ID: 25316 User updated by: polone at townnews dot com Reported By: polone at townnews dot com Status: Open -Bug Type: *PDF functions +Bug Type: Reproducible crash Operating System: Any PHP Version: 4.3.3 New Comment:
Changing category to a reproducible crash, accidentally set it to *PDF Functions. Previous Comments: ------------------------------------------------------------------------ [2003-08-29 13:49:54] polone at townnews dot com Description: ------------ (Please note, this looks like a similiar bug as #22753, but it is not - it's in a function layer much more abstract than the main/network.c bug, this one is in main/streams.c) A problem that occurs quite often with PHP scripts when remote hosts disconnect applications in PHP using the streams API is infinite looping with SIGPIPE. It appears an early attempt to remedy the situation was to ignore SIGPIPE, but this is not where the problem is. After reviewing the _php_stream_write() code and testing the loop in an error condition of -1, it became obvious why the looping occurs. The while() loop will never exit if an error occurs in the underlying send() call. This is because it returns a negative value (-1), but the type assigned in _php_stream_write() is size_t for the variable justwrote. For reference, "size_t" IS AN UNSIGNED INT, which means the condition: if (justwrote > 0) { // Buffering code } else { break; } will never execute the "else" condition. To fix this, change the following: size_t didwrite = 0, towrite; int justwrote; This bug has been present (as far as I can tell) since PHP 4.3.0. In addition, another change I've made is too main/network.c, in the php_sockop_write() function. Instead of ignoring SIGPIPE as the default handler, it would be better to set: didwrite = send(sock->socket, buf, count, MSG_NOSIGNAL); This will still work correctly when SIGPIPE would have been issued as EPIPE is still returned. Reproduce code: --------------- <?php $fp = fsockopen ("localhost", 80); while(fwrite($fp, "GET /doesntmatter HTTP/1.0\n\n")) { sleep(1); } ?> Expected result: ---------------- To end eventually. Instead, the script will eventually issue a SIGPIPE and create an infinite loop. Actual result: -------------- It never ends. ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=25316&edit=1