Communicating between C and PHP through Unix domain sockets
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Public domain    
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### server.c 
    
    /*
     * gcc server.c -o server
     *
     */
    
    #include <stdio.h>
    #include <stdlib.h>
    #include <errno.h>
    #include <string.h>
    #include <sys/types.h>
    #include <sys/socket.h>
    #include <sys/un.h>
    
    #define BUFSIZE 1024
    #define MSGSIZE 100
    #define SOCK_PATH "/var/run/mysocket.sock"
    #define PERM "0666"
    #define WAIT 0
    #define LISTEN_BACKLOG 50
    #define C_MSG "Server got this message: "
    #define handle_error(function) { perror(function); exit(EXIT_FAILURE); }
    
    int main()
    {
        int server_socket, accepted_socket, n;
        struct sockaddr_un my_addr, peer_addr;
        socklen_t peer_addr_size;
        char recvd_msg[BUFSIZE], out_str[BUFSIZE];
        mode_t mode = strtol(PERM, 0, 8);
    
        /* Creating a Unix domain socket */
        server_socket = socket(AF_UNIX, SOCK_STREAM, 0);
        if (server_socket  == -1)
                handle_error("socket");
    
        /* Binding the socket to a file */
        memset(&my_addr, 0, sizeof(struct sockaddr_un)); /* Clear structure */
        my_addr.sun_family = AF_UNIX;
        strncpy(my_addr.sun_path, SOCK_PATH, sizeof(my_addr.sun_path) - 1);
        unlink(my_addr.sun_path);
        if (bind(server_socket, (struct sockaddr *) &my_addr, 
                        sizeof(struct sockaddr_un)) == -1)
                handle_error("bind");
    
        /* Instructing the socket to listen for incoming connections */
        if (listen(server_socket, LISTEN_BACKLOG) == -1) 
                handle_error("listen");
        
        /* Changing permission of socket the file */
        if (chmod(SOCK_PATH, mode) == -1)
                handle_error("chmod");
    
        for(;;) 
        {
                /* Accepting incoming connections one at a time */
                printf("Waiting for a connection...\n");
                peer_addr_size = sizeof(struct sockaddr_un);
                accepted_socket = accept(server_socket, 
                        (struct sockaddr *) &peer_addr, &peer_addr_size);
                if (accepted_socket == -1)
                        handle_error("accept");
    
                printf("Connected.\n");
    
                /* Receiving data */
                n = recv(accepted_socket, recvd_msg, MSGSIZE, 0);
                if (n < 0) 
                        handle_error("recv");
    
                /* Printing received data */
                snprintf(out_str, strlen(C_MSG)+1, "%s", C_MSG);
                strncat(out_str,recvd_msg, n);
                printf("%s\n",out_str);
                fflush (stdout);
    
                /* Waiting just for fun */
                sleep(WAIT);
    
                /* Sending data */
                if (send(accepted_socket, out_str, strlen(out_str), 0) < 0)
                        handle_error("recv");
    
                /* Cleaning up */
                close(accepted_socket);
        }
    
        return 0;
    }
    
    
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### client.php
    
    <form method=post action=''>
    Message to send: <input type="text" name="message" />
    <input type="submit" value="Send" />
    </form>
    <br />
    
    <?php
    if(isset($_POST["message"])) {
        $snd_msg = $_POST["message"];
        $rcv_msg = "";
        $timeout = 10;
        $socket = stream_socket_client('unix:///var/run/mysocket.sock', 
                                        $errorno, $errorstr, $timeout);
        stream_set_timeout($socket, $timeout);
    
        echo("Sending Message...<br>\n");
        if(!fwrite($socket, $snd_msg))
                echo("Error while writing!!!<br>\n");
    
        echo("Receiving Message...<br>\n");
        if (!($rcv_msg = fread($socket, 1024))) 
                echo("Error while reading!!!<br>\n");
        else 
                echo($rcv_msg."<br>\n");
        echo("done<br>\n");
    }
    ?>
    
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### Links
    
    
    http://php.net/manual/en/function.stream-socket-client.php
    http://php.net/manual/en/transports.unix.php
    http://php.net/manual/en/function.fwrite.php
    http://php.net/manual/en/function.fread.php
    http://php.net/manual/en/function.fsockopen.php
    http://php.net/manual/en/ref.sockets.php
    http://php.net/manual/en/function.socket-write.php
    http://php.net/manual/en/function.socket-connect.php
    
    Programming UNIX Sockets in C - Frequently Asked Questions
    http://www.softlab.ntua.gr/facilities/documentation/unix/unix-socket-faq/unix-socket-faq.html
    
    LINUX SOCKET PART 18 - Advanced TCP/IP - OTHER TCP/IP INFO
    http://www.tenouk.com/Module43b.html
    
    BUFFER OVERFLOW 10 - Vulnerability & Exploit Example
    http://www.tenouk.com/Bufferoverflowc/Bufferoverflow6.html
    
    Beej's Guide to Unix IPC
    http://beej.us/guide/bgipc/output/html/multipage/unixsock.html
    http://beej.us/guide/bgipc/output/html/multipage/index.html
    
    Beej's Guide to Network Programming
    http://beej.us/guide/bgnet/
    
    
    The GNU C Library
    http://www.delorie.com/gnu/docs/glibc/libc_toc.html
    http://www.delorie.com/gnu/docs/glibc/libc_290.html
    
    Unix socket sniffer
    http://graag.blogspot.com/2007/10/unix-socket-sniffer.html
    
    unixdump UNIX-socket sniffer
    http://c-skills.blogspot.com/2009/09/unixdump-unix-socket-sniffer-available.html
    
    
    Secure programming with the OpenSSL API, Part 1: Overview of the API
    http://www.ibm.com/developerworks/linux/library/l-openssl/index.html
    Secure programming with the OpenSSL API, Part 2: Secure handshake
    http://www.ibm.com/developerworks/linux/library/l-openssl2/index.html
    Secure programming with the OpenSSL API, Part 3: Providing a secure service
    http://www.ibm.com/developerworks/linux/library/l-openssl3/index.html
    
    
    DNS Query Code in C with linux sockets
    http://www.binarytides.com/blog/dns-query-code-in-c-with-linux-sockets/
    
    ping 
    http://cboard.cprogramming.com/networking-device-communication/41635-ping-program.html
    http://www.mycplus.com/source-code/c-source-code/ping/
    http://ws.edu.isoc.org/materials/src/ping.c
    http://www.freelancer.com/projects/C-Programming-Linux/TCP-Ping-linux.html
    
   
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_BY: Pejman Moghadam_  
_TAG: php, socket_  
_DATE: 2012-07-04 17:10:31_