freebsd-dev/usr.sbin/rarpd/arptab.c
Bill Paul 112072599b Gave rarpd back the ability to poke temporary entries into the arp
table; arptab.c is really a hacked up version of arp.c that only
supports adding temporary entries. (This stuff is nasty -- I wish I
knew what was so wrong with SIOCSARP/SIOCGARP/etc... that made the
BSD developers decide to take it out.) The idea here is that the
client issuing the rarp is expected to be in the middle of booting
and would therefore be unable to answer arp queries from other machines
on the wire. Having rarpd stuff a temporary entry for the booting
host into the local arp table helps keep arp requests from going unanswered.

Also added ether_print() and ether_ntoa() to the ether_addr.c module.
Eventually I'll get ether_aton() and ether_hostton() written and
then this file can be dropped straight into libc. (Assuming no one
objects, of course. :)
1995-03-03 22:20:15 +00:00

220 lines
6.1 KiB
C

/*
* Copyright (c) 1984, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Sun Microsystems, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1984, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static char sccsid[] = "@(#)arp.c 8.2 (Berkeley) 1/2/94";
#endif /* not lint */
/*
* set arp table entries
*/
#include <sys/param.h>
#include <sys/file.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <errno.h>
#include <nlist.h>
#include <stdio.h>
#include <paths.h>
#include <syslog.h>
extern int errno;
static int pid;
static int s = -1;
getsocket() {
if (s < 0) {
s = socket(PF_ROUTE, SOCK_RAW, 0);
if (s < 0) {
perror("arp: socket");
exit(1);
}
}
}
struct sockaddr_in so_mask = {8, 0, 0, { 0xffffffff}};
struct sockaddr_inarp blank_sin = {sizeof(blank_sin), AF_INET }, sin_m;
struct sockaddr_dl blank_sdl = {sizeof(blank_sdl), AF_LINK }, sdl_m;
int expire_time, flags, export_only, doing_proxy;
struct {
struct rt_msghdr m_rtm;
char m_space[512];
} m_rtmsg;
/*
* Set an individual arp entry
*/
arptab_set(eaddr, host)
u_char *eaddr;
u_long host;
{
register struct sockaddr_inarp *sin = &sin_m;
register struct sockaddr_dl *sdl;
register struct rt_msghdr *rtm = &(m_rtmsg.m_rtm);
struct timeval time;
getsocket();
pid = getpid();
sdl_m = blank_sdl;
sin_m = blank_sin;
sin->sin_addr.s_addr = host;
bcopy((char *)eaddr, (u_char *)LLADDR(&sdl_m), 6);
sdl_m.sdl_alen = 6;
doing_proxy = flags = export_only = expire_time = 0;
gettimeofday(&time, 0);
expire_time = time.tv_sec + 20 * 60;
tryagain:
if (rtmsg(RTM_GET) < 0) {
syslog(LOG_ERR,"%s: %m", inet_ntoa(sin->sin_addr));
return (1);
}
sin = (struct sockaddr_inarp *)(rtm + 1);
sdl = (struct sockaddr_dl *)(sin->sin_len + (char *)sin);
if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) {
if (sdl->sdl_family == AF_LINK &&
(rtm->rtm_flags & RTF_LLINFO) &&
!(rtm->rtm_flags & RTF_GATEWAY)) switch (sdl->sdl_type) {
case IFT_ETHER: case IFT_FDDI: case IFT_ISO88023:
case IFT_ISO88024: case IFT_ISO88025:
goto overwrite;
}
if (doing_proxy == 0) {
syslog(LOG_ERR, "arptab_set: can only proxy for %s\n", inet_ntoa(sin->sin_addr));
return (1);
}
if (sin_m.sin_other & SIN_PROXY) {
syslog(LOG_ERR,"arptab_set: proxy entry exists for non 802 device\n");
return(1);
}
sin_m.sin_other = SIN_PROXY;
export_only = 1;
goto tryagain;
}
overwrite:
if (sdl->sdl_family != AF_LINK) {
syslog(LOG_ERR,"arptab_set: cannot intuit interface index and type for %s\n", inet_ntoa(sin->sin_addr));
return (1);
}
sdl_m.sdl_type = sdl->sdl_type;
sdl_m.sdl_index = sdl->sdl_index;
return (rtmsg(RTM_ADD));
}
rtmsg(cmd)
{
static int seq;
int rlen;
register struct rt_msghdr *rtm = &m_rtmsg.m_rtm;
register char *cp = m_rtmsg.m_space;
register int l;
errno = 0;
if (cmd == RTM_DELETE)
goto doit;
bzero((char *)&m_rtmsg, sizeof(m_rtmsg));
rtm->rtm_flags = flags;
rtm->rtm_version = RTM_VERSION;
switch (cmd) {
default:
syslog(LOG_ERR, "arptap_set: internal wrong cmd\n");
exit(1);
case RTM_ADD:
rtm->rtm_addrs |= RTA_GATEWAY;
rtm->rtm_rmx.rmx_expire = expire_time;
rtm->rtm_inits = RTV_EXPIRE;
rtm->rtm_flags |= (RTF_HOST | RTF_STATIC);
sin_m.sin_other = 0;
if (doing_proxy) {
if (export_only)
sin_m.sin_other = SIN_PROXY;
else {
rtm->rtm_addrs |= RTA_NETMASK;
rtm->rtm_flags &= ~RTF_HOST;
}
}
/* FALLTHROUGH */
case RTM_GET:
rtm->rtm_addrs |= RTA_DST;
}
#define NEXTADDR(w, s) \
if (rtm->rtm_addrs & (w)) { \
bcopy((char *)&s, cp, sizeof(s)); cp += sizeof(s);}
NEXTADDR(RTA_DST, sin_m);
NEXTADDR(RTA_GATEWAY, sdl_m);
NEXTADDR(RTA_NETMASK, so_mask);
rtm->rtm_msglen = cp - (char *)&m_rtmsg;
doit:
l = rtm->rtm_msglen;
rtm->rtm_seq = ++seq;
rtm->rtm_type = cmd;
if ((rlen = write(s, (char *)&m_rtmsg, l)) < 0) {
if (errno != ESRCH && errno != EEXIST) {
syslog(LOG_ERR, "writing to routing socket: %m");
return (-1);
}
}
do {
l = read(s, (char *)&m_rtmsg, sizeof(m_rtmsg));
} while (l > 0 && (rtm->rtm_seq != seq || rtm->rtm_pid != pid));
if (l < 0)
syslog(LOG_ERR, "arptab_set: read from routing socket: %m");
return (0);
}