Deal with aliasing warnings.

Reviewed by:	ru
Approved by:	silence on the lists

4 files changed, 63 insertions, 181 deletions

diff --git a/lib/libalias/alias.c b/lib/libalias/alias.c
index 19406d4..e02957f 100644
--- a/lib/libalias/alias.c
+++ b/lib/libalias/alias.c
@@ -136,8 +136,13 @@ __FBSDID("$FreeBSD$");
 #define TFTP_PORT_NUMBER 69
 #define PPTP_CONTROL_PORT_NUMBER 1723
 
+static __inline int
+twowords(void *p)
+{
+	u_short *s = p;
 
-
+	return (s[0] + s[1]);
+}
 
 /* TCP Handling Routines
 
@@ -295,9 +300,7 @@ IcmpAliasIn1(struct libalias *la, struct ip *pip)
 
 			original_address = GetOriginalAddress(link);
 			DifferentialChecksum(&pip->ip_sum,
-			    (u_short *) & original_address,
-			    (u_short *) & pip->ip_dst,
-			    2);
+			    &original_address, &pip->ip_dst, 2);
 			pip->ip_dst = original_address;
 		}
 
@@ -344,7 +347,6 @@ IcmpAliasIn2(struct libalias *la, struct ip *pip)
 
 	if (link != NULL) {
 		if (ip->ip_p == IPPROTO_UDP || ip->ip_p == IPPROTO_TCP) {
-			u_short *sptr;
 			int accumulate, accumulate2;
 			struct in_addr original_address;
 			u_short original_port;
@@ -353,12 +355,8 @@ IcmpAliasIn2(struct libalias *la, struct ip *pip)
 			original_port = GetOriginalPort(link);
 
 /* Adjust ICMP checksum */
-			sptr = (u_short *) & (ip->ip_src);
-			accumulate = *sptr++;
-			accumulate += *sptr;
-			sptr = (u_short *) & original_address;
-			accumulate -= *sptr++;
-			accumulate -= *sptr;
+			accumulate = twowords(&ip->ip_src);
+			accumulate -= twowords(&original_address);
 			accumulate += ud->uh_sport;
 			accumulate -= original_port;
 			accumulate2 = accumulate;
@@ -369,9 +367,7 @@ IcmpAliasIn2(struct libalias *la, struct ip *pip)
 
 /* Un-alias address in IP header */
 			DifferentialChecksum(&pip->ip_sum,
-			    (u_short *) & original_address,
-			    (u_short *) & pip->ip_dst,
-			    2);
+			    &original_address, &pip->ip_dst, 2);
 			pip->ip_dst = original_address;
 
 /* Un-alias address and port number of original IP packet
@@ -379,7 +375,6 @@ fragment contained in ICMP data section */
 			ip->ip_src = original_address;
 			ud->uh_sport = original_port;
 		} else if (ip->ip_p == IPPROTO_ICMP) {
-			u_short *sptr;
 			int accumulate, accumulate2;
 			struct in_addr original_address;
 			u_short original_id;
@@ -388,12 +383,8 @@ fragment contained in ICMP data section */
 			original_id = GetOriginalPort(link);
 
 /* Adjust ICMP checksum */
-			sptr = (u_short *) & (ip->ip_src);
-			accumulate = *sptr++;
-			accumulate += *sptr;
-			sptr = (u_short *) & original_address;
-			accumulate -= *sptr++;
-			accumulate -= *sptr;
+			accumulate = twowords(&ip->ip_src);
+			accumulate -= twowords(&original_address);
 			accumulate += ic2->icmp_id;
 			accumulate -= original_id;
 			accumulate2 = accumulate;
@@ -404,9 +395,7 @@ fragment contained in ICMP data section */
 
 /* Un-alias address in IP header */
 			DifferentialChecksum(&pip->ip_sum,
-			    (u_short *) & original_address,
-			    (u_short *) & pip->ip_dst,
-			    2);
+			    &original_address, &pip->ip_dst, 2);
 			pip->ip_dst = original_address;
 
 /* Un-alias address of original IP packet and sequence number of
@@ -489,9 +478,7 @@ IcmpAliasOut1(struct libalias *la, struct ip *pip)
 
 			alias_address = GetAliasAddress(link);
 			DifferentialChecksum(&pip->ip_sum,
-			    (u_short *) & alias_address,
-			    (u_short *) & pip->ip_src,
-			    2);
+			    &alias_address, &pip->ip_src, 2);
 			pip->ip_src = alias_address;
 		}
 
@@ -539,7 +526,6 @@ IcmpAliasOut2(struct libalias *la, struct ip *pip)
 
 	if (link != NULL) {
 		if (ip->ip_p == IPPROTO_UDP || ip->ip_p == IPPROTO_TCP) {
-			u_short *sptr;
 			int accumulate;
 			struct in_addr alias_address;
 			u_short alias_port;
@@ -548,12 +534,8 @@ IcmpAliasOut2(struct libalias *la, struct ip *pip)
 			alias_port = GetAliasPort(link);
 
 /* Adjust ICMP checksum */
-			sptr = (u_short *) & (ip->ip_dst);
-			accumulate = *sptr++;
-			accumulate += *sptr;
-			sptr = (u_short *) & alias_address;
-			accumulate -= *sptr++;
-			accumulate -= *sptr;
+			accumulate = twowords(&ip->ip_dst);
+			accumulate -= twowords(&alias_address);
 			accumulate += ud->uh_dport;
 			accumulate -= alias_port;
 			ADJUST_CHECKSUM(accumulate, ic->icmp_cksum);
@@ -564,9 +546,7 @@ IcmpAliasOut2(struct libalias *la, struct ip *pip)
  */
 			if (pip->ip_src.s_addr == ip->ip_dst.s_addr) {
 				DifferentialChecksum(&pip->ip_sum,
-				    (u_short *) & alias_address,
-				    (u_short *) & pip->ip_src,
-				    2);
+				    &alias_address, &pip->ip_src, 2);
 				pip->ip_src = alias_address;
 			}
 /* Alias address and port number of original IP packet
@@ -574,7 +554,6 @@ fragment contained in ICMP data section */
 			ip->ip_dst = alias_address;
 			ud->uh_dport = alias_port;
 		} else if (ip->ip_p == IPPROTO_ICMP) {
-			u_short *sptr;
 			int accumulate;
 			struct in_addr alias_address;
 			u_short alias_id;
@@ -583,12 +562,8 @@ fragment contained in ICMP data section */
 			alias_id = GetAliasPort(link);
 
 /* Adjust ICMP checksum */
-			sptr = (u_short *) & (ip->ip_dst);
-			accumulate = *sptr++;
-			accumulate += *sptr;
-			sptr = (u_short *) & alias_address;
-			accumulate -= *sptr++;
-			accumulate -= *sptr;
+			accumulate = twowords(&ip->ip_dst);
+			accumulate -= twowords(&alias_address);
 			accumulate += ic2->icmp_id;
 			accumulate -= alias_id;
 			ADJUST_CHECKSUM(accumulate, ic->icmp_cksum);
@@ -599,9 +574,7 @@ fragment contained in ICMP data section */
  */
 			if (pip->ip_src.s_addr == ip->ip_dst.s_addr) {
 				DifferentialChecksum(&pip->ip_sum,
-				    (u_short *) & alias_address,
-				    (u_short *) & pip->ip_src,
-				    2);
+				    &alias_address, &pip->ip_src, 2);
 				pip->ip_src = alias_address;
 			}
 /* Alias address of original IP packet and sequence number of
@@ -673,9 +646,7 @@ ProtoAliasIn(struct libalias *la, struct ip *pip)
 
 /* Restore original IP address */
 		DifferentialChecksum(&pip->ip_sum,
-		    (u_short *) & original_address,
-		    (u_short *) & pip->ip_dst,
-		    2);
+		    &original_address, &pip->ip_dst, 2);
 		pip->ip_dst = original_address;
 
 		return (PKT_ALIAS_OK);
@@ -706,9 +677,7 @@ ProtoAliasOut(struct libalias *la, struct ip *pip)
 
 /* Change source address */
 		DifferentialChecksum(&pip->ip_sum,
-		    (u_short *) & alias_address,
-		    (u_short *) & pip->ip_src,
-		    2);
+		    &alias_address, &pip->ip_src, 2);
 		pip->ip_src = alias_address;
 
 		return (PKT_ALIAS_OK);
@@ -737,7 +706,6 @@ UdpAliasIn(struct libalias *la, struct ip *pip)
 		struct in_addr original_address;
 		u_short alias_port;
 		int accumulate;
-		u_short *sptr;
 		int r = 0;
 
 		alias_address = GetAliasAddress(link);
@@ -762,19 +730,13 @@ UdpAliasIn(struct libalias *la, struct ip *pip)
 		if (ud->uh_sum != 0) {
 			accumulate = alias_port;
 			accumulate -= ud->uh_dport;
-			sptr = (u_short *) & alias_address;
-			accumulate += *sptr++;
-			accumulate += *sptr;
-			sptr = (u_short *) & original_address;
-			accumulate -= *sptr++;
-			accumulate -= *sptr;
+			accumulate += twowords(&alias_address);
+			accumulate -= twowords(&original_address);
 			ADJUST_CHECKSUM(accumulate, ud->uh_sum);
 		}
 /* Restore original IP address */
 		DifferentialChecksum(&pip->ip_sum,
-		    (u_short *) & original_address,
-		    (u_short *) & pip->ip_dst,
-		    2);
+		    &original_address, &pip->ip_dst, 2);
 		pip->ip_dst = original_address;
 
 		/*
@@ -834,16 +796,11 @@ UdpAliasOut(struct libalias *la, struct ip *pip)
 /* being aliased and source address is being altered        */
 		if (ud->uh_sum != 0) {
 			int accumulate;
-			u_short *sptr;
 
 			accumulate = ud->uh_sport;
 			accumulate -= alias_port;
-			sptr = (u_short *) & (pip->ip_src);
-			accumulate += *sptr++;
-			accumulate += *sptr;
-			sptr = (u_short *) & alias_address;
-			accumulate -= *sptr++;
-			accumulate -= *sptr;
+			accumulate += twowords(&pip->ip_src);
+			accumulate -= twowords(&alias_address);
 			ADJUST_CHECKSUM(accumulate, ud->uh_sum);
 		}
 /* Put alias port in UDP header */
@@ -851,9 +808,7 @@ UdpAliasOut(struct libalias *la, struct ip *pip)
 
 /* Change source address */
 		DifferentialChecksum(&pip->ip_sum,
-		    (u_short *) & alias_address,
-		    (u_short *) & pip->ip_src,
-		    2);
+		    &alias_address, &pip->ip_src, 2);
 		pip->ip_src = alias_address;
 
 		return (PKT_ALIAS_OK);
@@ -882,7 +837,6 @@ TcpAliasIn(struct libalias *la, struct ip *pip)
 		u_short alias_port;
 		u_short proxy_port;
 		int accumulate;
-		u_short *sptr;
 
 /* Special processing for IP encoding protocols */
 		if (ntohs(tc->th_dport) == PPTP_CONTROL_PORT_NUMBER
@@ -903,12 +857,8 @@ TcpAliasIn(struct libalias *la, struct ip *pip)
 /* and destination port is being altered.                        */
 		accumulate = alias_port;
 		accumulate -= tc->th_dport;
-		sptr = (u_short *) & alias_address;
-		accumulate += *sptr++;
-		accumulate += *sptr;
-		sptr = (u_short *) & original_address;
-		accumulate -= *sptr++;
-		accumulate -= *sptr;
+		accumulate += twowords(&alias_address);
+		accumulate -= twowords(&original_address);
 
 /* If this is a proxy, then modify the TCP source port and
    checksum accumulation */
@@ -916,13 +866,8 @@ TcpAliasIn(struct libalias *la, struct ip *pip)
 			accumulate += tc->th_sport;
 			tc->th_sport = proxy_port;
 			accumulate -= tc->th_sport;
-
-			sptr = (u_short *) & pip->ip_src;
-			accumulate += *sptr++;
-			accumulate += *sptr;
-			sptr = (u_short *) & proxy_address;
-			accumulate -= *sptr++;
-			accumulate -= *sptr;
+			accumulate += twowords(&pip->ip_src);
+			accumulate -= twowords(&proxy_address);
 		}
 /* See if ACK number needs to be modified */
 		if (GetAckModified(link) == 1) {
@@ -930,36 +875,23 @@ TcpAliasIn(struct libalias *la, struct ip *pip)
 
 			delta = GetDeltaAckIn(pip, link);
 			if (delta != 0) {
-				sptr = (u_short *) & tc->th_ack;
-				accumulate += *sptr++;
-				accumulate += *sptr;
+				accumulate += twowords(&tc->th_ack);
 				tc->th_ack = htonl(ntohl(tc->th_ack) - delta);
-				sptr = (u_short *) & tc->th_ack;
-				accumulate -= *sptr++;
-				accumulate -= *sptr;
+				accumulate -= twowords(&tc->th_ack);
 			}
 		}
 		ADJUST_CHECKSUM(accumulate, tc->th_sum);
 
 /* Restore original IP address */
-		sptr = (u_short *) & pip->ip_dst;
-		accumulate = *sptr++;
-		accumulate += *sptr;
-		pip->ip_dst = original_address;
-		sptr = (u_short *) & pip->ip_dst;
-		accumulate -= *sptr++;
-		accumulate -= *sptr;
+		accumulate = twowords(&pip->ip_dst);
+		accumulate -= twowords(&pip->ip_dst);
 
 /* If this is a transparent proxy packet, then modify the source
    address */
 		if (proxy_address.s_addr != 0) {
-			sptr = (u_short *) & pip->ip_src;
-			accumulate += *sptr++;
-			accumulate += *sptr;
+			accumulate += twowords(&pip->ip_src);
 			pip->ip_src = proxy_address;
-			sptr = (u_short *) & pip->ip_src;
-			accumulate -= *sptr++;
-			accumulate -= *sptr;
+			accumulate -= twowords(&pip->ip_src);
 		}
 		ADJUST_CHECKSUM(accumulate, pip->ip_sum);
 
@@ -995,29 +927,17 @@ TcpAliasOut(struct libalias *la, struct ip *pip, int maxpacketsize)
 	dest_address = pip->ip_dst;
 	if (proxy_type != 0) {
 		int accumulate;
-		u_short *sptr;
 
 		accumulate = tc->th_dport;
 		tc->th_dport = proxy_server_port;
 		accumulate -= tc->th_dport;
-
-		sptr = (u_short *) & (pip->ip_dst);
-		accumulate += *sptr++;
-		accumulate += *sptr;
-		sptr = (u_short *) & proxy_server_address;
-		accumulate -= *sptr++;
-		accumulate -= *sptr;
-
+		accumulate += twowords(&pip->ip_dst);
+		accumulate -= twowords(&proxy_server_address);
 		ADJUST_CHECKSUM(accumulate, tc->th_sum);
 
-		sptr = (u_short *) & (pip->ip_dst);
-		accumulate = *sptr++;
-		accumulate += *sptr;
+		accumulate = twowords(&pip->ip_dst);
 		pip->ip_dst = proxy_server_address;
-		sptr = (u_short *) & (pip->ip_dst);
-		accumulate -= *sptr++;
-		accumulate -= *sptr;
-
+		accumulate -= twowords(&pip->ip_dst);
 		ADJUST_CHECKSUM(accumulate, pip->ip_sum);
 	}
 	link = FindUdpTcpOut(la, pip->ip_src, pip->ip_dst,
@@ -1027,7 +947,6 @@ TcpAliasOut(struct libalias *la, struct ip *pip, int maxpacketsize)
 		u_short alias_port;
 		struct in_addr alias_address;
 		int accumulate;
-		u_short *sptr;
 
 /* Save original destination address, if this is a proxy packet.
    Also modify packet to include destination encoding.  This may
@@ -1069,13 +988,8 @@ TcpAliasOut(struct libalias *la, struct ip *pip, int maxpacketsize)
 		accumulate = tc->th_sport;
 		tc->th_sport = alias_port;
 		accumulate -= tc->th_sport;
-
-		sptr = (u_short *) & (pip->ip_src);
-		accumulate += *sptr++;
-		accumulate += *sptr;
-		sptr = (u_short *) & alias_address;
-		accumulate -= *sptr++;
-		accumulate -= *sptr;
+		accumulate += twowords(&pip->ip_src);
+		accumulate -= twowords(&alias_address);
 
 /* Modify sequence number if necessary */
 		if (GetAckModified(link) == 1) {
@@ -1083,26 +997,17 @@ TcpAliasOut(struct libalias *la, struct ip *pip, int maxpacketsize)
 
 			delta = GetDeltaSeqOut(pip, link);
 			if (delta != 0) {
-				sptr = (u_short *) & tc->th_seq;
-				accumulate += *sptr++;
-				accumulate += *sptr;
+				accumulate += twowords(&tc->th_seq);
 				tc->th_seq = htonl(ntohl(tc->th_seq) + delta);
-				sptr = (u_short *) & tc->th_seq;
-				accumulate -= *sptr++;
-				accumulate -= *sptr;
+				accumulate -= twowords(&tc->th_seq);
 			}
 		}
 		ADJUST_CHECKSUM(accumulate, tc->th_sum);
 
 /* Change source address */
-		sptr = (u_short *) & (pip->ip_src);
-		accumulate = *sptr++;
-		accumulate += *sptr;
+		accumulate = twowords(&pip->ip_src);
 		pip->ip_src = alias_address;
-		sptr = (u_short *) & (pip->ip_src);
-		accumulate -= *sptr++;
-		accumulate -= *sptr;
-
+		accumulate -= twowords(&pip->ip_src);
 		ADJUST_CHECKSUM(accumulate, pip->ip_sum);
 
 		return (PKT_ALIAS_OK);
@@ -1142,9 +1047,7 @@ FragmentIn(struct libalias *la, struct ip *pip)
 
 		GetFragmentAddr(link, &original_address);
 		DifferentialChecksum(&pip->ip_sum,
-		    (u_short *) & original_address,
-		    (u_short *) & pip->ip_dst,
-		    2);
+		    &original_address, &pip->ip_dst, 2);
 		pip->ip_dst = original_address;
 
 		return (PKT_ALIAS_OK);
@@ -1160,9 +1063,7 @@ FragmentOut(struct libalias *la, struct ip *pip)
 
 	alias_address = FindAliasAddress(la, pip->ip_src);
 	DifferentialChecksum(&pip->ip_sum,
-	    (u_short *) & alias_address,
-	    (u_short *) & pip->ip_src,
-	    2);
+	    &alias_address, &pip->ip_src, 2);
 	pip->ip_src = alias_address;
 
 	return (PKT_ALIAS_OK);
@@ -1240,9 +1141,7 @@ LibAliasFragmentIn(struct libalias *la, char *ptr,	/* Points to correctly
 	fpip = (struct ip *)ptr_fragment;
 
 	DifferentialChecksum(&fpip->ip_sum,
-	    (u_short *) & pip->ip_dst,
-	    (u_short *) & fpip->ip_dst,
-	    2);
+	    &pip->ip_dst, &fpip->ip_dst, 2);
 	fpip->ip_dst = pip->ip_dst;
 }
 
@@ -1443,7 +1342,6 @@ LibAliasUnaliasOut(struct libalias *la, char *ptr,	/* valid IP packet */
 	/* Change it from an aliased packet to an unaliased packet */
 	if (link != NULL) {
 		if (pip->ip_p == IPPROTO_UDP || pip->ip_p == IPPROTO_TCP) {
-			u_short *sptr;
 			int accumulate;
 			struct in_addr original_address;
 			u_short original_port;
@@ -1452,12 +1350,8 @@ LibAliasUnaliasOut(struct libalias *la, char *ptr,	/* valid IP packet */
 			original_port = GetOriginalPort(link);
 
 			/* Adjust TCP/UDP checksum */
-			sptr = (u_short *) & (pip->ip_src);
-			accumulate = *sptr++;
-			accumulate += *sptr;
-			sptr = (u_short *) & original_address;
-			accumulate -= *sptr++;
-			accumulate -= *sptr;
+			accumulate = twowords(&pip->ip_src);
+			accumulate -= twowords(&original_address);
 
 			if (pip->ip_p == IPPROTO_UDP) {
 				accumulate += ud->uh_sport;
@@ -1471,9 +1365,7 @@ LibAliasUnaliasOut(struct libalias *la, char *ptr,	/* valid IP packet */
 
 			/* Adjust IP checksum */
 			DifferentialChecksum(&pip->ip_sum,
-			    (u_short *) & original_address,
-			    (u_short *) & pip->ip_src,
-			    2);
+			    &original_address, &pip->ip_src, 2);
 
 			/* Un-alias source address and port number */
 			pip->ip_src = original_address;
@@ -1486,7 +1378,6 @@ LibAliasUnaliasOut(struct libalias *la, char *ptr,	/* valid IP packet */
 
 		} else if (pip->ip_p == IPPROTO_ICMP) {
 
-			u_short *sptr;
 			int accumulate;
 			struct in_addr original_address;
 			u_short original_id;
@@ -1495,21 +1386,15 @@ LibAliasUnaliasOut(struct libalias *la, char *ptr,	/* valid IP packet */
 			original_id = GetOriginalPort(link);
 
 			/* Adjust ICMP checksum */
-			sptr = (u_short *) & (pip->ip_src);
-			accumulate = *sptr++;
-			accumulate += *sptr;
-			sptr = (u_short *) & original_address;
-			accumulate -= *sptr++;
-			accumulate -= *sptr;
+			accumulate = twowords(&pip->ip_src);
+			accumulate -= twowords(&original_address);
 			accumulate += ic->icmp_id;
 			accumulate -= original_id;
 			ADJUST_CHECKSUM(accumulate, ic->icmp_cksum);
 
 			/* Adjust IP checksum */
 			DifferentialChecksum(&pip->ip_sum,
-			    (u_short *) & original_address,
-			    (u_short *) & pip->ip_src,
-			    2);
+			    &original_address, &pip->ip_src, 2);
 
 			/* Un-alias source address and port number */
 			pip->ip_src = original_address;
diff --git a/lib/libalias/alias_local.h b/lib/libalias/alias_local.h
index 420a435..b70fee6 100644
--- a/lib/libalias/alias_local.h
+++ b/lib/libalias/alias_local.h
@@ -168,8 +168,7 @@ struct libalias {
 u_short		IpChecksum(struct ip *_pip);
 u_short		TcpChecksum(struct ip *_pip);
 void
-DifferentialChecksum(u_short * _cksum, u_short * _new, u_short * _old,
-    int _n);
+DifferentialChecksum(u_short * _cksum, void * _new, void * _old, int _n);
 
 /* Internal data access */
 struct alias_link *
diff --git a/lib/libalias/alias_pptp.c b/lib/libalias/alias_pptp.c
index 5df60cb..24bce3e 100644
--- a/lib/libalias/alias_pptp.c
+++ b/lib/libalias/alias_pptp.c
@@ -338,9 +338,7 @@ AliasHandlePptpGreOut(struct libalias *la, struct ip *pip)
 
 		/* Change source IP address. */
 		DifferentialChecksum(&pip->ip_sum,
-		    (u_short *) & alias_addr,
-		    (u_short *) & pip->ip_src,
-		    2);
+		    &alias_addr, &pip->ip_src, 2);
 		pip->ip_src = alias_addr;
 	}
 	return (0);
@@ -368,9 +366,7 @@ AliasHandlePptpGreIn(struct libalias *la, struct ip *pip)
 
 		/* Restore original IP address. */
 		DifferentialChecksum(&pip->ip_sum,
-		    (u_short *) & src_addr,
-		    (u_short *) & pip->ip_dst,
-		    2);
+		    &src_addr, &pip->ip_dst, 2);
 		pip->ip_dst = src_addr;
 	}
 	return (0);
diff --git a/lib/libalias/alias_util.c b/lib/libalias/alias_util.c
index d7d0b3f..bec0ba7 100644
--- a/lib/libalias/alias_util.c
+++ b/lib/libalias/alias_util.c
@@ -136,10 +136,12 @@ TcpChecksum(struct ip *pip)
 
 
 void
-DifferentialChecksum(u_short * cksum, u_short * new, u_short * old, int n)
+DifferentialChecksum(u_short * cksum, void *newp, void *oldp, int n)
 {
 	int i;
 	int accumulate;
+	u_short *new = newp;
+	u_short *old = oldp;
 
 	accumulate = *cksum;
 	for (i = 0; i < n; i++) {