src/transports/smart.c

   1 /*
   2  * Copyright (C) the libgit2 contributors. All rights reserved.
   3  *
   4  * This file is part of libgit2, distributed under the GNU GPL v2 with
   5  * a Linking Exception. For full terms see the included COPYING file.
   6  */
   7
   8 #include "smart.h"
   9
  10 #include "git2.h"
  11 #include "refs.h"
  12 #include "refspec.h"
  13 #include "proxy.h"
  14
  15 static int git_smart__recv_cb(gitno_buffer *buf)
  16 {
  17         transport_smart *t = (transport_smart *) buf->cb_data;
  18         size_t old_len, bytes_read;
  19         int error;
  20
  21         assert(t->current_stream);
  22
  23         old_len = buf->offset;
  24
  25         if ((error = t->current_stream->read(t->current_stream, buf->data + buf->offset, buf->len - buf->offset, &bytes_read)) < 0)
  26                 return error;
  27
  28         buf->offset += bytes_read;
  29
  30         if (t->packetsize_cb && !t->cancelled.val) {
  31                 error = t->packetsize_cb(bytes_read, t->packetsize_payload);
  32                 if (error) {
  33                         git_atomic_set(&t->cancelled, 1);
  34                         return GIT_EUSER;
  35                 }
  36         }
  37
  38         return (int)(buf->offset - old_len);
  39 }
  40
  41 GIT_INLINE(int) git_smart__reset_stream(transport_smart *t, bool close_subtransport)
  42 {
  43         if (t->current_stream) {
  44                 t->current_stream->free(t->current_stream);
  45                 t->current_stream = NULL;
  46         }
  47
  48         if (close_subtransport) {
  49                 git__free(t->url);
  50                 t->url = NULL;
  51
  52                 if (t->wrapped->close(t->wrapped) < 0)
  53                         return -1;
  54         }
  55
  56         return 0;
  57 }
  58
  59 static int git_smart__set_callbacks(
  60         git_transport *transport,
  61         git_transport_message_cb progress_cb,
  62         git_transport_message_cb error_cb,
  63         git_transport_certificate_check_cb certificate_check_cb,
  64         void *message_cb_payload)
  65 {
  66         transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
  67
  68         t->progress_cb = progress_cb;
  69         t->error_cb = error_cb;
  70         t->certificate_check_cb = certificate_check_cb;
  71         t->message_cb_payload = message_cb_payload;
  72
  73         return 0;
  74 }
  75
  76 static size_t http_header_name_length(const char *http_header)
  77 {
  78         const char *colon = strchr(http_header, ':');
  79         if (!colon)
  80                 return 0;
  81         return colon - http_header;
  82 }
  83
  84 static bool is_malformed_http_header(const char *http_header)
  85 {
  86         const char *c;
  87         size_t name_len;
  88
  89         /* Disallow \r and \n */
  90         c = strchr(http_header, '\r');
  91         if (c)
  92                 return true;
  93         c = strchr(http_header, '\n');
  94         if (c)
  95                 return true;
  96
  97         /* Require a header name followed by : */
  98         name_len = http_header_name_length(http_header);
  99         if (name_len < 1)
 100                 return true;
 101
 102         return false;
 103 }
 104
 105 static char *forbidden_custom_headers[] = {
 106         "User-Agent",
 107         "Host",
 108         "Accept",
 109         "Content-Type",
 110         "Transfer-Encoding",
 111         "Content-Length",
 112 };
 113
 114 static bool is_forbidden_custom_header(const char *custom_header)
 115 {
 116         unsigned long i;
 117         size_t name_len = http_header_name_length(custom_header);
 118
 119         /* Disallow headers that we set */
 120         for (i = 0; i < ARRAY_SIZE(forbidden_custom_headers); i++)
 121                 if (strncmp(forbidden_custom_headers[i], custom_header, name_len) == 0)
 122                         return true;
 123
 124         return false;
 125 }
 126
 127 static int git_smart__set_custom_headers(
 128         git_transport *transport,
 129         const git_strarray *custom_headers)
 130 {
 131         transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 132         size_t i;
 133
 134         if (t->custom_headers.count)
 135                 git_strarray_dispose(&t->custom_headers);
 136
 137         if (!custom_headers)
 138                 return 0;
 139
 140         for (i = 0; i < custom_headers->count; i++) {
 141                 if (is_malformed_http_header(custom_headers->strings[i])) {
 142                         git_error_set(GIT_ERROR_INVALID, "custom HTTP header '%s' is malformed", custom_headers->strings[i]);
 143                         return -1;
 144                 }
 145                 if (is_forbidden_custom_header(custom_headers->strings[i])) {
 146                         git_error_set(GIT_ERROR_INVALID, "custom HTTP header '%s' is already set by libgit2", custom_headers->strings[i]);
 147                         return -1;
 148                 }
 149         }
 150
 151         return git_strarray_copy(&t->custom_headers, custom_headers);
 152 }
 153
 154 int git_smart__update_heads(transport_smart *t, git_vector *symrefs)
 155 {
 156         size_t i;
 157         git_pkt *pkt;
 158
 159         git_vector_clear(&t->heads);
 160         git_vector_foreach(&t->refs, i, pkt) {
 161                 git_pkt_ref *ref = (git_pkt_ref *) pkt;
 162                 if (pkt->type != GIT_PKT_REF)
 163                         continue;
 164
 165                 if (symrefs) {
 166                         git_refspec *spec;
 167                         git_buf buf = GIT_BUF_INIT;
 168                         size_t j;
 169                         int error = 0;
 170
 171                         git_vector_foreach(symrefs, j, spec) {
 172                                 git_buf_clear(&buf);
 173                                 if (git_refspec_src_matches(spec, ref->head.name) &&
 174                                     !(error = git_refspec_transform(&buf, spec, ref->head.name))) {
 175                                         git__free(ref->head.symref_target);
 176                                         ref->head.symref_target = git_buf_detach(&buf);
 177                                 }
 178                         }
 179
 180                         git_buf_dispose(&buf);
 181
 182                         if (error < 0)
 183                                 return error;
 184                 }
 185
 186                 if (git_vector_insert(&t->heads, &ref->head) < 0)
 187                         return -1;
 188         }
 189
 190         return 0;
 191 }
 192
 193 static void free_symrefs(git_vector *symrefs)
 194 {
 195         git_refspec *spec;
 196         size_t i;
 197
 198         git_vector_foreach(symrefs, i, spec) {
 199                 git_refspec__dispose(spec);
 200                 git__free(spec);
 201         }
 202
 203         git_vector_free(symrefs);
 204 }
 205
 206 static int git_smart__connect(
 207         git_transport *transport,
 208         const char *url,
 209         git_credential_acquire_cb cred_acquire_cb,
 210         void *cred_acquire_payload,
 211         const git_proxy_options *proxy,
 212         int direction,
 213         int flags)
 214 {
 215         transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 216         git_smart_subtransport_stream *stream;
 217         int error;
 218         git_pkt *pkt;
 219         git_pkt_ref *first;
 220         git_vector symrefs;
 221         git_smart_service_t service;
 222
 223         if (git_smart__reset_stream(t, true) < 0)
 224                 return -1;
 225
 226         t->url = git__strdup(url);
 227         GIT_ERROR_CHECK_ALLOC(t->url);
 228
 229         if (git_proxy_options_dup(&t->proxy, proxy) < 0)
 230                 return -1;
 231
 232         t->direction = direction;
 233         t->flags = flags;
 234         t->cred_acquire_cb = cred_acquire_cb;
 235         t->cred_acquire_payload = cred_acquire_payload;
 236
 237         if (GIT_DIRECTION_FETCH == t->direction)
 238                 service = GIT_SERVICE_UPLOADPACK_LS;
 239         else if (GIT_DIRECTION_PUSH == t->direction)
 240                 service = GIT_SERVICE_RECEIVEPACK_LS;
 241         else {
 242                 git_error_set(GIT_ERROR_NET, "invalid direction");
 243                 return -1;
 244         }
 245
 246         if ((error = t->wrapped->action(&stream, t->wrapped, t->url, service)) < 0)
 247                 return error;
 248
 249         /* Save off the current stream (i.e. socket) that we are working with */
 250         t->current_stream = stream;
 251
 252         gitno_buffer_setup_callback(&t->buffer, t->buffer_data, sizeof(t->buffer_data), git_smart__recv_cb, t);
 253
 254         /* 2 flushes for RPC; 1 for stateful */
 255         if ((error = git_smart__store_refs(t, t->rpc ? 2 : 1)) < 0)
 256                 return error;
 257
 258         /* Strip the comment packet for RPC */
 259         if (t->rpc) {
 260                 pkt = (git_pkt *)git_vector_get(&t->refs, 0);
 261
 262                 if (!pkt || GIT_PKT_COMMENT != pkt->type) {
 263                         git_error_set(GIT_ERROR_NET, "invalid response");
 264                         return -1;
 265                 } else {
 266                         /* Remove the comment pkt from the list */
 267                         git_vector_remove(&t->refs, 0);
 268                         git__free(pkt);
 269                 }
 270         }
 271
 272         /* We now have loaded the refs. */
 273         t->have_refs = 1;
 274
 275         pkt = (git_pkt *)git_vector_get(&t->refs, 0);
 276         if (pkt && GIT_PKT_REF != pkt->type) {
 277                 git_error_set(GIT_ERROR_NET, "invalid response");
 278                 return -1;
 279         }
 280         first = (git_pkt_ref *)pkt;
 281
 282         if ((error = git_vector_init(&symrefs, 1, NULL)) < 0)
 283                 return error;
 284
 285         /* Detect capabilities */
 286         if ((error = git_smart__detect_caps(first, &t->caps, &symrefs)) == 0) {
 287                 /* If the only ref in the list is capabilities^{} with OID_ZERO, remove it */
 288                 if (1 == t->refs.length && !strcmp(first->head.name, "capabilities^{}") &&
 289                         git_oid_is_zero(&first->head.oid)) {
 290                         git_vector_clear(&t->refs);
 291                         git_pkt_free((git_pkt *)first);
 292                 }
 293
 294                 /* Keep a list of heads for _ls */
 295                 git_smart__update_heads(t, &symrefs);
 296         } else if (error == GIT_ENOTFOUND) {
 297                 /* There was no ref packet received, or the cap list was empty */
 298                 error = 0;
 299         } else {
 300                 git_error_set(GIT_ERROR_NET, "invalid response");
 301                 goto cleanup;
 302         }
 303
 304         if (t->rpc && (error = git_smart__reset_stream(t, false)) < 0)
 305                 goto cleanup;
 306
 307         /* We're now logically connected. */
 308         t->connected = 1;
 309
 310 cleanup:
 311         free_symrefs(&symrefs);
 312
 313         return error;
 314 }
 315
 316 static int git_smart__ls(const git_remote_head ***out, size_t *size, git_transport *transport)
 317 {
 318         transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 319
 320         if (!t->have_refs) {
 321                 git_error_set(GIT_ERROR_NET, "the transport has not yet loaded the refs");
 322                 return -1;
 323         }
 324
 325         *out = (const git_remote_head **) t->heads.contents;
 326         *size = t->heads.length;
 327
 328         return 0;
 329 }
 330
 331 int git_smart__negotiation_step(git_transport *transport, void *data, size_t len)
 332 {
 333         transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 334         git_smart_subtransport_stream *stream;
 335         int error;
 336
 337         if (t->rpc && git_smart__reset_stream(t, false) < 0)
 338                 return -1;
 339
 340         if (GIT_DIRECTION_FETCH != t->direction) {
 341                 git_error_set(GIT_ERROR_NET, "this operation is only valid for fetch");
 342                 return -1;
 343         }
 344
 345         if ((error = t->wrapped->action(&stream, t->wrapped, t->url, GIT_SERVICE_UPLOADPACK)) < 0)
 346                 return error;
 347
 348         /* If this is a stateful implementation, the stream we get back should be the same */
 349         assert(t->rpc || t->current_stream == stream);
 350
 351         /* Save off the current stream (i.e. socket) that we are working with */
 352         t->current_stream = stream;
 353
 354         if ((error = stream->write(stream, (const char *)data, len)) < 0)
 355                 return error;
 356
 357         gitno_buffer_setup_callback(&t->buffer, t->buffer_data, sizeof(t->buffer_data), git_smart__recv_cb, t);
 358
 359         return 0;
 360 }
 361
 362 int git_smart__get_push_stream(transport_smart *t, git_smart_subtransport_stream **stream)
 363 {
 364         int error;
 365
 366         if (t->rpc && git_smart__reset_stream(t, false) < 0)
 367                 return -1;
 368
 369         if (GIT_DIRECTION_PUSH != t->direction) {
 370                 git_error_set(GIT_ERROR_NET, "this operation is only valid for push");
 371                 return -1;
 372         }
 373
 374         if ((error = t->wrapped->action(stream, t->wrapped, t->url, GIT_SERVICE_RECEIVEPACK)) < 0)
 375                 return error;
 376
 377         /* If this is a stateful implementation, the stream we get back should be the same */
 378         assert(t->rpc || t->current_stream == *stream);
 379
 380         /* Save off the current stream (i.e. socket) that we are working with */
 381         t->current_stream = *stream;
 382
 383         gitno_buffer_setup_callback(&t->buffer, t->buffer_data, sizeof(t->buffer_data), git_smart__recv_cb, t);
 384
 385         return 0;
 386 }
 387
 388 static void git_smart__cancel(git_transport *transport)
 389 {
 390         transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 391
 392         git_atomic_set(&t->cancelled, 1);
 393 }
 394
 395 static int git_smart__is_connected(git_transport *transport)
 396 {
 397         transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 398
 399         return t->connected;
 400 }
 401
 402 static int git_smart__read_flags(git_transport *transport, int *flags)
 403 {
 404         transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 405
 406         *flags = t->flags;
 407
 408         return 0;
 409 }
 410
 411 static int git_smart__close(git_transport *transport)
 412 {
 413         transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 414         git_vector *common = &t->common;
 415         unsigned int i;
 416         git_pkt *p;
 417         int ret;
 418         git_smart_subtransport_stream *stream;
 419         const char flush[] = "0000";
 420
 421         /*
 422          * If we're still connected at this point and not using RPC,
 423          * we should say goodbye by sending a flush, or git-daemon
 424          * will complain that we disconnected unexpectedly.
 425          */
 426         if (t->connected && !t->rpc &&
 427             !t->wrapped->action(&stream, t->wrapped, t->url, GIT_SERVICE_UPLOADPACK)) {
 428                 t->current_stream->write(t->current_stream, flush, 4);
 429         }
 430
 431         ret = git_smart__reset_stream(t, true);
 432
 433         git_vector_foreach(common, i, p)
 434                 git_pkt_free(p);
 435
 436         git_vector_free(common);
 437
 438         if (t->url) {
 439                 git__free(t->url);
 440                 t->url = NULL;
 441         }
 442
 443         t->connected = 0;
 444
 445         return ret;
 446 }
 447
 448 static void git_smart__free(git_transport *transport)
 449 {
 450         transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 451         git_vector *refs = &t->refs;
 452         unsigned int i;
 453         git_pkt *p;
 454
 455         /* Make sure that the current stream is closed, if we have one. */
 456         git_smart__close(transport);
 457
 458         /* Free the subtransport */
 459         t->wrapped->free(t->wrapped);
 460
 461         git_vector_free(&t->heads);
 462         git_vector_foreach(refs, i, p)
 463                 git_pkt_free(p);
 464
 465         git_vector_free(refs);
 466         git__free((char *)t->proxy.url);
 467
 468         git_strarray_dispose(&t->custom_headers);
 469
 470         git__free(t);
 471 }
 472
 473 static int ref_name_cmp(const void *a, const void *b)
 474 {
 475         const git_pkt_ref *ref_a = a, *ref_b = b;
 476
 477         return strcmp(ref_a->head.name, ref_b->head.name);
 478 }
 479
 480 int git_transport_smart_certificate_check(git_transport *transport, git_cert *cert, int valid, const char *hostname)
 481 {
 482         transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 483
 484         assert(transport && cert && hostname);
 485
 486         if (!t->certificate_check_cb)
 487                 return GIT_PASSTHROUGH;
 488
 489         return t->certificate_check_cb(cert, valid, hostname, t->message_cb_payload);
 490 }
 491
 492 int git_transport_smart_credentials(git_credential **out, git_transport *transport, const char *user, int methods)
 493 {
 494         transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 495
 496         assert(out && transport);
 497
 498         if (!t->cred_acquire_cb)
 499                 return GIT_PASSTHROUGH;
 500
 501         return t->cred_acquire_cb(out, t->url, user, methods, t->cred_acquire_payload);
 502 }
 503
 504 int git_transport_smart_proxy_options(git_proxy_options *out, git_transport *transport)
 505 {
 506         transport_smart *t = GIT_CONTAINER_OF(transport, transport_smart, parent);
 507         return git_proxy_options_dup(out, &t->proxy);
 508 }
 509
 510 int git_transport_smart(git_transport **out, git_remote *owner, void *param)
 511 {
 512         transport_smart *t;
 513         git_smart_subtransport_definition *definition = (git_smart_subtransport_definition *)param;
 514
 515         if (!param)
 516                 return -1;
 517
 518         t = git__calloc(1, sizeof(transport_smart));
 519         GIT_ERROR_CHECK_ALLOC(t);
 520
 521         t->parent.version = GIT_TRANSPORT_VERSION;
 522         t->parent.set_callbacks = git_smart__set_callbacks;
 523         t->parent.set_custom_headers = git_smart__set_custom_headers;
 524         t->parent.connect = git_smart__connect;
 525         t->parent.close = git_smart__close;
 526         t->parent.free = git_smart__free;
 527         t->parent.negotiate_fetch = git_smart__negotiate_fetch;
 528         t->parent.download_pack = git_smart__download_pack;
 529         t->parent.push = git_smart__push;
 530         t->parent.ls = git_smart__ls;
 531         t->parent.is_connected = git_smart__is_connected;
 532         t->parent.read_flags = git_smart__read_flags;
 533         t->parent.cancel = git_smart__cancel;
 534
 535         t->owner = owner;
 536         t->rpc = definition->rpc;
 537
 538         if (git_vector_init(&t->refs, 16, ref_name_cmp) < 0) {
 539                 git__free(t);
 540                 return -1;
 541         }
 542
 543         if (git_vector_init(&t->heads, 16, ref_name_cmp) < 0) {
 544                 git__free(t);
 545                 return -1;
 546         }
 547
 548         if (definition->callback(&t->wrapped, &t->parent, definition->param) < 0) {
 549                 git__free(t);
 550                 return -1;
 551         }
 552
 553         *out = (git_transport *) t;
 554         return 0;
 555 }