paging: pass struct osmo_mobile_identity, not encoded IE bytes

In get_paging_mi(), before this, an encoded buffer of Mobile Identity bytes is
returned. Code paths following this repeatedly decode the Mobile Identity
bytes, e.g. for logging. Also, in get_paging_mi(), since the TMSI is read in
from a different encoding than a typical Mobile Identity IE, the TMSI was
manually encoded into a typical Mobile Identity IE. This is essentially a code
dup of osmo_mobile_identity_encode(). Stop this madness.

Instead, in get_paging_mi(), return a decoded struct osmo_mobile_identity. Code
paths after this use the struct osmo_mobile_identity directly without repeated
decoding.

At the point of finally needing an encoded Mobile Identity IE (in
Encoding::write_paging_request()), do a proper osmo_mobile_identity_encode().

Since this may return errors, add an rc check for the caller of
write_paging_request(), gprs_rlcmac_paging_request().

A side effect is stricter validation of the Mobile Identity passing through the
Paging code path. Before, invalid MI might have passed through unnoticed.

Change-Id: Iad845acb0096b75dc453105c9c16b2252879b4ca

1 files changed, 1 insertions, 1 deletions

diff --git a/src/bts.h b/src/bts.h
index edccc280..5a1b162c 100644
--- a/src/bts.h
+++ b/src/bts.h
@@ -309,7 +309,7 @@ public:
 	int current_frame_number() const;
 
 	/** add paging to paging queue(s) */
-	int add_paging(uint8_t chan_needed, const uint8_t *mi, uint8_t mi_len);
+	int add_paging(uint8_t chan_needed, const struct osmo_mobile_identity *mi);
 
 	gprs_rlcmac_dl_tbf *dl_tbf_by_poll_fn(uint32_t fn, uint8_t trx, uint8_t ts);
 	gprs_rlcmac_ul_tbf *ul_tbf_by_poll_fn(uint32_t fn, uint8_t trx, uint8_t ts);