David Howells | bbb4c43 | 2018-10-04 14:27:55 +0100 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ |
| 2 | /* DNS resolver interface definitions. |
| 3 | * |
| 4 | * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved. |
| 5 | * Written by David Howells (dhowells@redhat.com) |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU General Public Licence |
| 9 | * as published by the Free Software Foundation; either version |
| 10 | * 2 of the Licence, or (at your option) any later version. |
| 11 | */ |
| 12 | |
| 13 | #ifndef _UAPI_LINUX_DNS_RESOLVER_H |
| 14 | #define _UAPI_LINUX_DNS_RESOLVER_H |
| 15 | |
| 16 | #include <linux/types.h> |
| 17 | |
| 18 | /* |
| 19 | * Type of payload. |
| 20 | */ |
| 21 | enum dns_payload_content_type { |
| 22 | DNS_PAYLOAD_IS_SERVER_LIST = 0, /* List of servers, requested by srv=1 */ |
| 23 | }; |
| 24 | |
| 25 | /* |
| 26 | * Type of address that might be found in an address record. |
| 27 | */ |
| 28 | enum dns_payload_address_type { |
| 29 | DNS_ADDRESS_IS_IPV4 = 0, /* 4-byte AF_INET address */ |
| 30 | DNS_ADDRESS_IS_IPV6 = 1, /* 16-byte AF_INET6 address */ |
| 31 | }; |
| 32 | |
| 33 | /* |
| 34 | * Type of protocol used to access a server. |
| 35 | */ |
| 36 | enum dns_payload_protocol_type { |
| 37 | DNS_SERVER_PROTOCOL_UNSPECIFIED = 0, |
| 38 | DNS_SERVER_PROTOCOL_UDP = 1, /* Use UDP to talk to the server */ |
| 39 | DNS_SERVER_PROTOCOL_TCP = 2, /* Use TCP to talk to the server */ |
| 40 | }; |
| 41 | |
| 42 | /* |
| 43 | * Source of record included in DNS resolver payload. |
| 44 | */ |
| 45 | enum dns_record_source { |
| 46 | DNS_RECORD_UNAVAILABLE = 0, /* No source available (empty record) */ |
| 47 | DNS_RECORD_FROM_CONFIG = 1, /* From local configuration data */ |
| 48 | DNS_RECORD_FROM_DNS_A = 2, /* From DNS A or AAAA record */ |
| 49 | DNS_RECORD_FROM_DNS_AFSDB = 3, /* From DNS AFSDB record */ |
| 50 | DNS_RECORD_FROM_DNS_SRV = 4, /* From DNS SRV record */ |
| 51 | DNS_RECORD_FROM_NSS = 5, /* From NSS */ |
| 52 | NR__dns_record_source |
| 53 | }; |
| 54 | |
| 55 | /* |
| 56 | * Status of record included in DNS resolver payload. |
| 57 | */ |
| 58 | enum dns_lookup_status { |
| 59 | DNS_LOOKUP_NOT_DONE = 0, /* No lookup has been made */ |
| 60 | DNS_LOOKUP_GOOD = 1, /* Good records obtained */ |
| 61 | DNS_LOOKUP_GOOD_WITH_BAD = 2, /* Good records, some decoding errors */ |
| 62 | DNS_LOOKUP_BAD = 3, /* Couldn't decode results */ |
| 63 | DNS_LOOKUP_GOT_NOT_FOUND = 4, /* Got a "Not Found" result */ |
| 64 | DNS_LOOKUP_GOT_LOCAL_FAILURE = 5, /* Local failure during lookup */ |
| 65 | DNS_LOOKUP_GOT_TEMP_FAILURE = 6, /* Temporary failure during lookup */ |
| 66 | DNS_LOOKUP_GOT_NS_FAILURE = 7, /* Name server failure */ |
| 67 | NR__dns_lookup_status |
| 68 | }; |
| 69 | |
| 70 | /* |
| 71 | * Header at the beginning of binary format payload. |
| 72 | */ |
| 73 | struct dns_payload_header { |
| 74 | __u8 zero; /* Zero byte: marks this as not being text */ |
| 75 | __u8 content; /* enum dns_payload_content_type */ |
| 76 | __u8 version; /* Encoding version */ |
| 77 | } __packed; |
| 78 | |
| 79 | /* |
| 80 | * Header at the beginning of a V1 server list. This is followed directly by |
| 81 | * the server records. Each server records begins with a struct of type |
| 82 | * dns_server_list_v1_server. |
| 83 | */ |
| 84 | struct dns_server_list_v1_header { |
| 85 | struct dns_payload_header hdr; |
| 86 | __u8 source; /* enum dns_record_source */ |
| 87 | __u8 status; /* enum dns_lookup_status */ |
| 88 | __u8 nr_servers; /* Number of server records following this */ |
| 89 | } __packed; |
| 90 | |
| 91 | /* |
| 92 | * Header at the beginning of each V1 server record. This is followed by the |
| 93 | * characters of the name with no NUL-terminator, followed by the address |
| 94 | * records for that server. Each address record begins with a struct of type |
| 95 | * struct dns_server_list_v1_address. |
| 96 | */ |
| 97 | struct dns_server_list_v1_server { |
| 98 | __u16 name_len; /* Length of name (LE) */ |
| 99 | __u16 priority; /* Priority (as SRV record) (LE) */ |
| 100 | __u16 weight; /* Weight (as SRV record) (LE) */ |
| 101 | __u16 port; /* UDP/TCP port number (LE) */ |
| 102 | __u8 source; /* enum dns_record_source */ |
| 103 | __u8 status; /* enum dns_lookup_status */ |
| 104 | __u8 protocol; /* enum dns_payload_protocol_type */ |
| 105 | __u8 nr_addrs; |
| 106 | } __packed; |
| 107 | |
| 108 | /* |
| 109 | * Header at the beginning of each V1 address record. This is followed by the |
| 110 | * bytes of the address, 4 for IPV4 and 16 for IPV6. |
| 111 | */ |
| 112 | struct dns_server_list_v1_address { |
| 113 | __u8 address_type; /* enum dns_payload_address_type */ |
| 114 | } __packed; |
| 115 | |
| 116 | #endif /* _UAPI_LINUX_DNS_RESOLVER_H */ |