For now it is read-only, but eventually the cycle that goes over
all fragments should be refactored and this MIB should also become
read/write.
This MIB will allow SNMP daemons to implement MIB-II ipReasmTimeout MIB
straightfoward. Right now net-snmp compilation is broken by 1922eb3e9c
.
The base system bsnmpd is not broken just because it ignored PR_SLOWTIMO,
and thus always returned incorrectly doubled value for ipReasmTimeout.
899 lines
24 KiB
C
899 lines
24 KiB
C
/*-
|
|
* Copyright (c) 2015 Gleb Smirnoff <glebius@FreeBSD.org>
|
|
* Copyright (c) 2015 Adrian Chadd <adrian@FreeBSD.org>
|
|
* Copyright (c) 1982, 1986, 1988, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* 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. 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.
|
|
*
|
|
* @(#)ip_input.c 8.2 (Berkeley) 1/4/94
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include "opt_rss.h"
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/eventhandler.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/hash.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/limits.h>
|
|
#include <sys/lock.h>
|
|
#include <sys/mutex.h>
|
|
#include <sys/sysctl.h>
|
|
#include <sys/socket.h>
|
|
|
|
#include <net/if.h>
|
|
#include <net/if_var.h>
|
|
#include <net/rss_config.h>
|
|
#include <net/netisr.h>
|
|
#include <net/vnet.h>
|
|
|
|
#include <netinet/in.h>
|
|
#include <netinet/ip.h>
|
|
#include <netinet/ip_var.h>
|
|
#include <netinet/in_rss.h>
|
|
#ifdef MAC
|
|
#include <security/mac/mac_framework.h>
|
|
#endif
|
|
|
|
SYSCTL_DECL(_net_inet_ip);
|
|
|
|
/*
|
|
* Reassembly headers are stored in hash buckets.
|
|
*/
|
|
#define IPREASS_NHASH_LOG2 10
|
|
#define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2)
|
|
#define IPREASS_HMASK (IPREASS_NHASH - 1)
|
|
|
|
struct ipqbucket {
|
|
TAILQ_HEAD(ipqhead, ipq) head;
|
|
struct mtx lock;
|
|
int count;
|
|
};
|
|
|
|
VNET_DEFINE_STATIC(struct ipqbucket, ipq[IPREASS_NHASH]);
|
|
#define V_ipq VNET(ipq)
|
|
VNET_DEFINE_STATIC(uint32_t, ipq_hashseed);
|
|
#define V_ipq_hashseed VNET(ipq_hashseed)
|
|
|
|
#define IPQ_LOCK(i) mtx_lock(&V_ipq[i].lock)
|
|
#define IPQ_TRYLOCK(i) mtx_trylock(&V_ipq[i].lock)
|
|
#define IPQ_UNLOCK(i) mtx_unlock(&V_ipq[i].lock)
|
|
#define IPQ_LOCK_ASSERT(i) mtx_assert(&V_ipq[i].lock, MA_OWNED)
|
|
|
|
VNET_DEFINE_STATIC(int, ipreass_maxbucketsize);
|
|
#define V_ipreass_maxbucketsize VNET(ipreass_maxbucketsize)
|
|
|
|
void ipreass_init(void);
|
|
void ipreass_vnet_init(void);
|
|
#ifdef VIMAGE
|
|
void ipreass_destroy(void);
|
|
#endif
|
|
static int sysctl_maxfragpackets(SYSCTL_HANDLER_ARGS);
|
|
static int sysctl_maxfragbucketsize(SYSCTL_HANDLER_ARGS);
|
|
static void ipreass_zone_change(void *);
|
|
static void ipreass_drain_tomax(void);
|
|
static void ipq_free(struct ipqbucket *, struct ipq *);
|
|
static struct ipq * ipq_reuse(int);
|
|
|
|
static inline void
|
|
ipq_timeout(struct ipqbucket *bucket, struct ipq *fp)
|
|
{
|
|
|
|
IPSTAT_ADD(ips_fragtimeout, fp->ipq_nfrags);
|
|
ipq_free(bucket, fp);
|
|
}
|
|
|
|
static inline void
|
|
ipq_drop(struct ipqbucket *bucket, struct ipq *fp)
|
|
{
|
|
|
|
IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags);
|
|
ipq_free(bucket, fp);
|
|
}
|
|
|
|
/*
|
|
* By default, limit the number of IP fragments across all reassembly
|
|
* queues to 1/32 of the total number of mbuf clusters.
|
|
*
|
|
* Limit the total number of reassembly queues per VNET to the
|
|
* IP fragment limit, but ensure the limit will not allow any bucket
|
|
* to grow above 100 items. (The bucket limit is
|
|
* IP_MAXFRAGPACKETS / (IPREASS_NHASH / 2), so the 50 is the correct
|
|
* multiplier to reach a 100-item limit.)
|
|
* The 100-item limit was chosen as brief testing seems to show that
|
|
* this produces "reasonable" performance on some subset of systems
|
|
* under DoS attack.
|
|
*/
|
|
#define IP_MAXFRAGS (nmbclusters / 32)
|
|
#define IP_MAXFRAGPACKETS (imin(IP_MAXFRAGS, IPREASS_NHASH * 50))
|
|
|
|
static int maxfrags;
|
|
static u_int __exclusive_cache_line nfrags;
|
|
SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfrags, CTLFLAG_RW,
|
|
&maxfrags, 0,
|
|
"Maximum number of IPv4 fragments allowed across all reassembly queues");
|
|
SYSCTL_UINT(_net_inet_ip, OID_AUTO, curfrags, CTLFLAG_RD,
|
|
&nfrags, 0,
|
|
"Current number of IPv4 fragments across all reassembly queues");
|
|
|
|
VNET_DEFINE_STATIC(uma_zone_t, ipq_zone);
|
|
#define V_ipq_zone VNET(ipq_zone)
|
|
SYSCTL_PROC(_net_inet_ip, OID_AUTO, maxfragpackets,
|
|
CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
|
|
NULL, 0, sysctl_maxfragpackets, "I",
|
|
"Maximum number of IPv4 fragment reassembly queue entries");
|
|
SYSCTL_UMA_CUR(_net_inet_ip, OID_AUTO, fragpackets, CTLFLAG_VNET,
|
|
&VNET_NAME(ipq_zone),
|
|
"Current number of IPv4 fragment reassembly queue entries");
|
|
|
|
VNET_DEFINE_STATIC(int, noreass);
|
|
#define V_noreass VNET(noreass)
|
|
|
|
VNET_DEFINE_STATIC(int, maxfragsperpacket);
|
|
#define V_maxfragsperpacket VNET(maxfragsperpacket)
|
|
SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_VNET | CTLFLAG_RW,
|
|
&VNET_NAME(maxfragsperpacket), 0,
|
|
"Maximum number of IPv4 fragments allowed per packet");
|
|
SYSCTL_PROC(_net_inet_ip, OID_AUTO, maxfragbucketsize,
|
|
CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0,
|
|
sysctl_maxfragbucketsize, "I",
|
|
"Maximum number of IPv4 fragment reassembly queue entries per bucket");
|
|
|
|
static u_int ipfragttl = IPFRAGTTL / 2;
|
|
SYSCTL_UINT(_net_inet_ip, OID_AUTO, fragttl, CTLFLAG_RD, &ipfragttl,
|
|
IPFRAGTTL / 2, "IP fragment life time on reassembly queue");
|
|
|
|
/*
|
|
* Take incoming datagram fragment and try to reassemble it into
|
|
* whole datagram. If the argument is the first fragment or one
|
|
* in between the function will return NULL and store the mbuf
|
|
* in the fragment chain. If the argument is the last fragment
|
|
* the packet will be reassembled and the pointer to the new
|
|
* mbuf returned for further processing. Only m_tags attached
|
|
* to the first packet/fragment are preserved.
|
|
* The IP header is *NOT* adjusted out of iplen.
|
|
*/
|
|
#define M_IP_FRAG M_PROTO9
|
|
struct mbuf *
|
|
ip_reass(struct mbuf *m)
|
|
{
|
|
struct ip *ip;
|
|
struct mbuf *p, *q, *nq, *t;
|
|
struct ipq *fp;
|
|
struct ifnet *srcifp;
|
|
struct ipqhead *head;
|
|
int i, hlen, next, tmpmax;
|
|
u_int8_t ecn, ecn0;
|
|
uint32_t hash, hashkey[3];
|
|
#ifdef RSS
|
|
uint32_t rss_hash, rss_type;
|
|
#endif
|
|
|
|
/*
|
|
* If no reassembling or maxfragsperpacket are 0,
|
|
* never accept fragments.
|
|
* Also, drop packet if it would exceed the maximum
|
|
* number of fragments.
|
|
*/
|
|
tmpmax = maxfrags;
|
|
if (V_noreass == 1 || V_maxfragsperpacket == 0 ||
|
|
(tmpmax >= 0 && atomic_load_int(&nfrags) >= (u_int)tmpmax)) {
|
|
IPSTAT_INC(ips_fragments);
|
|
IPSTAT_INC(ips_fragdropped);
|
|
m_freem(m);
|
|
return (NULL);
|
|
}
|
|
|
|
ip = mtod(m, struct ip *);
|
|
hlen = ip->ip_hl << 2;
|
|
|
|
/*
|
|
* Adjust ip_len to not reflect header,
|
|
* convert offset of this to bytes.
|
|
*/
|
|
ip->ip_len = htons(ntohs(ip->ip_len) - hlen);
|
|
/*
|
|
* Make sure that fragments have a data length
|
|
* that's a non-zero multiple of 8 bytes, unless
|
|
* this is the last fragment.
|
|
*/
|
|
if (ip->ip_len == htons(0) ||
|
|
((ip->ip_off & htons(IP_MF)) && (ntohs(ip->ip_len) & 0x7) != 0)) {
|
|
IPSTAT_INC(ips_toosmall); /* XXX */
|
|
IPSTAT_INC(ips_fragdropped);
|
|
m_freem(m);
|
|
return (NULL);
|
|
}
|
|
if (ip->ip_off & htons(IP_MF))
|
|
m->m_flags |= M_IP_FRAG;
|
|
else
|
|
m->m_flags &= ~M_IP_FRAG;
|
|
ip->ip_off = htons(ntohs(ip->ip_off) << 3);
|
|
|
|
/*
|
|
* Make sure the fragment lies within a packet of valid size.
|
|
*/
|
|
if (ntohs(ip->ip_len) + ntohs(ip->ip_off) > IP_MAXPACKET) {
|
|
IPSTAT_INC(ips_toolong);
|
|
IPSTAT_INC(ips_fragdropped);
|
|
m_freem(m);
|
|
return (NULL);
|
|
}
|
|
|
|
/*
|
|
* Store receive network interface pointer for later.
|
|
*/
|
|
srcifp = m->m_pkthdr.rcvif;
|
|
|
|
/*
|
|
* Attempt reassembly; if it succeeds, proceed.
|
|
* ip_reass() will return a different mbuf.
|
|
*/
|
|
IPSTAT_INC(ips_fragments);
|
|
m->m_pkthdr.PH_loc.ptr = ip;
|
|
|
|
/*
|
|
* Presence of header sizes in mbufs
|
|
* would confuse code below.
|
|
*/
|
|
m->m_data += hlen;
|
|
m->m_len -= hlen;
|
|
|
|
hashkey[0] = ip->ip_src.s_addr;
|
|
hashkey[1] = ip->ip_dst.s_addr;
|
|
hashkey[2] = (uint32_t)ip->ip_p << 16;
|
|
hashkey[2] += ip->ip_id;
|
|
hash = jenkins_hash32(hashkey, nitems(hashkey), V_ipq_hashseed);
|
|
hash &= IPREASS_HMASK;
|
|
head = &V_ipq[hash].head;
|
|
IPQ_LOCK(hash);
|
|
|
|
/*
|
|
* Look for queue of fragments
|
|
* of this datagram.
|
|
*/
|
|
TAILQ_FOREACH(fp, head, ipq_list)
|
|
if (ip->ip_id == fp->ipq_id &&
|
|
ip->ip_src.s_addr == fp->ipq_src.s_addr &&
|
|
ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
|
|
#ifdef MAC
|
|
mac_ipq_match(m, fp) &&
|
|
#endif
|
|
ip->ip_p == fp->ipq_p)
|
|
break;
|
|
/*
|
|
* If first fragment to arrive, create a reassembly queue.
|
|
*/
|
|
if (fp == NULL) {
|
|
if (V_ipq[hash].count < V_ipreass_maxbucketsize)
|
|
fp = uma_zalloc(V_ipq_zone, M_NOWAIT);
|
|
if (fp == NULL)
|
|
fp = ipq_reuse(hash);
|
|
if (fp == NULL)
|
|
goto dropfrag;
|
|
#ifdef MAC
|
|
if (mac_ipq_init(fp, M_NOWAIT) != 0) {
|
|
uma_zfree(V_ipq_zone, fp);
|
|
fp = NULL;
|
|
goto dropfrag;
|
|
}
|
|
mac_ipq_create(m, fp);
|
|
#endif
|
|
TAILQ_INSERT_HEAD(head, fp, ipq_list);
|
|
V_ipq[hash].count++;
|
|
fp->ipq_nfrags = 1;
|
|
atomic_add_int(&nfrags, 1);
|
|
fp->ipq_ttl = IPFRAGTTL;
|
|
fp->ipq_p = ip->ip_p;
|
|
fp->ipq_id = ip->ip_id;
|
|
fp->ipq_src = ip->ip_src;
|
|
fp->ipq_dst = ip->ip_dst;
|
|
fp->ipq_frags = m;
|
|
if (m->m_flags & M_IP_FRAG)
|
|
fp->ipq_maxoff = -1;
|
|
else
|
|
fp->ipq_maxoff = ntohs(ip->ip_off) + ntohs(ip->ip_len);
|
|
m->m_nextpkt = NULL;
|
|
goto done;
|
|
} else {
|
|
/*
|
|
* If we already saw the last fragment, make sure
|
|
* this fragment's offset looks sane. Otherwise, if
|
|
* this is the last fragment, record its endpoint.
|
|
*/
|
|
if (fp->ipq_maxoff > 0) {
|
|
i = ntohs(ip->ip_off) + ntohs(ip->ip_len);
|
|
if (((m->m_flags & M_IP_FRAG) && i >= fp->ipq_maxoff) ||
|
|
((m->m_flags & M_IP_FRAG) == 0 &&
|
|
i != fp->ipq_maxoff)) {
|
|
fp = NULL;
|
|
goto dropfrag;
|
|
}
|
|
} else if ((m->m_flags & M_IP_FRAG) == 0)
|
|
fp->ipq_maxoff = ntohs(ip->ip_off) + ntohs(ip->ip_len);
|
|
fp->ipq_nfrags++;
|
|
atomic_add_int(&nfrags, 1);
|
|
#ifdef MAC
|
|
mac_ipq_update(m, fp);
|
|
#endif
|
|
}
|
|
|
|
#define GETIP(m) ((struct ip*)((m)->m_pkthdr.PH_loc.ptr))
|
|
|
|
/*
|
|
* Handle ECN by comparing this segment with the first one;
|
|
* if CE is set, do not lose CE.
|
|
* drop if CE and not-ECT are mixed for the same packet.
|
|
*/
|
|
ecn = ip->ip_tos & IPTOS_ECN_MASK;
|
|
ecn0 = GETIP(fp->ipq_frags)->ip_tos & IPTOS_ECN_MASK;
|
|
if (ecn == IPTOS_ECN_CE) {
|
|
if (ecn0 == IPTOS_ECN_NOTECT)
|
|
goto dropfrag;
|
|
if (ecn0 != IPTOS_ECN_CE)
|
|
GETIP(fp->ipq_frags)->ip_tos |= IPTOS_ECN_CE;
|
|
}
|
|
if (ecn == IPTOS_ECN_NOTECT && ecn0 != IPTOS_ECN_NOTECT)
|
|
goto dropfrag;
|
|
|
|
/*
|
|
* Find a segment which begins after this one does.
|
|
*/
|
|
for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt)
|
|
if (ntohs(GETIP(q)->ip_off) > ntohs(ip->ip_off))
|
|
break;
|
|
|
|
/*
|
|
* If there is a preceding segment, it may provide some of
|
|
* our data already. If so, drop the data from the incoming
|
|
* segment. If it provides all of our data, drop us, otherwise
|
|
* stick new segment in the proper place.
|
|
*
|
|
* If some of the data is dropped from the preceding
|
|
* segment, then it's checksum is invalidated.
|
|
*/
|
|
if (p) {
|
|
i = ntohs(GETIP(p)->ip_off) + ntohs(GETIP(p)->ip_len) -
|
|
ntohs(ip->ip_off);
|
|
if (i > 0) {
|
|
if (i >= ntohs(ip->ip_len))
|
|
goto dropfrag;
|
|
m_adj(m, i);
|
|
m->m_pkthdr.csum_flags = 0;
|
|
ip->ip_off = htons(ntohs(ip->ip_off) + i);
|
|
ip->ip_len = htons(ntohs(ip->ip_len) - i);
|
|
}
|
|
m->m_nextpkt = p->m_nextpkt;
|
|
p->m_nextpkt = m;
|
|
} else {
|
|
m->m_nextpkt = fp->ipq_frags;
|
|
fp->ipq_frags = m;
|
|
}
|
|
|
|
/*
|
|
* While we overlap succeeding segments trim them or,
|
|
* if they are completely covered, dequeue them.
|
|
*/
|
|
for (; q != NULL && ntohs(ip->ip_off) + ntohs(ip->ip_len) >
|
|
ntohs(GETIP(q)->ip_off); q = nq) {
|
|
i = (ntohs(ip->ip_off) + ntohs(ip->ip_len)) -
|
|
ntohs(GETIP(q)->ip_off);
|
|
if (i < ntohs(GETIP(q)->ip_len)) {
|
|
GETIP(q)->ip_len = htons(ntohs(GETIP(q)->ip_len) - i);
|
|
GETIP(q)->ip_off = htons(ntohs(GETIP(q)->ip_off) + i);
|
|
m_adj(q, i);
|
|
q->m_pkthdr.csum_flags = 0;
|
|
break;
|
|
}
|
|
nq = q->m_nextpkt;
|
|
m->m_nextpkt = nq;
|
|
IPSTAT_INC(ips_fragdropped);
|
|
fp->ipq_nfrags--;
|
|
atomic_subtract_int(&nfrags, 1);
|
|
m_freem(q);
|
|
}
|
|
|
|
/*
|
|
* Check for complete reassembly and perform frag per packet
|
|
* limiting.
|
|
*
|
|
* Frag limiting is performed here so that the nth frag has
|
|
* a chance to complete the packet before we drop the packet.
|
|
* As a result, n+1 frags are actually allowed per packet, but
|
|
* only n will ever be stored. (n = maxfragsperpacket.)
|
|
*
|
|
*/
|
|
next = 0;
|
|
for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
|
|
if (ntohs(GETIP(q)->ip_off) != next) {
|
|
if (fp->ipq_nfrags > V_maxfragsperpacket)
|
|
ipq_drop(&V_ipq[hash], fp);
|
|
goto done;
|
|
}
|
|
next += ntohs(GETIP(q)->ip_len);
|
|
}
|
|
/* Make sure the last packet didn't have the IP_MF flag */
|
|
if (p->m_flags & M_IP_FRAG) {
|
|
if (fp->ipq_nfrags > V_maxfragsperpacket)
|
|
ipq_drop(&V_ipq[hash], fp);
|
|
goto done;
|
|
}
|
|
|
|
/*
|
|
* Reassembly is complete. Make sure the packet is a sane size.
|
|
*/
|
|
q = fp->ipq_frags;
|
|
ip = GETIP(q);
|
|
if (next + (ip->ip_hl << 2) > IP_MAXPACKET) {
|
|
IPSTAT_INC(ips_toolong);
|
|
ipq_drop(&V_ipq[hash], fp);
|
|
goto done;
|
|
}
|
|
|
|
/*
|
|
* Concatenate fragments.
|
|
*/
|
|
m = q;
|
|
t = m->m_next;
|
|
m->m_next = NULL;
|
|
m_cat(m, t);
|
|
nq = q->m_nextpkt;
|
|
q->m_nextpkt = NULL;
|
|
for (q = nq; q != NULL; q = nq) {
|
|
nq = q->m_nextpkt;
|
|
q->m_nextpkt = NULL;
|
|
m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
|
|
m->m_pkthdr.csum_data += q->m_pkthdr.csum_data;
|
|
m_demote_pkthdr(q);
|
|
m_cat(m, q);
|
|
}
|
|
/*
|
|
* In order to do checksumming faster we do 'end-around carry' here
|
|
* (and not in for{} loop), though it implies we are not going to
|
|
* reassemble more than 64k fragments.
|
|
*/
|
|
while (m->m_pkthdr.csum_data & 0xffff0000)
|
|
m->m_pkthdr.csum_data = (m->m_pkthdr.csum_data & 0xffff) +
|
|
(m->m_pkthdr.csum_data >> 16);
|
|
atomic_subtract_int(&nfrags, fp->ipq_nfrags);
|
|
#ifdef MAC
|
|
mac_ipq_reassemble(fp, m);
|
|
mac_ipq_destroy(fp);
|
|
#endif
|
|
|
|
/*
|
|
* Create header for new ip packet by modifying header of first
|
|
* packet; dequeue and discard fragment reassembly header.
|
|
* Make header visible.
|
|
*/
|
|
ip->ip_len = htons((ip->ip_hl << 2) + next);
|
|
ip->ip_src = fp->ipq_src;
|
|
ip->ip_dst = fp->ipq_dst;
|
|
TAILQ_REMOVE(head, fp, ipq_list);
|
|
V_ipq[hash].count--;
|
|
uma_zfree(V_ipq_zone, fp);
|
|
m->m_len += (ip->ip_hl << 2);
|
|
m->m_data -= (ip->ip_hl << 2);
|
|
/* some debugging cruft by sklower, below, will go away soon */
|
|
if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
|
|
m_fixhdr(m);
|
|
/* set valid receive interface pointer */
|
|
m->m_pkthdr.rcvif = srcifp;
|
|
}
|
|
IPSTAT_INC(ips_reassembled);
|
|
IPQ_UNLOCK(hash);
|
|
|
|
#ifdef RSS
|
|
/*
|
|
* Query the RSS layer for the flowid / flowtype for the
|
|
* mbuf payload.
|
|
*
|
|
* For now, just assume we have to calculate a new one.
|
|
* Later on we should check to see if the assigned flowid matches
|
|
* what RSS wants for the given IP protocol and if so, just keep it.
|
|
*
|
|
* We then queue into the relevant netisr so it can be dispatched
|
|
* to the correct CPU.
|
|
*
|
|
* Note - this may return 1, which means the flowid in the mbuf
|
|
* is correct for the configured RSS hash types and can be used.
|
|
*/
|
|
if (rss_mbuf_software_hash_v4(m, 0, &rss_hash, &rss_type) == 0) {
|
|
m->m_pkthdr.flowid = rss_hash;
|
|
M_HASHTYPE_SET(m, rss_type);
|
|
}
|
|
|
|
/*
|
|
* Queue/dispatch for reprocessing.
|
|
*
|
|
* Note: this is much slower than just handling the frame in the
|
|
* current receive context. It's likely worth investigating
|
|
* why this is.
|
|
*/
|
|
netisr_dispatch(NETISR_IP_DIRECT, m);
|
|
return (NULL);
|
|
#endif
|
|
|
|
/* Handle in-line */
|
|
return (m);
|
|
|
|
dropfrag:
|
|
IPSTAT_INC(ips_fragdropped);
|
|
if (fp != NULL) {
|
|
fp->ipq_nfrags--;
|
|
atomic_subtract_int(&nfrags, 1);
|
|
}
|
|
m_freem(m);
|
|
done:
|
|
IPQ_UNLOCK(hash);
|
|
return (NULL);
|
|
|
|
#undef GETIP
|
|
}
|
|
|
|
/*
|
|
* If a timer expires on a reassembly queue, discard it.
|
|
*/
|
|
static struct callout ipreass_callout;
|
|
static void
|
|
ipreass_slowtimo(void *arg __unused)
|
|
{
|
|
VNET_ITERATOR_DECL(vnet_iter);
|
|
struct ipq *fp, *tmp;
|
|
|
|
if (atomic_load_int(&nfrags) == 0)
|
|
return;
|
|
|
|
VNET_FOREACH(vnet_iter) {
|
|
CURVNET_SET(vnet_iter);
|
|
for (int i = 0; i < IPREASS_NHASH; i++) {
|
|
if (TAILQ_EMPTY(&V_ipq[i].head))
|
|
continue;
|
|
IPQ_LOCK(i);
|
|
TAILQ_FOREACH_SAFE(fp, &V_ipq[i].head, ipq_list, tmp)
|
|
if (--fp->ipq_ttl == 0)
|
|
ipq_timeout(&V_ipq[i], fp);
|
|
IPQ_UNLOCK(i);
|
|
}
|
|
CURVNET_RESTORE();
|
|
}
|
|
VNET_LIST_RUNLOCK_NOSLEEP();
|
|
|
|
callout_reset_sbt(&ipreass_callout, SBT_1MS * 500, SBT_1MS * 10,
|
|
ipreass_slowtimo, NULL, 0);
|
|
}
|
|
|
|
static void
|
|
ipreass_timer_init(void *arg __unused)
|
|
{
|
|
|
|
callout_init(&ipreass_callout, 1);
|
|
callout_reset_sbt(&ipreass_callout, SBT_1MS * 500, SBT_1MS * 10,
|
|
ipreass_slowtimo, NULL, 0);
|
|
}
|
|
SYSINIT(ipreass, SI_SUB_VNET_DONE, SI_ORDER_ANY, ipreass_timer_init, NULL);
|
|
|
|
/*
|
|
* Drain off all datagram fragments.
|
|
*/
|
|
static void
|
|
ipreass_drain(void)
|
|
{
|
|
VNET_ITERATOR_DECL(vnet_iter);
|
|
|
|
VNET_FOREACH(vnet_iter) {
|
|
CURVNET_SET(vnet_iter);
|
|
for (int i = 0; i < IPREASS_NHASH; i++) {
|
|
IPQ_LOCK(i);
|
|
while(!TAILQ_EMPTY(&V_ipq[i].head))
|
|
ipq_drop(&V_ipq[i],
|
|
TAILQ_FIRST(&V_ipq[i].head));
|
|
KASSERT(V_ipq[i].count == 0,
|
|
("%s: V_ipq[%d] count %d (V_ipq=%p)", __func__, i,
|
|
V_ipq[i].count, V_ipq));
|
|
IPQ_UNLOCK(i);
|
|
}
|
|
CURVNET_RESTORE();
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* Initialize IP reassembly structures.
|
|
*/
|
|
void
|
|
ipreass_vnet_init(void)
|
|
{
|
|
int max;
|
|
|
|
for (int i = 0; i < IPREASS_NHASH; i++) {
|
|
TAILQ_INIT(&V_ipq[i].head);
|
|
mtx_init(&V_ipq[i].lock, "IP reassembly", NULL,
|
|
MTX_DEF | MTX_DUPOK);
|
|
V_ipq[i].count = 0;
|
|
}
|
|
V_ipq_hashseed = arc4random();
|
|
V_maxfragsperpacket = 16;
|
|
V_ipq_zone = uma_zcreate("ipq", sizeof(struct ipq), NULL, NULL, NULL,
|
|
NULL, UMA_ALIGN_PTR, 0);
|
|
max = IP_MAXFRAGPACKETS;
|
|
max = uma_zone_set_max(V_ipq_zone, max);
|
|
V_ipreass_maxbucketsize = imax(max / (IPREASS_NHASH / 2), 1);
|
|
}
|
|
|
|
void
|
|
ipreass_init(void)
|
|
{
|
|
|
|
maxfrags = IP_MAXFRAGS;
|
|
EVENTHANDLER_REGISTER(nmbclusters_change, ipreass_zone_change,
|
|
NULL, EVENTHANDLER_PRI_ANY);
|
|
EVENTHANDLER_REGISTER(vm_lowmem, ipreass_drain, NULL,
|
|
LOWMEM_PRI_DEFAULT);
|
|
EVENTHANDLER_REGISTER(mbuf_lowmem, ipreass_drain, NULL,
|
|
LOWMEM_PRI_DEFAULT);
|
|
}
|
|
|
|
/*
|
|
* Drain off all datagram fragments belonging to
|
|
* the given network interface.
|
|
*/
|
|
static void
|
|
ipreass_cleanup(void *arg __unused, struct ifnet *ifp)
|
|
{
|
|
struct ipq *fp, *temp;
|
|
struct mbuf *m;
|
|
int i;
|
|
|
|
KASSERT(ifp != NULL, ("%s: ifp is NULL", __func__));
|
|
|
|
CURVNET_SET_QUIET(ifp->if_vnet);
|
|
|
|
/*
|
|
* Skip processing if IPv4 reassembly is not initialised or
|
|
* torn down by ipreass_destroy().
|
|
*/
|
|
if (V_ipq_zone == NULL) {
|
|
CURVNET_RESTORE();
|
|
return;
|
|
}
|
|
|
|
for (i = 0; i < IPREASS_NHASH; i++) {
|
|
IPQ_LOCK(i);
|
|
/* Scan fragment list. */
|
|
TAILQ_FOREACH_SAFE(fp, &V_ipq[i].head, ipq_list, temp) {
|
|
for (m = fp->ipq_frags; m != NULL; m = m->m_nextpkt) {
|
|
/* clear no longer valid rcvif pointer */
|
|
if (m->m_pkthdr.rcvif == ifp)
|
|
m->m_pkthdr.rcvif = NULL;
|
|
}
|
|
}
|
|
IPQ_UNLOCK(i);
|
|
}
|
|
CURVNET_RESTORE();
|
|
}
|
|
EVENTHANDLER_DEFINE(ifnet_departure_event, ipreass_cleanup, NULL, 0);
|
|
|
|
#ifdef VIMAGE
|
|
/*
|
|
* Destroy IP reassembly structures.
|
|
*/
|
|
void
|
|
ipreass_destroy(void)
|
|
{
|
|
|
|
ipreass_drain();
|
|
uma_zdestroy(V_ipq_zone);
|
|
V_ipq_zone = NULL;
|
|
for (int i = 0; i < IPREASS_NHASH; i++)
|
|
mtx_destroy(&V_ipq[i].lock);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* After maxnipq has been updated, propagate the change to UMA. The UMA zone
|
|
* max has slightly different semantics than the sysctl, for historical
|
|
* reasons.
|
|
*/
|
|
static void
|
|
ipreass_drain_tomax(void)
|
|
{
|
|
struct ipq *fp;
|
|
int target;
|
|
|
|
/*
|
|
* Make sure each bucket is under the new limit. If
|
|
* necessary, drop enough of the oldest elements from
|
|
* each bucket to get under the new limit.
|
|
*/
|
|
for (int i = 0; i < IPREASS_NHASH; i++) {
|
|
IPQ_LOCK(i);
|
|
while (V_ipq[i].count > V_ipreass_maxbucketsize &&
|
|
(fp = TAILQ_LAST(&V_ipq[i].head, ipqhead)) != NULL)
|
|
ipq_timeout(&V_ipq[i], fp);
|
|
IPQ_UNLOCK(i);
|
|
}
|
|
|
|
/*
|
|
* If we are over the maximum number of fragments,
|
|
* drain off enough to get down to the new limit,
|
|
* stripping off last elements on queues. Every
|
|
* run we strip the oldest element from each bucket.
|
|
*/
|
|
target = uma_zone_get_max(V_ipq_zone);
|
|
while (uma_zone_get_cur(V_ipq_zone) > target) {
|
|
for (int i = 0; i < IPREASS_NHASH; i++) {
|
|
IPQ_LOCK(i);
|
|
fp = TAILQ_LAST(&V_ipq[i].head, ipqhead);
|
|
if (fp != NULL)
|
|
ipq_timeout(&V_ipq[i], fp);
|
|
IPQ_UNLOCK(i);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
ipreass_zone_change(void *tag)
|
|
{
|
|
VNET_ITERATOR_DECL(vnet_iter);
|
|
int max;
|
|
|
|
maxfrags = IP_MAXFRAGS;
|
|
max = IP_MAXFRAGPACKETS;
|
|
VNET_LIST_RLOCK_NOSLEEP();
|
|
VNET_FOREACH(vnet_iter) {
|
|
CURVNET_SET(vnet_iter);
|
|
max = uma_zone_set_max(V_ipq_zone, max);
|
|
V_ipreass_maxbucketsize = imax(max / (IPREASS_NHASH / 2), 1);
|
|
ipreass_drain_tomax();
|
|
CURVNET_RESTORE();
|
|
}
|
|
VNET_LIST_RUNLOCK_NOSLEEP();
|
|
}
|
|
|
|
/*
|
|
* Change the limit on the UMA zone, or disable the fragment allocation
|
|
* at all. Since 0 and -1 is a special values here, we need our own handler,
|
|
* instead of sysctl_handle_uma_zone_max().
|
|
*/
|
|
static int
|
|
sysctl_maxfragpackets(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
int error, max;
|
|
|
|
if (V_noreass == 0) {
|
|
max = uma_zone_get_max(V_ipq_zone);
|
|
if (max == 0)
|
|
max = -1;
|
|
} else
|
|
max = 0;
|
|
error = sysctl_handle_int(oidp, &max, 0, req);
|
|
if (error || !req->newptr)
|
|
return (error);
|
|
if (max > 0) {
|
|
/*
|
|
* XXXRW: Might be a good idea to sanity check the argument
|
|
* and place an extreme upper bound.
|
|
*/
|
|
max = uma_zone_set_max(V_ipq_zone, max);
|
|
V_ipreass_maxbucketsize = imax(max / (IPREASS_NHASH / 2), 1);
|
|
ipreass_drain_tomax();
|
|
V_noreass = 0;
|
|
} else if (max == 0) {
|
|
V_noreass = 1;
|
|
ipreass_drain();
|
|
} else if (max == -1) {
|
|
V_noreass = 0;
|
|
uma_zone_set_max(V_ipq_zone, 0);
|
|
V_ipreass_maxbucketsize = INT_MAX;
|
|
} else
|
|
return (EINVAL);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Seek for old fragment queue header that can be reused. Try to
|
|
* reuse a header from currently locked hash bucket.
|
|
*/
|
|
static struct ipq *
|
|
ipq_reuse(int start)
|
|
{
|
|
struct ipq *fp;
|
|
int bucket, i;
|
|
|
|
IPQ_LOCK_ASSERT(start);
|
|
|
|
for (i = 0; i < IPREASS_NHASH; i++) {
|
|
bucket = (start + i) % IPREASS_NHASH;
|
|
if (bucket != start && IPQ_TRYLOCK(bucket) == 0)
|
|
continue;
|
|
fp = TAILQ_LAST(&V_ipq[bucket].head, ipqhead);
|
|
if (fp) {
|
|
struct mbuf *m;
|
|
|
|
IPSTAT_ADD(ips_fragtimeout, fp->ipq_nfrags);
|
|
atomic_subtract_int(&nfrags, fp->ipq_nfrags);
|
|
while (fp->ipq_frags) {
|
|
m = fp->ipq_frags;
|
|
fp->ipq_frags = m->m_nextpkt;
|
|
m_freem(m);
|
|
}
|
|
TAILQ_REMOVE(&V_ipq[bucket].head, fp, ipq_list);
|
|
V_ipq[bucket].count--;
|
|
if (bucket != start)
|
|
IPQ_UNLOCK(bucket);
|
|
break;
|
|
}
|
|
if (bucket != start)
|
|
IPQ_UNLOCK(bucket);
|
|
}
|
|
IPQ_LOCK_ASSERT(start);
|
|
return (fp);
|
|
}
|
|
|
|
/*
|
|
* Free a fragment reassembly header and all associated datagrams.
|
|
*/
|
|
static void
|
|
ipq_free(struct ipqbucket *bucket, struct ipq *fp)
|
|
{
|
|
struct mbuf *q;
|
|
|
|
atomic_subtract_int(&nfrags, fp->ipq_nfrags);
|
|
while (fp->ipq_frags) {
|
|
q = fp->ipq_frags;
|
|
fp->ipq_frags = q->m_nextpkt;
|
|
m_freem(q);
|
|
}
|
|
TAILQ_REMOVE(&bucket->head, fp, ipq_list);
|
|
bucket->count--;
|
|
uma_zfree(V_ipq_zone, fp);
|
|
}
|
|
|
|
/*
|
|
* Get or set the maximum number of reassembly queues per bucket.
|
|
*/
|
|
static int
|
|
sysctl_maxfragbucketsize(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
int error, max;
|
|
|
|
max = V_ipreass_maxbucketsize;
|
|
error = sysctl_handle_int(oidp, &max, 0, req);
|
|
if (error || !req->newptr)
|
|
return (error);
|
|
if (max <= 0)
|
|
return (EINVAL);
|
|
V_ipreass_maxbucketsize = max;
|
|
ipreass_drain_tomax();
|
|
return (0);
|
|
}
|