fixeria has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-sgsn/+/42594?usp=email )

Change subject: gprs_gmm: gsm48_rx_gmm_att_req(): drop stale PDP contexts on re-Attach ......................................................................

gprs_gmm: gsm48_rx_gmm_att_req(): drop stale PDP contexts on re-Attach

When an MS sends an Attach Request with a known IMSI or P-TMSI, it implies the MS has restarted and lost all its PDP context state. The SGSN must clean up any PDP contexts it still holds for that subscriber; otherwise it will not create new ones upon subsequent PDP Context Activation, causing data connectivity failure after a device reboot.

Change-Id: I20c1f5f741275115635188b2f4b1c5fe7c6e40f1 Related: OS#6922 --- M src/sgsn/gprs_gmm.c 1 file changed, 22 insertions(+), 0 deletions(-)

git pull ssh://gerrit.osmocom.org:29418/osmo-sgsn refs/changes/94/42594/1

diff --git a/src/sgsn/gprs_gmm.c b/src/sgsn/gprs_gmm.c index 3d4b940..fe7d4b4 100644 --- a/src/sgsn/gprs_gmm.c +++ b/src/sgsn/gprs_gmm.c @@ -1336,6 +1336,17 @@ goto rejected; } OSMO_STRLCPY_ARRAY(ctx->imsi, mi.imsi); + } else { + /* A re-Attach from a known IMSI means the MS has restarted + * and lost its PDP state. Clean up stale PDP contexts so the + * MS can activate new ones successfully. */ + struct sgsn_pdp_ctx *pdp, *pdp2; + llist_for_each_entry_safe(pdp, pdp2, &ctx->pdp_list, list) { + LOGMMCTXP(LOGL_NOTICE, ctx, + "Re-Attach: Dropping stale PDP context for NSAPI=%u\n", + pdp->nsapi); + sgsn_pdp_ctx_terminate(pdp); + } } break; case GSM_MI_TYPE_TMSI: @@ -1354,6 +1365,17 @@ goto rejected; } ctx->p_tmsi = mi.tmsi; + } else { + /* A re-Attach from a known P-TMSI means the MS has restarted + * and lost its PDP state. Clean up stale PDP contexts so the + * MS can activate new ones successfully. */ + struct sgsn_pdp_ctx *pdp, *pdp2; + llist_for_each_entry_safe(pdp, pdp2, &ctx->pdp_list, list) { + LOGMMCTXP(LOGL_NOTICE, ctx, + "Re-Attach: Dropping stale PDP context for NSAPI=%u\n", + pdp->nsapi); + sgsn_pdp_ctx_terminate(pdp); + } } break; default: