Use less memory for ip_addr in port_reason.

This was a sockaddr_storage, which is 128 bytes. This is a lot for a
structure that is part of Port. It is now a union of sockaddr_in and
sockaddr_in6, which is 28 bytes. A new set_ip_addr method sets the union
from a sockaddr_storage, where plain assignment was used before.

The sockaddr_storage was introduced in r23778, the first big IPv6 merge.

CHANGELOG

@@ -1,5 +1,9 @@
 # Nmap Changelog ($Id$); -*-text-*-
 
+o Reduced the size of Port structures by about a third (from 176 to 64
+  bytes on x86_64). They had accidentally been made bigger than they
+  should during the IPv6 code merge. [David Fifield]
+
 o [NSE] Added default values for Expires, Call-ID, Allow and Content-Length
   headers in SIP requests and removed redundant code sip library.
   [Hani Benhabiles]

output.cc

@@ -662,8 +662,11 @@ void printportoutput(Target *currenths, PortList *plist) {
         xml_attribute("state", "%s", state);
         xml_attribute("reason", "%s", reason_str(current->reason.reason_id, SINGULAR));
         xml_attribute("reason_ttl", "%d", current->reason.ttl);
-        if (current->reason.ip_addr.ss_family != AF_UNSPEC)
-          xml_attribute("reason_ip", "%s", inet_ntop_ez(&current->reason.ip_addr, sizeof(current->reason.ip_addr)));
+        if (current->reason.ip_addr.sockaddr.sa_family != AF_UNSPEC) {
+          struct sockaddr_storage ss;
+          memcpy(&ss, &current->reason.ip_addr, sizeof(current->reason.ip_addr));
+          xml_attribute("reason_ip", "%s", inet_ntop_ez(&ss, sizeof(ss)));
+        }
         xml_close_empty_tag();
 
         if (proto && proto->p_name && *proto->p_name) {
@@ -774,8 +777,11 @@ void printportoutput(Target *currenths, PortList *plist) {
         xml_attribute("state", "%s", state);
         xml_attribute("reason", "%s", reason_str(current->reason.reason_id, SINGULAR));
         xml_attribute("reason_ttl", "%d", current->reason.ttl);
-        if (current->reason.ip_addr.ss_family != AF_UNSPEC)
-          xml_attribute("reason_ip", "%s", inet_ntop_ez(&current->reason.ip_addr, sizeof(current->reason.ip_addr)));
+        if (current->reason.ip_addr.sockaddr.sa_family != AF_UNSPEC) {
+          struct sockaddr_storage ss;
+          memcpy(&ss, &current->reason.ip_addr, sizeof(current->reason.ip_addr));
+          xml_attribute("reason_ip", "%s", inet_ntop_ez(&ss, sizeof(ss)));
+        }
         xml_close_empty_tag();
 
         if (sd.name || sd.service_fp || sd.service_tunnel != SERVICE_TUNNEL_NONE)

portlist.cc

@@ -928,9 +928,9 @@ int PortList::setStateReason(u16 portno, u8 proto, reason_t reason, u8 ttl,
     /* set new reason and increment its count */
     answer->reason.reason_id = reason;
     if (ip_addr == NULL)
-      answer->reason.ip_addr.ss_family = AF_UNSPEC;
+      answer->reason.ip_addr.sockaddr.sa_family = AF_UNSPEC;
     else
-      answer->reason.ip_addr = *ip_addr;
+      answer->reason.set_ip_addr(ip_addr);
 	answer->reason.ttl = ttl;
     return 0;
 }

portreasons.cc

@@ -108,6 +108,21 @@
 extern NmapOps o;
 class PortList;
 
+/* Set the ip_addr union to the AF_INET or AF_INET6 value stored in *ss as
+   appropriate. Returns 0 on success or -1 if the address family of *ss is not
+   known. */
+int port_reason::set_ip_addr(const struct sockaddr_storage *ss) {
+  if (ss->ss_family == AF_INET) {
+    this->ip_addr.in = *(struct sockaddr_in *) ss;
+    return 0;
+  } else if (ss->ss_family == AF_INET6) {
+    this->ip_addr.in6 = *(struct sockaddr_in6 *) ss;
+    return 0;
+  } else {
+    return -1;
+  }
+}
+
 /* reason_string initializer */
 reason_string::reason_string(){
     this->plural = "unknown";
@@ -430,7 +445,7 @@ const char *reason_str(reason_t reason_code, unsigned int number) {
 
 void state_reason_init(state_reason_t *reason) {
 	reason->reason_id = ER_UNKNOWN;
-	reason->ip_addr.ss_family = AF_UNSPEC;
+	reason->ip_addr.sockaddr.sa_family = AF_UNSPEC;
 	reason->ttl = 0;
 }
 
@@ -506,8 +521,13 @@ char *target_reason_str(Target *t) {
 char *port_reason_str(state_reason_t r) {
 	static char reason[128];
 	memset(reason,'\0', 128);
-	Snprintf(reason, 128, "%s%s%s", reason_str(r.reason_id, SINGULAR),
-            (r.ip_addr.ss_family==AF_UNSPEC)?"":" from ",
-            (r.ip_addr.ss_family==AF_UNSPEC)?"":inet_ntop_ez(&r.ip_addr, sizeof(r.ip_addr)));
+	if (r.ip_addr.sockaddr.sa_family == AF_UNSPEC) {
+		Snprintf(reason, sizeof(reason), "%s", reason_str(r.reason_id, SINGULAR));
+	} else {
+		struct sockaddr_storage ss;
+		memcpy(&ss, &r.ip_addr, sizeof(r.ip_addr));
+		Snprintf(reason, sizeof(reason), "%s from %s", reason_str(r.reason_id, SINGULAR),
+			inet_ntop_ez(&ss, sizeof(ss)));
+	}
 	return reason;
 }

portreasons.h

@@ -128,8 +128,14 @@ public:
  * why a port is in a specific state */
 typedef struct port_reason {
 	reason_t reason_id;
-	struct sockaddr_storage ip_addr;
+	union {
+		struct sockaddr_in in;
+		struct sockaddr_in6 in6;
+		struct sockaddr sockaddr;
+	} ip_addr;
 	unsigned short ttl;
+
+	int set_ip_addr(const struct sockaddr_storage *ss);
 } state_reason_t;
 
 /* used to calculate state reason summaries.

scan_engine.cc

@@ -5381,7 +5381,7 @@ static int get_ping_pcap_result(UltraScanInfo *USI, struct timeval *stime) {
       hss->target->reason.reason_id = current_reason;
       hss->target->reason.ttl = hdr.ttl;
       if (sockaddr_storage_cmp(&hdr.src, &target_dst) != 0) {
-        hss->target->reason.ip_addr = hdr.src;
+        hss->target->reason.set_ip_addr(&hdr.src);
       }
     }
   }