summaryrefslogtreecommitdiff
path: root/src/libelogind/sd-bus/bus-signature.c
blob: 1ca37cbb5a56d5cce47789ba3d15a54e9b88760e (plain)
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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
/* SPDX-License-Identifier: LGPL-2.1+ */
/***
***/

#include <util.h>

#include "sd-bus.h"

#include "bus-signature.h"
#include "bus-type.h"

static int signature_element_length_internal(
                const char *s,
                bool allow_dict_entry,
                unsigned array_depth,
                unsigned struct_depth,
                size_t *l) {

        int r;

        if (!s)
                return -EINVAL;

        assert(l);

        if (bus_type_is_basic(*s) || *s == SD_BUS_TYPE_VARIANT) {
                *l = 1;
                return 0;
        }

        if (*s == SD_BUS_TYPE_ARRAY) {
                size_t t;

                if (array_depth >= 32)
                        return -EINVAL;

                r = signature_element_length_internal(s + 1, true, array_depth+1, struct_depth, &t);
                if (r < 0)
                        return r;

                *l = t + 1;
                return 0;
        }

        if (*s == SD_BUS_TYPE_STRUCT_BEGIN) {
                const char *p = s + 1;

                if (struct_depth >= 32)
                        return -EINVAL;

                while (*p != SD_BUS_TYPE_STRUCT_END) {
                        size_t t;

                        r = signature_element_length_internal(p, false, array_depth, struct_depth+1, &t);
                        if (r < 0)
                                return r;

                        p += t;
                }

                if (p - s < 2)
                        /* D-Bus spec: Empty structures are not allowed; there
                         * must be at least one type code between the parentheses.
                         */
                        return -EINVAL;

                *l = p - s + 1;
                return 0;
        }

        if (*s == SD_BUS_TYPE_DICT_ENTRY_BEGIN && allow_dict_entry) {
                const char *p = s + 1;
                unsigned n = 0;

                if (struct_depth >= 32)
                        return -EINVAL;

                while (*p != SD_BUS_TYPE_DICT_ENTRY_END) {
                        size_t t;

                        if (n == 0 && !bus_type_is_basic(*p))
                                return -EINVAL;

                        r = signature_element_length_internal(p, false, array_depth, struct_depth+1, &t);
                        if (r < 0)
                                return r;

                        p += t;
                        n++;
                }

                if (n != 2)
                        return -EINVAL;

                *l = p - s + 1;
                return 0;
        }

        return -EINVAL;
}

int signature_element_length(const char *s, size_t *l) {
        return signature_element_length_internal(s, true, 0, 0, l);
}

bool signature_is_single(const char *s, bool allow_dict_entry) {
        int r;
        size_t t;

        if (!s)
                return false;

        r = signature_element_length_internal(s, allow_dict_entry, 0, 0, &t);
        if (r < 0)
                return false;

        return s[t] == 0;
}

bool signature_is_pair(const char *s) {

        if (!s)
                return false;

        if (!bus_type_is_basic(*s))
                return false;

        return signature_is_single(s + 1, false);
}

bool signature_is_valid(const char *s, bool allow_dict_entry) {
        const char *p;
        int r;

        if (!s)
                return false;

        p = s;
        while (*p) {
                size_t t;

                r = signature_element_length_internal(p, allow_dict_entry, 0, 0, &t);
                if (r < 0)
                        return false;

                p += t;
        }

        return p - s <= 255;
}