2 This file is part of avahi.
4 avahi is free software; you can redistribute it and/or modify it
5 under the terms of the GNU Lesser General Public License as
6 published by the Free Software Foundation; either version 2.1 of the
7 License, or (at your option) any later version.
9 avahi is distributed in the hope that it will be useful, but WITHOUT
10 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
11 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
12 Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with avahi; if not, write to the Free Software
16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
29 #include <avahi-common/malloc.h>
33 #include "iface-linux.h"
36 #include <linux/if_addr.h>
37 #define IFLA_RTA(r) ((struct rtattr*)(((char*)(r)) + NLMSG_ALIGN(sizeof(struct ifinfomsg))))
41 #include <linux/if_addr.h>
42 #define IFA_RTA(r) ((struct rtattr*)(((char*)(r)) + NLMSG_ALIGN(sizeof(struct ifaddrmsg))))
45 static int netlink_list_items(AvahiNetlink *nl, uint16_t type, unsigned *ret_seq) {
50 /* Issue a wild dump NETLINK request */
52 memset(&req, 0, sizeof(req));
53 n = (struct nlmsghdr*) req;
54 n->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtgenmsg));
56 n->nlmsg_flags = NLM_F_ROOT|NLM_F_REQUEST;
60 memset(gen, 0, sizeof(struct rtgenmsg));
61 gen->rtgen_family = AF_UNSPEC;
63 return avahi_netlink_send(nl, n, ret_seq);
66 static void netlink_callback(AvahiNetlink *nl, struct nlmsghdr *n, void* userdata) {
67 AvahiInterfaceMonitor *m = userdata;
69 /* This routine is called for every RTNETLINK response packet */
73 assert(m->osdep.netlink == nl);
75 if (n->nlmsg_type == RTM_NEWLINK) {
77 /* A new interface appeared or an existing one has been modified */
79 struct ifinfomsg *ifinfomsg = NLMSG_DATA(n);
81 struct rtattr *a = NULL;
84 /* A (superfluous?) sanity check */
85 if (ifinfomsg->ifi_family != AF_UNSPEC)
88 /* Check whether there already is an AvahiHwInterface object
89 * for this link, so that we can update its data. Note that
90 * Netlink sends us an RTM_NEWLINK not only when a new
91 * interface appears, but when it changes, too */
93 if (!(hw = avahi_interface_monitor_get_hw_interface(m, ifinfomsg->ifi_index)))
95 /* No object found, so let's create a new
96 * one. avahi_hw_interface_new() will call
97 * avahi_interface_new() internally twice for IPv4 and
98 * IPv6, so there is no need for us to do that
100 if (!(hw = avahi_hw_interface_new(m, (AvahiIfIndex) ifinfomsg->ifi_index)))
103 /* Check whether the flags of this interface are OK for us */
105 (ifinfomsg->ifi_flags & IFF_UP) &&
106 (!m->server->config.use_iff_running || (ifinfomsg->ifi_flags & IFF_RUNNING)) &&
107 !(ifinfomsg->ifi_flags & IFF_LOOPBACK) &&
108 (ifinfomsg->ifi_flags & IFF_MULTICAST) &&
109 (m->server->config.allow_point_to_point || !(ifinfomsg->ifi_flags & IFF_POINTOPOINT));
111 /* Handle interface attributes */
112 l = NLMSG_PAYLOAD(n, sizeof(struct ifinfomsg));
113 a = IFLA_RTA(ifinfomsg);
115 while (RTA_OK(a, l)) {
116 switch(a->rta_type) {
119 /* Fill in interface name */
120 avahi_free(hw->name);
121 hw->name = avahi_strndup(RTA_DATA(a), RTA_PAYLOAD(a));
127 assert(RTA_PAYLOAD(a) == sizeof(unsigned int));
128 hw->mtu = *((unsigned int*) RTA_DATA(a));
133 /* Fill in hardware (MAC) address */
134 hw->mac_address_size = RTA_PAYLOAD(a);
135 if (hw->mac_address_size > AVAHI_MAC_ADDRESS_MAX)
136 hw->mac_address_size = AVAHI_MAC_ADDRESS_MAX;
138 memcpy(hw->mac_address, RTA_DATA(a), hw->mac_address_size);
148 /* Check whether this interface is now "relevant" for us. If
149 * it is Avahi will start to announce its records on this
150 * interface and send out queries for subscribed records on
152 avahi_hw_interface_check_relevant(hw);
154 /* Update any associated RRs of this interface. (i.e. the
155 * _workstation._tcp record containing the MAC address) */
156 avahi_hw_interface_update_rrs(hw, 0);
158 } else if (n->nlmsg_type == RTM_DELLINK) {
160 /* An interface has been removed */
162 struct ifinfomsg *ifinfomsg = NLMSG_DATA(n);
163 AvahiHwInterface *hw;
165 /* A (superfluous?) sanity check */
166 if (ifinfomsg->ifi_family != AF_UNSPEC)
169 /* Get a reference to our AvahiHwInterface object of this interface */
170 if (!(hw = avahi_interface_monitor_get_hw_interface(m, (AvahiIfIndex) ifinfomsg->ifi_index)))
173 /* Free our object */
174 avahi_hw_interface_free(hw, 0);
176 } else if (n->nlmsg_type == RTM_NEWADDR || n->nlmsg_type == RTM_DELADDR) {
178 /* An address has been added, modified or removed */
180 struct ifaddrmsg *ifaddrmsg = NLMSG_DATA(n);
182 struct rtattr *a = NULL;
187 /* We are only interested in IPv4 and IPv6 */
188 if (ifaddrmsg->ifa_family != AF_INET && ifaddrmsg->ifa_family != AF_INET6)
191 /* Try to get a reference to our AvahiInterface object for the
192 * interface this address is assigned to. If ther is no object
193 * for this interface, we ignore this address. */
194 if (!(i = avahi_interface_monitor_get_interface(m, (AvahiIfIndex) ifaddrmsg->ifa_index, avahi_af_to_proto(ifaddrmsg->ifa_family))))
197 /* Fill in address family for our new address */
198 raddr.proto = avahi_af_to_proto(ifaddrmsg->ifa_family);
200 l = NLMSG_PAYLOAD(n, sizeof(struct ifaddrmsg));
201 a = IFA_RTA(ifaddrmsg);
203 while (RTA_OK(a, l)) {
205 switch(a->rta_type) {
207 /* Fill in address data */
209 if ((raddr.proto == AVAHI_PROTO_INET6 && RTA_PAYLOAD(a) != 16) ||
210 (raddr.proto == AVAHI_PROTO_INET && RTA_PAYLOAD(a) != 4))
213 memcpy(raddr.data.data, RTA_DATA(a), RTA_PAYLOAD(a));
225 /* If there was no adress attached to this message, let's quit. */
229 if (n->nlmsg_type == RTM_NEWADDR) {
230 AvahiInterfaceAddress *addr;
232 /* This address is new or has been modified, so let's get an object for it */
233 if (!(addr = avahi_interface_monitor_get_address(m, i, &raddr)))
235 /* Mmm, no object existing yet, so let's create a new one */
236 if (!(addr = avahi_interface_address_new(m, i, &raddr, ifaddrmsg->ifa_prefixlen)))
239 /* Update the scope field for the address */
240 addr->global_scope = ifaddrmsg->ifa_scope == RT_SCOPE_UNIVERSE || ifaddrmsg->ifa_scope == RT_SCOPE_SITE;
242 AvahiInterfaceAddress *addr;
243 assert(n->nlmsg_type == RTM_DELADDR);
245 /* Try to get a reference to our AvahiInterfaceAddress object for this address */
246 if (!(addr = avahi_interface_monitor_get_address(m, i, &raddr)))
250 avahi_interface_address_free(addr);
253 /* Avahi only considers interfaces with at least one address
254 * attached relevant. Since we migh have added or removed an
255 * address, let's have it check again whether the interface is
257 avahi_interface_check_relevant(i);
259 /* Update any associated RRs, like A or AAAA for our new/removed address */
260 avahi_interface_update_rrs(i, 0);
262 } else if (n->nlmsg_type == NLMSG_DONE) {
264 /* This wild dump request ended, so let's see what we do next */
266 if (m->osdep.list == LIST_IFACE) {
268 /* Mmmm, interfaces have been wild dumped already, so
269 * let's go on with wild dumping the addresses */
271 if (netlink_list_items(m->osdep.netlink, RTM_GETADDR, &m->osdep.query_addr_seq) < 0) {
272 avahi_log_warn("NETLINK: Failed to list addrs: %s", strerror(errno));
273 m->osdep.list = LIST_DONE;
276 /* Update state information */
277 m->osdep.list = LIST_ADDR;
280 /* We're done. Tell avahi_interface_monitor_sync() to finish. */
281 m->osdep.list = LIST_DONE;
283 if (m->osdep.list == LIST_DONE) {
285 /* Only after this boolean variable has been set, Avahi
286 * will start to announce or browse on all interfaces. It
287 * is originaly set to 0, which means that relevancy
288 * checks and RR updates are disabled during the wild
290 m->list_complete = 1;
292 /* So let's check if any interfaces are relevant now */
293 avahi_interface_monitor_check_relevant(m);
295 /* And update all RRs attached to any interface */
296 avahi_interface_monitor_update_rrs(m, 0);
298 /* Tell the user that the wild dump is complete */
299 avahi_log_info("Network interface enumeration completed.");
302 } else if (n->nlmsg_type == NLMSG_ERROR &&
303 (n->nlmsg_seq == m->osdep.query_link_seq || n->nlmsg_seq == m->osdep.query_addr_seq)) {
304 struct nlmsgerr *e = NLMSG_DATA (n);
306 /* Some kind of error happened. Let's just tell the user and
307 * ignore it otherwise */
310 avahi_log_warn("NETLINK: Failed to browse: %s", strerror(-e->error));
314 int avahi_interface_monitor_init_osdep(AvahiInterfaceMonitor *m) {
317 /* Initialize our own data */
319 m->osdep.netlink = NULL;
320 m->osdep.query_addr_seq = m->osdep.query_link_seq = 0;
322 /* Create a netlink object for us. It abstracts some things and
323 * makes netlink easier to use. It will attach to the main loop
324 * for us and call netlink_callback() whenever an event
326 if (!(m->osdep.netlink = avahi_netlink_new(m->server->poll_api, RTMGRP_LINK|RTMGRP_IPV4_IFADDR|RTMGRP_IPV6_IFADDR, netlink_callback, m)))
329 /* Set the initial state. */
330 m->osdep.list = LIST_IFACE;
332 /* Start the wild dump for the interfaces */
333 if (netlink_list_items(m->osdep.netlink, RTM_GETLINK, &m->osdep.query_link_seq) < 0)
340 if (m->osdep.netlink) {
341 avahi_netlink_free(m->osdep.netlink);
342 m->osdep.netlink = NULL;
348 void avahi_interface_monitor_free_osdep(AvahiInterfaceMonitor *m) {
351 if (m->osdep.netlink) {
352 avahi_netlink_free(m->osdep.netlink);
353 m->osdep.netlink = NULL;
357 void avahi_interface_monitor_sync(AvahiInterfaceMonitor *m) {
360 /* Let's handle netlink events until we are done with wild
363 while (!m->list_complete)
364 if (!avahi_netlink_work(m->osdep.netlink, 1) == 0)
367 /* At this point Avahi knows about all local interfaces and
368 * addresses in existance. */