From 1eb598706f9000361f0059a303c3cf99be5a8ceb Mon Sep 17 00:00:00 2001
From: Hisham <hisham@gobolinux.org>
Date: Sun, 8 Jan 2017 13:31:27 -0200
Subject: Improve error checking in ownership check. See #664.

---
 src/luarocks/command_line.lua  | 15 +++++++++++++--
 src/luarocks/fs/lua.lua        |  8 +++++---
 src/luarocks/fs/unix/tools.lua |  5 ++++-
 src/luarocks/fs/win32.lua      |  2 +-
 4 files changed, 23 insertions(+), 7 deletions(-)

(limited to 'src')

diff --git a/src/luarocks/command_line.lua b/src/luarocks/command_line.lua
index 31948b33..ac5ccd35 100644
--- a/src/luarocks/command_line.lua
+++ b/src/luarocks/command_line.lua
@@ -40,6 +40,18 @@ local function replace_tree(flags, tree)
    path.use_tree(tree)
 end
 
+local function is_ownership_ok(directory)
+   local me = fs.current_user()
+   for _ = 1,3 do -- try up to grandparent
+      local owner = fs.attributes(directory, "owner")
+      if owner then
+         return owner == me
+      end
+      directory = dir.dir_name(directory)
+   end
+   return false
+end
+
 --- Main command-line processor.
 -- Parses input arguments and calls the appropriate driver function
 -- to execute the action requested on the command-line, forwarding
@@ -182,8 +194,7 @@ function command_line.run_command(...)
       die("Current directory does not exist. Please run LuaRocks from an existing directory.")
    end
 
-   if fs.attributes(cfg.local_cache, "owner") ~= fs.current_user() or
-      fs.attributes(dir.dir_name(cfg.local_cache), "owner") ~= fs.current_user() then
+   if not is_ownership_ok(cfg.local_cache) then
       util.warning("The directory '" .. cfg.local_cache .. "' or its parent directory "..
                    "is not owned by the current user and the cache has been disabled. "..
                    "Please check the permissions and owner of that directory. "..
diff --git a/src/luarocks/fs/lua.lua b/src/luarocks/fs/lua.lua
index 097f800f..841b7243 100644
--- a/src/luarocks/fs/lua.lua
+++ b/src/luarocks/fs/lua.lua
@@ -760,11 +760,13 @@ end
 
 function fs_lua.attributes(file, attrtype)
    if attrtype == "permissions" then
-      return posix.stat(file, "mode")
+      return posix.stat(file, "mode") or nil
    elseif attrtype == "owner" then
-      return posix.getpwuid(posix.stat(file, "uid")).pw_name
+      local uid = posix.stat(file, "uid")
+      if not uid then return nil end
+      return posix.getpwuid(uid).pw_name or nil
    else
-      return ""
+      return nil
    end
 end
 
diff --git a/src/luarocks/fs/unix/tools.lua b/src/luarocks/fs/unix/tools.lua
index 21cc8a19..f72001cb 100644
--- a/src/luarocks/fs/unix/tools.lua
+++ b/src/luarocks/fs/unix/tools.lua
@@ -204,9 +204,12 @@ function tools.attributes(filename, attrtype)
    local flag = ((attrtype == "permissions") and vars.STATPERMFLAG)
              or ((attrtype == "owner") and vars.STATOWNERFLAG)
    if not flag then return "" end
-   local pipe = io.popen(vars.STAT.." "..flag.." "..fs.Q(filename))
+   local pipe = io.popen(fs.quiet_stderr(vars.STAT.." "..flag.." "..fs.Q(filename)))
    local ret = pipe:read("*l")
    pipe:close()
+   if ret == "" then
+      return nil
+   end
    return ret
 end
 
diff --git a/src/luarocks/fs/win32.lua b/src/luarocks/fs/win32.lua
index 406ee8ce..55d69f9f 100644
--- a/src/luarocks/fs/win32.lua
+++ b/src/luarocks/fs/win32.lua
@@ -197,7 +197,7 @@ function win32.attributes(filename, attrtype)
    elseif attrtype == "owner" then
       return os.getenv("USERNAME") -- FIXME popen_read('powershell -Command "& {(get-acl '..filename..').owner}"'):gsub("^[^\\]*\\", "")
    end
-   return ""
+   return nil
 end
 
 --- Move a file on top of the other.
-- 
cgit v1.2.3-55-g6feb