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openggsn/ggsn/ggsn.c

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/*
* OpenGGSN - Gateway GPRS Support Node
* Copyright (C) 2002 Mondru AB.
*
* The contents of this file may be used under the terms of the GNU
* General Public License Version 2, provided that the above copyright
* notice and this permission notice is included in all copies or
* substantial portions of the software.
*
* The initial developer of the original code is
* Jens Jakobsen <jj@openggsn.org>
*
* Contributor(s):
*
*/
/* ggsn.c
*
*/
#ifdef __linux__
#define _GNU_SOURCE 1 /* strdup() prototype, broken arpa/inet.h */
#endif
#include <syslog.h>
#include <ctype.h>
#include <netdb.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <features.h>
#include <errno.h>
#include <asm/types.h>
#include <sys/socket.h>
#include <linux/netlink.h>
#include <time.h>
#include "tun.h"
#include "../gtp/pdp.h"
#include "../gtp/gtp.h"
#include "cmdline.h"
int maxfd = 0; /* For select() */
int tun_fd = -1; /* Network file descriptor */
struct tun_t *tun; /* TUN instance */
struct in_addr net, mask; /* Network interface */
int debug; /* Print debug output */
/* Used to write process ID to file. Assume someone else will delete */
void log_pid(char *pidfile) {
FILE *file;
mode_t oldmask;
oldmask = umask(022);
file = fopen(pidfile, "w");
umask(oldmask);
if(!file)
return;
fprintf(file, "%d\n", getpid());
fclose(file);
}
int encaps_printf(void *p, void *packet, unsigned len)
{
int i;
if (debug) {
printf("The packet looks like this:\n");
for( i=0; i<len; i++) {
printf("%02x ", (unsigned char)*(char *)(packet+i));
if (!((i+1)%16)) printf("\n");
};
printf("\n");
}
return 0;
}
int getip(struct pdp_t *pdp, void* ipif, struct ul66_t *eua,
struct in_addr *net, struct in_addr *mask) {
struct in_addr addr;
uint32_t ip_start, ip_end, ip_cur;
struct pdp_t *pdp_;
struct ul66_t eua_;
if (debug) {
printf("Begin getip %d %d %2x%2x%2x%2x\n", (unsigned)ipif, eua->l,
eua->v[2],eua->v[3],eua->v[4],eua->v[5]);
}
ip_start = ntoh32(net->s_addr & mask->s_addr);
ip_end = ntoh32(hton32(ip_start) | ~mask->s_addr);
/* By convention the first address is the network address, and the last */
/* address is the broadcast address. This way two IP addresses are "lost" */
ip_start++;
if (eua->l == 0) { /* No address supplied. Find one that is available! */
/* This routine does linear search. In order to support millions of
* addresses we should instead keep a linked list of available adresses */
for (ip_cur = ip_start; ip_cur < ip_end; ip_cur++) {
addr.s_addr = hton32(ip_cur);
pdp_ntoeua(&addr, &eua_);
if (pdp_ipget(&pdp_, ipif, &eua_) == -1) {
pdp_ntoeua(&addr, &pdp->eua);
pdp->ipif = ipif;
return 0;
};
}
return EOF; /* No addresses available */
}
else { /* Address supplied */
if (pdp_ipget(&pdp_, ipif, eua) == -1) {
pdp->ipif = ipif;
pdp->eua.l = eua->l;
memcpy(pdp->eua.v, eua->v, eua->l);
return 0;
}
else return EOF; /* Specified address not available */
}
}
int delete_context(struct pdp_t *pdp) {
pdp_ipdel(pdp);
return 0;
}
int create_context(struct pdp_t *pdp) {
if (debug) printf("Received create PDP context request\n");
pdp->eua.l=0; /* TODO: Indicates dynamic IP */
/* ulcpy(&pdp->qos_neg, &pdp->qos_req, sizeof(pdp->qos_req.v)); */
memcpy(pdp->qos_neg0, pdp->qos_req0, sizeof(pdp->qos_neg));
getip(pdp, tun, &pdp->eua, &net, &mask);
pdp_ipset(pdp, pdp->ipif, &pdp->eua);
return 0; /* Success */
}
int create_tun() {
char buf[1024];
char snet[100], smask[100];
if ((tun_fd = tun_newtun((struct tun_t**) &tun)) > maxfd)
maxfd = tun_fd;
if (tun_fd == -1) {
printf("Failed to open tun\n");
exit(1);
}
strncpy(snet, inet_ntoa(net), 100);
strncpy(smask, inet_ntoa(mask), 100);
sprintf(buf, "ifconfig %s %s mtu 1450 netmask %s",
tun->devname, snet, smask);
if (debug) printf("%s\n", buf);
system(buf);
system("echo 1 > /proc/sys/net/ipv4/ip_forward");
return 0;
}
int encaps_gtp(void *gsn, struct tun_t *tun, void *pack, unsigned len) {
struct pdp_t *pdp;
struct in_addr addr;
struct ul66_t eua;
/*printf("encaps_gtp. Packet received: forwarding to gtp.\n");*/
/* First we need to extract the IP destination address */
memcpy(&addr.s_addr, pack+16, 4); /* This ought to be dest addr */
pdp_ntoeua(&addr, &eua);
if (pdp_ipget(&pdp, tun, &eua) == 0) {
return gtp_gpdu((struct gsn_t*) gsn, pdp, pack, len);
}
else {
if (debug) printf("Received packet with no destination!!!\n");
return 0;
}
}
int encaps_tun(struct pdp_t *pdp, void *pack, unsigned len) {
/* printf("encaps_tun. Packet received: forwarding to tun\n");*/
return tun_encaps((struct tun_t*) pdp->ipif, pack, len);
}
int main(int argc, char **argv)
{
/* gengeopt declarations */
struct gengetopt_args_info args_info;
struct hostent *host;
struct in_addr listen;
int gtpfd = -1; /* Network file descriptor */
struct gsn_t *gsn; /* GSN instance */
fd_set fds; /* For select() */
struct timeval idleTime; /* How long to select() */
int i; /* for loop */
struct ul_t qos, apn;
unsigned char qosh[3], apnh[256];
int timelimit; /* Number of seconds to be connected */
int starttime; /* Time program was started */
/* open a connection to the syslog daemon */
/*openlog(PACKAGE, LOG_PID, LOG_DAEMON);*/
openlog(PACKAGE, (LOG_PID | LOG_PERROR), LOG_DAEMON);
if (cmdline_parser (argc, argv, &args_info) != 0)
exit(1);
if (args_info.debug_flag) {
printf("listen: %s\n", args_info.listen_arg);
printf("conf: %s\n", args_info.conf_arg);
printf("fg: %d\n", args_info.fg_flag);
printf("debug: %d\n", args_info.debug_flag);
printf("qos: %#08x\n", args_info.qos_arg);
printf("apn: %s\n", args_info.apn_arg);
printf("net: %s\n", args_info.net_arg);
printf("mask: %s\n", args_info.mask_arg);
printf("pidfile: %s\n", args_info.pidfile_arg);
printf("statedir: %s\n", args_info.statedir_arg);
printf("timelimit: %d\n", args_info.timelimit_arg);
}
/* Try out our new parser */
if (cmdline_parser_configfile (args_info.conf_arg, &args_info, 0) != 0)
exit(1);
if (args_info.debug_flag) {
printf("cmdline_parser_configfile\n");
printf("listen: %s\n", args_info.listen_arg);
printf("conf: %s\n", args_info.conf_arg);
printf("fg: %d\n", args_info.fg_flag);
printf("debug: %d\n", args_info.debug_flag);
printf("qos: %#08x\n", args_info.qos_arg);
printf("apn: %s\n", args_info.apn_arg);
printf("net: %s\n", args_info.net_arg);
printf("mask: %s\n", args_info.mask_arg);
printf("pidfile: %s\n", args_info.pidfile_arg);
printf("statedir: %s\n", args_info.statedir_arg);
printf("timelimit: %d\n", args_info.timelimit_arg);
}
/* Handle each option */
/* foreground */
/* If flag not given run as a daemon */
if (!args_info.fg_flag)
{
closelog();
/* Close the standard file descriptors. */
/* Is this really needed ? */
freopen("/dev/null", "w", stdout);
freopen("/dev/null", "w", stderr);
freopen("/dev/null", "r", stdin);
daemon(0, 0);
/* Open log again. This time with new pid */
openlog(PACKAGE, LOG_PID, LOG_DAEMON);
}
/* debug */
debug = args_info.debug_flag;
/* pidfile */
/* This has to be done after we have our final pid */
if (args_info.pidfile_arg) {
log_pid(args_info.pidfile_arg);
}
/* listen */
/* If no listen option is specified listen to any local port */
/* Do hostname lookup to translate hostname to IP address */
if (args_info.listen_arg) {
if (!(host = gethostbyname(args_info.listen_arg))) {
fprintf(stderr, "%s: Invalid listening address: %s!\n",
PACKAGE, args_info.listen_arg);
syslog(LOG_ERR, "Invalid listening address: %s!",
args_info.listen_arg);
return 1;
}
else {
memcpy(&listen.s_addr, host->h_addr, host->h_length);
}
}
else {
listen.s_addr = htonl(INADDR_ANY);
}
/* net */
/* Store net as in_addr */
if (args_info.net_arg) {
if (!inet_aton(args_info.net_arg, &net)) {
fprintf(stderr, "%s: Invalid network address: %s!\n",
PACKAGE, args_info.net_arg);
syslog(LOG_ERR, "Invalid network address: %s!",
args_info.net_arg);
return 1;
}
}
/* mask */
/* Store mask as in_addr */
if (args_info.mask_arg) {
if (!inet_aton(args_info.mask_arg, &mask)) {
fprintf(stderr, "%s: Invalid network mask: %s!\n",
PACKAGE, args_info.mask_arg);
syslog(LOG_ERR, "Invalid network mask: %s!",
args_info.mask_arg);
return 1;
}
}
/* Timelimit */
timelimit = args_info.timelimit_arg;
starttime = time(NULL);
/* qos */
qos.l = 3;
qos.v = qosh;
qos.v[2] = (args_info.qos_arg) & 0xff;
qos.v[1] = ((args_info.qos_arg) >> 8) & 0xff;
qos.v[0] = ((args_info.qos_arg) >> 16) & 0xff;
/* apn */
if (strlen(args_info.apn_arg)>255) {
printf("invalid APN\n");
exit(1);
}
apn.l = strlen(args_info.apn_arg) + 1;
apn.v = apnh;
apn.v[0] = (char) strlen(args_info.apn_arg);
strncpy(&apn.v[1], args_info.apn_arg, 255);
if (debug) printf("gtpclient: Initialising GTP tunnel\n");
if ((gtpfd = gtp_new(&gsn, args_info.statedir_arg, &listen)) > maxfd)
maxfd = gtpfd;
if ((gtpfd = gtp_fd(gsn)) > maxfd)
maxfd = gtpfd;
gtp_set_cb_gpdu(gsn, encaps_tun);
gtp_set_cb_delete_context(gsn, delete_context);
gtp_set_cb_create_context(gsn, create_context);
create_tun();
/******************************************************************/
/* Main select loop */
/******************************************************************/
while (((starttime + timelimit) > time(NULL)) || (0 == timelimit)) {
FD_ZERO(&fds);
if (tun_fd != -1) FD_SET(tun_fd, &fds);
if (gtpfd != -1) FD_SET(gtpfd, &fds);
gtp_retranstimeout(gsn, &idleTime);
switch (select(maxfd + 1, &fds, NULL, NULL, &idleTime)) {
case -1: /* Error with select() *
if (errno != EINTR)
syslog(LOG_ERR, "CTRL: Error with select(), quitting");
*goto leave_clear_call;*/
syslog(LOG_ERR, "GGSN: select = -1");
break;
case 0:
gtp_retrans(gsn); /* Only retransmit if nothing else */
break;
default:
break;
}
if (tun_fd != -1 && FD_ISSET(tun_fd, &fds) &&
tun_decaps(tun, encaps_gtp, gsn) < 0) {
syslog(LOG_ERR, "TUN read failed (fd)=(%d)", tun_fd);
}
if (gtpfd != -1 && FD_ISSET(gtpfd, &fds) &&
gtp_decaps(gsn) < 0) {
syslog(LOG_ERR, "GTP read failed (gre)=(%d)", gtpfd);
}
}
gtp_free(gsn);
return 1;
}
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