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 #ifndef O_CLOEXEC
  54 #define O_CLOEXEC 0
  55 #endif
  56
  57 #ifndef SOCK_CLOEXEC
  58 #define SOCK_CLOEXEC 0
  59 #endif
  60
  61 #if HAVE_VALGRIND
  62 # include <valgrind.h>
  63 /* http://valgrind.org/docs/manual/faq.html#faq.unhelpful */
  64 # define DO_DLCLOSE !RUNNING_ON_VALGRIND
  65 #elif defined(__SANITIZE_ADDRESS__)
  66 # define DO_DLCLOSE 0
  67 #else
  68 # define DO_DLCLOSE 1
  69 #endif
  70
  71 #define container_of(ptr, type, member) ({                       \
  72       const typeof (((type *) 0)->member) *__mptr = (ptr);       \
  73       (type *) ((char *) __mptr - offsetof(type, member));       \
  74     })
  75
  76 /* main.c */
  77 struct debug_flag {
  78   struct debug_flag *next;
  79   char *name;                   /* plugin or filter name */
  80   char *flag;                   /* flag name */
  81   int value;                    /* value of flag */
  82   bool used;                    /* if flag was successfully set */
  83 };
  84
  85 enum log_to {
  86   LOG_TO_DEFAULT,        /* --log not specified: log to stderr, unless
  87                             we forked into the background in which
  88                             case log to syslog */
  89   LOG_TO_STDERR,         /* --log=stderr forced on the command line */
  90   LOG_TO_SYSLOG,         /* --log=syslog forced on the command line */
  91 };
  92
  93 extern struct debug_flag *debug_flags;
  94 extern const char *exportname;
  95 extern bool foreground;
  96 extern const char *ipaddr;
  97 extern enum log_to log_to;
  98 extern bool newstyle;
  99 extern const char *port;
 100 extern bool readonly;
 101 extern const char *run;
 102 extern const char *selinux_label;
 103 extern int threads;
 104 extern int tls;
 105 extern const char *tls_certificates_dir;
 106 extern const char *tls_psk;
 107 extern bool tls_verify_peer;
 108 extern char *unixsocket;
 109 extern const char *user, *group;
 110 extern bool verbose;
 111
 112 extern struct backend *backend;
 113 #define for_each_backend(b) for (b = backend; b != NULL; b = b->next)
 114
 115 /* quit.c */
 116 extern volatile int quit;
 117 extern int quit_fd;
 118 extern void set_up_quit_pipe (void);
 119 extern void handle_quit (int sig);
 120 extern void set_quit (void);
 121
 122 /* signals.c */
 123 extern void set_up_signals (void);
 124
 125 /* background.c */
 126 extern bool forked_into_background;
 127 extern void fork_into_background (void);
 128
 129 /* captive.c */
 130 extern void run_command (void);
 131
 132 /* socket-activation.c */
 133 #define FIRST_SOCKET_ACTIVATION_FD 3 /* defined by systemd ABI */
 134 extern unsigned int get_socket_activation (void);
 135
 136 /* usergroup.c */
 137 extern void change_user (void);
 138
 139 /* connections.c */
 140 struct connection;
 141
 142 /* Flags for connection_send_function */
 143 enum {
 144   SEND_MORE = 1, /* Hint to use MSG_MORE/corking to group send()s */
 145 };
 146
 147 typedef int (*connection_recv_function) (struct connection *,
 148                                          void *buf, size_t len)
 149   __attribute__((__nonnull__ (1, 2)));
 150 typedef int (*connection_send_function) (struct connection *,
 151                                          const void *buf, size_t len,
 152                                          int flags)
 153   __attribute__((__nonnull__ (1, 2)));
 154 typedef void (*connection_close_function) (struct connection *)
 155   __attribute__((__nonnull__ (1)));
 156
 157 struct connection {
 158   pthread_mutex_t request_lock;
 159   pthread_mutex_t read_lock;
 160   pthread_mutex_t write_lock;
 161   pthread_mutex_t status_lock;
 162   int status; /* 1 for more I/O with client, 0 for shutdown, -1 on error */
 163   void *crypto_session;
 164   int nworkers;
 165
 166   void **handles;
 167   size_t nr_handles;
 168
 169   uint32_t cflags;
 170   uint64_t exportsize;
 171   uint16_t eflags;
 172   bool readonly;
 173   bool can_flush;
 174   bool is_rotational;
 175   bool can_trim;
 176   bool can_zero;
 177   bool can_fua;
 178   bool can_multi_conn;
 179   bool can_cache;
 180   bool emulate_cache;
 181   bool can_extents;
 182   bool using_tls;
 183   bool structured_replies;
 184   bool meta_context_base_allocation;
 185
 186   int sockin, sockout;
 187   connection_recv_function recv;
 188   connection_send_function send;
 189   connection_close_function close;
 190 };
 191
 192 extern int handle_single_connection (int sockin, int sockout);
 193 extern int connection_set_handle (struct connection *conn,
 194                                   size_t i, void *handle)
 195   __attribute__((__nonnull__ (1 /* not 3 */)));
 196 extern void *connection_get_handle (struct connection *conn, size_t i)
 197   __attribute__((__nonnull__ (1)));
 198 extern int connection_get_status (struct connection *conn)
 199   __attribute__((__nonnull__ (1)));
 200 extern int connection_set_status (struct connection *conn, int value)
 201   __attribute__((__nonnull__ (1)));
 202
 203 /* protocol-handshake.c */
 204 extern int protocol_handshake (struct connection *conn)
 205   __attribute__((__nonnull__ (1)));
 206 extern int protocol_compute_eflags (struct connection *conn, uint16_t *flags)
 207   __attribute__((__nonnull__ (1, 2)));
 208
 209 /* protocol-handshake-oldstyle.c */
 210 extern int protocol_handshake_oldstyle (struct connection *conn)
 211   __attribute__((__nonnull__ (1)));
 212
 213 /* protocol-handshake-newstyle.c */
 214 extern int protocol_handshake_newstyle (struct connection *conn)
 215   __attribute__((__nonnull__ (1)));
 216
 217 /* protocol.c */
 218 extern int protocol_recv_request_send_reply (struct connection *conn)
 219   __attribute__((__nonnull__ (1)));
 220
 221 /* The context ID of base:allocation.  As far as I can tell it doesn't
 222  * matter what this is as long as nbdkit always returns the same
 223  * number.
 224  */
 225 #define base_allocation_id 1
 226
 227 /* crypto.c */
 228 #define root_tls_certificates_dir sysconfdir "/pki/" PACKAGE_NAME
 229 extern void crypto_init (bool tls_set_on_cli);
 230 extern void crypto_free (void);
 231 extern int crypto_negotiate_tls (struct connection *conn,
 232                                  int sockin, int sockout)
 233   __attribute__((__nonnull__ (1)));
 234
 235 /* debug.c */
 236 #define debug nbdkit_debug
 237
 238 /* log-*.c */
 239 #if !HAVE_VFPRINTF_PERCENT_M
 240 #include <stdio.h>
 241 #define vfprintf nbdkit_vfprintf
 242 extern int nbdkit_vfprintf (FILE *f, const char *fmt, va_list args)
 243   __attribute__((__format__ (printf, 2, 0)));
 244 #endif
 245 extern void log_stderr_verror (const char *fs, va_list args)
 246   __attribute__((__format__ (printf, 1, 0)));
 247 extern void log_syslog_verror (const char *fs, va_list args)
 248   __attribute__((__format__ (printf, 1, 0)));
 249
 250 struct backend {
 251   /* Next filter or plugin in the chain.  This is always NULL for
 252    * plugins and never NULL for filters.
 253    */
 254   struct backend *next;
 255
 256   /* A unique index used to fetch the handle from the connections
 257    * object.  The plugin (last in the chain) has index 0, and the
 258    * filters have index 1, 2, ... depending how "far" they are from
 259    * the plugin.
 260    */
 261   size_t i;
 262
 263   void (*free) (struct backend *);
 264   int (*thread_model) (struct backend *);
 265   const char *(*name) (struct backend *);
 266   const char *(*plugin_name) (struct backend *);
 267   void (*usage) (struct backend *);
 268   const char *(*version) (struct backend *);
 269   void (*dump_fields) (struct backend *);
 270   void (*config) (struct backend *, const char *key, const char *value);
 271   void (*config_complete) (struct backend *);
 272   const char *(*magic_config_key) (struct backend *);
 273   int (*open) (struct backend *, struct connection *conn, int readonly);
 274   int (*prepare) (struct backend *, struct connection *conn);
 275   int (*finalize) (struct backend *, struct connection *conn);
 276   void (*close) (struct backend *, struct connection *conn);
 277
 278   int64_t (*get_size) (struct backend *, struct connection *conn);
 279   int (*can_write) (struct backend *, struct connection *conn);
 280   int (*can_flush) (struct backend *, struct connection *conn);
 281   int (*is_rotational) (struct backend *, struct connection *conn);
 282   int (*can_trim) (struct backend *, struct connection *conn);
 283   int (*can_zero) (struct backend *, struct connection *conn);
 284   int (*can_extents) (struct backend *, struct connection *conn);
 285   int (*can_fua) (struct backend *, struct connection *conn);
 286   int (*can_multi_conn) (struct backend *, struct connection *conn);
 287   int (*can_cache) (struct backend *, struct connection *conn);
 288
 289   int (*pread) (struct backend *, struct connection *conn, void *buf,
 290                 uint32_t count, uint64_t offset, uint32_t flags, int *err);
 291   int (*pwrite) (struct backend *, struct connection *conn, const void *buf,
 292                  uint32_t count, uint64_t offset, uint32_t flags, int *err);
 293   int (*flush) (struct backend *, struct connection *conn, uint32_t flags,
 294                 int *err);
 295   int (*trim) (struct backend *, struct connection *conn, uint32_t count,
 296                uint64_t offset, uint32_t flags, int *err);
 297   int (*zero) (struct backend *, struct connection *conn, uint32_t count,
 298                uint64_t offset, uint32_t flags, int *err);
 299   int (*extents) (struct backend *, struct connection *conn, uint32_t count,
 300                   uint64_t offset, uint32_t flags,
 301                   struct nbdkit_extents *extents, int *err);
 302   int (*cache) (struct backend *, struct connection *conn, uint32_t count,
 303                 uint64_t offset, uint32_t flags, int *err);
 304 };
 305
 306 /* plugins.c */
 307 extern struct backend *plugin_register (size_t index, const char *filename,
 308                                         void *dl, struct nbdkit_plugin *(*plugin_init) (void))
 309   __attribute__((__nonnull__ (2, 3, 4)));
 310 extern void set_debug_flags (void *dl, const char *name)
 311   __attribute__((__nonnull__ (1, 2)));
 312
 313 /* filters.c */
 314 extern struct backend *filter_register (struct backend *next, size_t index,
 315                                         const char *filename, void *dl,
 316                                         struct nbdkit_filter *(*filter_init) (void))
 317   __attribute__((__nonnull__ (1, 3, 4, 5)));
 318
 319 /* locks.c */
 320 extern void lock_init_thread_model (void);
 321 extern void lock_connection (void);
 322 extern void unlock_connection (void);
 323 extern void lock_request (struct connection *conn)
 324   __attribute__((__nonnull__ (1)));
 325 extern void unlock_request (struct connection *conn)
 326   __attribute__((__nonnull__ (1)));
 327 extern void lock_unload (void);
 328 extern void unlock_unload (void);
 329
 330 /* sockets.c */
 331 extern int *bind_unix_socket (size_t *)
 332   __attribute__((__nonnull__ (1)));
 333 extern int *bind_tcpip_socket (size_t *)
 334   __attribute__((__nonnull__ (1)));
 335 extern void accept_incoming_connections (int *socks, size_t nr_socks)
 336   __attribute__((__nonnull__ (1)));
 337 extern void free_listening_sockets (int *socks, size_t nr_socks)
 338   __attribute__((__nonnull__ (1)));
 339
 340 /* threadlocal.c */
 341 extern void threadlocal_init (void);
 342 extern void threadlocal_new_server_thread (void);
 343 extern void threadlocal_set_name (const char *name)
 344   __attribute__((__nonnull__ (1)));
 345 extern const char *threadlocal_get_name (void);
 346 extern void threadlocal_set_instance_num (size_t instance_num);
 347 extern size_t threadlocal_get_instance_num (void);
 348 extern void threadlocal_set_sockaddr (const struct sockaddr *addr,
 349                                       socklen_t addrlen)
 350   __attribute__((__nonnull__ (1)));
 351 /*extern void threadlocal_get_sockaddr ();*/
 352 extern void threadlocal_set_error (int err);
 353 extern int threadlocal_get_error (void);
 354 extern void *threadlocal_buffer (size_t size);
 355
 356 /* Declare program_name. */
 357 #if HAVE_DECL_PROGRAM_INVOCATION_SHORT_NAME == 1
 358 #include <errno.h>
 359 #define program_name program_invocation_short_name
 360 #else
 361 #define program_name "nbdkit"
 362 #endif
 363
 364 #endif /* NBDKIT_INTERNAL_H */