Move unix socket helper functions into socket-util.

This makes them available for use by the upcoming vconn_unix.

include/socket-util.h

@@ -35,6 +35,7 @@
 #define SOCKET_UTIL_H 1
 
 #include <netinet/in.h>
+#include <stdbool.h>
 #include <sys/socket.h>
 
 int set_nonblocking(int fd);
@@ -42,5 +43,7 @@ int lookup_ip(const char *host_name, struct in_addr *address);
 int get_socket_error(int sock);
 int check_connection_completion(int fd);
 int drain_rcvbuf(int fd);
+int make_unix_socket(int style, bool nonblock, bool passcred,
+                     const char *bind_path, const char *connect_path);
 
 #endif /* socket-util.h */

lib/socket-util.c

@@ -38,8 +38,13 @@
 #include <fcntl.h>
 #include <netdb.h>
 #include <poll.h>
+#include <stddef.h>
 #include <stdio.h>
 #include <string.h>
+#include <sys/un.h>
+#include <unistd.h>
+#include "fatal-signal.h"
+#include "util.h"
 
 #include "vlog.h"
 #define THIS_MODULE VLM_socket_util
@@ -160,3 +165,88 @@ drain_rcvbuf(int fd)
     }
     return 0;
 }
+
+/* Stores in '*un' a sockaddr_un that refers to file 'name'.  Stores in
+ * '*un_len' the size of the sockaddr_un. */
+static void
+make_sockaddr_un(const char *name, struct sockaddr_un* un, socklen_t *un_len)
+{
+    un->sun_family = AF_UNIX;
+    strncpy(un->sun_path, name, sizeof un->sun_path);
+    un->sun_path[sizeof un->sun_path - 1] = '\0';
+    *un_len = (offsetof(struct sockaddr_un, sun_path)
+                + strlen (un->sun_path) + 1);
+}
+
+/* Creates a Unix domain socket in the given 'style' (either SOCK_DGRAM or
+ * SOCK_STREAM) that is bound to '*bind_path' (if 'bind_path' is non-null) and
+ * connected to '*connect_path' (if 'connect_path' is non-null).  If 'nonblock'
+ * is true, the socket is made non-blocking.  If 'passcred' is true, the socket
+ * is configured to receive SCM_CREDENTIALS control messages.
+ *
+ * Returns the socket's fd if successful, otherwise a negative errno value. */
+int
+make_unix_socket(int style, bool nonblock, bool passcred UNUSED,
+                 const char *bind_path, const char *connect_path)
+{
+    int error;
+    int fd;
+
+    fd = socket(PF_UNIX, style, 0);
+    if (fd < 0) {
+        return -errno;
+    }
+
+    if (nonblock) {
+        int flags = fcntl(fd, F_GETFL, 0);
+        if (flags == -1) {
+            goto error;
+        }
+        if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1) {
+            goto error;
+        }
+    }
+
+    if (bind_path) {
+        struct sockaddr_un un;
+        socklen_t un_len;
+        make_sockaddr_un(bind_path, &un, &un_len);
+        if (unlink(un.sun_path) && errno != ENOENT) {
+            VLOG_WARN("unlinking \"%s\": %s\n", un.sun_path, strerror(errno));
+        }
+        fatal_signal_add_file_to_unlink(bind_path);
+        if (bind(fd, (struct sockaddr*) &un, un_len)
+            || fchmod(fd, S_IRWXU)) {
+            goto error;
+        }
+    }
+
+    if (connect_path) {
+        struct sockaddr_un un;
+        socklen_t un_len;
+        make_sockaddr_un(connect_path, &un, &un_len);
+        if (connect(fd, (struct sockaddr*) &un, un_len)
+            && errno != EINPROGRESS) {
+            goto error;
+        }
+    }
+
+#ifdef SCM_CREDENTIALS
+    if (passcred) {
+        int enable = 1;
+        if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &enable, sizeof(enable))) {
+            goto error;
+        }
+    }
+#endif
+
+    return fd;
+
+error:
+    if (bind_path) {
+        fatal_signal_remove_file_to_unlink(bind_path);
+    }
+    error = errno;
+    close(fd);
+    return -error;
+}

lib/vlog-socket.c

@@ -45,15 +45,13 @@
 #include <unistd.h>
 #include "fatal-signal.h"
 #include "poll-loop.h"
+#include "socket-util.h"
 #include "util.h"
 #include "vlog.h"
 
 #ifndef SCM_CREDENTIALS
 #include <time.h>
 #endif
-
-static int make_unix_socket(bool nonblock, bool passcred,
-                            const char *bind_path, const char *connect_path);
 
 /* Server for Vlog control connection. */
 struct vlog_server {
@@ -90,7 +88,7 @@ vlog_server_listen(const char *path, struct vlog_server **serverp)
                                  (long int) getpid(), path ? path : "");
     }
 
-    server->fd = make_unix_socket(true, true, server->path, NULL);
+    server->fd = make_unix_socket(SOCK_DGRAM, true, true, server->path, NULL);
     if (server->fd < 0) {
         int fd = server->fd;
         free(server->path);
@@ -295,7 +293,7 @@ vlog_client_connect(const char *path, struct vlog_client **clientp)
                             : xasprintf("/tmp/vlogs.%s", path));
 
     client->bind_path = xasprintf("/tmp/vlog.%ld", (long int) getpid());
-    fd = make_unix_socket(false, false,
+    fd = make_unix_socket(SOCK_DGRAM, false, false,
                           client->bind_path, client->connect_path);
 
     if (fd >= 0) {
@@ -435,89 +433,3 @@ vlog_client_target(const struct vlog_client *client)
     return client->connect_path;
 }
 
-/* Helper functions. */
-
-/* Stores in '*un' a sockaddr_un that refers to file 'name'.  Stores in
- * '*un_len' the size of the sockaddr_un. */
-static void
-make_sockaddr_un(const char *name, struct sockaddr_un* un, socklen_t *un_len)
-{
-    un->sun_family = AF_UNIX;
-    strncpy(un->sun_path, name, sizeof un->sun_path);
-    un->sun_path[sizeof un->sun_path - 1] = '\0';
-    *un_len = (offsetof(struct sockaddr_un, sun_path)
-                + strlen (un->sun_path) + 1);
-}
-
-/* Creates a Unix domain datagram socket that is bound to '*bind_path' (if
- * 'bind_path' is non-null) and connected to '*connect_path' (if 'connect_path'
- * is non-null).  If 'nonblock' is true, the socket is made non-blocking.  If
- * 'passcred' is true, the socket is configured to receive SCM_CREDENTIALS
- * control messages.
- *
- * Returns the socket's fd if successful, otherwise a negative errno value. */
-static int
-make_unix_socket(bool nonblock, bool passcred UNUSED,
-                 const char *bind_path, const char *connect_path)
-{
-    int error;
-    int fd;
-
-    fd = socket(PF_UNIX, SOCK_DGRAM, 0);
-    if (fd < 0) {
-        return -errno;
-    }
-
-    if (nonblock) {
-        int flags = fcntl(fd, F_GETFL, 0);
-        if (flags == -1) {
-            goto error;
-        }
-        if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1) {
-            goto error;
-        }
-    }
-
-    if (bind_path) {
-        struct sockaddr_un un;
-        socklen_t un_len;
-        make_sockaddr_un(bind_path, &un, &un_len);
-        if (unlink(un.sun_path) && errno != ENOENT) {
-            fprintf(stderr, "unlinking \"%s\": %s\n",
-                    un.sun_path, strerror(errno));
-        }
-        fatal_signal_add_file_to_unlink(bind_path);
-        if (bind(fd, (struct sockaddr*) &un, un_len)
-            || fchmod(fd, S_IRWXU)) {
-            goto error;
-        }
-    }
-
-    if (connect_path) {
-        struct sockaddr_un un;
-        socklen_t un_len;
-        make_sockaddr_un(connect_path, &un, &un_len);
-        if (connect(fd, (struct sockaddr*) &un, un_len)) {
-            goto error;
-        }
-    }
-
-#ifdef SCM_CREDENTIALS
-    if (passcred) {
-        int enable = 1;
-        if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &enable, sizeof(enable))) {
-            goto error;
-        }
-    }
-#endif
-
-    return fd;
-
-error:
-    if (bind_path) {
-        fatal_signal_remove_file_to_unlink(bind_path);
-    }
-    error = errno;
-    close(fd);
-    return -error;
-}