main.c

RTP Proxy,用于Voip网络数据的代理传递

/*
 * Copyright (c) 2004-2006 Maxim Sobolev <[e-mail]>
 * Copyright (c) 2006-2007 Sippy Software, Inc., http://www.sippysoft.com
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
 *
 * $Id: main.c,v 1.71 2008/04/03 20:51:45 sobomax Exp $
 *
 */

#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/resource.h>
#include <sys/un.h>
#include <sys/uio.h>
#include <ctype.h>
#include <sys/select.h>
#include <sys/stat.h>
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <netdb.h>
#include <poll.h>
#include <sched.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include <strings.h>
#include <unistd.h>

#include "rtp.h"
#include "rtp_resizer.h"
#include "rtp_server.h"
#include "rtpp_defines.h"
#include "rtpp_command.h"
#include "rtpp_log.h"
#include "rtpp_record.h"
#include "rtpp_session.h"
#include "rtpp_util.h"

static const char *cmd_sock = CMD_SOCK;
static const char *pid_file = PID_FILE;
static rtpp_log_t glog;

static void setbindhost(struct sockaddr *, int, const char *, const char *);
static void usage(void);
static void send_packet(struct cfg *, struct rtpp_session *, int,
  struct rtp_packet *);

static void
setbindhost(struct sockaddr *ia, int pf, const char *bindhost,
  const char *servname)
{
    int n;

    /*
     * If user specified * then change it to NULL,
     * that will make getaddrinfo to return addr_any socket
     */
    if (bindhost && (strcmp(bindhost, "*") == 0))
	bindhost = NULL;

    if ((n = resolve(ia, pf, bindhost, servname, AI_PASSIVE)) != 0)
	errx(1, "setbindhost: %s", gai_strerror(n));
}

static void
usage(void)
{

    fprintf(stderr, "usage: rtpproxy [-2fvF] [-l addr1[/addr2]] "
      "[-6 addr1[/addr2]] [-s path]\n\t[-t tos] [-r rdir [-S sdir]] [-T ttl] "
      "[-L nfiles] [-m port_min]\n\t[-M port_max] [-u uname[:gname]]\n");
    exit(1);
}

static void
fatsignal(int sig)
{

    rtpp_log_write(RTPP_LOG_INFO, glog, "got signal %d", sig);
    exit(0);
}

static void
ehandler(void)
{

    unlink(cmd_sock);
    unlink(pid_file);
    rtpp_log_write(RTPP_LOG_INFO, glog, "rtpproxy ended");
    rtpp_log_close(glog);
}

static void 
init_config(struct cfg *cf, int argc, char **argv)
{
    int ch, i;
    char *bh[2], *bh6[2], *cp;

    bh[0] = bh[1] = bh6[0] = bh6[1] = NULL;

    cf->port_min = PORT_MIN;
    cf->port_max = PORT_MAX;

    cf->max_ttl = SESSION_TIMEOUT;
    cf->tos = TOS;
    cf->rrtcp = 1;

    if (getrlimit(RLIMIT_NOFILE, &(cf->nofile_limit)) != 0)
	err(1, "getrlimit");

    while ((ch = getopt(argc, argv, "vf2Rl:6:s:S:t:r:p:T:L:m:M:u:F")) != -1)
	switch (ch) {
	case 'f':
	    cf->nodaemon = 1;
	    break;

	case 'l':
	    bh[0] = optarg;
	    bh[1] = strchr(bh[0], '/');
	    if (bh[1] != NULL) {
		*bh[1] = '\0';
		bh[1]++;
		cf->bmode = 1;
	    }
	    break;

	case '6':
	    bh6[0] = optarg;
	    bh6[1] = strchr(bh6[0], '/');
	    if (bh6[1] != NULL) {
		*bh6[1] = '\0';
		bh6[1]++;
		cf->bmode = 1;
	    }
	    break;

	case 's':
	    if (strncmp("udp:", optarg, 4) == 0) {
		cf->umode = 1;
		optarg += 4;
	    } else if (strncmp("udp6:", optarg, 5) == 0) {
		cf->umode = 6;
		optarg += 5;
	    } else if (strncmp("unix:", optarg, 5) == 0) {
		cf->umode = 0;
		optarg += 5;
	    }
	    cmd_sock = optarg;
	    break;

	case 't':
	    cf->tos = atoi(optarg);
	    break;

	case '2':
	    cf->dmode = 1;
	    break;

	case 'v':
	    printf("Basic version: %d\n", CPROTOVER);
	    for (i = 1; proto_caps[i].pc_id != NULL; ++i) {
		printf("Extension %s: %s\n", proto_caps[i].pc_id,
		    proto_caps[i].pc_description);
	    }
	    exit(0);
	    break;

	case 'r':
	    cf->rdir = optarg;
	    break;

	case 'S':
	    cf->sdir = optarg;
	    break;

	case 'R':
	    cf->rrtcp = 0;
	    break;

	case 'p':
	    pid_file = optarg;
	    break;

	case 'T':
	    cf->max_ttl = atoi(optarg);
	    break;

	case 'L':
	    cf->nofile_limit.rlim_cur = cf->nofile_limit.rlim_max = atoi(optarg);
	    if (setrlimit(RLIMIT_NOFILE, &(cf->nofile_limit)) != 0)
		err(1, "setrlimit");
	    if (getrlimit(RLIMIT_NOFILE, &(cf->nofile_limit)) != 0)
		err(1, "getrlimit");
	    if (cf->nofile_limit.rlim_max < atoi(optarg))
		warnx("limit allocated by setrlimit (%d) is less than "
		  "requested (%d)", (int) cf->nofile_limit.rlim_max,
		  atoi(optarg));
	    break;

	case 'm':
	    cf->port_min = atoi(optarg);
	    break;

	case 'M':
	    cf->port_max = atoi(optarg);
	    break;

	case 'u':
	    cf->run_uname = optarg;
	    cp = strchr(optarg, ':');
	    if (cp != NULL) {
		if (cp == optarg)
		    cf->run_uname = NULL;
		cp[0] = '\0';
		cp++;
	    }
	    cf->run_gname = cp;
	    break;

	case 'F':
	    cf->no_check = 1;
	    break;

	case '?':
	default:
	    usage();
	}
    if (cf->rdir == NULL && cf->sdir != NULL)
	errx(1, "-S switch requires -r switch");

    if (cf->no_check == 0 && getuid() == 0 && cf->run_uname == NULL) {
	if (cf->umode != 0) {
	    errx(1, "running this program as superuser in a remote control "
	      "mode is strongly not recommended, as it poses serious security "
	      "threat to your system. Use -u option to run as an unprivileged "
	      "user or -F is you want to run as a superuser anyway.");
	} else {
	    warnx("WARNING!!! Running this program as superuser is strongly "
	      "not recommended, as it may pose serious security threat to "
	      "your system. Use -u option to run as an unprivileged user "
	      "or -F to surpress this warning.");
	}
    }

    if (cf->port_min <= 0 || cf->port_min > 65535)
	errx(1, "invalid value of the port_min argument, "
	  "not in the range 1-65535");
    if (cf->port_max <= 0 || cf->port_max > 65535)
	errx(1, "invalid value of the port_max argument, "
	  "not in the range 1-65535");
    if (cf->port_min > cf->port_max)
	errx(1, "port_min should be less than port_max");

    /* make sure that port_min and port_max are even */
    if ((cf->port_min % 2) != 0)
	cf->port_min++;
    if ((cf->port_max % 2) != 0)
	cf->port_max--;

    cf->nextport[0] = cf->nextport[1] = cf->port_min;
    cf->sessions = malloc((sizeof cf->sessions[0]) *
      (((cf->port_max - cf->port_min + 1) * 2) + 1));
    cf->rtp_servers =  malloc((sizeof cf->rtp_servers[0]) *
      (((cf->port_max - cf->port_min + 1) * 2) + 1));
    cf->pfds = malloc((sizeof cf->pfds[0]) *
      (((cf->port_max - cf->port_min + 1) * 2) + 1));

    if (bh[0] == NULL && bh[1] == NULL && bh6[0] == NULL && bh6[1] == NULL) {
	if (cf->umode != 0)
	    errx(1, "explicit binding address has to be specified in UDP "
	      "command mode");
	bh[0] = "*";
    }

    for (i = 0; i < 2; i++) {
	if (bh[i] != NULL && *bh[i] == '\0')
	    bh[i] = NULL;
	if (bh6[i] != NULL && *bh6[i] == '\0')
	    bh6[i] = NULL;
    }

    i = ((bh[0] == NULL) ? 0 : 1) + ((bh[1] == NULL) ? 0 : 1) +
      ((bh6[0] == NULL) ? 0 : 1) + ((bh6[1] == NULL) ? 0 : 1);
    if (cf->bmode != 0) {
	if (bh[0] != NULL && bh6[0] != NULL)
	    errx(1, "either IPv4 or IPv6 should be configured for external "
	      "interface in bridging mode, not both");
	if (bh[1] != NULL && bh6[1] != NULL)
	    errx(1, "either IPv4 or IPv6 should be configured for internal "
	      "interface in bridging mode, not both");
	if (i != 2)
	    errx(1, "incomplete configuration of the bridging mode - exactly "
	      "2 listen addresses required, %d provided", i);
    } else if (i != 1) {
	errx(1, "exactly 1 listen addresses required, %d provided", i);
    }

    for (i = 0; i < 2; i++) {
	cf->bindaddr[i] = NULL;
	if (bh[i] != NULL) {
	    cf->bindaddr[i] = malloc(sizeof(struct sockaddr_storage));
	    setbindhost(cf->bindaddr[i], AF_INET, bh[i], SERVICE);
	    continue;
	}
	if (bh6[i] != NULL) {
	    cf->bindaddr[i] = malloc(sizeof(struct sockaddr_storage));
	    setbindhost(cf->bindaddr[i], AF_INET6, bh6[i], SERVICE);
	    continue;
	}
    }
    if (cf->bindaddr[0] == NULL) {
	cf->bindaddr[0] = cf->bindaddr[1];
	cf->bindaddr[1] = NULL;
    }
}

static int
init_controlfd(struct cfg *cf)
{
    struct sockaddr_un ifsun;
    struct sockaddr_storage ifsin;
    char *cp;
    int i, controlfd, flags;

    if (cf->umode == 0) {
	unlink(cmd_sock);
	memset(&ifsun, '\0', sizeof ifsun);
#if !defined(__linux__) && !defined(__solaris__)
	ifsun.sun_len = strlen(cmd_sock);
#endif
	ifsun.sun_family = AF_LOCAL;
	strcpy(ifsun.sun_path, cmd_sock);
	controlfd = socket(PF_LOCAL, SOCK_STREAM, 0);
	if (controlfd == -1)
	    err(1, "can't create socket");
	setsockopt(controlfd, SOL_SOCKET, SO_REUSEADDR, &controlfd,
	  sizeof controlfd);
	if (bind(controlfd, sstosa(&ifsun), sizeof ifsun) < 0)
	    err(1, "can't bind to a socket");
	if (listen(controlfd, 32) != 0)
	    err(1, "can't listen on a socket");
    } else {
	cp = strrchr(cmd_sock, ':');
	if (cp != NULL) {
	    *cp = '\0';
	    cp++;
	}
	if (cp == NULL || *cp == '\0')
	    cp = CPORT;
	i = (cf->umode == 6) ? AF_INET6 : AF_INET;
	setbindhost(sstosa(&ifsin), i, cmd_sock, cp);
	controlfd = socket(i, SOCK_DGRAM, 0);
	if (controlfd == -1)
	    err(1, "can't create socket");
	if (bind(controlfd, sstosa(&ifsin), SS_LEN(&ifsin)) < 0)
	    err(1, "can't bind to a socket");
    }
    flags = fcntl(controlfd, F_GETFL);
    fcntl(controlfd, F_SETFL, flags | O_NONBLOCK);