Introduce inline {ip,udp,tcp}_next() functions which take a pointer to an

{ip,udp,tcp} header and return a void * pointing to the payload (i.e. the
first byte past the end of the header and any required padding).  Use them
consistently throughout libalias to a) reduce code duplication, b) improve
code legibility, c) get rid of a bunch of alignment warnings.

1 files changed, 22 insertions, 22 deletions

diff --git a/lib/libalias/alias.c b/lib/libalias/alias.c
index 6acf03b..a2c2911 100644
--- a/lib/libalias/alias.c
+++ b/lib/libalias/alias.c
@@ -173,7 +173,7 @@ TcpMonitorIn(struct ip *pip, struct alias_link *lnk)
 {
 	struct tcphdr *tc;
 
-	tc = (struct tcphdr *)((char *)pip + (pip->ip_hl << 2));
+	tc = (struct tcphdr *)ip_next(pip);
 
 	switch (GetStateIn(lnk)) {
 	case ALIAS_TCP_STATE_NOT_CONNECTED:
@@ -194,7 +194,7 @@ TcpMonitorOut(struct ip *pip, struct alias_link *lnk)
 {
 	struct tcphdr *tc;
 
-	tc = (struct tcphdr *)((char *)pip + (pip->ip_hl << 2));
+	tc = (struct tcphdr *)ip_next(pip);
 
 	switch (GetStateOut(lnk)) {
 	case ALIAS_TCP_STATE_NOT_CONNECTED:
@@ -283,7 +283,7 @@ IcmpAliasIn1(struct libalias *la, struct ip *pip)
 	struct alias_link *lnk;
 	struct icmp *ic;
 
-	ic = (struct icmp *)((char *)pip + (pip->ip_hl << 2));
+	ic = (struct icmp *)ip_next(pip);
 
 /* Get source address from ICMP data field and restore original data */
 	lnk = FindIcmpIn(la, pip->ip_src, pip->ip_dst, ic->icmp_id, 1);
@@ -329,12 +329,12 @@ IcmpAliasIn2(struct libalias *la, struct ip *pip)
 	struct tcphdr *tc;
 	struct alias_link *lnk;
 
-	ic = (struct icmp *)((char *)pip + (pip->ip_hl << 2));
+	ic = (struct icmp *)ip_next(pip);
 	ip = &ic->icmp_ip;
 
-	ud = (struct udphdr *)((char *)ip + (ip->ip_hl << 2));
-	tc = (struct tcphdr *)ud;
-	ic2 = (struct icmp *)ud;
+	ud = (struct udphdr *)ip_next(ip);
+	tc = (struct tcphdr *)ip_next(ip);
+	ic2 = (struct icmp *)ip_next(ip);
 
 	if (ip->ip_p == IPPROTO_UDP)
 		lnk = FindUdpTcpIn(la, ip->ip_dst, ip->ip_src,
@@ -426,7 +426,7 @@ IcmpAliasIn(struct libalias *la, struct ip *pip)
 	if (la->packetAliasMode & PKT_ALIAS_PROXY_ONLY)
 		return (PKT_ALIAS_OK);
 
-	ic = (struct icmp *)((char *)pip + (pip->ip_hl << 2));
+	ic = (struct icmp *)ip_next(pip);
 
 	iresult = PKT_ALIAS_IGNORED;
 	switch (ic->icmp_type) {
@@ -461,7 +461,7 @@ IcmpAliasOut1(struct libalias *la, struct ip *pip)
 	struct alias_link *lnk;
 	struct icmp *ic;
 
-	ic = (struct icmp *)((char *)pip + (pip->ip_hl << 2));
+	ic = (struct icmp *)ip_next(pip);
 
 /* Save overwritten data for when echo packet returns */
 	lnk = FindIcmpOut(la, pip->ip_src, pip->ip_dst, ic->icmp_id, 1);
@@ -508,12 +508,12 @@ IcmpAliasOut2(struct libalias *la, struct ip *pip)
 	struct tcphdr *tc;
 	struct alias_link *lnk;
 
-	ic = (struct icmp *)((char *)pip + (pip->ip_hl << 2));
+	ic = (struct icmp *)ip_next(pip);
 	ip = &ic->icmp_ip;
 
-	ud = (struct udphdr *)((char *)ip + (ip->ip_hl << 2));
-	tc = (struct tcphdr *)ud;
-	ic2 = (struct icmp *)ud;
+	ud = (struct udphdr *)ip_next(ip);
+	tc = (struct tcphdr *)ip_next(ip);
+	ic2 = (struct icmp *)ip_next(ip);
 
 	if (ip->ip_p == IPPROTO_UDP)
 		lnk = FindUdpTcpOut(la, ip->ip_dst, ip->ip_src,
@@ -607,7 +607,7 @@ IcmpAliasOut(struct libalias *la, struct ip *pip, int create)
 	if (la->packetAliasMode & PKT_ALIAS_PROXY_ONLY)
 		return (PKT_ALIAS_OK);
 
-	ic = (struct icmp *)((char *)pip + (pip->ip_hl << 2));
+	ic = (struct icmp *)ip_next(pip);
 
 	iresult = PKT_ALIAS_IGNORED;
 	switch (ic->icmp_type) {
@@ -707,7 +707,7 @@ UdpAliasIn(struct libalias *la, struct ip *pip)
 	if (la->packetAliasMode & PKT_ALIAS_PROXY_ONLY)
 		return (PKT_ALIAS_OK);
 
-	ud = (struct udphdr *)((char *)pip + (pip->ip_hl << 2));
+	ud = (struct udphdr *)ip_next(pip);
 
 	lnk = FindUdpTcpIn(la, pip->ip_src, pip->ip_dst,
 	    ud->uh_sport, ud->uh_dport,
@@ -771,7 +771,7 @@ UdpAliasOut(struct libalias *la, struct ip *pip, int create)
 	if (la->packetAliasMode & PKT_ALIAS_PROXY_ONLY)
 		return (PKT_ALIAS_OK);
 
-	ud = (struct udphdr *)((char *)pip + (pip->ip_hl << 2));
+	ud = (struct udphdr *)ip_next(pip);
 
 	lnk = FindUdpTcpOut(la, pip->ip_src, pip->ip_dst,
 	    ud->uh_sport, ud->uh_dport,
@@ -835,7 +835,7 @@ TcpAliasIn(struct libalias *la, struct ip *pip)
 	struct tcphdr *tc;
 	struct alias_link *lnk;
 
-	tc = (struct tcphdr *)((char *)pip + (pip->ip_hl << 2));
+	tc = (struct tcphdr *)ip_next(pip);
 
 	lnk = FindUdpTcpIn(la, pip->ip_src, pip->ip_dst,
 	    tc->th_sport, tc->th_dport,
@@ -926,7 +926,7 @@ TcpAliasOut(struct libalias *la, struct ip *pip, int maxpacketsize, int create)
 	struct tcphdr *tc;
 	struct alias_link *lnk;
 
-	tc = (struct tcphdr *)((char *)pip + (pip->ip_hl << 2));
+	tc = (struct tcphdr *)ip_next(pip);
 
 	proxy_type = ProxyCheck(la, pip, &proxy_server_address, &proxy_server_port);
 
@@ -969,7 +969,7 @@ TcpAliasOut(struct libalias *la, struct ip *pip, int maxpacketsize, int create)
 			SetProxyPort(lnk, dest_port);
 			SetProxyAddress(lnk, dest_address);
 			ProxyModify(la, lnk, pip, maxpacketsize, proxy_type);
-			tc = (struct tcphdr *)((char *)pip + (pip->ip_hl << 2));
+			tc = (struct tcphdr *)ip_next(pip);
 		}
 /* Get alias address and port */
 		alias_port = GetAliasPort(lnk);
@@ -1346,9 +1346,9 @@ LibAliasUnaliasOut(struct libalias *la, char *ptr,	/* valid IP packet */
 	    || (pip->ip_hl << 2) > maxpacketsize)
 		return (iresult);
 
-	ud = (struct udphdr *)((char *)pip + (pip->ip_hl << 2));
-	tc = (struct tcphdr *)ud;
-	ic = (struct icmp *)ud;
+	ud = (struct udphdr *)ip_next(pip);
+	tc = (struct tcphdr *)ip_next(pip);
+	ic = (struct icmp *)ip_next(pip);
 
 	/* Find a link */
 	if (pip->ip_p == IPPROTO_UDP)