10 #include <sys/socket.h>
20 struct utcp_connection *c;
21 int dir = DIR_READ | DIR_WRITE;
28 long reorder_dist = 10;
37 int reorder_countdown;
40 void debug(const char *format, ...) {
42 gettimeofday(&now, NULL);
43 fprintf(stderr, "%lu.%lu ", now.tv_sec, now.tv_usec / 1000);
46 vfprintf(stderr, format, ap);
53 ssize_t do_recv(struct utcp_connection *c, const void *data, size_t len) {
56 debug("Error: %s\n", strerror(errno));
60 debug("Connection closed by peer\n");
66 if(fread(buf, len, 1, reference) != 1) {
67 debug("Error reading reference\n");
70 if(memcmp(buf, data, len)) {
71 debug("Received data differs from reference\n");
75 return write(1, data, len);
78 void do_accept(struct utcp_connection *nc, uint16_t port) {
79 utcp_accept(nc, do_recv, NULL);
81 utcp_set_accept_cb(c->utcp, NULL, NULL);
84 ssize_t do_send(struct utcp *utcp, const void *data, size_t len) {
85 int s = *(int *)utcp->priv;
87 if(outpktno >= dropfrom && outpktno < dropto) {
88 if(drand48() < dropout) {
89 debug("Dropped outgoing packet\n");
92 if(!reorder_data && drand48() < reorder) {
93 reorder_data = malloc(len);
95 debug("Out of memory\n");
99 memcpy(reorder_data, data, len);
100 reorder_countdown = 1 + drand48() * reorder_dist;
106 if(--reorder_countdown < 0) {
107 total_out += reorder_len;
108 send(s, reorder_data, reorder_len, MSG_DONTWAIT);
115 ssize_t result = send(s, data, len, MSG_DONTWAIT);
117 debug("Error sending UDP packet: %s\n", strerror(errno));
121 int main(int argc, char *argv[]) {
125 if(argc < 2 || argc > 3)
128 bool server = argc == 2;
129 bool connected = false;
131 if(getenv("DROPIN")) dropin = atof(getenv("DROPIN"));
132 if(getenv("DROPOUT")) dropout = atof(getenv("DROPOUT"));
133 if(getenv("DROPFROM")) dropfrom = atoi(getenv("DROPFROM"));
134 if(getenv("DROPTO")) dropto = atoi(getenv("DROPTO"));
135 if(getenv("REORDER")) reorder = atof(getenv("REORDER"));
136 if(getenv("REORDER_DIST")) reorder_dist = atoi(getenv("REORDER_DIST"));
138 char *reference_filename = getenv("REFERENCE");
139 if(reference_filename)
140 reference = fopen(reference_filename, "r");
142 if(dropto < dropfrom)
146 struct addrinfo hint = {
147 .ai_flags = server ? AI_PASSIVE : 0,
148 .ai_socktype = SOCK_DGRAM,
151 getaddrinfo(server ? NULL : argv[1], server ? argv[1] : argv[2], &hint, &ai);
155 int s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
160 if(bind(s, ai->ai_addr, ai->ai_addrlen))
163 if(connect(s, ai->ai_addr, ai->ai_addrlen))
170 struct utcp *u = utcp_init(server ? do_accept : NULL, NULL, do_send, &s);
174 utcp_set_mtu(u, 1300);
175 utcp_set_user_timeout(u, 10);
178 c = utcp_connect(u, 1, do_recv, NULL);
180 struct pollfd fds[2] = {
181 {.fd = 0, .events = POLLIN | POLLERR | POLLHUP},
182 {.fd = s, .events = POLLIN | POLLERR | POLLHUP},
186 struct timeval timeout = utcp_timeout(u);
188 while(!connected || utcp_is_active(u)) {
189 size_t max = c ? utcp_get_sndbuf_free(c) : 0;
193 int timeout_ms = timeout.tv_sec * 1000 + timeout.tv_usec / 1000 + 1;
195 debug("polling, dir = %d, timeout = %d\n", dir, timeout_ms);
196 if((dir & DIR_READ) && max)
197 poll(fds, 2, timeout_ms);
199 poll(fds + 1, 1, timeout_ms);
204 ssize_t len = read(0, buf, max);
209 utcp_shutdown(c, SHUT_WR);
216 ssize_t sent = utcp_send(c, buf, len);
218 debug("Short send: %zd != %zd\n", sent, len);
225 struct sockaddr_storage ss;
226 socklen_t sl = sizeof ss;
227 int len = recvfrom(s, buf, sizeof buf, MSG_DONTWAIT, (struct sockaddr *)&ss, &sl);
229 debug("Error receiving UDP packet: %s\n", strerror(errno));
233 if(!connect(s, (struct sockaddr *)&ss, sl))
236 if(inpktno >= dropto || inpktno < dropfrom || drand48() >= dropin) {
238 if(utcp_recv(u, buf, len) == -1)
239 debug("Error receiving UTCP packet: %s\n", strerror(errno));
241 debug("Dropped incoming packet\n");
245 timeout = utcp_timeout(u);
252 debug("Total bytes in: %ld, out: %ld\n", total_in, total_out);