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 /* main.c */
  69 struct debug_flag {
  70   struct debug_flag *next;
  71   char *name;                   /* plugin or filter name */
  72   char *flag;                   /* flag name */
  73   int value;                    /* value of flag */
  74   bool used;                    /* if flag was successfully set */
  75 };
  76
  77 enum log_to {
  78   LOG_TO_DEFAULT,        /* --log not specified: log to stderr, unless
  79                             we forked into the background in which
  80                             case log to syslog */
  81   LOG_TO_STDERR,         /* --log=stderr forced on the command line */
  82   LOG_TO_SYSLOG,         /* --log=syslog forced on the command line */
  83 };
  84
  85 extern struct debug_flag *debug_flags;
  86 extern const char *exportname;
  87 extern bool foreground;
  88 extern const char *ipaddr;
  89 extern enum log_to log_to;
  90 extern bool newstyle;
  91 extern bool no_sr;
  92 extern const char *port;
  93 extern bool readonly;
  94 extern const char *run;
  95 extern const char *selinux_label;
  96 extern int threads;
  97 extern int tls;
  98 extern const char *tls_certificates_dir;
  99 extern const char *tls_psk;
 100 extern bool tls_verify_peer;
 101 extern char *unixsocket;
 102 extern const char *user, *group;
 103 extern bool verbose;
 104
 105 extern struct backend *backend;
 106 #define for_each_backend(b) for (b = backend; b != NULL; b = b->next)
 107
 108 /* quit.c */
 109 extern volatile int quit;
 110 extern int quit_fd;
 111 extern void set_up_quit_pipe (void);
 112 extern void handle_quit (int sig);
 113 extern void set_quit (void);
 114
 115 /* signals.c */
 116 extern void set_up_signals (void);
 117
 118 /* background.c */
 119 extern bool forked_into_background;
 120 extern void fork_into_background (void);
 121
 122 /* captive.c */
 123 extern void run_command (void);
 124
 125 /* socket-activation.c */
 126 #define FIRST_SOCKET_ACTIVATION_FD 3 /* defined by systemd ABI */
 127 extern unsigned int get_socket_activation (void);
 128
 129 /* usergroup.c */
 130 extern void change_user (void);
 131
 132 /* connections.c */
 133 struct connection;
 134
 135 /* Flags for connection_send_function */
 136 enum {
 137   SEND_MORE = 1, /* Hint to use MSG_MORE/corking to group send()s */
 138 };
 139
 140 typedef int (*connection_recv_function) (struct connection *,
 141                                          void *buf, size_t len)
 142   __attribute__((__nonnull__ (1, 2)));
 143 typedef int (*connection_send_function) (struct connection *,
 144                                          const void *buf, size_t len,
 145                                          int flags)
 146   __attribute__((__nonnull__ (1, 2)));
 147 typedef void (*connection_close_function) (struct connection *)
 148   __attribute__((__nonnull__ (1)));
 149
 150 struct connection {
 151   pthread_mutex_t request_lock;
 152   pthread_mutex_t read_lock;
 153   pthread_mutex_t write_lock;
 154   pthread_mutex_t status_lock;
 155   int status; /* 1 for more I/O with client, 0 for shutdown, -1 on error */
 156   int status_pipe[2]; /* track status changes via poll when nworkers > 1 */
 157   void *crypto_session;
 158   int nworkers;
 159
 160   void **handles;
 161   size_t nr_handles;
 162
 163   uint32_t cflags;
 164   uint64_t exportsize;
 165   uint16_t eflags;
 166   bool readonly;
 167   bool can_flush;
 168   bool is_rotational;
 169   bool can_trim;
 170   bool can_zero;
 171   bool can_fua;
 172   bool can_multi_conn;
 173   bool can_cache;
 174   bool emulate_cache;
 175   bool can_extents;
 176   bool using_tls;
 177   bool structured_replies;
 178   bool meta_context_base_allocation;
 179
 180   int sockin, sockout;
 181   connection_recv_function recv;
 182   connection_send_function send;
 183   connection_close_function close;
 184 };
 185
 186 extern int handle_single_connection (int sockin, int sockout);
 187 extern int connection_set_handle (struct connection *conn,
 188                                   size_t i, void *handle)
 189   __attribute__((__nonnull__ (1 /* not 3 */)));
 190 extern void *connection_get_handle (struct connection *conn, size_t i)
 191   __attribute__((__nonnull__ (1)));
 192 extern int connection_get_status (struct connection *conn)
 193   __attribute__((__nonnull__ (1)));
 194 extern int connection_set_status (struct connection *conn, int value)
 195   __attribute__((__nonnull__ (1)));
 196
 197 /* protocol-handshake.c */
 198 extern int protocol_handshake (struct connection *conn)
 199   __attribute__((__nonnull__ (1)));
 200 extern int protocol_compute_eflags (struct connection *conn, uint16_t *flags)
 201   __attribute__((__nonnull__ (1, 2)));
 202
 203 /* protocol-handshake-oldstyle.c */
 204 extern int protocol_handshake_oldstyle (struct connection *conn)
 205   __attribute__((__nonnull__ (1)));
 206
 207 /* protocol-handshake-newstyle.c */
 208 extern int protocol_handshake_newstyle (struct connection *conn)
 209   __attribute__((__nonnull__ (1)));
 210
 211 /* protocol.c */
 212 extern int protocol_recv_request_send_reply (struct connection *conn)
 213   __attribute__((__nonnull__ (1)));
 214
 215 /* The context ID of base:allocation.  As far as I can tell it doesn't
 216  * matter what this is as long as nbdkit always returns the same
 217  * number.
 218  */
 219 #define base_allocation_id 1
 220
 221 /* crypto.c */
 222 #define root_tls_certificates_dir sysconfdir "/pki/" PACKAGE_NAME
 223 extern void crypto_init (bool tls_set_on_cli);
 224 extern void crypto_free (void);
 225 extern int crypto_negotiate_tls (struct connection *conn,
 226                                  int sockin, int sockout)
 227   __attribute__((__nonnull__ (1)));
 228
 229 /* debug.c */
 230 #define debug nbdkit_debug
 231
 232 /* log-*.c */
 233 #if !HAVE_VFPRINTF_PERCENT_M
 234 #include <stdio.h>
 235 #define vfprintf nbdkit_vfprintf
 236 extern int nbdkit_vfprintf (FILE *f, const char *fmt, va_list args)
 237   __attribute__((__format__ (printf, 2, 0)));
 238 #endif
 239 extern void log_stderr_verror (const char *fs, va_list args)
 240   __attribute__((__format__ (printf, 1, 0)));
 241 extern void log_syslog_verror (const char *fs, va_list args)
 242   __attribute__((__format__ (printf, 1, 0)));
 243
 244 struct backend {
 245   /* Next filter or plugin in the chain.  This is always NULL for
 246    * plugins and never NULL for filters.
 247    */
 248   struct backend *next;
 249
 250   /* A unique index used to fetch the handle from the connections
 251    * object.  The plugin (last in the chain) has index 0, and the
 252    * filters have index 1, 2, ... depending how "far" they are from
 253    * the plugin.
 254    */
 255   size_t i;
 256
 257   void (*free) (struct backend *);
 258   int (*thread_model) (struct backend *);
 259   const char *(*name) (struct backend *);
 260   const char *(*plugin_name) (struct backend *);
 261   void (*usage) (struct backend *);
 262   const char *(*version) (struct backend *);
 263   void (*dump_fields) (struct backend *);
 264   void (*config) (struct backend *, const char *key, const char *value);
 265   void (*config_complete) (struct backend *);
 266   const char *(*magic_config_key) (struct backend *);
 267   int (*open) (struct backend *, struct connection *conn, int readonly);
 268   int (*prepare) (struct backend *, struct connection *conn);
 269   int (*finalize) (struct backend *, struct connection *conn);
 270   void (*close) (struct backend *, struct connection *conn);
 271
 272   int64_t (*get_size) (struct backend *, struct connection *conn);
 273   int (*can_write) (struct backend *, struct connection *conn);
 274   int (*can_flush) (struct backend *, struct connection *conn);
 275   int (*is_rotational) (struct backend *, struct connection *conn);
 276   int (*can_trim) (struct backend *, struct connection *conn);
 277   int (*can_zero) (struct backend *, struct connection *conn);
 278   int (*can_extents) (struct backend *, struct connection *conn);
 279   int (*can_fua) (struct backend *, struct connection *conn);
 280   int (*can_multi_conn) (struct backend *, struct connection *conn);
 281   int (*can_cache) (struct backend *, struct connection *conn);
 282
 283   int (*pread) (struct backend *, struct connection *conn, void *buf,
 284                 uint32_t count, uint64_t offset, uint32_t flags, int *err);
 285   int (*pwrite) (struct backend *, struct connection *conn, const void *buf,
 286                  uint32_t count, uint64_t offset, uint32_t flags, int *err);
 287   int (*flush) (struct backend *, struct connection *conn, uint32_t flags,
 288                 int *err);
 289   int (*trim) (struct backend *, struct connection *conn, uint32_t count,
 290                uint64_t offset, uint32_t flags, int *err);
 291   int (*zero) (struct backend *, struct connection *conn, uint32_t count,
 292                uint64_t offset, uint32_t flags, int *err);
 293   int (*extents) (struct backend *, struct connection *conn, uint32_t count,
 294                   uint64_t offset, uint32_t flags,
 295                   struct nbdkit_extents *extents, int *err);
 296   int (*cache) (struct backend *, struct connection *conn, uint32_t count,
 297                 uint64_t offset, uint32_t flags, int *err);
 298 };
 299
 300 /* plugins.c */
 301 extern struct backend *plugin_register (size_t index, const char *filename,
 302                                         void *dl, struct nbdkit_plugin *(*plugin_init) (void))
 303   __attribute__((__nonnull__ (2, 3, 4)));
 304 extern void set_debug_flags (void *dl, const char *name)
 305   __attribute__((__nonnull__ (1, 2)));
 306
 307 /* filters.c */
 308 extern struct backend *filter_register (struct backend *next, size_t index,
 309                                         const char *filename, void *dl,
 310                                         struct nbdkit_filter *(*filter_init) (void))
 311   __attribute__((__nonnull__ (1, 3, 4, 5)));
 312
 313 /* locks.c */
 314 extern void lock_init_thread_model (void);
 315 extern const char *name_of_thread_model (int model);
 316 extern void lock_connection (void);
 317 extern void unlock_connection (void);
 318 extern void lock_request (struct connection *conn);
 319 extern void unlock_request (struct connection *conn);
 320 extern void lock_unload (void);
 321 extern void unlock_unload (void);
 322
 323 /* sockets.c */
 324 extern int *bind_unix_socket (size_t *)
 325   __attribute__((__nonnull__ (1)));
 326 extern int *bind_tcpip_socket (size_t *)
 327   __attribute__((__nonnull__ (1)));
 328 extern void accept_incoming_connections (int *socks, size_t nr_socks)
 329   __attribute__((__nonnull__ (1)));
 330 extern void free_listening_sockets (int *socks, size_t nr_socks)
 331   __attribute__((__nonnull__ (1)));
 332
 333 /* threadlocal.c */
 334 extern void threadlocal_init (void);
 335 extern void threadlocal_new_server_thread (void);
 336 extern void threadlocal_set_name (const char *name)
 337   __attribute__((__nonnull__ (1)));
 338 extern const char *threadlocal_get_name (void);
 339 extern void threadlocal_set_instance_num (size_t instance_num);
 340 extern size_t threadlocal_get_instance_num (void);
 341 extern void threadlocal_set_sockaddr (const struct sockaddr *addr,
 342                                       socklen_t addrlen)
 343   __attribute__((__nonnull__ (1)));
 344 /*extern void threadlocal_get_sockaddr ();*/
 345 extern void threadlocal_set_error (int err);
 346 extern int threadlocal_get_error (void);
 347 extern void *threadlocal_buffer (size_t size);
 348 extern void threadlocal_set_conn (struct connection *conn);
 349 extern struct connection *threadlocal_get_conn (void);
 350
 351 /* Declare program_name. */
 352 #if HAVE_DECL_PROGRAM_INVOCATION_SHORT_NAME == 1
 353 #include <errno.h>
 354 #define program_name program_invocation_short_name
 355 #else
 356 #define program_name "nbdkit"
 357 #endif
 358
 359 #endif /* NBDKIT_INTERNAL_H */