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 #include "config-host.h"
  30 #include "sysemu.h"
  31 #include "trace.h"
  32 #include "qemu_socket.h"
  33
  34 void *qemu_oom_check(void *ptr)
  35 {
  36     if (ptr == NULL) {
  37         fprintf(stderr, "Failed to allocate memory: %s\n", strerror(errno));
  38         abort();
  39     }
  40     return ptr;
  41 }
  42
  43 void *qemu_memalign(size_t alignment, size_t size)
  44 {
  45     void *ptr;
  46 #if defined(_POSIX_C_SOURCE) && !defined(__sun__)
  47     int ret;
  48     ret = posix_memalign(&ptr, alignment, size);
  49     if (ret != 0) {
  50         fprintf(stderr, "Failed to allocate %zu B: %s\n",
  51                 size, strerror(ret));
  52         abort();
  53     }
  54 #elif defined(CONFIG_BSD)
  55     ptr = qemu_oom_check(valloc(size));
  56 #else
  57     ptr = qemu_oom_check(memalign(alignment, size));
  58 #endif
  59     trace_qemu_memalign(alignment, size, ptr);
  60     return ptr;
  61 }
  62
  63 /* alloc shared memory pages */
  64 void *qemu_vmalloc(size_t size)
  65 {
  66     return qemu_memalign(getpagesize(), size);
  67 }
  68
  69 void qemu_vfree(void *ptr)
  70 {
  71     trace_qemu_vfree(ptr);
  72     free(ptr);
  73 }
  74
  75 void socket_set_nonblock(int fd)
  76 {
  77     int f;
  78     f = fcntl(fd, F_GETFL);
  79     fcntl(fd, F_SETFL, f | O_NONBLOCK);
  80 }
  81
  82 void qemu_set_cloexec(int fd)
  83 {
  84     int f;
  85     f = fcntl(fd, F_GETFD);
  86     fcntl(fd, F_SETFD, f | FD_CLOEXEC);
  87 }
  88
  89 /*
  90  * Creates a pipe with FD_CLOEXEC set on both file descriptors
  91  */
  92 int qemu_pipe(int pipefd[2])
  93 {
  94     int ret;
  95
  96 #ifdef CONFIG_PIPE2
  97     ret = pipe2(pipefd, O_CLOEXEC);
  98     if (ret != -1 || errno != ENOSYS) {
  99         return ret;
 100     }
 101 #endif
 102     ret = pipe(pipefd);
 103     if (ret == 0) {
 104         qemu_set_cloexec(pipefd[0]);
 105         qemu_set_cloexec(pipefd[1]);
 106     }
 107
 108     return ret;
 109 }
 110
 111 int qemu_utimensat(int dirfd, const char *path, const struct timespec *times,
 112                    int flags)
 113 {
 114     struct timeval tv[2], tv_now;
 115     struct stat st;
 116     int i;
 117 #ifdef CONFIG_UTIMENSAT
 118     int ret;
 119
 120     ret = utimensat(dirfd, path, times, flags);
 121     if (ret != -1 || errno != ENOSYS) {
 122         return ret;
 123     }
 124 #endif
 125     /* Fallback: use utimes() instead of utimensat() */
 126
 127     /* happy if special cases */
 128     if (times[0].tv_nsec == UTIME_OMIT && times[1].tv_nsec == UTIME_OMIT) {
 129         return 0;
 130     }
 131     if (times[0].tv_nsec == UTIME_NOW && times[1].tv_nsec == UTIME_NOW) {
 132         return utimes(path, NULL);
 133     }
 134
 135     /* prepare for hard cases */
 136     if (times[0].tv_nsec == UTIME_NOW || times[1].tv_nsec == UTIME_NOW) {
 137         gettimeofday(&tv_now, NULL);
 138     }
 139     if (times[0].tv_nsec == UTIME_OMIT || times[1].tv_nsec == UTIME_OMIT) {
 140         stat(path, &st);
 141     }
 142
 143     for (i = 0; i < 2; i++) {
 144         if (times[i].tv_nsec == UTIME_NOW) {
 145             tv[i].tv_sec = tv_now.tv_sec;
 146             tv[i].tv_usec = tv_now.tv_usec;
 147         } else if (times[i].tv_nsec == UTIME_OMIT) {
 148             tv[i].tv_sec = (i == 0) ? st.st_atime : st.st_mtime;
 149             tv[i].tv_usec = 0;
 150         } else {
 151             tv[i].tv_sec = times[i].tv_sec;
 152             tv[i].tv_usec = times[i].tv_nsec / 1000;
 153         }
 154     }
 155
 156     return utimes(path, &tv[0]);
 157 }