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 #include "cleanup.h"
  46
  47 #ifdef __APPLE__
  48 #define UNIX_PATH_MAX 104
  49 #else
  50 #define UNIX_PATH_MAX 108
  51 #endif
  52
  53 #if HAVE_VALGRIND
  54 # include <valgrind.h>
  55 /* http://valgrind.org/docs/manual/faq.html#faq.unhelpful */
  56 # define DO_DLCLOSE !RUNNING_ON_VALGRIND
  57 #elif defined(__SANITIZE_ADDRESS__)
  58 # define DO_DLCLOSE 0
  59 #else
  60 # define DO_DLCLOSE 1
  61 #endif
  62
  63 #define container_of(ptr, type, member) ({                       \
  64       const typeof (((type *) 0)->member) *__mptr = (ptr);       \
  65       (type *) ((char *) __mptr - offsetof(type, member));       \
  66     })
  67
  68 /* Maximum read or write request that we will handle. */
  69 #define MAX_REQUEST_SIZE (64 * 1024 * 1024)
  70
  71 /* main.c */
  72 struct debug_flag {
  73   struct debug_flag *next;
  74   char *name;                   /* plugin or filter name */
  75   char *flag;                   /* flag name */
  76   int value;                    /* value of flag */
  77   bool used;                    /* if flag was successfully set */
  78 };
  79
  80 enum log_to {
  81   LOG_TO_DEFAULT,        /* --log not specified: log to stderr, unless
  82                             we forked into the background in which
  83                             case log to syslog */
  84   LOG_TO_STDERR,         /* --log=stderr forced on the command line */
  85   LOG_TO_SYSLOG,         /* --log=syslog forced on the command line */
  86 };
  87
  88 extern struct debug_flag *debug_flags;
  89 extern const char *exportname;
  90 extern bool foreground;
  91 extern const char *ipaddr;
  92 extern enum log_to log_to;
  93 extern bool newstyle;
  94 extern bool no_sr;
  95 extern const char *port;
  96 extern bool readonly;
  97 extern const char *run;
  98 extern bool listen_stdin;
  99 extern const char *selinux_label;
 100 extern int threads;
 101 extern int tls;
 102 extern const char *tls_certificates_dir;
 103 extern const char *tls_psk;
 104 extern bool tls_verify_peer;
 105 extern char *unixsocket;
 106 extern const char *user, *group;
 107 extern bool verbose;
 108
 109 extern struct backend *backend;
 110 #define for_each_backend(b) for (b = backend; b != NULL; b = b->next)
 111
 112 /* quit.c */
 113 extern volatile int quit;
 114 extern int quit_fd;
 115 extern void set_up_quit_pipe (void);
 116 extern void handle_quit (int sig);
 117 extern void set_quit (void);
 118
 119 /* signals.c */
 120 extern void set_up_signals (void);
 121
 122 /* background.c */
 123 extern bool forked_into_background;
 124 extern void fork_into_background (void);
 125
 126 /* captive.c */
 127 extern void run_command (void);
 128
 129 /* socket-activation.c */
 130 #define FIRST_SOCKET_ACTIVATION_FD 3 /* defined by systemd ABI */
 131 extern unsigned int get_socket_activation (void);
 132
 133 /* usergroup.c */
 134 extern void change_user (void);
 135
 136 /* connections.c */
 137 struct connection;
 138
 139 /* Flags for connection_send_function */
 140 enum {
 141   SEND_MORE = 1, /* Hint to use MSG_MORE/corking to group send()s */
 142 };
 143
 144 typedef int (*connection_recv_function) (struct connection *,
 145                                          void *buf, size_t len)
 146   __attribute__((__nonnull__ (1, 2)));
 147 typedef int (*connection_send_function) (struct connection *,
 148                                          const void *buf, size_t len,
 149                                          int flags)
 150   __attribute__((__nonnull__ (1, 2)));
 151 typedef void (*connection_close_function) (struct connection *)
 152   __attribute__((__nonnull__ (1)));
 153
 154 struct b_conn_handle {
 155   void *handle;
 156
 157   uint64_t exportsize;
 158   int can_write;
 159 };
 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   int status_pipe[2]; /* track status changes via poll when nworkers > 1 */
 168   void *crypto_session;
 169   int nworkers;
 170
 171   struct b_conn_handle *handles;
 172   size_t nr_handles;
 173
 174   uint32_t cflags;
 175   uint16_t eflags;
 176   bool can_flush;
 177   bool is_rotational;
 178   bool can_trim;
 179   bool can_zero;
 180   bool can_fua;
 181   bool can_multi_conn;
 182   bool can_cache;
 183   bool emulate_cache;
 184   bool can_extents;
 185   bool using_tls;
 186   bool structured_replies;
 187   bool meta_context_base_allocation;
 188
 189   int sockin, sockout;
 190   connection_recv_function recv;
 191   connection_send_function send;
 192   connection_close_function close;
 193 };
 194
 195 extern int handle_single_connection (int sockin, int sockout);
 196 extern void *connection_get_handle (struct connection *conn, size_t i)
 197   __attribute__((__nonnull__ (1)));
 198 extern int connection_get_status (struct connection *conn)
 199   __attribute__((__nonnull__ (1)));
 200 extern int connection_set_status (struct connection *conn, int value)
 201   __attribute__((__nonnull__ (1)));
 202
 203 /* protocol-handshake.c */
 204 extern int protocol_handshake (struct connection *conn)
 205   __attribute__((__nonnull__ (1)));
 206 extern int protocol_compute_eflags (struct connection *conn, uint16_t *flags)
 207   __attribute__((__nonnull__ (1, 2)));
 208
 209 /* protocol-handshake-oldstyle.c */
 210 extern int protocol_handshake_oldstyle (struct connection *conn)
 211   __attribute__((__nonnull__ (1)));
 212
 213 /* protocol-handshake-newstyle.c */
 214 extern int protocol_handshake_newstyle (struct connection *conn)
 215   __attribute__((__nonnull__ (1)));
 216
 217 /* protocol.c */
 218 extern int protocol_recv_request_send_reply (struct connection *conn)
 219   __attribute__((__nonnull__ (1)));
 220
 221 /* The context ID of base:allocation.  As far as I can tell it doesn't
 222  * matter what this is as long as nbdkit always returns the same
 223  * number.
 224  */
 225 #define base_allocation_id 1
 226
 227 /* crypto.c */
 228 #define root_tls_certificates_dir sysconfdir "/pki/" PACKAGE_NAME
 229 extern void crypto_init (bool tls_set_on_cli);
 230 extern void crypto_free (void);
 231 extern int crypto_negotiate_tls (struct connection *conn,
 232                                  int sockin, int sockout)
 233   __attribute__((__nonnull__ (1)));
 234
 235 /* debug.c */
 236 #define debug nbdkit_debug
 237
 238 /* log-*.c */
 239 #if !HAVE_VFPRINTF_PERCENT_M
 240 #include <stdio.h>
 241 #define vfprintf nbdkit_vfprintf
 242 extern int nbdkit_vfprintf (FILE *f, const char *fmt, va_list args)
 243   __attribute__((__format__ (printf, 2, 0)));
 244 #endif
 245 extern void log_stderr_verror (const char *fs, va_list args)
 246   __attribute__((__format__ (printf, 1, 0)));
 247 extern void log_syslog_verror (const char *fs, va_list args)
 248   __attribute__((__format__ (printf, 1, 0)));
 249
 250 /* backend.c */
 251 struct backend {
 252   /* Next filter or plugin in the chain.  This is always NULL for
 253    * plugins and never NULL for filters.
 254    */
 255   struct backend *next;
 256
 257   /* A unique index used to fetch the handle from the connections
 258    * object.  The plugin (last in the chain) has index 0, and the
 259    * filters have index 1, 2, ... depending how "far" they are from
 260    * the plugin.
 261    */
 262   size_t i;
 263
 264   /* The type of backend: filter or plugin. */
 265   const char *type;
 266
 267   /* A copy of the backend name that survives a dlclose. */
 268   char *name;
 269
 270   /* The file the backend was loaded from. */
 271   char *filename;
 272
 273   /* The dlopen handle for the backend. */
 274   void *dl;
 275
 276   /* Backend callbacks. All are required. */
 277   void (*free) (struct backend *);
 278   int (*thread_model) (struct backend *);
 279   const char *(*plugin_name) (struct backend *);
 280   void (*usage) (struct backend *);
 281   const char *(*version) (struct backend *);
 282   void (*dump_fields) (struct backend *);
 283   void (*config) (struct backend *, const char *key, const char *value);
 284   void (*config_complete) (struct backend *);
 285   const char *(*magic_config_key) (struct backend *);
 286   int (*open) (struct backend *, struct connection *conn, int readonly);
 287   int (*prepare) (struct backend *, struct connection *conn);
 288   int (*finalize) (struct backend *, struct connection *conn);
 289   void (*close) (struct backend *, struct connection *conn);
 290
 291   int64_t (*get_size) (struct backend *, struct connection *conn);
 292   int (*can_write) (struct backend *, struct connection *conn);
 293   int (*can_flush) (struct backend *, struct connection *conn);
 294   int (*is_rotational) (struct backend *, struct connection *conn);
 295   int (*can_trim) (struct backend *, struct connection *conn);
 296   int (*can_zero) (struct backend *, struct connection *conn);
 297   int (*can_extents) (struct backend *, struct connection *conn);
 298   int (*can_fua) (struct backend *, struct connection *conn);
 299   int (*can_multi_conn) (struct backend *, struct connection *conn);
 300   int (*can_cache) (struct backend *, struct connection *conn);
 301
 302   int (*pread) (struct backend *, struct connection *conn, void *buf,
 303                 uint32_t count, uint64_t offset, uint32_t flags, int *err);
 304   int (*pwrite) (struct backend *, struct connection *conn, const void *buf,
 305                  uint32_t count, uint64_t offset, uint32_t flags, int *err);
 306   int (*flush) (struct backend *, struct connection *conn, uint32_t flags,
 307                 int *err);
 308   int (*trim) (struct backend *, struct connection *conn, uint32_t count,
 309                uint64_t offset, uint32_t flags, int *err);
 310   int (*zero) (struct backend *, struct connection *conn, uint32_t count,
 311                uint64_t offset, uint32_t flags, int *err);
 312   int (*extents) (struct backend *, struct connection *conn, uint32_t count,
 313                   uint64_t offset, uint32_t flags,
 314                   struct nbdkit_extents *extents, int *err);
 315   int (*cache) (struct backend *, struct connection *conn, uint32_t count,
 316                 uint64_t offset, uint32_t flags, int *err);
 317 };
 318
 319 extern void backend_init (struct backend *b, struct backend *next, size_t index,
 320                           const char *filename, void *dl, const char *type)
 321   __attribute__((__nonnull__ (1, 4, 5, 6)));
 322 extern void backend_load (struct backend *b, const char *name,
 323                           void (*load) (void))
 324   __attribute__((__nonnull__ (1 /* not 2 */)));
 325 extern void backend_unload (struct backend *b, void (*unload) (void))
 326   __attribute__((__nonnull__ (1)));
 327
 328 extern int backend_open (struct backend *b, struct connection *conn,
 329                          int readonly)
 330   __attribute__((__nonnull__ (1, 2)));
 331 extern void backend_set_handle (struct backend *b, struct connection *conn,
 332                                 void *handle)
 333   __attribute__((__nonnull__ (1, 2 /* not 3 */)));
 334
 335 extern int64_t backend_get_size (struct backend *b, struct connection *conn)
 336   __attribute__((__nonnull__ (1, 2)));
 337 extern int backend_can_write (struct backend *b, struct connection *conn)
 338   __attribute__((__nonnull__ (1, 2)));
 339 extern int backend_can_flush (struct backend *b, struct connection *conn)
 340   __attribute__((__nonnull__ (1, 2)));
 341 extern int backend_is_rotational (struct backend *b, struct connection *conn)
 342   __attribute__((__nonnull__ (1, 2)));
 343 extern int backend_can_trim (struct backend *b, struct connection *conn)
 344   __attribute__((__nonnull__ (1, 2)));
 345 extern int backend_can_zero (struct backend *b, struct connection *conn)
 346   __attribute__((__nonnull__ (1, 2)));
 347 extern int backend_can_extents (struct backend *b, struct connection *conn)
 348   __attribute__((__nonnull__ (1, 2)));
 349 extern int backend_can_fua (struct backend *b, struct connection *conn)
 350   __attribute__((__nonnull__ (1, 2)));
 351 extern int backend_can_multi_conn (struct backend *b, struct connection *conn)
 352   __attribute__((__nonnull__ (1, 2)));
 353 extern int backend_can_cache (struct backend *b, struct connection *conn)
 354   __attribute__((__nonnull__ (1, 2)));
 355
 356 extern int backend_pread (struct backend *b, struct connection *conn,
 357                           void *buf, uint32_t count, uint64_t offset,
 358                           uint32_t flags, int *err)
 359   __attribute__((__nonnull__ (1, 2, 3, 7)));
 360 extern int backend_pwrite (struct backend *b, struct connection *conn,
 361                            const void *buf, uint32_t count, uint64_t offset,
 362                            uint32_t flags, int *err)
 363   __attribute__((__nonnull__ (1, 2, 3, 7)));
 364 extern int backend_flush (struct backend *b, struct connection *conn,
 365                           uint32_t flags, int *err)
 366   __attribute__((__nonnull__ (1, 2, 4)));
 367 extern int backend_trim (struct backend *b, struct connection *conn,
 368                          uint32_t count, uint64_t offset, uint32_t flags,
 369                          int *err)
 370   __attribute__((__nonnull__ (1, 2, 6)));
 371 extern int backend_zero (struct backend *b, struct connection *conn,
 372                          uint32_t count, uint64_t offset, uint32_t flags,
 373                          int *err)
 374   __attribute__((__nonnull__ (1, 2, 6)));
 375 extern int backend_extents (struct backend *b, struct connection *conn,
 376                             uint32_t count, uint64_t offset, uint32_t flags,
 377                             struct nbdkit_extents *extents, int *err)
 378   __attribute__((__nonnull__ (1, 2, 6, 7)));
 379 extern int backend_cache (struct backend *b, struct connection *conn,
 380                           uint32_t count, uint64_t offset,
 381                           uint32_t flags, int *err)
 382   __attribute__((__nonnull__ (1, 2, 6)));
 383
 384 /* plugins.c */
 385 extern struct backend *plugin_register (size_t index, const char *filename,
 386                                         void *dl, struct nbdkit_plugin *(*plugin_init) (void))
 387   __attribute__((__nonnull__ (2, 3, 4)));
 388
 389 /* filters.c */
 390 extern struct backend *filter_register (struct backend *next, size_t index,
 391                                         const char *filename, void *dl,
 392                                         struct nbdkit_filter *(*filter_init) (void))
 393   __attribute__((__nonnull__ (1, 3, 4, 5)));
 394
 395 /* locks.c */
 396 extern void lock_init_thread_model (void);
 397 extern const char *name_of_thread_model (int model);
 398 extern void lock_connection (void);
 399 extern void unlock_connection (void);
 400 extern void lock_request (struct connection *conn);
 401 extern void unlock_request (struct connection *conn);
 402 extern void lock_unload (void);
 403 extern void unlock_unload (void);
 404
 405 /* sockets.c */
 406 extern int *bind_unix_socket (size_t *)
 407   __attribute__((__nonnull__ (1)));
 408 extern int *bind_tcpip_socket (size_t *)
 409   __attribute__((__nonnull__ (1)));
 410 extern void accept_incoming_connections (int *socks, size_t nr_socks)
 411   __attribute__((__nonnull__ (1)));
 412 extern void free_listening_sockets (int *socks, size_t nr_socks)
 413   __attribute__((__nonnull__ (1)));
 414
 415 /* threadlocal.c */
 416 extern void threadlocal_init (void);
 417 extern void threadlocal_new_server_thread (void);
 418 extern void threadlocal_set_name (const char *name)
 419   __attribute__((__nonnull__ (1)));
 420 extern const char *threadlocal_get_name (void);
 421 extern void threadlocal_set_instance_num (size_t instance_num);
 422 extern size_t threadlocal_get_instance_num (void);
 423 extern void threadlocal_set_sockaddr (const struct sockaddr *addr,
 424                                       socklen_t addrlen)
 425   __attribute__((__nonnull__ (1)));
 426 /*extern void threadlocal_get_sockaddr ();*/
 427 extern void threadlocal_set_error (int err);
 428 extern int threadlocal_get_error (void);
 429 extern void *threadlocal_buffer (size_t size);
 430 extern void threadlocal_set_conn (struct connection *conn);
 431 extern struct connection *threadlocal_get_conn (void);
 432
 433 /* Declare program_name. */
 434 #if HAVE_DECL_PROGRAM_INVOCATION_SHORT_NAME == 1
 435 #include <errno.h>
 436 #define program_name program_invocation_short_name
 437 #else
 438 #define program_name "nbdkit"
 439 #endif
 440
 441 #endif /* NBDKIT_INTERNAL_H */