ip/rtmon.c

   1 /*
   2  * rtmon.c              RTnetlink listener.
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  10  *
  11  */
  12
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <unistd.h>
  16 #include <syslog.h>
  17 #include <fcntl.h>
  18 #include <sys/socket.h>
  19 #include <sys/time.h>
  20 #include <net/if.h>
  21 #include <netinet/in.h>
  22 #include <string.h>
  23
  24 #include "SNAPSHOT.h"
  25
  26 #include "utils.h"
  27 #include "libnetlink.h"
  28
  29 int resolve_hosts = 0;
  30 static int init_phase = 1;
  31
  32 static void write_stamp(FILE *fp)
  33 {
  34         char buf[128];
  35         struct nlmsghdr *n1 = (void*)buf;
  36         struct timeval tv;
  37
  38         n1->nlmsg_type = 15;
  39         n1->nlmsg_flags = 0;
  40         n1->nlmsg_seq = 0;
  41         n1->nlmsg_pid = 0;
  42         n1->nlmsg_len = NLMSG_LENGTH(4*2);
  43         gettimeofday(&tv, NULL);
  44         ((__u32*)NLMSG_DATA(n1))[0] = tv.tv_sec;
  45         ((__u32*)NLMSG_DATA(n1))[1] = tv.tv_usec;
  46         fwrite((void*)n1, 1, NLMSG_ALIGN(n1->nlmsg_len), fp);
  47 }
  48
  49 static int dump_msg(const struct sockaddr_nl *who, struct nlmsghdr *n,
  50                     void *arg)
  51 {
  52         FILE *fp = (FILE*)arg;
  53         if (!init_phase)
  54                 write_stamp(fp);
  55         fwrite((void*)n, 1, NLMSG_ALIGN(n->nlmsg_len), fp);
  56         fflush(fp);
  57         return 0;
  58 }
  59
  60 void usage(void)
  61 {
  62         fprintf(stderr, "Usage: rtmon file FILE [ all | LISTofOBJECTS]\n");
  63         fprintf(stderr, "LISTofOBJECTS := [ link ] [ address ] [ route ]\n");
  64         exit(-1);
  65 }
  66
  67 int
  68 main(int argc, char **argv)
  69 {
  70         FILE *fp;
  71         struct rtnl_handle rth;
  72         int family = AF_UNSPEC;
  73         unsigned groups = ~0U;
  74         int llink = 0;
  75         int laddr = 0;
  76         int lroute = 0;
  77         char *file = NULL;
  78
  79         while (argc > 1) {
  80                 if (matches(argv[1], "-family") == 0) {
  81                         argc--;
  82                         argv++;
  83                         if (argc <= 1)
  84                                 usage();
  85                         if (strcmp(argv[1], "inet") == 0)
  86                                 family = AF_INET;
  87                         else if (strcmp(argv[1], "inet6") == 0)
  88                                 family = AF_INET6;
  89                         else if (strcmp(argv[1], "link") == 0)
  90                                 family = AF_INET6;
  91                         else if (strcmp(argv[1], "help") == 0)
  92                                 usage();
  93                         else {
  94                                 fprintf(stderr, "Protocol ID \"%s\" is unknown, try \"rtmon help\".\n", argv[1]);
  95                                 exit(-1);
  96                         }
  97                 } else if (strcmp(argv[1], "-4") == 0) {
  98                         family = AF_INET;
  99                 } else if (strcmp(argv[1], "-6") == 0) {
 100                         family = AF_INET6;
 101                 } else if (strcmp(argv[1], "-0") == 0) {
 102                         family = AF_PACKET;
 103                 } else if (matches(argv[1], "-Version") == 0) {
 104                         printf("rtmon utility, iproute2-ss%s\n", SNAPSHOT);
 105                         exit(0);
 106                 } else if (matches(argv[1], "file") == 0) {
 107                         argc--;
 108                         argv++;
 109                         if (argc <= 1)
 110                                 usage();
 111                         file = argv[1];
 112                 } else if (matches(argv[1], "link") == 0) {
 113                         llink=1;
 114                         groups = 0;
 115                 } else if (matches(argv[1], "address") == 0) {
 116                         laddr=1;
 117                         groups = 0;
 118                 } else if (matches(argv[1], "route") == 0) {
 119                         lroute=1;
 120                         groups = 0;
 121                 } else if (strcmp(argv[1], "all") == 0) {
 122                         groups = ~0U;
 123                 } else if (matches(argv[1], "help") == 0) {
 124                         usage();
 125                 } else {
 126                         fprintf(stderr, "Argument \"%s\" is unknown, try \"rtmon help\".\n", argv[1]);
 127                         exit(-1);
 128                 }
 129                 argc--; argv++;
 130         }
 131
 132         if (file == NULL) {
 133                 fprintf(stderr, "Not enough information: argument \"file\" is required\n");
 134                 exit(-1);
 135         }
 136         if (llink)
 137                 groups |= RTMGRP_LINK;
 138         if (laddr) {
 139                 if (!family || family == AF_INET)
 140                         groups |= RTMGRP_IPV4_IFADDR;
 141                 if (!family || family == AF_INET6)
 142                         groups |= RTMGRP_IPV6_IFADDR;
 143         }
 144         if (lroute) {
 145                 if (!family || family == AF_INET)
 146                         groups |= RTMGRP_IPV4_ROUTE;
 147                 if (!family || family == AF_INET6)
 148                         groups |= RTMGRP_IPV6_ROUTE;
 149         }
 150
 151         fp = fopen(file, "w");
 152         if (fp == NULL) {
 153                 perror("Cannot fopen");
 154                 exit(-1);
 155         }
 156
 157         if (rtnl_open(&rth, groups) < 0)
 158                 exit(1);
 159
 160         if (rtnl_wilddump_request(&rth, AF_UNSPEC, RTM_GETLINK) < 0) {
 161                 perror("Cannot send dump request");
 162                 exit(1);
 163         }
 164
 165         write_stamp(fp);
 166
 167         if (rtnl_dump_filter(&rth, dump_msg, fp, NULL, NULL) < 0) {
 168                 fprintf(stderr, "Dump terminated\n");
 169                 return 1;
 170         }
 171
 172         init_phase = 0;
 173
 174         if (rtnl_listen(&rth, dump_msg, (void*)fp) < 0)
 175                 exit(2);
 176
 177         exit(0);
 178 }