2 * Copyright (c) 2009, 2010, 2013, 2015 Nicira, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
19 #include "rtnetlink.h"
21 #include <sys/socket.h>
22 #include <linux/rtnetlink.h>
26 #include "netlink-notifier.h"
29 static struct nln *nln = NULL;
30 static struct rtnetlink_change rtn_change;
32 /* Returns true if the given netlink msg type corresponds to RTNLGRP_LINK. */
34 rtnetlink_type_is_rtnlgrp_link(uint16_t type)
36 return type == RTM_NEWLINK || type == RTM_DELLINK;
39 /* Returns true if the given netlink msg type corresponds to
40 * RTNLGRP_IPV4_IFADDR or RTNLGRP_IPV6_IFADDR. */
42 rtnetlink_type_is_rtnlgrp_addr(uint16_t type)
44 return type == RTM_NEWADDR || type == RTM_DELADDR;
47 /* Parses a rtnetlink message 'buf' into 'change'. If 'buf' is unparseable,
48 * leaves 'change' untouched and returns false. Otherwise, populates 'change'
49 * and returns true. */
51 rtnetlink_parse(struct ofpbuf *buf, struct rtnetlink_change *change)
53 const struct nlmsghdr *nlmsg = buf->data;
56 if (rtnetlink_type_is_rtnlgrp_link(nlmsg->nlmsg_type)) {
57 /* Policy for RTNLGRP_LINK messages.
59 * There are *many* more fields in these messages, but currently we
60 * only care about these fields. */
61 static const struct nl_policy policy[] = {
62 [IFLA_IFNAME] = { .type = NL_A_STRING, .optional = false },
63 [IFLA_MASTER] = { .type = NL_A_U32, .optional = true },
64 [IFLA_MTU] = { .type = NL_A_U32, .optional = true },
65 [IFLA_ADDRESS] = { .type = NL_A_UNSPEC, .optional = true },
68 struct nlattr *attrs[ARRAY_SIZE(policy)];
70 parsed = nl_policy_parse(buf, NLMSG_HDRLEN + sizeof(struct ifinfomsg),
71 policy, attrs, ARRAY_SIZE(policy));
74 const struct ifinfomsg *ifinfo;
76 ifinfo = ofpbuf_at(buf, NLMSG_HDRLEN, sizeof *ifinfo);
78 change->nlmsg_type = nlmsg->nlmsg_type;
79 change->if_index = ifinfo->ifi_index;
80 strncpy(change->ifname, nl_attr_get_string(attrs[IFLA_IFNAME]),
82 change->ifi_flags = ifinfo->ifi_flags;
83 change->master_ifindex = (attrs[IFLA_MASTER]
84 ? nl_attr_get_u32(attrs[IFLA_MASTER])
86 change->mtu = (attrs[IFLA_MTU]
87 ? nl_attr_get_u32(attrs[IFLA_MTU])
90 if (attrs[IFLA_ADDRESS] &&
91 nl_attr_get_size(attrs[IFLA_ADDRESS]) == ETH_ADDR_LEN) {
92 memcpy(&change->mac, nl_attr_get(attrs[IFLA_ADDRESS]),
95 memset(&change->mac, 0, ETH_ADDR_LEN);
98 } else if (rtnetlink_type_is_rtnlgrp_addr(nlmsg->nlmsg_type)) {
99 /* Policy for RTNLGRP_IPV4_IFADDR/RTNLGRP_IPV6_IFADDR messages.
101 * There are *many* more fields in these messages, but currently we
102 * only care about these fields. */
103 const struct ifaddrmsg *ifaddr;
105 ifaddr = ofpbuf_at(buf, NLMSG_HDRLEN, sizeof *ifaddr);
107 change->nlmsg_type = nlmsg->nlmsg_type;
108 change->if_index = ifaddr->ifa_index;
109 if_indextoname(ifaddr->ifa_index, change->ifname);
117 rtnetlink_parse_cb(struct ofpbuf *buf, void *change)
119 return rtnetlink_parse(buf, change);
122 /* Registers 'cb' to be called with auxiliary data 'aux' with network device
123 * change notifications. The notifier is stored in 'notifier', which the
124 * caller must not modify or free.
126 * This is probably not the function that you want. You should probably be
127 * using dpif_port_poll() or netdev_change_seq(), which unlike this function
128 * are not Linux-specific.
130 * xxx Joins more multicast groups when needed.
132 * Returns an initialized nln_notifier if successful, NULL otherwise. */
133 struct nln_notifier *
134 rtnetlink_notifier_create(rtnetlink_notify_func *cb, void *aux)
137 nln = nln_create(NETLINK_ROUTE, RTNLGRP_LINK, rtnetlink_parse_cb,
141 return nln_notifier_create(nln, (nln_notify_func *) cb, aux);
144 /* Destroys 'notifier', which must have previously been created with
145 * rtnetlink_notifier_register(). */
147 rtnetlink_notifier_destroy(struct nln_notifier *notifier)
149 nln_notifier_destroy(notifier);
152 /* Calls all of the registered notifiers, passing along any as-yet-unreported
153 * netdev change events. */
162 /* Causes poll_block() to wake up when network device change notifications are