*: introduce and use xfork()
[oweals/busybox.git] / networking / route.c
index 5c4ce8ca31dc6cf5288716c36398847b0cb349d0..0146fa02914c05f236696eb655a5b98ffc6ed7fd 100644 (file)
@@ -1,3 +1,4 @@
+/* vi: set sw=4 ts=4: */
 /* route
  *
  * Similar to the standard Unix route, but with only the necessary
@@ -9,13 +10,8 @@
  *              Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
  *              (derived from FvK's 'route.c     1.70    01/04/94')
  *
- * This program is free software; you can redistribute it
- * and/or  modify it under  the terms of  the GNU General
- * Public  License as  published  by  the  Free  Software
- * Foundation;  either  version 2 of the License, or  (at
- * your option) any later version.
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  *
- * $Id: route.c,v 1.18 2002/08/22 18:24:43 bug1 Exp $
  *
  * displayroute() code added by Vladimir N. Oleynik <dzo@simtreas.ru>
  * adjustments by Larry Doolittle  <LRDoolittle@lbl.gov>
  * IPV6 support added by Bart Visscher <magick@linux-fan.com>
  */
 
-#include <sys/types.h>
-#include <sys/ioctl.h>
-#include "inet_common.h"
+/* 2004/03/09  Manuel Novoa III <mjn3@codepoet.org>
+ *
+ * Rewritten to fix several bugs, add additional error checking, and
+ * remove ridiculous amounts of bloat.
+ */
+
 #include <net/route.h>
 #include <net/if.h>
-#include <linux/param.h>       /* HZ */
-#include <stdio.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <stdlib.h>
-#include <string.h>
-#include <getopt.h>
-#include <unistd.h>
-#include <ctype.h>
-#include "busybox.h"
-
-#define _(x) x
-
-#define RTACTION_ADD   1
-#define RTACTION_DEL   2
-#define RTACTION_HELP  3
-#define RTACTION_FLUSH 4
-#define RTACTION_SHOW  5
-
-#define E_NOTFOUND      8
-#define E_SOCK          7
-#define E_LOOKUP        6
-#define E_VERSION       5
-#define E_USAGE         4
-#define E_OPTERR        3
-#define E_INTERN        2
-#define E_NOSUPP        1
-
-#if defined (SIOCADDRTOLD) || defined (RTF_IRTT)       /* route */
-#define HAVE_NEW_ADDRT 1
+
+#include "libbb.h"
+#include "inet_common.h"
+
+
+#ifndef RTF_UP
+/* Keep this in sync with /usr/src/linux/include/linux/route.h */
+#define RTF_UP          0x0001 /* route usable                 */
+#define RTF_GATEWAY     0x0002 /* destination is a gateway     */
+#define RTF_HOST        0x0004 /* host entry (net otherwise)   */
+#define RTF_REINSTATE   0x0008 /* reinstate route after tmout  */
+#define RTF_DYNAMIC     0x0010 /* created dyn. (by redirect)   */
+#define RTF_MODIFIED    0x0020 /* modified dyn. (by redirect)  */
+#define RTF_MTU         0x0040 /* specific MTU for this route  */
+#ifndef RTF_MSS
+#define RTF_MSS         RTF_MTU        /* Compatibility :-(            */
 #endif
-#ifdef RTF_IRTT                        /* route */
-#define HAVE_RTF_IRTT 1
+#define RTF_WINDOW      0x0080 /* per route window clamping    */
+#define RTF_IRTT        0x0100 /* Initial round trip time      */
+#define RTF_REJECT      0x0200 /* Reject route                 */
 #endif
-#ifdef RTF_REJECT              /* route */
-#define HAVE_RTF_REJECT 1
+
+#if defined(SIOCADDRTOLD) || defined(RTF_IRTT) /* route */
+#define HAVE_NEW_ADDRT 1
 #endif
 
 #if HAVE_NEW_ADDRT
 #define full_mask(x) (((struct sockaddr_in *)&(x))->sin_addr.s_addr)
 #endif
 
+/* The RTACTION entries must agree with tbl_verb[] below! */
+#define RTACTION_ADD 1
+#define RTACTION_DEL 2
+
+/* For the various tbl_*[] arrays, the 1st byte is the offset to
+ * the next entry and the 2nd byte is return value. */
+
+#define NET_FLAG  1
+#define HOST_FLAG 2
+
+/* We remap '-' to '#' to avoid problems with getopt. */
+static const char tbl_hash_net_host[] ALIGN1 =
+       "\007\001#net\0"
+/*     "\010\002#host\0" */
+       "\007\002#host"                         /* Since last, we can save a byte. */
+;
+
+#define KW_TAKES_ARG            020
+#define KW_SETS_FLAG            040
+
+#define KW_IPVx_METRIC          020
+#define KW_IPVx_NETMASK         021
+#define KW_IPVx_GATEWAY         022
+#define KW_IPVx_MSS             023
+#define KW_IPVx_WINDOW          024
+#define KW_IPVx_IRTT            025
+#define KW_IPVx_DEVICE          026
+
+#define KW_IPVx_FLAG_ONLY       040
+#define KW_IPVx_REJECT          040
+#define KW_IPVx_MOD             041
+#define KW_IPVx_DYN             042
+#define KW_IPVx_REINSTATE       043
+
+static const char tbl_ipvx[] ALIGN1 =
+       /* 020 is the "takes an arg" bit */
+#if HAVE_NEW_ADDRT
+       "\011\020metric\0"
+#endif
+       "\012\021netmask\0"
+       "\005\022gw\0"
+       "\012\022gateway\0"
+       "\006\023mss\0"
+       "\011\024window\0"
+#ifdef RTF_IRTT
+       "\007\025irtt\0"
+#endif
+       "\006\026dev\0"
+       "\011\026device\0"
+       /* 040 is the "sets a flag" bit - MUST match flags_ipvx[] values below. */
+#ifdef RTF_REJECT
+       "\011\040reject\0"
+#endif
+       "\006\041mod\0"
+       "\006\042dyn\0"
+/*     "\014\043reinstate\0" */
+       "\013\043reinstate"                     /* Since last, we can save a byte. */
+;
+
+static const int flags_ipvx[] = { /* MUST match tbl_ipvx[] values above. */
+#ifdef RTF_REJECT
+       RTF_REJECT,
+#endif
+       RTF_MODIFIED,
+       RTF_DYNAMIC,
+       RTF_REINSTATE
+};
 
+static int kw_lookup(const char *kwtbl, char ***pargs)
+{
+       if (**pargs) {
+               do {
+                       if (strcmp(kwtbl+2, **pargs) == 0) { /* Found a match. */
+                               *pargs += 1;
+                               if (kwtbl[1] & KW_TAKES_ARG) {
+                                       if (!**pargs) { /* No more args! */
+                                               bb_show_usage();
+                                       }
+                                       *pargs += 1; /* Calling routine will use args[-1]. */
+                               }
+                               return kwtbl[1];
+                       }
+                       kwtbl += *kwtbl;
+               } while (*kwtbl);
+       }
+       return 0;
+}
 
-/* add or delete a route depending on action */
+/* Add or delete a route, depending on action. */
 
-static int INET_setroute(int action, int options, char **args)
+static void INET_setroute(int action, char **args)
 {
        struct rtentry rt;
-       char target[128], gateway[128] = "NONE";
-       const char *netmask = bb_INET_default;
-       int xflag, isnet;
-       int skfd;
-
-       xflag = 0;
-
-       if (*args == NULL)
-               show_usage();
-       if (strcmp(*args, "-net") == 0) {
-               xflag = 1;
-               args++;
-       } else if (strcmp(*args, "-host") == 0) {
-               xflag = 2;
-               args++;
+       const char *netmask = NULL;
+       int skfd, isnet, xflag;
+
+       /* Grab the -net or -host options.  Remember they were transformed. */
+       xflag = kw_lookup(tbl_hash_net_host, &args);
+
+       /* If we did grab -net or -host, make sure we still have an arg left. */
+       if (*args == NULL) {
+               bb_show_usage();
        }
-       if (*args == NULL)
-               show_usage();
-       safe_strncpy(target, *args++, (sizeof target));
 
        /* Clean out the RTREQ structure. */
-       memset((char *) &rt, 0, sizeof(struct rtentry));
+       memset(&rt, 0, sizeof(rt));
 
+       {
+               const char *target = *args++;
+               char *prefix;
 
-       if ((isnet =
-                INET_resolve(target, (struct sockaddr_in *) &rt.rt_dst,
-                                         xflag != 1)) < 0) {
-               error_msg(_("can't resolve %s"), target);
-               return EXIT_FAILURE;    /* XXX change to E_something */
-       }
-
-       switch (xflag) {
-       case 1:
-               isnet = 1;
-               break;
+               /* recognize x.x.x.x/mask format. */
+               prefix = strchr(target, '/');
+               if (prefix) {
+                       int prefix_len;
 
-       case 2:
-               isnet = 0;
-               break;
+                       prefix_len = xatoul_range(prefix+1, 0, 32);
+                       mask_in_addr(rt) = htonl( ~ (0xffffffffUL >> prefix_len));
+                       *prefix = '\0';
+#if HAVE_NEW_ADDRT
+                       rt.rt_genmask.sa_family = AF_INET;
+#endif
+               } else {
+                       /* Default netmask. */
+                       netmask = bb_str_default;
+               }
+               /* Prefer hostname lookup is -host flag (xflag==1) was given. */
+               isnet = INET_resolve(target, (struct sockaddr_in *) &rt.rt_dst,
+                                                        (xflag & HOST_FLAG));
+               if (isnet < 0) {
+                       bb_error_msg_and_die("resolving %s", target);
+               }
+               if (prefix) {
+                       /* do not destroy prefix for process args */
+                       *prefix = '/';
+               }
+       }
 
-       default:
-               break;
+       if (xflag) {            /* Reinit isnet if -net or -host was specified. */
+               isnet = (xflag & NET_FLAG);
        }
 
        /* Fill in the other fields. */
-       rt.rt_flags = (RTF_UP | RTF_HOST);
-       if (isnet)
-               rt.rt_flags &= ~RTF_HOST;
+       rt.rt_flags = ((isnet) ? RTF_UP : (RTF_UP | RTF_HOST));
 
        while (*args) {
-               if (strcmp(*args, "metric") == 0) {
-                       int metric;
+               int k = kw_lookup(tbl_ipvx, &args);
+               const char *args_m1 = args[-1];
+
+               if (k & KW_IPVx_FLAG_ONLY) {
+                       rt.rt_flags |= flags_ipvx[k & 3];
+                       continue;
+               }
 
-                       args++;
-                       if (!*args || !isdigit(**args))
-                               show_usage();
-                       metric = atoi(*args);
 #if HAVE_NEW_ADDRT
-                       rt.rt_metric = metric + 1;
-#else
-                       ENOSUPP("inet_setroute", "NEW_ADDRT (metric)"); /* XXX Fixme */
-#endif
-                       args++;
+               if (k == KW_IPVx_METRIC) {
+                       rt.rt_metric = xatoul(args_m1) + 1;
                        continue;
                }
+#endif
 
-               if (strcmp(*args, "netmask") == 0) {
+               if (k == KW_IPVx_NETMASK) {
                        struct sockaddr mask;
 
-                       args++;
-                       if (!*args || mask_in_addr(rt))
-                               show_usage();
-                       netmask = *args;
-                       if ((isnet =
-                                INET_resolve(netmask, (struct sockaddr_in *) &mask,
-                                                         0)) < 0) {
-                               error_msg(_("can't resolve netmask %s"), netmask);
-                               return E_LOOKUP;
+                       if (mask_in_addr(rt)) {
+                               bb_show_usage();
+                       }
+
+                       netmask = args_m1;
+                       isnet = INET_resolve(netmask, (struct sockaddr_in *) &mask, 0);
+                       if (isnet < 0) {
+                               bb_error_msg_and_die("resolving %s", netmask);
                        }
                        rt.rt_genmask = full_mask(mask);
-                       args++;
                        continue;
                }
 
-               if (strcmp(*args, "gw") == 0 || strcmp(*args, "gateway") == 0) {
-                       args++;
-                       if (!*args)
-                               show_usage();
-                       if (rt.rt_flags & RTF_GATEWAY)
-                               show_usage();
-                       safe_strncpy(gateway, *args, (sizeof gateway));
-                       if ((isnet =
-                                INET_resolve(gateway, (struct sockaddr_in *) &rt.rt_gateway,
-                                                         1)) < 0) {
-                               error_msg(_("can't resolve gw %s"), gateway);
-                               return E_LOOKUP;
+               if (k == KW_IPVx_GATEWAY) {
+                       if (rt.rt_flags & RTF_GATEWAY) {
+                               bb_show_usage();
                        }
+
+                       isnet = INET_resolve(args_m1,
+                                                                (struct sockaddr_in *) &rt.rt_gateway, 1);
+                       rt.rt_flags |= RTF_GATEWAY;
+
                        if (isnet) {
-                               error_msg(_("%s: cannot use a NETWORK as gateway!"), gateway);
-                               return E_OPTERR;
+                               if (isnet < 0) {
+                                       bb_error_msg_and_die("resolving %s", args_m1);
+                               }
+                               bb_error_msg_and_die("gateway %s is a NETWORK", args_m1);
                        }
-                       rt.rt_flags |= RTF_GATEWAY;
-                       args++;
                        continue;
                }
 
-               if (strcmp(*args, "mss") == 0) {
-                       args++;
+               if (k == KW_IPVx_MSS) { /* Check valid MSS bounds. */
                        rt.rt_flags |= RTF_MSS;
-                       if (!*args)
-                               show_usage();
-                       rt.rt_mss = atoi(*args);
-                       args++;
-                       if (rt.rt_mss < 64 || rt.rt_mss > 32768) {
-                               error_msg(_("Invalid MSS."));
-                               return E_OPTERR;
-                       }
+                       rt.rt_mss = xatoul_range(args_m1, 64, 32768);
                        continue;
                }
 
-               if (strcmp(*args, "window") == 0) {
-                       args++;
-                       if (!*args)
-                               show_usage();
+               if (k == KW_IPVx_WINDOW) {      /* Check valid window bounds. */
                        rt.rt_flags |= RTF_WINDOW;
-                       rt.rt_window = atoi(*args);
-                       args++;
-                       if (rt.rt_window < 128) {
-                               error_msg(_("Invalid window."));
-                               return E_OPTERR;
-                       }
+                       rt.rt_window = xatoul_range(args_m1, 128, INT_MAX);
                        continue;
                }
 
-               if (strcmp(*args, "irtt") == 0) {
-                       args++;
-                       if (!*args)
-                               show_usage();
-                       args++;
-#if HAVE_RTF_IRTT
+#ifdef RTF_IRTT
+               if (k == KW_IPVx_IRTT) {
                        rt.rt_flags |= RTF_IRTT;
-                       rt.rt_irtt = atoi(*(args - 1));
-                       rt.rt_irtt *= (HZ / 100);       /* FIXME */
+                       rt.rt_irtt = xatoul(args_m1);
+                       rt.rt_irtt *= (sysconf(_SC_CLK_TCK) / 100);     /* FIXME */
 #if 0                                  /* FIXME: do we need to check anything of this? */
                        if (rt.rt_irtt < 1 || rt.rt_irtt > (120 * HZ)) {
-                               error_msg(_("Invalid initial rtt."));
-                               return E_OPTERR;
+                               bb_error_msg_and_die("bad irtt");
                        }
-#endif
-#else
-                       ENOSUPP("inet_setroute", "RTF_IRTT");   /* XXX Fixme */
 #endif
                        continue;
                }
-
-               if (strcmp(*args, "reject") == 0) {
-                       args++;
-#if HAVE_RTF_REJECT
-                       rt.rt_flags |= RTF_REJECT;
-#else
-                       ENOSUPP("inet_setroute", "RTF_REJECT"); /* XXX Fixme */
 #endif
+
+               /* Device is special in that it can be the last arg specified
+                * and doesn't requre the dev/device keyword in that case. */
+               if (!rt.rt_dev && ((k == KW_IPVx_DEVICE) || (!k && !*++args))) {
+                       /* Don't use args_m1 here since args may have changed! */
+                       rt.rt_dev = args[-1];
                        continue;
                }
-               if (strcmp(*args, "mod") == 0) {
-                       args++;
-                       rt.rt_flags |= RTF_MODIFIED;
-                       continue;
-               }
-               if (strcmp(*args, "dyn") == 0) {
-                       args++;
-                       rt.rt_flags |= RTF_DYNAMIC;
-                       continue;
-               }
-               if (strcmp(*args, "reinstate") == 0) {
-                       args++;
-                       rt.rt_flags |= RTF_REINSTATE;
-                       continue;
-               }
-               if (strcmp(*args, "device") == 0 || strcmp(*args, "dev") == 0) {
-                       args++;
-                       if (rt.rt_dev || *args == NULL)
-                               show_usage();
-                       rt.rt_dev = *args++;
-                       continue;
-               }
-               /* nothing matches */
-               if (!rt.rt_dev) {
-                       rt.rt_dev = *args++;
-                       if (*args)
-                               show_usage();   /* must be last to catch typos */
-               } else {
-                       show_usage();
-               }
+
+               /* Nothing matched. */
+               bb_show_usage();
        }
 
-#if HAVE_RTF_REJECT
-       if ((rt.rt_flags & RTF_REJECT) && !rt.rt_dev)
-               rt.rt_dev = "lo";
+#ifdef RTF_REJECT
+       if ((rt.rt_flags & RTF_REJECT) && !rt.rt_dev) {
+               rt.rt_dev = (char*)"lo";
+       }
 #endif
 
        /* sanity checks.. */
@@ -288,420 +306,394 @@ static int INET_setroute(int action, int options, char **args)
 
                mask = ~ntohl(mask);
                if ((rt.rt_flags & RTF_HOST) && mask != 0xffffffff) {
-                       error_msg(_("netmask %.8x doesn't make sense with host route"),
-                                         (unsigned int) mask);
-                       return E_OPTERR;
+                       bb_error_msg_and_die("netmask %.8x and host route conflict",
+                                                                (unsigned int) mask);
                }
                if (mask & (mask + 1)) {
-                       error_msg(_("bogus netmask %s"), netmask);
-                       return E_OPTERR;
+                       bb_error_msg_and_die("bogus netmask %s", netmask);
                }
                mask = ((struct sockaddr_in *) &rt.rt_dst)->sin_addr.s_addr;
                if (mask & ~mask_in_addr(rt)) {
-                       error_msg(_("netmask doesn't match route address"));
-                       return E_OPTERR;
+                       bb_error_msg_and_die("netmask and route address conflict");
                }
        }
+
        /* Fill out netmask if still unset */
-       if ((action == RTACTION_ADD) && rt.rt_flags & RTF_HOST)
+       if ((action == RTACTION_ADD) && (rt.rt_flags & RTF_HOST)) {
                mask_in_addr(rt) = 0xffffffff;
+       }
 
        /* Create a socket to the INET kernel. */
-       if ((skfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
-               perror("socket");
-               return E_SOCK;
-       }
-       /* Tell the kernel to accept this route. */
-       if (action == RTACTION_DEL) {
-               if (ioctl(skfd, SIOCDELRT, &rt) < 0) {
-                       perror("SIOCDELRT");
-                       close(skfd);
-                       return E_SOCK;
-               }
-       } else {
-               if (ioctl(skfd, SIOCADDRT, &rt) < 0) {
-                       perror("SIOCADDRT");
-                       close(skfd);
-                       return E_SOCK;
-               }
-       }
+       skfd = xsocket(AF_INET, SOCK_DGRAM, 0);
 
-       /* Close the socket. */
-       (void) close(skfd);
-       return EXIT_SUCCESS;
+       if (action == RTACTION_ADD)
+               xioctl(skfd, SIOCADDRT, &rt);
+       else
+               xioctl(skfd, SIOCDELRT, &rt);
+
+       if (ENABLE_FEATURE_CLEAN_UP) close(skfd);
 }
 
-#if CONFIG_FEATURE_IPV6
-static int INET6_setroute(int action, int options, char **args)
+#if ENABLE_FEATURE_IPV6
+
+static void INET6_setroute(int action, char **args)
 {
-       struct in6_rtmsg rt;
-       struct ifreq ifr;
        struct sockaddr_in6 sa6;
-       char target[128], gateway[128] = "NONE";
-       int metric, prefix_len;
-       char *devname = NULL;
-       char *cp;
-       int skfd;
-
-       if (*args == NULL)
-               show_usage();
-
-       strcpy(target, *args++);
-       if (!strcmp(target, "default")) {
-               prefix_len = 0;
-               memset(&sa6, 0, sizeof(sa6));
-       } else {
-               if ((cp = strchr(target, '/'))) {
-                       prefix_len = atol(cp + 1);
-                       if ((prefix_len < 0) || (prefix_len > 128))
-                               show_usage();
-                       *cp = 0;
+       struct in6_rtmsg rt;
+       int prefix_len, skfd;
+       const char *devname;
+
+               /* We know args isn't NULL from the check in route_main. */
+               const char *target = *args++;
+
+               if (strcmp(target, bb_str_default) == 0) {
+                       prefix_len = 0;
+                       memset(&sa6, 0, sizeof(sa6));
                } else {
-                       prefix_len = 128;
-               }
-               if (INET6_resolve(target, (struct sockaddr_in6 *) &sa6) < 0) {
-                       error_msg(_("can't resolve %s"), target);
-                       return EXIT_FAILURE;    /* XXX change to E_something */
+                       char *cp;
+                       cp = strchr(target, '/'); /* Yes... const to non is ok. */
+                       if (cp) {
+                               *cp = '\0';
+                               prefix_len = xatoul_range(cp + 1, 0, 128);
+                       } else {
+                               prefix_len = 128;
+                       }
+                       if (INET6_resolve(target, (struct sockaddr_in6 *) &sa6) < 0) {
+                               bb_error_msg_and_die("resolving %s", target);
+                       }
                }
-       }
 
        /* Clean out the RTREQ structure. */
-       memset((char *) &rt, 0, sizeof(struct in6_rtmsg));
+       memset(&rt, 0, sizeof(rt));
 
        memcpy(&rt.rtmsg_dst, sa6.sin6_addr.s6_addr, sizeof(struct in6_addr));
 
        /* Fill in the other fields. */
-       rt.rtmsg_flags = RTF_UP;
-       if (prefix_len == 128)
-               rt.rtmsg_flags |= RTF_HOST;
-       rt.rtmsg_metric = 1;
        rt.rtmsg_dst_len = prefix_len;
+       rt.rtmsg_flags = ((prefix_len == 128) ? (RTF_UP|RTF_HOST) : RTF_UP);
+       rt.rtmsg_metric = 1;
+
+       devname = NULL;
 
        while (*args) {
-               if (!strcmp(*args, "metric")) {
-
-                       args++;
-                       if (!*args || !isdigit(**args))
-                               show_usage();
-                       metric = atoi(*args);
-                       rt.rtmsg_metric = metric;
-                       args++;
+               int k = kw_lookup(tbl_ipvx, &args);
+               const char *args_m1 = args[-1];
+
+               if ((k == KW_IPVx_MOD) || (k == KW_IPVx_DYN)) {
+                       rt.rtmsg_flags |= flags_ipvx[k & 3];
+                       continue;
+               }
+
+               if (k == KW_IPVx_METRIC) {
+                       rt.rtmsg_metric = xatoul(args_m1);
                        continue;
                }
-               if (!strcmp(*args, "gw") || !strcmp(*args, "gateway")) {
-                       args++;
-                       if (!*args)
-                               show_usage();
-                       if (rt.rtmsg_flags & RTF_GATEWAY)
-                               show_usage();
-                       strcpy(gateway, *args);
-                       if (INET6_resolve(gateway, (struct sockaddr_in6 *) &sa6) < 0) {
-                               error_msg(_("can't resolve gw %s"), gateway);
-                               return (E_LOOKUP);
+
+               if (k == KW_IPVx_GATEWAY) {
+                       if (rt.rtmsg_flags & RTF_GATEWAY) {
+                               bb_show_usage();
+                       }
+
+                       if (INET6_resolve(args_m1, (struct sockaddr_in6 *) &sa6) < 0) {
+                               bb_error_msg_and_die("resolving %s", args_m1);
                        }
                        memcpy(&rt.rtmsg_gateway, sa6.sin6_addr.s6_addr,
                                   sizeof(struct in6_addr));
                        rt.rtmsg_flags |= RTF_GATEWAY;
-                       args++;
                        continue;
                }
-               if (!strcmp(*args, "mod")) {
-                       args++;
-                       rt.rtmsg_flags |= RTF_MODIFIED;
-                       continue;
-               }
-               if (!strcmp(*args, "dyn")) {
-                       args++;
-                       rt.rtmsg_flags |= RTF_DYNAMIC;
+
+               /* Device is special in that it can be the last arg specified
+                * and doesn't requre the dev/device keyword in that case. */
+               if (!devname && ((k == KW_IPVx_DEVICE) || (!k && !*++args))) {
+                       /* Don't use args_m1 here since args may have changed! */
+                       devname = args[-1];
                        continue;
                }
-               if (!strcmp(*args, "device") || !strcmp(*args, "dev")) {
-                       args++;
-                       if (!*args)
-                               show_usage();
-               } else if (args[1])
-                       show_usage();
-
-               devname = *args;
-               args++;
+
+               /* Nothing matched. */
+               bb_show_usage();
        }
 
        /* Create a socket to the INET6 kernel. */
-       if ((skfd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
-               perror("socket");
-               return (E_SOCK);
-       }
+       skfd = xsocket(AF_INET6, SOCK_DGRAM, 0);
+
+       rt.rtmsg_ifindex = 0;
+
        if (devname) {
+               struct ifreq ifr;
                memset(&ifr, 0, sizeof(ifr));
-               strcpy(ifr.ifr_name, devname);
-
-               if (ioctl(skfd, SIOGIFINDEX, &ifr) < 0) {
-                       perror("SIOGIFINDEX");
-                       return (E_SOCK);
-               }
+               strncpy(ifr.ifr_name, devname, sizeof(ifr.ifr_name));
+               xioctl(skfd, SIOGIFINDEX, &ifr);
                rt.rtmsg_ifindex = ifr.ifr_ifindex;
-       } else
-               rt.rtmsg_ifindex = 0;
+       }
 
        /* Tell the kernel to accept this route. */
-       if (action == RTACTION_DEL) {
-               if (ioctl(skfd, SIOCDELRT, &rt) < 0) {
-                       perror("SIOCDELRT");
-                       close(skfd);
-                       return (E_SOCK);
-               }
-       } else {
-               if (ioctl(skfd, SIOCADDRT, &rt) < 0) {
-                       perror("SIOCADDRT");
-                       close(skfd);
-                       return (E_SOCK);
-               }
-       }
+       if (action == RTACTION_ADD)
+               xioctl(skfd, SIOCADDRT, &rt);
+       else
+               xioctl(skfd, SIOCDELRT, &rt);
 
-       /* Close the socket. */
-       (void) close(skfd);
-       return (0);
+       if (ENABLE_FEATURE_CLEAN_UP) close(skfd);
 }
 #endif
 
-#ifndef RTF_UP
-/* Keep this in sync with /usr/src/linux/include/linux/route.h */
-#define RTF_UP          0x0001 /* route usable                 */
-#define RTF_GATEWAY     0x0002 /* destination is a gateway     */
-#define RTF_HOST        0x0004 /* host entry (net otherwise)   */
-#define RTF_REINSTATE   0x0008 /* reinstate route after tmout  */
-#define RTF_DYNAMIC     0x0010 /* created dyn. (by redirect)   */
-#define RTF_MODIFIED    0x0020 /* modified dyn. (by redirect)  */
-#define RTF_MTU         0x0040 /* specific MTU for this route  */
-#ifndef RTF_MSS
-#define RTF_MSS         RTF_MTU        /* Compatibility :-(            */
+static const unsigned flagvals[] = { /* Must agree with flagchars[]. */
+       RTF_GATEWAY,
+       RTF_HOST,
+       RTF_REINSTATE,
+       RTF_DYNAMIC,
+       RTF_MODIFIED,
+#if ENABLE_FEATURE_IPV6
+       RTF_DEFAULT,
+       RTF_ADDRCONF,
+       RTF_CACHE
 #endif
-#define RTF_WINDOW      0x0080 /* per route window clamping    */
-#define RTF_IRTT        0x0100 /* Initial round trip time      */
-#define RTF_REJECT      0x0200 /* Reject route                 */
+};
+
+#define IPV4_MASK (RTF_GATEWAY|RTF_HOST|RTF_REINSTATE|RTF_DYNAMIC|RTF_MODIFIED)
+#define IPV6_MASK (RTF_GATEWAY|RTF_HOST|RTF_DEFAULT|RTF_ADDRCONF|RTF_CACHE)
+
+/* Must agree with flagvals[]. */
+static const char flagchars[] ALIGN1 =
+       "GHRDM"
+#if ENABLE_FEATURE_IPV6
+       "DAC"
 #endif
+;
 
-void displayroutes(int noresolve, int netstatfmt)
+static void set_flags(char *flagstr, int flags)
 {
-       char buff[256];
-       int nl = 0;
-       struct in_addr dest;
-       struct in_addr gw;
-       struct in_addr mask;
-       int flgs, ref, use, metric, mtu, win, ir;
-       char flags[64];
-       unsigned long int d, g, m;
+       int i;
+
+       *flagstr++ = 'U';
+
+       for (i = 0; (*flagstr = flagchars[i]) != 0; i++) {
+               if (flags & flagvals[i]) {
+                       ++flagstr;
+               }
+       }
+}
 
-       char sdest[16], sgw[16];
+/* also used in netstat */
+void FAST_FUNC bb_displayroutes(int noresolve, int netstatfmt)
+{
+       char devname[64], flags[16], *sdest, *sgw;
+       unsigned long d, g, m;
+       int flgs, ref, use, metric, mtu, win, ir;
+       struct sockaddr_in s_addr;
+       struct in_addr mask;
 
        FILE *fp = xfopen("/proc/net/route", "r");
 
-       if (noresolve)
-               noresolve = 0x0fff;
-
-       while (fgets(buff, sizeof(buff), fp) != NULL) {
-               if (nl) {
-                       int ifl = 0;
-                       int numeric;
-                       struct sockaddr_in s_addr;
-
-                       while (buff[ifl] != ' ' && buff[ifl] != '\t' && buff[ifl] != '\0')
-                               ifl++;
-                       buff[ifl] = 0;  /* interface */
-                       if (sscanf(buff + ifl + 1, "%lx%lx%X%d%d%d%lx%d%d%d",
-                                          &d, &g, &flgs, &ref, &use, &metric, &m, &mtu, &win,
-                                          &ir) != 10) {
-                               error_msg_and_die("Unsuported kernel route format\n");
-                       }
-                       if (nl == 1) {
-                               printf("Kernel IP routing table\n");
-                               printf
-                                       ("Destination     Gateway         Genmask         Flags %s Iface\n",
-                                        netstatfmt ? "  MSS Window  irtt" : "Metric Ref    Use");
-                       }
-                       ifl = 0;        /* parse flags */
-                       if (flgs & RTF_UP) {
-                               if (flgs & RTF_REJECT)
-                                       flags[ifl++] = '!';
-                               else
-                                       flags[ifl++] = 'U';
-                               if (flgs & RTF_GATEWAY)
-                                       flags[ifl++] = 'G';
-                               if (flgs & RTF_HOST)
-                                       flags[ifl++] = 'H';
-                               if (flgs & RTF_REINSTATE)
-                                       flags[ifl++] = 'R';
-                               if (flgs & RTF_DYNAMIC)
-                                       flags[ifl++] = 'D';
-                               if (flgs & RTF_MODIFIED)
-                                       flags[ifl++] = 'M';
-                               flags[ifl] = 0;
-                               dest.s_addr = d;
-                               gw.s_addr = g;
-                               mask.s_addr = m;
-                               memset(&s_addr, 0, sizeof(struct sockaddr_in));
-                               s_addr.sin_family = AF_INET;
-                               s_addr.sin_addr = dest;
-                               numeric = noresolve | 0x8000;   /* default instead of * */
-                               INET_rresolve(sdest, sizeof(sdest), &s_addr, numeric, m);
-                               numeric = noresolve | 0x4000;   /* host instead of net */
-                               s_addr.sin_addr = gw;
-                               INET_rresolve(sgw, sizeof(sgw), &s_addr, numeric, m);
-
-                               printf("%-16s%-16s%-16s%-6s", sdest, sgw, inet_ntoa(mask),
-                                          flags);
-                               if (netstatfmt)
-                                       printf("%5d %-5d %6d %s\n", mtu, win, ir, buff);
-                               else
-                                       printf("%-6d %-2d %7d %s\n", metric, ref, use, buff);
+       printf("Kernel IP routing table\n"
+              "Destination     Gateway         Genmask         Flags %s Iface\n",
+                       netstatfmt ? "  MSS Window  irtt" : "Metric Ref    Use");
+
+       if (fscanf(fp, "%*[^\n]\n") < 0) { /* Skip the first line. */
+               goto ERROR;                /* Empty or missing line, or read error. */
+       }
+       while (1) {
+               int r;
+               r = fscanf(fp, "%63s%lx%lx%X%d%d%d%lx%d%d%d\n",
+                                  devname, &d, &g, &flgs, &ref, &use, &metric, &m,
+                                  &mtu, &win, &ir);
+               if (r != 11) {
+                       if ((r < 0) && feof(fp)) { /* EOF with no (nonspace) chars read. */
+                               break;
                        }
+ ERROR:
+                       bb_error_msg_and_die("fscanf");
+               }
+
+               if (!(flgs & RTF_UP)) { /* Skip interfaces that are down. */
+                       continue;
+               }
+
+               set_flags(flags, (flgs & IPV4_MASK));
+#ifdef RTF_REJECT
+               if (flgs & RTF_REJECT) {
+                       flags[0] = '!';
+               }
+#endif
+
+               memset(&s_addr, 0, sizeof(struct sockaddr_in));
+               s_addr.sin_family = AF_INET;
+               s_addr.sin_addr.s_addr = d;
+               sdest = INET_rresolve(&s_addr, (noresolve | 0x8000), m); /* 'default' instead of '*' */
+               s_addr.sin_addr.s_addr = g;
+               sgw = INET_rresolve(&s_addr, (noresolve | 0x4000), m); /* Host instead of net */
+               mask.s_addr = m;
+               /* "%15.15s" truncates hostnames, do we really want that? */
+               printf("%-15.15s %-15.15s %-16s%-6s", sdest, sgw, inet_ntoa(mask), flags);
+               free(sdest);
+               free(sgw);
+               if (netstatfmt) {
+                       printf("%5d %-5d %6d %s\n", mtu, win, ir, devname);
+               } else {
+                       printf("%-6d %-2d %7d %s\n", metric, ref, use, devname);
                }
-               nl++;
        }
 }
 
-#if CONFIG_FEATURE_IPV6
-static void INET6_displayroutes(int noresolve)
+#if ENABLE_FEATURE_IPV6
+
+static void INET6_displayroutes(void)
 {
-       char buff[256];
+       char addr6[128], *naddr6;
+       /* In addr6x, we store both 40-byte ':'-delimited ipv6 addresses.
+        * We read the non-delimited strings into the tail of the buffer
+        * using fscanf and then modify the buffer by shifting forward
+        * while inserting ':'s and the nul terminator for the first string.
+        * Hence the strings are at addr6x and addr6x+40.  This generates
+        * _much_ less code than the previous (upstream) approach. */
+       char addr6x[80];
        char iface[16], flags[16];
-       char addr6[128], naddr6[128];
-       struct sockaddr_in6 saddr6, snaddr6;
        int iflags, metric, refcnt, use, prefix_len, slen;
-       int numeric;
-
-       char addr6p[8][5], saddr6p[8][5], naddr6p[8][5];
+       struct sockaddr_in6 snaddr6;
 
        FILE *fp = xfopen("/proc/net/ipv6_route", "r");
 
-       flags[0] = 'U';
-
-       if (noresolve)
-               noresolve = 0x0fff;
-       numeric = noresolve | 0x8000;   /* default instead of * */
-
-       printf("Kernel IPv6 routing table\n"
-                  "Destination                                 "
-                  "Next Hop                                "
-                  "Flags Metric Ref    Use Iface\n");
-
-       while (fgets(buff, sizeof(buff), fp) != NULL) {
-               int ifl;
-
-               if (sscanf(buff, "%4s%4s%4s%4s%4s%4s%4s%4s %02x "
-                                  "%4s%4s%4s%4s%4s%4s%4s%4s %02x "
-                                  "%4s%4s%4s%4s%4s%4s%4s%4s %08x %08x %08x %08x %s\n",
-                                  addr6p[0], addr6p[1], addr6p[2], addr6p[3],
-                                  addr6p[4], addr6p[5], addr6p[6], addr6p[7],
-                                  &prefix_len,
-                                  saddr6p[0], saddr6p[1], saddr6p[2], saddr6p[3],
-                                  saddr6p[4], saddr6p[5], saddr6p[6], saddr6p[7],
-                                  &slen,
-                                  naddr6p[0], naddr6p[1], naddr6p[2], naddr6p[3],
-                                  naddr6p[4], naddr6p[5], naddr6p[6], naddr6p[7],
-                                  &metric, &use, &refcnt, &iflags, iface) != 31) {
-                       error_msg_and_die("Unsuported kernel route format\n");
+       printf("Kernel IPv6 routing table\n%-44s%-40s"
+                         "Flags Metric Ref    Use Iface\n",
+                         "Destination", "Next Hop");
+
+       while (1) {
+               int r;
+               r = fscanf(fp, "%32s%x%*s%x%32s%x%x%x%x%s\n",
+                                  addr6x+14, &prefix_len, &slen, addr6x+40+7,
+                                  &metric, &use, &refcnt, &iflags, iface);
+               if (r != 9) {
+                       if ((r < 0) && feof(fp)) { /* EOF with no (nonspace) chars read. */
+                               break;
+                       }
+ ERROR:
+                       bb_error_msg_and_die("fscanf");
+               }
+
+               /* Do the addr6x shift-and-insert changes to ':'-delimit addresses.
+                * For now, always do this to validate the proc route format, even
+                * if the interface is down. */
+               {
+                       int i = 0;
+                       char *p = addr6x+14;
+
+                       do {
+                               if (!*p) {
+                                       if (i == 40) { /* nul terminator for 1st address? */
+                                               addr6x[39] = 0; /* Fixup... need 0 instead of ':'. */
+                                               ++p;    /* Skip and continue. */
+                                               continue;
+                                       }
+                                       goto ERROR;
+                               }
+                               addr6x[i++] = *p++;
+                               if (!((i+1) % 5)) {
+                                       addr6x[i++] = ':';
+                               }
+                       } while (i < 40+28+7);
                }
 
-               ifl = 1;                /* parse flags */
-               if (!(iflags & RTF_UP))
+               if (!(iflags & RTF_UP)) { /* Skip interfaces that are down. */
                        continue;
-               if (iflags & RTF_GATEWAY)
-                       flags[ifl++] = 'G';
-               if (iflags & RTF_HOST)
-                       flags[ifl++] = 'H';
-               if (iflags & RTF_DEFAULT)
-                       flags[ifl++] = 'D';
-               if (iflags & RTF_ADDRCONF)
-                       flags[ifl++] = 'A';
-               if (iflags & RTF_CACHE)
-                       flags[ifl++] = 'C';
-               flags[ifl] = 0;
-
-               /* Fetch and resolve the target address. */
-               snprintf(addr6, sizeof(addr6), "%s:%s:%s:%s:%s:%s:%s:%s",
-                                addr6p[0], addr6p[1], addr6p[2], addr6p[3],
-                                addr6p[4], addr6p[5], addr6p[6], addr6p[7]);
-               inet_pton(AF_INET6, addr6, (struct sockaddr *) &saddr6.sin6_addr);
-               saddr6.sin6_family = AF_INET6;
-
-               INET6_rresolve(addr6, sizeof(addr6), (struct sockaddr_in6 *) &saddr6,
-                                          numeric);
-               snprintf(addr6, sizeof(addr6), "%s/%d", addr6, prefix_len);
-
-               /* Fetch and resolve the nexthop address. */
-               snprintf(naddr6, sizeof(naddr6), "%s:%s:%s:%s:%s:%s:%s:%s",
-                                naddr6p[0], naddr6p[1], naddr6p[2], naddr6p[3],
-                                naddr6p[4], naddr6p[5], naddr6p[6], naddr6p[7]);
-               inet_pton(AF_INET6, naddr6, (struct sockaddr *) &snaddr6.sin6_addr);
-               snaddr6.sin6_family = AF_INET6;
-
-               INET6_rresolve(naddr6, sizeof(naddr6),
-                                          (struct sockaddr_in6 *) &snaddr6, numeric);
-
-               /* Print the info. */
-               printf("%-43s %-39s %-5s %-6d %-2d %7d %-8s\n",
-                          addr6, naddr6, flags, metric, refcnt, use, iface);
+               }
+
+               set_flags(flags, (iflags & IPV6_MASK));
+
+               r = 0;
+               do {
+                       inet_pton(AF_INET6, addr6x + r,
+                                         (struct sockaddr *) &snaddr6.sin6_addr);
+                       snaddr6.sin6_family = AF_INET6;
+                       naddr6 = INET6_rresolve((struct sockaddr_in6 *) &snaddr6,
+                                                  0x0fff /* Apparently, upstream never resolves. */
+                                                  );
+
+                       if (!r) {                       /* 1st pass */
+                               snprintf(addr6, sizeof(addr6), "%s/%d", naddr6, prefix_len);
+                               r += 40;
+                               free(naddr6);
+                       } else {                        /* 2nd pass */
+                               /* Print the info. */
+                               printf("%-43s %-39s %-5s %-6d %-2d %7d %-8s\n",
+                                               addr6, naddr6, flags, metric, refcnt, use, iface);
+                               free(naddr6);
+                               break;
+                       }
+               } while (1);
        }
 }
+
 #endif
 
-int route_main(int argc, char **argv)
+#define ROUTE_OPT_A     0x01
+#define ROUTE_OPT_n     0x02
+#define ROUTE_OPT_e     0x04
+#define ROUTE_OPT_INET6 0x08 /* Not an actual option. See below. */
+
+/* 1st byte is offset to next entry offset.  2nd byte is return value. */
+/* 2nd byte matches RTACTION_* code */
+static const char tbl_verb[] ALIGN1 =
+       "\006\001add\0"
+       "\006\002del\0"
+/*     "\011\002delete\0" */
+       "\010\002delete"  /* Since it's last, we can save a byte. */
+;
+
+int route_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int route_main(int argc ATTRIBUTE_UNUSED, char **argv)
 {
-       int opt;
-       int what = 0;
-
-#if CONFIG_FEATURE_IPV6
-       int af = AF_INET;
-#endif
+       unsigned opt;
+       int what;
+       char *family;
+       char **p;
+
+       /* First, remap '-net' and '-host' to avoid getopt problems. */
+       p = argv;
+       while (*++p) {
+               if (strcmp(*p, "-net") == 0 || strcmp(*p, "-host") == 0) {
+                       p[0][0] = '#';
+               }
+       }
 
-       if (!argv[1] || (argv[1][0] == '-')) {
-               /* check options */
-               int noresolve = 0;
-               int extended = 0;
+       opt = getopt32(argv, "A:ne", &family);
 
-               while ((opt = getopt(argc, argv, "A:ne")) > 0) {
-                       switch (opt) {
-                       case 'n':
-                               noresolve = 1;
-                               break;
-                       case 'e':
-                               extended = 1;
-                               break;
-                       case 'A':
-#if CONFIG_FEATURE_IPV6
-                               if (strcmp(optarg, "inet6") == 0)
-                                       af = AF_INET6;
-                               break;
+       if ((opt & ROUTE_OPT_A) && strcmp(family, "inet") != 0) {
+#if ENABLE_FEATURE_IPV6
+               if (strcmp(family, "inet6") == 0) {
+                       opt |= ROUTE_OPT_INET6; /* Set flag for ipv6. */
+               } else
 #endif
-                       default:
-                               show_usage();
-                       }
-               }
+               bb_show_usage();
+       }
+
+       argv += optind;
 
-#if CONFIG_FEATURE_IPV6
-               if (af == AF_INET6)
-                       INET6_displayroutes(*argv != NULL);
+       /* No more args means display the routing table. */
+       if (!*argv) {
+               int noresolve = (opt & ROUTE_OPT_n) ? 0x0fff : 0;
+#if ENABLE_FEATURE_IPV6
+               if (opt & ROUTE_OPT_INET6)
+                       INET6_displayroutes();
                else
 #endif
-                       displayroutes(noresolve, extended);
-               return EXIT_SUCCESS;
-       } else {
-               /* check verb */
-               if (strcmp(argv[1], "add") == 0)
-                       what = RTACTION_ADD;
-               else if (strcmp(argv[1], "del") == 0
-                                || strcmp(argv[1], "delete") == 0)
-                       what = RTACTION_DEL;
-               else if (strcmp(argv[1], "flush") == 0)
-                       what = RTACTION_FLUSH;
-               else
-                       show_usage();
+                       bb_displayroutes(noresolve, opt & ROUTE_OPT_e);
+
+               fflush_stdout_and_exit(EXIT_SUCCESS);
+       }
+
+       /* Check verb.  At the moment, must be add, del, or delete. */
+       what = kw_lookup(tbl_verb, &argv);
+       if (!what || !*argv) {          /* Unknown verb or no more args. */
+               bb_show_usage();
        }
 
-#if CONFIG_FEATURE_IPV6
-       if (af == AF_INET6)
-               return INET6_setroute(what, 0, argv + 2);
+#if ENABLE_FEATURE_IPV6
+       if (opt & ROUTE_OPT_INET6)
+               INET6_setroute(what, argv);
+       else
 #endif
-       return INET_setroute(what, 0, argv + 2);
+               INET_setroute(what, argv);
+
+       return EXIT_SUCCESS;
 }