1 #include <sys/types.h> 2 #include <sys/socket.h> 3 #include <netinet/in.h> 4 #include <arpa/inet.h> 5 #include <errno.h> 6 #include <string.h> 7 #include <stdlib.h> 8 #include <unistd.h> 9 #include <stdio.h> 10 #include <netdb.h> 11 12 #define MAXBUFSIZ 8096 13 14 static int errors; 15 16 int main(int argc, char *argv[]) 17 { 18 int s; 19 struct in_addr gimr; 20 struct ip_mreq simr; 21 22 unsigned i1, i2, i3, i4; 23 struct hostent *hp, *gethostbyname(); 24 25 char sintf[20], gintf[20]; 26 unsigned char ttl; 27 char loop = 0; 28 unsigned int len = 0; 29 30 if (argc != 2) { 31 fprintf(stderr, 32 "usage: %s interface_name (or i.i.i.i)\n", argv[0]); 33 exit(1); 34 } 35 s = socket(AF_INET, SOCK_DGRAM, 0); 36 if (s == -1) { 37 perror("Error: can't open socket"); 38 exit(1); 39 } 40 41 printf("agrv sub 1 is %s\n", argv[1]); 42 hp = gethostbyname(argv[1]); 43 if (hp) 44 memcpy(&simr.imr_interface.s_addr, hp->h_addr, hp->h_length); 45 else if (sscanf(argv[1], "%u.%u.%u.%u", &i1, &i2, &i3, &i4) != 4) { 46 fprintf(stderr, "Bad interface address\n"); 47 exit(1); 48 } else 49 simr.imr_interface.s_addr = 50 htonl((i1 << 24) | (i2 << 16) | (i3 << 8) | i4); 51 strcpy(sintf, inet_ntoa(simr.imr_interface)); 52 53 /* verify socket options */ 54 if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF, 55 &simr.imr_interface.s_addr, 56 sizeof(simr.imr_interface.s_addr)) != 0) { 57 perror("Error: Setting IP_MULTICAST_IF"); 58 errors++; 59 } else 60 printf("Set interface: %s for multicasting\n", sintf); 61 62 len = sizeof(gimr); 63 if (getsockopt 64 (s, IPPROTO_IP, IP_MULTICAST_IF, &gimr, (socklen_t *)&len) != 0) { 65 perror("Getting IP_MULTICAST_IF"); 66 errors++; 67 } else { 68 strcpy(gintf, inet_ntoa(gimr)); 69 printf("Got multicasting socket interface: %s\n", gintf); 70 } 71 72 /* Verify that the multicastion for the interface was set */ 73 if (strcmp(sintf, gintf) != 0) { 74 printf("Error: IP_MULTICAST_IF was not set\n"); 75 errors++; 76 } else 77 printf 78 ("Socket has been set for multicasting on interface: %s\n", 79 sintf); 80 81 len = sizeof(ttl); 82 if (getsockopt 83 (s, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, (socklen_t *)&len) != 0) { 84 perror("Error: Gettting IP_MULTICAST_TTL"); 85 errors++; 86 } else 87 printf("getsockopt: got ttl = %i\n", ttl); 88 if (ttl != 1) 89 printf("Error: IP_MULTICAST_TTL not default value, ttl = %i\n", 90 ttl); 91 ttl = 10; /* Set ttl to 10 */ 92 len = sizeof(ttl); 93 if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL, 94 &ttl, sizeof(ttl)) != 0) { 95 perror("Error: Setting IP_MULTICAST_TTL"); 96 errors++; 97 } else 98 printf("TTL set on multicast socket\n"); 99 if (getsockopt 100 (s, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, (socklen_t *)&len) != 0) { 101 perror("Error: Getting IP_MULTICAST_TTL"); 102 errors++; 103 } 104 if (ttl != 10) { 105 printf("Error: IP_MULTICAST_TTL not set, ttl = %i\n", ttl); 106 errors++; 107 } 108 109 len = sizeof(loop); 110 if (getsockopt 111 (s, IPPROTO_IP, IP_MULTICAST_LOOP, &loop, 112 (socklen_t *)&len) != 0) { 113 perror("Error: Getting IP_MULTICAST_LOOP"); 114 errors++; 115 } else 116 printf("Got loopback setting\n"); 117 if (loop != 1) { 118 printf("Error: IP_MULTICAST_LOOP not enabled, loop = %i\n", 119 loop); 120 errors++; 121 } else 122 printf("IP_MULTICAST_LOOP is enabled\n"); 123 124 loop = 0; /* Disable IP_MULTICAST_LOOP */ 125 if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_LOOP, &loop, sizeof(char)) != 126 0) { 127 errors++; 128 perror("Error: Setting IP_MULTICAST_LOOP"); 129 } else 130 printf("Multicast loopback disabled\n"); 131 if (getsockopt 132 (s, IPPROTO_IP, IP_MULTICAST_LOOP, &loop, 133 (socklen_t *)&len) != 0) { 134 perror("Error: Getting IP_MULTICAST_LOOP"); 135 errors++; 136 } else 137 printf("Got multicast loopback value\n"); 138 if (loop != 0) { 139 printf("Error: IP_MULTICAST_LOOP not disabled, loop = %i\n", 140 loop); 141 errors++; 142 } else 143 printf("IP_MULTICAST_LOOP disabled\n"); 144 145 close(s); 146 if (errors) 147 exit(1); 148 exit(0); 149 } 150
