diff --git a/openbsc/include/openbsc/gprs_gmm.h b/openbsc/include/openbsc/gprs_gmm.h index 044978b0a..8a3ffea41 100644 --- a/openbsc/include/openbsc/gprs_gmm.h +++ b/openbsc/include/openbsc/gprs_gmm.h @@ -4,13 +4,16 @@ #include #include +#include + int gsm48_tx_gsm_deact_pdp_req(struct sgsn_pdp_ctx *pdp, uint8_t sm_cause); int gsm48_tx_gsm_act_pdp_rej(struct sgsn_mm_ctx *mm, uint8_t tid, uint8_t cause, uint8_t pco_len, uint8_t *pco_v); int gsm48_tx_gsm_act_pdp_acc(struct sgsn_pdp_ctx *pdp); int gsm48_tx_gsm_deact_pdp_acc(struct sgsn_pdp_ctx *pdp); -int gsm0408_gprs_rcvmsg_gb(struct msgb *msg, struct gprs_llc_llme *llme); +int gsm0408_gprs_rcvmsg_gb(struct msgb *msg, struct gprs_llc_llme *llme, + bool drop_cipherable); int gsm0408_gprs_force_reattach(struct sgsn_mm_ctx *mmctx); int gsm0408_gprs_force_reattach_oldmsg(struct msgb *msg, struct gprs_llc_llme *llme); diff --git a/openbsc/include/openbsc/gprs_llc.h b/openbsc/include/openbsc/gprs_llc.h index d7a480bf4..0e497a080 100644 --- a/openbsc/include/openbsc/gprs_llc.h +++ b/openbsc/include/openbsc/gprs_llc.h @@ -2,6 +2,7 @@ #define _GPRS_LLC_H #include +#include #include /* Section 4.7 LLC Layer Structure */ @@ -211,7 +212,7 @@ int gprs_llc_rcvmsg(struct msgb *msg, struct tlv_parsed *tv); /* LL-UNITDATA.req */ int gprs_llc_tx_ui(struct msgb *msg, uint8_t sapi, int command, - void *mmctx); + struct sgsn_mm_ctx *mmctx, bool encryptable); /* Chapter 7.2.1.2 LLGMM-RESET.req */ int gprs_llgmm_reset(struct gprs_llc_llme *llme); diff --git a/openbsc/src/gprs/gprs_gmm.c b/openbsc/src/gprs/gprs_gmm.c index 61edc650a..80f653afe 100644 --- a/openbsc/src/gprs/gprs_gmm.c +++ b/openbsc/src/gprs/gprs_gmm.c @@ -26,7 +26,7 @@ #include #include #include - +#include #include #include #include @@ -132,13 +132,13 @@ time_t gprs_max_time_to_idle(void) /* Send a message through the underlying layer */ static int gsm48_gmm_sendmsg(struct msgb *msg, int command, - struct sgsn_mm_ctx *mm) + struct sgsn_mm_ctx *mm, bool encryptable) { if (mm) rate_ctr_inc(&mm->ctrg->ctr[GMM_CTR_PKTS_SIG_OUT]); /* caller needs to provide TLLI, BVCI and NSEI */ - return gprs_llc_tx_ui(msg, GPRS_SAPI_GMM, command, mm); + return gprs_llc_tx_ui(msg, GPRS_SAPI_GMM, command, mm, encryptable); } /* copy identifiers from old message to new message, this @@ -196,7 +196,7 @@ static int _tx_status(struct msgb *msg, uint8_t cause, } gh->data[0] = cause; - return gsm48_gmm_sendmsg(msg, 0, mmctx); + return gsm48_gmm_sendmsg(msg, 0, mmctx, true); } static int gsm48_tx_gmm_status(struct sgsn_mm_ctx *mmctx, uint8_t cause) @@ -234,7 +234,7 @@ static int _tx_detach_req(struct msgb *msg, uint8_t detach_type, uint8_t cause, msgb_tv_put(msg, GSM48_IE_GMM_CAUSE, cause); - return gsm48_gmm_sendmsg(msg, 0, mmctx); + return gsm48_gmm_sendmsg(msg, 0, mmctx, true); } static int gsm48_tx_gmm_detach_req(struct sgsn_mm_ctx *mmctx, @@ -330,7 +330,7 @@ static int gsm48_tx_gmm_att_ack(struct sgsn_mm_ctx *mm) /* Optional: MS-identity (combined attach) */ /* Optional: GMM cause (partial attach result for combined attach) */ - return gsm48_gmm_sendmsg(msg, 0, mm); + return gsm48_gmm_sendmsg(msg, 0, mm, true); } /* Chapter 9.4.5: Attach reject */ @@ -347,7 +347,7 @@ static int _tx_gmm_att_rej(struct msgb *msg, uint8_t gmm_cause, gh->msg_type = GSM48_MT_GMM_ATTACH_REJ; gh->data[0] = gmm_cause; - return gsm48_gmm_sendmsg(msg, 0, NULL); + return gsm48_gmm_sendmsg(msg, 0, NULL, false); } static int gsm48_tx_gmm_att_rej_oldmsg(const struct msgb *old_msg, uint8_t gmm_cause) @@ -379,7 +379,7 @@ static int _tx_detach_ack(struct msgb *msg, uint8_t force_stby, gh->msg_type = GSM48_MT_GMM_DETACH_ACK; gh->data[0] = force_stby; - return gsm48_gmm_sendmsg(msg, 0, mm); + return gsm48_gmm_sendmsg(msg, 0, mm, true); } static int gsm48_tx_gmm_det_ack(struct sgsn_mm_ctx *mm, uint8_t force_stby) @@ -415,7 +415,7 @@ static int gsm48_tx_gmm_id_req(struct sgsn_mm_ctx *mm, uint8_t id_type) /* 10.5.5.9 ID type 2 + identity type and 10.5.5.7 'force to standby' IE */ gh->data[0] = id_type & 0xf; - return gsm48_gmm_sendmsg(msg, 1, mm); + return gsm48_gmm_sendmsg(msg, 1, mm, false); } /* 3GPP TS 24.008 Section 9.4.9: Authentication and Ciphering Request */ @@ -463,7 +463,7 @@ static int gsm48_tx_gmm_auth_ciph_req(struct sgsn_mm_ctx *mm, uint8_t *rnd, /* FIXME: add AUTN for 3g auth according to 3GPP TS 24.008 § 10.5.3.1.1 */ /* FIXME: make sure we don't send any other messages to the MS */ - return gsm48_gmm_sendmsg(msg, 1, mm); + return gsm48_gmm_sendmsg(msg, 1, mm, false); } /* Section 9.4.11: Authentication and Ciphering Reject */ @@ -480,7 +480,7 @@ static int gsm48_tx_gmm_auth_ciph_rej(struct sgsn_mm_ctx *mm) gh->proto_discr = GSM48_PDISC_MM_GPRS; gh->msg_type = GSM48_MT_GMM_AUTH_CIPH_REJ; - return gsm48_gmm_sendmsg(msg, 0, mm); + return gsm48_gmm_sendmsg(msg, 0, mm, false); } /* Section 9.4.10: Authentication and Ciphering Response */ @@ -1094,7 +1094,7 @@ static int gsm48_tx_gmm_ra_upd_ack(struct sgsn_mm_ctx *mm) gprs_secs_to_tmr_floor(sgsn->cfg.timers.T3314)); /* Option: MS ID, ... */ - return gsm48_gmm_sendmsg(msg, 0, mm); + return gsm48_gmm_sendmsg(msg, 0, mm, true); } /* Chapter 9.4.17: Routing area update reject */ @@ -1114,7 +1114,7 @@ static int gsm48_tx_gmm_ra_upd_rej(struct msgb *old_msg, uint8_t cause) gh->data[1] = 0; /* ? */ /* Option: P-TMSI signature, allocated P-TMSI, MS ID, ... */ - return gsm48_gmm_sendmsg(msg, 0, NULL); + return gsm48_gmm_sendmsg(msg, 0, NULL, false); } static void process_ms_ctx_status(struct sgsn_mm_ctx *mmctx, @@ -1328,13 +1328,20 @@ static int gsm48_rx_gmm_status(struct sgsn_mm_ctx *mmctx, struct msgb *msg) /* GPRS Mobility Management */ static int gsm0408_rcv_gmm(struct sgsn_mm_ctx *mmctx, struct msgb *msg, - struct gprs_llc_llme *llme) + struct gprs_llc_llme *llme, bool drop_cipherable) { struct sgsn_signal_data sig_data; struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg); int rc; /* MMCTX can be NULL when called */ + if (drop_cipherable && gsm48_hdr_gmm_cipherable(gh)) { + LOGMMCTXP(LOGL_NOTICE, mmctx, "Dropping cleartext GMM %s which " + "is expected to be encrypted for TLLI 0x%08x\n", + get_value_string(gprs_msgt_gmm_names, gh->msg_type), + llme->tlli); + return -EBADMSG; + } if (llme && !mmctx && gh->msg_type != GSM48_MT_GMM_ATTACH_REQ && @@ -1646,7 +1653,7 @@ int gsm48_tx_gsm_act_pdp_acc(struct sgsn_pdp_ctx *pdp) /* Optional: Packet Flow Identifier */ - return gsm48_gmm_sendmsg(msg, 0, pdp->mm); + return gsm48_gmm_sendmsg(msg, 0, pdp->mm, true); } /* Section 9.5.3: Activate PDP Context reject */ @@ -1669,7 +1676,7 @@ int gsm48_tx_gsm_act_pdp_rej(struct sgsn_mm_ctx *mm, uint8_t tid, if (pco_len && pco_v) msgb_tlv_put(msg, GSM48_IE_GSM_PROTO_CONF_OPT, pco_len, pco_v); - return gsm48_gmm_sendmsg(msg, 0, mm); + return gsm48_gmm_sendmsg(msg, 0, mm, true); } /* Section 9.5.8: Deactivate PDP Context Request */ @@ -1690,7 +1697,7 @@ static int _gsm48_tx_gsm_deact_pdp_req(struct sgsn_mm_ctx *mm, uint8_t tid, msgb_v_put(msg, sm_cause); - return gsm48_gmm_sendmsg(msg, 0, mm); + return gsm48_gmm_sendmsg(msg, 0, mm, true); } int gsm48_tx_gsm_deact_pdp_req(struct sgsn_pdp_ctx *pdp, uint8_t sm_cause) { @@ -1714,7 +1721,7 @@ static int _gsm48_tx_gsm_deact_pdp_acc(struct sgsn_mm_ctx *mm, uint8_t tid) gh->proto_discr = GSM48_PDISC_SM_GPRS | (transaction_id << 4); gh->msg_type = GSM48_MT_GSM_DEACT_PDP_ACK; - return gsm48_gmm_sendmsg(msg, 0, mm); + return gsm48_gmm_sendmsg(msg, 0, mm, true); } int gsm48_tx_gsm_deact_pdp_acc(struct sgsn_pdp_ctx *pdp) { @@ -2163,7 +2170,8 @@ int gsm0408_gprs_force_reattach(struct sgsn_mm_ctx *mmctx) } /* Main entry point for incoming 04.08 GPRS messages from Gb */ -int gsm0408_gprs_rcvmsg_gb(struct msgb *msg, struct gprs_llc_llme *llme) +int gsm0408_gprs_rcvmsg_gb(struct msgb *msg, struct gprs_llc_llme *llme, + bool drop_cipherable) { struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg); uint8_t pdisc = gsm48_hdr_pdisc(gh); @@ -2183,7 +2191,7 @@ int gsm0408_gprs_rcvmsg_gb(struct msgb *msg, struct gprs_llc_llme *llme) switch (pdisc) { case GSM48_PDISC_MM_GPRS: - rc = gsm0408_rcv_gmm(mmctx, msg, llme); + rc = gsm0408_rcv_gmm(mmctx, msg, llme, drop_cipherable); break; case GSM48_PDISC_SM_GPRS: rc = gsm0408_rcv_gsm(mmctx, msg, llme); diff --git a/openbsc/src/gprs/gprs_llc.c b/openbsc/src/gprs/gprs_llc.c index bc856e98e..e6639ce66 100644 --- a/openbsc/src/gprs/gprs_llc.c +++ b/openbsc/src/gprs/gprs_llc.c @@ -21,6 +21,7 @@ #include #include +#include #include @@ -346,9 +347,12 @@ static int gprs_llc_tx_xid(struct gprs_llc_lle *lle, struct msgb *msg, return gprs_llc_tx_u(msg, lle->sapi, command, GPRS_LLC_U_XID, 1); } -/* Transmit a UI frame over the given SAPI */ +/* Transmit a UI frame over the given SAPI: + 'encryptable' indicates whether particular message can be encrypted according + to 3GPP TS 24.008 § 4.7.1.2 + */ int gprs_llc_tx_ui(struct msgb *msg, uint8_t sapi, int command, - void *mmctx) + struct sgsn_mm_ctx *mmctx, bool encryptable) { struct gprs_llc_lle *lle; uint8_t *fcs, *llch; @@ -409,7 +413,7 @@ int gprs_llc_tx_ui(struct msgb *msg, uint8_t sapi, int command, fcs[2] = (fcs_calc >> 16) & 0xff; /* encrypt information field + FCS, if needed! */ - if (lle->llme->algo != GPRS_ALGO_GEA0) { + if (lle->llme->algo != GPRS_ALGO_GEA0 && encryptable) { uint32_t iov_ui = 0; /* FIXME: randomly select for TLLI */ uint16_t crypt_len = (fcs + 3) - (llch + 3); uint8_t cipher_out[GSM0464_CIPH_MAX_BLOCK]; @@ -567,6 +571,7 @@ int gprs_llc_rcvmsg(struct msgb *msg, struct tlv_parsed *tv) struct gprs_llc_hdr *lh = (struct gprs_llc_hdr *) msgb_llch(msg); struct gprs_llc_hdr_parsed llhp; struct gprs_llc_lle *lle; + bool drop_cipherable = false; int rc = 0; /* Identifiers from DOWN: NSEI, BVCI, TLLI */ @@ -640,11 +645,9 @@ int gprs_llc_rcvmsg(struct msgb *msg, struct tlv_parsed *tv) for (i = 0; i < crypt_len; i++) *(llhp.data + i) ^= cipher_out[i]; } else { - if (lle->llme->algo != GPRS_ALGO_GEA0) { - LOGP(DLLC, LOGL_NOTICE, "unencrypted frame for LLC " - "that is supposed to be encrypted. Dropping.\n"); - return 0; - } + if (lle->llme->algo != GPRS_ALGO_GEA0 && + lle->llme->cksn != GSM_KEY_SEQ_INVAL) + drop_cipherable = true; } /* We have to do the FCS check _after_ decryption */ @@ -669,7 +672,8 @@ int gprs_llc_rcvmsg(struct msgb *msg, struct tlv_parsed *tv) switch (llhp.sapi) { case GPRS_SAPI_GMM: /* send LL_UNITDATA_IND to GMM */ - rc = gsm0408_gprs_rcvmsg_gb(msg, lle->llme); + rc = gsm0408_gprs_rcvmsg_gb(msg, lle->llme, + drop_cipherable); break; case GPRS_SAPI_SNDCP3: case GPRS_SAPI_SNDCP5: diff --git a/openbsc/src/gprs/gprs_sndcp.c b/openbsc/src/gprs/gprs_sndcp.c index 46d779b4c..75f95c9c4 100644 --- a/openbsc/src/gprs/gprs_sndcp.c +++ b/openbsc/src/gprs/gprs_sndcp.c @@ -22,6 +22,7 @@ #include #include +#include #include #include @@ -417,7 +418,7 @@ static int sndcp_send_ud_frag(struct sndcp_frag_state *fs) /* set the MORE bit of the SNDCP header accordingly */ sch->more = more; - rc = gprs_llc_tx_ui(fmsg, lle->sapi, 0, fs->mmcontext); + rc = gprs_llc_tx_ui(fmsg, lle->sapi, 0, fs->mmcontext, true); /* abort in case of error, do not advance frag_nr / next_byte */ if (rc < 0) { msgb_free(fs->msg); @@ -498,7 +499,7 @@ int sndcp_unitdata_req(struct msgb *msg, struct gprs_llc_lle *lle, uint8_t nsapi sch->type = 1; sch->nsapi = nsapi; - return gprs_llc_tx_ui(msg, lle->sapi, 0, mmcontext); + return gprs_llc_tx_ui(msg, lle->sapi, 0, mmcontext, true); } /* Section 5.1.2.17 LL-UNITDATA.ind */ diff --git a/openbsc/tests/sgsn/sgsn_test.c b/openbsc/tests/sgsn/sgsn_test.c index e8e05f6e9..1c9563436 100644 --- a/openbsc/tests/sgsn/sgsn_test.c +++ b/openbsc/tests/sgsn/sgsn_test.c @@ -215,7 +215,7 @@ static void send_0408_message(struct gprs_llc_llme *llme, uint32_t tlli, msg = create_msg(data, data_len); msgb_tlli(msg) = tlli; bssgp_create_cell_id(msgb_bcid(msg), bssgp_raid, 0); - gsm0408_gprs_rcvmsg_gb(msg, llme); + gsm0408_gprs_rcvmsg_gb(msg, llme, false); msgb_free(msg); }