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 a26b11381b9e53b63f3f34ad7d2bc7bab49f9159..31502af4dcad58b4e021bf432884a1df07201e62 100644 (file)
--- 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)