4 This file is part of avahi.
6 avahi is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as
8 published by the Free Software Foundation; either version 2.1 of the
9 License, or (at your option) any later version.
11 avahi is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
14 Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with avahi; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
31 #include <avahi-common/malloc.h>
35 #include "iface-linux.h"
37 static int netlink_list_items(AvahiNetlink *nl, uint16_t type, unsigned *ret_seq) {
42 /* Issue a wild dump NETLINK request */
44 memset(&req, 0, sizeof(req));
45 n = (struct nlmsghdr*) req;
46 n->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtgenmsg));
48 n->nlmsg_flags = NLM_F_ROOT|NLM_F_REQUEST;
52 memset(gen, 0, sizeof(struct rtgenmsg));
53 gen->rtgen_family = AF_UNSPEC;
55 return avahi_netlink_send(nl, n, ret_seq);
58 static void netlink_callback(AvahiNetlink *nl, struct nlmsghdr *n, void* userdata) {
59 AvahiInterfaceMonitor *m = userdata;
61 /* This routine is called for every RTNETLINK response packet */
65 assert(m->osdep.netlink == nl);
67 if (n->nlmsg_type == RTM_NEWLINK) {
69 /* A new interface appeared or an existing one has been modified */
71 struct ifinfomsg *ifinfomsg = NLMSG_DATA(n);
73 struct rtattr *a = NULL;
76 /* A (superfluous?) sanity check */
77 if (ifinfomsg->ifi_family != AF_UNSPEC)
80 /* Check whether there already is an AvahiHwInterface object
81 * for this link, so that we can update its data. Note that
82 * Netlink sends us an RTM_NEWLINK not only when a new
83 * interface appears, but when it changes, too */
85 if (!(hw = avahi_interface_monitor_get_hw_interface(m, ifinfomsg->ifi_index)))
87 /* No object found, so let's create a new
88 * one. avahi_hw_interface_new() will call
89 * avahi_interface_new() internally twice for IPv4 and
90 * IPv6, so there is no need for us to do that
92 if (!(hw = avahi_hw_interface_new(m, (AvahiIfIndex) ifinfomsg->ifi_index)))
95 /* Check whether the flags of this interface are OK for us */
97 (ifinfomsg->ifi_flags & IFF_UP) &&
98 (!m->server->config.use_iff_running || (ifinfomsg->ifi_flags & IFF_RUNNING)) &&
99 !(ifinfomsg->ifi_flags & IFF_LOOPBACK) &&
100 (ifinfomsg->ifi_flags & IFF_MULTICAST) &&
101 (m->server->config.allow_point_to_point || !(ifinfomsg->ifi_flags & IFF_POINTOPOINT));
103 /* Handle interface attributes */
104 l = NLMSG_PAYLOAD(n, sizeof(struct ifinfomsg));
105 a = IFLA_RTA(ifinfomsg);
107 while (RTA_OK(a, l)) {
108 switch(a->rta_type) {
111 /* Fill in interface name */
112 avahi_free(hw->name);
113 hw->name = avahi_strndup(RTA_DATA(a), RTA_PAYLOAD(a));
119 assert(RTA_PAYLOAD(a) == sizeof(unsigned int));
120 hw->mtu = *((unsigned int*) RTA_DATA(a));
125 /* Fill in hardware (MAC) address */
126 hw->mac_address_size = RTA_PAYLOAD(a);
127 if (hw->mac_address_size > AVAHI_MAC_ADDRESS_MAX)
128 hw->mac_address_size = AVAHI_MAC_ADDRESS_MAX;
130 memcpy(hw->mac_address, RTA_DATA(a), hw->mac_address_size);
140 /* Check whether this interface is now "relevant" for us. If
141 * it is Avahi will start to announce its records on this
142 * interface and send out queries for subscribed records on
144 avahi_hw_interface_check_relevant(hw);
146 /* Update any associated RRs of this interface. (i.e. the
147 * _workstation._tcp record containing the MAC address) */
148 avahi_hw_interface_update_rrs(hw, 0);
150 } else if (n->nlmsg_type == RTM_DELLINK) {
152 /* An interface has been removed */
154 struct ifinfomsg *ifinfomsg = NLMSG_DATA(n);
155 AvahiHwInterface *hw;
157 /* A (superfluous?) sanity check */
158 if (ifinfomsg->ifi_family != AF_UNSPEC)
161 /* Get a reference to our AvahiHwInterface object of this interface */
162 if (!(hw = avahi_interface_monitor_get_hw_interface(m, (AvahiIfIndex) ifinfomsg->ifi_index)))
165 /* Free our object */
166 avahi_hw_interface_free(hw, 0);
168 } else if (n->nlmsg_type == RTM_NEWADDR || n->nlmsg_type == RTM_DELADDR) {
170 /* An address has been added, modified or removed */
172 struct ifaddrmsg *ifaddrmsg = NLMSG_DATA(n);
174 struct rtattr *a = NULL;
179 /* We are only interested in IPv4 and IPv6 */
180 if (ifaddrmsg->ifa_family != AF_INET && ifaddrmsg->ifa_family != AF_INET6)
183 /* Try to get a reference to our AvahiInterface object for the
184 * interface this address is assigned to. If ther is no object
185 * for this interface, we ignore this address. */
186 if (!(i = avahi_interface_monitor_get_interface(m, (AvahiIfIndex) ifaddrmsg->ifa_index, avahi_af_to_proto(ifaddrmsg->ifa_family))))
189 /* Fill in address family for our new address */
190 raddr.proto = avahi_af_to_proto(ifaddrmsg->ifa_family);
192 l = NLMSG_PAYLOAD(n, sizeof(struct ifaddrmsg));
193 a = IFA_RTA(ifaddrmsg);
195 while (RTA_OK(a, l)) {
197 switch(a->rta_type) {
199 /* Fill in address data */
201 if ((raddr.proto == AVAHI_PROTO_INET6 && RTA_PAYLOAD(a) != 16) ||
202 (raddr.proto == AVAHI_PROTO_INET && RTA_PAYLOAD(a) != 4))
205 memcpy(raddr.data.data, RTA_DATA(a), RTA_PAYLOAD(a));
217 /* If there was no adress attached to this message, let's quit. */
221 if (n->nlmsg_type == RTM_NEWADDR) {
222 AvahiInterfaceAddress *addr;
224 /* This address is new or has been modified, so let's get an object for it */
225 if (!(addr = avahi_interface_monitor_get_address(m, i, &raddr)))
227 /* Mmm, no object existing yet, so let's create a new one */
228 if (!(addr = avahi_interface_address_new(m, i, &raddr, ifaddrmsg->ifa_prefixlen)))
231 /* Update the scope field for the address */
232 addr->global_scope = ifaddrmsg->ifa_scope == RT_SCOPE_UNIVERSE || ifaddrmsg->ifa_scope == RT_SCOPE_SITE;
234 AvahiInterfaceAddress *addr;
235 assert(n->nlmsg_type == RTM_DELADDR);
237 /* Try to get a reference to our AvahiInterfaceAddress object for this address */
238 if (!(addr = avahi_interface_monitor_get_address(m, i, &raddr)))
242 avahi_interface_address_free(addr);
245 /* Avahi only considers interfaces with at least one address
246 * attached relevant. Since we migh have added or removed an
247 * address, let's have it check again whether the interface is
249 avahi_interface_check_relevant(i);
251 /* Update any associated RRs, like A or AAAA for our new/removed address */
252 avahi_interface_update_rrs(i, 0);
254 } else if (n->nlmsg_type == NLMSG_DONE) {
256 /* This wild dump request ended, so let's see what we do next */
258 if (m->osdep.list == LIST_IFACE) {
260 /* Mmmm, interfaces have been wild dumped already, so
261 * let's go on with wild dumping the addresses */
263 if (netlink_list_items(m->osdep.netlink, RTM_GETADDR, &m->osdep.query_addr_seq) < 0) {
264 avahi_log_warn("NETLINK: Failed to list addrs: %s", strerror(errno));
265 m->osdep.list = LIST_DONE;
268 /* Update state information */
269 m->osdep.list = LIST_ADDR;
272 /* We're done. Tell avahi_interface_monitor_sync() to finish. */
273 m->osdep.list = LIST_DONE;
275 if (m->osdep.list == LIST_DONE) {
277 /* Only after this boolean variable has been set, Avahi
278 * will start to announce or browse on all interfaces. It
279 * is originaly set to 0, which means that relevancy
280 * checks and RR updates are disabled during the wild
282 m->list_complete = 1;
284 /* So let's check if any interfaces are relevant now */
285 avahi_interface_monitor_check_relevant(m);
287 /* And update all RRs attached to any interface */
288 avahi_interface_monitor_update_rrs(m, 0);
290 /* Tell the user that the wild dump is complete */
291 avahi_log_info("Network interface enumeration completed.");
294 } else if (n->nlmsg_type == NLMSG_ERROR &&
295 (n->nlmsg_seq == m->osdep.query_link_seq || n->nlmsg_seq == m->osdep.query_addr_seq)) {
296 struct nlmsgerr *e = NLMSG_DATA (n);
298 /* Some kind of error happened. Let's just tell the user and
299 * ignore it otherwise */
302 avahi_log_warn("NETLINK: Failed to browse: %s", strerror(-e->error));
306 int avahi_interface_monitor_init_osdep(AvahiInterfaceMonitor *m) {
309 /* Initialize our own data */
311 m->osdep.netlink = NULL;
312 m->osdep.query_addr_seq = m->osdep.query_link_seq = 0;
314 /* Create a netlink object for us. It abstracts some things and
315 * makes netlink easier to use. It will attach to the main loop
316 * for us and call netlink_callback() whenever an event
318 if (!(m->osdep.netlink = avahi_netlink_new(m->server->poll_api, RTMGRP_LINK|RTMGRP_IPV4_IFADDR|RTMGRP_IPV6_IFADDR, netlink_callback, m)))
321 /* Set the initial state. */
322 m->osdep.list = LIST_IFACE;
324 /* Start the wild dump for the interfaces */
325 if (netlink_list_items(m->osdep.netlink, RTM_GETLINK, &m->osdep.query_link_seq) < 0)
332 if (m->osdep.netlink) {
333 avahi_netlink_free(m->osdep.netlink);
334 m->osdep.netlink = NULL;
340 void avahi_interface_monitor_free_osdep(AvahiInterfaceMonitor *m) {
343 if (m->osdep.netlink) {
344 avahi_netlink_free(m->osdep.netlink);
345 m->osdep.netlink = NULL;
349 void avahi_interface_monitor_sync(AvahiInterfaceMonitor *m) {
352 /* Let's handle netlink events until we are done with wild
355 while (!m->list_complete)
356 if (!avahi_netlink_work(m->osdep.netlink, 1) == 0)
359 /* At this point Avahi knows about all local interfaces and
360 * addresses in existance. */