1
2#include <errno.h>
3#include <stdbool.h>
4#include <stdio.h>
5#include <string.h>
6#include <unistd.h>
7
8#include <arpa/inet.h>
9
10#include <linux/err.h>
11#include <linux/in.h>
12#include <linux/in6.h>
13
14#include "bpf_util.h"
15#include "network_helpers.h"
16
17#define clean_errno() (errno == 0 ? "None" : strerror(errno))
18#define log_err(MSG, ...) ({ \
19 int __save = errno; \
20 fprintf(stderr, "(%s:%d: errno: %s) " MSG "\n", \
21 __FILE__, __LINE__, clean_errno(), \
22 ##__VA_ARGS__); \
23 errno = __save; \
24})
25
26struct ipv4_packet pkt_v4 = {
27 .eth.h_proto = __bpf_constant_htons(ETH_P_IP),
28 .iph.ihl = 5,
29 .iph.protocol = IPPROTO_TCP,
30 .iph.tot_len = __bpf_constant_htons(MAGIC_BYTES),
31 .tcp.urg_ptr = 123,
32 .tcp.doff = 5,
33};
34
35struct ipv6_packet pkt_v6 = {
36 .eth.h_proto = __bpf_constant_htons(ETH_P_IPV6),
37 .iph.nexthdr = IPPROTO_TCP,
38 .iph.payload_len = __bpf_constant_htons(MAGIC_BYTES),
39 .tcp.urg_ptr = 123,
40 .tcp.doff = 5,
41};
42
43static int settimeo(int fd, int timeout_ms)
44{
45 struct timeval timeout = { .tv_sec = 3 };
46
47 if (timeout_ms > 0) {
48 timeout.tv_sec = timeout_ms / 1000;
49 timeout.tv_usec = (timeout_ms % 1000) * 1000;
50 }
51
52 if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &timeout,
53 sizeof(timeout))) {
54 log_err("Failed to set SO_RCVTIMEO");
55 return -1;
56 }
57
58 if (setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &timeout,
59 sizeof(timeout))) {
60 log_err("Failed to set SO_SNDTIMEO");
61 return -1;
62 }
63
64 return 0;
65}
66
67#define save_errno_close(fd) ({ int __save = errno; close(fd); errno = __save; })
68
69int start_server(int family, int type, const char *addr_str, __u16 port,
70 int timeout_ms)
71{
72 struct sockaddr_storage addr = {};
73 socklen_t len;
74 int fd;
75
76 if (make_sockaddr(family, addr_str, port, &addr, &len))
77 return -1;
78
79 fd = socket(family, type, 0);
80 if (fd < 0) {
81 log_err("Failed to create server socket");
82 return -1;
83 }
84
85 if (settimeo(fd, timeout_ms))
86 goto error_close;
87
88 if (bind(fd, (const struct sockaddr *)&addr, len) < 0) {
89 log_err("Failed to bind socket");
90 goto error_close;
91 }
92
93 if (type == SOCK_STREAM) {
94 if (listen(fd, 1) < 0) {
95 log_err("Failed to listed on socket");
96 goto error_close;
97 }
98 }
99
100 return fd;
101
102error_close:
103 save_errno_close(fd);
104 return -1;
105}
106
107int fastopen_connect(int server_fd, const char *data, unsigned int data_len,
108 int timeout_ms)
109{
110 struct sockaddr_storage addr;
111 socklen_t addrlen = sizeof(addr);
112 struct sockaddr_in *addr_in;
113 int fd, ret;
114
115 if (getsockname(server_fd, (struct sockaddr *)&addr, &addrlen)) {
116 log_err("Failed to get server addr");
117 return -1;
118 }
119
120 addr_in = (struct sockaddr_in *)&addr;
121 fd = socket(addr_in->sin_family, SOCK_STREAM, 0);
122 if (fd < 0) {
123 log_err("Failed to create client socket");
124 return -1;
125 }
126
127 if (settimeo(fd, timeout_ms))
128 goto error_close;
129
130 ret = sendto(fd, data, data_len, MSG_FASTOPEN, (struct sockaddr *)&addr,
131 addrlen);
132 if (ret != data_len) {
133 log_err("sendto(data, %u) != %d\n", data_len, ret);
134 goto error_close;
135 }
136
137 return fd;
138
139error_close:
140 save_errno_close(fd);
141 return -1;
142}
143
144static int connect_fd_to_addr(int fd,
145 const struct sockaddr_storage *addr,
146 socklen_t addrlen)
147{
148 if (connect(fd, (const struct sockaddr *)addr, addrlen)) {
149 log_err("Failed to connect to server");
150 return -1;
151 }
152
153 return 0;
154}
155
156int connect_to_fd(int server_fd, int timeout_ms)
157{
158 struct sockaddr_storage addr;
159 struct sockaddr_in *addr_in;
160 socklen_t addrlen, optlen;
161 int fd, type;
162
163 optlen = sizeof(type);
164 if (getsockopt(server_fd, SOL_SOCKET, SO_TYPE, &type, &optlen)) {
165 log_err("getsockopt(SOL_TYPE)");
166 return -1;
167 }
168
169 addrlen = sizeof(addr);
170 if (getsockname(server_fd, (struct sockaddr *)&addr, &addrlen)) {
171 log_err("Failed to get server addr");
172 return -1;
173 }
174
175 addr_in = (struct sockaddr_in *)&addr;
176 fd = socket(addr_in->sin_family, type, 0);
177 if (fd < 0) {
178 log_err("Failed to create client socket");
179 return -1;
180 }
181
182 if (settimeo(fd, timeout_ms))
183 goto error_close;
184
185 if (connect_fd_to_addr(fd, &addr, addrlen))
186 goto error_close;
187
188 return fd;
189
190error_close:
191 save_errno_close(fd);
192 return -1;
193}
194
195int connect_fd_to_fd(int client_fd, int server_fd, int timeout_ms)
196{
197 struct sockaddr_storage addr;
198 socklen_t len = sizeof(addr);
199
200 if (settimeo(client_fd, timeout_ms))
201 return -1;
202
203 if (getsockname(server_fd, (struct sockaddr *)&addr, &len)) {
204 log_err("Failed to get server addr");
205 return -1;
206 }
207
208 if (connect_fd_to_addr(client_fd, &addr, len))
209 return -1;
210
211 return 0;
212}
213
214int make_sockaddr(int family, const char *addr_str, __u16 port,
215 struct sockaddr_storage *addr, socklen_t *len)
216{
217 if (family == AF_INET) {
218 struct sockaddr_in *sin = (void *)addr;
219
220 sin->sin_family = AF_INET;
221 sin->sin_port = htons(port);
222 if (addr_str &&
223 inet_pton(AF_INET, addr_str, &sin->sin_addr) != 1) {
224 log_err("inet_pton(AF_INET, %s)", addr_str);
225 return -1;
226 }
227 if (len)
228 *len = sizeof(*sin);
229 return 0;
230 } else if (family == AF_INET6) {
231 struct sockaddr_in6 *sin6 = (void *)addr;
232
233 sin6->sin6_family = AF_INET6;
234 sin6->sin6_port = htons(port);
235 if (addr_str &&
236 inet_pton(AF_INET6, addr_str, &sin6->sin6_addr) != 1) {
237 log_err("inet_pton(AF_INET6, %s)", addr_str);
238 return -1;
239 }
240 if (len)
241 *len = sizeof(*sin6);
242 return 0;
243 }
244 return -1;
245}
246
