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         stop();
  34 }
  35
  36 void HTTPD::start(int port)
  37 {
  38         mhd = MHD_start_daemon(MHD_USE_THREAD_PER_CONNECTION | MHD_USE_POLL_INTERNALLY | MHD_USE_DUAL_STACK,
  39                                port,
  40                                nullptr, nullptr,
  41                                &answer_to_connection_thunk, this,
  42                                MHD_OPTION_NOTIFY_COMPLETED, nullptr, this,
  43                                MHD_OPTION_END);
  44         if (mhd == nullptr) {
  45                 fprintf(stderr, "Warning: Could not open HTTP server. (Port already in use?)\n");
  46         }
  47 }
  48
  49 void HTTPD::stop()
  50 {
  51         if (mhd) {
  52                 MHD_quiesce_daemon(mhd);
  53                 for (Stream *stream : streams) {
  54                         stream->stop();
  55                 }
  56                 MHD_stop_daemon(mhd);
  57                 mhd = nullptr;
  58         }
  59 }
  60
  61 void HTTPD::add_data(const char *buf, size_t size, bool keyframe, int64_t time, AVRational timebase)
  62 {
  63         unique_lock<mutex> lock(streams_mutex);
  64         for (Stream *stream : streams) {
  65                 stream->add_data(buf, size, keyframe ? Stream::DATA_TYPE_KEYFRAME : Stream::DATA_TYPE_OTHER, time, timebase);
  66         }
  67 }
  68
  69 int HTTPD::answer_to_connection_thunk(void *cls, MHD_Connection *connection,
  70                                       const char *url, const char *method,
  71                                       const char *version, const char *upload_data,
  72                                       size_t *upload_data_size, void **con_cls)
  73 {
  74         HTTPD *httpd = (HTTPD *)cls;
  75         return httpd->answer_to_connection(connection, url, method, version, upload_data, upload_data_size, con_cls);
  76 }
  77
  78 int HTTPD::answer_to_connection(MHD_Connection *connection,
  79                                 const char *url, const char *method,
  80                                 const char *version, const char *upload_data,
  81                                 size_t *upload_data_size, void **con_cls)
  82 {
  83         // See if the URL ends in “.metacube”.
  84         HTTPD::Stream::Framing framing;
  85         if (strstr(url, ".metacube") == url + strlen(url) - strlen(".metacube")) {
  86                 framing = HTTPD::Stream::FRAMING_METACUBE;
  87         } else {
  88                 framing = HTTPD::Stream::FRAMING_RAW;
  89         }
  90
  91         if (strcmp(url, "/metrics") == 0) {
  92                 string contents = global_metrics.serialize();
  93                 MHD_Response *response = MHD_create_response_from_buffer(
  94                         contents.size(), &contents[0], MHD_RESPMEM_MUST_COPY);
  95                 MHD_add_response_header(response, "Content-type", "text/plain");
  96                 int ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
  97                 MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
  98                 return ret;
  99         }
 100         if (endpoints.count(url)) {
 101                 pair<string, string> contents_and_type = endpoints[url].callback();
 102                 MHD_Response *response = MHD_create_response_from_buffer(
 103                         contents_and_type.first.size(), &contents_and_type.first[0], MHD_RESPMEM_MUST_COPY);
 104                 MHD_add_response_header(response, "Content-type", contents_and_type.second.c_str());
 105                 if (endpoints[url].cors_policy == ALLOW_ALL_ORIGINS) {
 106                         MHD_add_response_header(response, "Access-Control-Allow-Origin", "*");
 107                 }
 108                 int ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
 109                 MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
 110                 return ret;
 111         }
 112
 113         // Small hack; reject unknown /channels/foo.
 114         if (string(url).find("/channels/") == 0) {
 115                 string contents = "Not found.";
 116                 MHD_Response *response = MHD_create_response_from_buffer(
 117                         contents.size(), &contents[0], MHD_RESPMEM_MUST_COPY);
 118                 MHD_add_response_header(response, "Content-type", "text/plain");
 119                 int ret = MHD_queue_response(connection, MHD_HTTP_NOT_FOUND, response);
 120                 MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
 121                 return ret;
 122         }
 123
 124         HTTPD::Stream *stream = new HTTPD::Stream(this, framing);
 125         stream->add_data(header.data(), header.size(), Stream::DATA_TYPE_HEADER, AV_NOPTS_VALUE, AVRational{ 1, 0 });
 126         {
 127                 unique_lock<mutex> lock(streams_mutex);
 128                 streams.insert(stream);
 129         }
 130         ++metric_num_connected_clients;
 131         *con_cls = stream;
 132
 133         // Does not strictly have to be equal to MUX_BUFFER_SIZE.
 134         MHD_Response *response = MHD_create_response_from_callback(
 135                 (size_t)-1, MUX_BUFFER_SIZE, &HTTPD::Stream::reader_callback_thunk, stream, &HTTPD::free_stream);
 136         // TODO: Content-type?
 137         if (framing == HTTPD::Stream::FRAMING_METACUBE) {
 138                 MHD_add_response_header(response, "Content-encoding", "metacube");
 139         }
 140
 141         int ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
 142         MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
 143
 144         return ret;
 145 }
 146
 147 void HTTPD::free_stream(void *cls)
 148 {
 149         HTTPD::Stream *stream = (HTTPD::Stream *)cls;
 150         HTTPD *httpd = stream->get_parent();
 151         {
 152                 unique_lock<mutex> lock(httpd->streams_mutex);
 153                 delete stream;
 154                 httpd->streams.erase(stream);
 155         }
 156         --httpd->metric_num_connected_clients;
 157 }
 158
 159 ssize_t HTTPD::Stream::reader_callback_thunk(void *cls, uint64_t pos, char *buf, size_t max)
 160 {
 161         HTTPD::Stream *stream = (HTTPD::Stream *)cls;
 162         return stream->reader_callback(pos, buf, max);
 163 }
 164
 165 ssize_t HTTPD::Stream::reader_callback(uint64_t pos, char *buf, size_t max)
 166 {
 167         unique_lock<mutex> lock(buffer_mutex);
 168         has_buffered_data.wait(lock, [this]{ return should_quit || !buffered_data.empty(); });
 169         if (should_quit) {
 170                 return 0;
 171         }
 172
 173         ssize_t ret = 0;
 174         while (max > 0 && !buffered_data.empty()) {
 175                 const string &s = buffered_data.front();
 176                 assert(s.size() > used_of_buffered_data);
 177                 size_t len = s.size() - used_of_buffered_data;
 178                 if (max >= len) {
 179                         // Consume the entire (rest of the) string.
 180                         memcpy(buf, s.data() + used_of_buffered_data, len);
 181                         buf += len;
 182                         ret += len;
 183                         max -= len;
 184                         buffered_data.pop_front();
 185                         used_of_buffered_data = 0;
 186                 } else {
 187                         // We don't need the entire string; just use the first part of it.
 188                         memcpy(buf, s.data() + used_of_buffered_data, max);
 189                         buf += max;
 190                         used_of_buffered_data += max;
 191                         ret += max;
 192                         max = 0;
 193                 }
 194         }
 195
 196         return ret;
 197 }
 198
 199 void HTTPD::Stream::add_data(const char *buf, size_t buf_size, HTTPD::Stream::DataType data_type, int64_t time, AVRational timebase)
 200 {
 201         if (buf_size == 0) {
 202                 return;
 203         }
 204         if (data_type == DATA_TYPE_KEYFRAME) {
 205                 seen_keyframe = true;
 206         } else if (data_type == DATA_TYPE_OTHER && !seen_keyframe) {
 207                 // Start sending only once we see a keyframe.
 208                 return;
 209         }
 210
 211         unique_lock<mutex> lock(buffer_mutex);
 212
 213         if (framing == FRAMING_METACUBE) {
 214                 int flags = 0;
 215                 if (data_type == DATA_TYPE_HEADER) {
 216                         flags |= METACUBE_FLAGS_HEADER;
 217                 } else if (data_type == DATA_TYPE_OTHER) {
 218                         flags |= METACUBE_FLAGS_NOT_SUITABLE_FOR_STREAM_START;
 219                 }
 220
 221                 // If we're about to send a keyframe, send a pts metadata block
 222                 // to mark its time.
 223                 if ((flags & METACUBE_FLAGS_NOT_SUITABLE_FOR_STREAM_START) == 0 && time != AV_NOPTS_VALUE) {
 224                         metacube2_pts_packet packet;
 225                         packet.type = htobe64(METACUBE_METADATA_TYPE_NEXT_BLOCK_PTS);
 226                         packet.pts = htobe64(time);
 227                         packet.timebase_num = htobe64(timebase.num);
 228                         packet.timebase_den = htobe64(timebase.den);
 229
 230                         metacube2_block_header hdr;
 231                         memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
 232                         hdr.size = htonl(sizeof(packet));
 233                         hdr.flags = htons(METACUBE_FLAGS_METADATA);
 234                         hdr.csum = htons(metacube2_compute_crc(&hdr));
 235                         buffered_data.emplace_back((char *)&hdr, sizeof(hdr));
 236                         buffered_data.emplace_back((char *)&packet, sizeof(packet));
 237                 }
 238
 239                 metacube2_block_header hdr;
 240                 memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
 241                 hdr.size = htonl(buf_size);
 242                 hdr.flags = htons(flags);
 243                 hdr.csum = htons(metacube2_compute_crc(&hdr));
 244                 buffered_data.emplace_back((char *)&hdr, sizeof(hdr));
 245         }
 246         buffered_data.emplace_back(buf, buf_size);
 247
 248         // Send a Metacube2 timestamp every keyframe.
 249         if (framing == FRAMING_METACUBE && data_type == DATA_TYPE_KEYFRAME) {
 250                 timespec now;
 251                 clock_gettime(CLOCK_REALTIME, &now);
 252
 253                 metacube2_timestamp_packet packet;
 254                 packet.type = htobe64(METACUBE_METADATA_TYPE_ENCODER_TIMESTAMP);
 255                 packet.tv_sec = htobe64(now.tv_sec);
 256                 packet.tv_nsec = htobe64(now.tv_nsec);
 257
 258                 metacube2_block_header hdr;
 259                 memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
 260                 hdr.size = htonl(sizeof(packet));
 261                 hdr.flags = htons(METACUBE_FLAGS_METADATA);
 262                 hdr.csum = htons(metacube2_compute_crc(&hdr));
 263                 buffered_data.emplace_back((char *)&hdr, sizeof(hdr));
 264                 buffered_data.emplace_back((char *)&packet, sizeof(packet));
 265         }
 266
 267         has_buffered_data.notify_all();
 268 }
 269
 270 void HTTPD::Stream::stop()
 271 {
 272         unique_lock<mutex> lock(buffer_mutex);
 273         should_quit = true;
 274         has_buffered_data.notify_all();
 275 }