nbd/server: Add va_list form of nbd_negotiate_send_rep_err()

This will be useful for the next patch.

Based on a patch by Vladimir Sementsov-Ogievskiy

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180110230825.18321-5-eblake@redhat.com>

1 files changed, 18 insertions, 6 deletions

diff --git a/nbd/server.c b/nbd/server.c
index 31c1d32..04da1c2 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -186,18 +186,15 @@ static int nbd_negotiate_send_rep(NBDClient *client, uint32_t type,
 
 /* Send an error reply.
  * Return -errno on error, 0 on success. */
-static int GCC_FMT_ATTR(4, 5)
-nbd_negotiate_send_rep_err(NBDClient *client, uint32_t type,
-                           Error **errp, const char *fmt, ...)
+static int GCC_FMT_ATTR(4, 0)
+nbd_negotiate_send_rep_verr(NBDClient *client, uint32_t type,
+                            Error **errp, const char *fmt, va_list va)
 {
-    va_list va;
     char *msg;
     int ret;
     size_t len;
 
-    va_start(va, fmt);
     msg = g_strdup_vprintf(fmt, va);
-    va_end(va);
     len = strlen(msg);
     assert(len < 4096);
     trace_nbd_negotiate_send_rep_err(msg);
@@ -217,6 +214,21 @@ out:
     return ret;
 }
 
+/* Send an error reply.
+ * Return -errno on error, 0 on success. */
+static int GCC_FMT_ATTR(4, 5)
+nbd_negotiate_send_rep_err(NBDClient *client, uint32_t type,
+                           Error **errp, const char *fmt, ...)
+{
+    va_list va;
+    int ret;
+
+    va_start(va, fmt);
+    ret = nbd_negotiate_send_rep_verr(client, type, errp, fmt, va);
+    va_end(va);
+    return ret;
+}
+
 /* Send a single NBD_REP_SERVER reply to NBD_OPT_LIST, including payload.
  * Return -errno on error, 0 on success. */
 static int nbd_negotiate_send_rep_list(NBDClient *client, NBDExport *exp,