Merge bk://kernel.bkbits.net/acme/net-2.5

into nuts.ninka.net:/home/davem/src/BK/net-2.5

39 files changed, 700 insertions, 738 deletions

diff --git a/include/linux/netfilter_ipv4/ip_tables.h b/include/linux/netfilter_ipv4/ip_tables.h
index d2a7f4b40ccd..fb557e487797 100644
--- a/include/linux/netfilter_ipv4/ip_tables.h
+++ b/include/linux/netfilter_ipv4/ip_tables.h
@@ -347,13 +347,14 @@ struct ipt_match
 
 	/* Return true or false: return FALSE and set *hotdrop = 1 to
            force immediate packet drop. */
+	/* Arguments changed since 2.4, as this must now handle
+           non-linear skbs, using skb_copy_bits and
+           skb_ip_make_writable. */
 	int (*match)(const struct sk_buff *skb,
 		     const struct net_device *in,
 		     const struct net_device *out,
 		     const void *matchinfo,
 		     int offset,
-		     const void *hdr,
-		     u_int16_t datalen,
 		     int *hotdrop);
 
 	/* Called when user tries to insert an entry of this type. */
@@ -367,7 +368,7 @@ struct ipt_match
 	/* Called when entry of this type deleted. */
 	void (*destroy)(void *matchinfo, unsigned int matchinfosize);
 
-	/* Set this to THIS_MODULE if you are a module, otherwise NULL */
+	/* Set this to THIS_MODULE. */
 	struct module *me;
 };
 
@@ -378,14 +379,6 @@ struct ipt_target
 
 	const char name[IPT_FUNCTION_MAXNAMELEN];
 
-	/* Returns verdict. */
-	unsigned int (*target)(struct sk_buff **pskb,
-			       unsigned int hooknum,
-			       const struct net_device *in,
-			       const struct net_device *out,
-			       const void *targinfo,
-			       void *userdata);
-
 	/* Called when user tries to insert an entry of this type:
            hook_mask is a bitmask of hooks from which it can be
            called. */
@@ -399,7 +392,17 @@ struct ipt_target
 	/* Called when entry of this type deleted. */
 	void (*destroy)(void *targinfo, unsigned int targinfosize);
 
-	/* Set this to THIS_MODULE if you are a module, otherwise NULL */
+	/* Returns verdict.  Argument order changed since 2.4, as this
+           must now handle non-linear skbs, using skb_copy_bits and
+           skb_ip_make_writable. */
+	unsigned int (*target)(struct sk_buff **pskb,
+			       const struct net_device *in,
+			       const struct net_device *out,
+			       unsigned int hooknum,
+			       const void *targinfo,
+			       void *userdata);
+
+	/* Set this to THIS_MODULE. */
 	struct module *me;
 };
 
@@ -429,7 +432,7 @@ struct ipt_table
 	/* Man behind the curtain... */
 	struct ipt_table_info *private;
 
-	/* Set this to THIS_MODULE if you are a module, otherwise NULL */
+	/* Set to THIS_MODULE. */
 	struct module *me;
 };
 
diff --git a/include/net/transp_v6.h b/include/net/transp_v6.h
index e27d15ea2f18..8b075ab7a26c 100644
--- a/include/net/transp_v6.h
+++ b/include/net/transp_v6.h
@@ -16,7 +16,6 @@ extern struct proto tcpv6_prot;
 struct flowi;
 
 /* extention headers */
-extern void				ipv6_hopopts_init(void);
 extern void				ipv6_rthdr_init(void);
 extern void				ipv6_frag_init(void);
 extern void				ipv6_nodata_init(void);
diff --git a/net/core/dev.c b/net/core/dev.c
index d6d458ec7e4a..4a6c784220ef 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2863,9 +2863,6 @@ int unregister_netdevice(struct net_device *dev)
 
 extern void net_device_init(void);
 extern void ip_auto_config(void);
-#ifdef CONFIG_NET_DIVERT
-extern void dv_init(void);
-#endif /* CONFIG_NET_DIVERT */
 
 
 /*
@@ -2889,10 +2886,6 @@ static int __init net_dev_init(void)
 	for (i = 0; i < 16; i++) 
 		INIT_LIST_HEAD(&ptype_base[i]);
 
-#ifdef CONFIG_NET_DIVERT
-	dv_init();
-#endif /* CONFIG_NET_DIVERT */
-
 	/*
 	 *	Initialise the packet receive queues.
 	 */
diff --git a/net/core/dst.c b/net/core/dst.c
index 293a6e4987a1..02d61283873a 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -123,6 +123,7 @@ void * dst_alloc(struct dst_ops * ops)
 	if (!dst)
 		return NULL;
 	memset(dst, 0, ops->entry_size);
+	atomic_set(&dst->__refcnt, 0);
 	dst->ops = ops;
 	dst->lastuse = jiffies;
 	dst->path = dst;
diff --git a/net/core/dv.c b/net/core/dv.c
index d2b2920312d1..d8ce4366f667 100644
--- a/net/core/dv.c
+++ b/net/core/dv.c
@@ -40,11 +40,12 @@
 
 const char sysctl_divert_version[32]="0.46";	/* Current version */
 
-int __init dv_init(void)
+static int __init dv_init(void)
 {
 	printk(KERN_INFO "NET4: Frame Diverter %s\n", sysctl_divert_version);
 	return 0;
 }
+module_init(dv_init);
 
 /*
  * Allocate a divert_blk for a device. This must be an ethernet nic.
diff --git a/net/ipv4/netfilter/ip_nat_rule.c b/net/ipv4/netfilter/ip_nat_rule.c
index e994863bedc5..d6d14ad65d46 100644
--- a/net/ipv4/netfilter/ip_nat_rule.c
+++ b/net/ipv4/netfilter/ip_nat_rule.c
@@ -111,9 +111,9 @@ static struct ipt_table nat_table = {
 
 /* Source NAT */
 static unsigned int ipt_snat_target(struct sk_buff **pskb,
-				    unsigned int hooknum,
 				    const struct net_device *in,
 				    const struct net_device *out,
+				    unsigned int hooknum,
 				    const void *targinfo,
 				    void *userinfo)
 {
@@ -132,9 +132,9 @@ static unsigned int ipt_snat_target(struct sk_buff **pskb,
 }
 
 static unsigned int ipt_dnat_target(struct sk_buff **pskb,
-				    unsigned int hooknum,
 				    const struct net_device *in,
 				    const struct net_device *out,
+				    unsigned int hooknum,
 				    const void *targinfo,
 				    void *userinfo)
 {
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index d89effc16d0b..9a218ac068e2 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -214,9 +214,9 @@ ip_checkentry(const struct ipt_ip *ip)
 
 static unsigned int
 ipt_error(struct sk_buff **pskb,
-	  unsigned int hooknum,
 	  const struct net_device *in,
 	  const struct net_device *out,
+	  unsigned int hooknum,
 	  const void *targinfo,
 	  void *userinfo)
 {
@@ -232,13 +232,10 @@ int do_match(struct ipt_entry_match *m,
 	     const struct net_device *in,
 	     const struct net_device *out,
 	     int offset,
-	     const void *hdr,
-	     u_int16_t datalen,
 	     int *hotdrop)
 {
 	/* Stop iteration if it doesn't match */
-	if (!m->u.kernel.match->match(skb, in, out, m->data,
-				      offset, hdr, datalen, hotdrop))
+	if (!m->u.kernel.match->match(skb, in, out, m->data, offset, hotdrop))
 		return 1;
 	else
 		return 0;
@@ -262,7 +259,6 @@ ipt_do_table(struct sk_buff **pskb,
 	static const char nulldevname[IFNAMSIZ] = { 0 };
 	u_int16_t offset;
 	struct iphdr *ip;
-	void *protohdr;
 	u_int16_t datalen;
 	int hotdrop = 0;
 	/* Initializing verdict to NF_DROP keeps gcc happy. */
@@ -271,13 +267,8 @@ ipt_do_table(struct sk_buff **pskb,
 	void *table_base;
 	struct ipt_entry *e, *back;
 
-	/* FIXME: Push down to extensions --RR */
-	if (skb_is_nonlinear(*pskb) && skb_linearize(*pskb, GFP_ATOMIC) != 0)
-		return NF_DROP;
-
 	/* Initialization */
 	ip = (*pskb)->nh.iph;
-	protohdr = (u_int32_t *)ip + ip->ihl;
 	datalen = (*pskb)->len - ip->ihl * 4;
 	indev = in ? in->name : nulldevname;
 	outdev = out ? out->name : nulldevname;
@@ -320,8 +311,7 @@ ipt_do_table(struct sk_buff **pskb,
 
 			if (IPT_MATCH_ITERATE(e, do_match,
 					      *pskb, in, out,
-					      offset, protohdr,
-					      datalen, &hotdrop) != 0)
+					      offset, &hotdrop) != 0)
 				goto no_match;
 
 			ADD_COUNTER(e->counters, ntohs(ip->tot_len), 1);
@@ -364,8 +354,8 @@ ipt_do_table(struct sk_buff **pskb,
 					= 0xeeeeeeec;
 #endif
 				verdict = t->u.kernel.target->target(pskb,
-								     hook,
 								     in, out,
+								     hook,
 								     t->data,
 								     userdata);
 
@@ -382,7 +372,6 @@ ipt_do_table(struct sk_buff **pskb,
 #endif
 				/* Target might have changed stuff. */
 				ip = (*pskb)->nh.iph;
-				protohdr = (u_int32_t *)ip + ip->ihl;
 				datalen = (*pskb)->len - ip->ihl * 4;
 
 				if (verdict == IPT_CONTINUE)
@@ -1458,22 +1447,24 @@ port_match(u_int16_t min, u_int16_t max, u_int16_t port, int invert)
 
 static int
 tcp_find_option(u_int8_t option,
-		const struct tcphdr *tcp,
-		u_int16_t datalen,
+		const struct sk_buff *skb,
+		unsigned int optlen,
 		int invert,
 		int *hotdrop)
 {
-	unsigned int i = sizeof(struct tcphdr);
-	const u_int8_t *opt = (u_int8_t *)tcp;
+	/* tcp.doff is only 4 bits, ie. max 15 * 4 bytes */
+	char opt[60 - sizeof(struct tcphdr)];
+	unsigned int i;
 
 	duprintf("tcp_match: finding option\n");
 	/* If we don't have the whole header, drop packet. */
-	if (tcp->doff * 4 > datalen) {
+	if (skb_copy_bits(skb, skb->nh.iph->ihl*4 + sizeof(struct tcphdr),
+			  opt, optlen) < 0) {
 		*hotdrop = 1;
 		return 0;
 	}
 
-	while (i < tcp->doff * 4) {
+	for (i = 0; i < optlen; ) {
 		if (opt[i] == option) return !invert;
 		if (opt[i] < 2) i++;
 		else i += opt[i+1]?:1;
@@ -1488,25 +1479,29 @@ tcp_match(const struct sk_buff *skb,
 	  const struct net_device *out,
 	  const void *matchinfo,
 	  int offset,
-	  const void *hdr,
-	  u_int16_t datalen,
 	  int *hotdrop)
 {
-	const struct tcphdr *tcp = hdr;
+	struct tcphdr tcph;
 	const struct ipt_tcp *tcpinfo = matchinfo;
 
-	/* To quote Alan:
-
-	   Don't allow a fragment of TCP 8 bytes in. Nobody normal
-	   causes this. Its a cracker trying to break in by doing a
-	   flag overwrite to pass the direction checks.
-	*/
+	if (offset) {
+		/* To quote Alan:
 
-	if (offset == 1) {
-		duprintf("Dropping evil TCP offset=1 frag.\n");
-		*hotdrop = 1;
+		   Don't allow a fragment of TCP 8 bytes in. Nobody normal
+		   causes this. Its a cracker trying to break in by doing a
+		   flag overwrite to pass the direction checks.
+		*/
+		if (offset == 1) {
+			duprintf("Dropping evil TCP offset=1 frag.\n");
+			*hotdrop = 1;
+		}
+		/* Must not be a fragment. */
 		return 0;
-	} else if (offset == 0 && datalen < sizeof(struct tcphdr)) {
+	}
+
+#define FWINVTCP(bool,invflg) ((bool) ^ !!(tcpinfo->invflags & invflg))
+
+	if (skb_copy_bits(skb, skb->nh.iph->ihl*4, &tcph, sizeof(tcph)) < 0) {
 		/* We've been asked to examine this packet, and we
 		   can't.  Hence, no choice but to drop. */
 		duprintf("Dropping evil TCP offset=0 tinygram.\n");
@@ -1514,27 +1509,24 @@ tcp_match(const struct sk_buff *skb,
 		return 0;
 	}
 
-	/* FIXME: Try tcp doff >> packet len against various stacks --RR */
-
-#define FWINVTCP(bool,invflg) ((bool) ^ !!(tcpinfo->invflags & invflg))
-
-	/* Must not be a fragment. */
-	return !offset
-		&& port_match(tcpinfo->spts[0], tcpinfo->spts[1],
-			      ntohs(tcp->source),
-			      !!(tcpinfo->invflags & IPT_TCP_INV_SRCPT))
-		&& port_match(tcpinfo->dpts[0], tcpinfo->dpts[1],
-			      ntohs(tcp->dest),
-			      !!(tcpinfo->invflags & IPT_TCP_INV_DSTPT))
-		&& FWINVTCP((((unsigned char *)tcp)[13]
-			     & tcpinfo->flg_mask)
-			    == tcpinfo->flg_cmp,
-			    IPT_TCP_INV_FLAGS)
-		&& (!tcpinfo->option
-		    || tcp_find_option(tcpinfo->option, tcp, datalen,
-				       tcpinfo->invflags
-				       & IPT_TCP_INV_OPTION,
-				       hotdrop));
+	if (!port_match(tcpinfo->spts[0], tcpinfo->spts[1],
+			ntohs(tcph.source),
+			!!(tcpinfo->invflags & IPT_TCP_INV_SRCPT)))
+		return 0;
+	if (!port_match(tcpinfo->dpts[0], tcpinfo->dpts[1],
+			ntohs(tcph.dest),
+			!!(tcpinfo->invflags & IPT_TCP_INV_DSTPT)))
+		return 0;
+	if (!FWINVTCP((((unsigned char *)&tcph)[13] & tcpinfo->flg_mask)
+		      == tcpinfo->flg_cmp,
+		      IPT_TCP_INV_FLAGS))
+		return 0;
+	if (tcpinfo->option &&
+	    !tcp_find_option(tcpinfo->option, skb, tcph.doff*4 - sizeof(tcph),
+			     tcpinfo->invflags & IPT_TCP_INV_OPTION,
+			     hotdrop))
+		return 0;
+	return 1;
 }
 
 /* Called when user tries to insert an entry of this type. */
@@ -1560,14 +1552,16 @@ udp_match(const struct sk_buff *skb,
 	  const struct net_device *out,
 	  const void *matchinfo,
 	  int offset,
-	  const void *hdr,
-	  u_int16_t datalen,
 	  int *hotdrop)
 {
-	const struct udphdr *udp = hdr;
+	struct udphdr udph;
 	const struct ipt_udp *udpinfo = matchinfo;
 
-	if (offset == 0 && datalen < sizeof(struct udphdr)) {
+	/* Must not be a fragment. */
+	if (offset)
+		return 0;
+
+	if (skb_copy_bits(skb, skb->nh.iph->ihl*4, &udph, sizeof(udph)) < 0) {
 		/* We've been asked to examine this packet, and we
 		   can't.  Hence, no choice but to drop. */
 		duprintf("Dropping evil UDP tinygram.\n");
@@ -1575,13 +1569,11 @@ udp_match(const struct sk_buff *skb,
 		return 0;
 	}
 
-	/* Must not be a fragment. */
-	return !offset
-		&& port_match(udpinfo->spts[0], udpinfo->spts[1],
-			      ntohs(udp->source),
-			      !!(udpinfo->invflags & IPT_UDP_INV_SRCPT))
+	return port_match(udpinfo->spts[0], udpinfo->spts[1],
+			  ntohs(udph.source),
+			  !!(udpinfo->invflags & IPT_UDP_INV_SRCPT))
 		&& port_match(udpinfo->dpts[0], udpinfo->dpts[1],
-			      ntohs(udp->dest),
+			      ntohs(udph.dest),
 			      !!(udpinfo->invflags & IPT_UDP_INV_DSTPT));
 }
 
@@ -1631,14 +1623,16 @@ icmp_match(const struct sk_buff *skb,
 	   const struct net_device *out,
 	   const void *matchinfo,
 	   int offset,
-	   const void *hdr,
-	   u_int16_t datalen,
 	   int *hotdrop)
 {
-	const struct icmphdr *icmp = hdr;
+	struct icmphdr icmph;
 	const struct ipt_icmp *icmpinfo = matchinfo;
 
-	if (offset == 0 && datalen < 2) {
+	/* Must not be a fragment. */
+	if (offset)
+		return 0;
+
+	if (skb_copy_bits(skb, skb->nh.iph->ihl*4, &icmph, sizeof(icmph)) < 0){
 		/* We've been asked to examine this packet, and we
 		   can't.  Hence, no choice but to drop. */
 		duprintf("Dropping evil ICMP tinygram.\n");
@@ -1646,13 +1640,11 @@ icmp_match(const struct sk_buff *skb,
 		return 0;
 	}
 
-	/* Must not be a fragment. */
-	return !offset
-		&& icmp_type_code_match(icmpinfo->type,
-					icmpinfo->code[0],
-					icmpinfo->code[1],
-					icmp->type, icmp->code,
-					!!(icmpinfo->invflags&IPT_ICMP_INV));
+	return icmp_type_code_match(icmpinfo->type,
+				    icmpinfo->code[0],
+				    icmpinfo->code[1],
+				    icmph.type, icmph.code,
+				    !!(icmpinfo->invflags&IPT_ICMP_INV));
 }
 
 /* Called when user tries to insert an entry of this type. */
diff --git a/net/ipv4/netfilter/ipt_DSCP.c b/net/ipv4/netfilter/ipt_DSCP.c
index 0b7827279481..ddd16bb681eb 100644
--- a/net/ipv4/netfilter/ipt_DSCP.c
+++ b/net/ipv4/netfilter/ipt_DSCP.c
@@ -23,37 +23,31 @@ MODULE_LICENSE("GPL");
 
 static unsigned int
 target(struct sk_buff **pskb,
-       unsigned int hooknum,
        const struct net_device *in,
        const struct net_device *out,
+       unsigned int hooknum,
        const void *targinfo,
        void *userinfo)
 {
-	struct iphdr *iph = (*pskb)->nh.iph;
 	const struct ipt_DSCP_info *dinfo = targinfo;
 	u_int8_t sh_dscp = ((dinfo->dscp << IPT_DSCP_SHIFT) & IPT_DSCP_MASK);
 
 
-	if ((iph->tos & IPT_DSCP_MASK) != sh_dscp) {
+	if (((*pskb)->nh.iph->tos & IPT_DSCP_MASK) != sh_dscp) {
 		u_int16_t diffs[2];
 
-		/* raw socket (tcpdump) may have clone of incoming
-		 * skb: don't disturb it --RR */
-		if (skb_cloned(*pskb) && !(*pskb)->sk) {
-			struct sk_buff *nskb = skb_copy(*pskb, GFP_ATOMIC);
-			if (!nskb)
-				return NF_DROP;
-			kfree_skb(*pskb);
-			*pskb = nskb;
-			iph = (*pskb)->nh.iph;
-		}
-
-		diffs[0] = htons(iph->tos) ^ 0xFFFF;
-		iph->tos = (iph->tos & ~IPT_DSCP_MASK) | sh_dscp;
-		diffs[1] = htons(iph->tos);
-		iph->check = csum_fold(csum_partial((char *)diffs,
-		                                    sizeof(diffs),
-		                                    iph->check^0xFFFF));
+		if (!skb_ip_make_writable(pskb, sizeof(struct iphdr)))
+			return NF_DROP;
+
+		diffs[0] = htons((*pskb)->nh.iph->tos) ^ 0xFFFF;
+		(*pskb)->nh.iph->tos = ((*pskb)->nh.iph->tos & ~IPT_DSCP_MASK)
+			| sh_dscp;
+		diffs[1] = htons((*pskb)->nh.iph->tos);
+		(*pskb)->nh.iph->check
+			= csum_fold(csum_partial((char *)diffs,
+						 sizeof(diffs),
+						 (*pskb)->nh.iph->check
+						 ^ 0xFFFF));
 		(*pskb)->nfcache |= NFC_ALTERED;
 	}
 	return IPT_CONTINUE;
diff --git a/net/ipv4/netfilter/ipt_ECN.c b/net/ipv4/netfilter/ipt_ECN.c
index 02fa43bc08b8..6930e6240fdf 100644
--- a/net/ipv4/netfilter/ipt_ECN.c
+++ b/net/ipv4/netfilter/ipt_ECN.c
@@ -19,105 +19,85 @@
 MODULE_LICENSE("GPL");
 
 /* set ECT codepoint from IP header.
- * 	return 0 in case there was no ECT codepoint
- * 	return 1 in case ECT codepoint has been overwritten
- * 	return < 0 in case there was error */
+ * 	return 0 if there was an error. */
 static inline int
-set_ect_ip(struct sk_buff **pskb, struct iphdr *iph,
-	   const struct ipt_ECN_info *einfo)
+set_ect_ip(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
 {
-	if ((iph->tos & IPT_ECN_IP_MASK)
+	if (((*pskb)->nh.iph->tos & IPT_ECN_IP_MASK)
 	    != (einfo->ip_ect & IPT_ECN_IP_MASK)) {
 		u_int16_t diffs[2];
 
-		/* raw socket (tcpdump) may have clone of incoming
-		 * skb: don't disturb it --RR */
-		if (skb_cloned(*pskb) && !(*pskb)->sk) {
-			struct sk_buff *nskb = skb_copy(*pskb, GFP_ATOMIC);
-			if (!nskb)
-				return NF_DROP;
-			kfree_skb(*pskb);
-			*pskb = nskb;
-			iph = (*pskb)->nh.iph;
-		}
-
-		diffs[0] = htons(iph->tos) ^ 0xFFFF;
-		iph->tos = iph->tos & ~IPT_ECN_IP_MASK;
-		iph->tos = iph->tos | (einfo->ip_ect & IPT_ECN_IP_MASK);
-		diffs[1] = htons(iph->tos);
-		iph->check = csum_fold(csum_partial((char *)diffs,
-		                                    sizeof(diffs),
-		                                    iph->check^0xFFFF));
+		if (!skb_ip_make_writable(pskb, sizeof(struct iphdr)))
+			return 0;
+
+		diffs[0] = htons((*pskb)->nh.iph->tos) ^ 0xFFFF;
+		(*pskb)->nh.iph->tos &= ~IPT_ECN_IP_MASK;
+		(*pskb)->nh.iph->tos |= (einfo->ip_ect & IPT_ECN_IP_MASK);
+		diffs[1] = htons((*pskb)->nh.iph->tos);
+		(*pskb)->nh.iph->check
+			= csum_fold(csum_partial((char *)diffs,
+						 sizeof(diffs),
+						 (*pskb)->nh.iph->check
+						 ^0xFFFF));
 		(*pskb)->nfcache |= NFC_ALTERED;
-
-		return 1;
 	} 
-	return 0;
+	return 1;
 }
 
+/* Return 0 if there was an error. */
 static inline int
-set_ect_tcp(struct sk_buff **pskb, struct iphdr *iph,
-	    const struct ipt_ECN_info *einfo)
+set_ect_tcp(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
 {
-
-	struct tcphdr *tcph = (void *) iph + iph->ihl * 4;
-	u_int16_t *tcpflags = (u_int16_t *)tcph + 6;
+	struct tcphdr tcph;
 	u_int16_t diffs[2];
 
-	/* raw socket (tcpdump) may have clone of incoming
-	 * skb: don't disturb it --RR */
-	if (skb_cloned(*pskb) && !(*pskb)->sk) {
-		struct sk_buff *nskb = skb_copy(*pskb, GFP_ATOMIC);
-		if (!nskb)
-			return NF_DROP;
-		kfree_skb(*pskb);
-		*pskb = nskb;
-		iph = (*pskb)->nh.iph;
-	}
+	/* Not enought header? */
+	if (skb_copy_bits(*pskb, (*pskb)->nh.iph->ihl*4, &tcph, sizeof(tcph))
+	    < 0)
+		return 0;
 
-	diffs[0] = *tcpflags;
+	diffs[0] = ((u_int16_t *)&tcph)[6];
+	if (einfo->operation & IPT_ECN_OP_SET_ECE)
+		tcph.ece = einfo->proto.tcp.ece;
 
-	if (einfo->operation & IPT_ECN_OP_SET_ECE
-	    && tcph->ece != einfo->proto.tcp.ece) {
-		tcph->ece = einfo->proto.tcp.ece;
-	}
+	if (einfo->operation & IPT_ECN_OP_SET_CWR)
+		tcph.cwr = einfo->proto.tcp.cwr;
+	diffs[1] = ((u_int16_t *)&tcph)[6];
 
-	if (einfo->operation & IPT_ECN_OP_SET_CWR
-	    && tcph->cwr != einfo->proto.tcp.cwr) {
-		tcph->cwr = einfo->proto.tcp.cwr;
-	}
-	
-	if (diffs[0] != *tcpflags) {
+	/* Only mangle if it's changed. */
+	if (diffs[0] != diffs[1]) {
 		diffs[0] = diffs[0] ^ 0xFFFF;
-		diffs[1] = *tcpflags;
-		tcph->check = csum_fold(csum_partial((char *)diffs,
+		if (!skb_ip_make_writable(pskb,
+					  (*pskb)->nh.iph->ihl*4+sizeof(tcph)))
+			return 0;
+		tcph.check = csum_fold(csum_partial((char *)diffs,
 		                                    sizeof(diffs),
-		                                    tcph->check^0xFFFF));
+		                                    tcph.check^0xFFFF));
+		memcpy((*pskb)->data + (*pskb)->nh.iph->ihl*4,
+		       &tcph, sizeof(tcph));
 		(*pskb)->nfcache |= NFC_ALTERED;
-
-		return 1;
 	}
-
-	return 0;
+	return 1;
 }
 
 static unsigned int
 target(struct sk_buff **pskb,
-       unsigned int hooknum,
        const struct net_device *in,
        const struct net_device *out,
+       unsigned int hooknum,
        const void *targinfo,
        void *userinfo)
 {
-	struct iphdr *iph = (*pskb)->nh.iph;
 	const struct ipt_ECN_info *einfo = targinfo;
 
 	if (einfo->operation & IPT_ECN_OP_SET_IP)
-		set_ect_ip(pskb, iph, einfo);
+		if (!set_ect_ip(pskb, einfo))
+			return NF_DROP;
 
 	if (einfo->operation & (IPT_ECN_OP_SET_ECE | IPT_ECN_OP_SET_CWR)
-	    && iph->protocol == IPPROTO_TCP)
-		set_ect_tcp(pskb, iph, einfo);
+	    && (*pskb)->nh.iph->protocol == IPPROTO_TCP)
+		if (!set_ect_tcp(pskb, einfo))
+			return NF_DROP;
 
 	return IPT_CONTINUE;
 }
diff --git a/net/ipv4/netfilter/ipt_LOG.c b/net/ipv4/netfilter/ipt_LOG.c
index 2b0dca70ddc7..56c5238a6129 100644
--- a/net/ipv4/netfilter/ipt_LOG.c
+++ b/net/ipv4/netfilter/ipt_LOG.c
@@ -29,127 +29,151 @@ static spinlock_t log_lock = SPIN_LOCK_UNLOCKED;
 
 /* One level of recursion won't kill us */
 static void dump_packet(const struct ipt_log_info *info,
-			struct iphdr *iph, unsigned int len, int recurse)
+			const struct sk_buff *skb,
+			unsigned int iphoff)
 {
-	void *protoh = (u_int32_t *)iph + iph->ihl;
-	unsigned int datalen = len - iph->ihl * 4;
+	struct iphdr iph;
+
+	if (skb_copy_bits(skb, iphoff, &iph, sizeof(iph)) < 0) {
+		printk("TRUNCATED");
+		return;
+	}
 
 	/* Important fields:
 	 * TOS, len, DF/MF, fragment offset, TTL, src, dst, options. */
 	/* Max length: 40 "SRC=255.255.255.255 DST=255.255.255.255 " */
 	printk("SRC=%u.%u.%u.%u DST=%u.%u.%u.%u ",
-	       NIPQUAD(iph->saddr), NIPQUAD(iph->daddr));
+	       NIPQUAD(iph.saddr), NIPQUAD(iph.daddr));
 
 	/* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */
 	printk("LEN=%u TOS=0x%02X PREC=0x%02X TTL=%u ID=%u ",
-	       ntohs(iph->tot_len), iph->tos & IPTOS_TOS_MASK,
-	       iph->tos & IPTOS_PREC_MASK, iph->ttl, ntohs(iph->id));
+	       ntohs(iph.tot_len), iph.tos & IPTOS_TOS_MASK,
+	       iph.tos & IPTOS_PREC_MASK, iph.ttl, ntohs(iph.id));
 
 	/* Max length: 6 "CE DF MF " */
-	if (ntohs(iph->frag_off) & IP_CE)
+	if (ntohs(iph.frag_off) & IP_CE)
 		printk("CE ");
-	if (ntohs(iph->frag_off) & IP_DF)
+	if (ntohs(iph.frag_off) & IP_DF)
 		printk("DF ");
-	if (ntohs(iph->frag_off) & IP_MF)
+	if (ntohs(iph.frag_off) & IP_MF)
 		printk("MF ");
 
 	/* Max length: 11 "FRAG:65535 " */
-	if (ntohs(iph->frag_off) & IP_OFFSET)
-		printk("FRAG:%u ", ntohs(iph->frag_off) & IP_OFFSET);
+	if (ntohs(iph.frag_off) & IP_OFFSET)
+		printk("FRAG:%u ", ntohs(iph.frag_off) & IP_OFFSET);
 
 	if ((info->logflags & IPT_LOG_IPOPT)
-	    && iph->ihl * 4 != sizeof(struct iphdr)) {
-		unsigned int i;
+	    && iph.ihl * 4 != sizeof(struct iphdr)) {
+		unsigned char opt[4 * 15 - sizeof(struct iphdr)];
+		unsigned int i, optsize;
+
+		optsize = iph.ihl * 4 - sizeof(struct iphdr);
+		if (skb_copy_bits(skb, iphoff+sizeof(iph), opt, optsize) < 0) {
+			printk("TRUNCATED");
+			return;
+		}
 
 		/* Max length: 127 "OPT (" 15*4*2chars ") " */
 		printk("OPT (");
-		for (i = sizeof(struct iphdr); i < iph->ihl * 4; i++)
-			printk("%02X", ((u_int8_t *)iph)[i]);
+		for (i = 0; i < optsize; i++)
+			printk("%02X", opt[i]);
 		printk(") ");
 	}
 
-	switch (iph->protocol) {
+	switch (iph.protocol) {
 	case IPPROTO_TCP: {
-		struct tcphdr *tcph = protoh;
+		struct tcphdr tcph;
 
 		/* Max length: 10 "PROTO=TCP " */
 		printk("PROTO=TCP ");
 
-		if (ntohs(iph->frag_off) & IP_OFFSET)
+		if (ntohs(iph.frag_off) & IP_OFFSET)
 			break;
 
 		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
-		if (datalen < sizeof (*tcph)) {
-			printk("INCOMPLETE [%u bytes] ", datalen);
+		if (skb_copy_bits(skb, iphoff+iph.ihl*4, &tcph, sizeof(tcph))
+		    < 0) {
+			printk("INCOMPLETE [%u bytes] ",
+			       skb->len - iphoff - iph.ihl*4);
 			break;
 		}
 
 		/* Max length: 20 "SPT=65535 DPT=65535 " */
 		printk("SPT=%u DPT=%u ",
-		       ntohs(tcph->source), ntohs(tcph->dest));
+		       ntohs(tcph.source), ntohs(tcph.dest));
 		/* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */
 		if (info->logflags & IPT_LOG_TCPSEQ)
 			printk("SEQ=%u ACK=%u ",
-			       ntohl(tcph->seq), ntohl(tcph->ack_seq));
+			       ntohl(tcph.seq), ntohl(tcph.ack_seq));
 		/* Max length: 13 "WINDOW=65535 " */
-		printk("WINDOW=%u ", ntohs(tcph->window));
+		printk("WINDOW=%u ", ntohs(tcph.window));
 		/* Max length: 9 "RES=0x3F " */
-		printk("RES=0x%02x ", (u_int8_t)(ntohl(tcp_flag_word(tcph) & TCP_RESERVED_BITS) >> 22));
+		printk("RES=0x%02x ", (u8)(ntohl(tcp_flag_word(&tcph) & TCP_RESERVED_BITS) >> 22));
 		/* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */
-		if (tcph->cwr)
+		if (tcph.cwr)
 			printk("CWR ");
-		if (tcph->ece)
+		if (tcph.ece)
 			printk("ECE ");
-		if (tcph->urg)
+		if (tcph.urg)
 			printk("URG ");
-		if (tcph->ack)
+		if (tcph.ack)
 			printk("ACK ");
-		if (tcph->psh)
+		if (tcph.psh)
 			printk("PSH ");
-		if (tcph->rst)
+		if (tcph.rst)
 			printk("RST ");
-		if (tcph->syn)
+		if (tcph.syn)
 			printk("SYN ");
-		if (tcph->fin)
+		if (tcph.fin)
 			printk("FIN ");
 		/* Max length: 11 "URGP=65535 " */
-		printk("URGP=%u ", ntohs(tcph->urg_ptr));
+		printk("URGP=%u ", ntohs(tcph.urg_ptr));
 
 		if ((info->logflags & IPT_LOG_TCPOPT)
-		    && tcph->doff * 4 != sizeof(struct tcphdr)) {
-			unsigned int i;
+		    && tcph.doff * 4 != sizeof(struct tcphdr)) {
+			unsigned char opt[4 * 15 - sizeof(struct tcphdr)];
+			unsigned int i, optsize;
+
+			optsize = tcph.doff * 4 - sizeof(struct tcphdr);
+			if (skb_copy_bits(skb, iphoff+iph.ihl*4 + sizeof(tcph),
+					  opt, optsize) < 0) {
+				printk("TRUNCATED");
+				return;
+			}
 
 			/* Max length: 127 "OPT (" 15*4*2chars ") " */
 			printk("OPT (");
-			for (i =sizeof(struct tcphdr); i < tcph->doff * 4; i++)
-				printk("%02X", ((u_int8_t *)tcph)[i]);
+			for (i = 0; i < optsize; i++)
+				printk("%02X", opt[i]);
 			printk(") ");
 		}
 		break;
 	}
 	case IPPROTO_UDP: {
-		struct udphdr *udph = protoh;
+		struct udphdr udph;
 
 		/* Max length: 10 "PROTO=UDP " */
 		printk("PROTO=UDP ");
 
-		if (ntohs(iph->frag_off) & IP_OFFSET)
+		if (ntohs(iph.frag_off) & IP_OFFSET)
 			break;
 
 		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
-		if (datalen < sizeof (*udph)) {
-			printk("INCOMPLETE [%u bytes] ", datalen);
+		if (skb_copy_bits(skb, iphoff+iph.ihl*4, &udph, sizeof(udph))
+		    < 0) {
+			printk("INCOMPLETE [%u bytes] ",
+			       skb->len - iphoff - iph.ihl*4);
 			break;
 		}
 
 		/* Max length: 20 "SPT=65535 DPT=65535 " */
 		printk("SPT=%u DPT=%u LEN=%u ",
-		       ntohs(udph->source), ntohs(udph->dest),
-		       ntohs(udph->len));
+		       ntohs(udph.source), ntohs(udph.dest),
+		       ntohs(udph.len));
 		break;
 	}
 	case IPPROTO_ICMP: {
-		struct icmphdr *icmph = protoh;
+		struct icmphdr icmph;
 		static size_t required_len[NR_ICMP_TYPES+1]
 			= { [ICMP_ECHOREPLY] = 4,
 			    [ICMP_DEST_UNREACH]
@@ -171,89 +195,93 @@ static void dump_packet(const struct ipt_log_info *info,
 		/* Max length: 11 "PROTO=ICMP " */
 		printk("PROTO=ICMP ");
 
-		if (ntohs(iph->frag_off) & IP_OFFSET)
+		if (ntohs(iph.frag_off) & IP_OFFSET)
 			break;
 
 		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
-		if (datalen < 4) {
-			printk("INCOMPLETE [%u bytes] ", datalen);
+		if (skb_copy_bits(skb, iphoff+iph.ihl*4, &icmph, sizeof(icmph))
+		    < 0) {
+			printk("INCOMPLETE [%u bytes] ",
+			       skb->len - iphoff - iph.ihl*4);
 			break;
 		}
 
 		/* Max length: 18 "TYPE=255 CODE=255 " */
-		printk("TYPE=%u CODE=%u ", icmph->type, icmph->code);
+		printk("TYPE=%u CODE=%u ", icmph.type, icmph.code);
 
 		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
-		if (icmph->type <= NR_ICMP_TYPES
-		    && required_len[icmph->type]
-		    && datalen < required_len[icmph->type]) {
-			printk("INCOMPLETE [%u bytes] ", datalen);
+		if (icmph.type <= NR_ICMP_TYPES
+		    && required_len[icmph.type]
+		    && skb->len-iphoff-iph.ihl*4 < required_len[icmph.type]) {
+			printk("INCOMPLETE [%u bytes] ",
+			       skb->len - iphoff - iph.ihl*4);
 			break;
 		}
 
-		switch (icmph->type) {
+		switch (icmph.type) {
 		case ICMP_ECHOREPLY:
 		case ICMP_ECHO:
 			/* Max length: 19 "ID=65535 SEQ=65535 " */
 			printk("ID=%u SEQ=%u ",
-			       ntohs(icmph->un.echo.id),
-			       ntohs(icmph->un.echo.sequence));
+			       ntohs(icmph.un.echo.id),
+			       ntohs(icmph.un.echo.sequence));
 			break;
 
 		case ICMP_PARAMETERPROB:
 			/* Max length: 14 "PARAMETER=255 " */
 			printk("PARAMETER=%u ",
-			       ntohl(icmph->un.gateway) >> 24);
+			       ntohl(icmph.un.gateway) >> 24);
 			break;
 		case ICMP_REDIRECT:
 			/* Max length: 24 "GATEWAY=255.255.255.255 " */
-			printk("GATEWAY=%u.%u.%u.%u ", NIPQUAD(icmph->un.gateway));
+			printk("GATEWAY=%u.%u.%u.%u ",
+			       NIPQUAD(icmph.un.gateway));
 			/* Fall through */
 		case ICMP_DEST_UNREACH:
 		case ICMP_SOURCE_QUENCH:
 		case ICMP_TIME_EXCEEDED:
 			/* Max length: 3+maxlen */
-			if (recurse) {
+			if (!iphoff) { /* Only recurse once. */
 				printk("[");
-				dump_packet(info,
-					    (struct iphdr *)(icmph + 1),
-					    datalen-sizeof(struct icmphdr),
-					    0);
+				dump_packet(info, skb,
+					    iphoff + iph.ihl*4+sizeof(icmph));
 				printk("] ");
 			}
 
 			/* Max length: 10 "MTU=65535 " */
-			if (icmph->type == ICMP_DEST_UNREACH
-			    && icmph->code == ICMP_FRAG_NEEDED)
-				printk("MTU=%u ", ntohs(icmph->un.frag.mtu));
+			if (icmph.type == ICMP_DEST_UNREACH
+			    && icmph.code == ICMP_FRAG_NEEDED)
+				printk("MTU=%u ", ntohs(icmph.un.frag.mtu));
 		}
 		break;
 	}
 	/* Max Length */
 	case IPPROTO_AH:
 	case IPPROTO_ESP: {
-		struct esphdr *esph = protoh;
-		int esp= (iph->protocol==IPPROTO_ESP);
+		struct esphdr esph;
+		int esp = (iph.protocol==IPPROTO_ESP);
 
 		/* Max length: 10 "PROTO=ESP " */
 		printk("PROTO=%s ",esp? "ESP" : "AH");
 
-		if (ntohs(iph->frag_off) & IP_OFFSET)
+		if (ntohs(iph.frag_off) & IP_OFFSET)
 			break;
 
 		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
-		if (datalen < sizeof (*esph)) {
-			printk("INCOMPLETE [%u bytes] ", datalen);
+		if (skb_copy_bits(skb, iphoff+iph.ihl*4, &esph, sizeof(esph))
+		    < 0) {
+			printk("INCOMPLETE [%u bytes] ",
+			       skb->len - iphoff - iph.ihl*4);
 			break;
 		}
 
 		/* Length: 15 "SPI=0xF1234567 " */
-		printk("SPI=0x%x ", ntohl(esph->spi) );
+		printk("SPI=0x%x ", ntohl(esph.spi));
 		break;
 	}
 	/* Max length: 10 "PROTO 255 " */
 	default:
-		printk("PROTO=%u ", iph->protocol);
+		printk("PROTO=%u ", iph.protocol);
 	}
 
 	/* Proto    Max log string length */
@@ -272,13 +300,12 @@ static void dump_packet(const struct ipt_log_info *info,
 
 static unsigned int
 ipt_log_target(struct sk_buff **pskb,
-	       unsigned int hooknum,
 	       const struct net_device *in,
 	       const struct net_device *out,
+	       unsigned int hooknum,
 	       const void *targinfo,
 	       void *userinfo)
 {
-	struct iphdr *iph = (*pskb)->nh.iph;
 	const struct ipt_log_info *loginfo = targinfo;
 	char level_string[4] = "< >";
 
@@ -304,7 +331,8 @@ ipt_log_target(struct sk_buff **pskb,
 	if (in && !out) {
 		/* MAC logging for input chain only. */
 		printk("MAC=");
-		if ((*pskb)->dev && (*pskb)->dev->hard_header_len && (*pskb)->mac.raw != (void*)iph) {
+		if ((*pskb)->dev && (*pskb)->dev->hard_header_len
+		    && (*pskb)->mac.raw != (void*)(*pskb)->nh.iph) {
 			int i;
 			unsigned char *p = (*pskb)->mac.raw;
 			for (i = 0; i < (*pskb)->dev->hard_header_len; i++,p++)
@@ -315,7 +343,7 @@ ipt_log_target(struct sk_buff **pskb,
 			printk(" ");
 	}
 
-	dump_packet(loginfo, iph, (*pskb)->len, 1);
+	dump_packet(loginfo, *pskb, 0);
 	printk("\n");
 	spin_unlock_bh(&log_lock);
 
diff --git a/net/ipv4/netfilter/ipt_MARK.c b/net/ipv4/netfilter/ipt_MARK.c
index 88ee79eee79d..e84b3616c396 100644
--- a/net/ipv4/netfilter/ipt_MARK.c
+++ b/net/ipv4/netfilter/ipt_MARK.c
@@ -9,9 +9,9 @@
 
 static unsigned int
 target(struct sk_buff **pskb,
-       unsigned int hooknum,
        const struct net_device *in,
        const struct net_device *out,
+       unsigned int hooknum,
        const void *targinfo,
        void *userinfo)
 {
diff --git a/net/ipv4/netfilter/ipt_MASQUERADE.c b/net/ipv4/netfilter/ipt_MASQUERADE.c
index 17123f5be547..6f191a380b2b 100644
--- a/net/ipv4/netfilter/ipt_MASQUERADE.c
+++ b/net/ipv4/netfilter/ipt_MASQUERADE.c
@@ -57,9 +57,9 @@ masquerade_check(const char *tablename,
 
 static unsigned int
 masquerade_target(struct sk_buff **pskb,
-		  unsigned int hooknum,
 		  const struct net_device *in,
 		  const struct net_device *out,
+		  unsigned int hooknum,
 		  const void *targinfo,
 		  void *userinfo)
 {
diff --git a/net/ipv4/netfilter/ipt_MIRROR.c b/net/ipv4/netfilter/ipt_MIRROR.c
index 7d4e28a407f1..fcd424bd73b8 100644
--- a/net/ipv4/netfilter/ipt_MIRROR.c
+++ b/net/ipv4/netfilter/ipt_MIRROR.c
@@ -65,18 +65,22 @@ static int route_mirror(struct sk_buff *skb)
 	return 0;
 }
 
-static void
-ip_rewrite(struct sk_buff *skb)
+static int ip_rewrite(struct sk_buff **pskb)
 {
-	struct iphdr *iph = skb->nh.iph;
-	u32 odaddr = iph->saddr;
-	u32 osaddr = iph->daddr;
+	u32 odaddr, osaddr;
 
-	skb->nfcache |= NFC_ALTERED;
+	if (!skb_ip_make_writable(pskb, sizeof(struct iphdr)))
+		return 0;
+
+	odaddr = (*pskb)->nh.iph->saddr;
+	osaddr = (*pskb)->nh.iph->daddr;
+
+	(*pskb)->nfcache |= NFC_ALTERED;
 
 	/* Rewrite IP header */
-	iph->daddr = odaddr;
-	iph->saddr = osaddr;
+	(*pskb)->nh.iph->daddr = odaddr;
+	(*pskb)->nh.iph->saddr = osaddr;
+	return 1;
 }
 
 /* Stolen from ip_finish_output2 */
@@ -100,29 +104,28 @@ static void ip_direct_send(struct sk_buff *skb)
 }
 
 static unsigned int ipt_mirror_target(struct sk_buff **pskb,
-				      unsigned int hooknum,
 				      const struct net_device *in,
 				      const struct net_device *out,
+				      unsigned int hooknum,
 				      const void *targinfo,
 				      void *userinfo)
 {
-	if (((*pskb)->dst != NULL) &&
-	    route_mirror(*pskb)) {
-
-		ip_rewrite(*pskb);
+	if (((*pskb)->dst != NULL) && route_mirror(*pskb)) {
+		if (!ip_rewrite(pskb))
+			return NF_DROP;
 
 		/* If we are not at FORWARD hook (INPUT/PREROUTING),
 		 * the TTL isn't decreased by the IP stack */
 		if (hooknum != NF_IP_FORWARD) {
-			struct iphdr *iph = (*pskb)->nh.iph;
-			if (iph->ttl <= 1) {
+			if ((*pskb)->nh.iph->ttl <= 1) {
 				/* this will traverse normal stack, and 
 				 * thus call conntrack on the icmp packet */
 				icmp_send(*pskb, ICMP_TIME_EXCEEDED, 
 					  ICMP_EXC_TTL, 0);
 				return NF_DROP;
 			}
-			ip_decrease_ttl(iph);
+			/* Made writable by ip_rewrite */
+			ip_decrease_ttl((*pskb)->nh.iph);
 		}
 
 		/* Don't let conntrack code see this packet:
diff --git a/net/ipv4/netfilter/ipt_REDIRECT.c b/net/ipv4/netfilter/ipt_REDIRECT.c
index 133abf5395bf..6556510af361 100644
--- a/net/ipv4/netfilter/ipt_REDIRECT.c
+++ b/net/ipv4/netfilter/ipt_REDIRECT.c
@@ -53,9 +53,9 @@ redirect_check(const char *tablename,
 
 static unsigned int
 redirect_target(struct sk_buff **pskb,
-		unsigned int hooknum,
 		const struct net_device *in,
 		const struct net_device *out,
+		unsigned int hooknum,
 		const void *targinfo,
 		void *userinfo)
 {
diff --git a/net/ipv4/netfilter/ipt_REJECT.c b/net/ipv4/netfilter/ipt_REJECT.c
index f844457fbdff..2582a825f499 100644
--- a/net/ipv4/netfilter/ipt_REJECT.c
+++ b/net/ipv4/netfilter/ipt_REJECT.c
@@ -29,152 +29,140 @@ static void connection_attach(struct sk_buff *new_skb, struct nf_ct_info *nfct)
 	void (*attach)(struct sk_buff *, struct nf_ct_info *);
 
 	/* Avoid module unload race with ip_ct_attach being NULLed out */
-	if (nfct && (attach = ip_ct_attach) != NULL)
+	if (nfct && (attach = ip_ct_attach) != NULL) {
+		mb(); /* Just to be sure: must be read before executing this */
 		attach(new_skb, nfct);
+	}
 }
 
 /* Send RST reply */
-static void send_reset(struct sk_buff *oldskb, int local)
+static unsigned int send_reset(struct sk_buff **pskb, int local)
 {
-	struct sk_buff *nskb;
-	struct tcphdr *otcph, *tcph;
+	struct tcphdr tcph;
 	struct rtable *rt;
-	unsigned int otcplen;
 	u_int16_t tmp_port;
 	u_int32_t tmp_addr;
-	int needs_ack;
-	int hh_len;
+	int needs_ack, hh_len, datalen;
+	struct nf_ct_info *oldnfct;
 
-	/* IP header checks: fragment, too short. */
-	if (oldskb->nh.iph->frag_off & htons(IP_OFFSET)
-	    || oldskb->len < (oldskb->nh.iph->ihl<<2) + sizeof(struct tcphdr))
-		return;
+	/* No RSTs for fragments. */
+	if ((*pskb)->nh.iph->frag_off & htons(IP_OFFSET))
+		return NF_DROP;
 
-	otcph = (struct tcphdr *)((u_int32_t*)oldskb->nh.iph + oldskb->nh.iph->ihl);
-	otcplen = oldskb->len - oldskb->nh.iph->ihl*4;
+	if (skb_copy_bits(*pskb, (*pskb)->nh.iph->ihl*4,
+			  &tcph, sizeof(tcph)) < 0)
+		return NF_DROP;
 
 	/* No RST for RST. */
-	if (otcph->rst)
-		return;
-
-	/* Check checksum. */
-	if (tcp_v4_check(otcph, otcplen, oldskb->nh.iph->saddr,
-			 oldskb->nh.iph->daddr,
-			 csum_partial((char *)otcph, otcplen, 0)) != 0)
-		return;
-
+	if (tcph.rst)
+		return NF_DROP;
 
+	/* FIXME: Check checksum. */
 	{
 		struct flowi fl = { .nl_u = { .ip4_u =
-					      { .daddr = oldskb->nh.iph->saddr,
+					      { .daddr = (*pskb)->nh.iph->saddr,
 						.saddr = (local ?
-							  oldskb->nh.iph->daddr :
+							  (*pskb)->nh.iph->daddr :
 							  0),
-						.tos = RT_TOS(oldskb->nh.iph->tos) } } };
+						.tos = RT_TOS((*pskb)->nh.iph->tos) } } };
 
 		/* Routing: if not headed for us, route won't like source */
 		if (ip_route_output_key(&rt, &fl))
-			return;
-	
+			return NF_DROP;
+
 		hh_len = (rt->u.dst.dev->hard_header_len + 15)&~15;
 	}
 
-
-	/* Copy skb (even if skb is about to be dropped, we can't just
-           clone it because there may be other things, such as tcpdump,
-           interested in it). We also need to expand headroom in case
-	   hh_len of incoming interface < hh_len of outgoing interface */
-	nskb = skb_copy_expand(oldskb, hh_len, skb_tailroom(oldskb),
-			       GFP_ATOMIC);
-	if (!nskb) {
-		dst_release(&rt->u.dst);
-		return;
+	/* We're going to flip the header around, drop options and data. */
+	if (!skb_ip_make_writable(pskb, (*pskb)->nh.iph->ihl*4+sizeof(tcph))) {
+		ip_rt_put(rt);
+		return NF_DROP;
 	}
 
-	dst_release(nskb->dst);
-	nskb->dst = &rt->u.dst;
+	(*pskb)->h.th = (void *)(*pskb)->nh.iph + sizeof(tcph);
+	datalen = (*pskb)->len - (*pskb)->nh.iph->ihl*4 - tcph.doff*4;
+
+	/* Change over route. */
+	dst_release((*pskb)->dst);
+	(*pskb)->dst = &rt->u.dst;
 
 	/* This packet will not be the same as the other: clear nf fields */
-	nf_conntrack_put(nskb->nfct);
-	nskb->nfct = NULL;
-	nskb->nfcache = 0;
+	(*pskb)->nfcache = 0;
 #ifdef CONFIG_NETFILTER_DEBUG
-	nskb->nf_debug = 0;
+	(*pskb)->nf_debug = 0;
 #endif
-	nskb->nfmark = 0;
-
-	tcph = (struct tcphdr *)((u_int32_t*)nskb->nh.iph + nskb->nh.iph->ihl);
+	(*pskb)->nfmark = 0;
 
 	/* Swap source and dest */
-	tmp_addr = nskb->nh.iph->saddr;
-	nskb->nh.iph->saddr = nskb->nh.iph->daddr;
-	nskb->nh.iph->daddr = tmp_addr;
-	tmp_port = tcph->source;
-	tcph->source = tcph->dest;
-	tcph->dest = tmp_port;
+	tmp_addr = (*pskb)->nh.iph->saddr;
+	(*pskb)->nh.iph->saddr = (*pskb)->nh.iph->daddr;
+	(*pskb)->nh.iph->daddr = tmp_addr;
+	tmp_port = (*pskb)->h.th->source;
+	(*pskb)->h.th->source = (*pskb)->h.th->dest;
+	(*pskb)->h.th->dest = tmp_port;
 
 	/* Truncate to length (no data) */
-	tcph->doff = sizeof(struct tcphdr)/4;
-	skb_trim(nskb, nskb->nh.iph->ihl*4 + sizeof(struct tcphdr));
-	nskb->nh.iph->tot_len = htons(nskb->len);
+	(*pskb)->h.th->doff = sizeof(struct tcphdr)/4;
+	skb_trim(*pskb, (*pskb)->nh.iph->ihl*4 + sizeof(struct tcphdr));
+	(*pskb)->nh.iph->tot_len = htons((*pskb)->len);
 
-	if (tcph->ack) {
+	if ((*pskb)->h.th->ack) {
 		needs_ack = 0;
-		tcph->seq = otcph->ack_seq;
-		tcph->ack_seq = 0;
+		(*pskb)->h.th->seq = tcph.ack_seq;
+		(*pskb)->h.th->ack_seq = 0;
 	} else {
 		needs_ack = 1;
-		tcph->ack_seq = htonl(ntohl(otcph->seq) + otcph->syn + otcph->fin
-				      + otcplen - (otcph->doff<<2));
-		tcph->seq = 0;
+		(*pskb)->h.th->ack_seq = htonl(ntohl(tcph.seq)
+						 + tcph.syn + tcph.fin
+						 + datalen);
+		(*pskb)->h.th->seq = 0;
 	}
 
 	/* Reset flags */
-	((u_int8_t *)tcph)[13] = 0;
-	tcph->rst = 1;
-	tcph->ack = needs_ack;
+	memset((*pskb)->h.raw + 13, 0, 1);
+	(*pskb)->h.th->rst = 1;
+	(*pskb)->h.th->ack = needs_ack;
 
-	tcph->window = 0;
-	tcph->urg_ptr = 0;
+	(*pskb)->h.th->window = 0;
+	(*pskb)->h.th->urg_ptr = 0;
 
 	/* Adjust TCP checksum */
-	tcph->check = 0;
-	tcph->check = tcp_v4_check(tcph, sizeof(struct tcphdr),
-				   nskb->nh.iph->saddr,
-				   nskb->nh.iph->daddr,
-				   csum_partial((char *)tcph,
-						sizeof(struct tcphdr), 0));
+	(*pskb)->h.th->check = 0;
+	(*pskb)->h.th->check
+		= tcp_v4_check((*pskb)->h.th,
+			       sizeof(struct tcphdr),
+			       (*pskb)->nh.iph->saddr,
+			       (*pskb)->nh.iph->daddr,
+			       csum_partial((*pskb)->h.raw,
+					    sizeof(struct tcphdr), 0));
 
 	/* Adjust IP TTL, DF */
-	nskb->nh.iph->ttl = MAXTTL;
+	(*pskb)->nh.iph->ttl = MAXTTL;
 	/* Set DF, id = 0 */
-	nskb->nh.iph->frag_off = htons(IP_DF);
-	nskb->nh.iph->id = 0;
+	(*pskb)->nh.iph->frag_off = htons(IP_DF);
+	(*pskb)->nh.iph->id = 0;
 
 	/* Adjust IP checksum */
-	nskb->nh.iph->check = 0;
-	nskb->nh.iph->check = ip_fast_csum((unsigned char *)nskb->nh.iph, 
-					   nskb->nh.iph->ihl);
+	(*pskb)->nh.iph->check = 0;
+	(*pskb)->nh.iph->check = ip_fast_csum((*pskb)->nh.raw, 
+					      (*pskb)->nh.iph->ihl);
 
 	/* "Never happens" */
-	if (nskb->len > dst_pmtu(nskb->dst))
-		goto free_nskb;
+	if ((*pskb)->len > dst_pmtu((*pskb)->dst))
+		return NF_DROP;
 
-	connection_attach(nskb, oldskb->nfct);
+	/* Related to old connection. */
+	oldnfct = (*pskb)->nfct;
+	connection_attach(*pskb, oldnfct);
+	nf_conntrack_put(oldnfct);
 
-	NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, nskb, NULL, nskb->dst->dev,
+	NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, *pskb, NULL, (*pskb)->dst->dev,
 		ip_finish_output);
-	return;
-
- free_nskb:
-	kfree_skb(nskb);
+	return NF_STOLEN;
 }
 
-static void send_unreach(struct sk_buff *skb_in, int code)
+static void send_unreach(const struct sk_buff *skb_in, int code)
 {
-	struct iphdr *iph;
-	struct udphdr *udph;
-	struct icmphdr *icmph;
 	struct sk_buff *nskb;
 	u32 saddr;
 	u8 tos;
@@ -189,8 +177,6 @@ static void send_unreach(struct sk_buff *skb_in, int code)
 	if (!xrlim_allow(&rt->u.dst, 1*HZ))
 		return;
 
-	iph = skb_in->nh.iph;
-
 	/* No replies to physical multicast/broadcast */
 	if (skb_in->pkt_type!=PACKET_HOST)
 		return;
@@ -200,46 +186,41 @@ static void send_unreach(struct sk_buff *skb_in, int code)
 		return;
 
 	/* Only reply to fragment 0. */
-	if (iph->frag_off&htons(IP_OFFSET))
+	if (skb_in->nh.iph->frag_off&htons(IP_OFFSET))
+		return;
+
+	/* Ensure we have at least 8 bytes of proto header. */
+	if (skb_in->len < skb_in->nh.iph->ihl*4 + 8)
 		return;
 
-	/* if UDP checksum is set, verify it's correct */
-	if (iph->protocol == IPPROTO_UDP
-	    && skb_in->tail-(u8*)iph >= sizeof(struct udphdr)) {
-		int datalen = skb_in->len - (iph->ihl<<2);
-		udph = (struct udphdr *)((char *)iph + (iph->ihl<<2));
-		if (udph->check
-		    && csum_tcpudp_magic(iph->saddr, iph->daddr,
-		                         datalen, IPPROTO_UDP,
-		                         csum_partial((char *)udph, datalen,
-		                                      0)) != 0)
-			return;
-	}
-		    
 	/* If we send an ICMP error to an ICMP error a mess would result.. */
-	if (iph->protocol == IPPROTO_ICMP
-	    && skb_in->tail-(u8*)iph >= sizeof(struct icmphdr)) {
-		icmph = (struct icmphdr *)((char *)iph + (iph->ihl<<2));
+	if (skb_in->nh.iph->protocol == IPPROTO_ICMP) {
+		struct icmphdr icmph;
+
+		if (skb_copy_bits(skb_in, skb_in->nh.iph->ihl*4,
+				  &icmph, sizeof(icmph)) < 0)
+			return;
+
 		/* Between echo-reply (0) and timestamp (13),
 		   everything except echo-request (8) is an error.
 		   Also, anything greater than NR_ICMP_TYPES is
 		   unknown, and hence should be treated as an error... */
-		if ((icmph->type < ICMP_TIMESTAMP
-		     && icmph->type != ICMP_ECHOREPLY
-		     && icmph->type != ICMP_ECHO)
-		    || icmph->type > NR_ICMP_TYPES)
+		if ((icmph.type < ICMP_TIMESTAMP
+		     && icmph.type != ICMP_ECHOREPLY
+		     && icmph.type != ICMP_ECHO)
+		    || icmph.type > NR_ICMP_TYPES)
 			return;
 	}
 
-	saddr = iph->daddr;
+	saddr = skb_in->nh.iph->daddr;
 	if (!(rt->rt_flags & RTCF_LOCAL))
 		saddr = 0;
 
-	tos = (iph->tos & IPTOS_TOS_MASK) | IPTOS_PREC_INTERNETCONTROL;
-
+	tos = (skb_in->nh.iph->tos & IPTOS_TOS_MASK)
+		| IPTOS_PREC_INTERNETCONTROL;
 	{
 		struct flowi fl = { .nl_u = { .ip4_u =
-					      { .daddr = iph->saddr,
+					      { .daddr = skb_in->nh.iph->saddr,
 						.saddr = saddr,
 						.tos = RT_TOS(tos) } } };
 		if (ip_route_output_key(&rt, &fl))
@@ -266,40 +247,38 @@ static void send_unreach(struct sk_buff *skb_in, int code)
 	skb_reserve(nskb, hh_len);
 
 	/* Set up IP header */
-	iph = nskb->nh.iph
-		= (struct iphdr *)skb_put(nskb, sizeof(struct iphdr));
-	iph->version=4;
-	iph->ihl=5;
-	iph->tos=tos;
-	iph->tot_len = htons(length);
+	nskb->nh.iph = (struct iphdr *)skb_put(nskb, sizeof(struct iphdr));
+	nskb->nh.iph->version=4;
+	nskb->nh.iph->ihl=5;
+	nskb->nh.iph->tos=tos;
+	nskb->nh.iph->tot_len = htons(length);
 
 	/* PMTU discovery never applies to ICMP packets. */
-	iph->frag_off = 0;
+	nskb->nh.iph->frag_off = 0;
 
-	iph->ttl = MAXTTL;
-	ip_select_ident(iph, &rt->u.dst, NULL);
-	iph->protocol=IPPROTO_ICMP;
-	iph->saddr=rt->rt_src;
-	iph->daddr=rt->rt_dst;
-	iph->check=0;
-	iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
+	nskb->nh.iph->ttl = MAXTTL;
+	ip_select_ident(nskb->nh.iph, &rt->u.dst, NULL);
+	nskb->nh.iph->protocol=IPPROTO_ICMP;
+	nskb->nh.iph->saddr=rt->rt_src;
+	nskb->nh.iph->daddr=rt->rt_dst;
+	nskb->nh.iph->check=0;
+	nskb->nh.iph->check = ip_fast_csum(nskb->nh.raw,
+					   nskb->nh.iph->ihl);
 
 	/* Set up ICMP header. */
-	icmph = nskb->h.icmph
-		= (struct icmphdr *)skb_put(nskb, sizeof(struct icmphdr));
-	icmph->type = ICMP_DEST_UNREACH;
-	icmph->code = code;	
-	icmph->un.gateway = 0;
-	icmph->checksum = 0;
+	nskb->h.icmph = (struct icmphdr *)skb_put(nskb,sizeof(struct icmphdr));
+	nskb->h.icmph->type = ICMP_DEST_UNREACH;
+	nskb->h.icmph->code = code;	
+	nskb->h.icmph->un.gateway = 0;
+	nskb->h.icmph->checksum = 0;
 	
 	/* Copy as much of original packet as will fit */
 	data = skb_put(nskb,
 		       length - sizeof(struct iphdr) - sizeof(struct icmphdr));
-	/* FIXME: won't work with nonlinear skbs --RR */
-	memcpy(data, skb_in->nh.iph,
-	       length - sizeof(struct iphdr) - sizeof(struct icmphdr));
-	icmph->checksum = ip_compute_csum((unsigned char *)icmph,
-					  length - sizeof(struct iphdr));
+	skb_copy_bits(skb_in, 0, data,
+		      length - sizeof(struct iphdr) - sizeof(struct icmphdr));
+	nskb->h.icmph->checksum = ip_compute_csum(nskb->h.raw,
+						  length-sizeof(struct iphdr));
 
 	connection_attach(nskb, skb_in->nfct);
 
@@ -308,9 +287,9 @@ static void send_unreach(struct sk_buff *skb_in, int code)
 }	
 
 static unsigned int reject(struct sk_buff **pskb,
-			   unsigned int hooknum,
 			   const struct net_device *in,
 			   const struct net_device *out,
+			   unsigned int hooknum,
 			   const void *targinfo,
 			   void *userinfo)
 {
@@ -344,7 +323,7 @@ static unsigned int reject(struct sk_buff **pskb,
     		send_unreach(*pskb, ICMP_HOST_ANO);
     		break;
 	case IPT_TCP_RESET:
-		send_reset(*pskb, hooknum == NF_IP_LOCAL_IN);
+		return send_reset(pskb, hooknum == NF_IP_LOCAL_IN);
 	case IPT_ICMP_ECHOREPLY:
 		/* Doesn't happen. */
 		break;
diff --git a/net/ipv4/netfilter/ipt_TCPMSS.c b/net/ipv4/netfilter/ipt_TCPMSS.c
index 637cf61d27e2..04d86da8b95e 100644
--- a/net/ipv4/netfilter/ipt_TCPMSS.c
+++ b/net/ipv4/netfilter/ipt_TCPMSS.c
@@ -36,9 +36,9 @@ optlen(const u_int8_t *opt, unsigned int offset)
 
 static unsigned int
 ipt_tcpmss_target(struct sk_buff **pskb,
-		  unsigned int hooknum,
 		  const struct net_device *in,
 		  const struct net_device *out,
+		  unsigned int hooknum,
 		  const void *targinfo,
 		  void *userinfo)
 {
@@ -49,15 +49,8 @@ ipt_tcpmss_target(struct sk_buff **pskb,
 	unsigned int i;
 	u_int8_t *opt;
 
-	/* raw socket (tcpdump) may have clone of incoming skb: don't
-	   disturb it --RR */
-	if (skb_cloned(*pskb) && !(*pskb)->sk) {
-		struct sk_buff *nskb = skb_copy(*pskb, GFP_ATOMIC);
-		if (!nskb)
-			return NF_DROP;
-		kfree_skb(*pskb);
-		*pskb = nskb;
-	}
+	if (!skb_ip_make_writable(pskb, (*pskb)->len))
+		return NF_DROP;
 
 	iph = (*pskb)->nh.iph;
 	tcplen = (*pskb)->len - iph->ihl*4;
diff --git a/net/ipv4/netfilter/ipt_TOS.c b/net/ipv4/netfilter/ipt_TOS.c
index 05d9a727c122..ed780929606c 100644
--- a/net/ipv4/netfilter/ipt_TOS.c
+++ b/net/ipv4/netfilter/ipt_TOS.c
@@ -9,35 +9,30 @@
 
 static unsigned int
 target(struct sk_buff **pskb,
-       unsigned int hooknum,
        const struct net_device *in,
        const struct net_device *out,
+       unsigned int hooknum,
        const void *targinfo,
        void *userinfo)
 {
-	struct iphdr *iph = (*pskb)->nh.iph;
 	const struct ipt_tos_target_info *tosinfo = targinfo;
 
-	if ((iph->tos & IPTOS_TOS_MASK) != tosinfo->tos) {
+	if (((*pskb)->nh.iph->tos & IPTOS_TOS_MASK) != tosinfo->tos) {
 		u_int16_t diffs[2];
 
-		/* raw socket (tcpdump) may have clone of incoming
-                   skb: don't disturb it --RR */
-		if (skb_cloned(*pskb) && !(*pskb)->sk) {
-			struct sk_buff *nskb = skb_copy(*pskb, GFP_ATOMIC);
-			if (!nskb)
-				return NF_DROP;
-			kfree_skb(*pskb);
-			*pskb = nskb;
-			iph = (*pskb)->nh.iph;
-		}
+		if (!skb_ip_make_writable(pskb, sizeof(struct iphdr)))
+			return NF_DROP;
 
-		diffs[0] = htons(iph->tos) ^ 0xFFFF;
-		iph->tos = (iph->tos & IPTOS_PREC_MASK) | tosinfo->tos;
-		diffs[1] = htons(iph->tos);
-		iph->check = csum_fold(csum_partial((char *)diffs,
-		                                    sizeof(diffs),
-		                                    iph->check^0xFFFF));
+		diffs[0] = htons((*pskb)->nh.iph->tos) ^ 0xFFFF;
+		(*pskb)->nh.iph->tos
+			= ((*pskb)->nh.iph->tos & IPTOS_PREC_MASK)
+			| tosinfo->tos;
+		diffs[1] = htons((*pskb)->nh.iph->tos);
+		(*pskb)->nh.iph->check
+			= csum_fold(csum_partial((char *)diffs,
+						 sizeof(diffs),
+						 (*pskb)->nh.iph->check
+						 ^0xFFFF));
 		(*pskb)->nfcache |= NFC_ALTERED;
 	}
 	return IPT_CONTINUE;
diff --git a/net/ipv4/netfilter/ipt_ULOG.c b/net/ipv4/netfilter/ipt_ULOG.c
index f96309864ec7..51023be976ab 100644
--- a/net/ipv4/netfilter/ipt_ULOG.c
+++ b/net/ipv4/netfilter/ipt_ULOG.c
@@ -155,9 +155,9 @@ struct sk_buff *ulog_alloc_skb(unsigned int size)
 }
 
 static unsigned int ipt_ulog_target(struct sk_buff **pskb,
-				    unsigned int hooknum,
 				    const struct net_device *in,
 				    const struct net_device *out,
+				    unsigned int hooknum,
 				    const void *targinfo, void *userinfo)
 {
 	ulog_buff_t *ub;
@@ -238,8 +238,9 @@ static unsigned int ipt_ulog_target(struct sk_buff **pskb,
 	else
 		pm->outdev_name[0] = '\0';
 
-	if (copy_len)
-		memcpy(pm->payload, (*pskb)->data, copy_len);
+	/* copy_len <= (*pskb)->len, so can't fail. */
+	if (skb_copy_bits(*pskb, 0, pm->payload, copy_len) < 0)
+		BUG();
 	
 	/* check if we are building multi-part messages */
 	if (ub->qlen > 1) {
diff --git a/net/ipv4/netfilter/ipt_ah.c b/net/ipv4/netfilter/ipt_ah.c
index 61bdc7a39a37..af69c2b3420c 100644
--- a/net/ipv4/netfilter/ipt_ah.c
+++ b/net/ipv4/netfilter/ipt_ah.c
@@ -35,14 +35,16 @@ match(const struct sk_buff *skb,
       const struct net_device *out,
       const void *matchinfo,
       int offset,
-      const void *hdr,
-      u_int16_t datalen,
       int *hotdrop)
 {
-	const struct ahhdr *ah = hdr;
+	struct ahhdr ah;
 	const struct ipt_ah *ahinfo = matchinfo;
 
-	if (offset == 0 && datalen < sizeof(struct ahhdr)) {
+	/* Must not be a fragment. */
+	if (offset)
+		return 0;
+
+	if (skb_copy_bits(skb, skb->nh.iph->ihl*4, &ah, sizeof(ah)) < 0) {
 		/* We've been asked to examine this packet, and we
 		   can't.  Hence, no choice but to drop. */
 		duprintf("Dropping evil AH tinygram.\n");
@@ -50,11 +52,9 @@ match(const struct sk_buff *skb,
 		return 0;
 	}
 
-	/* Must not be a fragment. */
-	return !offset
-		&& spi_match(ahinfo->spis[0], ahinfo->spis[1],
-			      ntohl(ah->spi),
-			      !!(ahinfo->invflags & IPT_AH_INV_SPI));
+	return spi_match(ahinfo->spis[0], ahinfo->spis[1],
+			 ntohl(ah.spi),
+			 !!(ahinfo->invflags & IPT_AH_INV_SPI));
 }
 
 /* Called when user tries to insert an entry of this type. */
diff --git a/net/ipv4/netfilter/ipt_conntrack.c b/net/ipv4/netfilter/ipt_conntrack.c
index af9d3912a20c..1183e61fa871 100644
--- a/net/ipv4/netfilter/ipt_conntrack.c
+++ b/net/ipv4/netfilter/ipt_conntrack.c
@@ -14,8 +14,6 @@ match(const struct sk_buff *skb,
       const struct net_device *out,
       const void *matchinfo,
       int offset,
-      const void *hdr,
-      u_int16_t datalen,
       int *hotdrop)
 {
 	const struct ipt_conntrack_info *sinfo = matchinfo;
diff --git a/net/ipv4/netfilter/ipt_dscp.c b/net/ipv4/netfilter/ipt_dscp.c
index 7d840322b99b..cc48b65ab191 100644
--- a/net/ipv4/netfilter/ipt_dscp.c
+++ b/net/ipv4/netfilter/ipt_dscp.c
@@ -19,8 +19,7 @@ MODULE_LICENSE("GPL");
 
 static int match(const struct sk_buff *skb, const struct net_device *in,
 		 const struct net_device *out, const void *matchinfo,
-		 int offset, const void *hdr, u_int16_t datalen,
-		 int *hotdrop)
+		 int offset, int *hotdrop)
 {
 	const struct ipt_dscp_info *info = matchinfo;
 	const struct iphdr *iph = skb->nh.iph;
diff --git a/net/ipv4/netfilter/ipt_ecn.c b/net/ipv4/netfilter/ipt_ecn.c
index 58d12ff190f4..34947c2c03b7 100644
--- a/net/ipv4/netfilter/ipt_ecn.c
+++ b/net/ipv4/netfilter/ipt_ecn.c
@@ -19,34 +19,40 @@ MODULE_DESCRIPTION("IP tables ECN matching module");
 MODULE_LICENSE("GPL");
 
 static inline int match_ip(const struct sk_buff *skb,
-			   const struct iphdr *iph,
 			   const struct ipt_ecn_info *einfo)
 {
-	return ((iph->tos&IPT_ECN_IP_MASK) == einfo->ip_ect);
+	return ((skb->nh.iph->tos&IPT_ECN_IP_MASK) == einfo->ip_ect);
 }
 
 static inline int match_tcp(const struct sk_buff *skb,
-			    const struct iphdr *iph,
-			    const struct ipt_ecn_info *einfo)
+			    const struct ipt_ecn_info *einfo,
+			    int *hotdrop)
 {
-	struct tcphdr *tcph = (void *)iph + iph->ihl*4;
+	struct tcphdr tcph;
+
+	/* In practice, TCP match does this, so can't fail.  But let's
+           be good citizens. */
+	if (skb_copy_bits(skb, skb->nh.iph->ihl*4, &tcph, sizeof(tcph)) < 0) {
+		*hotdrop = 0;
+		return 0;
+	}
 
 	if (einfo->operation & IPT_ECN_OP_MATCH_ECE) {
 		if (einfo->invert & IPT_ECN_OP_MATCH_ECE) {
-			if (tcph->ece == 1)
+			if (tcph.ece == 1)
 				return 0;
 		} else {
-			if (tcph->ece == 0)
+			if (tcph.ece == 0)
 				return 0;
 		}
 	}
 
 	if (einfo->operation & IPT_ECN_OP_MATCH_CWR) {
 		if (einfo->invert & IPT_ECN_OP_MATCH_CWR) {
-			if (tcph->cwr == 1)
+			if (tcph.cwr == 1)
 				return 0;
 		} else {
-			if (tcph->cwr == 0)
+			if (tcph.cwr == 0)
 				return 0;
 		}
 	}
@@ -56,20 +62,18 @@ static inline int match_tcp(const struct sk_buff *skb,
 
 static int match(const struct sk_buff *skb, const struct net_device *in,
 		 const struct net_device *out, const void *matchinfo,
-		 int offset, const void *hdr, u_int16_t datalen,
-		 int *hotdrop)
+		 int offset, int *hotdrop)
 {
 	const struct ipt_ecn_info *info = matchinfo;
-	const struct iphdr *iph = skb->nh.iph;
 
 	if (info->operation & IPT_ECN_OP_MATCH_IP)
-		if (!match_ip(skb, iph, info))
+		if (!match_ip(skb, info))
 			return 0;
 
 	if (info->operation & (IPT_ECN_OP_MATCH_ECE|IPT_ECN_OP_MATCH_CWR)) {
-		if (iph->protocol != IPPROTO_TCP)
+		if (skb->nh.iph->protocol != IPPROTO_TCP)
 			return 0;
-		if (!match_tcp(skb, iph, info))
+		if (!match_tcp(skb, info, hotdrop))
 			return 0;
 	}
 
diff --git a/net/ipv4/netfilter/ipt_esp.c b/net/ipv4/netfilter/ipt_esp.c
index 46ca560f358b..1a52aae22e01 100644
--- a/net/ipv4/netfilter/ipt_esp.c
+++ b/net/ipv4/netfilter/ipt_esp.c
@@ -35,14 +35,16 @@ match(const struct sk_buff *skb,
       const struct net_device *out,
       const void *matchinfo,
       int offset,
-      const void *hdr,
-      u_int16_t datalen,
       int *hotdrop)
 {
-	const struct esphdr *esp = hdr;
+	struct esphdr esp;
 	const struct ipt_esp *espinfo = matchinfo;
 
-	if (offset == 0 && datalen < sizeof(struct esphdr)) {
+	/* Must not be a fragment. */
+	if (offset)
+		return 0;
+
+	if (skb_copy_bits(skb, skb->nh.iph->ihl*4, &esp, sizeof(esp)) < 0) {
 		/* We've been asked to examine this packet, and we
 		   can't.  Hence, no choice but to drop. */
 		duprintf("Dropping evil ESP tinygram.\n");
@@ -50,11 +52,9 @@ match(const struct sk_buff *skb,
 		return 0;
 	}
 
-	/* Must not be a fragment. */
-	return !offset
-		&& spi_match(espinfo->spis[0], espinfo->spis[1],
-			      ntohl(esp->spi),
-			      !!(espinfo->invflags & IPT_ESP_INV_SPI));
+	return spi_match(espinfo->spis[0], espinfo->spis[1],
+			 ntohl(esp.spi),
+			 !!(espinfo->invflags & IPT_ESP_INV_SPI));
 }
 
 /* Called when user tries to insert an entry of this type. */
diff --git a/net/ipv4/netfilter/ipt_helper.c b/net/ipv4/netfilter/ipt_helper.c
index 7f0997fbef5e..1f7efb91c5e8 100644
--- a/net/ipv4/netfilter/ipt_helper.c
+++ b/net/ipv4/netfilter/ipt_helper.c
@@ -28,8 +28,6 @@ match(const struct sk_buff *skb,
       const struct net_device *out,
       const void *matchinfo,
       int offset,
-      const void *hdr,
-      u_int16_t datalen,
       int *hotdrop)
 {
 	const struct ipt_helper_info *info = matchinfo;
diff --git a/net/ipv4/netfilter/ipt_length.c b/net/ipv4/netfilter/ipt_length.c
index 91cf0a76a89c..7f3d05827fca 100644
--- a/net/ipv4/netfilter/ipt_length.c
+++ b/net/ipv4/netfilter/ipt_length.c
@@ -15,8 +15,6 @@ match(const struct sk_buff *skb,
       const struct net_device *out,
       const void *matchinfo,
       int offset,
-      const void *hdr,
-      u_int16_t datalen,
       int *hotdrop)
 {
 	const struct ipt_length_info *info = matchinfo;
diff --git a/net/ipv4/netfilter/ipt_limit.c b/net/ipv4/netfilter/ipt_limit.c
index 515acef2279e..d2fa9c57b0f2 100644
--- a/net/ipv4/netfilter/ipt_limit.c
+++ b/net/ipv4/netfilter/ipt_limit.c
@@ -47,8 +47,6 @@ ipt_limit_match(const struct sk_buff *skb,
 		const struct net_device *out,
 		const void *matchinfo,
 		int offset,
-		const void *hdr,
-		u_int16_t datalen,
 		int *hotdrop)
 {
 	struct ipt_rateinfo *r = ((struct ipt_rateinfo *)matchinfo)->master;
diff --git a/net/ipv4/netfilter/ipt_mac.c b/net/ipv4/netfilter/ipt_mac.c
index 7a5ed1c5993e..fc6a47974030 100644
--- a/net/ipv4/netfilter/ipt_mac.c
+++ b/net/ipv4/netfilter/ipt_mac.c
@@ -12,8 +12,6 @@ match(const struct sk_buff *skb,
       const struct net_device *out,
       const void *matchinfo,
       int offset,
-      const void *hdr,
-      u_int16_t datalen,
       int *hotdrop)
 {
     const struct ipt_mac_info *info = matchinfo;
diff --git a/net/ipv4/netfilter/ipt_mark.c b/net/ipv4/netfilter/ipt_mark.c
index 14154f02aa80..2673b477fa2b 100644
--- a/net/ipv4/netfilter/ipt_mark.c
+++ b/net/ipv4/netfilter/ipt_mark.c
@@ -11,8 +11,6 @@ match(const struct sk_buff *skb,
       const struct net_device *out,
       const void *matchinfo,
       int offset,
-      const void *hdr,
-      u_int16_t datalen,
       int *hotdrop)
 {
 	const struct ipt_mark_info *info = matchinfo;
diff --git a/net/ipv4/netfilter/ipt_multiport.c b/net/ipv4/netfilter/ipt_multiport.c
index 6b7bc044f58d..ffe25aa899a3 100644
--- a/net/ipv4/netfilter/ipt_multiport.c
+++ b/net/ipv4/netfilter/ipt_multiport.c
@@ -39,15 +39,18 @@ match(const struct sk_buff *skb,
       const struct net_device *out,
       const void *matchinfo,
       int offset,
-      const void *hdr,
-      u_int16_t datalen,
       int *hotdrop)
 {
-	const struct udphdr *udp = hdr;
+	u16 ports[2];
 	const struct ipt_multiport *multiinfo = matchinfo;
 
-	/* Must be big enough to read ports. */
-	if (offset == 0 && datalen < sizeof(struct udphdr)) {
+	/* Must not be a fragment. */
+	if (offset)
+		return 0;
+
+	/* Must be big enough to read ports (both UDP and TCP have
+           them at the start). */
+	if (skb_copy_bits(skb, skb->nh.iph->ihl*4, ports, sizeof(ports)) < 0) {
 		/* We've been asked to examine this packet, and we
 		   can't.  Hence, no choice but to drop. */
 			duprintf("ipt_multiport:"
@@ -56,11 +59,9 @@ match(const struct sk_buff *skb,
 			return 0;
 	}
 
-	/* Must not be a fragment. */
-	return !offset
-		&& ports_match(multiinfo->ports,
-			       multiinfo->flags, multiinfo->count,
-			       ntohs(udp->source), ntohs(udp->dest));
+	return ports_match(multiinfo->ports,
+			   multiinfo->flags, multiinfo->count,
+			   ntohs(ports[0]), ntohs(ports[1]));
 }
 
 /* Called when user tries to insert an entry of this type. */
diff --git a/net/ipv4/netfilter/ipt_owner.c b/net/ipv4/netfilter/ipt_owner.c
index d1d439096820..5cd5efa04d04 100644
--- a/net/ipv4/netfilter/ipt_owner.c
+++ b/net/ipv4/netfilter/ipt_owner.c
@@ -115,8 +115,6 @@ match(const struct sk_buff *skb,
       const struct net_device *out,
       const void *matchinfo,
       int offset,
-      const void *hdr,
-      u_int16_t datalen,
       int *hotdrop)
 {
 	const struct ipt_owner_info *info = matchinfo;
@@ -170,8 +168,11 @@ checkentry(const char *tablename,
                 return 0;
         }
 
-	if (matchsize != IPT_ALIGN(sizeof(struct ipt_owner_info)))
+	if (matchsize != IPT_ALIGN(sizeof(struct ipt_owner_info))) {
+		printk("Matchsize %u != %Zu\n", matchsize,
+		       IPT_ALIGN(sizeof(struct ipt_owner_info)));
 		return 0;
+	}
 
 	return 1;
 }
diff --git a/net/ipv4/netfilter/ipt_physdev.c b/net/ipv4/netfilter/ipt_physdev.c
index 642d32d3288b..bc439d4f95e0 100644
--- a/net/ipv4/netfilter/ipt_physdev.c
+++ b/net/ipv4/netfilter/ipt_physdev.c
@@ -14,8 +14,6 @@ match(const struct sk_buff *skb,
       const struct net_device *out,
       const void *matchinfo,
       int offset,
-      const void *hdr,
-      u_int16_t datalen,
       int *hotdrop)
 {
 	int i;
diff --git a/net/ipv4/netfilter/ipt_pkttype.c b/net/ipv4/netfilter/ipt_pkttype.c
index b59cd2fddb2a..047700095dca 100644
--- a/net/ipv4/netfilter/ipt_pkttype.c
+++ b/net/ipv4/netfilter/ipt_pkttype.c
@@ -13,8 +13,6 @@ static int match(const struct sk_buff *skb,
       const struct net_device *out,
       const void *matchinfo,
       int offset,
-      const void *hdr,
-      u_int16_t datalen,
       int *hotdrop)
 {
     const struct ipt_pkttype_info *info = matchinfo;
diff --git a/net/ipv4/netfilter/ipt_state.c b/net/ipv4/netfilter/ipt_state.c
index 026f1039dc9e..0f3eaeddfa92 100644
--- a/net/ipv4/netfilter/ipt_state.c
+++ b/net/ipv4/netfilter/ipt_state.c
@@ -13,8 +13,6 @@ match(const struct sk_buff *skb,
       const struct net_device *out,
       const void *matchinfo,
       int offset,
-      const void *hdr,
-      u_int16_t datalen,
       int *hotdrop)
 {
 	const struct ipt_state_info *sinfo = matchinfo;
diff --git a/net/ipv4/netfilter/ipt_tcpmss.c b/net/ipv4/netfilter/ipt_tcpmss.c
index 0f3e38b9951e..7ddfe78d5a3d 100644
--- a/net/ipv4/netfilter/ipt_tcpmss.c
+++ b/net/ipv4/netfilter/ipt_tcpmss.c
@@ -11,24 +11,32 @@
 /* Returns 1 if the mss option is set and matched by the range, 0 otherwise */
 static inline int
 mssoption_match(u_int16_t min, u_int16_t max,
-		const struct tcphdr *tcp,
-		u_int16_t datalen,
+		const struct sk_buff *skb,
 		int invert,
 		int *hotdrop)
 {
-	unsigned int i;
-	const u_int8_t *opt = (u_int8_t *)tcp;
+	struct tcphdr tcph;
+	/* tcp.doff is only 4 bits, ie. max 15 * 4 bytes */
+	u8 opt[15 * 4 - sizeof(tcph)];
+	unsigned int i, optlen;
 
 	/* If we don't have the whole header, drop packet. */
-	if (tcp->doff * 4 > datalen) {
-		*hotdrop = 1;
-		return 0;
-	}
-
-	for (i = sizeof(struct tcphdr); i < tcp->doff * 4; ) {
-		if ((opt[i] == TCPOPT_MSS)
-		    && ((tcp->doff * 4 - i) >= TCPOLEN_MSS)
-		    && (opt[i+1] == TCPOLEN_MSS)) {
+	if (skb_copy_bits(skb, skb->nh.iph->ihl*4, &tcph, sizeof(tcph)) < 0)
+		goto dropit;
+
+	/* Malformed. */
+	if (tcph.doff*4 < sizeof(tcph))
+		goto dropit;
+
+	optlen = tcph.doff*4 - sizeof(tcph);
+	/* Truncated options. */
+	if (skb_copy_bits(skb, skb->nh.iph->ihl*4+sizeof(tcph), opt, optlen)<0)
+		goto dropit;
+
+	for (i = 0; i < optlen; ) {
+		if (opt[i] == TCPOPT_MSS
+		    && (optlen - i) >= TCPOLEN_MSS
+		    && opt[i+1] == TCPOLEN_MSS) {
 			u_int16_t mssval;
 
 			mssval = (opt[i+2] << 8) | opt[i+3];
@@ -38,8 +46,11 @@ mssoption_match(u_int16_t min, u_int16_t max,
 		if (opt[i] < 2) i++;
 		else i += opt[i+1]?:1;
 	}
-
 	return invert;
+
+ dropit:
+	*hotdrop = 1;
+	return 0;
 }
 
 static int
@@ -48,15 +59,11 @@ match(const struct sk_buff *skb,
       const struct net_device *out,
       const void *matchinfo,
       int offset,
-      const void *hdr,
-      u_int16_t datalen,
       int *hotdrop)
 {
 	const struct ipt_tcpmss_match_info *info = matchinfo;
-	const struct tcphdr *tcph = (void *)skb->nh.iph + skb->nh.iph->ihl*4;
 
-	return mssoption_match(info->mss_min, info->mss_max, tcph,
-			       skb->len - skb->nh.iph->ihl*4,
+	return mssoption_match(info->mss_min, info->mss_max, skb,
 			       info->invert, hotdrop);
 }
 
diff --git a/net/ipv4/netfilter/ipt_tos.c b/net/ipv4/netfilter/ipt_tos.c
index 11c94302c774..2c58fa826660 100644
--- a/net/ipv4/netfilter/ipt_tos.c
+++ b/net/ipv4/netfilter/ipt_tos.c
@@ -11,14 +11,11 @@ match(const struct sk_buff *skb,
       const struct net_device *out,
       const void *matchinfo,
       int offset,
-      const void *hdr,
-      u_int16_t datalen,
       int *hotdrop)
 {
 	const struct ipt_tos_info *info = matchinfo;
-	const struct iphdr *iph = skb->nh.iph;
 
-	return (iph->tos == info->tos) ^ info->invert;
+	return (skb->nh.iph->tos == info->tos) ^ info->invert;
 }
 
 static int
diff --git a/net/ipv4/netfilter/ipt_ttl.c b/net/ipv4/netfilter/ipt_ttl.c
index b9657e1d9200..15534e77dd4c 100644
--- a/net/ipv4/netfilter/ipt_ttl.c
+++ b/net/ipv4/netfilter/ipt_ttl.c
@@ -19,24 +19,22 @@ MODULE_LICENSE("GPL");
 
 static int match(const struct sk_buff *skb, const struct net_device *in,
 		 const struct net_device *out, const void *matchinfo,
-		 int offset, const void *hdr, u_int16_t datalen,
-		 int *hotdrop)
+		 int offset, int *hotdrop)
 {
 	const struct ipt_ttl_info *info = matchinfo;
-	const struct iphdr *iph = skb->nh.iph;
 
 	switch (info->mode) {
 		case IPT_TTL_EQ:
-			return (iph->ttl == info->ttl);
+			return (skb->nh.iph->ttl == info->ttl);
 			break;
 		case IPT_TTL_NE:
-			return (!(iph->ttl == info->ttl));
+			return (!(skb->nh.iph->ttl == info->ttl));
 			break;
 		case IPT_TTL_LT:
-			return (iph->ttl < info->ttl);
+			return (skb->nh.iph->ttl < info->ttl);
 			break;
 		case IPT_TTL_GT:
-			return (iph->ttl > info->ttl);
+			return (skb->nh.iph->ttl > info->ttl);
 			break;
 		default:
 			printk(KERN_WARNING "ipt_ttl: unknown mode %d\n", 
diff --git a/net/ipv4/netfilter/ipt_unclean.c b/net/ipv4/netfilter/ipt_unclean.c
index 6c96d2729d94..16c3c9879f5e 100644
--- a/net/ipv4/netfilter/ipt_unclean.c
+++ b/net/ipv4/netfilter/ipt_unclean.c
@@ -31,16 +31,17 @@ struct icmp_info
 };
 
 static int
-check_ip(struct iphdr *iph, size_t length, int embedded);
+check_ip(const struct sk_buff *skb, unsigned int offset);
 
 /* ICMP-specific checks. */
 static int
-check_icmp(const struct icmphdr *icmph,
-	   u_int16_t datalen,
+check_icmp(const struct sk_buff *skb,
 	   unsigned int offset,
+	   unsigned int fragoff,
 	   int more_frags,
 	   int embedded)
 {
+	struct icmphdr icmph;
 	static struct icmp_info info[]
 		= { [ICMP_ECHOREPLY]
 		    = { 8, 65536, ICMP_NOT_ERROR, 0, 0 },
@@ -76,92 +77,95 @@ check_icmp(const struct icmphdr *icmph,
 		    = { 12, 12, ICMP_NOT_ERROR, 0, 0 } };
 
 	/* Can't do anything if it's a fragment. */
-	if (offset)
+	if (fragoff)
 		return 1;
 
-	/* Must cover type and code. */
-	if (datalen < 2) {
-		limpk("ICMP len=%u too short\n", datalen);
+	/* CHECK: Must have whole header.. */
+	if (skb_copy_bits(skb, offset, &icmph, sizeof(icmph)) < 0) {
+		limpk("ICMP len=%u too short\n", skb->len - offset);
 		return 0;
 	}
 
-	/* If not embedded. */
+	/* If not embedded in an ICMP error already. */
 	if (!embedded) {
-		/* Bad checksum?  Don't print, just ignore. */
-		if (!more_frags
-		    && ip_compute_csum((unsigned char *) icmph, datalen) != 0)
-			return 0;
-
 		/* CHECK: Truncated ICMP (even if first fragment). */
-		if (icmph->type < sizeof(info)/sizeof(struct icmp_info)
-		    && info[icmph->type].min_len != 0
-		    && datalen < info[icmph->type].min_len) {
+		if (icmph.type < sizeof(info)/sizeof(struct icmp_info)
+		    && info[icmph.type].min_len != 0
+		    && skb->len - offset < info[icmph.type].min_len) {
 			limpk("ICMP type %u len %u too short\n",
-			      icmph->type, datalen);
+			      icmph.type, skb->len - offset);
 			return 0;
 		}
 
 		/* CHECK: Check within known error ICMPs. */
-		if (icmph->type < sizeof(info)/sizeof(struct icmp_info)
-		    && info[icmph->type].err == ICMP_IS_ERROR) {
+		if (icmph.type < sizeof(info)/sizeof(struct icmp_info)
+		    && info[icmph.type].err == ICMP_IS_ERROR) {
+			/* Max IP header size = 60 */
+			char inner[60 + 8];
+			struct iphdr *inner_ip = (struct iphdr *)inner;
+
 			/* CHECK: Embedded packet must be at least
 			   length of iph + 8 bytes. */
-			struct iphdr *inner = (void *)icmph + 8;
-
-			/* datalen > 8 since all ICMP_IS_ERROR types
-                           have min length > 8 */
-			if (datalen - 8 < sizeof(struct iphdr)) {
+			if (skb_copy_bits(skb, offset + sizeof(icmph),
+					  inner, sizeof(struct iphdr)+8) < 0) {
 				limpk("ICMP error internal way too short\n");
 				return 0;
 			}
-			if (datalen - 8 < inner->ihl*4 + 8) {
+
+			/* iphhdr may actually be longer: still need 8
+                           actual protocol bytes. */
+			if (offset + sizeof(icmph) + inner_ip->ihl*4 + 8
+			    > skb->len) {
 				limpk("ICMP error internal too short\n");
 				return 0;
 			}
-			if (!check_ip(inner, datalen - 8, 1))
+			if (!check_ip(skb, offset + sizeof(icmph)))
 				return 0;
 		}
 	} else {
 		/* CHECK: Can't embed ICMP unless known non-error. */
-		if (icmph->type >= sizeof(info)/sizeof(struct icmp_info)
-		    || info[icmph->type].err != ICMP_NOT_ERROR) {
+		if (icmph.type >= sizeof(info)/sizeof(struct icmp_info)
+		    || info[icmph.type].err != ICMP_NOT_ERROR) {
 			limpk("ICMP type %u not embeddable\n",
-			      icmph->type);
+			      icmph.type);
 			return 0;
 		}
 	}
 
 	/* CHECK: Invalid ICMP codes. */
-	if (icmph->type < sizeof(info)/sizeof(struct icmp_info)
-	    && (icmph->code < info[icmph->type].min_code
-		|| icmph->code > info[icmph->type].max_code)) {
+	if (icmph.type < sizeof(info)/sizeof(struct icmp_info)
+	    && (icmph.code < info[icmph.type].min_code
+		|| icmph.code > info[icmph.type].max_code)) {
 		limpk("ICMP type=%u code=%u\n",
-		      icmph->type, icmph->code);
+		      icmph.type, icmph.code);
 		return 0;
 	}
 
 	/* CHECK: Above maximum length. */
-	if (icmph->type < sizeof(info)/sizeof(struct icmp_info)
-	    && info[icmph->type].max_len != 0
-	    && datalen > info[icmph->type].max_len) {
+	if (icmph.type < sizeof(info)/sizeof(struct icmp_info)
+	    && info[icmph.type].max_len != 0
+	    && skb->len - offset > info[icmph.type].max_len) {
 		limpk("ICMP type=%u too long: %u bytes\n",
-		      icmph->type, datalen);
+		      icmph.type, skb->len - offset);
 		return 0;
 	}
 
-	switch (icmph->type) {
+	switch (icmph.type) {
 	case ICMP_PARAMETERPROB: {
 		/* CHECK: Problem param must be within error packet's
 		 * IP header. */
-		struct iphdr *iph = (void *)icmph + 8;
-		u_int32_t arg = ntohl(icmph->un.gateway);
+		u_int32_t arg = ntohl(icmph.un.gateway);
 
-		if (icmph->code == 0) {
+		if (icmph.code == 0) {
+			/* We've already made sure it's long enough. */
+			struct iphdr iph;
+			skb_copy_bits(skb, offset + sizeof(icmph), &iph,
+				      sizeof(iph));
 			/* Code 0 means that upper 8 bits is pointer
                            to problem. */
-			if ((arg >> 24) >= iph->ihl*4) {
+			if ((arg >> 24) >= iph.ihl*4) {
 				limpk("ICMP PARAMETERPROB ptr = %u\n",
-				      ntohl(icmph->un.gateway) >> 24);
+				      ntohl(icmph.un.gateway) >> 24);
 				return 0;
 			}
 			arg &= 0x00FFFFFF;
@@ -179,9 +183,9 @@ check_icmp(const struct icmphdr *icmph,
 	case ICMP_TIME_EXCEEDED:
 	case ICMP_SOURCE_QUENCH:
 		/* CHECK: Unused must be zero. */
-		if (icmph->un.gateway != 0) {
+		if (icmph.un.gateway != 0) {
 			limpk("ICMP type=%u unused = %u\n",
-			      icmph->type, ntohl(icmph->un.gateway));
+			      icmph.type, ntohl(icmph.un.gateway));
 			return 0;
 		}
 		break;
@@ -192,32 +196,26 @@ check_icmp(const struct icmphdr *icmph,
 
 /* UDP-specific checks. */
 static int
-check_udp(const struct iphdr *iph,
-	  const struct udphdr *udph,
-	  u_int16_t datalen,
+check_udp(const struct sk_buff *skb,
 	  unsigned int offset,
+	  unsigned int fragoff,
 	  int more_frags,
 	  int embedded)
 {
+	struct udphdr udph;
+
 	/* Can't do anything if it's a fragment. */
-	if (offset)
+	if (fragoff)
 		return 1;
 
 	/* CHECK: Must cover UDP header. */
-	if (datalen < sizeof(struct udphdr)) {
-		limpk("UDP len=%u too short\n", datalen);
+	if (skb_copy_bits(skb, offset, &udph, sizeof(udph)) < 0) {
+		limpk("UDP len=%u too short\n", skb->len - offset);
 		return 0;
 	}
 
-	/* Bad checksum?  Don't print, just say it's unclean. */
-	/* FIXME: SRC ROUTE packets won't match checksum --RR */
-	if (!more_frags && !embedded && udph->check
-	    && csum_tcpudp_magic(iph->saddr, iph->daddr, datalen, IPPROTO_UDP,
-				 csum_partial((char *)udph, datalen, 0)) != 0)
-		return 0;
-
 	/* CHECK: Destination port can't be zero. */
-	if (!udph->dest) {
+	if (!udph.dest) {
 		limpk("UDP zero destination port\n");
 		return 0;
 	}
@@ -225,24 +223,24 @@ check_udp(const struct iphdr *iph,
 	if (!more_frags) {
 		if (!embedded) {
 			/* CHECK: UDP length must match. */
-			if (ntohs(udph->len) != datalen) {
+			if (ntohs(udph.len) != skb->len - offset) {
 				limpk("UDP len too short %u vs %u\n",
-				      ntohs(udph->len), datalen);
+				      ntohs(udph.len), skb->len - offset);
 				return 0;
 			}
 		} else {
 			/* CHECK: UDP length be >= this truncated pkt. */
-			if (ntohs(udph->len) < datalen) {
+			if (ntohs(udph.len) < skb->len - offset) {
 				limpk("UDP len too long %u vs %u\n",
-				      ntohs(udph->len), datalen);
+				      ntohs(udph.len), skb->len - offset);
 				return 0;
 			}
 		}
 	} else {
 		/* CHECK: UDP length must be > this frag's length. */
-		if (ntohs(udph->len) <= datalen) {
+		if (ntohs(udph.len) <= skb->len - offset) {
 			limpk("UDP fragment len too short %u vs %u\n",
-			      ntohs(udph->len), datalen);
+			      ntohs(udph.len), skb->len - offset);
 			return 0;
 		}
 	}
@@ -250,104 +248,104 @@ check_udp(const struct iphdr *iph,
 	return 1;
 }
 
-#define	TH_FIN	0x01
-#define	TH_SYN	0x02
-#define	TH_RST	0x04
-#define	TH_PUSH	0x08
-#define	TH_ACK	0x10
-#define	TH_URG	0x20
-#define	TH_ECE	0x40
-#define	TH_CWR	0x80
-
 /* TCP-specific checks. */
 static int
-check_tcp(const struct iphdr *iph,
-	  const struct tcphdr *tcph,
-	  u_int16_t datalen,
+check_tcp(const struct sk_buff *skb,
 	  unsigned int offset,
+	  unsigned int fragoff,
 	  int more_frags,
 	  int embedded)
 {
-	u_int8_t *opt = (u_int8_t *)tcph;
-	u_int8_t *endhdr = (u_int8_t *)tcph + tcph->doff * 4;
-	u_int8_t tcpflags;
+	struct tcphdr tcph; 
+	unsigned char opt[15 * 4 - sizeof(struct tcphdr)];
+	u32 tcpflags;
 	int end_of_options = 0;
-	size_t i;
+	unsigned int i, optlen;
 
 	/* CHECK: Can't have offset=1: used to override TCP syn-checks. */
 	/* In fact, this is caught below (offset < 516). */
 
 	/* Can't do anything if it's a fragment. */
-	if (offset)
+	if (fragoff)
 		return 1;
 
 	/* CHECK: Smaller than minimal TCP hdr. */
-	if (datalen < sizeof(struct tcphdr)) {
+	if (skb_copy_bits(skb, offset, &tcph, sizeof(tcph)) < 0) {
+		u16 ports[2];
+
 		if (!embedded) {
-			limpk("Packet length %u < TCP header.\n", datalen);
+			limpk("Packet length %u < TCP header.\n",
+			      skb->len - offset);
 			return 0;
 		}
+
 		/* Must have ports available (datalen >= 8), from
                    check_icmp which set embedded = 1 */
 		/* CHECK: TCP ports inside ICMP error */
-		if (!tcph->source || !tcph->dest) {
+		skb_copy_bits(skb, offset, ports, sizeof(ports));
+		if (!ports[0] || !ports[1]) {
 			limpk("Zero TCP ports %u/%u.\n",
-			      htons(tcph->source), htons(tcph->dest));
+			      htons(ports[0]), htons(ports[1]));
 			return 0;
 		}
 		return 1;
 	}
 
-	/* CHECK: Smaller than actual TCP hdr. */
-	if (datalen < tcph->doff * 4) {
+	/* CHECK: TCP header claims tiny size. */
+	if (tcph.doff * 4 < sizeof(tcph)) {
+		limpk("TCP header claims tiny size %u\n", tcph.doff * 4);
+		return 0;
+	}
+
+	/* CHECK: Packet smaller than actual TCP hdr. */
+	optlen = tcph.doff*4 - sizeof(tcph);
+	if (skb_copy_bits(skb, offset + sizeof(tcph), opt, optlen) < 0) {
 		if (!embedded) {
 			limpk("Packet length %u < actual TCP header.\n",
-			      datalen);
+			      skb->len - offset);
 			return 0;
 		} else
 			return 1;
 	}
 
-	/* Bad checksum?  Don't print, just say it's unclean. */
-	/* FIXME: SRC ROUTE packets won't match checksum --RR */
-	if (!more_frags && !embedded
-	    && csum_tcpudp_magic(iph->saddr, iph->daddr, datalen, IPPROTO_TCP,
-				 csum_partial((char *)tcph, datalen, 0)) != 0)
-		return 0;
-
 	/* CHECK: TCP ports non-zero */
-	if (!tcph->source || !tcph->dest) {
+	if (!tcph.source || !tcph.dest) {
 		limpk("Zero TCP ports %u/%u.\n",
-		      htons(tcph->source), htons(tcph->dest));
+		      htons(tcph.source), htons(tcph.dest));
 		return 0;
 	}
 
+	tcpflags = tcp_flag_word(&tcph);
+
 	/* CHECK: TCP reserved bits zero. */
-	if(tcp_flag_word(tcph) & TCP_RESERVED_BITS) {
+	if (tcpflags & TCP_RESERVED_BITS) {
 		limpk("TCP reserved bits not zero\n");
 		return 0;
 	}
 
+	tcpflags &= ~(TCP_DATA_OFFSET | TCP_FLAG_CWR | TCP_FLAG_ECE
+		      | __constant_htonl(0x0000FFFF));
+
 	/* CHECK: TCP flags. */
-	tcpflags = (((u_int8_t *)tcph)[13] & ~(TH_ECE|TH_CWR));
-	if (tcpflags != TH_SYN
-	    && tcpflags != (TH_SYN|TH_ACK)
-		&& tcpflags != TH_RST
-	    && tcpflags != (TH_RST|TH_ACK)
-	    && tcpflags != (TH_RST|TH_ACK|TH_PUSH)
-	    && tcpflags != (TH_FIN|TH_ACK)
-	    && tcpflags != TH_ACK
-	    && tcpflags != (TH_ACK|TH_PUSH)
-	    && tcpflags != (TH_ACK|TH_URG)
-	    && tcpflags != (TH_ACK|TH_URG|TH_PUSH)
-	    && tcpflags != (TH_FIN|TH_ACK|TH_PUSH)
-	    && tcpflags != (TH_FIN|TH_ACK|TH_URG)
-	    && tcpflags != (TH_FIN|TH_ACK|TH_URG|TH_PUSH)) {
-		limpk("TCP flags bad: %u\n", tcpflags);
+	if (tcpflags != TCP_FLAG_SYN
+	    && tcpflags != (TCP_FLAG_SYN|TCP_FLAG_ACK)
+	    && tcpflags != TCP_FLAG_RST
+	    && tcpflags != (TCP_FLAG_RST|TCP_FLAG_ACK)
+	    && tcpflags != (TCP_FLAG_RST|TCP_FLAG_ACK|TCP_FLAG_PSH)
+	    && tcpflags != (TCP_FLAG_FIN|TCP_FLAG_ACK)
+	    && tcpflags != TCP_FLAG_ACK
+	    && tcpflags != (TCP_FLAG_ACK|TCP_FLAG_PSH)
+	    && tcpflags != (TCP_FLAG_ACK|TCP_FLAG_URG)
+	    && tcpflags != (TCP_FLAG_ACK|TCP_FLAG_URG|TCP_FLAG_PSH)
+	    && tcpflags != (TCP_FLAG_FIN|TCP_FLAG_ACK|TCP_FLAG_PSH)
+	    && tcpflags != (TCP_FLAG_FIN|TCP_FLAG_ACK|TCP_FLAG_URG)
+	    && tcpflags != (TCP_FLAG_FIN|TCP_FLAG_ACK|TCP_FLAG_URG
+			    |TCP_FLAG_PSH)) {
+		limpk("TCP flags bad: 0x%04X\n", ntohl(tcpflags) >> 16);
 		return 0;
 	}
 
-	for (i = sizeof(struct tcphdr); i < tcph->doff * 4; ) {
+	for (i = 0; i < optlen; ) {
 		switch (opt[i]) {
 		case 0:
 			end_of_options = 1;
@@ -364,7 +362,7 @@ check_tcp(const struct iphdr *iph,
 				return 0;
 			}
 			/* CHECK: options at tail. */
-			else if (i+1 >= tcph->doff * 4) {
+			else if (i+1 >= optlen) {
 				limpk("TCP option %u at tail\n",
 				      opt[i]);
 				return 0;
@@ -376,8 +374,8 @@ check_tcp(const struct iphdr *iph,
 				return 0;
 			}
 			/* CHECK: oversize options. */
-			else if (&opt[i] + opt[i+1] > endhdr) {
-				limpk("TCP option %u at %Zu too long\n",
+			else if (i + opt[i+1] > optlen) {
+				limpk("TCP option %u at %u too long\n",
 				      (unsigned int) opt[i], i);
 				return 0;
 			}
@@ -392,34 +390,44 @@ check_tcp(const struct iphdr *iph,
 /* Returns 1 if ok */
 /* Standard IP checks. */
 static int
-check_ip(struct iphdr *iph, size_t length, int embedded)
+check_ip(const struct sk_buff *skb, unsigned int offset)
 {
-	u_int8_t *opt = (u_int8_t *)iph;
-	u_int8_t *endhdr = (u_int8_t *)iph + iph->ihl * 4;
 	int end_of_options = 0;
-	void *protoh;
-	size_t datalen;
+	unsigned int datalen, optlen;
 	unsigned int i;
-	unsigned int offset;
+	unsigned int fragoff;
+	struct iphdr iph;
+	unsigned char opt[15 * 4 - sizeof(struct iphdr)];
+	int embedded = offset;
 
 	/* Should only happen for local outgoing raw-socket packets. */
 	/* CHECK: length >= ip header. */
-	if (length < sizeof(struct iphdr) || length < iph->ihl * 4) {
-		limpk("Packet length %Zu < IP header.\n", length);
+	if (skb_copy_bits(skb, offset, &iph, sizeof(iph)) < 0) {
+		limpk("Packet length %u < IP header.\n", skb->len - offset);
+		return 0;
+	}
+	if (iph.ihl * 4 < sizeof(iph)) {
+		limpk("IP len %u < minimum IP header.\n", iph.ihl*4);
+		return 0;
+	}
+
+	optlen = iph.ihl * 4 - sizeof(iph);
+	if (skb_copy_bits(skb, offset+sizeof(struct iphdr), opt, optlen)<0) {
+		limpk("Packet length %u < IP header %u.\n",
+		      skb->len - offset, iph.ihl * 4);
 		return 0;
 	}
 
-	offset = ntohs(iph->frag_off) & IP_OFFSET;
-	protoh = (void *)iph + iph->ihl * 4;
-	datalen = length - iph->ihl * 4;
+	fragoff = (ntohs(iph.frag_off) & IP_OFFSET);
+	datalen = skb->len - (offset + sizeof(struct iphdr) + optlen);
 
 	/* CHECK: Embedded fragment. */
-	if (embedded && offset) {
+	if (offset && fragoff) {
 		limpk("Embedded fragment.\n");
 		return 0;
 	}
 
-	for (i = sizeof(struct iphdr); i < iph->ihl * 4; ) {
+	for (i = 0; i < optlen; ) {
 		switch (opt[i]) {
 		case 0:
 			end_of_options = 1;
@@ -436,7 +444,7 @@ check_ip(struct iphdr *iph, size_t length, int embedded)
 				return 0;
 			}
 			/* CHECK: options at tail. */
-			else if (i+1 >= iph->ihl * 4) {
+			else if (i+1 >= optlen) {
 				limpk("IP option %u at tail\n",
 				      opt[i]);
 				return 0;
@@ -448,7 +456,7 @@ check_ip(struct iphdr *iph, size_t length, int embedded)
 				return 0;
 			}
 			/* CHECK: oversize options. */
-			else if (&opt[i] + opt[i+1] > endhdr) {
+			else if (i + opt[i+1] > optlen) {
 				limpk("IP option %u at %u too long\n",
 				      opt[i], i);
 				return 0;
@@ -461,30 +469,30 @@ check_ip(struct iphdr *iph, size_t length, int embedded)
 	/* Fragment checks. */
 
 	/* CHECK: More fragments, but doesn't fill 8-byte boundary. */
-	if ((ntohs(iph->frag_off) & IP_MF)
-	    && (ntohs(iph->tot_len) % 8) != 0) {
-		limpk("Truncated fragment %u long.\n", ntohs(iph->tot_len));
+	if ((ntohs(iph.frag_off) & IP_MF)
+	    && (ntohs(iph.tot_len) % 8) != 0) {
+		limpk("Truncated fragment %u long.\n", ntohs(iph.tot_len));
 		return 0;
 	}
 
 	/* CHECK: Oversize fragment a-la Ping of Death. */
-	if (offset * 8 + datalen > 65535) {
-		limpk("Oversize fragment to %u.\n", offset * 8);
+	if (fragoff * 8 + datalen > 65535) {
+		limpk("Oversize fragment to %u.\n", fragoff * 8);
 		return 0;
 	}
 
-	/* CHECK: DF set and offset or MF set. */
-	if ((ntohs(iph->frag_off) & IP_DF)
-	    && (offset || (ntohs(iph->frag_off) & IP_MF))) {
+	/* CHECK: DF set and fragoff or MF set. */
+	if ((ntohs(iph.frag_off) & IP_DF)
+	    && (fragoff || (ntohs(iph.frag_off) & IP_MF))) {
 		limpk("DF set and offset=%u, MF=%u.\n",
-		      offset, ntohs(iph->frag_off) & IP_MF);
+		      fragoff, ntohs(iph.frag_off) & IP_MF);
 		return 0;
 	}
 
 	/* CHECK: Zero-sized fragments. */
-	if ((offset || (ntohs(iph->frag_off) & IP_MF))
+	if ((fragoff || (ntohs(iph.frag_off) & IP_MF))
 	    && datalen == 0) {
-		limpk("Zero size fragment offset=%u\n", offset);
+		limpk("Zero size fragment offset=%u\n", fragoff);
 		return 0;
 	}
 
@@ -500,52 +508,54 @@ check_ip(struct iphdr *iph, size_t length, int embedded)
 	   here. */
 #define MIN_LIKELY_MTU 128
 	/* CHECK: Min size of first frag = 128. */
-	if ((ntohs(iph->frag_off) & IP_MF)
-	    && offset == 0
-	    && ntohs(iph->tot_len) < MIN_LIKELY_MTU) {
-		limpk("First fragment size %u < %u\n", ntohs(iph->tot_len),
+	if ((ntohs(iph.frag_off) & IP_MF)
+	    && fragoff == 0
+	    && ntohs(iph.tot_len) < MIN_LIKELY_MTU) {
+		limpk("First fragment size %u < %u\n", ntohs(iph.tot_len),
 		      MIN_LIKELY_MTU);
 		return 0;
 	}
 
 	/* CHECK: Min offset of frag = 128 - IP hdr len. */
-	if (offset && offset * 8 < MIN_LIKELY_MTU - iph->ihl * 4) {
-		limpk("Fragment starts at %u < %u\n", offset * 8,
-		      MIN_LIKELY_MTU - iph->ihl * 4);
+	if (fragoff && fragoff * 8 < MIN_LIKELY_MTU - iph.ihl * 4) {
+		limpk("Fragment starts at %u < %u\n", fragoff * 8,
+		      MIN_LIKELY_MTU - iph.ihl * 4);
 		return 0;
 	}
 
 	/* CHECK: Protocol specification non-zero. */
-	if (iph->protocol == 0) {
+	if (iph.protocol == 0) {
 		limpk("Zero protocol\n");
 		return 0;
 	}
 
+	/* FIXME: This is already checked for in "Oversize fragment"
+           above --RR */
 	/* CHECK: Do not use what is unused.
 	 * First bit of fragmentation flags should be unused.
 	 * May be used by OS fingerprinting tools.
 	 * 04 Jun 2002, Maciej Soltysiak, solt@dns.toxicfilms.tv
 	 */
-	if (ntohs(iph->frag_off)>>15) {
+	if (ntohs(iph.frag_off)>>15) {
 		limpk("IP unused bit set\n");
 		return 0;
 	}
 
 	/* Per-protocol checks. */
-	switch (iph->protocol) {
+	switch (iph.protocol) {
 	case IPPROTO_ICMP:
-		return check_icmp(protoh, datalen, offset,
-				  (ntohs(iph->frag_off) & IP_MF),
+		return check_icmp(skb, offset + iph.ihl*4, fragoff,
+				  (ntohs(iph.frag_off) & IP_MF),
 				  embedded);
 
 	case IPPROTO_UDP:
-		return check_udp(iph, protoh, datalen, offset,
-				 (ntohs(iph->frag_off) & IP_MF),
+		return check_udp(skb, offset + iph.ihl*4, fragoff,
+				 (ntohs(iph.frag_off) & IP_MF),
 				 embedded);
 
 	case IPPROTO_TCP:
-		return check_tcp(iph, protoh, datalen, offset,
-				 (ntohs(iph->frag_off) & IP_MF),
+		return check_tcp(skb, offset + iph.ihl*4, fragoff,
+				 (ntohs(iph.frag_off) & IP_MF),
 				 embedded);
 	default:
 		/* Ignorance is bliss. */
@@ -559,11 +569,9 @@ match(const struct sk_buff *skb,
       const struct net_device *out,
       const void *matchinfo,
       int offset,
-      const void *hdr,
-      u_int16_t datalen,
       int *hotdrop)
 {
-	return !check_ip(skb->nh.iph, skb->len, 0);
+	return !check_ip(skb, 0);
 }
 
 /* Called when user tries to insert an entry of this type. */
diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c
index 1fd038191f34..5dcfcf8a121f 100644
--- a/net/ipv6/anycast.c
+++ b/net/ipv6/anycast.c
@@ -127,8 +127,8 @@ int ipv6_sock_ac_join(struct sock *sk, int ifindex, struct in6_addr *addr)
 			dev_hold(dev);
 			dst_release(&rt->u.dst);
 		} else if (ishost) {
-			sock_kfree_s(sk, pac, sizeof(*pac));
-			return -EADDRNOTAVAIL;
+			err = -EADDRNOTAVAIL;
+			goto out_free_pac;
 		} else {
 			/* router, no matching interface: just pick one */
 
@@ -138,18 +138,17 @@ int ipv6_sock_ac_join(struct sock *sk, int ifindex, struct in6_addr *addr)
 		dev = dev_get_by_index(ifindex);
 
 	if (dev == NULL) {
-		sock_kfree_s(sk, pac, sizeof(*pac));
-		return -ENODEV;
+		err = -ENODEV;
+		goto out_free_pac;
 	}
 
 	idev = in6_dev_get(dev);
 	if (!idev) {
-		sock_kfree_s(sk, pac, sizeof(*pac));
-		dev_put(dev);
 		if (ifindex)
-			return -ENODEV;
+			err = -ENODEV;
 		else
-			return -EADDRNOTAVAIL;
+			err = -EADDRNOTAVAIL;
+		goto out_dev_put;
 	}
 	/* reset ishost, now that we have a specific device */
 	ishost = !idev->cnf.forwarding;
@@ -170,21 +169,17 @@ int ipv6_sock_ac_join(struct sock *sk, int ifindex, struct in6_addr *addr)
 			err = -EADDRNOTAVAIL;
 		else if (!capable(CAP_NET_ADMIN))
 			err = -EPERM;
-		if (err) {
-			sock_kfree_s(sk, pac, sizeof(*pac));
-			dev_put(dev);
-			return err;
-		}
+		if (err)
+			goto out_dev_put;
 	} else if (!(ipv6_addr_type(addr) & IPV6_ADDR_ANYCAST) &&
-		   !capable(CAP_NET_ADMIN))
-		return -EPERM;
+		   !capable(CAP_NET_ADMIN)) {
+		err = -EPERM;
+		goto out_dev_put;
+	}
 
 	err = ipv6_dev_ac_inc(dev, addr);
-	if (err) {
-		sock_kfree_s(sk, pac, sizeof(*pac));
-		dev_put(dev);
-		return err;
-	}
+	if (err)
+		goto out_dev_put;
 
 	write_lock_bh(&ipv6_sk_ac_lock);
 	pac->acl_next = np->ipv6_ac_list;
@@ -194,6 +189,12 @@ int ipv6_sock_ac_join(struct sock *sk, int ifindex, struct in6_addr *addr)
 	dev_put(dev);
 
 	return 0;
+
+out_dev_put:
+	dev_put(dev);
+out_free_pac:
+	sock_kfree_s(sk, pac, sizeof(*pac));
+	return err;
 }
 
 /*
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 6e7a4ce74e4d..48ecdcc35dae 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -441,8 +441,10 @@ static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
 		src_addr = solicited_addr;
 		in6_ifa_put(ifp);
 	} else {
-		if (ipv6_dev_get_saddr(dev, daddr, &tmpaddr, 0))
+		if (ipv6_dev_get_saddr(dev, daddr, &tmpaddr, 0)) {
+			dst_free(dst);
 			return;
+		}
 		src_addr = &tmpaddr;
 	}
 
@@ -450,11 +452,10 @@ static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
 	ndisc_rt_init(rt, dev, neigh);	
 
 	dst = (struct dst_entry*)rt;
-	dst_clone(dst);
 
 	err = xfrm_lookup(&dst, &fl, NULL, 0);
 	if (err < 0) {
-		dst_release(dst);
+		dst_free(dst);
 		return;
 	}
 
@@ -470,6 +471,7 @@ static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
 
 	if (skb == NULL) {
 		ND_PRINTK1("send_na: alloc skb failed\n");
+		dst_free(dst);
 		return;
 	}