diff options
author | Jacob Erlbeck <jerlbeck@sysmocom.de> | 2014-10-13 10:32:00 +0200 |
---|---|---|
committer | Holger Hans Peter Freyther <holger@moiji-mobile.com> | 2014-10-27 10:25:13 +0100 |
commit | 99985b5ea8e2d69d1e63a9423fbe40b872b0c0f5 (patch) | |
tree | 06257bc6fdf1bfbc1f260fdf2e54e448746eba52 /openbsc/src/gprs/gprs_sgsn.c | |
parent | ae20b4b31b679d7ea057f4db8427b99293068ec5 (diff) |
sgsn: Delete PDP contexts properly
Currently the PDP contexts are hard freed (via sgsn_pdp_ctx_free)
at some places in gprs_gmm.c on the reception of a Detach Req and on
re-use of an IMSI that is already associated with an MM context. This
can lead to segfaults when there is a pending request or a data
indication at libgtp.
This patch add a new function sgsn_pdp_ctx_terminate that de-associates
the PTP context from the MM context, deactivates SNDCP, sets pdp->mm
to NULL and then calls sgsn_delete_pdp_ctx. sgsn_libgtp is updated to
check for pdp->mm being non-NULL before dereferencing it. The
sgsn_pdp_ctx_terminate function will be called for each PDP context of
an MM context before this context is going to be deleted via
sgsn_mm_ctx_free. To ensure, that the ctx->llme (which is accessed
during the deactivation of SNDCP) remains valid, the call to
gprs_llgmm_assign is moved after the call to sgsn_mm_ctx_free. The
handling of re-used IMSIs is changed to mimic the processing of a
Detach Req.
Addresses:
<0002> gprs_gmm.c:654 MM(/f6b31ab0) Deleting old MM Context for same
IMSI p_tmsi_old=0xc6f19134
<000f> gprs_sgsn.c:259 PDP freeing PDP context that still has a
libgtp handle attached to it, this shouldn't happen!
[...]
SEGFAULT
Ticket: OW#1311
Sponsored-by: On-Waves ehf
Diffstat (limited to 'openbsc/src/gprs/gprs_sgsn.c')
-rw-r--r-- | openbsc/src/gprs/gprs_sgsn.c | 34 |
1 files changed, 32 insertions, 2 deletions
diff --git a/openbsc/src/gprs/gprs_sgsn.c b/openbsc/src/gprs/gprs_sgsn.c index e68471313..75f8ae5f0 100644 --- a/openbsc/src/gprs/gprs_sgsn.c +++ b/openbsc/src/gprs/gprs_sgsn.c @@ -35,6 +35,7 @@ #include <openbsc/sgsn.h> #include <openbsc/gsm_04_08_gprs.h> #include <openbsc/gprs_gmm.h> +#include "openbsc/gprs_llc.h" extern struct sgsn_instance *sgsn; @@ -247,11 +248,40 @@ struct sgsn_pdp_ctx *sgsn_pdp_ctx_alloc(struct sgsn_mm_ctx *mm, } #include <pdp.h> -/* you probably want to call sgsn_delete_pdp_ctx() instead */ +/* + * This function will not trigger any GSM DEACT PDP ACK messages, so you + * probably want to call sgsn_delete_pdp_ctx() instead if the connection + * isn't detached already. + */ +void sgsn_pdp_ctx_terminate(struct sgsn_pdp_ctx *pdp) +{ + OSMO_ASSERT(pdp->mm != NULL); + + /* There might still be pending callbacks in libgtp. So the parts of + * this object relevant to GTP need to remain intact in this case. */ + + LOGPDPCTXP(LOGL_INFO, pdp, "Forcing release of PDP context\n"); + + /* Force the deactivation of the SNDCP layer */ + sndcp_sm_deactivate_ind(&pdp->mm->llme->lle[pdp->sapi], pdp->nsapi); + + /* Detach from MM context */ + llist_del(&pdp->list); + pdp->mm = NULL; + + sgsn_delete_pdp_ctx(pdp); +} + +/* + * Don't call this function directly unless you know what you are doing. + * In normal conditions use sgsn_delete_pdp_ctx and in unspecified or + * implementation dependent abnormal ones sgsn_pdp_ctx_terminate. + */ void sgsn_pdp_ctx_free(struct sgsn_pdp_ctx *pdp) { rate_ctr_group_free(pdp->ctrg); - llist_del(&pdp->list); + if (pdp->mm) + llist_del(&pdp->list); llist_del(&pdp->g_list); /* _if_ we still have a library handle, at least set it to NULL |