nat: Implement accepting a USSD Provider connection, do authentication

This commit is contained in:
Holger Hans Peter Freyther 2010-10-13 20:22:36 +02:00
parent 64b12924bf
commit c16c2dc5d3
4 changed files with 205 additions and 1 deletions

View File

@ -43,6 +43,7 @@ struct sccp_source_reference;
struct sccp_connections;
struct bsc_nat_parsed;
struct bsc_nat;
struct bsc_nat_ussd_con;
enum {
NAT_CON_TYPE_NONE,
@ -165,6 +166,10 @@ struct bsc_nat_statistics {
struct {
struct counter *reconn;
} msc;
struct {
struct counter *reconn;
} ussd;
};
enum bsc_nat_acc_ctr {
@ -237,6 +242,8 @@ struct bsc_nat {
char *ussd_query;
char *ussd_token;
char *ussd_local;
struct bsc_fd ussd_listen;
struct bsc_nat_ussd_con *ussd_con;
/* statistics */
struct bsc_nat_statistics stats;
@ -328,6 +335,7 @@ int bsc_conn_type_to_ctr(struct sccp_connections *conn);
struct gsm48_hdr *bsc_unpack_dtap(struct bsc_nat_parsed *parsed, struct msgb *msg, uint32_t *len);
/** USSD filtering */
int bsc_ussd_init(struct bsc_nat *nat);
int bsc_check_ussd(struct sccp_connections *con, struct bsc_nat_parsed *parsed, struct msgb *msg);
#endif

View File

@ -1279,6 +1279,12 @@ int main(int argc, char **argv)
exit(1);
}
rc = bsc_ussd_init(nat);
if (rc != 0) {
LOGP(DNAT, LOGL_ERROR, "Failed to bind the USSD socket.\n");
exit(1);
}
signal(SIGABRT, &signal_handler);
signal(SIGUSR1, &signal_handler);
signal(SIGPIPE, SIG_IGN);

View File

@ -93,6 +93,7 @@ struct bsc_nat *bsc_nat_alloc(void)
nat->stats.bsc.reconn = counter_alloc("nat.bsc.conn");
nat->stats.bsc.auth_fail = counter_alloc("nat.bsc.auth_fail");
nat->stats.msc.reconn = counter_alloc("nat.msc.conn");
nat->stats.ussd.reconn = counter_alloc("nat.ussd.conn");
nat->msc_ip = talloc_strdup(nat, "127.0.0.1");
nat->msc_port = 5000;
nat->auth_timeout = 2;

View File

@ -23,13 +23,202 @@
#include <openbsc/bsc_nat.h>
#include <openbsc/bsc_nat_sccp.h>
#include <openbsc/ipaccess.h>
#include <openbsc/socket.h>
#include <osmocore/protocol/gsm_08_08.h>
#include <osmocore/gsm0480.h>
#include <osmocore/talloc.h>
#include <osmocore/tlv.h>
#include <sys/socket.h>
#include <string.h>
#include <unistd.h>
struct bsc_nat_ussd_con {
struct write_queue queue;
struct bsc_nat *nat;
int authorized;
struct timer_list auth_timeout;
};
static void ussd_auth_con(struct tlv_parsed *, struct bsc_nat_ussd_con *);
static struct bsc_nat_ussd_con *bsc_nat_ussd_alloc(struct bsc_nat *nat)
{
struct bsc_nat_ussd_con *con;
con = talloc_zero(nat, struct bsc_nat_ussd_con);
if (!con)
return NULL;
con->nat = nat;
return con;
}
static void bsc_nat_ussd_destroy(struct bsc_nat_ussd_con *con)
{
if (con->nat->ussd_con == con)
con->nat->ussd_con = NULL;
close(con->queue.bfd.fd);
bsc_unregister_fd(&con->queue.bfd);
bsc_del_timer(&con->auth_timeout);
write_queue_clear(&con->queue);
talloc_free(con);
}
static int ussd_read_cb(struct bsc_fd *bfd)
{
int error;
struct bsc_nat_ussd_con *conn = bfd->data;
struct msgb *msg = ipaccess_read_msg(bfd, &error);
struct ipaccess_head *hh;
if (!msg) {
LOGP(DNAT, LOGL_ERROR, "USSD Connection was lost.\n");
bsc_nat_ussd_destroy(conn);
return -1;
}
LOGP(DNAT, LOGL_NOTICE, "MSG from USSD: %s proto: %d\n",
hexdump(msg->data, msg->len), msg->l2h[0]);
hh = (struct ipaccess_head *) msg->data;
if (hh->proto == IPAC_PROTO_IPACCESS) {
if (msg->l2h[0] == IPAC_MSGT_ID_RESP) {
struct tlv_parsed tvp;
ipaccess_idtag_parse(&tvp,
(unsigned char *) msg->l2h + 2,
msgb_l2len(msg) - 2);
if (TLVP_PRESENT(&tvp, IPAC_IDTAG_UNITNAME))
ussd_auth_con(&tvp, conn);
}
msgb_free(msg);
} else if (hh->proto == IPAC_PROTO_SCCP) {
LOGP(DNAT, LOGL_ERROR, "USSD SCCP is not handled\n");
msgb_free(msg);
} else {
msgb_free(msg);
}
return 0;
}
static void ussd_auth_cb(void *_data)
{
LOGP(DNAT, LOGL_ERROR, "USSD module didn't authenticate\n");
bsc_nat_ussd_destroy((struct bsc_nat_ussd_con *) _data);
}
static void ussd_auth_con(struct tlv_parsed *tvp, struct bsc_nat_ussd_con *conn)
{
const char *token;
int len;
if (!conn->nat->ussd_token) {
LOGP(DNAT, LOGL_ERROR, "No USSD token set. Closing\n");
bsc_nat_ussd_destroy(conn);
return;
}
token = (const char *) TLVP_VAL(tvp, IPAC_IDTAG_UNITNAME);
len = TLVP_LEN(tvp, IPAC_IDTAG_UNITNAME);
if (strncmp(conn->nat->ussd_token, token, len) != 0) {
LOGP(DNAT, LOGL_ERROR, "Wrong USSD token by client: %d\n",
conn->queue.bfd.fd);
bsc_nat_ussd_destroy(conn);
return;
}
/* it is authenticated now */
if (conn->nat->ussd_con && conn->nat->ussd_con != conn)
bsc_nat_ussd_destroy(conn->nat->ussd_con);
LOGP(DNAT, LOGL_ERROR, "USSD token specified. USSD provider is connected.\n");
bsc_del_timer(&conn->auth_timeout);
conn->authorized = 1;
conn->nat->ussd_con = conn;
}
static void ussd_start_auth(struct bsc_nat_ussd_con *conn)
{
struct msgb *msg;
conn->auth_timeout.data = conn;
conn->auth_timeout.cb = ussd_auth_cb;
bsc_schedule_timer(&conn->auth_timeout, conn->nat->auth_timeout, 0);
msg = msgb_alloc_headroom(4096, 128, "auth message");
if (!msg) {
LOGP(DNAT, LOGL_ERROR, "Failed to allocate auth msg\n");
return;
}
msgb_v_put(msg, IPAC_MSGT_ID_GET);
bsc_do_write(&conn->queue, msg, IPAC_PROTO_IPACCESS);
}
static int ussd_listen_cb(struct bsc_fd *bfd, unsigned int what)
{
struct bsc_nat_ussd_con *conn;
struct bsc_nat *nat;
struct sockaddr_in sa;
socklen_t sa_len = sizeof(sa);
int fd;
if (!(what & BSC_FD_READ))
return 0;
fd = accept(bfd->fd, (struct sockaddr *) &sa, &sa_len);
if (fd < 0) {
perror("accept");
return fd;
}
nat = (struct bsc_nat *) bfd->data;
counter_inc(nat->stats.ussd.reconn);
conn = bsc_nat_ussd_alloc(nat);
if (!conn) {
LOGP(DNAT, LOGL_ERROR, "Failed to allocate USSD con struct.\n");
close(fd);
return -1;
}
write_queue_init(&conn->queue, 10);
conn->queue.bfd.data = conn;
conn->queue.bfd.fd = fd;
conn->queue.bfd.when = BSC_FD_READ;
conn->queue.read_cb = ussd_read_cb;
conn->queue.write_cb = bsc_write_cb;
if (bsc_register_fd(&conn->queue.bfd) < 0) {
LOGP(DNAT, LOGL_ERROR, "Failed to register USSD fd.\n");
bsc_nat_ussd_destroy(conn);
return -1;
}
LOGP(DNAT, LOGL_NOTICE, "USSD Connection on %d with IP: %s\n",
fd, inet_ntoa(sa.sin_addr));
/* do authentication */
ussd_start_auth(conn);
return 0;
}
int bsc_ussd_init(struct bsc_nat *nat)
{
struct in_addr addr;
addr.s_addr = INADDR_ANY;
if (nat->ussd_local)
inet_aton(nat->ussd_local, &addr);
nat->ussd_listen.data = nat;
return make_sock(&nat->ussd_listen, IPPROTO_TCP,
ntohl(addr.s_addr), 5001, ussd_listen_cb);
}
int bsc_check_ussd(struct sccp_connections *con, struct bsc_nat_parsed *parsed,
struct msgb *msg)