From: Timo Sirainen <tss@iki.fi>
Date: Fri, 28 Jun 2013 16:48:15 +0000 (+0300)
Subject: Added net_gethostbyaddr() for DNS PTR lookups.
X-Git-Tag: 2.2.5~84
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=684b65874c28386cc14e4d90eecf002ffefa15a4;p=thirdparty%2Fdovecot%2Fcore.git

Added net_gethostbyaddr() for DNS PTR lookups.
This code assumes we have IPv6 capability. Perhaps we should just require it
everywhere already..
---

diff --git a/src/lib/net.c b/src/lib/net.c
index 4162bf1f1d..b78657b34f 100644
--- a/src/lib/net.c
+++ b/src/lib/net.c
@@ -663,6 +663,24 @@ int net_gethostbyname(const char *addr, struct ip_addr **ips,
 	return 0;
 }
 
+int net_gethostbyaddr(const struct ip_addr *ip, const char **name_r)
+{
+	union sockaddr_union so;
+	socklen_t addrlen = sizeof(so);
+	char hbuf[NI_MAXHOST];
+	int ret;
+
+	memset(&so, 0, sizeof(so));
+	sin_set_ip(&so, ip);
+	ret = getnameinfo(&so.sa, addrlen, hbuf, sizeof(hbuf), NULL, 0,
+			  NI_NAMEREQD);
+	if (ret != 0)
+		return ret;
+
+	*name_r = t_strdup(hbuf);
+	return 0;
+}
+
 int net_getsockname(int fd, struct ip_addr *addr, unsigned int *port)
 {
 	union sockaddr_union so;
diff --git a/src/lib/net.h b/src/lib/net.h
index ed084e0fee..6248733576 100644
--- a/src/lib/net.h
+++ b/src/lib/net.h
@@ -105,6 +105,9 @@ ssize_t net_transmit(int fd, const void *data, size_t len);
    to be free'd. Returns 0 = ok, others = error code for net_gethosterror() */
 int net_gethostbyname(const char *addr, struct ip_addr **ips,
 		      unsigned int *ips_count);
+/* Return host for the IP address. Returns 0 = ok, others = error code for
+   net_gethosterror(). */
+int net_gethostbyaddr(const struct ip_addr *ip, const char **name_r);
 /* get error of net_gethostname() */
 const char *net_gethosterror(int error) ATTR_CONST;
 /* return TRUE if host lookup failed because it didn't exist (ie. not