netfilter: nf_nat: change sequence number adjustments to 32 bits

Using 16 bits is too small, when many adjustments happen the offsets might
overflow and break the connection.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

7 files changed, 13 insertions, 13 deletions

diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index f4bbf2cd22d8..655d5d198d49 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -330,7 +330,7 @@ extern struct nfq_ct_hook __rcu *nfq_ct_hook;
 
 struct nfq_ct_nat_hook {
         void (*seq_adjust)(struct sk_buff *skb, struct nf_conn *ct,
-                           u32 ctinfo, int off);
+                           u32 ctinfo, s32 off);
 };
 extern struct nfq_ct_nat_hook __rcu *nfq_ct_nat_hook;
 #else
diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index 939aced35a02..e5eb8b62538c 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -234,7 +234,7 @@ static inline bool nf_ct_kill(struct nf_conn *ct)
 }
 
 /* These are for NAT.  Icky. */
-extern s16 (*nf_ct_nat_offset)(const struct nf_conn *ct,
+extern s32 (*nf_ct_nat_offset)(const struct nf_conn *ct,
                                enum ip_conntrack_dir dir,
                                u32 seq);
 
diff --git a/include/net/netfilter/nf_nat.h b/include/net/netfilter/nf_nat.h
index ad14a799fd2e..e2441413675c 100644
--- a/include/net/netfilter/nf_nat.h
+++ b/include/net/netfilter/nf_nat.h
@@ -19,7 +19,7 @@ struct nf_nat_seq {
         u_int32_t correction_pos;
 
         /* sequence number offset before and after last modification */
-        int16_t offset_before, offset_after;
+        int32_t offset_before, offset_after;
 };
 
 #include <linux/list.h>
diff --git a/include/net/netfilter/nf_nat_helper.h b/include/net/netfilter/nf_nat_helper.h
index b4d6bfc2af03..194c34794923 100644
--- a/include/net/netfilter/nf_nat_helper.h
+++ b/include/net/netfilter/nf_nat_helper.h
@@ -41,7 +41,7 @@ extern int nf_nat_mangle_udp_packet(struct sk_buff *skb,
 
 extern void nf_nat_set_seq_adjust(struct nf_conn *ct,
                                   enum ip_conntrack_info ctinfo,
-                                  __be32 seq, s16 off);
+                                  __be32 seq, s32 off);
 extern int nf_nat_seq_adjust(struct sk_buff *skb,
                              struct nf_conn *ct,
                              enum ip_conntrack_info ctinfo,
@@ -56,11 +56,11 @@ extern int (*nf_nat_seq_adjust_hook)(struct sk_buff *skb,
 extern void nf_nat_follow_master(struct nf_conn *ct,
                                  struct nf_conntrack_expect *this);
 
-extern s16 nf_nat_get_offset(const struct nf_conn *ct,
+extern s32 nf_nat_get_offset(const struct nf_conn *ct,
                              enum ip_conntrack_dir dir,
                              u32 seq);
 
 extern void nf_nat_tcp_seq_adjust(struct sk_buff *skb, struct nf_conn *ct,
-                                  u32 dir, int off);
+                                  u32 dir, s32 off);
 
 #endif
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 089e408676fa..0934611ff9f3 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1695,7 +1695,7 @@ err_stat:
         return ret;
 }
 
-s16 (*nf_ct_nat_offset)(const struct nf_conn *ct,
+s32 (*nf_ct_nat_offset)(const struct nf_conn *ct,
                         enum ip_conntrack_dir dir,
                         u32 seq);
 EXPORT_SYMBOL_GPL(nf_ct_nat_offset);
diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
index 7dcc376eea5f..8f308d896324 100644
--- a/net/netfilter/nf_conntrack_proto_tcp.c
+++ b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -496,7 +496,7 @@ static void tcp_sack(const struct sk_buff *skb, unsigned int dataoff,
 }
 
 #ifdef CONFIG_NF_NAT_NEEDED
-static inline s16 nat_offset(const struct nf_conn *ct,
+static inline s32 nat_offset(const struct nf_conn *ct,
                              enum ip_conntrack_dir dir,
                              u32 seq)
 {
@@ -525,7 +525,7 @@ static bool tcp_in_window(const struct nf_conn *ct,
         struct ip_ct_tcp_state *receiver = &state->seen[!dir];
         const struct nf_conntrack_tuple *tuple = &ct->tuplehash[dir].tuple;
         __u32 seq, ack, sack, end, win, swin;
-        s16 receiver_offset;
+        s32 receiver_offset;
         bool res;
 
         /*
diff --git a/net/netfilter/nf_nat_helper.c b/net/netfilter/nf_nat_helper.c
index a7262ed055c6..ff4a589e3e39 100644
--- a/net/netfilter/nf_nat_helper.c
+++ b/net/netfilter/nf_nat_helper.c
@@ -68,13 +68,13 @@ adjust_tcp_sequence(u32 seq,
 }
 
 /* Get the offset value, for conntrack */
-s16 nf_nat_get_offset(const struct nf_conn *ct,
+s32 nf_nat_get_offset(const struct nf_conn *ct,
                       enum ip_conntrack_dir dir,
                       u32 seq)
 {
         struct nf_conn_nat *nat = nfct_nat(ct);
         struct nf_nat_seq *this_way;
-        s16 offset;
+        s32 offset;
 
         if (!nat)
                 return 0;
@@ -143,7 +143,7 @@ static int enlarge_skb(struct sk_buff *skb, unsigned int extra)
 }
 
 void nf_nat_set_seq_adjust(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
-                           __be32 seq, s16 off)
+                           __be32 seq, s32 off)
 {
         if (!off)
                 return;
@@ -370,7 +370,7 @@ nf_nat_seq_adjust(struct sk_buff *skb,
         struct tcphdr *tcph;
         int dir;
         __be32 newseq, newack;
-        s16 seqoff, ackoff;
+        s32 seqoff, ackoff;
         struct nf_conn_nat *nat = nfct_nat(ct);
         struct nf_nat_seq *this_way, *other_way;
         int res;