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-rw-r--r--llmnr.c130
-rw-r--r--llmnr.h3
-rw-r--r--llmnrd.c11
-rw-r--r--socket.c23
-rw-r--r--util.h9
5 files changed, 121 insertions, 55 deletions
diff --git a/llmnr.c b/llmnr.c
index 01f25d9..f08c5d1 100644
--- a/llmnr.c
+++ b/llmnr.c
@@ -16,6 +16,7 @@
* along with llmnrd. If not, see <http://www.gnu.org/licenses/>.
*/
+#define _GNU_SOURCE
#include <ctype.h>
#include <errno.h>
#include <stdbool.h>
@@ -36,8 +37,8 @@
#include "llmnr-packet.h"
#include "llmnr.h"
-static int llmnr_sock = -1;
-static int llmnr_sock_v6 = -1;
+static int llmnr_sock_ipv4 = -1;
+static int llmnr_sock_ipv6 = -1;
static bool llmnr_running = true;
/*
* Host name in DNS name format (length octet + name + 0 byte)
@@ -48,10 +49,10 @@ static void llmnr_iface_event_handle(enum iface_event_type type, int af, unsigne
{
switch (af) {
case AF_INET:
- socket_mcast_group_ipv4(llmnr_sock, ifindex, type == IFACE_ADD);
+ socket_mcast_group_ipv4(llmnr_sock_ipv4, ifindex, type == IFACE_ADD);
break;
case AF_INET6:
- socket_mcast_group_ipv6(llmnr_sock_v6, ifindex, type == IFACE_ADD);
+ socket_mcast_group_ipv6(llmnr_sock_ipv6, ifindex, type == IFACE_ADD);
break;
default:
/* ignore */
@@ -59,17 +60,23 @@ static void llmnr_iface_event_handle(enum iface_event_type type, int af, unsigne
}
}
-int llmnr_init(const char *hostname, uint16_t port)
+int llmnr_init(const char *hostname, uint16_t port, bool ipv6)
{
llmnr_hostname[0] = strlen(hostname);
strncpy(&llmnr_hostname[1], hostname, LLMNR_LABEL_MAX_SIZE);
llmnr_hostname[LLMNR_LABEL_MAX_SIZE + 1] = '\0';
log_info("Starting llmnrd on port %u, hostname %s\n", port, hostname);
- llmnr_sock = socket_open_ipv4(port);
- if (llmnr_sock < 0)
+ llmnr_sock_ipv4 = socket_open_ipv4(port);
+ if (llmnr_sock_ipv4 < 0)
return -1;
+ if (ipv6) {
+ llmnr_sock_ipv6 = socket_open_ipv6(port);
+ if (llmnr_sock_ipv6 < 0)
+ return -1;
+ }
+
iface_register_event_handler(&llmnr_iface_event_handle);
return 0;
@@ -94,7 +101,7 @@ static bool llmnr_name_matches(const uint8_t *query)
static void llmnr_respond(unsigned int ifindex, const struct llmnr_hdr *hdr,
const uint8_t *query, size_t query_len, int sock,
- const struct sockaddr *sa)
+ const struct sockaddr_storage *sst)
{
uint16_t qtype, qclass;
uint8_t name_len = query[0];
@@ -196,14 +203,14 @@ static void llmnr_respond(unsigned int ifindex, const struct llmnr_hdr *hdr,
memcpy(pkt_put(p, addr_size), addr, addr_size);
}
- if (sendto(sock, p->data, pkt_len(p), 0, sa, sizeof(struct sockaddr_in)) < 0)
+ if (sendto(sock, p->data, pkt_len(p), 0, (struct sockaddr *)sst, sizeof(*sst)) < 0)
log_err("Failed to send response: %s\n", strerror(errno));
pkt_free(p);
}
static void llmnr_packet_process(unsigned int ifindex, const uint8_t *pktbuf, size_t len,
- int sock, const struct sockaddr *sa)
+ int sock, const struct sockaddr_storage *sst)
{
const struct llmnr_hdr *hdr = (const struct llmnr_hdr *)pktbuf;
uint16_t flags, qdcount;
@@ -232,7 +239,51 @@ static void llmnr_packet_process(unsigned int ifindex, const uint8_t *pktbuf, si
/* Authoritative? */
if (llmnr_name_matches(query))
- llmnr_respond(ifindex, hdr, query, query_len, sock, sa);
+ llmnr_respond(ifindex, hdr, query, query_len, sock, sst);
+}
+
+static void llmnr_recv(int sock)
+{
+ uint8_t pktbuf[2048], aux[128];
+ struct msghdr msg;
+ struct iovec io;
+ struct sockaddr_storage sin_r;
+ struct cmsghdr *cmsg;
+ ssize_t recvlen;
+ int ifindex = -1;
+
+ io.iov_base = pktbuf;
+ io.iov_len = sizeof(pktbuf);
+
+ memset(&msg, 0, sizeof(msg));
+ msg.msg_name = &sin_r;
+ msg.msg_namelen = sizeof(sin_r);
+ msg.msg_iov = &io;
+ msg.msg_iovlen = 1;
+ msg.msg_control = aux;
+ msg.msg_controllen = sizeof(aux);
+
+ if ((recvlen = recvmsg(sock, &msg, 0)) < 0) {
+ if (errno != EINTR)
+ log_err("Failed to receive packet: %s\n", strerror(errno));
+ return;
+ }
+
+ for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+ if (cmsg->cmsg_level == IPPROTO_IP && cmsg->cmsg_type == IP_PKTINFO) {
+ struct in_pktinfo *in = (struct in_pktinfo *)CMSG_DATA(cmsg);
+ ifindex = in->ipi_ifindex;
+ } else if (cmsg->cmsg_level == IPPROTO_IPV6 && cmsg->cmsg_type == IPV6_PKTINFO) {
+ struct in6_pktinfo *in6 = (struct in6_pktinfo *)CMSG_DATA(cmsg);
+ ifindex = in6->ipi6_ifindex;
+ }
+ }
+
+ if (ifindex >= 0)
+ llmnr_packet_process(ifindex, pktbuf, recvlen, sock,
+ (const struct sockaddr_storage *)&sin_r);
+ else
+ log_warn("Could not get interface of incoming packet\n");
}
int llmnr_run(void)
@@ -240,44 +291,39 @@ int llmnr_run(void)
int ret = -1;
while (llmnr_running) {
- uint8_t pktbuf[2048], aux[128];
- struct msghdr msg;
- struct iovec io;
- struct sockaddr_in saddr_r;
- struct cmsghdr *cmsg;
- ssize_t recvlen;
- unsigned int ifindex = 0;
-
- io.iov_base = pktbuf;
- io.iov_len = sizeof(pktbuf);
-
- memset(&msg, 0, sizeof(msg));
- msg.msg_name = &saddr_r;
- msg.msg_namelen = sizeof(saddr_r);
- msg.msg_iov = &io;
- msg.msg_iovlen = 1;
- msg.msg_control = aux;
- msg.msg_controllen = sizeof(aux);
-
- if ((recvlen = recvmsg(llmnr_sock, &msg, 0)) < 0) {
+ fd_set rfds;
+ struct timeval tv;
+ int nfds, ret;
+
+ FD_ZERO(&rfds);
+ FD_SET(llmnr_sock_ipv4, &rfds);
+ if (llmnr_sock_ipv6 >= 0) {
+ FD_SET(llmnr_sock_ipv6, &rfds);
+ nfds = max(llmnr_sock_ipv4, llmnr_sock_ipv6) + 1;
+ } else
+ nfds = llmnr_sock_ipv4 + 1;
+
+ tv.tv_sec = 0;
+ tv.tv_usec = 200;
+
+ ret = select(nfds, &rfds, NULL, NULL, &tv);
+ if (ret < 0) {
if (errno != EINTR)
- log_err("Failed to receive packet: %s\n", strerror(errno));
+ log_err("Failed to select() on socket: %s\n", strerror(errno));
goto out;
+ } else if (ret) {
+ if (FD_ISSET(llmnr_sock_ipv4, &rfds))
+ llmnr_recv(llmnr_sock_ipv4);
+ if (llmnr_sock_ipv6 >= 0 && FD_ISSET(llmnr_sock_ipv6, &rfds))
+ llmnr_recv(llmnr_sock_ipv6);
}
-
- for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
- if (cmsg->cmsg_level == IPPROTO_IP && cmsg->cmsg_type == IP_PKTINFO) {
- struct in_pktinfo *info = (struct in_pktinfo *)CMSG_DATA(cmsg);
- ifindex = info->ipi_ifindex;
- }
- }
-
- llmnr_packet_process(ifindex, pktbuf, recvlen, llmnr_sock, (const struct sockaddr *)&saddr_r);
}
ret = 0;
out:
- close(llmnr_sock);
+ close(llmnr_sock_ipv4);
+ if (llmnr_sock_ipv6 >= 0)
+ close(llmnr_sock_ipv6);
return ret;
}
diff --git a/llmnr.h b/llmnr.h
index cc515f1..da86440 100644
--- a/llmnr.h
+++ b/llmnr.h
@@ -19,9 +19,10 @@
#ifndef LLMNR_H
#define LLMNR_H
+#include <stdbool.h>
#include <stdint.h>
-int llmnr_init(const char *hostname, uint16_t port);
+int llmnr_init(const char *hostname, uint16_t port, bool ipv6);
int llmnr_run(void);
void llmnr_stop(void);
diff --git a/llmnrd.c b/llmnrd.c
index 4da5c4e..fb56b30 100644
--- a/llmnrd.c
+++ b/llmnrd.c
@@ -38,10 +38,11 @@
#include "llmnr.h"
#include "llmnr-packet.h"
-static const char *short_opts = "H:p:dhV";
+static const char *short_opts = "H:p:6dhV";
static const struct option long_opts[] = {
{ "hostname", required_argument, NULL, 'H' },
{ "port", required_argument, NULL, 'p' },
+ { "ipv6", no_argument, NULL, '6' },
{ "daemonize", no_argument, NULL, 'd' },
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, 'V' },
@@ -54,6 +55,7 @@ static void __noreturn usage_and_exit(int status)
"Options:\n"
" -H, --hostname NAME set hostname to respond with (default: system hostname)\n"
" -p, --port NUM set port number to listen on (default: %d)\n"
+ " -6, --ipv6 enable LLMNR name resolution over IPv6\n"
" -d, --daemonize run as daemon in the background\n"
" -h, --help show this help and exit\n"
" -V, --version show version information and exit\n",
@@ -107,7 +109,7 @@ int main(int argc, char **argv)
{
int c, ret = EXIT_FAILURE;
long num_arg;
- bool daemonize = false;
+ bool daemonize = false, ipv6 = false;
char *hostname = NULL;
uint16_t port = LLMNR_UDP_PORT;
@@ -126,6 +128,9 @@ int main(int argc, char **argv)
return EXIT_FAILURE;
}
port = num_arg;
+ case '6':
+ ipv6 = true;
+ break;
case 'V':
version_and_exit();
case 'h':
@@ -156,7 +161,7 @@ int main(int argc, char **argv)
}
}
- if (llmnr_init(hostname, port) < 0)
+ if (llmnr_init(hostname, port, ipv6) < 0)
goto out;
if (iface_start_thread() < 0)
diff --git a/socket.c b/socket.c
index 2e2b28e..6e9b035 100644
--- a/socket.c
+++ b/socket.c
@@ -88,7 +88,13 @@ int socket_open_ipv6(uint16_t port)
opt_pktinfo = IPV6_PKTINFO;
#endif
if (setsockopt(sock, IPPROTO_IPV6, opt_pktinfo, &YES, sizeof(YES)) < 0) {
- log_err("Failed to set IPv4 packet info socket option: %s\n", strerror(errno));
+ log_err("Failed to set IPv6 packet info socket option: %s\n", strerror(errno));
+ goto err;
+ }
+
+ /* IPv6 only socket */
+ if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &YES, sizeof(YES)) < 0) {
+ log_err("Failed to set IPv6 only socket option: %s\n", strerror(errno));
goto err;
}
@@ -156,7 +162,7 @@ int socket_mcast_group_ipv4(int sock, unsigned int ifindex, bool join)
if (setsockopt(sock, IPPROTO_IP, join ? IP_ADD_MEMBERSHIP : IP_DROP_MEMBERSHIP,
&mreq, sizeof(mreq)) < 0) {
- log_err("Failed to join multicast group on interface %s: %s\n",
+ log_err("Failed to join IPv4 multicast group on interface %s: %s\n",
if_indextoname(ifindex, ifname), strerror(errno));
return -1;
}
@@ -166,19 +172,20 @@ int socket_mcast_group_ipv4(int sock, unsigned int ifindex, bool join)
int socket_mcast_group_ipv6(int sock, unsigned int ifindex, bool join)
{
- struct ipv6_mreq mreq;
+ struct ipv6_mreq mreq6;
char ifname[IF_NAMESIZE];
/* silently ignore, we might not be listening on an IPv6 socket */
if (sock < 0)
return -1;
- memset(&mreq, 0, sizeof(mreq));
- inet_pton(AF_INET6, LLMNR_IPV6_MCAST_ADDR, &mreq.ipv6mr_multiaddr);
+ memset(&mreq6, 0, sizeof(mreq6));
+ mreq6.ipv6mr_interface = ifindex;
+ inet_pton(AF_INET6, LLMNR_IPV6_MCAST_ADDR, &mreq6.ipv6mr_multiaddr);
- if (setsockopt(sock, IPPROTO_IP, join ? IP_ADD_MEMBERSHIP : IP_DROP_MEMBERSHIP,
- &mreq, sizeof(mreq)) < 0) {
- log_err("Failed to join multicast group on interface %s: %s\n",
+ if (setsockopt(sock, IPPROTO_IPV6, join ? IPV6_ADD_MEMBERSHIP : IPV6_DROP_MEMBERSHIP,
+ &mreq6, sizeof(mreq6)) < 0) {
+ log_err("Failed to join IPv6 multicast group on interface %s: %s\n",
if_indextoname(ifindex, ifname), strerror(errno));
return -1;
}
diff --git a/util.h b/util.h
index 13a8637..d4933c4 100644
--- a/util.h
+++ b/util.h
@@ -30,7 +30,7 @@
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
/*
- * min() macro with strict type-checking.
+ * min()/max() macros with strict type-checking.
* Taken from linux/kernel.h
*/
#undef min
@@ -40,6 +40,13 @@
(void) (&_min1 == &_min2); \
_min1 < _min2 ? _min1 : _min2; })
+#undef max
+#define max(x, y) ({ \
+ typeof(x) _max1 = (x); \
+ typeof(y) _max2 = (y); \
+ (void) (&_max1 == &_max2); \
+ _max1 > _max2 ? _max1 : _max2; })
+
static inline void __noreturn panic(const char *fmt, ...)
{
va_list vl;
generated by cgit v1.2.3-54-g00ecf (git 2.39.0) at 2024-11-22 17:06:30 +0000