From: Frédéric Marchal <fmarchal@users.sourceforge.net>
Date: Fri, 17 Feb 2012 17:05:59 +0000 (+0100)
Subject: Prepare the ip resolving for other resolving methods
X-Git-Tag: v2.3.3-pre1~22
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2846a495be480bc00eb31b58df4fe191a4771613;p=thirdparty%2Fsarg.git

Prepare the ip resolving for other resolving methods

The ip resolving is moved into a distinct function that will be called
based on the configured options.
---

diff --git a/ip2name.c b/ip2name.c
index a26b113..31502af 100644
--- a/ip2name.c
+++ b/ip2name.c
@@ -30,7 +30,27 @@
 #include <ws2tcpip.h> //define getnameinfo on windows
 #endif
 
-void ip2name(char *ip,int ip_len)
+//! The possible return code of ip2name subfunctions.
+enum ip2name_retcode
+{
+	//! Error encountered during the 
+	INRC_Error=-1,
+	//! No match found.
+	INRC_NotFound,
+	//! A match was found.
+	INRC_Found,
+};
+
+/*!
+Resolve the IP address using a reverse DNS entry.
+
+\param ip The IP address. It is replaced by the corresponding name if one
+can be found.
+\param ip_len The length of the \c ip buffer.
+
+\return One of the ::ip2name_retcode value.
+*/
+static enum ip2name_retcode ip2name_dns(char *ip,int ip_len)
 {
 #ifdef HAVE_GETNAMEINFO
 	struct sockaddr_storage sa;
@@ -42,19 +62,19 @@ void ip2name(char *ip,int ip_len)
 	memset(&sa,0,sizeof(sa));
 	if (sscanf(ip,"%d.%d.%d.%d%n",&n1,&n2,&n3,&n4,&next)==4 && ip[next]=='\0') {
 		struct sockaddr_in *s4=(struct sockaddr_in *)&sa;
-		if (inet_pton(AF_INET,ip,&s4->sin_addr)!=1) return;
+		if (inet_pton(AF_INET,ip,&s4->sin_addr)!=1) return(INRC_Error);
 		sa.ss_family=AF_INET;
 		sockaddr_size=sizeof(*s4);
 	} else {
 		struct sockaddr_in6 *s6=(struct sockaddr_in6 *)&sa;
-		if (inet_pton(AF_INET6,ip,&s6->sin6_addr)!=1) return;
+		if (inet_pton(AF_INET6,ip,&s6->sin6_addr)!=1) return(INRC_Error);
 		sa.ss_family=AF_INET6;
 		sockaddr_size=sizeof(*s6);
 	}
 #ifdef HAVE_SOCKADDR_SA_LEN
 	sa.ss_len=sockaddr_size;
 #endif
-	error=getnameinfo((struct sockaddr *)&sa,sockaddr_size,host,sizeof(host),NULL,0,0);
+	error=getnameinfo((struct sockaddr *)&sa,sockaddr_size,host,sizeof(host),NULL,0,NI_NAMEREQD);
 	if (error==EAI_AGAIN) {
 		/*
 		This is a temporary failure. According to the man page we should try again but
@@ -64,29 +84,35 @@ void ip2name(char *ip,int ip_len)
 		of serious consequences should some IP fail to be resolved properly, it is best
 		not waste too much time on this.
 		*/
-		error=getnameinfo((struct sockaddr *)&sa,sizeof(sa),host,sizeof(host),NULL,0,0);
+		error=getnameinfo((struct sockaddr *)&sa,sizeof(sa),host,sizeof(host),NULL,0,NI_NAMEREQD);
 	}
-	if (error==0) {
-		safe_strcpy(ip,host,ip_len);
-	} else {
+	if (error==EAI_NONAME)
+		return(INRC_NotFound);
+	if (error!=0) {
 		debuga(_("IP to name resolution (getnameinfo) on IP address %s failed with error %d - %s\n"),ip,error,gai_strerror(error));
+		return(INRC_Error);
 	}
-#else
+	safe_strcpy(ip,host,ip_len);
+#else //HAVE_GETNAMEINFO
 	struct in_addr addr;
 	struct hostent *hp;
 	char **p;
+	extern int h_errno;
 
 #ifdef HAVE_INET_ATON
 	if (inet_aton(ip,&addr) == 0)
-		return;
+		return(INRC_Error);
 #else
 	addr.s_addr=inet_addr(ip);
-	if (addr.s_addr==-1) return;
+	if (addr.s_addr==-1) return(INRC_Error);
 #endif
 
 	hp = gethostbyaddr((void *)&addr, sizeof (addr), AF_INET);
-	if (hp == NULL)
-		return;
+	if (hp == NULL) {
+		if (h_errno==HOST_NOT_FOUND)
+			return(INRC_NotFound);
+		return(INRC_Error);
+	}
 
 	for (p = hp->h_addr_list; *p != 0; p++) {
 		struct in_addr in;
@@ -95,7 +121,22 @@ void ip2name(char *ip,int ip_len)
 		safe_strcpy(ip,hp->h_name,ip_len);
 	}
 #endif
-	return;
+	return(INRC_Found);
+}
+
+/*!
+Convert an IP address into a name.
+
+\param ip The IP address. It is replaced by the corresponding name if one
+can be found.
+\param ip_len The length of the \c ip buffer.
+*/
+void ip2name(char *ip,int ip_len)
+{
+	enum ip2name_retcode Status;
+	
+	Status=ip2name_dns(ip,ip_len);
+	if (Status==INRC_Found) return;
 }
 
 void name2ip(char *name,int name_size)