networking/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 1.3 2001/02/14 21:23:06 andersen Exp $
  19  *
  20  * displayroute() code added by Vladimir N. Oleynik <dzo@simtreas.ru>
  21  */
  22
  23 #include "busybox.h"
  24 #include <sys/types.h>
  25 #include <sys/ioctl.h>
  26 #include <sys/socket.h>
  27 #include <net/route.h>
  28 #include <linux/param.h>  // HZ
  29 #include <netinet/in.h>
  30 #include <arpa/inet.h>
  31 #include <stdio.h>
  32 #include <errno.h>
  33 #include <fcntl.h>
  34 #include <stdlib.h>
  35 #include <string.h>
  36 #include <getopt.h>
  37 #include <unistd.h>
  38 #include <ctype.h>
  39
  40 #define _(x) x
  41
  42 #define RTACTION_ADD   1
  43 #define RTACTION_DEL   2
  44 #define RTACTION_HELP  3
  45 #define RTACTION_FLUSH 4
  46 #define RTACTION_SHOW  5
  47
  48 #define E_NOTFOUND      8
  49 #define E_SOCK          7
  50 #define E_LOOKUP        6
  51 #define E_VERSION       5
  52 #define E_USAGE         4
  53 #define E_OPTERR        3
  54 #define E_INTERN        2
  55 #define E_NOSUPP        1
  56
  57 /* resolve XXX.YYY.ZZZ.QQQ -> binary */
  58
  59 static int
  60 INET_resolve(char *name, struct sockaddr *sa)
  61 {
  62         struct sockaddr_in *sin = (struct sockaddr_in *)sa;
  63
  64         sin->sin_family = AF_INET;
  65         sin->sin_port = 0;
  66
  67         /* Default is special, meaning 0.0.0.0. */
  68         if (!strcmp(name, "default")) {
  69                 sin->sin_addr.s_addr = INADDR_ANY;
  70                 return (1);
  71         }
  72         /* Look to see if it's a dotted quad. */
  73         if (inet_aton(name, &sin->sin_addr)) {
  74                 return 0;
  75         }
  76         /* guess not.. */
  77         return -1;
  78 }
  79
  80 #if defined (SIOCADDRTOLD) || defined (RTF_IRTT)        /* route */
  81 #define HAVE_NEW_ADDRT 1
  82 #endif
  83 #ifdef RTF_IRTT                 /* route */
  84 #define HAVE_RTF_IRTT 1
  85 #endif
  86 #ifdef RTF_REJECT               /* route */
  87 #define HAVE_RTF_REJECT 1
  88 #endif
  89
  90 #if HAVE_NEW_ADDRT
  91 #define mask_in_addr(x) (((struct sockaddr_in *)&((x).rt_genmask))->sin_addr.s_addr)
  92 #define full_mask(x) (x)
  93 #else
  94 #define mask_in_addr(x) ((x).rt_genmask)
  95 #define full_mask(x) (((struct sockaddr_in *)&(x))->sin_addr.s_addr)
  96 #endif
  97
  98 /* add or delete a route depending on action */
  99
 100 static int
 101 INET_setroute(int action, int options, char **args)
 102 {
 103         struct rtentry rt;
 104         char target[128], gateway[128] = "NONE", netmask[128] = "default";
 105         int xflag, isnet;
 106         int skfd;
 107
 108         xflag = 0;
 109
 110         if (!strcmp(*args, "-net")) {
 111                 xflag = 1;
 112                 args++;
 113         } else if (!strcmp(*args, "-host")) {
 114                 xflag = 2;
 115                 args++;
 116         }
 117         if (*args == NULL)
 118                 show_usage();
 119
 120         safe_strncpy(target, *args++, (sizeof target));
 121
 122         /* Clean out the RTREQ structure. */
 123         memset((char *) &rt, 0, sizeof(struct rtentry));
 124
 125
 126         if ((isnet = INET_resolve(target, &rt.rt_dst)) < 0) {
 127                 fprintf(stderr, "cant resolve %s\n", target);
 128                 return (1);
 129         }
 130
 131         switch (xflag) {
 132                 case 1:
 133                         isnet = 1;
 134                         break;
 135
 136                 case 2:
 137                         isnet = 0;
 138                         break;
 139
 140                 default:
 141                         break;
 142         }
 143
 144         /* Fill in the other fields. */
 145         rt.rt_flags = (RTF_UP | RTF_HOST);
 146         if (isnet)
 147                 rt.rt_flags &= ~RTF_HOST;
 148
 149         while (*args) {
 150                 if (!strcmp(*args, "metric")) {
 151                         int metric;
 152
 153                         args++;
 154                         if (!*args || !isdigit(**args))
 155                                 show_usage();
 156                         metric = atoi(*args);
 157 #if HAVE_NEW_ADDRT
 158                         rt.rt_metric = metric + 1;
 159 #else
 160                         ENOSUPP("inet_setroute", "NEW_ADDRT (metric)");
 161 #endif
 162                         args++;
 163                         continue;
 164                 }
 165
 166                 if (!strcmp(*args, "netmask")) {
 167                         struct sockaddr mask;
 168
 169                         args++;
 170                         if (!*args || mask_in_addr(rt))
 171                                 show_usage();
 172                         safe_strncpy(netmask, *args, (sizeof netmask));
 173                         if ((isnet = INET_resolve(netmask, &mask)) < 0) {
 174                                 fprintf(stderr, "cant resolve netmask %s\n", netmask);
 175                                 return (E_LOOKUP);
 176                         }
 177                         rt.rt_genmask = full_mask(mask);
 178                         args++;
 179                         continue;
 180                 }
 181
 182                 if (!strcmp(*args, "gw") || !strcmp(*args, "gateway")) {
 183                         args++;
 184                         if (!*args)
 185                                 show_usage();
 186                         if (rt.rt_flags & RTF_GATEWAY)
 187                                 show_usage();
 188                         safe_strncpy(gateway, *args, (sizeof gateway));
 189                         if ((isnet = INET_resolve(gateway, &rt.rt_gateway)) < 0) {
 190                                 fprintf(stderr, "cant resolve gw %s\n", gateway);
 191                                 return (E_LOOKUP);
 192                         }
 193                         if (isnet) {
 194                                 fprintf(stderr,
 195                                         _("route: %s: cannot use a NETWORK as gateway!\n"),
 196                                         gateway);
 197                                 return (E_OPTERR);
 198                         }
 199                         rt.rt_flags |= RTF_GATEWAY;
 200                         args++;
 201                         continue;
 202                 }
 203
 204                 if (!strcmp(*args, "mss")) {
 205                         args++;
 206                         rt.rt_flags |= RTF_MSS;
 207                         if (!*args)
 208                                 show_usage();
 209                         rt.rt_mss = atoi(*args);
 210                         args++;
 211                         if (rt.rt_mss < 64 || rt.rt_mss > 32768) {
 212                                 fprintf(stderr, _("route: Invalid MSS.\n"));
 213                                 return (E_OPTERR);
 214                         }
 215                         continue;
 216                 }
 217
 218                 if (!strcmp(*args, "window")) {
 219                         args++;
 220                         if (!*args)
 221                                 show_usage();
 222                         rt.rt_flags |= RTF_WINDOW;
 223                         rt.rt_window = atoi(*args);
 224                         args++;
 225                         if (rt.rt_window < 128) {
 226                                 fprintf(stderr, _("route: Invalid window.\n"));
 227                                 return (E_OPTERR);
 228                         }
 229                         continue;
 230                 }
 231
 232                 if (!strcmp(*args, "irtt")) {
 233                         args++;
 234                         if (!*args)
 235                                 show_usage();
 236                         args++;
 237 #if HAVE_RTF_IRTT
 238                         rt.rt_flags |= RTF_IRTT;
 239                         rt.rt_irtt = atoi(*(args - 1));
 240                         rt.rt_irtt *= (HZ / 100);       /* FIXME */
 241 #if 0                           /* FIXME: do we need to check anything of this? */
 242                         if (rt.rt_irtt < 1 || rt.rt_irtt > (120 * HZ)) {
 243                                 fprintf(stderr, _("route: Invalid initial rtt.\n"));
 244                                 return (E_OPTERR);
 245                         }
 246 #endif
 247 #else
 248                         ENOSUPP("inet_setroute", "RTF_IRTT");
 249 #endif
 250                         continue;
 251                 }
 252
 253                 if (!strcmp(*args, "reject")) {
 254                         args++;
 255 #if HAVE_RTF_REJECT
 256                         rt.rt_flags |= RTF_REJECT;
 257 #else
 258                         ENOSUPP("inet_setroute", "RTF_REJECT");
 259 #endif
 260                         continue;
 261                 }
 262                 if (!strcmp(*args, "mod")) {
 263                         args++;
 264                         rt.rt_flags |= RTF_MODIFIED;
 265                         continue;
 266                 }
 267                 if (!strcmp(*args, "dyn")) {
 268                         args++;
 269                         rt.rt_flags |= RTF_DYNAMIC;
 270                         continue;
 271                 }
 272                 if (!strcmp(*args, "reinstate")) {
 273                         args++;
 274                         rt.rt_flags |= RTF_REINSTATE;
 275                         continue;
 276                 }
 277                 if (!strcmp(*args, "device") || !strcmp(*args, "dev")) {
 278                         args++;
 279                         if (rt.rt_dev || *args == NULL)
 280                                 show_usage();
 281                         rt.rt_dev = *args++;
 282                         continue;
 283                 }
 284                 /* nothing matches */
 285                 if (!rt.rt_dev) {
 286                         rt.rt_dev = *args++;
 287                         if (*args)
 288                                 show_usage();   /* must be last to catch typos */
 289                 } else
 290                         show_usage();
 291         }
 292
 293 #if HAVE_RTF_REJECT
 294         if ((rt.rt_flags & RTF_REJECT) && !rt.rt_dev)
 295                 rt.rt_dev = "lo";
 296 #endif
 297
 298         /* sanity checks.. */
 299         if (mask_in_addr(rt)) {
 300                 unsigned long mask = mask_in_addr(rt);
 301                 mask = ~ntohl(mask);
 302                 if ((rt.rt_flags & RTF_HOST) && mask != 0xffffffff) {
 303                         fprintf(stderr,
 304                                 _("route: netmask %.8x doesn't make sense with host route\n"),
 305                                 (unsigned int)mask);
 306                         return (E_OPTERR);
 307                 }
 308                 if (mask & (mask + 1)) {
 309                         fprintf(stderr, _("route: bogus netmask %s\n"), netmask);
 310                         return (E_OPTERR);
 311                 }
 312                 mask = ((struct sockaddr_in *) &rt.rt_dst)->sin_addr.s_addr;
 313                 if (mask & ~mask_in_addr(rt)) {
 314                         fprintf(stderr, _("route: netmask doesn't match route address\n"));
 315                         return (E_OPTERR);
 316                 }
 317         }
 318         /* Fill out netmask if still unset */
 319         if ((action == RTACTION_ADD) && rt.rt_flags & RTF_HOST)
 320                 mask_in_addr(rt) = 0xffffffff;
 321
 322         /* Create a socket to the INET kernel. */
 323         if ((skfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
 324                 perror("socket");
 325                 return (E_SOCK);
 326         }
 327         /* Tell the kernel to accept this route. */
 328         if (action == RTACTION_DEL) {
 329                 if (ioctl(skfd, SIOCDELRT, &rt) < 0) {
 330                         perror("SIOCDELRT");
 331                         close(skfd);
 332                         return (E_SOCK);
 333                 }
 334         } else {
 335                 if (ioctl(skfd, SIOCADDRT, &rt) < 0) {
 336                         perror("SIOCADDRT");
 337                         close(skfd);
 338                         return (E_SOCK);
 339                 }
 340         }
 341
 342         /* Close the socket. */
 343         (void) close(skfd);
 344         return (0);
 345 }
 346
 347 void displayroutes(void)
 348 {
 349         char buff[256];
 350         int  nl = 0 ;
 351         struct in_addr dest;
 352         struct in_addr gw;
 353         struct in_addr mask;
 354         int flgs, ref, use, metric;
 355         char flags[4];
 356         unsigned long int d,g,m;
 357
 358         char sdest[16], sgw[16];
 359
 360
 361         FILE *fp = fopen("/proc/net/route", "r");
 362
 363         if(fp==0) {
 364                 perror_msg_and_die("/proc/net/route");
 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                         dest.s_addr = d;
 377                         gw.s_addr   = g;
 378                         mask.s_addr = m;
 379                         if(nl==1)
 380                                 printf("Kernel IP routing table\n\
 381 Destination\tGateway\t\tGenmask\t\tFlags Metric Ref    Use Iface\n");
 382
 383                         ifl = 0;        /* parse flags */
 384                         if(flgs&1)
 385                                 flags[ifl++]='U';
 386                         if(flgs&2)
 387                                 flags[ifl++]='G';
 388                         if(flgs&4)
 389                                 flags[ifl++]='H';
 390                         flags[ifl]=0;
 391                         strcpy(sdest,  (dest.s_addr==0 ? "default" :
 392                                         inet_ntoa(dest)));
 393                         strcpy(sgw,    (gw.s_addr==0   ? "*"       :
 394                                         inet_ntoa(gw)));
 395                         printf("%-16s%-16s%-16s%-6s%-7d%-9d%-2d%s\n",
 396                                 sdest, sgw,
 397                                 inet_ntoa(mask),
 398                                 flags, metric, ref, use, buff);
 399                 }
 400         nl++;
 401         }
 402 }
 403
 404 int route_main(int argc, char **argv)
 405 {
 406         int what = 0;
 407
 408         argc--;
 409         argv++;
 410
 411         if (*argv == NULL) {
 412                 displayroutes();
 413                 exit(EXIT_SUCCESS);
 414         } else {
 415                 /* check verb */
 416                 if (!strcmp(*argv, "add"))
 417                         what = RTACTION_ADD;
 418                 else if (!strcmp(*argv, "del") || !strcmp(*argv, "delete"))
 419                         what = RTACTION_DEL;
 420                 else if (!strcmp(*argv, "flush"))
 421                         what = RTACTION_FLUSH;
 422                 else
 423                         show_usage();
 424         }
 425
 426         INET_setroute(what, 0, ++argv);
 427
 428         exit(EXIT_SUCCESS);
 429 }