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 void *__calloc_a(size_t len, ...)
  31 {
  32         va_list ap, ap1;
  33         void *ret;
  34         void **cur_addr;
  35         size_t cur_len;
  36         int alloc_len = 0;
  37         char *ptr;
  38
  39         va_start(ap, len);
  40
  41         va_copy(ap1, ap);
  42         foreach_arg(ap1, cur_addr, cur_len, &ret, len)
  43                 alloc_len += cur_len;
  44         va_end(ap1);
  45
  46         ptr = calloc(1, alloc_len);
  47         if (!ptr)
  48                 return NULL;
  49         alloc_len = 0;
  50         foreach_arg(ap, cur_addr, cur_len, &ret, len) {
  51                 *cur_addr = &ptr[alloc_len];
  52                 alloc_len += cur_len;
  53         }
  54         va_end(ap);
  55
  56         return ret;
  57 }
  58
  59 #ifdef LIBUBOX_COMPAT_CLOCK_GETTIME
  60 #include <mach/mach_host.h>             /* host_get_clock_service() */
  61 #include <mach/mach_port.h>             /* mach_port_deallocate() */
  62 #include <mach/mach_init.h>             /* mach_host_self(), mach_task_self() */
  63 #include <mach/clock.h>                 /* clock_get_time() */
  64
  65 static clock_serv_t clock_realtime;
  66 static clock_serv_t clock_monotonic;
  67
  68 static void __constructor clock_name_init(void)
  69 {
  70         mach_port_t host_self = mach_host_self();
  71
  72         host_get_clock_service(host_self, CLOCK_REALTIME, &clock_realtime);
  73         host_get_clock_service(host_self, CLOCK_MONOTONIC, &clock_monotonic);
  74 }
  75
  76 static void __destructor clock_name_dealloc(void)
  77 {
  78         mach_port_t self = mach_task_self();
  79
  80         mach_port_deallocate(self, clock_realtime);
  81         mach_port_deallocate(self, clock_monotonic);
  82 }
  83
  84 int clock_gettime(int type, struct timespec *tv)
  85 {
  86         int retval = -1;
  87         mach_timespec_t mts;
  88
  89         switch (type) {
  90                 case CLOCK_REALTIME:
  91                         retval = clock_get_time(clock_realtime, &mts);
  92                         break;
  93                 case CLOCK_MONOTONIC:
  94                         retval = clock_get_time(clock_monotonic, &mts);
  95                         break;
  96                 default:
  97                         goto out;
  98         }
  99
 100         tv->tv_sec = mts.tv_sec;
 101         tv->tv_nsec = mts.tv_nsec;
 102 out:
 103         return retval;
 104 }
 105
 106 #endif
 107
 108 void *cbuf_alloc(unsigned int order)
 109 {
 110         char path[] = "/tmp/cbuf-XXXXXX";
 111         unsigned long size = cbuf_size(order);
 112         void *ret = NULL;
 113         int fd;
 114
 115         fd = mkstemp(path);
 116         if (fd < 0)
 117                 return NULL;
 118
 119         if (unlink(path))
 120                 goto close;
 121
 122         if (ftruncate(fd, cbuf_size(order)))
 123                 goto close;
 124
 125 #ifndef MAP_ANONYMOUS
 126 #define MAP_ANONYMOUS MAP_ANON
 127 #endif
 128
 129         ret = mmap(NULL, size * 2, PROT_NONE, MAP_ANON | MAP_PRIVATE, -1, 0);
 130         if (ret == MAP_FAILED) {
 131                 ret = NULL;
 132                 goto close;
 133         }
 134
 135         if (mmap(ret, size, PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED,
 136                  fd, 0) != ret ||
 137             mmap(ret + size, size, PROT_READ | PROT_WRITE,
 138                  MAP_FIXED | MAP_SHARED, fd, 0) != ret + size) {
 139                 munmap(ret, size * 2);
 140                 ret = NULL;
 141         }
 142
 143 close:
 144         close(fd);
 145         return ret;
 146 }
 147
 148 void cbuf_free(void *ptr, unsigned int order)
 149 {
 150         munmap(ptr, cbuf_size(order) * 2);
 151 }