[Nbd] [PATCH 1/3] nbd-server: fix open_modern() to report errors

[Tuomas Räsänen <tuomasjjrasanen@...1258...>]

This commit is part of the refactoring work on internal error
management. The goal of the work is to separate error reporting from
error handling to make it possible to call functions from different code
paths with varying needs for error handling.

Another goal is to unify the error management throughout the code base.

Signed-off-by: Tuomas Räsänen <tuomasjjrasanen@...1261...>
---
 nbd-server.c |   63 +++++++++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 49 insertions(+), 14 deletions(-)

diff --git a/nbd-server.c b/nbd-server.c
index 3d1266c..b75e290 100644
--- a/nbd-server.c
+++ b/nbd-server.c
@@ -640,6 +640,10 @@ typedef enum {
         SETUP_ERROR_SO_LINGER,               /**< Failed to set SO_LINGER to a socket */
         SETUP_ERROR_SO_REUSEADDR,            /**< Failed to set SO_REUSEADDR to a socket */
         SETUP_ERROR_SO_KEEPALIVE,            /**< Failed to set SO_KEEPALIVE to a socket */
+        SETUP_ERROR_GAI,                     /**< Failed to get address info */
+        SETUP_ERROR_SOCKET,                  /**< Failed to create a socket */
+        SETUP_ERROR_BIND,                    /**< Failed to bind an address to socket */
+        SETUP_ERROR_LISTEN,                  /**< Failed to start listening on a socket */
 } SETUP_ERRORS;
 
 /**
@@ -2461,12 +2465,13 @@ int setup_serve(SERVER *serve) {
 	}
 }
 
-void open_modern(const gchar *const addr, const gchar *const port) {
+int open_modern(const gchar *const addr, const gchar *const port,
+                GError **const gerror) {
 	struct addrinfo hints;
 	struct addrinfo* ai = NULL;
 	struct sock_flags;
 	int e;
-        GError *gerror = NULL;
+        int retval = -1;
 
 	memset(&hints, '\0', sizeof(hints));
 	hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG;
@@ -2475,28 +2480,52 @@ void open_modern(const gchar *const addr, const gchar *const port) {
 	hints.ai_protocol = IPPROTO_TCP;
 	e = getaddrinfo(addr, port ? port : NBD_DEFAULT_PORT, &hints, &ai);
 	if(e != 0) {
-		fprintf(stderr, "getaddrinfo failed: %s\n", gai_strerror(e));
-		exit(EXIT_FAILURE);
+                g_set_error(gerror, SETUP_ERROR, SETUP_ERROR_GAI,
+                            "failed to open a modern socket: "
+                            "failed to get address info: %s",
+                            gai_strerror(e));
+                goto out;
 	}
+
 	if((modernsock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol))<0) {
-		err("socket: %m");
+                g_set_error(gerror, SETUP_ERROR, SETUP_ERROR_SOCKET,
+                            "failed to open a modern socket: "
+                            "failed to create a socket: %s",
+                            strerror(errno));
+                goto out;
 	}
 
-	if (dosockopts(modernsock, &gerror) == -1) {
-                msg(LOG_ERR, "failed to open service-wide socket: %s",
-                    gerror->message);
-                g_clear_error(&gerror);
-                exit(EXIT_FAILURE);
+	if (dosockopts(modernsock, gerror) == -1) {
+                g_prefix_error(gerror, "failed to open a modern socket: ");
+                goto out;
         }
 
 	if(bind(modernsock, ai->ai_addr, ai->ai_addrlen)) {
-		err("bind: %m");
+                g_set_error(gerror, SETUP_ERROR, SETUP_ERROR_BIND,
+                            "failed to open a modern socket: "
+                            "failed to bind an address to a socket: %s",
+                            strerror(errno));
+                goto out;
 	}
+
 	if(listen(modernsock, 10) <0) {
-		err("listen: %m");
+                g_set_error(gerror, SETUP_ERROR, SETUP_ERROR_BIND,
+                            "failed to open a modern socket: "
+                            "failed to start listening on a socket: %s",
+                            strerror(errno));
+                goto out;
 	}
 
-	freeaddrinfo(ai);
+        retval = 0;
+out:
+
+        if (retval == -1 && modernsock >= 0) {
+                close(modernsock);
+                modernsock = -1;
+        }
+        freeaddrinfo(ai);
+
+        return retval;
 }
 
 /**
@@ -2512,7 +2541,13 @@ void setup_servers(GArray *const servers, const gchar *const modernaddr,
 		want_modern |= setup_serve(&(g_array_index(servers, SERVER, i)));
 	}
 	if(want_modern) {
-		open_modern(modernaddr, modernport);
+                GError *gerror = NULL;
+                if (open_modern(modernaddr, modernport, &gerror) == -1) {
+                        msg(LOG_ERR, "failed to setup servers: %s",
+                            gerror->message);
+                        g_clear_error(&gerror);
+                        exit(EXIT_FAILURE);
+                }
 	}
 	children=g_hash_table_new_full(g_int_hash, g_int_equal, NULL, destroy_pid_t);
 
-- 
1.7.10.4