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| author |   Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> | 2016-06-02 15:05:41 -0300 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2016-06-03 19:37:21 -0400 |
| commit | ae7ef81ef000adeee7a87585b9135ff8a8064acc (patch) | |
| tree | 50968928f3eed74570ba0b79afc8eef29200c86e /net/core/skbuff.c | |
| parent | sk_buff: allow segmenting based on frag sizes (diff) | |
| download | linux-dev-ae7ef81ef000adeee7a87585b9135ff8a8064acc.tar.xz linux-dev-ae7ef81ef000adeee7a87585b9135ff8a8064acc.zip | |
skbuff: introduce skb_gso_validate_mtu
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/skbuff.c')
| -rw-r--r-- | net/core/skbuff.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 97c32c75e704..5ca562b56ec3 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) { |