server/internal.h

   1 /* nbdkit
   2  * Copyright (C) 2013-2019 Red Hat Inc.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  * * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *
  11  * * Redistributions in binary form must reproduce the above copyright
  12  * notice, this list of conditions and the following disclaimer in the
  13  * documentation and/or other materials provided with the distribution.
  14  *
  15  * * Neither the name of Red Hat nor the names of its contributors may be
  16  * used to endorse or promote products derived from this software without
  17  * specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  22  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
  23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  26  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  27  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  28  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  29  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #ifndef NBDKIT_INTERNAL_H
  34 #define NBDKIT_INTERNAL_H
  35
  36 #include <stdbool.h>
  37 #include <stddef.h>
  38 #include <stdarg.h>
  39 #include <sys/socket.h>
  40 #include <pthread.h>
  41
  42 #define NBDKIT_API_VERSION 2
  43 #include "nbdkit-plugin.h"
  44 #include "nbdkit-filter.h"
  45
  46 #ifdef __APPLE__
  47 #define UNIX_PATH_MAX 104
  48 #else
  49 #define UNIX_PATH_MAX 108
  50 #endif
  51
  52 #ifndef O_CLOEXEC
  53 #define O_CLOEXEC 0
  54 #endif
  55
  56 #ifndef SOCK_CLOEXEC
  57 #define SOCK_CLOEXEC 0
  58 #endif
  59
  60 #if HAVE_VALGRIND
  61 # include <valgrind.h>
  62 /* http://valgrind.org/docs/manual/faq.html#faq.unhelpful */
  63 # define DO_DLCLOSE !RUNNING_ON_VALGRIND
  64 #elif defined(__SANITIZE_ADDRESS__)
  65 # define DO_DLCLOSE 0
  66 #else
  67 # define DO_DLCLOSE 1
  68 #endif
  69
  70 #define container_of(ptr, type, member) ({                       \
  71       const typeof (((type *) 0)->member) *__mptr = (ptr);       \
  72       (type *) ((char *) __mptr - offsetof(type, member));       \
  73     })
  74
  75 /* main.c */
  76 struct debug_flag {
  77   struct debug_flag *next;
  78   char *name;                   /* plugin or filter name */
  79   char *flag;                   /* flag name */
  80   int value;                    /* value of flag */
  81   bool used;                    /* if flag was successfully set */
  82 };
  83
  84 enum log_to {
  85   LOG_TO_DEFAULT,        /* --log not specified: log to stderr, unless
  86                             we forked into the background in which
  87                             case log to syslog */
  88   LOG_TO_STDERR,         /* --log=stderr forced on the command line */
  89   LOG_TO_SYSLOG,         /* --log=syslog forced on the command line */
  90 };
  91
  92 extern struct debug_flag *debug_flags;
  93 extern const char *exportname;
  94 extern bool foreground;
  95 extern const char *ipaddr;
  96 extern enum log_to log_to;
  97 extern bool newstyle;
  98 extern const char *port;
  99 extern bool readonly;
 100 extern const char *run;
 101 extern const char *selinux_label;
 102 extern int threads;
 103 extern int tls;
 104 extern const char *tls_certificates_dir;
 105 extern const char *tls_psk;
 106 extern bool tls_verify_peer;
 107 extern char *unixsocket;
 108 extern const char *user, *group;
 109 extern bool verbose;
 110
 111 extern struct backend *backend;
 112 #define for_each_backend(b) for (b = backend; b != NULL; b = b->next)
 113
 114 /* quit.c */
 115 extern volatile int quit;
 116 extern int quit_fd;
 117 extern void set_up_quit_pipe (void);
 118 extern void handle_quit (int sig);
 119 extern void set_quit (void);
 120
 121 /* signals.c */
 122 extern void set_up_signals (void);
 123
 124 /* background.c */
 125 extern bool forked_into_background;
 126 extern void fork_into_background (void);
 127
 128 /* captive.c */
 129 extern void run_command (void);
 130
 131 /* socket-activation.c */
 132 #define FIRST_SOCKET_ACTIVATION_FD 3 /* defined by systemd ABI */
 133 extern unsigned int get_socket_activation (void);
 134
 135 /* usergroup.c */
 136 extern void change_user (void);
 137
 138 /* cleanup.c */
 139 extern void cleanup_free (void *ptr);
 140 #define CLEANUP_FREE __attribute__((cleanup (cleanup_free)))
 141 extern void cleanup_extents_free (void *ptr);
 142 #define CLEANUP_EXTENTS_FREE __attribute__((cleanup (cleanup_extents_free)))
 143 extern void cleanup_unlock (pthread_mutex_t **ptr);
 144 #define CLEANUP_UNLOCK __attribute__((cleanup (cleanup_unlock)))
 145 #define ACQUIRE_LOCK_FOR_CURRENT_SCOPE(mutex) \
 146   CLEANUP_UNLOCK pthread_mutex_t *_lock = mutex; \
 147   pthread_mutex_lock (_lock)
 148
 149 /* connections.c */
 150 struct connection;
 151
 152 typedef int (*connection_recv_function) (struct connection *,
 153                                          void *buf, size_t len)
 154   __attribute__((__nonnull__ (1, 2)));
 155 typedef int (*connection_send_function) (struct connection *,
 156                                          const void *buf, size_t len)
 157   __attribute__((__nonnull__ (1, 2)));
 158 typedef void (*connection_close_function) (struct connection *)
 159   __attribute__((__nonnull__ (1)));
 160
 161 struct connection {
 162   pthread_mutex_t request_lock;
 163   pthread_mutex_t read_lock;
 164   pthread_mutex_t write_lock;
 165   pthread_mutex_t status_lock;
 166   int status; /* 1 for more I/O with client, 0 for shutdown, -1 on error */
 167   void *crypto_session;
 168   int nworkers;
 169
 170   void **handles;
 171   size_t nr_handles;
 172
 173   uint32_t cflags;
 174   uint64_t exportsize;
 175   uint16_t eflags;
 176   bool readonly;
 177   bool can_flush;
 178   bool is_rotational;
 179   bool can_trim;
 180   bool can_zero;
 181   bool can_fua;
 182   bool can_multi_conn;
 183   bool can_extents;
 184   bool using_tls;
 185   bool structured_replies;
 186   bool meta_context_base_allocation;
 187
 188   int sockin, sockout;
 189   connection_recv_function recv;
 190   connection_send_function send;
 191   connection_close_function close;
 192 };
 193
 194 extern int handle_single_connection (int sockin, int sockout);
 195 extern int connection_set_handle (struct connection *conn,
 196                                   size_t i, void *handle)
 197   __attribute__((__nonnull__ (1 /* not 3 */)));
 198 extern void *connection_get_handle (struct connection *conn, size_t i)
 199   __attribute__((__nonnull__ (1)));
 200 extern int connection_get_status (struct connection *conn)
 201   __attribute__((__nonnull__ (1)));
 202 extern int connection_set_status (struct connection *conn, int value)
 203   __attribute__((__nonnull__ (1)));
 204
 205 /* protocol-handshake.c */
 206 extern int protocol_handshake (struct connection *conn)
 207   __attribute__((__nonnull__ (1)));
 208 extern int protocol_compute_eflags (struct connection *conn, uint16_t *flags)
 209   __attribute__((__nonnull__ (1, 2)));
 210
 211 /* protocol-handshake-oldstyle.c */
 212 extern int protocol_handshake_oldstyle (struct connection *conn)
 213   __attribute__((__nonnull__ (1)));
 214
 215 /* protocol-handshake-newstyle.c */
 216 extern int protocol_handshake_newstyle (struct connection *conn)
 217   __attribute__((__nonnull__ (1)));
 218
 219 /* protocol.c */
 220 extern int protocol_recv_request_send_reply (struct connection *conn)
 221   __attribute__((__nonnull__ (1)));
 222
 223 /* The context ID of base:allocation.  As far as I can tell it doesn't
 224  * matter what this is as long as nbdkit always returns the same
 225  * number.
 226  */
 227 #define base_allocation_id 1
 228
 229 /* crypto.c */
 230 #define root_tls_certificates_dir sysconfdir "/pki/" PACKAGE_NAME
 231 extern void crypto_init (bool tls_set_on_cli);
 232 extern void crypto_free (void);
 233 extern int crypto_negotiate_tls (struct connection *conn,
 234                                  int sockin, int sockout)
 235   __attribute__((__nonnull__ (1)));
 236
 237 /* debug.c */
 238 #define debug nbdkit_debug
 239
 240 /* log-*.c */
 241 #if !HAVE_VFPRINTF_PERCENT_M
 242 #include <stdio.h>
 243 #define vfprintf nbdkit_vfprintf
 244 extern int nbdkit_vfprintf (FILE *f, const char *fmt, va_list args)
 245   __attribute__((__format__ (printf, 2, 0)));
 246 #endif
 247 extern void log_stderr_verror (const char *fs, va_list args)
 248   __attribute__((__format__ (printf, 1, 0)));
 249 extern void log_syslog_verror (const char *fs, va_list args)
 250   __attribute__((__format__ (printf, 1, 0)));
 251
 252 struct backend {
 253   /* Next filter or plugin in the chain.  This is always NULL for
 254    * plugins and never NULL for filters.
 255    */
 256   struct backend *next;
 257
 258   /* A unique index used to fetch the handle from the connections
 259    * object.  The plugin (last in the chain) has index 0, and the
 260    * filters have index 1, 2, ... depending how "far" they are from
 261    * the plugin.
 262    */
 263   size_t i;
 264
 265   void (*free) (struct backend *);
 266   int (*thread_model) (struct backend *);
 267   const char *(*name) (struct backend *);
 268   const char *(*plugin_name) (struct backend *);
 269   void (*usage) (struct backend *);
 270   const char *(*version) (struct backend *);
 271   void (*dump_fields) (struct backend *);
 272   void (*config) (struct backend *, const char *key, const char *value);
 273   void (*config_complete) (struct backend *);
 274   const char *(*magic_config_key) (struct backend *);
 275   int (*open) (struct backend *, struct connection *conn, int readonly);
 276   int (*prepare) (struct backend *, struct connection *conn);
 277   int (*finalize) (struct backend *, struct connection *conn);
 278   void (*close) (struct backend *, struct connection *conn);
 279
 280   int64_t (*get_size) (struct backend *, struct connection *conn);
 281   int (*can_write) (struct backend *, struct connection *conn);
 282   int (*can_flush) (struct backend *, struct connection *conn);
 283   int (*is_rotational) (struct backend *, struct connection *conn);
 284   int (*can_trim) (struct backend *, struct connection *conn);
 285   int (*can_zero) (struct backend *, struct connection *conn);
 286   int (*can_extents) (struct backend *, struct connection *conn);
 287   int (*can_fua) (struct backend *, struct connection *conn);
 288   int (*can_multi_conn) (struct backend *, struct connection *conn);
 289
 290   int (*pread) (struct backend *, struct connection *conn, void *buf,
 291                 uint32_t count, uint64_t offset, uint32_t flags, int *err);
 292   int (*pwrite) (struct backend *, struct connection *conn, const void *buf,
 293                  uint32_t count, uint64_t offset, uint32_t flags, int *err);
 294   int (*flush) (struct backend *, struct connection *conn, uint32_t flags,
 295                 int *err);
 296   int (*trim) (struct backend *, struct connection *conn, uint32_t count,
 297                uint64_t offset, uint32_t flags, int *err);
 298   int (*zero) (struct backend *, struct connection *conn, uint32_t count,
 299                uint64_t offset, uint32_t flags, int *err);
 300   int (*extents) (struct backend *, struct connection *conn, uint32_t count,
 301                   uint64_t offset, uint32_t flags,
 302                   struct nbdkit_extents *extents, int *err);
 303 };
 304
 305 /* plugins.c */
 306 extern struct backend *plugin_register (size_t index, const char *filename,
 307                                         void *dl, struct nbdkit_plugin *(*plugin_init) (void))
 308   __attribute__((__nonnull__ (2, 3, 4)));
 309 extern void set_debug_flags (void *dl, const char *name)
 310   __attribute__((__nonnull__ (1, 2)));
 311
 312 /* filters.c */
 313 extern struct backend *filter_register (struct backend *next, size_t index,
 314                                         const char *filename, void *dl,
 315                                         struct nbdkit_filter *(*filter_init) (void))
 316   __attribute__((__nonnull__ (1, 3, 4, 5)));
 317
 318 /* locks.c */
 319 extern void lock_init_thread_model (void);
 320 extern void lock_connection (void);
 321 extern void unlock_connection (void);
 322 extern void lock_request (struct connection *conn)
 323   __attribute__((__nonnull__ (1)));
 324 extern void unlock_request (struct connection *conn)
 325   __attribute__((__nonnull__ (1)));
 326 extern void lock_unload (void);
 327 extern void unlock_unload (void);
 328
 329 /* sockets.c */
 330 extern int *bind_unix_socket (size_t *)
 331   __attribute__((__nonnull__ (1)));
 332 extern int *bind_tcpip_socket (size_t *)
 333   __attribute__((__nonnull__ (1)));
 334 extern void accept_incoming_connections (int *socks, size_t nr_socks)
 335   __attribute__((__nonnull__ (1)));
 336 extern void free_listening_sockets (int *socks, size_t nr_socks)
 337   __attribute__((__nonnull__ (1)));
 338
 339 /* threadlocal.c */
 340 extern void threadlocal_init (void);
 341 extern void threadlocal_new_server_thread (void);
 342 extern void threadlocal_set_name (const char *name)
 343   __attribute__((__nonnull__ (1)));
 344 extern void threadlocal_set_instance_num (size_t instance_num);
 345 extern void threadlocal_set_sockaddr (const struct sockaddr *addr,
 346                                       socklen_t addrlen)
 347   __attribute__((__nonnull__ (1)));
 348 extern const char *threadlocal_get_name (void);
 349 extern size_t threadlocal_get_instance_num (void);
 350 extern void threadlocal_set_error (int err);
 351 extern int threadlocal_get_error (void);
 352 /*extern void threadlocal_get_sockaddr ();*/
 353
 354 /* Declare program_name. */
 355 #if HAVE_DECL_PROGRAM_INVOCATION_SHORT_NAME == 1
 356 #include <errno.h>
 357 #define program_name program_invocation_short_name
 358 #else
 359 #define program_name "nbdkit"
 360 #endif
 361
 362 #endif /* NBDKIT_INTERNAL_H */