2 * Copyright (c) 2009, 2010, 2013, 2015, 2016 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"
27 #include "openvswitch/ofpbuf.h"
30 static struct nln
*nln
= NULL
;
31 static struct rtnetlink_change rtn_change
;
33 /* Returns true if the given netlink msg type corresponds to RTNLGRP_LINK. */
35 rtnetlink_type_is_rtnlgrp_link(uint16_t type
)
37 return type
== RTM_NEWLINK
|| type
== RTM_DELLINK
;
40 /* Returns true if the given netlink msg type corresponds to
41 * RTNLGRP_IPV4_IFADDR or RTNLGRP_IPV6_IFADDR. */
43 rtnetlink_type_is_rtnlgrp_addr(uint16_t type
)
45 return type
== RTM_NEWADDR
|| type
== RTM_DELADDR
;
48 /* Parses a rtnetlink message 'buf' into 'change'. If 'buf' is unparseable,
49 * leaves 'change' untouched and returns false. Otherwise, populates 'change'
50 * and returns true. */
52 rtnetlink_parse(struct ofpbuf
*buf
, struct rtnetlink_change
*change
)
54 const struct nlmsghdr
*nlmsg
= buf
->data
;
57 if (rtnetlink_type_is_rtnlgrp_link(nlmsg
->nlmsg_type
)) {
58 /* Policy for RTNLGRP_LINK messages.
60 * There are *many* more fields in these messages, but currently we
61 * only care about these fields. */
62 static const struct nl_policy policy
[] = {
63 [IFLA_IFNAME
] = { .type
= NL_A_STRING
, .optional
= false },
64 [IFLA_MASTER
] = { .type
= NL_A_U32
, .optional
= true },
65 [IFLA_MTU
] = { .type
= NL_A_U32
, .optional
= true },
66 [IFLA_ADDRESS
] = { .type
= NL_A_UNSPEC
, .optional
= true },
69 struct nlattr
*attrs
[ARRAY_SIZE(policy
)];
71 parsed
= nl_policy_parse(buf
, NLMSG_HDRLEN
+ sizeof(struct ifinfomsg
),
72 policy
, attrs
, ARRAY_SIZE(policy
));
75 const struct ifinfomsg
*ifinfo
;
77 ifinfo
= ofpbuf_at(buf
, NLMSG_HDRLEN
, sizeof *ifinfo
);
79 change
->nlmsg_type
= nlmsg
->nlmsg_type
;
80 change
->if_index
= ifinfo
->ifi_index
;
81 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 static const struct nl_policy policy
[] = {
104 [IFA_LABEL
] = { .type
= NL_A_STRING
, .optional
= true },
107 struct nlattr
*attrs
[ARRAY_SIZE(policy
)];
109 parsed
= nl_policy_parse(buf
, NLMSG_HDRLEN
+ sizeof(struct ifaddrmsg
),
110 policy
, attrs
, ARRAY_SIZE(policy
));
113 const struct ifaddrmsg
*ifaddr
;
115 ifaddr
= ofpbuf_at(buf
, NLMSG_HDRLEN
, sizeof *ifaddr
);
117 change
->nlmsg_type
= nlmsg
->nlmsg_type
;
118 change
->if_index
= ifaddr
->ifa_index
;
119 change
->ifname
= (attrs
[IFA_LABEL
]
120 ? nl_attr_get_string(attrs
[IFA_LABEL
])
128 /* Return RTNLGRP_LINK on success, 0 on parse error. */
130 rtnetlink_parse_cb(struct ofpbuf
*buf
, void *change
)
132 return rtnetlink_parse(buf
, change
) ? RTNLGRP_LINK
: 0;
135 /* Registers 'cb' to be called with auxiliary data 'aux' with network device
136 * change notifications. The notifier is stored in 'notifier', which the
137 * caller must not modify or free.
139 * This is probably not the function that you want. You should probably be
140 * using dpif_port_poll() or netdev_change_seq(), which unlike this function
141 * are not Linux-specific.
143 * xxx Joins more multicast groups when needed.
145 * Returns an initialized nln_notifier if successful, NULL otherwise. */
146 struct nln_notifier
*
147 rtnetlink_notifier_create(rtnetlink_notify_func
*cb
, void *aux
)
150 nln
= nln_create(NETLINK_ROUTE
, rtnetlink_parse_cb
, &rtn_change
);
153 return nln_notifier_create(nln
, RTNLGRP_LINK
, (nln_notify_func
*) cb
, aux
);
156 /* Destroys 'notifier', which must have previously been created with
157 * rtnetlink_notifier_register(). */
159 rtnetlink_notifier_destroy(struct nln_notifier
*notifier
)
161 nln_notifier_destroy(notifier
);
164 /* Calls all of the registered notifiers, passing along any as-yet-unreported
165 * netdev change events. */
174 /* Causes poll_block() to wake up when network device change notifications are