struct tcphdr *tcp = data + sizeof(*iph);
void *data_end = (void *)(long)skb->data_end;
int ret;
/* single length check */
if (data + sizeof(*iph) + sizeof(*tcp) > data_end) {
ERROR(1);
return TC_ACT_SHOT;
}
key.tunnel_ttl = 64;
if (iph->protocol == IPPROTO_ICMP) {
key.remote_ipv4 = 0xac100164; /* 172.16.1.100 */
} else {
if (iph->protocol != IPPROTO_TCP || iph->ihl != 5)
return TC_ACT_SHOT;
if (tcp->dest == htons(5200))
key.remote_ipv4 = 0xac100164; /* 172.16.1.100 */
else if (tcp->dest == htons(5201))
key.remote_ipv4 = 0xac100165; /* 172.16.1.101 */
else
return TC_ACT_SHOT;
}
ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key), 0);
if (ret < 0) {
ERROR(ret);
return TC_ACT_SHOT;
}
return TC_ACT_OK;
}
SEC("ipip_get_tunnel")
int _ipip_get_tunnel(struct __sk_buff *skb)
{
int ret;
struct bpf_tunnel_key key;
char fmt[] = "remote ip 0x%x\n";
ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
if (ret < 0) {
ERROR(ret);
return TC_ACT_SHOT;
}
bpf_trace_printk(fmt, sizeof(fmt), key.remote_ipv4);
return TC_ACT_OK;
}
SEC("ipip6_set_tunnel")
int _ipip6_set_tunnel(struct __sk_buff *skb)
{
struct bpf_tunnel_key key = {};
void *data = (void *)(long)skb->data;
struct iphdr *iph = data;
struct tcphdr *tcp = data + sizeof(*iph);
void *data_end = (void *)(long)skb->data_end;
int ret;
/* single length check */
if (data + sizeof(*iph) + sizeof(*tcp) > data_end) {
ERROR(1);
return TC_ACT_SHOT;
}
key.remote_ipv6[0] = _htonl(0x2401db00);
key.tunnel_ttl = 64;
if (iph->protocol == IPPROTO_ICMP) {
key.remote_ipv6[3] = _htonl(1);
} else {
if (iph->protocol != IPPROTO_TCP || iph->ihl != 5) {
ERROR(iph->protocol);
return TC_ACT_SHOT;
}
if (tcp->dest == htons(5200)) {
key.remote_ipv6[3] = _htonl(1);
} else if (tcp->dest == htons(5201)) {
key.remote_ipv6[3] = _htonl(2);
} else {
ERROR(tcp->dest);
return TC_ACT_SHOT;
}
}
ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key), BPF_F_TUNINFO_IPV6);
if (ret < 0) {
ERROR(ret);
return TC_ACT_SHOT;
}
return TC_ACT_OK;
}
SEC("ipip6_get_tunnel")
int _ipip6_get_tunnel(struct __sk_buff *skb)
{
int ret;
struct bpf_tunnel_key key;
char fmt[] = "remote ip6 %x::%x\n";
ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), BPF_F_TUNINFO_IPV6);
if (ret < 0) {
ERROR(ret);
return TC_ACT_SHOT;
}
bpf_trace_printk(fmt, sizeof(fmt), _htonl(key.remote_ipv6[0]),
_htonl(key.remote_ipv6[3]));
return TC_ACT_OK;
}
SEC("ip6ip6_set_tunnel")
int _ip6ip6_set_tunnel(struct __sk_buff *skb)
{
struct bpf_tunnel_key key = {};
void *data = (void *)(long)skb->data;
struct ipv6hdr *iph = data;
struct tcphdr *tcp = data + sizeof(*iph);
void *data_end = (void *)(long)skb->data_end;
int ret;
/* single length check */
if (data + sizeof(*iph) + sizeof(*tcp) > data_end) {
ERROR(1);
return TC_ACT_SHOT;
}
key.remote_ipv6[0] = _htonl(0x2401db00);
key.tunnel_ttl = 64;
if (iph->nexthdr == NEXTHDR_ICMP) {
key.remote_ipv6[3] = _htonl(1);
} else {
if (iph->nexthdr != NEXTHDR_TCP) {
ERROR(iph->nexthdr);
return TC_ACT_SHOT;
}
if (tcp->dest == htons(5200)) {
key.remote_ipv6[3] = _htonl(1);
} else if (tcp->dest == htons(5201)) {
key.remote_ipv6[3] = _htonl(2);
} else {
ERROR(tcp->dest);
return TC_ACT_SHOT;
}
}
ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key), BPF_F_TUNINFO_IPV6);
if (ret < 0) {
ERROR(ret);
return TC_ACT_SHOT;
}
return TC_ACT_OK;
}
SEC("ip6ip6_get_tunnel")
int _ip6ip6_get_tunnel(struct __sk_buff *skb)
{
int ret;
struct bpf_tunnel_key key;
char fmt[] = "remote ip6 %x::%x\n";
ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), BPF_F_TUNINFO_IPV6);
if (ret < 0) {
ERROR(ret);
return TC_ACT_SHOT;
}
bpf_trace_printk(fmt, sizeof(fmt), _htonl(key.remote_ipv6[0]),
_htonl(key.remote_ipv6[3]));
return TC_ACT_OK;
}
char _license[] SEC("license") = "GPL";
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