lib/util/sys_rw_data.c

   1 /*
   2  * Unix SMB/CIFS implementation.
   3  * Samba system utilities
   4  * Copyright (C) Andrew Tridgell 1992-1998
   5  * Copyright (C) Jeremy Allison  1998-2005
   6  * Copyright (C) Timur Bakeyev        2005
   7  * Copyright (C) Bjoern Jacke    2006-2007
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 3 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21  */
  22
  23 #include "replace.h"
  24 #include "system/filesys.h"
  25 #include "lib/util/sys_rw_data.h"
  26 #include "lib/util/sys_rw.h"
  27 #include "lib/util/iov_buf.h"
  28
  29 /****************************************************************************
  30  Write all data from an iov array
  31  NB. This can be called with a non-socket fd, don't add dependencies
  32  on socket calls.
  33 ****************************************************************************/
  34
  35 ssize_t write_data_iov(int fd, const struct iovec *orig_iov, int iovcnt)
  36 {
  37         ssize_t to_send;
  38         ssize_t thistime;
  39         size_t sent;
  40         struct iovec iov_copy[iovcnt];
  41         struct iovec *iov;
  42
  43         to_send = iov_buflen(orig_iov, iovcnt);
  44         if (to_send == -1) {
  45                 errno = EINVAL;
  46                 return -1;
  47         }
  48
  49         thistime = sys_writev(fd, orig_iov, iovcnt);
  50         if ((thistime <= 0) || (thistime == to_send)) {
  51                 return thistime;
  52         }
  53         sent = thistime;
  54
  55         /*
  56          * We could not send everything in one call. Make a copy of iov that
  57          * we can mess with.
  58          */
  59
  60         memcpy(iov_copy, orig_iov, sizeof(struct iovec) * iovcnt);
  61         iov = iov_copy;
  62
  63         while (sent < to_send) {
  64                 bool ok;
  65
  66                 ok = iov_advance(&iov, &iovcnt, thistime);
  67                 if (!ok) {
  68                         errno = EIO;
  69                         return -1;
  70                 }
  71
  72                 thistime = sys_writev(fd, iov, iovcnt);
  73                 if (thistime <= 0) {
  74                         break;
  75                 }
  76                 sent += thistime;
  77         }
  78
  79         return sent;
  80 }
  81
  82 /****************************************************************************
  83  Write data to a fd.
  84  NB. This can be called with a non-socket fd, don't add dependencies
  85  on socket calls.
  86 ****************************************************************************/
  87
  88 ssize_t write_data(int fd, const void *buffer, size_t n)
  89 {
  90         struct iovec iov;
  91
  92         iov.iov_base = discard_const_p(void, buffer);
  93         iov.iov_len = n;
  94         return write_data_iov(fd, &iov, 1);
  95 }
  96
  97 /*
  98  * Blocking read n bytes from a fd
  99  */
 100
 101 ssize_t read_data(int fd, void *buffer, size_t n)
 102 {
 103         ssize_t nread;
 104
 105         nread = 0;
 106
 107         while (nread < n) {
 108                 ssize_t ret;
 109                 ret = sys_read(fd, ((char *)buffer) + nread, n - nread);
 110                 if (ret <= 0) {
 111                         return ret;
 112                 }
 113                 nread += ret;
 114         }
 115
 116         return nread;
 117 }