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_helpers.h"
14 #include "bpf_endian.h"
15 #include "test_tcpbpf.h"
16 
17 struct {
18 	__uint(type, BPF_MAP_TYPE_ARRAY);
19 	__uint(max_entries, 4);
20 	__type(key, __u32);
21 	__type(value, struct tcpbpf_globals);
22 } global_map SEC(".maps");
23 
24 struct {
25 	__uint(type, BPF_MAP_TYPE_ARRAY);
26 	__uint(max_entries, 2);
27 	__type(key, __u32);
28 	__type(value, int);
29 } sockopt_results SEC(".maps");
30 
31 static inline void update_event_map(int event)
32 {
33 	__u32 key = 0;
34 	struct tcpbpf_globals g, *gp;
35 
36 	gp = bpf_map_lookup_elem(&global_map, &key);
37 	if (gp == NULL) {
38 		struct tcpbpf_globals g = {0};
39 
40 		g.event_map |= (1 << event);
41 		bpf_map_update_elem(&global_map, &key, &g,
42 			    BPF_ANY);
43 	} else {
44 		g = *gp;
45 		g.event_map |= (1 << event);
46 		bpf_map_update_elem(&global_map, &key, &g,
47 			    BPF_ANY);
48 	}
49 }
50 
51 int _version SEC("version") = 1;
52 
53 SEC("sockops")
54 int bpf_testcb(struct bpf_sock_ops *skops)
55 {
56 	char header[sizeof(struct ipv6hdr) + sizeof(struct tcphdr)];
57 	struct tcphdr *thdr;
58 	int good_call_rv = 0;
59 	int bad_call_rv = 0;
60 	int save_syn = 1;
61 	int rv = -1;
62 	int v = 0;
63 	int op;
64 
65 	op = (int) skops->op;
66 
67 	update_event_map(op);
68 
69 	switch (op) {
70 	case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
71 		/* Test failure to set largest cb flag (assumes not defined) */
72 		bad_call_rv = bpf_sock_ops_cb_flags_set(skops, 0x80);
73 		/* Set callback */
74 		good_call_rv = bpf_sock_ops_cb_flags_set(skops,
75 						 BPF_SOCK_OPS_STATE_CB_FLAG);
76 		/* Update results */
77 		{
78 			__u32 key = 0;
79 			struct tcpbpf_globals g, *gp;
80 
81 			gp = bpf_map_lookup_elem(&global_map, &key);
82 			if (!gp)
83 				break;
84 			g = *gp;
85 			g.bad_cb_test_rv = bad_call_rv;
86 			g.good_cb_test_rv = good_call_rv;
87 			bpf_map_update_elem(&global_map, &key, &g,
88 					    BPF_ANY);
89 		}
90 		break;
91 	case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
92 		skops->sk_txhash = 0x12345f;
93 		v = 0xff;
94 		rv = bpf_setsockopt(skops, SOL_IPV6, IPV6_TCLASS, &v,
95 				    sizeof(v));
96 		if (skops->family == AF_INET6) {
97 			v = bpf_getsockopt(skops, IPPROTO_TCP, TCP_SAVED_SYN,
98 					   header, (sizeof(struct ipv6hdr) +
99 						    sizeof(struct tcphdr)));
100 			if (!v) {
101 				int offset = sizeof(struct ipv6hdr);
102 
103 				thdr = (struct tcphdr *)(header + offset);
104 				v = thdr->syn;
105 				__u32 key = 1;
106 
107 				bpf_map_update_elem(&sockopt_results, &key, &v,
108 						    BPF_ANY);
109 			}
110 		}
111 		break;
112 	case BPF_SOCK_OPS_RTO_CB:
113 		break;
114 	case BPF_SOCK_OPS_RETRANS_CB:
115 		break;
116 	case BPF_SOCK_OPS_STATE_CB:
117 		if (skops->args[1] == BPF_TCP_CLOSE) {
118 			__u32 key = 0;
119 			struct tcpbpf_globals g, *gp;
120 
121 			gp = bpf_map_lookup_elem(&global_map, &key);
122 			if (!gp)
123 				break;
124 			g = *gp;
125 			if (skops->args[0] == BPF_TCP_LISTEN) {
126 				g.num_listen++;
127 			} else {
128 				g.total_retrans = skops->total_retrans;
129 				g.data_segs_in = skops->data_segs_in;
130 				g.data_segs_out = skops->data_segs_out;
131 				g.bytes_received = skops->bytes_received;
132 				g.bytes_acked = skops->bytes_acked;
133 			}
134 			g.num_close_events++;
135 			bpf_map_update_elem(&global_map, &key, &g,
136 					    BPF_ANY);
137 		}
138 		break;
139 	case BPF_SOCK_OPS_TCP_LISTEN_CB:
140 		bpf_sock_ops_cb_flags_set(skops, BPF_SOCK_OPS_STATE_CB_FLAG);
141 		v = bpf_setsockopt(skops, IPPROTO_TCP, TCP_SAVE_SYN,
142 				   &save_syn, sizeof(save_syn));
143 		/* Update global map w/ result of setsock opt */
144 		__u32 key = 0;
145 
146 		bpf_map_update_elem(&sockopt_results, &key, &v, BPF_ANY);
147 		break;
148 	default:
149 		rv = -1;
150 	}
151 	skops->reply = rv;
152 	return 1;
153 }
154 char _license[] SEC("license") = "GPL";
155