2005-04-16 22:20:36 +00:00
|
|
|
/*
|
|
|
|
* INET An implementation of the TCP/IP protocol suite for the LINUX
|
|
|
|
* operating system. INET is implemented using the BSD Socket
|
|
|
|
* interface as the means of communication with the user level.
|
|
|
|
*
|
|
|
|
* The IP fragmentation functionality.
|
2007-02-09 14:24:47 +00:00
|
|
|
*
|
2005-04-16 22:20:36 +00:00
|
|
|
* Authors: Fred N. van Kempen <waltje@uWalt.NL.Mugnet.ORG>
|
2008-10-14 02:01:08 +00:00
|
|
|
* Alan Cox <alan@lxorguk.ukuu.org.uk>
|
2005-04-16 22:20:36 +00:00
|
|
|
*
|
|
|
|
* Fixes:
|
|
|
|
* Alan Cox : Split from ip.c , see ip_input.c for history.
|
|
|
|
* David S. Miller : Begin massive cleanup...
|
|
|
|
* Andi Kleen : Add sysctls.
|
|
|
|
* xxxx : Overlapfrag bug.
|
|
|
|
* Ultima : ip_expire() kernel panic.
|
|
|
|
* Bill Hawes : Frag accounting and evictor fixes.
|
|
|
|
* John McDonald : 0 length frag bug.
|
|
|
|
* Alexey Kuznetsov: SMP races, threading, cleanup.
|
|
|
|
* Patrick McHardy : LRU queue of frag heads for evictor.
|
|
|
|
*/
|
|
|
|
|
2012-03-12 07:03:32 +00:00
|
|
|
#define pr_fmt(fmt) "IPv4: " fmt
|
|
|
|
|
2005-12-14 07:14:27 +00:00
|
|
|
#include <linux/compiler.h>
|
2005-04-16 22:20:36 +00:00
|
|
|
#include <linux/module.h>
|
|
|
|
#include <linux/types.h>
|
|
|
|
#include <linux/mm.h>
|
|
|
|
#include <linux/jiffies.h>
|
|
|
|
#include <linux/skbuff.h>
|
|
|
|
#include <linux/list.h>
|
|
|
|
#include <linux/ip.h>
|
|
|
|
#include <linux/icmp.h>
|
|
|
|
#include <linux/netdevice.h>
|
|
|
|
#include <linux/jhash.h>
|
|
|
|
#include <linux/random.h>
|
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
|
|
|
#include <linux/slab.h>
|
2010-01-23 09:57:42 +00:00
|
|
|
#include <net/route.h>
|
|
|
|
#include <net/dst.h>
|
2005-04-16 22:20:36 +00:00
|
|
|
#include <net/sock.h>
|
|
|
|
#include <net/ip.h>
|
|
|
|
#include <net/icmp.h>
|
|
|
|
#include <net/checksum.h>
|
2005-12-14 07:14:27 +00:00
|
|
|
#include <net/inetpeer.h>
|
2007-10-15 09:24:19 +00:00
|
|
|
#include <net/inet_frag.h>
|
2005-04-16 22:20:36 +00:00
|
|
|
#include <linux/tcp.h>
|
|
|
|
#include <linux/udp.h>
|
|
|
|
#include <linux/inet.h>
|
|
|
|
#include <linux/netfilter_ipv4.h>
|
2011-01-05 07:52:55 +00:00
|
|
|
#include <net/inet_ecn.h>
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
/* NOTE. Logic of IP defragmentation is parallel to corresponding IPv6
|
|
|
|
* code now. If you change something here, _PLEASE_ update ipv6/reassembly.c
|
|
|
|
* as well. Or notify me, at least. --ANK
|
|
|
|
*/
|
|
|
|
|
2008-01-22 13:58:31 +00:00
|
|
|
static int sysctl_ipfrag_max_dist __read_mostly = 64;
|
2005-12-14 07:14:27 +00:00
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
struct ipfrag_skb_cb
|
|
|
|
{
|
|
|
|
struct inet_skb_parm h;
|
|
|
|
int offset;
|
|
|
|
};
|
|
|
|
|
2008-11-03 10:47:38 +00:00
|
|
|
#define FRAG_CB(skb) ((struct ipfrag_skb_cb *)((skb)->cb))
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
/* Describe an entry in the "incomplete datagrams" queue. */
|
|
|
|
struct ipq {
|
2007-10-15 09:24:19 +00:00
|
|
|
struct inet_frag_queue q;
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
u32 user;
|
2006-09-27 05:19:02 +00:00
|
|
|
__be32 saddr;
|
|
|
|
__be32 daddr;
|
|
|
|
__be16 id;
|
2005-04-16 22:20:36 +00:00
|
|
|
u8 protocol;
|
2011-01-05 07:52:55 +00:00
|
|
|
u8 ecn; /* RFC3168 support */
|
2005-12-14 07:14:27 +00:00
|
|
|
int iif;
|
|
|
|
unsigned int rid;
|
|
|
|
struct inet_peer *peer;
|
2005-04-16 22:20:36 +00:00
|
|
|
};
|
|
|
|
|
2011-05-16 08:37:37 +00:00
|
|
|
/* RFC 3168 support :
|
|
|
|
* We want to check ECN values of all fragments, do detect invalid combinations.
|
|
|
|
* In ipq->ecn, we store the OR value of each ip4_frag_ecn() fragment value.
|
|
|
|
*/
|
2011-05-17 21:28:02 +00:00
|
|
|
#define IPFRAG_ECN_NOT_ECT 0x01 /* one frag had ECN_NOT_ECT */
|
|
|
|
#define IPFRAG_ECN_ECT_1 0x02 /* one frag had ECN_ECT_1 */
|
|
|
|
#define IPFRAG_ECN_ECT_0 0x04 /* one frag had ECN_ECT_0 */
|
|
|
|
#define IPFRAG_ECN_CE 0x08 /* one frag had ECN_CE */
|
2011-01-05 07:52:55 +00:00
|
|
|
|
|
|
|
static inline u8 ip4_frag_ecn(u8 tos)
|
|
|
|
{
|
2011-05-16 08:37:37 +00:00
|
|
|
return 1 << (tos & INET_ECN_MASK);
|
2011-01-05 07:52:55 +00:00
|
|
|
}
|
|
|
|
|
2011-05-16 08:37:37 +00:00
|
|
|
/* Given the OR values of all fragments, apply RFC 3168 5.3 requirements
|
|
|
|
* Value : 0xff if frame should be dropped.
|
|
|
|
* 0 or INET_ECN_CE value, to be ORed in to final iph->tos field
|
|
|
|
*/
|
|
|
|
static const u8 ip4_frag_ecn_table[16] = {
|
|
|
|
/* at least one fragment had CE, and others ECT_0 or ECT_1 */
|
|
|
|
[IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0] = INET_ECN_CE,
|
|
|
|
[IPFRAG_ECN_CE | IPFRAG_ECN_ECT_1] = INET_ECN_CE,
|
|
|
|
[IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = INET_ECN_CE,
|
|
|
|
|
|
|
|
/* invalid combinations : drop frame */
|
|
|
|
[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE] = 0xff,
|
|
|
|
[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_0] = 0xff,
|
|
|
|
[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_1] = 0xff,
|
|
|
|
[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = 0xff,
|
|
|
|
[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0] = 0xff,
|
|
|
|
[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_1] = 0xff,
|
|
|
|
[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = 0xff,
|
|
|
|
};
|
|
|
|
|
2007-10-15 09:31:52 +00:00
|
|
|
static struct inet_frags ip4_frags;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2008-01-22 14:06:23 +00:00
|
|
|
int ip_frag_nqueues(struct net *net)
|
2007-10-15 09:31:52 +00:00
|
|
|
{
|
2008-01-22 14:06:23 +00:00
|
|
|
return net->ipv4.frags.nqueues;
|
2007-10-15 09:31:52 +00:00
|
|
|
}
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2008-01-22 14:07:25 +00:00
|
|
|
int ip_frag_mem(struct net *net)
|
2007-10-15 09:31:52 +00:00
|
|
|
{
|
2008-01-22 14:07:25 +00:00
|
|
|
return atomic_read(&net->ipv4.frags.mem);
|
2007-10-15 09:31:52 +00:00
|
|
|
}
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-10-14 07:38:15 +00:00
|
|
|
static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
|
|
|
|
struct net_device *dev);
|
|
|
|
|
2007-10-18 02:46:47 +00:00
|
|
|
struct ip4_create_arg {
|
|
|
|
struct iphdr *iph;
|
|
|
|
u32 user;
|
|
|
|
};
|
|
|
|
|
2006-09-27 05:19:02 +00:00
|
|
|
static unsigned int ipqhashfn(__be16 id, __be32 saddr, __be32 daddr, u8 prot)
|
2005-04-16 22:20:36 +00:00
|
|
|
{
|
2006-09-27 05:19:02 +00:00
|
|
|
return jhash_3words((__force u32)id << 16 | prot,
|
|
|
|
(__force u32)saddr, (__force u32)daddr,
|
2007-10-15 09:31:52 +00:00
|
|
|
ip4_frags.rnd) & (INETFRAGS_HASHSZ - 1);
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
2007-10-15 09:38:08 +00:00
|
|
|
static unsigned int ip4_hashfn(struct inet_frag_queue *q)
|
2005-04-16 22:20:36 +00:00
|
|
|
{
|
2007-10-15 09:38:08 +00:00
|
|
|
struct ipq *ipq;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-10-15 09:38:08 +00:00
|
|
|
ipq = container_of(q, struct ipq, q);
|
|
|
|
return ipqhashfn(ipq->id, ipq->saddr, ipq->daddr, ipq->protocol);
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
2012-05-18 03:57:13 +00:00
|
|
|
static bool ip4_frag_match(struct inet_frag_queue *q, void *a)
|
2007-10-18 02:47:21 +00:00
|
|
|
{
|
|
|
|
struct ipq *qp;
|
|
|
|
struct ip4_create_arg *arg = a;
|
|
|
|
|
|
|
|
qp = container_of(q, struct ipq, q);
|
2010-09-22 20:43:57 +00:00
|
|
|
return qp->id == arg->iph->id &&
|
2012-05-18 03:57:13 +00:00
|
|
|
qp->saddr == arg->iph->saddr &&
|
|
|
|
qp->daddr == arg->iph->daddr &&
|
|
|
|
qp->protocol == arg->iph->protocol &&
|
|
|
|
qp->user == arg->user;
|
2007-10-18 02:47:21 +00:00
|
|
|
}
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
/* Memory Tracking Functions. */
|
2010-06-13 23:22:43 +00:00
|
|
|
static void frag_kfree_skb(struct netns_frags *nf, struct sk_buff *skb)
|
2005-04-16 22:20:36 +00:00
|
|
|
{
|
2008-01-22 14:07:25 +00:00
|
|
|
atomic_sub(skb->truesize, &nf->mem);
|
2005-04-16 22:20:36 +00:00
|
|
|
kfree_skb(skb);
|
|
|
|
}
|
|
|
|
|
2007-10-18 02:46:47 +00:00
|
|
|
static void ip4_frag_init(struct inet_frag_queue *q, void *a)
|
|
|
|
{
|
|
|
|
struct ipq *qp = container_of(q, struct ipq, q);
|
2012-06-08 01:21:40 +00:00
|
|
|
struct netns_ipv4 *ipv4 = container_of(q->net, struct netns_ipv4,
|
|
|
|
frags);
|
|
|
|
struct net *net = container_of(ipv4, struct net, ipv4);
|
|
|
|
|
2007-10-18 02:46:47 +00:00
|
|
|
struct ip4_create_arg *arg = a;
|
|
|
|
|
|
|
|
qp->protocol = arg->iph->protocol;
|
|
|
|
qp->id = arg->iph->id;
|
2011-01-05 07:52:55 +00:00
|
|
|
qp->ecn = ip4_frag_ecn(arg->iph->tos);
|
2007-10-18 02:46:47 +00:00
|
|
|
qp->saddr = arg->iph->saddr;
|
|
|
|
qp->daddr = arg->iph->daddr;
|
|
|
|
qp->user = arg->user;
|
|
|
|
qp->peer = sysctl_ipfrag_max_dist ?
|
2012-06-10 02:12:36 +00:00
|
|
|
inet_getpeer_v4(net->ipv4.peers, arg->iph->saddr, 1) : NULL;
|
2007-10-18 02:46:47 +00:00
|
|
|
}
|
|
|
|
|
2007-10-15 09:39:14 +00:00
|
|
|
static __inline__ void ip4_frag_free(struct inet_frag_queue *q)
|
2005-04-16 22:20:36 +00:00
|
|
|
{
|
2007-10-15 09:39:14 +00:00
|
|
|
struct ipq *qp;
|
|
|
|
|
|
|
|
qp = container_of(q, struct ipq, q);
|
|
|
|
if (qp->peer)
|
|
|
|
inet_putpeer(qp->peer);
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/* Destruction primitives. */
|
|
|
|
|
2007-10-15 09:41:09 +00:00
|
|
|
static __inline__ void ipq_put(struct ipq *ipq)
|
2005-04-16 22:20:36 +00:00
|
|
|
{
|
2007-10-15 09:41:56 +00:00
|
|
|
inet_frag_put(&ipq->q, &ip4_frags);
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/* Kill ipq entry. It is not destroyed immediately,
|
|
|
|
* because caller (and someone more) holds reference count.
|
|
|
|
*/
|
|
|
|
static void ipq_kill(struct ipq *ipq)
|
|
|
|
{
|
2007-10-15 09:37:18 +00:00
|
|
|
inet_frag_kill(&ipq->q, &ip4_frags);
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
2007-02-09 14:24:47 +00:00
|
|
|
/* Memory limiting on fragments. Evictor trashes the oldest
|
2005-04-16 22:20:36 +00:00
|
|
|
* fragment queue until we are back under the threshold.
|
|
|
|
*/
|
2008-01-22 14:07:25 +00:00
|
|
|
static void ip_evictor(struct net *net)
|
2005-04-16 22:20:36 +00:00
|
|
|
{
|
2007-10-15 09:40:06 +00:00
|
|
|
int evicted;
|
|
|
|
|
2008-01-22 14:07:25 +00:00
|
|
|
evicted = inet_frag_evictor(&net->ipv4.frags, &ip4_frags);
|
2007-10-15 09:40:06 +00:00
|
|
|
if (evicted)
|
2008-07-17 03:20:33 +00:00
|
|
|
IP_ADD_STATS_BH(net, IPSTATS_MIB_REASMFAILS, evicted);
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Oops, a fragment queue timed out. Kill it and send an ICMP reply.
|
|
|
|
*/
|
|
|
|
static void ip_expire(unsigned long arg)
|
|
|
|
{
|
2007-10-18 02:45:23 +00:00
|
|
|
struct ipq *qp;
|
2008-07-17 03:19:08 +00:00
|
|
|
struct net *net;
|
2007-10-18 02:45:23 +00:00
|
|
|
|
|
|
|
qp = container_of((struct inet_frag_queue *) arg, struct ipq, q);
|
2008-07-17 03:19:08 +00:00
|
|
|
net = container_of(qp->q.net, struct net, ipv4.frags);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-10-15 09:24:19 +00:00
|
|
|
spin_lock(&qp->q.lock);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2008-03-28 23:35:27 +00:00
|
|
|
if (qp->q.last_in & INET_FRAG_COMPLETE)
|
2005-04-16 22:20:36 +00:00
|
|
|
goto out;
|
|
|
|
|
|
|
|
ipq_kill(qp);
|
|
|
|
|
2008-07-17 03:20:11 +00:00
|
|
|
IP_INC_STATS_BH(net, IPSTATS_MIB_REASMTIMEOUT);
|
|
|
|
IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2008-03-28 23:35:27 +00:00
|
|
|
if ((qp->q.last_in & INET_FRAG_FIRST_IN) && qp->q.fragments != NULL) {
|
2007-10-15 09:24:19 +00:00
|
|
|
struct sk_buff *head = qp->q.fragments;
|
2011-05-04 10:02:26 +00:00
|
|
|
const struct iphdr *iph;
|
|
|
|
int err;
|
2008-03-24 22:31:00 +00:00
|
|
|
|
2009-11-06 04:59:47 +00:00
|
|
|
rcu_read_lock();
|
|
|
|
head->dev = dev_get_by_index_rcu(net, qp->iif);
|
2010-01-23 09:57:42 +00:00
|
|
|
if (!head->dev)
|
|
|
|
goto out_rcu_unlock;
|
|
|
|
|
2011-05-04 10:02:26 +00:00
|
|
|
/* skb dst is stale, drop it, and perform route lookup again */
|
|
|
|
skb_dst_drop(head);
|
|
|
|
iph = ip_hdr(head);
|
|
|
|
err = ip_route_input_noref(head, iph->daddr, iph->saddr,
|
2012-06-26 23:14:15 +00:00
|
|
|
iph->tos, head->dev, false);
|
2011-05-04 10:02:26 +00:00
|
|
|
if (err)
|
|
|
|
goto out_rcu_unlock;
|
|
|
|
|
2010-01-23 09:57:42 +00:00
|
|
|
/*
|
2011-05-04 10:02:26 +00:00
|
|
|
* Only an end host needs to send an ICMP
|
|
|
|
* "Fragment Reassembly Timeout" message, per RFC792.
|
2010-01-23 09:57:42 +00:00
|
|
|
*/
|
2011-07-05 08:05:48 +00:00
|
|
|
if (qp->user == IP_DEFRAG_AF_PACKET ||
|
|
|
|
(qp->user == IP_DEFRAG_CONNTRACK_IN &&
|
|
|
|
skb_rtable(head)->rt_type != RTN_LOCAL))
|
2011-05-04 10:02:26 +00:00
|
|
|
goto out_rcu_unlock;
|
|
|
|
|
2010-01-23 09:57:42 +00:00
|
|
|
|
|
|
|
/* Send an ICMP "Fragment Reassembly Timeout" message. */
|
|
|
|
icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
|
|
|
|
out_rcu_unlock:
|
2010-02-02 19:46:50 +00:00
|
|
|
rcu_read_unlock();
|
|
|
|
}
|
2005-04-16 22:20:36 +00:00
|
|
|
out:
|
2007-10-15 09:24:19 +00:00
|
|
|
spin_unlock(&qp->q.lock);
|
2007-10-15 09:41:09 +00:00
|
|
|
ipq_put(qp);
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
2007-10-18 02:47:21 +00:00
|
|
|
/* Find the correct entry in the "incomplete datagrams" queue for
|
|
|
|
* this IP datagram, and create new one, if nothing is found.
|
|
|
|
*/
|
2008-01-22 14:02:14 +00:00
|
|
|
static inline struct ipq *ip_find(struct net *net, struct iphdr *iph, u32 user)
|
2005-04-16 22:20:36 +00:00
|
|
|
{
|
2007-10-18 02:46:47 +00:00
|
|
|
struct inet_frag_queue *q;
|
|
|
|
struct ip4_create_arg arg;
|
2007-10-18 02:47:21 +00:00
|
|
|
unsigned int hash;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-10-18 02:46:47 +00:00
|
|
|
arg.iph = iph;
|
|
|
|
arg.user = user;
|
2008-06-28 03:06:08 +00:00
|
|
|
|
|
|
|
read_lock(&ip4_frags.lock);
|
2007-10-18 02:47:21 +00:00
|
|
|
hash = ipqhashfn(iph->id, iph->saddr, iph->daddr, iph->protocol);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2008-01-22 14:02:14 +00:00
|
|
|
q = inet_frag_find(&net->ipv4.frags, &ip4_frags, &arg, hash);
|
2007-10-18 02:46:47 +00:00
|
|
|
if (q == NULL)
|
|
|
|
goto out_nomem;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-10-18 02:46:47 +00:00
|
|
|
return container_of(q, struct ipq, q);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
out_nomem:
|
2012-03-12 07:03:32 +00:00
|
|
|
LIMIT_NETDEBUG(KERN_ERR pr_fmt("ip_frag_create: no memory left !\n"));
|
2005-04-16 22:20:36 +00:00
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
2005-12-14 07:14:27 +00:00
|
|
|
/* Is the fragment too far ahead to be part of ipq? */
|
|
|
|
static inline int ip_frag_too_far(struct ipq *qp)
|
|
|
|
{
|
|
|
|
struct inet_peer *peer = qp->peer;
|
|
|
|
unsigned int max = sysctl_ipfrag_max_dist;
|
|
|
|
unsigned int start, end;
|
|
|
|
|
|
|
|
int rc;
|
|
|
|
|
|
|
|
if (!peer || !max)
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
start = qp->rid;
|
|
|
|
end = atomic_inc_return(&peer->rid);
|
|
|
|
qp->rid = end;
|
|
|
|
|
2007-10-15 09:24:19 +00:00
|
|
|
rc = qp->q.fragments && (end - start) > max;
|
2005-12-14 07:14:27 +00:00
|
|
|
|
|
|
|
if (rc) {
|
2008-07-17 03:20:11 +00:00
|
|
|
struct net *net;
|
|
|
|
|
|
|
|
net = container_of(qp->q.net, struct net, ipv4.frags);
|
|
|
|
IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS);
|
2005-12-14 07:14:27 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
return rc;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int ip_frag_reinit(struct ipq *qp)
|
|
|
|
{
|
|
|
|
struct sk_buff *fp;
|
|
|
|
|
2008-01-22 14:09:37 +00:00
|
|
|
if (!mod_timer(&qp->q.timer, jiffies + qp->q.net->timeout)) {
|
2007-10-15 09:24:19 +00:00
|
|
|
atomic_inc(&qp->q.refcnt);
|
2005-12-14 07:14:27 +00:00
|
|
|
return -ETIMEDOUT;
|
|
|
|
}
|
|
|
|
|
2007-10-15 09:24:19 +00:00
|
|
|
fp = qp->q.fragments;
|
2005-12-14 07:14:27 +00:00
|
|
|
do {
|
|
|
|
struct sk_buff *xp = fp->next;
|
2010-06-13 23:22:43 +00:00
|
|
|
frag_kfree_skb(qp->q.net, fp);
|
2005-12-14 07:14:27 +00:00
|
|
|
fp = xp;
|
|
|
|
} while (fp);
|
|
|
|
|
2007-10-15 09:24:19 +00:00
|
|
|
qp->q.last_in = 0;
|
|
|
|
qp->q.len = 0;
|
|
|
|
qp->q.meat = 0;
|
|
|
|
qp->q.fragments = NULL;
|
2010-06-29 04:39:37 +00:00
|
|
|
qp->q.fragments_tail = NULL;
|
2005-12-14 07:14:27 +00:00
|
|
|
qp->iif = 0;
|
2011-01-05 07:52:55 +00:00
|
|
|
qp->ecn = 0;
|
2005-12-14 07:14:27 +00:00
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
/* Add new segment to existing queue. */
|
2007-10-14 07:38:15 +00:00
|
|
|
static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
|
2005-04-16 22:20:36 +00:00
|
|
|
{
|
|
|
|
struct sk_buff *prev, *next;
|
2007-10-14 07:38:15 +00:00
|
|
|
struct net_device *dev;
|
2005-04-16 22:20:36 +00:00
|
|
|
int flags, offset;
|
|
|
|
int ihl, end;
|
2007-10-14 07:38:15 +00:00
|
|
|
int err = -ENOENT;
|
2011-01-05 07:52:55 +00:00
|
|
|
u8 ecn;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2008-03-28 23:35:27 +00:00
|
|
|
if (qp->q.last_in & INET_FRAG_COMPLETE)
|
2005-04-16 22:20:36 +00:00
|
|
|
goto err;
|
|
|
|
|
2005-12-14 07:14:27 +00:00
|
|
|
if (!(IPCB(skb)->flags & IPSKB_FRAG_COMPLETE) &&
|
2007-10-14 07:38:15 +00:00
|
|
|
unlikely(ip_frag_too_far(qp)) &&
|
|
|
|
unlikely(err = ip_frag_reinit(qp))) {
|
2005-12-14 07:14:27 +00:00
|
|
|
ipq_kill(qp);
|
|
|
|
goto err;
|
|
|
|
}
|
|
|
|
|
2011-01-05 07:52:55 +00:00
|
|
|
ecn = ip4_frag_ecn(ip_hdr(skb)->tos);
|
2007-04-21 05:47:35 +00:00
|
|
|
offset = ntohs(ip_hdr(skb)->frag_off);
|
2005-04-16 22:20:36 +00:00
|
|
|
flags = offset & ~IP_OFFSET;
|
|
|
|
offset &= IP_OFFSET;
|
|
|
|
offset <<= 3; /* offset is in 8-byte chunks */
|
2007-03-12 23:09:15 +00:00
|
|
|
ihl = ip_hdrlen(skb);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
/* Determine the position of this fragment. */
|
2007-02-09 14:24:47 +00:00
|
|
|
end = offset + skb->len - ihl;
|
2007-10-14 07:38:15 +00:00
|
|
|
err = -EINVAL;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
/* Is this the final fragment? */
|
|
|
|
if ((flags & IP_MF) == 0) {
|
|
|
|
/* If we already have some bits beyond end
|
2011-11-29 04:31:00 +00:00
|
|
|
* or have different end, the segment is corrupted.
|
2005-04-16 22:20:36 +00:00
|
|
|
*/
|
2007-10-15 09:24:19 +00:00
|
|
|
if (end < qp->q.len ||
|
2008-03-28 23:35:27 +00:00
|
|
|
((qp->q.last_in & INET_FRAG_LAST_IN) && end != qp->q.len))
|
2005-04-16 22:20:36 +00:00
|
|
|
goto err;
|
2008-03-28 23:35:27 +00:00
|
|
|
qp->q.last_in |= INET_FRAG_LAST_IN;
|
2007-10-15 09:24:19 +00:00
|
|
|
qp->q.len = end;
|
2005-04-16 22:20:36 +00:00
|
|
|
} else {
|
|
|
|
if (end&7) {
|
|
|
|
end &= ~7;
|
|
|
|
if (skb->ip_summed != CHECKSUM_UNNECESSARY)
|
|
|
|
skb->ip_summed = CHECKSUM_NONE;
|
|
|
|
}
|
2007-10-15 09:24:19 +00:00
|
|
|
if (end > qp->q.len) {
|
2005-04-16 22:20:36 +00:00
|
|
|
/* Some bits beyond end -> corruption. */
|
2008-03-28 23:35:27 +00:00
|
|
|
if (qp->q.last_in & INET_FRAG_LAST_IN)
|
2005-04-16 22:20:36 +00:00
|
|
|
goto err;
|
2007-10-15 09:24:19 +00:00
|
|
|
qp->q.len = end;
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
if (end == offset)
|
|
|
|
goto err;
|
|
|
|
|
2007-10-14 07:38:15 +00:00
|
|
|
err = -ENOMEM;
|
2005-04-16 22:20:36 +00:00
|
|
|
if (pskb_pull(skb, ihl) == NULL)
|
|
|
|
goto err;
|
2007-10-14 07:38:15 +00:00
|
|
|
|
|
|
|
err = pskb_trim_rcsum(skb, end - offset);
|
|
|
|
if (err)
|
2005-04-16 22:20:36 +00:00
|
|
|
goto err;
|
|
|
|
|
|
|
|
/* Find out which fragments are in front and at the back of us
|
|
|
|
* in the chain of fragments so far. We must know where to put
|
|
|
|
* this fragment, right?
|
|
|
|
*/
|
2010-06-29 04:39:37 +00:00
|
|
|
prev = qp->q.fragments_tail;
|
|
|
|
if (!prev || FRAG_CB(prev)->offset < offset) {
|
|
|
|
next = NULL;
|
|
|
|
goto found;
|
|
|
|
}
|
2005-04-16 22:20:36 +00:00
|
|
|
prev = NULL;
|
2007-10-15 09:24:19 +00:00
|
|
|
for (next = qp->q.fragments; next != NULL; next = next->next) {
|
2005-04-16 22:20:36 +00:00
|
|
|
if (FRAG_CB(next)->offset >= offset)
|
|
|
|
break; /* bingo! */
|
|
|
|
prev = next;
|
|
|
|
}
|
|
|
|
|
2010-06-29 04:39:37 +00:00
|
|
|
found:
|
2005-04-16 22:20:36 +00:00
|
|
|
/* We found where to put this one. Check for overlap with
|
|
|
|
* preceding fragment, and, if needed, align things so that
|
|
|
|
* any overlaps are eliminated.
|
|
|
|
*/
|
|
|
|
if (prev) {
|
|
|
|
int i = (FRAG_CB(prev)->offset + prev->len) - offset;
|
|
|
|
|
|
|
|
if (i > 0) {
|
|
|
|
offset += i;
|
2007-10-14 07:38:15 +00:00
|
|
|
err = -EINVAL;
|
2005-04-16 22:20:36 +00:00
|
|
|
if (end <= offset)
|
|
|
|
goto err;
|
2007-10-14 07:38:15 +00:00
|
|
|
err = -ENOMEM;
|
2005-04-16 22:20:36 +00:00
|
|
|
if (!pskb_pull(skb, i))
|
|
|
|
goto err;
|
|
|
|
if (skb->ip_summed != CHECKSUM_UNNECESSARY)
|
|
|
|
skb->ip_summed = CHECKSUM_NONE;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2007-10-14 07:38:15 +00:00
|
|
|
err = -ENOMEM;
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
while (next && FRAG_CB(next)->offset < end) {
|
|
|
|
int i = end - FRAG_CB(next)->offset; /* overlap is 'i' bytes */
|
|
|
|
|
|
|
|
if (i < next->len) {
|
|
|
|
/* Eat head of the next overlapped fragment
|
|
|
|
* and leave the loop. The next ones cannot overlap.
|
|
|
|
*/
|
|
|
|
if (!pskb_pull(next, i))
|
|
|
|
goto err;
|
|
|
|
FRAG_CB(next)->offset += i;
|
2007-10-15 09:24:19 +00:00
|
|
|
qp->q.meat -= i;
|
2005-04-16 22:20:36 +00:00
|
|
|
if (next->ip_summed != CHECKSUM_UNNECESSARY)
|
|
|
|
next->ip_summed = CHECKSUM_NONE;
|
|
|
|
break;
|
|
|
|
} else {
|
|
|
|
struct sk_buff *free_it = next;
|
|
|
|
|
2006-12-12 18:48:59 +00:00
|
|
|
/* Old fragment is completely overridden with
|
2005-04-16 22:20:36 +00:00
|
|
|
* new one drop it.
|
|
|
|
*/
|
|
|
|
next = next->next;
|
|
|
|
|
|
|
|
if (prev)
|
|
|
|
prev->next = next;
|
|
|
|
else
|
2007-10-15 09:24:19 +00:00
|
|
|
qp->q.fragments = next;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-10-15 09:24:19 +00:00
|
|
|
qp->q.meat -= free_it->len;
|
2010-06-13 23:22:43 +00:00
|
|
|
frag_kfree_skb(qp->q.net, free_it);
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
FRAG_CB(skb)->offset = offset;
|
|
|
|
|
|
|
|
/* Insert this fragment in the chain of fragments. */
|
|
|
|
skb->next = next;
|
2010-06-29 04:39:37 +00:00
|
|
|
if (!next)
|
|
|
|
qp->q.fragments_tail = skb;
|
2005-04-16 22:20:36 +00:00
|
|
|
if (prev)
|
|
|
|
prev->next = skb;
|
|
|
|
else
|
2007-10-15 09:24:19 +00:00
|
|
|
qp->q.fragments = skb;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-10-14 07:38:15 +00:00
|
|
|
dev = skb->dev;
|
|
|
|
if (dev) {
|
|
|
|
qp->iif = dev->ifindex;
|
|
|
|
skb->dev = NULL;
|
|
|
|
}
|
2007-10-15 09:24:19 +00:00
|
|
|
qp->q.stamp = skb->tstamp;
|
|
|
|
qp->q.meat += skb->len;
|
2011-01-05 07:52:55 +00:00
|
|
|
qp->ecn |= ecn;
|
2008-01-22 14:07:25 +00:00
|
|
|
atomic_add(skb->truesize, &qp->q.net->mem);
|
2005-04-16 22:20:36 +00:00
|
|
|
if (offset == 0)
|
2008-03-28 23:35:27 +00:00
|
|
|
qp->q.last_in |= INET_FRAG_FIRST_IN;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2008-03-28 23:35:27 +00:00
|
|
|
if (qp->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
|
|
|
|
qp->q.meat == qp->q.len)
|
2007-10-14 07:38:15 +00:00
|
|
|
return ip_frag_reasm(qp, prev, dev);
|
|
|
|
|
2007-10-15 09:31:52 +00:00
|
|
|
write_lock(&ip4_frags.lock);
|
2008-01-22 14:11:48 +00:00
|
|
|
list_move_tail(&qp->q.lru_list, &qp->q.net->lru_list);
|
2007-10-15 09:31:52 +00:00
|
|
|
write_unlock(&ip4_frags.lock);
|
2007-10-14 07:38:15 +00:00
|
|
|
return -EINPROGRESS;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
err:
|
|
|
|
kfree_skb(skb);
|
2007-10-14 07:38:15 +00:00
|
|
|
return err;
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/* Build a new IP datagram from all its fragments. */
|
|
|
|
|
2007-10-14 07:38:15 +00:00
|
|
|
static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
|
|
|
|
struct net_device *dev)
|
2005-04-16 22:20:36 +00:00
|
|
|
{
|
2009-03-19 06:26:11 +00:00
|
|
|
struct net *net = container_of(qp->q.net, struct net, ipv4.frags);
|
2005-04-16 22:20:36 +00:00
|
|
|
struct iphdr *iph;
|
2007-10-15 09:24:19 +00:00
|
|
|
struct sk_buff *fp, *head = qp->q.fragments;
|
2005-04-16 22:20:36 +00:00
|
|
|
int len;
|
|
|
|
int ihlen;
|
2007-10-14 07:38:15 +00:00
|
|
|
int err;
|
2012-05-19 03:02:20 +00:00
|
|
|
int sum_truesize;
|
2011-05-16 08:37:37 +00:00
|
|
|
u8 ecn;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
ipq_kill(qp);
|
|
|
|
|
2011-05-16 08:37:37 +00:00
|
|
|
ecn = ip4_frag_ecn_table[qp->ecn];
|
|
|
|
if (unlikely(ecn == 0xff)) {
|
|
|
|
err = -EINVAL;
|
|
|
|
goto out_fail;
|
|
|
|
}
|
2007-10-14 07:38:15 +00:00
|
|
|
/* Make the one we just received the head. */
|
|
|
|
if (prev) {
|
|
|
|
head = prev->next;
|
|
|
|
fp = skb_clone(head, GFP_ATOMIC);
|
|
|
|
if (!fp)
|
|
|
|
goto out_nomem;
|
|
|
|
|
|
|
|
fp->next = head->next;
|
2010-06-29 04:39:37 +00:00
|
|
|
if (!fp->next)
|
|
|
|
qp->q.fragments_tail = fp;
|
2007-10-14 07:38:15 +00:00
|
|
|
prev->next = fp;
|
|
|
|
|
2007-10-15 09:24:19 +00:00
|
|
|
skb_morph(head, qp->q.fragments);
|
|
|
|
head->next = qp->q.fragments->next;
|
2007-10-14 07:38:15 +00:00
|
|
|
|
2012-04-19 06:10:26 +00:00
|
|
|
consume_skb(qp->q.fragments);
|
2007-10-15 09:24:19 +00:00
|
|
|
qp->q.fragments = head;
|
2007-10-14 07:38:15 +00:00
|
|
|
}
|
|
|
|
|
2008-07-26 04:43:18 +00:00
|
|
|
WARN_ON(head == NULL);
|
|
|
|
WARN_ON(FRAG_CB(head)->offset != 0);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
/* Allocate a new buffer for the datagram. */
|
2007-03-12 23:09:15 +00:00
|
|
|
ihlen = ip_hdrlen(head);
|
2007-10-15 09:24:19 +00:00
|
|
|
len = ihlen + qp->q.len;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-10-14 07:38:15 +00:00
|
|
|
err = -E2BIG;
|
2007-03-09 04:44:43 +00:00
|
|
|
if (len > 65535)
|
2005-04-16 22:20:36 +00:00
|
|
|
goto out_oversize;
|
|
|
|
|
|
|
|
/* Head of list must not be cloned. */
|
|
|
|
if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
|
|
|
|
goto out_nomem;
|
|
|
|
|
|
|
|
/* If the first fragment is fragmented itself, we split
|
|
|
|
* it to two chunks: the first with data and paged part
|
|
|
|
* and the second, holding only fragments. */
|
2010-08-23 07:13:46 +00:00
|
|
|
if (skb_has_frag_list(head)) {
|
2005-04-16 22:20:36 +00:00
|
|
|
struct sk_buff *clone;
|
|
|
|
int i, plen = 0;
|
|
|
|
|
|
|
|
if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL)
|
|
|
|
goto out_nomem;
|
|
|
|
clone->next = head->next;
|
|
|
|
head->next = clone;
|
|
|
|
skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
|
2009-06-09 07:19:37 +00:00
|
|
|
skb_frag_list_init(head);
|
2011-10-18 21:00:24 +00:00
|
|
|
for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
|
|
|
|
plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
|
2005-04-16 22:20:36 +00:00
|
|
|
clone->len = clone->data_len = head->data_len - plen;
|
|
|
|
head->data_len -= clone->len;
|
|
|
|
head->len -= clone->len;
|
|
|
|
clone->csum = 0;
|
|
|
|
clone->ip_summed = head->ip_summed;
|
2008-01-22 14:07:25 +00:00
|
|
|
atomic_add(clone->truesize, &qp->q.net->mem);
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
2007-04-11 03:50:43 +00:00
|
|
|
skb_push(head, head->data - skb_network_header(head));
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2012-05-19 03:02:20 +00:00
|
|
|
sum_truesize = head->truesize;
|
|
|
|
for (fp = head->next; fp;) {
|
|
|
|
bool headstolen;
|
|
|
|
int delta;
|
|
|
|
struct sk_buff *next = fp->next;
|
|
|
|
|
|
|
|
sum_truesize += fp->truesize;
|
2005-04-16 22:20:36 +00:00
|
|
|
if (head->ip_summed != fp->ip_summed)
|
|
|
|
head->ip_summed = CHECKSUM_NONE;
|
2006-08-29 23:44:56 +00:00
|
|
|
else if (head->ip_summed == CHECKSUM_COMPLETE)
|
2005-04-16 22:20:36 +00:00
|
|
|
head->csum = csum_add(head->csum, fp->csum);
|
2012-05-19 03:02:20 +00:00
|
|
|
|
|
|
|
if (skb_try_coalesce(head, fp, &headstolen, &delta)) {
|
|
|
|
kfree_skb_partial(fp, headstolen);
|
|
|
|
} else {
|
|
|
|
if (!skb_shinfo(head)->frag_list)
|
|
|
|
skb_shinfo(head)->frag_list = fp;
|
|
|
|
head->data_len += fp->len;
|
|
|
|
head->len += fp->len;
|
|
|
|
head->truesize += fp->truesize;
|
|
|
|
}
|
|
|
|
fp = next;
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
2012-05-19 03:02:20 +00:00
|
|
|
atomic_sub(sum_truesize, &qp->q.net->mem);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
head->next = NULL;
|
|
|
|
head->dev = dev;
|
2007-10-15 09:24:19 +00:00
|
|
|
head->tstamp = qp->q.stamp;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-04-21 05:47:35 +00:00
|
|
|
iph = ip_hdr(head);
|
2005-04-16 22:20:36 +00:00
|
|
|
iph->frag_off = 0;
|
|
|
|
iph->tot_len = htons(len);
|
2011-05-16 08:37:37 +00:00
|
|
|
iph->tos |= ecn;
|
2009-03-19 06:26:11 +00:00
|
|
|
IP_INC_STATS_BH(net, IPSTATS_MIB_REASMOKS);
|
2007-10-15 09:24:19 +00:00
|
|
|
qp->q.fragments = NULL;
|
2010-06-29 04:39:37 +00:00
|
|
|
qp->q.fragments_tail = NULL;
|
2007-10-14 07:38:15 +00:00
|
|
|
return 0;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
out_nomem:
|
2012-03-12 07:03:32 +00:00
|
|
|
LIMIT_NETDEBUG(KERN_ERR pr_fmt("queue_glue: no memory for gluing queue %p\n"),
|
|
|
|
qp);
|
2007-10-18 04:37:22 +00:00
|
|
|
err = -ENOMEM;
|
2005-04-16 22:20:36 +00:00
|
|
|
goto out_fail;
|
|
|
|
out_oversize:
|
2012-05-13 21:56:26 +00:00
|
|
|
net_info_ratelimited("Oversized IP packet from %pI4\n", &qp->saddr);
|
2005-04-16 22:20:36 +00:00
|
|
|
out_fail:
|
2009-11-30 07:02:22 +00:00
|
|
|
IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS);
|
2007-10-14 07:38:15 +00:00
|
|
|
return err;
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/* Process an incoming IP datagram fragment. */
|
2007-10-14 07:38:32 +00:00
|
|
|
int ip_defrag(struct sk_buff *skb, u32 user)
|
2005-04-16 22:20:36 +00:00
|
|
|
{
|
|
|
|
struct ipq *qp;
|
2008-01-22 14:02:14 +00:00
|
|
|
struct net *net;
|
2007-02-09 14:24:47 +00:00
|
|
|
|
2009-06-02 05:19:30 +00:00
|
|
|
net = skb->dev ? dev_net(skb->dev) : dev_net(skb_dst(skb)->dev);
|
2008-07-17 03:20:11 +00:00
|
|
|
IP_INC_STATS_BH(net, IPSTATS_MIB_REASMREQDS);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
/* Start by cleaning up the memory. */
|
2008-01-22 14:10:13 +00:00
|
|
|
if (atomic_read(&net->ipv4.frags.mem) > net->ipv4.frags.high_thresh)
|
2008-01-22 14:07:25 +00:00
|
|
|
ip_evictor(net);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
/* Lookup (or create) queue header */
|
2008-01-22 14:02:14 +00:00
|
|
|
if ((qp = ip_find(net, ip_hdr(skb), user)) != NULL) {
|
2007-10-14 07:38:15 +00:00
|
|
|
int ret;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-10-15 09:24:19 +00:00
|
|
|
spin_lock(&qp->q.lock);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-10-14 07:38:15 +00:00
|
|
|
ret = ip_frag_queue(qp, skb);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-10-15 09:24:19 +00:00
|
|
|
spin_unlock(&qp->q.lock);
|
2007-10-15 09:41:09 +00:00
|
|
|
ipq_put(qp);
|
2007-10-14 07:38:32 +00:00
|
|
|
return ret;
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
2008-07-17 03:20:11 +00:00
|
|
|
IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS);
|
2005-04-16 22:20:36 +00:00
|
|
|
kfree_skb(skb);
|
2007-10-14 07:38:32 +00:00
|
|
|
return -ENOMEM;
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
2010-07-09 21:22:10 +00:00
|
|
|
EXPORT_SYMBOL(ip_defrag);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2011-10-06 10:28:31 +00:00
|
|
|
struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user)
|
|
|
|
{
|
|
|
|
const struct iphdr *iph;
|
|
|
|
u32 len;
|
|
|
|
|
|
|
|
if (skb->protocol != htons(ETH_P_IP))
|
|
|
|
return skb;
|
|
|
|
|
|
|
|
if (!pskb_may_pull(skb, sizeof(struct iphdr)))
|
|
|
|
return skb;
|
|
|
|
|
|
|
|
iph = ip_hdr(skb);
|
|
|
|
if (iph->ihl < 5 || iph->version != 4)
|
|
|
|
return skb;
|
|
|
|
if (!pskb_may_pull(skb, iph->ihl*4))
|
|
|
|
return skb;
|
|
|
|
iph = ip_hdr(skb);
|
|
|
|
len = ntohs(iph->tot_len);
|
|
|
|
if (skb->len < len || len < (iph->ihl * 4))
|
|
|
|
return skb;
|
|
|
|
|
|
|
|
if (ip_is_fragment(ip_hdr(skb))) {
|
|
|
|
skb = skb_share_check(skb, GFP_ATOMIC);
|
|
|
|
if (skb) {
|
|
|
|
if (pskb_trim_rcsum(skb, len))
|
|
|
|
return skb;
|
|
|
|
memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
|
|
|
|
if (ip_defrag(skb, user))
|
|
|
|
return NULL;
|
|
|
|
skb->rxhash = 0;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return skb;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(ip_check_defrag);
|
|
|
|
|
2008-01-22 13:58:31 +00:00
|
|
|
#ifdef CONFIG_SYSCTL
|
|
|
|
static int zero;
|
|
|
|
|
2008-05-19 20:51:29 +00:00
|
|
|
static struct ctl_table ip4_frags_ns_ctl_table[] = {
|
2008-01-22 13:58:31 +00:00
|
|
|
{
|
|
|
|
.procname = "ipfrag_high_thresh",
|
2008-01-22 14:10:13 +00:00
|
|
|
.data = &init_net.ipv4.frags.high_thresh,
|
2008-01-22 13:58:31 +00:00
|
|
|
.maxlen = sizeof(int),
|
|
|
|
.mode = 0644,
|
2008-11-04 02:21:05 +00:00
|
|
|
.proc_handler = proc_dointvec
|
2008-01-22 13:58:31 +00:00
|
|
|
},
|
|
|
|
{
|
|
|
|
.procname = "ipfrag_low_thresh",
|
2008-01-22 14:10:13 +00:00
|
|
|
.data = &init_net.ipv4.frags.low_thresh,
|
2008-01-22 13:58:31 +00:00
|
|
|
.maxlen = sizeof(int),
|
|
|
|
.mode = 0644,
|
2008-11-04 02:21:05 +00:00
|
|
|
.proc_handler = proc_dointvec
|
2008-01-22 13:58:31 +00:00
|
|
|
},
|
|
|
|
{
|
|
|
|
.procname = "ipfrag_time",
|
2008-01-22 14:09:37 +00:00
|
|
|
.data = &init_net.ipv4.frags.timeout,
|
2008-01-22 13:58:31 +00:00
|
|
|
.maxlen = sizeof(int),
|
|
|
|
.mode = 0644,
|
2008-11-04 02:21:05 +00:00
|
|
|
.proc_handler = proc_dointvec_jiffies,
|
2008-01-22 13:58:31 +00:00
|
|
|
},
|
2008-05-19 20:53:02 +00:00
|
|
|
{ }
|
|
|
|
};
|
|
|
|
|
|
|
|
static struct ctl_table ip4_frags_ctl_table[] = {
|
2008-01-22 13:58:31 +00:00
|
|
|
{
|
|
|
|
.procname = "ipfrag_secret_interval",
|
2008-01-22 14:11:04 +00:00
|
|
|
.data = &ip4_frags.secret_interval,
|
2008-01-22 13:58:31 +00:00
|
|
|
.maxlen = sizeof(int),
|
|
|
|
.mode = 0644,
|
2008-11-04 02:21:05 +00:00
|
|
|
.proc_handler = proc_dointvec_jiffies,
|
2008-01-22 13:58:31 +00:00
|
|
|
},
|
|
|
|
{
|
|
|
|
.procname = "ipfrag_max_dist",
|
|
|
|
.data = &sysctl_ipfrag_max_dist,
|
|
|
|
.maxlen = sizeof(int),
|
|
|
|
.mode = 0644,
|
2008-11-04 02:21:05 +00:00
|
|
|
.proc_handler = proc_dointvec_minmax,
|
2008-01-22 13:58:31 +00:00
|
|
|
.extra1 = &zero
|
|
|
|
},
|
|
|
|
{ }
|
|
|
|
};
|
|
|
|
|
2010-01-17 03:35:32 +00:00
|
|
|
static int __net_init ip4_frags_ns_ctl_register(struct net *net)
|
2008-01-22 13:58:31 +00:00
|
|
|
{
|
2008-01-22 14:08:36 +00:00
|
|
|
struct ctl_table *table;
|
2008-01-22 13:58:31 +00:00
|
|
|
struct ctl_table_header *hdr;
|
|
|
|
|
2008-05-19 20:51:29 +00:00
|
|
|
table = ip4_frags_ns_ctl_table;
|
2009-11-25 23:14:13 +00:00
|
|
|
if (!net_eq(net, &init_net)) {
|
2008-05-19 20:51:29 +00:00
|
|
|
table = kmemdup(table, sizeof(ip4_frags_ns_ctl_table), GFP_KERNEL);
|
2008-01-22 14:08:36 +00:00
|
|
|
if (table == NULL)
|
|
|
|
goto err_alloc;
|
|
|
|
|
2008-01-22 14:10:13 +00:00
|
|
|
table[0].data = &net->ipv4.frags.high_thresh;
|
|
|
|
table[1].data = &net->ipv4.frags.low_thresh;
|
2008-01-22 14:09:37 +00:00
|
|
|
table[2].data = &net->ipv4.frags.timeout;
|
2008-01-22 14:08:36 +00:00
|
|
|
}
|
|
|
|
|
2012-04-19 13:44:49 +00:00
|
|
|
hdr = register_net_sysctl(net, "net/ipv4", table);
|
2008-01-22 14:08:36 +00:00
|
|
|
if (hdr == NULL)
|
|
|
|
goto err_reg;
|
|
|
|
|
|
|
|
net->ipv4.frags_hdr = hdr;
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
err_reg:
|
2009-11-25 23:14:13 +00:00
|
|
|
if (!net_eq(net, &init_net))
|
2008-01-22 14:08:36 +00:00
|
|
|
kfree(table);
|
|
|
|
err_alloc:
|
|
|
|
return -ENOMEM;
|
|
|
|
}
|
|
|
|
|
2010-01-17 03:35:32 +00:00
|
|
|
static void __net_exit ip4_frags_ns_ctl_unregister(struct net *net)
|
2008-01-22 14:08:36 +00:00
|
|
|
{
|
|
|
|
struct ctl_table *table;
|
|
|
|
|
|
|
|
table = net->ipv4.frags_hdr->ctl_table_arg;
|
|
|
|
unregister_net_sysctl_table(net->ipv4.frags_hdr);
|
|
|
|
kfree(table);
|
2008-01-22 13:58:31 +00:00
|
|
|
}
|
2008-05-19 20:53:02 +00:00
|
|
|
|
|
|
|
static void ip4_frags_ctl_register(void)
|
|
|
|
{
|
2012-04-19 13:22:55 +00:00
|
|
|
register_net_sysctl(&init_net, "net/ipv4", ip4_frags_ctl_table);
|
2008-05-19 20:53:02 +00:00
|
|
|
}
|
2008-01-22 13:58:31 +00:00
|
|
|
#else
|
2008-05-19 20:51:29 +00:00
|
|
|
static inline int ip4_frags_ns_ctl_register(struct net *net)
|
2008-01-22 13:58:31 +00:00
|
|
|
{
|
|
|
|
return 0;
|
|
|
|
}
|
2008-01-22 14:08:36 +00:00
|
|
|
|
2008-05-19 20:51:29 +00:00
|
|
|
static inline void ip4_frags_ns_ctl_unregister(struct net *net)
|
2008-01-22 14:08:36 +00:00
|
|
|
{
|
|
|
|
}
|
2008-05-19 20:53:02 +00:00
|
|
|
|
|
|
|
static inline void ip4_frags_ctl_register(void)
|
|
|
|
{
|
|
|
|
}
|
2008-01-22 13:58:31 +00:00
|
|
|
#endif
|
|
|
|
|
2010-01-17 03:35:32 +00:00
|
|
|
static int __net_init ipv4_frags_init_net(struct net *net)
|
2008-01-22 13:58:31 +00:00
|
|
|
{
|
2008-01-22 14:10:13 +00:00
|
|
|
/*
|
|
|
|
* Fragment cache limits. We will commit 256K at one time. Should we
|
|
|
|
* cross that limit we will prune down to 192K. This should cope with
|
|
|
|
* even the most extreme cases without allowing an attacker to
|
|
|
|
* measurably harm machine performance.
|
|
|
|
*/
|
|
|
|
net->ipv4.frags.high_thresh = 256 * 1024;
|
|
|
|
net->ipv4.frags.low_thresh = 192 * 1024;
|
2008-01-22 14:09:37 +00:00
|
|
|
/*
|
|
|
|
* Important NOTE! Fragment queue must be destroyed before MSL expires.
|
|
|
|
* RFC791 is wrong proposing to prolongate timer each fragment arrival
|
|
|
|
* by TTL.
|
|
|
|
*/
|
|
|
|
net->ipv4.frags.timeout = IP_FRAG_TIME;
|
|
|
|
|
2008-01-22 14:06:23 +00:00
|
|
|
inet_frags_init_net(&net->ipv4.frags);
|
|
|
|
|
2008-05-19 20:51:29 +00:00
|
|
|
return ip4_frags_ns_ctl_register(net);
|
2008-01-22 13:58:31 +00:00
|
|
|
}
|
|
|
|
|
2010-01-17 03:35:32 +00:00
|
|
|
static void __net_exit ipv4_frags_exit_net(struct net *net)
|
2008-01-22 14:12:39 +00:00
|
|
|
{
|
2008-05-19 20:51:29 +00:00
|
|
|
ip4_frags_ns_ctl_unregister(net);
|
2008-01-22 14:12:39 +00:00
|
|
|
inet_frags_exit_net(&net->ipv4.frags, &ip4_frags);
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct pernet_operations ip4_frags_ops = {
|
|
|
|
.init = ipv4_frags_init_net,
|
|
|
|
.exit = ipv4_frags_exit_net,
|
|
|
|
};
|
|
|
|
|
2007-04-19 23:16:32 +00:00
|
|
|
void __init ipfrag_init(void)
|
2005-04-16 22:20:36 +00:00
|
|
|
{
|
2008-05-19 20:53:02 +00:00
|
|
|
ip4_frags_ctl_register();
|
2008-01-22 14:12:39 +00:00
|
|
|
register_pernet_subsys(&ip4_frags_ops);
|
2007-10-15 09:38:08 +00:00
|
|
|
ip4_frags.hashfn = ip4_hashfn;
|
2007-10-18 02:46:47 +00:00
|
|
|
ip4_frags.constructor = ip4_frag_init;
|
2007-10-15 09:39:14 +00:00
|
|
|
ip4_frags.destructor = ip4_frag_free;
|
|
|
|
ip4_frags.skb_free = NULL;
|
|
|
|
ip4_frags.qsize = sizeof(struct ipq);
|
2007-10-18 02:47:21 +00:00
|
|
|
ip4_frags.match = ip4_frag_match;
|
2007-10-18 02:45:23 +00:00
|
|
|
ip4_frags.frag_expire = ip_expire;
|
2008-01-22 14:11:04 +00:00
|
|
|
ip4_frags.secret_interval = 10 * 60 * HZ;
|
2007-10-15 09:31:52 +00:00
|
|
|
inet_frags_init(&ip4_frags);
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|