1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
| | // 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 <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_UINT
|