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/*
* arp-bsd.c
*
* Copyright (c) 2000 Dug Song <dugsong@monkey.org>
*
* $Id: arp-bsd.c 539 2005-01-23 07:36:54Z dugsong $
*/
#include "config.h"
#include <sys/param.h>
#include <sys/types.h>
#include <sys/socket.h>
#ifdef HAVE_SYS_SYSCTL_H
#include <sys/sysctl.h>
#endif
#ifdef HAVE_STREAMS_ROUTE
#include <sys/stream.h>
#include <sys/stropts.h>
#endif
#include <net/if.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "dnet.h"
struct arp_handle {
int fd;
int seq;
};
struct arpmsg {
struct rt_msghdr rtm;
u_char addrs[256];
};
arp_t *
arp_open(void)
{
arp_t *arp;
if ((arp = calloc(1, sizeof(*arp))) != NULL) {
#ifdef HAVE_STREAMS_ROUTE
if ((arp->fd = open("/dev/route", O_RDWR, 0)) < 0)
#else
if ((arp->fd = socket(PF_ROUTE, SOCK_RAW, 0)) < 0)
#endif
return (arp_close(arp));
}
return (arp);
}
static int
arp_msg(arp_t *arp, struct arpmsg *msg)
{
struct arpmsg smsg;
int len, i = 0;
pid_t pid;
msg->rtm.rtm_version = RTM_VERSION;
msg->rtm.rtm_seq = ++arp->seq;
memcpy(&smsg, msg, sizeof(smsg));
#ifdef HAVE_STREAMS_ROUTE
return (ioctl(arp->fd, RTSTR_SEND, &msg->rtm));
#else
if (write(arp->fd, &smsg, smsg.rtm.rtm_msglen) < 0) {
if (errno != ESRCH || msg->rtm.rtm_type != RTM_DELETE)
return (-1);
}
pid = getpid();
/* XXX - should we only read RTM_GET responses here? */
while ((len = read(arp->fd, msg, sizeof(*msg))) > 0) {
if (len < (int)sizeof(msg->rtm))
return (-1);
if (msg->rtm.rtm_pid == pid) {
if (msg->rtm.rtm_seq == arp->seq)
break;
continue;
} else if ((i++ % 2) == 0)
continue;
/* Repeat request. */
if (write(arp->fd, &smsg, smsg.rtm.rtm_msglen) < 0) {
if (errno != ESRCH || msg->rtm.rtm_type != RTM_DELETE)
return (-1);
}
}
if (len < 0)
return (-1);
return (0);
#endif
}
int
arp_add(arp_t *arp, const struct arp_entry *entry)
{
struct arpmsg msg;
struct sockaddr_in *sin;
struct sockaddr *sa;
int index, type;
if (entry->arp_pa.addr_type != ADDR_TYPE_IP ||
entry->arp_ha.addr_type != ADDR_TYPE_ETH) {
errno = EAFNOSUPPORT;
return (-1);
}
sin = (struct sockaddr_in *)msg.addrs;
sa = (struct sockaddr *)(sin + 1);
if (addr_ntos(&entry->arp_pa, (struct sockaddr *)sin) < 0)
return (-1);
memset(&msg.rtm, 0, sizeof(msg.rtm));
msg.rtm.rtm_type = RTM_GET;
msg.rtm.rtm_addrs = RTA_DST;
msg.rtm.rtm_msglen = sizeof(msg.rtm) + sizeof(*sin);
if (arp_msg(arp, &msg) < 0)
return (-1);
if (msg.rtm.rtm_msglen < (int)sizeof(msg.rtm) +
sizeof(*sin) + sizeof(*sa)) {
errno = EADDRNOTAVAIL;
return (-1);
}
if (sin->sin_addr.s_addr == entry->arp_pa.addr_ip) {
if ((msg.rtm.rtm_flags & RTF_LLINFO) == 0 ||
(msg.rtm.rtm_flags & RTF_GATEWAY) != 0) {
errno = EADDRINUSE;
return (-1);
}
}
if (sa->sa_family != AF_LINK) {
errno = EADDRNOTAVAIL;
return (-1);
} else {
index = ((struct sockaddr_dl *)sa)->sdl_index;
type = ((struct sockaddr_dl *)sa)->sdl_type;
}
if (addr_ntos(&entry->arp_pa, (struct sockaddr *)sin) < 0 ||
addr_ntos(&entry->arp_ha, sa) < 0)
return (-1);
((struct sockaddr_dl *)sa)->sdl_index = index;
((struct sockaddr_dl *)sa)->sdl_type = type;
memset(&msg.rtm, 0, sizeof(msg.rtm));
msg.rtm.rtm_type = RTM_ADD;
msg.rtm.rtm_addrs = RTA_DST | RTA_GATEWAY;
msg.rtm.rtm_inits = RTV_EXPIRE;
msg.rtm.rtm_flags = RTF_HOST | RTF_STATIC;
#ifdef HAVE_SOCKADDR_SA_LEN
msg.rtm.rtm_msglen = sizeof(msg.rtm) + sin->sin_len + sa->sa_len;
#else
msg.rtm.rtm_msglen = sizeof(msg.rtm) + sizeof(*sin) + sizeof(*sa);
#endif
return (arp_msg(arp, &msg));
}
int
arp_delete(arp_t *arp, const struct arp_entry *entry)
{
struct arpmsg msg;
struct sockaddr_in *sin;
struct sockaddr *sa;
if (entry->arp_pa.addr_type != ADDR_TYPE_IP) {
errno = EAFNOSUPPORT;
return (-1);
}
sin = (struct sockaddr_in *)msg.addrs;
sa = (struct sockaddr *)(sin + 1);
if (addr_ntos(&entry->arp_pa, (struct sockaddr *)sin) < 0)
return (-1);
memset(&msg.rtm, 0, sizeof(msg.rtm));
msg.rtm.rtm_type = RTM_GET;
msg.rtm.rtm_addrs = RTA_DST;
msg.rtm.rtm_msglen = sizeof(msg.rtm) + sizeof(*sin);
if (arp_msg(arp, &msg) < 0)
return (-1);
if (msg.rtm.rtm_msglen < (int)sizeof(msg.rtm) +
sizeof(*sin) + sizeof(*sa)) {
errno = ESRCH;
return (-1);
}
if (sin->sin_addr.s_addr == entry->arp_pa.addr_ip) {
if ((msg.rtm.rtm_flags & RTF_LLINFO) == 0 ||
(msg.rtm.rtm_flags & RTF_GATEWAY) != 0) {
errno = EADDRINUSE;
return (-1);
}
}
if (sa->sa_family != AF_LINK) {
errno = ESRCH;
return (-1);
}
msg.rtm.rtm_type = RTM_DELETE;
return (arp_msg(arp, &msg));
}
int
arp_get(arp_t *arp, struct arp_entry *entry)
{
struct arpmsg msg;
struct sockaddr_in *sin;
struct sockaddr *sa;
if (entry->arp_pa.addr_type != ADDR_TYPE_IP) {
errno = EAFNOSUPPORT;
return (-1);
}
sin = (struct sockaddr_in *)msg.addrs;
sa = (struct sockaddr *)(sin + 1);
if (addr_ntos(&entry->arp_pa, (struct sockaddr *)sin) < 0)
return (-1);
memset(&msg.rtm, 0, sizeof(msg.rtm));
msg.rtm.rtm_type = RTM_GET;
msg.rtm.rtm_addrs = RTA_DST;
msg.rtm.rtm_flags = RTF_LLINFO;
msg.rtm.rtm_msglen = sizeof(msg.rtm) + sizeof(*sin);
if (arp_msg(arp, &msg) < 0)
return (-1);
if (msg.rtm.rtm_msglen < (int)sizeof(msg.rtm) +
sizeof(*sin) + sizeof(*sa) ||
sin->sin_addr.s_addr != entry->arp_pa.addr_ip ||
sa->sa_family != AF_LINK) {
errno = ESRCH;
return (-1);
}
if (addr_ston(sa, &entry->arp_ha) < 0)
return (-1);
return (0);
}
#ifdef HAVE_SYS_SYSCTL_H
int
arp_loop(arp_t *arp, arp_handler callback, void *arg)
{
struct arp_entry entry;
struct rt_msghdr *rtm;
struct sockaddr_in *sin;
struct sockaddr *sa;
char *buf, *lim, *next;
size_t len;
int ret, mib[6] = { CTL_NET, PF_ROUTE, 0, AF_INET,
NET_RT_FLAGS, RTF_LLINFO };
if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0)
return (-1);
if (len == 0)
return (0);
if ((buf = malloc(len)) == NULL)
return (-1);
if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) {
free(buf);
return (-1);
}
lim = buf + len;
ret = 0;
for (next = buf; next < lim; next += rtm->rtm_msglen) {
rtm = (struct rt_msghdr *)next;
sin = (struct sockaddr_in *)(rtm + 1);
sa = (struct sockaddr *)(sin + 1);
if (addr_ston((struct sockaddr *)sin, &entry.arp_pa) < 0 ||
addr_ston(sa, &entry.arp_ha) < 0)
continue;
if ((ret = callback(&entry, arg)) != 0)
break;
}
free(buf);
return (ret);
}
#else
int
arp_loop(arp_t *arp, arp_handler callback, void *arg)
{
errno = ENOSYS;
return (-1);
}
#endif
arp_t *
arp_close(arp_t *arp)
{
if (arp != NULL) {
if (arp->fd >= 0)
close(arp->fd);
free(arp);
}
return (NULL);
}
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