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/* $OpenBSD: kroute.c,v 1.6 2003/12/24 19:23:26 henning Exp $ */
/*
* Copyright (c) 2003 Henning Brauer <henning@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/tree.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/route.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "bgpd.h"
struct kroute_node {
RB_ENTRY(kroute_node) entry;
struct kroute r;
int flags;
};
int kroute_msg(int, int, struct kroute *);
int kroute_compare(struct kroute_node *, struct kroute_node *);
RB_HEAD(kroute_tree, kroute_node) kroute_tree, krt;
RB_PROTOTYPE(kroute_tree, kroute_node, entry, kroute_compare);
RB_GENERATE(kroute_tree, kroute_node, entry, kroute_compare);
u_int32_t rtseq = 1;
#define F_BGPD_INSERTED 0x0001
int
kroute_init(void)
{
int s, opt;
if ((s = socket(AF_ROUTE, SOCK_RAW, 0)) < 0)
fatal("route socket", errno);
if (fcntl(s, F_SETFL, O_NONBLOCK) == -1)
fatal(NULL, errno);
/* not intrested in my own messages */
if (setsockopt(s, SOL_SOCKET, SO_USELOOPBACK, &opt, sizeof(opt)) == -1)
fatal("route setsockopt", errno);
RB_INIT(&krt);
return (s);
}
int
kroute_msg(int fd, int action, struct kroute *kroute)
{
struct {
struct rt_msghdr hdr;
struct sockaddr_in prefix;
struct sockaddr_in nexthop;
struct sockaddr_in mask;
} r;
ssize_t n;
bzero(&r, sizeof(r));
r.hdr.rtm_msglen = sizeof(r);
r.hdr.rtm_version = RTM_VERSION;
r.hdr.rtm_type = action;
r.hdr.rtm_flags = RTF_GATEWAY|RTF_PROTO1; /* XXX */
r.hdr.rtm_seq = rtseq++; /* overflow doesn't matter */
r.hdr.rtm_addrs = RTA_DST|RTA_GATEWAY|RTA_NETMASK;
r.prefix.sin_len = sizeof(r.prefix);
r.prefix.sin_family = AF_INET;
r.prefix.sin_addr.s_addr = kroute->prefix;
r.nexthop.sin_len = sizeof(r.nexthop);
r.nexthop.sin_family = AF_INET;
r.nexthop.sin_addr.s_addr = kroute->nexthop;
r.mask.sin_len = sizeof(r.mask);
r.mask.sin_family = AF_INET;
r.mask.sin_addr.s_addr = htonl(0xffffffff << (32 - kroute->prefixlen));
retry:
if ((n = write(fd, &r, sizeof(r))) == -1) {
switch (errno) {
case ESRCH:
if (r.hdr.rtm_type == RTM_CHANGE) {
r.hdr.rtm_type = RTM_ADD;
goto retry;
} else if (r.hdr.rtm_type == RTM_DELETE) {
logit(LOG_INFO, "route vanished before delete");
return (0);
}
break;
case EEXIST: /* connected route */
return (-2);
default:
logit(LOG_INFO, "kroute_msg: %s", strerror(errno));
return (-1);
}
}
if (n == sizeof(r))
return (0);
/* XXX we could not write everything... bad bad bad. cope. */
return (n);
}
int
kroute_add(int fd, struct kroute *kroute)
{
struct kroute_node *kr;
int n;
if ((n = kroute_msg(fd, RTM_ADD, kroute)) == -2) /* connected route */
return (0);
if (n == -1)
return (-1);
if ((kr = calloc(1, sizeof(struct kroute_node))) == NULL)
fatal(NULL, errno);
kr->r.prefix = kroute->prefix;
kr->r.prefixlen = kroute->prefixlen;
kr->r.nexthop = kroute->nexthop;
kr->flags = F_BGPD_INSERTED;
if (RB_INSERT(kroute_tree, &krt, kr) != NULL) {
logit(LOG_CRIT, "RB_INSERT failed!");
return (-1);
}
return (n);
}
int
kroute_change(int fd, struct kroute *kroute)
{
struct kroute_node *kr, s;
s.r.prefix = kroute->prefix;
s.r.prefixlen = kroute->prefixlen;
if ((kr = RB_FIND(kroute_tree, &krt, &s)) == NULL) {
log_kroute(LOG_CRIT, "kroute_change: no match for", kroute);
return (-1);
}
if (!(kr->flags & F_BGPD_INSERTED)) {
logit(LOG_CRIT, "trying to change route not inserted by bgpd");
return (0);
}
kr->r.nexthop = kroute->nexthop;
return (kroute_msg(fd, RTM_CHANGE, kroute));
}
int
kroute_delete(int fd, struct kroute *kroute)
{
struct kroute_node *kr, s;
int n;
s.r.prefix = kroute->prefix;
s.r.prefixlen = kroute->prefixlen;
if ((kr = RB_FIND(kroute_tree, &krt, &s)) == NULL) {
/* at the moment this is totally valid... */
log_kroute(LOG_CRIT, "kroute_delete: no match for", kroute);
return (0);
}
if (!(kr->flags & F_BGPD_INSERTED))
return (0);
if ((n = kroute_msg(fd, RTM_DELETE, kroute)) == -1)
return (-1);
RB_REMOVE(kroute_tree, &krt, kr);
free(kr);
return (0);
}
int
kroute_compare(struct kroute_node *a, struct kroute_node *b)
{
if (a->r.prefix < b->r.prefix)
return (-1);
if (a->r.prefix > b->r.prefix)
return (1);
if (a->r.prefixlen < b->r.prefixlen)
return (-1);
if (a->r.prefixlen > b->r.prefixlen)
return (1);
return (0);
}
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