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Commit 2721637c authored by Paul Durrant's avatar Paul Durrant Committed by David S. Miller
Browse files

xen-netback: use new skb_checksum_setup function 



Use skb_checksum_setup to set up partial checksum offsets rather
then a private implementation.

Signed-off-by: default avatarPaul Durrant <paul.durrant@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Acked-by: default avatarWei Liu <wei.liu2@citrix.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ed1f50c3

drivers/net/xen-netback/netback.c

+3 −257
Original line number Diff line number Diff line
@@ -39,7 +39,6 @@ 
#include <linux/udp.h>



#include <net/tcp.h>

#include <net/ip6_checksum.h>



#include <xen/xen.h>

#include <xen/events.h>
@@ -1051,257 +1050,9 @@ static int xenvif_set_skb_gso(struct xenvif *vif, 
	return 0;

}



static inline int maybe_pull_tail(struct sk_buff *skb, unsigned int len,

				  unsigned int max)

{

	if (skb_headlen(skb) >= len)

		return 0;



	/* If we need to pullup then pullup to the max, so we

	 * won't need to do it again.

	 */

	if (max > skb->len)

		max = skb->len;



	if (__pskb_pull_tail(skb, max - skb_headlen(skb)) == NULL)

		return -ENOMEM;



	if (skb_headlen(skb) < len)

		return -EPROTO;



	return 0;

}



/* This value should be large enough to cover a tagged ethernet header plus

 * maximally sized IP and TCP or UDP headers.

 */

#define MAX_IP_HDR_LEN 128



static int checksum_setup_ip(struct xenvif *vif, struct sk_buff *skb,

			     int recalculate_partial_csum)

{

	unsigned int off;

	bool fragment;

	int err;



	fragment = false;



	err = maybe_pull_tail(skb,

			      sizeof(struct iphdr),

			      MAX_IP_HDR_LEN);

	if (err < 0)

		goto out;



	if (ip_hdr(skb)->frag_off & htons(IP_OFFSET | IP_MF))

		fragment = true;



	off = ip_hdrlen(skb);



	err = -EPROTO;



	if (fragment)

		goto out;



	switch (ip_hdr(skb)->protocol) {

	case IPPROTO_TCP:

		err = maybe_pull_tail(skb,

				      off + sizeof(struct tcphdr),

				      MAX_IP_HDR_LEN);

		if (err < 0)

			goto out;



		if (!skb_partial_csum_set(skb, off,

					  offsetof(struct tcphdr, check))) {

			err = -EPROTO;

			goto out;

		}



		if (recalculate_partial_csum)

			tcp_hdr(skb)->check =

				~csum_tcpudp_magic(ip_hdr(skb)->saddr,

						   ip_hdr(skb)->daddr,

						   skb->len - off,

						   IPPROTO_TCP, 0);

		break;

	case IPPROTO_UDP:

		err = maybe_pull_tail(skb,

				      off + sizeof(struct udphdr),

				      MAX_IP_HDR_LEN);

		if (err < 0)

			goto out;



		if (!skb_partial_csum_set(skb, off,

					  offsetof(struct udphdr, check))) {

			err = -EPROTO;

			goto out;

		}



		if (recalculate_partial_csum)

			udp_hdr(skb)->check =

				~csum_tcpudp_magic(ip_hdr(skb)->saddr,

						   ip_hdr(skb)->daddr,

						   skb->len - off,

						   IPPROTO_UDP, 0);

		break;

	default:

		goto out;

	}



	err = 0;



out:

	return err;

}



/* This value should be large enough to cover a tagged ethernet header plus

 * an IPv6 header, all options, and a maximal TCP or UDP header.

 */

#define MAX_IPV6_HDR_LEN 256



#define OPT_HDR(type, skb, off) \

	(type *)(skb_network_header(skb) + (off))



static int checksum_setup_ipv6(struct xenvif *vif, struct sk_buff *skb,

			       int recalculate_partial_csum)

{

	int err;

	u8 nexthdr;

	unsigned int off;

	unsigned int len;

	bool fragment;

	bool done;



	fragment = false;

	done = false;



	off = sizeof(struct ipv6hdr);



	err = maybe_pull_tail(skb, off, MAX_IPV6_HDR_LEN);

	if (err < 0)

		goto out;



	nexthdr = ipv6_hdr(skb)->nexthdr;



	len = sizeof(struct ipv6hdr) + ntohs(ipv6_hdr(skb)->payload_len);

	while (off <= len && !done) {

		switch (nexthdr) {

		case IPPROTO_DSTOPTS:

		case IPPROTO_HOPOPTS:

		case IPPROTO_ROUTING: {

			struct ipv6_opt_hdr *hp;



			err = maybe_pull_tail(skb,

					      off +

					      sizeof(struct ipv6_opt_hdr),

					      MAX_IPV6_HDR_LEN);

			if (err < 0)

				goto out;



			hp = OPT_HDR(struct ipv6_opt_hdr, skb, off);

			nexthdr = hp->nexthdr;

			off += ipv6_optlen(hp);

			break;

		}

		case IPPROTO_AH: {

			struct ip_auth_hdr *hp;



			err = maybe_pull_tail(skb,

					      off +

					      sizeof(struct ip_auth_hdr),

					      MAX_IPV6_HDR_LEN);

			if (err < 0)

				goto out;



			hp = OPT_HDR(struct ip_auth_hdr, skb, off);

			nexthdr = hp->nexthdr;

			off += ipv6_authlen(hp);

			break;

		}

		case IPPROTO_FRAGMENT: {

			struct frag_hdr *hp;



			err = maybe_pull_tail(skb,

					      off +

					      sizeof(struct frag_hdr),

					      MAX_IPV6_HDR_LEN);

			if (err < 0)

				goto out;



			hp = OPT_HDR(struct frag_hdr, skb, off);



			if (hp->frag_off & htons(IP6_OFFSET | IP6_MF))

				fragment = true;



			nexthdr = hp->nexthdr;

			off += sizeof(struct frag_hdr);

			break;

		}

		default:

			done = true;

			break;

		}

	}



	err = -EPROTO;



	if (!done || fragment)

		goto out;



	switch (nexthdr) {

	case IPPROTO_TCP:

		err = maybe_pull_tail(skb,

				      off + sizeof(struct tcphdr),

				      MAX_IPV6_HDR_LEN);

		if (err < 0)

			goto out;



		if (!skb_partial_csum_set(skb, off,

					  offsetof(struct tcphdr, check))) {

			err = -EPROTO;

			goto out;

		}



		if (recalculate_partial_csum)

			tcp_hdr(skb)->check =

				~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,

						 &ipv6_hdr(skb)->daddr,

						 skb->len - off,

						 IPPROTO_TCP, 0);

		break;

	case IPPROTO_UDP:

		err = maybe_pull_tail(skb,

				      off + sizeof(struct udphdr),

				      MAX_IPV6_HDR_LEN);

		if (err < 0)

			goto out;



		if (!skb_partial_csum_set(skb, off,

					  offsetof(struct udphdr, check))) {

			err = -EPROTO;

			goto out;

		}



		if (recalculate_partial_csum)

			udp_hdr(skb)->check =

				~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,

						 &ipv6_hdr(skb)->daddr,

						 skb->len - off,

						 IPPROTO_UDP, 0);

		break;

	default:

		goto out;

	}



	err = 0;



out:

	return err;

}



static int checksum_setup(struct xenvif *vif, struct sk_buff *skb)

{

	int err = -EPROTO;

	int recalculate_partial_csum = 0;

	bool recalculate_partial_csum = false;



	/* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy

	 * peers can fail to set NETRXF_csum_blank when sending a GSO
@@ -1311,19 +1062,14 @@ static int checksum_setup(struct xenvif *vif, struct sk_buff *skb) 
	if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {

		vif->rx_gso_checksum_fixup++;

		skb->ip_summed = CHECKSUM_PARTIAL;

		recalculate_partial_csum = 1;

		recalculate_partial_csum = true;

	}



	/* A non-CHECKSUM_PARTIAL SKB does not require setup. */

	if (skb->ip_summed != CHECKSUM_PARTIAL)

		return 0;



	if (skb->protocol == htons(ETH_P_IP))

		err = checksum_setup_ip(vif, skb, recalculate_partial_csum);

	else if (skb->protocol == htons(ETH_P_IPV6))

		err = checksum_setup_ipv6(vif, skb, recalculate_partial_csum);



	return err;

	return skb_checksum_setup(skb, recalculate_partial_csum);

}



static bool tx_credit_exceeded(struct xenvif *vif, unsigned size)