usr/src/cmd/ssh/libopenbsd-compat/common/bsd-asprintf.c

   1 /*
   2  * Copyright (c) 2004 Darren Tucker.
   3  *
   4  * Based originally on asprintf.c from OpenBSD:
   5  * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
   6  *
   7  * Permission to use, copy, modify, and distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 #pragma ident   "%Z%%M% %I%     %E% SMI"
  21
  22 #include "includes.h"
  23
  24 #ifndef HAVE_VASPRINTF
  25
  26 #include <errno.h>
  27 #include <stdarg.h>
  28 #include <stdlib.h>
  29
  30 #ifndef VA_COPY
  31 #ifdef HAVE_VA_COPY
  32 #define VA_COPY(dest, src) va_copy(dest, src)
  33 #else
  34 #ifdef HAVE___VA_COPY
  35 #define VA_COPY(dest, src) __va_copy(dest, src)
  36 #else
  37 #define VA_COPY(dest, src) (dest) = (src)
  38 #endif
  39 #endif
  40 #endif
  41
  42 #define INIT_SZ 128
  43
  44 int
  45 vasprintf(char **str, const char *fmt, va_list ap)
  46 {
  47         int ret = -1;
  48         va_list ap2;
  49         char *string, *newstr;
  50         size_t len;
  51
  52         VA_COPY(ap2, ap);
  53         if ((string = malloc(INIT_SZ)) == NULL)
  54                 goto fail;
  55
  56         ret = vsnprintf(string, INIT_SZ, fmt, ap2);
  57         if (ret >= 0 && ret < INIT_SZ) { /* succeeded with initial alloc */
  58                 *str = string;
  59         } else if (ret == INT_MAX || ret < 0) { /* Bad length */
  60                 free(string);
  61                 goto fail;
  62         } else {        /* bigger than initial, realloc allowing for nul */
  63                 len = (size_t)ret + 1;
  64                 if ((newstr = realloc(string, len)) == NULL) {
  65                         free(string);
  66                         goto fail;
  67                 } else {
  68                         va_end(ap2);
  69                         VA_COPY(ap2, ap);
  70                         ret = vsnprintf(newstr, len, fmt, ap2);
  71                         if (ret >= 0 && (size_t)ret < len) {
  72                                 *str = newstr;
  73                         } else { /* failed with realloc'ed string, give up */
  74                                 free(newstr);
  75                                 goto fail;
  76                         }
  77                 }
  78         }
  79         va_end(ap2);
  80         return (ret);
  81
  82 fail:
  83         *str = NULL;
  84         errno = ENOMEM;
  85         va_end(ap2);
  86         return (-1);
  87 }
  88 #endif
  89
  90 #ifndef HAVE_ASPRINTF
  91 int
  92 asprintf(char **str, const char *fmt, ...)
  93 {
  94         va_list ap;
  95         int ret;
  96
  97         *str = NULL;
  98         va_start(ap, fmt);
  99         ret = vasprintf(str, fmt, ap);
 100         va_end(ap);
 101
 102         return (ret);
 103 }
 104 #endif