474 lines
10 KiB
C
474 lines
10 KiB
C
|
// 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_helpers.h"
|
||
|
|
#include "test_iptunnel_common.h"
|
||
|
|
#include "bpf_endian.h"
|
||
|
|
|
||
|
|
int _version SEC("version") = 1;
|
||
|
|
|
||
|
|
static __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 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;
|
||
|
|
}
|
||
|
|
|
||
|
|
static u32 __jhash_nwords(u32 a, u32 b, u32 c, u32 initval)
|
||
|
|
{
|
||
|
|
a += initval;
|
||
|
|
b += initval;
|
||
|
|
c += initval;
|
||
|
|
__jhash_final(a, b, c);
|
||
|
|
return c;
|
||
|
|
}
|
||
|
|
|
||
|
|
static u32 jhash_2words(u32 a, u32 b, u32 initval)
|
||
|
|
{
|
||
|
|
return __jhash_nwords(a, b, 0, initval + JHASH_INITVAL + (2 << 2));
|
||
|
|
}
|
||
|
|
|
||
|
|
#define PCKT_FRAGMENTED 65343
|
||
|
|
#define IPV4_HDR_LEN_NO_OPT 20
|
||
|
|
#define IPV4_PLUS_ICMP_HDR 28
|
||
|
|
#define IPV6_PLUS_ICMP_HDR 48
|
||
|
|
#define RING_SIZE 2
|
||
|
|
#define MAX_VIPS 12
|
||
|
|
#define MAX_REALS 5
|
||
|
|
#define CTL_MAP_SIZE 16
|
||
|
|
#define CH_RINGS_SIZE (MAX_VIPS * RING_SIZE)
|
||
|
|
#define F_IPV6 (1 << 0)
|
||
|
|
#define F_HASH_NO_SRC_PORT (1 << 0)
|
||
|
|
#define F_ICMP (1 << 0)
|
||
|
|
#define F_SYN_SET (1 << 1)
|
||
|
|
|
||
|
|
struct packet_description {
|
||
|
|
union {
|
||
|
|
__be32 src;
|
||
|
|
__be32 srcv6[4];
|
||
|
|
};
|
||
|
|
union {
|
||
|
|
__be32 dst;
|
||
|
|
__be32 dstv6[4];
|
||
|
|
};
|
||
|
|
union {
|
||
|
|
__u32 ports;
|
||
|
|
__u16 port16[2];
|
||
|
|
};
|
||
|
|
__u8 proto;
|
||
|
|
__u8 flags;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct ctl_value {
|
||
|
|
union {
|
||
|
|
__u64 value;
|
||
|
|
__u32 ifindex;
|
||
|
|
__u8 mac[6];
|
||
|
|
};
|
||
|
|
};
|
||
|
|
|
||
|
|
struct vip_meta {
|
||
|
|
__u32 flags;
|
||
|
|
__u32 vip_num;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct real_definition {
|
||
|
|
union {
|
||
|
|
__be32 dst;
|
||
|
|
__be32 dstv6[4];
|
||
|
|
};
|
||
|
|
__u8 flags;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct vip_stats {
|
||
|
|
__u64 bytes;
|
||
|
|
__u64 pkts;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct eth_hdr {
|
||
|
|
unsigned char eth_dest[ETH_ALEN];
|
||
|
|
unsigned char eth_source[ETH_ALEN];
|
||
|
|
unsigned short eth_proto;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct bpf_map_def SEC("maps") vip_map = {
|
||
|
|
.type = BPF_MAP_TYPE_HASH,
|
||
|
|
.key_size = sizeof(struct vip),
|
||
|
|
.value_size = sizeof(struct vip_meta),
|
||
|
|
.max_entries = MAX_VIPS,
|
||
|
|
};
|
||
|
|
|
||
|
|
struct bpf_map_def SEC("maps") ch_rings = {
|
||
|
|
.type = BPF_MAP_TYPE_ARRAY,
|
||
|
|
.key_size = sizeof(__u32),
|
||
|
|
.value_size = sizeof(__u32),
|
||
|
|
.max_entries = CH_RINGS_SIZE,
|
||
|
|
};
|
||
|
|
|
||
|
|
struct bpf_map_def SEC("maps") reals = {
|
||
|
|
.type = BPF_MAP_TYPE_ARRAY,
|
||
|
|
.key_size = sizeof(__u32),
|
||
|
|
.value_size = sizeof(struct real_definition),
|
||
|
|
.max_entries = MAX_REALS,
|
||
|
|
};
|
||
|
|
|
||
|
|
struct bpf_map_def SEC("maps") stats = {
|
||
|
|
.type = BPF_MAP_TYPE_PERCPU_ARRAY,
|
||
|
|
.key_size = sizeof(__u32),
|
||
|
|
.value_size = sizeof(struct vip_stats),
|
||
|
|
.max_entries = MAX_VIPS,
|
||
|
|
};
|
||
|
|
|
||
|
|
struct bpf_map_def SEC("maps") ctl_array = {
|
||
|
|
.type = BPF_MAP_TYPE_ARRAY,
|
||
|
|
.key_size = sizeof(__u32),
|
||
|
|
.value_size = sizeof(struct ctl_value),
|
||
|
|
.max_entries = CTL_MAP_SIZE,
|
||
|
|
};
|
||
|
|
|
||
|
|
static __u32 get_packet_hash(struct packet_description *pckt,
|
||
|
|
bool ipv6)
|
||
|
|
{
|
||
|
|
if (ipv6)
|
||
|
|
return jhash_2words(jhash(pckt->srcv6, 16, MAX_VIPS),
|
||
|
|
pckt->ports, CH_RINGS_SIZE);
|
||
|
|
else
|
||
|
|
return jhash_2words(pckt->src, pckt->ports, CH_RINGS_SIZE);
|
||
|
|
}
|
||
|
|
|
||
|
|
static bool get_packet_dst(struct real_definition **real,
|
||
|
|
struct packet_description *pckt,
|
||
|
|
struct vip_meta *vip_info,
|
||
|
|
bool is_ipv6)
|
||
|
|
{
|
||
|
|
__u32 hash = get_packet_hash(pckt, is_ipv6);
|
||
|
|
__u32 key = RING_SIZE * vip_info->vip_num + hash % RING_SIZE;
|
||
|
|
__u32 *real_pos;
|
||
|
|
|
||
|
|
if (hash != 0x358459b7 /* jhash of ipv4 packet */ &&
|
||
|
|
hash != 0x2f4bc6bb /* jhash of ipv6 packet */)
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
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;
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
static 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 TC_ACT_SHOT;
|
||
|
|
if (icmp_hdr->icmp6_type != ICMPV6_PKT_TOOBIG)
|
||
|
|
return TC_ACT_OK;
|
||
|
|
off += sizeof(struct icmp6hdr);
|
||
|
|
ip6h = data + off;
|
||
|
|
if (ip6h + 1 > data_end)
|
||
|
|
return TC_ACT_SHOT;
|
||
|
|
pckt->proto = ip6h->nexthdr;
|
||
|
|
pckt->flags |= F_ICMP;
|
||
|
|
memcpy(pckt->srcv6, ip6h->daddr.s6_addr32, 16);
|
||
|
|
memcpy(pckt->dstv6, ip6h->saddr.s6_addr32, 16);
|
||
|
|
return TC_ACT_UNSPEC;
|
||
|
|
}
|
||
|
|
|
||
|
|
static 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 TC_ACT_SHOT;
|
||
|
|
if (icmp_hdr->type != ICMP_DEST_UNREACH ||
|
||
|
|
icmp_hdr->code != ICMP_FRAG_NEEDED)
|
||
|
|
return TC_ACT_OK;
|
||
|
|
off += sizeof(struct icmphdr);
|
||
|
|
iph = data + off;
|
||
|
|
if (iph + 1 > data_end)
|
||
|
|
return TC_ACT_SHOT;
|
||
|
|
if (iph->ihl != 5)
|
||
|
|
return TC_ACT_SHOT;
|
||
|
|
pckt->proto = iph->protocol;
|
||
|
|
pckt->flags |= F_ICMP;
|
||
|
|
pckt->src = iph->daddr;
|
||
|
|
pckt->dst = iph->saddr;
|
||
|
|
return TC_ACT_UNSPEC;
|
||
|
|
}
|
||
|
|
|
||
|
|
static bool parse_udp(void *data, __u64 off, void *data_end,
|
||
|
|
struct packet_description *pckt)
|
||
|
|
{
|
||
|
|
struct udphdr *udp;
|
||
|
|
udp = data + off;
|
||
|
|
|
||
|
|
if (udp + 1 > data_end)
|
||
|
|
return false;
|
||
|
|
|
||
|
|
if (!(pckt->flags & F_ICMP)) {
|
||
|
|
pckt->port16[0] = udp->source;
|
||
|
|
pckt->port16[1] = udp->dest;
|
||
|
|
} else {
|
||
|
|
pckt->port16[0] = udp->dest;
|
||
|
|
pckt->port16[1] = udp->source;
|
||
|
|
}
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
static bool parse_tcp(void *data, __u64 off, void *data_end,
|
||
|
|
struct packet_description *pckt)
|
||
|
|
{
|
||
|
|
struct tcphdr *tcp;
|
||
|
|
|
||
|
|
tcp = data + off;
|
||
|
|
if (tcp + 1 > data_end)
|
||
|
|
return false;
|
||
|
|
|
||
|
|
if (tcp->syn)
|
||
|
|
pckt->flags |= F_SYN_SET;
|
||
|
|
|
||
|
|
if (!(pckt->flags & F_ICMP)) {
|
||
|
|
pckt->port16[0] = tcp->source;
|
||
|
|
pckt->port16[1] = tcp->dest;
|
||
|
|
} else {
|
||
|
|
pckt->port16[0] = tcp->dest;
|
||
|
|
pckt->port16[1] = tcp->source;
|
||
|
|
}
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int process_packet(void *data, __u64 off, void *data_end,
|
||
|
|
bool is_ipv6, struct __sk_buff *skb)
|
||
|
|
{
|
||
|
|
void *pkt_start = (void *)(long)skb->data;
|
||
|
|
struct packet_description pckt = {};
|
||
|
|
struct eth_hdr *eth = pkt_start;
|
||
|
|
struct bpf_tunnel_key tkey = {};
|
||
|
|
struct vip_stats *data_stats;
|
||
|
|
struct real_definition *dst;
|
||
|
|
struct vip_meta *vip_info;
|
||
|
|
struct ctl_value *cval;
|
||
|
|
__u32 v4_intf_pos = 1;
|
||
|
|
__u32 v6_intf_pos = 2;
|
||
|
|
struct ipv6hdr *ip6h;
|
||
|
|
struct vip vip = {};
|
||
|
|
struct iphdr *iph;
|
||
|
|
int tun_flag = 0;
|
||
|
|
__u16 pkt_bytes;
|
||
|
|
__u64 iph_len;
|
||
|
|
__u32 ifindex;
|
||
|
|
__u8 protocol;
|
||
|
|
__u32 vip_num;
|
||
|
|
int action;
|
||
|
|
|
||
|
|
tkey.tunnel_ttl = 64;
|
||
|
|
if (is_ipv6) {
|
||
|
|
ip6h = data + off;
|
||
|
|
if (ip6h + 1 > data_end)
|
||
|
|
return TC_ACT_SHOT;
|
||
|
|
|
||
|
|
iph_len = sizeof(struct ipv6hdr);
|
||
|
|
protocol = ip6h->nexthdr;
|
||
|
|
pckt.proto = protocol;
|
||
|
|
pkt_bytes = bpf_ntohs(ip6h->payload_len);
|
||
|
|
off += iph_len;
|
||
|
|
if (protocol == IPPROTO_FRAGMENT) {
|
||
|
|
return TC_ACT_SHOT;
|
||
|
|
} else if (protocol == IPPROTO_ICMPV6) {
|
||
|
|
action = parse_icmpv6(data, data_end, off, &pckt);
|
||
|
|
if (action >= 0)
|
||
|
|
return action;
|
||
|
|
off += IPV6_PLUS_ICMP_HDR;
|
||
|
|
} else {
|
||
|
|
memcpy(pckt.srcv6, ip6h->saddr.s6_addr32, 16);
|
||
|
|
memcpy(pckt.dstv6, ip6h->daddr.s6_addr32, 16);
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
iph = data + off;
|
||
|
|
if (iph + 1 > data_end)
|
||
|
|
return TC_ACT_SHOT;
|
||
|
|
if (iph->ihl != 5)
|
||
|
|
return TC_ACT_SHOT;
|
||
|
|
|
||
|
|
protocol = iph->protocol;
|
||
|
|
pckt.proto = protocol;
|
||
|
|
pkt_bytes = bpf_ntohs(iph->tot_len);
|
||
|
|
off += IPV4_HDR_LEN_NO_OPT;
|
||
|
|
|
||
|
|
if (iph->frag_off & PCKT_FRAGMENTED)
|
||
|
|
return TC_ACT_SHOT;
|
||
|
|
if (protocol == IPPROTO_ICMP) {
|
||
|
|
action = parse_icmp(data, data_end, off, &pckt);
|
||
|
|
if (action >= 0)
|
||
|
|
return action;
|
||
|
|
off += IPV4_PLUS_ICMP_HDR;
|
||
|
|
} else {
|
||
|
|
pckt.src = iph->saddr;
|
||
|
|
pckt.dst = iph->daddr;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
protocol = pckt.proto;
|
||
|
|
|
||
|
|
if (protocol == IPPROTO_TCP) {
|
||
|
|
if (!parse_tcp(data, off, data_end, &pckt))
|
||
|
|
return TC_ACT_SHOT;
|
||
|
|
} else if (protocol == IPPROTO_UDP) {
|
||
|
|
if (!parse_udp(data, off, data_end, &pckt))
|
||
|
|
return TC_ACT_SHOT;
|
||
|
|
} else {
|
||
|
|
return TC_ACT_SHOT;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (is_ipv6)
|
||
|
|
memcpy(vip.daddr.v6, pckt.dstv6, 16);
|
||
|
|
else
|
||
|
|
vip.daddr.v4 = pckt.dst;
|
||
|
|
|
||
|
|
vip.dport = pckt.port16[1];
|
||
|
|
vip.protocol = pckt.proto;
|
||
|
|
vip_info = bpf_map_lookup_elem(&vip_map, &vip);
|
||
|
|
if (!vip_info) {
|
||
|
|
vip.dport = 0;
|
||
|
|
vip_info = bpf_map_lookup_elem(&vip_map, &vip);
|
||
|
|
if (!vip_info)
|
||
|
|
return TC_ACT_SHOT;
|
||
|
|
pckt.port16[1] = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (vip_info->flags & F_HASH_NO_SRC_PORT)
|
||
|
|
pckt.port16[0] = 0;
|
||
|
|
|
||
|
|
if (!get_packet_dst(&dst, &pckt, vip_info, is_ipv6))
|
||
|
|
return TC_ACT_SHOT;
|
||
|
|
|
||
|
|
if (dst->flags & F_IPV6) {
|
||
|
|
cval = bpf_map_lookup_elem(&ctl_array, &v6_intf_pos);
|
||
|
|
if (!cval)
|
||
|
|
return TC_ACT_SHOT;
|
||
|
|
ifindex = cval->ifindex;
|
||
|
|
memcpy(tkey.remote_ipv6, dst->dstv6, 16);
|
||
|
|
tun_flag = BPF_F_TUNINFO_IPV6;
|
||
|
|
} else {
|
||
|
|
cval = bpf_map_lookup_elem(&ctl_array, &v4_intf_pos);
|
||
|
|
if (!cval)
|
||
|
|
return TC_ACT_SHOT;
|
||
|
|
ifindex = cval->ifindex;
|
||
|
|
tkey.remote_ipv4 = dst->dst;
|
||
|
|
}
|
||
|
|
vip_num = vip_info->vip_num;
|
||
|
|
data_stats = bpf_map_lookup_elem(&stats, &vip_num);
|
||
|
|
if (!data_stats)
|
||
|
|
return TC_ACT_SHOT;
|
||
|
|
data_stats->pkts++;
|
||
|
|
data_stats->bytes += pkt_bytes;
|
||
|
|
bpf_skb_set_tunnel_key(skb, &tkey, sizeof(tkey), tun_flag);
|
||
|
|
*(u32 *)eth->eth_dest = tkey.remote_ipv4;
|
||
|
|
return bpf_redirect(ifindex, 0);
|
||
|
|
}
|
||
|
|
|
||
|
|
SEC("l4lb-demo")
|
||
|
|
int balancer_ingress(struct __sk_buff *ctx)
|
||
|
|
{
|
||
|
|
void *data_end = (void *)(long)ctx->data_end;
|
||
|
|
void *data = (void *)(long)ctx->data;
|
||
|
|
struct eth_hdr *eth = data;
|
||
|
|
__u32 eth_proto;
|
||
|
|
__u32 nh_off;
|
||
|
|
|
||
|
|
nh_off = sizeof(struct eth_hdr);
|
||
|
|
if (data + nh_off > data_end)
|
||
|
|
return TC_ACT_SHOT;
|
||
|
|
eth_proto = eth->eth_proto;
|
||
|
|
if (eth_proto == bpf_htons(ETH_P_IP))
|
||
|
|
return process_packet(data, nh_off, data_end, false, ctx);
|
||
|
|
else if (eth_proto == bpf_htons(ETH_P_IPV6))
|
||
|
|
return process_packet(data, nh_off, data_end, true, ctx);
|
||
|
|
else
|
||
|
|
return TC_ACT_SHOT;
|
||
|
|
}
|
||
|
|
char _license[] SEC("license") = "GPL";
|