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");
osmo_timer_del(&conn->auth_timeout);
conn->authorized = 1;
conn->nat->ussd_con = conn;
}
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);
/* last byte should be a NULL */
if (strlen(conn->nat->ussd_token) != len - 1)
goto disconnect;
/* compare everything including the null byte */
if (memcmp(conn->nat->ussd_token, token, len) != 0)
goto disconnect;
/* 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");
osmo_timer_del(&conn->auth_timeout);
conn->authorized = 1;
conn->nat->ussd_con = conn;
return;
disconnect:
LOGP(DNAT, LOGL_ERROR, "Wrong USSD token by client: %d\n",
conn->queue.bfd.fd);
bsc_nat_ussd_destroy(conn);
}
static int ussd_read_cb(struct osmo_fd *bfd)
{
struct bsc_nat_ussd_con *conn = bfd->data;
struct msgb *msg = NULL;
struct ipaccess_head *hh;
int ret;
ret = ipa_msg_recv_buffered(bfd->fd, &msg, &conn->pending_msg);
if (ret <= 0) {
if (ret == -EAGAIN)
return 0;
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",
osmo_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;
int ret;
ret = ipa_ccm_idtag_parse(&tvp,
(unsigned char *) msg->l2h + 2,
msgb_l2len(msg) - 2);
if (ret < 0) {
LOGP(DNAT, LOGL_ERROR, "ignoring IPA response "
"message with malformed TLVs\n");
msgb_free(msg);
return ret;
}
if (TLVP_PRESENT(&tvp, IPAC_IDTAG_UNITNAME))
ussd_auth_con(&tvp, conn);
} else if (msg->l2h[0] == IPAC_MSGT_PING) {
LOGP(DNAT, LOGL_DEBUG, "Got USSD ping request.\n");
ussd_pong(conn);
} else {
LOGP(DNAT, LOGL_NOTICE, "Got unknown IPACCESS message 0x%02x.\n", msg->l2h[0]);
}
msgb_free(msg);
} else if (hh->proto == IPAC_PROTO_SCCP) {
forward_sccp(conn->nat, msg);
} else {
msgb_free(msg);
}
return 0;
}
static int ussd_listen_cb(struct osmo_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;
osmo_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;
}
osmo_wqueue_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 (osmo_fd_register(&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;
}
static int ussd_read_cb(struct osmo_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",
osmo_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;
int ret;
ret = ipaccess_idtag_parse(&tvp,
(unsigned char *) msg->l2h + 2,
msgb_l2len(msg) - 2);
if (ret < 0) {
LOGP(DNAT, LOGL_ERROR, "ignoring IPA response "
"message with malformed TLVs\n");
return ret;
}
if (TLVP_PRESENT(&tvp, IPAC_IDTAG_UNITNAME))
ussd_auth_con(&tvp, conn);
}
msgb_free(msg);
} else if (hh->proto == IPAC_PROTO_SCCP) {
forward_sccp(conn->nat, 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);
}
