[NET] generalise tcp_add_data, skb_split and tcp_copy_to_page

Signed-off-by: Arnaldo Carvalho de Melo <acme@conectiva.com.br>

include/linux/errqueue.h

@@ -22,6 +22,10 @@ struct sock_extended_err
 #ifdef __KERNEL__
 
 #include <linux/config.h>
+#include <net/ip.h>
+#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+#include <linux/ipv6.h>
+#endif
 
 #define SKB_EXT_ERR(skb) ((struct sock_exterr_skb *) ((skb)->cb))
 

include/linux/skbuff.h

@@ -27,6 +27,7 @@
 #include <linux/highmem.h>
 #include <linux/poll.h>
 #include <linux/net.h>
+#include <net/checksum.h>
 
 #define HAVE_ALLOC_SKB		/* For the drivers to know */
 #define HAVE_ALIGNABLE_SKB	/* Ditto 8)		   */
@@ -971,6 +972,27 @@ static inline struct sk_buff *skb_padto(struct sk_buff *skb, unsigned int len)
 	return skb_pad(skb, len-size);
 }
 
+static inline int skb_add_data(struct sk_buff *skb,
+			       char __user *from, int copy)
+{
+	const int off = skb->len;
+
+	if (skb->ip_summed == CHECKSUM_NONE) {
+		int err = 0;
+		unsigned int csum = csum_and_copy_from_user(from,
+							    skb_put(skb, copy),
+							    copy, 0, &err);
+		if (!err) {
+			skb->csum = csum_block_add(skb->csum, csum, off);
+			return 0;
+		}
+	} else if (!copy_from_user(skb_put(skb, copy), from, copy))
+		return 0;
+
+	__skb_trim(skb, off);
+	return -EFAULT;
+}
+
 /**
  *	skb_linearize - convert paged skb to linear one
  *	@skb: buffer to linarize
@@ -1034,6 +1056,8 @@ extern unsigned int    skb_copy_and_csum_bits(const struct sk_buff *skb,
 					      int offset, u8 *to, int len,
 					      unsigned int csum);
 extern void	       skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
+extern void	       skb_split(struct sk_buff *skb,
+				 struct sk_buff *skb1, const u32 len);
 
 extern void skb_init(void);
 extern void skb_add_mtu(int mtu);

include/net/checksum.h

@@ -16,83 +16,15 @@
  *		2 of the License, or (at your option) any later version.
  */
 
-/*
- *	Fixes:
- *
- *	Ralf Baechle			:	generic ipv6 checksum
- *	<ralf@waldorf-gmbh.de>
- */
-
 #ifndef _CHECKSUM_H
 #define _CHECKSUM_H
 
+#include <linux/errno.h>
 #include <asm/types.h>
 #include <asm/byteorder.h>
-#include <net/ip.h>
-#include <linux/in6.h>
 #include <asm/uaccess.h>
 #include <asm/checksum.h>
 
-#ifndef _HAVE_ARCH_IPV6_CSUM
-
-static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
-						     struct in6_addr *daddr,
-						     __u16 len,
-						     unsigned short proto,
-						     unsigned int csum) 
-{
-
-	int carry;
-	__u32 ulen;
-	__u32 uproto;
-
-	csum += saddr->s6_addr32[0];
-	carry = (csum < saddr->s6_addr32[0]);
-	csum += carry;
-
-	csum += saddr->s6_addr32[1];
-	carry = (csum < saddr->s6_addr32[1]);
-	csum += carry;
-
-	csum += saddr->s6_addr32[2];
-	carry = (csum < saddr->s6_addr32[2]);
-	csum += carry;
-
-	csum += saddr->s6_addr32[3];
-	carry = (csum < saddr->s6_addr32[3]);
-	csum += carry;
-
-	csum += daddr->s6_addr32[0];
-	carry = (csum < daddr->s6_addr32[0]);
-	csum += carry;
-
-	csum += daddr->s6_addr32[1];
-	carry = (csum < daddr->s6_addr32[1]);
-	csum += carry;
-
-	csum += daddr->s6_addr32[2];
-	carry = (csum < daddr->s6_addr32[2]);
-	csum += carry;
-
-	csum += daddr->s6_addr32[3];
-	carry = (csum < daddr->s6_addr32[3]);
-	csum += carry;
-
-	ulen = htonl((__u32) len);
-	csum += ulen;
-	carry = (csum < ulen);
-	csum += carry;
-
-	uproto = htonl(proto);
-	csum += uproto;
-	carry = (csum < uproto);
-	csum += carry;
-
-	return csum_fold(csum);
-}
-
-#endif
-
 #ifndef _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
 static inline
 unsigned int csum_and_copy_from_user (const char __user *src, char *dst,

include/net/ip.h

@@ -37,7 +37,7 @@
 #include <net/snmp.h>
 #endif
 
-#include <net/sock.h>	/* struct sock */
+struct sock;
 
 struct inet_skb_parm
 {

include/net/ip6_checksum.h

+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Checksumming functions for IPv6
+ *
+ * Authors:	Jorge Cwik, <jorge@laser.satlink.net>
+ *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
+ *		Borrows very liberally from tcp.c and ip.c, see those
+ *		files for more names.
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+
+/*
+ *	Fixes:
+ *
+ *	Ralf Baechle			:	generic ipv6 checksum
+ *	<ralf@waldorf-gmbh.de>
+ */
+
+#ifndef _CHECKSUM_IPV6_H
+#define _CHECKSUM_IPV6_H
+
+#include <asm/types.h>
+#include <asm/byteorder.h>
+#include <net/ip.h>
+#include <asm/checksum.h>
+#include <linux/in6.h>
+
+#ifndef _HAVE_ARCH_IPV6_CSUM
+
+static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
+						     struct in6_addr *daddr,
+						     __u16 len,
+						     unsigned short proto,
+						     unsigned int csum) 
+{
+
+	int carry;
+	__u32 ulen;
+	__u32 uproto;
+
+	csum += saddr->s6_addr32[0];
+	carry = (csum < saddr->s6_addr32[0]);
+	csum += carry;
+
+	csum += saddr->s6_addr32[1];
+	carry = (csum < saddr->s6_addr32[1]);
+	csum += carry;
+
+	csum += saddr->s6_addr32[2];
+	carry = (csum < saddr->s6_addr32[2]);
+	csum += carry;
+
+	csum += saddr->s6_addr32[3];
+	carry = (csum < saddr->s6_addr32[3]);
+	csum += carry;
+
+	csum += daddr->s6_addr32[0];
+	carry = (csum < daddr->s6_addr32[0]);
+	csum += carry;
+
+	csum += daddr->s6_addr32[1];
+	carry = (csum < daddr->s6_addr32[1]);
+	csum += carry;
+
+	csum += daddr->s6_addr32[2];
+	carry = (csum < daddr->s6_addr32[2]);
+	csum += carry;
+
+	csum += daddr->s6_addr32[3];
+	carry = (csum < daddr->s6_addr32[3]);
+	csum += carry;
+
+	ulen = htonl((__u32) len);
+	csum += ulen;
+	carry = (csum < ulen);
+	csum += carry;
+
+	uproto = htonl(proto);
+	csum += uproto;
+	carry = (csum < uproto);
+	csum += carry;
+
+	return csum_fold(csum);
+}
+
+#endif
+#endif

include/net/sock.h

@@ -53,6 +53,7 @@
 
 #include <asm/atomic.h>
 #include <net/dst.h>
+#include <net/checksum.h>
 
 /*
  * This structure really needs to be cleaned up.
@@ -923,6 +924,29 @@ static inline void sk_charge_skb(struct sock *sk, struct sk_buff *skb)
 	sk->sk_forward_alloc -= skb->truesize;
 }
 
+static inline int skb_copy_to_page(struct sock *sk, char __user *from,
+				   struct sk_buff *skb, struct page *page,
+				   int off, int copy)
+{
+	if (skb->ip_summed == CHECKSUM_NONE) {
+		int err = 0;
+		unsigned int csum = csum_and_copy_from_user(from,
+						     page_address(page) + off,
+							    copy, 0, &err);
+		if (err)
+			return err;
+		skb->csum = csum_block_add(skb->csum, csum, skb->len);
+	} else if (copy_from_user(page_address(page) + off, from, copy))
+		return -EFAULT;
+
+	skb->len	     += copy;
+	skb->data_len	     += copy;
+	skb->truesize	     += copy;
+	sk->sk_wmem_queued   += copy;
+	sk->sk_forward_alloc -= copy;
+	return 0;
+}
+
 /*
  * 	Queue a received datagram if it will fit. Stream and sequenced
  *	protocols can't normally use this as they need to fit buffers in

include/net/tcp.h

@@ -33,6 +33,7 @@
 #include <net/checksum.h>
 #include <net/sock.h>
 #include <net/snmp.h>
+#include <net/ip.h>
 #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
 #include <linux/ipv6.h>
 #endif

net/core/skbuff.c

@@ -1263,6 +1263,81 @@ void skb_add_mtu(int mtu)
 }
 #endif
 
+static void inline skb_split_inside_header(struct sk_buff *skb,
+					   struct sk_buff* skb1,
+					   const u32 len, const int pos)
+{
+	int i;
+
+	memcpy(skb_put(skb1, pos - len), skb->data + len, pos - len);
+
+	/* And move data appendix as is. */
+	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
+		skb_shinfo(skb1)->frags[i] = skb_shinfo(skb)->frags[i];
+
+	skb_shinfo(skb1)->nr_frags = skb_shinfo(skb)->nr_frags;
+	skb_shinfo(skb)->nr_frags  = 0;
+	skb1->data_len		   = skb->data_len;
+	skb1->len		   += skb1->data_len;
+	skb->data_len		   = 0;
+	skb->len		   = len;
+	skb->tail		   = skb->data + len;
+}
+
+static void inline skb_split_no_header(struct sk_buff *skb,
+				       struct sk_buff* skb1,
+				       const u32 len, int pos)
+{
+	int i, k = 0;
+	const int nfrags = skb_shinfo(skb)->nr_frags;
+
+	skb_shinfo(skb)->nr_frags = 0;
+	skb1->len		  = skb1->data_len = skb->len - len;
+	skb->len		  = len;
+	skb->data_len		  = len - pos;
+
+	for (i = 0; i < nfrags; i++) {
+		int size = skb_shinfo(skb)->frags[i].size;
+
+		if (pos + size > len) {
+			skb_shinfo(skb1)->frags[k] = skb_shinfo(skb)->frags[i];
+
+			if (pos < len) {
+				/* Split frag.
+				 * We have to variants in this case:
+				 * 1. Move all the frag to the second
+				 *    part, if it is possible. F.e.
+				 *    this approach is mandatory for TUX,
+				 *    where splitting is expensive.
+				 * 2. Split is accurately. We make this.
+				 */
+				get_page(skb_shinfo(skb)->frags[i].page);
+				skb_shinfo(skb1)->frags[0].page_offset += len - pos;
+				skb_shinfo(skb1)->frags[0].size -= len - pos;
+				skb_shinfo(skb)->frags[i].size	= len - pos;
+				skb_shinfo(skb)->nr_frags++;
+			}
+			k++;
+		} else
+			skb_shinfo(skb)->nr_frags++;
+		pos += size;
+	}
+	skb_shinfo(skb1)->nr_frags = k;
+}
+
+/**
+ * skb_split - Split fragmented skb to two parts at length len.
+ */
+void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len)
+{
+	int pos = skb_headlen(skb);
+
+	if (len < pos)	/* Split line is inside header. */
+		skb_split_inside_header(skb, skb1, len, pos);
+	else		/* Second chunk has no header, nothing to copy. */
+		skb_split_no_header(skb, skb1, len, pos);
+}
+
 void __init skb_init(void)
 {
 	skbuff_head_cache = kmem_cache_create("skbuff_head_cache",
@@ -1300,3 +1375,4 @@ EXPORT_SYMBOL(skb_queue_head);
 EXPORT_SYMBOL(skb_queue_tail);
 EXPORT_SYMBOL(skb_unlink);
 EXPORT_SYMBOL(skb_append);
+EXPORT_SYMBOL(skb_split);

net/ipv4/netfilter/ip_conntrack_core.c

@@ -28,6 +28,7 @@
 #include <linux/proc_fs.h>
 #include <linux/vmalloc.h>
 #include <net/checksum.h>
+#include <net/ip.h>
 #include <linux/stddef.h>
 #include <linux/sysctl.h>
 #include <linux/slab.h>

net/ipv4/netfilter/ip_conntrack_standalone.c

@@ -24,6 +24,7 @@
 #include <linux/sysctl.h>
 #endif
 #include <net/checksum.h>
+#include <net/ip.h>
 
 #define ASSERT_READ_LOCK(x) MUST_BE_READ_LOCKED(&ip_conntrack_lock)
 #define ASSERT_WRITE_LOCK(x) MUST_BE_WRITE_LOCKED(&ip_conntrack_lock)

net/ipv4/netfilter/ip_fw_compat_redir.c

@@ -22,6 +22,7 @@
 #include <linux/udp.h>
 #include <linux/tcp.h>
 #include <net/checksum.h>
+#include <net/ip.h>
 #include <linux/timer.h>
 #include <linux/netdevice.h>
 #include <linux/if.h>

net/ipv4/netfilter/ip_nat_standalone.c

@@ -27,6 +27,7 @@
 #include <linux/module.h>
 #include <linux/skbuff.h>
 #include <linux/proc_fs.h>
+#include <net/ip.h>
 #include <net/checksum.h>
 #include <linux/spinlock.h>
 

net/ipv4/netfilter/ipt_MASQUERADE.c

@@ -16,6 +16,7 @@
 #include <linux/module.h>
 #include <linux/netfilter.h>
 #include <net/protocol.h>
+#include <net/ip.h>
 #include <net/checksum.h>
 #include <linux/netfilter_ipv4.h>
 #include <linux/netfilter_ipv4/ip_nat_rule.h>

net/ipv4/tcp.c

@@ -948,53 +948,6 @@ ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset,
 #define TCP_PAGE(sk)	(inet_sk(sk)->sndmsg_page)
 #define TCP_OFF(sk)	(inet_sk(sk)->sndmsg_off)
 
-static inline int tcp_copy_to_page(struct sock *sk, char __user *from,
-				   struct sk_buff *skb, struct page *page,
-				   int off, int copy)
-{
-	int err = 0;
-	unsigned int csum;
-
-	if (skb->ip_summed == CHECKSUM_NONE) {
-		csum = csum_and_copy_from_user(from, page_address(page) + off,
-				       copy, 0, &err);
-		if (err) return err;
-		skb->csum = csum_block_add(skb->csum, csum, skb->len);
-	} else {
-		if (copy_from_user(page_address(page) + off, from, copy))
-			return -EFAULT;
-	}
-
-	skb->len += copy;
-	skb->data_len += copy;
-	skb->truesize += copy;
-	sk->sk_wmem_queued += copy;
-	sk->sk_forward_alloc -= copy;
-	return 0;
-}
-
-static inline int skb_add_data(struct sk_buff *skb, char __user *from, int copy)
-{
-	int err = 0;
-	unsigned int csum;
-	int off = skb->len;
-
-	if (skb->ip_summed == CHECKSUM_NONE) {
-		csum = csum_and_copy_from_user(from, skb_put(skb, copy),
-				       copy, 0, &err);
-		if (!err) {
-			skb->csum = csum_block_add(skb->csum, csum, off);
-			return 0;
-		}
-	} else {
-		if (!copy_from_user(skb_put(skb, copy), from, copy))
-			return 0;
-	}
-
-	__skb_trim(skb, off);
-	return -EFAULT;
-}
-
 static inline int select_size(struct sock *sk, struct tcp_opt *tp)
 {
 	int tmp = tp->mss_cache_std;
@@ -1138,7 +1091,7 @@ int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 
 				/* Time to copy data. We are close to
 				 * the end! */
-				err = tcp_copy_to_page(sk, from, skb, page,
+				err = skb_copy_to_page(sk, from, skb, page,
 						       off, copy);
 				if (err) {
 					/* If this page was new, give it to the

net/ipv4/tcp_output.c

@@ -354,70 +354,6 @@ void tcp_push_one(struct sock *sk, unsigned cur_mss)
 	}
 }
 
-/* Split fragmented skb to two parts at length len. */
-
-static void skb_split(struct sk_buff *skb, struct sk_buff *skb1, u32 len)
-{
-	int i;
-	int pos = skb_headlen(skb);
-
-	if (len < pos) {
-		/* Split line is inside header. */
-		memcpy(skb_put(skb1, pos-len), skb->data + len, pos-len);
-
-		/* And move data appendix as is. */
-		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
-			skb_shinfo(skb1)->frags[i] = skb_shinfo(skb)->frags[i];
-
-		skb_shinfo(skb1)->nr_frags = skb_shinfo(skb)->nr_frags;
-		skb_shinfo(skb)->nr_frags = 0;
-
-		skb1->data_len = skb->data_len;
-		skb1->len += skb1->data_len;
-		skb->data_len = 0;
-		skb->len = len;
-		skb->tail = skb->data+len;
-	} else {
-		int k = 0;
-		int nfrags = skb_shinfo(skb)->nr_frags;
-
-		/* Second chunk has no header, nothing to copy. */
-
-		skb_shinfo(skb)->nr_frags = 0;
-		skb1->len = skb1->data_len = skb->len - len;
-		skb->len = len;
-		skb->data_len = len - pos;
-
-		for (i=0; i<nfrags; i++) {
-			int size = skb_shinfo(skb)->frags[i].size;
-			if (pos + size > len) {
-				skb_shinfo(skb1)->frags[k] = skb_shinfo(skb)->frags[i];
-
-				if (pos < len) {
-					/* Split frag.
-					 * We have to variants in this case:
-					 * 1. Move all the frag to the second
-					 *    part, if it is possible. F.e.
-					 *    this approach is mandatory for TUX,
-					 *    where splitting is expensive.
-					 * 2. Split is accurately. We make this.
-					 */
-					get_page(skb_shinfo(skb)->frags[i].page);
-					skb_shinfo(skb1)->frags[0].page_offset += (len-pos);
-					skb_shinfo(skb1)->frags[0].size -= (len-pos);
-					skb_shinfo(skb)->frags[i].size = len-pos;
-					skb_shinfo(skb)->nr_frags++;
-				}
-				k++;
-			} else {
-				skb_shinfo(skb)->nr_frags++;
-			}
-			pos += size;
-		}
-		skb_shinfo(skb1)->nr_frags = k;
-	}
-}
-
 /* Function to create two new TCP segments.  Shrinks the given segment
  * to the specified size and appends a new segment with the rest of the
  * packet to the list.  This won't be called frequently, I hope. 

net/ipv6/icmp.c

@@ -55,7 +55,7 @@
 #include <net/sock.h>
 
 #include <net/ipv6.h>
-#include <net/checksum.h>
+#include <net/ip6_checksum.h>
 #include <net/protocol.h>
 #include <net/raw.h>
 #include <net/rawv6.h>

net/ipv6/mcast.c

@@ -60,7 +60,7 @@
 #include <net/addrconf.h>
 #include <net/ip6_route.h>
 
-#include <net/checksum.h>
+#include <net/ip6_checksum.h>
 
 /* Set to 3 to get tracing... */
 #define MCAST_DEBUG 2

net/ipv6/ndisc.c

@@ -77,7 +77,7 @@
 #include <net/icmp.h>
 
 #include <net/flow.h>
-#include <net/checksum.h>
+#include <net/ip6_checksum.h>
 #include <linux/proc_fs.h>
 
 #include <linux/netfilter.h>

net/ipv6/raw.c

@@ -35,6 +35,7 @@
 #include <asm/uaccess.h>
 #include <asm/ioctls.h>
 
+#include <net/ip.h>
 #include <net/sock.h>
 #include <net/snmp.h>
 
@@ -42,6 +43,7 @@
 #include <net/ndisc.h>
 #include <net/protocol.h>
 #include <net/ip6_route.h>
+#include <net/ip6_checksum.h>
 #include <net/addrconf.h>
 #include <net/transp_v6.h>
 #include <net/udp.h>

net/ipv6/tcp_ipv6.c

@@ -51,6 +51,7 @@
 #include <net/transp_v6.h>
 #include <net/addrconf.h>
 #include <net/ip6_route.h>
+#include <net/ip6_checksum.h>
 #include <net/inet_ecn.h>
 #include <net/protocol.h>
 #include <net/xfrm.h>

net/ipv6/udp.c

@@ -51,7 +51,7 @@
 #include <net/udp.h>
 #include <net/inet_common.h>
 
-#include <net/checksum.h>
+#include <net/ip6_checksum.h>
 #include <net/xfrm.h>
 
 #include <linux/proc_fs.h>