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RSL: Properly reject RSL CHAN_NR IE for incompatible PCHAN 

If we receive a message for a dedicated channel, whose channel number
structure doesn't match with the physical channel (timeslot) type,
we must properly reject this.  For RSL CHAN ACT it means sending a NACK,
and for all other cases it means sending an RSL ERROR REPORT.

Related: OS#2972, OS#2971
Change-Id: Iebd2571726d1284a7431b3f9b23ad3185e832ed1
This commit is contained in:
Harald Welte 2018-02-21 15:54:16 +01:00
parent df72b1fdbd
commit 5e60186bec
1 changed files with 78 additions and 34 deletions
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112
src/common/rsl.c
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@ -1,7 +1,7 @@
/* GSM TS 08.58 RSL, BTS Side */
/* (C) 2011 by Andreas Eversberg <jolly@eversberg.eu>
* (C) 2011-2014 by Harald Welte <laforge@gnumonks.org>
* (C) 2011-2017 by Harald Welte <laforge@gnumonks.org>
*
* All Rights Reserved
*
@ -135,18 +135,6 @@ static void lchan_tchmode_from_cmode(struct gsm_lchan *lchan,
* support
*/
/**
* Handle GSM 08.58 7 Error Handling for the given input. This method will
* send either a CHANNEL ACTIVATION NACK, MODE MODIFY NACK or ERROR REPORT
* depending on the input of the method.
*
* TODO: actually make the decision
*/
static int report_error(struct gsm_bts_trx *trx)
{
return rsl_tx_error_report(trx, RSL_ERR_IE_CONTENT);
}
static struct gsm_lchan *lchan_lookup(struct gsm_bts_trx *trx, uint8_t chan_nr,
const char *log_name)
{
@ -159,9 +147,11 @@ static struct gsm_lchan *lchan_lookup(struct gsm_bts_trx *trx, uint8_t chan_nr,
return NULL;
}
if (rc < 0)
if (rc < 0) {
LOGP(DRSL, LOGL_ERROR, "%s %smismatching chan_nr=0x%02x\n",
gsm_ts_and_pchan_name(lchan->ts), log_name, chan_nr);
return NULL;
}
return lchan;
}
@ -643,14 +633,16 @@ int rsl_tx_hando_det(struct gsm_lchan *lchan, uint8_t *ho_delay)
}
/* 8.4.3 sending CHANnel ACTIVation Negative ACK */
static int rsl_tx_chan_act_nack(struct gsm_lchan *lchan, uint8_t cause)
static int _rsl_tx_chan_act_nack(struct gsm_bts_trx *trx, uint8_t chan_nr, uint8_t cause,
struct gsm_lchan *lchan)
{
struct msgb *msg;
uint8_t chan_nr = gsm_lchan2chan_nr(lchan);
LOGP(DRSL, LOGL_NOTICE,
"%s Sending Channel Activated NACK: cause = 0x%02x\n",
gsm_lchan_name(lchan), cause);
if (lchan)
LOGP(DRSL, LOGL_NOTICE, "%s: ", gsm_lchan_name(lchan));
else
LOGP(DRSL, LOGL_NOTICE, "0x%02x: ", chan_nr);
LOGPC(DRSL, LOGL_NOTICE, "Sending Channel Activated NACK: cause = 0x%02x\n", cause);
msg = rsl_msgb_alloc(sizeof(struct abis_rsl_dchan_hdr));
if (!msg)
@ -659,10 +651,13 @@ static int rsl_tx_chan_act_nack(struct gsm_lchan *lchan, uint8_t cause)
/* 9.3.26 Cause */
msgb_tlv_put(msg, RSL_IE_CAUSE, 1, &cause);
rsl_dch_push_hdr(msg, RSL_MT_CHAN_ACTIV_NACK, chan_nr);
msg->trx = lchan->ts->trx;
msg->trx = trx;
return abis_bts_rsl_sendmsg(msg);
}
static int rsl_tx_chan_act_nack(struct gsm_lchan *lchan, uint8_t cause) {
return _rsl_tx_chan_act_nack(lchan->ts->trx, gsm_lchan2chan_nr(lchan), cause, lchan);
}
/* Send an RSL Channel Activation Ack if cause is zero, a Nack otherwise. */
int rsl_tx_chan_act_acknack(struct gsm_lchan *lchan, uint8_t cause)
@ -1229,13 +1224,16 @@ static int rsl_rx_encr_cmd(struct msgb *msg)
}
/* 8.4.11 MODE MODIFY NEGATIVE ACKNOWLEDGE */
static int rsl_tx_mode_modif_nack(struct gsm_lchan *lchan, uint8_t cause)
static int _rsl_tx_mode_modif_nack(struct gsm_bts_trx *trx, uint8_t chan_nr, uint8_t cause,
struct gsm_lchan *lchan)
{
struct msgb *msg;
uint8_t chan_nr = gsm_lchan2chan_nr(lchan);
LOGP(DRSL, LOGL_NOTICE, "%s Tx MODE MODIFY NACK (cause = 0x%02x)\n",
gsm_lchan_name(lchan), cause);
if (lchan)
LOGP(DRSL, LOGL_NOTICE, "%s: ", gsm_lchan_name(lchan));
else
LOGP(DRSL, LOGL_NOTICE, "0x%02x: ", chan_nr);
LOGPC(DRSL, LOGL_NOTICE, "Tx MODE MODIFY NACK (cause = 0x%02x)\n", cause);
msg = rsl_msgb_alloc(sizeof(struct abis_rsl_dchan_hdr));
if (!msg)
@ -1247,11 +1245,15 @@ static int rsl_tx_mode_modif_nack(struct gsm_lchan *lchan, uint8_t cause)
/* 9.3.26 Cause */
msgb_tlv_put(msg, RSL_IE_CAUSE, 1, &cause);
rsl_dch_push_hdr(msg, RSL_MT_MODE_MODIFY_NACK, chan_nr);
msg->lchan = lchan;
msg->trx = lchan->ts->trx;
msg->trx = trx;
return abis_bts_rsl_sendmsg(msg);
}
static int rsl_tx_mode_modif_nack(struct gsm_lchan *lchan, uint8_t cause)
{
return _rsl_tx_mode_modif_nack(lchan->ts->trx, gsm_lchan2chan_nr(lchan), cause, lchan);
}
/* 8.4.10 MODE MODIFY ACK */
static int rsl_tx_mode_modif_ack(struct gsm_lchan *lchan)
@ -2190,6 +2192,52 @@ void ipacc_dyn_pdch_complete(struct gsm_bts_trx_ts *ts, int rc)
pdch_act? "ACT" : "DEACT", rc);
}
/* handle a message with an RSL CHAN_NR that is incompatible/unknown */
static int rsl_reject_unknown_lchan(struct msgb *msg)
{
struct abis_rsl_common_hdr *rh = msgb_l2(msg);
struct abis_rsl_dchan_hdr *dch;
int rc;
/* Handle GSM 08.58 7 Error Handling for the given input. This method will
* send either a CHANNEL ACTIVATION NACK, MODE MODIFY NACK or ERROR REPORT
* depending on the input of the method. */
/* TS 48.058 Section 7 explains how to do error handling */
switch (rh->msg_discr & 0xfe) {
case ABIS_RSL_MDISC_DED_CHAN:
dch = msgb_l2(msg);
switch (dch->c.msg_type) {
case RSL_MT_CHAN_ACTIV:
rc = _rsl_tx_chan_act_nack(msg->trx, dch->chan_nr,
RSL_ERR_MAND_IE_ERROR, NULL);
break;
case RSL_MT_MODE_MODIFY_REQ:
rc = _rsl_tx_mode_modif_nack(msg->trx, dch->chan_nr,
RSL_ERR_MAND_IE_ERROR, NULL);
break;
default:
rc = rsl_tx_error_report(msg->trx, RSL_ERR_MAND_IE_ERROR);
break;
}
break;
case ABIS_RSL_MDISC_RLL:
/* fall-through */
case ABIS_RSL_MDISC_COM_CHAN:
/* fall-through */
case ABIS_RSL_MDISC_TRX:
/* fall-through */
case ABIS_RSL_MDISC_IPACCESS:
/* fall-through */
default:
/* ERROR REPORT */
rc = rsl_tx_error_report(msg->trx, RSL_ERR_MAND_IE_ERROR);
}
msgb_free(msg);
return rc;
}
/*
* selecting message
*/
@ -2210,8 +2258,7 @@ static int rsl_rx_rll(struct gsm_bts_trx *trx, struct msgb *msg)
if (!lchan) {
LOGP(DRLL, LOGL_NOTICE, "Rx RLL %s for unknown lchan\n",
rsl_msg_name(rh->c.msg_type));
msgb_free(msg);
return report_error(trx);
return rsl_reject_unknown_lchan(msg);
}
DEBUGP(DRLL, "%s Rx RLL %s Abis -> LAPDm\n", gsm_lchan_name(lchan),
@ -2402,8 +2449,7 @@ static int rsl_rx_cchan(struct gsm_bts_trx *trx, struct msgb *msg)
if (!msg->lchan) {
LOGP(DRSL, LOGL_ERROR, "Rx RSL %s for unknown lchan\n",
rsl_msg_name(cch->c.msg_type));
msgb_free(msg);
return report_error(trx);
return rsl_reject_unknown_lchan(msg);
}
LOGP(DRSL, LOGL_INFO, "%s Rx RSL %s\n", gsm_lchan_name(msg->lchan),
@ -2456,8 +2502,7 @@ static int rsl_rx_dchan(struct gsm_bts_trx *trx, struct msgb *msg)
if (!msg->lchan) {
LOGP(DRSL, LOGL_ERROR, "Rx RSL %s for unknown lchan\n",
rsl_or_ipac_msg_name(dch->c.msg_type));
msgb_free(msg);
return report_error(trx);
return rsl_reject_unknown_lchan(msg);
}
LOGP(DRSL, LOGL_INFO, "%s Rx RSL %s\n", gsm_lchan_name(msg->lchan),
@ -2555,8 +2600,7 @@ static int rsl_rx_ipaccess(struct gsm_bts_trx *trx, struct msgb *msg)
if (!msg->lchan) {
LOGP(DRSL, LOGL_ERROR, "Rx RSL %s for unknow lchan\n",
rsl_msg_name(dch->c.msg_type));
msgb_free(msg);
return report_error(trx);
return rsl_reject_unknown_lchan(msg);
}
LOGP(DRSL, LOGL_INFO, "%s Rx RSL %s\n", gsm_lchan_name(msg->lchan),