fix partial checksum errors in DCCP decoder, IPv4 case

11 files changed, 57 insertions, 10 deletions

diff --git a/ip.h b/ip.h
index fd8ee92b..2fcb40ea 100644
--- a/ip.h
+++ b/ip.h
@@ -160,4 +160,4 @@ struct	ip_timestamp {
 #define	IP_MSS		576		/* default maximum segment size */
 
 /* in print-ip.c */
-extern int nextproto4_cksum(const struct ip *, const u_int8_t *, u_int, u_int);
+extern int nextproto4_cksum(const struct ip *, const u_int8_t *, u_int, u_int, u_int);
diff --git a/netdissect.h b/netdissect.h
index bdf2ebdb..37bc59e0 100644
--- a/netdissect.h
+++ b/netdissect.h
@@ -416,7 +416,6 @@ extern void igmp_print(netdissect_options *,
 		       register const u_char *, u_int);
 extern void igrp_print(netdissect_options *,const u_char *, u_int,
 		       const u_char *);
-extern int nextproto4_cksum(const struct ip *, const u_int8_t *, u_int, u_int);
 extern void ipN_print(netdissect_options *,const u_char *, u_int);
 extern void ipx_print(netdissect_options *,const u_char *, u_int);
 extern void isoclns_print(netdissect_options *,const u_char *,
diff --git a/print-dccp.c b/print-dccp.c
index 1c354a6a..0d020d65 100644
--- a/print-dccp.c
+++ b/print-dccp.c
@@ -184,8 +184,8 @@ static inline u_int dccp_csum_coverage(const struct dccp_hdr* dh, u_int len)
 static int dccp_cksum(const struct ip *ip,
 	const struct dccp_hdr *dh, u_int len)
 {
-	return nextproto4_cksum(ip, (const u_int8_t *)(void *)dh,
-	    dccp_csum_coverage(dh, len), IPPROTO_DCCP);
+	return nextproto4_cksum(ip, (const u_int8_t *)(void *)dh, len,
+				dccp_csum_coverage(dh, len), IPPROTO_DCCP);
 }
 
 #ifdef INET6
diff --git a/print-ip.c b/print-ip.c
index 22bd8005..3c7f107f 100644
--- a/print-ip.c
+++ b/print-ip.c
@@ -131,7 +131,7 @@ trunc:
  */
 int
 nextproto4_cksum(const struct ip *ip, const u_int8_t *data,
-		 u_int len, u_int next_proto)
+		 u_int len, u_int covlen, u_int next_proto)
 {
 	struct phdr {
 		u_int32_t src;
@@ -155,7 +155,7 @@ nextproto4_cksum(const struct ip *ip, const u_int8_t *data,
 	vec[0].ptr = (const u_int8_t *)(void *)&ph;
 	vec[0].len = sizeof(ph);
 	vec[1].ptr = data;
-	vec[1].len = len;
+	vec[1].len = covlen;
 	return (in_cksum(vec, 2));
 }
 
diff --git a/print-tcp.c b/print-tcp.c
index bb76ac7c..eee98fe9 100644
--- a/print-tcp.c
+++ b/print-tcp.c
@@ -142,8 +142,8 @@ static int tcp_cksum(register const struct ip *ip,
 		     register const struct tcphdr *tp,
 		     register u_int len)
 {
-	return (nextproto4_cksum(ip, (const u_int8_t *)tp, len,
-	    IPPROTO_TCP));
+	return nextproto4_cksum(ip, (const u_int8_t *)tp, len, len,
+				IPPROTO_TCP);
 }
 
 void
diff --git a/print-udp.c b/print-udp.c
index babdf7c2..a8566d04 100644
--- a/print-udp.c
+++ b/print-udp.c
@@ -281,8 +281,8 @@ static int udp_cksum(register const struct ip *ip,
 		     register const struct udphdr *up,
 		     register u_int len)
 {
-	return (nextproto4_cksum(ip, (const u_int8_t *)(void *)up, len,
-	    IPPROTO_UDP));
+	return nextproto4_cksum(ip, (const u_int8_t *)(void *)up, len, len,
+				IPPROTO_UDP);
 }
 
 #ifdef INET6
diff --git a/tests/TESTLIST b/tests/TESTLIST
index f2ab95b9..4f4d9ea6 100644
--- a/tests/TESTLIST
+++ b/tests/TESTLIST
@@ -173,3 +173,7 @@ ipv6-bad-version.pcap	ipv6-bad-version.pcap 	ipv6-bad-version.out	-t
 
 # Loopback/CTP test case
 loopback	loopback.pcap		loopback.out		-t
+
+# DCCP partial checksums tests
+dccp_partial_csum_v4_simple	dccp_partial_csum_v4_simple.pcap	dccp_partial_csum_v4_simple.out -t -v
+dccp_partial_csum_v4_longer	dccp_partial_csum_v4_longer.pcap	dccp_partial_csum_v4_longer.out -t -v
diff --git a/tests/dccp_partial_csum_v4_longer.out b/tests/dccp_partial_csum_v4_longer.out
new file mode 100644
index 00000000..a9b6413a
--- /dev/null
+++ b/tests/dccp_partial_csum_v4_longer.out
@@ -0,0 +1,30 @@
+IP (tos 0x0, ttl 64, id 65312, offset 0, flags [DF], proto DCCP (33), length 52)
+    139.133.209.176.39420 > 139.133.209.65.5001: CCVal 0, CsCov 0, cksum 0xaaf3 (correct), request (service=0) 
+IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto DCCP (33), length 68)
+    139.133.209.65.5001 > 139.133.209.176.39420: CCVal 0, CsCov 0, cksum 0xb04b (correct), response (service=0) (ack=38464816766) 
+IP (tos 0x0, ttl 64, id 65313, offset 0, flags [DF], proto DCCP (33), length 56)
+    139.133.209.176.39420 > 139.133.209.65.5001: CCVal 0, CsCov 0, cksum 0xf53a (correct), ack (ack=1960341146) 
+IP (tos 0x0, ttl 64, id 65314, offset 0, flags [DF], proto DCCP (33), length 152)
+    139.133.209.176.39420 > 139.133.209.65.5001: CCVal 0, CsCov 6, cksum 0x7d28 (correct), dataack (ack=1960341146) 
+IP (tos 0x0, ttl 64, id 3176, offset 0, flags [DF], proto DCCP (33), length 52)
+    139.133.209.65.5001 > 139.133.209.176.39420: CCVal 0, CsCov 0, cksum 0xfc63 (correct), ack (ack=38464816768) 
+IP (tos 0x0, ttl 64, id 65315, offset 0, flags [DF], proto DCCP (33), length 148)
+    139.133.209.176.39420 > 139.133.209.65.5001: CCVal 0, CsCov 6, cksum 0x5e05 (correct), dataack (ack=1960341147) 
+IP (tos 0x0, ttl 64, id 3177, offset 0, flags [DF], proto DCCP (33), length 52)
+    139.133.209.65.5001 > 139.133.209.176.39420: CCVal 0, CsCov 0, cksum 0x0165 (correct), ack (ack=38464816769) 
+IP (tos 0x0, ttl 64, id 65316, offset 0, flags [DF], proto DCCP (33), length 148)
+    139.133.209.176.39420 > 139.133.209.65.5001: CCVal 0, CsCov 6, cksum 0x5e1e (correct), dataack (ack=1960341148) 
+IP (tos 0x0, ttl 64, id 65317, offset 0, flags [DF], proto DCCP (33), length 148)
+    139.133.209.176.39420 > 139.133.209.65.5001: CCVal 0, CsCov 6, cksum 0x5e15 (correct), dataack (ack=1960341148) 
+IP (tos 0x0, ttl 64, id 3178, offset 0, flags [DF], proto DCCP (33), length 56)
+    139.133.209.65.5001 > 139.133.209.176.39420: CCVal 0, CsCov 0, cksum 0xfb32 (correct), ack (ack=38464816770) 
+IP (tos 0x0, ttl 64, id 3179, offset 0, flags [DF], proto DCCP (33), length 56)
+    139.133.209.65.5001 > 139.133.209.176.39420: CCVal 0, CsCov 0, cksum 0xfa2f (correct), ack (ack=38464816771) 
+IP (tos 0x0, ttl 64, id 65318, offset 0, flags [DF], proto DCCP (33), length 148)
+    139.133.209.176.39420 > 139.133.209.65.5001: CCVal 0, CsCov 6, cksum 0x5e35 (correct), dataack (ack=1960341150) 
+IP (tos 0x0, ttl 64, id 65319, offset 0, flags [DF], proto DCCP (33), length 52)
+    139.133.209.176.39420 > 139.133.209.65.5001: CCVal 0, CsCov 0, cksum 0xf638 (correct), close (ack=1960341150) 
+IP (tos 0x0, ttl 64, id 3180, offset 0, flags [DF], proto DCCP (33), length 56)
+    139.133.209.65.5001 > 139.133.209.176.39420: CCVal 0, CsCov 0, cksum 0xfb2c (correct), ack (ack=38464816772) 
+IP (tos 0x0, ttl 64, id 3181, offset 0, flags [DF], proto DCCP (33), length 60)
+    139.133.209.65.5001 > 139.133.209.176.39420: CCVal 0, CsCov 0, cksum 0xef25 (correct), reset (code=closed) (ack=38464816773) 
diff --git a/tests/dccp_partial_csum_v4_longer.pcap b/tests/dccp_partial_csum_v4_longer.pcap
new file mode 100644
index 00000000..f1176c03
--- /dev/null
+++ b/tests/dccp_partial_csum_v4_longer.pcap
diff --git a/tests/dccp_partial_csum_v4_simple.out b/tests/dccp_partial_csum_v4_simple.out
new file mode 100644
index 00000000..413ae05a
--- /dev/null
+++ b/tests/dccp_partial_csum_v4_simple.out
@@ -0,0 +1,14 @@
+IP (tos 0x0, ttl 64, id 30095, offset 0, flags [DF], proto DCCP (33), length 52)
+    139.133.209.176.52667 > 139.133.209.65.5001: CCVal 0, CsCov 0, cksum 0xa766 (correct), request (service=0) 
+IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto DCCP (33), length 68)
+    139.133.209.65.5001 > 139.133.209.176.52667: CCVal 0, CsCov 0, cksum 0x9a1a (correct), response (service=0) (ack=33164071488) 
+IP (tos 0x0, ttl 64, id 30096, offset 0, flags [DF], proto DCCP (33), length 56)
+    139.133.209.176.52667 > 139.133.209.65.5001: CCVal 0, CsCov 0, cksum 0xdf09 (correct), ack (ack=1925546833) 
+IP (tos 0x0, ttl 64, id 30097, offset 0, flags [DF], proto DCCP (33), length 68)
+    139.133.209.176.52667 > 139.133.209.65.5001: CCVal 0, CsCov 1, cksum 0x9dfa (correct), dataack (ack=1925546833) 
+IP (tos 0x0, ttl 64, id 24713, offset 0, flags [DF], proto DCCP (33), length 52)
+    139.133.209.65.5001 > 139.133.209.176.52667: CCVal 0, CsCov 0, cksum 0xe632 (correct), ack (ack=33164071490) 
+IP (tos 0x0, ttl 64, id 30098, offset 0, flags [DF], proto DCCP (33), length 52)
+    139.133.209.176.52667 > 139.133.209.65.5001: CCVal 0, CsCov 0, cksum 0xdf8d (correct), close (ack=1925546834) 
+IP (tos 0x0, ttl 64, id 24714, offset 0, flags [DF], proto DCCP (33), length 60)
+    139.133.209.65.5001 > 139.133.209.176.52667: CCVal 0, CsCov 0, cksum 0xd900 (correct), reset (code=closed) (ack=33164071491) 
diff --git a/tests/dccp_partial_csum_v4_simple.pcap b/tests/dccp_partial_csum_v4_simple.pcap
new file mode 100644
index 00000000..a9c3d66c
--- /dev/null
+++ b/tests/dccp_partial_csum_v4_simple.pcap