utils.c

   1 /*
   2  * utils - misc libubox utility functions
   3  *
   4  * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <sys/mman.h>
  20 #include <stdarg.h>
  21 #include <stdlib.h>
  22 #include <stdio.h>
  23 #include "utils.h"
  24
  25 #define foreach_arg(_arg, _addr, _len, _first_addr, _first_len) \
  26         for (_addr = (_first_addr), _len = (_first_len); \
  27                 _addr; \
  28                 _addr = va_arg(_arg, void **), _len = _addr ? va_arg(_arg, size_t) : 0)
  29
  30 #define C_PTR_ALIGN     (sizeof(size_t))
  31 #define C_PTR_MASK      (-C_PTR_ALIGN)
  32
  33 void *__calloc_a(size_t len, ...)
  34 {
  35         va_list ap, ap1;
  36         void *ret;
  37         void **cur_addr;
  38         size_t cur_len;
  39         int alloc_len = 0;
  40         char *ptr;
  41
  42         va_start(ap, len);
  43
  44         va_copy(ap1, ap);
  45         foreach_arg(ap1, cur_addr, cur_len, &ret, len)
  46                 alloc_len += (cur_len + C_PTR_ALIGN - 1 ) & C_PTR_MASK;
  47         va_end(ap1);
  48
  49         ptr = calloc(1, alloc_len);
  50         if (!ptr)
  51                 return NULL;
  52         alloc_len = 0;
  53         foreach_arg(ap, cur_addr, cur_len, &ret, len) {
  54                 *cur_addr = &ptr[alloc_len];
  55                 alloc_len += (cur_len + C_PTR_ALIGN - 1) & C_PTR_MASK;
  56         }
  57         va_end(ap);
  58
  59         return ret;
  60 }
  61
  62 #ifdef LIBUBOX_COMPAT_CLOCK_GETTIME
  63 #include <mach/mach_host.h>             /* host_get_clock_service() */
  64 #include <mach/mach_port.h>             /* mach_port_deallocate() */
  65 #include <mach/mach_init.h>             /* mach_host_self(), mach_task_self() */
  66 #include <mach/clock.h>                 /* clock_get_time() */
  67
  68 static clock_serv_t clock_realtime;
  69 static clock_serv_t clock_monotonic;
  70
  71 static void __constructor clock_name_init(void)
  72 {
  73         mach_port_t host_self = mach_host_self();
  74
  75         host_get_clock_service(host_self, CLOCK_REALTIME, &clock_realtime);
  76         host_get_clock_service(host_self, CLOCK_MONOTONIC, &clock_monotonic);
  77 }
  78
  79 static void __destructor clock_name_dealloc(void)
  80 {
  81         mach_port_t self = mach_task_self();
  82
  83         mach_port_deallocate(self, clock_realtime);
  84         mach_port_deallocate(self, clock_monotonic);
  85 }
  86
  87 int clock_gettime(int type, struct timespec *tv)
  88 {
  89         int retval = -1;
  90         mach_timespec_t mts;
  91
  92         switch (type) {
  93                 case CLOCK_REALTIME:
  94                         retval = clock_get_time(clock_realtime, &mts);
  95                         break;
  96                 case CLOCK_MONOTONIC:
  97                         retval = clock_get_time(clock_monotonic, &mts);
  98                         break;
  99                 default:
 100                         goto out;
 101         }
 102
 103         tv->tv_sec = mts.tv_sec;
 104         tv->tv_nsec = mts.tv_nsec;
 105 out:
 106         return retval;
 107 }
 108
 109 #endif
 110
 111 void *cbuf_alloc(unsigned int order)
 112 {
 113         char path[] = "/tmp/cbuf-XXXXXX";
 114         unsigned long size = cbuf_size(order);
 115         void *ret = NULL;
 116         int fd;
 117
 118         fd = mkstemp(path);
 119         if (fd < 0)
 120                 return NULL;
 121
 122         if (unlink(path))
 123                 goto close;
 124
 125         if (ftruncate(fd, cbuf_size(order)))
 126                 goto close;
 127
 128 #ifndef MAP_ANONYMOUS
 129 #define MAP_ANONYMOUS MAP_ANON
 130 #endif
 131
 132         ret = mmap(NULL, size * 2, PROT_NONE, MAP_ANON | MAP_PRIVATE, -1, 0);
 133         if (ret == MAP_FAILED) {
 134                 ret = NULL;
 135                 goto close;
 136         }
 137
 138         if (mmap(ret, size, PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED,
 139                  fd, 0) != ret ||
 140             mmap(ret + size, size, PROT_READ | PROT_WRITE,
 141                  MAP_FIXED | MAP_SHARED, fd, 0) != ret + size) {
 142                 munmap(ret, size * 2);
 143                 ret = NULL;
 144         }
 145
 146 close:
 147         close(fd);
 148         return ret;
 149 }
 150
 151 void cbuf_free(void *ptr, unsigned int order)
 152 {
 153         munmap(ptr, cbuf_size(order) * 2);
 154 }