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_END);
  49         if (mhd == nullptr) {
  50                 fprintf(stderr, "Warning: Could not open HTTP server. (Port already in use?)\n");
  51         }
  52 }
  53
  54 void HTTPD::stop()
  55 {
  56         if (mhd) {
  57                 MHD_quiesce_daemon(mhd);
  58                 for (Stream *stream : streams) {
  59                         stream->stop();
  60                 }
  61                 MHD_stop_daemon(mhd);
  62                 mhd = nullptr;
  63         }
  64 }
  65
  66 void HTTPD::set_header(StreamID stream_id, const string &data)
  67 {
  68         lock_guard<mutex> lock(streams_mutex);
  69         header[stream_id] = data;
  70         add_data_locked(stream_id, data.data(), data.size(), Stream::DATA_TYPE_HEADER, AV_NOPTS_VALUE, AVRational{ 1, 0 });
  71 }
  72
  73 void HTTPD::add_data(StreamID stream_id, const char *buf, size_t size, bool keyframe, int64_t time, AVRational timebase)
  74 {
  75         lock_guard<mutex> lock(streams_mutex);
  76         add_data_locked(stream_id, buf, size, keyframe ? Stream::DATA_TYPE_KEYFRAME : Stream::DATA_TYPE_OTHER, time, timebase);
  77 }
  78
  79 void HTTPD::add_data_locked(StreamID stream_id, const char *buf, size_t size, Stream::DataType data_type, int64_t time, AVRational timebase)
  80 {
  81         for (Stream *stream : streams) {
  82                 if (stream->get_stream_id() == stream_id) {
  83                         stream->add_data(buf, size, data_type, time, timebase);
  84                 }
  85         }
  86 }
  87
  88 int HTTPD::answer_to_connection_thunk(void *cls, MHD_Connection *connection,
  89                                       const char *url, const char *method,
  90                                       const char *version, const char *upload_data,
  91                                       size_t *upload_data_size, void **con_cls)
  92 {
  93         HTTPD *httpd = (HTTPD *)cls;
  94         return httpd->answer_to_connection(connection, url, method, version, upload_data, upload_data_size, con_cls);
  95 }
  96
  97 int HTTPD::answer_to_connection(MHD_Connection *connection,
  98                                 const char *url, const char *method,
  99                                 const char *version, const char *upload_data,
 100                                 size_t *upload_data_size, void **con_cls)
 101 {
 102         // See if the URL ends in “.metacube”.
 103         HTTPD::Stream::Framing framing;
 104         if (strstr(url, ".metacube") == url + strlen(url) - strlen(".metacube")) {
 105                 framing = HTTPD::Stream::FRAMING_METACUBE;
 106         } else {
 107                 framing = HTTPD::Stream::FRAMING_RAW;
 108         }
 109         HTTPD::StreamID stream_id;
 110         if (strcmp(url, "/multicam.mp4") == 0) {
 111                 stream_id.type = HTTPD::StreamType::MULTICAM_STREAM;
 112                 stream_id.index = 0;
 113         } else if (strncmp(url, "/feeds/", 7) == 0) {
 114                 stream_id.type = HTTPD::StreamType::SIPHON_STREAM;
 115                 stream_id.index = atoi(url + 7);
 116         } else {
 117                 stream_id.type = HTTPD::StreamType::MAIN_STREAM;
 118                 stream_id.index = 0;
 119         }
 120
 121         if (strcmp(url, "/metrics") == 0) {
 122                 string contents = global_metrics.serialize();
 123                 MHD_Response *response = MHD_create_response_from_buffer(
 124                         contents.size(), &contents[0], MHD_RESPMEM_MUST_COPY);
 125                 MHD_add_response_header(response, "Content-type", "text/plain");
 126                 int ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
 127                 MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
 128                 return ret;
 129         }
 130         if (endpoints.count(url)) {
 131                 pair<string, string> contents_and_type = endpoints[url].callback();
 132                 MHD_Response *response = MHD_create_response_from_buffer(
 133                         contents_and_type.first.size(), &contents_and_type.first[0], MHD_RESPMEM_MUST_COPY);
 134                 MHD_add_response_header(response, "Content-type", contents_and_type.second.c_str());
 135                 if (endpoints[url].cors_policy == ALLOW_ALL_ORIGINS) {
 136                         MHD_add_response_header(response, "Access-Control-Allow-Origin", "*");
 137                 }
 138                 int ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
 139                 MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
 140                 return ret;
 141         }
 142
 143         // Small hack; reject unknown /channels/foo.
 144         if (string(url).find("/channels/") == 0) {
 145                 string contents = "Not found.";
 146                 MHD_Response *response = MHD_create_response_from_buffer(
 147                         contents.size(), &contents[0], MHD_RESPMEM_MUST_COPY);
 148                 MHD_add_response_header(response, "Content-type", "text/plain");
 149                 int ret = MHD_queue_response(connection, MHD_HTTP_NOT_FOUND, response);
 150                 MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
 151                 return ret;
 152         }
 153
 154         HTTPD::Stream *stream = new HTTPD::Stream(this, framing, stream_id);
 155         const string &hdr = header[stream_id];
 156         stream->add_data(hdr.data(), hdr.size(), Stream::DATA_TYPE_HEADER, AV_NOPTS_VALUE, AVRational{ 1, 0 });
 157         {
 158                 lock_guard<mutex> lock(streams_mutex);
 159                 streams.insert(stream);
 160         }
 161         ++metric_num_connected_clients;
 162         if (stream_id.type == HTTPD::StreamType::MULTICAM_STREAM) {
 163                 ++metric_num_connected_multicam_clients;
 164         }
 165         if (stream_id.type == HTTPD::StreamType::SIPHON_STREAM) {
 166                 ++metric_num_connected_siphon_clients[stream_id.index];
 167         }
 168         *con_cls = stream;
 169
 170         // Does not strictly have to be equal to MUX_BUFFER_SIZE.
 171         MHD_Response *response = MHD_create_response_from_callback(
 172                 (size_t)-1, MUX_BUFFER_SIZE, &HTTPD::Stream::reader_callback_thunk, stream, &HTTPD::free_stream);
 173         // TODO: Content-type?
 174         if (framing == HTTPD::Stream::FRAMING_METACUBE) {
 175                 MHD_add_response_header(response, "Content-encoding", "metacube");
 176         }
 177
 178         int ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
 179         MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
 180
 181         return ret;
 182 }
 183
 184 void HTTPD::free_stream(void *cls)
 185 {
 186         HTTPD::Stream *stream = (HTTPD::Stream *)cls;
 187         HTTPD *httpd = stream->get_parent();
 188         if (stream->get_stream_id().type == HTTPD::StreamType::MULTICAM_STREAM) {
 189                 --httpd->metric_num_connected_multicam_clients;
 190         }
 191         if (stream->get_stream_id().type == HTTPD::StreamType::SIPHON_STREAM) {
 192                 --httpd->metric_num_connected_siphon_clients[stream->get_stream_id().index];
 193         }
 194         {
 195                 lock_guard<mutex> lock(httpd->streams_mutex);
 196                 delete stream;
 197                 httpd->streams.erase(stream);
 198         }
 199         --httpd->metric_num_connected_clients;
 200 }
 201
 202 ssize_t HTTPD::Stream::reader_callback_thunk(void *cls, uint64_t pos, char *buf, size_t max)
 203 {
 204         HTTPD::Stream *stream = (HTTPD::Stream *)cls;
 205         return stream->reader_callback(pos, buf, max);
 206 }
 207
 208 ssize_t HTTPD::Stream::reader_callback(uint64_t pos, char *buf, size_t max)
 209 {
 210         unique_lock<mutex> lock(buffer_mutex);
 211         bool has_data = has_buffered_data.wait_for(lock, std::chrono::seconds(60), [this] { return should_quit || !buffered_data.empty(); });
 212         if (should_quit) {
 213                 return -1;
 214         }
 215         if (!has_data) {
 216                 // The wait timed out, so tell microhttpd to clean out the socket;
 217                 // it's not unlikely that the client has given up anyway.
 218                 // This is seemingly the only way to actually reap sockets if we
 219                 // do not get any data; returning 0 does nothing, and
 220                 // MHD_OPTION_NOTIFY_CONNECTION does not trigger for these cases.
 221                 // If not, an instance that has no data to send (typically an instance
 222                 // of kaeru connected to a nonfunctional backend) would get a steadily
 223                 // increasing amount of sockets in CLOSE_WAIT (ie., the other end has
 224                 // hung up, but we haven't called close() yet, as our thread is stuck
 225                 // in this callback).
 226                 return -1;
 227         }
 228
 229         ssize_t ret = 0;
 230         while (max > 0 && !buffered_data.empty()) {
 231                 const string &s = buffered_data.front();
 232                 assert(s.size() > used_of_buffered_data);
 233                 size_t len = s.size() - used_of_buffered_data;
 234                 if (max >= len) {
 235                         // Consume the entire (rest of the) string.
 236                         memcpy(buf, s.data() + used_of_buffered_data, len);
 237                         buf += len;
 238                         ret += len;
 239                         max -= len;
 240                         buffered_data_bytes -= s.size();
 241                         buffered_data.pop_front();
 242                         used_of_buffered_data = 0;
 243                 } else {
 244                         // We don't need the entire string; just use the first part of it.
 245                         memcpy(buf, s.data() + used_of_buffered_data, max);
 246                         buf += max;
 247                         used_of_buffered_data += max;
 248                         ret += max;
 249                         max = 0;
 250                 }
 251         }
 252
 253         return ret;
 254 }
 255
 256 void HTTPD::Stream::add_data(const char *buf, size_t buf_size, HTTPD::Stream::DataType data_type, int64_t time, AVRational timebase)
 257 {
 258         if (buf_size == 0 || should_quit) {
 259                 return;
 260         }
 261         if (data_type == DATA_TYPE_KEYFRAME) {
 262                 seen_keyframe = true;
 263         } else if (data_type == DATA_TYPE_OTHER && !seen_keyframe) {
 264                 // Start sending only once we see a keyframe.
 265                 return;
 266         }
 267
 268         lock_guard<mutex> lock(buffer_mutex);
 269
 270         if (buffered_data_bytes + buf_size > (1ULL << 30)) {
 271                 // More than 1GB of backlog; the client obviously isn't keeping up,
 272                 // so kill it instead of going out of memory. Note that this
 273                 // won't kill the client immediately, but will cause the next callback
 274                 // to kill the client.
 275                 fprintf(stderr, "HTTP client had more than 1 GB backlog; killing.\n");
 276                 should_quit = true;
 277                 buffered_data.clear();
 278                 has_buffered_data.notify_all();
 279                 return;
 280         }
 281
 282         if (framing == FRAMING_METACUBE) {
 283                 int flags = 0;
 284                 if (data_type == DATA_TYPE_HEADER) {
 285                         flags |= METACUBE_FLAGS_HEADER;
 286                 } else if (data_type == DATA_TYPE_OTHER) {
 287                         flags |= METACUBE_FLAGS_NOT_SUITABLE_FOR_STREAM_START;
 288                 }
 289
 290                 // If we're about to send a keyframe, send a pts metadata block
 291                 // to mark its time.
 292                 if ((flags & METACUBE_FLAGS_NOT_SUITABLE_FOR_STREAM_START) == 0 && time != AV_NOPTS_VALUE) {
 293                         metacube2_pts_packet packet;
 294                         packet.type = htobe64(METACUBE_METADATA_TYPE_NEXT_BLOCK_PTS);
 295                         packet.pts = htobe64(time);
 296                         packet.timebase_num = htobe64(timebase.num);
 297                         packet.timebase_den = htobe64(timebase.den);
 298
 299                         metacube2_block_header hdr;
 300                         memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
 301                         hdr.size = htonl(sizeof(packet));
 302                         hdr.flags = htons(METACUBE_FLAGS_METADATA);
 303                         hdr.csum = htons(metacube2_compute_crc(&hdr));
 304                         buffered_data.emplace_back((char *)&hdr, sizeof(hdr));
 305                         buffered_data.emplace_back((char *)&packet, sizeof(packet));
 306                         buffered_data_bytes += sizeof(hdr) + sizeof(packet);
 307                 }
 308
 309                 metacube2_block_header hdr;
 310                 memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
 311                 hdr.size = htonl(buf_size);
 312                 hdr.flags = htons(flags);
 313                 hdr.csum = htons(metacube2_compute_crc(&hdr));
 314                 buffered_data.emplace_back((char *)&hdr, sizeof(hdr));
 315                 buffered_data_bytes += sizeof(hdr);
 316         }
 317         buffered_data.emplace_back(buf, buf_size);
 318         buffered_data_bytes += buf_size;
 319
 320         // Send a Metacube2 timestamp every keyframe.
 321         if (framing == FRAMING_METACUBE && data_type == DATA_TYPE_KEYFRAME) {
 322                 timespec now;
 323                 clock_gettime(CLOCK_REALTIME, &now);
 324
 325                 metacube2_timestamp_packet packet;
 326                 packet.type = htobe64(METACUBE_METADATA_TYPE_ENCODER_TIMESTAMP);
 327                 packet.tv_sec = htobe64(now.tv_sec);
 328                 packet.tv_nsec = htobe64(now.tv_nsec);
 329
 330                 metacube2_block_header hdr;
 331                 memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
 332                 hdr.size = htonl(sizeof(packet));
 333                 hdr.flags = htons(METACUBE_FLAGS_METADATA);
 334                 hdr.csum = htons(metacube2_compute_crc(&hdr));
 335                 buffered_data.emplace_back((char *)&hdr, sizeof(hdr));
 336                 buffered_data.emplace_back((char *)&packet, sizeof(packet));
 337                 buffered_data_bytes += sizeof(hdr) + sizeof(packet);
 338         }
 339
 340         has_buffered_data.notify_all();
 341 }
 342
 343 void HTTPD::Stream::stop()
 344 {
 345         lock_guard<mutex> lock(buffer_mutex);
 346         should_quit = true;
 347         has_buffered_data.notify_all();
 348 }