netecho.c

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/*
 * Copyright (c) 2009 Lukas Mejdrech
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <str.h>
#include <task.h>
#include <arg_parse.h>

#include <net/in.h>
#include <net/in6.h>
#include <net/inet.h>
#include <net/socket.h>
#include <net/socket_parse.h>

#include "print_error.h"

#define NAME "netecho"

static int count = -1;
static int family = PF_INET;
static sock_type_t type = SOCK_DGRAM;
static uint16_t port = 7;
static int backlog = 3;
static size_t size = 1024;
static int verbose = 0;

static char *reply = NULL;
static size_t reply_length;

static char *data;

static void echo_print_help(void)
{
        printf(
            "Network echo server\n"
            "Usage: " NAME " [options]\n"
            "Where options are:\n"
            "-b backlog | --backlog=size\n"
            "\tThe size of the accepted sockets queue. Only for SOCK_STREAM. "
            "The default is 3.\n"
            "\n"
            "-c count | --count=count\n"
            "\tThe number of received messages to handle. A negative number "
            "means infinity. The default is infinity.\n"
            "\n"
            "-f protocol_family | --family=protocol_family\n"
            "\tThe listenning socket protocol family. Only the PF_INET and "
            "PF_INET6 are supported.\n"
            "\n"
            "-h | --help\n"
            "\tShow this application help.\n"
            "\n"
            "-p port_number | --port=port_number\n"
            "\tThe port number the application should listen at. The default "
            "is 7.\n"
            "\n"
            "-r reply_string | --reply=reply_string\n"
            "\tThe constant reply string. The default is the original data "
            "received.\n"
            "\n"
            "-s receive_size | --size=receive_size\n"
            "\tThe maximum receive data size the application should accept. "
            "The default is 1024 bytes.\n"
            "\n"
            "-t socket_type | --type=socket_type\n"
            "\tThe listenning socket type. Only the SOCK_DGRAM and the "
            "SOCK_STREAM are supported.\n"
            "\n"
            "-v | --verbose\n"
            "\tShow all output messages.\n"
        );
}

static int netecho_parse_option(int argc, char *argv[], int *index)
{
        int value;
        int rc;

        switch (argv[*index][1]) {
        case 'b':
                rc = arg_parse_int(argc, argv, index, &backlog, 0);
                if (rc != EOK)
                        return rc;
                break;
        case 'c':
                rc = arg_parse_int(argc, argv, index, &count, 0);
                if (rc != EOK)
                        return rc;
                break;
        case 'f':
                rc = arg_parse_name_int(argc, argv, index, &family, 0,
                    socket_parse_protocol_family);
                if (rc != EOK)
                        return rc;
                break;
        case 'h':
                echo_print_help();
                exit(0);
                break;
        case 'p':
                rc = arg_parse_int(argc, argv, index, &value, 0);
                if (rc != EOK)
                        return rc;
                port = (uint16_t) value;
                break;
        case 'r':
                rc = arg_parse_string(argc, argv, index, &reply, 0);
                if (rc != EOK)
                        return rc;
                break;
        case 's':
                rc = arg_parse_int(argc, argv, index, &value, 0);
                if (rc != EOK)
                        return rc;
                size = (value >= 0) ? (size_t) value : 0;
                break;
        case 't':
                rc = arg_parse_name_int(argc, argv, index, &value, 0,
                    socket_parse_socket_type);
                if (rc != EOK)
                        return rc;
                type = (sock_type_t) value;
                break;
        case 'v':
                verbose = 1;
                break;
        /* Long options with double dash */
        case '-':
                if (str_lcmp(argv[*index] + 2, "backlog=", 6) == 0) {
                        rc = arg_parse_int(argc, argv, index, &backlog, 8);
                        if (rc != EOK)
                                return rc;
                } else if (str_lcmp(argv[*index] + 2, "count=", 6) == 0) {
                        rc = arg_parse_int(argc, argv, index, &count, 8);
                        if (rc != EOK)
                                return rc;
                } else if (str_lcmp(argv[*index] + 2, "family=", 7) == 0) {
                        rc = arg_parse_name_int(argc, argv, index, &family, 9,
                            socket_parse_protocol_family);
                        if (rc != EOK)
                                return rc;
                } else if (str_lcmp(argv[*index] + 2, "help", 5) == 0) {
                        echo_print_help();
                        exit(0);
                } else if (str_lcmp(argv[*index] + 2, "port=", 5) == 0) {
                        rc = arg_parse_int(argc, argv, index, &value, 7);
                        if (rc != EOK)
                                return rc;
                        port = (uint16_t) value;
                } else if (str_lcmp(argv[*index] + 2, "reply=", 6) == 0) {
                        rc = arg_parse_string(argc, argv, index, &reply, 8);
                        if (rc != EOK)
                                return rc;
                } else if (str_lcmp(argv[*index] + 2, "size=", 5) == 0) {
                        rc = arg_parse_int(argc, argv, index, &value, 7);
                        if (rc != EOK)
                                return rc;
                        size = (value >= 0) ? (size_t) value : 0;
                } else if (str_lcmp(argv[*index] + 2, "type=", 5) == 0) {
                        rc = arg_parse_name_int(argc, argv, index, &value, 7,
                            socket_parse_socket_type);
                        if (rc != EOK)
                                return rc;
                        type = (sock_type_t) value;
                } else if (str_lcmp(argv[*index] + 2, "verbose", 8) == 0) {
                        verbose = 1;
                } else {
                        echo_print_help();
                        return EINVAL;
                }
                break;
        default:
                echo_print_help();
                return EINVAL;
        }

        return EOK;
}

static int netecho_socket_process_message(int listening_id)
{
        uint8_t address_buf[sizeof(struct sockaddr_in6)];

        socklen_t addrlen;
        int socket_id;
        ssize_t rcv_size;
        size_t length;
        uint8_t *address_start;

        char address_string[INET6_ADDRSTRLEN];
        struct sockaddr_in *address_in = (struct sockaddr_in *) address_buf;
        struct sockaddr_in6 *address_in6 = (struct sockaddr_in6 *) address_buf;
        struct sockaddr *address = (struct sockaddr *) address_buf;

        int rc;

        if (type == SOCK_STREAM) {
                /* Accept a socket if a stream socket is used */
                addrlen = sizeof(address_buf);
                socket_id = accept(listening_id, (void *) address_buf, &addrlen);
                if (socket_id <= 0) {
                        socket_print_error(stderr, socket_id, "Socket accept: ", "\n");
                } else {
                        if (verbose)
                                printf("Socket %d accepted\n", socket_id);
                }

                assert((size_t) addrlen <= sizeof(address_buf));
        } else {
                socket_id = listening_id;
        }

        /* if the datagram socket is used or the stream socked was accepted */
        if (socket_id > 0) {

                /* Receive a message to echo */
                rcv_size = recvfrom(socket_id, data, size, 0, address,
                    &addrlen);
                if (rcv_size < 0) {
                        socket_print_error(stderr, rcv_size, "Socket receive: ", "\n");
                } else {
                        length = (size_t) rcv_size;
                        if (verbose) {
                                /* Print the header */

                                /* Get the source port and prepare the address buffer */
                                address_start = NULL;
                                switch (address->sa_family) {
                                case AF_INET:
                                        port = ntohs(address_in->sin_port);
                                        address_start = (uint8_t *) &address_in->sin_addr.s_addr;
                                        break;
                                case AF_INET6:
                                        port = ntohs(address_in6->sin6_port);
                                        address_start = (uint8_t *) &address_in6->sin6_addr.s6_addr;
                                        break;
                                default:
                                        fprintf(stderr, "Address family %u (%#x) is not supported.\n",
                                            address->sa_family, address->sa_family);
                                }

                                /* Parse source address */
                                if (address_start) {
                                        rc = inet_ntop(address->sa_family, address_start, address_string, sizeof(address_string));
                                        if (rc != EOK) {
                                                fprintf(stderr, "Received address error %d\n", rc);
                                        } else {
                                                data[length] = '\0';
                                                printf("Socket %d received %zu bytes from %s:%d\n%s\n",
                                                    socket_id, length, address_string, port, data);
                                        }
                                }
                        }

                        /* Answer the request either with the static reply or the original data */
                        rc = sendto(socket_id, reply ? reply : data, reply ? reply_length : length, 0, address, addrlen);
                        if (rc != EOK)
                                socket_print_error(stderr, rc, "Socket send: ", "\n");
                }

                /* Close accepted stream socket */
                if (type == SOCK_STREAM) {
                        rc = closesocket(socket_id);
                        if (rc != EOK)
                                socket_print_error(stderr, rc, "Close socket: ", "\n");
                }

        }

        return EOK;
}


int main(int argc, char *argv[])
{
        struct sockaddr *address;;
        struct sockaddr_in address_in;
        struct sockaddr_in6 address_in6;
        socklen_t addrlen;

        int listening_id;
        int index;
        int rc;

        /* Parse command line arguments */
        for (index = 1; index < argc; ++index) {
                if (argv[index][0] == '-') {
                        rc = netecho_parse_option(argc, argv, &index);
                        if (rc != EOK)
                                return rc;
                } else {
                        echo_print_help();
                        return EINVAL;
                }
        }

        /* Check buffer size */
        if (size <= 0) {
                fprintf(stderr, "Receive size too small (%zu). Using 1024 bytes instead.\n", size);
                size = 1024;
        }

        /* size plus the terminating null character. */
        data = (char *) malloc(size + 1);
        if (!data) {
                fprintf(stderr, "Failed to allocate receive buffer.\n");
                return ENOMEM;
        }

        /* Set the reply size if set */
        reply_length = reply ? str_length(reply) : 0;

        /* Prepare the address buffer */
        switch (family) {
        case PF_INET:
                address_in.sin_family = AF_INET;
                address_in.sin_port = htons(port);
                address = (struct sockaddr *) &address_in;
                addrlen = sizeof(address_in);
                break;
        case PF_INET6:
                address_in6.sin6_family = AF_INET6;
                address_in6.sin6_port = htons(port);
                address = (struct sockaddr *) &address_in6;
                addrlen = sizeof(address_in6);
                break;
        default:
                fprintf(stderr, "Protocol family is not supported\n");
                return EAFNOSUPPORT;
        }

        /* Get a listening socket */
        listening_id = socket(family, type, 0);
        if (listening_id < 0) {
                socket_print_error(stderr, listening_id, "Socket create: ", "\n");
                return listening_id;
        }

        /* if the stream socket is used */
        if (type == SOCK_STREAM) {
                /* Check backlog size */
                if (backlog <= 0) {
                        fprintf(stderr, "Accepted sockets queue size too small (%zu). Using 3 instead.\n", size);
                        backlog = 3;
                }

                /* Set the backlog */
                rc = listen(listening_id, backlog);
                if (rc != EOK) {
                        socket_print_error(stderr, rc, "Socket listen: ", "\n");
                        return rc;
                }
        }

        /* Bind the listening socket */
        rc = bind(listening_id, address, addrlen);
        if (rc != EOK) {
                socket_print_error(stderr, rc, "Socket bind: ", "\n");
                return rc;
        }

        if (verbose)
                printf("Socket %d listenning at %d\n", listening_id, port);

        /*
         * do count times
         * or indefinitely if set to a negative value
         */
        while (count) {
                rc = netecho_socket_process_message(listening_id);
                if (rc != EOK)
                        break;

                /* Decrease count if positive */
                if (count > 0) {
                        count--;
                        if (verbose)
                                printf("Waiting for next %d message(s)\n", count);
                }
        }

        if (verbose)
                printf("Closing the socket\n");

        /* Close listenning socket */
        rc = closesocket(listening_id);
        if (rc != EOK) {
                socket_print_error(stderr, rc, "Close socket: ", "\n");
                return rc;
        }

        if (verbose)
                printf("Exiting\n");

        return EOK;
}

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