tools/xenstore: use talloc_asprintf_append() in do_control_help()

Instead of calculating the length of all help output and then
allocating the space for it, just use talloc_asprintf_append() to
expand the text as needed.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>

diff --git a/tools/xenstore/xenstored_control.c b/tools/xenstore/xenstored_control.c
index 7b4300ef777716388ad33a321a5b43cbf291b6c8..f0e00db633ec43aaddd68aa9744a6f3aa1549057 100644 (file)
--- a/tools/xenstore/xenstored_control.c
+++ b/tools/xenstore/xenstored_control.c
@@ -853,36 +853,23 @@ static struct cmd_s cmds[] = {
 static int do_control_help(void *ctx, struct connection *conn,
                           char **vec, int num)
 {
-       int cmd, len = 0;
+       int cmd;
        char *resp;
 
        if (num)
                return EINVAL;
 
-       for (cmd = 0; cmd < ARRAY_SIZE(cmds); cmd++) {
-               len += strlen(cmds[cmd].cmd) + 1;
-               len += strlen(cmds[cmd].pars) + 1;
-       }
-       len++;
-
-       resp = talloc_array(ctx, char, len);
+       resp = talloc_asprintf(ctx, "%s", "");
        if (!resp)
                return ENOMEM;
-
-       len = 0;
        for (cmd = 0; cmd < ARRAY_SIZE(cmds); cmd++) {
-               strcpy(resp + len, cmds[cmd].cmd);
-               len += strlen(cmds[cmd].cmd);
-               resp[len] = '\t';
-               len++;
-               strcpy(resp + len, cmds[cmd].pars);
-               len += strlen(cmds[cmd].pars);
-               resp[len] = '\n';
-               len++;
+               resp = talloc_asprintf_append(resp, "%s\t%s\n",
+                                             cmds[cmd].cmd, cmds[cmd].pars);
+               if (!resp)
+                       return ENOMEM;
        }
-       resp[len] = 0;
 
-       send_reply(conn, XS_CONTROL, resp, len);
+       send_reply(conn, XS_CONTROL, resp, strlen(resp) + 1);
        return 0;
 }