6 #include <sys/socket.h>
12 * Returns the IPv6 address with which you have connectivity at the moment.
15 static void print_ipv6_addr() {
16 static char buf[INET6_ADDRSTRLEN+1];
17 struct addrinfo hints;
18 struct addrinfo *result, *resp;
21 memset(&hints, 0, sizeof(struct addrinfo));
22 hints.ai_family = AF_INET6;
24 /* We resolve the K root server to get a public IPv6 address. You can
25 * replace this with any other host which has an AAAA record, but the
26 * K root server is a pretty safe bet. */
27 if (getaddrinfo("k.root-servers.net", "domain", &hints, &result) != 0) {
28 /* We don’t display the error here because most
29 * likely, there just is no connectivity.
30 * Thus, don’t spam the user’s console. */
35 for (resp = result; resp != NULL; resp = resp->ai_next) {
36 if ((fd = socket(resp->ai_family, SOCK_DGRAM, 0)) == -1) {
41 /* Since the socket was created with SOCK_DGRAM, this is
42 * actually not establishing a connection or generating
43 * any other network traffic. Instead, as a side-effect,
44 * it saves the local address with which packets would
45 * be sent to the destination. */
46 if (connect(fd, resp->ai_addr, resp->ai_addrlen) == -1) {
47 /* We don’t display the error here because most
48 * likely, there just is no IPv6 connectivity.
49 * Thus, don’t spam the user’s console but just
50 * try the next address. */
55 struct sockaddr_storage local;
56 socklen_t local_len = sizeof(struct sockaddr_storage);
57 if (getsockname(fd, (struct sockaddr*)&local, &local_len) == -1) {
58 perror("getsockname()");
66 memset(buf, 0, INET6_ADDRSTRLEN + 1);
68 if ((ret = getnameinfo((struct sockaddr*)&local, local_len,
69 buf, sizeof(buf), NULL, 0,
70 NI_NUMERICHOST)) != 0) {
71 fprintf(stderr, "getnameinfo(): %s\n", gai_strerror(ret));
85 void print_ipv6_info(const char *format) {
88 for (walk = format; *walk != '\0'; walk++) {
94 if (strncmp(walk+1, "ip", strlen("ip")) == 0) {