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Diffstat (limited to 'ggsn/ggsn.c')
| -rw-r--r-- | ggsn/ggsn.c | 424 |
1 files changed, 424 insertions, 0 deletions
diff --git a/ggsn/ggsn.c b/ggsn/ggsn.c new file mode 100644 index 0000000..a850de8 --- /dev/null +++ b/ggsn/ggsn.c @@ -0,0 +1,424 @@ +/* + * 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; + +} + |