From b8dd6a223eb86d537c2c6d8d28916c1f0ba3ea3c Mon Sep 17 00:00:00 2001 From: Hannes Frederic Sowa Date: Sun, 24 Mar 2013 15:20:51 +0000 Subject: [PATCH] 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 Cc: Jesper Dangaard Brouer Cc: YOSHIFUJI Hideaki Signed-off-by: Hannes Frederic Sowa Signed-off-by: Pablo Neira Ayuso --- net/ipv6/netfilter/nf_conntrack_reasm.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c index 6700069949dd..dffdc1a389c5 100644 --- a/net/ipv6/netfilter/nf_conntrack_reasm.c +++ b/net/ipv6/netfilter/nf_conntrack_reasm.c @@ -41,6 +41,7 @@ #include #include #include +#include #include #include #include @@ -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; -- 2.20.1