File:  [Qemu by Fabrice Bellard] / qemu / osdep.c
Revision 1.1.1.10 (vendor branch): download - view: text, annotated - select for diffs
Tue Apr 24 18:34:11 2018 UTC (3 years, 1 month ago) by root
Branches: qemu, MAIN
CVS tags: qemu0150, qemu0141, qemu0140, HEAD
qemu 0.14.0

    1: /*
    2:  * QEMU low level functions
    3:  *
    4:  * Copyright (c) 2003 Fabrice Bellard
    5:  *
    6:  * Permission is hereby granted, free of charge, to any person obtaining a copy
    7:  * of this software and associated documentation files (the "Software"), to deal
    8:  * in the Software without restriction, including without limitation the rights
    9:  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   10:  * copies of the Software, and to permit persons to whom the Software is
   11:  * furnished to do so, subject to the following conditions:
   12:  *
   13:  * The above copyright notice and this permission notice shall be included in
   14:  * all copies or substantial portions of the Software.
   15:  *
   16:  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   17:  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   18:  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
   19:  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   20:  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   21:  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   22:  * THE SOFTWARE.
   23:  */
   24: #include <stdlib.h>
   25: #include <stdio.h>
   26: #include <stdarg.h>
   27: #include <string.h>
   28: #include <errno.h>
   29: #include <unistd.h>
   30: #include <fcntl.h>
   31: 
   32: /* Needed early for CONFIG_BSD etc. */
   33: #include "config-host.h"
   34: 
   35: #if defined(CONFIG_MADVISE) || defined(CONFIG_POSIX_MADVISE)
   36: #include <sys/mman.h>
   37: #endif
   38: 
   39: #ifdef CONFIG_SOLARIS
   40: #include <sys/types.h>
   41: #include <sys/statvfs.h>
   42: /* See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for
   43:    discussion about Solaris header problems */
   44: extern int madvise(caddr_t, size_t, int);
   45: #endif
   46: 
   47: #include "qemu-common.h"
   48: #include "trace.h"
   49: #include "sysemu.h"
   50: #include "qemu_socket.h"
   51: 
   52: int qemu_madvise(void *addr, size_t len, int advice)
   53: {
   54:     if (advice == QEMU_MADV_INVALID) {
   55:         errno = EINVAL;
   56:         return -1;
   57:     }
   58: #if defined(CONFIG_MADVISE)
   59:     return madvise(addr, len, advice);
   60: #elif defined(CONFIG_POSIX_MADVISE)
   61:     return posix_madvise(addr, len, advice);
   62: #else
   63:     errno = EINVAL;
   64:     return -1;
   65: #endif
   66: }
   67: 
   68: 
   69: /*
   70:  * Opens a file with FD_CLOEXEC set
   71:  */
   72: int qemu_open(const char *name, int flags, ...)
   73: {
   74:     int ret;
   75:     int mode = 0;
   76: 
   77:     if (flags & O_CREAT) {
   78:         va_list ap;
   79: 
   80:         va_start(ap, flags);
   81:         mode = va_arg(ap, int);
   82:         va_end(ap);
   83:     }
   84: 
   85: #ifdef O_CLOEXEC
   86:     ret = open(name, flags | O_CLOEXEC, mode);
   87: #else
   88:     ret = open(name, flags, mode);
   89:     if (ret >= 0) {
   90:         qemu_set_cloexec(ret);
   91:     }
   92: #endif
   93: 
   94:     return ret;
   95: }
   96: 
   97: /*
   98:  * A variant of write(2) which handles partial write.
   99:  *
  100:  * Return the number of bytes transferred.
  101:  * Set errno if fewer than `count' bytes are written.
  102:  *
  103:  * This function don't work with non-blocking fd's.
  104:  * Any of the possibilities with non-bloking fd's is bad:
  105:  *   - return a short write (then name is wrong)
  106:  *   - busy wait adding (errno == EAGAIN) to the loop
  107:  */
  108: ssize_t qemu_write_full(int fd, const void *buf, size_t count)
  109: {
  110:     ssize_t ret = 0;
  111:     ssize_t total = 0;
  112: 
  113:     while (count) {
  114:         ret = write(fd, buf, count);
  115:         if (ret < 0) {
  116:             if (errno == EINTR)
  117:                 continue;
  118:             break;
  119:         }
  120: 
  121:         count -= ret;
  122:         buf += ret;
  123:         total += ret;
  124:     }
  125: 
  126:     return total;
  127: }
  128: 
  129: /*
  130:  * Opens a socket with FD_CLOEXEC set
  131:  */
  132: int qemu_socket(int domain, int type, int protocol)
  133: {
  134:     int ret;
  135: 
  136: #ifdef SOCK_CLOEXEC
  137:     ret = socket(domain, type | SOCK_CLOEXEC, protocol);
  138:     if (ret != -1 || errno != EINVAL) {
  139:         return ret;
  140:     }
  141: #endif
  142:     ret = socket(domain, type, protocol);
  143:     if (ret >= 0) {
  144:         qemu_set_cloexec(ret);
  145:     }
  146: 
  147:     return ret;
  148: }
  149: 
  150: /*
  151:  * Accept a connection and set FD_CLOEXEC
  152:  */
  153: int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
  154: {
  155:     int ret;
  156: 
  157: #ifdef CONFIG_ACCEPT4
  158:     ret = accept4(s, addr, addrlen, SOCK_CLOEXEC);
  159:     if (ret != -1 || errno != ENOSYS) {
  160:         return ret;
  161:     }
  162: #endif
  163:     ret = accept(s, addr, addrlen);
  164:     if (ret >= 0) {
  165:         qemu_set_cloexec(ret);
  166:     }
  167: 
  168:     return ret;
  169: }

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