T2759: collect output from validators in a buffer and print it only if validation fails.

2 files changed, 15 insertions, 6 deletions

diff --git a/debian/rules b/debian/rules
index b3ff1c6..e3462af 100755
--- a/debian/rules
+++ b/debian/rules
@@ -9,7 +9,7 @@ override_dh_auto_build:
 	eval `opam env`
 	mkdir -p _build
 	ocamlfind ocamlopt -o _build/numeric -package num -linkpkg src/numeric.ml
-	ocamlfind ocamlopt -o _build/validate-value -package pcre,unix -linkpkg src/validate_value.ml
+	ocamlfind ocamlopt -o _build/validate-value -package pcre,unix,containers -linkpkg src/validate_value.ml
 
 override_dh_auto_install:
 	mkdir -p $(DIR)/usr/libexec/vyos/validators
diff --git a/src/validate_value.ml b/src/validate_value.ml
index 250f9f1..02cd15a 100644
--- a/src/validate_value.ml
+++ b/src/validate_value.ml
@@ -1,23 +1,27 @@
 type check = Regex of string | Exec of string
 
-let validate_value value_constraint value =
+let validate_value buf value_constraint value =
     match value_constraint with
     | Regex s ->
         (try
            let _ = Pcre.exec ~pat:s value in true
        with Not_found -> false)
     | Exec c ->
-        (* XXX: Using Unix.system is a bad idea on multiple levels,
+        (* XXX: Unix.open_process_in is "shelling out", which is a bad idea on multiple levels,
                 especially when the input comes directly from the user...
                 We should do something about it.
          *)
-        let result = Unix.system (Printf.sprintf "%s \'%s\'" c value) in
+        let chan = Unix.open_process_in (Printf.sprintf "%s \'%s\' 2>&1" c value) in
+        let out = try CCIO.read_all chan with _ -> "" in
+        let result = Unix.close_process_in chan in
         match result with
         | Unix.WEXITED 0 -> true
         | Unix.WEXITED 127 ->
           let () = Printf.printf "Could not execute validator %s" c in
           false
-        | _ -> false
+        | _ ->
+          let () = Buffer.add_string buf out; Buffer.add_string buf "\n" in
+          false
 
 let value = ref ""
 
@@ -33,10 +37,15 @@ let usage = Printf.sprintf "Usage: %s [OPTIONS] <number>" Sys.argv.(0)
 let () = Arg.parse args (fun _ -> ()) usage
 
 let _ =
+  let buf = Buffer.create 4096 in
   let value = !value in
   let checks = !checks in
   match checks with
   | [] -> exit 0
   | _ ->
-    List.iter (fun c -> if (validate_value c value) then exit 0 else ()) checks;
+    List.iter (fun c -> if (validate_value buf c value) then exit 0 else ()) checks;
+    (* If we got this far, value validation failed.
+       Show the user output from the validators.
+     *)
+    Buffer.contents buf |> print_endline;
     exit 1