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busybox/networking/route.c

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/* 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')
*
* 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.
*
* $Id: route.c,v 1.26 2004/03/19 23:27:08 mjn3 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <unistd.h>
#include <fcntl.h>
#include <getopt.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <net/route.h>
#include <net/if.h>
#include "busybox.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
#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;
int skfd, isnet, xflag;
assert((action == RTACTION_ADD) || (action == RTACTION_DEL));
/* 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++;
/* 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 (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));
netmask = bb_INET_default;
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 = bb_xgetularg10(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 = bb_xgetularg10_bnd(args_m1, 64, 32768);
continue;
}
if (k == KW_IPVx_WINDOW) { /* Check valid window bounds. */
rt.rt_flags |= RTF_WINDOW;
rt.rt_window = bb_xgetularg10_bnd(args_m1, 128, INT_MAX);
continue;
}
#ifdef RTF_IRTT
if (k == KW_IPVx_IRTT) {
rt.rt_flags |= RTF_IRTT;
rt.rt_irtt = bb_xgetularg10(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. */
if ((skfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
bb_perror_msg_and_die("socket");
}
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;
assert((action == RTACTION_ADD) || (action == RTACTION_DEL));
{
/* We know args isn't NULL from the check in route_main. */
const char *target = *args++;
if (strcmp(target, "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 = bb_xgetularg10_bnd(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 = bb_xgetularg10(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. */
if ((skfd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
bb_perror_msg_and_die("socket");
}
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) {
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
#ifndef CONFIG_FEATURE_IPV6
__inline
#endif
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 = bb_xfopen("/proc/net/route", "r");
bb_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;
bb_printf("%-16s%-16s%-16s%-6s", sdest, sgw, inet_ntoa(mask), flags);
if (netstatfmt) {
bb_printf("%5d %-5d %6d %s\n", mtu, win, ir, devname);
} else {
bb_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 = bb_xfopen("/proc/net/ipv6_route", "r");
bb_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,
#if 0
(noresolve | 0x8000) /* Default instead of *. */
#else
0x0fff /* Apparently, upstream never resolves. */
#endif
);
if (!r) { /* 1st pass */
snprintf(addr6, sizeof(addr6), "%s/%d", naddr6, prefix_len);
r += 40;
} else { /* 2nd pass */
/* Print the info. */
bb_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 long opt;
int what;
char *family;
/* First, remap '-net' and '-host' to avoid getopt problems. */
{
char **p = argv;
while (*++p) {
if ((strcmp(*p, "-net") == 0) || (strcmp(*p, "-host") == 0)) {
p[0][0] = '#';
}
}
}
opt = bb_getopt_ulflags(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);
bb_xferror_stdout();
bb_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;
}
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