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authorEric Dumazet <edumazet@google.com>2019-10-19 09:26:37 -0700
committerDavid S. Miller <davem@davemloft.net>2019-10-21 10:46:42 -0700
commite7a409c3f46cb0dbc7bfd4f6f9421d53e92614a5 (patch)
tree1a87acde604b1a6eaacb4a7c87fbf5342923e659 /net
parent40c5b2bd2473d54b5e274e877fa7bd32fc814f7a (diff)
downloadlwn-e7a409c3f46cb0dbc7bfd4f6f9421d53e92614a5.tar.gz
lwn-e7a409c3f46cb0dbc7bfd4f6f9421d53e92614a5.zip
ipv4: fix IPSKB_FRAG_PMTU handling with fragmentation
This patch removes the iph field from the state structure, which is not properly initialized. Instead, add a new field to make the "do we want to set DF" be the state bit and move the code to set the DF flag from ip_frag_next(). Joint work with Pablo and Linus. Fixes: 19c3401a917b ("net: ipv4: place control buffer handling away from fragmentation iterators") Reported-by: Patrick Schönthaler <patrick@notvads.ovh> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/bridge/netfilter/nf_conntrack_bridge.c2
-rw-r--r--net/ipv4/ip_output.c11
2 files changed, 7 insertions, 6 deletions
diff --git a/net/bridge/netfilter/nf_conntrack_bridge.c b/net/bridge/netfilter/nf_conntrack_bridge.c
index 506d6141e44e..809673222382 100644
--- a/net/bridge/netfilter/nf_conntrack_bridge.c
+++ b/net/bridge/netfilter/nf_conntrack_bridge.c
@@ -95,7 +95,7 @@ slow_path:
* This may also be a clone skbuff, we could preserve the geometry for
* the copies but probably not worth the effort.
*/
- ip_frag_init(skb, hlen, ll_rs, frag_max_size, &state);
+ ip_frag_init(skb, hlen, ll_rs, frag_max_size, false, &state);
while (state.left > 0) {
struct sk_buff *skb2;
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 814b9b8882a0..3d8baaaf7086 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -645,11 +645,12 @@ void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter)
EXPORT_SYMBOL(ip_fraglist_prepare);
void ip_frag_init(struct sk_buff *skb, unsigned int hlen,
- unsigned int ll_rs, unsigned int mtu,
+ unsigned int ll_rs, unsigned int mtu, bool DF,
struct ip_frag_state *state)
{
struct iphdr *iph = ip_hdr(skb);
+ state->DF = DF;
state->hlen = hlen;
state->ll_rs = ll_rs;
state->mtu = mtu;
@@ -668,9 +669,6 @@ static void ip_frag_ipcb(struct sk_buff *from, struct sk_buff *to,
/* Copy the flags to each fragment. */
IPCB(to)->flags = IPCB(from)->flags;
- if (IPCB(from)->flags & IPSKB_FRAG_PMTU)
- state->iph->frag_off |= htons(IP_DF);
-
/* ANK: dirty, but effective trick. Upgrade options only if
* the segment to be fragmented was THE FIRST (otherwise,
* options are already fixed) and make it ONCE
@@ -738,6 +736,8 @@ struct sk_buff *ip_frag_next(struct sk_buff *skb, struct ip_frag_state *state)
*/
iph = ip_hdr(skb2);
iph->frag_off = htons((state->offset >> 3));
+ if (state->DF)
+ iph->frag_off |= htons(IP_DF);
/*
* Added AC : If we are fragmenting a fragment that's not the
@@ -883,7 +883,8 @@ slow_path:
* Fragment the datagram.
*/
- ip_frag_init(skb, hlen, ll_rs, mtu, &state);
+ ip_frag_init(skb, hlen, ll_rs, mtu, IPCB(skb)->flags & IPSKB_FRAG_PMTU,
+ &state);
/*
* Keep copying data until we run out.