lib/krb5/store_fd.c

   1 /*
   2  * Copyright (c) 1997 - 2004 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "krb5_locl.h"
  35 #include "store-int.h"
  36
  37 typedef struct fd_storage {
  38     int fd;
  39 } fd_storage;
  40
  41 #define FD(S) (((fd_storage*)(S)->data)->fd)
  42
  43 static ssize_t
  44 fd_fetch(krb5_storage * sp, void *data, size_t size)
  45 {
  46     char *cbuf = (char *)data;
  47     ssize_t count;
  48     size_t rem = size;
  49
  50     /* similar pattern to net_read() to support pipes */
  51     while (rem > 0) {
  52         count = read (FD(sp), cbuf, rem);
  53         if (count < 0) {
  54             if (errno == EINTR)
  55                 continue;
  56             else
  57                 return count;
  58         } else if (count == 0) {
  59             return count;
  60         }
  61         cbuf += count;
  62         rem -= count;
  63     }
  64     return size;
  65 }
  66
  67 static ssize_t
  68 fd_store(krb5_storage * sp, const void *data, size_t size)
  69 {
  70     const char *cbuf = (const char *)data;
  71     ssize_t count;
  72     size_t rem = size;
  73
  74     /* similar pattern to net_write() to support pipes */
  75     while (rem > 0) {
  76         count = write(FD(sp), cbuf, rem);
  77         if (count < 0) {
  78             if (errno == EINTR)
  79                 continue;
  80             else
  81                 return count;
  82         }
  83         cbuf += count;
  84         rem -= count;
  85     }
  86     return size;
  87 }
  88
  89 static off_t
  90 fd_seek(krb5_storage * sp, off_t offset, int whence)
  91 {
  92     return lseek(FD(sp), offset, whence);
  93 }
  94
  95 static int
  96 fd_trunc(krb5_storage * sp, off_t offset)
  97 {
  98     if (ftruncate(FD(sp), offset) == -1)
  99         return errno;
 100     return 0;
 101 }
 102
 103 static int
 104 fd_sync(krb5_storage * sp)
 105 {
 106     if (fsync(FD(sp)) == -1)
 107         return errno;
 108     return 0;
 109 }
 110
 111 static void
 112 fd_free(krb5_storage * sp)
 113 {
 114     int save_errno = errno;
 115     if (close(FD(sp)) == 0)
 116         errno = save_errno;
 117 }
 118
 119 /**
 120  *
 121  *
 122  * @return A krb5_storage on success, or NULL on out of memory error.
 123  *
 124  * @ingroup krb5_storage
 125  *
 126  * @sa krb5_storage_emem()
 127  * @sa krb5_storage_from_mem()
 128  * @sa krb5_storage_from_readonly_mem()
 129  * @sa krb5_storage_from_data()
 130  * @sa krb5_storage_from_socket()
 131  */
 132
 133 KRB5_LIB_FUNCTION krb5_storage * KRB5_LIB_CALL
 134 krb5_storage_from_fd(int fd_in)
 135 {
 136     krb5_storage *sp;
 137     int saved_errno;
 138     int fd;
 139
 140 #ifdef _MSC_VER
 141     /*
 142      * This function used to try to pass the input to
 143      * _get_osfhandle() to test if the value is a HANDLE
 144      * but this doesn't work because doing so throws an
 145      * exception that will result in Watson being triggered
 146      * to file a Windows Error Report.
 147      */
 148     fd = _dup(fd_in);
 149 #else
 150     fd = dup(fd_in);
 151 #endif
 152
 153     if (fd < 0)
 154         return NULL;
 155
 156     errno = ENOMEM;
 157     sp = malloc(sizeof(krb5_storage));
 158     if (sp == NULL) {
 159         saved_errno = errno;
 160         close(fd);
 161         errno = saved_errno;
 162         return NULL;
 163     }
 164
 165     errno = ENOMEM;
 166     sp->data = malloc(sizeof(fd_storage));
 167     if (sp->data == NULL) {
 168         saved_errno = errno;
 169         close(fd);
 170         free(sp);
 171         errno = saved_errno;
 172         return NULL;
 173     }
 174     sp->flags = 0;
 175     sp->eof_code = HEIM_ERR_EOF;
 176     FD(sp) = fd;
 177     sp->fetch = fd_fetch;
 178     sp->store = fd_store;
 179     sp->seek = fd_seek;
 180     sp->trunc = fd_trunc;
 181     sp->fsync = fd_sync;
 182     sp->free = fd_free;
 183     sp->max_alloc = UINT_MAX/8;
 184     return sp;
 185 }