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

   1 #include "httpd.h"
   2
   3 #include <assert.h>
   4 #include <byteswap.h>
   5 #include <endian.h>
   6 #include <microhttpd.h>
   7 #include <netinet/in.h>
   8 #include <stdio.h>
   9 #include <string.h>
  10 #include <sys/time.h>
  11 #include <time.h>
  12 #include <memory>
  13 extern "C" {
  14 #include <libavutil/avutil.h>
  15 }
  16
  17 #include "defs.h"
  18 #include "metacube2.h"
  19 #include "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 }
  30
  31 HTTPD::~HTTPD()
  32 {
  33         if (mhd) {
  34                 MHD_quiesce_daemon(mhd);
  35                 for (Stream *stream : streams) {
  36                         stream->stop();
  37                 }
  38                 MHD_stop_daemon(mhd);
  39         }
  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::add_data(const char *buf, size_t size, bool keyframe, int64_t time, AVRational timebase)
  56 {
  57         unique_lock<mutex> lock(streams_mutex);
  58         for (Stream *stream : streams) {
  59                 stream->add_data(buf, size, keyframe ? Stream::DATA_TYPE_KEYFRAME : Stream::DATA_TYPE_OTHER, time, timebase);
  60         }
  61 }
  62
  63 int HTTPD::answer_to_connection_thunk(void *cls, MHD_Connection *connection,
  64                                       const char *url, const char *method,
  65                                       const char *version, const char *upload_data,
  66                                       size_t *upload_data_size, void **con_cls)
  67 {
  68         HTTPD *httpd = (HTTPD *)cls;
  69         return httpd->answer_to_connection(connection, url, method, version, upload_data, upload_data_size, con_cls);
  70 }
  71
  72 int HTTPD::answer_to_connection(MHD_Connection *connection,
  73                                 const char *url, const char *method,
  74                                 const char *version, const char *upload_data,
  75                                 size_t *upload_data_size, void **con_cls)
  76 {
  77         // See if the URL ends in “.metacube”.
  78         HTTPD::Stream::Framing framing;
  79         if (strstr(url, ".metacube") == url + strlen(url) - strlen(".metacube")) {
  80                 framing = HTTPD::Stream::FRAMING_METACUBE;
  81         } else {
  82                 framing = HTTPD::Stream::FRAMING_RAW;
  83         }
  84
  85         if (strcmp(url, "/metrics") == 0) {
  86                 string contents = global_metrics.serialize();
  87                 MHD_Response *response = MHD_create_response_from_buffer(
  88                         contents.size(), &contents[0], MHD_RESPMEM_MUST_COPY);
  89                 MHD_add_response_header(response, "Content-type", "text/plain");
  90                 int ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
  91                 MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
  92                 return ret;
  93         }
  94         if (endpoints.count(url)) {
  95                 pair<string, string> contents_and_type = endpoints[url].callback();
  96                 MHD_Response *response = MHD_create_response_from_buffer(
  97                         contents_and_type.first.size(), &contents_and_type.first[0], MHD_RESPMEM_MUST_COPY);
  98                 MHD_add_response_header(response, "Content-type", contents_and_type.second.c_str());
  99                 if (endpoints[url].cors_policy == ALLOW_ALL_ORIGINS) {
 100                         MHD_add_response_header(response, "Access-Control-Allow-Origin", "*");
 101                 }
 102                 int ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
 103                 MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
 104                 return ret;
 105         }
 106
 107         // Small hack; reject unknown /channels/foo.
 108         if (string(url).find("/channels/") == 0) {
 109                 string contents = "Not found.";
 110                 MHD_Response *response = MHD_create_response_from_buffer(
 111                         contents.size(), &contents[0], MHD_RESPMEM_MUST_COPY);
 112                 MHD_add_response_header(response, "Content-type", "text/plain");
 113                 int ret = MHD_queue_response(connection, MHD_HTTP_NOT_FOUND, response);
 114                 MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
 115                 return ret;
 116         }
 117
 118         HTTPD::Stream *stream = new HTTPD::Stream(this, framing);
 119         stream->add_data(header.data(), header.size(), Stream::DATA_TYPE_HEADER, AV_NOPTS_VALUE, AVRational{ 1, 0 });
 120         {
 121                 unique_lock<mutex> lock(streams_mutex);
 122                 streams.insert(stream);
 123         }
 124         ++metric_num_connected_clients;
 125         *con_cls = stream;
 126
 127         // Does not strictly have to be equal to MUX_BUFFER_SIZE.
 128         MHD_Response *response = MHD_create_response_from_callback(
 129                 (size_t)-1, MUX_BUFFER_SIZE, &HTTPD::Stream::reader_callback_thunk, stream, &HTTPD::free_stream);
 130         // TODO: Content-type?
 131         if (framing == HTTPD::Stream::FRAMING_METACUBE) {
 132                 MHD_add_response_header(response, "Content-encoding", "metacube");
 133         }
 134
 135         int ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
 136         MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
 137
 138         return ret;
 139 }
 140
 141 void HTTPD::free_stream(void *cls)
 142 {
 143         HTTPD::Stream *stream = (HTTPD::Stream *)cls;
 144         HTTPD *httpd = stream->get_parent();
 145         {
 146                 unique_lock<mutex> lock(httpd->streams_mutex);
 147                 delete stream;
 148                 httpd->streams.erase(stream);
 149         }
 150         --httpd->metric_num_connected_clients;
 151 }
 152
 153 ssize_t HTTPD::Stream::reader_callback_thunk(void *cls, uint64_t pos, char *buf, size_t max)
 154 {
 155         HTTPD::Stream *stream = (HTTPD::Stream *)cls;
 156         return stream->reader_callback(pos, buf, max);
 157 }
 158
 159 ssize_t HTTPD::Stream::reader_callback(uint64_t pos, char *buf, size_t max)
 160 {
 161         unique_lock<mutex> lock(buffer_mutex);
 162         has_buffered_data.wait(lock, [this]{ return should_quit || !buffered_data.empty(); });
 163         if (should_quit) {
 164                 return 0;
 165         }
 166
 167         ssize_t ret = 0;
 168         while (max > 0 && !buffered_data.empty()) {
 169                 const string &s = buffered_data.front();
 170                 assert(s.size() > used_of_buffered_data);
 171                 size_t len = s.size() - used_of_buffered_data;
 172                 if (max >= len) {
 173                         // Consume the entire (rest of the) string.
 174                         memcpy(buf, s.data() + used_of_buffered_data, len);
 175                         buf += len;
 176                         ret += len;
 177                         max -= len;
 178                         buffered_data.pop_front();
 179                         used_of_buffered_data = 0;
 180                 } else {
 181                         // We don't need the entire string; just use the first part of it.
 182                         memcpy(buf, s.data() + used_of_buffered_data, max);
 183                         buf += max;
 184                         used_of_buffered_data += max;
 185                         ret += max;
 186                         max = 0;
 187                 }
 188         }
 189
 190         return ret;
 191 }
 192
 193 void HTTPD::Stream::add_data(const char *buf, size_t buf_size, HTTPD::Stream::DataType data_type, int64_t time, AVRational timebase)
 194 {
 195         if (buf_size == 0) {
 196                 return;
 197         }
 198         if (data_type == DATA_TYPE_KEYFRAME) {
 199                 seen_keyframe = true;
 200         } else if (data_type == DATA_TYPE_OTHER && !seen_keyframe) {
 201                 // Start sending only once we see a keyframe.
 202                 return;
 203         }
 204
 205         unique_lock<mutex> lock(buffer_mutex);
 206
 207         if (framing == FRAMING_METACUBE) {
 208                 int flags = 0;
 209                 if (data_type == DATA_TYPE_HEADER) {
 210                         flags |= METACUBE_FLAGS_HEADER;
 211                 } else if (data_type == DATA_TYPE_OTHER) {
 212                         flags |= METACUBE_FLAGS_NOT_SUITABLE_FOR_STREAM_START;
 213                 }
 214
 215                 // If we're about to send a keyframe, send a pts metadata block
 216                 // to mark its time.
 217                 if ((flags & METACUBE_FLAGS_NOT_SUITABLE_FOR_STREAM_START) == 0 && time != AV_NOPTS_VALUE) {
 218                         metacube2_pts_packet packet;
 219                         packet.type = htobe64(METACUBE_METADATA_TYPE_NEXT_BLOCK_PTS);
 220                         packet.pts = htobe64(time);
 221                         packet.timebase_num = htobe64(timebase.num);
 222                         packet.timebase_den = htobe64(timebase.den);
 223
 224                         metacube2_block_header hdr;
 225                         memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
 226                         hdr.size = htonl(sizeof(packet));
 227                         hdr.flags = htons(METACUBE_FLAGS_METADATA);
 228                         hdr.csum = htons(metacube2_compute_crc(&hdr));
 229                         buffered_data.emplace_back((char *)&hdr, sizeof(hdr));
 230                         buffered_data.emplace_back((char *)&packet, sizeof(packet));
 231                 }
 232
 233                 metacube2_block_header hdr;
 234                 memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
 235                 hdr.size = htonl(buf_size);
 236                 hdr.flags = htons(flags);
 237                 hdr.csum = htons(metacube2_compute_crc(&hdr));
 238                 buffered_data.emplace_back((char *)&hdr, sizeof(hdr));
 239         }
 240         buffered_data.emplace_back(buf, buf_size);
 241
 242         // Send a Metacube2 timestamp every keyframe.
 243         if (framing == FRAMING_METACUBE && data_type == DATA_TYPE_KEYFRAME) {
 244                 timespec now;
 245                 clock_gettime(CLOCK_REALTIME, &now);
 246
 247                 metacube2_timestamp_packet packet;
 248                 packet.type = htobe64(METACUBE_METADATA_TYPE_ENCODER_TIMESTAMP);
 249                 packet.tv_sec = htobe64(now.tv_sec);
 250                 packet.tv_nsec = htobe64(now.tv_nsec);
 251
 252                 metacube2_block_header hdr;
 253                 memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
 254                 hdr.size = htonl(sizeof(packet));
 255                 hdr.flags = htons(METACUBE_FLAGS_METADATA);
 256                 hdr.csum = htons(metacube2_compute_crc(&hdr));
 257                 buffered_data.emplace_back((char *)&hdr, sizeof(hdr));
 258                 buffered_data.emplace_back((char *)&packet, sizeof(packet));
 259         }
 260
 261         has_buffered_data.notify_all();
 262 }
 263
 264 void HTTPD::Stream::stop()
 265 {
 266         unique_lock<mutex> lock(buffer_mutex);
 267         should_quit = true;
 268         has_buffered_data.notify_all();
 269 }