1*73610d44SSepherosa Ziehau #include <sys/types.h>
2*73610d44SSepherosa Ziehau #include <sys/socket.h>
3*73610d44SSepherosa Ziehau #include <sys/wait.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 CHECKFD_CMD	"checkfd"
17*73610d44SSepherosa Ziehau #define CHECKFD_PATH	"/usr/local/bin/" CHECKFD_CMD
18*73610d44SSepherosa Ziehau 
19*73610d44SSepherosa Ziehau static void
usage(const char * cmd)20*73610d44SSepherosa Ziehau usage(const char *cmd)
21*73610d44SSepherosa Ziehau {
22*73610d44SSepherosa Ziehau 	fprintf(stderr, "%s -p port\n", cmd);
23*73610d44SSepherosa Ziehau 	exit(1);
24*73610d44SSepherosa Ziehau }
25*73610d44SSepherosa Ziehau 
26*73610d44SSepherosa Ziehau static void
connect_client(int port)27*73610d44SSepherosa Ziehau connect_client(int port)
28*73610d44SSepherosa Ziehau {
29*73610d44SSepherosa Ziehau 	struct sockaddr_in in;
30*73610d44SSepherosa Ziehau 	int s;
31*73610d44SSepherosa Ziehau 
32*73610d44SSepherosa Ziehau 	memset(&in, 0, sizeof(in));
33*73610d44SSepherosa Ziehau 	in.sin_family = AF_INET;
34*73610d44SSepherosa Ziehau 	in.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
35*73610d44SSepherosa Ziehau 	in.sin_port = htons(port);
36*73610d44SSepherosa Ziehau 
37*73610d44SSepherosa Ziehau 	s = socket(AF_INET, SOCK_STREAM, 0);
38*73610d44SSepherosa Ziehau 	if (s < 0)
39*73610d44SSepherosa Ziehau 		err(1, "client socket failed");
40*73610d44SSepherosa Ziehau 	if (connect(s, (const struct sockaddr *)&in, sizeof(in)) < 0)
41*73610d44SSepherosa Ziehau 		err(1, "connect failed");
42*73610d44SSepherosa Ziehau 
43*73610d44SSepherosa Ziehau 	pause();
44*73610d44SSepherosa Ziehau 	exit(0);
45*73610d44SSepherosa Ziehau }
46*73610d44SSepherosa Ziehau 
47*73610d44SSepherosa Ziehau int
main(int argc,char * argv[])48*73610d44SSepherosa Ziehau main(int argc, char *argv[])
49*73610d44SSepherosa Ziehau {
50*73610d44SSepherosa Ziehau 	pid_t pid;
51*73610d44SSepherosa Ziehau 	struct sockaddr_in in;
52*73610d44SSepherosa Ziehau 	int serv_s, s;
53*73610d44SSepherosa Ziehau 	int opt, port, status, ecode, error;
54*73610d44SSepherosa Ziehau 
55*73610d44SSepherosa Ziehau 	port = 0;
56*73610d44SSepherosa Ziehau 	while ((opt = getopt(argc, argv, "p:")) != -1) {
57*73610d44SSepherosa Ziehau 		char *endptr;
58*73610d44SSepherosa Ziehau 
59*73610d44SSepherosa Ziehau 		switch (opt) {
60*73610d44SSepherosa Ziehau 		case 'p':
61*73610d44SSepherosa Ziehau 			port = strtol(optarg, &endptr, 0);
62*73610d44SSepherosa Ziehau 			if (*endptr != '\0')
63*73610d44SSepherosa Ziehau 				errx(1, "invalid -p %s", optarg);
64*73610d44SSepherosa Ziehau 			break;
65*73610d44SSepherosa Ziehau 
66*73610d44SSepherosa Ziehau 		default:
67*73610d44SSepherosa Ziehau 			usage(argv[0]);
68*73610d44SSepherosa Ziehau 		}
69*73610d44SSepherosa Ziehau 	}
70*73610d44SSepherosa Ziehau 	if (port <= 0)
71*73610d44SSepherosa Ziehau 		usage(argv[0]);
72*73610d44SSepherosa Ziehau 
73*73610d44SSepherosa Ziehau 	serv_s = socket(AF_INET, SOCK_STREAM, 0);
74*73610d44SSepherosa Ziehau 	if (serv_s < 0)
75*73610d44SSepherosa Ziehau 		err(1, "socket failed");
76*73610d44SSepherosa Ziehau 
77*73610d44SSepherosa Ziehau 	memset(&in, 0, sizeof(in));
78*73610d44SSepherosa Ziehau 	in.sin_family = AF_INET;
79*73610d44SSepherosa Ziehau 	in.sin_port = htons(port);
80*73610d44SSepherosa Ziehau 	if (bind(serv_s, (const struct sockaddr *)&in, sizeof(in)) < 0)
81*73610d44SSepherosa Ziehau 		err(1, "bind failed");
82*73610d44SSepherosa Ziehau 
83*73610d44SSepherosa Ziehau 	if (listen(serv_s, 0) < 0)
84*73610d44SSepherosa Ziehau 		err(1, "listen failed");
85*73610d44SSepherosa Ziehau 
86*73610d44SSepherosa Ziehau 	pid = fork();
87*73610d44SSepherosa Ziehau 	if (pid < 0) {
88*73610d44SSepherosa Ziehau 		err(1, "fork failed");
89*73610d44SSepherosa Ziehau 	} else if (pid == 0) {
90*73610d44SSepherosa Ziehau 		connect_client(port);
91*73610d44SSepherosa Ziehau 		abort();
92*73610d44SSepherosa Ziehau 		/* NEVER REACHED */
93*73610d44SSepherosa Ziehau 	}
94*73610d44SSepherosa Ziehau 
95*73610d44SSepherosa Ziehau 	s = accept4(serv_s, NULL, NULL, SOCK_CLOEXEC);
96*73610d44SSepherosa Ziehau 	if (s < 0)
97*73610d44SSepherosa Ziehau 		error = errno;
98*73610d44SSepherosa Ziehau 	else
99*73610d44SSepherosa Ziehau 		error = 0;
100*73610d44SSepherosa Ziehau 
101*73610d44SSepherosa Ziehau 	/* Kill connect_client */
102*73610d44SSepherosa Ziehau 	kill(pid, SIGKILL);
103*73610d44SSepherosa Ziehau 	waitpid(pid, &status, 0);
104*73610d44SSepherosa Ziehau 
105*73610d44SSepherosa Ziehau 	if (error)
106*73610d44SSepherosa Ziehau 		errc(1, error, "accept4 failed");
107*73610d44SSepherosa Ziehau 
108*73610d44SSepherosa Ziehau 	pid = fork();
109*73610d44SSepherosa Ziehau 	if (pid < 0) {
110*73610d44SSepherosa Ziehau 		err(1, "fork failed");
111*73610d44SSepherosa Ziehau 	} else if (pid == 0) {
112*73610d44SSepherosa Ziehau 		char fd[8];
113*73610d44SSepherosa Ziehau 
114*73610d44SSepherosa Ziehau 		snprintf(fd, sizeof(fd), "%d", s);
115*73610d44SSepherosa Ziehau 		execl(CHECKFD_PATH, CHECKFD_CMD, fd, NULL);
116*73610d44SSepherosa Ziehau 	}
117*73610d44SSepherosa Ziehau 
118*73610d44SSepherosa Ziehau 	if (waitpid(pid, &status, 0) < 0)
119*73610d44SSepherosa Ziehau 		err(1, "waitpid failed");
120*73610d44SSepherosa Ziehau 	if (!WIFEXITED(status))
121*73610d44SSepherosa Ziehau 		errx(1, "not exited");
122*73610d44SSepherosa Ziehau 	ecode = WEXITSTATUS(status);
123*73610d44SSepherosa Ziehau 	if (ecode != 0) {
124*73610d44SSepherosa Ziehau 		warnx("exit code %d", ecode);
125*73610d44SSepherosa Ziehau 		abort();
126*73610d44SSepherosa Ziehau 	}
127*73610d44SSepherosa Ziehau 
128*73610d44SSepherosa Ziehau 	fprintf(stderr, "passed\n");
129*73610d44SSepherosa Ziehau 	exit(0);
130*73610d44SSepherosa Ziehau }
131