Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2
3#include "vmlinux.h"
4
5#include <bpf/bpf_helpers.h>
6#include <bpf/bpf_tracing.h>
7#include "bpf_tracing_net.h"
8
9char _license[] SEC("license") = "GPL";
10
11#ifndef SMC_HS_CTRL_NAME_MAX
12#define SMC_HS_CTRL_NAME_MAX 16
13#endif
14
15enum {
16 BPF_SMC_LISTEN = 10,
17};
18
19struct smc_sock___local {
20 struct sock sk;
21 struct smc_sock *listen_smc;
22 bool use_fallback;
23} __attribute__((preserve_access_index));
24
25struct smc_hs_ctrl___local {
26 char name[SMC_HS_CTRL_NAME_MAX];
27 int (*syn_option)(struct tcp_sock *);
28 int (*synack_option)(const struct tcp_sock *, struct inet_request_sock *);
29} __attribute__((preserve_access_index));
30
31struct netns_smc___local {
32 struct smc_hs_ctrl___local *hs_ctrl;
33} __attribute__((preserve_access_index));
34
35struct net___local {
36 struct netns_smc___local smc;
37} __attribute__((preserve_access_index));
38
39int smc_cnt = 0;
40int fallback_cnt = 0;
41
42SEC("fentry/smc_release")
43int BPF_PROG(bpf_smc_release, struct socket *sock)
44{
45 /* only count from one side (client) */
46 if (sock->sk->__sk_common.skc_state == BPF_SMC_LISTEN)
47 return 0;
48 smc_cnt++;
49 return 0;
50}
51
52SEC("fentry/smc_switch_to_fallback")
53int BPF_PROG(bpf_smc_switch_to_fallback, struct smc_sock___local *smc)
54{
55 /* only count from one side (client) */
56 if (smc && !smc->listen_smc)
57 fallback_cnt++;
58 return 0;
59}
60
61/* go with default value if no strat was found */
62bool default_ip_strat_value = true;
63
64struct smc_policy_ip_key {
65 __u32 sip;
66 __u32 dip;
67};
68
69struct smc_policy_ip_value {
70 __u8 mode;
71};
72
73struct {
74 __uint(type, BPF_MAP_TYPE_HASH);
75 __uint(key_size, sizeof(struct smc_policy_ip_key));
76 __uint(value_size, sizeof(struct smc_policy_ip_value));
77 __uint(max_entries, 128);
78 __uint(map_flags, BPF_F_NO_PREALLOC);
79} smc_policy_ip SEC(".maps");
80
81static bool smc_check(__u32 src, __u32 dst)
82{
83 struct smc_policy_ip_value *value;
84 struct smc_policy_ip_key key = {
85 .sip = src,
86 .dip = dst,
87 };
88
89 value = bpf_map_lookup_elem(&smc_policy_ip, &key);
90 return value ? value->mode : default_ip_strat_value;
91}
92
93SEC("fmod_ret/update_socket_protocol")
94int BPF_PROG(smc_run, int family, int type, int protocol)
95{
96 struct task_struct *task;
97
98 if (family != AF_INET && family != AF_INET6)
99 return protocol;
100
101 if ((type & 0xf) != SOCK_STREAM)
102 return protocol;
103
104 if (protocol != 0 && protocol != IPPROTO_TCP)
105 return protocol;
106
107 task = bpf_get_current_task_btf();
108 /* Prevent from affecting other tests */
109 if (!task) {
110 return protocol;
111 } else {
112 struct net___local *net = (struct net___local *)task->nsproxy->net_ns;
113
114 if (!bpf_core_field_exists(struct net___local, smc) || !net->smc.hs_ctrl)
115 return protocol;
116 }
117
118 return IPPROTO_SMC;
119}
120
121SEC("struct_ops")
122int BPF_PROG(bpf_smc_set_tcp_option_cond, const struct tcp_sock *tp,
123 struct inet_request_sock *ireq)
124{
125 return smc_check(ireq->req.__req_common.skc_daddr,
126 ireq->req.__req_common.skc_rcv_saddr);
127}
128
129SEC("struct_ops")
130int BPF_PROG(bpf_smc_set_tcp_option, struct tcp_sock *tp)
131{
132 return smc_check(tp->inet_conn.icsk_inet.sk.__sk_common.skc_rcv_saddr,
133 tp->inet_conn.icsk_inet.sk.__sk_common.skc_daddr);
134}
135
136SEC(".struct_ops")
137struct smc_hs_ctrl___local linkcheck = {
138 .name = "linkcheck",
139 .syn_option = (void *)bpf_smc_set_tcp_option,
140 .synack_option = (void *)bpf_smc_set_tcp_option_cond,
141};