freebsd-src/usr.sbin/ppp/arp.c
Brian Somers a33b2ef772 Change some log levels. ALERTs are only logged when
something that can't happen happens or when everyone
needs to know.  ERRORs are only logged when something
unexpected happens.
1998-06-16 19:40:42 +00:00

331 lines
8.9 KiB
C

/*
* sys-bsd.c - System-dependent procedures for setting up
* PPP interfaces on bsd-4.4-ish systems (including 386BSD, NetBSD, etc.)
*
* Copyright (c) 1989 Carnegie Mellon University.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by Carnegie Mellon University. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* $Id: arp.c,v 1.28 1998/05/21 21:43:51 brian Exp $
*
*/
/*
* TODO:
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/route.h>
#include <net/if_dl.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <arpa/inet.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <sys/un.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/errno.h>
#include <sys/sysctl.h>
#include <unistd.h>
#include "mbuf.h"
#include "log.h"
#include "id.h"
#include "timer.h"
#include "fsm.h"
#include "defs.h"
#include "iplist.h"
#include "throughput.h"
#include "slcompress.h"
#include "ipcp.h"
#include "filter.h"
#include "descriptor.h"
#include "lqr.h"
#include "hdlc.h"
#include "lcp.h"
#include "ccp.h"
#include "link.h"
#include "mp.h"
#include "bundle.h"
#include "arp.h"
/*
* SET_SA_FAMILY - set the sa_family field of a struct sockaddr,
* if it exists.
*/
#define SET_SA_FAMILY(addr, family) \
memset((char *) &(addr), '\0', sizeof(addr)); \
addr.sa_family = (family); \
addr.sa_len = sizeof(addr);
#if RTM_VERSION >= 3
/*
* arp_SetProxy - Make a proxy ARP entry for the peer.
*/
static struct {
struct rt_msghdr hdr;
struct sockaddr_inarp dst;
struct sockaddr_dl hwa;
char extra[128];
} arpmsg;
static int arpmsg_valid;
int
arp_SetProxy(struct bundle *bundle, struct in_addr addr, int s)
{
int routes;
/*
* Get the hardware address of an interface on the same subnet as our local
* address.
*/
memset(&arpmsg, 0, sizeof arpmsg);
if (!get_ether_addr(s, addr, &arpmsg.hwa)) {
log_Printf(LogWARN, "Cannot determine ethernet address for proxy ARP\n");
return 0;
}
routes = ID0socket(PF_ROUTE, SOCK_RAW, AF_INET);
if (routes < 0) {
log_Printf(LogERROR, "arp_SetProxy: opening routing socket: %s\n",
strerror(errno));
return 0;
}
arpmsg.hdr.rtm_type = RTM_ADD;
arpmsg.hdr.rtm_flags = RTF_ANNOUNCE | RTF_HOST | RTF_STATIC;
arpmsg.hdr.rtm_version = RTM_VERSION;
arpmsg.hdr.rtm_seq = ++bundle->routing_seq;
arpmsg.hdr.rtm_addrs = RTA_DST | RTA_GATEWAY;
arpmsg.hdr.rtm_inits = RTV_EXPIRE;
arpmsg.dst.sin_len = sizeof(struct sockaddr_inarp);
arpmsg.dst.sin_family = AF_INET;
arpmsg.dst.sin_addr.s_addr = addr.s_addr;
arpmsg.dst.sin_other = SIN_PROXY;
arpmsg.hdr.rtm_msglen = (char *) &arpmsg.hwa - (char *) &arpmsg
+ arpmsg.hwa.sdl_len;
if (write(routes, &arpmsg, arpmsg.hdr.rtm_msglen) < 0) {
log_Printf(LogERROR, "Add proxy arp entry: %s\n", strerror(errno));
close(routes);
return 0;
}
close(routes);
arpmsg_valid = 1;
return 1;
}
/*
* arp_ClearProxy - Delete the proxy ARP entry for the peer.
*/
int
arp_ClearProxy(struct bundle *bundle, struct in_addr addr, int s)
{
int routes;
if (!arpmsg_valid)
return 0;
arpmsg_valid = 0;
arpmsg.hdr.rtm_type = RTM_DELETE;
arpmsg.hdr.rtm_seq = ++bundle->routing_seq;
routes = ID0socket(PF_ROUTE, SOCK_RAW, AF_INET);
if (routes < 0) {
log_Printf(LogERROR, "arp_SetProxy: opening routing socket: %s\n",
strerror(errno));
return 0;
}
if (write(routes, &arpmsg, arpmsg.hdr.rtm_msglen) < 0) {
log_Printf(LogERROR, "Delete proxy arp entry: %s\n", strerror(errno));
close(routes);
return 0;
}
close(routes);
return 1;
}
#else /* RTM_VERSION */
/*
* arp_SetProxy - Make a proxy ARP entry for the peer.
*/
int
arp_SetProxy(struct bundle *bundle, struct in_addr addr, int s)
{
struct arpreq arpreq;
struct {
struct sockaddr_dl sdl;
char space[128];
} dls;
memset(&arpreq, '\0', sizeof arpreq);
/*
* Get the hardware address of an interface on the same subnet as our local
* address.
*/
if (!get_ether_addr(s, addr, &dls.sdl)) {
log_Printf(LOG_PHASE_BIT, "Cannot determine ethernet address for proxy ARP\n");
return 0;
}
arpreq.arp_ha.sa_len = sizeof(struct sockaddr);
arpreq.arp_ha.sa_family = AF_UNSPEC;
memcpy(arpreq.arp_ha.sa_data, LLADDR(&dls.sdl), dls.sdl.sdl_alen);
SET_SA_FAMILY(arpreq.arp_pa, AF_INET);
((struct sockaddr_in *)&arpreq.arp_pa)->sin_addr.s_addr = addr.s_addr;
arpreq.arp_flags = ATF_PERM | ATF_PUBL;
if (ID0ioctl(s, SIOCSARP, (caddr_t) & arpreq) < 0) {
log_Printf(LogERROR, "arp_SetProxy: ioctl(SIOCSARP): %s\n",
strerror(errno));
return 0;
}
return 1;
}
/*
* arp_ClearProxy - Delete the proxy ARP entry for the peer.
*/
int
arp_ClearProxy(struct bundle *bundle, struct in_addr addr, int s)
{
struct arpreq arpreq;
memset(&arpreq, '\0', sizeof arpreq);
SET_SA_FAMILY(arpreq.arp_pa, AF_INET);
((struct sockaddr_in *)&arpreq.arp_pa)->sin_addr.s_addr = addr.s_addr;
if (ID0ioctl(s, SIOCDARP, (caddr_t) & arpreq) < 0) {
log_Printf(LogERROR, "arp_ClearProxy: ioctl(SIOCDARP): %s\n",
strerror(errno));
return 0;
}
return 1;
}
#endif /* RTM_VERSION */
/*
* get_ether_addr - get the hardware address of an interface on the
* the same subnet as ipaddr.
*/
int
get_ether_addr(int s, struct in_addr ipaddr, struct sockaddr_dl *hwaddr)
{
int mib[6], sa_len, skip, b;
size_t needed;
char *buf, *ptr, *end;
struct if_msghdr *ifm;
struct ifa_msghdr *ifam;
struct sockaddr *sa;
struct sockaddr_dl *dl;
struct sockaddr_in *ifa, *mask;
mib[0] = CTL_NET;
mib[1] = PF_ROUTE;
mib[2] = 0;
mib[3] = 0;
mib[4] = NET_RT_IFLIST;
mib[5] = 0;
if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) {
log_Printf(LogERROR, "get_ether_addr: sysctl: estimate: %s\n",
strerror(errno));
return 0;
}
if ((buf = malloc(needed)) == NULL)
return 0;
if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) {
free(buf);
return 0;
}
end = buf + needed;
ptr = buf;
while (ptr < end) {
ifm = (struct if_msghdr *)ptr; /* On if_msghdr */
if (ifm->ifm_type != RTM_IFINFO)
break;
dl = (struct sockaddr_dl *)(ifm + 1); /* Single _dl at end */
skip = (ifm->ifm_flags & (IFF_UP | IFF_BROADCAST | IFF_POINTOPOINT |
IFF_NOARP | IFF_LOOPBACK)) != (IFF_UP | IFF_BROADCAST);
ptr += ifm->ifm_msglen; /* First ifa_msghdr */
while (ptr < end) {
ifam = (struct ifa_msghdr *)ptr; /* Next ifa_msghdr (alias) */
if (ifam->ifam_type != RTM_NEWADDR) /* finished ? */
break;
sa = (struct sockaddr *)(ifam+1); /* pile of sa's at end */
ptr += ifam->ifam_msglen;
if (skip || (ifam->ifam_addrs & (RTA_NETMASK|RTA_IFA)) !=
(RTA_NETMASK|RTA_IFA))
continue;
/* Found a candidate. Do the addresses match ? */
if (log_IsKept(LogDEBUG) &&
ptr == (char *)ifm + ifm->ifm_msglen + ifam->ifam_msglen)
log_Printf(LogDEBUG, "%.*s interface is a candidate for proxy\n",
dl->sdl_nlen, dl->sdl_data);
b = 1;
ifa = mask = NULL;
while (b < (RTA_NETMASK|RTA_IFA) && sa < (struct sockaddr *)ptr) {
switch (b) {
case RTA_IFA:
ifa = (struct sockaddr_in *)sa;
break;
case RTA_NETMASK:
/*
* Careful here ! this sockaddr doesn't have sa_family set to
* AF_INET, and is only 8 bytes big ! I have no idea why !
*/
mask = (struct sockaddr_in *)sa;
break;
}
if (ifam->ifam_addrs & b) {
#define ALN sizeof(ifa->sin_addr.s_addr)
sa_len = sa->sa_len > 0 ? ((sa->sa_len-1)|(ALN-1))+1 : ALN;
sa = (struct sockaddr *)((char *)sa + sa_len);
}
b <<= 1;
}
if (log_IsKept(LogDEBUG)) {
char a[16];
strncpy(a, inet_ntoa(mask->sin_addr), sizeof a - 1);
a[sizeof a - 1] = '\0';
log_Printf(LogDEBUG, "Check addr %s, mask %s\n",
inet_ntoa(ifa->sin_addr), a);
}
if (ifa->sin_family == AF_INET &&
(ifa->sin_addr.s_addr & mask->sin_addr.s_addr) ==
(ipaddr.s_addr & mask->sin_addr.s_addr)) {
log_Printf(LogPHASE, "Found interface %.*s for %s\n",
dl->sdl_alen, dl->sdl_data, inet_ntoa(ipaddr));
memcpy(hwaddr, dl, dl->sdl_len);
free(buf);
return 1;
}
}
}
free(buf);
return 0;
}