osmith has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-bsc-nat/+/27476 )
Change subject: Support forwarding messages with multiple BSCs ......................................................................
Support forwarding messages with multiple BSCs
Implement a proper connection mapping (conn) per subscriber. Create a new conn when one of the stored BSCs sends a conn.ind and use that conn for all related connection-oriented messages with the same RAN-side conn_id to send messages back and forth between BSC and MSC.
Add bsc_nat_conn_get_next_id based on OsmoBSC's bsc_sccp_inst_next_conn_id.
With this patch, it's possible to do a successful Location Updating procedure between MS2 and MSC in the following network:
MS1 --- BTS1 --- BSC1 --. BSCNAT --- MSC MS2 --- BTS2 --- BSC2 --'
Related: SYS#5560 Change-Id: I1556aa665fbb0a97507f98794e74820731fa6935 --- M doc/examples/osmo-bsc-nat/osmo-bsc-nat.cfg M include/osmocom/bsc_nat/bsc_nat.h M src/osmo-bsc-nat/bsc_nat.c M src/osmo-bsc-nat/bsc_nat_fsm.c 4 files changed, 194 insertions(+), 85 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-bsc-nat refs/changes/76/27476/1
diff --git a/doc/examples/osmo-bsc-nat/osmo-bsc-nat.cfg b/doc/examples/osmo-bsc-nat/osmo-bsc-nat.cfg index f56dcb0..2f5ff39 100644 --- a/doc/examples/osmo-bsc-nat/osmo-bsc-nat.cfg +++ b/doc/examples/osmo-bsc-nat/osmo-bsc-nat.cfg @@ -13,10 +13,6 @@ asp asp-clnt-OsmoBSCNAT-RAN 2905 0 m3ua remote-ip 127.0.0.2 local-ip 127.0.0.4 - sccp-address bsc - routing-indicator PC - point-code 0.23.3 - subsystem-number 254
bsc-nat cs7-instance-cn 0 diff --git a/include/osmocom/bsc_nat/bsc_nat.h b/include/osmocom/bsc_nat/bsc_nat.h index 0807d83..0f2fc3a 100644 --- a/include/osmocom/bsc_nat/bsc_nat.h +++ b/include/osmocom/bsc_nat/bsc_nat.h @@ -21,6 +21,11 @@ #include <osmocom/core/fsm.h> #include <osmocom/sigtran/sccp_sap.h>
+enum bsc_nat_net { + BSC_NAT_CN = 0, + BSC_NAT_RAN +}; + struct bsc_nat_sccp_inst { uint32_t ss7_id; struct osmo_ss7_instance *ss7_inst; @@ -40,6 +45,16 @@ struct osmo_sccp_addr addr; };
+/* connection for one subscriber */ +struct conn { + struct llist_head list; + + struct msc *msc; + struct bsc *bsc; + + uint32_t id[2]; /* conn_id for CN, RAN */ +}; + struct bsc_nat { struct osmo_fsm_inst *fi;
@@ -48,6 +63,9 @@
struct llist_head mscs; /* list of struct msc */ struct llist_head bscs; /* list of struct bsc */ + struct llist_head conns; /* list of struct conn */ + + uint32_t conn_id_next[2]; /* for CN, RAN */ };
struct bsc_nat *bsc_nat_alloc(void *tall_ctx); @@ -62,6 +80,12 @@ struct bsc *bsc_nat_bsc_get_by_pc(struct bsc_nat *bsc_nat, uint32_t pointcode); void bsc_nat_bsc_del(struct bsc_nat *bsc_nat, struct bsc *bsc);
+struct conn *bsc_nat_conn_add(struct bsc_nat *bsc_nat, struct msc *msc, struct bsc *bsc, uint32_t conn_id_cn, + uint32_t conn_id_ran); +struct conn *bsc_nat_conn_get_by_id(struct bsc_nat *bsc_nat, uint32_t conn_id, enum bsc_nat_net net); +int bsc_nat_conn_get_next_id(struct bsc_nat *bsc_nat, enum bsc_nat_net net); +void bsc_nat_conn_del(struct conn *conn); + const char *bsc_nat_print_addr(struct bsc_nat_sccp_inst *sccp_inst, struct osmo_sccp_addr *addr);
extern void *tall_bsc_nat_ctx; diff --git a/src/osmo-bsc-nat/bsc_nat.c b/src/osmo-bsc-nat/bsc_nat.c index 0a42c96..0d57421 100644 --- a/src/osmo-bsc-nat/bsc_nat.c +++ b/src/osmo-bsc-nat/bsc_nat.c @@ -18,6 +18,7 @@ */
#include "config.h" +#include <inttypes.h> #include <osmocom/bsc_nat/bsc_nat.h> #include <osmocom/bsc_nat/bsc_nat_fsm.h> #include <osmocom/bsc_nat/logging.h> @@ -42,12 +43,97 @@
INIT_LLIST_HEAD(&bsc_nat->mscs); INIT_LLIST_HEAD(&bsc_nat->bscs); + INIT_LLIST_HEAD(&bsc_nat->conns);
bsc_nat_fsm_alloc(bsc_nat);
return bsc_nat; }
+/* Get the next available conn_id in either CN or RAN. */ +int bsc_nat_conn_get_next_id(struct bsc_nat *bsc_nat, enum bsc_nat_net net) +{ + for (int i = 0; i < 0xFFFFFF; i++) { + struct conn *conn; + uint32_t conn_id = bsc_nat->conn_id_next[net]; + bool already_used = false; + bsc_nat->conn_id_next[net] = (conn_id + 1) & 0xffffff; + + llist_for_each_entry(conn, &bsc_nat->conns, list) { + if (conn->id[net] == conn_id) { + already_used = true; + break; + } + } + + if (!already_used) + return conn_id; + } + return -1; +} + +struct conn *bsc_nat_conn_add(struct bsc_nat *bsc_nat, struct msc *msc, struct bsc *bsc, uint32_t conn_id_cn, + uint32_t conn_id_ran) +{ + struct conn *conn = talloc_zero(bsc_nat, struct conn); + + OSMO_ASSERT(conn); + talloc_set_name(conn, "CONN %s:%" PRIu32 " <=> %s:%" PRIu32, + talloc_get_name(msc), conn_id_cn, + talloc_get_name(bsc), conn_id_ran); + + LOGP(DMAIN, LOGL_DEBUG, "Add %s\n", talloc_get_name(conn)); + + conn->msc = msc; + conn->bsc = bsc; + conn->id[BSC_NAT_CN] = conn_id_cn; + conn->id[BSC_NAT_RAN] = conn_id_ran; + + INIT_LLIST_HEAD(&conn->list); + llist_add(&conn->list, &bsc_nat->conns); + + return conn; +} + +struct conn *bsc_nat_conn_get_by_id(struct bsc_nat *bsc_nat, uint32_t conn_id, enum bsc_nat_net net) +{ + struct conn *conn; + + llist_for_each_entry(conn, &bsc_nat->conns, list) { + if (conn->id[net] == conn_id) + return conn; + } + + return NULL; +} + +void bsc_nat_conn_del(struct conn *conn) +{ + LOGP(DMAIN, LOGL_DEBUG, "Del %s\n", talloc_get_name(conn)); + llist_del(&conn->list); + talloc_free(conn); +} + +static void conn_del_by_bsc(struct bsc_nat *bsc_nat, struct bsc *bsc) +{ + struct conn *conn; + + llist_for_each_entry(conn, &bsc_nat->conns, list) { + if (conn->bsc == bsc) + bsc_nat_conn_del(conn); + } +} + +static void conn_del_by_msc(struct bsc_nat *bsc_nat, struct msc *msc) +{ + struct conn *conn; + + llist_for_each_entry(conn, &bsc_nat->conns, list) { + if (conn->msc == msc) + bsc_nat_conn_del(conn); + } +} + struct msc *bsc_nat_msc_add(struct bsc_nat *bsc_nat, struct osmo_sccp_addr *addr) { struct msc *msc = talloc_zero(bsc_nat, struct msc); @@ -94,6 +180,7 @@ void bsc_nat_msc_del(struct bsc_nat *bsc_nat, struct msc *msc) { LOGP(DMAIN, LOGL_DEBUG, "Del %s\n", talloc_get_name(msc)); + conn_del_by_msc(bsc_nat, msc); llist_del(&msc->list); osmo_fsm_inst_free(msc->fi); talloc_free(msc); @@ -131,6 +218,7 @@ void bsc_nat_bsc_del(struct bsc_nat *bsc_nat, struct bsc *bsc) { LOGP(DMAIN, LOGL_DEBUG, "Del %s\n", talloc_get_name(bsc)); + conn_del_by_bsc(bsc_nat, bsc); llist_del(&bsc->list); talloc_free(bsc); } @@ -139,12 +227,17 @@ { struct msc *msc; struct bsc *bsc; + struct conn *conn;
if (bsc_nat->fi) { osmo_fsm_inst_free(bsc_nat->fi); bsc_nat->fi = NULL; }
+ llist_for_each_entry(conn, &bsc_nat->conns, list) { + bsc_nat_conn_del(conn); + } + llist_for_each_entry(msc, &bsc_nat->mscs, list) { bsc_nat_msc_del(bsc_nat, msc); } diff --git a/src/osmo-bsc-nat/bsc_nat_fsm.c b/src/osmo-bsc-nat/bsc_nat_fsm.c index cea32db..303f3ef 100644 --- a/src/osmo-bsc-nat/bsc_nat_fsm.c +++ b/src/osmo-bsc-nat/bsc_nat_fsm.c @@ -19,6 +19,7 @@
#include "config.h" #include <errno.h> +#include <inttypes.h> #include <osmocom/bsc_nat/bsc_nat.h> #include <osmocom/bsc_nat/bsc_nat_fsm.h> #include <osmocom/bsc_nat/bssap.h> @@ -47,13 +48,6 @@ BSC_NAT_FSM_EV_STOP, };
-static struct bsc_nat_sccp_inst *sccp_inst_dest(struct bsc_nat_sccp_inst *src) -{ - if (src == g_bsc_nat->cn) - return g_bsc_nat->ran; - return g_bsc_nat->cn; -} - /* For connection-oriented messages, figure out which side is not the BSCNAT, * either the called_addr or calling_addr. */ static int sccp_sap_get_peer_addr_in(struct bsc_nat_sccp_inst *src, struct osmo_sccp_addr **peer_addr_in, @@ -79,37 +73,13 @@ return -1; }
-/* Figure out who will receive the message. - * For now this is simplified by assuming there is only one MSC, one BSC. */ -static int sccp_sap_get_peer_addr_out(struct bsc_nat_sccp_inst *src, struct osmo_sccp_addr *peer_addr_in, - struct osmo_sccp_addr *peer_addr_out) -{ - struct bsc_nat_sccp_inst *dest = sccp_inst_dest(src); - - if (src == g_bsc_nat->ran) { - if (osmo_sccp_addr_by_name_local(peer_addr_out, "msc", dest->ss7_inst) < 0) { - LOGP(DMAIN, LOGL_ERROR, "Could not find MSC in address book\n"); - return -1; - } - } else { - if (osmo_sccp_addr_by_name_local(peer_addr_out, "bsc", dest->ss7_inst) < 0) { - LOGP(DMAIN, LOGL_ERROR, "Could not find BSC in address book\n"); - return -2; - } - } - - return 0; -} - -/* Handle incoming messages from CN (MSC). For now this is simplified by - * assuming there is only one MSC, one BSC (not yet translating connection ids - * etc.). */ +/* Handle incoming messages from CN (MSC) */ static int sccp_sap_up_cn(struct osmo_prim_hdr *oph, void *scu) { struct bsc_nat_sccp_inst *sccp_inst = osmo_sccp_user_get_priv(scu); struct osmo_scu_prim *prim = (struct osmo_scu_prim *) oph; struct osmo_sccp_addr *addr; /* MSC's address */ - struct osmo_sccp_addr peer_addr_out; + struct conn *conn; int rc = -1;
LOGP(DMAIN, LOGL_DEBUG, "Rx %s from CN\n", osmo_scu_prim_name(oph)); @@ -117,23 +87,9 @@ switch (OSMO_PRIM_HDR(oph)) { case OSMO_PRIM(OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_INDICATION): /* indication of new inbound connection request */ - if (sccp_sap_get_peer_addr_in(sccp_inst, &addr, &prim->u.connect.called_addr, - &prim->u.connect.calling_addr) < 0) - goto error; - - if (sccp_sap_get_peer_addr_out(sccp_inst, addr, &peer_addr_out) < 0) - goto error; - - LOGP(DMAIN, LOGL_DEBUG, "Fwd to %s\n", bsc_nat_print_addr(g_bsc_nat->ran, &peer_addr_out)); - - msgb_pull_to_l2(oph->msg); - osmo_sccp_tx_conn_req(g_bsc_nat->ran->scu, - prim->u.connect.conn_id, - &g_bsc_nat->ran->addr, - &peer_addr_out, - oph->msg->data, - msgb_length(oph->msg)); - rc = 0; + /* FIXME: MSC has sent a message without conn_id, figure out to + * which BSC to forward this. */ + LOGP(DMAIN, LOGL_ERROR, "%s(%s) is not implemented!\n", __func__, osmo_scu_prim_name(oph)); break;
case OSMO_PRIM(OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_CONFIRM): @@ -142,15 +98,19 @@ &prim->u.connect.calling_addr) < 0) goto error;
- if (sccp_sap_get_peer_addr_out(sccp_inst, addr, &peer_addr_out) < 0) + conn = bsc_nat_conn_get_by_id(g_bsc_nat, prim->u.connect.conn_id, BSC_NAT_CN); + if (!conn) { + LOGP(DMAIN, LOGL_ERROR, "Unknown conn_id=%" PRIu32 " from %s\n", prim->u.connect.conn_id, + bsc_nat_print_addr(sccp_inst, addr)); goto error; + }
- LOGP(DMAIN, LOGL_DEBUG, "Fwd to %s\n", bsc_nat_print_addr(g_bsc_nat->ran, &peer_addr_out)); + LOGP(DMAIN, LOGL_DEBUG, "Fwd via %s\n", talloc_get_name(conn));
msgb_pull_to_l2(oph->msg); osmo_sccp_tx_conn_resp(g_bsc_nat->ran->scu, - prim->u.connect.conn_id, - &peer_addr_out, + conn->id[BSC_NAT_RAN], + &conn->bsc->addr, oph->msg->data, msgb_length(oph->msg)); rc = 0; @@ -158,14 +118,18 @@
case OSMO_PRIM(OSMO_SCU_PRIM_N_DATA, PRIM_OP_INDICATION): /* connection-oriented data received */ - if (sccp_sap_get_peer_addr_out(sccp_inst, NULL, &peer_addr_out) < 0) + conn = bsc_nat_conn_get_by_id(g_bsc_nat, prim->u.data.conn_id, BSC_NAT_CN); + if (!conn) { + LOGP(DMAIN, LOGL_ERROR, "Unknown conn_id=%" PRIu32 " from %s\n", prim->u.data.conn_id, + bsc_nat_print_addr(sccp_inst, addr)); goto error; + }
- LOGP(DMAIN, LOGL_DEBUG, "Fwd to %s\n", bsc_nat_print_addr(g_bsc_nat->ran, &peer_addr_out)); + LOGP(DMAIN, LOGL_DEBUG, "Fwd via %s\n", talloc_get_name(conn));
msgb_pull_to_l2(oph->msg); osmo_sccp_tx_data(g_bsc_nat->ran->scu, - prim->u.data.conn_id, + conn->id[BSC_NAT_RAN], oph->msg->data, msgb_length(oph->msg)); rc = 0; @@ -173,15 +137,22 @@
case OSMO_PRIM(OSMO_SCU_PRIM_N_DISCONNECT, PRIM_OP_INDICATION): /* indication of disconnect */ - if (sccp_sap_get_peer_addr_out(sccp_inst, NULL, &peer_addr_out) < 0) + conn = bsc_nat_conn_get_by_id(g_bsc_nat, prim->u.disconnect.conn_id, BSC_NAT_CN); + if (!conn) { + LOGP(DMAIN, LOGL_ERROR, "Unknown conn_id=%" PRIu32 " from %s\n", prim->u.disconnect.conn_id, + bsc_nat_print_addr(sccp_inst, addr)); goto error; + }
- LOGP(DMAIN, LOGL_DEBUG, "Fwd to %s\n", bsc_nat_print_addr(g_bsc_nat->ran, &peer_addr_out)); + LOGP(DMAIN, LOGL_DEBUG, "Fwd via %s\n", talloc_get_name(conn));
osmo_sccp_tx_disconn(g_bsc_nat->ran->scu, - prim->u.disconnect.conn_id, - &prim->u.disconnect.responding_addr, + conn->id[BSC_NAT_RAN], + &g_bsc_nat->ran->addr, prim->u.disconnect.cause); + + bsc_nat_conn_del(conn); + rc = 0; break;
@@ -200,16 +171,15 @@ return rc; }
-/* Handle incoming messages from RAN (BSC). For now this is simplified by - * assuming there is only one MSC, one BSC (not yet translating connection ids - * etc.). */ +/* Handle incoming messages from RAN (BSC) */ static int sccp_sap_up_ran(struct osmo_prim_hdr *oph, void *scu) { struct bsc_nat_sccp_inst *sccp_inst = osmo_sccp_user_get_priv(scu); struct osmo_scu_prim *prim = (struct osmo_scu_prim *) oph; struct osmo_sccp_addr *addr; /* BSC's address */ - struct osmo_sccp_addr peer_addr_out; + struct conn *conn; struct msc *msc; + struct bsc *bsc; int rc = -1;
LOGP(DMAIN, LOGL_DEBUG, "Rx %s from RAN\n", osmo_scu_prim_name(oph)); @@ -227,16 +197,27 @@ &prim->u.connect.calling_addr) < 0) goto error;
- if (sccp_sap_get_peer_addr_out(sccp_inst, addr, &peer_addr_out) < 0) - goto error; + bsc = bsc_nat_bsc_get_by_pc(g_bsc_nat, addr->pc); + if (!bsc) + bsc = bsc_nat_bsc_add(g_bsc_nat, addr);
- LOGP(DMAIN, LOGL_DEBUG, "Fwd to %s\n", bsc_nat_print_addr(g_bsc_nat->cn, &peer_addr_out)); + if (bsc_nat_conn_get_by_id(g_bsc_nat, prim->u.connect.conn_id, BSC_NAT_RAN)) { + LOGP(DMAIN, LOGL_ERROR, "%s attempted to create new connection with already used" + " conn_id=%" PRIu32 ", ignoring\n", talloc_get_name(bsc), prim->u.connect.conn_id); + goto error; + } + + conn = bsc_nat_conn_add(g_bsc_nat, msc, bsc, + bsc_nat_conn_get_next_id(g_bsc_nat, BSC_NAT_CN), + prim->u.connect.conn_id); + + LOGP(DMAIN, LOGL_DEBUG, "Fwd via %s\n", talloc_get_name(conn));
msgb_pull_to_l2(oph->msg); osmo_sccp_tx_conn_req(g_bsc_nat->cn->scu, - prim->u.connect.conn_id, + conn->id[BSC_NAT_CN], &g_bsc_nat->cn->addr, - &peer_addr_out, + &conn->msc->addr, oph->msg->data, msgb_length(oph->msg)); rc = 0; @@ -248,15 +229,19 @@ &prim->u.connect.calling_addr) < 0) goto error;
- if (sccp_sap_get_peer_addr_out(sccp_inst, addr, &peer_addr_out) < 0) + conn = bsc_nat_conn_get_by_id(g_bsc_nat, prim->u.connect.conn_id, BSC_NAT_RAN); + if (!conn) { + LOGP(DMAIN, LOGL_ERROR, "Unknown conn_id=%" PRIu32 " from %s\n", prim->u.connect.conn_id, + bsc_nat_print_addr(sccp_inst, addr)); goto error; + }
- LOGP(DMAIN, LOGL_DEBUG, "Fwd to %s\n", bsc_nat_print_addr(g_bsc_nat->cn, &peer_addr_out)); + LOGP(DMAIN, LOGL_DEBUG, "Fwd via %s\n", talloc_get_name(conn));
msgb_pull_to_l2(oph->msg); osmo_sccp_tx_conn_resp(g_bsc_nat->cn->scu, - prim->u.connect.conn_id, - &peer_addr_out, + conn->id[BSC_NAT_CN], + &conn->msc->addr, oph->msg->data, msgb_length(oph->msg)); rc = 0; @@ -264,14 +249,18 @@
case OSMO_PRIM(OSMO_SCU_PRIM_N_DATA, PRIM_OP_INDICATION): /* connection-oriented data received */ - if (sccp_sap_get_peer_addr_out(sccp_inst, NULL, &peer_addr_out) < 0) + conn = bsc_nat_conn_get_by_id(g_bsc_nat, prim->u.data.conn_id, BSC_NAT_RAN); + if (!conn) { + LOGP(DMAIN, LOGL_ERROR, "Unknown conn_id=%" PRIu32 " from %s\n", prim->u.data.conn_id, + bsc_nat_print_addr(sccp_inst, addr)); goto error; + }
- LOGP(DMAIN, LOGL_DEBUG, "Fwd to %s\n", bsc_nat_print_addr(g_bsc_nat->cn, &peer_addr_out)); + LOGP(DMAIN, LOGL_DEBUG, "Fwd via %s\n", talloc_get_name(conn));
msgb_pull_to_l2(oph->msg); osmo_sccp_tx_data(g_bsc_nat->cn->scu, - prim->u.data.conn_id, + conn->id[BSC_NAT_CN], oph->msg->data, msgb_length(oph->msg)); rc = 0; @@ -279,15 +268,22 @@
case OSMO_PRIM(OSMO_SCU_PRIM_N_DISCONNECT, PRIM_OP_INDICATION): /* indication of disconnect */ - if (sccp_sap_get_peer_addr_out(sccp_inst, NULL, &peer_addr_out) < 0) + conn = bsc_nat_conn_get_by_id(g_bsc_nat, prim->u.disconnect.conn_id, BSC_NAT_RAN); + if (!conn) { + LOGP(DMAIN, LOGL_ERROR, "Unknown conn_id=%" PRIu32 " from %s\n", prim->u.disconnect.conn_id, + bsc_nat_print_addr(sccp_inst, addr)); goto error; + }
- LOGP(DMAIN, LOGL_DEBUG, "Fwd to %s\n", bsc_nat_print_addr(g_bsc_nat->cn, &peer_addr_out)); + LOGP(DMAIN, LOGL_DEBUG, "Fwd via %s\n", talloc_get_name(conn));
osmo_sccp_tx_disconn(g_bsc_nat->cn->scu, - prim->u.disconnect.conn_id, - &prim->u.disconnect.responding_addr, + conn->id[BSC_NAT_CN], + &g_bsc_nat->cn->addr, prim->u.disconnect.cause); + + bsc_nat_conn_del(conn); + rc = 0; break;
-
osmith