// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2017 Facebook
#include <stddef.h>
#include <stdbool.h>
#include <string.h>
#include <linux/pkt_cls.h>
#include <linux/bpf.h>
#include <linux/in.h>
#include <linux/if_ether.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/icmp.h>
#include <linux/icmpv6.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_endian.h>
#include "bpf_compiler.h"
static __always_inline __u32 rol32(__u32 word, unsigned int shift)
{
return (word << shift) | (word >> ((-shift) & 31));
}
/* copy paste of jhash from kernel sources to make sure llvm
* can compile it into valid sequence of bpf instructions
*/
#define __jhash_mix(a, b, c) \
{ \
a -= c; a ^= rol32(c, 4); c += b; \
b -= a; b ^= rol32(a, 6); a += c; \
c -= b; c ^= rol32(b, 8); b += a; \
a -= c; a ^= rol32(c, 16); c += b; \
b -= a; b ^= rol32(a, 19); a += c; \
c -= b; c ^= rol32(b, 4); b += a; \
}
#define __jhash_final(a, b, c) \
{ \
c ^= b; c -= rol32(b, 14); \
a ^= c; a -= rol32(c, 11); \
b ^= a; b -= rol32(a, 25); \
c ^= b; c -= rol32(b, 16); \
a ^= c; a -= rol32(c, 4); \
b ^= a; b -= rol32(a, 14); \
c ^= b; c -= rol32(b, 24); \
}
#define JHASH_INITVAL 0xdeadbeef
typedef unsigned int u32;
static __noinline
u32 jhash(const void *key, u32 length, u32 initval)
{
u32 a, b, c;
const unsigned char *k = key;
a = b = c = JHASH_INITVAL + length + initval;
while (length > 12) {
a += *(u32 *)(k);
b += *(u32 *)(k + 4);
c += *(u32 *)(k + 8);
__jhash_mix(a, b, c);
length -= 12;
k += 12;
}
switch (length) {
case 12: c += (u32)k[11]<<24;
case 11: c += (u32)k[10]<<16;
case 10: c += (u32)k[9]<<8;
case 9: c += k[8];
case 8: b += (u32)k[7]<<24;
case 7: b += (u32)k[6]<<16;
case 6: b += (u32)k[5]<<8;
case 5: b += k[4];
case 4: a += (u32)k[3]<<24;
case 3: a += (u32)k[2]<<16;
case 2: a += (u32)k[1]<<8;
case 1: a += k[0];
__jhash_final(a, b, c);
case 0: /* Nothing left to add */
break;
}
return c;
}
__noinline
u32 __jhash_nwords(u32 a, u32 b, u32 c, u32 initval)
{
a += initval;
b += initval;
c += initval;
__jhash_final(a, b, c);
return c;
}
__noinline
u32 jhash_2words(u32 a, u32 b, u32 initval)
{
return __jhash_nwords(a, b, 0, initval + JHASH_INITVAL + (2 << 2));
}
struct flow_key {
union {
__be32 src;
__be32 srcv6[4];
};
union {
__be32 dst;
__be32 dstv6[4];
};
union {
__u32 ports;
__u16 port16[2];
};
__u8 proto;
};
struct packet_description {
struct flow_key flow;
__u8 flags;
};
struct ctl_value {
union {
__u64 value;
__u32 ifindex;
__u8 mac[6];
};
};
struct vip_definition {
union {
__be32 vip;
__be32 vipv6[4];
};
__u16 port;
__u16 family;
__u8 proto;
};
struct vip_meta {
__u32 flags;
__u32 vip_num;
};
struct real_pos_lru {
__u32 pos;
__u64 atime;
};
struct real_definition {
union {
__be32 dst;
__be32 dstv6[4];
};
__u8 flags;
};
struct lb_stats {
__u64 v2;
__u64 v1;
};
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__uint(max_entries, 512);
__type(key, struct vip_definition);
__type(value, struct vip_meta);
} vip_map SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_LRU_HASH);
__uint(max_entries, 300);
__uint(map_flags, 1U << 1);
__type(key, struct flow_key);
__type(value, struct real_pos_lru);
} lru_cache SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, 12 * 655);
__type(key, __u32);
__type(value, __u32);
} ch_rings SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, 40);
__type(key, __u32);
__type(value, struct real_definition);
} reals SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
__uint(max_entries, 515);
__type(key, __u32);
__type(value, struct lb_stats);
} stats SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, 16);
__type(key, __u32);
__type(value, struct ctl_value);
} ctl_array SEC(".maps");
struct eth_hdr {
unsigned char eth_dest[6];
unsigned char eth_source[6];
unsigned short eth_proto;
};
static __noinline __u64 calc_offset(bool is_ipv6, bool is_icmp)
{
__u64 off = sizeof(struct eth_hdr);
if (is_ipv6) {
off += sizeof(struct ipv6hdr);
if (is_icmp)
off += sizeof(struct icmp6hdr) + sizeof(struct ipv6hdr);
} else {
off += sizeof(struct iphdr);
if (is_icmp)
off += sizeof(struct icmphdr) + sizeof(struct iphdr);
}
return off;
}
static __attribute__ ((noinline))
bool parse_udp(void *data, void *data_end,
bool is_ipv6, struct packet_description *pckt)
{
bool is_icmp = !((pckt->flags & (1 << 0)) == 0);
__u64 off = calc_offset(is_ipv6, is_icmp);
struct udphdr *udp;
udp = data + off;
if (udp + 1 > data_end)
return false;
if (!is_icmp) {
pckt->flow.port16[0] = udp->source;
pckt->flow.port16[1] = udp->dest;
} else {
pckt->flow.port16[0] = udp->dest;
pckt->flow.port16[1] = udp->source;
}
return true;
}
static __attribute__ ((noinline))
bool parse_tcp(void *data, void *data_end,
bool is_ipv6, struct packet_description *pckt)
{
bool is_icmp = !((pckt->flags & (1 << 0)) == 0);
__u64 off = calc_offset(is_ipv6, is_icmp);
struct tcphdr *tcp;
tcp = data + off;
if (tcp + 1 > data_end)
return false;
if (tcp->syn)
pckt->flags |= (1 << 1);
if (!is_icmp) {
pckt->flow.port16[0] = tcp->source;
pckt->flow.port16[1] = tcp->dest;
} else {
pckt->flow.port16[0] = tcp->dest;
pckt->flow.port16[1] = tcp->source;
}
return true;
}
static __attribute__ ((noinline))
bool encap_v6(struct xdp_md *xdp, struct ctl_value *cval,
struct packet_description *pckt,
struct real_definition *dst, __u32 pkt_bytes)
{
struct eth_hdr *new_eth;
struct eth_hdr *old_eth;
struct ipv6hdr *ip6h;
__u32 ip_suffix;
void *data_end;
void *data;
if (bpf_xdp_adjust_head(xdp, 0 - (int)sizeof(struct ipv6hdr)))
return false;
data = (void *)(long)xdp->data;
data_end = (void *)(long)xdp->data_end;
new_eth = data;
ip6h = data + sizeof(struct eth_hdr);
old_eth = data + sizeof(struct ipv6hdr);
if (new_eth + 1 > data_end ||
old_eth + 1 > data_end || ip6h + 1 > data_end)
return false;
memcpy(new_eth->eth_dest, cval->mac, 6);
memcpy(new_eth->eth_source, old_eth->eth_dest, 6);
new_eth->eth_proto = 56710;
ip6h->version = 6;
ip6h->priority = 0;
memset(ip6h->flow_lbl, 0, sizeof(ip6h->flow_lbl));
ip6h->nexthdr = IPPROTO_IPV6;
ip_suffix = pckt->flow.srcv6[3] ^ pckt->flow.port16[0];
ip6h->payload_len =
bpf_htons(pkt_bytes + sizeof(struct ipv6hdr));
ip6h->hop_limit = 4;
ip6h->saddr.in6_u.u6_addr32[0] = 1;
ip6h->saddr.in6_u.u6_addr32[1] = 2;
ip6h->saddr.in6_u.u6_addr32[2] = 3;
ip6h->saddr.in6_u.u6_addr32[3] = ip_suffix;
memcpy(ip6h->daddr.in6_u.u6_addr32, dst->dstv6, 16);
return true;
}
#ifndef __clang__
#pragma GCC push_options
/* GCC optimization collapses functions and increases the number of arguments
* beyond the compatible amount supported by BPF.
*/
#pragma GCC optimize("-fno-ipa-sra")
#endif
static __attribute__ ((noinline))
bool encap_v4(struct xdp_md *xdp, struct ctl_value *cval,
struct packet_description *pckt,
struct real_definition *dst, __u32 pkt_bytes)
{
__u32 ip_suffix = bpf_ntohs(pckt->flow.port16[0]);
struct eth_hdr *new_eth;
struct eth_hdr *old_eth;
__u16 *next_iph_u16;
struct iphdr *iph;
__u32 csum = 0;
void *data_end;
void *data;
ip_suffix <<= 15;
ip_suffix ^= pckt->flow.src;
if (bpf_xdp_adjust_head(xdp, 0 - (int)sizeof(struct iphdr)))
return false;
data = (void *)(long)xdp->data;
data_end = (void *)(long)xdp->data_end;
new_eth = data;
iph = data + sizeof(struct eth_hdr);
old_eth = data + sizeof(struct iphdr);
if (new_eth + 1 > data_end ||
old_eth + 1 > data_end || iph + 1 > data_end)
return false;
memcpy(new_eth->eth_dest, cval->mac, 6);
memcpy(new_eth->eth_source, old_eth->eth_dest, 6);
new_eth->eth_proto = 8;
iph->version = 4;
iph->ihl = 5;
iph->frag_off = 0;
iph->protocol = IPPROTO_IPIP;
iph->check = 0;
iph->tos = 1;
iph->tot_len = bpf_htons(pkt_bytes + sizeof(struct iphdr));
/* don't update iph->daddr, since it will overwrite old eth_proto
* and multiple iterations of bpf_prog_run() will fail
*/
iph->saddr = ((0xFFFF0000 & ip_suffix) | 4268) ^ dst->dst;
iph->ttl = 4;
next_iph_u16 = (__u16 *) iph;
__pragma_loop_unroll_full
for (int i = 0; i < sizeof(struct iphdr) >> 1; i++)
csum += *next_iph_u16++;
iph->check = ~((csum & 0xffff) + (csum >> 16));
if (bpf_xdp_adjust_head(xdp, (int)sizeof(struct iphdr)))
return false;
return true;
}
#ifndef __clang__
#pragma GCC pop_options
#endif
static __attribute__ ((noinline))
int swap_mac_and_send(void *data, void *data_end)
{
unsigned char tmp_mac[6];
struct eth_hdr *eth;
eth = data;
memcpy(tmp_mac, eth->eth_source, 6);
memcpy(eth->eth_source, eth->eth_dest, 6);
memcpy(eth->eth_dest, tmp_mac, 6);
return XDP_TX;
}
static __attribute__ ((noinline))
int send_icmp_reply(void *data, void *data_end)
{
struct icmphdr *icmp_hdr;
__u16 *next_iph_u16;
__u32 tmp_addr = 0;
struct iphdr *iph;
__u32 csum = 0;
__u64 off = 0;
if (data + sizeof(struct eth_hdr)
+ sizeof(struct iphdr) + sizeof(struct icmphdr) > data_end)
return XDP_DROP;
off += sizeof(struct eth_hdr);
iph = data + off;
off += sizeof(struct iphdr);
icmp_hdr = data + off;
icmp_hdr->type = 0;
icmp_hdr->checksum += 0x0007;
iph->ttl = 4;
tmp_addr = iph->daddr;
iph->daddr = iph->saddr;
iph->saddr = tmp_addr;
iph->check = 0;
next_iph_u16 = (__u16 *) iph;
__pragma_loop_unroll_full
for (int i = 0; i < sizeof(struct iphdr) >> 1; i++)
csum += *next_iph_u16++;
iph->check = ~((csum & 0xffff) + (csum >> 16));
return swap_mac_and_send(data, data_end);
}
static __attribute__ ((noinline))
int send_icmp6_reply(void *data, void *data_end)
{
struct icmp6hdr *icmp_hdr;
struct ipv6hdr *ip6h;
__be32 tmp_addr[4];
__u64 off = 0;
if (data + sizeof(struct eth_hdr)
+ sizeof(struct ipv6hdr) + sizeof(struct icmp6hdr) > data_end)
return XDP_DROP;
off += sizeof(struct eth_hdr);
ip6h = data + off;
off += sizeof(struct ipv6hdr);
icmp_hdr = data + off;
icmp_hdr->icmp6_type = 129;
icmp_hdr->icmp6_cksum -= 0x0001;
ip6h->hop_limit = 4;
memcpy(tmp_addr, ip6h->saddr.in6_u.u6_addr32, 16);
memcpy(ip6h->saddr.in6_u.u6_addr32, ip6h->daddr.in6_u.u6_addr32, 16);
memcpy(ip6h->daddr.in6_u.u6_addr32, tmp_addr, 16);
return swap_mac_and_send(data, data_end);
}
static __attribute__ ((noinline))
int parse_icmpv6(void *data, void *data_end, __u64 off,
struct packet_description *pckt)
{
struct icmp6hdr *icmp_hdr;
struct ipv6hdr *ip6h;
icmp_hdr = data + off;
if (icmp_hdr + 1 > data_end)
return XDP_DROP;
if (icmp_hdr->icmp6_type == 128)
return send_icmp6_reply(data, data_end);
if (icmp_hdr->icmp6_type != 3)
return XDP_PASS;
off += sizeof(struct icmp6hdr);
ip6h = data + off;
if (ip6h + 1 > data_end)
return XDP_DROP;
pckt->flow.proto = ip6h->nexthdr;
pckt->flags |= (1 << 0);
memcpy(pckt->flow.srcv6, ip6h->daddr.in6_u.u6_addr32, 16);
memcpy(pckt->flow.dstv6, ip6h->saddr.in6_u.u6_addr32, 16);
return -1;
}
static __attribute__ ((noinline))
int parse_icmp(void *data, void *data_end, __u64 off,
struct packet_description *pckt)
{
struct icmphdr *icmp_hdr;
struct iphdr *iph;
icmp_hdr = data + off;
if (icmp_hdr + 1 > data_end)
return XDP_DROP;
if (icmp_hdr->type == 8)
return send_icmp_reply(data, data_end);
if ((icmp_hdr->type != 3) || (icmp_hdr->code != 4))
return XDP_PASS;
off += sizeof(struct icmphdr);
iph = data + off;
if (iph + 1 > data_end)
return XDP_DROP;
if (iph->ihl != 5)
return XDP_DROP;
pckt->flow.proto = iph->protocol;
pckt->flags |= (1 << 0);
pckt->flow.src = iph->daddr;
pckt->flow.dst = iph->saddr;
return -1;
}
static __attribute__ ((noinline))
__u32 get_packet_hash(struct packet_description *pckt,
bool hash_16bytes)
{
if (hash_16bytes)
return jhash_2words(jhash(pckt->flow.srcv6, 16, 12),
pckt->flow.ports, 24);
else
return jhash_2words(pckt->flow.src, pckt->flow.ports,
24);
}
__attribute__ ((noinline))
static bool get_packet_dst(struct real_definition **real,
struct packet_description *pckt,
struct vip_meta *vip_info,
bool is_ipv6, void *lru_map)
{
struct real_pos_lru new_dst_lru = { };
bool hash_16bytes = is_ipv6;
__u32 *real_pos, hash, key;
__u64 cur_time;
if (vip_info->flags & (1 << 2))
hash_16bytes = 1;
if (vip_info->flags & (1 << 3)) {
pckt->flow.port16[0] = pckt->flow.port16[1];
memset(pckt->flow.srcv6, 0, 16);
}
hash = get_packet_hash(pckt, hash_16bytes);
if (hash != 0x358459b7 /* jhash of ipv4 packet */ &&
hash != 0x2f4bc6bb /* jhash of ipv6 packet */)
return false;
key = 2 * vip_info->vip_num + hash % 2;
real_pos = bpf_map_lookup_elem(&ch_rings, &key);
if (!real_pos)
return false;
key = *real_pos;
*real = bpf_map_lookup_elem(&reals, &key);
if (!(*real))
return false;
if (!(vip_info->flags & (1 << 1))) {
__u32 conn_rate_key = 512 + 2;
struct lb_stats *conn_rate_stats =
bpf_map_lookup_elem(&stats, &conn_rate_key);
if (!conn_rate_stats)
return true;
cur_time = bpf_ktime_get_ns();
if ((cur_time - conn_rate_stats->v2) >> 32 > 0xffFFFF) {
conn_rate_stats->v1 = 1;
conn_rate_stats->v2 = cur_time;
} else {
conn_rate_stats->v1 += 1;
if (conn_rate_stats->v1 >= 1)
return true;
}
if (pckt->flow.proto == IPPROTO_UDP)
new_dst_lru.atime = cur_time;
new_dst_lru.pos = key;
bpf_map_update_elem(lru_map, &pckt->flow, &new_dst_lru, 0);
}
return true;
}
__attribute__ ((noinline))
static void connection_table_lookup(struct real_definition **real,
struct packet_description *pckt,
void *lru_map)
{
struct real_pos_lru *dst_lru;
__u64 cur_time;
__u32 key;
dst_lru = bpf_map_lookup_elem(lru_map, &pckt->flow);
if (!dst_lru)
return;
if (pckt->flow.proto == IPPROTO_UDP) {
cur_time = bpf_ktime_get_ns();
if (cur_time - dst_lru->atime > 300000)
return;
dst_lru->atime = cur_time;
}
key = dst_lru->pos;
*real = bpf_map_lookup_elem(&reals, &key);
}
/* don't believe your eyes!
* below function has 6 arguments whereas bpf and llvm allow maximum of 5
* but since it's _static_ llvm can optimize one argument away
*/
__attribute__ ((noinline))
static int process_l3_headers_v6(struct packet_description *pckt,
__u8 *protocol, __u64 off,
__u16 *pkt_bytes, void *extra_args[2])
{
struct ipv6hdr *ip6h;
__u64 iph_len;
int action;
void *data = extra_args[0];
void *data_end = extra_args[1];
ip6h = data + off;
if (ip6h + 1 > data_end)
return XDP_DROP;
iph_len = sizeof(struct ipv6hdr);
*protocol = ip6h->nexthdr;
pckt->flow.proto = *protocol;
*pkt_bytes = bpf_ntohs(ip6h->payload_len);
off += iph_len;
if (*protocol == 45) {
return XDP_DROP;
} else if (*protocol == 59) {
action = parse_icmpv6(data, data_end, off, pckt);
if (action >= 0)
return action;
} else {
memcpy(pckt->flow.srcv6, ip6h->saddr.in6_u.u6_addr32, 16);
memcpy(pckt->flow.dstv6, ip6h->daddr.in6_u.u6_addr32, 16);
}
return -1;
}
__attribute__ ((noinline))
static int process_l3_headers_v4(struct packet_description *pckt,
__u8 *protocol, __u64 off,
__u16 *pkt_bytes, void *extra_args[2])
{
struct iphdr *iph;
int action;
void *data = extra_args[0];
void *data_end = extra_args[1];
iph = data + off;
if (iph + 1 > data_end)
return XDP_DROP;
if (iph->ihl != 5)
return XDP_DROP;
*protocol = iph->protocol;
pckt->flow.proto = *protocol;
*pkt_bytes = bpf_ntohs(iph->tot_len);
off += 20;
if (iph->frag_off & 65343)
return XDP_DROP;
if (*protocol == IPPROTO_ICMP) {
action = parse_icmp(data, data_end, off, pckt);
if (action >= 0)
return action;
} else {
pckt->flow.src = iph->saddr;
pckt->flow.dst = iph->daddr;
}
return -1;
}
__attribute__ ((noinline))
static int process_packet(void *data, __u64 off, void *data_end,
bool is_ipv6, struct xdp_md *xdp)
{
struct real_definition *dst = NULL;
struct packet_description pckt = { };
struct vip_definition vip = { };
struct lb_stats *data_stats;
void *lru_map = &lru_cache;
struct vip_meta *vip_info;
__u32 lru_stats_key = 513;
__u32 mac_addr_pos = 0;
__u32 stats_key = 512;
struct ctl_value *cval;
__u16 pkt_bytes;
__u8 protocol;
__u32 vip_num;
int action;
void *extra_args[2] = { data, data_end };
if (is_ipv6)
action = process_l3_headers_v6(&pckt, &protocol, off,
&pkt_bytes, extra_args);
else
action = process_l3_headers_v4(&pckt, &protocol, off,
&pkt_bytes, extra_args);
if (action >= 0)
return action;
protocol = pckt.flow.proto;
if (protocol == IPPROTO_TCP) {
if (!parse_tcp(data, data_end, is_ipv6, &pckt))
return XDP_DROP;
} else if (protocol == IPPROTO_UDP) {
if (!parse_udp(data, data_end, is_ipv6, &pckt))
return XDP_DROP;
} else {
return XDP_TX;
}
if (is_ipv6)
memcpy(vip.vipv6, pckt.flow.dstv6, 16);
else
vip.vip = pckt.flow.dst;
vip.port = pckt.flow.port16[1];
vip.proto = pckt.flow.proto;
vip_info = bpf_map_lookup_elem(&vip_map, &vip);
if (!vip_info) {
vip.port = 0;
vip_info = bpf_map_lookup_elem(&vip_map, &vip);
if (!vip_info)
return XDP_PASS;
if (!(vip_info->flags & (1 << 4)))
pckt.flow.port16[1] = 0;
}
if (data_end - data > 1400)
return XDP_DROP;
data_stats = bpf_map_lookup_elem(&stats, &stats_key);
if (!data_stats)
return XDP_DROP;
data_stats->v1 += 1;
if (!dst) {
if (vip_info->flags & (1 << 0))
pckt.flow.port16[0] = 0;
if (!(pckt.flags & (1 << 1)) && !(vip_info->flags & (1 << 1)))
connection_table_lookup(&dst, &pckt, lru_map);
if (dst)
goto out;
if (pckt.flow.proto == IPPROTO_TCP) {
struct lb_stats *lru_stats =
bpf_map_lookup_elem(&stats, &lru_stats_key);
if (!lru_stats)
return XDP_DROP;
if (pckt.flags & (1 << 1))
lru_stats->v1 += 1;
else
lru_stats->v2 += 1;
}
if (!get_packet_dst(&dst, &pckt, vip_info, is_ipv6, lru_map))
return XDP_DROP;
data_stats->v2 += 1;
}
out:
cval = bpf_map_lookup_elem(&ctl_array, &mac_addr_pos);
if (!cval)
return XDP_DROP;
if (dst->flags & (1 << 0)) {
if (!encap_v6(xdp, cval, &pckt, dst, pkt_bytes))
return XDP_DROP;
} else {
if (!encap_v4(xdp, cval, &pckt, dst, pkt_bytes))
return XDP_DROP;
}
vip_num = vip_info->vip_num;
data_stats = bpf_map_lookup_elem(&stats, &vip_num);
if (!data_stats)
return XDP_DROP;
data_stats->v1 += 1;
data_stats->v2 += pkt_bytes;
data = (void *)(long)xdp->data;
data_end = (void *)(long)xdp->data_end;
if (data + 4 > data_end)
return XDP_DROP;
*(u32 *)data = dst->dst;
return XDP_DROP;
}
SEC("xdp")
int balancer_ingress_v4(struct xdp_md *ctx)
{
void *data = (void *)(long)ctx->data;
void *data_end = (void *)(long)ctx->data_end;
struct eth_hdr *eth = data;
__u32 eth_proto;
__u32 nh_off;
nh_off = sizeof(struct eth_hdr);
if (data + nh_off > data_end)
return XDP_DROP;
eth_proto = bpf_ntohs(eth->eth_proto);
if (eth_proto == ETH_P_IP)
return process_packet(data, nh_off, data_end, 0, ctx);
else
return XDP_DROP;
}
SEC("xdp")
int balancer_ingress_v6(struct xdp_md *ctx)
{
void *data = (void *)(long)ctx->data;
void *data_end = (void *)(long)ctx->data_end;
struct eth_hdr *eth = data;
__u32 eth_proto;
__u32 nh_off;
nh_off = sizeof(struct eth_hdr);
if (data + nh_off > data_end)
return XDP_DROP;
eth_proto = bpf_ntohs(eth->eth_proto);
if (eth_proto == ETH_P_IPV6)
return process_packet(data, nh_off, data_end, 1, ctx);
else
return XDP_DROP;
}
char _license[] SEC("license") = "GPL";
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