oslib-posix.c

   1 /*
   2  * os-posix-lib.c
   3  *
   4  * Copyright (c) 2003-2008 Fabrice Bellard
   5  * Copyright (c) 2010 Red Hat, Inc.
   6  *
   7  * QEMU library functions on POSIX which are shared between QEMU and
   8  * the QEMU tools.
   9  *
  10  * Permission is hereby granted, free of charge, to any person obtaining a copy
  11  * of this software and associated documentation files (the "Software"), to deal
  12  * in the Software without restriction, including without limitation the rights
  13  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  14  * copies of the Software, and to permit persons to whom the Software is
  15  * furnished to do so, subject to the following conditions:
  16  *
  17  * The above copyright notice and this permission notice shall be included in
  18  * all copies or substantial portions of the Software.
  19  *
  20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  23  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  25  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  26  * THE SOFTWARE.
  27  */
  28
  29 /* The following block of code temporarily renames the daemon() function so the
  30    compiler does not see the warning associated with it in stdlib.h on OSX */
  31 #ifdef __APPLE__
  32 #define daemon qemu_fake_daemon_function
  33 #include <stdlib.h>
  34 #undef daemon
  35 extern int daemon(int, int);
  36 #endif
  37
  38 #include "config-host.h"
  39 #include "sysemu.h"
  40 #include "trace.h"
  41 #include "qemu_socket.h"
  42
  43
  44
  45 int qemu_daemon(int nochdir, int noclose)
  46 {
  47     return daemon(nochdir, noclose);
  48 }
  49
  50 void *qemu_oom_check(void *ptr)
  51 {
  52     if (ptr == NULL) {
  53         fprintf(stderr, "Failed to allocate memory: %s\n", strerror(errno));
  54         abort();
  55     }
  56     return ptr;
  57 }
  58
  59 void *qemu_memalign(size_t alignment, size_t size)
  60 {
  61     void *ptr;
  62 #if defined(_POSIX_C_SOURCE) && !defined(__sun__)
  63     int ret;
  64     ret = posix_memalign(&ptr, alignment, size);
  65     if (ret != 0) {
  66         fprintf(stderr, "Failed to allocate %zu B: %s\n",
  67                 size, strerror(ret));
  68         abort();
  69     }
  70 #elif defined(CONFIG_BSD)
  71     ptr = qemu_oom_check(valloc(size));
  72 #else
  73     ptr = qemu_oom_check(memalign(alignment, size));
  74 #endif
  75     trace_qemu_memalign(alignment, size, ptr);
  76     return ptr;
  77 }
  78
  79 /* alloc shared memory pages */
  80 void *qemu_vmalloc(size_t size)
  81 {
  82     void *ptr;
  83     ptr = qemu_memalign(getpagesize(), size);
  84     trace_qemu_vmalloc(size, ptr);
  85     return ptr;
  86 }
  87
  88 void qemu_vfree(void *ptr)
  89 {
  90     trace_qemu_vfree(ptr);
  91     free(ptr);
  92 }
  93
  94 void socket_set_nonblock(int fd)
  95 {
  96     int f;
  97     f = fcntl(fd, F_GETFL);
  98     fcntl(fd, F_SETFL, f | O_NONBLOCK);
  99 }
 100
 101 void qemu_set_cloexec(int fd)
 102 {
 103     int f;
 104     f = fcntl(fd, F_GETFD);
 105     fcntl(fd, F_SETFD, f | FD_CLOEXEC);
 106 }
 107
 108 /*
 109  * Creates a pipe with FD_CLOEXEC set on both file descriptors
 110  */
 111 int qemu_pipe(int pipefd[2])
 112 {
 113     int ret;
 114
 115 #ifdef CONFIG_PIPE2
 116     ret = pipe2(pipefd, O_CLOEXEC);
 117     if (ret != -1 || errno != ENOSYS) {
 118         return ret;
 119     }
 120 #endif
 121     ret = pipe(pipefd);
 122     if (ret == 0) {
 123         qemu_set_cloexec(pipefd[0]);
 124         qemu_set_cloexec(pipefd[1]);
 125     }
 126
 127     return ret;
 128 }
 129
 130 int qemu_utimensat(int dirfd, const char *path, const struct timespec *times,
 131                    int flags)
 132 {
 133     struct timeval tv[2], tv_now;
 134     struct stat st;
 135     int i;
 136 #ifdef CONFIG_UTIMENSAT
 137     int ret;
 138
 139     ret = utimensat(dirfd, path, times, flags);
 140     if (ret != -1 || errno != ENOSYS) {
 141         return ret;
 142     }
 143 #endif
 144     /* Fallback: use utimes() instead of utimensat() */
 145
 146     /* happy if special cases */
 147     if (times[0].tv_nsec == UTIME_OMIT && times[1].tv_nsec == UTIME_OMIT) {
 148         return 0;
 149     }
 150     if (times[0].tv_nsec == UTIME_NOW && times[1].tv_nsec == UTIME_NOW) {
 151         return utimes(path, NULL);
 152     }
 153
 154     /* prepare for hard cases */
 155     if (times[0].tv_nsec == UTIME_NOW || times[1].tv_nsec == UTIME_NOW) {
 156         gettimeofday(&tv_now, NULL);
 157     }
 158     if (times[0].tv_nsec == UTIME_OMIT || times[1].tv_nsec == UTIME_OMIT) {
 159         stat(path, &st);
 160     }
 161
 162     for (i = 0; i < 2; i++) {
 163         if (times[i].tv_nsec == UTIME_NOW) {
 164             tv[i].tv_sec = tv_now.tv_sec;
 165             tv[i].tv_usec = tv_now.tv_usec;
 166         } else if (times[i].tv_nsec == UTIME_OMIT) {
 167             tv[i].tv_sec = (i == 0) ? st.st_atime : st.st_mtime;
 168             tv[i].tv_usec = 0;
 169         } else {
 170             tv[i].tv_sec = times[i].tv_sec;
 171             tv[i].tv_usec = times[i].tv_nsec / 1000;
 172         }
 173     }
 174
 175     return utimes(path, &tv[0]);
 176 }