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 /* Define unlikely macro, but only for GCC.  These are used to move
  49  * debug and error handling code out of hot paths.
  50  */
  51 #if defined(__GNUC__)
  52 #define unlikely(x) __builtin_expect (!!(x), 0)
  53 #define if_verbose if (unlikely (verbose))
  54 #else
  55 #define unlikely(x) (x)
  56 #define if_verbose if (verbose)
  57 #endif
  58
  59 #ifdef __APPLE__
  60 #define UNIX_PATH_MAX 104
  61 #else
  62 #define UNIX_PATH_MAX 108
  63 #endif
  64
  65 #if HAVE_VALGRIND
  66 # include <valgrind.h>
  67 /* http://valgrind.org/docs/manual/faq.html#faq.unhelpful */
  68 # define DO_DLCLOSE !RUNNING_ON_VALGRIND
  69 #elif defined(__SANITIZE_ADDRESS__)
  70 # define DO_DLCLOSE 0
  71 #else
  72 # define DO_DLCLOSE 1
  73 #endif
  74
  75 #define container_of(ptr, type, member) ({                       \
  76       const typeof (((type *) 0)->member) *__mptr = (ptr);       \
  77       (type *) ((char *) __mptr - offsetof(type, member));       \
  78     })
  79
  80 /* Maximum read or write request that we will handle. */
  81 #define MAX_REQUEST_SIZE (64 * 1024 * 1024)
  82
  83 /* main.c */
  84 struct debug_flag {
  85   struct debug_flag *next;
  86   char *name;                   /* plugin or filter name */
  87   char *flag;                   /* flag name */
  88   int value;                    /* value of flag */
  89   bool used;                    /* if flag was successfully set */
  90 };
  91
  92 enum log_to {
  93   LOG_TO_DEFAULT,        /* --log not specified: log to stderr, unless
  94                             we forked into the background in which
  95                             case log to syslog */
  96   LOG_TO_STDERR,         /* --log=stderr forced on the command line */
  97   LOG_TO_SYSLOG,         /* --log=syslog forced on the command line */
  98   LOG_TO_NULL,           /* --log=null forced on the command line */
  99 };
 100
 101 extern struct debug_flag *debug_flags;
 102 extern const char *exportname;
 103 extern bool foreground;
 104 extern const char *ipaddr;
 105 extern enum log_to log_to;
 106 extern unsigned mask_handshake;
 107 extern bool newstyle;
 108 extern bool no_sr;
 109 extern const char *port;
 110 extern bool read_only;
 111 extern const char *run;
 112 extern bool listen_stdin;
 113 extern const char *selinux_label;
 114 extern unsigned threads;
 115 extern int tls;
 116 extern const char *tls_certificates_dir;
 117 extern const char *tls_psk;
 118 extern bool tls_verify_peer;
 119 extern char *unixsocket;
 120 extern const char *user, *group;
 121 extern bool verbose;
 122
 123 extern struct backend *backend;
 124 #define for_each_backend(b) for (b = backend; b != NULL; b = b->next)
 125
 126 /* quit.c */
 127 extern volatile int quit;
 128 extern int quit_fd;
 129 extern void set_up_quit_pipe (void);
 130 extern void handle_quit (int sig);
 131 extern void set_quit (void);
 132
 133 /* signals.c */
 134 extern void set_up_signals (void);
 135
 136 /* background.c */
 137 extern bool forked_into_background;
 138 extern void fork_into_background (void);
 139
 140 /* captive.c */
 141 extern void run_command (void);
 142
 143 /* socket-activation.c */
 144 #define FIRST_SOCKET_ACTIVATION_FD 3 /* defined by systemd ABI */
 145 extern unsigned int get_socket_activation (void);
 146
 147 /* usergroup.c */
 148 extern void change_user (void);
 149
 150 /* connections.c */
 151 struct connection;
 152
 153 /* Flags for connection_send_function */
 154 enum {
 155   SEND_MORE = 1, /* Hint to use MSG_MORE/corking to group send()s */
 156 };
 157
 158 typedef int (*connection_recv_function) (struct connection *,
 159                                          void *buf, size_t len)
 160   __attribute__((__nonnull__ (1, 2)));
 161 typedef int (*connection_send_function) (struct connection *,
 162                                          const void *buf, size_t len,
 163                                          int flags)
 164   __attribute__((__nonnull__ (1, 2)));
 165 typedef void (*connection_close_function) (struct connection *)
 166   __attribute__((__nonnull__ (1)));
 167
 168 enum {
 169   HANDLE_OPEN = 1,      /* Set if .open passed, so .close is needed */
 170   HANDLE_CONNECTED = 2, /* Set if .prepare passed, so .finalize is needed */
 171   HANDLE_FAILED = 4,    /* Set if .finalize failed */
 172 };
 173
 174 struct b_conn_handle {
 175   void *handle;
 176
 177   unsigned char state; /* Bitmask of HANDLE_* values */
 178
 179   uint64_t exportsize;
 180   int can_write;
 181   int can_flush;
 182   int is_rotational;
 183   int can_trim;
 184   int can_zero;
 185   int can_fast_zero;
 186   int can_fua;
 187   int can_multi_conn;
 188   int can_extents;
 189   int can_cache;
 190 };
 191
 192 static inline void
 193 reset_b_conn_handle (struct b_conn_handle *h)
 194 {
 195   h->handle = NULL;
 196   h->state = 0;
 197   h->exportsize = -1;
 198   h->can_write = -1;
 199   h->can_flush = -1;
 200   h->is_rotational = -1;
 201   h->can_trim = -1;
 202   h->can_zero = -1;
 203   h->can_fast_zero = -1;
 204   h->can_fua = -1;
 205   h->can_multi_conn = -1;
 206   h->can_extents = -1;
 207   h->can_cache = -1;
 208 }
 209
 210 struct connection {
 211   pthread_mutex_t request_lock;
 212   pthread_mutex_t read_lock;
 213   pthread_mutex_t write_lock;
 214   pthread_mutex_t status_lock;
 215   int status; /* 1 for more I/O with client, 0 for shutdown, -1 on error */
 216   int status_pipe[2]; /* track status changes via poll when nworkers > 1 */
 217   void *crypto_session;
 218   int nworkers;
 219
 220   struct b_conn_handle *handles;
 221   size_t nr_handles;
 222
 223   char exportname[NBD_MAX_STRING + 1];
 224   uint32_t exportnamelen;
 225   uint32_t cflags;
 226   uint16_t eflags;
 227   bool using_tls;
 228   bool structured_replies;
 229   bool meta_context_base_allocation;
 230
 231   int sockin, sockout;
 232   connection_recv_function recv;
 233   connection_send_function send;
 234   connection_close_function close;
 235 };
 236
 237 extern void handle_single_connection (int sockin, int sockout);
 238 extern int connection_get_status (struct connection *conn)
 239   __attribute__((__nonnull__ (1)));
 240 extern int connection_set_status (struct connection *conn, int value)
 241   __attribute__((__nonnull__ (1)));
 242
 243 /* protocol-handshake.c */
 244 extern int protocol_handshake (struct connection *conn)
 245   __attribute__((__nonnull__ (1)));
 246 extern int protocol_common_open (struct connection *conn,
 247                                  uint64_t *exportsize, uint16_t *flags)
 248   __attribute__((__nonnull__ (1, 2, 3)));
 249
 250 /* protocol-handshake-oldstyle.c */
 251 extern int protocol_handshake_oldstyle (struct connection *conn)
 252   __attribute__((__nonnull__ (1)));
 253
 254 /* protocol-handshake-newstyle.c */
 255 extern int protocol_handshake_newstyle (struct connection *conn)
 256   __attribute__((__nonnull__ (1)));
 257
 258 /* protocol.c */
 259 extern int protocol_recv_request_send_reply (struct connection *conn)
 260   __attribute__((__nonnull__ (1)));
 261
 262 /* The context ID of base:allocation.  As far as I can tell it doesn't
 263  * matter what this is as long as nbdkit always returns the same
 264  * number.
 265  */
 266 #define base_allocation_id 1
 267
 268 /* crypto.c */
 269 #define root_tls_certificates_dir sysconfdir "/pki/" PACKAGE_NAME
 270 extern void crypto_init (bool tls_set_on_cli);
 271 extern void crypto_free (void);
 272 extern int crypto_negotiate_tls (struct connection *conn,
 273                                  int sockin, int sockout)
 274   __attribute__((__nonnull__ (1)));
 275
 276 /* debug.c */
 277 #define debug(fs, ...)                                   \
 278   do {                                                   \
 279     if_verbose                                           \
 280       nbdkit_debug ((fs), ##__VA_ARGS__);                \
 281   } while (0)
 282
 283 /* log-*.c */
 284 #if !HAVE_VFPRINTF_PERCENT_M
 285 #include <stdio.h>
 286 #define vfprintf nbdkit_vfprintf
 287 extern int nbdkit_vfprintf (FILE *f, const char *fmt, va_list args)
 288   __attribute__((__format__ (printf, 2, 0)));
 289 #endif
 290 extern void log_stderr_verror (const char *fs, va_list args)
 291   __attribute__((__format__ (printf, 1, 0)));
 292 extern void log_syslog_verror (const char *fs, va_list args)
 293   __attribute__((__format__ (printf, 1, 0)));
 294
 295 /* backend.c */
 296 struct backend {
 297   /* Next filter or plugin in the chain.  This is always NULL for
 298    * plugins and never NULL for filters.
 299    */
 300   struct backend *next;
 301
 302   /* A unique index used to fetch the handle from the connections
 303    * object.  The plugin (last in the chain) has index 0, and the
 304    * filters have index 1, 2, ... depending how "far" they are from
 305    * the plugin.
 306    */
 307   size_t i;
 308
 309   /* The type of backend: filter or plugin. */
 310   const char *type;
 311
 312   /* A copy of the backend name that survives a dlclose. */
 313   char *name;
 314
 315   /* The file the backend was loaded from. */
 316   char *filename;
 317
 318   /* The dlopen handle for the backend. */
 319   void *dl;
 320
 321   /* Backend callbacks. All are required. */
 322   void (*free) (struct backend *);
 323   int (*thread_model) (struct backend *);
 324   const char *(*plugin_name) (struct backend *);
 325   void (*usage) (struct backend *);
 326   const char *(*version) (struct backend *);
 327   void (*dump_fields) (struct backend *);
 328   void (*config) (struct backend *, const char *key, const char *value);
 329   void (*config_complete) (struct backend *);
 330   const char *(*magic_config_key) (struct backend *);
 331   void *(*open) (struct backend *, struct connection *conn, int readonly);
 332   int (*prepare) (struct backend *, struct connection *conn, void *handle,
 333                   int readonly);
 334   int (*finalize) (struct backend *, struct connection *conn, void *handle);
 335   void (*close) (struct backend *, struct connection *conn, void *handle);
 336
 337   int64_t (*get_size) (struct backend *, struct connection *conn, void *handle);
 338   int (*can_write) (struct backend *, struct connection *conn, void *handle);
 339   int (*can_flush) (struct backend *, struct connection *conn, void *handle);
 340   int (*is_rotational) (struct backend *, struct connection *conn,
 341                         void *handle);
 342   int (*can_trim) (struct backend *, struct connection *conn, void *handle);
 343   int (*can_zero) (struct backend *, struct connection *conn, void *handle);
 344   int (*can_fast_zero) (struct backend *, struct connection *conn,
 345                         void *handle);
 346   int (*can_extents) (struct backend *, struct connection *conn, void *handle);
 347   int (*can_fua) (struct backend *, struct connection *conn, void *handle);
 348   int (*can_multi_conn) (struct backend *, struct connection *conn,
 349                          void *handle);
 350   int (*can_cache) (struct backend *, struct connection *conn, void *handle);
 351
 352   int (*pread) (struct backend *, struct connection *conn, void *handle,
 353                 void *buf, uint32_t count, uint64_t offset,
 354                 uint32_t flags, int *err);
 355   int (*pwrite) (struct backend *, struct connection *conn, void *handle,
 356                  const void *buf, uint32_t count, uint64_t offset,
 357                  uint32_t flags, int *err);
 358   int (*flush) (struct backend *, struct connection *conn, void *handle,
 359                 uint32_t flags, int *err);
 360   int (*trim) (struct backend *, struct connection *conn, void *handle,
 361                uint32_t count, uint64_t offset, uint32_t flags, int *err);
 362   int (*zero) (struct backend *, struct connection *conn, void *handle,
 363                uint32_t count, uint64_t offset, uint32_t flags, int *err);
 364   int (*extents) (struct backend *, struct connection *conn, void *handle,
 365                   uint32_t count, uint64_t offset, uint32_t flags,
 366                   struct nbdkit_extents *extents, int *err);
 367   int (*cache) (struct backend *, struct connection *conn, void *handle,
 368                 uint32_t count, uint64_t offset, uint32_t flags, int *err);
 369 };
 370
 371 extern void backend_init (struct backend *b, struct backend *next, size_t index,
 372                           const char *filename, void *dl, const char *type)
 373   __attribute__((__nonnull__ (1, 4, 5, 6)));
 374 extern void backend_load (struct backend *b, const char *name,
 375                           void (*load) (void))
 376   __attribute__((__nonnull__ (1 /* not 2 */)));
 377 extern void backend_unload (struct backend *b, void (*unload) (void))
 378   __attribute__((__nonnull__ (1)));
 379
 380 extern int backend_open (struct backend *b, struct connection *conn,
 381                          int readonly)
 382   __attribute__((__nonnull__ (1, 2)));
 383 extern int backend_prepare (struct backend *b, struct connection *conn)
 384   __attribute__((__nonnull__ (1, 2)));
 385 extern int backend_finalize (struct backend *b, struct connection *conn)
 386   __attribute__((__nonnull__ (1, 2)));
 387 extern void backend_close (struct backend *b, struct connection *conn)
 388   __attribute__((__nonnull__ (1, 2)));
 389 extern bool backend_valid_range (struct backend *b, struct connection *conn,
 390                                  uint64_t offset, uint32_t count)
 391   __attribute__((__nonnull__ (1, 2)));
 392
 393 extern int backend_reopen (struct backend *b, struct connection *conn,
 394                            int readonly)
 395   __attribute__((__nonnull__ (1, 2)));
 396 extern int64_t backend_get_size (struct backend *b, struct connection *conn)
 397   __attribute__((__nonnull__ (1, 2)));
 398 extern int backend_can_write (struct backend *b, struct connection *conn)
 399   __attribute__((__nonnull__ (1, 2)));
 400 extern int backend_can_flush (struct backend *b, struct connection *conn)
 401   __attribute__((__nonnull__ (1, 2)));
 402 extern int backend_is_rotational (struct backend *b, struct connection *conn)
 403   __attribute__((__nonnull__ (1, 2)));
 404 extern int backend_can_trim (struct backend *b, struct connection *conn)
 405   __attribute__((__nonnull__ (1, 2)));
 406 extern int backend_can_zero (struct backend *b, struct connection *conn)
 407   __attribute__((__nonnull__ (1, 2)));
 408 extern int backend_can_fast_zero (struct backend *b, struct connection *conn)
 409   __attribute__((__nonnull__ (1, 2)));
 410 extern int backend_can_extents (struct backend *b, struct connection *conn)
 411   __attribute__((__nonnull__ (1, 2)));
 412 extern int backend_can_fua (struct backend *b, struct connection *conn)
 413   __attribute__((__nonnull__ (1, 2)));
 414 extern int backend_can_multi_conn (struct backend *b, struct connection *conn)
 415   __attribute__((__nonnull__ (1, 2)));
 416 extern int backend_can_cache (struct backend *b, struct connection *conn)
 417   __attribute__((__nonnull__ (1, 2)));
 418
 419 extern int backend_pread (struct backend *b, struct connection *conn,
 420                           void *buf, uint32_t count, uint64_t offset,
 421                           uint32_t flags, int *err)
 422   __attribute__((__nonnull__ (1, 2, 3, 7)));
 423 extern int backend_pwrite (struct backend *b, struct connection *conn,
 424                            const void *buf, uint32_t count, uint64_t offset,
 425                            uint32_t flags, int *err)
 426   __attribute__((__nonnull__ (1, 2, 3, 7)));
 427 extern int backend_flush (struct backend *b, struct connection *conn,
 428                           uint32_t flags, int *err)
 429   __attribute__((__nonnull__ (1, 2, 4)));
 430 extern int backend_trim (struct backend *b, struct connection *conn,
 431                          uint32_t count, uint64_t offset, uint32_t flags,
 432                          int *err)
 433   __attribute__((__nonnull__ (1, 2, 6)));
 434 extern int backend_zero (struct backend *b, struct connection *conn,
 435                          uint32_t count, uint64_t offset, uint32_t flags,
 436                          int *err)
 437   __attribute__((__nonnull__ (1, 2, 6)));
 438 extern int backend_extents (struct backend *b, struct connection *conn,
 439                             uint32_t count, uint64_t offset, uint32_t flags,
 440                             struct nbdkit_extents *extents, int *err)
 441   __attribute__((__nonnull__ (1, 2, 6, 7)));
 442 extern int backend_cache (struct backend *b, struct connection *conn,
 443                           uint32_t count, uint64_t offset,
 444                           uint32_t flags, int *err)
 445   __attribute__((__nonnull__ (1, 2, 6)));
 446
 447 /* plugins.c */
 448 extern struct backend *plugin_register (size_t index, const char *filename,
 449                                         void *dl, struct nbdkit_plugin *(*plugin_init) (void))
 450   __attribute__((__nonnull__ (2, 3, 4)));
 451
 452 /* filters.c */
 453 extern struct backend *filter_register (struct backend *next, size_t index,
 454                                         const char *filename, void *dl,
 455                                         struct nbdkit_filter *(*filter_init) (void))
 456   __attribute__((__nonnull__ (1, 3, 4, 5)));
 457
 458 /* locks.c */
 459 extern void lock_init_thread_model (void);
 460 extern const char *name_of_thread_model (int model);
 461 extern void lock_connection (void);
 462 extern void unlock_connection (void);
 463 extern void lock_request (struct connection *conn);
 464 extern void unlock_request (struct connection *conn);
 465 extern void lock_unload (void);
 466 extern void unlock_unload (void);
 467
 468 /* sockets.c */
 469 extern int *bind_unix_socket (size_t *)
 470   __attribute__((__nonnull__ (1)));
 471 extern int *bind_tcpip_socket (size_t *)
 472   __attribute__((__nonnull__ (1)));
 473 extern int *bind_vsock (size_t *)
 474   __attribute__((__nonnull__ (1)));
 475 extern void accept_incoming_connections (int *socks, size_t nr_socks)
 476   __attribute__((__nonnull__ (1)));
 477
 478 /* threadlocal.c */
 479 extern void threadlocal_init (void);
 480 extern void threadlocal_new_server_thread (void);
 481 extern void threadlocal_set_name (const char *name)
 482   __attribute__((__nonnull__ (1)));
 483 extern const char *threadlocal_get_name (void);
 484 extern void threadlocal_set_instance_num (size_t instance_num);
 485 extern size_t threadlocal_get_instance_num (void);
 486 extern void threadlocal_set_error (int err);
 487 extern int threadlocal_get_error (void);
 488 extern void *threadlocal_buffer (size_t size);
 489 extern void threadlocal_set_conn (struct connection *conn);
 490 extern struct connection *threadlocal_get_conn (void);
 491
 492 /* Declare program_name. */
 493 #if HAVE_DECL_PROGRAM_INVOCATION_SHORT_NAME == 1
 494 #include <errno.h>
 495 #define program_name program_invocation_short_name
 496 #else
 497 #define program_name "nbdkit"
 498 #endif
 499
 500 #endif /* NBDKIT_INTERNAL_H */