1 files changed, 149 insertions, 0 deletions
diff --git a/rfc1035/rfc1035qptr.c b/rfc1035/rfc1035qptr.c
new file mode 100644
index 0000000..704d849
--- /dev/null
+++ b/rfc1035/rfc1035qptr.c
@@ -0,0 +1,149 @@
+/*
+** Copyright 1998 - 2011 Double Precision, Inc.
+** See COPYING for distribution information.
+*/
+
+#include	"rfc1035.h"
+#include	<string.h>
+#include	<errno.h>
+
+
+static int ptr(struct rfc1035_res *, const void *, int,
+	       void (*)(const char *, void *),
+	       void *);
+
+static void save_name(const char *name, void *void_arg)
+{
+	strcpy((char *)void_arg, name);
+}
+
+int rfc1035_ptr(struct rfc1035_res *res, const RFC1035_ADDR *addr,
+		  char *name)
+{
+	return rfc1035_ptr_x(res, addr, save_name, name);
+}
+
+/* Convenient function to do reverse IP lookup */
+#if	RFC1035_IPV6
+
+int rfc1035_ptr_x(struct rfc1035_res *res, const RFC1035_ADDR *addr,
+		  void (*cb_func)(const char *, void *),
+		  void *cb_arg)
+{
+struct	in_addr	in4;
+
+	if (IN6_IS_ADDR_V4MAPPED(addr))
+	{
+		rfc1035_ipv6to4(&in4, addr);
+		if (ptr(res, &in4, AF_INET, cb_func, cb_arg) == 0) return (0);
+		return (-1);
+	}
+	return (ptr(res, addr, AF_INET6, cb_func,cb_arg));
+}
+
+#else
+int rfc1035_ptr_x(struct rfc1035_res *res, const RFC1035_ADDR *a,
+		  void (*cb_func)(const char *, void *),
+		  void *cb_arg)
+{
+	return (ptr(res, a, AF_INET, cb_func, cb_arg));
+}
+#endif
+
+static int ptr(struct rfc1035_res *res, const void *addr, int af,
+	       void (*cb_func)(const char *, void *),
+	       void *cb_arg)
+{
+struct	rfc1035_reply *reply;
+int	n;
+char	name[256], ptrbuf[256];
+
+#if	RFC1035_IPV6
+
+	if (af == AF_INET6)
+	{
+	const char *sin6=(const char *)addr;
+	unsigned i;
+
+		*name=0;
+		for (i=sizeof(struct in6_addr); i; )
+		{
+		char	buf[10];
+
+			--i;
+			sprintf(buf, "%x.%x.",
+				(int)(unsigned char)(sin6[i] & 0x0F),
+				(int)(unsigned char)((sin6[i] >> 4) & 0x0F));
+			strcat(name, buf);
+		}
+		strcat(name, "ip6.arpa");
+	}
+	else
+#endif
+	if (af != AF_INET)
+	{
+		errno=ENOENT;
+		return (-1); /* hard error */
+	}
+	else
+	{
+	const char *p;
+	unsigned char a=0,b=0,c=0,d=0;
+	struct	in_addr	ia;
+
+		memcpy(&ia, addr, sizeof(ia));
+		rfc1035_ntoa_ipv4(&ia, name);
+		p=name;
+
+		while (*p >= '0' && *p <= '9')
+			a= (int)a * 10 + (*p++ - '0');
+		if (*p)	p++;
+		while (*p >= '0' && *p <= '9')
+			b= (int)b * 10 + (*p++ - '0');
+		if (*p)	p++;
+		while (*p >= '0' && *p <= '9')
+			c= (int)c * 10 + (*p++ - '0');
+		if (*p)	p++;
+		while (*p >= '0' && *p <= '9')
+			d= (int)d * 10 + (*p++ - '0');
+
+		sprintf(name, "%d.%d.%d.%d.in-addr.arpa",
+			(int)d, (int)c, (int)b, (int)a);
+	}
+
+	if (rfc1035_resolve_cname(res, name,
+		RFC1035_TYPE_PTR, RFC1035_CLASS_IN, &reply, 0) < 0 ||
+		reply == 0 ||
+		(n=rfc1035_replysearch_an( res, reply, name, RFC1035_TYPE_PTR,
+			RFC1035_CLASS_IN, 0)) < 0 ||
+		rfc1035_replyhostname(reply, reply->allrrs[n]->rr.domainname,
+			ptrbuf) == 0)
+	{
+		if (reply && reply->rcode != RFC1035_RCODE_NXDOMAIN &&
+			reply->rcode != RFC1035_RCODE_NOERROR)
+		{
+			rfc1035_replyfree(reply);
+			errno=EAGAIN;
+			return (-1);
+		}
+
+		if (reply) rfc1035_replyfree(reply);
+		errno=ENOENT;
+		return (-1); /* hard error */
+	}
+
+	(*cb_func)(ptrbuf, cb_arg);
+
+	while ((n=rfc1035_replysearch_an(res, reply, name,
+					 RFC1035_TYPE_PTR,
+					 RFC1035_CLASS_IN, n+1)) >= 0)
+	{
+		if (rfc1035_replyhostname(reply,
+					  reply->allrrs[n]->rr.domainname,
+					  ptrbuf))
+			(*cb_func)(ptrbuf, cb_arg);
+	}
+
+	rfc1035_replyfree(reply);
+	return (0);
+}