[NETFILTER]: Convert conntrack/ipt_REJECT to new checksumming functions

Besides removing lots of duplicate code, all converted users benefit
from improved HW checksum error handling. Tested with and without HW
checksums in almost all combinations.

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

5 files changed, 13 insertions, 53 deletions

diff --git a/net/ipv4/netfilter/ip_conntrack_proto_icmp.c b/net/ipv4/netfilter/ip_conntrack_proto_icmp.c
index 3021af0..d8b14a9 100644
--- a/net/ipv4/netfilter/ip_conntrack_proto_icmp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_icmp.c
@@ -224,25 +224,14 @@ icmp_error(struct sk_buff *skb, enum ip_conntrack_info *ctinfo,
 	}
 
 	/* See ip_conntrack_proto_tcp.c */
-	if (hooknum != NF_IP_PRE_ROUTING)
-		goto checksum_skipped;
-
-	switch (skb->ip_summed) {
-	case CHECKSUM_HW:
-		if (!(u16)csum_fold(skb->csum)) 
-			break;
-		/* fall through */
-	case CHECKSUM_NONE:
-		skb->csum = 0;
-		if (__skb_checksum_complete(skb)) {
-			if (LOG_INVALID(IPPROTO_ICMP))
-				nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
-					      "ip_ct_icmp: bad ICMP checksum ");
-			return -NF_ACCEPT;
-		}
+	if (hooknum == NF_IP_PRE_ROUTING &&
+	    nf_ip_checksum(skb, hooknum, skb->nh.iph->ihl * 4, 0)) {
+		if (LOG_INVALID(IPPROTO_ICMP))
+			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
+				      "ip_ct_icmp: bad ICMP checksum ");
+		return -NF_ACCEPT;
 	}
 
-checksum_skipped:
 	/*
 	 *	18 is the highest 'known' ICMP type. Anything else is a mystery
 	 *
diff --git a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
index e0dc370..062b252 100644
--- a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
@@ -870,11 +870,8 @@ static int tcp_error(struct sk_buff *skb,
 	 * and moreover root might send raw packets.
 	 */
 	/* FIXME: Source route IP option packets --RR */
-	if (hooknum == NF_IP_PRE_ROUTING
-	    && skb->ip_summed != CHECKSUM_UNNECESSARY
-	    && csum_tcpudp_magic(iph->saddr, iph->daddr, tcplen, IPPROTO_TCP,
-			         skb->ip_summed == CHECKSUM_HW ? skb->csum
-			      	 : skb_checksum(skb, iph->ihl*4, tcplen, 0))) {
+	if (hooknum == NF_IP_PRE_ROUTING &&
+	    nf_ip_checksum(skb, hooknum, iph->ihl * 4, IPPROTO_TCP)) {
 		if (LOG_INVALID(IPPROTO_TCP))
 			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
 				  "ip_ct_tcp: bad TCP checksum ");
diff --git a/net/ipv4/netfilter/ip_conntrack_proto_udp.c b/net/ipv4/netfilter/ip_conntrack_proto_udp.c
index 55b7d32..7089986 100644
--- a/net/ipv4/netfilter/ip_conntrack_proto_udp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_udp.c
@@ -120,11 +120,8 @@ static int udp_error(struct sk_buff *skb, enum ip_conntrack_info *ctinfo,
 	 * because the semantic of CHECKSUM_HW is different there 
 	 * and moreover root might send raw packets.
 	 * FIXME: Source route IP option packets --RR */
-	if (hooknum == NF_IP_PRE_ROUTING
-	    && skb->ip_summed != CHECKSUM_UNNECESSARY
-	    && csum_tcpudp_magic(iph->saddr, iph->daddr, udplen, IPPROTO_UDP,
-			         skb->ip_summed == CHECKSUM_HW ? skb->csum
-			      	 : skb_checksum(skb, iph->ihl*4, udplen, 0))) {
+	if (hooknum == NF_IP_PRE_ROUTING &&
+	    nf_ip_checksum(skb, hooknum, iph->ihl * 4, IPPROTO_UDP)) {
 		if (LOG_INVALID(IPPROTO_UDP))
 			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
 				  "ip_ct_udp: bad UDP checksum ");
diff --git a/net/ipv4/netfilter/ipt_REJECT.c b/net/ipv4/netfilter/ipt_REJECT.c
index 4269a54..0bba3c2 100644
--- a/net/ipv4/netfilter/ipt_REJECT.c
+++ b/net/ipv4/netfilter/ipt_REJECT.c
@@ -106,7 +106,6 @@ static void send_reset(struct sk_buff *oldskb, int hook)
 	struct rtable *rt;
 	u_int16_t tmp_port;
 	u_int32_t tmp_addr;
-	unsigned int tcplen;
 	int needs_ack;
 	int hh_len;
 
@@ -124,13 +123,7 @@ static void send_reset(struct sk_buff *oldskb, int hook)
 		return;
 
 	/* Check checksum */
-	tcplen = oldskb->len - iph->ihl * 4;
-	if (((hook != NF_IP_LOCAL_IN && oldskb->ip_summed != CHECKSUM_HW) ||
-	     (hook == NF_IP_LOCAL_IN &&
-	      oldskb->ip_summed != CHECKSUM_UNNECESSARY)) &&
-	    csum_tcpudp_magic(iph->saddr, iph->daddr, tcplen, IPPROTO_TCP,
-	                      oldskb->ip_summed == CHECKSUM_HW ? oldskb->csum :
-	                      skb_checksum(oldskb, iph->ihl * 4, tcplen, 0)))
+	if (nf_ip_checksum(oldskb, hook, iph->ihl * 4, IPPROTO_TCP))
 		return;
 
 	if ((rt = route_reverse(oldskb, oth, hook)) == NULL)
diff --git a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
index 52dc175..4b0d361 100644
--- a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
+++ b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
@@ -235,30 +235,14 @@ icmp_error(struct sk_buff *skb, unsigned int dataoff,
 	}
 
 	/* See ip_conntrack_proto_tcp.c */
-	if (hooknum != NF_IP_PRE_ROUTING)
-		goto checksum_skipped;
-
-	switch (skb->ip_summed) {
-	case CHECKSUM_HW:
-		if (!(u16)csum_fold(skb->csum))
-			break;
+	if (hooknum == NF_IP_PRE_ROUTING &&
+	    nf_ip_checksum(skb, hooknum, dataoff, 0)) {
 		if (LOG_INVALID(IPPROTO_ICMP))
 			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
 				      "nf_ct_icmp: bad HW ICMP checksum ");
 		return -NF_ACCEPT;
-	case CHECKSUM_NONE:
-		if ((u16)csum_fold(skb_checksum(skb, 0, skb->len, 0))) {
-			if (LOG_INVALID(IPPROTO_ICMP))
-				nf_log_packet(PF_INET, 0, skb, NULL, NULL,
-					      NULL,
-					      "nf_ct_icmp: bad ICMP checksum ");
-			return -NF_ACCEPT;
-		}
-	default:
-		break;
 	}
 
-checksum_skipped:
 	/*
 	 *	18 is the highest 'known' ICMP type. Anything else is a mystery
 	 *