From 879934a987d63e87b2960ff044be80b42caaf41a Mon Sep 17 00:00:00 2001
From: Art Cancro <ajc@citadel.org>
Date: Mon, 16 Aug 2010 17:04:07 +0000
Subject: [PATCH] * citserver locate_host() migrated to getpeername() and
 getnameinfo().  These API's are both simpler and IPv4/IPv6 compatible.

---
 citadel/citserver.c   | 13 +++----
 citadel/locate_host.c | 88 ++++---------------------------------------
 citadel/locate_host.h |  4 +-
 3 files changed, 15 insertions(+), 90 deletions(-)

diff --git a/citadel/citserver.c b/citadel/citserver.c
index 44139cce1..9b522032d 100644
--- a/citadel/citserver.c
+++ b/citadel/citserver.c
@@ -907,15 +907,14 @@ void begin_session(CitContext *con)
 	con->cs_host[sizeof con->cs_host - 1] = 0;
 	len = sizeof sin;
 	if (!CC->is_local_socket) {
-		if (!getpeername(con->client_socket, (struct sockaddr *) &sin, &len)) {
-			locate_host(con->cs_host, sizeof con->cs_host,
-				con->cs_addr, sizeof con->cs_addr,
-				&sin.sin_addr
-			);
-		}
+		locate_host(con->cs_host, sizeof con->cs_host,
+			con->cs_addr, sizeof con->cs_addr,
+			con->client_socket
+		);
 	}
 	else {
-		strcpy(con->cs_host, "");
+		con->cs_host[0] = 0;
+		con->cs_addr[0] = 0;
 #ifdef HAVE_STRUCT_UCRED
 		{
 			/* as http://www.wsinnovations.com/softeng/articles/uds.html told us... */
diff --git a/citadel/locate_host.c b/citadel/locate_host.c
index 3e0a36d0b..0331d82df 100644
--- a/citadel/locate_host.c
+++ b/citadel/locate_host.c
@@ -38,89 +38,17 @@
 #endif
 
 
-/* Hacks to work around nameser.h declarations missing on OpenBSD
- * see also: http://search.cpan.org/src/MIKER/Net-DNS-ToolKit-0.30/ToolKit.h
- */
-
-#ifndef NS_INT16SZ
-# ifdef INT16SZ
-#  define NS_INT16SZ INT16SZ
-# endif
-#endif
-
-#ifndef NS_INT32SZ
-# ifdef INT32SZ
-#  define NS_INT32SZ INT32SZ
-# endif
-#endif
-
-#ifndef NS_GET16
-# ifdef GETSHORT
-#  define NS_GET16 GETSHORT
-# endif
-#endif
-
-
-/***************************************************************************/
-
-
-void locate_host(char *tbuf, size_t n,
-		char *abuf, size_t na,
-		const struct in_addr *addr)
+void locate_host(char *tbuf, size_t n, char *abuf, size_t na, int client_socket)
 {
-	struct hostent *ch;
-	const char *i;
-	char *j;
-	int a1, a2, a3, a4;
-	char address_string[SIZ];
-
+	struct sockaddr_in6 clientaddr;
+	unsigned int addrlen = sizeof(clientaddr);
 
-#ifdef HAVE_NONREENTRANT_NETDB
-	begin_critical_section(S_NETDB);
-#endif
-
-	i = (const char *) addr;
-	a1 = ((*i++) & 0xff);
-	a2 = ((*i++) & 0xff);
-	a3 = ((*i++) & 0xff);
-	a4 = ((*i++) & 0xff);
-	sprintf(address_string, "%d.%d.%d.%d", a1, a2, a3, a4);
-
-	if (abuf != NULL) {
-		safestrncpy(abuf, address_string, na);
-	}
-
-	if ((ch = gethostbyaddr((const char *) addr,
-	   sizeof(*addr), AF_INET)) == NULL) {
-bad_dns:
-		safestrncpy(tbuf, address_string, n);
-		goto end;	/* because we might need to end the critical
-				   section */
-	}
-	/* check if the forward DNS agrees; if not, they're spoofing */
-	j = strdup(ch->h_name);
-	ch = gethostbyname(j);
-	free(j);
-	if (ch == NULL)
-		goto bad_dns;
-
-	/* check address for consistency */
-	for (; *ch->h_addr_list; ch->h_addr_list++)
-		if (!memcmp(*ch->h_addr_list, addr,
-			    sizeof *addr)) {
-			safestrncpy(tbuf, ch->h_name, 63);
-			goto end;
-		}
-	goto bad_dns;		/* they were spoofing. report a numeric IP
-				   address. */
-
-      end:
-
-#ifdef HAVE_NONREENTRANT_NETDB
-	end_critical_section(S_NETDB);
-#endif
+	tbuf[0] = 0;
+	abuf[0] = 0;
 
-	tbuf[63] = 0;
+	getpeername(client_socket, (struct sockaddr *)&clientaddr, &addrlen);
+	getnameinfo((struct sockaddr *)&clientaddr, addrlen, tbuf, n, NULL, 0, 0);
+	getnameinfo((struct sockaddr *)&clientaddr, addrlen, abuf, na, NULL, 0, NI_NUMERICHOST);
 }
 
 
diff --git a/citadel/locate_host.h b/citadel/locate_host.h
index b71d389c7..21ae5bdfd 100644
--- a/citadel/locate_host.h
+++ b/citadel/locate_host.h
@@ -1,7 +1,5 @@
 /* $Id$ */
-void locate_host(char *tbuf, size_t n,
-		char *abuf, size_t na,
-		const struct in_addr *addr);
+void locate_host(char *tbuf, size_t n, char *abuf, size_t na, int client_socket);
 int rbl_check(char *message_to_spammer);
 int hostname_to_dotted_quad(char *addr, char *host);
 int rblcheck_backend(char *domain, char *txtbuf, int txtbufsize);
-- 
2.30.2