#21033 [Opn->Fbk]: Socket_recvfrom call will truncate returning string if data had a 0 in it.

ID: 21033 Updated by: iliaa@php.net Reported By: aron@qvix.biz -Status: Open +Status: Feedback Bug Type: Zend Engine 2 problem Operating System: Linux PHP Version: 4.2.2 New Comment: Please try using this CVS snapshot: http://snaps.php.net/php4-latest.tar.gz For Windows: http://snaps.php.net/win32/php4-win32-latest.zip Previous Comments: ------------------------------------------------------------------------ [2002-12-15 18:10:21] aron@qvix.biz When using the socket_recvfrom call with a UDP socket - if you sent a string to the socket that was $length = socket_recvfrom($sock, $buf, 2048, 0 , $name, $port ); pppppppp0pppppppp - the $length would be the full amount read off the socket, but the $buf will only contain the data up to the first 0 (value is zero, i.e. NULL) and nothing beyond it. It seems that the string handling routines of the engine truncate the memory/length if the network read data contains a 0. Attached are the server side php code that will show this and a C program to generate the packets. The server program will printout the chars in the packet seperated by a ~ <**** begin server php script ****> <?php //***** // Server Connection Script // Receive : UDP packets from clients and act based on control bytes. //***** set_time_limit(0);//***** Don't let the script stop $addr = "192.168.1.2";//***** Server info $port = 9000; $sock = socket_create(AF_INET, SOCK_DGRAM, 0); //*****Create socket for UDP if ($sock < 0 ) die(print $sock); if (($ret = socket_bind($sock, $addr, $port)) < 0) //***** Complete socket connection die(print $ret); $read = socket_recvfrom($sock, $buf, 2048, 0 , $name, $port ); //process information in buffer for ($k=0;$k < $read ;$k++) { echo $buf[$k]; echo "~"; } print "\r\nRead $read bytes from Network\r\n"; print "IP Addy: $name\r\n"; print "Port: $port\r\n"; socket_close($sock); ?> <****** End server php script******> <****** begin client C program ******> /* Generate Some udp packet for network. */ #include <sys/types.h> #include <sys/socket.h> #include <sys/ioctl.h> #include <netinet/in.h> #include <linux/inet.h> #include <arpa/inet.h> #include <unistd.h> #include <stdio.h> #include <netdb.h> #include <string.h> unsigned int ConvertHostname(char *hostname); void main(void) { int connSocket; sockaddr_in sin_connect; sin_connect.sin_port = htons(9001); sin_connect.sin_addr.s_addr = INADDR_ANY; sin_connect.sin_family = AF_INET; connSocket = socket(AF_INET, SOCK_DGRAM, 0); if(bind(connSocket,(sockaddr*)&sin_connect,sizeof(sockaddr_in)) == -1) { connSocket = 0; printf("Socket Bind error"); return 0; } sin_connect.sin_addr.s_addr = ConvertHostname("192.168.1.2"); sin_connect.sin_port = htons(9000); int dataLength = 64 char *data = new char[dataLength]; memset(data,80,dataLength); // put a P in the data packet data[10] = 0; // put a zero in the data stream int a = sendto(connSocket,(char *)data,dataLength,0,(sockaddr *) &sin_connect,sizeof(struct sockaddr)$ printf("Sendto did %d\n",a); delete [] data; close(connSocket); } unsigned int ConvertHostname(char *hostname) { struct hostent *phost; struct in_addr addr; addr.s_addr = inet_addr(hostname); if(addr.s_addr == 0) return 0; if(addr.s_addr == -1) { phost = gethostbyname(hostname); if(phost == NULL) { printf("Error: Couldn't resolve hostname."); return 0; } memcpy((char *)&addr.s_addr, phost->h_addr,phost->h_length); } return addr.s_addr; } <****** end client C program ******> ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=21033&edit=1