text: /*
   * RTMP input format
   * Copyright (c) 2009 Konstantin Shishkov
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  #include "libavcodec/bytestream.h"
  #include "libavutil/avstring.h"
  #include "libavutil/intfloat.h"
  #include "avformat.h"
  
  #include "rtmppkt.h"
  #include "flv.h"
  #include "url.h"
  
  void ff_amf_write_bool(uint8_t **dst, int val)
  {
      bytestream_put_byte(dst, AMF_DATA_TYPE_BOOL);
      bytestream_put_byte(dst, val);
  }
  
  void ff_amf_write_number(uint8_t **dst, double val)
  {
      bytestream_put_byte(dst, AMF_DATA_TYPE_NUMBER);
      bytestream_put_be64(dst, av_double2int(val));
  }
  
  void ff_amf_write_string(uint8_t **dst, const char *str)
  {
      bytestream_put_byte(dst, AMF_DATA_TYPE_STRING);
      bytestream_put_be16(dst, strlen(str));
      bytestream_put_buffer(dst, str, strlen(str));
  }
  
  void ff_amf_write_string2(uint8_t **dst, const char *str1, const char *str2)
  {
      int len1 = 0, len2 = 0;
      if (str1)
          len1 = strlen(str1);
      if (str2)
          len2 = strlen(str2);
      bytestream_put_byte(dst, AMF_DATA_TYPE_STRING);
      bytestream_put_be16(dst, len1 + len2);
      bytestream_put_buffer(dst, str1, len1);
      bytestream_put_buffer(dst, str2, len2);
  }
  
  void ff_amf_write_null(uint8_t **dst)
  {
      bytestream_put_byte(dst, AMF_DATA_TYPE_NULL);
  }
  
  void ff_amf_write_object_start(uint8_t **dst)
  {
      bytestream_put_byte(dst, AMF_DATA_TYPE_OBJECT);
  }
  
  void ff_amf_write_field_name(uint8_t **dst, const char *str)
  {
      bytestream_put_be16(dst, strlen(str));
      bytestream_put_buffer(dst, str, strlen(str));
  }
  
  void ff_amf_write_object_end(uint8_t **dst)
  {
      /* first two bytes are field name length = 0,
       * AMF object should end with it and end marker
       */
      bytestream_put_be24(dst, AMF_DATA_TYPE_OBJECT_END);
  }
  
  int ff_amf_read_bool(GetByteContext *bc, int *val)
  {
      if (bytestream2_get_byte(bc) != AMF_DATA_TYPE_BOOL)
          return AVERROR_INVALIDDATA;
      *val = bytestream2_get_byte(bc);
      return 0;
  }
  
  int ff_amf_read_number(GetByteContext *bc, double *val)
  {
      uint64_t read;
      if (bytestream2_get_byte(bc) != AMF_DATA_TYPE_NUMBER)
          return AVERROR_INVALIDDATA;
      read = bytestream2_get_be64(bc);
      *val = av_int2double(read);
      return 0;
  }
  
  int ff_amf_get_string(GetByteContext *bc, uint8_t *str,
                        int strsize, int *length)
  {
      int stringlen = 0;
      int readsize;
      stringlen = bytestream2_get_be16(bc);
      if (stringlen + 1 > strsize)
          return AVERROR(EINVAL);
      readsize = bytestream2_get_buffer(bc, str, stringlen);
      if (readsize != stringlen) {
          av_log(NULL, AV_LOG_WARNING,
                 "Unable to read as many bytes as AMF string signaled\n");
      }
      str[readsize] = '\0';
      *length = FFMIN(stringlen, readsize);
      return 0;
  }
  
  int ff_amf_read_string(GetByteContext *bc, uint8_t *str,
                         int strsize, int *length)
  {
      if (bytestream2_get_byte(bc) != AMF_DATA_TYPE_STRING)
          return AVERROR_INVALIDDATA;
      return ff_amf_get_string(bc, str, strsize, length);
  }
  
  int ff_amf_read_null(GetByteContext *bc)
  {
      if (bytestream2_get_byte(bc) != AMF_DATA_TYPE_NULL)
          return AVERROR_INVALIDDATA;
      return 0;
  }
  
  int ff_rtmp_check_alloc_array(RTMPPacket **prev_pkt, int *nb_prev_pkt,
                                int channel)
  {
      int nb_alloc;
      RTMPPacket *ptr;
      if (channel < *nb_prev_pkt)
          return 0;
  
      nb_alloc = channel + 16;
      // This can't use the av_reallocp family of functions, since we
      // would need to free each element in the array before the array
      // itself is freed.
      ptr = av_realloc_array(*prev_pkt, nb_alloc, sizeof(**prev_pkt));
      if (!ptr)
          return AVERROR(ENOMEM);
      memset(ptr + *nb_prev_pkt, 0, (nb_alloc - *nb_prev_pkt) * sizeof(*ptr));
      *prev_pkt = ptr;
      *nb_prev_pkt = nb_alloc;
      return 0;
  }
  
  int ff_rtmp_packet_read(URLContext *h, RTMPPacket *p,
                          int chunk_size, RTMPPacket **prev_pkt, int *nb_prev_pkt)
  {
      uint8_t hdr;
  
      if (ffurl_read(h, &hdr, 1) != 1)
          return AVERROR(EIO);
  
      return ff_rtmp_packet_read_internal(h, p, chunk_size, prev_pkt,
                                          nb_prev_pkt, hdr);
  }
  
  static int rtmp_packet_read_one_chunk(URLContext *h, RTMPPacket *p,
                                        int chunk_size, RTMPPacket **prev_pkt_ptr,
                                        int *nb_prev_pkt, uint8_t hdr)
  {
  
      uint8_t buf[16];
      int channel_id, timestamp, size;
      uint32_t ts_field; // non-extended timestamp or delta field
      uint32_t extra = 0;
      enum RTMPPacketType type;
      int written = 0;
      int ret, toread;
      RTMPPacket *prev_pkt;
  
      written++;
      channel_id = hdr & 0x3F;
  
      if (channel_id < 2) { //special case for channel number >= 64
          buf[1] = 0;
          if (ffurl_read_complete(h, buf, channel_id + 1) != channel_id + 1)
              return AVERROR(EIO);
          written += channel_id + 1;
          channel_id = AV_RL16(buf) + 64;
      }
      if ((ret = ff_rtmp_check_alloc_array(prev_pkt_ptr, nb_prev_pkt,
                                           channel_id)) < 0)
          return ret;
      prev_pkt = *prev_pkt_ptr;
      size  = prev_pkt[channel_id].size;
      type  = prev_pkt[channel_id].type;
      extra = prev_pkt[channel_id].extra;
  
      hdr >>= 6; // header size indicator
      if (hdr == RTMP_PS_ONEBYTE) {
          ts_field = prev_pkt[channel_id].ts_field;
      } else {
          if (ffurl_read_complete(h, buf, 3) != 3)
              return AVERROR(EIO);
          written += 3;
          ts_field = AV_RB24(buf);
          if (hdr != RTMP_PS_FOURBYTES) {
              if (ffurl_read_complete(h, buf, 3) != 3)
                  return AVERROR(EIO);
              written += 3;
              size = AV_RB24(buf);
              if (ffurl_read_complete(h, buf, 1) != 1)
                  return AVERROR(EIO);
              written++;
              type = buf[0];
              if (hdr == RTMP_PS_TWELVEBYTES) {
                  if (ffurl_read_complete(h, buf, 4) != 4)
                      return AVERROR(EIO);
                  written += 4;
                  extra = AV_RL32(buf);
              }
          }
      }
      if (ts_field == 0xFFFFFF) {
          if (ffurl_read_complete(h, buf, 4) != 4)
              return AVERROR(EIO);
          timestamp = AV_RB32(buf);
      } else {
          timestamp = ts_field;
      }
      if (hdr != RTMP_PS_TWELVEBYTES)
          timestamp += prev_pkt[channel_id].timestamp;
  
      if (prev_pkt[channel_id].read && size != prev_pkt[channel_id].size) {
          av_log(NULL, AV_LOG_ERROR, "RTMP packet size mismatch %d != %d\n",
                  size,
                  prev_pkt[channel_id].size);
          ff_rtmp_packet_destroy(&prev_pkt[channel_id]);
          prev_pkt[channel_id].read = 0;
      }
  
      if (!prev_pkt[channel_id].read) {
          if ((ret = ff_rtmp_packet_create(p, channel_id, type, timestamp,
                                           size)) < 0)
              return ret;
          p->read = written;
          p->offset = 0;
          prev_pkt[channel_id].ts_field   = ts_field;
          prev_pkt[channel_id].timestamp  = timestamp;
      } else {
          // previous packet in this channel hasn't completed reading
          RTMPPacket *prev = &prev_pkt[channel_id];
          p->data          = prev->data;
          p->size          = prev->size;
          p->channel_id    = prev->channel_id;
          p->type          = prev->type;
          p->ts_field      = prev->ts_field;
          p->extra         = prev->extra;
          p->offset        = prev->offset;
          p->read          = prev->read + written;
          p->timestamp     = prev->timestamp;
          prev->data       = NULL;
      }
      p->extra = extra;
      // save history
      prev_pkt[channel_id].channel_id = channel_id;
      prev_pkt[channel_id].type       = type;
      prev_pkt[channel_id].size       = size;
      prev_pkt[channel_id].extra      = extra;
      size = size - p->offset;
  
      toread = FFMIN(size, chunk_size);
      if (ffurl_read_complete(h, p->data + p->offset, toread) != toread) {
          ff_rtmp_packet_destroy(p);
          return AVERROR(EIO);
      }
      size      -= toread;
      p->read   += toread;
      p->offset += toread;
  
      if (size > 0) {
         RTMPPacket *prev = &prev_pkt[channel_id];
         prev->data = p->data;
         prev->read = p->read;
         prev->offset = p->offset;
         p->data      = NULL;
         return AVERROR(EAGAIN);
      }
  
      prev_pkt[channel_id].read = 0; // read complete; reset if needed
      return p->read;
  }
  
  int ff_rtmp_packet_read_internal(URLContext *h, RTMPPacket *p, int chunk_size,
                                   RTMPPacket **prev_pkt, int *nb_prev_pkt,
                                   uint8_t hdr)
  {
      while (1) {
          int ret = rtmp_packet_read_one_chunk(h, p, chunk_size, prev_pkt,
                                               nb_prev_pkt, hdr);
          if (ret > 0 || ret != AVERROR(EAGAIN))
              return ret;
  
          if (ffurl_read(h, &hdr, 1) != 1)
              return AVERROR(EIO);
      }
  }
  
  int ff_rtmp_packet_write(URLContext *h, RTMPPacket *pkt,
                           int chunk_size, RTMPPacket **prev_pkt_ptr,
                           int *nb_prev_pkt)
  {
      uint8_t pkt_hdr[16], *p = pkt_hdr;
      int mode = RTMP_PS_TWELVEBYTES;
      int off = 0;
      int written = 0;
      int ret;
      RTMPPacket *prev_pkt;
      int use_delta; // flag if using timestamp delta, not RTMP_PS_TWELVEBYTES
      uint32_t timestamp; // full 32-bit timestamp or delta value
  
      if ((ret = ff_rtmp_check_alloc_array(prev_pkt_ptr, nb_prev_pkt,
                                           pkt->channel_id)) < 0)
          return ret;
      prev_pkt = *prev_pkt_ptr;
  
      //if channel_id = 0, this is first presentation of prev_pkt, send full hdr.
      use_delta = prev_pkt[pkt->channel_id].channel_id &&
          pkt->extra == prev_pkt[pkt->channel_id].extra &&
          pkt->timestamp >= prev_pkt[pkt->channel_id].timestamp;
  
      timestamp = pkt->timestamp;
      if (use_delta) {
          timestamp -= prev_pkt[pkt->channel_id].timestamp;
      }
      if (timestamp >= 0xFFFFFF) {
          pkt->ts_field = 0xFFFFFF;
      } else {
          pkt->ts_field = timestamp;
      }
  
      if (use_delta) {
          if (pkt->type == prev_pkt[pkt->channel_id].type &&
              pkt->size == prev_pkt[pkt->channel_id].size) {
              mode = RTMP_PS_FOURBYTES;
              if (pkt->ts_field == prev_pkt[pkt->channel_id].ts_field)
                  mode = RTMP_PS_ONEBYTE;
          } else {
              mode = RTMP_PS_EIGHTBYTES;
          }
      }
  
      if (pkt->channel_id < 64) {
          bytestream_put_byte(&p, pkt->channel_id | (mode << 6));
      } else if (pkt->channel_id < 64 + 256) {
          bytestream_put_byte(&p, 0               | (mode << 6));
          bytestream_put_byte(&p, pkt->channel_id - 64);
      } else {
          bytestream_put_byte(&p, 1               | (mode << 6));
          bytestream_put_le16(&p, pkt->channel_id - 64);
      }
      if (mode != RTMP_PS_ONEBYTE) {
          bytestream_put_be24(&p, pkt->ts_field);
          if (mode != RTMP_PS_FOURBYTES) {
              bytestream_put_be24(&p, pkt->size);
              bytestream_put_byte(&p, pkt->type);
              if (mode == RTMP_PS_TWELVEBYTES)
                  bytestream_put_le32(&p, pkt->extra);
          }
      }
      if (pkt->ts_field == 0xFFFFFF)
          bytestream_put_be32(&p, timestamp);
      // save history
      prev_pkt[pkt->channel_id].channel_id = pkt->channel_id;
      prev_pkt[pkt->channel_id].type       = pkt->type;
      prev_pkt[pkt->channel_id].size       = pkt->size;
      prev_pkt[pkt->channel_id].timestamp  = pkt->timestamp;
      prev_pkt[pkt->channel_id].ts_field   = pkt->ts_field;
      prev_pkt[pkt->channel_id].extra      = pkt->extra;
  
      if ((ret = ffurl_write(h, pkt_hdr, p - pkt_hdr)) < 0)
          return ret;
      written = p - pkt_hdr + pkt->size;
      while (off < pkt->size) {
          int towrite = FFMIN(chunk_size, pkt->size - off);
          if ((ret = ffurl_write(h, pkt->data + off, towrite)) < 0)
              return ret;
          off += towrite;
          if (off < pkt->size) {
              uint8_t marker = 0xC0 | pkt->channel_id;
              if ((ret = ffurl_write(h, &marker, 1)) < 0)
                  return ret;
              written++;
              if (pkt->ts_field == 0xFFFFFF) {
                  uint8_t ts_header[4];
                  AV_WB32(ts_header, timestamp);
                  if ((ret = ffurl_write(h, ts_header, 4)) < 0)
                      return ret;
                  written += 4;
              }
          }
      }
      return written;
  }
  
  int ff_rtmp_packet_create(RTMPPacket *pkt, int channel_id, RTMPPacketType type,
                            int timestamp, int size)
  {
      if (size) {
          pkt->data = av_realloc(NULL, size);
          if (!pkt->data)
              return AVERROR(ENOMEM);
      }
      pkt->size       = size;
      pkt->channel_id = channel_id;
      pkt->type       = type;
      pkt->timestamp  = timestamp;
      pkt->extra      = 0;
      pkt->ts_field   = 0;
  
      return 0;
  }
  
  void ff_rtmp_packet_destroy(RTMPPacket *pkt)
  {
      if (!pkt)
          return;
      av_freep(&pkt->data);
      pkt->size = 0;
  }
  
  int ff_amf_tag_size(const uint8_t *data, const uint8_t *data_end)
  {
      const uint8_t *base = data;
      AMFDataType type;
      unsigned nb   = -1;
      int parse_key = 1;
  
      if (data >= data_end)
          return -1;
      switch ((type = *data++)) {
      case AMF_DATA_TYPE_NUMBER:      return 9;
      case AMF_DATA_TYPE_BOOL:        return 2;
      case AMF_DATA_TYPE_STRING:      return 3 + AV_RB16(data);
      case AMF_DATA_TYPE_LONG_STRING: return 5 + AV_RB32(data);
      case AMF_DATA_TYPE_NULL:        return 1;
      case AMF_DATA_TYPE_DATE:        return 11;
      case AMF_DATA_TYPE_ARRAY:
          parse_key = 0;
      case AMF_DATA_TYPE_MIXEDARRAY:
          nb = bytestream_get_be32(&data);
      case AMF_DATA_TYPE_OBJECT:
          while (nb-- > 0 || type != AMF_DATA_TYPE_ARRAY) {
              int t;
              if (parse_key) {
                  int size = bytestream_get_be16(&data);
                  if (!size) {
                      data++;
                      break;
                  }
                  if (size < 0 || size >= data_end - data)
                      return -1;
                  data += size;
              }
              t = ff_amf_tag_size(data, data_end);
              if (t < 0 || t >= data_end - data)
                  return -1;
              data += t;
          }
          return data - base;
      case AMF_DATA_TYPE_OBJECT_END:  return 1;
      default:                        return -1;
      }
  }
  
  int ff_amf_get_field_value(const uint8_t *data, const uint8_t *data_end,
                             const uint8_t *name, uint8_t *dst, int dst_size)
  {
      int namelen = strlen(name);
      int len;
  
      while (*data != AMF_DATA_TYPE_OBJECT && data < data_end) {
          len = ff_amf_tag_size(data, data_end);
          if (len < 0)
              len = data_end - data;
          data += len;
      }
      if (data_end - data < 3)
          return -1;
      data++;
      for (;;) {
          int size = bytestream_get_be16(&data);
          if (!size)
              break;
          if (size < 0 || size >= data_end - data)
              return -1;
          data += size;
          if (size == namelen && !memcmp(data-size, name, namelen)) {
              switch (*data++) {
              case AMF_DATA_TYPE_NUMBER:
                  snprintf(dst, dst_size, "%g", av_int2double(AV_RB64(data)));
                  break;
              case AMF_DATA_TYPE_BOOL:
                  snprintf(dst, dst_size, "%s", *data ? "true" : "false");
                  break;
              case AMF_DATA_TYPE_STRING:
                  len = bytestream_get_be16(&data);
                  av_strlcpy(dst, data, FFMIN(len+1, dst_size));
                  break;
              default:
                  return -1;
              }
              return 0;
          }
          len = ff_amf_tag_size(data, data_end);
          if (len < 0 || len >= data_end - data)
              return -1;
          data += len;
      }
      return -1;
  }
  
  static const char* rtmp_packet_type(int type)
  {
      switch (type) {
      case RTMP_PT_CHUNK_SIZE:     return "chunk size";
      case RTMP_PT_BYTES_READ:     return "bytes read";
      case RTMP_PT_PING:           return "ping";
      case RTMP_PT_SERVER_BW:      return "server bandwidth";
      case RTMP_PT_CLIENT_BW:      return "client bandwidth";
      case RTMP_PT_AUDIO:          return "audio packet";
      case RTMP_PT_VIDEO:          return "video packet";
      case RTMP_PT_FLEX_STREAM:    return "Flex shared stream";
      case RTMP_PT_FLEX_OBJECT:    return "Flex shared object";
      case RTMP_PT_FLEX_MESSAGE:   return "Flex shared message";
      case RTMP_PT_NOTIFY:         return "notification";
      case RTMP_PT_SHARED_OBJ:     return "shared object";
      case RTMP_PT_INVOKE:         return "invoke";
      case RTMP_PT_METADATA:       return "metadata";
      default:                     return "unknown";
      }
  }
  
  static void amf_tag_contents(void *ctx, const uint8_t *data,
                               const uint8_t *data_end)
  {
      unsigned int size, nb = -1;
      char buf[1024];
      AMFDataType type;
      int parse_key = 1;
  
      if (data >= data_end)
          return;
      switch ((type = *data++)) {
      case AMF_DATA_TYPE_NUMBER:
          av_log(ctx, AV_LOG_DEBUG, " number %g\n", av_int2double(AV_RB64(data)));
          return;
      case AMF_DATA_TYPE_BOOL:
          av_log(ctx, AV_LOG_DEBUG, " bool %d\n", *data);
          return;
      case AMF_DATA_TYPE_STRING:
      case AMF_DATA_TYPE_LONG_STRING:
          if (type == AMF_DATA_TYPE_STRING) {
              size = bytestream_get_be16(&data);
          } else {
              size = bytestream_get_be32(&data);
          }
          size = FFMIN(size, sizeof(buf) - 1);
          memcpy(buf, data, size);
          buf[size] = 0;
          av_log(ctx, AV_LOG_DEBUG, " string '%s'\n", buf);
          return;
      case AMF_DATA_TYPE_NULL:
          av_log(ctx, AV_LOG_DEBUG, " NULL\n");
          return;
      case AMF_DATA_TYPE_ARRAY:
          parse_key = 0;
      case AMF_DATA_TYPE_MIXEDARRAY:
          nb = bytestream_get_be32(&data);
      case AMF_DATA_TYPE_OBJECT:
          av_log(ctx, AV_LOG_DEBUG, " {\n");
          while (nb-- > 0 || type != AMF_DATA_TYPE_ARRAY) {
              int t;
              if (parse_key) {
                  size = bytestream_get_be16(&data);
                  size = FFMIN(size, sizeof(buf) - 1);
                  if (!size) {
                      av_log(ctx, AV_LOG_DEBUG, " }\n");
                      data++;
                      break;
                  }
                  memcpy(buf, data, size);
                  buf[size] = 0;
                  if (size >= data_end - data)
                      return;
                  data += size;
                  av_log(ctx, AV_LOG_DEBUG, "  %s: ", buf);
              }
              amf_tag_contents(ctx, data, data_end);
              t = ff_amf_tag_size(data, data_end);
              if (t < 0 || t >= data_end - data)
                  return;
              data += t;
          }
          return;
      case AMF_DATA_TYPE_OBJECT_END:
          av_log(ctx, AV_LOG_DEBUG, " }\n");
          return;
      default:
          return;
      }
  }
  
  void ff_rtmp_packet_dump(void *ctx, RTMPPacket *p)
  {
      av_log(ctx, AV_LOG_DEBUG, "RTMP packet type '%s'(%d) for channel %d, timestamp %d, extra field %d size %d\n",
             rtmp_packet_type(p->type), p->type, p->channel_id, p->timestamp, p->extra, p->size);
      if (p->type == RTMP_PT_INVOKE || p->type == RTMP_PT_NOTIFY) {
          uint8_t *src = p->data, *src_end = p->data + p->size;
          while (src < src_end) {
              int sz;
              amf_tag_contents(ctx, src, src_end);
              sz = ff_amf_tag_size(src, src_end);
              if (sz < 0)
                  break;
              src += sz;
          }
      } else if (p->type == RTMP_PT_SERVER_BW){
          av_log(ctx, AV_LOG_DEBUG, "Server BW = %d\n", AV_RB32(p->data));
      } else if (p->type == RTMP_PT_CLIENT_BW){
          av_log(ctx, AV_LOG_DEBUG, "Client BW = %d\n", AV_RB32(p->data));
      } else if (p->type != RTMP_PT_AUDIO && p->type != RTMP_PT_VIDEO && p->type != RTMP_PT_METADATA) {
          int i;
          for (i = 0; i < p->size; i++)
              av_log(ctx, AV_LOG_DEBUG, " %02X", p->data[i]);
          av_log(ctx, AV_LOG_DEBUG, "\n");
      }
  }
  
  int ff_amf_match_string(const uint8_t *data, int size, const char *str)
  {
      int len = strlen(str);
      int amf_len, type;
  
      if (size < 1)
          return 0;
  
      type = *data++;
  
      if (type != AMF_DATA_TYPE_LONG_STRING &&
          type != AMF_DATA_TYPE_STRING)
          return 0;
  
      if (type == AMF_DATA_TYPE_LONG_STRING) {
          if ((size -= 4 + 1) < 0)
              return 0;
          amf_len = bytestream_get_be32(&data);
      } else {
          if ((size -= 2 + 1) < 0)
              return 0;
          amf_len = bytestream_get_be16(&data);
      }
  
      if (amf_len > size)
          return 0;
  
      if (amf_len != len)
          return 0;
  
      return !memcmp(data, str, len);
  }
  