1 #include <sys/types.h> 2 #include <sys/socket.h> 3 #include <sys/time.h> 4 #include <sys/un.h> 5 #include <sys/wait.h> 6 7 #include <arpa/inet.h> 8 #include <netinet/in.h> 9 10 #include <err.h> 11 #include <errno.h> 12 #include <signal.h> 13 #include <stdio.h> 14 #include <stdlib.h> 15 #include <string.h> 16 #include <unistd.h> 17 18 static void 19 usage(const char *cmd) 20 { 21 fprintf(stderr, "%s -p port\n", cmd); 22 exit(1); 23 } 24 25 static void 26 connect_client(int port, int ctrl_s) 27 { 28 struct sockaddr_in in; 29 int s, dummy; 30 31 s = socket(AF_INET, SOCK_STREAM, 0); 32 if (s < 0) 33 err(1, "client socket failed"); 34 35 memset(&in, 0, sizeof(in)); 36 in.sin_family = AF_INET; 37 in.sin_addr.s_addr = htonl(INADDR_LOOPBACK); 38 in.sin_port = htons(port); 39 if (connect(s, (const struct sockaddr *)&in, sizeof(in)) < 0) 40 err(1, "connect failed"); 41 42 /* connect is done */ 43 write(ctrl_s, &dummy, sizeof(dummy)); 44 45 pause(); 46 exit(0); 47 } 48 49 int 50 main(int argc, char *argv[]) 51 { 52 struct sockaddr_in in; 53 int serv_s, s, ctrl_s[2]; 54 int opt, port, dummy, n, status, panic, ex; 55 pid_t pid; 56 57 ex = 1; 58 panic = 0; 59 60 port = 0; 61 while ((opt = getopt(argc, argv, "p:")) != -1) { 62 char *endptr; 63 64 switch (opt) { 65 case 'p': 66 port = strtol(optarg, &endptr, 0); 67 if (*endptr != '\0') 68 errx(1, "invalid -p"); 69 break; 70 71 default: 72 usage(argv[0]); 73 } 74 } 75 if (port <= 0) 76 usage(argv[0]); 77 78 if (socketpair(AF_UNIX, SOCK_DGRAM, 0, ctrl_s) < 0) 79 err(1, "socketpair failed"); 80 81 serv_s = socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, 0); 82 if (serv_s < 0) 83 err(1, "socket failed"); 84 85 memset(&in, 0, sizeof(in)); 86 in.sin_family = AF_INET; 87 in.sin_port = htons(port); 88 if (bind(serv_s, (const struct sockaddr *)&in, sizeof(in)) < 0) 89 err(1, "bind failed"); 90 91 if (listen(serv_s, 0) < 0) 92 err(1, "listen failed"); 93 94 pid = fork(); 95 if (pid < 0) { 96 err(1, "fork failed"); 97 } else if (pid == 0) { 98 close(ctrl_s[0]); 99 connect_client(port, ctrl_s[1]); 100 abort(); 101 } 102 103 /* Wait for the connect */ 104 read(ctrl_s[0], &dummy, sizeof(dummy)); 105 106 s = accept(serv_s, NULL, NULL); 107 if (s < 0) { 108 warn("accept failed"); 109 goto done; 110 } 111 panic = 1; 112 113 n = read(s, &dummy, sizeof(dummy)); 114 if (n < 0) { 115 int error = errno; 116 117 if (error != EAGAIN) { 118 warnx("invaid errno %d\n", error); 119 goto done; 120 } 121 } else { 122 warnx("read works"); 123 goto done; 124 } 125 126 ex = 0; 127 panic = 0; 128 fprintf(stderr, "passed\n"); 129 done: 130 kill(pid, SIGKILL); 131 waitpid(pid, &status, 0); 132 if (panic) 133 abort(); 134 exit(ex); 135 } 136