2  *  Message Processing Stack, Reader implementation
5  *  SPDX-License-Identifier: Apache-2.0
11  *  http://www.apache.org/licenses/LICENSE-2.0
47  * and significantly increases the C-code line count, but
60  *     on failure - this in turn has two benefits:
67  *           and/or non-sensical calls.
68  *     Moreover, it might even reduce code-size because
78     if( rd->acc == NULL )  in mps_reader_is_accumulating()
81     acc_remaining = rd->acc_share.acc_remaining;  in mps_reader_is_accumulating()
88     unsigned char *frag = rd->frag;  in mps_reader_is_producing()
101     unsigned char *acc = rd->acc;  in mps_reader_get_fragment_offset()
107     frag_offset = rd->acc_share.frag_offset;  in mps_reader_get_fragment_offset()
117     end = rd->end;  in mps_reader_serving_from_accumulator()
126      * to overlook fields which should not be zero-initialized.  in mps_reader_zero()
133           .commit        = 0,  in mps_reader_zero()
152     rd->acc = acc;  in mbedtls_mps_reader_init()
153     rd->acc_len = acc_len;  in mbedtls_mps_reader_init()
181         unsigned char *acc    = rd->acc;  in mbedtls_mps_reader_feed()
182         mbedtls_mps_size_t acc_remaining = rd->acc_share.acc_remaining;  in mbedtls_mps_reader_feed()
183         mbedtls_mps_size_t acc_available = rd->acc_available;  in mbedtls_mps_reader_feed()
200         acc_remaining -= copy_to_acc;  in mbedtls_mps_reader_feed()
205             rd->acc_share.acc_remaining = acc_remaining;  in mbedtls_mps_reader_feed()
206             rd->acc_available = acc_available;  in mbedtls_mps_reader_feed()
216         rd->acc_share.frag_offset = acc_available;  in mbedtls_mps_reader_feed()
218         rd->acc_available = acc_available;  in mbedtls_mps_reader_feed()
222         rd->acc_share.frag_offset = 0;  in mbedtls_mps_reader_feed()
225     rd->frag = new_frag;  in mbedtls_mps_reader_feed()
226     rd->frag_len = new_frag_len;  in mbedtls_mps_reader_feed()
227     rd->commit = 0;  in mbedtls_mps_reader_feed()
228     rd->end = 0;  in mbedtls_mps_reader_feed()
247     end = rd->end;  in mbedtls_mps_reader_get()
255          * - Allowed #1  in mbedtls_mps_reader_get()
257          *                          +-----------------------------------+  in mbedtls_mps_reader_get()
259          *                          +-----------------------------------+  in mbedtls_mps_reader_get()
263          *        +-----v-------v-------------+  in mbedtls_mps_reader_get()
265          *        +---------------------------+  in mbedtls_mps_reader_get()
269          * - Allowed #2  in mbedtls_mps_reader_get()
271          *                          +-----------------------------------+  in mbedtls_mps_reader_get()
273          *                          +-----------------------------------+  in mbedtls_mps_reader_get()
277          *        +----------v----------------v  in mbedtls_mps_reader_get()
279          *        +---------------------------+  in mbedtls_mps_reader_get()
283          * - Not allowed #1 (could be served, but we don't actually use it):  in mbedtls_mps_reader_get()
285          *                      +-----------------------------------+  in mbedtls_mps_reader_get()
287          *                      +-----------------------------------+  in mbedtls_mps_reader_get()
291          *        +------v-------------v------+  in mbedtls_mps_reader_get()
293          *        +---------------------------+  in mbedtls_mps_reader_get()
298          * - Not allowed #2 (can't be served with a contiguous buffer):  in mbedtls_mps_reader_get()
300          *                      +-----------------------------------+  in mbedtls_mps_reader_get()
302          *                      +-----------------------------------+  in mbedtls_mps_reader_get()
306          *        +------v--------------------+   v  in mbedtls_mps_reader_get()
308          *        +---------------------------+  in mbedtls_mps_reader_get()
320         if( frag_offset - end < desired )  in mbedtls_mps_reader_get()
323             acc_available = rd->acc_available;  in mbedtls_mps_reader_get()
324             if( acc_available - end != desired )  in mbedtls_mps_reader_get()
341         acc = rd->acc;  in mbedtls_mps_reader_get()
349         rd->end = end;  in mbedtls_mps_reader_get()
350         rd->pending = 0;  in mbedtls_mps_reader_get()
359     frag_len = rd->frag_len;  in mbedtls_mps_reader_get()
360     frag_fetched = end - frag_offset; /* The amount of data from the current  in mbedtls_mps_reader_get()
363     frag_remaining = frag_len - frag_fetched; /* Remaining data in fragment */  in mbedtls_mps_reader_get()
377                 rd->pending = desired - frag_remaining;  in mbedtls_mps_reader_get()
379                        "Remember to collect %u bytes before re-opening",  in mbedtls_mps_reader_get()
380                        (unsigned) rd->pending );  in mbedtls_mps_reader_get()
391     frag = rd->frag;  in mbedtls_mps_reader_get()
399     rd->end = end;  in mbedtls_mps_reader_get()
400     rd->pending = 0;  in mbedtls_mps_reader_get()
411     end = rd->end;  in mbedtls_mps_reader_commit()
412     rd->commit = end;  in mbedtls_mps_reader_commit()
421     mbedtls_mps_size_t pending, commit;  in mbedtls_mps_reader_reclaim()  local
431     frag     = rd->frag;  in mbedtls_mps_reader_reclaim()
432     acc      = rd->acc;  in mbedtls_mps_reader_reclaim()
433     pending  = rd->pending;  in mbedtls_mps_reader_reclaim()
434     commit   = rd->commit;  in mbedtls_mps_reader_reclaim()
435     frag_len = rd->frag_len;  in mbedtls_mps_reader_reclaim()
442                            "No unsatisfied read-request has been logged." );  in mbedtls_mps_reader_reclaim()
445         if( commit < frag_offset || commit - frag_offset < frag_len )  in mbedtls_mps_reader_reclaim()
449             rd->end = commit;  in mbedtls_mps_reader_reclaim()
453         rd->acc_available = 0;  in mbedtls_mps_reader_reclaim()
454         rd->acc_share.acc_remaining = 0;  in mbedtls_mps_reader_reclaim()
482         acc_len = rd->acc_len;  in mbedtls_mps_reader_reclaim()
486         if( commit < frag_offset )  in mbedtls_mps_reader_reclaim()
491             acc_backup_offset = commit;  in mbedtls_mps_reader_reclaim()
492             acc_backup_len = frag_offset - commit;  in mbedtls_mps_reader_reclaim()
497             frag_backup_offset = commit - frag_offset;  in mbedtls_mps_reader_reclaim()
498             frag_backup_len = frag_len - frag_backup_offset;  in mbedtls_mps_reader_reclaim()
514              * since the last commit. */  in mbedtls_mps_reader_reclaim()
515             rd->end = commit;  in mbedtls_mps_reader_reclaim()
516             rd->pending = 0;  in mbedtls_mps_reader_reclaim()
543         rd->acc_available = backup_len;  in mbedtls_mps_reader_reclaim()
544         rd->acc_share.acc_remaining = pending;  in mbedtls_mps_reader_reclaim()
550     rd->frag     = NULL;  in mbedtls_mps_reader_reclaim()
551     rd->frag_len = 0;  in mbedtls_mps_reader_reclaim()
553     rd->commit  = 0;  in mbedtls_mps_reader_reclaim()
554     rd->end     = 0;  in mbedtls_mps_reader_reclaim()
555     rd->pending = 0;  in mbedtls_mps_reader_reclaim()
559                        (unsigned) rd->acc_available, (unsigned) rd->acc_len,  in mbedtls_mps_reader_reclaim()
560                        (unsigned) rd->acc_share.acc_remaining );  in mbedtls_mps_reader_reclaim()