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 ? cred->uid : (uid_t)-1;
  60 }
  61
  62 gid_t
  63 heim_ipc_cred_get_gid(heim_icred cred)
  64 {
  65     return cred ? cred->gid : (gid_t)-1;
  66 }
  67
  68 pid_t
  69 heim_ipc_cred_get_pid(heim_icred cred)
  70 {
  71     return cred ? cred->pid : (pid_t)0;
  72 }
  73
  74 pid_t
  75 heim_ipc_cred_get_session(heim_icred cred)
  76 {
  77     return cred ? cred->session : (pid_t)-1;
  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 #ifdef ENABLE_PTHREAD_SUPPORT
  98     pthread_cond_t cond;
  99 #endif
 100     long counter;
 101 };
 102 #endif
 103
 104 heim_isemaphore
 105 heim_ipc_semaphore_create(long value)
 106 {
 107 #ifdef HAVE_GCD
 108     return (heim_isemaphore)dispatch_semaphore_create(value);
 109 #elif !defined(ENABLE_PTHREAD_SUPPORT)
 110     heim_assert(0, "no semaphore support w/o pthreads");
 111     return NULL;
 112 #else
 113     heim_isemaphore s = malloc(sizeof(*s));
 114     if (s == NULL)
 115         return NULL;
 116     HEIMDAL_MUTEX_init(&s->mutex);
 117     pthread_cond_init(&s->cond, NULL);
 118     s->counter = value;
 119     return s;
 120 #endif
 121 }
 122
 123 long
 124 heim_ipc_semaphore_wait(heim_isemaphore s, time_t t)
 125 {
 126 #ifdef HAVE_GCD
 127     uint64_t timeout;
 128     if (t == HEIM_IPC_WAIT_FOREVER)
 129         timeout = DISPATCH_TIME_FOREVER;
 130     else
 131         timeout = (uint64_t)t * NSEC_PER_SEC;
 132
 133     return dispatch_semaphore_wait((dispatch_semaphore_t)s, timeout);
 134 #elif !defined(ENABLE_PTHREAD_SUPPORT)
 135     heim_assert(0, "no semaphore support w/o pthreads");
 136     return 0;
 137 #else
 138     HEIMDAL_MUTEX_lock(&s->mutex);
 139     /* if counter hits below zero, we get to wait */
 140     if (--s->counter < 0) {
 141         int ret;
 142
 143         if (t == HEIM_IPC_WAIT_FOREVER)
 144             ret = pthread_cond_wait(&s->cond, &s->mutex);
 145         else {
 146             struct timespec ts;
 147             ts.tv_sec = t;
 148             ts.tv_nsec = 0;
 149             ret = pthread_cond_timedwait(&s->cond, &s->mutex, &ts);
 150         }
 151         if (ret) {
 152             HEIMDAL_MUTEX_unlock(&s->mutex);
 153             return errno;
 154         }
 155     }
 156     HEIMDAL_MUTEX_unlock(&s->mutex);
 157
 158     return 0;
 159 #endif
 160 }
 161
 162 long
 163 heim_ipc_semaphore_signal(heim_isemaphore s)
 164 {
 165 #ifdef HAVE_GCD
 166     return dispatch_semaphore_signal((dispatch_semaphore_t)s);
 167 #elif !defined(ENABLE_PTHREAD_SUPPORT)
 168     heim_assert(0, "no semaphore support w/o pthreads");
 169     return EINVAL;
 170 #else
 171     int wakeup;
 172     HEIMDAL_MUTEX_lock(&s->mutex);
 173     wakeup = (++s->counter == 0) ;
 174     HEIMDAL_MUTEX_unlock(&s->mutex);
 175     if (wakeup)
 176         pthread_cond_signal(&s->cond);
 177     return 0;
 178 #endif
 179 }
 180
 181 void
 182 heim_ipc_semaphore_release(heim_isemaphore s)
 183 {
 184 #ifdef HAVE_GCD
 185     dispatch_release((dispatch_semaphore_t)s);
 186 #elif !defined(ENABLE_PTHREAD_SUPPORT)
 187     heim_assert(0, "no semaphore support w/o pthreads");
 188 #else
 189     HEIMDAL_MUTEX_lock(&s->mutex);
 190     if (s->counter != 0)
 191         abort();
 192     HEIMDAL_MUTEX_unlock(&s->mutex);
 193     HEIMDAL_MUTEX_destroy(&s->mutex);
 194     pthread_cond_destroy(&s->cond);
 195     free(s);
 196 #endif
 197 }
 198
 199 void
 200 heim_ipc_free_data(heim_idata *data)
 201 {
 202     if (data->data)
 203         free(data->data);
 204     data->data = NULL;
 205     data->length = 0;
 206 }