diff options
author | Jonathan Santos <jrsantos@jonathanrsantos.com> | 2011-05-25 13:54:02 -0400 |
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committer | Jonathan Santos <jrsantos@jonathanrsantos.com> | 2011-05-25 13:54:02 -0400 |
commit | 03fd8d014f9871896a86534432c8757d65a576fe (patch) | |
tree | bad087cacfb6b106f6ca542bf92ef2e2ecea5dd3 /src/osmo-bsc_nat/bsc_ussd.c | |
parent | e7dae79f5839029279c9fd4543804882c019bf42 (diff) |
Import upstream version 0.9.13upstream/0.9.13
Diffstat (limited to 'src/osmo-bsc_nat/bsc_ussd.c')
-rw-r--r-- | src/osmo-bsc_nat/bsc_ussd.c | 363 |
1 files changed, 363 insertions, 0 deletions
diff --git a/src/osmo-bsc_nat/bsc_ussd.c b/src/osmo-bsc_nat/bsc_ussd.c new file mode 100644 index 000000000..c121abe5d --- /dev/null +++ b/src/osmo-bsc_nat/bsc_ussd.c @@ -0,0 +1,363 @@ +/* USSD Filter Code */ + +/* + * (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org> + * (C) 2010 by On-Waves + * All Rights Reserved + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation; either version 3 of the License, or + * (at your option) any later version. + * + * This program 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 Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + */ + +#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 <osmocom/sccp/sccp.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) { + bsc_close_ussd_connections(con->nat); + 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 forward_sccp(struct bsc_nat *nat, struct msgb *msg) +{ + struct sccp_connections *con; + struct bsc_nat_parsed *parsed; + + + parsed = bsc_nat_parse(msg); + if (!parsed) { + LOGP(DNAT, LOGL_ERROR, "Can not parse msg from USSD.\n"); + msgb_free(msg); + return -1; + } + + if (!parsed->dest_local_ref) { + LOGP(DNAT, LOGL_ERROR, "No destination local reference.\n"); + msgb_free(msg); + return -1; + } + + con = bsc_nat_find_con_by_bsc(nat, parsed->dest_local_ref); + if (!con || !con->bsc) { + LOGP(DNAT, LOGL_ERROR, "No active connection found.\n"); + msgb_free(msg); + return -1; + } + + talloc_free(parsed); + bsc_write_msg(&con->bsc->write_queue, msg); + return 0; +} + +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) { + 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); +} + +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); +} + +static int forward_ussd(struct sccp_connections *con, const struct ussd_request *req, + struct msgb *input) +{ + struct msgb *msg, *copy; + struct ipac_msgt_sccp_state *state; + struct bsc_nat_ussd_con *ussd; + + if (!con->bsc->nat->ussd_con) + return -1; + + msg = msgb_alloc_headroom(4096, 128, "forward ussd"); + if (!msg) { + LOGP(DNAT, LOGL_ERROR, "Allocation failed, not forwarding.\n"); + return -1; + } + + copy = msgb_alloc_headroom(4096, 128, "forward bts"); + if (!copy) { + LOGP(DNAT, LOGL_ERROR, "Allocation failed, not forwarding.\n"); + msgb_free(msg); + return -1; + } + + copy->l2h = msgb_put(copy, msgb_l2len(input)); + memcpy(copy->l2h, input->l2h, msgb_l2len(input)); + + msg->l2h = msgb_put(msg, 1); + msg->l2h[0] = IPAC_MSGT_SCCP_OLD; + + /* fill out the data */ + state = (struct ipac_msgt_sccp_state *) msgb_put(msg, sizeof(*state)); + state->trans_id = req->transaction_id; + state->invoke_id = req->invoke_id; + memcpy(&state->src_ref, &con->remote_ref, sizeof(con->remote_ref)); + memcpy(&state->dst_ref, &con->real_ref, sizeof(con->real_ref)); + memcpy(state->imsi, con->imsi, strlen(con->imsi)); + + ussd = con->bsc->nat->ussd_con; + bsc_do_write(&ussd->queue, msg, IPAC_PROTO_IPACCESS); + bsc_do_write(&ussd->queue, copy, IPAC_PROTO_SCCP); + + return 0; +} + +int bsc_check_ussd(struct sccp_connections *con, struct bsc_nat_parsed *parsed, + struct msgb *msg) +{ + uint32_t len; + uint8_t msg_type; + struct gsm48_hdr *hdr48; + struct bsc_nat_acc_lst *lst; + struct ussd_request req; + + /* + * various checks to avoid the decoding work. Right now we only want to + * decode if the connection was created for USSD, we do have a USSD access + * list, a query, a IMSI and such... + */ + if (con->con_type != NAT_CON_TYPE_SSA) + return 0; + + if (!con->imsi) + return 0; + + if (!con->bsc->nat->ussd_lst_name) + return 0; + if (!con->bsc->nat->ussd_query) + return 0; + + if (parsed->bssap != BSSAP_MSG_DTAP) + return 0; + + if (strlen(con->imsi) > GSM_IMSI_LENGTH) + return 0; + + hdr48 = bsc_unpack_dtap(parsed, msg, &len); + if (!hdr48) + return 0; + + msg_type = hdr48->msg_type & 0xbf; + if (hdr48->proto_discr != GSM48_PDISC_NC_SS || msg_type != GSM0480_MTYPE_REGISTER) + return 0; + + /* now check if it is a IMSI we care about */ + lst = bsc_nat_acc_lst_find(con->bsc->nat, con->bsc->nat->ussd_lst_name); + if (!lst) + return 0; + + if (bsc_nat_lst_check_allow(lst, con->imsi) != 0) + return 0; + + /* now decode the message and see if we really want to handle it */ + memset(&req, 0, sizeof(req)); + if (gsm0480_decode_ussd_request(hdr48, len, &req) != 1) + return 0; + if (req.text[0] == 0xff) + return 0; + + if (strcmp(req.text, con->bsc->nat->ussd_query) != 0) + return 0; + + /* found a USSD query for our subscriber */ + LOGP(DNAT, LOGL_NOTICE, "Found USSD query for %s\n", con->imsi); + if (forward_ussd(con, &req, msg) != 0) + return 0; + return 1; +} |