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 <signal.h>
  15 #include <errno.h>
  16 #include <vector>
  17 #include <string>
  18 #include <map>
  19
  20 #include "metacube.h"
  21 #include "mutexlock.h"
  22 #include "input.h"
  23 #include "server.h"
  24 #include "serverpool.h"
  25 #include "parse.h"
  26 #include "state.pb.h"
  27
  28 using namespace std;
  29
  30 extern ServerPool *servers;
  31
  32 // Extremely rudimentary URL parsing.
  33 bool parse_url(const string &url, string *host, string *port, string *path)
  34 {
  35         if (url.find("http://") != 0) {
  36                 return false;
  37         }
  38
  39         string rest = url.substr(strlen("http://"));
  40         size_t split = rest.find_first_of(":/");
  41         if (split == string::npos) {
  42                 // http://foo
  43                 *host = rest;
  44                 *port = "http";
  45                 *path = "/";
  46                 return true;
  47         }
  48
  49         *host = string(rest.begin(), rest.begin() + split);
  50         char ch = rest[split];  // Colon or slash.
  51         rest = string(rest.begin() + split + 1, rest.end());
  52
  53         if (ch == ':') {
  54                 // Parse the port.
  55                 split = rest.find_first_of('/');
  56                 if (split == string::npos) {
  57                         // http://foo:1234
  58                         *port = rest;
  59                         *path = "/";
  60                         return true;
  61                 } else {
  62                         // http://foo:1234/bar
  63                         *port = string(rest.begin(), rest.begin() + split);
  64                         *path = string(rest.begin() + split, rest.end());
  65                         return true;
  66                 }
  67         }
  68
  69         // http://foo/bar
  70         *port = "http";
  71         *path = rest;
  72         return true;
  73 }
  74
  75 Input::Input(const string &stream_id, const string &url)
  76         : state(NOT_CONNECTED),
  77           stream_id(stream_id),
  78           url(url),
  79           has_metacube_header(false),
  80           sock(-1)
  81 {
  82 }
  83
  84 Input::Input(const InputProto &serialized)
  85         : state(State(serialized.state())),
  86           stream_id(serialized.stream_id()),
  87           url(serialized.url()),
  88           request(serialized.request()),
  89           request_bytes_sent(serialized.request_bytes_sent()),
  90           response(serialized.response()),
  91           http_header(serialized.http_header()),
  92           has_metacube_header(serialized.has_metacube_header()),
  93           sock(serialized.sock())
  94 {
  95         pending_data.resize(serialized.pending_data().size());
  96         memcpy(&pending_data[0], serialized.pending_data().data(), serialized.pending_data().size());
  97
  98         parse_url(url, &host, &port, &path);  // Don't care if it fails.
  99 }
 100
 101 InputProto Input::serialize() const
 102 {
 103         InputProto serialized;
 104         serialized.set_state(state);
 105         serialized.set_stream_id(stream_id);
 106         serialized.set_url(url);
 107         serialized.set_request(request);
 108         serialized.set_request_bytes_sent(request_bytes_sent);
 109         serialized.set_response(response);
 110         serialized.set_http_header(http_header);
 111         serialized.set_pending_data(string(pending_data.begin(), pending_data.end()));
 112         serialized.set_has_metacube_header(has_metacube_header);
 113         serialized.set_sock(sock);
 114         return serialized;
 115 }
 116
 117 void Input::run()
 118 {
 119         should_stop = false;
 120
 121         // Joinable is already the default, but it's good to be certain.
 122         pthread_attr_t attr;
 123         pthread_attr_init(&attr);
 124         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
 125         pthread_create(&worker_thread, &attr, Input::do_work_thunk, this);
 126 }
 127
 128 void Input::stop()
 129 {
 130         should_stop = true;
 131
 132         pthread_kill(worker_thread, SIGHUP);
 133         if (pthread_join(worker_thread, NULL) == -1) {
 134                 perror("pthread_join");
 135                 exit(1);
 136         }
 137 }
 138
 139 void *Input::do_work_thunk(void *arg)
 140 {
 141         Input *input = static_cast<Input *>(arg);
 142         input->do_work();
 143         return NULL;
 144 }
 145
 146 int Input::lookup_and_connect(const string &host, const string &port)
 147 {
 148         addrinfo *ai;
 149         int err = getaddrinfo(host.c_str(), port.c_str(), NULL, &ai);
 150         if (err == -1) {
 151                 fprintf(stderr, "WARNING: Lookup of '%s' failed (%s).\n",
 152                         host.c_str(), gai_strerror(err));
 153                 freeaddrinfo(ai);
 154                 return -1;
 155         }
 156
 157         // Connect to everything in turn until we have a socket.
 158         while (ai && !should_stop) {
 159                 int sock = socket(ai->ai_family, SOCK_STREAM, IPPROTO_TCP);
 160                 if (sock == -1) {
 161                         // Could be e.g. EPROTONOSUPPORT. The show must go on.
 162                         continue;
 163                 }
 164
 165                 do {
 166                         err = connect(sock, ai->ai_addr, ai->ai_addrlen);
 167                 } while (err == -1 && errno == EINTR);
 168
 169                 if (err != -1) {
 170                         freeaddrinfo(ai);
 171                         return sock;
 172                 }
 173
 174                 ai = ai->ai_next;
 175         }
 176
 177         // Give the last one as error.
 178         fprintf(stderr, "WARNING: Connect to '%s' failed (%s)\n",
 179                 host.c_str(), strerror(errno));
 180         freeaddrinfo(ai);
 181         return -1;
 182 }
 183
 184 bool Input::parse_response(const std::string &request)
 185 {
 186         vector<string> lines = split_lines(response);
 187         if (lines.empty()) {
 188                 fprintf(stderr, "WARNING: Empty HTTP response from input.\n");
 189                 return false;
 190         }
 191
 192         vector<string> first_line_tokens = split_tokens(lines[0]);
 193         if (first_line_tokens.size() < 2) {
 194                 fprintf(stderr, "WARNING: Malformed response line '%s' from input.\n",
 195                         lines[0].c_str());
 196                 return false;
 197         }
 198
 199         int response = atoi(first_line_tokens[1].c_str());
 200         if (response != 200) {
 201                 fprintf(stderr, "WARNING: Non-200 response '%s' from input.\n",
 202                         lines[0].c_str());
 203                 return false;
 204         }
 205
 206         multimap<string, string> parameters;
 207         for (size_t i = 1; i < lines.size(); ++i) {
 208                 size_t split = lines[i].find(":");
 209                 if (split == string::npos) {
 210                         fprintf(stderr, "WARNING: Ignoring malformed HTTP response line '%s'\n",
 211                                 lines[i].c_str());
 212                         continue;
 213                 }
 214
 215                 string key(lines[i].begin(), lines[i].begin() + split);
 216
 217                 // Skip any spaces after the colon.
 218                 do {
 219                         ++split;
 220                 } while (split < lines[i].size() && lines[i][split] == ' ');
 221
 222                 string value(lines[i].begin() + split, lines[i].end());
 223
 224                 // Remove “Content-encoding: metacube”.
 225                 // TODO: Make case-insensitive.
 226                 if (key == "Content-encoding" && value == "metacube") {
 227                         continue;
 228                 }
 229
 230                 parameters.insert(make_pair(key, value));
 231         }
 232
 233         // Change “Server: foo” to “Server: metacube/0.1 (reflecting: foo)”
 234         // TODO: Make case-insensitive.
 235         // XXX: Use a Via: instead?
 236         if (parameters.count("Server") == 0) {
 237                 parameters.insert(make_pair("Server", "metacube/0.1"));
 238         } else {
 239                 for (multimap<string, string>::iterator it = parameters.begin();
 240                      it != parameters.end();
 241                      ++it) {
 242                         if (it->first != "Server") {
 243                                 continue;
 244                         }
 245                         it->second = "metacube/0.1 (reflecting: " + it->second + ")";
 246                 }
 247         }
 248
 249         // Construct the new HTTP header.
 250         http_header = "HTTP/1.0 200 OK\r\n";
 251         for (multimap<string, string>::iterator it = parameters.begin();
 252              it != parameters.end();
 253              ++it) {
 254                 http_header.append(it->first + ": " + it->second + "\r\n");
 255         }
 256         http_header.append("\r\n");
 257         servers->set_header(stream_id, http_header);
 258
 259         return true;
 260 }
 261
 262 void Input::do_work()
 263 {
 264         while (!should_stop) {
 265                 if (state == SENDING_REQUEST || state == RECEIVING_HEADER || state == RECEIVING_DATA) {
 266                         // Since we are non-blocking, we need to wait for the right state first.
 267                         // Wait up to 50 ms, then check should_stop.
 268                         pollfd pfd;
 269                         pfd.fd = sock;
 270                         pfd.events = (state == SENDING_REQUEST) ? POLLOUT : POLLIN;
 271                         pfd.events |= POLLRDHUP;
 272
 273                         int nfds = poll(&pfd, 1, 50);
 274                         if (nfds == 0 || (nfds == -1 && errno == EINTR)) {
 275                                 continue;
 276                         }
 277                         if (nfds == -1) {
 278                                 perror("poll");
 279                                 state = CLOSING_SOCKET;
 280                         }
 281                 }
 282
 283                 switch (state) {
 284                 case NOT_CONNECTED:
 285                         request.clear();
 286                         request_bytes_sent = 0;
 287                         response.clear();
 288
 289                         if (!parse_url(url, &host, &port, &path)) {
 290                                 fprintf(stderr, "Failed to parse URL '%s'\n", url.c_str());
 291                                 break;
 292                         }
 293
 294                         sock = lookup_and_connect(host, port);
 295                         if (sock != -1) {
 296                                 // Yay, successful connect. Try to set it as nonblocking.
 297                                 int one = 1;
 298                                 if (ioctl(sock, FIONBIO, &one) == -1) {
 299                                         perror("ioctl(FIONBIO)");
 300                                         state = CLOSING_SOCKET;
 301                                 } else {
 302                                         state = SENDING_REQUEST;
 303                                         request = "GET " + path + " HTTP/1.0\r\nUser-Agent: cubemap\r\n\r\n";
 304                                         request_bytes_sent = 0;
 305                                 }
 306                         }
 307                         break;
 308                 case SENDING_REQUEST: {
 309                         size_t to_send = request.size() - request_bytes_sent;
 310                         int ret;
 311
 312                         do {
 313                                 ret = write(sock, request.data() + request_bytes_sent, to_send);
 314                         } while (ret == -1 && errno == EINTR);
 315
 316                         if (ret == -1) {
 317                                 perror("write");
 318                                 state = CLOSING_SOCKET;
 319                                 continue;
 320                         }
 321
 322                         assert(ret >= 0);
 323                         request_bytes_sent += ret;
 324
 325                         if (request_bytes_sent == request.size()) {
 326                                 state = RECEIVING_HEADER;
 327                         }
 328                         break;
 329                 }
 330                 case RECEIVING_HEADER: {
 331                         char buf[4096];
 332                         int ret;
 333
 334                         do {
 335                                 ret = read(sock, buf, sizeof(buf));
 336                         } while (ret == -1 && errno == EINTR);
 337
 338                         if (ret == -1) {
 339                                 perror("read");
 340                                 state = CLOSING_SOCKET;
 341                                 continue;
 342                         }
 343
 344                         if (ret == 0) {
 345                                 // This really shouldn't happen...
 346                                 fprintf(stderr, "Socket unexpectedly closed while reading header\n");
 347                                 state = CLOSING_SOCKET;
 348                                 continue;
 349                         }
 350
 351                         RequestParseStatus status = wait_for_double_newline(&response, buf, ret);
 352
 353                         if (status == RP_OUT_OF_SPACE) {
 354                                 fprintf(stderr, "WARNING: fd %d sent overlong response!\n", sock);
 355                                 state = CLOSING_SOCKET;
 356                                 continue;
 357                         } else if (status == RP_NOT_FINISHED_YET) {
 358                                 continue;
 359                         }
 360
 361                         // OK, so we're fine, but there might be some of the actual data after the response.
 362                         // We'll need to deal with that separately.
 363                         string extra_data;
 364                         if (status == RP_EXTRA_DATA) {
 365                                 char *ptr = static_cast<char *>(
 366                                         memmem(response.data(), response.size(), "\r\n\r\n", 4));
 367                                 assert(ptr != NULL);
 368                                 extra_data = string(ptr, &response[0] + response.size());
 369                                 response.resize(ptr - response.data());
 370                         }
 371
 372                         if (!parse_response(response)) {
 373                                 state = CLOSING_SOCKET;
 374                                 continue;
 375                         }
 376
 377                         if (!extra_data.empty()) {
 378                                 process_data(&extra_data[0], extra_data.size());
 379                         }
 380
 381                         state = RECEIVING_DATA;
 382                         break;
 383                 }
 384                 case RECEIVING_DATA: {
 385                         char buf[4096];
 386                         int ret;
 387
 388                         do {
 389                                 ret = read(sock, buf, sizeof(buf));
 390                         } while (ret == -1 && errno == EINTR);
 391
 392                         if (ret == -1) {
 393                                 perror("read");
 394                                 state = CLOSING_SOCKET;
 395                                 continue;
 396                         }
 397
 398                         if (ret == 0) {
 399                                 // This really shouldn't happen...
 400                                 fprintf(stderr, "Socket unexpectedly closed while reading header\n");
 401                                 state = CLOSING_SOCKET;
 402                                 continue;
 403                         }
 404
 405                         process_data(buf, ret);
 406                         break;
 407                 }
 408                 case CLOSING_SOCKET: {
 409                         int err;
 410                         do {
 411                                 err = close(sock);
 412                         } while (err == -1 && errno == EINTR);
 413
 414                         if (err == -1) {
 415                                 perror("close");
 416                         }
 417
 418                         state = NOT_CONNECTED;
 419                         break;
 420                 }
 421                 default:
 422                         assert(false);
 423                 }
 424
 425                 // If we are still in NOT_CONNECTED, either something went wrong,
 426                 // or the connection just got closed.
 427                 // The earlier steps have already given the error message, if any.
 428                 if (state == NOT_CONNECTED && !should_stop) {
 429                         fprintf(stderr, "Waiting 0.2 second and restarting...\n");
 430                         usleep(200000);
 431                 }
 432         }
 433 }
 434
 435 void Input::process_data(char *ptr, size_t bytes)
 436 {
 437         pending_data.insert(pending_data.end(), ptr, ptr + bytes);
 438
 439         for ( ;; ) {
 440                 // If we don't have enough data (yet) for even the Metacube header, just return.
 441                 if (pending_data.size() < sizeof(metacube_block_header)) {
 442                         return;
 443                 }
 444
 445                 // Make sure we have the Metacube sync header at the start.
 446                 // We may need to skip over junk data (it _should_ not happen, though).
 447                 if (!has_metacube_header) {
 448                         char *ptr = static_cast<char *>(
 449                                 memmem(pending_data.data(), pending_data.size(),
 450                                        METACUBE_SYNC, strlen(METACUBE_SYNC)));
 451                         if (ptr == NULL) {
 452                                 // OK, so we didn't find the sync marker. We know then that
 453                                 // we do not have the _full_ marker in the buffer, but we
 454                                 // could have N-1 bytes. Drop everything before that,
 455                                 // and then give up.
 456                                 drop_pending_data(pending_data.size() - (strlen(METACUBE_SYNC) - 1));
 457                                 return;
 458                         } else {
 459                                 // Yay, we found the header. Drop everything (if anything) before it.
 460                                 drop_pending_data(ptr - pending_data.data());
 461                                 has_metacube_header = true;
 462
 463                                 // Re-check that we have the entire header; we could have dropped data.
 464                                 if (pending_data.size() < sizeof(metacube_block_header)) {
 465                                         return;
 466                                 }
 467                         }
 468                 }
 469
 470                 // Now it's safe to read the header.
 471                 metacube_block_header *hdr = reinterpret_cast<metacube_block_header *>(pending_data.data());
 472                 assert(memcmp(hdr->sync, METACUBE_SYNC, sizeof(hdr->sync)) == 0);
 473                 uint32_t size = ntohl(hdr->size);
 474                 uint32_t flags = ntohl(hdr->flags);
 475
 476                 // See if we have the entire block. If not, wait for more data.
 477                 if (pending_data.size() < sizeof(metacube_block_header) + size) {
 478                         return;
 479                 }
 480
 481                 // Send this block on to the data.
 482                 char *inner_data = pending_data.data() + sizeof(metacube_block_header);
 483                 if (flags & METACUBE_FLAGS_HEADER) {
 484                         string header(inner_data, inner_data + size);
 485                         servers->set_header(stream_id, http_header + header);
 486                 } else {
 487                         servers->add_data(stream_id, inner_data, size);
 488                 }
 489
 490                 // Consume the block. This isn't the most efficient way of dealing with things
 491                 // should we have many blocks, but these routines don't need to be too efficient
 492                 // anyway.
 493                 pending_data.erase(pending_data.begin(), pending_data.begin() + sizeof(metacube_block_header) + size);
 494                 has_metacube_header = false;
 495         }
 496 }
 497
 498 void Input::drop_pending_data(size_t num_bytes)
 499 {
 500         if (num_bytes == 0) {
 501                 return;
 502         }
 503         fprintf(stderr, "Warning: Dropping %lld junk bytes from stream, maybe it is not a Metacube stream?\n",
 504                 (long long)num_bytes);
 505         pending_data.erase(pending_data.begin(), pending_data.begin() + num_bytes);
 506 }
 507