2 * util/edns.h - handle base EDNS options.
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39 * This file contains functions for base EDNS options.
45 #include "util/storage/dnstree.h"
53 * Structure containing all EDNS strings.
56 /** Tree of EDNS client strings to use in upstream queries, per address
57 * prefix. Contains nodes of type edns_string_addr. */
58 rbtree_type client_strings;
59 /** EDNS opcode to use for client strings */
60 uint16_t client_string_opcode;
61 /** region to allocate tree nodes in */
62 struct regional* region;
66 * EDNS string. Node of rbtree, containing string and prefix.
68 struct edns_string_addr {
69 /** node in address tree, used for tree lookups. Need to be the first
70 * member of this struct. */
71 struct addr_tree_node node;
72 /** string, ascii format */
74 /** length of string */
78 enum edns_cookie_val_status {
79 COOKIE_STATUS_CLIENT_ONLY = -3,
80 COOKIE_STATUS_FUTURE = -2,
81 COOKIE_STATUS_EXPIRED = -1,
82 COOKIE_STATUS_INVALID = 0,
83 COOKIE_STATUS_VALID = 1,
84 COOKIE_STATUS_VALID_RENEW = 2,
88 * Create structure to hold EDNS strings
89 * @return: newly created edns_strings, NULL on alloc failure.
91 struct edns_strings* edns_strings_create(void);
93 /** Delete EDNS strings structure
94 * @param edns_strings: struct to delete
96 void edns_strings_delete(struct edns_strings* edns_strings);
99 * Add configured EDNS strings
100 * @param edns_strings: edns strings to apply config to
101 * @param config: struct containing EDNS strings configuration
104 int edns_strings_apply_cfg(struct edns_strings* edns_strings,
105 struct config_file* config);
108 * Find string for address.
109 * @param tree: tree containing EDNS strings per address prefix.
110 * @param addr: address to use for tree lookup
111 * @param addrlen: length of address
112 * @return: matching tree node, NULL otherwise
114 struct edns_string_addr*
115 edns_string_addr_lookup(rbtree_type* tree, struct sockaddr_storage* addr,
119 * Compute the interoperable DNS cookie (RFC9018) hash.
120 * @param in: buffer input for the hash generation. It needs to be:
121 * Client Cookie | Version | Reserved | Timestamp | Client-IP
122 * @param secret: the server secret; implicit length of 16 octets.
123 * @param v4: if the client IP is v4 or v6.
124 * @param hash: buffer to write the hash to.
125 * return a pointer to the hash.
127 uint8_t* edns_cookie_server_hash(const uint8_t* in, const uint8_t* secret,
128 int v4, uint8_t* hash);
131 * Write an interoperable DNS server cookie (RFC9018).
132 * @param buf: buffer to write to. It should have a size of at least 32 octets
133 * as it doubles as the output buffer and the hash input buffer.
134 * The first 8 octets are expected to be the Client Cookie and will be
136 * The next 8 octets will be written with Version | Reserved | Timestamp.
137 * The next 4 or 16 octets are expected to be the IPv4 or the IPv6 address
138 * based on the v4 flag.
139 * Thus the first 20 or 32 octets, based on the v4 flag, will be used as
141 * The server hash (8 octets) will be written after the first 16 octets;
142 * overwriting the address information.
143 * The caller expects a complete, 24 octet long cookie in the buffer.
144 * @param secret: the server secret; implicit length of 16 octets.
145 * @param v4: if the client IP is v4 or v6.
146 * @param timestamp: the timestamp to use.
148 void edns_cookie_server_write(uint8_t* buf, const uint8_t* secret, int v4,
152 * Validate an interoperable DNS cookie (RFC9018).
153 * @param cookie: pointer to the cookie data.
154 * @param cookie_len: the length of the cookie data.
155 * @param secret: pointer to the server secret.
156 * @param secret_len: the length of the secret.
157 * @param v4: if the client IP is v4 or v6.
158 * @param hash_input: pointer to the hash input for validation. It needs to be:
159 * Client Cookie | Version | Reserved | Timestamp | Client-IP
160 * @param now: the current time.
161 * return edns_cookie_val_status with the cookie validation status i.e.,
162 * <=0 for invalid, else valid.
164 enum edns_cookie_val_status edns_cookie_server_validate(const uint8_t* cookie,
165 size_t cookie_len, const uint8_t* secret, size_t secret_len, int v4,
166 const uint8_t* hash_input, uint32_t now);