destination.c

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/*
 * Copyright (C) 2010-2013 Christian Samsel <christian.samsel@rwth-aachen.de>
 * Copyright (C) 2009 Tim Kosse <tim.kosse@gmx.de>
 * Copyright (C) 2007-2008 Daniel Schaffrath <daniel.schaffrath@mac.com>
 *
 * This file is part of Flowgrind.
 *
 * Flowgrind is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Flowgrind is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Flowgrind.  If not, see <http://www.gnu.org/licenses/>.
 *
 */
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif /* HAVE_CONFIG_H */
 
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <strings.h>
#include <signal.h>
#include <string.h>
#include <fcntl.h>
#include <math.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/param.h>
#include <sys/select.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <sys/wait.h>
#include <errno.h>
#include <time.h>
#include <syslog.h>
#include <sys/time.h>
#include <netdb.h>
#include <pthread.h>
#include <float.h>
 
#include "common.h"
#include "debug.h"
#include "fg_socket.h"
#include "fg_time.h"
#include "fg_math.h"
#include "fg_log.h"
#include "daemon.h"
 
#ifdef HAVE_LIBPCAP
#include "fg_pcap.h"
#endif /* HAVE_LIBPCAP */
 
void remove_flow(unsigned i);
 
#ifdef HAVE_TCP_INFO
int get_tcp_info(struct flow *flow, struct tcp_info *info);
#endif /* HAVE_TCP_INFO */
 
void init_flow(struct flow* flow, int is_source);
void uninit_flow(struct flow *flow);
 
/* listen_port will receive the port of the created socket */
static int create_listen_socket(struct flow *flow, char *bind_addr,
                                unsigned short *listen_port)
{
        int port;
        int rc;
        int fd;
        struct addrinfo hints, *res, *ressave;
 
        bzero(&hints, sizeof(struct addrinfo));
        hints.ai_flags = bind_addr ? 0 : AI_PASSIVE;
        hints.ai_family = AF_UNSPEC;
        hints.ai_socktype = SOCK_STREAM;
 
        /* Any port will be fine */
        if ((rc = getaddrinfo(bind_addr, "0", &hints, &res)) != 0) {
                logging(LOG_ALERT, "getaddrinfo() failed: %s",
                        gai_strerror(rc));
                flow_error(flow, "getaddrinfo() failed: %s",
                           gai_strerror(rc));
                return -1;
        }
 
        ressave = res;
 
        do {
                fd = socket(res->ai_family, res->ai_socktype,
                            res->ai_protocol);
                if (fd < 0)
                        continue;
                if (bind(fd, res->ai_addr, res->ai_addrlen) == 0)
                        break;
                close(fd);
        } while ((res = res->ai_next) != NULL);
 
        if (res == NULL) {
                logging(LOG_ALERT, "failed to create listen socket: %s",
                        strerror(errno));
                flow_error(flow, "failed to create listen socket: %s",
                           strerror(errno));
                freeaddrinfo(ressave);
                return -1;
        }
 
        freeaddrinfo(ressave);
 
        /* we need to set sockopt mtcp before we start listen() */
        if (flow->settings.mtcp)
                set_tcp_mtcp(fd);
 
        if (flow->settings.cc_alg)
                set_congestion_control(fd, flow->settings.cc_alg);
 
        if (listen(fd, 0) < 0) {
                logging(LOG_ALERT, "listen failed: %s", strerror(errno));
                flow_error(flow, "listen failed: %s", strerror(errno));
                return -1;
        }
 
        set_non_blocking(fd);
 
        port = get_port(fd);
        if (port < 0) {
                flow_error(flow, "Could not get port: %s", strerror(errno));
                close(fd);
                return -1;
        }
        DEBUG_MSG(LOG_DEBUG, "listening on port %d", port);
        *listen_port = (unsigned short)port;
 
        return fd;
}
 
void add_flow_destination(struct request_add_flow_destination *request)
{
        struct flow *flow;
        unsigned short server_data_port;
 
        if (fg_list_size(&flows) >= MAX_FLOWS_DAEMON) {
                logging(LOG_WARNING, "can not accept another flow, already "
                        "handling %zu flows", fg_list_size(&flows));
                request_error(&request->r, "Can not accept another flow, "
                             "already handling %zu flows.", fg_list_size(&flows));
                return;
        }
 
        flow = malloc(sizeof(struct flow));
        if (!flow) {
                logging(LOG_ALERT, "could not allocate memory for flow");
                return;
        }
 
        init_flow(flow, 0);
 
        flow->settings = request->settings;
        flow->write_block = calloc(1, flow->settings.maximum_block_size );
        flow->read_block = calloc(1, flow->settings.maximum_block_size );
        /* Controller flow ID is set in the daemon */
        flow->id=flow->settings.flow_id;
        if (flow->write_block == NULL || flow->read_block == NULL) {
                logging(LOG_ALERT, "could not allocate memory for read/write "
                        "blocks");
                request_error(&request->r, "could not allocate memory "
                              "for read/write blocks");
                uninit_flow(flow);
                return;
        }
 
        if (flow->settings.byte_counting) {
                int byte_idx;
                for (byte_idx = 0; byte_idx < flow->settings.maximum_block_size;
                     byte_idx++)
                        *(flow->write_block + byte_idx) =
                                (unsigned char)(byte_idx & 0xff);
        }
 
        /* Create listen socket for data connection */
        if ((flow->listenfd_data =
                        create_listen_socket(flow,
                                             flow->settings.bind_address[0]
                                                ? flow->settings.bind_address : 0,
                                             &server_data_port)) == -1) {
                logging(LOG_ALERT, "could not create listen socket for "
                        "data connection: %s", flow->error);
                request_error(&request->r, "could not create listen socket "
                              "for data connection: %s", flow->error);
                uninit_flow(flow);
                return;
        } else {
                /* FIXME: currently we use portable select() API, which
                 * is limited by the number of bits in an fd_set */
                if (flow->listenfd_data >= FD_SETSIZE) {
                        logging(LOG_ALERT, "failed to add listen socket: "
                                "fd number too high (fd=%u)", flow->listenfd_data);
                        flow_error(flow, "failed to add listen socket: too many"
                                "file descriptors in use by this daemon");
                        uninit_flow(flow);
                        return;
                }
                DEBUG_MSG(LOG_WARNING, "listening on %s port %u for data "
                          "connection (fd=%u)", flow->settings.bind_address,
                          server_data_port, flow->listenfd_data);
        }
 
        flow->real_listen_send_buffer_size =
                set_window_size_directed(flow->listenfd_data,
                                         flow->settings.requested_send_buffer_size,
                                         SO_SNDBUF);
        flow->real_listen_receive_buffer_size =
                set_window_size_directed(flow->listenfd_data,
                                         flow->settings.requested_read_buffer_size,
                                         SO_RCVBUF);
 
        request->listen_data_port = (int)server_data_port;
        request->real_listen_send_buffer_size =
                flow->real_listen_send_buffer_size;
        request->real_listen_read_buffer_size =
                flow->real_listen_receive_buffer_size;
        request->flow_id = flow->id;
 
        fg_list_push_back(&flows, flow);
 
        return;
}
 
int accept_data(struct flow *flow)
{
        struct sockaddr_storage caddr;
        socklen_t addrlen = sizeof(caddr);
        unsigned real_send_buffer_size;
        unsigned real_receive_buffer_size;
 
        flow->fd = accept(flow->listenfd_data, (struct sockaddr *)&caddr,
                          &addrlen);
        if (flow->fd == -1) {
                /* try again later .... */
                if (errno == EINTR || errno == EAGAIN)
                        return 0;
                logging(LOG_ALERT, "accept() failed: %s", strerror(errno));
                return -1;
        }
 
        /* FIXME: currently we use portable select() API, which
         * is limited by the number of bits in an fd_set */
        if (flow->fd >= FD_SETSIZE) {
                logging(LOG_ALERT, "too many file descriptors are "
                        "already in use by this daemon (FD number=%u)", flow->fd);
                flow_error(flow, "failed to add test connection: too many"
                        "file descriptors in use by this daemon");
                close(flow->fd);
                return -1;
        }
 
        if (close(flow->listenfd_data) == -1)
                logging(LOG_WARNING, "close() failed");
        flow->listenfd_data = -1;
 
        logging(LOG_NOTICE, "client %s connected for testing (fd=%u)",
                fg_nameinfo((struct sockaddr *)&caddr, addrlen), flow->fd);
 
#ifdef HAVE_LIBPCAP
        fg_pcap_go(flow);
#endif /* HAVE_LIBPCAP */
 
        real_send_buffer_size =
                set_window_size_directed(flow->fd,
                                         flow->settings.requested_send_buffer_size,
                                         SO_SNDBUF);
        if (flow->requested_server_test_port &&
            flow->real_listen_send_buffer_size != real_send_buffer_size) {
                logging(LOG_WARNING, "failed to set send buffer size of test "
                        "socket to send buffer size size of listen socket "
                        "(listen = %u, test = %u)",
                        flow->real_listen_send_buffer_size, real_send_buffer_size);
                return -1;
        }
        real_receive_buffer_size =
                set_window_size_directed(flow->fd,
                                         flow->settings.requested_read_buffer_size,
                                         SO_RCVBUF);
        if (flow->requested_server_test_port &&
            flow->real_listen_receive_buffer_size != real_receive_buffer_size) {
                logging(LOG_WARNING, "failed to set receive buffer size "
                        "(advertised window) of test socket to receive "
                        "buffer size of listen socket (listen = %u, "
                        "test = %u)", flow->real_listen_receive_buffer_size,
                        real_receive_buffer_size);
                return -1;
        }
        if (set_flow_tcp_options(flow) == -1)
                return -1;
        DEBUG_MSG(LOG_NOTICE, "data socket accepted");
        flow->state = GRIND;
        flow->connect_called = 1;
 
        return 0;
}