git.sesse.net Git - nageru/blob - shared/httpd.cpp

   1 #include "shared/httpd.h"
   2
   3 #include <assert.h>
   4 #include <byteswap.h>
   5 #include <endian.h>
   6 #include <memory>
   7 #include <microhttpd.h>
   8 #include <netinet/in.h>
   9 #include <stdio.h>
  10 #include <string.h>
  11 #include <sys/time.h>
  12 #include <time.h>
  13 extern "C" {
  14 #include <libavutil/avutil.h>
  15 }
  16
  17 #include "shared/shared_defs.h"
  18 #include "shared/metacube2.h"
  19 #include "shared/metrics.h"
  20
  21 struct MHD_Connection;
  22 struct MHD_Response;
  23
  24 using namespace std;
  25
  26 HTTPD::HTTPD()
  27 {
  28         global_metrics.add("num_connected_clients", &metric_num_connected_clients, Metrics::TYPE_GAUGE);
  29         global_metrics.add("num_connected_multicam_clients", &metric_num_connected_multicam_clients, Metrics::TYPE_GAUGE);
  30         for (unsigned stream_idx = 0; stream_idx < MAX_VIDEO_CARDS; ++stream_idx) {
  31                 global_metrics.add("num_connected_siphon_clients",
  32                         {{ "card", to_string(stream_idx) }},
  33                         &metric_num_connected_siphon_clients[stream_idx], Metrics::TYPE_GAUGE);
  34         }
  35 }
  36
  37 HTTPD::~HTTPD()
  38 {
  39         stop();
  40 }
  41
  42 void HTTPD::start(int port)
  43 {
  44         mhd = MHD_start_daemon(MHD_USE_THREAD_PER_CONNECTION | MHD_USE_POLL_INTERNALLY | MHD_USE_DUAL_STACK,
  45                                port,
  46                                nullptr, nullptr,
  47                                &answer_to_connection_thunk, this,
  48                                MHD_OPTION_NOTIFY_COMPLETED, nullptr, this,
  49                                MHD_OPTION_END);
  50         if (mhd == nullptr) {
  51                 fprintf(stderr, "Warning: Could not open HTTP server. (Port already in use?)\n");
  52         }
  53 }
  54
  55 void HTTPD::stop()
  56 {
  57         if (mhd) {
  58                 MHD_quiesce_daemon(mhd);
  59                 for (Stream *stream : streams) {
  60                         stream->stop();
  61                 }
  62                 MHD_stop_daemon(mhd);
  63                 mhd = nullptr;
  64         }
  65 }
  66
  67 void HTTPD::set_header(StreamID stream_id, const string &data)
  68 {
  69         lock_guard<mutex> lock(streams_mutex);
  70         header[stream_id] = data;
  71         add_data_locked(stream_id, data.data(), data.size(), Stream::DATA_TYPE_HEADER, AV_NOPTS_VALUE, AVRational{ 1, 0 });
  72 }
  73
  74 void HTTPD::add_data(StreamID stream_id, const char *buf, size_t size, bool keyframe, int64_t time, AVRational timebase)
  75 {
  76         lock_guard<mutex> lock(streams_mutex);
  77         add_data_locked(stream_id, buf, size, keyframe ? Stream::DATA_TYPE_KEYFRAME : Stream::DATA_TYPE_OTHER, time, timebase);
  78 }
  79
  80 void HTTPD::add_data_locked(StreamID stream_id, const char *buf, size_t size, Stream::DataType data_type, int64_t time, AVRational timebase)
  81 {
  82         for (Stream *stream : streams) {
  83                 if (stream->get_stream_id() == stream_id) {
  84                         stream->add_data(buf, size, data_type, time, timebase);
  85                 }
  86         }
  87 }
  88
  89 int HTTPD::answer_to_connection_thunk(void *cls, MHD_Connection *connection,
  90                                       const char *url, const char *method,
  91                                       const char *version, const char *upload_data,
  92                                       size_t *upload_data_size, void **con_cls)
  93 {
  94         HTTPD *httpd = (HTTPD *)cls;
  95         return httpd->answer_to_connection(connection, url, method, version, upload_data, upload_data_size, con_cls);
  96 }
  97
  98 int HTTPD::answer_to_connection(MHD_Connection *connection,
  99                                 const char *url, const char *method,
 100                                 const char *version, const char *upload_data,
 101                                 size_t *upload_data_size, void **con_cls)
 102 {
 103         // See if the URL ends in “.metacube”.
 104         HTTPD::Stream::Framing framing;
 105         if (strstr(url, ".metacube") == url + strlen(url) - strlen(".metacube")) {
 106                 framing = HTTPD::Stream::FRAMING_METACUBE;
 107         } else {
 108                 framing = HTTPD::Stream::FRAMING_RAW;
 109         }
 110         HTTPD::StreamID stream_id;
 111         if (strcmp(url, "/multicam.mp4") == 0) {
 112                 stream_id.type = HTTPD::StreamType::MULTICAM_STREAM;
 113                 stream_id.index = 0;
 114         } else if (strncmp(url, "/feeds/", 7) == 0) {
 115                 stream_id.type = HTTPD::StreamType::SIPHON_STREAM;
 116                 stream_id.index = atoi(url + 7);
 117         } else {
 118                 stream_id.type = HTTPD::StreamType::MAIN_STREAM;
 119                 stream_id.index = 0;
 120         }
 121
 122         if (strcmp(url, "/metrics") == 0) {
 123                 string contents = global_metrics.serialize();
 124                 MHD_Response *response = MHD_create_response_from_buffer(
 125                         contents.size(), &contents[0], MHD_RESPMEM_MUST_COPY);
 126                 MHD_add_response_header(response, "Content-type", "text/plain");
 127                 int ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
 128                 MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
 129                 return ret;
 130         }
 131         if (endpoints.count(url)) {
 132                 pair<string, string> contents_and_type = endpoints[url].callback();
 133                 MHD_Response *response = MHD_create_response_from_buffer(
 134                         contents_and_type.first.size(), &contents_and_type.first[0], MHD_RESPMEM_MUST_COPY);
 135                 MHD_add_response_header(response, "Content-type", contents_and_type.second.c_str());
 136                 if (endpoints[url].cors_policy == ALLOW_ALL_ORIGINS) {
 137                         MHD_add_response_header(response, "Access-Control-Allow-Origin", "*");
 138                 }
 139                 int ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
 140                 MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
 141                 return ret;
 142         }
 143
 144         // Small hack; reject unknown /channels/foo.
 145         if (string(url).find("/channels/") == 0) {
 146                 string contents = "Not found.";
 147                 MHD_Response *response = MHD_create_response_from_buffer(
 148                         contents.size(), &contents[0], MHD_RESPMEM_MUST_COPY);
 149                 MHD_add_response_header(response, "Content-type", "text/plain");
 150                 int ret = MHD_queue_response(connection, MHD_HTTP_NOT_FOUND, response);
 151                 MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
 152                 return ret;
 153         }
 154
 155         HTTPD::Stream *stream = new HTTPD::Stream(this, framing, stream_id);
 156         const string &hdr = header[stream_id];
 157         stream->add_data(hdr.data(), hdr.size(), Stream::DATA_TYPE_HEADER, AV_NOPTS_VALUE, AVRational{ 1, 0 });
 158         {
 159                 lock_guard<mutex> lock(streams_mutex);
 160                 streams.insert(stream);
 161         }
 162         ++metric_num_connected_clients;
 163         if (stream_id.type == HTTPD::StreamType::MULTICAM_STREAM) {
 164                 ++metric_num_connected_multicam_clients;
 165         }
 166         if (stream_id.type == HTTPD::StreamType::SIPHON_STREAM) {
 167                 ++metric_num_connected_siphon_clients[stream_id.index];
 168         }
 169         *con_cls = stream;
 170
 171         // Does not strictly have to be equal to MUX_BUFFER_SIZE.
 172         MHD_Response *response = MHD_create_response_from_callback(
 173                 (size_t)-1, MUX_BUFFER_SIZE, &HTTPD::Stream::reader_callback_thunk, stream, &HTTPD::free_stream);
 174         // TODO: Content-type?
 175         if (framing == HTTPD::Stream::FRAMING_METACUBE) {
 176                 MHD_add_response_header(response, "Content-encoding", "metacube");
 177         }
 178
 179         int ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
 180         MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
 181
 182         return ret;
 183 }
 184
 185 void HTTPD::free_stream(void *cls)
 186 {
 187         HTTPD::Stream *stream = (HTTPD::Stream *)cls;
 188         HTTPD *httpd = stream->get_parent();
 189         if (stream->get_stream_id().type == HTTPD::StreamType::MULTICAM_STREAM) {
 190                 --httpd->metric_num_connected_multicam_clients;
 191         }
 192         if (stream->get_stream_id().type == HTTPD::StreamType::SIPHON_STREAM) {
 193                 --httpd->metric_num_connected_siphon_clients[stream->get_stream_id().index];
 194         }
 195         {
 196                 lock_guard<mutex> lock(httpd->streams_mutex);
 197                 delete stream;
 198                 httpd->streams.erase(stream);
 199         }
 200         --httpd->metric_num_connected_clients;
 201 }
 202
 203 ssize_t HTTPD::Stream::reader_callback_thunk(void *cls, uint64_t pos, char *buf, size_t max)
 204 {
 205         HTTPD::Stream *stream = (HTTPD::Stream *)cls;
 206         return stream->reader_callback(pos, buf, max);
 207 }
 208
 209 ssize_t HTTPD::Stream::reader_callback(uint64_t pos, char *buf, size_t max)
 210 {
 211         unique_lock<mutex> lock(buffer_mutex);
 212         has_buffered_data.wait(lock, [this] { return should_quit || !buffered_data.empty(); });
 213         if (should_quit) {
 214                 return -1;
 215         }
 216
 217         ssize_t ret = 0;
 218         while (max > 0 && !buffered_data.empty()) {
 219                 const string &s = buffered_data.front();
 220                 assert(s.size() > used_of_buffered_data);
 221                 size_t len = s.size() - used_of_buffered_data;
 222                 if (max >= len) {
 223                         // Consume the entire (rest of the) string.
 224                         memcpy(buf, s.data() + used_of_buffered_data, len);
 225                         buf += len;
 226                         ret += len;
 227                         max -= len;
 228                         buffered_data_bytes -= s.size();
 229                         buffered_data.pop_front();
 230                         used_of_buffered_data = 0;
 231                 } else {
 232                         // We don't need the entire string; just use the first part of it.
 233                         memcpy(buf, s.data() + used_of_buffered_data, max);
 234                         buf += max;
 235                         used_of_buffered_data += max;
 236                         ret += max;
 237                         max = 0;
 238                 }
 239         }
 240
 241         return ret;
 242 }
 243
 244 void HTTPD::Stream::add_data(const char *buf, size_t buf_size, HTTPD::Stream::DataType data_type, int64_t time, AVRational timebase)
 245 {
 246         if (buf_size == 0 || should_quit) {
 247                 return;
 248         }
 249         if (data_type == DATA_TYPE_KEYFRAME) {
 250                 seen_keyframe = true;
 251         } else if (data_type == DATA_TYPE_OTHER && !seen_keyframe) {
 252                 // Start sending only once we see a keyframe.
 253                 return;
 254         }
 255
 256         lock_guard<mutex> lock(buffer_mutex);
 257
 258         if (buffered_data_bytes + buf_size > (1ULL << 30)) {
 259                 // More than 1GB of backlog; the client obviously isn't keeping up,
 260                 // so kill it instead of going out of memory. Note that this
 261                 // won't kill the client immediately, but will cause the next callback
 262                 // to kill the client.
 263                 should_quit = true;
 264                 buffered_data.clear();
 265                 has_buffered_data.notify_all();
 266                 return;
 267         }
 268
 269         if (framing == FRAMING_METACUBE) {
 270                 int flags = 0;
 271                 if (data_type == DATA_TYPE_HEADER) {
 272                         flags |= METACUBE_FLAGS_HEADER;
 273                 } else if (data_type == DATA_TYPE_OTHER) {
 274                         flags |= METACUBE_FLAGS_NOT_SUITABLE_FOR_STREAM_START;
 275                 }
 276
 277                 // If we're about to send a keyframe, send a pts metadata block
 278                 // to mark its time.
 279                 if ((flags & METACUBE_FLAGS_NOT_SUITABLE_FOR_STREAM_START) == 0 && time != AV_NOPTS_VALUE) {
 280                         metacube2_pts_packet packet;
 281                         packet.type = htobe64(METACUBE_METADATA_TYPE_NEXT_BLOCK_PTS);
 282                         packet.pts = htobe64(time);
 283                         packet.timebase_num = htobe64(timebase.num);
 284                         packet.timebase_den = htobe64(timebase.den);
 285
 286                         metacube2_block_header hdr;
 287                         memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
 288                         hdr.size = htonl(sizeof(packet));
 289                         hdr.flags = htons(METACUBE_FLAGS_METADATA);
 290                         hdr.csum = htons(metacube2_compute_crc(&hdr));
 291                         buffered_data.emplace_back((char *)&hdr, sizeof(hdr));
 292                         buffered_data.emplace_back((char *)&packet, sizeof(packet));
 293                         buffered_data_bytes += sizeof(hdr) + sizeof(packet);
 294                 }
 295
 296                 metacube2_block_header hdr;
 297                 memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
 298                 hdr.size = htonl(buf_size);
 299                 hdr.flags = htons(flags);
 300                 hdr.csum = htons(metacube2_compute_crc(&hdr));
 301                 buffered_data.emplace_back((char *)&hdr, sizeof(hdr));
 302                 buffered_data_bytes += sizeof(hdr);
 303         }
 304         buffered_data.emplace_back(buf, buf_size);
 305         buffered_data_bytes += buf_size;
 306
 307         // Send a Metacube2 timestamp every keyframe.
 308         if (framing == FRAMING_METACUBE && data_type == DATA_TYPE_KEYFRAME) {
 309                 timespec now;
 310                 clock_gettime(CLOCK_REALTIME, &now);
 311
 312                 metacube2_timestamp_packet packet;
 313                 packet.type = htobe64(METACUBE_METADATA_TYPE_ENCODER_TIMESTAMP);
 314                 packet.tv_sec = htobe64(now.tv_sec);
 315                 packet.tv_nsec = htobe64(now.tv_nsec);
 316
 317                 metacube2_block_header hdr;
 318                 memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
 319                 hdr.size = htonl(sizeof(packet));
 320                 hdr.flags = htons(METACUBE_FLAGS_METADATA);
 321                 hdr.csum = htons(metacube2_compute_crc(&hdr));
 322                 buffered_data.emplace_back((char *)&hdr, sizeof(hdr));
 323                 buffered_data.emplace_back((char *)&packet, sizeof(packet));
 324                 buffered_data_bytes += sizeof(hdr) + sizeof(packet);
 325         }
 326
 327         has_buffered_data.notify_all();
 328 }
 329
 330 void HTTPD::Stream::stop()
 331 {
 332         lock_guard<mutex> lock(buffer_mutex);
 333         should_quit = true;
 334         has_buffered_data.notify_all();
 335 }