From 003fa072fcc5cb2349ceee6798efaaaa1e63d64f Mon Sep 17 00:00:00 2001 From: brain Date: Tue, 7 Mar 2006 20:21:54 +0000 Subject: Safety checking (a really really clever trick btw) in CullList, to make sure that the user we're removing IS the user that was marked for deletion X seconds ago, even if the user has since quit, to be replaced by another unfortunate wretch who was given the same pointer address (eeep) git-svn-id: http://svn.inspircd.org/repository/trunk/inspircd@3529 e03df62e-2008-0410-955e-edbf42e46eb7 --- src/cull_list.cpp | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) (limited to 'src') diff --git a/src/cull_list.cpp b/src/cull_list.cpp index 7c4afa16c..224a9e3da 100644 --- a/src/cull_list.cpp +++ b/src/cull_list.cpp @@ -54,10 +54,29 @@ extern user_hash clientlist; bool CullList::IsValid(userrec* user) { + time_t esignon = 0; + std::map::iterator es = exempt.find(user); + if (es != exempt.end()) + esignon = es->second; + for (user_hash::iterator u = clientlist.begin(); u != clientlist.end(); u++) { + /* + * BUGFIX + * + * Because there is an undetermined period of time between a user existing, + * and this function being called, we have to check for the following condition: + * + * Between CullList::AddItem(u) being called, and CullList::IsValid(u) being called, + * the user with the pointer u has quit, but only to be REPLACED WITH A NEW USER WHO + * BECAUSE OF ALLOCATION RULES, HAS THE SAME MEMORY ADDRESS! To prevent this, we + * cross reference each pointer to the user's signon time, and if the signon times + * do not match, we return false here to indicate this user is NOT valid as it + * seems to differ from the pointer snapshot we got a few seconds earlier. Should + * prevent a few random crashes during netsplits. + */ if (user == u->second) - return true; + return (u->second->signon == esignon); } return false; } @@ -90,7 +109,7 @@ void CullList::AddItem(userrec* user, std::string reason) { CullItem item(user,reason); list.push_back(item); - exempt[user] = 1; + exempt[user] = user->signon; } } -- cgit v1.2.3