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
| | // 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
*
* parse.c - Composable parsing helpers
*
* Copyright Red Hat
* Author: David Gibson <david@gibson.dropbear.id.au>
*/
#include <assert.h>
#include <stddef.h>
#include <fcntl.h>
#include <string.h>
#include <stdbool.h>
#include <unistd.h>
#include "common.h"
/**
* DOC: Theory of Operation
*
* These are a number of primitives which can be combined into parsers for
* moderately complex input. For simpler composability, they have common
* conventions.
*
* - Functions return a bool indicating whether they successfully parsed.
* - Any specific output from the parse is as output parameters
* - First argument is always @cursor, a const char **.
* - On entry, *@cursor has the point to start parsing.
* - On successful exit, *@cursor is updated to the next character after the
parsed portion of the input
* - On failure, *@cursor and any output arguments are not modified
*
* For brevity the common parameters and return information are omitted from the
* individual function documentation comments.
*/
/**
* parse_literal() - Parse a specified literal string
* @lit: Keyword to accept
*/
bool parse_literal(const char **cursor, const char *lit)
{
size_t len = strlen(lit);
if (strlen(*cursor) < len || memcmp(*cursor, lit, len))
return false;
*cursor += len;
return true;
}
/**
* parse_eoi() - Parse end of input
* @cursor: Current parse pointer
*
* Return: true if @p is at End of Input (\0), false otherwise
*/
bool parse_eoi(const char *cursor)
{
return !(*cursor);
}
|