pespin has uploaded this change for review. ( https://gerrit.osmocom.org/c/libosmo-netif/+/29512 ) Change subject: osmux: Proper encoding of osmux frames when when AMR FT changes ...................................................................... osmux: Proper encoding of osmux frames when when AMR FT changes The AMR FT (and hence payload content and size) may well change over the lifetime of an RTP stream. Since all AMR payloads in an osmux batch share the same FT (its joined payload is calculated based on osmuxh->ctr*amr_bytes((osmuxh->amr_ft)), if a new RTP/AMR with a different FT arrives we cannot simply append it to the current batch. Instead, the current batch must be considered done and a new batch with anew osmuxh header must be prepared for the resulting osmux frame to send over UDP. Before this patch, when a packet with a different AMR FT was submitted for batching, it would be added in the same batch and decoding would fail since the sizes of the batches would be wrong. Related: SYS#5987 Change-Id: I25eb6ee54c898f575cc71ccfd6d190fe51d56dbe --- M src/osmux.c 1 file changed, 52 insertions(+), 29 deletions(-) git pull ssh://gerrit.osmocom.org:29418/libosmo-netif refs/changes/12/29512/1 diff --git a/src/osmux.c b/src/osmux.c index ac3cd06..07d2b2e 100644 --- a/src/osmux.c +++ b/src/osmux.c @@ -398,23 +398,6 @@ return 0; } -static int osmux_xfrm_encode_amr(struct osmux_batch *batch, - struct osmux_input_state *state) -{ - uint32_t amr_len; - - state->amrh = osmo_rtp_get_payload(state->rtph, state->msg, &amr_len); - if (state->amrh == NULL) - return -1; - - state->amr_payload_len = amr_len - sizeof(struct amr_hdr); - - if (osmux_batch_put(batch, state) < 0) - return -1; - - return 0; -} - static void osmux_encode_dummy(struct osmux_batch *batch, uint8_t batch_factor, struct osmux_input_state *state) { @@ -457,6 +440,7 @@ llist_for_each_entry(circuit, &batch->circuit_list, head) { struct msgb *cur, *tmp; int ctr = 0; + int prev_amr_ft; if (circuit->dummy) { struct osmux_input_state state = { @@ -473,6 +457,7 @@ .out_msg = batch_msg, .ccid = circuit->ccid, }; + uint32_t amr_len; #ifdef DEBUG_MSG char buf[4096]; @@ -482,20 +467,31 @@ #endif state.rtph = osmo_rtp_get_hdr(cur); - if (state.rtph == NULL) + if (!state.rtph) return NULL; + state.amrh = osmo_rtp_get_payload(state.rtph, state.msg, &amr_len); + if (!state.amrh) + return NULL; + state.amr_payload_len = amr_len - sizeof(struct amr_hdr); if (ctr == 0) { #ifdef DEBUG_MSG - LOGP(DLMUX, LOGL_DEBUG, "add osmux header\n"); + LOGP(DLMUX, LOGL_DEBUG, "Add osmux header (First in batch)\n"); +#endif + state.add_osmux_hdr = 1; + } else if (prev_amr_ft != state.amrh->ft) { + /* If AMR FT changed, we have to generate an extra batch osmux header: */ +#ifdef DEBUG_MSG + LOGP(DLMUX, LOGL_DEBUG, "Add osmux header (New AMR FT)\n"); #endif state.add_osmux_hdr = 1; } - osmux_xfrm_encode_amr(batch, &state); + osmux_batch_put(batch, &state); osmux_batch_dequeue(cur, circuit); - msgb_free(cur); + prev_amr_ft = state.amrh->ft; ctr++; + msgb_free(cur); batch->nmsgs--; } } @@ -536,16 +532,10 @@ osmux_xfrm_input_deliver(h); } -static int osmux_rtp_amr_payload_len(struct msgb *msg, struct rtp_hdr *rtph) +static int osmux_rtp_amr_payload_len(struct amr_hdr *amrh, uint32_t amr_len) { - struct amr_hdr *amrh; - unsigned int amr_len; int amr_payload_len; - amrh = osmo_rtp_get_payload(rtph, msg, &amr_len); - if (amrh == NULL) - return -1; - if (!osmo_amr_ft_valid(amrh->ft)) return -1; @@ -561,6 +551,28 @@ return amr_payload_len; } +/* Last stored AMR FT to be added in the current osmux batch. -1 if none stored yet */ +static int osmux_circuit_get_last_stored_amr_ft(struct osmux_circuit *circuit) +{ + struct msgb *last; + struct rtp_hdr *rtph; + struct amr_hdr *amrh; + uint32_t amr_len; + /* Have we seen any RTP packet in this batch before? */ + if (llist_empty(&circuit->msg_list)) + return -1; + OSMO_ASSERT(circuit->nmsgs > 0); + + /* Get last RTP packet seen in this batch */ + last = llist_entry(circuit->msg_list.prev, struct msgb, list); + rtph = osmo_rtp_get_hdr(last); + amrh = osmo_rtp_get_payload(rtph, last, &amr_len); + if (amrh == NULL) + return -1; + return amrh->ft; + +} + /* returns: 1 if batch is full, 0 if batch still not full, negative on error. */ static int osmux_replay_lost_packets(struct osmux_circuit *circuit, struct rtp_hdr *cur_rtph, int batch_factor) @@ -683,6 +695,8 @@ struct osmux_circuit *circuit; struct msgb *cur; int rc; + struct amr_hdr *amrh; + uint32_t amr_len; circuit = osmux_batch_find_circuit(batch, ccid); if (!circuit) @@ -693,7 +707,11 @@ circuit->dummy = 0; batch->ndummy--; } - amr_payload_len = osmux_rtp_amr_payload_len(msg, rtph); + + amrh = osmo_rtp_get_payload(rtph, msg, &amr_len); + if (amrh == NULL) + return -1; + amr_payload_len = osmux_rtp_amr_payload_len(amrh, amr_len); if (amr_payload_len < 0) { LOGP(DLMUX, LOGL_NOTICE, "AMR payload invalid\n"); return -1; @@ -723,8 +741,13 @@ } /* First check if there is room for this message in the batch */ + /* First in batch comes after the batch header: */ if (circuit->nmsgs == 0) bytes += sizeof(struct osmux_hdr); + /* If AMR FT changes in the middle of current batch a new header is + * required to adapt to size change: */ + else if (osmux_circuit_get_last_stored_amr_ft(circuit) != amrh->ft) + bytes += sizeof(struct osmux_hdr); bytes += amr_payload_len; /* No room, sorry. You'll have to retry */ -- To view, visit https://gerrit.osmocom.org/c/libosmo-netif/+/29512 To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings Gerrit-Project: libosmo-netif Gerrit-Branch: master Gerrit-Change-Id: I25eb6ee54c898f575cc71ccfd6d190fe51d56dbe Gerrit-Change-Number: 29512 Gerrit-PatchSet: 1 Gerrit-Owner: pespin <pespin@sysmocom.de> Gerrit-MessageType: newchange