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

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