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* Improve error checking for arp messages.

Browse Source 
* Clean stale headers from if_ether.c.

Reported by:	rozhuk.im at gmail.com
Reviewed by:	ae
MFC after:	2 weeks
This commit is contained in:
Alexander V. Chernikov 2015-09-14 10:28:47 +00:00
parent 7b6660c9aa
commit deb6bda6e3
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=287779
1 changed files with 48 additions and 20 deletions
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68
sys/netinet/if_ether.c
View File

@ -58,7 +58,6 @@ __FBSDID("$FreeBSD$");
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/if_llc.h>
#include <net/ethernet.h>
#include <net/route.h>
#include <net/vnet.h>
@ -71,9 +70,6 @@ __FBSDID("$FreeBSD$");
#include <netinet/ip_carp.h>
#endif
#include <net/if_arc.h>
#include <net/iso88025.h>
#include <security/mac/mac_framework.h>
#define SIN(s) ((const struct sockaddr_in *)(s))
@ -529,6 +525,8 @@ static void
arpintr(struct mbuf *m)
{
struct arphdr *ar;
char *layer;
int hlen;
if (m->m_len < sizeof(struct arphdr) &&
((m = m_pullup(m, sizeof(struct arphdr))) == NULL)) {
@ -537,26 +535,56 @@ arpintr(struct mbuf *m)
}
ar = mtod(m, struct arphdr *);
if (ntohs(ar->ar_hrd) != ARPHRD_ETHER &&
ntohs(ar->ar_hrd) != ARPHRD_IEEE802 &&
ntohs(ar->ar_hrd) != ARPHRD_ARCNET &&
ntohs(ar->ar_hrd) != ARPHRD_IEEE1394 &&
ntohs(ar->ar_hrd) != ARPHRD_INFINIBAND) {
log(LOG_NOTICE, "arp: unknown hardware address format (0x%2D)"
" (from %*D to %*D)\n", (unsigned char *)&ar->ar_hrd, "",
ETHER_ADDR_LEN, (u_char *)ar_sha(ar), ":",
ETHER_ADDR_LEN, (u_char *)ar_tha(ar), ":");
/* Check if length is sufficient */
if ((m = m_pullup(m, arphdr_len(ar))) == NULL) {
log(LOG_NOTICE, "arp: short header received\n");
return;
}
ar = mtod(m, struct arphdr *);
hlen = 0;
layer = "";
switch (ntohs(ar->ar_hrd)) {
case ARPHRD_ETHER:
hlen = ETHER_ADDR_LEN; /* RFC 826 */
layer = "ethernet";
break;
case ARPHRD_IEEE802:
hlen = 6; /* RFC 1390, FDDI_ADDR_LEN */
layer = "fddi";
break;
case ARPHRD_ARCNET:
hlen = 1; /* RFC 1201, ARC_ADDR_LEN */
layer = "arcnet";
break;
case ARPHRD_INFINIBAND:
hlen = 20; /* RFC 4391, INFINIBAND_ALEN */
layer = "infiniband";
break;
case ARPHRD_IEEE1394:
hlen = 0; /* SHALL be 16 */ /* RFC 2734 */
layer = "firewire";
/*
* Restrict too long harware addresses.
* Currently we are capable of handling 20-byte
* addresses ( sizeof(lle->ll_addr) )
*/
if (ar->ar_hln >= 20)
hlen = 16;
break;
default:
log(LOG_NOTICE, "arp: unknown hardware address format (0x%2d)\n",
htons(ar->ar_hrd));
m_freem(m);
return;
}
if (m->m_len < arphdr_len(ar)) {
if ((m = m_pullup(m, arphdr_len(ar))) == NULL) {
log(LOG_NOTICE, "arp: runt packet\n");
m_freem(m);
return;
}
ar = mtod(m, struct arphdr *);
if (hlen != 0 && hlen != ar->ar_hln) {
log(LOG_NOTICE, "arp: bad %s header length: %d\n", layer,
ar->ar_hln);
m_freem(m);
return;
}
ARPSTAT_INC(received);