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 { |
74 | __u8 ; /* Zero byte: marks this as not being text */ |
75 | __u8 ; /* enum dns_payload_content_type */ |
76 | __u8 ; /* 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 { |
85 | struct dns_payload_header ; |
86 | __u8 ; /* enum dns_record_source */ |
87 | __u8 ; /* enum dns_lookup_status */ |
88 | __u8 ; /* 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 */ |
117 | |