lib/route-table-bsd.c

   1 /*
   2  * Copyright (c) 2012 Ed Maste. All rights reserved.
   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
  19 #include "route-table.h"
  20
  21 #include <sys/socket.h>
  22 #include <sys/types.h>
  23
  24 #include <net/if.h>
  25 #include <net/route.h>
  26 #include <net/if_dl.h>
  27 #include <netinet/in.h>
  28
  29 #include <string.h>
  30 #include <unistd.h>
  31
  32 VLOG_DEFINE_THIS_MODULE(route_table);
  33
  34 static int pid;
  35 static unsigned int register_count = 0;
  36
  37 bool
  38 route_table_get_name(ovs_be32 ip, char name[IFNAMSIZ])
  39 {
  40     struct {
  41         struct rt_msghdr rtm;
  42         char space[512];
  43     } rtmsg;
  44
  45     struct rt_msghdr *rtm = &rtmsg.rtm;
  46     struct sockaddr_dl *ifp = NULL;
  47     struct sockaddr_in *sin;
  48     struct sockaddr *sa;
  49     static int seq;
  50     int i, len, namelen, rtsock;
  51
  52     rtsock = socket(PF_ROUTE, SOCK_RAW, 0);
  53     if (rtsock < 0)
  54         return false;
  55
  56     memset(&rtmsg, 0, sizeof(rtmsg));
  57
  58     rtm->rtm_msglen = sizeof(struct rt_msghdr) + sizeof(struct sockaddr_in);
  59     rtm->rtm_version = RTM_VERSION;
  60     rtm->rtm_type = RTM_GET;
  61     rtm->rtm_addrs = RTA_DST | RTA_IFP;
  62     rtm->rtm_seq = ++seq;
  63
  64     sin = (struct sockaddr_in *)(rtm + 1);
  65     sin->sin_len = len = sizeof(struct sockaddr_in);
  66     sin->sin_family = AF_INET;
  67     sin->sin_addr.s_addr = ip;
  68
  69     if ((write(rtsock, (char *)&rtmsg, rtm->rtm_msglen)) < 0) {
  70         close(rtsock);
  71         return false;
  72     }
  73
  74     do {
  75         len = read(rtsock, (char *)&rtmsg, sizeof(rtmsg));
  76     } while (len > 0 && (rtmsg.rtm.rtm_seq != seq ||
  77         rtmsg.rtm.rtm_pid != pid));
  78
  79     close(rtsock);
  80
  81     if (len < 0) {
  82         return false;
  83     }
  84
  85     sa = (struct sockaddr *)(rtm + 1);
  86     for (i = 1; i; i <<= 1) {
  87         if (rtm->rtm_addrs & i) {
  88             if (i == RTA_IFP && sa->sa_family == AF_LINK &&
  89               ((struct sockaddr_dl *)sa)->sdl_nlen) {
  90                 ifp = (struct sockaddr_dl *)sa;
  91                 namelen = ifp->sdl_nlen;
  92                 if (namelen > IFNAMSIZ - 1)
  93                     namelen = IFNAMSIZ - 1;
  94                 memcpy(name, ifp->sdl_data, namelen);
  95                 name[namelen] = '\0';
  96                 return true;
  97             }
  98             sa = (struct sockaddr *)((char *)sa + SA_SIZE(sa));
  99         }
 100     }
 101     return false;
 102 }
 103
 104 void
 105 route_table_register()
 106 {
 107     if (!register_count)
 108     {
 109         pid = getpid();
 110     }
 111
 112     register_count++;
 113 }
 114
 115 void
 116 route_table_unregister()
 117 {
 118     register_count--;
 119 }
 120
 121 void
 122 route_table_run(void)
 123 {
 124 }
 125
 126 void
 127 route_table_wait(void)
 128 {
 129 }