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Commit f4c50d99 authored by Herbert Xu's avatar Herbert Xu Committed by David S. Miller
Browse files

[NET]: Add software TSOv4 



This patch adds the GSO implementation for IPv4 TCP.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f6a78bfc

include/linux/skbuff.h

+1 −0
Original line number Diff line number Diff line
@@ -1297,6 +1297,7 @@ extern void skb_split(struct sk_buff *skb, 
				 struct sk_buff *skb1, const u32 len);



extern void	       skb_release_data(struct sk_buff *skb);

extern struct sk_buff *skb_segment(struct sk_buff *skb, int sg);



static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,

				       int len, void *buffer)

include/net/protocol.h

+1 −0
Original line number Diff line number Diff line
@@ -36,6 +36,7 @@ 
struct net_protocol {

	int			(*handler)(struct sk_buff *skb);

	void			(*err_handler)(struct sk_buff *skb, u32 info);

	struct sk_buff	       *(*gso_segment)(struct sk_buff *skb, int sg);

	int			no_policy;

};

include/net/tcp.h

+2 −0
Original line number Diff line number Diff line
@@ -1086,6 +1086,8 @@ extern struct request_sock_ops tcp_request_sock_ops; 


extern int tcp_v4_destroy_sock(struct sock *sk);



extern struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int sg);



#ifdef CONFIG_PROC_FS

extern int  tcp4_proc_init(void);

extern void tcp4_proc_exit(void);

net/core/skbuff.c

+126 −0
Original line number Diff line number Diff line
@@ -1842,6 +1842,132 @@ unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len) 


EXPORT_SYMBOL_GPL(skb_pull_rcsum);



/**

 *	skb_segment - Perform protocol segmentation on skb.

 *	@skb: buffer to segment

 *	@sg: whether scatter-gather can be used for generated segments

 *

 *	This function performs segmentation on the given skb.  It returns

 *	the segment at the given position.  It returns NULL if there are

 *	no more segments to generate, or when an error is encountered.

 */

struct sk_buff *skb_segment(struct sk_buff *skb, int sg)

{

	struct sk_buff *segs = NULL;

	struct sk_buff *tail = NULL;

	unsigned int mss = skb_shinfo(skb)->gso_size;

	unsigned int doffset = skb->data - skb->mac.raw;

	unsigned int offset = doffset;

	unsigned int headroom;

	unsigned int len;

	int nfrags = skb_shinfo(skb)->nr_frags;

	int err = -ENOMEM;

	int i = 0;

	int pos;



	__skb_push(skb, doffset);

	headroom = skb_headroom(skb);

	pos = skb_headlen(skb);



	do {

		struct sk_buff *nskb;

		skb_frag_t *frag;

		int hsize, nsize;

		int k;

		int size;



		len = skb->len - offset;

		if (len > mss)

			len = mss;



		hsize = skb_headlen(skb) - offset;

		if (hsize < 0)

			hsize = 0;

		nsize = hsize + doffset;

		if (nsize > len + doffset || !sg)

			nsize = len + doffset;



		nskb = alloc_skb(nsize + headroom, GFP_ATOMIC);

		if (unlikely(!nskb))

			goto err;



		if (segs)

			tail->next = nskb;

		else

			segs = nskb;

		tail = nskb;



		nskb->dev = skb->dev;

		nskb->priority = skb->priority;

		nskb->protocol = skb->protocol;

		nskb->dst = dst_clone(skb->dst);

		memcpy(nskb->cb, skb->cb, sizeof(skb->cb));

		nskb->pkt_type = skb->pkt_type;

		nskb->mac_len = skb->mac_len;



		skb_reserve(nskb, headroom);

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

		nskb->nh.raw = nskb->data + skb->mac_len;

		nskb->h.raw = nskb->nh.raw + (skb->h.raw - skb->nh.raw);

		memcpy(skb_put(nskb, doffset), skb->data, doffset);



		if (!sg) {

			nskb->csum = skb_copy_and_csum_bits(skb, offset,

							    skb_put(nskb, len),

							    len, 0);

			continue;

		}



		frag = skb_shinfo(nskb)->frags;

		k = 0;



		nskb->ip_summed = CHECKSUM_HW;

		nskb->csum = skb->csum;

		memcpy(skb_put(nskb, hsize), skb->data + offset, hsize);



		while (pos < offset + len) {

			BUG_ON(i >= nfrags);



			*frag = skb_shinfo(skb)->frags[i];

			get_page(frag->page);

			size = frag->size;



			if (pos < offset) {

				frag->page_offset += offset - pos;

				frag->size -= offset - pos;

			}



			k++;



			if (pos + size <= offset + len) {

				i++;

				pos += size;

			} else {

				frag->size -= pos + size - (offset + len);

				break;

			}



			frag++;

		}



		skb_shinfo(nskb)->nr_frags = k;

		nskb->data_len = len - hsize;

		nskb->len += nskb->data_len;

		nskb->truesize += nskb->data_len;

	} while ((offset += len) < skb->len);



	return segs;



err:

	while ((skb = segs)) {

		segs = skb->next;

		kfree(skb);

	}

	return ERR_PTR(err);

}



EXPORT_SYMBOL_GPL(skb_segment);



void __init skb_init(void)

{

	skbuff_head_cache = kmem_cache_create("skbuff_head_cache",

net/ipv4/af_inet.c

+51 −0
Original line number Diff line number Diff line
@@ -68,6 +68,7 @@ 
 */



#include <linux/config.h>

#include <linux/err.h>

#include <linux/errno.h>

#include <linux/types.h>

#include <linux/socket.h>
@@ -1096,6 +1097,54 @@ int inet_sk_rebuild_header(struct sock *sk) 


EXPORT_SYMBOL(inet_sk_rebuild_header);



static struct sk_buff *inet_gso_segment(struct sk_buff *skb, int sg)

{

	struct sk_buff *segs = ERR_PTR(-EINVAL);

	struct iphdr *iph;

	struct net_protocol *ops;

	int proto;

	int ihl;

	int id;



	if (!pskb_may_pull(skb, sizeof(*iph)))

		goto out;



	iph = skb->nh.iph;

	ihl = iph->ihl * 4;

	if (ihl < sizeof(*iph))

		goto out;



	if (!pskb_may_pull(skb, ihl))

		goto out;



	skb->h.raw = __skb_pull(skb, ihl);

	iph = skb->nh.iph;

	id = ntohs(iph->id);

	proto = iph->protocol & (MAX_INET_PROTOS - 1);

	segs = ERR_PTR(-EPROTONOSUPPORT);



	rcu_read_lock();

	ops = rcu_dereference(inet_protos[proto]);

	if (ops && ops->gso_segment)

		segs = ops->gso_segment(skb, sg);

	rcu_read_unlock();



	if (IS_ERR(segs))

		goto out;



	skb = segs;

	do {

		iph = skb->nh.iph;

		iph->id = htons(id++);

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

		iph->check = 0;

		iph->check = ip_fast_csum(skb->nh.raw, iph->ihl);

	} while ((skb = skb->next));



out:

	return segs;

}



#ifdef CONFIG_IP_MULTICAST

static struct net_protocol igmp_protocol = {

	.handler =	igmp_rcv,
@@ -1105,6 +1154,7 @@ static struct net_protocol igmp_protocol = { 
static struct net_protocol tcp_protocol = {

	.handler =	tcp_v4_rcv,

	.err_handler =	tcp_v4_err,

	.gso_segment =	tcp_tso_segment,

	.no_policy =	1,

};
@@ -1150,6 +1200,7 @@ static int ipv4_proc_init(void); 
static struct packet_type ip_packet_type = {

	.type = __constant_htons(ETH_P_IP),

	.func = ip_rcv,

	.gso_segment = inet_gso_segment,

};



static int __init inet_init(void)