busybox/networking/route.c

/* vi: set sw=4 ts=4: */
/* route
 *
 * Similar to the standard Unix route, but with only the necessary
 * parts for AF_INET and AF_INET6
 *
 * Bjorn Wesen, Axis Communications AB
 *
 * Author of the original route:
 *              Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
 *              (derived from FvK's 'route.c     1.70    01/04/94')
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 *
 * $Id: route.c,v 1.1 2007-09-01 22:43:53 niro 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>
 */

/* 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 "busybox.h"
#include "inet_common.h"
#include <getopt.h>
#include <net/route.h>
#include <net/if.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
#define RTF_WINDOW      0x0080	/* per route window clamping    */
#define RTF_IRTT        0x0100	/* Initial round trip time      */
#define RTF_REJECT      0x0200	/* Reject route                 */
#endif

#if defined (SIOCADDRTOLD) || defined (RTF_IRTT)	/* route */
#define HAVE_NEW_ADDRT 1
#endif

#if HAVE_NEW_ADDRT
#define mask_in_addr(x) (((struct sockaddr_in *)&((x).rt_genmask))->sin_addr.s_addr)
#define full_mask(x) (x)
#else
#define mask_in_addr(x) ((x).rt_genmask)
#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[] =
	"\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[] =
	/* 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. */

static void INET_setroute(int action, char **args)
{
	struct rtentry rt;
	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();
	}

	/* Clean out the RTREQ structure. */
	memset((char *) &rt, 0, sizeof(struct rtentry));

	{
		const char *target = *args++;
		char *prefix;

		/* recognize x.x.x.x/mask format. */
		prefix = strchr(target, '/');
		if(prefix) {
			int prefix_len;

			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 = '/';
		}
	}

	if (xflag) {		/* Reinit isnet if -net or -host was specified. */
		isnet = (xflag & NET_FLAG);
	}

	/* Fill in the other fields. */
	rt.rt_flags = ((isnet) ? RTF_UP : (RTF_UP | RTF_HOST));

	while (*args) {
		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;
		}

#if HAVE_NEW_ADDRT
		if (k == KW_IPVx_METRIC) {
			rt.rt_metric = xatoul(args_m1) + 1;
			continue;
		}
#endif

		if (k == KW_IPVx_NETMASK) {
			struct sockaddr mask;

			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);
			continue;
		}

		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) {
				if (isnet < 0) {
					bb_error_msg_and_die("resolving %s", args_m1);
				}
				bb_error_msg_and_die("gateway %s is a NETWORK", args_m1);
			}
			continue;
		}

		if (k == KW_IPVx_MSS) {	/* Check valid MSS bounds. */
			rt.rt_flags |= RTF_MSS;
			rt.rt_mss = xatoul_range(args_m1, 64, 32768);
			continue;
		}

		if (k == KW_IPVx_WINDOW) {	/* Check valid window bounds. */
			rt.rt_flags |= RTF_WINDOW;
			rt.rt_window = xatoul_range(args_m1, 128, INT_MAX);
			continue;
		}

#ifdef RTF_IRTT
		if (k == KW_IPVx_IRTT) {
			rt.rt_flags |= RTF_IRTT;
			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)) {
				bb_error_msg_and_die("bad irtt");
			}
#endif
			continue;
		}
#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;
		}

		/* Nothing matched. */
		bb_show_usage();
	}

#ifdef RTF_REJECT
	if ((rt.rt_flags & RTF_REJECT) && !rt.rt_dev) {
		rt.rt_dev = "lo";
	}
#endif

	/* sanity checks.. */
	if (mask_in_addr(rt)) {
		unsigned long mask = mask_in_addr(rt);

		mask = ~ntohl(mask);
		if ((rt.rt_flags & RTF_HOST) && mask != 0xffffffff) {
			bb_error_msg_and_die("netmask %.8x and host route conflict",
								 (unsigned int) mask);
		}
		if (mask & (mask + 1)) {
			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)) {
			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)) {
		mask_in_addr(rt) = 0xffffffff;
	}

	/* Create a socket to the INET kernel. */
	skfd = xsocket(AF_INET, SOCK_DGRAM, 0);

	if (ioctl(skfd, ((action==RTACTION_ADD) ? SIOCADDRT : SIOCDELRT), &rt)<0) {
		bb_perror_msg_and_die("SIOC[ADD|DEL]RT");
	}

	if (ENABLE_FEATURE_CLEAN_UP) close(skfd);
}

#ifdef CONFIG_FEATURE_IPV6

static void INET6_setroute(int action, char **args)
{
	struct sockaddr_in6 sa6;
	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 {
			char *cp;
			if ((cp = strchr(target, '/'))) { /* Yes... const to non is ok. */
				*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));

	memcpy(&rt.rtmsg_dst, sa6.sin6_addr.s6_addr, sizeof(struct in6_addr));

	/* Fill in the other fields. */
	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) {
		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 (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;
			continue;
		}

		/* 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;
		}

		/* Nothing matched. */
		bb_show_usage();
	}

	/* Create a socket to the INET6 kernel. */
	skfd = xsocket(AF_INET6, SOCK_DGRAM, 0);

	rt.rtmsg_ifindex = 0;

	if (devname) {
		struct ifreq ifr;
		memset(&ifr, 0, sizeof(ifr));
		strncpy(ifr.ifr_name, devname, sizeof(ifr.ifr_name));

		if (ioctl(skfd, SIOGIFINDEX, &ifr) < 0) {
			bb_perror_msg_and_die("SIOGIFINDEX");
		}
		rt.rtmsg_ifindex = ifr.ifr_ifindex;
	}

	/* Tell the kernel to accept this route. */
	if (ioctl(skfd, ((action==RTACTION_ADD) ? SIOCADDRT : SIOCDELRT), &rt)<0) {
		bb_perror_msg_and_die("SIOC[ADD|DEL]RT");
	}

	if (ENABLE_FEATURE_CLEAN_UP) close(skfd);
}
#endif

static const unsigned int flagvals[] = { /* Must agree with flagchars[]. */
	RTF_GATEWAY,
	RTF_HOST,
	RTF_REINSTATE,
	RTF_DYNAMIC,
	RTF_MODIFIED,
#ifdef CONFIG_FEATURE_IPV6
	RTF_DEFAULT,
	RTF_ADDRCONF,
	RTF_CACHE
#endif
};

#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)

static const char flagchars[] =		/* Must agree with flagvals[]. */
	"GHRDM"
#ifdef CONFIG_FEATURE_IPV6
	"DAC"
#endif
;

static void set_flags(char *flagstr, int flags)
{
	int i;

	*flagstr++ = 'U';

	for (i = 0; (*flagstr = flagchars[i]) != 0; i++) {
		if (flags & flagvals[i]) {
			++flagstr;
		}
	}
}

/* also used in netstat */
void displayroutes(int noresolve, int netstatfmt)
{
	char devname[64], flags[16], sdest[16], sgw[16];
	unsigned long int 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");

	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;
		INET_rresolve(sdest, sizeof(sdest), &s_addr,
					  (noresolve | 0x8000), m);	/* Default instead of *. */

		s_addr.sin_addr.s_addr = g;
		INET_rresolve(sgw, sizeof(sgw), &s_addr,
					  (noresolve | 0x4000), m);	/* Host instead of net. */

		mask.s_addr = m;
		printf("%-16s%-16s%-16s%-6s", sdest, sgw, inet_ntoa(mask), flags);
		if (netstatfmt) {
			printf("%5d %-5d %6d %s\n", mtu, win, ir, devname);
		} else {
			printf("%-6d %-2d %7d %s\n", metric, ref, use, devname);
		}
	}
}

#ifdef CONFIG_FEATURE_IPV6

static void INET6_displayroutes(int noresolve)
{
	char addr6[128], naddr6[128];
	/* 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];
	int iflags, metric, refcnt, use, prefix_len, slen;
	struct sockaddr_in6 snaddr6;

	FILE *fp = xfopen("/proc/net/ipv6_route", "r");

	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);
		}

		if (!(iflags & RTF_UP)) { /* Skip interfaces that are down. */
			continue;
		}

		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;
			INET6_rresolve(naddr6, sizeof(naddr6),
						   (struct sockaddr_in6 *) &snaddr6,
						   0x0fff /* Apparently, upstream never resolves. */
						   );

			if (!r) {			/* 1st pass */
				snprintf(addr6, sizeof(addr6), "%s/%d", naddr6, prefix_len);
				r += 40;
			} else {			/* 2nd pass */
				/* Print the info. */
				printf("%-43s %-39s %-5s %-6d %-2d %7d %-8s\n",
						  addr6, naddr6, flags, metric, refcnt, use, iface);
				break;
			}
		} while (1);
	}
}

#endif

#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. */
static const char tbl_verb[] =	/* 2nd byte matches RTACTION_* code */
	"\006\001add\0"
	"\006\002del\0"
/*	"\011\002delete\0" */
	"\010\002delete"			/* Since last, we can save a byte. */
;

int route_main(int argc, char **argv)
{
	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] = '#';
		}
	}

	opt = getopt32(argc, argv, "A:ne", &family);

	if ((opt & ROUTE_OPT_A) && strcmp(family, "inet")) {
#ifdef CONFIG_FEATURE_IPV6
		if (strcmp(family, "inet6") == 0) {
			opt |= ROUTE_OPT_INET6;	/* Set flag for ipv6. */
		} else
#endif
		bb_show_usage();
	}

	argv += optind;

	/* No more args means display the routing table. */
	if (!*argv) {
		int noresolve = (opt & ROUTE_OPT_n) ? 0x0fff : 0;
#ifdef CONFIG_FEATURE_IPV6
		if (opt & ROUTE_OPT_INET6)
			INET6_displayroutes(noresolve);
		else
#endif
			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();
	}

#ifdef CONFIG_FEATURE_IPV6
	if (opt & ROUTE_OPT_INET6)
		INET6_setroute(what, argv);
	else
#endif
		INET_setroute(what, argv);

	return EXIT_SUCCESS;
}
1	/* vi: set sw=4 ts=4: */
2	/* route
3	*
4	* Similar to the standard Unix route, but with only the necessary
5	* parts for AF_INET and AF_INET6
6	*
7	* Bjorn Wesen, Axis Communications AB
8	*
9	* Author of the original route:
10	* Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
11	* (derived from FvK's 'route.c 1.70 01/04/94')
12	*
13	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
14	*
15	* $Id: route.c,v 1.1 2007-09-01 22:43:53 niro Exp $
16	*
17	* displayroute() code added by Vladimir N. Oleynik <dzo@simtreas.ru>
18	* adjustments by Larry Doolittle <LRDoolittle@lbl.gov>
19	*
20	* IPV6 support added by Bart Visscher <magick@linux-fan.com>
21	*/
22
23	/* 2004/03/09 Manuel Novoa III <mjn3@codepoet.org>
24	*
25	* Rewritten to fix several bugs, add additional error checking, and
26	* remove ridiculous amounts of bloat.
27	*/
28
29	#include "busybox.h"
30	#include "inet_common.h"
31	#include <getopt.h>
32	#include <net/route.h>
33	#include <net/if.h>
34
35
36	#ifndef RTF_UP
37	/* Keep this in sync with /usr/src/linux/include/linux/route.h */
38	#define RTF_UP 0x0001 /* route usable */
39	#define RTF_GATEWAY 0x0002 /* destination is a gateway */
40	#define RTF_HOST 0x0004 /* host entry (net otherwise) */
41	#define RTF_REINSTATE 0x0008 /* reinstate route after tmout */
42	#define RTF_DYNAMIC 0x0010 /* created dyn. (by redirect) */
43	#define RTF_MODIFIED 0x0020 /* modified dyn. (by redirect) */
44	#define RTF_MTU 0x0040 /* specific MTU for this route */
45	#ifndef RTF_MSS
46	#define RTF_MSS RTF_MTU /* Compatibility :-( */
47	#endif
48	#define RTF_WINDOW 0x0080 /* per route window clamping */
49	#define RTF_IRTT 0x0100 /* Initial round trip time */
50	#define RTF_REJECT 0x0200 /* Reject route */
51	#endif
52
53	#if defined (SIOCADDRTOLD) \|\| defined (RTF_IRTT) /* route */
54	#define HAVE_NEW_ADDRT 1
55	#endif
56
57	#if HAVE_NEW_ADDRT
58	#define mask_in_addr(x) (((struct sockaddr_in *)&((x).rt_genmask))->sin_addr.s_addr)
59	#define full_mask(x) (x)
60	#else
61	#define mask_in_addr(x) ((x).rt_genmask)
62	#define full_mask(x) (((struct sockaddr_in *)&(x))->sin_addr.s_addr)
63	#endif
64
65	/* The RTACTION entries must agree with tbl_verb[] below! */
66	#define RTACTION_ADD 1
67	#define RTACTION_DEL 2
68
69	/* For the various tbl_*[] arrays, the 1st byte is the offset to
70	* the next entry and the 2nd byte is return value. */
71
72	#define NET_FLAG 1
73	#define HOST_FLAG 2
74
75	/* We remap '-' to '#' to avoid problems with getopt. */
76	static const char tbl_hash_net_host[] =
77	"\007\001#net\0"
78	/* "\010\002#host\0" */
79	"\007\002#host" /* Since last, we can save a byte. */
80	;
81
82	#define KW_TAKES_ARG 020
83	#define KW_SETS_FLAG 040
84
85	#define KW_IPVx_METRIC 020
86	#define KW_IPVx_NETMASK 021
87	#define KW_IPVx_GATEWAY 022
88	#define KW_IPVx_MSS 023
89	#define KW_IPVx_WINDOW 024
90	#define KW_IPVx_IRTT 025
91	#define KW_IPVx_DEVICE 026
92
93	#define KW_IPVx_FLAG_ONLY 040
94	#define KW_IPVx_REJECT 040
95	#define KW_IPVx_MOD 041
96	#define KW_IPVx_DYN 042
97	#define KW_IPVx_REINSTATE 043
98
99	static const char tbl_ipvx[] =
100	/* 020 is the "takes an arg" bit */
101	#if HAVE_NEW_ADDRT
102	"\011\020metric\0"
103	#endif
104	"\012\021netmask\0"
105	"\005\022gw\0"
106	"\012\022gateway\0"
107	"\006\023mss\0"
108	"\011\024window\0"
109	#ifdef RTF_IRTT
110	"\007\025irtt\0"
111	#endif
112	"\006\026dev\0"
113	"\011\026device\0"
114	/* 040 is the "sets a flag" bit - MUST match flags_ipvx[] values below. */
115	#ifdef RTF_REJECT
116	"\011\040reject\0"
117	#endif
118	"\006\041mod\0"
119	"\006\042dyn\0"
120	/* "\014\043reinstate\0" */
121	"\013\043reinstate" /* Since last, we can save a byte. */
122	;
123
124	static const int flags_ipvx[] = { /* MUST match tbl_ipvx[] values above. */
125	#ifdef RTF_REJECT
126	RTF_REJECT,
127	#endif
128	RTF_MODIFIED,
129	RTF_DYNAMIC,
130	RTF_REINSTATE
131	};
132
133	static int kw_lookup(const char kwtbl, char **pargs)
134	{
135	if (**pargs) {
136	do {
137	if (strcmp(kwtbl+2, *pargs) == 0) { / Found a match. */
138	*pargs += 1;
139	if (kwtbl[1] & KW_TAKES_ARG) {
140	if (!*pargs) { / No more args! */
141	bb_show_usage();
142	}
143	pargs += 1; / Calling routine will use args[-1]. */
144	}
145	return kwtbl[1];
146	}
147	kwtbl += *kwtbl;
148	} while (*kwtbl);
149	}
150	return 0;
151	}
152
153	/* Add or delete a route, depending on action. */
154
155	static void INET_setroute(int action, char **args)
156	{
157	struct rtentry rt;
158	const char *netmask = NULL;
159	int skfd, isnet, xflag;
160
161	/* Grab the -net or -host options. Remember they were transformed. */
162	xflag = kw_lookup(tbl_hash_net_host, &args);
163
164	/* If we did grab -net or -host, make sure we still have an arg left. */
165	if (*args == NULL) {
166	bb_show_usage();
167	}
168
169	/* Clean out the RTREQ structure. */
170	memset((char *) &rt, 0, sizeof(struct rtentry));
171
172	{
173	const char target = args++;
174	char *prefix;
175
176	/* recognize x.x.x.x/mask format. */
177	prefix = strchr(target, '/');
178	if(prefix) {
179	int prefix_len;
180
181	prefix_len = xatoul_range(prefix+1, 0, 32);
182	mask_in_addr(rt) = htonl( ~ (0xffffffffUL >> prefix_len));
183	*prefix = '\0';
184	#if HAVE_NEW_ADDRT
185	rt.rt_genmask.sa_family = AF_INET;
186	#endif
187	} else {
188	/* Default netmask. */
189	netmask = bb_str_default;
190	}
191	/* Prefer hostname lookup is -host flag (xflag==1) was given. */
192	isnet = INET_resolve(target, (struct sockaddr_in *) &rt.rt_dst,
193	(xflag & HOST_FLAG));
194	if (isnet < 0) {
195	bb_error_msg_and_die("resolving %s", target);
196	}
197	if(prefix) {
198	/* do not destroy prefix for process args */
199	*prefix = '/';
200	}
201	}
202
203	if (xflag) { /* Reinit isnet if -net or -host was specified. */
204	isnet = (xflag & NET_FLAG);
205	}
206
207	/* Fill in the other fields. */
208	rt.rt_flags = ((isnet) ? RTF_UP : (RTF_UP \| RTF_HOST));
209
210	while (*args) {
211	int k = kw_lookup(tbl_ipvx, &args);
212	const char *args_m1 = args[-1];
213
214	if (k & KW_IPVx_FLAG_ONLY) {
215	rt.rt_flags \|= flags_ipvx[k & 3];
216	continue;
217	}
218
219	#if HAVE_NEW_ADDRT
220	if (k == KW_IPVx_METRIC) {
221	rt.rt_metric = xatoul(args_m1) + 1;
222	continue;
223	}
224	#endif
225
226	if (k == KW_IPVx_NETMASK) {
227	struct sockaddr mask;
228
229	if (mask_in_addr(rt)) {
230	bb_show_usage();
231	}
232
233	netmask = args_m1;
234	isnet = INET_resolve(netmask, (struct sockaddr_in *) &mask, 0);
235	if (isnet < 0) {
236	bb_error_msg_and_die("resolving %s", netmask);
237	}
238	rt.rt_genmask = full_mask(mask);
239	continue;
240	}
241
242	if (k == KW_IPVx_GATEWAY) {
243	if (rt.rt_flags & RTF_GATEWAY) {
244	bb_show_usage();
245	}
246
247	isnet = INET_resolve(args_m1,
248	(struct sockaddr_in *) &rt.rt_gateway, 1);
249	rt.rt_flags \|= RTF_GATEWAY;
250
251	if (isnet) {
252	if (isnet < 0) {
253	bb_error_msg_and_die("resolving %s", args_m1);
254	}
255	bb_error_msg_and_die("gateway %s is a NETWORK", args_m1);
256	}
257	continue;
258	}
259
260	if (k == KW_IPVx_MSS) { /* Check valid MSS bounds. */
261	rt.rt_flags \|= RTF_MSS;
262	rt.rt_mss = xatoul_range(args_m1, 64, 32768);
263	continue;
264	}
265
266	if (k == KW_IPVx_WINDOW) { /* Check valid window bounds. */
267	rt.rt_flags \|= RTF_WINDOW;
268	rt.rt_window = xatoul_range(args_m1, 128, INT_MAX);
269	continue;
270	}
271
272	#ifdef RTF_IRTT
273	if (k == KW_IPVx_IRTT) {
274	rt.rt_flags \|= RTF_IRTT;
275	rt.rt_irtt = xatoul(args_m1);
276	rt.rt_irtt = (sysconf(_SC_CLK_TCK) / 100); / FIXME */
277	#if 0 /* FIXME: do we need to check anything of this? */
278	if (rt.rt_irtt < 1 \|\| rt.rt_irtt > (120 * HZ)) {
279	bb_error_msg_and_die("bad irtt");
280	}
281	#endif
282	continue;
283	}
284	#endif
285
286	/* Device is special in that it can be the last arg specified
287	* and doesn't requre the dev/device keyword in that case. */
288	if (!rt.rt_dev && ((k == KW_IPVx_DEVICE) \|\| (!k && !*++args))) {
289	/* Don't use args_m1 here since args may have changed! */
290	rt.rt_dev = args[-1];
291	continue;
292	}
293
294	/* Nothing matched. */
295	bb_show_usage();
296	}
297
298	#ifdef RTF_REJECT
299	if ((rt.rt_flags & RTF_REJECT) && !rt.rt_dev) {
300	rt.rt_dev = "lo";
301	}
302	#endif
303
304	/* sanity checks.. */
305	if (mask_in_addr(rt)) {
306	unsigned long mask = mask_in_addr(rt);
307
308	mask = ~ntohl(mask);
309	if ((rt.rt_flags & RTF_HOST) && mask != 0xffffffff) {
310	bb_error_msg_and_die("netmask %.8x and host route conflict",
311	(unsigned int) mask);
312	}
313	if (mask & (mask + 1)) {
314	bb_error_msg_and_die("bogus netmask %s", netmask);
315	}
316	mask = ((struct sockaddr_in *) &rt.rt_dst)->sin_addr.s_addr;
317	if (mask & ~mask_in_addr(rt)) {
318	bb_error_msg_and_die("netmask and route address conflict");
319	}
320	}
321
322	/* Fill out netmask if still unset */
323	if ((action == RTACTION_ADD) && (rt.rt_flags & RTF_HOST)) {
324	mask_in_addr(rt) = 0xffffffff;
325	}
326
327	/* Create a socket to the INET kernel. */
328	skfd = xsocket(AF_INET, SOCK_DGRAM, 0);
329
330	if (ioctl(skfd, ((action==RTACTION_ADD) ? SIOCADDRT : SIOCDELRT), &rt)<0) {
331	bb_perror_msg_and_die("SIOC[ADD\|DEL]RT");
332	}
333
334	if (ENABLE_FEATURE_CLEAN_UP) close(skfd);
335	}
336
337	#ifdef CONFIG_FEATURE_IPV6
338
339	static void INET6_setroute(int action, char **args)
340	{
341	struct sockaddr_in6 sa6;
342	struct in6_rtmsg rt;
343	int prefix_len, skfd;
344	const char *devname;
345
346	/* We know args isn't NULL from the check in route_main. */
347	const char target = args++;
348
349	if (strcmp(target, bb_str_default) == 0) {
350	prefix_len = 0;
351	memset(&sa6, 0, sizeof(sa6));
352	} else {
353	char *cp;
354	if ((cp = strchr(target, '/'))) { /* Yes... const to non is ok. */
355	*cp = 0;
356	prefix_len = xatoul_range(cp+1, 0, 128);
357	} else {
358	prefix_len = 128;
359	}
360	if (INET6_resolve(target, (struct sockaddr_in6 *) &sa6) < 0) {
361	bb_error_msg_and_die("resolving %s", target);
362	}
363	}
364
365	/* Clean out the RTREQ structure. */
366	memset((char *) &rt, 0, sizeof(struct in6_rtmsg));
367
368	memcpy(&rt.rtmsg_dst, sa6.sin6_addr.s6_addr, sizeof(struct in6_addr));
369
370	/* Fill in the other fields. */
371	rt.rtmsg_dst_len = prefix_len;
372	rt.rtmsg_flags = ((prefix_len == 128) ? (RTF_UP\|RTF_HOST) : RTF_UP);
373	rt.rtmsg_metric = 1;
374
375	devname = NULL;
376
377	while (*args) {
378	int k = kw_lookup(tbl_ipvx, &args);
379	const char *args_m1 = args[-1];
380
381	if ((k == KW_IPVx_MOD) \|\| (k == KW_IPVx_DYN)) {
382	rt.rtmsg_flags \|= flags_ipvx[k & 3];
383	continue;
384	}
385
386	if (k == KW_IPVx_METRIC) {
387	rt.rtmsg_metric = xatoul(args_m1);
388	continue;
389	}
390
391	if (k == KW_IPVx_GATEWAY) {
392	if (rt.rtmsg_flags & RTF_GATEWAY) {
393	bb_show_usage();
394	}
395
396	if (INET6_resolve(args_m1, (struct sockaddr_in6 *) &sa6) < 0) {
397	bb_error_msg_and_die("resolving %s", args_m1);
398	}
399	memcpy(&rt.rtmsg_gateway, sa6.sin6_addr.s6_addr,
400	sizeof(struct in6_addr));
401	rt.rtmsg_flags \|= RTF_GATEWAY;
402	continue;
403	}
404
405	/* Device is special in that it can be the last arg specified
406	* and doesn't requre the dev/device keyword in that case. */
407	if (!devname && ((k == KW_IPVx_DEVICE) \|\| (!k && !*++args))) {
408	/* Don't use args_m1 here since args may have changed! */
409	devname = args[-1];
410	continue;
411	}
412
413	/* Nothing matched. */
414	bb_show_usage();
415	}
416
417	/* Create a socket to the INET6 kernel. */
418	skfd = xsocket(AF_INET6, SOCK_DGRAM, 0);
419
420	rt.rtmsg_ifindex = 0;
421
422	if (devname) {
423	struct ifreq ifr;
424	memset(&ifr, 0, sizeof(ifr));
425	strncpy(ifr.ifr_name, devname, sizeof(ifr.ifr_name));
426
427	if (ioctl(skfd, SIOGIFINDEX, &ifr) < 0) {
428	bb_perror_msg_and_die("SIOGIFINDEX");
429	}
430	rt.rtmsg_ifindex = ifr.ifr_ifindex;
431	}
432
433	/* Tell the kernel to accept this route. */
434	if (ioctl(skfd, ((action==RTACTION_ADD) ? SIOCADDRT : SIOCDELRT), &rt)<0) {
435	bb_perror_msg_and_die("SIOC[ADD\|DEL]RT");
436	}
437
438	if (ENABLE_FEATURE_CLEAN_UP) close(skfd);
439	}
440	#endif
441
442	static const unsigned int flagvals[] = { /* Must agree with flagchars[]. */
443	RTF_GATEWAY,
444	RTF_HOST,
445	RTF_REINSTATE,
446	RTF_DYNAMIC,
447	RTF_MODIFIED,
448	#ifdef CONFIG_FEATURE_IPV6
449	RTF_DEFAULT,
450	RTF_ADDRCONF,
451	RTF_CACHE
452	#endif
453	};
454
455	#define IPV4_MASK (RTF_GATEWAY\|RTF_HOST\|RTF_REINSTATE\|RTF_DYNAMIC\|RTF_MODIFIED)
456	#define IPV6_MASK (RTF_GATEWAY\|RTF_HOST\|RTF_DEFAULT\|RTF_ADDRCONF\|RTF_CACHE)
457
458	static const char flagchars[] = /* Must agree with flagvals[]. */
459	"GHRDM"
460	#ifdef CONFIG_FEATURE_IPV6
461	"DAC"
462	#endif
463	;
464
465	static void set_flags(char *flagstr, int flags)
466	{
467	int i;
468
469	*flagstr++ = 'U';
470
471	for (i = 0; (*flagstr = flagchars[i]) != 0; i++) {
472	if (flags & flagvals[i]) {
473	++flagstr;
474	}
475	}
476	}
477
478	/* also used in netstat */
479	void displayroutes(int noresolve, int netstatfmt)
480	{
481	char devname[64], flags[16], sdest[16], sgw[16];
482	unsigned long int d, g, m;
483	int flgs, ref, use, metric, mtu, win, ir;
484	struct sockaddr_in s_addr;
485	struct in_addr mask;
486
487	FILE *fp = xfopen("/proc/net/route", "r");
488
489	printf("Kernel IP routing table\n"
490	"Destination Gateway Genmask Flags %s Iface\n",
491	netstatfmt ? " MSS Window irtt" : "Metric Ref Use");
492
493	if (fscanf(fp, "%[^\n]\n") < 0) { / Skip the first line. */
494	goto ERROR; /* Empty or missing line, or read error. */
495	}
496	while (1) {
497	int r;
498	r = fscanf(fp, "%63s%lx%lx%X%d%d%d%lx%d%d%d\n",
499	devname, &d, &g, &flgs, &ref, &use, &metric, &m,
500	&mtu, &win, &ir);
501	if (r != 11) {
502	if ((r < 0) && feof(fp)) { /* EOF with no (nonspace) chars read. */
503	break;
504	}
505	ERROR:
506	bb_error_msg_and_die("fscanf");
507	}
508
509	if (!(flgs & RTF_UP)) { /* Skip interfaces that are down. */
510	continue;
511	}
512
513	set_flags(flags, (flgs & IPV4_MASK));
514	#ifdef RTF_REJECT
515	if (flgs & RTF_REJECT) {
516	flags[0] = '!';
517	}
518	#endif
519
520	memset(&s_addr, 0, sizeof(struct sockaddr_in));
521	s_addr.sin_family = AF_INET;
522	s_addr.sin_addr.s_addr = d;
523	INET_rresolve(sdest, sizeof(sdest), &s_addr,
524	(noresolve \| 0x8000), m); /* Default instead of . /
525
526	s_addr.sin_addr.s_addr = g;
527	INET_rresolve(sgw, sizeof(sgw), &s_addr,
528	(noresolve \| 0x4000), m); /* Host instead of net. */
529
530	mask.s_addr = m;
531	printf("%-16s%-16s%-16s%-6s", sdest, sgw, inet_ntoa(mask), flags);
532	if (netstatfmt) {
533	printf("%5d %-5d %6d %s\n", mtu, win, ir, devname);
534	} else {
535	printf("%-6d %-2d %7d %s\n", metric, ref, use, devname);
536	}
537	}
538	}
539
540	#ifdef CONFIG_FEATURE_IPV6
541
542	static void INET6_displayroutes(int noresolve)
543	{
544	char addr6[128], naddr6[128];
545	/* In addr6x, we store both 40-byte ':'-delimited ipv6 addresses.
546	* We read the non-delimited strings into the tail of the buffer
547	* using fscanf and then modify the buffer by shifting forward
548	* while inserting ':'s and the nul terminator for the first string.
549	* Hence the strings are at addr6x and addr6x+40. This generates
550	* _much_ less code than the previous (upstream) approach. */
551	char addr6x[80];
552	char iface[16], flags[16];
553	int iflags, metric, refcnt, use, prefix_len, slen;
554	struct sockaddr_in6 snaddr6;
555
556	FILE *fp = xfopen("/proc/net/ipv6_route", "r");
557
558	printf("Kernel IPv6 routing table\n%-44s%-40s"
559	"Flags Metric Ref Use Iface\n",
560	"Destination", "Next Hop");
561
562	while (1) {
563	int r;
564	r = fscanf(fp, "%32s%x%*s%x%32s%x%x%x%x%s\n",
565	addr6x+14, &prefix_len, &slen, addr6x+40+7,
566	&metric, &use, &refcnt, &iflags, iface);
567	if (r != 9) {
568	if ((r < 0) && feof(fp)) { /* EOF with no (nonspace) chars read. */
569	break;
570	}
571	ERROR:
572	bb_error_msg_and_die("fscanf");
573	}
574
575	/* Do the addr6x shift-and-insert changes to ':'-delimit addresses.
576	* For now, always do this to validate the proc route format, even
577	* if the interface is down. */
578	{
579	int i = 0;
580	char *p = addr6x+14;
581
582	do {
583	if (!*p) {
584	if (i==40) { /* nul terminator for 1st address? */
585	addr6x[39] = 0; /* Fixup... need 0 instead of ':'. */
586	++p; /* Skip and continue. */
587	continue;
588	}
589	goto ERROR;
590	}
591	addr6x[i++] = *p++;
592	if (!((i+1)%5)) {
593	addr6x[i++] = ':';
594	}
595	} while (i < 40+28+7);
596	}
597
598	if (!(iflags & RTF_UP)) { /* Skip interfaces that are down. */
599	continue;
600	}
601
602	set_flags(flags, (iflags & IPV6_MASK));
603
604	r = 0;
605	do {
606	inet_pton(AF_INET6, addr6x + r,
607	(struct sockaddr *) &snaddr6.sin6_addr);
608	snaddr6.sin6_family = AF_INET6;
609	INET6_rresolve(naddr6, sizeof(naddr6),
610	(struct sockaddr_in6 *) &snaddr6,
611	0x0fff /* Apparently, upstream never resolves. */
612	);
613
614	if (!r) { /* 1st pass */
615	snprintf(addr6, sizeof(addr6), "%s/%d", naddr6, prefix_len);
616	r += 40;
617	} else { /* 2nd pass */
618	/* Print the info. */
619	printf("%-43s %-39s %-5s %-6d %-2d %7d %-8s\n",
620	addr6, naddr6, flags, metric, refcnt, use, iface);
621	break;
622	}
623	} while (1);
624	}
625	}
626
627	#endif
628
629	#define ROUTE_OPT_A 0x01
630	#define ROUTE_OPT_n 0x02
631	#define ROUTE_OPT_e 0x04
632	#define ROUTE_OPT_INET6 0x08 /* Not an actual option. See below. */
633
634	/* 1st byte is offset to next entry offset. 2nd byte is return value. */
635	static const char tbl_verb[] = /* 2nd byte matches RTACTION_* code */
636	"\006\001add\0"
637	"\006\002del\0"
638	/* "\011\002delete\0" */
639	"\010\002delete" /* Since last, we can save a byte. */
640	;
641
642	int route_main(int argc, char **argv)
643	{
644	unsigned opt;
645	int what;
646	char *family;
647	char **p;
648
649	/* First, remap '-net' and '-host' to avoid getopt problems. */
650	p = argv;
651	while (*++p) {
652	if ((strcmp(p, "-net") == 0) \|\| (strcmp(p, "-host") == 0)) {
653	p[0][0] = '#';
654	}
655	}
656
657	opt = getopt32(argc, argv, "A:ne", &family);
658
659	if ((opt & ROUTE_OPT_A) && strcmp(family, "inet")) {
660	#ifdef CONFIG_FEATURE_IPV6
661	if (strcmp(family, "inet6") == 0) {
662	opt \|= ROUTE_OPT_INET6; /* Set flag for ipv6. */
663	} else
664	#endif
665	bb_show_usage();
666	}
667
668	argv += optind;
669
670	/* No more args means display the routing table. */
671	if (!*argv) {
672	int noresolve = (opt & ROUTE_OPT_n) ? 0x0fff : 0;
673	#ifdef CONFIG_FEATURE_IPV6
674	if (opt & ROUTE_OPT_INET6)
675	INET6_displayroutes(noresolve);
676	else
677	#endif
678	displayroutes(noresolve, opt & ROUTE_OPT_e);
679
680	fflush_stdout_and_exit(EXIT_SUCCESS);
681	}
682
683	/* Check verb. At the moment, must be add, del, or delete. */
684	what = kw_lookup(tbl_verb, &argv);
685	if (!what \|\| !argv) { / Unknown verb or no more args. */
686	bb_show_usage();
687	}
688
689	#ifdef CONFIG_FEATURE_IPV6
690	if (opt & ROUTE_OPT_INET6)
691	INET6_setroute(what, argv);
692	else
693	#endif
694	INET_setroute(what, argv);
695
696	return EXIT_SUCCESS;
697	}