src/common/services.c
/* $Id$ */
/*
* Copyright (c) 2001-2010 Aaron Turner <aturner at synfin dot net>
* Copyright (c) 2013-2022 Fred Klassen <tcpreplay at appneta dot com> - AppNeta
*
* The Tcpreplay Suite of tools 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 with the authors permission any later version.
*
* The Tcpreplay Suite 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 the Tcpreplay Suite. If not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include "defines.h"
#include "common.h"
#include <regex.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
/**
* parses /etc/services so we know which ports are service ports
*/
void
parse_services(const char *file, tcpr_services_t *services)
{
FILE *service = NULL;
char service_line[MAXLINE], port[10], proto[10];
regex_t preg;
size_t nmatch = 3;
regmatch_t pmatch[3];
static const char regex[] = "([0-9]+)/(tcp|udp)"; /* matches the port as pmatch[1], service pmatch[2] */
assert(file);
assert(services);
dbgx(1, "Parsing %s", file);
memset(service_line, '\0', MAXLINE);
/* mark all ports not a service */
memset(&services->tcp[0], '\0', sizeof(services->tcp));
memset(&services->udp[0], '\0', sizeof(services->udp));
if ((service = fopen(file, "r")) == NULL) {
errx(-1, "Unable to open service file: %s\n%s", file, strerror(errno));
}
/* compile our regexes */
if ((regcomp(&preg, regex, REG_ICASE|REG_EXTENDED)) != 0) {
errx(-1, "Unable to compile regex: %s", regex);
}
/* parse the entire file */
while ((fgets(service_line, MAXLINE, service)) != NULL) {
/* zero out our vars */
memset(port, '\0', 10);
memset(proto, '\0', 10);
dbgx(4, "Processing: %s", service_line);
/* look for format of 1234/tcp */
if ((regexec(&preg, service_line, nmatch, pmatch, 0)) == 0) { /* matches */
uint16_t portc;
/* strip out the port & proto from the line */
strncpy(port, &service_line[pmatch[1].rm_so], (pmatch[1].rm_eo - pmatch[1].rm_so));
strncpy(proto, &service_line[pmatch[2].rm_so], (pmatch[2].rm_eo - pmatch[2].rm_so));
/* convert port[] into an integer */
portc = (uint16_t)strtol(port, NULL, 10);
/* update appropriate service array with the server port */
if (strcmp(proto, "tcp") == 0) {
dbgx(3, "Setting TCP/%d as a server port", portc);
services->tcp[portc] = 1; /* mark it as a service port */
} else if (strcmp(proto, "udp") == 0) {
dbgx(3, "Setting UDP/%d as a server port", portc);
services->udp[portc] = 1;
} else {
warnx("Skipping unknown protocol service %s/%d", proto, portc);
}
}
}
regfree(&preg);
fclose(service);
}