[PATCH 2/6] daemon: make host resolution into a separate function

[Jonathan Nieder <jrnieder@gmail.com>]

For each incoming connection, the git daemon runs a DNS query using
the client-supplied hostname parameter, to determine the canonical
hostname and IP address in case it is needed by the
--interpolated-path feature (to distinguish between virtual hosts).
Put the code for this in a separate function so the details of this
lookup can be easily tweaked.

Signed-off-by; Jonathan Nieder <jrnieder@gmail.com>
---
 daemon.c |  112 +++++++++++++++++++++++++++++++++++---------------------------
 1 files changed, 63 insertions(+), 49 deletions(-)

diff --git a/daemon.c b/daemon.c
index 4c8346d..3958cb6 100644
--- a/daemon.c
+++ b/daemon.c
@@ -432,6 +432,65 @@ static void parse_host_and_port(char *hostport, char **host,
 	}
 }
 
+#ifndef NO_IPV6
+
+static void locate_host(const char *hostname, char **ip_address,
+						char **canon_hostname)
+{
+	struct addrinfo hints;
+	struct addrinfo *ai;
+	int gai;
+	static char addrbuf[HOST_NAME_MAX + 1];
+	struct sockaddr_in *sin_addr;
+
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_flags = AI_CANONNAME;
+
+	gai = getaddrinfo(hostname, NULL, &hints, &ai);
+	if (gai)
+		return;
+
+	sin_addr = (void *)ai->ai_addr;
+	inet_ntop(AF_INET, &sin_addr->sin_addr, addrbuf, sizeof(addrbuf));
+	free(*ip_address);
+	*ip_address = xstrdup(addrbuf);
+
+	free(*canon_hostname);
+	*canon_hostname = xstrdup(ai->ai_canonname ?
+				  ai->ai_canonname : *ip_address);
+
+	freeaddrinfo(ai);
+}
+
+#else
+
+static void locate_host(const char *hostname, char **ip_address,
+						char **canon_hostname)
+{
+	struct hostent *hent;
+	struct sockaddr_in sa;
+	char **ap;
+	static char addrbuf[HOST_NAME_MAX + 1];
+
+	hent = gethostbyname(hostname);
+
+	ap = hent->h_addr_list;
+	memset(&sa, 0, sizeof sa);
+	sa.sin_family = hent->h_addrtype;
+	sa.sin_port = htons(0);
+	memcpy(&sa.sin_addr, *ap, hent->h_length);
+
+	inet_ntop(hent->h_addrtype, &sa.sin_addr,
+		  addrbuf, sizeof(addrbuf));
+
+	free(*canon_hostname);
+	*canon_hostname = xstrdup(hent->h_name);
+	free(*ip_address);
+	*ip_address = xstrdup(addrbuf);
+}
+
+#endif
+
 /*
  * Read the host as supplied by the client connection.
  */
@@ -467,56 +526,11 @@ static void parse_host_arg(char *extra_args, int buflen)
 	}
 
 	/*
-	 * Locate canonical hostname and its IP address.
+	 * Locate canonical hostname and its IP address,
+	 * if possible.
 	 */
-	if (hostname) {
-#ifndef NO_IPV6
-		struct addrinfo hints;
-		struct addrinfo *ai;
-		int gai;
-		static char addrbuf[HOST_NAME_MAX + 1];
-
-		memset(&hints, 0, sizeof(hints));
-		hints.ai_flags = AI_CANONNAME;
-
-		gai = getaddrinfo(hostname, NULL, &hints, &ai);
-		if (!gai) {
-			struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
-
-			inet_ntop(AF_INET, &sin_addr->sin_addr,
-				  addrbuf, sizeof(addrbuf));
-			free(ip_address);
-			ip_address = xstrdup(addrbuf);
-
-			free(canon_hostname);
-			canon_hostname = xstrdup(ai->ai_canonname ?
-						 ai->ai_canonname : ip_address);
-
-			freeaddrinfo(ai);
-		}
-#else
-		struct hostent *hent;
-		struct sockaddr_in sa;
-		char **ap;
-		static char addrbuf[HOST_NAME_MAX + 1];
-
-		hent = gethostbyname(hostname);
-
-		ap = hent->h_addr_list;
-		memset(&sa, 0, sizeof sa);
-		sa.sin_family = hent->h_addrtype;
-		sa.sin_port = htons(0);
-		memcpy(&sa.sin_addr, *ap, hent->h_length);
-
-		inet_ntop(hent->h_addrtype, &sa.sin_addr,
-			  addrbuf, sizeof(addrbuf));
-
-		free(canon_hostname);
-		canon_hostname = xstrdup(hent->h_name);
-		free(ip_address);
-		ip_address = xstrdup(addrbuf);
-#endif
-	}
+	if (hostname)
+		locate_host(hostname, &ip_address, &canon_hostname);
 }
 
 
-- 
1.7.5.3