git.sesse.net Git - cubemap/blob - input.cpp

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include <stdint.h>
   4 #include <assert.h>
   5 #include <arpa/inet.h>
   6 #include <sys/socket.h>
   7 #include <pthread.h>
   8 #include <sys/types.h>
   9 #include <sys/ioctl.h>
  10 #include <sys/types.h>
  11 #include <sys/socket.h>
  12 #include <netdb.h>
  13 #include <poll.h>
  14 #include <errno.h>
  15 #include <vector>
  16 #include <string>
  17 #include <map>
  18
  19 #include "metacube.h"
  20 #include "mutexlock.h"
  21 #include "input.h"
  22 #include "server.h"
  23 #include "serverpool.h"
  24 #include "parse.h"
  25 #include "state.pb.h"
  26
  27 using namespace std;
  28
  29 extern ServerPool *servers;
  30
  31 // Extremely rudimentary URL parsing.
  32 bool parse_url(const string &url, string *host, string *port, string *path)
  33 {
  34         if (url.find("http://") != 0) {
  35                 return false;
  36         }
  37
  38         string rest = url.substr(strlen("http://"));
  39         size_t split = rest.find_first_of(":/");
  40         if (split == string::npos) {
  41                 // http://foo
  42                 *host = rest;
  43                 *port = "http";
  44                 *path = "/";
  45                 return true;
  46         }
  47
  48         *host = string(rest.begin(), rest.begin() + split);
  49         char ch = rest[split];  // Colon or slash.
  50         rest = string(rest.begin() + split + 1, rest.end());
  51
  52         if (ch == ':') {
  53                 // Parse the port.
  54                 split = rest.find_first_of('/');
  55                 if (split == string::npos) {
  56                         // http://foo:1234
  57                         *port = rest;
  58                         *path = "/";
  59                         return true;
  60                 } else {
  61                         // http://foo:1234/bar
  62                         *port = string(rest.begin(), rest.begin() + split);
  63                         *path = string(rest.begin() + split, rest.end());
  64                         return true;
  65                 }
  66         }
  67
  68         // http://foo/bar
  69         *port = "http";
  70         *path = rest;
  71         return true;
  72 }
  73
  74 Input::Input(const string &stream_id, const string &url)
  75         : state(NOT_CONNECTED),
  76           stream_id(stream_id),
  77           url(url),
  78           has_metacube_header(false),
  79           sock(-1)
  80 {
  81 }
  82
  83 Input::Input(const InputProto &serialized)
  84         : state(State(serialized.state())),
  85           stream_id(serialized.stream_id()),
  86           url(serialized.url()),
  87           request(serialized.request()),
  88           request_bytes_sent(serialized.request_bytes_sent()),
  89           response(serialized.response()),
  90           http_header(serialized.http_header()),
  91           has_metacube_header(serialized.has_metacube_header()),
  92           sock(serialized.sock())
  93 {
  94         pending_data.resize(serialized.pending_data().size());
  95         memcpy(&pending_data[0], serialized.pending_data().data(), serialized.pending_data().size());
  96
  97         parse_url(url, &host, &port, &path);  // Don't care if it fails.
  98 }
  99
 100 InputProto Input::serialize() const
 101 {
 102         InputProto serialized;
 103         serialized.set_state(state);
 104         serialized.set_stream_id(stream_id);
 105         serialized.set_url(url);
 106         serialized.set_request(request);
 107         serialized.set_request_bytes_sent(request_bytes_sent);
 108         serialized.set_response(response);
 109         serialized.set_http_header(http_header);
 110         serialized.set_pending_data(string(pending_data.begin(), pending_data.end()));
 111         serialized.set_has_metacube_header(has_metacube_header);
 112         serialized.set_sock(sock);
 113         return serialized;
 114 }
 115
 116 void Input::run()
 117 {
 118         should_stop = false;
 119
 120         // Joinable is already the default, but it's good to be certain.
 121         pthread_attr_t attr;
 122         pthread_attr_init(&attr);
 123         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
 124         pthread_create(&worker_thread, &attr, Input::do_work_thunk, this);
 125 }
 126
 127 void Input::stop()
 128 {
 129         should_stop = true;
 130
 131         if (pthread_join(worker_thread, NULL) == -1) {
 132                 perror("pthread_join");
 133                 exit(1);
 134         }
 135 }
 136
 137 void *Input::do_work_thunk(void *arg)
 138 {
 139         Input *input = static_cast<Input *>(arg);
 140         input->do_work();
 141         return NULL;
 142 }
 143
 144 int Input::lookup_and_connect(const string &host, const string &port)
 145 {
 146         addrinfo *ai;
 147         int err = getaddrinfo(host.c_str(), port.c_str(), NULL, &ai);
 148         if (err == -1) {
 149                 fprintf(stderr, "WARNING: Lookup of '%s' failed (%s).\n",
 150                         host.c_str(), gai_strerror(err));
 151                 freeaddrinfo(ai);
 152                 return -1;
 153         }
 154
 155         // Connect to everything in turn until we have a socket.
 156         while (ai && !should_stop) {
 157                 int sock = socket(ai->ai_family, SOCK_STREAM, IPPROTO_TCP);
 158                 if (sock == -1) {
 159                         // Could be e.g. EPROTONOSUPPORT. The show must go on.
 160                         continue;
 161                 }
 162
 163                 do {
 164                         err = connect(sock, ai->ai_addr, ai->ai_addrlen);
 165                 } while (err == -1 && errno == EINTR);
 166
 167                 if (err != -1) {
 168                         freeaddrinfo(ai);
 169                         return sock;
 170                 }
 171
 172                 ai = ai->ai_next;
 173         }
 174
 175         // Give the last one as error.
 176         fprintf(stderr, "WARNING: Connect to '%s' failed (%s)\n",
 177                 host.c_str(), strerror(errno));
 178         freeaddrinfo(ai);
 179         return -1;
 180 }
 181
 182 bool Input::parse_response(const std::string &request)
 183 {
 184         vector<string> lines = split_lines(response);
 185         if (lines.empty()) {
 186                 fprintf(stderr, "WARNING: Empty HTTP response from input.\n");
 187                 return false;
 188         }
 189
 190         vector<string> first_line_tokens = split_tokens(lines[0]);
 191         if (first_line_tokens.size() < 2) {
 192                 fprintf(stderr, "WARNING: Malformed response line '%s' from input.\n",
 193                         lines[0].c_str());
 194                 return false;
 195         }
 196
 197         int response = atoi(first_line_tokens[1].c_str());
 198         if (response != 200) {
 199                 fprintf(stderr, "WARNING: Non-200 response '%s' from input.\n",
 200                         lines[0].c_str());
 201                 return false;
 202         }
 203
 204         multimap<string, string> parameters;
 205         for (size_t i = 1; i < lines.size(); ++i) {
 206                 size_t split = lines[i].find(":");
 207                 if (split == string::npos) {
 208                         fprintf(stderr, "WARNING: Ignoring malformed HTTP response line '%s'\n",
 209                                 lines[i].c_str());
 210                         continue;
 211                 }
 212
 213                 string key(lines[i].begin(), lines[i].begin() + split);
 214
 215                 // Skip any spaces after the colon.
 216                 do {
 217                         ++split;
 218                 } while (split < lines[i].size() && lines[i][split] == ' ');
 219
 220                 string value(lines[i].begin() + split, lines[i].end());
 221
 222                 // Remove “Content-encoding: metacube”.
 223                 // TODO: Make case-insensitive.
 224                 if (key == "Content-encoding" && value == "metacube") {
 225                         continue;
 226                 }
 227
 228                 parameters.insert(make_pair(key, value));
 229         }
 230
 231         // Change “Server: foo” to “Server: metacube/0.1 (reflecting: foo)”
 232         // TODO: Make case-insensitive.
 233         // XXX: Use a Via: instead?
 234         if (parameters.count("Server") == 0) {
 235                 parameters.insert(make_pair("Server", "metacube/0.1"));
 236         } else {
 237                 for (multimap<string, string>::iterator it = parameters.begin();
 238                      it != parameters.end();
 239                      ++it) {
 240                         if (it->first != "Server") {
 241                                 continue;
 242                         }
 243                         it->second = "metacube/0.1 (reflecting: " + it->second + ")";
 244                 }
 245         }
 246
 247         // Construct the new HTTP header.
 248         http_header = "HTTP/1.0 200 OK\r\n";
 249         for (multimap<string, string>::iterator it = parameters.begin();
 250              it != parameters.end();
 251              ++it) {
 252                 http_header.append(it->first + ": " + it->second + "\r\n");
 253         }
 254         http_header.append("\r\n");
 255         servers->set_header(stream_id, http_header);
 256
 257         return true;
 258 }
 259
 260 void Input::do_work()
 261 {
 262         while (!should_stop) {
 263                 if (state == SENDING_REQUEST || state == RECEIVING_HEADER || state == RECEIVING_DATA) {
 264                         // Since we are non-blocking, we need to wait for the right state first.
 265                         // Wait up to 50 ms, then check should_stop.
 266                         pollfd pfd;
 267                         pfd.fd = sock;
 268                         pfd.events = (state == SENDING_REQUEST) ? POLLOUT : POLLIN;
 269                         pfd.events |= POLLRDHUP;
 270
 271                         int nfds = poll(&pfd, 1, 50);
 272                         if (nfds == 0 || (nfds == -1 && errno == EAGAIN)) {
 273                                 continue;
 274                         }
 275                         if (nfds == -1) {
 276                                 perror("poll");
 277                                 state = CLOSING_SOCKET;
 278                         }
 279                 }
 280
 281                 switch (state) {
 282                 case NOT_CONNECTED:
 283                         request.clear();
 284                         request_bytes_sent = 0;
 285                         response.clear();
 286
 287                         if (!parse_url(url, &host, &port, &path)) {
 288                                 fprintf(stderr, "Failed to parse URL '%s'\n", url.c_str());
 289                                 break;
 290                         }
 291
 292                         sock = lookup_and_connect(host, port);
 293                         if (sock != -1) {
 294                                 // Yay, successful connect. Try to set it as nonblocking.
 295                                 int one = 1;
 296                                 if (ioctl(sock, FIONBIO, &one) == -1) {
 297                                         perror("ioctl(FIONBIO)");
 298                                         state = CLOSING_SOCKET;
 299                                 } else {
 300                                         state = SENDING_REQUEST;
 301                                         request = "GET " + path + " HTTP/1.0\r\nUser-Agent: cubemap\r\n\r\n";
 302                                         request_bytes_sent = 0;
 303                                 }
 304                         }
 305                         break;
 306                 case SENDING_REQUEST: {
 307                         size_t to_send = request.size() - request_bytes_sent;
 308                         int ret;
 309
 310                         do {
 311                                 ret = write(sock, request.data() + request_bytes_sent, to_send);
 312                         } while (ret == -1 && errno == EINTR);
 313
 314                         if (ret == -1) {
 315                                 perror("write");
 316                                 state = CLOSING_SOCKET;
 317                                 continue;
 318                         }
 319
 320                         assert(ret >= 0);
 321                         request_bytes_sent += ret;
 322
 323                         if (request_bytes_sent == request.size()) {
 324                                 state = RECEIVING_HEADER;
 325                         }
 326                         break;
 327                 }
 328                 case RECEIVING_HEADER: {
 329                         char buf[4096];
 330                         int ret;
 331
 332                         do {
 333                                 ret = read(sock, buf, sizeof(buf));
 334                         } while (ret == -1 && errno == EINTR);
 335
 336                         if (ret == -1) {
 337                                 perror("read");
 338                                 state = CLOSING_SOCKET;
 339                                 continue;
 340                         }
 341
 342                         if (ret == 0) {
 343                                 // This really shouldn't happen...
 344                                 fprintf(stderr, "Socket unexpectedly closed while reading header\n");
 345                                 state = CLOSING_SOCKET;
 346                                 continue;
 347                         }
 348
 349                         RequestParseStatus status = wait_for_double_newline(&response, buf, ret);
 350
 351                         if (status == RP_OUT_OF_SPACE) {
 352                                 fprintf(stderr, "WARNING: fd %d sent overlong response!\n", sock);
 353                                 state = CLOSING_SOCKET;
 354                                 continue;
 355                         } else if (status == RP_NOT_FINISHED_YET) {
 356                                 continue;
 357                         }
 358
 359                         // OK, so we're fine, but there might be some of the actual data after the response.
 360                         // We'll need to deal with that separately.
 361                         string extra_data;
 362                         if (status == RP_EXTRA_DATA) {
 363                                 char *ptr = static_cast<char *>(
 364                                         memmem(response.data(), response.size(), "\r\n\r\n", 4));
 365                                 assert(ptr != NULL);
 366                                 extra_data = string(ptr, &response[0] + response.size());
 367                                 response.resize(ptr - response.data());
 368                         }
 369
 370                         if (!parse_response(response)) {
 371                                 state = CLOSING_SOCKET;
 372                                 continue;
 373                         }
 374
 375                         if (!extra_data.empty()) {
 376                                 process_data(&extra_data[0], extra_data.size());
 377                         }
 378
 379                         state = RECEIVING_DATA;
 380                         break;
 381                 }
 382                 case RECEIVING_DATA: {
 383                         char buf[4096];
 384                         int ret;
 385
 386                         do {
 387                                 ret = read(sock, buf, sizeof(buf));
 388                         } while (ret == -1 && errno == EINTR);
 389
 390                         if (ret == -1) {
 391                                 perror("read");
 392                                 state = CLOSING_SOCKET;
 393                                 continue;
 394                         }
 395
 396                         if (ret == 0) {
 397                                 // This really shouldn't happen...
 398                                 fprintf(stderr, "Socket unexpectedly closed while reading header\n");
 399                                 state = CLOSING_SOCKET;
 400                                 continue;
 401                         }
 402
 403                         process_data(buf, ret);
 404                         break;
 405                 }
 406                 case CLOSING_SOCKET: {
 407                         int err;
 408                         do {
 409                                 err = close(sock);
 410                         } while (err == -1 && errno == EINTR);
 411
 412                         if (err == -1) {
 413                                 perror("close");
 414                         }
 415
 416                         state = NOT_CONNECTED;
 417                         break;
 418                 }
 419                 default:
 420                         assert(false);
 421                 }
 422
 423                 // If we are still in NOT_CONNECTED, either something went wrong,
 424                 // or the connection just got closed.
 425                 // The earlier steps have already given the error message, if any.
 426                 if (state == NOT_CONNECTED && !should_stop) {
 427                         fprintf(stderr, "Waiting 0.2 second and restarting...\n");
 428                         usleep(200000);
 429                 }
 430         }
 431 }
 432
 433 void Input::process_data(char *ptr, size_t bytes)
 434 {
 435         pending_data.insert(pending_data.end(), ptr, ptr + bytes);
 436
 437         for ( ;; ) {
 438                 // If we don't have enough data (yet) for even the Metacube header, just return.
 439                 if (pending_data.size() < sizeof(metacube_block_header)) {
 440                         return;
 441                 }
 442
 443                 // Make sure we have the Metacube sync header at the start.
 444                 // We may need to skip over junk data (it _should_ not happen, though).
 445                 if (!has_metacube_header) {
 446                         char *ptr = static_cast<char *>(
 447                                 memmem(pending_data.data(), pending_data.size(),
 448                                        METACUBE_SYNC, strlen(METACUBE_SYNC)));
 449                         if (ptr == NULL) {
 450                                 // OK, so we didn't find the sync marker. We know then that
 451                                 // we do not have the _full_ marker in the buffer, but we
 452                                 // could have N-1 bytes. Drop everything before that,
 453                                 // and then give up.
 454                                 drop_pending_data(pending_data.size() - (strlen(METACUBE_SYNC) - 1));
 455                                 return;
 456                         } else {
 457                                 // Yay, we found the header. Drop everything (if anything) before it.
 458                                 drop_pending_data(ptr - pending_data.data());
 459                                 has_metacube_header = true;
 460
 461                                 // Re-check that we have the entire header; we could have dropped data.
 462                                 if (pending_data.size() < sizeof(metacube_block_header)) {
 463                                         return;
 464                                 }
 465                         }
 466                 }
 467
 468                 // Now it's safe to read the header.
 469                 metacube_block_header *hdr = reinterpret_cast<metacube_block_header *>(pending_data.data());
 470                 assert(memcmp(hdr->sync, METACUBE_SYNC, sizeof(hdr->sync)) == 0);
 471                 uint32_t size = ntohl(hdr->size);
 472                 uint32_t flags = ntohl(hdr->flags);
 473
 474                 // See if we have the entire block. If not, wait for more data.
 475                 if (pending_data.size() < sizeof(metacube_block_header) + size) {
 476                         return;
 477                 }
 478
 479                 // Send this block on to the data.
 480                 char *inner_data = pending_data.data() + sizeof(metacube_block_header);
 481                 if (flags & METACUBE_FLAGS_HEADER) {
 482                         string header(inner_data, inner_data + size);
 483                         servers->set_header(stream_id, http_header + header);
 484                 } else {
 485                         servers->add_data(stream_id, inner_data, size);
 486                 }
 487
 488                 // Consume the block. This isn't the most efficient way of dealing with things
 489                 // should we have many blocks, but these routines don't need to be too efficient
 490                 // anyway.
 491                 pending_data.erase(pending_data.begin(), pending_data.begin() + sizeof(metacube_block_header) + size);
 492                 has_metacube_header = false;
 493         }
 494 }
 495
 496 void Input::drop_pending_data(size_t num_bytes)
 497 {
 498         if (num_bytes == 0) {
 499                 return;
 500         }
 501         fprintf(stderr, "Warning: Dropping %lld junk bytes from stream, maybe it is not a Metacube stream?\n",
 502                 (long long)num_bytes);
 503         pending_data.erase(pending_data.begin(), pending_data.begin() + num_bytes);
 504 }
 505