Commit 7b277b1a authored by Herbert Xu's avatar Herbert Xu Committed by David S. Miller
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[IPSEC]: Set skb->data to payload in x->mode->output 



This patch changes the calling convention so that on entry from
x->mode->output and before entry into x->type->output skb->data
will point to the payload instead of the IP header.

This is essentially a redistribution of skb_push/skb_pull calls
with the aim of minimising them on the common path of tunnel +
ESP.

It'll also let us use the same calling convention between IPv4
and IPv6 with the next patch.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent bee0b40c

net/ipv4/ah4.c

+1 −0
Original line number Diff line number Diff line
@@ -66,6 +66,7 @@ static int ah_output(struct xfrm_state *x, struct sk_buff *skb) 
		char 		buf[60];

	} tmp_iph;



	skb_push(skb, -skb_network_offset(skb));

	top_iph = ip_hdr(skb);

	iph = &tmp_iph.iph;

net/ipv4/esp4.c

+2 −4
Original line number Diff line number Diff line
@@ -28,9 +28,7 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb) 
	int alen;

	int nfrags;



	/* Strip IP+ESP header. */

	__skb_pull(skb, skb_transport_offset(skb));

	/* Now skb is pure payload to encrypt */

	/* skb is pure payload to encrypt */



	err = -ENOMEM;
@@ -60,7 +58,7 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb) 
	tail[clen - skb->len - 2] = (clen - skb->len) - 2;

	pskb_put(skb, trailer, clen - skb->len);



	__skb_push(skb, -skb_network_offset(skb));

	skb_push(skb, -skb_network_offset(skb));

	top_iph = ip_hdr(skb);

	esph = (struct ip_esp_hdr *)(skb_network_header(skb) +

				     top_iph->ihl * 4);

net/ipv4/ipcomp.c

+1 −0
Original line number Diff line number Diff line
@@ -134,6 +134,7 @@ static int ipcomp_output(struct xfrm_state *x, struct sk_buff *skb) 
	int hdr_len = 0;

	struct iphdr *iph = ip_hdr(skb);



	skb_push(skb, -skb_network_offset(skb));

	iph->tot_len = htons(skb->len);

	hdr_len = iph->ihl * 4;

	if ((skb->len - hdr_len) < ipcd->threshold) {

net/ipv4/xfrm4_mode_beet.c

+3 −2
Original line number Diff line number Diff line
@@ -40,10 +40,11 @@ static int xfrm4_beet_output(struct xfrm_state *x, struct sk_buff *skb) 
	if (unlikely(optlen))

		hdrlen += IPV4_BEET_PHMAXLEN - (optlen & 4);



	skb_push(skb, x->props.header_len - IPV4_BEET_PHMAXLEN + hdrlen);

	skb_reset_network_header(skb);

	skb_set_network_header(skb, IPV4_BEET_PHMAXLEN - x->props.header_len -

				    hdrlen);

	top_iph = ip_hdr(skb);

	skb->transport_header += sizeof(*iph) - hdrlen;

	__skb_pull(skb, sizeof(*iph) - hdrlen);



	memmove(top_iph, iph, sizeof(*iph));

	if (unlikely(optlen)) {

net/ipv4/xfrm4_mode_transport.c

+2 −2
Original line number Diff line number Diff line
@@ -27,8 +27,8 @@ static int xfrm4_transport_output(struct xfrm_state *x, struct sk_buff *skb) 
	int ihl = iph->ihl * 4;



	skb->transport_header = skb->network_header + ihl;

	skb_push(skb, x->props.header_len);

	skb_reset_network_header(skb);

	skb_set_network_header(skb, -x->props.header_len);

	__skb_pull(skb, ihl);

	memmove(skb_network_header(skb), iph, ihl);

	return 0;

}

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