parseutil.h revision 356345 
1/*
2 * parseutil.h - parse utilities for string and wire conversion
3 *
4 * (c) NLnet Labs, 2004
5 *
6 * See the file LICENSE for the license
7 */
8/**
9 * \file
10 *
11 * Utility functions for parsing, base32(DNS variant) and base64 encoding
12 * and decoding, Hex, Time units, Escape codes.
13 */
14
15#ifndef LDNS_PARSEUTIL_H
16#define LDNS_PARSEUTIL_H
17struct tm;
18
19/**
20 *  A general purpose lookup table
21 *
22 *  Lookup tables are arrays of (id, name) pairs,
23 *  So you can for instance lookup the RCODE 3, which is "NXDOMAIN",
24 *  and vice versa. The lookup tables themselves are defined wherever needed,
25 *  for instance in host2str.c
26 */
27struct sldns_struct_lookup_table {
28        int id;
29        const char *name;
30};
31typedef struct sldns_struct_lookup_table sldns_lookup_table;
32
33/**
34 * Looks up the table entry by name, returns NULL if not found.
35 * \param[in] table the lookup table to search in
36 * \param[in] name what to search for
37 * \return the item found
38 */
39sldns_lookup_table *sldns_lookup_by_name(sldns_lookup_table table[],
40                                       const char *name);
41/**
42 * Looks up the table entry by id, returns NULL if not found.
43 * \param[in] table the lookup table to search in
44 * \param[in] id what to search for
45 * \return the item found
46 */
47sldns_lookup_table *sldns_lookup_by_id(sldns_lookup_table table[], int id);
48
49/**
50 * Convert TM to seconds since epoch (midnight, January 1st, 1970).
51 * Like timegm(3), which is not always available.
52 * \param[in] tm a struct tm* with the date
53 * \return the seconds since epoch
54 */
55time_t sldns_mktime_from_utc(const struct tm *tm);
56
57/**
58 * The function interprets time as the number of seconds since epoch
59 * with respect to now using serial arithmetics (rfc1982).
60 * That number of seconds is then converted to broken-out time information.
61 * This is especially usefull when converting the inception and expiration
62 * fields of RRSIG records.
63 *
64 * \param[in] time number of seconds since epoch (midnight, January 1st, 1970)
65 *            to be interpreted as a serial arithmetics number relative to now.
66 * \param[in] now number of seconds since epoch (midnight, January 1st, 1970)
67 *            to which the time value is compared to determine the final value.
68 * \param[out] result the struct with the broken-out time information
69 * \return result on success or NULL on error
70 */
71struct tm * sldns_serial_arithmetics_gmtime_r(int32_t time, time_t now, struct tm *result);
72
73/**
74 * converts a ttl value (like 5d2h) to a long.
75 * \param[in] nptr the start of the string
76 * \param[out] endptr points to the last char in case of error
77 * \return the convert duration value
78 */
79uint32_t sldns_str2period(const char *nptr, const char **endptr);
80
81/**
82 * Returns the int value of the given (hex) digit
83 * \param[in] ch the hex char to convert
84 * \return the converted decimal value
85 */
86int sldns_hexdigit_to_int(char ch);
87
88/**
89 * calculates the size needed to store the result of b64_ntop
90 */
91size_t sldns_b64_ntop_calculate_size(size_t srcsize);
92
93int sldns_b64_ntop(uint8_t const *src, size_t srclength,
94	char *target, size_t targsize);
95
96/**
97 * calculates the size needed to store the result of sldns_b64_pton
98 */
99size_t sldns_b64_pton_calculate_size(size_t srcsize);
100
101int sldns_b64_pton(char const *src, uint8_t *target, size_t targsize);
102
103/**
104 * calculates the size needed to store the result of b32_ntop
105 */
106size_t sldns_b32_ntop_calculate_size(size_t src_data_length);
107
108size_t sldns_b32_ntop_calculate_size_no_padding(size_t src_data_length);
109
110int sldns_b32_ntop(const uint8_t* src_data, size_t src_data_length,
111	char* target_text_buffer, size_t target_text_buffer_size);
112
113int sldns_b32_ntop_extended_hex(const uint8_t* src_data, size_t src_data_length,
114	char* target_text_buffer, size_t target_text_buffer_size);
115
116/**
117 * calculates the size needed to store the result of b32_pton
118 */
119size_t sldns_b32_pton_calculate_size(size_t src_text_length);
120
121int sldns_b32_pton(const char* src_text, size_t src_text_length,
122	uint8_t* target_data_buffer, size_t target_data_buffer_size);
123
124int sldns_b32_pton_extended_hex(const char* src_text, size_t src_text_length,
125	uint8_t* target_data_buffer, size_t target_data_buffer_size);
126
127/*
128 * Checks whether the escaped value at **s is an octal value or
129 * a 'normally' escaped character (and not eos)
130 *
131 * @param ch_p: the parsed character
132 * @param str_p: the string. moved along for characters read.
133 * The string pointer at *s is increased by either 0 (on error), 1 (on
134 * normal escapes), or 3 (on octals)
135 *
136 * @return 0 on error
137 */
138int sldns_parse_escape(uint8_t *ch_p, const char** str_p);
139
140/**
141 * Parse one character, with escape codes,
142 * @param ch_p: the parsed character
143 * @param str_p: the string. moved along for characters read.
144 * @return 0 on error
145 */
146int sldns_parse_char(uint8_t *ch_p, const char** str_p);
147
148#endif /* LDNS_PARSEUTIL_H */
149