10 #include <sys/socket.h>
20 struct utcp_connection *c;
21 int dir = DIR_READ | DIR_WRITE;
36 int reorder_countdown;
38 void debug(const char *format, ...) {
40 gettimeofday(&now, NULL);
41 fprintf(stderr, "%lu.%lu ", now.tv_sec, now.tv_usec / 1000);
44 vfprintf(stderr, format, ap);
48 ssize_t do_recv(struct utcp_connection *c, const void *data, size_t len) {
51 debug("Error: %s\n", strerror(errno));
55 debug("Connection closed by peer\n");
59 return write(1, data, len);
62 void do_accept(struct utcp_connection *nc, uint16_t port) {
63 utcp_accept(nc, do_recv, NULL);
65 utcp_set_accept_cb(c->utcp, NULL, NULL);
68 ssize_t do_send(struct utcp *utcp, const void *data, size_t len) {
69 int s = *(int *)utcp->priv;
71 if(outpktno >= dropfrom && outpktno < dropto) {
72 if(drand48() < dropout)
74 if(!reorder_data && drand48() < reorder) {
75 reorder_data = malloc(len);
77 memcpy(reorder_data, data, len);
78 reorder_countdown = 1 + drand48() * reorder_dist;
84 if(--reorder_countdown < 0) {
85 total_out += reorder_len;
86 send(s, reorder_data, reorder_len, MSG_DONTWAIT);
93 ssize_t result = send(s, data, len, MSG_DONTWAIT);
95 debug("Error sending UDP packet: %s\n", strerror(errno));
99 int main(int argc, char *argv[]) {
103 if(argc < 2 || argc > 3)
106 bool server = argc == 2;
107 bool connected = false;
109 dropin = atof(getenv("DROPIN") ?: "0");
110 dropout = atof(getenv("DROPOUT") ?: "0");
111 dropfrom = atoi(getenv("DROPFROM") ?: "0");
112 dropto = atoi(getenv("DROPTO") ?: "0");
113 reorder = atof(getenv("REORDER") ?: "0");
114 reorder_dist = atoi(getenv("REORDER_DIST") ?: "10");
116 if(dropto < dropfrom)
120 struct addrinfo hint = {
121 .ai_flags = server ? AI_PASSIVE : 0,
122 .ai_socktype = SOCK_DGRAM,
125 getaddrinfo(server ? NULL : argv[1], server ? argv[1] : argv[2], &hint, &ai);
129 int s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
134 if(bind(s, ai->ai_addr, ai->ai_addrlen))
137 if(connect(s, ai->ai_addr, ai->ai_addrlen))
144 struct utcp *u = utcp_init(server ? do_accept : NULL, NULL, do_send, &s);
148 utcp_set_mtu(u, 1300);
149 utcp_set_user_timeout(u, 10);
152 c = utcp_connect(u, 1, do_recv, NULL);
154 struct pollfd fds[2] = {
155 {.fd = 0, .events = POLLIN | POLLERR | POLLHUP},
156 {.fd = s, .events = POLLIN | POLLERR | POLLHUP},
160 struct timeval timeout = utcp_timeout(u);
162 while(!connected || utcp_is_active(u)) {
163 size_t max = c ? utcp_get_sndbuf_free(c) : 0;
167 int timeout_ms = timeout.tv_sec * 1000 + timeout.tv_usec / 1000 + 1;
169 debug("polling, dir = %d, timeout = %d\n", dir, timeout_ms);
170 if((dir & DIR_READ) && max)
171 poll(fds, 2, timeout_ms);
173 poll(fds + 1, 1, timeout_ms);
178 ssize_t len = read(0, buf, max);
183 utcp_shutdown(c, SHUT_WR);
190 ssize_t sent = utcp_send(c, buf, len);
192 debug("Short send: %zd != %zd\n", sent, len);
199 struct sockaddr_storage ss;
200 socklen_t sl = sizeof ss;
201 int len = recvfrom(s, buf, sizeof buf, MSG_DONTWAIT, (struct sockaddr *)&ss, &sl);
203 debug("Error receiving UDP packet: %s\n", strerror(errno));
207 if(!connect(s, (struct sockaddr *)&ss, sl))
210 if(inpktno >= dropto || inpktno < dropfrom || drand48() >= dropin) {
212 utcp_recv(u, buf, len);
216 timeout = utcp_timeout(u);
223 debug("Total bytes in: %ld, out: %ld\n", total_in, total_out);