1 // SPDX-License-Identifier: GPL-2.0-only
10 #include <linux/err.h>
12 #include <linux/in6.h>
15 #include "network_helpers.h"
17 #define clean_errno() (errno == 0 ? "None" : strerror(errno))
18 #define log_err(MSG, ...) ({ \
20 fprintf(stderr, "(%s:%d: errno: %s) " MSG "\n", \
21 __FILE__, __LINE__, clean_errno(), \
26 struct ipv4_packet pkt_v4 = {
27 .eth.h_proto = __bpf_constant_htons(ETH_P_IP),
29 .iph.protocol = IPPROTO_TCP,
30 .iph.tot_len = __bpf_constant_htons(MAGIC_BYTES),
35 struct 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),
43 static int settimeo(int fd, int timeout_ms)
45 struct timeval timeout = { .tv_sec = 3 };
48 timeout.tv_sec = timeout_ms / 1000;
49 timeout.tv_usec = (timeout_ms % 1000) * 1000;
52 if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &timeout,
54 log_err("Failed to set SO_RCVTIMEO");
58 if (setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &timeout,
60 log_err("Failed to set SO_SNDTIMEO");
67 #define save_errno_close(fd) ({ int __save = errno; close(fd); errno = __save; })
69 int start_server(int family, int type, const char *addr_str, __u16 port,
72 struct sockaddr_storage addr = {};
76 if (make_sockaddr(family, addr_str, port, &addr, &len))
79 fd = socket(family, type, 0);
81 log_err("Failed to create server socket");
85 if (settimeo(fd, timeout_ms))
88 if (bind(fd, (const struct sockaddr *)&addr, len) < 0) {
89 log_err("Failed to bind socket");
93 if (type == SOCK_STREAM) {
94 if (listen(fd, 1) < 0) {
95 log_err("Failed to listed on socket");
103 save_errno_close(fd);
107 static int connect_fd_to_addr(int fd,
108 const struct sockaddr_storage *addr,
111 if (connect(fd, (const struct sockaddr *)addr, addrlen)) {
112 log_err("Failed to connect to server");
119 int connect_to_fd(int server_fd, int timeout_ms)
121 struct sockaddr_storage addr;
122 struct sockaddr_in *addr_in;
123 socklen_t addrlen, optlen;
126 optlen = sizeof(type);
127 if (getsockopt(server_fd, SOL_SOCKET, SO_TYPE, &type, &optlen)) {
128 log_err("getsockopt(SOL_TYPE)");
132 addrlen = sizeof(addr);
133 if (getsockname(server_fd, (struct sockaddr *)&addr, &addrlen)) {
134 log_err("Failed to get server addr");
138 addr_in = (struct sockaddr_in *)&addr;
139 fd = socket(addr_in->sin_family, type, 0);
141 log_err("Failed to create client socket");
145 if (settimeo(fd, timeout_ms))
148 if (connect_fd_to_addr(fd, &addr, addrlen))
154 save_errno_close(fd);
158 int connect_fd_to_fd(int client_fd, int server_fd, int timeout_ms)
160 struct sockaddr_storage addr;
161 socklen_t len = sizeof(addr);
163 if (settimeo(client_fd, timeout_ms))
166 if (getsockname(server_fd, (struct sockaddr *)&addr, &len)) {
167 log_err("Failed to get server addr");
171 if (connect_fd_to_addr(client_fd, &addr, len))
177 int make_sockaddr(int family, const char *addr_str, __u16 port,
178 struct sockaddr_storage *addr, socklen_t *len)
180 if (family == AF_INET) {
181 struct sockaddr_in *sin = (void *)addr;
183 sin->sin_family = AF_INET;
184 sin->sin_port = htons(port);
186 inet_pton(AF_INET, addr_str, &sin->sin_addr) != 1) {
187 log_err("inet_pton(AF_INET, %s)", addr_str);
193 } else if (family == AF_INET6) {
194 struct sockaddr_in6 *sin6 = (void *)addr;
196 sin6->sin6_family = AF_INET6;
197 sin6->sin6_port = htons(port);
199 inet_pton(AF_INET6, addr_str, &sin6->sin6_addr) != 1) {
200 log_err("inet_pton(AF_INET6, %s)", addr_str);
204 *len = sizeof(*sin6);