1 // SPDX-License-Identifier: GPL-2.0
2 #include <stddef.h>
3 #include <string.h>
4 #include <netinet/in.h>
5 #include <linux/bpf.h>
6 #include <linux/if_ether.h>
7 #include <linux/if_packet.h>
8 #include <linux/ip.h>
9 #include <linux/ipv6.h>
10 #include <linux/types.h>
11 #include <linux/socket.h>
12 #include <linux/tcp.h>
13 #include <bpf/bpf_helpers.h>
14 #include <bpf/bpf_endian.h>
15 #include "bpf_tcp_helpers.h"
16 #include "test_tcpbpf.h"
17
18 struct tcpbpf_globals global = {};
19
20 /**
21 * SOL_TCP is defined in <netinet/tcp.h> while
22 * TCP_SAVED_SYN is defined in already included <linux/tcp.h>
23 */
24 #ifndef SOL_TCP
25 #define SOL_TCP 6
26 #endif
27
get_tp_window_clamp(struct bpf_sock_ops * skops)28 static __always_inline int get_tp_window_clamp(struct bpf_sock_ops *skops)
29 {
30 struct bpf_sock *sk;
31 struct tcp_sock *tp;
32
33 sk = skops->sk;
34 if (!sk)
35 return -1;
36 tp = bpf_skc_to_tcp_sock(sk);
37 if (!tp)
38 return -1;
39 return tp->window_clamp;
40 }
41
42 SEC("sockops")
bpf_testcb(struct bpf_sock_ops * skops)43 int bpf_testcb(struct bpf_sock_ops *skops)
44 {
45 char header[sizeof(struct ipv6hdr) + sizeof(struct tcphdr)];
46 struct bpf_sock_ops *reuse = skops;
47 struct tcphdr *thdr;
48 int window_clamp = 9216;
49 int good_call_rv = 0;
50 int bad_call_rv = 0;
51 int save_syn = 1;
52 int rv = -1;
53 int v = 0;
54 int op;
55
56 /* Test reading fields in bpf_sock_ops using single register */
57 asm volatile (
58 "%[reuse] = *(u32 *)(%[reuse] +96)"
59 : [reuse] "+r"(reuse)
60 :);
61
62 asm volatile (
63 "%[op] = *(u32 *)(%[skops] +96)"
64 : [op] "+r"(op)
65 : [skops] "r"(skops)
66 :);
67
68 asm volatile (
69 "r9 = %[skops];\n"
70 "r8 = *(u32 *)(r9 +164);\n"
71 "*(u32 *)(r9 +164) = r8;\n"
72 :: [skops] "r"(skops)
73 : "r9", "r8");
74
75 asm volatile (
76 "r1 = %[skops];\n"
77 "r1 = *(u64 *)(r1 +184);\n"
78 "if r1 == 0 goto +1;\n"
79 "r1 = *(u32 *)(r1 +4);\n"
80 :: [skops] "r"(skops):"r1");
81
82 asm volatile (
83 "r9 = %[skops];\n"
84 "r9 = *(u64 *)(r9 +184);\n"
85 "if r9 == 0 goto +1;\n"
86 "r9 = *(u32 *)(r9 +4);\n"
87 :: [skops] "r"(skops):"r9");
88
89 asm volatile (
90 "r1 = %[skops];\n"
91 "r2 = *(u64 *)(r1 +184);\n"
92 "if r2 == 0 goto +1;\n"
93 "r2 = *(u32 *)(r2 +4);\n"
94 :: [skops] "r"(skops):"r1", "r2");
95
96 op = (int) skops->op;
97
98 global.event_map |= (1 << op);
99
100 switch (op) {
101 case BPF_SOCK_OPS_TCP_CONNECT_CB:
102 rv = bpf_setsockopt(skops, SOL_TCP, TCP_WINDOW_CLAMP,
103 &window_clamp, sizeof(window_clamp));
104 global.window_clamp_client = get_tp_window_clamp(skops);
105 break;
106 case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
107 /* Test failure to set largest cb flag (assumes not defined) */
108 global.bad_cb_test_rv = bpf_sock_ops_cb_flags_set(skops, 0x80);
109 /* Set callback */
110 global.good_cb_test_rv = bpf_sock_ops_cb_flags_set(skops,
111 BPF_SOCK_OPS_STATE_CB_FLAG);
112 break;
113 case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
114 skops->sk_txhash = 0x12345f;
115 v = 0xff;
116 rv = bpf_setsockopt(skops, SOL_IPV6, IPV6_TCLASS, &v,
117 sizeof(v));
118 if (skops->family == AF_INET6) {
119 v = bpf_getsockopt(skops, IPPROTO_TCP, TCP_SAVED_SYN,
120 header, (sizeof(struct ipv6hdr) +
121 sizeof(struct tcphdr)));
122 if (!v) {
123 int offset = sizeof(struct ipv6hdr);
124
125 thdr = (struct tcphdr *)(header + offset);
126 v = thdr->syn;
127
128 global.tcp_saved_syn = v;
129 }
130 }
131 rv = bpf_setsockopt(skops, SOL_TCP, TCP_WINDOW_CLAMP,
132 &window_clamp, sizeof(window_clamp));
133
134 global.window_clamp_server = get_tp_window_clamp(skops);
135 break;
136 case BPF_SOCK_OPS_RTO_CB:
137 break;
138 case BPF_SOCK_OPS_RETRANS_CB:
139 break;
140 case BPF_SOCK_OPS_STATE_CB:
141 if (skops->args[1] == BPF_TCP_CLOSE) {
142 if (skops->args[0] == BPF_TCP_LISTEN) {
143 global.num_listen++;
144 } else {
145 global.total_retrans = skops->total_retrans;
146 global.data_segs_in = skops->data_segs_in;
147 global.data_segs_out = skops->data_segs_out;
148 global.bytes_received = skops->bytes_received;
149 global.bytes_acked = skops->bytes_acked;
150 }
151 global.num_close_events++;
152 }
153 break;
154 case BPF_SOCK_OPS_TCP_LISTEN_CB:
155 bpf_sock_ops_cb_flags_set(skops, BPF_SOCK_OPS_STATE_CB_FLAG);
156 v = bpf_setsockopt(skops, IPPROTO_TCP, TCP_SAVE_SYN,
157 &save_syn, sizeof(save_syn));
158 /* Update global map w/ result of setsock opt */
159 global.tcp_save_syn = v;
160 break;
161 default:
162 rv = -1;
163 }
164 skops->reply = rv;
165 return 1;
166 }
167 char _license[] SEC("license") = "GPL";
168