utilities/nlmon.c

   1 /*
   2  * Copyright (c) 2009 Nicira Networks.
   3  *
   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:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  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.
  15  */
  16
  17 #include <config.h>
  18 #include <errno.h>
  19 #include <inttypes.h>
  20 #include <net/if.h>
  21 #include <poll.h>
  22 #include <sys/socket.h>
  23 #include <sys/uio.h>
  24 #include <stddef.h>
  25 #include <linux/rtnetlink.h>
  26 #include "netlink.h"
  27 #include "ofpbuf.h"
  28 #include "poll-loop.h"
  29 #include "timeval.h"
  30 #include "util.h"
  31 #include "vlog.h"
  32
  33 static const struct nl_policy rtnlgrp_link_policy[] = {
  34     [IFLA_IFNAME] = { .type = NL_A_STRING, .optional = false },
  35     [IFLA_MASTER] = { .type = NL_A_U32, .optional = true },
  36 };
  37
  38 int
  39 main(int argc UNUSED, char *argv[])
  40 {
  41     struct nl_sock *sock;
  42     int error;
  43
  44     set_program_name(argv[0]);
  45     time_init();
  46     vlog_init();
  47     vlog_set_levels(VLM_ANY_MODULE, VLF_ANY_FACILITY, VLL_DBG);
  48
  49     error = nl_sock_create(NETLINK_ROUTE, RTNLGRP_LINK, 0, 0, &sock);
  50     if (error) {
  51         ovs_fatal(error, "could not create rtnetlink socket");
  52     }
  53
  54     for (;;) {
  55         struct ofpbuf *buf;
  56
  57         error = nl_sock_recv(sock, &buf, false);
  58         if (error == EAGAIN) {
  59             /* Nothing to do. */
  60         } else if (error == ENOBUFS) {
  61             ovs_error(0, "network monitor socket overflowed");
  62         } else if (error) {
  63             ovs_fatal(error, "error on network monitor socket");
  64         } else {
  65             struct nlattr *attrs[ARRAY_SIZE(rtnlgrp_link_policy)];
  66             struct nlmsghdr *nlh;
  67             struct ifinfomsg *iim;
  68
  69             nlh = ofpbuf_at(buf, 0, NLMSG_HDRLEN);
  70             iim = ofpbuf_at(buf, NLMSG_HDRLEN, sizeof *iim);
  71             if (!iim) {
  72                 ovs_error(0, "received bad rtnl message (no ifinfomsg)");
  73                 ofpbuf_delete(buf);
  74                 continue;
  75             }
  76
  77             if (!nl_policy_parse(buf, NLMSG_HDRLEN + sizeof(struct ifinfomsg),
  78                                  rtnlgrp_link_policy,
  79                                  attrs, ARRAY_SIZE(rtnlgrp_link_policy))) {
  80                 ovs_error(0, "received bad rtnl message (policy)");
  81                 ofpbuf_delete(buf);
  82                 continue;
  83             }
  84             printf("netdev %s changed (%s):\n",
  85                    nl_attr_get_string(attrs[IFLA_IFNAME]),
  86                    (nlh->nlmsg_type == RTM_NEWLINK ? "RTM_NEWLINK"
  87                     : nlh->nlmsg_type == RTM_DELLINK ? "RTM_DELLINK"
  88                     : nlh->nlmsg_type == RTM_GETLINK ? "RTM_GETLINK"
  89                     : nlh->nlmsg_type == RTM_SETLINK ? "RTM_SETLINK"
  90                     : "other"));
  91             if (attrs[IFLA_MASTER]) {
  92                 uint32_t idx = nl_attr_get_u32(attrs[IFLA_MASTER]);
  93                 char ifname[IFNAMSIZ];
  94                 if (!if_indextoname(idx, ifname)) {
  95                     strcpy(ifname, "unknown");
  96                 }
  97                 printf("\tmaster=%"PRIu32" (%s)\n", idx, ifname);
  98             }
  99             ofpbuf_delete(buf);
 100         }
 101
 102         nl_sock_wait(sock, POLLIN);
 103         poll_block();
 104     }
 105 }
 106