From: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
To: netdev@vger.kernel.org
Cc: linux-sctp@vger.kernel.org, Xin Long <lucien.xin@gmail.com>,
Neil Horman <nhorman@tuxdriver.com>,
David Laight <David.Laight@ACULAB.COM>,
Vlad Yasevich <vyasevich@gmail.com>,
Alexander Duyck <alexander.duyck@gmail.com>,
Daniel Borkmann <daniel@iogearbox.net>,
Florian Westphal <fw@strlen.de>,
Eric Dumazet <eric.dumazet@gmail.com>
Subject: [PATCH v2 4/7] skbuff: introduce skb_gso_validate_mtu
Date: Tue, 31 May 2016 18:55:47 +0000 [thread overview]
Message-ID: <e88d8905cf03bac8995be6d722f8b5abfc7afcc5.1464718103.git.marcelo.leitner@gmail.com> (raw)
In-Reply-To: <cover.1464718103.git.marcelo.leitner@gmail.com>
skb_gso_network_seglen is not enough for checking fragment sizes if
skb is using GSO_BY_FRAGS as we have to check frag per frag.
This patch introduces skb_gso_validate_mtu, based on the former, which
will wrap the use case inside it as all calls to skb_gso_network_seglen
were to validate if it fits on a given TMU, and improve the check.
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Tested-by: Xin Long <lucien.xin@gmail.com>
---
include/linux/skbuff.h | 1 +
net/core/skbuff.c | 31 +++++++++++++++++++++++++++++++
net/ipv4/ip_forward.c | 2 +-
net/ipv4/ip_output.c | 2 +-
net/ipv6/ip6_output.c | 2 +-
net/mpls/af_mpls.c | 2 +-
6 files changed, 36 insertions(+), 4 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 1f713541cb2fc232cb0e8417232cb9942409c9fc..2109c2dc9767d454b2cd08696af039b6bcd1ace7 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2992,6 +2992,7 @@ void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len);
int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen);
void skb_scrub_packet(struct sk_buff *skb, bool xnet);
unsigned int skb_gso_transport_seglen(const struct sk_buff *skb);
+bool skb_gso_validate_mtu(const struct sk_buff *skb, unsigned int mtu);
struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
int skb_ensure_writable(struct sk_buff *skb, int write_len);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 97c32c75e704af1f31b064e8f1e0475ff1505d67..5ca562b56ec39d39e1225d96547e242732518ffe 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -4392,6 +4392,37 @@ unsigned int skb_gso_transport_seglen(const struct sk_buff *skb)
}
EXPORT_SYMBOL_GPL(skb_gso_transport_seglen);
+/**
+ * skb_gso_validate_mtu - Return in case such skb fits a given MTU
+ *
+ * @skb: GSO skb
+ *
+ * skb_gso_validate_mtu validates if a given skb will fit a wanted MTU
+ * once split.
+ */
+bool skb_gso_validate_mtu(const struct sk_buff *skb, unsigned int mtu)
+{
+ const struct skb_shared_info *shinfo = skb_shinfo(skb);
+ const struct sk_buff *iter;
+ unsigned int hlen;
+
+ hlen = skb_gso_network_seglen(skb);
+
+ if (shinfo->gso_size != GSO_BY_FRAGS)
+ return hlen <= mtu;
+
+ /* Undo this so we can re-use header sizes */
+ hlen -= GSO_BY_FRAGS;
+
+ skb_walk_frags(skb, iter) {
+ if (hlen + skb_headlen(iter) > mtu)
+ return false;
+ }
+
+ return true;
+}
+EXPORT_SYMBOL_GPL(skb_gso_validate_mtu);
+
static struct sk_buff *skb_reorder_vlan_header(struct sk_buff *skb)
{
if (skb_cow(skb, skb_headroom(skb)) < 0) {
diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c
index cbfb1808fcc490b94dc0bbdab6142acb8fa37815..9f0a7b96646f368021d9cd51bc3f728ba49eed0d 100644
--- a/net/ipv4/ip_forward.c
+++ b/net/ipv4/ip_forward.c
@@ -54,7 +54,7 @@ static bool ip_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu)
if (skb->ignore_df)
return false;
- if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu)
+ if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
return false;
return true;
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 124bf0a663283502deb03397343160d493a378b1..cbac493c913ac37b57a97314f9e7099b14b8246c 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -225,7 +225,7 @@ static int ip_finish_output_gso(struct net *net, struct sock *sk,
/* common case: locally created skb or seglen is <= mtu */
if (((IPCB(skb)->flags & IPSKB_FORWARDED) = 0) ||
- skb_gso_network_seglen(skb) <= mtu)
+ skb_gso_validate_mtu(skb, mtu))
return ip_finish_output2(net, sk, skb);
/* Slowpath - GSO segment length is exceeding the dst MTU.
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index cbf127ae7c676650cc626cbf12cd61b6b570ea43..6b2f60a5c1de3063bb65c07b2b77c13f33890af8 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -368,7 +368,7 @@ static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
if (skb->ignore_df)
return false;
- if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu)
+ if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
return false;
return true;
diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 0b80a7140cc494d8c39bd3efba2423272d1b8844..7a4aa3450dd71039e73516bd711ba7392493eb5e 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -91,7 +91,7 @@ bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
if (skb->len <= mtu)
return false;
- if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu)
+ if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
return false;
return true;
--
2.5.5
next prev parent reply other threads:[~2016-05-31 18:55 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-31 18:55 [PATCH v2 0/7] sctp: Add GSO support Marcelo Ricardo Leitner
2016-05-31 18:55 ` [PATCH v2 1/7] loopback: make use of NETIF_F_GSO_SOFTWARE Marcelo Ricardo Leitner
2016-05-31 18:55 ` [PATCH v2 2/7] skbuff: export skb_gro_receive Marcelo Ricardo Leitner
2016-05-31 18:55 ` [PATCH v2 3/7] sk_buff: allow segmenting based on frag sizes Marcelo Ricardo Leitner
2016-05-31 18:55 ` Marcelo Ricardo Leitner [this message]
2016-05-31 19:07 ` [PATCH v2 4/7] skbuff: introduce skb_gso_validate_mtu Alexander Duyck
2016-05-31 19:54 ` Marcelo Ricardo Leitner
2016-05-31 20:47 ` Alexander Duyck
2016-05-31 18:55 ` [PATCH v2 5/7] sctp: delay as much as possible skb_linearize Marcelo Ricardo Leitner
2016-05-31 18:55 ` [PATCH v2 6/7] sctp: Add GSO support Marcelo Ricardo Leitner
2016-05-31 18:55 ` [PATCH v2 7/7] sctp: improve debug message to also log curr pkt and new chunk size Marcelo Ricardo Leitner
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