/* * route-linux.c * * Copyright (c) 2000 Dug Song <dugsong@monkey.org> * * $Id: route-linux.c,v 1.15 2005/01/23 07:36:54 dugsong Exp $ */#include "config.h"#include <sys/types.h>#include <sys/ioctl.h>#include <sys/socket.h>#include <sys/uio.h>#include <asm/types.h>#include <linux/netlink.h>#include <linux/rtnetlink.h>#include <net/route.h>#include <ctype.h>#include <errno.h>#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include "dnet.h"#define ADDR_ISHOST(a)	(((a)->addr_type == ADDR_TYPE_IP &&	\			  (a)->addr_bits == IP_ADDR_BITS) ||	\			 ((a)->addr_type == ADDR_TYPE_IP6 &&	\			  (a)->addr_bits == IP6_ADDR_BITS))#define PROC_ROUTE_FILE	"/proc/net/route"struct route_handle {	int	 fd;	int	 nlfd;};route_t *route_open(void){	struct sockaddr_nl snl;	route_t *r;	if ((r = calloc(1, sizeof(*r))) != NULL) {		r->fd = r->nlfd = -1;				if ((r->fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0)			return (route_close(r));				if ((r->nlfd = socket(AF_NETLINK, SOCK_RAW,			 NETLINK_ROUTE)) < 0)			return (route_close(r));				memset(&snl, 0, sizeof(snl));		snl.nl_family = AF_NETLINK;				if (bind(r->nlfd, (struct sockaddr *)&snl, sizeof(snl)) < 0)			return (route_close(r));	}	return (r);}introute_add(route_t *r, const struct route_entry *entry){	struct rtentry rt;	struct addr dst;	memset(&rt, 0, sizeof(rt));	rt.rt_flags = RTF_UP | RTF_GATEWAY;	if (ADDR_ISHOST(&entry->route_dst)) {		rt.rt_flags |= RTF_HOST;		memcpy(&dst, &entry->route_dst, sizeof(dst));	} else		addr_net(&entry->route_dst, &dst);		if (addr_ntos(&dst, &rt.rt_dst) < 0 ||	    addr_ntos(&entry->route_gw, &rt.rt_gateway) < 0 ||	    addr_btos(entry->route_dst.addr_bits, &rt.rt_genmask) < 0)		return (-1);		return (ioctl(r->fd, SIOCADDRT, &rt));}introute_delete(route_t *r, const struct route_entry *entry){	struct rtentry rt;	struct addr dst;		memset(&rt, 0, sizeof(rt));	rt.rt_flags = RTF_UP;	if (ADDR_ISHOST(&entry->route_dst)) {		rt.rt_flags |= RTF_HOST;		memcpy(&dst, &entry->route_dst, sizeof(dst));	} else		addr_net(&entry->route_dst, &dst);		if (addr_ntos(&dst, &rt.rt_dst) < 0 ||	    addr_btos(entry->route_dst.addr_bits, &rt.rt_genmask) < 0)		return (-1);		return (ioctl(r->fd, SIOCDELRT, &rt));}introute_get(route_t *r, struct route_entry *entry){	static int seq;	struct nlmsghdr *nmsg;	struct rtmsg *rmsg;	struct rtattr *rta;	struct sockaddr_nl snl;	struct iovec iov;	struct msghdr msg;	u_char buf[512];	int i;	if (entry->route_dst.addr_type != ADDR_TYPE_IP) {		errno = EINVAL;		return (-1);	}	memset(buf, 0, sizeof(buf));	nmsg = (struct nlmsghdr *)buf;	nmsg->nlmsg_len = NLMSG_LENGTH(sizeof(*nmsg)) +	    RTA_LENGTH(IP_ADDR_LEN);	nmsg->nlmsg_flags = NLM_F_REQUEST;	nmsg->nlmsg_type = RTM_GETROUTE;	nmsg->nlmsg_seq = ++seq;	rmsg = (struct rtmsg *)(nmsg + 1);	rmsg->rtm_family = AF_INET;	rmsg->rtm_dst_len = entry->route_dst.addr_bits;		rta = RTM_RTA(rmsg);	rta->rta_type = RTA_DST;	rta->rta_len = RTA_LENGTH(IP_ADDR_LEN);	/* XXX - gross hack for default route */	if (entry->route_dst.addr_ip == IP_ADDR_ANY) {		i = htonl(0x60060606);		memcpy(RTA_DATA(rta), &i, IP_ADDR_LEN);	} else		memcpy(RTA_DATA(rta), &entry->route_dst.addr_ip, IP_ADDR_LEN);		memset(&snl, 0, sizeof(snl));	snl.nl_family = AF_NETLINK;	iov.iov_base = nmsg;	iov.iov_len = nmsg->nlmsg_len;		memset(&msg, 0, sizeof(msg));	msg.msg_name = &snl;	msg.msg_namelen = sizeof(snl);	msg.msg_iov = &iov;	msg.msg_iovlen = 1;		if (sendmsg(r->nlfd, &msg, 0) < 0)		return (-1);	iov.iov_base = buf;	iov.iov_len = sizeof(buf);		if ((i = recvmsg(r->nlfd, &msg, 0)) <= 0)		return (-1);	if (nmsg->nlmsg_len < (int)sizeof(*nmsg) || nmsg->nlmsg_len > i ||	    nmsg->nlmsg_seq != seq) {		errno = EINVAL;		return (-1);	}	if (nmsg->nlmsg_type == NLMSG_ERROR)		return (-1);		i -= NLMSG_LENGTH(sizeof(*nmsg));		while (RTA_OK(rta, i)) {		if (rta->rta_type == RTA_GATEWAY) {			entry->route_gw.addr_type = ADDR_TYPE_IP;			memcpy(&entry->route_gw.addr_ip,			    RTA_DATA(rta), IP_ADDR_LEN);			entry->route_gw.addr_bits = IP_ADDR_BITS;			return (0);		}		rta = RTA_NEXT(rta, i);	}	errno = ESRCH;		return (-1);}introute_loop(route_t *r, route_handler callback, void *arg){	FILE *fp;	char buf[BUFSIZ], ifbuf[16];	int i, iflags, refcnt, use, metric, mss, win, irtt, ret;	struct route_entry entry;	uint32_t mask;	entry.route_dst.addr_type = entry.route_gw.addr_type = ADDR_TYPE_IP;	entry.route_dst.addr_bits = entry.route_gw.addr_bits = IP_ADDR_BITS;	if ((fp = fopen(PROC_ROUTE_FILE, "r")) == NULL)		return (-1);	ret = 0;	while (fgets(buf, sizeof(buf), fp) != NULL) {		i = sscanf(buf,		    "%16s %X %X %X %d %d %d %X %d %d %d\n",		    ifbuf, &entry.route_dst.addr_ip, &entry.route_gw.addr_ip,		    &iflags, &refcnt, &use, &metric, &mask, &mss, &win, &irtt);				if (i < 10 || !(iflags & RTF_UP))			continue;				if (entry.route_gw.addr_ip == IP_ADDR_ANY)			continue;				entry.route_dst.addr_type = entry.route_gw.addr_type =		    ADDR_TYPE_IP;				if (addr_mtob(&mask, IP_ADDR_LEN,		    &entry.route_dst.addr_bits) < 0)			continue;				if ((ret = callback(&entry, arg)) != 0)			break;	}	if (ferror(fp)) {		fclose(fp);		return (-1);	}	fclose(fp);		return (ret);}route_t *route_close(route_t *r){	if (r != NULL) {		if (r->fd >= 0)			close(r->fd);		if (r->nlfd >= 0)			close(r->nlfd);		free(r);	}	return (NULL);}