src/tls.c

   1 /* nbdkit
   2  * Copyright (C) 2013 Red Hat Inc.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met:
   8  *
   9  * * Redistributions of source code must retain the above copyright
  10  * notice, this list of conditions and the following disclaimer.
  11  *
  12  * * Redistributions in binary form must reproduce the above copyright
  13  * notice, this list of conditions and the following disclaimer in the
  14  * documentation and/or other materials provided with the distribution.
  15  *
  16  * * Neither the name of Red Hat nor the names of its contributors may be
  17  * used to endorse or promote products derived from this software without
  18  * specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  22  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  23  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
  24  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  25  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  26  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  27  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  28  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  30  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <config.h>
  35
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <string.h>
  39 #include <unistd.h>
  40 #include <assert.h>
  41
  42 #include <pthread.h>
  43
  44 #include "nbdkit-plugin.h"
  45 #include "internal.h"
  46
  47 /* Note currently all thread-local storage data is informational.
  48  * It's mainly used for smart error and debug messages.
  49  *
  50  * The main thread does not have any associated TLS, *unless* it is
  51  * serving a request (the '-s' option).
  52  */
  53
  54 struct tls {
  55   const char *name;             /* Can be NULL. */
  56   size_t instance_num;          /* Can be 0. */
  57   struct sockaddr addr;
  58   socklen_t addrlen;
  59 };
  60
  61 static pthread_key_t tls_key;
  62
  63 static void
  64 free_tls (void *tlsv)
  65 {
  66   struct tls *tls = tlsv;
  67
  68   free (tls);
  69 }
  70
  71 void
  72 tls_init (void)
  73 {
  74   int err;
  75
  76   err = pthread_key_create (&tls_key, free_tls);
  77   if (err != 0) {
  78     fprintf (stderr, "%s: pthread_key_create: %s\n",
  79              program_name, strerror (err));
  80     exit (EXIT_FAILURE);
  81   }
  82 }
  83
  84 void
  85 tls_new_server_thread (void)
  86 {
  87   struct tls *tls;
  88
  89   tls = calloc (1, sizeof *tls);
  90   if (tls == NULL) {
  91     perror ("malloc");
  92     exit (EXIT_FAILURE);
  93   }
  94   pthread_setspecific (tls_key, tls);
  95 }
  96
  97 void
  98 tls_set_name (const char *name)
  99 {
 100   struct tls *tls = pthread_getspecific (tls_key);
 101
 102   if (tls)
 103     tls->name = name;
 104 }
 105
 106 void
 107 tls_set_instance_num (size_t instance_num)
 108 {
 109   struct tls *tls = pthread_getspecific (tls_key);
 110
 111   if (tls)
 112     tls->instance_num = instance_num;
 113 }
 114
 115 void
 116 tls_set_sockaddr (struct sockaddr *addr, socklen_t addrlen)
 117 {
 118   struct tls *tls = pthread_getspecific (tls_key);
 119
 120   if (tls) {
 121     tls->addrlen = addrlen;
 122     memcpy (&tls->addr, addr, addrlen);
 123   }
 124 }
 125
 126 const char *
 127 tls_get_name (void)
 128 {
 129   struct tls *tls = pthread_getspecific (tls_key);
 130
 131   if (!tls)
 132     return NULL;
 133
 134   return tls->name;
 135 }
 136
 137 size_t
 138 tls_get_instance_num (void)
 139 {
 140   struct tls *tls = pthread_getspecific (tls_key);
 141
 142   if (!tls)
 143     return 0;
 144
 145   return tls->instance_num;
 146 }