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Edit File: dns_resolver.h
/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ /* DNS resolver interface definitions. * * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public Licence * as published by the Free Software Foundation; either version * 2 of the Licence, or (at your option) any later version. */ #ifndef _LINUX_DNS_RESOLVER_H #define _LINUX_DNS_RESOLVER_H #include <linux/types.h> /* * Type of payload. */ enum dns_payload_content_type { DNS_PAYLOAD_IS_SERVER_LIST = 0, /* List of servers, requested by srv=1 */ }; /* * Type of address that might be found in an address record. */ enum dns_payload_address_type { DNS_ADDRESS_IS_IPV4 = 0, /* 4-byte AF_INET address */ DNS_ADDRESS_IS_IPV6 = 1, /* 16-byte AF_INET6 address */ }; /* * Type of protocol used to access a server. */ enum dns_payload_protocol_type { DNS_SERVER_PROTOCOL_UNSPECIFIED = 0, DNS_SERVER_PROTOCOL_UDP = 1, /* Use UDP to talk to the server */ DNS_SERVER_PROTOCOL_TCP = 2, /* Use TCP to talk to the server */ }; /* * Source of record included in DNS resolver payload. */ enum dns_record_source { DNS_RECORD_UNAVAILABLE = 0, /* No source available (empty record) */ DNS_RECORD_FROM_CONFIG = 1, /* From local configuration data */ DNS_RECORD_FROM_DNS_A = 2, /* From DNS A or AAAA record */ DNS_RECORD_FROM_DNS_AFSDB = 3, /* From DNS AFSDB record */ DNS_RECORD_FROM_DNS_SRV = 4, /* From DNS SRV record */ DNS_RECORD_FROM_NSS = 5, /* From NSS */ NR__dns_record_source }; /* * Status of record included in DNS resolver payload. */ enum dns_lookup_status { DNS_LOOKUP_NOT_DONE = 0, /* No lookup has been made */ DNS_LOOKUP_GOOD = 1, /* Good records obtained */ DNS_LOOKUP_GOOD_WITH_BAD = 2, /* Good records, some decoding errors */ DNS_LOOKUP_BAD = 3, /* Couldn't decode results */ DNS_LOOKUP_GOT_NOT_FOUND = 4, /* Got a "Not Found" result */ DNS_LOOKUP_GOT_LOCAL_FAILURE = 5, /* Local failure during lookup */ DNS_LOOKUP_GOT_TEMP_FAILURE = 6, /* Temporary failure during lookup */ DNS_LOOKUP_GOT_NS_FAILURE = 7, /* Name server failure */ NR__dns_lookup_status }; /* * Header at the beginning of binary format payload. */ struct dns_payload_header { __u8 zero; /* Zero byte: marks this as not being text */ __u8 content; /* enum dns_payload_content_type */ __u8 version; /* Encoding version */ } __attribute__((packed)); /* * Header at the beginning of a V1 server list. This is followed directly by * the server records. Each server records begins with a struct of type * dns_server_list_v1_server. */ struct dns_server_list_v1_header { struct dns_payload_header hdr; __u8 source; /* enum dns_record_source */ __u8 status; /* enum dns_lookup_status */ __u8 nr_servers; /* Number of server records following this */ } __attribute__((packed)); /* * Header at the beginning of each V1 server record. This is followed by the * characters of the name with no NUL-terminator, followed by the address * records for that server. Each address record begins with a struct of type * struct dns_server_list_v1_address. */ struct dns_server_list_v1_server { __u16 name_len; /* Length of name (LE) */ __u16 priority; /* Priority (as SRV record) (LE) */ __u16 weight; /* Weight (as SRV record) (LE) */ __u16 port; /* UDP/TCP port number (LE) */ __u8 source; /* enum dns_record_source */ __u8 status; /* enum dns_lookup_status */ __u8 protocol; /* enum dns_payload_protocol_type */ __u8 nr_addrs; } __attribute__((packed)); /* * Header at the beginning of each V1 address record. This is followed by the * bytes of the address, 4 for IPV4 and 16 for IPV6. */ struct dns_server_list_v1_address { __u8 address_type; /* enum dns_payload_address_type */ } __attribute__((packed)); #endif /* _LINUX_DNS_RESOLVER_H */