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author | Herbert Xu <herbert@gondor.apana.org.au> | 2006-03-20 22:43:56 -0800 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2006-03-20 22:43:56 -0800 |
commit | cbb042f9e1292434e3cacb90e67d8d381aeac5a9 (patch) | |
tree | cc42f42232e56b68111cfebdc175197d8607bdd7 /net | |
parent | ecba320f2e95c9a0c35011d1ecb1db4419980536 (diff) | |
download | linux-3.10-cbb042f9e1292434e3cacb90e67d8d381aeac5a9.tar.gz linux-3.10-cbb042f9e1292434e3cacb90e67d8d381aeac5a9.tar.bz2 linux-3.10-cbb042f9e1292434e3cacb90e67d8d381aeac5a9.zip |
[NET]: Replace skb_pull/skb_postpull_rcsum with skb_pull_rcsum
We're now starting to have quite a number of places that do skb_pull
followed immediately by an skb_postpull_rcsum. We can merge these two
operations into one function with skb_pull_rcsum. This makes sense
since most pull operations on receive skb's need to update the
checksum.
I've decided to make this out-of-line since it is fairly big and the
fast path where hardware checksums are enabled need to call
csum_partial anyway.
Since this is a brand new function we get to add an extra check on the
len argument. As it is most callers of skb_pull ignore its return
value which essentially means that there is no check on the len
argument.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r-- | net/802/psnap.c | 3 | ||||
-rw-r--r-- | net/8021q/vlan_dev.c | 6 | ||||
-rw-r--r-- | net/bridge/br_netfilter.c | 6 | ||||
-rw-r--r-- | net/core/skbuff.c | 21 |
4 files changed, 26 insertions, 10 deletions
diff --git a/net/802/psnap.c b/net/802/psnap.c index 34e42968b47..97c95eec79e 100644 --- a/net/802/psnap.c +++ b/net/802/psnap.c @@ -61,8 +61,7 @@ static int snap_rcv(struct sk_buff *skb, struct net_device *dev, /* Pass the frame on. */ u8 *hdr = skb->data; skb->h.raw += 5; - skb_pull(skb, 5); - skb_postpull_rcsum(skb, hdr, 5); + skb_pull_rcsum(skb, 5); rc = proto->rcvfunc(skb, dev, &snap_packet_type, orig_dev); } else { skb->sk = NULL; diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c index 0f604d227da..da9cfe92715 100644 --- a/net/8021q/vlan_dev.c +++ b/net/8021q/vlan_dev.c @@ -163,10 +163,8 @@ int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev, stats->rx_packets++; stats->rx_bytes += skb->len; - skb_pull(skb, VLAN_HLEN); /* take off the VLAN header (4 bytes currently) */ - - /* Need to correct hardware checksum */ - skb_postpull_rcsum(skb, vhdr, VLAN_HLEN); + /* Take off the VLAN header (4 bytes currently) */ + skb_pull_rcsum(skb, VLAN_HLEN); /* Ok, lets check to make sure the device (dev) we * came in on is what this VLAN is attached to. diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index e060aad8624..6787bc5197f 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -425,8 +425,7 @@ static unsigned int br_nf_pre_routing(unsigned int hook, struct sk_buff **pskb, if (skb->protocol == __constant_htons(ETH_P_8021Q)) { u8 *vhdr = skb->data; - skb_pull(skb, VLAN_HLEN); - skb_postpull_rcsum(skb, vhdr, VLAN_HLEN); + skb_pull_rcsum(skb, VLAN_HLEN); skb->nh.raw += VLAN_HLEN; } return br_nf_pre_routing_ipv6(hook, skb, in, out, okfn); @@ -444,8 +443,7 @@ static unsigned int br_nf_pre_routing(unsigned int hook, struct sk_buff **pskb, if (skb->protocol == __constant_htons(ETH_P_8021Q)) { u8 *vhdr = skb->data; - skb_pull(skb, VLAN_HLEN); - skb_postpull_rcsum(skb, vhdr, VLAN_HLEN); + skb_pull_rcsum(skb, VLAN_HLEN); skb->nh.raw += VLAN_HLEN; } diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 01abf1e8990..2960c8b82b2 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -1795,6 +1795,27 @@ int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb, return 0; } +/** + * skb_pull_rcsum - pull skb and update receive checksum + * @skb: buffer to update + * @start: start of data before pull + * @len: length of data pulled + * + * This function performs an skb_pull on the packet and updates + * update the CHECKSUM_HW checksum. It should be used on receive + * path processing instead of skb_pull unless you know that the + * checksum difference is zero (e.g., a valid IP header) or you + * are setting ip_summed to CHECKSUM_NONE. + */ +unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len) +{ + BUG_ON(len > skb->len); + skb->len -= len; + BUG_ON(skb->len < skb->data_len); + skb_postpull_rcsum(skb, skb->data, len); + return skb->data += len; +} + void __init skb_init(void) { skbuff_head_cache = kmem_cache_create("skbuff_head_cache", |