// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2019 Facebook */
#include <linux/bpf.h>
#include <netinet/in.h>
#include <stdbool.h>
#include "bpf_helpers.h"
#include "bpf_endian.h"
enum bpf_addr_array_idx {
ADDR_SRV_IDX,
ADDR_CLI_IDX,
__NR_BPF_ADDR_ARRAY_IDX,
};
enum bpf_result_array_idx {
EGRESS_SRV_IDX,
EGRESS_CLI_IDX,
INGRESS_LISTEN_IDX,
__NR_BPF_RESULT_ARRAY_IDX,
};
enum bpf_linum_array_idx {
EGRESS_LINUM_IDX,
INGRESS_LINUM_IDX,
__NR_BPF_LINUM_ARRAY_IDX,
};
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, __NR_BPF_ADDR_ARRAY_IDX);
__type(key, __u32);
__type(value, struct sockaddr_in6);
} addr_map SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, __NR_BPF_RESULT_ARRAY_IDX);
__type(key, __u32);
__type(value, struct bpf_sock);
} sock_result_map SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, __NR_BPF_RESULT_ARRAY_IDX);
__type(key, __u32);
__type(value, struct bpf_tcp_sock);
} tcp_sock_result_map SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, __NR_BPF_LINUM_ARRAY_IDX);
__type(key, __u32);
__type(value, __u32);
} linum_map SEC(".maps");
struct bpf_spinlock_cnt {
struct bpf_spin_lock lock;
__u32 cnt;
};
struct {
__uint(type, BPF_MAP_TYPE_SK_STORAGE);
__uint(map_flags, BPF_F_NO_PREALLOC);
__type(key, int);
__type(value, struct bpf_spinlock_cnt);
} sk_pkt_out_cnt SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_SK_STORAGE);
__uint(map_flags, BPF_F_NO_PREALLOC);
__type(key, int);
__type(value, struct bpf_spinlock_cnt);
} sk_pkt_out_cnt10 SEC(".maps");
static bool is_loopback6(__u32 *a6)
{
return !a6[0] && !a6[1] && !a6[2] && a6[3] == bpf_htonl(1);
}
static void skcpy(struct bpf_sock *dst,
const struct bpf_sock *src)
{
dst->bound_dev_if = src->bound_dev_if;
dst->family = src->family;
dst->type = src->type;
dst->protocol = src->protocol;
dst->mark = src->mark;
dst->priority = src->priority;
dst->src_ip4 = src->src_ip4;
dst->src_ip6[0] = src->src_ip6[0];
dst->src_ip6[1] = src->src_ip6[1];
dst->src_ip6[2] = src->src_ip6[2];
dst->src_ip6[3] = src->src_ip6[3];
dst->src_port = src->src_port;
dst->dst_ip4 = src->dst_ip4;
dst->dst_ip6[0] = src->dst_ip6[0];
dst->dst_ip6[1] = src->dst_ip6[1];
dst->dst_ip6[2] = src->dst_ip6[2];
dst->dst_ip6[3] = src->dst_ip6[3];
dst->dst_port = src->dst_port;
dst->state = src->state;
}
static void tpcpy(struct bpf_tcp_sock *dst,
const struct bpf_tcp_sock *src)
{
dst->snd_cwnd = src->snd_cwnd;
dst->srtt_us = src->srtt_us;
dst->rtt_min = src->rtt_min;
dst->snd_ssthresh = src->snd_ssthresh;
dst->rcv_nxt = src->rcv_nxt;
dst->snd_nxt = src->snd_nxt;
dst->snd_una = src->snd_una;
dst->mss_cache = src->mss_cache;
dst->ecn_flags = src->ecn_flags;
dst->rate_delivered = src->rate_delivered;
dst->rate_interval_us = src->rate_interval_us;
dst->packets_out = src->packets_out;
dst->retrans_out = src->retrans_out;
dst->total_retrans = src->total_retrans;
dst->segs_in = src->segs_in;
dst->data_segs_in = src->data_segs_in;
dst->segs_out = src->segs_out;
dst->data_segs_out = src->data_segs_out;
dst->lost_out = src->lost_out;
dst->sacked_out = src->sacked_out;
dst->bytes_received = src->bytes_received;
dst->bytes_acked = src->bytes_acked;
}
#define RETURN { \
linum = __LINE__; \
bpf_map_update_elem(&linum_map, &linum_idx, &linum, 0); \
return 1; \
}
SEC("cgroup_skb/egress")
int egress_read_sock_fields(struct __sk_buff *skb)
{
struct bpf_spinlock_cnt cli_cnt_init = { .lock = 0, .cnt = 0xeB9F };
__u32 srv_idx = ADDR_SRV_IDX, cli_idx = ADDR_CLI_IDX, result_idx;
struct bpf_spinlock_cnt *pkt_out_cnt, *pkt_out_cnt10;
struct sockaddr_in6 *srv_sa6, *cli_sa6;
struct bpf_tcp_sock *tp, *tp_ret;
struct bpf_sock *sk, *sk_ret;
__u32 linum, linum_idx;
linum_idx = EGRESS_LINUM_IDX;
sk = skb->sk;
if (!sk || sk->state == 10)
RETURN;
sk = bpf_sk_fullsock(sk);
if (!sk || sk->family != AF_INET6 || sk->protocol != IPPROTO_TCP ||
!is_loopback6(sk->src_ip6))
RETURN;
tp = bpf_tcp_sock(sk);
if (!tp)
RETURN;
srv_sa6 = bpf_map_lookup_elem(&addr_map, &srv_idx);
cli_sa6 = bpf_map_lookup_elem(&addr_map, &cli_idx);
if (!srv_sa6 || !cli_sa6)
RETURN;
if (sk->src_port == bpf_ntohs(srv_sa6->sin6_port))
result_idx = EGRESS_SRV_IDX;
else if (sk->src_port == bpf_ntohs(cli_sa6->sin6_port))
result_idx = EGRESS_CLI_IDX;
else
RETURN;
sk_ret = bpf_map_lookup_elem(&sock_result_map, &result_idx);
tp_ret = bpf_map_lookup_elem(&tcp_sock_result_map, &result_idx);
if (!sk_ret || !tp_ret)
RETURN;
skcpy(sk_ret, sk);
tpcpy(tp_ret, tp);
if (result_idx == EGRESS_SRV_IDX) {
/* The userspace has created it for srv sk */
pkt_out_cnt = bpf_sk_storage_get(&sk_pkt_out_cnt, sk, 0, 0);
pkt_out_cnt10 = bpf_sk_storage_get(&sk_pkt_out_cnt10, sk,
0, 0);
} else {
pkt_out_cnt = bpf_sk_storage_get(&sk_pkt_out_cnt, sk,
&cli_cnt_init,
BPF_SK_STORAGE_GET_F_CREATE);
pkt_out_cnt10 = bpf_sk_storage_get(&sk_pkt_out_cnt10,
sk, &cli_cnt_init,
BPF_SK_STORAGE_GET_F_CREATE);
}
if (!pkt_out_cnt || !pkt_out_cnt10)
RETURN;
/* Even both cnt and cnt10 have lock defined in their BTF,
* intentionally one cnt takes lock while one does not
* as a test for the spinlock support in BPF_MAP_TYPE_SK_STORAGE.
*/
pkt_out_cnt->cnt += 1;
bpf_spin_lock(&pkt_out_cnt10->lock);
pkt_out_cnt10->cnt += 10;
bpf_spin_unlock(&pkt_out_cnt10->lock);
RETURN;
}
SEC("cgroup_skb/ingress")
int ingress_read_sock_fields(struct __sk_buff *skb)
{
__u32 srv_idx = ADDR_SRV_IDX, result_idx = INGRESS_LISTEN_IDX;
struct bpf_tcp_sock *tp, *tp_ret;
struct bpf_sock *sk, *sk_ret;
struct sockaddr_in6 *srv_sa6;
__u32 linum, linum_idx;
linum_idx = INGRESS_LINUM_IDX;
sk = skb->sk;
if (!sk || sk->family != AF_INET6 || !is_loopback6(sk->src_ip6))
RETURN;
srv_sa6 = bpf_map_lookup_elem(&addr_map, &srv_idx);
if (!srv_sa6 || sk->src_port != bpf_ntohs(srv_sa6->sin6_port))
RETURN;
if (sk->state != 10 && sk->state != 12)
RETURN;
sk = bpf_get_listener_sock(sk);
if (!sk)
RETURN;
tp = bpf_tcp_sock(sk);
if (!tp)
RETURN;
sk_ret = bpf_map_lookup_elem(&sock_result_map, &result_idx);
tp_ret = bpf_map_lookup_elem(&tcp_sock_result_map, &result_idx);
if (!sk_ret || !tp_ret)
RETURN;
skcpy(sk_ret, sk);
tpcpy(tp_ret, tp);
RETURN;
}
char _license[] SEC("license") = "GPL";
