daemon: debug segv correct use of dereferencing NULL.

[libguestfs.git] / generator / generator_daemon.ml

diff --git a/generator/generator_daemon.ml b/generator/generator_daemon.ml
index 8c3a548..9f15abd 100644 (file)
--- a/generator/generator_daemon.ml
+++ b/generator/generator_daemon.ml
@@ -42,7 +42,7 @@ let generate_daemon_actions_h () =
         iteri (
           fun i arg ->
             let uc_shortname = String.uppercase shortname in
-            let n = name_of_argt arg in
+            let n = name_of_optargt arg in
             let uc_n = String.uppercase n in
             pr "#define GUESTFS_%s_%s_BITMASK (UINT64_C(1)<<%d)\n"
               uc_shortname uc_n i
@@ -52,7 +52,7 @@ let generate_daemon_actions_h () =
 
   List.iter (
     fun (name, (ret, args, optargs), _, _, _, _, _) ->
-      let style = ret, args @ optargs, [] in
+      let style = ret, args @ args_of_optargs optargs, [] in
       generate_prototype
         ~single_line:true ~newline:true ~in_daemon:true ~prefix:"do_"
         name style;
@@ -115,25 +115,36 @@ and generate_daemon_actions () =
               pr "  const char *%s;\n" n;
               pr "  size_t %s_size;\n" n
           | Pointer _ -> assert false
-        ) (args @ optargs)
+        ) (args @ args_of_optargs optargs)
       );
       pr "\n";
 
       let is_filein =
         List.exists (function FileIn _ -> true | _ -> false) args in
 
-      (* Reject unknown optional arguments. *)
+      (* Reject unknown optional arguments.
+       * Note this code is included even for calls with no optional
+       * args because the caller must not pass optargs_bitmask != 0
+       * in that case.
+       *)
       if optargs <> [] then (
         let len = List.length optargs in
         let mask = Int64.lognot (Int64.pred (Int64.shift_left 1L len)) in
         pr "  if (optargs_bitmask & UINT64_C(0x%Lx)) {\n" mask;
         if is_filein then
-          pr "    if (cancel_receive () != -2)\n";
+          pr "    cancel_receive ();\n";
         pr "    reply_with_error (\"unknown option in optional arguments bitmask (this can happen if a program is compiled against a newer version of libguestfs, then run against an older version of the daemon)\");\n";
         pr "    goto done;\n";
         pr "  }\n";
-        pr "\n"
+      ) else (
+        pr "  if (optargs_bitmask != 0) {\n";
+        if is_filein then
+          pr "    cancel_receive ();\n";
+        pr "    reply_with_error (\"header optargs_bitmask field must be passed as 0 for calls that don't take optional arguments\");\n";
+        pr "    goto done;\n";
+        pr "  }\n";
       );
+      pr "\n";
 
       (* Decode arguments. *)
       if args <> [] || optargs <> [] then (
@@ -141,8 +152,8 @@ and generate_daemon_actions () =
         pr "\n";
         pr "  if (!xdr_guestfs_%s_args (xdr_in, &args)) {\n" name;
         if is_filein then
-          pr "    if (cancel_receive () != -2)\n";
-        pr "      reply_with_error (\"daemon failed to decode procedure arguments\");\n";
+          pr "    cancel_receive ();\n";
+        pr "    reply_with_error (\"daemon failed to decode procedure arguments\");\n";
         pr "    goto done;\n";
         pr "  }\n";
         let pr_args n =
@@ -153,8 +164,8 @@ and generate_daemon_actions () =
           pr "                sizeof (char *) * (args.%s.%s_len+1));\n" n n;
           pr "  if (%s == NULL) {\n" n;
           if is_filein then
-            pr "    if (cancel_receive () != -2)\n";
-          pr "      reply_with_perror (\"realloc\");\n";
+            pr "    cancel_receive ();\n";
+          pr "    reply_with_perror (\"realloc\");\n";
           pr "    goto done;\n";
           pr "  }\n";
           pr "  %s[args.%s.%s_len] = NULL;\n" n n n;
@@ -197,7 +208,7 @@ and generate_daemon_actions () =
               pr "  %s = args.%s.%s_val;\n" n n n;
               pr "  %s_size = args.%s.%s_len;\n" n n n
           | Pointer _ -> assert false
-        ) (args @ optargs);
+        ) (args @ args_of_optargs optargs);
         pr "\n"
       );
 
@@ -216,7 +227,7 @@ and generate_daemon_actions () =
         let args' =
           List.filter
             (function FileIn _ | FileOut _ -> false | _ -> true) args in
-        let style = ret, args' @ optargs, [] in
+        let style = ret, args' @ args_of_optargs optargs, [] in
         pr "  r = do_%s " name;
         generate_c_call_args style;
         pr ";\n" in
@@ -278,6 +289,7 @@ and generate_daemon_actions () =
         | RStruct (n, _) ->
             pr "  struct guestfs_%s_ret ret;\n" name;
             pr "  ret.%s = *r;\n" n;
+            pr "  free (r);\n";
             pr "  reply ((xdrproc_t) xdr_guestfs_%s_ret, (char *) &ret);\n"
               name;
             pr "  xdr_free ((xdrproc_t) xdr_guestfs_%s_ret, (char *) &ret);\n"
@@ -285,6 +297,7 @@ and generate_daemon_actions () =
         | RStructList (n, _) ->
             pr "  struct guestfs_%s_ret ret;\n" name;
             pr "  ret.%s = *r;\n" n;
+            pr "  free (r);\n";
             pr "  reply ((xdrproc_t) xdr_guestfs_%s_ret, (char *) &ret);\n"
               name;
             pr "  xdr_free ((xdrproc_t) xdr_guestfs_%s_ret, (char *) &ret);\n"