dns.h

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// Copyright (c) 2017-2019 The Bitcoin developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
#ifndef BITCOIN_SEEDER_DNS_H
#define BITCOIN_SEEDER_DNS_H 1
 
#include <cstddef>
#include <cstdint>
 
constexpr int MAX_LABEL_LENGTH = 63;
constexpr int MAX_QUERY_NAME_LENGTH = 255;
// Max size of the null-terminated buffer parse_name() writes to.
constexpr int MAX_QUERY_NAME_BUFFER_LENGTH = MAX_QUERY_NAME_LENGTH + 1;
 
struct addr_t {
    int v;
    union {
        uint8_t v4[4];
        uint8_t v6[16];
    } data;
};
 
struct dns_opt_t {
    int port;
    int datattl;
    int nsttl;
    const char *host;
    const char *addr;
    const char *ns;
    const char *mbox;
    uint32_t (*cb)(void *opt, char *requested_hostname, addr_t *addr,
                   uint32_t max, uint32_t ipv4, uint32_t ipv6);
    // stats
    uint64_t nRequests;
};
 
enum class ParseNameStatus {
    OK,
    // Premature end of input, forward reference, component > 63 char, invalid
    // character
    InputError,
    // Insufficient space in output
    OutputBufferError,
};
 
ParseNameStatus parse_name(const uint8_t **inpos, const uint8_t *inend,
                           const uint8_t *inbuf, char *buf, size_t bufsize);
 
//  0: k
// -1: component > 63 characters
// -2: insufficent space in output
// -3: two subsequent dots
int write_name(uint8_t **outpos, const uint8_t *outend, const char *name,
               int offset);
 
int dnsserver(dns_opt_t *opt);
 
#endif // BITCOIN_SEEDER_DNS_H