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 #include "nbd-protocol.h"
  47
  48 #ifdef __APPLE__
  49 #define UNIX_PATH_MAX 104
  50 #else
  51 #define UNIX_PATH_MAX 108
  52 #endif
  53
  54 #if HAVE_VALGRIND
  55 # include <valgrind.h>
  56 /* http://valgrind.org/docs/manual/faq.html#faq.unhelpful */
  57 # define DO_DLCLOSE !RUNNING_ON_VALGRIND
  58 #elif defined(__SANITIZE_ADDRESS__)
  59 # define DO_DLCLOSE 0
  60 #else
  61 # define DO_DLCLOSE 1
  62 #endif
  63
  64 #define container_of(ptr, type, member) ({                       \
  65       const typeof (((type *) 0)->member) *__mptr = (ptr);       \
  66       (type *) ((char *) __mptr - offsetof(type, member));       \
  67     })
  68
  69 /* Maximum read or write request that we will handle. */
  70 #define MAX_REQUEST_SIZE (64 * 1024 * 1024)
  71
  72 /* main.c */
  73 struct debug_flag {
  74   struct debug_flag *next;
  75   char *name;                   /* plugin or filter name */
  76   char *flag;                   /* flag name */
  77   int value;                    /* value of flag */
  78   bool used;                    /* if flag was successfully set */
  79 };
  80
  81 enum log_to {
  82   LOG_TO_DEFAULT,        /* --log not specified: log to stderr, unless
  83                             we forked into the background in which
  84                             case log to syslog */
  85   LOG_TO_STDERR,         /* --log=stderr forced on the command line */
  86   LOG_TO_SYSLOG,         /* --log=syslog forced on the command line */
  87 };
  88
  89 extern struct debug_flag *debug_flags;
  90 extern const char *exportname;
  91 extern bool foreground;
  92 extern const char *ipaddr;
  93 extern enum log_to log_to;
  94 extern unsigned mask_handshake;
  95 extern bool newstyle;
  96 extern bool no_sr;
  97 extern const char *port;
  98 extern bool read_only;
  99 extern const char *run;
 100 extern bool listen_stdin;
 101 extern const char *selinux_label;
 102 extern unsigned 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 /* connections.c */
 139 struct connection;
 140
 141 /* Flags for connection_send_function */
 142 enum {
 143   SEND_MORE = 1, /* Hint to use MSG_MORE/corking to group send()s */
 144 };
 145
 146 typedef int (*connection_recv_function) (struct connection *,
 147                                          void *buf, size_t len)
 148   __attribute__((__nonnull__ (1, 2)));
 149 typedef int (*connection_send_function) (struct connection *,
 150                                          const void *buf, size_t len,
 151                                          int flags)
 152   __attribute__((__nonnull__ (1, 2)));
 153 typedef void (*connection_close_function) (struct connection *)
 154   __attribute__((__nonnull__ (1)));
 155
 156 struct b_conn_handle {
 157   void *handle;
 158
 159   uint64_t exportsize;
 160   int can_write;
 161   int can_flush;
 162   int is_rotational;
 163   int can_trim;
 164   int can_zero;
 165   int can_fast_zero;
 166   int can_fua;
 167   int can_multi_conn;
 168   int can_extents;
 169   int can_cache;
 170 };
 171
 172 static inline void
 173 reset_b_conn_handle (struct b_conn_handle *h)
 174 {
 175   h->handle = NULL;
 176   h->exportsize = -1;
 177   h->can_write = -1;
 178   h->can_flush = -1;
 179   h->is_rotational = -1;
 180   h->can_trim = -1;
 181   h->can_zero = -1;
 182   h->can_fast_zero = -1;
 183   h->can_fua = -1;
 184   h->can_multi_conn = -1;
 185   h->can_extents = -1;
 186   h->can_cache = -1;
 187 }
 188
 189 struct connection {
 190   pthread_mutex_t request_lock;
 191   pthread_mutex_t read_lock;
 192   pthread_mutex_t write_lock;
 193   pthread_mutex_t status_lock;
 194   int status; /* 1 for more I/O with client, 0 for shutdown, -1 on error */
 195   int status_pipe[2]; /* track status changes via poll when nworkers > 1 */
 196   void *crypto_session;
 197   int nworkers;
 198
 199   struct b_conn_handle *handles;
 200   size_t nr_handles;
 201
 202   char exportname[NBD_MAX_STRING + 1];
 203   uint32_t exportnamelen;
 204   uint32_t cflags;
 205   uint16_t eflags;
 206   bool using_tls;
 207   bool structured_replies;
 208   bool meta_context_base_allocation;
 209
 210   int sockin, sockout;
 211   connection_recv_function recv;
 212   connection_send_function send;
 213   connection_close_function close;
 214 };
 215
 216 extern int handle_single_connection (int sockin, int sockout);
 217 extern void *connection_get_handle (struct connection *conn, size_t i)
 218   __attribute__((__nonnull__ (1)));
 219 extern int connection_get_status (struct connection *conn)
 220   __attribute__((__nonnull__ (1)));
 221 extern int connection_set_status (struct connection *conn, int value)
 222   __attribute__((__nonnull__ (1)));
 223
 224 /* protocol-handshake.c */
 225 extern int protocol_handshake (struct connection *conn)
 226   __attribute__((__nonnull__ (1)));
 227 extern int protocol_common_open (struct connection *conn,
 228                                  uint64_t *exportsize, uint16_t *flags)
 229   __attribute__((__nonnull__ (1, 2, 3)));
 230
 231 /* protocol-handshake-oldstyle.c */
 232 extern int protocol_handshake_oldstyle (struct connection *conn)
 233   __attribute__((__nonnull__ (1)));
 234
 235 /* protocol-handshake-newstyle.c */
 236 extern int protocol_handshake_newstyle (struct connection *conn)
 237   __attribute__((__nonnull__ (1)));
 238
 239 /* protocol.c */
 240 extern int protocol_recv_request_send_reply (struct connection *conn)
 241   __attribute__((__nonnull__ (1)));
 242
 243 /* The context ID of base:allocation.  As far as I can tell it doesn't
 244  * matter what this is as long as nbdkit always returns the same
 245  * number.
 246  */
 247 #define base_allocation_id 1
 248
 249 /* crypto.c */
 250 #define root_tls_certificates_dir sysconfdir "/pki/" PACKAGE_NAME
 251 extern void crypto_init (bool tls_set_on_cli);
 252 extern void crypto_free (void);
 253 extern int crypto_negotiate_tls (struct connection *conn,
 254                                  int sockin, int sockout)
 255   __attribute__((__nonnull__ (1)));
 256
 257 /* debug.c */
 258 #define debug nbdkit_debug
 259
 260 /* log-*.c */
 261 #if !HAVE_VFPRINTF_PERCENT_M
 262 #include <stdio.h>
 263 #define vfprintf nbdkit_vfprintf
 264 extern int nbdkit_vfprintf (FILE *f, const char *fmt, va_list args)
 265   __attribute__((__format__ (printf, 2, 0)));
 266 #endif
 267 extern void log_stderr_verror (const char *fs, va_list args)
 268   __attribute__((__format__ (printf, 1, 0)));
 269 extern void log_syslog_verror (const char *fs, va_list args)
 270   __attribute__((__format__ (printf, 1, 0)));
 271
 272 /* backend.c */
 273 struct backend {
 274   /* Next filter or plugin in the chain.  This is always NULL for
 275    * plugins and never NULL for filters.
 276    */
 277   struct backend *next;
 278
 279   /* A unique index used to fetch the handle from the connections
 280    * object.  The plugin (last in the chain) has index 0, and the
 281    * filters have index 1, 2, ... depending how "far" they are from
 282    * the plugin.
 283    */
 284   size_t i;
 285
 286   /* The type of backend: filter or plugin. */
 287   const char *type;
 288
 289   /* A copy of the backend name that survives a dlclose. */
 290   char *name;
 291
 292   /* The file the backend was loaded from. */
 293   char *filename;
 294
 295   /* The dlopen handle for the backend. */
 296   void *dl;
 297
 298   /* Backend callbacks. All are required. */
 299   void (*free) (struct backend *);
 300   int (*thread_model) (struct backend *);
 301   const char *(*plugin_name) (struct backend *);
 302   void (*usage) (struct backend *);
 303   const char *(*version) (struct backend *);
 304   void (*dump_fields) (struct backend *);
 305   void (*config) (struct backend *, const char *key, const char *value);
 306   void (*config_complete) (struct backend *);
 307   const char *(*magic_config_key) (struct backend *);
 308   int (*open) (struct backend *, struct connection *conn, int readonly);
 309   int (*prepare) (struct backend *, struct connection *conn, int readonly);
 310   int (*finalize) (struct backend *, struct connection *conn);
 311   void (*close) (struct backend *, struct connection *conn);
 312
 313   int64_t (*get_size) (struct backend *, struct connection *conn);
 314   int (*can_write) (struct backend *, struct connection *conn);
 315   int (*can_flush) (struct backend *, struct connection *conn);
 316   int (*is_rotational) (struct backend *, struct connection *conn);
 317   int (*can_trim) (struct backend *, struct connection *conn);
 318   int (*can_zero) (struct backend *, struct connection *conn);
 319   int (*can_fast_zero) (struct backend *, struct connection *conn);
 320   int (*can_extents) (struct backend *, struct connection *conn);
 321   int (*can_fua) (struct backend *, struct connection *conn);
 322   int (*can_multi_conn) (struct backend *, struct connection *conn);
 323   int (*can_cache) (struct backend *, struct connection *conn);
 324
 325   int (*pread) (struct backend *, struct connection *conn, void *buf,
 326                 uint32_t count, uint64_t offset, uint32_t flags, int *err);
 327   int (*pwrite) (struct backend *, struct connection *conn, const void *buf,
 328                  uint32_t count, uint64_t offset, uint32_t flags, int *err);
 329   int (*flush) (struct backend *, struct connection *conn, uint32_t flags,
 330                 int *err);
 331   int (*trim) (struct backend *, struct connection *conn, uint32_t count,
 332                uint64_t offset, uint32_t flags, int *err);
 333   int (*zero) (struct backend *, struct connection *conn, uint32_t count,
 334                uint64_t offset, uint32_t flags, int *err);
 335   int (*extents) (struct backend *, struct connection *conn, uint32_t count,
 336                   uint64_t offset, uint32_t flags,
 337                   struct nbdkit_extents *extents, int *err);
 338   int (*cache) (struct backend *, struct connection *conn, uint32_t count,
 339                 uint64_t offset, uint32_t flags, int *err);
 340 };
 341
 342 extern void backend_init (struct backend *b, struct backend *next, size_t index,
 343                           const char *filename, void *dl, const char *type)
 344   __attribute__((__nonnull__ (1, 4, 5, 6)));
 345 extern void backend_load (struct backend *b, const char *name,
 346                           void (*load) (void))
 347   __attribute__((__nonnull__ (1 /* not 2 */)));
 348 extern void backend_unload (struct backend *b, void (*unload) (void))
 349   __attribute__((__nonnull__ (1)));
 350
 351 extern int backend_open (struct backend *b, struct connection *conn,
 352                          int readonly)
 353   __attribute__((__nonnull__ (1, 2)));
 354 extern int backend_prepare (struct backend *b, struct connection *conn)
 355   __attribute__((__nonnull__ (1, 2)));
 356 extern void backend_close (struct backend *b, struct connection *conn)
 357   __attribute__((__nonnull__ (1, 2)));
 358 extern void backend_set_handle (struct backend *b, struct connection *conn,
 359                                 void *handle)
 360   __attribute__((__nonnull__ (1, 2, 3)));
 361 extern bool backend_valid_range (struct backend *b, struct connection *conn,
 362                                  uint64_t offset, uint32_t count)
 363   __attribute__((__nonnull__ (1, 2)));
 364
 365 extern int backend_reopen (struct backend *b, struct connection *conn,
 366                            int readonly)
 367   __attribute__((__nonnull__ (1, 2)));
 368 extern int64_t backend_get_size (struct backend *b, struct connection *conn)
 369   __attribute__((__nonnull__ (1, 2)));
 370 extern int backend_can_write (struct backend *b, struct connection *conn)
 371   __attribute__((__nonnull__ (1, 2)));
 372 extern int backend_can_flush (struct backend *b, struct connection *conn)
 373   __attribute__((__nonnull__ (1, 2)));
 374 extern int backend_is_rotational (struct backend *b, struct connection *conn)
 375   __attribute__((__nonnull__ (1, 2)));
 376 extern int backend_can_trim (struct backend *b, struct connection *conn)
 377   __attribute__((__nonnull__ (1, 2)));
 378 extern int backend_can_zero (struct backend *b, struct connection *conn)
 379   __attribute__((__nonnull__ (1, 2)));
 380 extern int backend_can_fast_zero (struct backend *b, struct connection *conn)
 381   __attribute__((__nonnull__ (1, 2)));
 382 extern int backend_can_extents (struct backend *b, struct connection *conn)
 383   __attribute__((__nonnull__ (1, 2)));
 384 extern int backend_can_fua (struct backend *b, struct connection *conn)
 385   __attribute__((__nonnull__ (1, 2)));
 386 extern int backend_can_multi_conn (struct backend *b, struct connection *conn)
 387   __attribute__((__nonnull__ (1, 2)));
 388 extern int backend_can_cache (struct backend *b, struct connection *conn)
 389   __attribute__((__nonnull__ (1, 2)));
 390
 391 extern int backend_pread (struct backend *b, struct connection *conn,
 392                           void *buf, uint32_t count, uint64_t offset,
 393                           uint32_t flags, int *err)
 394   __attribute__((__nonnull__ (1, 2, 3, 7)));
 395 extern int backend_pwrite (struct backend *b, struct connection *conn,
 396                            const void *buf, uint32_t count, uint64_t offset,
 397                            uint32_t flags, int *err)
 398   __attribute__((__nonnull__ (1, 2, 3, 7)));
 399 extern int backend_flush (struct backend *b, struct connection *conn,
 400                           uint32_t flags, int *err)
 401   __attribute__((__nonnull__ (1, 2, 4)));
 402 extern int backend_trim (struct backend *b, struct connection *conn,
 403                          uint32_t count, uint64_t offset, uint32_t flags,
 404                          int *err)
 405   __attribute__((__nonnull__ (1, 2, 6)));
 406 extern int backend_zero (struct backend *b, struct connection *conn,
 407                          uint32_t count, uint64_t offset, uint32_t flags,
 408                          int *err)
 409   __attribute__((__nonnull__ (1, 2, 6)));
 410 extern int backend_extents (struct backend *b, struct connection *conn,
 411                             uint32_t count, uint64_t offset, uint32_t flags,
 412                             struct nbdkit_extents *extents, int *err)
 413   __attribute__((__nonnull__ (1, 2, 6, 7)));
 414 extern int backend_cache (struct backend *b, struct connection *conn,
 415                           uint32_t count, uint64_t offset,
 416                           uint32_t flags, int *err)
 417   __attribute__((__nonnull__ (1, 2, 6)));
 418
 419 /* plugins.c */
 420 extern struct backend *plugin_register (size_t index, const char *filename,
 421                                         void *dl, struct nbdkit_plugin *(*plugin_init) (void))
 422   __attribute__((__nonnull__ (2, 3, 4)));
 423
 424 /* filters.c */
 425 extern struct backend *filter_register (struct backend *next, size_t index,
 426                                         const char *filename, void *dl,
 427                                         struct nbdkit_filter *(*filter_init) (void))
 428   __attribute__((__nonnull__ (1, 3, 4, 5)));
 429
 430 /* locks.c */
 431 extern void lock_init_thread_model (void);
 432 extern const char *name_of_thread_model (int model);
 433 extern void lock_connection (void);
 434 extern void unlock_connection (void);
 435 extern void lock_request (struct connection *conn);
 436 extern void unlock_request (struct connection *conn);
 437 extern void lock_unload (void);
 438 extern void unlock_unload (void);
 439
 440 /* sockets.c */
 441 extern int *bind_unix_socket (size_t *)
 442   __attribute__((__nonnull__ (1)));
 443 extern int *bind_tcpip_socket (size_t *)
 444   __attribute__((__nonnull__ (1)));
 445 extern void accept_incoming_connections (int *socks, size_t nr_socks)
 446   __attribute__((__nonnull__ (1)));
 447 extern void free_listening_sockets (int *socks, size_t nr_socks)
 448   __attribute__((__nonnull__ (1)));
 449
 450 /* threadlocal.c */
 451 extern void threadlocal_init (void);
 452 extern void threadlocal_new_server_thread (void);
 453 extern void threadlocal_set_name (const char *name)
 454   __attribute__((__nonnull__ (1)));
 455 extern const char *threadlocal_get_name (void);
 456 extern void threadlocal_set_instance_num (size_t instance_num);
 457 extern size_t threadlocal_get_instance_num (void);
 458 extern void threadlocal_set_error (int err);
 459 extern int threadlocal_get_error (void);
 460 extern void *threadlocal_buffer (size_t size);
 461 extern void threadlocal_set_conn (struct connection *conn);
 462 extern struct connection *threadlocal_get_conn (void);
 463
 464 /* Declare program_name. */
 465 #if HAVE_DECL_PROGRAM_INVOCATION_SHORT_NAME == 1
 466 #include <errno.h>
 467 #define program_name program_invocation_short_name
 468 #else
 469 #define program_name "nbdkit"
 470 #endif
 471
 472 #endif /* NBDKIT_INTERNAL_H */