[NET]: Replace CHECKSUM_HW by CHECKSUM_PARTIAL/CHECKSUM_COMPLETE

Replace CHECKSUM_HW by CHECKSUM_PARTIAL (for outgoing packets, whose
checksum still needs to be completed) and CHECKSUM_COMPLETE (for
incoming packets, device supplied full checksum).

Patch originally from Herbert Xu, updated by myself for 2.6.18-rc3.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

40 files changed, 98 insertions, 101 deletions

diff --git a/net/core/datagram.c b/net/core/datagram.c
index aecddcc..f558c61 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -417,7 +417,7 @@ unsigned int __skb_checksum_complete(struct sk_buff *skb)
 
 	sum = (u16)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum));
 	if (likely(!sum)) {
-		if (unlikely(skb->ip_summed == CHECKSUM_HW))
+		if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE))
 			netdev_rx_csum_fault(skb->dev);
 		skb->ip_summed = CHECKSUM_UNNECESSARY;
 	}
@@ -462,7 +462,7 @@ int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
 			goto fault;
 		if ((unsigned short)csum_fold(csum))
 			goto csum_error;
-		if (unlikely(skb->ip_summed == CHECKSUM_HW))
+		if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE))
 			netdev_rx_csum_fault(skb->dev);
 		iov->iov_len -= chunk;
 		iov->iov_base += chunk;
diff --git a/net/core/dev.c b/net/core/dev.c
index d4a1ec3..fc82f6f 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1166,12 +1166,12 @@ EXPORT_SYMBOL(netif_device_attach);
  * Invalidate hardware checksum when packet is to be mangled, and
  * complete checksum manually on outgoing path.
  */
-int skb_checksum_help(struct sk_buff *skb, int inward)
+int skb_checksum_help(struct sk_buff *skb)
 {
 	unsigned int csum;
 	int ret = 0, offset = skb->h.raw - skb->data;
 
-	if (inward)
+	if (skb->ip_summed == CHECKSUM_COMPLETE)
 		goto out_set_summed;
 
 	if (unlikely(skb_shinfo(skb)->gso_size)) {
@@ -1223,7 +1223,7 @@ struct sk_buff *skb_gso_segment(struct sk_buff *skb, int features)
 	skb->mac_len = skb->nh.raw - skb->data;
 	__skb_pull(skb, skb->mac_len);
 
-	if (unlikely(skb->ip_summed != CHECKSUM_HW)) {
+	if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
 		if (skb_header_cloned(skb) &&
 		    (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
 			return ERR_PTR(err);
@@ -1232,7 +1232,7 @@ struct sk_buff *skb_gso_segment(struct sk_buff *skb, int features)
 	rcu_read_lock();
 	list_for_each_entry_rcu(ptype, &ptype_base[ntohs(type) & 15], list) {
 		if (ptype->type == type && !ptype->dev && ptype->gso_segment) {
-			if (unlikely(skb->ip_summed != CHECKSUM_HW)) {
+			if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
 				err = ptype->gso_send_check(skb);
 				segs = ERR_PTR(err);
 				if (err || skb_gso_ok(skb, features))
@@ -1444,11 +1444,11 @@ int dev_queue_xmit(struct sk_buff *skb)
 	/* If packet is not checksummed and device does not support
 	 * checksumming for this protocol, complete checksumming here.
 	 */
-	if (skb->ip_summed == CHECKSUM_HW &&
+	if (skb->ip_summed == CHECKSUM_PARTIAL &&
 	    (!(dev->features & NETIF_F_GEN_CSUM) &&
 	     (!(dev->features & NETIF_F_IP_CSUM) ||
 	      skb->protocol != htons(ETH_P_IP))))
-	      	if (skb_checksum_help(skb, 0))
+	      	if (skb_checksum_help(skb))
 	      		goto out_kfree_skb;
 
 gso:
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index 471da45..ead5920 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -110,7 +110,7 @@ static int checksum_udp(struct sk_buff *skb, struct udphdr *uh,
 
 	psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
 
-	if (skb->ip_summed == CHECKSUM_HW &&
+	if (skb->ip_summed == CHECKSUM_COMPLETE &&
 	    !(u16)csum_fold(csum_add(psum, skb->csum)))
 		return 0;
 
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index c54f366..8a476f1 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1397,7 +1397,7 @@ void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to)
 	unsigned int csum;
 	long csstart;
 
-	if (skb->ip_summed == CHECKSUM_HW)
+	if (skb->ip_summed == CHECKSUM_PARTIAL)
 		csstart = skb->h.raw - skb->data;
 	else
 		csstart = skb_headlen(skb);
@@ -1411,7 +1411,7 @@ void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to)
 		csum = skb_copy_and_csum_bits(skb, csstart, to + csstart,
 					      skb->len - csstart, 0);
 
-	if (skb->ip_summed == CHECKSUM_HW) {
+	if (skb->ip_summed == CHECKSUM_PARTIAL) {
 		long csstuff = csstart + skb->csum;
 
 		*((unsigned short *)(to + csstuff)) = csum_fold(csum);
@@ -1898,10 +1898,10 @@ int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
  *	@len: length of data pulled
  *
  *	This function performs an skb_pull on the packet and updates
- *	update the CHECKSUM_HW checksum.  It should be used on receive
- *	path processing instead of skb_pull unless you know that the
- *	checksum difference is zero (e.g., a valid IP header) or you
- *	are setting ip_summed to CHECKSUM_NONE.
+ *	update the CHECKSUM_COMPLETE checksum.  It should be used on
+ *	receive path processing instead of skb_pull unless you know
+ *	that the checksum difference is zero (e.g., a valid IP header)
+ *	or you are setting ip_summed to CHECKSUM_NONE.
  */
 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len)
 {
@@ -1994,7 +1994,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, int features)
 		frag = skb_shinfo(nskb)->frags;
 		k = 0;
 
-		nskb->ip_summed = CHECKSUM_HW;
+		nskb->ip_summed = CHECKSUM_PARTIAL;
 		nskb->csum = skb->csum;
 		memcpy(skb_put(nskb, hsize), skb->data + offset, hsize);
 
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 6ad797c..6d223e5 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -930,7 +930,7 @@ int icmp_rcv(struct sk_buff *skb)
 	ICMP_INC_STATS_BH(ICMP_MIB_INMSGS);
 
 	switch (skb->ip_summed) {
-	case CHECKSUM_HW:
+	case CHECKSUM_COMPLETE:
 		if (!(u16)csum_fold(skb->csum))
 			break;
 		/* fall through */
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 8e8117c..7003e76 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -931,7 +931,7 @@ int igmp_rcv(struct sk_buff *skb)
 		goto drop;
 
 	switch (skb->ip_summed) {
-	case CHECKSUM_HW:
+	case CHECKSUM_COMPLETE:
 		if (!(u16)csum_fold(skb->csum))
 			break;
 		/* fall through */
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index b84b53a..8d7f107 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -665,7 +665,7 @@ static struct sk_buff *ip_frag_reasm(struct ipq *qp, struct net_device *dev)
 		head->len += fp->len;
 		if (head->ip_summed != fp->ip_summed)
 			head->ip_summed = CHECKSUM_NONE;
-		else if (head->ip_summed == CHECKSUM_HW)
+		else if (head->ip_summed == CHECKSUM_COMPLETE)
 			head->csum = csum_add(head->csum, fp->csum);
 		head->truesize += fp->truesize;
 		atomic_sub(fp->truesize, &ip_frag_mem);
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 0f9b3a3..e66f6ff 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -576,7 +576,7 @@ static int ipgre_rcv(struct sk_buff *skb)
 
 		if (flags&GRE_CSUM) {
 			switch (skb->ip_summed) {
-			case CHECKSUM_HW:
+			case CHECKSUM_COMPLETE:
 				csum = (u16)csum_fold(skb->csum);
 				if (!csum)
 					break;
@@ -584,7 +584,7 @@ static int ipgre_rcv(struct sk_buff *skb)
 			case CHECKSUM_NONE:
 				skb->csum = 0;
 				csum = __skb_checksum_complete(skb);
-				skb->ip_summed = CHECKSUM_HW;
+				skb->ip_summed = CHECKSUM_COMPLETE;
 			}
 			offset += 4;
 		}
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 308bdea..1b9b674 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -680,7 +680,7 @@ ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk
 {
 	struct iovec *iov = from;
 
-	if (skb->ip_summed == CHECKSUM_HW) {
+	if (skb->ip_summed == CHECKSUM_PARTIAL) {
 		if (memcpy_fromiovecend(to, iov, offset, len) < 0)
 			return -EFAULT;
 	} else {
@@ -736,7 +736,7 @@ static inline int ip_ufo_append_data(struct sock *sk,
 		/* initialize protocol header pointer */
 		skb->h.raw = skb->data + fragheaderlen;
 
-		skb->ip_summed = CHECKSUM_HW;
+		skb->ip_summed = CHECKSUM_PARTIAL;
 		skb->csum = 0;
 		sk->sk_sndmsg_off = 0;
 	}
@@ -844,7 +844,7 @@ int ip_append_data(struct sock *sk,
 	    length + fragheaderlen <= mtu &&
 	    rt->u.dst.dev->features & NETIF_F_ALL_CSUM &&
 	    !exthdrlen)
-		csummode = CHECKSUM_HW;
+		csummode = CHECKSUM_PARTIAL;
 
 	inet->cork.length += length;
 	if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) &&
diff --git a/net/ipv4/ipvs/ip_vs_proto_tcp.c b/net/ipv4/ipvs/ip_vs_proto_tcp.c
index bc28b11..820e831 100644
--- a/net/ipv4/ipvs/ip_vs_proto_tcp.c
+++ b/net/ipv4/ipvs/ip_vs_proto_tcp.c
@@ -151,7 +151,7 @@ tcp_snat_handler(struct sk_buff **pskb,
 		/* Only port and addr are changed, do fast csum update */
 		tcp_fast_csum_update(tcph, cp->daddr, cp->vaddr,
 				     cp->dport, cp->vport);
-		if ((*pskb)->ip_summed == CHECKSUM_HW)
+		if ((*pskb)->ip_summed == CHECKSUM_COMPLETE)
 			(*pskb)->ip_summed = CHECKSUM_NONE;
 	} else {
 		/* full checksum calculation */
@@ -204,7 +204,7 @@ tcp_dnat_handler(struct sk_buff **pskb,
 		/* Only port and addr are changed, do fast csum update */
 		tcp_fast_csum_update(tcph, cp->vaddr, cp->daddr,
 				     cp->vport, cp->dport);
-		if ((*pskb)->ip_summed == CHECKSUM_HW)
+		if ((*pskb)->ip_summed == CHECKSUM_COMPLETE)
 			(*pskb)->ip_summed = CHECKSUM_NONE;
 	} else {
 		/* full checksum calculation */
@@ -229,7 +229,7 @@ tcp_csum_check(struct sk_buff *skb, struct ip_vs_protocol *pp)
 	switch (skb->ip_summed) {
 	case CHECKSUM_NONE:
 		skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0);
-	case CHECKSUM_HW:
+	case CHECKSUM_COMPLETE:
 		if (csum_tcpudp_magic(skb->nh.iph->saddr, skb->nh.iph->daddr,
 				      skb->len - tcphoff,
 				      skb->nh.iph->protocol, skb->csum)) {
@@ -239,7 +239,7 @@ tcp_csum_check(struct sk_buff *skb, struct ip_vs_protocol *pp)
 		}
 		break;
 	default:
-		/* CHECKSUM_UNNECESSARY */
+		/* No need to checksum. */
 		break;
 	}
 
diff --git a/net/ipv4/ipvs/ip_vs_proto_udp.c b/net/ipv4/ipvs/ip_vs_proto_udp.c
index 89d9175..90c8166 100644
--- a/net/ipv4/ipvs/ip_vs_proto_udp.c
+++ b/net/ipv4/ipvs/ip_vs_proto_udp.c
@@ -161,7 +161,7 @@ udp_snat_handler(struct sk_buff **pskb,
 		/* Only port and addr are changed, do fast csum update */
 		udp_fast_csum_update(udph, cp->daddr, cp->vaddr,
 				     cp->dport, cp->vport);
-		if ((*pskb)->ip_summed == CHECKSUM_HW)
+		if ((*pskb)->ip_summed == CHECKSUM_COMPLETE)
 			(*pskb)->ip_summed = CHECKSUM_NONE;
 	} else {
 		/* full checksum calculation */
@@ -216,7 +216,7 @@ udp_dnat_handler(struct sk_buff **pskb,
 		/* Only port and addr are changed, do fast csum update */
 		udp_fast_csum_update(udph, cp->vaddr, cp->daddr,
 				     cp->vport, cp->dport);
-		if ((*pskb)->ip_summed == CHECKSUM_HW)
+		if ((*pskb)->ip_summed == CHECKSUM_COMPLETE)
 			(*pskb)->ip_summed = CHECKSUM_NONE;
 	} else {
 		/* full checksum calculation */
@@ -250,7 +250,7 @@ udp_csum_check(struct sk_buff *skb, struct ip_vs_protocol *pp)
 		case CHECKSUM_NONE:
 			skb->csum = skb_checksum(skb, udphoff,
 						 skb->len - udphoff, 0);
-		case CHECKSUM_HW:
+		case CHECKSUM_COMPLETE:
 			if (csum_tcpudp_magic(skb->nh.iph->saddr,
 					      skb->nh.iph->daddr,
 					      skb->len - udphoff,
@@ -262,7 +262,7 @@ udp_csum_check(struct sk_buff *skb, struct ip_vs_protocol *pp)
 			}
 			break;
 		default:
-			/* CHECKSUM_UNNECESSARY */
+			/* No need to checksum. */
 			break;
 		}
 	}
diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c
index 6a9e34b..f88347d 100644
--- a/net/ipv4/netfilter.c
+++ b/net/ipv4/netfilter.c
@@ -168,7 +168,7 @@ unsigned int nf_ip_checksum(struct sk_buff *skb, unsigned int hook,
 	unsigned int csum = 0;
 
 	switch (skb->ip_summed) {
-	case CHECKSUM_HW:
+	case CHECKSUM_COMPLETE:
 		if (hook != NF_IP_PRE_ROUTING && hook != NF_IP_LOCAL_IN)
 			break;
 		if ((protocol == 0 && !(u16)csum_fold(skb->csum)) ||
diff --git a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
index fb920e7..9de81ff 100644
--- a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
@@ -865,8 +865,7 @@ static int tcp_error(struct sk_buff *skb,
   
 	/* Checksum invalid? Ignore.
 	 * We skip checking packets on the outgoing path
-	 * because the semantic of CHECKSUM_HW is different there 
-	 * and moreover root might send raw packets.
+	 * because it is assumed to be correct.
 	 */
 	/* FIXME: Source route IP option packets --RR */
 	if (ip_conntrack_checksum && hooknum == NF_IP_PRE_ROUTING &&
diff --git a/net/ipv4/netfilter/ip_conntrack_proto_udp.c b/net/ipv4/netfilter/ip_conntrack_proto_udp.c
index 9b2c16b..e58e52f 100644
--- a/net/ipv4/netfilter/ip_conntrack_proto_udp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_udp.c
@@ -117,8 +117,7 @@ static int udp_error(struct sk_buff *skb, enum ip_conntrack_info *ctinfo,
 
 	/* Checksum invalid? Ignore.
 	 * We skip checking packets on the outgoing path
-	 * because the semantic of CHECKSUM_HW is different there 
-	 * and moreover root might send raw packets.
+	 * because the checksum is assumed to be correct.
 	 * FIXME: Source route IP option packets --RR */
 	if (ip_conntrack_checksum && hooknum == NF_IP_PRE_ROUTING &&
 	    nf_ip_checksum(skb, hooknum, iph->ihl * 4, IPPROTO_UDP)) {
diff --git a/net/ipv4/netfilter/ip_nat_standalone.c b/net/ipv4/netfilter/ip_nat_standalone.c
index 17de077..f4f00c8 100644
--- a/net/ipv4/netfilter/ip_nat_standalone.c
+++ b/net/ipv4/netfilter/ip_nat_standalone.c
@@ -111,8 +111,9 @@ ip_nat_fn(unsigned int hooknum,
 		       & htons(IP_MF|IP_OFFSET)));
 
 	/* If we had a hardware checksum before, it's now invalid */
-	if ((*pskb)->ip_summed == CHECKSUM_HW)
-		if (skb_checksum_help(*pskb, (out == NULL)))
+	if ((*pskb)->ip_summed == CHECKSUM_PARTIAL ||
+	    (*pskb)->ip_summed == CHECKSUM_COMPLETE)
+		if (skb_checksum_help(*pskb))
 			return NF_DROP;
 
 	ct = ip_conntrack_get(*pskb, &ctinfo);
diff --git a/net/ipv4/netfilter/ip_queue.c b/net/ipv4/netfilter/ip_queue.c
index 198ac36..276a964 100644
--- a/net/ipv4/netfilter/ip_queue.c
+++ b/net/ipv4/netfilter/ip_queue.c
@@ -208,9 +208,9 @@ ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
 		break;
 	
 	case IPQ_COPY_PACKET:
-		if (entry->skb->ip_summed == CHECKSUM_HW &&
-		    (*errp = skb_checksum_help(entry->skb,
-		                               entry->info->outdev == NULL))) {
+		if ((entry->skb->ip_summed == CHECKSUM_PARTIAL ||
+		     entry->skb->ip_summed == CHECKSUM_COMPLETE) &&
+		    (*errp = skb_checksum_help(entry->skb))) {
 			read_unlock_bh(&queue_lock);
 			return NULL;
 		}
diff --git a/net/ipv4/netfilter/ipt_ECN.c b/net/ipv4/netfilter/ipt_ECN.c
index 4adf5c9..4ec43f9 100644
--- a/net/ipv4/netfilter/ipt_ECN.c
+++ b/net/ipv4/netfilter/ipt_ECN.c
@@ -49,7 +49,7 @@ set_ect_ip(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
 
 /* Return 0 if there was an error. */
 static inline int
-set_ect_tcp(struct sk_buff **pskb, const struct ipt_ECN_info *einfo, int inward)
+set_ect_tcp(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
 {
 	struct tcphdr _tcph, *tcph;
 	u_int16_t diffs[2];
@@ -70,8 +70,9 @@ set_ect_tcp(struct sk_buff **pskb, const struct ipt_ECN_info *einfo, int inward)
 		return 0;
 	tcph = (void *)(*pskb)->nh.iph + (*pskb)->nh.iph->ihl*4;
 
-	if ((*pskb)->ip_summed == CHECKSUM_HW &&
-	    skb_checksum_help(*pskb, inward))
+	if (((*pskb)->ip_summed == CHECKSUM_PARTIAL ||
+	     (*pskb)->ip_summed == CHECKSUM_COMPLETE) &&
+	    skb_checksum_help(*pskb))
 		return 0;
 
 	diffs[0] = ((u_int16_t *)tcph)[6];
@@ -106,7 +107,7 @@ target(struct sk_buff **pskb,
 
 	if (einfo->operation & (IPT_ECN_OP_SET_ECE | IPT_ECN_OP_SET_CWR)
 	    && (*pskb)->nh.iph->protocol == IPPROTO_TCP)
-		if (!set_ect_tcp(pskb, einfo, (out == NULL)))
+		if (!set_ect_tcp(pskb, einfo))
 			return NF_DROP;
 
 	return IPT_CONTINUE;
diff --git a/net/ipv4/netfilter/ipt_TCPMSS.c b/net/ipv4/netfilter/ipt_TCPMSS.c
index ef2fe5b..c998dc0 100644
--- a/net/ipv4/netfilter/ipt_TCPMSS.c
+++ b/net/ipv4/netfilter/ipt_TCPMSS.c
@@ -62,8 +62,9 @@ ipt_tcpmss_target(struct sk_buff **pskb,
 	if (!skb_make_writable(pskb, (*pskb)->len))
 		return NF_DROP;
 
-	if ((*pskb)->ip_summed == CHECKSUM_HW &&
-	    skb_checksum_help(*pskb, out == NULL))
+	if (((*pskb)->ip_summed == CHECKSUM_PARTIAL ||
+	     (*pskb)->ip_summed == CHECKSUM_COMPLETE) &&
+	    skb_checksum_help(*pskb))
 		return NF_DROP;
 
 	iph = (*pskb)->nh.iph;
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 934396b..b0124e69 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -568,7 +568,7 @@ new_segment:
 		skb->truesize += copy;
 		sk->sk_wmem_queued += copy;
 		sk->sk_forward_alloc -= copy;
-		skb->ip_summed = CHECKSUM_HW;
+		skb->ip_summed = CHECKSUM_PARTIAL;
 		tp->write_seq += copy;
 		TCP_SKB_CB(skb)->end_seq += copy;
 		skb_shinfo(skb)->gso_segs = 0;
@@ -723,7 +723,7 @@ new_segment:
 				 * Check whether we can use HW checksum.
 				 */
 				if (sk->sk_route_caps & NETIF_F_ALL_CSUM)
-					skb->ip_summed = CHECKSUM_HW;
+					skb->ip_summed = CHECKSUM_PARTIAL;
 
 				skb_entail(sk, tp, skb);
 				copy = size_goal;
@@ -2205,7 +2205,7 @@ struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features)
 		th->fin = th->psh = 0;
 
 		th->check = ~csum_fold(th->check + delta);
-		if (skb->ip_summed != CHECKSUM_HW)
+		if (skb->ip_summed != CHECKSUM_PARTIAL)
 			th->check = csum_fold(csum_partial(skb->h.raw, thlen,
 							   skb->csum));
 
@@ -2219,7 +2219,7 @@ struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features)
 
 	delta = htonl(oldlen + (skb->tail - skb->h.raw) + skb->data_len);
 	th->check = ~csum_fold(th->check + delta);
-	if (skb->ip_summed != CHECKSUM_HW)
+	if (skb->ip_summed != CHECKSUM_PARTIAL)
 		th->check = csum_fold(csum_partial(skb->h.raw, thlen,
 						   skb->csum));
 
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 43f6740..b2aa512 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -484,7 +484,7 @@ void tcp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb)
 	struct inet_sock *inet = inet_sk(sk);
 	struct tcphdr *th = skb->h.th;
 
-	if (skb->ip_summed == CHECKSUM_HW) {
+	if (skb->ip_summed == CHECKSUM_PARTIAL) {
 		th->check = ~tcp_v4_check(th, len, inet->saddr, inet->daddr, 0);
 		skb->csum = offsetof(struct tcphdr, check);
 	} else {
@@ -509,7 +509,7 @@ int tcp_v4_gso_send_check(struct sk_buff *skb)
 	th->check = 0;
 	th->check = ~tcp_v4_check(th, skb->len, iph->saddr, iph->daddr, 0);
 	skb->csum = offsetof(struct tcphdr, check);
-	skb->ip_summed = CHECKSUM_HW;
+	skb->ip_summed = CHECKSUM_PARTIAL;
 	return 0;
 }
 
@@ -973,7 +973,7 @@ static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
 
 static int tcp_v4_checksum_init(struct sk_buff *skb)
 {
-	if (skb->ip_summed == CHECKSUM_HW) {
+	if (skb->ip_summed == CHECKSUM_COMPLETE) {
 		if (!tcp_v4_check(skb->h.th, skb->len, skb->nh.iph->saddr,
 				  skb->nh.iph->daddr, skb->csum)) {
 			skb->ip_summed = CHECKSUM_UNNECESSARY;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index b4f3ffe..9252a50 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -577,7 +577,7 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss
 	TCP_SKB_CB(buff)->sacked = TCP_SKB_CB(skb)->sacked;
 	TCP_SKB_CB(skb)->sacked &= ~TCPCB_AT_TAIL;
 
-	if (!skb_shinfo(skb)->nr_frags && skb->ip_summed != CHECKSUM_HW) {
+	if (!skb_shinfo(skb)->nr_frags && skb->ip_summed != CHECKSUM_PARTIAL) {
 		/* Copy and checksum data tail into the new buffer. */
 		buff->csum = csum_partial_copy_nocheck(skb->data + len, skb_put(buff, nsize),
 						       nsize, 0);
@@ -586,7 +586,7 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss
 
 		skb->csum = csum_block_sub(skb->csum, buff->csum, len);
 	} else {
-		skb->ip_summed = CHECKSUM_HW;
+		skb->ip_summed = CHECKSUM_PARTIAL;
 		skb_split(skb, buff, len);
 	}
 
@@ -689,7 +689,7 @@ int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
 		__pskb_trim_head(skb, len - skb_headlen(skb));
 
 	TCP_SKB_CB(skb)->seq += len;
-	skb->ip_summed = CHECKSUM_HW;
+	skb->ip_summed = CHECKSUM_PARTIAL;
 
 	skb->truesize	     -= len;
 	sk->sk_wmem_queued   -= len;
@@ -1062,7 +1062,7 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
 	/* This packet was never sent out yet, so no SACK bits. */
 	TCP_SKB_CB(buff)->sacked = 0;
 
-	buff->ip_summed = skb->ip_summed = CHECKSUM_HW;
+	buff->ip_summed = skb->ip_summed = CHECKSUM_PARTIAL;
 	skb_split(skb, buff, len);
 
 	/* Fix up tso_factor for both original and new SKB.  */
@@ -1206,8 +1206,7 @@ static int tcp_mtu_probe(struct sock *sk)
 	TCP_SKB_CB(nskb)->flags = TCPCB_FLAG_ACK;
 	TCP_SKB_CB(nskb)->sacked = 0;
 	nskb->csum = 0;
-	if (skb->ip_summed == CHECKSUM_HW)
-		nskb->ip_summed = CHECKSUM_HW;
+	nskb->ip_summed = skb->ip_summed;
 
 	len = 0;
 	while (len < probe_size) {
@@ -1231,7 +1230,7 @@ static int tcp_mtu_probe(struct sock *sk)
 			                           ~(TCPCB_FLAG_FIN|TCPCB_FLAG_PSH);
 			if (!skb_shinfo(skb)->nr_frags) {
 				skb_pull(skb, copy);
-				if (skb->ip_summed != CHECKSUM_HW)
+				if (skb->ip_summed != CHECKSUM_PARTIAL)
 					skb->csum = csum_partial(skb->data, skb->len, 0);
 			} else {
 				__pskb_trim_head(skb, copy);
@@ -1572,10 +1571,9 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, int m
 
 		memcpy(skb_put(skb, next_skb_size), next_skb->data, next_skb_size);
 
-		if (next_skb->ip_summed == CHECKSUM_HW)
-			skb->ip_summed = CHECKSUM_HW;
+		skb->ip_summed = next_skb->ip_summed;
 
-		if (skb->ip_summed != CHECKSUM_HW)
+		if (skb->ip_summed != CHECKSUM_PARTIAL)
 			skb->csum = csum_block_add(skb->csum, next_skb->csum, skb_size);
 
 		/* Update sequence range on original skb. */
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index a4d005e..8715251 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -429,7 +429,7 @@ static int udp_push_pending_frames(struct sock *sk, struct udp_sock *up)
 		/*
 		 * Only one fragment on the socket.
 		 */
-		if (skb->ip_summed == CHECKSUM_HW) {
+		if (skb->ip_summed == CHECKSUM_PARTIAL) {
 			skb->csum = offsetof(struct udphdr, check);
 			uh->check = ~csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst,
 					up->len, IPPROTO_UDP, 0);
@@ -448,7 +448,7 @@ static int udp_push_pending_frames(struct sock *sk, struct udp_sock *up)
 		 * fragments on the socket so that all csums of sk_buffs
 		 * should be together.
 		 */
-		if (skb->ip_summed == CHECKSUM_HW) {
+		if (skb->ip_summed == CHECKSUM_PARTIAL) {
 			int offset = (unsigned char *)uh - skb->data;
 			skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
 
@@ -1088,7 +1088,7 @@ static void udp_checksum_init(struct sk_buff *skb, struct udphdr *uh,
 {
 	if (uh->check == 0) {
 		skb->ip_summed = CHECKSUM_UNNECESSARY;
-	} else if (skb->ip_summed == CHECKSUM_HW) {
+	} else if (skb->ip_summed == CHECKSUM_COMPLETE) {
 		if (!udp_check(uh, ulen, saddr, daddr, skb->csum))
 			skb->ip_summed = CHECKSUM_UNNECESSARY;
 	}
diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c
index d16f863..4a96a9e 100644
--- a/net/ipv4/xfrm4_output.c
+++ b/net/ipv4/xfrm4_output.c
@@ -48,8 +48,8 @@ static int xfrm4_output_one(struct sk_buff *skb)
 	struct xfrm_state *x = dst->xfrm;
 	int err;
 	
-	if (skb->ip_summed == CHECKSUM_HW) {
-		err = skb_checksum_help(skb, 0);
+	if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		err = skb_checksum_help(skb);
 		if (err)
 			goto error_nolock;
 	}
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 86dac10..05afa6b 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -294,7 +294,7 @@ looped_back:
 		hdr = (struct ipv6_rt_hdr *) skb2->h.raw;
 	}
 
-	if (skb->ip_summed == CHECKSUM_HW)
+	if (skb->ip_summed == CHECKSUM_COMPLETE)
 		skb->ip_summed = CHECKSUM_NONE;
 
 	i = n - --hdr->segments_left;
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index dbfce08..1030551 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -606,7 +606,7 @@ static int icmpv6_rcv(struct sk_buff **pskb)
 
 	/* Perform checksum. */
 	switch (skb->ip_summed) {
-	case CHECKSUM_HW:
+	case CHECKSUM_COMPLETE:
 		if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6,
 				     skb->csum))
 			break;
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 4fb47a2..65514f2 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -866,7 +866,7 @@ static inline int ip6_ufo_append_data(struct sock *sk,
 		/* initialize protocol header pointer */
 		skb->h.raw = skb->data + fragheaderlen;
 
-		skb->ip_summed = CHECKSUM_HW;
+		skb->ip_summed = CHECKSUM_PARTIAL;
 		skb->csum = 0;
 		sk->sk_sndmsg_off = 0;
 	}
diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c
index 395a417..580b1ab 100644
--- a/net/ipv6/netfilter.c
+++ b/net/ipv6/netfilter.c
@@ -87,7 +87,7 @@ unsigned int nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,
 	unsigned int csum = 0;
 
 	switch (skb->ip_summed) {
-	case CHECKSUM_HW:
+	case CHECKSUM_COMPLETE:
 		if (hook != NF_IP6_PRE_ROUTING && hook != NF_IP6_LOCAL_IN)
 			break;
 		if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
diff --git a/net/ipv6/netfilter/ip6_queue.c b/net/ipv6/netfilter/ip6_queue.c
index 968a14b..c01c126 100644
--- a/net/ipv6/netfilter/ip6_queue.c
+++ b/net/ipv6/netfilter/ip6_queue.c
@@ -206,9 +206,9 @@ ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
 		break;
 	
 	case IPQ_COPY_PACKET:
-		if (entry->skb->ip_summed == CHECKSUM_HW &&
-		    (*errp = skb_checksum_help(entry->skb,
-		                               entry->info->outdev == NULL))) {
+		if ((entry->skb->ip_summed == CHECKSUM_PARTIAL ||
+		     entry->skb->ip_summed == CHECKSUM_COMPLETE) &&
+		    (*errp = skb_checksum_help(entry->skb))) {
 			read_unlock_bh(&queue_lock);
 			return NULL;
 		}
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index 00d5583..7a4e4c2 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -408,7 +408,7 @@ static int nf_ct_frag6_queue(struct nf_ct_frag6_queue *fq, struct sk_buff *skb,
  		return -1;
 	}
 
- 	if (skb->ip_summed == CHECKSUM_HW)
+ 	if (skb->ip_summed == CHECKSUM_COMPLETE)
  		skb->csum = csum_sub(skb->csum,
  				     csum_partial(skb->nh.raw,
 						  (u8*)(fhdr + 1) - skb->nh.raw,
@@ -640,7 +640,7 @@ nf_ct_frag6_reasm(struct nf_ct_frag6_queue *fq, struct net_device *dev)
 		head->len += fp->len;
 		if (head->ip_summed != fp->ip_summed)
 			head->ip_summed = CHECKSUM_NONE;
-		else if (head->ip_summed == CHECKSUM_HW)
+		else if (head->ip_summed == CHECKSUM_COMPLETE)
 			head->csum = csum_add(head->csum, fp->csum);
 		head->truesize += fp->truesize;
 		atomic_sub(fp->truesize, &nf_ct_frag6_mem);
@@ -652,7 +652,7 @@ nf_ct_frag6_reasm(struct nf_ct_frag6_queue *fq, struct net_device *dev)
 	head->nh.ipv6h->payload_len = htons(payload_len);
 
 	/* Yes, and fold redundant checksum back. 8) */
-	if (head->ip_summed == CHECKSUM_HW)
+	if (head->ip_summed == CHECKSUM_COMPLETE)
 		head->csum = csum_partial(head->nh.raw, head->h.raw-head->nh.raw, head->csum);
 
 	fq->fragments = NULL;
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index d5040e1..d4af1cb 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -334,7 +334,7 @@ int rawv6_rcv(struct sock *sk, struct sk_buff *skb)
 	if (!rp->checksum)
 		skb->ip_summed = CHECKSUM_UNNECESSARY;
 
-	if (skb->ip_summed == CHECKSUM_HW) {
+	if (skb->ip_summed == CHECKSUM_COMPLETE) {
 		skb_postpull_rcsum(skb, skb->nh.raw,
 		                   skb->h.raw - skb->nh.raw);
 		if (!csum_ipv6_magic(&skb->nh.ipv6h->saddr,
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index 4e299c6..a8623d2 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -433,7 +433,7 @@ static void ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
  		return;
 	}
 
- 	if (skb->ip_summed == CHECKSUM_HW)
+ 	if (skb->ip_summed == CHECKSUM_COMPLETE)
  		skb->csum = csum_sub(skb->csum,
  				     csum_partial(skb->nh.raw, (u8*)(fhdr+1)-skb->nh.raw, 0));
 
@@ -647,7 +647,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff **skb_in,
 		head->len += fp->len;
 		if (head->ip_summed != fp->ip_summed)
 			head->ip_summed = CHECKSUM_NONE;
-		else if (head->ip_summed == CHECKSUM_HW)
+		else if (head->ip_summed == CHECKSUM_COMPLETE)
 			head->csum = csum_add(head->csum, fp->csum);
 		head->truesize += fp->truesize;
 		atomic_sub(fp->truesize, &ip6_frag_mem);
@@ -662,7 +662,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff **skb_in,
 	*skb_in = head;
 
 	/* Yes, and fold redundant checksum back. 8) */
-	if (head->ip_summed == CHECKSUM_HW)
+	if (head->ip_summed == CHECKSUM_COMPLETE)
 		head->csum = csum_partial(head->nh.raw, head->h.raw-head->nh.raw, head->csum);
 
 	IP6_INC_STATS_BH(IPSTATS_MIB_REASMOKS);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 302786a..7f1b660 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -545,7 +545,7 @@ static void tcp_v6_send_check(struct sock *sk, int len, struct sk_buff *skb)
 	struct ipv6_pinfo *np = inet6_sk(sk);
 	struct tcphdr *th = skb->h.th;
 
-	if (skb->ip_summed == CHECKSUM_HW) {
+	if (skb->ip_summed == CHECKSUM_PARTIAL) {
 		th->check = ~csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP,  0);
 		skb->csum = offsetof(struct tcphdr, check);
 	} else {
@@ -570,7 +570,7 @@ static int tcp_v6_gso_send_check(struct sk_buff *skb)
 	th->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len,
 				     IPPROTO_TCP, 0);
 	skb->csum = offsetof(struct tcphdr, check);
-	skb->ip_summed = CHECKSUM_HW;
+	skb->ip_summed = CHECKSUM_PARTIAL;
 	return 0;
 }
 
@@ -1033,7 +1033,7 @@ out:
 
 static int tcp_v6_checksum_init(struct sk_buff *skb)
 {
-	if (skb->ip_summed == CHECKSUM_HW) {
+	if (skb->ip_summed == CHECKSUM_COMPLETE) {
 		if (!tcp_v6_check(skb->h.th,skb->len,&skb->nh.ipv6h->saddr,
 				  &skb->nh.ipv6h->daddr,skb->csum)) {
 			skb->ip_summed = CHECKSUM_UNNECESSARY;
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 82c7c9c..780b89f 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -475,7 +475,7 @@ static int udpv6_rcv(struct sk_buff **pskb)
 		uh = skb->h.uh;
 	}
 
-	if (skb->ip_summed == CHECKSUM_HW &&
+	if (skb->ip_summed == CHECKSUM_COMPLETE &&
 	    !csum_ipv6_magic(saddr, daddr, ulen, IPPROTO_UDP, skb->csum))
 		skb->ip_summed = CHECKSUM_UNNECESSARY;
 
diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
index c8c8b44..6d11174 100644
--- a/net/ipv6/xfrm6_output.c
+++ b/net/ipv6/xfrm6_output.c
@@ -41,8 +41,8 @@ static int xfrm6_output_one(struct sk_buff *skb)
 	struct xfrm_state *x = dst->xfrm;
 	int err;
 	
-	if (skb->ip_summed == CHECKSUM_HW) {
-		err = skb_checksum_help(skb, 0);
+	if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		err = skb_checksum_help(skb);
 		if (err)
 			goto error_nolock;
 	}
diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
index af8adcb..308d2ab 100644
--- a/net/netfilter/nf_conntrack_proto_tcp.c
+++ b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -823,8 +823,7 @@ static int tcp_error(struct sk_buff *skb,
   
 	/* Checksum invalid? Ignore.
 	 * We skip checking packets on the outgoing path
-	 * because the semantic of CHECKSUM_HW is different there 
-	 * and moreover root might send raw packets.
+	 * because the checksum is assumed to be correct.
 	 */
 	/* FIXME: Source route IP option packets --RR */
 	if (nf_conntrack_checksum &&
diff --git a/net/netfilter/nf_conntrack_proto_udp.c b/net/netfilter/nf_conntrack_proto_udp.c
index ae07ebe..d36e031 100644
--- a/net/netfilter/nf_conntrack_proto_udp.c
+++ b/net/netfilter/nf_conntrack_proto_udp.c
@@ -131,8 +131,7 @@ static int udp_error(struct sk_buff *skb, unsigned int dataoff,
 
 	/* Checksum invalid? Ignore.
 	 * We skip checking packets on the outgoing path
-	 * because the semantic of CHECKSUM_HW is different there
-	 * and moreover root might send raw packets.
+	 * because the checksum is assumed to be correct.
 	 * FIXME: Source route IP option packets --RR */
 	if (nf_conntrack_checksum &&
 	    ((pf == PF_INET && hooknum == NF_IP_PRE_ROUTING) ||
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index 49ef41e..eddfbe4 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -377,9 +377,9 @@ nfqnl_build_packet_message(struct nfqnl_instance *queue,
 		break;
 	
 	case NFQNL_COPY_PACKET:
-		if (entskb->ip_summed == CHECKSUM_HW &&
-		    (*errp = skb_checksum_help(entskb,
-		                               outdev == NULL))) {
+		if ((entskb->ip_summed == CHECKSUM_PARTIAL ||
+		     entskb->ip_summed == CHECKSUM_COMPLETE) &&
+		    (*errp = skb_checksum_help(entskb))) {
 			spin_unlock_bh(&queue->lock);
 			return NULL;
 		}
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 4172a52..300215b 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -586,7 +586,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, struct packe
 		else if (skb->pkt_type == PACKET_OUTGOING) {
 			/* Special case: outgoing packets have ll header at head */
 			skb_pull(skb, skb->nh.raw - skb->data);
-			if (skb->ip_summed == CHECKSUM_HW)
+			if (skb->ip_summed == CHECKSUM_PARTIAL)
 				status |= TP_STATUS_CSUMNOTREADY;
 		}
 	}
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index a08ec4c7c..45939ba 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -192,8 +192,8 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 	 */
 	if (q->corrupt && q->corrupt >= get_crandom(&q->corrupt_cor)) {
 		if (!(skb = skb_unshare(skb, GFP_ATOMIC))
-		    || (skb->ip_summed == CHECKSUM_HW
-			&& skb_checksum_help(skb, 0))) {
+		    || (skb->ip_summed == CHECKSUM_PARTIAL
+			&& skb_checksum_help(skb))) {
 			sch->qstats.drops++;
 			return NET_XMIT_DROP;
 		}
diff --git a/net/sunrpc/socklib.c b/net/sunrpc/socklib.c
index eb330d4..6f17527 100644
--- a/net/sunrpc/socklib.c
+++ b/net/sunrpc/socklib.c
@@ -168,7 +168,7 @@ int csum_partial_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
 		return -1;
 	if ((unsigned short)csum_fold(desc.csum))
 		return -1;
-	if (unlikely(skb->ip_summed == CHECKSUM_HW))
+	if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE))
 		netdev_rx_csum_fault(skb->dev);
 	return 0;
 no_checksum: