include/git2/sys/transport.h

   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 #ifndef INCLUDE_sys_git_transport_h
   9 #define INCLUDE_sys_git_transport_h
  10
  11 #include "git2/net.h"
  12 #include "git2/types.h"
  13
  14 /**
  15  * @file git2/sys/transport.h
  16  * @brief Git custom transport registration interfaces and functions
  17  * @defgroup git_transport Git custom transport registration
  18  * @ingroup Git
  19  * @{
  20  */
  21
  22 GIT_BEGIN_DECL
  23
  24 typedef enum {
  25         GIT_TRANSPORTFLAGS_NONE = 0,
  26         /* If the connection is secured with SSL/TLS, the authenticity
  27          * of the server certificate should not be verified. */
  28         GIT_TRANSPORTFLAGS_NO_CHECK_CERT = 1
  29 } git_transport_flags_t;
  30
  31 typedef struct git_transport git_transport;
  32
  33 struct git_transport {
  34         unsigned int version;
  35         /* Set progress and error callbacks */
  36         int (*set_callbacks)(
  37                 git_transport *transport,
  38                 git_transport_message_cb progress_cb,
  39                 git_transport_message_cb error_cb,
  40                 void *payload);
  41
  42         /* Connect the transport to the remote repository, using the given
  43          * direction. */
  44         int (*connect)(
  45                 git_transport *transport,
  46                 const char *url,
  47                 git_cred_acquire_cb cred_acquire_cb,
  48                 void *cred_acquire_payload,
  49                 int direction,
  50                 int flags);
  51
  52         /* This function may be called after a successful call to
  53          * connect(). The array returned is owned by the transport and
  54          * is guranteed until the next call of a transport function. */
  55         int (*ls)(
  56                 const git_remote_head ***out,
  57                 size_t *size,
  58                 git_transport *transport);
  59
  60         /* Executes the push whose context is in the git_push object. */
  61         int (*push)(git_transport *transport, git_push *push);
  62
  63         /* This function may be called after a successful call to connect(), when
  64          * the direction is FETCH. The function performs a negotiation to calculate
  65          * the wants list for the fetch. */
  66         int (*negotiate_fetch)(
  67                 git_transport *transport,
  68                 git_repository *repo,
  69                 const git_remote_head * const *refs,
  70                 size_t count);
  71
  72         /* This function may be called after a successful call to negotiate_fetch(),
  73          * when the direction is FETCH. This function retrieves the pack file for
  74          * the fetch from the remote end. */
  75         int (*download_pack)(
  76                 git_transport *transport,
  77                 git_repository *repo,
  78                 git_transfer_progress *stats,
  79                 git_transfer_progress_cb progress_cb,
  80                 void *progress_payload);
  81
  82         /* Checks to see if the transport is connected */
  83         int (*is_connected)(git_transport *transport);
  84
  85         /* Reads the flags value previously passed into connect() */
  86         int (*read_flags)(git_transport *transport, int *flags);
  87
  88         /* Cancels any outstanding transport operation */
  89         void (*cancel)(git_transport *transport);
  90
  91         /* This function is the reverse of connect() -- it terminates the
  92          * connection to the remote end. */
  93         int (*close)(git_transport *transport);
  94
  95         /* Frees/destructs the git_transport object. */
  96         void (*free)(git_transport *transport);
  97 };
  98
  99 #define GIT_TRANSPORT_VERSION 1
 100 #define GIT_TRANSPORT_INIT {GIT_TRANSPORT_VERSION}
 101
 102 /**
 103  * Initializes a `git_transport` with default values. Equivalent to
 104  * creating an instance with GIT_TRANSPORT_INIT.
 105  *
 106  * @param opts the `git_transport` struct to initialize
 107  * @param version Version of struct; pass `GIT_TRANSPORT_VERSION`
 108  * @return Zero on success; -1 on failure.
 109  */
 110 GIT_EXTERN(int) git_transport_init(
 111         git_transport *opts,
 112         unsigned int version);
 113
 114 /**
 115  * Function to use to create a transport from a URL. The transport database
 116  * is scanned to find a transport that implements the scheme of the URI (i.e.
 117  * git:// or http://) and a transport object is returned to the caller.
 118  *
 119  * @param out The newly created transport (out)
 120  * @param owner The git_remote which will own this transport
 121  * @param url The URL to connect to
 122  * @return 0 or an error code
 123  */
 124 GIT_EXTERN(int) git_transport_new(git_transport **out, git_remote *owner, const char *url);
 125
 126 /**
 127  * Create an ssh transport with custom git command paths
 128  *
 129  * This is a factory function suitable for setting as the transport
 130  * callback in a remote (or for a clone in the options).
 131  *
 132  * The payload argument must be a strarray pointer with the paths for
 133  * the `git-upload-pack` and `git-receive-pack` at index 0 and 1.
 134  *
 135  * @param out the resulting transport
 136  * @param owner the owning remote
 137  * @param payload a strarray with the paths
 138  * @return 0 or an error code
 139  */
 140 GIT_EXTERN(int) git_transport_ssh_with_paths(git_transport **out, git_remote *owner, void *payload);
 141
 142 /* Signature of a function which creates a transport */
 143 typedef int (*git_transport_cb)(git_transport **out, git_remote *owner, void *param);
 144
 145 /**
 146  * Add a custom transport definition, to be used in addition to the built-in
 147  * set of transports that come with libgit2.
 148  *
 149  * The caller is responsible for synchronizing calls to git_transport_register
 150  * and git_transport_unregister with other calls to the library that
 151  * instantiate transports.
 152  *
 153  * @param prefix The scheme (ending in "://") to match, i.e. "git://"
 154  * @param cb The callback used to create an instance of the transport
 155  * @param param A fixed parameter to pass to cb at creation time
 156  * @return 0 or an error code
 157  */
 158 GIT_EXTERN(int) git_transport_register(
 159         const char *prefix,
 160         git_transport_cb cb,
 161         void *param);
 162
 163 /**
 164  *
 165  * Unregister a custom transport definition which was previously registered
 166  * with git_transport_register.
 167  *
 168  * @param prefix From the previous call to git_transport_register
 169  * @return 0 or an error code
 170  */
 171 GIT_EXTERN(int) git_transport_unregister(
 172         const char *prefix);
 173
 174 /* Transports which come with libgit2 (match git_transport_cb). The expected
 175  * value for "param" is listed in-line below. */
 176
 177 /**
 178  * Create an instance of the dummy transport.
 179  *
 180  * @param out The newly created transport (out)
 181  * @param owner The git_remote which will own this transport
 182  * @param payload You must pass NULL for this parameter.
 183  * @return 0 or an error code
 184  */
 185 GIT_EXTERN(int) git_transport_dummy(
 186         git_transport **out,
 187         git_remote *owner,
 188         /* NULL */ void *payload);
 189
 190 /**
 191  * Create an instance of the local transport.
 192  *
 193  * @param out The newly created transport (out)
 194  * @param owner The git_remote which will own this transport
 195  * @param payload You must pass NULL for this parameter.
 196  * @return 0 or an error code
 197  */
 198 GIT_EXTERN(int) git_transport_local(
 199         git_transport **out,
 200         git_remote *owner,
 201         /* NULL */ void *payload);
 202
 203 /**
 204  * Create an instance of the smart transport.
 205  *
 206  * @param out The newly created transport (out)
 207  * @param owner The git_remote which will own this transport
 208  * @param payload A pointer to a git_smart_subtransport_definition
 209  * @return 0 or an error code
 210  */
 211 GIT_EXTERN(int) git_transport_smart(
 212         git_transport **out,
 213         git_remote *owner,
 214         /* (git_smart_subtransport_definition *) */ void *payload);
 215
 216 /*
 217  *** End of base transport interface ***
 218  *** Begin interface for subtransports for the smart transport ***
 219  */
 220
 221 /* The smart transport knows how to speak the git protocol, but it has no
 222  * knowledge of how to establish a connection between it and another endpoint,
 223  * or how to move data back and forth. For this, a subtransport interface is
 224  * declared, and the smart transport delegates this work to the subtransports.
 225  * Three subtransports are implemented: git, http, and winhttp. (The http and
 226  * winhttp transports each implement both http and https.) */
 227
 228 /* Subtransports can either be RPC = 0 (persistent connection) or RPC = 1
 229  * (request/response). The smart transport handles the differences in its own
 230  * logic. The git subtransport is RPC = 0, while http and winhttp are both
 231  * RPC = 1. */
 232
 233 /* Actions that the smart transport can ask
 234  * a subtransport to perform */
 235 typedef enum {
 236         GIT_SERVICE_UPLOADPACK_LS = 1,
 237         GIT_SERVICE_UPLOADPACK = 2,
 238         GIT_SERVICE_RECEIVEPACK_LS = 3,
 239         GIT_SERVICE_RECEIVEPACK = 4,
 240 } git_smart_service_t;
 241
 242 typedef struct git_smart_subtransport git_smart_subtransport;
 243 typedef struct git_smart_subtransport_stream git_smart_subtransport_stream;
 244
 245 /* A stream used by the smart transport to read and write data
 246  * from a subtransport */
 247 struct git_smart_subtransport_stream {
 248         /* The owning subtransport */
 249         git_smart_subtransport *subtransport;
 250
 251         int (*read)(
 252                 git_smart_subtransport_stream *stream,
 253                 char *buffer,
 254                 size_t buf_size,
 255                 size_t *bytes_read);
 256
 257         int (*write)(
 258                 git_smart_subtransport_stream *stream,
 259                 const char *buffer,
 260                 size_t len);
 261
 262         void (*free)(
 263                 git_smart_subtransport_stream *stream);
 264 };
 265
 266 /* An implementation of a subtransport which carries data for the
 267  * smart transport */
 268 struct git_smart_subtransport {
 269         int (* action)(
 270                         git_smart_subtransport_stream **out,
 271                         git_smart_subtransport *transport,
 272                         const char *url,
 273                         git_smart_service_t action);
 274
 275         /* Subtransports are guaranteed a call to close() between
 276          * calls to action(), except for the following two "natural" progressions
 277          * of actions against a constant URL.
 278          *
 279          * 1. UPLOADPACK_LS -> UPLOADPACK
 280          * 2. RECEIVEPACK_LS -> RECEIVEPACK */
 281         int (*close)(git_smart_subtransport *transport);
 282
 283         void (*free)(git_smart_subtransport *transport);
 284 };
 285
 286 /* A function which creates a new subtransport for the smart transport */
 287 typedef int (*git_smart_subtransport_cb)(
 288         git_smart_subtransport **out,
 289         git_transport* owner);
 290
 291 typedef struct git_smart_subtransport_definition {
 292         /* The function to use to create the git_smart_subtransport */
 293         git_smart_subtransport_cb callback;
 294
 295         /* True if the protocol is stateless; false otherwise. For example,
 296          * http:// is stateless, but git:// is not. */
 297         unsigned rpc;
 298 } git_smart_subtransport_definition;
 299
 300 /* Smart transport subtransports that come with libgit2 */
 301
 302 /**
 303  * Create an instance of the http subtransport. This subtransport
 304  * also supports https. On Win32, this subtransport may be implemented
 305  * using the WinHTTP library.
 306  *
 307  * @param out The newly created subtransport
 308  * @param owner The smart transport to own this subtransport
 309  * @return 0 or an error code
 310  */
 311 GIT_EXTERN(int) git_smart_subtransport_http(
 312         git_smart_subtransport **out,
 313         git_transport* owner);
 314
 315 /**
 316  * Create an instance of the git subtransport.
 317  *
 318  * @param out The newly created subtransport
 319  * @param owner The smart transport to own this subtransport
 320  * @return 0 or an error code
 321  */
 322 GIT_EXTERN(int) git_smart_subtransport_git(
 323         git_smart_subtransport **out,
 324         git_transport* owner);
 325
 326 /**
 327  * Create an instance of the ssh subtransport.
 328  *
 329  * @param out The newly created subtransport
 330  * @param owner The smart transport to own this subtransport
 331  * @return 0 or an error code
 332  */
 333 GIT_EXTERN(int) git_smart_subtransport_ssh(
 334         git_smart_subtransport **out,
 335         git_transport* owner);
 336
 337 /**
 338  * Sets a custom transport factory for the remote. The caller can use this
 339  * function to override the transport used for this remote when performing
 340  * network operations.
 341  *
 342  * @param remote the remote to configure
 343  * @param transport_cb the function to use to create a transport
 344  * @param payload opaque parameter passed to transport_cb
 345  * @return 0 or an error code
 346  */
 347 GIT_EXTERN(int) git_remote_set_transport(
 348         git_remote *remote,
 349         git_transport_cb transport_cb,
 350         void *payload);
 351
 352 /** @} */
 353 GIT_END_DECL
 354 #endif