source.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 "debug.h"
#include "fg_error.h"
#include "fg_math.h"
#include "fg_socket.h"
#include "fg_time.h"
#include "fg_log.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);
 
static int name2socket(struct flow *flow, char *server_name, unsigned port, struct sockaddr **saptr,
                socklen_t *lenp,
                const int read_buffer_size_req, int *read_buffer_size,
                const int send_buffer_size_req, int *send_buffer_size)
{
        int fd, n;
        struct addrinfo hints, *res, *ressave;
        char service[7];
 
        bzero(&hints, sizeof(struct addrinfo));
        hints.ai_family = AF_UNSPEC;
        hints.ai_socktype = SOCK_STREAM;
 
        snprintf(service, sizeof(service), "%u", port);
 
        if ((n = getaddrinfo(server_name, service, &hints, &res)) != 0) {
                flow_error(flow, "getaddrinfo() failed: %s",
                                gai_strerror(n));
                return -1;
        }
        ressave = res;
 
        do {
 
                fd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
 
                if (fd < 0)
                        continue;
                /* FIXME: currently we use portable select() API, which
                 * is limited by the number of bits in an fd_set */
                if (fd >= FD_SETSIZE) {
                        logging(LOG_ALERT, "too many file descriptors are"
                                "already in use by this daemon");
                        flow_error(flow, "failed to create listen socket: too many"
                                "file descriptors in use by this daemon");
                        close(fd);
                        freeaddrinfo(ressave);
                        return -1;
                }
 
                if (send_buffer_size)
                        *send_buffer_size = set_window_size_directed(fd, send_buffer_size_req, SO_SNDBUF);
                if (read_buffer_size)
                        *read_buffer_size = set_window_size_directed(fd, read_buffer_size_req, SO_RCVBUF);
 
                break;
 
        } while ((res = res->ai_next) != NULL);
 
        if (res == NULL) {
                flow_error(flow, "Could not create socket for "
                                "\"%s:%d\": %s", server_name, port, strerror(errno));
                freeaddrinfo(ressave);
                return -1;
        }
 
        if (saptr && lenp) {
                *saptr = malloc(res->ai_addrlen);
                if (*saptr == NULL)
                        crit("malloc(): failed");
                memcpy(*saptr, res->ai_addr, res->ai_addrlen);
                *lenp = res->ai_addrlen;
        }
 
        freeaddrinfo(ressave);
 
        return fd;
}
 
int do_connect(struct flow *flow) {
        int rc;
 
        rc = connect(flow->fd, flow->addr, flow->addr_len);
        if (rc == -1 && errno != EINPROGRESS) {
                flow_error(flow, "connect() failed: %s",
                                strerror(errno));
                err("failed to connect flow %u", flow->id);
                return rc;
        }
        flow->connect_called = 1;
        flow->pmtu = get_pmtu(flow->fd);
        return 0;
}
 
int add_flow_source(struct request_add_flow_source *request)
{
#ifdef HAVE_SO_TCP_CONGESTION
        socklen_t opt_len = 0;
#endif /* HAVE_SO_TCP_CONGESTION */
        struct flow *flow;
 
        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 -1;
        }
 
        flow = malloc(sizeof(struct flow));
        if (!flow) {
                logging(LOG_ALERT, "could not allocate memory for flow");
                return -1;
        }
 
        init_flow(flow, 1);
 
        flow->settings = request->settings;
        flow->source_settings = request->source_settings;
        /* be greedy with buffer sizes */
        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 -1;
        }
        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);
        }
 
        flow->state = GRIND_WAIT_CONNECT;
        flow->fd = name2socket(flow, flow->source_settings.destination_host,
                        flow->source_settings.destination_port,
                        &flow->addr, &flow->addr_len,
                        flow->settings.requested_read_buffer_size, &request->real_read_buffer_size,
                        flow->settings.requested_send_buffer_size, &request->real_send_buffer_size);
        if (flow->fd == -1) {
                logging(LOG_ALERT, "could not create data socket: %s",
                        flow->error);
                request_error(&request->r, "Could not create data socket: %s", flow->error);
                uninit_flow(flow);
                return -1;
        }
 
        if (set_flow_tcp_options(flow) == -1) {
                request->r.error = flow->error;
                flow->error = NULL;
                uninit_flow(flow);
                return -1;
        }
 
#ifdef HAVE_SO_TCP_CONGESTION
        opt_len = sizeof(request->cc_alg);
        if (getsockopt(flow->fd, IPPROTO_TCP, TCP_CONGESTION,
                                request->cc_alg, &opt_len) == -1) {
                request_error(&request->r, "failed to determine actual congestion control algorithm: %s",
                        strerror(errno));
                uninit_flow(flow);
                return -1;
        }
#endif /* HAVE_SO_TCP_CONGESTION */
 
#ifdef HAVE_LIBPCAP
        fg_pcap_go(flow);
#endif /* HAVE_LIBPCAP */
        if (!flow->source_settings.late_connect) {
                DEBUG_MSG(4, "(early) connecting test socket (fd=%u)", flow->fd);
                if (do_connect(flow) == -1) {
                        request->r.error = flow->error;
                        flow->error = NULL;
                        uninit_flow(flow);
                        return -1;
                }
        }
 
        request->flow_id = flow->id;
 
        fg_list_push_back(&flows, flow);
 
        return 0;
}