netfilter: implement RFC3168 5.3 (ecn protection) for ipv6 fragmentation handling

This change brings netfilter reassembly logic on par with
reassembly.c. The corresponding change in net-next is
(eec2e61 ipv6: implement RFC3168 5.3 (ecn protection) for
ipv6 fragmentation handling)

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jesper Dangaard Brouer <jbrouer@redhat.com>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Hannes Frederic Sowa 2013-03-24 15:20:51 +00:00 committed by Pablo Neira Ayuso
parent 12202fa757
commit b8dd6a223e

View File

@ -41,6 +41,7 @@
#include <net/rawv6.h>
#include <net/ndisc.h>
#include <net/addrconf.h>
#include <net/inet_ecn.h>
#include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
#include <linux/sysctl.h>
#include <linux/netfilter.h>
@ -138,6 +139,11 @@ static void __net_exit nf_ct_frags6_sysctl_unregister(struct net *net)
}
#endif
static inline u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h)
{
return 1 << (ipv6_get_dsfield(ipv6h) & INET_ECN_MASK);
}
static unsigned int nf_hashfn(struct inet_frag_queue *q)
{
const struct frag_queue *nq;
@ -166,7 +172,7 @@ static void nf_ct_frag6_expire(unsigned long data)
/* Creation primitives. */
static inline struct frag_queue *fq_find(struct net *net, __be32 id,
u32 user, struct in6_addr *src,
struct in6_addr *dst)
struct in6_addr *dst, u8 ecn)
{
struct inet_frag_queue *q;
struct ip6_create_arg arg;
@ -176,6 +182,7 @@ static inline struct frag_queue *fq_find(struct net *net, __be32 id,
arg.user = user;
arg.src = src;
arg.dst = dst;
arg.ecn = ecn;
read_lock_bh(&nf_frags.lock);
hash = inet6_hash_frag(id, src, dst, nf_frags.rnd);
@ -196,6 +203,7 @@ static int nf_ct_frag6_queue(struct frag_queue *fq, struct sk_buff *skb,
struct sk_buff *prev, *next;
unsigned int payload_len;
int offset, end;
u8 ecn;
if (fq->q.last_in & INET_FRAG_COMPLETE) {
pr_debug("Already completed\n");
@ -213,6 +221,8 @@ static int nf_ct_frag6_queue(struct frag_queue *fq, struct sk_buff *skb,
return -1;
}
ecn = ip6_frag_ecn(ipv6_hdr(skb));
if (skb->ip_summed == CHECKSUM_COMPLETE) {
const unsigned char *nh = skb_network_header(skb);
skb->csum = csum_sub(skb->csum,
@ -317,6 +327,7 @@ found:
}
fq->q.stamp = skb->tstamp;
fq->q.meat += skb->len;
fq->ecn |= ecn;
if (payload_len > fq->q.max_size)
fq->q.max_size = payload_len;
add_frag_mem_limit(&fq->q, skb->truesize);
@ -352,12 +363,17 @@ nf_ct_frag6_reasm(struct frag_queue *fq, struct net_device *dev)
{
struct sk_buff *fp, *op, *head = fq->q.fragments;
int payload_len;
u8 ecn;
inet_frag_kill(&fq->q, &nf_frags);
WARN_ON(head == NULL);
WARN_ON(NFCT_FRAG6_CB(head)->offset != 0);
ecn = ip_frag_ecn_table[fq->ecn];
if (unlikely(ecn == 0xff))
goto out_fail;
/* Unfragmented part is taken from the first segment. */
payload_len = ((head->data - skb_network_header(head)) -
sizeof(struct ipv6hdr) + fq->q.len -
@ -428,6 +444,7 @@ nf_ct_frag6_reasm(struct frag_queue *fq, struct net_device *dev)
head->dev = dev;
head->tstamp = fq->q.stamp;
ipv6_hdr(head)->payload_len = htons(payload_len);
ipv6_change_dsfield(ipv6_hdr(head), 0xff, ecn);
IP6CB(head)->frag_max_size = sizeof(struct ipv6hdr) + fq->q.max_size;
/* Yes, and fold redundant checksum back. 8) */
@ -572,7 +589,8 @@ struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb, u32 user)
inet_frag_evictor(&net->nf_frag.frags, &nf_frags, false);
local_bh_enable();
fq = fq_find(net, fhdr->identification, user, &hdr->saddr, &hdr->daddr);
fq = fq_find(net, fhdr->identification, user, &hdr->saddr, &hdr->daddr,
ip6_frag_ecn(hdr));
if (fq == NULL) {
pr_debug("Can't find and can't create new queue\n");
goto ret_orig;