diff options
Diffstat (limited to 'llmnr-query.c')
| -rw-r--r-- | llmnr-query.c | 55 |
1 files changed, 44 insertions, 11 deletions
diff --git a/llmnr-query.c b/llmnr-query.c index a1fac67..cf738e4 100644 --- a/llmnr-query.c +++ b/llmnr-query.c @@ -25,6 +25,7 @@ #include <unistd.h> #include <arpa/inet.h> +#include <net/if.h> #include <sys/select.h> #include <sys/socket.h> #include <sys/time.h> @@ -35,10 +36,11 @@ #include "log.h" #include "pkt.h" -static const char *short_ops = "c:i:p:T:6hV"; +static const char *short_ops = "c:i:I:T:6hV"; static const struct option long_opts[] = { { "count", required_argument, NULL, 'c' }, { "interval", required_argument, NULL, 'i' }, + { "interface", required_argument, NULL, 'I' }, { "type", required_argument, NULL, 'T' }, { "ipv6", no_argument, NULL, '6' }, { "help", no_argument, NULL, 'h' }, @@ -48,14 +50,15 @@ static const struct option long_opts[] = { static void __noreturn usage_and_exit(int status) { - fprintf(stdout, "Usage: llmnr-query [OPTIONS...] <query-name>\n" + fprintf(stdout, "Usage: llmnr-query [OPTIONS...] NAME\n" "Options:\n" - " -c, --count <number> number of queries to send (default: 1)\n" - " -i, --interval <number> interval between queries in ms (default: 500)\n" - " -T, --type <type> set query type; must be one of A, AAAA, ANY (default: A)\n" - " -6, --ipv6 use IPv6\n" - " -h, --help show this help and exit\n" - " -V, --version show version information and exit\n"); + " -c, --count NUM number of queries to send (default: 1)\n" + " -i, --interval NUM interval between queries in ms (default: 500)\n" + " -I, --interface NAME send multicast over specified interface\n" + " -T, --type TYPE set query type; must be one of A, AAAA, ANY (default: A)\n" + " -6, --ipv6 send queries over IPv6\n" + " -h, --help show this help and exit\n" + " -V, --version show version information and exit\n"); exit(status); } @@ -85,7 +88,7 @@ static const char *query_type(uint16_t qtype) int main(int argc, char **argv) { int c, sock; - const char *query_name; + const char *query_name, *iface = NULL; size_t query_name_len; unsigned long i, count = 1, interval = 500; uint16_t qtype = LLMNR_QTYPE_A; @@ -100,6 +103,9 @@ int main(int argc, char **argv) case 'i': interval = strtoul(optarg, NULL, 0); break; + case 'I': + iface = xstrdup(optarg); + break; case 'T': if (xstreq("A", optarg)) qtype = LLMNR_QTYPE_A; @@ -140,6 +146,34 @@ int main(int argc, char **argv) return -1; } + if (iface != NULL) { + unsigned int ifindex = if_nametoindex(iface); + + if (ifindex == 0 && errno != 0) { + log_err("Could not get interface %s: %s\n", iface, strerror(errno)); + goto err; + } + + if (ipv6) { + if (setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_IF, &ifindex, sizeof(ifindex)) < 0) { + log_err("Failed to set interface '%s' for IPv6 multicast socket: %s\n", + iface, strerror(errno)); + goto err; + } + } else { + struct ip_mreqn mreq; + + memset(&mreq, 0, sizeof(mreq)); + mreq.imr_ifindex = ifindex; + + if (setsockopt(sock, IPPROTO_IP, IP_MULTICAST_IF, &mreq, sizeof(mreq)) < 0) { + log_err("Failed to set interface '%s' for IPv4 multicast socket: %s\n", + iface, strerror(errno)); + goto err; + } + } + } + p = pkt_alloc(128); log_info("LLMNR query: %s IN %s\n", query_name, query_type(qtype)); @@ -265,8 +299,7 @@ int main(int argc, char **argv) } pkt_free(p); - +err: close(sock); - return 0; } |