/*
 * svn_server.h :  declarations for the svn server
 *
 * ====================================================================
 *    Licensed to the Apache Software Foundation (ASF) under one
 *    or more contributor license agreements.  See the NOTICE file
 *    distributed with this work for additional information
 *    regarding copyright ownership.  The ASF licenses this file
 *    to you under the Apache License, Version 2.0 (the
 *    "License"); you may not use this file except in compliance
 *    with the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing,
 *    software distributed under the License is distributed on an
 *    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *    KIND, either express or implied.  See the License for the
 *    specific language governing permissions and limitations
 *    under the License.
 * ====================================================================
 */


#ifndef SERVER_H
#define SERVER_H

#include <apr_network_io.h>

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

#include "svn_config.h"
#include "svn_repos.h"
#include "svn_ra_svn.h"

#include "private/svn_atomic.h"
#include "private/svn_mutex.h"
#include "private/svn_repos_private.h"
#include "private/svn_subr_private.h"

enum username_case_type { CASE_FORCE_UPPER, CASE_FORCE_LOWER, CASE_ASIS };

enum authn_type { UNAUTHENTICATED, AUTHENTICATED };
enum access_type { NO_ACCESS, READ_ACCESS, WRITE_ACCESS };

typedef struct repository_t {
  svn_repos_t *repos;
  const char *repos_name;  /* URI-encoded name of repository (not for authz) */
  const char *repos_root;  /* Repository root directory */
  svn_fs_t *fs;            /* For convenience; same as svn_repos_fs(repos) */
  const char *base;        /* Base directory for config files */
  svn_config_t *pwdb;      /* Parsed password database */
  svn_authz_t *authzdb;    /* Parsed authz rules */
  const char *authz_repos_name; /* The name of the repository for authz */
  const char *realm;       /* Authentication realm */
  const char *repos_url;   /* URL to base of repository */
  const char *hooks_env;   /* Path to the hooks environment file or NULL */
  const char *uuid;        /* Repository ID */
  apr_array_header_t *capabilities;
                           /* Client capabilities (SVN_RA_CAPABILITY_*) */
  svn_stringbuf_t *fs_path;/* Decoded base in-repos path (w/ leading slash) */
  enum username_case_type username_case; /* Case-normalize the username? */
  svn_boolean_t use_sasl;  /* Use Cyrus SASL for authentication;
                              always false if SVN_HAVE_SASL not defined */
#ifdef SVN_HAVE_SASL
  unsigned min_ssf;        /* min-encryption SASL parameter */
  unsigned max_ssf;        /* max-encryption SASL parameter */
#endif

  enum access_type auth_access; /* access granted to authenticated users */
  enum access_type anon_access; /* access granted to annonymous users */

} repository_t;

typedef struct client_info_t {
  const char *user;        /* Authenticated username of the user */
  const char *remote_host; /* IP of the client that contacted the server */
  const char *authz_user;  /* Username for authz ('user' + 'username_case') */
  svn_boolean_t tunnel;    /* Tunneled through login agent */
  const char *tunnel_user; /* Allow EXTERNAL to authenticate as this */
} client_info_t;

typedef struct server_baton_t {
  repository_t *repository; /* repository-specific data to use */
  client_info_t *client_info; /* client-specific data to use */
  struct logger_t *logger; /* Log file data structure.
                              May be NULL even if log_file is not. */
  svn_boolean_t read_only; /* Disallow write access (global flag) */
  svn_boolean_t vhost;     /* Use virtual-host-based path to repo. */
  apr_pool_t *pool;
} server_baton_t;

typedef struct serve_params_t {
  /* The virtual root of the repositories to serve.  The client URL
     path is interpreted relative to this root and is not allowed to
     escape it. */
  const char *root;

  /* True if the connection is tunneled over an ssh-like transport,
     such that the client may use EXTERNAL to authenticate as the
     current uid's username. */
  svn_boolean_t tunnel;

  /* If tunnel is true, overrides the current uid's username as the
     identity EXTERNAL authenticates as. */
  const char *tunnel_user;

  /* True if the read-only flag was specified on the command-line,
     which forces all connections to be read-only. */
  svn_boolean_t read_only;

  /* The base directory for any relative configuration files. */
  const char *base;

  /* A parsed repository svnserve configuration file, ala
     svnserve.conf.  If this is NULL, then no configuration file was
     specified on the command line.  If this is non-NULL, then
     per-repository svnserve.conf are not read. */
  svn_config_t *cfg;

  /* logging data structure; possibly NULL. */
  struct logger_t *logger;

  /* all configurations should be opened through this factory */
  svn_repos__config_pool_t *config_pool;

  /* The FS configuration to be applied to all repositories.
     It mainly contains things like cache settings. */
  apr_hash_t *fs_config;

  /* Username case normalization style. */
  enum username_case_type username_case;

  /* Size of the in-memory cache (used by FSFS only). */
  apr_uint64_t memory_cache_size;

  /* Data compression level to reduce for network traffic. If this
     is 0, no compression should be applied and the protocol may
     fall back to svndiff "version 0" bypassing zlib entirely.
     Defaults to SVN_DELTA_COMPRESSION_LEVEL_DEFAULT. */
  int compression_level;

  /* Item size up to which we use the zero-copy code path to transmit
     them over the network.  0 disables that code path. */
  apr_size_t zero_copy_limit;

  /* Amount of data to send between checks for cancellation requests
     coming in from the client. */
  apr_size_t error_check_interval;

  /* If not 0, error out on requests exceeding this value. */
  apr_uint64_t max_request_size;

  /* If not 0, stop sending a response once it exceeds this value. */
  apr_uint64_t max_response_size;

  /* Use virtual-host-based path to repo. */
  svn_boolean_t vhost;
} serve_params_t;

/* This structure contains all data that describes a client / server
   connection.  Their lifetime is separated from the thread-local
   serving pools. */
typedef struct connection_t
{
  /* socket return by accept() */
  apr_socket_t *usock;

  /* server-global parameters */
  serve_params_t *params;

  /* connection-specific objects */
  server_baton_t *baton;

  /* buffered connection object used by the marshaller */
  svn_ra_svn_conn_t *conn;

  /* memory pool for objects with connection lifetime */
  apr_pool_t *pool;

  /* Number of threads using the pool.
     The pool passed to apr_thread_create can only be released when both

        A: the call to apr_thread_create has returned to the calling thread
        B: the new thread has started running and reached apr_thread_start_t

     So we set the atomic counter to 2 then both the calling thread and
     the new thread decrease it and when it reaches 0 the pool can be
     released.  */
  svn_atomic_t ref_count;

} connection_t;

/* Return a client_info_t structure allocated in POOL and initialize it
 * with data from CONN. */
client_info_t * get_client_info(svn_ra_svn_conn_t *conn,
                                serve_params_t *params,
                                apr_pool_t *pool);

/* Serve the connection CONN according to the parameters PARAMS. */
svn_error_t *serve(svn_ra_svn_conn_t *conn, serve_params_t *params,
                   apr_pool_t *pool);

/* Serve the connection CONNECTION for as long as IS_BUSY does not
   return TRUE.  If IS_BUSY is NULL, serve the connection until it
   either gets terminated or there is an error.  If TERMINATE_P is
   not NULL, set *TERMINATE_P to TRUE if the connection got
   terminated.

   For the first call, CONNECTION->CONN may be NULL in which case we
   will create an ra_svn connection object.  Subsequent calls will
   check for an open repository and automatically re-open the repo
   in pool if necessary.
 */
svn_error_t *
serve_interruptable(svn_boolean_t *terminate_p,
                    connection_t *connection,
                    svn_boolean_t (* is_busy)(connection_t *),
                    apr_pool_t *pool);

/* Initialize the Cyrus SASL library. POOL is used for allocations. */
svn_error_t *cyrus_init(apr_pool_t *pool);

/* Authenticate using Cyrus SASL. */
svn_error_t *cyrus_auth_request(svn_ra_svn_conn_t *conn,
                                apr_pool_t *pool,
                                server_baton_t *b,
                                enum access_type required,
                                svn_boolean_t needs_username);

/* Escape SOURCE into DEST where SOURCE is null-terminated and DEST is
   size BUFLEN DEST will be null-terminated.  Returns number of bytes
   written, including terminating null byte. */
apr_size_t escape_errorlog_item(char *dest, const char *source,
                                apr_size_t buflen);

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif  /* SERVER_H */