utilities/nlmon.c

   1 /*
   2  * Copyright (c) 2009, 2010, 2011, 2012 Nicira, Inc.
   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 "netlink-socket.h"
  28 #include "openvswitch/ofpbuf.h"
  29 #include "openvswitch/poll-loop.h"
  30 #include "timeval.h"
  31 #include "util.h"
  32 #include "openvswitch/vlog.h"
  33
  34 static const struct nl_policy rtnlgrp_link_policy[] = {
  35     [IFLA_IFNAME] = { .type = NL_A_STRING, .optional = false },
  36     [IFLA_MASTER] = { .type = NL_A_U32, .optional = true },
  37 };
  38
  39 int
  40 main(int argc OVS_UNUSED, char *argv[])
  41 {
  42     uint64_t buf_stub[4096 / 64];
  43     struct nl_sock *sock;
  44     struct ofpbuf buf;
  45     int error;
  46
  47     set_program_name(argv[0]);
  48     vlog_set_levels(NULL, VLF_ANY_DESTINATION, VLL_DBG);
  49
  50     error = nl_sock_create(NETLINK_ROUTE, &sock);
  51     if (error) {
  52         ovs_fatal(error, "could not create rtnetlink socket");
  53     }
  54
  55     error = nl_sock_join_mcgroup(sock, RTNLGRP_LINK);
  56     if (error) {
  57         ovs_fatal(error, "could not join RTNLGRP_LINK multicast group");
  58     }
  59
  60     ofpbuf_use_stub(&buf, buf_stub, sizeof buf_stub);
  61     for (;;) {
  62         error = nl_sock_recv(sock, &buf, NULL, false);
  63         if (error == EAGAIN) {
  64             /* Nothing to do. */
  65         } else if (error == ENOBUFS) {
  66             ovs_error(0, "network monitor socket overflowed");
  67         } else if (error) {
  68             ovs_fatal(error, "error on network monitor socket");
  69         } else {
  70             struct iff_flag {
  71                 unsigned int flag;
  72                 const char *name;
  73             };
  74
  75             static const struct iff_flag flags[] = {
  76                 { IFF_UP, "UP", },
  77                 { IFF_BROADCAST, "BROADCAST", },
  78                 { IFF_DEBUG, "DEBUG", },
  79                 { IFF_LOOPBACK, "LOOPBACK", },
  80                 { IFF_POINTOPOINT, "POINTOPOINT", },
  81                 { IFF_NOTRAILERS, "NOTRAILERS", },
  82                 { IFF_RUNNING, "RUNNING", },
  83                 { IFF_NOARP, "NOARP", },
  84                 { IFF_PROMISC, "PROMISC", },
  85                 { IFF_ALLMULTI, "ALLMULTI", },
  86                 { IFF_MASTER, "MASTER", },
  87                 { IFF_SLAVE, "SLAVE", },
  88                 { IFF_MULTICAST, "MULTICAST", },
  89                 { IFF_PORTSEL, "PORTSEL", },
  90                 { IFF_AUTOMEDIA, "AUTOMEDIA", },
  91                 { IFF_DYNAMIC, "DYNAMIC", },
  92             };
  93
  94             struct nlattr *attrs[ARRAY_SIZE(rtnlgrp_link_policy)];
  95             struct nlmsghdr *nlh;
  96             struct ifinfomsg *iim;
  97             int i;
  98
  99             nlh = ofpbuf_at(&buf, 0, NLMSG_HDRLEN);
 100             iim = ofpbuf_at(&buf, NLMSG_HDRLEN, sizeof *iim);
 101             if (!iim) {
 102                 ovs_error(0, "received bad rtnl message (no ifinfomsg)");
 103                 continue;
 104             }
 105
 106             if (!nl_policy_parse(&buf, NLMSG_HDRLEN + sizeof(struct ifinfomsg),
 107                                  rtnlgrp_link_policy,
 108                                  attrs, ARRAY_SIZE(rtnlgrp_link_policy))) {
 109                 ovs_error(0, "received bad rtnl message (policy)");
 110                 continue;
 111             }
 112             printf("netdev %s changed (%s):\n",
 113                    nl_attr_get_string(attrs[IFLA_IFNAME]),
 114                    (nlh->nlmsg_type == RTM_NEWLINK ? "RTM_NEWLINK"
 115                     : nlh->nlmsg_type == RTM_DELLINK ? "RTM_DELLINK"
 116                     : nlh->nlmsg_type == RTM_GETLINK ? "RTM_GETLINK"
 117                     : nlh->nlmsg_type == RTM_SETLINK ? "RTM_SETLINK"
 118                     : "other"));
 119             printf("\tflags:");
 120             for (i = 0; i < ARRAY_SIZE(flags); i++) {
 121                 if (iim->ifi_flags & flags[i].flag) {
 122                     printf(" %s", flags[i].name);
 123                 }
 124             }
 125             printf("\n");
 126             if (attrs[IFLA_MASTER]) {
 127                 uint32_t idx = nl_attr_get_u32(attrs[IFLA_MASTER]);
 128                 char ifname[IFNAMSIZ];
 129                 if (!if_indextoname(idx, ifname)) {
 130                     strcpy(ifname, "unknown");
 131                 }
 132                 printf("\tmaster=%"PRIu32" (%s)\n", idx, ifname);
 133             }
 134         }
 135
 136         nl_sock_wait(sock, POLLIN);
 137         poll_block();
 138     }
 139 }
 140