1*bbb4c432SDavid Howells /* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ 2*bbb4c432SDavid Howells /* DNS resolver interface definitions. 3*bbb4c432SDavid Howells * 4*bbb4c432SDavid Howells * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved. 5*bbb4c432SDavid Howells * Written by David Howells (dhowells@redhat.com) 6*bbb4c432SDavid Howells * 7*bbb4c432SDavid Howells * This program is free software; you can redistribute it and/or 8*bbb4c432SDavid Howells * modify it under the terms of the GNU General Public Licence 9*bbb4c432SDavid Howells * as published by the Free Software Foundation; either version 10*bbb4c432SDavid Howells * 2 of the Licence, or (at your option) any later version. 11*bbb4c432SDavid Howells */ 12*bbb4c432SDavid Howells 13*bbb4c432SDavid Howells #ifndef _UAPI_LINUX_DNS_RESOLVER_H 14*bbb4c432SDavid Howells #define _UAPI_LINUX_DNS_RESOLVER_H 15*bbb4c432SDavid Howells 16*bbb4c432SDavid Howells #include <linux/types.h> 17*bbb4c432SDavid Howells 18*bbb4c432SDavid Howells /* 19*bbb4c432SDavid Howells * Type of payload. 20*bbb4c432SDavid Howells */ 21*bbb4c432SDavid Howells enum dns_payload_content_type { 22*bbb4c432SDavid Howells DNS_PAYLOAD_IS_SERVER_LIST = 0, /* List of servers, requested by srv=1 */ 23*bbb4c432SDavid Howells }; 24*bbb4c432SDavid Howells 25*bbb4c432SDavid Howells /* 26*bbb4c432SDavid Howells * Type of address that might be found in an address record. 27*bbb4c432SDavid Howells */ 28*bbb4c432SDavid Howells enum dns_payload_address_type { 29*bbb4c432SDavid Howells DNS_ADDRESS_IS_IPV4 = 0, /* 4-byte AF_INET address */ 30*bbb4c432SDavid Howells DNS_ADDRESS_IS_IPV6 = 1, /* 16-byte AF_INET6 address */ 31*bbb4c432SDavid Howells }; 32*bbb4c432SDavid Howells 33*bbb4c432SDavid Howells /* 34*bbb4c432SDavid Howells * Type of protocol used to access a server. 35*bbb4c432SDavid Howells */ 36*bbb4c432SDavid Howells enum dns_payload_protocol_type { 37*bbb4c432SDavid Howells DNS_SERVER_PROTOCOL_UNSPECIFIED = 0, 38*bbb4c432SDavid Howells DNS_SERVER_PROTOCOL_UDP = 1, /* Use UDP to talk to the server */ 39*bbb4c432SDavid Howells DNS_SERVER_PROTOCOL_TCP = 2, /* Use TCP to talk to the server */ 40*bbb4c432SDavid Howells }; 41*bbb4c432SDavid Howells 42*bbb4c432SDavid Howells /* 43*bbb4c432SDavid Howells * Source of record included in DNS resolver payload. 44*bbb4c432SDavid Howells */ 45*bbb4c432SDavid Howells enum dns_record_source { 46*bbb4c432SDavid Howells DNS_RECORD_UNAVAILABLE = 0, /* No source available (empty record) */ 47*bbb4c432SDavid Howells DNS_RECORD_FROM_CONFIG = 1, /* From local configuration data */ 48*bbb4c432SDavid Howells DNS_RECORD_FROM_DNS_A = 2, /* From DNS A or AAAA record */ 49*bbb4c432SDavid Howells DNS_RECORD_FROM_DNS_AFSDB = 3, /* From DNS AFSDB record */ 50*bbb4c432SDavid Howells DNS_RECORD_FROM_DNS_SRV = 4, /* From DNS SRV record */ 51*bbb4c432SDavid Howells DNS_RECORD_FROM_NSS = 5, /* From NSS */ 52*bbb4c432SDavid Howells NR__dns_record_source 53*bbb4c432SDavid Howells }; 54*bbb4c432SDavid Howells 55*bbb4c432SDavid Howells /* 56*bbb4c432SDavid Howells * Status of record included in DNS resolver payload. 57*bbb4c432SDavid Howells */ 58*bbb4c432SDavid Howells enum dns_lookup_status { 59*bbb4c432SDavid Howells DNS_LOOKUP_NOT_DONE = 0, /* No lookup has been made */ 60*bbb4c432SDavid Howells DNS_LOOKUP_GOOD = 1, /* Good records obtained */ 61*bbb4c432SDavid Howells DNS_LOOKUP_GOOD_WITH_BAD = 2, /* Good records, some decoding errors */ 62*bbb4c432SDavid Howells DNS_LOOKUP_BAD = 3, /* Couldn't decode results */ 63*bbb4c432SDavid Howells DNS_LOOKUP_GOT_NOT_FOUND = 4, /* Got a "Not Found" result */ 64*bbb4c432SDavid Howells DNS_LOOKUP_GOT_LOCAL_FAILURE = 5, /* Local failure during lookup */ 65*bbb4c432SDavid Howells DNS_LOOKUP_GOT_TEMP_FAILURE = 6, /* Temporary failure during lookup */ 66*bbb4c432SDavid Howells DNS_LOOKUP_GOT_NS_FAILURE = 7, /* Name server failure */ 67*bbb4c432SDavid Howells NR__dns_lookup_status 68*bbb4c432SDavid Howells }; 69*bbb4c432SDavid Howells 70*bbb4c432SDavid Howells /* 71*bbb4c432SDavid Howells * Header at the beginning of binary format payload. 72*bbb4c432SDavid Howells */ 73*bbb4c432SDavid Howells struct dns_payload_header { 74*bbb4c432SDavid Howells __u8 zero; /* Zero byte: marks this as not being text */ 75*bbb4c432SDavid Howells __u8 content; /* enum dns_payload_content_type */ 76*bbb4c432SDavid Howells __u8 version; /* Encoding version */ 77*bbb4c432SDavid Howells } __packed; 78*bbb4c432SDavid Howells 79*bbb4c432SDavid Howells /* 80*bbb4c432SDavid Howells * Header at the beginning of a V1 server list. This is followed directly by 81*bbb4c432SDavid Howells * the server records. Each server records begins with a struct of type 82*bbb4c432SDavid Howells * dns_server_list_v1_server. 83*bbb4c432SDavid Howells */ 84*bbb4c432SDavid Howells struct dns_server_list_v1_header { 85*bbb4c432SDavid Howells struct dns_payload_header hdr; 86*bbb4c432SDavid Howells __u8 source; /* enum dns_record_source */ 87*bbb4c432SDavid Howells __u8 status; /* enum dns_lookup_status */ 88*bbb4c432SDavid Howells __u8 nr_servers; /* Number of server records following this */ 89*bbb4c432SDavid Howells } __packed; 90*bbb4c432SDavid Howells 91*bbb4c432SDavid Howells /* 92*bbb4c432SDavid Howells * Header at the beginning of each V1 server record. This is followed by the 93*bbb4c432SDavid Howells * characters of the name with no NUL-terminator, followed by the address 94*bbb4c432SDavid Howells * records for that server. Each address record begins with a struct of type 95*bbb4c432SDavid Howells * struct dns_server_list_v1_address. 96*bbb4c432SDavid Howells */ 97*bbb4c432SDavid Howells struct dns_server_list_v1_server { 98*bbb4c432SDavid Howells __u16 name_len; /* Length of name (LE) */ 99*bbb4c432SDavid Howells __u16 priority; /* Priority (as SRV record) (LE) */ 100*bbb4c432SDavid Howells __u16 weight; /* Weight (as SRV record) (LE) */ 101*bbb4c432SDavid Howells __u16 port; /* UDP/TCP port number (LE) */ 102*bbb4c432SDavid Howells __u8 source; /* enum dns_record_source */ 103*bbb4c432SDavid Howells __u8 status; /* enum dns_lookup_status */ 104*bbb4c432SDavid Howells __u8 protocol; /* enum dns_payload_protocol_type */ 105*bbb4c432SDavid Howells __u8 nr_addrs; 106*bbb4c432SDavid Howells } __packed; 107*bbb4c432SDavid Howells 108*bbb4c432SDavid Howells /* 109*bbb4c432SDavid Howells * Header at the beginning of each V1 address record. This is followed by the 110*bbb4c432SDavid Howells * bytes of the address, 4 for IPV4 and 16 for IPV6. 111*bbb4c432SDavid Howells */ 112*bbb4c432SDavid Howells struct dns_server_list_v1_address { 113*bbb4c432SDavid Howells __u8 address_type; /* enum dns_payload_address_type */ 114*bbb4c432SDavid Howells } __packed; 115*bbb4c432SDavid Howells 116*bbb4c432SDavid Howells #endif /* _UAPI_LINUX_DNS_RESOLVER_H */ 117