lib/ipc/common.c

   1 /*
   2  * Copyright (c) 2009 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Portions Copyright (c) 2009 Apple Inc. All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * 3. Neither the name of the Institute nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include "hi_locl.h"
  37 #ifdef HAVE_GCD
  38 #include <dispatch/dispatch.h>
  39 #else
  40 #include "heim_threads.h"
  41 #endif
  42
  43 struct heim_icred {
  44     uid_t uid;
  45     gid_t gid;
  46     pid_t pid;
  47     pid_t session;
  48 };
  49
  50 void
  51 heim_ipc_free_cred(heim_icred cred)
  52 {
  53     free(cred);
  54 }
  55
  56 uid_t
  57 heim_ipc_cred_get_uid(heim_icred cred)
  58 {
  59     return cred->uid;
  60 }
  61
  62 gid_t
  63 heim_ipc_cred_get_gid(heim_icred cred)
  64 {
  65     return cred->gid;
  66 }
  67
  68 pid_t
  69 heim_ipc_cred_get_pid(heim_icred cred)
  70 {
  71     return cred->pid;
  72 }
  73
  74 pid_t
  75 heim_ipc_cred_get_session(heim_icred cred)
  76 {
  77     return cred->session;
  78 }
  79
  80
  81 int
  82 _heim_ipc_create_cred(uid_t uid, gid_t gid, pid_t pid, pid_t session, heim_icred *cred)
  83 {
  84     *cred = calloc(1, sizeof(**cred));
  85     if (*cred == NULL)
  86         return ENOMEM;
  87     (*cred)->uid = uid;
  88     (*cred)->gid = gid;
  89     (*cred)->pid = pid;
  90     (*cred)->session = session;
  91     return 0;
  92 }
  93
  94 #ifndef HAVE_GCD
  95 struct heim_isemaphore {
  96     HEIMDAL_MUTEX mutex;
  97     pthread_cond_t cond;
  98     long counter;
  99 };
 100 #endif
 101
 102 heim_isemaphore
 103 heim_ipc_semaphore_create(long value)
 104 {
 105 #ifdef HAVE_GCD
 106     return (heim_isemaphore)dispatch_semaphore_create(value);
 107 #elif !defined(ENABLE_PTHREAD_SUPPORT)
 108     heim_assert(0, "no semaphore support w/o pthreads");
 109     return NULL;
 110 #else
 111     heim_isemaphore s = malloc(sizeof(*s));
 112     if (s == NULL)
 113         return NULL;
 114     HEIMDAL_MUTEX_init(&s->mutex);
 115     pthread_cond_init(&s->cond, NULL);
 116     s->counter = value;
 117     return s;
 118 #endif
 119 }
 120
 121 long
 122 heim_ipc_semaphore_wait(heim_isemaphore s, time_t t)
 123 {
 124 #ifdef HAVE_GCD
 125     uint64_t timeout;
 126     if (t == HEIM_IPC_WAIT_FOREVER)
 127         timeout = DISPATCH_TIME_FOREVER;
 128     else
 129         timeout = (uint64_t)t * NSEC_PER_SEC;
 130
 131     return dispatch_semaphore_wait((dispatch_semaphore_t)s, timeout);
 132 #elif !defined(ENABLE_PTHREAD_SUPPORT)
 133     heim_assert(0, "no semaphore support w/o pthreads");
 134     return 0;
 135 #else
 136     HEIMDAL_MUTEX_lock(&s->mutex);
 137     /* if counter hits below zero, we get to wait */
 138     if (--s->counter < 0) {
 139         int ret;
 140
 141         if (t == HEIM_IPC_WAIT_FOREVER)
 142             ret = pthread_cond_wait(&s->cond, &s->mutex);
 143         else {
 144             struct timespec ts;
 145             ts.tv_sec = t;
 146             ts.tv_nsec = 0;
 147             ret = pthread_cond_timedwait(&s->cond, &s->mutex, &ts);
 148         }
 149         if (ret) {
 150             HEIMDAL_MUTEX_unlock(&s->mutex);
 151             return errno;
 152         }
 153     }
 154     HEIMDAL_MUTEX_unlock(&s->mutex);
 155
 156     return 0;
 157 #endif
 158 }
 159
 160 long
 161 heim_ipc_semaphore_signal(heim_isemaphore s)
 162 {
 163 #ifdef HAVE_GCD
 164     return dispatch_semaphore_signal((dispatch_semaphore_t)s);
 165 #elif !defined(ENABLE_PTHREAD_SUPPORT)
 166     heim_assert(0, "no semaphore support w/o pthreads");
 167     return EINVAL;
 168 #else
 169     int wakeup;
 170     HEIMDAL_MUTEX_lock(&s->mutex);
 171     wakeup = (++s->counter == 0) ;
 172     HEIMDAL_MUTEX_unlock(&s->mutex);
 173     if (wakeup)
 174         pthread_cond_signal(&s->cond);
 175     return 0;
 176 #endif
 177 }
 178
 179 void
 180 heim_ipc_semaphore_release(heim_isemaphore s)
 181 {
 182 #ifdef HAVE_GCD
 183     dispatch_release((dispatch_semaphore_t)s);
 184 #elif !defined(ENABLE_PTHREAD_SUPPORT)
 185     heim_assert(0, "no semaphore support w/o pthreads");
 186 #else
 187     HEIMDAL_MUTEX_lock(&s->mutex);
 188     if (s->counter != 0)
 189         abort();
 190     HEIMDAL_MUTEX_unlock(&s->mutex);
 191     HEIMDAL_MUTEX_destroy(&s->mutex);
 192     pthread_cond_destroy(&s->cond);
 193     free(s);
 194 #endif
 195 }
 196
 197 void
 198 heim_ipc_free_data(heim_idata *data)
 199 {
 200     if (data->data)
 201         free(data->data);
 202     data->data = NULL;
 203     data->length = 0;
 204 }