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| | // SPDX-License-Identifier: GPL-2.0-or-later
/* PASST - Plug A Simple Socket Transport
* for qemu/UNIX domain socket mode
*
* PASTA - Pack A Subtle Tap Abstraction
* for network namespace/tap device mode
*
* serialise.c - Serialisation of data structures over bytestreams
*
* Copyright Red Hat
* Author: David Gibson <david@gibson.dropbear.id.au>
*/
#include <assert.h>
#include <errno.h>
#include <unistd.h>
#include "serialise.h"
/**
* seread_buf() - Fill a whole buffer from a file descriptor
* @fd: File descriptor
* @buf: Pointer to base of buffer
* @len: Length of buffer
*
* Return: 0 on success, -1 on error (with errno set)
*
* #syscalls read
*/
int seread_buf(int fd, void *buf, size_t len)
{
size_t left = len;
char *p = buf;
while (left) {
ssize_t rc;
assert(left <= len);
do
rc = read(fd, p, left);
while ((rc < 0) && errno == EINTR);
if (rc < 0)
return -1;
if (rc == 0) {
errno = ENODATA;
return -1;
}
p += rc;
left -= rc;
}
return 0;
}
/**
* sewrite_buf() - write all of a buffer to an fd
* @fd: File descriptor
* @buf: Pointer to base of buffer
* @len: Length of buffer
*
* Return: 0 on success, -1 on error (with errno set)
*
* #syscalls write
*/
int sewrite_buf(int fd, const void *buf, size_t len)
{
const char *p = buf;
size_t left = len;
while (left) {
ssize_t rc;
do
rc = write(fd, p, left);
while ((rc < 0) && errno == EINTR);
if (rc < 0)
return -1;
p += rc;
left -= rc;
}
return 0;
}
|