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Commit cbb042f9 authored by Herbert Xu's avatar Herbert Xu Committed by David S. Miller
Browse files

[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: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ecba320f

drivers/net/ppp_generic.c

+2 −2
Original line number Diff line number Diff line
@@ -1691,8 +1691,8 @@ ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 
		    || ppp->npmode[npi] != NPMODE_PASS) {

			kfree_skb(skb);

		} else {

			skb_pull(skb, 2);	/* chop off protocol */

			skb_postpull_rcsum(skb, skb->data - 2, 2);

			/* chop off protocol */

			skb_pull_rcsum(skb, 2);

			skb->dev = ppp->dev;

			skb->protocol = htons(npindex_to_ethertype[npi]);

			skb->mac.raw = skb->data;

drivers/net/pppoe.c

+1 −2
Original line number Diff line number Diff line
@@ -337,8 +337,7 @@ static int pppoe_rcv_core(struct sock *sk, struct sk_buff *skb) 
	if (sk->sk_state & PPPOX_BOUND) {

		struct pppoe_hdr *ph = (struct pppoe_hdr *) skb->nh.raw;

		int len = ntohs(ph->length);

		skb_pull(skb, sizeof(struct pppoe_hdr));

		skb_postpull_rcsum(skb, ph, sizeof(*ph));

		skb_pull_rcsum(skb, sizeof(struct pppoe_hdr));

		if (pskb_trim_rcsum(skb, len))

			goto abort_kfree;

include/linux/skbuff.h

+3 −1
Original line number Diff line number Diff line
@@ -1159,12 +1159,14 @@ static inline int skb_linearize(struct sk_buff *skb, gfp_t gfp) 
 */



static inline void skb_postpull_rcsum(struct sk_buff *skb,

					 const void *start, int len)

				      const void *start, unsigned int len)

{

	if (skb->ip_summed == CHECKSUM_HW)

		skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));

}



unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);



/**

 *	pskb_trim_rcsum - trim received skb and update checksum

 *	@skb: buffer to trim

net/802/psnap.c

+1 −2
Original line number Diff line number Diff line
@@ -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;

net/8021q/vlan_dev.c

+2 −4
Original line number Diff line number Diff line
@@ -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.