iproute.c

busybox-1.2.0,标准的Linux工具集[最新].对linux下软件的开发有着非常大的作用.

/* vi: set sw=4 ts=4: */
/*
 * iproute.c		"ip route".
 *
 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 *
 * Authors:	Alexey Kuznetsov, <[e-mail]>
 *
 *
 * Changes:
 *
 * Rani Assaf <[e-mail]> 980929:	resolve addresses
 * Kunihiro Ishiguro <[e-mail]> 001102: rtnh_ifindex was not initialized
 */

#include "libbb.h"

#include <sys/socket.h>

#include <string.h>
#include <fcntl.h>
#include <unistd.h>

#include "rt_names.h"
#include "utils.h"
#include "ip_common.h"

#ifndef RTAX_RTTVAR
#define RTAX_RTTVAR RTAX_HOPS
#endif


static struct
{
	int tb;
	int flushed;
	char *flushb;
	int flushp;
	int flushe;
	struct rtnl_handle *rth;
	int protocol, protocolmask;
	int scope, scopemask;
	int type, typemask;
	int tos, tosmask;
	int iif, iifmask;
	int oif, oifmask;
	int realm, realmmask;
	inet_prefix rprefsrc;
	inet_prefix rvia;
	inet_prefix rdst;
	inet_prefix mdst;
	inet_prefix rsrc;
	inet_prefix msrc;
} filter;

static int flush_update(void)
{
	if (rtnl_send(filter.rth, filter.flushb, filter.flushp) < 0) {
		perror("Failed to send flush request\n");
		return -1;
	}
	filter.flushp = 0;
	return 0;
}

static int print_route(struct sockaddr_nl *who ATTRIBUTE_UNUSED,
		struct nlmsghdr *n, void *arg)
{
	FILE *fp = (FILE*)arg;
	struct rtmsg *r = NLMSG_DATA(n);
	int len = n->nlmsg_len;
	struct rtattr * tb[RTA_MAX+1];
	char abuf[256];
	inet_prefix dst;
	inet_prefix src;
	int host_len = -1;
	SPRINT_BUF(b1);


	if (n->nlmsg_type != RTM_NEWROUTE && n->nlmsg_type != RTM_DELROUTE) {
		fprintf(stderr, "Not a route: %08x %08x %08x\n",
			n->nlmsg_len, n->nlmsg_type, n->nlmsg_flags);
		return 0;
	}
	if (filter.flushb && n->nlmsg_type != RTM_NEWROUTE)
		return 0;
	len -= NLMSG_LENGTH(sizeof(*r));
	if (len < 0) {
		bb_error_msg("wrong nlmsg len %d", len);
		return -1;
	}

	if (r->rtm_family == AF_INET6)
		host_len = 128;
	else if (r->rtm_family == AF_INET)
		host_len = 32;

	if (r->rtm_family == AF_INET6) {
		if (filter.tb) {
			if (filter.tb < 0) {
				if (!(r->rtm_flags&RTM_F_CLONED)) {
					return 0;
				}
			} else {
				if (r->rtm_flags&RTM_F_CLONED) {
					return 0;
				}
				if (filter.tb == RT_TABLE_LOCAL) {
					if (r->rtm_type != RTN_LOCAL) {
						return 0;
					}
				} else if (filter.tb == RT_TABLE_MAIN) {
					if (r->rtm_type == RTN_LOCAL) {
						return 0;
					}
				} else {
					return 0;
				}
			}
		}
	} else {
		if (filter.tb > 0 && filter.tb != r->rtm_table) {
			return 0;
		}
	}
	if (filter.rdst.family &&
	    (r->rtm_family != filter.rdst.family || filter.rdst.bitlen > r->rtm_dst_len)) {
		return 0;
	}
	if (filter.mdst.family &&
	    (r->rtm_family != filter.mdst.family ||
	     (filter.mdst.bitlen >= 0 && filter.mdst.bitlen < r->rtm_dst_len))) {
		return 0;
	}
	if (filter.rsrc.family &&
	    (r->rtm_family != filter.rsrc.family || filter.rsrc.bitlen > r->rtm_src_len)) {
		return 0;
	}
	if (filter.msrc.family &&
	    (r->rtm_family != filter.msrc.family ||
	     (filter.msrc.bitlen >= 0 && filter.msrc.bitlen < r->rtm_src_len))) {
		return 0;
	}

	memset(tb, 0, sizeof(tb));
	parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);

	if (filter.rdst.family && inet_addr_match(&dst, &filter.rdst, filter.rdst.bitlen))
		return 0;
	if (filter.mdst.family && filter.mdst.bitlen >= 0 &&
	    inet_addr_match(&dst, &filter.mdst, r->rtm_dst_len))
		return 0;

	if (filter.rsrc.family && inet_addr_match(&src, &filter.rsrc, filter.rsrc.bitlen))
		return 0;
	if (filter.msrc.family && filter.msrc.bitlen >= 0 &&
	    inet_addr_match(&src, &filter.msrc, r->rtm_src_len))
		return 0;

	if (filter.flushb &&
	    r->rtm_family == AF_INET6 &&
	    r->rtm_dst_len == 0 &&
	    r->rtm_type == RTN_UNREACHABLE &&
	    tb[RTA_PRIORITY] &&
	    *(int*)RTA_DATA(tb[RTA_PRIORITY]) == -1)
		return 0;

	if (filter.flushb) {
		struct nlmsghdr *fn;
		if (NLMSG_ALIGN(filter.flushp) + n->nlmsg_len > filter.flushe) {
			if (flush_update())
				return -1;
		}
		fn = (struct nlmsghdr*)(filter.flushb + NLMSG_ALIGN(filter.flushp));
		memcpy(fn, n, n->nlmsg_len);
		fn->nlmsg_type = RTM_DELROUTE;
		fn->nlmsg_flags = NLM_F_REQUEST;
		fn->nlmsg_seq = ++filter.rth->seq;
		filter.flushp = (((char*)fn) + n->nlmsg_len) - filter.flushb;
		filter.flushed++;
		return 0;
	}

	if (n->nlmsg_type == RTM_DELROUTE) {
		fprintf(fp, "Deleted ");
	}
	if (r->rtm_type != RTN_UNICAST && !filter.type) {
		fprintf(fp, "%s ", rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1)));
	}

	if (tb[RTA_DST]) {
		if (r->rtm_dst_len != host_len) {
			fprintf(fp, "%s/%u ", rt_addr_n2a(r->rtm_family,
							 RTA_PAYLOAD(tb[RTA_DST]),
							 RTA_DATA(tb[RTA_DST]),
							 abuf, sizeof(abuf)),
				r->rtm_dst_len
				);
		} else {
			fprintf(fp, "%s ", format_host(r->rtm_family,
						       RTA_PAYLOAD(tb[RTA_DST]),
						       RTA_DATA(tb[RTA_DST]),
						       abuf, sizeof(abuf))
				);
		}
	} else if (r->rtm_dst_len) {
		fprintf(fp, "0/%d ", r->rtm_dst_len);
	} else {
		fprintf(fp, "default ");
	}
	if (tb[RTA_SRC]) {
		if (r->rtm_src_len != host_len) {
			fprintf(fp, "from %s/%u ", rt_addr_n2a(r->rtm_family,
							 RTA_PAYLOAD(tb[RTA_SRC]),
							 RTA_DATA(tb[RTA_SRC]),
							 abuf, sizeof(abuf)),
				r->rtm_src_len
				);
		} else {
			fprintf(fp, "from %s ", format_host(r->rtm_family,
						       RTA_PAYLOAD(tb[RTA_SRC]),
						       RTA_DATA(tb[RTA_SRC]),
						       abuf, sizeof(abuf))
				);
		}
	} else if (r->rtm_src_len) {
		fprintf(fp, "from 0/%u ", r->rtm_src_len);
	}
	if (tb[RTA_GATEWAY] && filter.rvia.bitlen != host_len) {
		fprintf(fp, "via %s ",
			format_host(r->rtm_family,
				    RTA_PAYLOAD(tb[RTA_GATEWAY]),
				    RTA_DATA(tb[RTA_GATEWAY]),
				    abuf, sizeof(abuf)));
	}
	if (tb[RTA_OIF] && filter.oifmask != -1) {
		fprintf(fp, "dev %s ", ll_index_to_name(*(int*)RTA_DATA(tb[RTA_OIF])));
	}

	if (tb[RTA_PREFSRC] && filter.rprefsrc.bitlen != host_len) {
		/* Do not use format_host(). It is our local addr
		   and symbolic name will not be useful.
		 */
		fprintf(fp, " src %s ",
			rt_addr_n2a(r->rtm_family,
				    RTA_PAYLOAD(tb[RTA_PREFSRC]),
				    RTA_DATA(tb[RTA_PREFSRC]),
				    abuf, sizeof(abuf)));
	}
	if (tb[RTA_PRIORITY]) {
		fprintf(fp, " metric %d ", *(__u32*)RTA_DATA(tb[RTA_PRIORITY]));
	}
	if (r->rtm_family == AF_INET6) {
		struct rta_cacheinfo *ci = NULL;
		if (tb[RTA_CACHEINFO]) {
			ci = RTA_DATA(tb[RTA_CACHEINFO]);
		}
		if ((r->rtm_flags & RTM_F_CLONED) || (ci && ci->rta_expires)) {
			static int hz;
			if (!hz) {
				hz = get_hz();
			}
			if (r->rtm_flags & RTM_F_CLONED) {
				fprintf(fp, "%s    cache ", _SL_);
			}
			if (ci->rta_expires) {
				fprintf(fp, " expires %dsec", ci->rta_expires/hz);
			}
			if (ci->rta_error != 0) {
				fprintf(fp, " error %d", ci->rta_error);
			}
		} else if (ci) {
			if (ci->rta_error != 0)
				fprintf(fp, " error %d", ci->rta_error);
		}
	}
	if (tb[RTA_IIF] && filter.iifmask != -1) {
		fprintf(fp, " iif %s", ll_index_to_name(*(int*)RTA_DATA(tb[RTA_IIF])));
	}
	fprintf(fp, "\n");
	fflush(fp);
	return 0;
}

static int iproute_modify(int cmd, unsigned flags, int argc, char **argv)
{
	struct rtnl_handle rth;
	struct {
		struct nlmsghdr		n;
		struct rtmsg		r;
		char			buf[1024];
	} req;
	char  mxbuf[256];
	struct rtattr * mxrta = (void*)mxbuf;
	unsigned mxlock = 0;
	char  *d = NULL;
	int gw_ok = 0;
	int dst_ok = 0;
	int proto_ok = 0;
	int type_ok = 0;

	memset(&req, 0, sizeof(req));

	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
	req.n.nlmsg_flags = NLM_F_REQUEST|flags;
	req.n.nlmsg_type = cmd;
	req.r.rtm_family = preferred_family;
	req.r.rtm_table = RT_TABLE_MAIN;
	req.r.rtm_scope = RT_SCOPE_NOWHERE;

	if (cmd != RTM_DELROUTE) {
		req.r.rtm_protocol = RTPROT_BOOT;
		req.r.rtm_scope = RT_SCOPE_UNIVERSE;
		req.r.rtm_type = RTN_UNICAST;
	}

	mxrta->rta_type = RTA_METRICS;
	mxrta->rta_len = RTA_LENGTH(0);

	while (argc > 0) {
		if (strcmp(*argv, "src") == 0) {
			inet_prefix addr;
			NEXT_ARG();
			get_addr(&addr, *argv, req.r.rtm_family);
			if (req.r.rtm_family == AF_UNSPEC) {
				req.r.rtm_family = addr.family;
			}
			addattr_l(&req.n, sizeof(req), RTA_PREFSRC, &addr.data, addr.bytelen);
		} else if (strcmp(*argv, "via") == 0) {
			inet_prefix addr;
			gw_ok = 1;
			NEXT_ARG();
			get_addr(&addr, *argv, req.r.rtm_family);
			if (req.r.rtm_family == AF_UNSPEC) {
				req.r.rtm_family = addr.family;
			}
			addattr_l(&req.n, sizeof(req), RTA_GATEWAY, &addr.data, addr.bytelen);
		} else if (strcmp(*argv, "mtu") == 0) {
			unsigned mtu;
			NEXT_ARG();
			if (strcmp(*argv, "lock") == 0) {
				mxlock |= (1<<RTAX_MTU);
				NEXT_ARG();
			}
			if (get_unsigned(&mtu, *argv, 0)) {
				invarg(*argv, "mtu");
			}
			rta_addattr32(mxrta, sizeof(mxbuf), RTAX_MTU, mtu);
		} else if (matches(*argv, "protocol") == 0) {
			uint32_t prot;
			NEXT_ARG();
			if (rtnl_rtprot_a2n(&prot, *argv))
				invarg(*argv, "protocol");
			req.r.rtm_protocol = prot;
			proto_ok =1;
		} else if (strcmp(*argv, "dev") == 0 ||
			   strcmp(*argv, "oif") == 0) {
			NEXT_ARG();
			d = *argv;
		} else {
			int type;
			inet_prefix dst;

			if (strcmp(*argv, "to") == 0) {
				NEXT_ARG();
			}
			if ((**argv < '0' || **argv > '9') &&
			    rtnl_rtntype_a2n(&type, *argv) == 0) {
				NEXT_ARG();
				req.r.rtm_type = type;
				type_ok = 1;
			}

			if (dst_ok) {
				duparg2("to", *argv);
			}
			get_prefix(&dst, *argv, req.r.rtm_family);
			if (req.r.rtm_family == AF_UNSPEC) {
				req.r.rtm_family = dst.family;
			}
			req.r.rtm_dst_len = dst.bitlen;
			dst_ok = 1;
			if (dst.bytelen) {
				addattr_l(&req.n, sizeof(req), RTA_DST, &dst.data, dst.bytelen);
			}
		}
		argc--; argv++;
	}

	if (rtnl_open(&rth, 0) < 0) {
		exit(1);
	}

	if (d)  {
		int idx;

		ll_init_map(&rth);

		if (d) {
			if ((idx = ll_name_to_index(d)) == 0) {
				bb_error_msg("Cannot find device \"%s\"", d);
				return -1;
			}
			addattr32(&req.n, sizeof(req), RTA_OIF, idx);
		}
	}

	if (mxrta->rta_len > RTA_LENGTH(0)) {
		if (mxlock) {
			rta_addattr32(mxrta, sizeof(mxbuf), RTAX_LOCK, mxlock);
		}
		addattr_l(&req.n, sizeof(req), RTA_METRICS, RTA_DATA(mxrta), RTA_PAYLOAD(mxrta));
	}

	if (req.r.rtm_family == AF_UNSPEC) {
		req.r.rtm_family = AF_INET;
	}

	if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0) {
		exit(2);
	}

	return 0;
}

static int rtnl_rtcache_request(struct rtnl_handle *rth, int family)
{
	struct {
		struct nlmsghdr nlh;