The combination of gethostname and getnameinfo does not seem to work very well to find an IP address for a system that doesn't seem have a host name, or for one that has IPv6 configured in the kernel without actually using it.
Switch to a simple loop over getifaddrs which works reliably everywhere. Signed-off-by: Christoph Hellwig <[email protected]> diff --git a/lib/net.c b/lib/net.c index db952dd..bebc108 100644 --- a/lib/net.c +++ b/lib/net.c @@ -16,6 +16,8 @@ #include <string.h> #include <unistd.h> #include <arpa/inet.h> +#include <ifaddrs.h> +#include <net/if.h> #include <netinet/in.h> #include <netinet/tcp.h> #include <sys/epoll.h> @@ -443,54 +445,43 @@ int set_timeout(int fd) int get_local_addr(uint8_t *bytes) { - int ret; - char name[INET6_ADDRSTRLEN]; - struct addrinfo hints, *res, *res0; - - gethostname(name, sizeof(name)); + struct ifaddrs *ifaddr, *ifa; + int ret = 0; - memset(&hints, 0, sizeof(hints)); + if (getifaddrs(&ifaddr) == -1) { + eprintf("getifaddrs failed: %m\n"); + return -1; + } - hints.ai_family = AF_INET; - hints.ai_socktype = SOCK_STREAM; - ret = getaddrinfo(name, NULL, &hints, &res0); - if (ret) - exit(1); - for (res = res0; res; res = res->ai_next) { - if (res->ai_family == AF_INET) { - struct sockaddr_in *addr; - addr = (struct sockaddr_in *)res->ai_addr; + for (ifa = ifaddr; ifa; ifa = ifa->ifa_next) { + struct sockaddr_in *sin; + struct sockaddr_in6 *sin6; - if (((char *) &addr->sin_addr)[0] == 127) - continue; + if (ifa->ifa_flags & IFF_LOOPBACK) + continue; + if (!ifa->ifa_addr) + continue; + switch (ifa->ifa_addr->sa_family) { + case AF_INET: + sin = (struct sockaddr_in *)ifa->ifa_addr; memset(bytes, 0, 12); - memcpy(bytes + 12, &addr->sin_addr, 4); - break; - } else if (res->ai_family == AF_INET6) { - struct sockaddr_in6 *addr; - uint8_t localhost[16] = { 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 1 }; - - addr = (struct sockaddr_in6 *)res->ai_addr; - - if (memcmp(&addr->sin6_addr, localhost, 16) == 0) - continue; - - memcpy(bytes, &addr->sin6_addr, 16); - break; - } else - dprintf("unknown address family\n"); - } - - if (res == NULL) { - eprintf("failed to get address info\n"); - return -1; + memcpy(bytes + 12, &sin->sin_addr, 4); + memcpy(bytes + 12, &sin->sin_addr, 4); + eprintf("found IPv4 address\n"); + goto out; + case AF_INET6: + sin6 = (struct sockaddr_in6 *)ifa->ifa_addr; + memcpy(bytes, &sin6->sin6_addr, 16); + eprintf("found IPv6 address\n"); + goto out; + } } - freeaddrinfo(res0); - - return 0; + eprintf("no valid interface found\n"); + ret = -1; +out: + freeifaddrs(ifaddr); + return ret; } - -- sheepdog mailing list [email protected] http://lists.wpkg.org/mailman/listinfo/sheepdog
