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 <netinet/in.h>
  21 #include <string.h>
  22
  23 #include "SNAPSHOT.h"
  24
  25 #include "utils.h"
  26 #include "libnetlink.h"
  27
  28 int resolve_hosts = 0;
  29 static int init_phase = 1;
  30
  31 static void write_stamp(FILE *fp)
  32 {
  33         char buf[128];
  34         struct nlmsghdr *n1 = (void*)buf;
  35         struct timeval tv;
  36
  37         n1->nlmsg_type = 15;
  38         n1->nlmsg_flags = 0;
  39         n1->nlmsg_seq = 0;
  40         n1->nlmsg_pid = 0;
  41         n1->nlmsg_len = NLMSG_LENGTH(4*2);
  42         gettimeofday(&tv, NULL);
  43         ((__u32*)NLMSG_DATA(n1))[0] = tv.tv_sec;
  44         ((__u32*)NLMSG_DATA(n1))[1] = tv.tv_usec;
  45         fwrite((void*)n1, 1, NLMSG_ALIGN(n1->nlmsg_len), fp);
  46 }
  47
  48 static int dump_msg(const struct sockaddr_nl *who, struct nlmsghdr *n,
  49                     void *arg)
  50 {
  51         FILE *fp = (FILE*)arg;
  52         if (!init_phase)
  53                 write_stamp(fp);
  54         fwrite((void*)n, 1, NLMSG_ALIGN(n->nlmsg_len), fp);
  55         fflush(fp);
  56         return 0;
  57 }
  58
  59 static void usage(void)
  60 {
  61         fprintf(stderr, "Usage: rtmon file FILE [ all | LISTofOBJECTS]\n");
  62         fprintf(stderr, "LISTofOBJECTS := [ link ] [ address ] [ route ]\n");
  63         exit(-1);
  64 }
  65
  66 int
  67 main(int argc, char **argv)
  68 {
  69         FILE *fp;
  70         struct rtnl_handle rth;
  71         int family = AF_UNSPEC;
  72         unsigned groups = ~0U;
  73         int llink = 0;
  74         int laddr = 0;
  75         int lroute = 0;
  76         char *file = NULL;
  77
  78         while (argc > 1) {
  79                 if (matches(argv[1], "-family") == 0) {
  80                         argc--;
  81                         argv++;
  82                         if (argc <= 1)
  83                                 usage();
  84                         if (strcmp(argv[1], "inet") == 0)
  85                                 family = AF_INET;
  86                         else if (strcmp(argv[1], "inet6") == 0)
  87                                 family = AF_INET6;
  88                         else if (strcmp(argv[1], "link") == 0)
  89                                 family = AF_INET6;
  90                         else if (strcmp(argv[1], "help") == 0)
  91                                 usage();
  92                         else {
  93                                 fprintf(stderr, "Protocol ID \"%s\" is unknown, try \"rtmon help\".\n", argv[1]);
  94                                 exit(-1);
  95                         }
  96                 } else if (strcmp(argv[1], "-4") == 0) {
  97                         family = AF_INET;
  98                 } else if (strcmp(argv[1], "-6") == 0) {
  99                         family = AF_INET6;
 100                 } else if (strcmp(argv[1], "-0") == 0) {
 101                         family = AF_PACKET;
 102                 } else if (matches(argv[1], "-Version") == 0) {
 103                         printf("rtmon utility, iproute2-ss%s\n", SNAPSHOT);
 104                         exit(0);
 105                 } else if (matches(argv[1], "file") == 0) {
 106                         argc--;
 107                         argv++;
 108                         if (argc <= 1)
 109                                 usage();
 110                         file = argv[1];
 111                 } else if (matches(argv[1], "link") == 0) {
 112                         llink=1;
 113                         groups = 0;
 114                 } else if (matches(argv[1], "address") == 0) {
 115                         laddr=1;
 116                         groups = 0;
 117                 } else if (matches(argv[1], "route") == 0) {
 118                         lroute=1;
 119                         groups = 0;
 120                 } else if (strcmp(argv[1], "all") == 0) {
 121                         groups = ~0U;
 122                 } else if (matches(argv[1], "help") == 0) {
 123                         usage();
 124                 } else {
 125                         fprintf(stderr, "Argument \"%s\" is unknown, try \"rtmon help\".\n", argv[1]);
 126                         exit(-1);
 127                 }
 128                 argc--; argv++;
 129         }
 130
 131         if (file == NULL) {
 132                 fprintf(stderr, "Not enough information: argument \"file\" is required\n");
 133                 exit(-1);
 134         }
 135         if (llink)
 136                 groups |= nl_mgrp(RTNLGRP_LINK);
 137         if (laddr) {
 138                 if (!family || family == AF_INET)
 139                         groups |= nl_mgrp(RTNLGRP_IPV4_IFADDR);
 140                 if (!family || family == AF_INET6)
 141                         groups |= nl_mgrp(RTNLGRP_IPV6_IFADDR);
 142         }
 143         if (lroute) {
 144                 if (!family || family == AF_INET)
 145                         groups |= nl_mgrp(RTNLGRP_IPV4_ROUTE);
 146                 if (!family || family == AF_INET6)
 147                         groups |= nl_mgrp(RTNLGRP_IPV6_ROUTE);
 148         }
 149
 150         fp = fopen(file, "w");
 151         if (fp == NULL) {
 152                 perror("Cannot fopen");
 153                 exit(-1);
 154         }
 155
 156         if (rtnl_open(&rth, groups) < 0)
 157                 exit(1);
 158
 159         if (rtnl_wilddump_request(&rth, AF_UNSPEC, RTM_GETLINK) < 0) {
 160                 perror("Cannot send dump request");
 161                 exit(1);
 162         }
 163
 164         write_stamp(fp);
 165
 166         if (rtnl_dump_filter(&rth, dump_msg, fp) < 0) {
 167                 fprintf(stderr, "Dump terminated\n");
 168                 return 1;
 169         }
 170
 171         init_phase = 0;
 172
 173         if (rtnl_listen(&rth, dump_msg, (void*)fp) < 0)
 174                 exit(2);
 175
 176         exit(0);
 177 }