+/*
+ * SARG Squid Analysis Report Generator http://sarg.sourceforge.net
+ * 1998, 2012
+ *
+ * SARG donations:
+ * please look at http://sarg.sourceforge.net/donations.php
+ * Support:
+ * http://sourceforge.net/projects/sarg/forums/forum/363374
+ * ---------------------------------------------------------------------
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
+ *
+ */
+
+#include "include/conf.h"
+#include "include/defs.h"
+#include "include/ip2name.h"
+#ifdef HAVE_WS2TCPIP_H
+#include <ws2tcpip.h> //define getnameinfo on windows
+#endif
+
+static enum ip2name_retcode ip2name_dns(char *ip,int ip_len);
+
+//! The functions to resolve an IP address through tne dns.
+struct Ip2NameProcess Ip2NameDns=
+{
+ "dns",
+ NULL,//no next item yet
+ NULL,//no configuration
+ ip2name_dns
+};
+
+/*!
+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;
+ int sockaddr_size;
+ char host[NI_MAXHOST];
+ int n1,n2,n3,n4,next=0;
+ int error;
+
+ 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(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(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,NI_NAMEREQD);
+ if (error==EAI_AGAIN) {
+ /*
+ This is a temporary failure. According to the man page we should try again but
+ it doesn't say if the program should wait before trying again nor how many attempts
+ before it becomes a fatal error. I could find no clues on internet so I try once and
+ leave it at that. Considering the number of IP addresses to resolve and the absence
+ 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,NI_NAMEREQD);
+ }
+ 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);
+ }
+ 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(INRC_Error);
+#else
+ addr.s_addr=inet_addr(ip);
+ if (addr.s_addr==-1) return(INRC_Error);
+#endif
+
+ hp = gethostbyaddr((void *)&addr, sizeof (addr), AF_INET);
+ 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;
+
+ (void) memcpy(&in.s_addr, *p, sizeof (in.s_addr));
+ safe_strcpy(ip,hp->h_name,ip_len);
+ }
+#endif
+ return(INRC_Found);
+}
+