From 2a3e55ec4dd8692331c54d3b23eb3c13173242cf Mon Sep 17 00:00:00 2001
From: Con Kolivas <kernel@kolivas.org>
Date: Thu, 17 Apr 2014 15:31:07 +1000
Subject: [PATCH] Add a helper function for opening a listening unix socket

---
 configure.ac    |  2 +-
 src/libckpool.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++++
 src/libckpool.h |  2 ++
 3 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 88cbd7c5..00ae505d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -38,7 +38,7 @@ AC_CHECK_HEADERS(stdio.h stdlib.h fcntl.h sys/time.h unistd.h)
 AC_CHECK_HEADERS(ctype.h errno.h byteswap.h string.h time.h)
 AC_CHECK_HEADERS(endian.h sys/endian.h arpa/inet.h syslog.h)
 AC_CHECK_HEADERS(alloca.h pthread.h stdio.h math.h)
-AC_CHECK_HEADERS(sys/types.h sys/socket.h netdb.h)
+AC_CHECK_HEADERS(sys/types.h sys/socket.h linux/un.h netdb.h)
 AC_CHECK_HEADERS(stdint.h netinet/in.h netinet/tcp.h)
 AC_CHECK_HEADERS(jansson.h)
 
diff --git a/src/libckpool.c b/src/libckpool.c
index cb3788e8..6d9dc545 100644
--- a/src/libckpool.c
+++ b/src/libckpool.c
@@ -11,6 +11,11 @@
 
 #include <sys/types.h>
 #include <sys/socket.h>
+#ifdef HAVE_LINUX_UN_H
+#include <linux/un.h>
+#else
+#include <sys/un.h>
+#endif
 #include <netdb.h>
 #include <unistd.h>
 #include <fcntl.h>
@@ -26,6 +31,10 @@
 #include "libckpool.h"
 #include "sha2.h"
 
+#ifndef UNIX_PATH_MAX
+#define UNIX_PATH_MAX 108
+#endif
+
 /* Place holders for when we add lock debugging */
 #define GETLOCK(_lock, _file, _func, _line)
 #define GOTLOCK(_lock, _file, _func, _line)
@@ -220,6 +229,7 @@ void _ck_wunlock(cklock_t *lock, const char *file, const char *func, const int l
 	_mutex_unlock(&lock->mutex, file, func, line);
 }
 
+
 bool extract_sockaddr(char *url, char **sockaddr_url, char **sockaddr_port)
 {
 	char *url_begin, *url_end, *ipv6_begin, *ipv6_end, *port_start = NULL;
@@ -490,6 +500,53 @@ void empty_socket(int fd)
 	} while (ret > 0);
 }
 
+int open_unix_server(const char *server_path)
+{
+	struct sockaddr_un serveraddr;
+	int sockd = -1, len, ret;
+
+	if (likely(server_path)) {
+		len = strlen(server_path);
+		if (unlikely(len < 1 || len > UNIX_PATH_MAX)) {
+			LOGERR("Invalid server path length %d in open_unix_server", len);
+			goto out;
+		}
+	} else {
+		LOGERR("Null passed as server_path to open_unix_server");
+		goto out;
+	}
+
+	sockd = socket(AF_UNIX, SOCK_STREAM, 0);
+	if (unlikely(sockd < 0)) {
+		LOGERR("Failed to open socket in open_unix_server with errno %d", errno);
+		goto out;
+	}
+	memset(&serveraddr, 0, sizeof(serveraddr));
+	serveraddr.sun_family = AF_UNIX;
+	strcpy(serveraddr.sun_path, server_path);
+
+	ret = bind(sockd, (struct sockaddr *)&serveraddr, sizeof(&serveraddr));
+	if (unlikely(ret < 0)) {
+		LOGERR("Failed to bind to socket in open_unix_server with errno %d", errno);
+		close(sockd);
+		sockd = -1;
+		goto out;
+	}
+
+	ret = listen(sockd, 1);
+	if (unlikely(ret < 0)) {
+		LOGERR("Failed to listen to socket in open_unix_server with errno %d", errno);
+		close(sockd);
+		sockd = -1;
+		goto out;
+	}
+
+	LOGDEBUG("Opened server path %s successfully on socket %d", server_path, sockd);
+out:
+	return sockd;
+}
+
+
 json_t *json_rpc_call(connsock_t *cs, const char *rpc_req)
 {
 	char http_req[PAGESIZE];
diff --git a/src/libckpool.h b/src/libckpool.h
index e4615256..27caa598 100644
--- a/src/libckpool.h
+++ b/src/libckpool.h
@@ -182,6 +182,8 @@ int connect_socket(char *url, char *port);
 int write_socket(int fd, const void *buf, size_t nbyte);
 int read_socket_line(connsock_t *cs);
 void empty_socket(int fd);
+int open_unix_server(const char *server_path);
+
 json_t *json_rpc_call(connsock_t *cs, const char *rpc_req);
 
 void align_len(size_t *len);