xref: /dragonfly/contrib/ldns/ldns/wire2host.h (revision ec1c3f3a)
1 /*
2  * wire2host.h - from wire conversion routines
3  *
4  * a Net::DNS like library for C
5  *
6  * (c) NLnet Labs, 2005-2006
7  *
8  * See the file LICENSE for the license
9  */
10 
11 /**
12  * \file
13  *
14  * Contains functions that translate dns data from the wire format (as sent
15  * by servers and clients) to the internal structures.
16  */
17 
18 #ifndef LDNS_WIRE2HOST_H
19 #define LDNS_WIRE2HOST_H
20 
21 #include <ldns/rdata.h>
22 #include <ldns/common.h>
23 #include <ldns/error.h>
24 #include <ldns/rr.h>
25 #include <ldns/packet.h>
26 
27 #ifdef __cplusplus
28 extern "C" {
29 #endif
30 
31 /* The length of the header */
32 #define	LDNS_HEADER_SIZE	12
33 
34 /* First octet of flags */
35 #define	LDNS_RD_MASK		0x01U
36 #define	LDNS_RD_SHIFT	0
37 #define	LDNS_RD_WIRE(wirebuf)	(*(wirebuf+2) & LDNS_RD_MASK)
38 #define	LDNS_RD_SET(wirebuf)	(*(wirebuf+2) |= LDNS_RD_MASK)
39 #define	LDNS_RD_CLR(wirebuf)	(*(wirebuf+2) &= ~LDNS_RD_MASK)
40 
41 #define LDNS_TC_MASK		0x02U
42 #define LDNS_TC_SHIFT	1
43 #define	LDNS_TC_WIRE(wirebuf)	(*(wirebuf+2) & LDNS_TC_MASK)
44 #define	LDNS_TC_SET(wirebuf)	(*(wirebuf+2) |= LDNS_TC_MASK)
45 #define	LDNS_TC_CLR(wirebuf)	(*(wirebuf+2) &= ~LDNS_TC_MASK)
46 
47 #define	LDNS_AA_MASK		0x04U
48 #define	LDNS_AA_SHIFT	2
49 #define	LDNS_AA_WIRE(wirebuf)	(*(wirebuf+2) & LDNS_AA_MASK)
50 #define	LDNS_AA_SET(wirebuf)	(*(wirebuf+2) |= LDNS_AA_MASK)
51 #define	LDNS_AA_CLR(wirebuf)	(*(wirebuf+2) &= ~LDNS_AA_MASK)
52 
53 #define	LDNS_OPCODE_MASK	0x78U
54 #define	LDNS_OPCODE_SHIFT	3
55 #define	LDNS_OPCODE_WIRE(wirebuf)	((*(wirebuf+2) & LDNS_OPCODE_MASK) >> LDNS_OPCODE_SHIFT)
56 #define	LDNS_OPCODE_SET(wirebuf, opcode) \
57 	(*(wirebuf+2) = ((*(wirebuf+2)) & ~LDNS_OPCODE_MASK) | ((opcode) << LDNS_OPCODE_SHIFT))
58 
59 #define	LDNS_QR_MASK		0x80U
60 #define	LDNS_QR_SHIFT	7
61 #define	LDNS_QR_WIRE(wirebuf)	(*(wirebuf+2) & LDNS_QR_MASK)
62 #define	LDNS_QR_SET(wirebuf)	(*(wirebuf+2) |= LDNS_QR_MASK)
63 #define	LDNS_QR_CLR(wirebuf)	(*(wirebuf+2) &= ~LDNS_QR_MASK)
64 
65 /* Second octet of flags */
66 #define	LDNS_RCODE_MASK	0x0fU
67 #define	LDNS_RCODE_SHIFT	0
68 #define	LDNS_RCODE_WIRE(wirebuf)	(*(wirebuf+3) & LDNS_RCODE_MASK)
69 #define	LDNS_RCODE_SET(wirebuf, rcode) \
70 	(*(wirebuf+3) = ((*(wirebuf+3)) & ~LDNS_RCODE_MASK) | (rcode))
71 
72 #define	LDNS_CD_MASK		0x10U
73 #define	LDNS_CD_SHIFT	4
74 #define	LDNS_CD_WIRE(wirebuf)	(*(wirebuf+3) & LDNS_CD_MASK)
75 #define	LDNS_CD_SET(wirebuf)	(*(wirebuf+3) |= LDNS_CD_MASK)
76 #define	LDNS_CD_CLR(wirebuf)	(*(wirebuf+3) &= ~LDNS_CD_MASK)
77 
78 #define	LDNS_AD_MASK		0x20U
79 #define	LDNS_AD_SHIFT	5
80 #define	LDNS_AD_WIRE(wirebuf)	(*(wirebuf+3) & LDNS_AD_MASK)
81 #define	LDNS_AD_SET(wirebuf)	(*(wirebuf+3) |= LDNS_AD_MASK)
82 #define	LDNS_AD_CLR(wirebuf)	(*(wirebuf+3) &= ~LDNS_AD_MASK)
83 
84 #define	LDNS_Z_MASK		0x40U
85 #define	LDNS_Z_SHIFT		6
86 #define	LDNS_Z_WIRE(wirebuf)	(*(wirebuf+3) & LDNS_Z_MASK)
87 #define	LDNS_Z_SET(wirebuf)	(*(wirebuf+3) |= LDNS_Z_MASK)
88 #define	LDNS_Z_CLR(wirebuf)	(*(wirebuf+3) &= ~LDNS_Z_MASK)
89 
90 #define	LDNS_RA_MASK		0x80U
91 #define	LDNS_RA_SHIFT	7
92 #define	LDNS_RA_WIRE(wirebuf)	(*(wirebuf+3) & LDNS_RA_MASK)
93 #define	LDNS_RA_SET(wirebuf)	(*(wirebuf+3) |= LDNS_RA_MASK)
94 #define	LDNS_RA_CLR(wirebuf)	(*(wirebuf+3) &= ~LDNS_RA_MASK)
95 
96 /* Query ID */
97 #define	LDNS_ID_WIRE(wirebuf)		(ldns_read_uint16(wirebuf))
98 #define	LDNS_ID_SET(wirebuf, id)	(ldns_write_uint16(wirebuf, id))
99 
100 /* Counter of the question section */
101 #define LDNS_QDCOUNT_OFF		4
102 #define	LDNS_QDCOUNT(wirebuf)		(ldns_read_uint16(wirebuf+LDNS_QDCOUNT_OFF))
103 
104 /* Counter of the answer section */
105 #define LDNS_ANCOUNT_OFF		6
106 #define	LDNS_ANCOUNT(wirebuf)		(ldns_read_uint16(wirebuf+LDNS_ANCOUNT_OFF))
107 
108 /* Counter of the authority section */
109 #define LDNS_NSCOUNT_OFF		8
110 #define	LDNS_NSCOUNT(wirebuf)		(ldns_read_uint16(wirebuf+LDNS_NSCOUNT_OFF))
111 
112 /* Counter of the additional section */
113 #define LDNS_ARCOUNT_OFF		10
114 #define	LDNS_ARCOUNT(wirebuf)		(ldns_read_uint16(wirebuf+LDNS_ARCOUNT_OFF))
115 
116 /**
117  * converts the data on the uint8_t bytearray (in wire format) to a DNS packet.
118  * This function will initialize and allocate memory space for the packet
119  * structure.
120  *
121  * \param[out] packet pointer to the structure to hold the packet
122  * \param[in] data pointer to the buffer with the data
123  * \param[in] len the length of the data buffer (in bytes)
124  * \return LDNS_STATUS_OK if everything succeeds, error otherwise
125  */
126 ldns_status ldns_wire2pkt(ldns_pkt **packet, const uint8_t *data, size_t len);
127 
128 /**
129  * converts the data in the ldns_buffer (in wire format) to a DNS packet.
130  * This function will initialize and allocate memory space for the packet
131  * structure.
132  *
133  * \param[out] packet pointer to the structure to hold the packet
134  * \param[in] buffer the buffer with the data
135  * \return LDNS_STATUS_OK if everything succeeds, error otherwise
136  */
137 ldns_status ldns_buffer2pkt_wire(ldns_pkt **packet, const ldns_buffer *buffer);
138 
139 /**
140  * converts the data on the uint8_t bytearray (in wire format) to a DNS
141  * dname rdata field. This function will initialize and allocate memory
142  * space for the dname structure. The length of the wiredata of this rdf
143  * is added to the *pos value.
144  *
145  * \param[out] dname pointer to the structure to hold the rdata value
146  * \param[in] wire pointer to the buffer with the data
147  * \param[in] max the length of the data buffer (in bytes)
148  * \param[in] pos the position of the rdf in the buffer (ie. the number of bytes
149  *            from the start of the buffer)
150  * \return LDNS_STATUS_OK if everything succeeds, error otherwise
151  */
152 ldns_status ldns_wire2dname(ldns_rdf **dname, const uint8_t *wire, size_t max, size_t *pos);
153 
154 /**
155  * converts the data on the uint8_t bytearray (in wire format) to DNS
156  * rdata fields, and adds them to the list of rdfs of the given rr.
157  * This function will initialize and allocate memory space for the dname
158  * structures.
159  * The length of the wiredata of these rdfs is added to the *pos value.
160  *
161  * All rdfs belonging to the RR are read; the rr should have no rdfs
162  * yet. An error is returned if the format cannot be parsed.
163  *
164  * \param[in] rr pointer to the ldns_rr structure to hold the rdata value
165  * \param[in] wire pointer to the buffer with the data
166  * \param[in] max the length of the data buffer (in bytes)
167  * \param[in] pos the position of the rdf in the buffer (ie. the number of bytes
168  *            from the start of the buffer)
169  * \return LDNS_STATUS_OK if everything succeeds, error otherwise
170  */
171 ldns_status ldns_wire2rdf(ldns_rr *rr, const uint8_t *wire, size_t max, size_t *pos);
172 
173 /**
174  * converts the data on the uint8_t bytearray (in wire format) to a DNS
175  * resource record.
176  * This function will initialize and allocate memory space for the rr
177  * structure.
178  * The length of the wiredata of this rr is added to the *pos value.
179  *
180  * \param[out] rr pointer to the structure to hold the rdata value
181  * \param[in] wire pointer to the buffer with the data
182  * \param[in] max the length of the data buffer (in bytes)
183  * \param[in] pos the position of the rr in the buffer (ie. the number of bytes
184  *            from the start of the buffer)
185  * \param[in] section the section in the packet the rr is meant for
186  * \return LDNS_STATUS_OK if everything succeeds, error otherwise
187  */
188 ldns_status ldns_wire2rr(ldns_rr **rr, const uint8_t *wire, size_t max, size_t *pos, ldns_pkt_section section);
189 
190 #ifdef __cplusplus
191 }
192 #endif
193 
194 #endif /* LDNS_WIRE2HOST_H */
195