Bug #15639 Updated: detecting end of UDP packets

ID: 15639 Updated by: wez@php.net Reported By: rip@undernet.org Status: Feedback Bug Type: *Network Functions Operating System: All PHP Version: 4.1.1 New Comment: Can you try changing the FG(def_chunk_size) assignment in the file_globals_ctor function in ext/standard/file.c and hard-code it to 1. Then try your UDP script. If that solves the problem, I will add a method of setting this from script (using set_file_buffer). I still don't think using recvfrom will make any difference. Previous Comments: ------------------------------------------------------------------------ [2002-03-16 14:51:31] rip@undernet.org It also says it should only be used in connected sockets. Here is a working exemple from a porky sourcecode I have : loop: len = recvfrom(sock, data, 50, 0, (struct sockaddr *)&sai, &s_sai); printf("%d bytes from %s:%d - %s\n",len,inet_ntoa(sai.sin_addr),ntohs(sai.sin_port),data); goto loop; The default size is 50, if the UDP packet is < 50 (ie:42) it will print : 42 bytes from 192.168.0.1:8000 - This is only a test. This is only a test!! So if you modify the recv call to a recvfrom call, it won't break TCP and will make UDP work a better way. ------------------------------------------------------------------------ [2002-03-16 12:16:29] wez@php.net My man page says that recv is identical to recvfrom with a NULL from parameter, so I don't see how this can fix it. I still don't think this is technically possible over UDP. If you can show me some real working C code where it works, I will implement it. ------------------------------------------------------------------------ [2002-02-21 20:07:45] rip@undernet.org In C, recvfrom() takes a length argument, but behaves with UDP like fread should : "Reading stops when length bytes have been read or EOF is reached, whichever comes first." Using recvfrom() with length set to 4096 will get the 20 bytes packets without blocking anything. The bug has prolly something to do with the use of recv() versus recvfrom(). ------------------------------------------------------------------------ [2002-02-20 22:42:53] wez@php.net I'll look into UDP sockets in PHP in more detail soon. In the meantime, I'm not sure that what you are suggesting is possible, since UDP is a connectionless protocol, how can we detect the end of a packet/stream? UDP is supposed to be used with known packet sizes. If you can show me some C code where what you propose works, I'll integrate it with the new PHP streams code. --Wez. ------------------------------------------------------------------------ [2002-02-20 07:02:31] rip@undernet.org In fact it's worst than that, setting the socket non-blocking makes fread not working on unix/win. ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at http://bugs.php.net/15639 -- Edit this bug report at http://bugs.php.net/?id=15639&edit=1