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 #elif ENABLE_LIBFUZZER
  72 /* XXX This causes dlopen in the server to leak during fuzzing.
  73  * However it is necessary because of
  74  * https://bugs.llvm.org/show_bug.cgi?id=43917
  75  */
  76 # define DO_DLCLOSE 0
  77 #else
  78 # define DO_DLCLOSE 1
  79 #endif
  80
  81 #define container_of(ptr, type, member) ({                       \
  82       const typeof (((type *) 0)->member) *__mptr = (ptr);       \
  83       (type *) ((char *) __mptr - offsetof(type, member));       \
  84     })
  85
  86 /* Maximum read or write request that we will handle. */
  87 #define MAX_REQUEST_SIZE (64 * 1024 * 1024)
  88
  89 /* main.c */
  90 enum log_to {
  91   LOG_TO_DEFAULT,        /* --log not specified: log to stderr, unless
  92                             we forked into the background in which
  93                             case log to syslog */
  94   LOG_TO_STDERR,         /* --log=stderr forced on the command line */
  95   LOG_TO_SYSLOG,         /* --log=syslog forced on the command line */
  96   LOG_TO_NULL,           /* --log=null forced on the command line */
  97 };
  98
  99 extern struct debug_flag *debug_flags;
 100 extern const char *exportname;
 101 extern bool foreground;
 102 extern const char *ipaddr;
 103 extern enum log_to log_to;
 104 extern unsigned mask_handshake;
 105 extern bool newstyle;
 106 extern bool no_sr;
 107 extern const char *port;
 108 extern bool read_only;
 109 extern const char *run;
 110 extern bool listen_stdin;
 111 extern const char *selinux_label;
 112 extern unsigned threads;
 113 extern int tls;
 114 extern const char *tls_certificates_dir;
 115 extern const char *tls_psk;
 116 extern bool tls_verify_peer;
 117 extern char *unixsocket;
 118 extern const char *user, *group;
 119 extern bool verbose;
 120
 121 extern struct backend *backend;
 122 #define for_each_backend(b) for (b = backend; b != NULL; b = b->next)
 123
 124 /* quit.c */
 125 extern volatile int quit;
 126 extern int quit_fd;
 127 extern void set_up_quit_pipe (void);
 128 extern void close_quit_pipe (void);
 129 extern void handle_quit (int sig);
 130 extern void set_quit (void);
 131
 132 /* signals.c */
 133 extern void set_up_signals (void);
 134
 135 /* background.c */
 136 extern bool forked_into_background;
 137 extern void fork_into_background (void);
 138
 139 /* captive.c */
 140 extern void run_command (void);
 141
 142 /* socket-activation.c */
 143 #define FIRST_SOCKET_ACTIVATION_FD 3 /* defined by systemd ABI */
 144 extern unsigned int get_socket_activation (void);
 145
 146 /* usergroup.c */
 147 extern void change_user (void);
 148
 149 /* connections.c */
 150 struct connection;
 151
 152 /* Flags for connection_send_function */
 153 enum {
 154   SEND_MORE = 1, /* Hint to use MSG_MORE/corking to group send()s */
 155 };
 156
 157 typedef int (*connection_recv_function) (struct connection *,
 158                                          void *buf, size_t len)
 159   __attribute__((__nonnull__ (1, 2)));
 160 typedef int (*connection_send_function) (struct connection *,
 161                                          const void *buf, size_t len,
 162                                          int flags)
 163   __attribute__((__nonnull__ (1, 2)));
 164 typedef void (*connection_close_function) (struct connection *)
 165   __attribute__((__nonnull__ (1)));
 166
 167 enum {
 168   HANDLE_OPEN = 1,      /* Set if .open passed, so .close is needed */
 169   HANDLE_CONNECTED = 2, /* Set if .prepare passed, so .finalize is needed */
 170   HANDLE_FAILED = 4,    /* Set if .finalize failed */
 171 };
 172
 173 struct b_conn_handle {
 174   void *handle;
 175
 176   unsigned char state; /* Bitmask of HANDLE_* values */
 177
 178   uint64_t exportsize;
 179   int can_write;
 180   int can_flush;
 181   int is_rotational;
 182   int can_trim;
 183   int can_zero;
 184   int can_fast_zero;
 185   int can_fua;
 186   int can_multi_conn;
 187   int can_extents;
 188   int can_cache;
 189 };
 190
 191 static inline void
 192 reset_b_conn_handle (struct b_conn_handle *h)
 193 {
 194   h->handle = NULL;
 195   h->state = 0;
 196   h->exportsize = -1;
 197   h->can_write = -1;
 198   h->can_flush = -1;
 199   h->is_rotational = -1;
 200   h->can_trim = -1;
 201   h->can_zero = -1;
 202   h->can_fast_zero = -1;
 203   h->can_fua = -1;
 204   h->can_multi_conn = -1;
 205   h->can_extents = -1;
 206   h->can_cache = -1;
 207 }
 208
 209 struct connection {
 210   pthread_mutex_t request_lock;
 211   pthread_mutex_t read_lock;
 212   pthread_mutex_t write_lock;
 213   pthread_mutex_t status_lock;
 214   int status; /* 1 for more I/O with client, 0 for shutdown, -1 on error */
 215   int status_pipe[2]; /* track status changes via poll when nworkers > 1 */
 216   void *crypto_session;
 217   int nworkers;
 218
 219   struct b_conn_handle *handles;
 220   size_t nr_handles;
 221
 222   char exportname[NBD_MAX_STRING + 1];
 223   uint32_t exportnamelen;
 224   uint32_t cflags;
 225   uint16_t eflags;
 226   bool using_tls;
 227   bool structured_replies;
 228   bool meta_context_base_allocation;
 229
 230   int sockin, sockout;
 231   connection_recv_function recv;
 232   connection_send_function send;
 233   connection_close_function close;
 234 };
 235
 236 extern void handle_single_connection (int sockin, int sockout);
 237 extern int connection_get_status (struct connection *conn)
 238   __attribute__((__nonnull__ (1)));
 239 extern int connection_set_status (struct connection *conn, int value)
 240   __attribute__((__nonnull__ (1)));
 241
 242 /* protocol-handshake.c */
 243 extern int protocol_handshake (struct connection *conn)
 244   __attribute__((__nonnull__ (1)));
 245 extern int protocol_common_open (struct connection *conn,
 246                                  uint64_t *exportsize, uint16_t *flags)
 247   __attribute__((__nonnull__ (1, 2, 3)));
 248
 249 /* protocol-handshake-oldstyle.c */
 250 extern int protocol_handshake_oldstyle (struct connection *conn)
 251   __attribute__((__nonnull__ (1)));
 252
 253 /* protocol-handshake-newstyle.c */
 254 extern int protocol_handshake_newstyle (struct connection *conn)
 255   __attribute__((__nonnull__ (1)));
 256
 257 /* protocol.c */
 258 extern int protocol_recv_request_send_reply (struct connection *conn)
 259   __attribute__((__nonnull__ (1)));
 260
 261 /* The context ID of base:allocation.  As far as I can tell it doesn't
 262  * matter what this is as long as nbdkit always returns the same
 263  * number.
 264  */
 265 #define base_allocation_id 1
 266
 267 /* crypto.c */
 268 #define root_tls_certificates_dir sysconfdir "/pki/" PACKAGE_NAME
 269 extern void crypto_init (bool tls_set_on_cli);
 270 extern void crypto_free (void);
 271 extern int crypto_negotiate_tls (struct connection *conn,
 272                                  int sockin, int sockout)
 273   __attribute__((__nonnull__ (1)));
 274
 275 /* debug.c */
 276 #define debug(fs, ...)                                   \
 277   do {                                                   \
 278     if_verbose                                           \
 279       nbdkit_debug ((fs), ##__VA_ARGS__);                \
 280   } while (0)
 281
 282 /* debug-flags.c */
 283 extern void add_debug_flag (const char *arg);
 284 extern void apply_debug_flags (void *dl, const char *name);
 285 extern void free_debug_flags (void);
 286
 287 /* log-*.c */
 288 #if !HAVE_VFPRINTF_PERCENT_M
 289 #include <stdio.h>
 290 #define vfprintf nbdkit_vfprintf
 291 extern int nbdkit_vfprintf (FILE *f, const char *fmt, va_list args)
 292   __attribute__((__format__ (printf, 2, 0)));
 293 #endif
 294 extern void log_stderr_verror (const char *fs, va_list args)
 295   __attribute__((__format__ (printf, 1, 0)));
 296 extern void log_syslog_verror (const char *fs, va_list args)
 297   __attribute__((__format__ (printf, 1, 0)));
 298
 299 /* backend.c */
 300 struct backend {
 301   /* Next filter or plugin in the chain.  This is always NULL for
 302    * plugins and never NULL for filters.
 303    */
 304   struct backend *next;
 305
 306   /* A unique index used to fetch the handle from the connections
 307    * object.  The plugin (last in the chain) has index 0, and the
 308    * filters have index 1, 2, ... depending how "far" they are from
 309    * the plugin.
 310    */
 311   size_t i;
 312
 313   /* The type of backend: filter or plugin. */
 314   const char *type;
 315
 316   /* A copy of the backend name that survives a dlclose. */
 317   char *name;
 318
 319   /* The file the backend was loaded from. */
 320   char *filename;
 321
 322   /* The dlopen handle for the backend. */
 323   void *dl;
 324
 325   /* Backend callbacks. All are required. */
 326   void (*free) (struct backend *);
 327   int (*thread_model) (struct backend *);
 328   const char *(*plugin_name) (struct backend *);
 329   void (*usage) (struct backend *);
 330   const char *(*version) (struct backend *);
 331   void (*dump_fields) (struct backend *);
 332   void (*config) (struct backend *, const char *key, const char *value);
 333   void (*config_complete) (struct backend *);
 334   const char *(*magic_config_key) (struct backend *);
 335   int (*preconnect) (struct backend *, struct connection *conn, int readonly);
 336   void *(*open) (struct backend *, struct connection *conn, int readonly);
 337   int (*prepare) (struct backend *, struct connection *conn, void *handle,
 338                   int readonly);
 339   int (*finalize) (struct backend *, struct connection *conn, void *handle);
 340   void (*close) (struct backend *, struct connection *conn, void *handle);
 341
 342   int64_t (*get_size) (struct backend *, struct connection *conn, void *handle);
 343   int (*can_write) (struct backend *, struct connection *conn, void *handle);
 344   int (*can_flush) (struct backend *, struct connection *conn, void *handle);
 345   int (*is_rotational) (struct backend *, struct connection *conn,
 346                         void *handle);
 347   int (*can_trim) (struct backend *, struct connection *conn, void *handle);
 348   int (*can_zero) (struct backend *, struct connection *conn, void *handle);
 349   int (*can_fast_zero) (struct backend *, struct connection *conn,
 350                         void *handle);
 351   int (*can_extents) (struct backend *, struct connection *conn, void *handle);
 352   int (*can_fua) (struct backend *, struct connection *conn, void *handle);
 353   int (*can_multi_conn) (struct backend *, struct connection *conn,
 354                          void *handle);
 355   int (*can_cache) (struct backend *, struct connection *conn, void *handle);
 356
 357   int (*pread) (struct backend *, struct connection *conn, void *handle,
 358                 void *buf, uint32_t count, uint64_t offset,
 359                 uint32_t flags, int *err);
 360   int (*pwrite) (struct backend *, struct connection *conn, void *handle,
 361                  const void *buf, uint32_t count, uint64_t offset,
 362                  uint32_t flags, int *err);
 363   int (*flush) (struct backend *, struct connection *conn, void *handle,
 364                 uint32_t flags, int *err);
 365   int (*trim) (struct backend *, struct connection *conn, void *handle,
 366                uint32_t count, uint64_t offset, uint32_t flags, int *err);
 367   int (*zero) (struct backend *, struct connection *conn, void *handle,
 368                uint32_t count, uint64_t offset, uint32_t flags, int *err);
 369   int (*extents) (struct backend *, struct connection *conn, void *handle,
 370                   uint32_t count, uint64_t offset, uint32_t flags,
 371                   struct nbdkit_extents *extents, int *err);
 372   int (*cache) (struct backend *, struct connection *conn, void *handle,
 373                 uint32_t count, uint64_t offset, uint32_t flags, int *err);
 374 };
 375
 376 extern void backend_init (struct backend *b, struct backend *next, size_t index,
 377                           const char *filename, void *dl, const char *type)
 378   __attribute__((__nonnull__ (1, 4, 5, 6)));
 379 extern void backend_load (struct backend *b, const char *name,
 380                           void (*load) (void))
 381   __attribute__((__nonnull__ (1 /* not 2 */)));
 382 extern void backend_unload (struct backend *b, void (*unload) (void))
 383   __attribute__((__nonnull__ (1)));
 384
 385 extern int backend_open (struct backend *b, struct connection *conn,
 386                          int readonly)
 387   __attribute__((__nonnull__ (1, 2)));
 388 extern int backend_prepare (struct backend *b, struct connection *conn)
 389   __attribute__((__nonnull__ (1, 2)));
 390 extern int backend_finalize (struct backend *b, struct connection *conn)
 391   __attribute__((__nonnull__ (1, 2)));
 392 extern void backend_close (struct backend *b, struct connection *conn)
 393   __attribute__((__nonnull__ (1, 2)));
 394 extern bool backend_valid_range (struct backend *b, struct connection *conn,
 395                                  uint64_t offset, uint32_t count)
 396   __attribute__((__nonnull__ (1, 2)));
 397
 398 extern int backend_reopen (struct backend *b, struct connection *conn,
 399                            int readonly)
 400   __attribute__((__nonnull__ (1, 2)));
 401 extern int64_t backend_get_size (struct backend *b, struct connection *conn)
 402   __attribute__((__nonnull__ (1, 2)));
 403 extern int backend_can_write (struct backend *b, struct connection *conn)
 404   __attribute__((__nonnull__ (1, 2)));
 405 extern int backend_can_flush (struct backend *b, struct connection *conn)
 406   __attribute__((__nonnull__ (1, 2)));
 407 extern int backend_is_rotational (struct backend *b, struct connection *conn)
 408   __attribute__((__nonnull__ (1, 2)));
 409 extern int backend_can_trim (struct backend *b, struct connection *conn)
 410   __attribute__((__nonnull__ (1, 2)));
 411 extern int backend_can_zero (struct backend *b, struct connection *conn)
 412   __attribute__((__nonnull__ (1, 2)));
 413 extern int backend_can_fast_zero (struct backend *b, struct connection *conn)
 414   __attribute__((__nonnull__ (1, 2)));
 415 extern int backend_can_extents (struct backend *b, struct connection *conn)
 416   __attribute__((__nonnull__ (1, 2)));
 417 extern int backend_can_fua (struct backend *b, struct connection *conn)
 418   __attribute__((__nonnull__ (1, 2)));
 419 extern int backend_can_multi_conn (struct backend *b, struct connection *conn)
 420   __attribute__((__nonnull__ (1, 2)));
 421 extern int backend_can_cache (struct backend *b, struct connection *conn)
 422   __attribute__((__nonnull__ (1, 2)));
 423
 424 extern int backend_pread (struct backend *b, struct connection *conn,
 425                           void *buf, uint32_t count, uint64_t offset,
 426                           uint32_t flags, int *err)
 427   __attribute__((__nonnull__ (1, 2, 3, 7)));
 428 extern int backend_pwrite (struct backend *b, struct connection *conn,
 429                            const void *buf, uint32_t count, uint64_t offset,
 430                            uint32_t flags, int *err)
 431   __attribute__((__nonnull__ (1, 2, 3, 7)));
 432 extern int backend_flush (struct backend *b, struct connection *conn,
 433                           uint32_t flags, int *err)
 434   __attribute__((__nonnull__ (1, 2, 4)));
 435 extern int backend_trim (struct backend *b, struct connection *conn,
 436                          uint32_t count, uint64_t offset, uint32_t flags,
 437                          int *err)
 438   __attribute__((__nonnull__ (1, 2, 6)));
 439 extern int backend_zero (struct backend *b, struct connection *conn,
 440                          uint32_t count, uint64_t offset, uint32_t flags,
 441                          int *err)
 442   __attribute__((__nonnull__ (1, 2, 6)));
 443 extern int backend_extents (struct backend *b, struct connection *conn,
 444                             uint32_t count, uint64_t offset, uint32_t flags,
 445                             struct nbdkit_extents *extents, int *err)
 446   __attribute__((__nonnull__ (1, 2, 6, 7)));
 447 extern int backend_cache (struct backend *b, struct connection *conn,
 448                           uint32_t count, uint64_t offset,
 449                           uint32_t flags, int *err)
 450   __attribute__((__nonnull__ (1, 2, 6)));
 451
 452 /* plugins.c */
 453 extern struct backend *plugin_register (size_t index, const char *filename,
 454                                         void *dl, struct nbdkit_plugin *(*plugin_init) (void))
 455   __attribute__((__nonnull__ (2, 3, 4)));
 456
 457 /* filters.c */
 458 extern struct backend *filter_register (struct backend *next, size_t index,
 459                                         const char *filename, void *dl,
 460                                         struct nbdkit_filter *(*filter_init) (void))
 461   __attribute__((__nonnull__ (1, 3, 4, 5)));
 462
 463 /* locks.c */
 464 extern void lock_init_thread_model (void);
 465 extern const char *name_of_thread_model (int model);
 466 extern void lock_connection (void);
 467 extern void unlock_connection (void);
 468 extern void lock_request (struct connection *conn);
 469 extern void unlock_request (struct connection *conn);
 470 extern void lock_unload (void);
 471 extern void unlock_unload (void);
 472
 473 /* sockets.c */
 474 extern int *bind_unix_socket (size_t *)
 475   __attribute__((__nonnull__ (1)));
 476 extern int *bind_tcpip_socket (size_t *)
 477   __attribute__((__nonnull__ (1)));
 478 extern int *bind_vsock (size_t *)
 479   __attribute__((__nonnull__ (1)));
 480 extern void accept_incoming_connections (int *socks, size_t nr_socks)
 481   __attribute__((__nonnull__ (1)));
 482
 483 /* threadlocal.c */
 484 extern void threadlocal_init (void);
 485 extern void threadlocal_new_server_thread (void);
 486 extern void threadlocal_set_name (const char *name)
 487   __attribute__((__nonnull__ (1)));
 488 extern const char *threadlocal_get_name (void);
 489 extern void threadlocal_set_instance_num (size_t instance_num);
 490 extern size_t threadlocal_get_instance_num (void);
 491 extern void threadlocal_set_error (int err);
 492 extern int threadlocal_get_error (void);
 493 extern void *threadlocal_buffer (size_t size);
 494 extern void threadlocal_set_conn (struct connection *conn);
 495 extern struct connection *threadlocal_get_conn (void);
 496
 497 /* Declare program_name. */
 498 #if HAVE_DECL_PROGRAM_INVOCATION_SHORT_NAME == 1
 499 #include <errno.h>
 500 #define program_name program_invocation_short_name
 501 #else
 502 #define program_name "nbdkit"
 503 #endif
 504
 505 #endif /* NBDKIT_INTERNAL_H */