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 int _version SEC("version") = 1;
20
21 /**
22 * SOL_TCP is defined in <netinet/tcp.h> while
23 * TCP_SAVED_SYN is defined in already included <linux/tcp.h>
24 */
25 #ifndef SOL_TCP
26 #define SOL_TCP 6
27 #endif
28
get_tp_window_clamp(struct bpf_sock_ops * skops)29 static __always_inline int get_tp_window_clamp(struct bpf_sock_ops *skops)
30 {
31 struct bpf_sock *sk;
32 struct tcp_sock *tp;
33
34 sk = skops->sk;
35 if (!sk)
36 return -1;
37 tp = bpf_skc_to_tcp_sock(sk);
38 if (!tp)
39 return -1;
40 return tp->window_clamp;
41 }
42
43 SEC("sockops")
bpf_testcb(struct bpf_sock_ops * skops)44 int bpf_testcb(struct bpf_sock_ops *skops)
45 {
46 char header[sizeof(struct ipv6hdr) + sizeof(struct tcphdr)];
47 struct bpf_sock_ops *reuse = skops;
48 struct tcphdr *thdr;
49 int window_clamp = 9216;
50 int good_call_rv = 0;
51 int bad_call_rv = 0;
52 int save_syn = 1;
53 int rv = -1;
54 int v = 0;
55 int op;
56
57 /* Test reading fields in bpf_sock_ops using single register */
58 asm volatile (
59 "%[reuse] = *(u32 *)(%[reuse] +96)"
60 : [reuse] "+r"(reuse)
61 :);
62
63 asm volatile (
64 "%[op] = *(u32 *)(%[skops] +96)"
65 : [op] "+r"(op)
66 : [skops] "r"(skops)
67 :);
68
69 asm volatile (
70 "r9 = %[skops];\n"
71 "r8 = *(u32 *)(r9 +164);\n"
72 "*(u32 *)(r9 +164) = r8;\n"
73 :: [skops] "r"(skops)
74 : "r9", "r8");
75
76 asm volatile (
77 "r1 = %[skops];\n"
78 "r1 = *(u64 *)(r1 +184);\n"
79 "if r1 == 0 goto +1;\n"
80 "r1 = *(u32 *)(r1 +4);\n"
81 :: [skops] "r"(skops):"r1");
82
83 asm volatile (
84 "r9 = %[skops];\n"
85 "r9 = *(u64 *)(r9 +184);\n"
86 "if r9 == 0 goto +1;\n"
87 "r9 = *(u32 *)(r9 +4);\n"
88 :: [skops] "r"(skops):"r9");
89
90 asm volatile (
91 "r1 = %[skops];\n"
92 "r2 = *(u64 *)(r1 +184);\n"
93 "if r2 == 0 goto +1;\n"
94 "r2 = *(u32 *)(r2 +4);\n"
95 :: [skops] "r"(skops):"r1", "r2");
96
97 op = (int) skops->op;
98
99 global.event_map |= (1 << op);
100
101 switch (op) {
102 case BPF_SOCK_OPS_TCP_CONNECT_CB:
103 rv = bpf_setsockopt(skops, SOL_TCP, TCP_WINDOW_CLAMP,
104 &window_clamp, sizeof(window_clamp));
105 global.window_clamp_client = get_tp_window_clamp(skops);
106 break;
107 case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
108 /* Test failure to set largest cb flag (assumes not defined) */
109 global.bad_cb_test_rv = bpf_sock_ops_cb_flags_set(skops, 0x80);
110 /* Set callback */
111 global.good_cb_test_rv = bpf_sock_ops_cb_flags_set(skops,
112 BPF_SOCK_OPS_STATE_CB_FLAG);
113 break;
114 case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
115 skops->sk_txhash = 0x12345f;
116 v = 0xff;
117 rv = bpf_setsockopt(skops, SOL_IPV6, IPV6_TCLASS, &v,
118 sizeof(v));
119 if (skops->family == AF_INET6) {
120 v = bpf_getsockopt(skops, IPPROTO_TCP, TCP_SAVED_SYN,
121 header, (sizeof(struct ipv6hdr) +
122 sizeof(struct tcphdr)));
123 if (!v) {
124 int offset = sizeof(struct ipv6hdr);
125
126 thdr = (struct tcphdr *)(header + offset);
127 v = thdr->syn;
128
129 global.tcp_saved_syn = v;
130 }
131 }
132 rv = bpf_setsockopt(skops, SOL_TCP, TCP_WINDOW_CLAMP,
133 &window_clamp, sizeof(window_clamp));
134
135 global.window_clamp_server = get_tp_window_clamp(skops);
136 break;
137 case BPF_SOCK_OPS_RTO_CB:
138 break;
139 case BPF_SOCK_OPS_RETRANS_CB:
140 break;
141 case BPF_SOCK_OPS_STATE_CB:
142 if (skops->args[1] == BPF_TCP_CLOSE) {
143 if (skops->args[0] == BPF_TCP_LISTEN) {
144 global.num_listen++;
145 } else {
146 global.total_retrans = skops->total_retrans;
147 global.data_segs_in = skops->data_segs_in;
148 global.data_segs_out = skops->data_segs_out;
149 global.bytes_received = skops->bytes_received;
150 global.bytes_acked = skops->bytes_acked;
151 }
152 global.num_close_events++;
153 }
154 break;
155 case BPF_SOCK_OPS_TCP_LISTEN_CB:
156 bpf_sock_ops_cb_flags_set(skops, BPF_SOCK_OPS_STATE_CB_FLAG);
157 v = bpf_setsockopt(skops, IPPROTO_TCP, TCP_SAVE_SYN,
158 &save_syn, sizeof(save_syn));
159 /* Update global map w/ result of setsock opt */
160 global.tcp_save_syn = v;
161 break;
162 default:
163 rv = -1;
164 }
165 skops->reply = rv;
166 return 1;
167 }
168 char _license[] SEC("license") = "GPL";
169