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