Add support of endianness for st40_rfc8331_rtp_hdr (#1203)

Added option to support conversion from big to little endian in st40 RTP
header.

Author: Magda-Pytel

ecosystem/gstreamer_plugin/gst_mtl_st40_rx.c

@@ -381,7 +381,11 @@ static GstFlowReturn gst_mtl_st40_rx_fill_buffer(Gst_Mtl_St40_Rx* src, GstBuffer
   gint udw_size;
 
   hdr = (struct st40_rfc8331_rtp_hdr*)usrptr;
+
   payload_hdr = (struct st40_rfc8331_payload_hdr*)(&hdr[1]);
+
+  hdr->swapped_first_hdr_chunk = ntohl(hdr->swapped_first_hdr_chunk);
+
   payload_hdr_swapped.swapped_second_hdr_chunk =
       ntohl(payload_hdr->swapped_second_hdr_chunk);
   udw_size = payload_hdr_swapped.second_hdr_chunk.data_count & 0xff;

include/st40_api.h

@@ -84,23 +84,49 @@ enum st40_type {
 /**
  * A structure describing a st2110-40(ancillary) rfc8331 rtp header
  */
+#ifdef MTL_LITTLE_ENDIAN
 MTL_PACK(struct st40_rfc8331_rtp_hdr {
   /** Rtp rfc3550 base hdr */
   struct st_rfc3550_rtp_hdr base;
   /** Extended Sequence Number */
   uint16_t seq_number_ext;
   /** Number of octets of the ANC data RTP payload */
   uint16_t length;
-
-  struct {
-    /** the count of the total number of ANC data packets carried in the RTP payload */
-    uint32_t anc_count : 8;
-    /** signaling the field specified by the RTP timestamp in an interlaced SDI raster */
-    uint32_t f : 2;
-    /** reserved */
-    uint32_t reserved : 22;
+  union {
+    struct {
+      /** reserved */
+      uint32_t reserved : 22;
+      /** signaling the field specified by the RTP timestamp in an interlaced SDI raster
+       */
+      uint32_t f : 2;
+      /** the count of the total number of ANC data packets carried in the RTP payload */
+      uint32_t anc_count : 8;
+    } first_hdr_chunk;
+    uint32_t swapped_first_hdr_chunk;
   };
 });
+#else
+MTL_PACK(struct st40_rfc8331_rtp_hdr {
+  /** Rtp rfc3550 base hdr */
+  struct st_rfc3550_rtp_hdr base;
+  /** Extended Sequence Number */
+  uint16_t seq_number_ext;
+  /** Number of octets of the ANC data RTP payload */
+  uint16_t length;
+  union {
+    struct {
+      /** the count of the total number of ANC data packets carried in the RTP payload */
+      uint32_t anc_count : 8;
+      /** signaling the field specified by the RTP timestamp in an interlaced SDI raster
+       */
+      uint32_t f : 2;
+      /** reserved */
+      uint32_t reserved : 22;
+    } first_hdr_chunk;
+    uint32_t swapped_first_hdr_chunk;
+  };
+});
+#endif
 
 /* A structure describing the first 32 bits of an ST 2110-40 (ancillary) payload header */
 #ifdef MTL_LITTLE_ENDIAN

lib/src/st2110/st_rx_ancillary_session.c

@@ -93,6 +93,7 @@ static int rx_ancillary_session_handle_pkt(struct mtl_main_impl* impl,
   uint16_t seq_id = ntohs(rtp->seq_number);
   uint8_t payload_type = rtp->payload_type;
   struct st40_rfc8331_rtp_hdr* rfc8331 = (struct st40_rfc8331_rtp_hdr*)rtp;
+  rfc8331->swapped_first_hdr_chunk = ntohl(rfc8331->swapped_first_hdr_chunk);
   MTL_MAY_UNUSED(s_port);
   uint32_t pkt_len = mbuf->data_len - sizeof(struct st40_rfc8331_rtp_hdr);
   MTL_MAY_UNUSED(pkt_len);
@@ -115,14 +116,14 @@ static int rx_ancillary_session_handle_pkt(struct mtl_main_impl* impl,
   }
 
   /* Drop if F is 0b01 (invalid: bit 0 set, bit 1 clear) */
-  if ((rfc8331->f & 0x3) == 0x1) {
+  if ((rfc8331->first_hdr_chunk.f & 0x3) == 0x1) {
     s->stat_pkts_wrong_interlace_dropped++;
     return -EINVAL;
   }
   /* 0b10: first field (bit 1 set, bit 0 clear)
      0b11: second field (bit 1 set, bit 0 set) */
-  if (rfc8331->f & 0x2) {
-    if (rfc8331->f & 0x1)
+  if (rfc8331->first_hdr_chunk.f & 0x2) {
+    if (rfc8331->first_hdr_chunk.f & 0x1)
       s->stat_interlace_second_field++;
     else
       s->stat_interlace_first_field++;

lib/src/st2110/st_tx_ancillary_session.c

@@ -131,6 +131,8 @@ static int tx_ancillary_session_init_hdr(struct mtl_main_impl* impl,
   struct rte_ipv4_hdr* ipv4 = &hdr->ipv4;
   struct rte_udp_hdr* udp = &hdr->udp;
   struct st40_rfc8331_rtp_hdr* rtp = &hdr->rtp;
+
+  /* Print rtp_header in both host and network byte order to check endianness */
   uint8_t* dip = ops->dip_addr[s_port];
   uint8_t* sip = mt_sip_addr(impl, port);
   struct rte_ether_addr* d_addr = mt_eth_d_addr(eth);
@@ -465,19 +467,21 @@ static int tx_ancillary_session_build_packet(struct st_tx_ancillary_session_impl
   pkt->data_len += payload_size + sizeof(struct st40_rfc8331_rtp_hdr);
   pkt->pkt_len = pkt->data_len;
   rtp->length = htons(payload_size);
-  rtp->anc_count = idx - s->st40_pkt_idx;
+  rtp->first_hdr_chunk.anc_count = idx - s->st40_pkt_idx;
   if (s->ops.interlaced) {
     if (frame_info->tc_meta.second_field)
-      rtp->f = 0b11;
+      rtp->first_hdr_chunk.f = 0b11;
     else
-      rtp->f = 0b10;
+      rtp->first_hdr_chunk.f = 0b10;
   } else {
-    rtp->f = 0b00;
+    rtp->first_hdr_chunk.f = 0b00;
   }
   if (idx == anc_count) rtp->base.marker = 1;
   dbg("%s(%d), anc_count %d, payload_size %d\n", __func__, s->idx, anc_count,
       payload_size);
 
+  rtp->swapped_first_hdr_chunk = htonl(rtp->swapped_first_hdr_chunk);
+
   udp->dgram_len = htons(pkt->pkt_len - pkt->l2_len - pkt->l3_len);
   ipv4->total_length = htons(pkt->pkt_len - pkt->l2_len);
 
@@ -553,16 +557,19 @@ static int tx_ancillary_session_build_rtp_packet(struct st_tx_ancillary_session_
   pkt->data_len = payload_size + sizeof(struct st40_rfc8331_rtp_hdr);
   pkt->pkt_len = pkt->data_len;
   rtp->length = htons(payload_size);
-  rtp->anc_count = idx - anc_idx;
+  rtp->first_hdr_chunk.anc_count = idx - anc_idx;
   if (s->ops.interlaced) {
     if (frame_info->tc_meta.second_field)
-      rtp->f = 0b11;
+      rtp->first_hdr_chunk.f = 0b11;
     else
-      rtp->f = 0b10;
+      rtp->first_hdr_chunk.f = 0b10;
   } else {
-    rtp->f = 0b00;
+    rtp->first_hdr_chunk.f = 0b00;
   }
   if (idx == anc_count) rtp->base.marker = 1;
+
+  rtp->swapped_first_hdr_chunk = htonl(rtp->swapped_first_hdr_chunk);
+
   dbg("%s(%d), anc_count %d, payload_size %d\n", __func__, s->idx, anc_count,
       payload_size);
   return idx;
@@ -595,7 +602,8 @@ static int tx_ancillary_session_rtp_update_packet(struct mtl_main_impl* impl,
     bool second_field = false;
     if (s->ops.interlaced) {
       struct st40_rfc8331_rtp_hdr* rfc8331 = (struct st40_rfc8331_rtp_hdr*)rtp;
-      second_field = (rfc8331->f == 0b11) ? true : false;
+      second_field = (rfc8331->first_hdr_chunk.f == 0b11) ? true : false;
+      rfc8331->swapped_first_hdr_chunk = htonl(rfc8331->swapped_first_hdr_chunk);
     }
     tx_ancillary_session_sync_pacing(impl, s, false, 0, second_field);
   }
@@ -651,14 +659,16 @@ static int tx_ancillary_session_build_packet_chain(struct mtl_main_impl* impl,
         bool second_field = false;
         if (s->ops.interlaced) {
           struct st40_rfc8331_rtp_hdr* rfc8331 = (struct st40_rfc8331_rtp_hdr*)&udp[1];
-          second_field = (rfc8331->f == 0b11) ? true : false;
+          second_field = (rfc8331->first_hdr_chunk.f == 0b11) ? true : false;
+          rfc8331->swapped_first_hdr_chunk = htonl(rfc8331->swapped_first_hdr_chunk);
         }
         tx_ancillary_session_sync_pacing(impl, s, false, 0, second_field);
       }
       if (s->ops.flags & ST40_TX_FLAG_USER_TIMESTAMP) {
         s->pacing.rtp_time_stamp = ntohl(rtp->base.tmstamp);
       }
       rtp->base.tmstamp = htonl(s->pacing.rtp_time_stamp);
+      rtp->swapped_first_hdr_chunk = htonl(rtp->swapped_first_hdr_chunk);
     }
   }
 

tests/tools/RxTxApp/src/rx_ancillary_app.c

@@ -8,7 +8,8 @@ static void app_rx_anc_handle_rtp(struct st_app_rx_anc_session* s, void* usrptr)
   struct st40_rfc8331_rtp_hdr* hdr = (struct st40_rfc8331_rtp_hdr*)usrptr;
   struct st40_rfc8331_payload_hdr* payload_hdr =
       (struct st40_rfc8331_payload_hdr*)(&hdr[1]);
-  int anc_count = hdr->anc_count;
+
+  int anc_count = hdr->first_hdr_chunk.anc_count;
   int idx, total_size, payload_len;
   dbg("%s(%d), anc_count %d\n", __func__, s->idx, anc_count);
 

tests/tools/RxTxApp/src/tx_ancillary_app.c

@@ -196,20 +196,21 @@ static void app_tx_anc_build_rtp(struct st_app_tx_anc_session* s, void* usrptr,
                                  uint16_t* mbuf_len) {
   /* generate one anc rtp for test purpose */
   struct st40_rfc8331_rtp_hdr* hdr = (struct st40_rfc8331_rtp_hdr*)usrptr;
+
   struct st40_rfc8331_payload_hdr* payload_hdr =
       (struct st40_rfc8331_payload_hdr*)(&hdr[1]);
   uint16_t udw_size = s->st40_source_end - s->st40_frame_cursor > 255
                           ? 255
                           : s->st40_source_end - s->st40_frame_cursor;
   uint16_t check_sum, total_size, payload_len;
   hdr->base.marker = 1;
-  hdr->anc_count = 1;
+  hdr->first_hdr_chunk.anc_count = 1;
   hdr->base.payload_type = s->st40_payload_type;
   hdr->base.version = 2;
   hdr->base.extension = 0;
   hdr->base.padding = 0;
   hdr->base.csrc_count = 0;
-  hdr->f = 0b00;
+  hdr->first_hdr_chunk.f = 0b00;
   hdr->base.tmstamp = s->st40_rtp_tmstamp;
   hdr->base.ssrc = htonl(0x88888888 + s->idx);
   /* update rtp seq*/
@@ -242,6 +243,7 @@ static void app_tx_anc_build_rtp(struct st_app_tx_anc_session* s, void* usrptr,
       sizeof(struct st40_rfc8331_payload_hdr) - 4 + total_size;  // Full size of one ANC
   *mbuf_len = payload_len + sizeof(struct st40_rfc8331_rtp_hdr);
   hdr->length = htons(payload_len);
+
   s->st40_frame_cursor += udw_size;
   if (s->st40_frame_cursor == s->st40_source_end)
     s->st40_frame_cursor = s->st40_source_begin;

tests/unittest/st40_test.cpp

@@ -36,13 +36,13 @@ static int tx_anc_build_rtp_packet(tests_context* s, struct st40_rfc8331_rtp_hdr
   /* rtp hdr */
   memset(rtp, 0x0, sizeof(*rtp));
   rtp->base.marker = 1;
-  rtp->anc_count = 0;
+  rtp->first_hdr_chunk.anc_count = 0;
   rtp->base.payload_type = ST40_TEST_PAYLOAD_TYPE;
   rtp->base.version = 2;
   rtp->base.extension = 0;
   rtp->base.padding = 0;
   rtp->base.csrc_count = 0;
-  rtp->f = 0b00;
+  rtp->first_hdr_chunk.f = 0b00;
   rtp->base.tmstamp = s->rtp_tmstamp;
   rtp->base.ssrc = htonl(0x88888888 + s->idx);
   /* update rtp seq*/
@@ -64,7 +64,7 @@ static int tx_anc_build_rtp_packet(tests_context* s, struct st40_rfc8331_rtp_hdr
     payload_hdr->second_hdr_chunk.data_count = st40_add_parity_bits(udw_size);
     payload_hdr->swapped_first_hdr_chunk = htonl(payload_hdr->swapped_first_hdr_chunk);
     payload_hdr->swapped_second_hdr_chunk = htonl(payload_hdr->swapped_second_hdr_chunk);
-    rtp->anc_count = 1;
+    rtp->first_hdr_chunk.anc_count = 1;
     for (int i = 0; i < udw_size; i++) {
       st40_set_udw(i + 3,
                    st40_add_parity_bits(s->frame_buf[s->seq_id % TEST_SHA_HIST_NUM][i]),
@@ -131,7 +131,7 @@ static int tx_rtp_done(void* args) {
 static void rx_handle_rtp(tests_context* s, struct st40_rfc8331_rtp_hdr* hdr) {
   struct st40_rfc8331_payload_hdr* payload_hdr =
       (struct st40_rfc8331_payload_hdr*)(&hdr[1]);
-  int anc_count = hdr->anc_count;
+  int anc_count = hdr->first_hdr_chunk.anc_count;
   int idx, total_size, payload_len;
 
   for (idx = 0; idx < anc_count; idx++) {