route.c

   1 /* route
   2  *
   3  * Similar to the standard Unix route, but with only the necessary
   4  * parts for AF_INET
   5  *
   6  * Bjorn Wesen, Axis Communications AB
   7  *
   8  * Author of the original route:
   9  *              Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
  10  *              (derived from FvK's 'route.c     1.70    01/04/94')
  11  *
  12  * This program is free software; you can redistribute it
  13  * and/or  modify it under  the terms of  the GNU General
  14  * Public  License as  published  by  the  Free  Software
  15  * Foundation;  either  version 2 of the License, or  (at
  16  * your option) any later version.
  17  *
  18  * $Id: route.c,v 1.7 2001/02/20 06:14:08 andersen Exp $
  19  *
  20  * displayroute() code added by Vladimir N. Oleynik <dzo@simtreas.ru>
  21  * busybox style adjustments by Larry Doolittle  <LRDoolittle@lbl.gov>
  22  * displayroute() format now matches net-tools-1.57/lib/inet_gr.c line 173.
  23  */
  24
  25 #include <sys/types.h>
  26 #include <sys/ioctl.h>
  27 #include <sys/socket.h>
  28 #include <net/route.h>
  29 #include <linux/param.h>  // HZ
  30 #include <netinet/in.h>
  31 #include <arpa/inet.h>
  32 #include <stdio.h>
  33 #include <errno.h>
  34 #include <fcntl.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <getopt.h>
  38 #include <unistd.h>
  39 #include <ctype.h>
  40 #include "busybox.h"
  41
  42 #define _(x) x
  43
  44 #define RTACTION_ADD   1
  45 #define RTACTION_DEL   2
  46 #define RTACTION_HELP  3
  47 #define RTACTION_FLUSH 4
  48 #define RTACTION_SHOW  5
  49
  50 #define E_NOTFOUND      8
  51 #define E_SOCK          7
  52 #define E_LOOKUP        6
  53 #define E_VERSION       5
  54 #define E_USAGE         4
  55 #define E_OPTERR        3
  56 #define E_INTERN        2
  57 #define E_NOSUPP        1
  58
  59 /* resolve XXX.YYY.ZZZ.QQQ -> binary */
  60
  61 static int
  62 INET_resolve(char *name, struct sockaddr *sa)
  63 {
  64         struct sockaddr_in *sin = (struct sockaddr_in *)sa;
  65
  66         sin->sin_family = AF_INET;
  67         sin->sin_port = 0;
  68
  69         /* Default is special, meaning 0.0.0.0. */
  70         if (strcmp(name, "default")==0) {
  71                 sin->sin_addr.s_addr = INADDR_ANY;
  72                 return 1;
  73         }
  74         /* Look to see if it's a dotted quad. */
  75         if (inet_aton(name, &sin->sin_addr)) {
  76                 return 0;
  77         }
  78         /* guess not.. */
  79         return -1;
  80 }
  81
  82 #if defined (SIOCADDRTOLD) || defined (RTF_IRTT)        /* route */
  83 #define HAVE_NEW_ADDRT 1
  84 #endif
  85 #ifdef RTF_IRTT                 /* route */
  86 #define HAVE_RTF_IRTT 1
  87 #endif
  88 #ifdef RTF_REJECT               /* route */
  89 #define HAVE_RTF_REJECT 1
  90 #endif
  91
  92 #if HAVE_NEW_ADDRT
  93 #define mask_in_addr(x) (((struct sockaddr_in *)&((x).rt_genmask))->sin_addr.s_addr)
  94 #define full_mask(x) (x)
  95 #else
  96 #define mask_in_addr(x) ((x).rt_genmask)
  97 #define full_mask(x) (((struct sockaddr_in *)&(x))->sin_addr.s_addr)
  98 #endif
  99
 100 /* add or delete a route depending on action */
 101
 102 static int
 103 INET_setroute(int action, int options, char **args)
 104 {
 105         struct rtentry rt;
 106         char target[128], gateway[128] = "NONE", netmask[128] = "default";
 107         int xflag, isnet;
 108         int skfd;
 109
 110         xflag = 0;
 111
 112         if (strcmp(*args, "-net")==0) {
 113                 xflag = 1;
 114                 args++;
 115         } else if (strcmp(*args, "-host")==0) {
 116                 xflag = 2;
 117                 args++;
 118         }
 119         if (*args == NULL)
 120                 show_usage();
 121
 122         safe_strncpy(target, *args++, (sizeof target));
 123
 124         /* Clean out the RTREQ structure. */
 125         memset((char *) &rt, 0, sizeof(struct rtentry));
 126
 127
 128         if ((isnet = INET_resolve(target, &rt.rt_dst)) < 0) {
 129                 error_msg(_("can't resolve %s"), target);
 130                 return EXIT_FAILURE;   /* XXX change to E_something */
 131         }
 132
 133         switch (xflag) {
 134                 case 1:
 135                         isnet = 1;
 136                         break;
 137
 138                 case 2:
 139                         isnet = 0;
 140                         break;
 141
 142                 default:
 143                         break;
 144         }
 145
 146         /* Fill in the other fields. */
 147         rt.rt_flags = (RTF_UP | RTF_HOST);
 148         if (isnet)
 149                 rt.rt_flags &= ~RTF_HOST;
 150
 151         while (*args) {
 152                 if (strcmp(*args, "metric")==0) {
 153                         int metric;
 154
 155                         args++;
 156                         if (!*args || !isdigit(**args))
 157                                 show_usage();
 158                         metric = atoi(*args);
 159 #if HAVE_NEW_ADDRT
 160                         rt.rt_metric = metric + 1;
 161 #else
 162                         ENOSUPP("inet_setroute", "NEW_ADDRT (metric)");  /* XXX Fixme */
 163 #endif
 164                         args++;
 165                         continue;
 166                 }
 167
 168                 if (strcmp(*args, "netmask")==0) {
 169                         struct sockaddr mask;
 170
 171                         args++;
 172                         if (!*args || mask_in_addr(rt))
 173                                 show_usage();
 174                         safe_strncpy(netmask, *args, (sizeof netmask));
 175                         if ((isnet = INET_resolve(netmask, &mask)) < 0) {
 176                                 error_msg(_("can't resolve netmask %s"), netmask);
 177                                 return E_LOOKUP;
 178                         }
 179                         rt.rt_genmask = full_mask(mask);
 180                         args++;
 181                         continue;
 182                 }
 183
 184                 if (strcmp(*args, "gw")==0 || strcmp(*args, "gateway")==0) {
 185                         args++;
 186                         if (!*args)
 187                                 show_usage();
 188                         if (rt.rt_flags & RTF_GATEWAY)
 189                                 show_usage();
 190                         safe_strncpy(gateway, *args, (sizeof gateway));
 191                         if ((isnet = INET_resolve(gateway, &rt.rt_gateway)) < 0) {
 192                                 error_msg(_("can't resolve gw %s"), gateway);
 193                                 return E_LOOKUP;
 194                         }
 195                         if (isnet) {
 196                                 error_msg(
 197                                         _("%s: cannot use a NETWORK as gateway!"),
 198                                         gateway);
 199                                 return E_OPTERR;
 200                         }
 201                         rt.rt_flags |= RTF_GATEWAY;
 202                         args++;
 203                         continue;
 204                 }
 205
 206                 if (strcmp(*args, "mss")==0) {
 207                         args++;
 208                         rt.rt_flags |= RTF_MSS;
 209                         if (!*args)
 210                                 show_usage();
 211                         rt.rt_mss = atoi(*args);
 212                         args++;
 213                         if (rt.rt_mss < 64 || rt.rt_mss > 32768) {
 214                                 error_msg(_("Invalid MSS."));
 215                                 return E_OPTERR;
 216                         }
 217                         continue;
 218                 }
 219
 220                 if (strcmp(*args, "window")==0) {
 221                         args++;
 222                         if (!*args)
 223                                 show_usage();
 224                         rt.rt_flags |= RTF_WINDOW;
 225                         rt.rt_window = atoi(*args);
 226                         args++;
 227                         if (rt.rt_window < 128) {
 228                                 error_msg(_("Invalid window."));
 229                                 return E_OPTERR;
 230                         }
 231                         continue;
 232                 }
 233
 234                 if (strcmp(*args, "irtt")==0) {
 235                         args++;
 236                         if (!*args)
 237                                 show_usage();
 238                         args++;
 239 #if HAVE_RTF_IRTT
 240                         rt.rt_flags |= RTF_IRTT;
 241                         rt.rt_irtt = atoi(*(args - 1));
 242                         rt.rt_irtt *= (HZ / 100);       /* FIXME */
 243 #if 0                           /* FIXME: do we need to check anything of this? */
 244                         if (rt.rt_irtt < 1 || rt.rt_irtt > (120 * HZ)) {
 245                                 error_msg(_("Invalid initial rtt."));
 246                                 return E_OPTERR;
 247                         }
 248 #endif
 249 #else
 250                         ENOSUPP("inet_setroute", "RTF_IRTT"); /* XXX Fixme */
 251 #endif
 252                         continue;
 253                 }
 254
 255                 if (strcmp(*args, "reject")==0) {
 256                         args++;
 257 #if HAVE_RTF_REJECT
 258                         rt.rt_flags |= RTF_REJECT;
 259 #else
 260                         ENOSUPP("inet_setroute", "RTF_REJECT"); /* XXX Fixme */
 261 #endif
 262                         continue;
 263                 }
 264                 if (strcmp(*args, "mod")==0) {
 265                         args++;
 266                         rt.rt_flags |= RTF_MODIFIED;
 267                         continue;
 268                 }
 269                 if (strcmp(*args, "dyn")==0) {
 270                         args++;
 271                         rt.rt_flags |= RTF_DYNAMIC;
 272                         continue;
 273                 }
 274                 if (strcmp(*args, "reinstate")==0) {
 275                         args++;
 276                         rt.rt_flags |= RTF_REINSTATE;
 277                         continue;
 278                 }
 279                 if (strcmp(*args, "device")==0 || strcmp(*args, "dev")==0) {
 280                         args++;
 281                         if (rt.rt_dev || *args == NULL)
 282                                 show_usage();
 283                         rt.rt_dev = *args++;
 284                         continue;
 285                 }
 286                 /* nothing matches */
 287                 if (!rt.rt_dev) {
 288                         rt.rt_dev = *args++;
 289                         if (*args)
 290                                 show_usage();   /* must be last to catch typos */
 291                 } else {
 292                         show_usage();
 293                 }
 294         }
 295
 296 #if HAVE_RTF_REJECT
 297         if ((rt.rt_flags & RTF_REJECT) && !rt.rt_dev)
 298                 rt.rt_dev = "lo";
 299 #endif
 300
 301         /* sanity checks.. */
 302         if (mask_in_addr(rt)) {
 303                 unsigned long mask = mask_in_addr(rt);
 304                 mask = ~ntohl(mask);
 305                 if ((rt.rt_flags & RTF_HOST) && mask != 0xffffffff) {
 306                         error_msg(
 307                                 _("netmask %.8x doesn't make sense with host route"),
 308                                 (unsigned int)mask);
 309                         return E_OPTERR;
 310                 }
 311                 if (mask & (mask + 1)) {
 312                         error_msg(_("bogus netmask %s"), netmask);
 313                         return E_OPTERR;
 314                 }
 315                 mask = ((struct sockaddr_in *) &rt.rt_dst)->sin_addr.s_addr;
 316                 if (mask & ~mask_in_addr(rt)) {
 317                         error_msg(_("netmask doesn't match route address"));
 318                         return E_OPTERR;
 319                 }
 320         }
 321         /* Fill out netmask if still unset */
 322         if ((action == RTACTION_ADD) && rt.rt_flags & RTF_HOST)
 323                 mask_in_addr(rt) = 0xffffffff;
 324
 325         /* Create a socket to the INET kernel. */
 326         if ((skfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
 327                 perror("socket");
 328                 return E_SOCK;
 329         }
 330         /* Tell the kernel to accept this route. */
 331         if (action == RTACTION_DEL) {
 332                 if (ioctl(skfd, SIOCDELRT, &rt) < 0) {
 333                         perror("SIOCDELRT");
 334                         close(skfd);
 335                         return E_SOCK;
 336                 }
 337         } else {
 338                 if (ioctl(skfd, SIOCADDRT, &rt) < 0) {
 339                         perror("SIOCADDRT");
 340                         close(skfd);
 341                         return E_SOCK;
 342                 }
 343         }
 344
 345         /* Close the socket. */
 346         (void) close(skfd);
 347         return EXIT_SUCCESS;
 348 }
 349
 350 void displayroutes(void)
 351 {
 352         char buff[256];
 353         int  nl = 0 ;
 354         struct in_addr dest;
 355         struct in_addr gw;
 356         struct in_addr mask;
 357         int flgs, ref, use, metric;
 358         char flags[4];
 359         unsigned long int d,g,m;
 360
 361         char sdest[16], sgw[16];
 362
 363
 364         FILE *fp = xfopen("/proc/net/route", "r");
 365
 366         while( fgets(buff, sizeof(buff), fp) != NULL ) {
 367                 if(nl) {
 368                         int ifl = 0;
 369                         while(buff[ifl]!=' ' && buff[ifl]!='\t' && buff[ifl]!='\0')
 370                                 ifl++;
 371                         buff[ifl]=0;    /* interface */
 372                         if(sscanf(buff+ifl+1, "%lx%lx%d%d%d%d%lx",
 373                            &d, &g, &flgs, &ref, &use, &metric, &m)!=7) {
 374                                 error_msg_and_die( "Unsuported kernel route format\n");
 375                         }
 376                         if(nl==1) {
 377                 printf("Kernel IP routing table\n"
 378 "Destination     Gateway         Genmask         Flags Metric Ref    Use Iface\n");
 379                         }
 380
 381
 382                         ifl = 0;        /* parse flags */
 383                         if(flgs&1)
 384                                 flags[ifl++]='U';
 385                         if(flgs&2)
 386                                 flags[ifl++]='G';
 387                         if(flgs&4)
 388                                 flags[ifl++]='H';
 389                         flags[ifl]=0;
 390                         dest.s_addr = d;
 391                         gw.s_addr   = g;
 392                         mask.s_addr = m;
 393                         strcpy(sdest,  (dest.s_addr==0 ? "default" :
 394                                         inet_ntoa(dest)));
 395                         strcpy(sgw,    (gw.s_addr==0   ? "*"       :
 396                                         inet_ntoa(gw)));
 397                         printf("%-15s %-15s %-15s %-5s %-6d %-2d %7d %s\n",
 398                                 sdest, sgw,
 399                                 inet_ntoa(mask),
 400                                 flags, metric, ref, use, buff);
 401                 }
 402         nl++;
 403         }
 404 }
 405
 406 int route_main(int argc, char **argv)
 407 {
 408         int what = 0;
 409
 410         argc--;
 411         argv++;
 412
 413         if (*argv == NULL) {
 414                 displayroutes();
 415                 exit(EXIT_SUCCESS);
 416         } else {
 417                 /* check verb */
 418                 if (strcmp(*argv, "add")==0)
 419                         what = RTACTION_ADD;
 420                 else if (strcmp(*argv, "del")==0 || strcmp(*argv, "delete")==0)
 421                         what = RTACTION_DEL;
 422                 else if (strcmp(*argv, "flush")==0)
 423                         what = RTACTION_FLUSH;
 424                 else
 425                         show_usage();
 426         }
 427
 428         return INET_setroute(what, 0, ++argv);
 429 }