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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
*
* PESTO - Programmable Extensible Socket Translation Orchestrator
* front-end for passt(1) and pasta(1) forwarding configuration
*
* serialise.c - Serialisation of data structures over bytestreams
*
* Copyright Red Hat
* Author: David Gibson <david@gibson.dropbear.id.au>
*/
#include <assert.h>
#include <endian.h>
#include <errno.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h>
#include "serialise.h"
/**
* read_all_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 read_all_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;
}
/**
* write_all_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 write_all_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;
}
/**
* read_uXXX() - Receive a uXXX value from an fd
* @fd: File descriptor to read from
* @valp: Pointer to variable to update with read value
*
* Return: 0 on success, -1 on error
*/
/**
* write_uXXX() - Send a uXXX value to an fd
* @fd: File descriptor to write to
* @val: Value to send
*
* Return: 0 on success, -1 on error
*/
#define SERIALISE_UINT(bits) \
int read_u##bits(int fd, uint##bits##_t *val) \
{ \
uint##bits##_t beval; \
if (read_all_buf(fd, &beval, sizeof(beval)) < 0) \
return -1; \
*val = be##bits##toh(beval); \
return 0; \
} \
int write_u##bits(int fd, uint##bits##_t val) \
{ \
uint##bits##_t beval = htobe##bits(val); \
return write_all_buf(fd, &beval, sizeof(beval)); \
}
#define be8toh(x) (x)
#define htobe8(x) (x)
SERIALISE_UINT(8)
SERIALISE_UINT(32)
#undef SERIALISE_UNIT
/**
* write_str() - Write a string to an fd in length/value format
* @fd: Socket to the client
* @s: String to send
*
* Return: 0 on success, -1 on error
*/
int write_str(int fd, const char *s)
{
uint32_t len = strlen(s) + 1; /* Include \0 */
if (write_u32(fd, len) < 0)
return -1;
return write_all_buf(fd, s, len);
}
|