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 int Input::lookup_and_connect(const string &host, const string &port)
 118 {
 119         addrinfo *ai;
 120         int err = getaddrinfo(host.c_str(), port.c_str(), NULL, &ai);
 121         if (err == -1) {
 122                 fprintf(stderr, "WARNING: Lookup of '%s' failed (%s).\n",
 123                         host.c_str(), gai_strerror(err));
 124                 freeaddrinfo(ai);
 125                 return -1;
 126         }
 127
 128         // Connect to everything in turn until we have a socket.
 129         while (ai && !should_stop) {
 130                 int sock = socket(ai->ai_family, SOCK_STREAM, IPPROTO_TCP);
 131                 if (sock == -1) {
 132                         // Could be e.g. EPROTONOSUPPORT. The show must go on.
 133                         continue;
 134                 }
 135
 136                 do {
 137                         err = connect(sock, ai->ai_addr, ai->ai_addrlen);
 138                 } while (err == -1 && errno == EINTR);
 139
 140                 if (err != -1) {
 141                         freeaddrinfo(ai);
 142                         return sock;
 143                 }
 144
 145                 ai = ai->ai_next;
 146         }
 147
 148         // Give the last one as error.
 149         fprintf(stderr, "WARNING: Connect to '%s' failed (%s)\n",
 150                 host.c_str(), strerror(errno));
 151         freeaddrinfo(ai);
 152         return -1;
 153 }
 154
 155 bool Input::parse_response(const std::string &request)
 156 {
 157         vector<string> lines = split_lines(response);
 158         if (lines.empty()) {
 159                 fprintf(stderr, "WARNING: Empty HTTP response from input.\n");
 160                 return false;
 161         }
 162
 163         vector<string> first_line_tokens = split_tokens(lines[0]);
 164         if (first_line_tokens.size() < 2) {
 165                 fprintf(stderr, "WARNING: Malformed response line '%s' from input.\n",
 166                         lines[0].c_str());
 167                 return false;
 168         }
 169
 170         int response = atoi(first_line_tokens[1].c_str());
 171         if (response != 200) {
 172                 fprintf(stderr, "WARNING: Non-200 response '%s' from input.\n",
 173                         lines[0].c_str());
 174                 return false;
 175         }
 176
 177         multimap<string, string> parameters;
 178         for (size_t i = 1; i < lines.size(); ++i) {
 179                 size_t split = lines[i].find(":");
 180                 if (split == string::npos) {
 181                         fprintf(stderr, "WARNING: Ignoring malformed HTTP response line '%s'\n",
 182                                 lines[i].c_str());
 183                         continue;
 184                 }
 185
 186                 string key(lines[i].begin(), lines[i].begin() + split);
 187
 188                 // Skip any spaces after the colon.
 189                 do {
 190                         ++split;
 191                 } while (split < lines[i].size() && lines[i][split] == ' ');
 192
 193                 string value(lines[i].begin() + split, lines[i].end());
 194
 195                 // Remove “Content-encoding: metacube”.
 196                 // TODO: Make case-insensitive.
 197                 if (key == "Content-encoding" && value == "metacube") {
 198                         continue;
 199                 }
 200
 201                 parameters.insert(make_pair(key, value));
 202         }
 203
 204         // Change “Server: foo” to “Server: metacube/0.1 (reflecting: foo)”
 205         // TODO: Make case-insensitive.
 206         // XXX: Use a Via: instead?
 207         if (parameters.count("Server") == 0) {
 208                 parameters.insert(make_pair("Server", "metacube/0.1"));
 209         } else {
 210                 for (multimap<string, string>::iterator it = parameters.begin();
 211                      it != parameters.end();
 212                      ++it) {
 213                         if (it->first != "Server") {
 214                                 continue;
 215                         }
 216                         it->second = "metacube/0.1 (reflecting: " + it->second + ")";
 217                 }
 218         }
 219
 220         // Construct the new HTTP header.
 221         http_header = "HTTP/1.0 200 OK\r\n";
 222         for (multimap<string, string>::iterator it = parameters.begin();
 223              it != parameters.end();
 224              ++it) {
 225                 http_header.append(it->first + ": " + it->second + "\r\n");
 226         }
 227         http_header.append("\r\n");
 228         servers->set_header(stream_id, http_header);
 229
 230         return true;
 231 }
 232
 233 void Input::do_work()
 234 {
 235         while (!should_stop) {
 236                 if (state == SENDING_REQUEST || state == RECEIVING_HEADER || state == RECEIVING_DATA) {
 237                         // Since we are non-blocking, we need to wait for the right state first.
 238                         // Wait up to 50 ms, then check should_stop.
 239                         pollfd pfd;
 240                         pfd.fd = sock;
 241                         pfd.events = (state == SENDING_REQUEST) ? POLLOUT : POLLIN;
 242                         pfd.events |= POLLRDHUP;
 243
 244                         int nfds = poll(&pfd, 1, 50);
 245                         if (nfds == 0 || (nfds == -1 && errno == EINTR)) {
 246                                 continue;
 247                         }
 248                         if (nfds == -1) {
 249                                 perror("poll");
 250                                 state = CLOSING_SOCKET;
 251                         }
 252                 }
 253
 254                 switch (state) {
 255                 case NOT_CONNECTED:
 256                         request.clear();
 257                         request_bytes_sent = 0;
 258                         response.clear();
 259
 260                         if (!parse_url(url, &host, &port, &path)) {
 261                                 fprintf(stderr, "Failed to parse URL '%s'\n", url.c_str());
 262                                 break;
 263                         }
 264
 265                         sock = lookup_and_connect(host, port);
 266                         if (sock != -1) {
 267                                 // Yay, successful connect. Try to set it as nonblocking.
 268                                 int one = 1;
 269                                 if (ioctl(sock, FIONBIO, &one) == -1) {
 270                                         perror("ioctl(FIONBIO)");
 271                                         state = CLOSING_SOCKET;
 272                                 } else {
 273                                         state = SENDING_REQUEST;
 274                                         request = "GET " + path + " HTTP/1.0\r\nUser-Agent: cubemap\r\n\r\n";
 275                                         request_bytes_sent = 0;
 276                                 }
 277                         }
 278                         break;
 279                 case SENDING_REQUEST: {
 280                         size_t to_send = request.size() - request_bytes_sent;
 281                         int ret;
 282
 283                         do {
 284                                 ret = write(sock, request.data() + request_bytes_sent, to_send);
 285                         } while (ret == -1 && errno == EINTR);
 286
 287                         if (ret == -1) {
 288                                 perror("write");
 289                                 state = CLOSING_SOCKET;
 290                                 continue;
 291                         }
 292
 293                         assert(ret >= 0);
 294                         request_bytes_sent += ret;
 295
 296                         if (request_bytes_sent == request.size()) {
 297                                 state = RECEIVING_HEADER;
 298                         }
 299                         break;
 300                 }
 301                 case RECEIVING_HEADER: {
 302                         char buf[4096];
 303                         int ret;
 304
 305                         do {
 306                                 ret = read(sock, buf, sizeof(buf));
 307                         } while (ret == -1 && errno == EINTR);
 308
 309                         if (ret == -1) {
 310                                 perror("read");
 311                                 state = CLOSING_SOCKET;
 312                                 continue;
 313                         }
 314
 315                         if (ret == 0) {
 316                                 // This really shouldn't happen...
 317                                 fprintf(stderr, "Socket unexpectedly closed while reading header\n");
 318                                 state = CLOSING_SOCKET;
 319                                 continue;
 320                         }
 321
 322                         RequestParseStatus status = wait_for_double_newline(&response, buf, ret);
 323
 324                         if (status == RP_OUT_OF_SPACE) {
 325                                 fprintf(stderr, "WARNING: fd %d sent overlong response!\n", sock);
 326                                 state = CLOSING_SOCKET;
 327                                 continue;
 328                         } else if (status == RP_NOT_FINISHED_YET) {
 329                                 continue;
 330                         }
 331
 332                         // OK, so we're fine, but there might be some of the actual data after the response.
 333                         // We'll need to deal with that separately.
 334                         string extra_data;
 335                         if (status == RP_EXTRA_DATA) {
 336                                 char *ptr = static_cast<char *>(
 337                                         memmem(response.data(), response.size(), "\r\n\r\n", 4));
 338                                 assert(ptr != NULL);
 339                                 extra_data = string(ptr, &response[0] + response.size());
 340                                 response.resize(ptr - response.data());
 341                         }
 342
 343                         if (!parse_response(response)) {
 344                                 state = CLOSING_SOCKET;
 345                                 continue;
 346                         }
 347
 348                         if (!extra_data.empty()) {
 349                                 process_data(&extra_data[0], extra_data.size());
 350                         }
 351
 352                         state = RECEIVING_DATA;
 353                         break;
 354                 }
 355                 case RECEIVING_DATA: {
 356                         char buf[4096];
 357                         int ret;
 358
 359                         do {
 360                                 ret = read(sock, buf, sizeof(buf));
 361                         } while (ret == -1 && errno == EINTR);
 362
 363                         if (ret == -1) {
 364                                 perror("read");
 365                                 state = CLOSING_SOCKET;
 366                                 continue;
 367                         }
 368
 369                         if (ret == 0) {
 370                                 // This really shouldn't happen...
 371                                 fprintf(stderr, "Socket unexpectedly closed while reading header\n");
 372                                 state = CLOSING_SOCKET;
 373                                 continue;
 374                         }
 375
 376                         process_data(buf, ret);
 377                         break;
 378                 }
 379                 case CLOSING_SOCKET: {
 380                         int err;
 381                         do {
 382                                 err = close(sock);
 383                         } while (err == -1 && errno == EINTR);
 384
 385                         if (err == -1) {
 386                                 perror("close");
 387                         }
 388
 389                         state = NOT_CONNECTED;
 390                         break;
 391                 }
 392                 default:
 393                         assert(false);
 394                 }
 395
 396                 // If we are still in NOT_CONNECTED, either something went wrong,
 397                 // or the connection just got closed.
 398                 // The earlier steps have already given the error message, if any.
 399                 if (state == NOT_CONNECTED && !should_stop) {
 400                         fprintf(stderr, "Waiting 0.2 second and restarting...\n");
 401                         usleep(200000);
 402                 }
 403         }
 404 }
 405
 406 void Input::process_data(char *ptr, size_t bytes)
 407 {
 408         pending_data.insert(pending_data.end(), ptr, ptr + bytes);
 409
 410         for ( ;; ) {
 411                 // If we don't have enough data (yet) for even the Metacube header, just return.
 412                 if (pending_data.size() < sizeof(metacube_block_header)) {
 413                         return;
 414                 }
 415
 416                 // Make sure we have the Metacube sync header at the start.
 417                 // We may need to skip over junk data (it _should_ not happen, though).
 418                 if (!has_metacube_header) {
 419                         char *ptr = static_cast<char *>(
 420                                 memmem(pending_data.data(), pending_data.size(),
 421                                        METACUBE_SYNC, strlen(METACUBE_SYNC)));
 422                         if (ptr == NULL) {
 423                                 // OK, so we didn't find the sync marker. We know then that
 424                                 // we do not have the _full_ marker in the buffer, but we
 425                                 // could have N-1 bytes. Drop everything before that,
 426                                 // and then give up.
 427                                 drop_pending_data(pending_data.size() - (strlen(METACUBE_SYNC) - 1));
 428                                 return;
 429                         } else {
 430                                 // Yay, we found the header. Drop everything (if anything) before it.
 431                                 drop_pending_data(ptr - pending_data.data());
 432                                 has_metacube_header = true;
 433
 434                                 // Re-check that we have the entire header; we could have dropped data.
 435                                 if (pending_data.size() < sizeof(metacube_block_header)) {
 436                                         return;
 437                                 }
 438                         }
 439                 }
 440
 441                 // Now it's safe to read the header.
 442                 metacube_block_header *hdr = reinterpret_cast<metacube_block_header *>(pending_data.data());
 443                 assert(memcmp(hdr->sync, METACUBE_SYNC, sizeof(hdr->sync)) == 0);
 444                 uint32_t size = ntohl(hdr->size);
 445                 uint32_t flags = ntohl(hdr->flags);
 446
 447                 // See if we have the entire block. If not, wait for more data.
 448                 if (pending_data.size() < sizeof(metacube_block_header) + size) {
 449                         return;
 450                 }
 451
 452                 // Send this block on to the data.
 453                 char *inner_data = pending_data.data() + sizeof(metacube_block_header);
 454                 if (flags & METACUBE_FLAGS_HEADER) {
 455                         string header(inner_data, inner_data + size);
 456                         servers->set_header(stream_id, http_header + header);
 457                 } else {
 458                         servers->add_data(stream_id, inner_data, size);
 459                 }
 460
 461                 // Consume the block. This isn't the most efficient way of dealing with things
 462                 // should we have many blocks, but these routines don't need to be too efficient
 463                 // anyway.
 464                 pending_data.erase(pending_data.begin(), pending_data.begin() + sizeof(metacube_block_header) + size);
 465                 has_metacube_header = false;
 466         }
 467 }
 468
 469 void Input::drop_pending_data(size_t num_bytes)
 470 {
 471         if (num_bytes == 0) {
 472                 return;
 473         }
 474         fprintf(stderr, "Warning: Dropping %lld junk bytes from stream, maybe it is not a Metacube stream?\n",
 475                 (long long)num_bytes);
 476         pending_data.erase(pending_data.begin(), pending_data.begin() + num_bytes);
 477 }
 478