1*73610d44SSepherosa Ziehau #include <sys/types.h>
2*73610d44SSepherosa Ziehau #include <sys/socket.h>
3*73610d44SSepherosa Ziehau #include <sys/time.h>
4*73610d44SSepherosa Ziehau
5*73610d44SSepherosa Ziehau #include <arpa/inet.h>
6*73610d44SSepherosa Ziehau #include <netinet/in.h>
7*73610d44SSepherosa Ziehau
8*73610d44SSepherosa Ziehau #include <err.h>
9*73610d44SSepherosa Ziehau #include <errno.h>
10*73610d44SSepherosa Ziehau #include <signal.h>
11*73610d44SSepherosa Ziehau #include <stdio.h>
12*73610d44SSepherosa Ziehau #include <stdlib.h>
13*73610d44SSepherosa Ziehau #include <string.h>
14*73610d44SSepherosa Ziehau #include <unistd.h>
15*73610d44SSepherosa Ziehau
16*73610d44SSepherosa Ziehau #define READ_BLOCK_TIME 5 /* unit: sec */
17*73610d44SSepherosa Ziehau
18*73610d44SSepherosa Ziehau static void
sig_alarm(int sig __unused)19*73610d44SSepherosa Ziehau sig_alarm(int sig __unused)
20*73610d44SSepherosa Ziehau {
21*73610d44SSepherosa Ziehau #define PANIC_STRING "read blocks\n"
22*73610d44SSepherosa Ziehau
23*73610d44SSepherosa Ziehau write(2, PANIC_STRING, strlen(PANIC_STRING));
24*73610d44SSepherosa Ziehau abort();
25*73610d44SSepherosa Ziehau }
26*73610d44SSepherosa Ziehau
27*73610d44SSepherosa Ziehau static void
usage(const char * cmd)28*73610d44SSepherosa Ziehau usage(const char *cmd)
29*73610d44SSepherosa Ziehau {
30*73610d44SSepherosa Ziehau fprintf(stderr, "%s -p port\n", cmd);
31*73610d44SSepherosa Ziehau exit(1);
32*73610d44SSepherosa Ziehau }
33*73610d44SSepherosa Ziehau
34*73610d44SSepherosa Ziehau int
main(int argc,char * argv[])35*73610d44SSepherosa Ziehau main(int argc, char *argv[])
36*73610d44SSepherosa Ziehau {
37*73610d44SSepherosa Ziehau struct sockaddr_in in;
38*73610d44SSepherosa Ziehau struct itimerval it;
39*73610d44SSepherosa Ziehau int s, n, error, port, opt;
40*73610d44SSepherosa Ziehau char buf;
41*73610d44SSepherosa Ziehau
42*73610d44SSepherosa Ziehau port = 0;
43*73610d44SSepherosa Ziehau while ((opt = getopt(argc, argv, "p:")) != -1) {
44*73610d44SSepherosa Ziehau char *endptr;
45*73610d44SSepherosa Ziehau
46*73610d44SSepherosa Ziehau switch (opt) {
47*73610d44SSepherosa Ziehau case 'p':
48*73610d44SSepherosa Ziehau port = strtol(optarg, &endptr, 0);
49*73610d44SSepherosa Ziehau if (*endptr != '\0')
50*73610d44SSepherosa Ziehau errx(1, "invalid -p argument");
51*73610d44SSepherosa Ziehau break;
52*73610d44SSepherosa Ziehau
53*73610d44SSepherosa Ziehau default:
54*73610d44SSepherosa Ziehau usage(argv[0]);
55*73610d44SSepherosa Ziehau }
56*73610d44SSepherosa Ziehau }
57*73610d44SSepherosa Ziehau if (port <= 0)
58*73610d44SSepherosa Ziehau usage(argv[0]);
59*73610d44SSepherosa Ziehau
60*73610d44SSepherosa Ziehau s = socket(AF_INET, SOCK_DGRAM | SOCK_NONBLOCK, 0);
61*73610d44SSepherosa Ziehau if (s < 0)
62*73610d44SSepherosa Ziehau err(1, "socket failed");
63*73610d44SSepherosa Ziehau
64*73610d44SSepherosa Ziehau memset(&in, 0, sizeof(in));
65*73610d44SSepherosa Ziehau in.sin_family = AF_INET;
66*73610d44SSepherosa Ziehau in.sin_port = htons(port);
67*73610d44SSepherosa Ziehau if (bind(s, (const struct sockaddr *)&in, sizeof(in)) < 0)
68*73610d44SSepherosa Ziehau err(1, "bind %d failed", port);
69*73610d44SSepherosa Ziehau
70*73610d44SSepherosa Ziehau memset(&it, 0, sizeof(it));
71*73610d44SSepherosa Ziehau it.it_value.tv_sec = READ_BLOCK_TIME;
72*73610d44SSepherosa Ziehau if (signal(SIGALRM, sig_alarm) == SIG_ERR)
73*73610d44SSepherosa Ziehau err(1, "signal failed");
74*73610d44SSepherosa Ziehau if (setitimer(ITIMER_REAL, &it, NULL) < 0)
75*73610d44SSepherosa Ziehau err(1, "setitimer failed");
76*73610d44SSepherosa Ziehau
77*73610d44SSepherosa Ziehau n = read(s, &buf, 1);
78*73610d44SSepherosa Ziehau if (n < 0) {
79*73610d44SSepherosa Ziehau error = errno;
80*73610d44SSepherosa Ziehau if (error != EAGAIN) {
81*73610d44SSepherosa Ziehau warnx("invalid errno %d", error);
82*73610d44SSepherosa Ziehau abort();
83*73610d44SSepherosa Ziehau }
84*73610d44SSepherosa Ziehau } else {
85*73610d44SSepherosa Ziehau warnx("read works");
86*73610d44SSepherosa Ziehau abort();
87*73610d44SSepherosa Ziehau }
88*73610d44SSepherosa Ziehau
89*73610d44SSepherosa Ziehau fprintf(stderr, "passed\n");
90*73610d44SSepherosa Ziehau exit(0);
91*73610d44SSepherosa Ziehau }
92