X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/24d43bea075354ecd8546131529a064140b9039c..8d504e6b3dcacd333c0b07387e7acd3bf8a65d9c:/doc/plugins/contrib/cvs/discussion.mdwn

diff --git a/doc/plugins/contrib/cvs/discussion.mdwn b/doc/plugins/contrib/cvs/discussion.mdwn
index 847d0f92a..2de938fb7 100644
--- a/doc/plugins/contrib/cvs/discussion.mdwn
+++ b/doc/plugins/contrib/cvs/discussion.mdwn
@@ -20,16 +20,69 @@ the "cvs add <directory>" call and avoid doing anything in that case?
 >
 > Thing 1 can probably be handled within ikiwiki, if that seems less
 > gross to you.
->
+
+>> It seems like it might be. You can use a `getopt` hook to check
+>> `@ARGV` to see how it was called. --[[Joey]] 
+
+>>> This does the trick iff the post-commit wrapper passes its args
+>>> along. Committed on my branch. This seems potentially dangerous,
+>>> since the args passed to ikiwiki are influenced by web commits.
+>>> I don't see an exploit, but for paranoia's sake, maybe the wrapper
+>>> should only be built with execv() if the cvs plugin is loaded?
+>>> --[[schmonz]]
+
+>>>> Hadn't considered that. While in wrapper mode the normal getopt is not
+>>>> done, plugin getopt still runs, and so any unsafe options that 
+>>>> other plugins support could be a problem if another user runs
+>>>> the setuid wrapper and passes those options through. --[[Joey]]
+
+>>>>> I've tried compiling the argument check into the wrapper as
+>>>>> the first thing main() does, and was surprised to find that
+>>>>> this doesn't prevent the `cvs add <dir>` deadlock in a web
+>>>>> commit. I was convinced this'd be a reasonable solution,
+>>>>> especially if conditionalized on the cvs plugin being loaded,
+>>>>> but it doesn't work. And I stuck debug printfs at the beginning
+>>>>> of all the rcs_foo() subs, and whatever `cvs add <dir>` is
+>>>>> doing to ikiwiki isn't visible to my plugin, because none of
+>>>>> those subs are getting called. Nuts. Can you think of anything
+>>>>> else that might solve the problem, or should I go back to
+>>>>> generating a minimal wrapper wrapper that checks for just
+>>>>> this one thing? --[[schmonz]]
+
 > Thing 2 I'm less sure of. (I'd like to see the web UI return
 > immediately on save anyway, to a temporary "rebuilding, please wait
 > if you feel like knowing when it's done" page, but this problem
 > with CVS happens with any kind of commit, and could conceivably
 > happen with some other VCS.)
->
+
+>> None of the other VCSes let a write lock block a read lock, apparently.
+>> 
+>> Anyway, re the backgrounding, when committing via the web, the
+>> post-commit hook doesn't run anyway; the rendering is done via the
+>> ikiwiki CGI. It would certianly be nice if it popped up a quick "working"
+>> page and replaced it with the updated page when done, but that's
+>> unrelated;  the post-commit
+>> hook only does rendering when committing using the VCS directly. The
+>> backgrounding you do actually seems safe enough -- but tacking
+>> on a " &" to the ikiwiki wrapper call doesn't need a wrapper script,
+>> does it? --[[Joey]]
+
+>>> Nope, it works fine to append it to the `CVSROOT/loginfo` line.
+>>> Fixed on my branch. --[[schmonz]]
+
 > Thing 3 I think I did in order to squelch the error messages that
 > were bollixing up the CGI. It was easy to do this in the wrapper
 > wrapper, but if that's going away, it can be done just as easily
 > with output redirection in `CVSROOT/loginfo`.
 >
 > --[[schmonz]]
+
+>> If the error messages screw up the CGI they must go to stdout.
+>> I thought we had stderr even in the the CVS dark ages. ;-) --[[Joey]] 
+
+>>> Some messages go to stderr, but definitely not all. That's why
+>>> I wound up reaching for IPC::Cmd, to execute the command line
+>>> safely while shutting CVS up. Anyway, I've tested what happens
+>>> if a configured post-commit hook is missing, and it seems fine,
+>>> probably also thanks to IPC::Cmd.
+>>> --[[schmonz]]