doc/share/security/patches/SA-01:52/frag-3.x.patch
Bjoern A. Zeeb 3571e53040 Import FreeBSD Security Advisories and Errata Notices, as well as their
patches for easier mirroring, to eliminate a special copy, to make
www.freebsd.org/security a full copy of security.freebsd.org and be
eventually be the same.

For now files are just sitting there.   The symlinks are missing.

Discussed on:	www (repository location)
Discussed with:	simon (so)
2012-08-15 06:19:40 +00:00

84 lines
2.4 KiB
Diff

Index: sys/netinet/ip_input.c
===================================================================
RCS file: /mnt/ncvs/src/sys/netinet/ip_input.c,v
retrieving revision 1.111.2.9
retrieving revision 1.111.2.10
diff -u -r1.111.2.9 -r1.111.2.10
--- sys/netinet/ip_input.c 2000/06/13 07:12:34 1.111.2.9
+++ sys/netinet/ip_input.c 2001/08/06 09:20:57 1.111.2.10
@@ -175,6 +175,12 @@
#endif
+static int ip_nfragpackets = 0;
+static int ip_maxfragpackets; /* initialized in ip_init() */
+SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_RW,
+ &ip_maxfragpackets, 0,
+ "Maximum number of IPv4 fragment reassembly queue entries");
+
/*
* We need to save the IP options in case a protocol wants to respond
* to an incoming packet over the same route if the packet got here
@@ -235,7 +241,8 @@
for (i = 0; i < IPREASS_NHASH; i++)
ipq[i].next = ipq[i].prev = &ipq[i];
- maxnipq = nmbclusters/4;
+ maxnipq = nmbclusters / 4;
+ ip_maxfragpackets = nmbclusters / 4;
ip_id = time_second & 0xffff;
ipintrq.ifq_maxlen = ipqmaxlen;
@@ -766,6 +773,15 @@
* If first fragment to arrive, create a reassembly queue.
*/
if (fp == 0) {
+ /*
+ * Enforce upper bound on number of fragmented packets
+ * for which we attempt reassembly;
+ * If maxfrag is 0, never accept fragments.
+ * If maxfrag is -1, accept all fragments without limitation.
+ */
+ if ((ip_maxfragpackets >= 0) && (ip_nfragpackets >= ip_maxfragpackets))
+ goto dropfrag;
+ ip_nfragpackets++;
if ((t = m_get(M_DONTWAIT, MT_FTABLE)) == NULL)
goto dropfrag;
fp = mtod(t, struct ipq *);
@@ -908,6 +924,7 @@
remque(fp);
nipq--;
(void) m_free(dtom(fp));
+ ip_nfragpackets--;
m->m_len += (IP_VHL_HL(ip->ip_vhl) << 2);
m->m_data -= (IP_VHL_HL(ip->ip_vhl) << 2);
/* some debugging cruft by sklower, below, will go away soon */
@@ -948,6 +965,7 @@
}
remque(fp);
(void) m_free(dtom(fp));
+ ip_nfragpackets--;
nipq--;
}
@@ -973,6 +991,20 @@
if (fp->prev->ipq_ttl == 0) {
ipstat.ips_fragtimeout++;
ip_freef(fp->prev);
+ }
+ }
+ }
+ /*
+ * If we are over the maximum number of fragments
+ * (due to the limit being lowered), drain off
+ * enough to get down to the new limit.
+ */
+ for (i = 0; i < IPREASS_NHASH; i++) {
+ if (ip_maxfragpackets >= 0) {
+ while ((ip_nfragpackets > ip_maxfragpackets) &&
+ (ipq[i].next != &ipq[i])) {
+ ipstat.ips_fragdropped++;
+ ip_freef(ipq[i].next);
}
}
}