9 files changed, 20 insertions, 16 deletions

diff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c
index 6fa5ae00039f..01805319e1e0 100644
--- a/drivers/net/ppp/pptp.c
+++ b/drivers/net/ppp/pptp.c
@@ -281,7 +281,7 @@ static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
         nf_reset(skb);
 
         skb->ip_summed = CHECKSUM_NONE;
-        ip_select_ident(iph, &rt->dst, NULL);
+        ip_select_ident(skb, &rt->dst, NULL);
         ip_send_check(iph);
 
         ip_local_out(skb);
diff --git a/include/net/ip.h b/include/net/ip.h
index 48f55979d842..5e5268807a1c 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -264,9 +264,11 @@ int ip_dont_fragment(struct sock *sk, struct dst_entry *dst)
 
 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more);
 
-static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk)
+static inline void ip_select_ident(struct sk_buff *skb, struct dst_entry *dst, struct sock *sk)
 {
-        if (iph->frag_off & htons(IP_DF)) {
+        struct iphdr *iph = ip_hdr(skb);
+
+        if ((iph->frag_off & htons(IP_DF)) && !skb->local_df) {
                 /* This is only to work around buggy Windows95/2000
                  * VJ compression implementations.  If the ID field
                  * does not change, they drop every other packet in
@@ -278,9 +280,11 @@ static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, str
                 __ip_select_ident(iph, dst, 0);
 }
 
-static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more)
+static inline void ip_select_ident_more(struct sk_buff *skb, struct dst_entry *dst, struct sock *sk, int more)
 {
-        if (iph->frag_off & htons(IP_DF)) {
+        struct iphdr *iph = ip_hdr(skb);
+
+        if ((iph->frag_off & htons(IP_DF)) && !skb->local_df) {
                 if (sk && inet_sk(sk)->inet_daddr) {
                         iph->id = htons(inet_sk(sk)->inet_id);
                         inet_sk(sk)->inet_id += 1 + more;
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index d6c0e64ec97f..dace87f06e5f 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -369,7 +369,7 @@ static struct sk_buff *igmpv3_newpack(struct net_device *dev, int size)
         pip->saddr    = fl4.saddr;
         pip->protocol = IPPROTO_IGMP;
         pip->tot_len  = 0;      /* filled in later */
-        ip_select_ident(pip, &rt->dst, NULL);
+        ip_select_ident(skb, &rt->dst, NULL);
         ((u8 *)&pip[1])[0] = IPOPT_RA;
         ((u8 *)&pip[1])[1] = 4;
         ((u8 *)&pip[1])[2] = 0;
@@ -714,7 +714,7 @@ static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc,
         iph->daddr    = dst;
         iph->saddr    = fl4.saddr;
         iph->protocol = IPPROTO_IGMP;
-        ip_select_ident(iph, &rt->dst, NULL);
+        ip_select_ident(skb, &rt->dst, NULL);
         ((u8 *)&iph[1])[0] = IPOPT_RA;
         ((u8 *)&iph[1])[1] = 4;
         ((u8 *)&iph[1])[2] = 0;
diff --git a/net/ipv4/inetpeer.c b/net/ipv4/inetpeer.c
index 000e3d239d64..33d5537881ed 100644
--- a/net/ipv4/inetpeer.c
+++ b/net/ipv4/inetpeer.c
@@ -32,8 +32,8 @@
  *  At the moment of writing this notes identifier of IP packets is generated
  *  to be unpredictable using this code only for packets subjected
  *  (actually or potentially) to defragmentation.  I.e. DF packets less than
- *  PMTU in size uses a constant ID and do not use this code (see
- *  ip_select_ident() in include/net/ip.h).
+ *  PMTU in size when local fragmentation is disabled use a constant ID and do
+ *  not use this code (see ip_select_ident() in include/net/ip.h).
  *
  *  Route cache entries hold references to our nodes.
  *  New cache entries get references via lookup by destination IP address in
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index eae2e262fbe5..a04d872c54f9 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -148,7 +148,7 @@ int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
         iph->daddr    = (opt && opt->opt.srr ? opt->opt.faddr : daddr);
         iph->saddr    = saddr;
         iph->protocol = sk->sk_protocol;
-        ip_select_ident(iph, &rt->dst, sk);
+        ip_select_ident(skb, &rt->dst, sk);
 
         if (opt && opt->opt.optlen) {
                 iph->ihl += opt->opt.optlen>>2;
@@ -386,7 +386,7 @@ packet_routed:
                 ip_options_build(skb, &inet_opt->opt, inet->inet_daddr, rt, 0);
         }
 
-        ip_select_ident_more(iph, &rt->dst, sk,
+        ip_select_ident_more(skb, &rt->dst, sk,
                              (skb_shinfo(skb)->gso_segs ?: 1) - 1);
 
         skb->priority = sk->sk_priority;
@@ -1324,7 +1324,7 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
         iph->ttl = ttl;
         iph->protocol = sk->sk_protocol;
         ip_copy_addrs(iph, fl4);
-        ip_select_ident(iph, &rt->dst, sk);
+        ip_select_ident(skb, &rt->dst, sk);
 
         if (opt) {
                 iph->ihl += opt->optlen>>2;
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 9ae54b09254f..62212c772a4b 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -1658,7 +1658,7 @@ static void ip_encap(struct sk_buff *skb, __be32 saddr, __be32 daddr)
         iph->protocol   =       IPPROTO_IPIP;
         iph->ihl        =       5;
         iph->tot_len    =       htons(skb->len);
-        ip_select_ident(iph, skb_dst(skb), NULL);
+        ip_select_ident(skb, skb_dst(skb), NULL);
         ip_send_check(iph);
 
         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index a86c7ae71881..bfec521c717f 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -387,7 +387,7 @@ static int raw_send_hdrinc(struct sock *sk, struct flowi4 *fl4,
                 iph->check   = 0;
                 iph->tot_len = htons(length);
                 if (!iph->id)
-                        ip_select_ident(iph, &rt->dst, NULL);
+                        ip_select_ident(skb, &rt->dst, NULL);
 
                 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
         }
diff --git a/net/ipv4/xfrm4_mode_tunnel.c b/net/ipv4/xfrm4_mode_tunnel.c
index eb1dd4d643f2..b5663c37f089 100644
--- a/net/ipv4/xfrm4_mode_tunnel.c
+++ b/net/ipv4/xfrm4_mode_tunnel.c
@@ -117,7 +117,7 @@ static int xfrm4_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
 
         top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
                 0 : (XFRM_MODE_SKB_CB(skb)->frag_off & htons(IP_DF));
-        ip_select_ident(top_iph, dst->child, NULL);
+        ip_select_ident(skb, dst->child, NULL);
 
         top_iph->ttl = ip4_dst_hoplimit(dst->child);
 
diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c
index b75ff6429a04..c47444e4cf8c 100644
--- a/net/netfilter/ipvs/ip_vs_xmit.c
+++ b/net/netfilter/ipvs/ip_vs_xmit.c
@@ -883,7 +883,7 @@ ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
         iph->daddr              =       cp->daddr.ip;
         iph->saddr              =       saddr;
         iph->ttl                =       old_iph->ttl;
-        ip_select_ident(iph, &rt->dst, NULL);
+        ip_select_ident(skb, &rt->dst, NULL);
 
         /* Another hack: avoid icmp_send in ip_fragment */
         skb->local_df = 1;