udp_test_proxy.c

/* 
 * $Id$
 *
 *
 * Copyright (C) 2001-2003 FhG Fokus
 *
 * This file is part of ser, a free SIP server.
 *
 * ser 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 2 of the License, or
 * (at your option) any later version
 *
 * For a license to use the ser software under conditions
 * other than those described here, or to purchase support for this
 * software, please contact iptel.org by e-mail at the following addresses:
 *    info@iptel.org
 *
 * ser 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 this program; if not, write to the Free Software 
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <ctype.h>
#include <netdb.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>



static char *id="$Id$";
static char *version="udp_test_proxy 0.1";
static char* help_msg="\
Usage: udp_test_proxy  -l address -s port -d address -p port [-n no] [-v]\n\
Options:\n\
    -l address    listen address\n\
    -s port       listen(source) port\n\
    -d address    destination address\n\
    -p port       destination port\n\
    -n no         number of processes\n\
    -2            use a different socket for sending\n\
    -v            increase verbosity level\n\
    -V            version number\n\
    -h            this help message\n\
";
#define BUF_SIZE 65535
static char buf[BUF_SIZE];

int main(int argc, char** argv)
{
        int sock;
        int s_sock;
        pid_t pid;
        struct sockaddr_in addr;
        struct sockaddr_in to;
        int r, n, len;
        char c;
        struct hostent* he;
        int verbose;
        int sport, dport;
        char *dst;
        char *src;
        char* tmp;
        int use_diff_ssock;


        /* init */
        verbose=0;
        dst=0;
        sport=dport=0;
        src=dst=0;
        n=0;
        use_diff_ssock=0;
        
        opterr=0;
        while ((c=getopt(argc,argv, "l:p:d:s:n:2vhV"))!=-1){
                switch(c){
                        case '2':
                                use_diff_ssock=1;
                                break;
                        case 'v':
                                verbose++;
                                break;
                        case 'd':
                                dst=optarg;
                                break;
                        case 'l':
                                src=optarg;
                                break;
                        case 'p':
                                dport=strtol(optarg, &tmp, 10);
                                if ((tmp==0)||(*tmp)){
                                        fprintf(stderr, "bad port number: -p %s\n", optarg);
                                        goto error;
                                }
                                break;
                        case 's':
                                sport=strtol(optarg, &tmp, 10);
                                if ((tmp==0)||(*tmp)){
                                        fprintf(stderr, "bad port number: -s %s\n", optarg);
                                        goto error;
                                }
                                break;
                        case 'n':
                                n=strtol(optarg, &tmp, 10);
                                if ((tmp==0)||(*tmp)){
                                        fprintf(stderr, "bad process number: -n %s\n", optarg);
                                        goto error;
                                }
                                break;
                        case 'V':
                                printf("version: %s\n", version);
                                printf("%s\n",id);
                                exit(0);
                                break;
                        case 'h':
                                printf("version: %s\n", version);
                                printf("%s", help_msg);
                                exit(0);
                                break;
                        case '?':
                                if (isprint(optopt))
                                        fprintf(stderr, "Unknown option `-%c´\n", optopt);
                                else
                                        fprintf(stderr, "Unknown character `\\x%x´\n", optopt);
                                goto error;
                        case ':':
                                fprintf(stderr, "Option `-%c´ requires an argument.\n",
                                                optopt);
                                goto error;
                                break;
                        default:
                                        abort();
                }
        }

        /* check if all the required params are present */
        if (dst==0){
                fprintf(stderr, "Missing destination (-d ...)\n");
                exit(-1);
        }
        if (src==0){
                fprintf(stderr, "Missing listen address (-l ...)\n");
                exit(-1);
        }
        if(sport==0){
                fprintf(stderr, "Missing source port number (-s port)\n");
                exit(-1);
        }else if(sport<0){
                fprintf(stderr, "Invalid source port number (-s %d)\n", sport);
                exit(-1);
        }
        if(dport==0){
                fprintf(stderr, "Missing destination port number (-p port)\n");
                exit(-1);
        }else if(dport<0){
                fprintf(stderr, "Invalid destination port number (-p %d)\n", dport);
                exit(-1);
        }
        if(n<0){
                fprintf(stderr, "Invalid process no (-n %d)\n", n);
                exit(-1);
        }


        /* resolve destination */
        he=gethostbyname(dst);
        if (he==0){
                fprintf(stderr, "ERROR: could not resolve %s\n", dst);
                goto error;
        }

        /* set to*/
        to.sin_family=he->h_addrtype;
        to.sin_port=htons(dport);
        memcpy(&to.sin_addr.s_addr, he->h_addr_list[0], he->h_length);

        /* resolve source/listen */
        he=gethostbyname(src);
        if (he==0){
                fprintf(stderr, "ERROR: could not resolve %s\n", dst);
                goto error;
        }
        /* open socket*/
        addr.sin_family=he->h_addrtype;
        addr.sin_port=htons(sport);
        memcpy(&addr.sin_addr.s_addr, he->h_addr_list[0], he->h_length);

        s_sock=-1;
        sock = socket(he->h_addrtype, SOCK_DGRAM, 0);
        if (use_diff_ssock && (sock!=-1))
                s_sock = socket(he->h_addrtype, SOCK_DGRAM, 0);
        else
                s_sock=sock;
        
        if ((sock==-1)||(s_sock==-1)){
                fprintf(stderr, "ERROR: socket: %s\n", strerror(errno));
                goto error;
        }
        if (bind(sock, (struct sockaddr*) &addr, sizeof(struct sockaddr_in))==-1){
                fprintf(stderr, "ERROR: bind: %s\n", strerror(errno));
                goto error;
        }
        if (use_diff_ssock){
                if (connect(s_sock, (struct sockaddr*) &to,
                                        sizeof(struct sockaddr_in))==-1){
                        fprintf(stderr, "ERROR: connect: %s\n", strerror(errno));
                        goto error;
                }
        }

        for(r=1; r<n; r++){
                if ((pid=fork())==-1){
                        fprintf(stderr, "ERROR: fork: %s\n", strerror(errno));
                        goto error;
                }
                if (pid==0) break; /* child, skip */
        }

        if (verbose>3) printf("process starting\n");
        for(;;){
                len=read(sock, buf, BUF_SIZE);
                if (len==-1){
                        fprintf(stderr, "ERROR: read: %s\n", strerror(errno));
                        continue;
                }
                if (verbose>2) putchar('r');
                /* send it back*/
                if (use_diff_ssock)
                        len=send(s_sock, buf, len, 0);
                else
                        len=sendto(s_sock, buf, len, 0,
                                        (struct sockaddr*) &to, sizeof(struct sockaddr_in));
                if (len==-1){
                        fprintf(stderr, "ERROR: send: %s\n", strerror(errno));
                        continue;
                }
                if (verbose>1) putchar('.');
        }
error:
        exit(-1);
}