1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ 2*4882a593Smuzhiyun /* DNS resolver interface definitions. 3*4882a593Smuzhiyun * 4*4882a593Smuzhiyun * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved. 5*4882a593Smuzhiyun * Written by David Howells (dhowells@redhat.com) 6*4882a593Smuzhiyun * 7*4882a593Smuzhiyun * This program is free software; you can redistribute it and/or 8*4882a593Smuzhiyun * modify it under the terms of the GNU General Public Licence 9*4882a593Smuzhiyun * as published by the Free Software Foundation; either version 10*4882a593Smuzhiyun * 2 of the Licence, or (at your option) any later version. 11*4882a593Smuzhiyun */ 12*4882a593Smuzhiyun 13*4882a593Smuzhiyun #ifndef _UAPI_LINUX_DNS_RESOLVER_H 14*4882a593Smuzhiyun #define _UAPI_LINUX_DNS_RESOLVER_H 15*4882a593Smuzhiyun 16*4882a593Smuzhiyun #include <linux/types.h> 17*4882a593Smuzhiyun 18*4882a593Smuzhiyun /* 19*4882a593Smuzhiyun * Type of payload. 20*4882a593Smuzhiyun */ 21*4882a593Smuzhiyun enum dns_payload_content_type { 22*4882a593Smuzhiyun DNS_PAYLOAD_IS_SERVER_LIST = 0, /* List of servers, requested by srv=1 */ 23*4882a593Smuzhiyun }; 24*4882a593Smuzhiyun 25*4882a593Smuzhiyun /* 26*4882a593Smuzhiyun * Type of address that might be found in an address record. 27*4882a593Smuzhiyun */ 28*4882a593Smuzhiyun enum dns_payload_address_type { 29*4882a593Smuzhiyun DNS_ADDRESS_IS_IPV4 = 0, /* 4-byte AF_INET address */ 30*4882a593Smuzhiyun DNS_ADDRESS_IS_IPV6 = 1, /* 16-byte AF_INET6 address */ 31*4882a593Smuzhiyun }; 32*4882a593Smuzhiyun 33*4882a593Smuzhiyun /* 34*4882a593Smuzhiyun * Type of protocol used to access a server. 35*4882a593Smuzhiyun */ 36*4882a593Smuzhiyun enum dns_payload_protocol_type { 37*4882a593Smuzhiyun DNS_SERVER_PROTOCOL_UNSPECIFIED = 0, 38*4882a593Smuzhiyun DNS_SERVER_PROTOCOL_UDP = 1, /* Use UDP to talk to the server */ 39*4882a593Smuzhiyun DNS_SERVER_PROTOCOL_TCP = 2, /* Use TCP to talk to the server */ 40*4882a593Smuzhiyun }; 41*4882a593Smuzhiyun 42*4882a593Smuzhiyun /* 43*4882a593Smuzhiyun * Source of record included in DNS resolver payload. 44*4882a593Smuzhiyun */ 45*4882a593Smuzhiyun enum dns_record_source { 46*4882a593Smuzhiyun DNS_RECORD_UNAVAILABLE = 0, /* No source available (empty record) */ 47*4882a593Smuzhiyun DNS_RECORD_FROM_CONFIG = 1, /* From local configuration data */ 48*4882a593Smuzhiyun DNS_RECORD_FROM_DNS_A = 2, /* From DNS A or AAAA record */ 49*4882a593Smuzhiyun DNS_RECORD_FROM_DNS_AFSDB = 3, /* From DNS AFSDB record */ 50*4882a593Smuzhiyun DNS_RECORD_FROM_DNS_SRV = 4, /* From DNS SRV record */ 51*4882a593Smuzhiyun DNS_RECORD_FROM_NSS = 5, /* From NSS */ 52*4882a593Smuzhiyun NR__dns_record_source 53*4882a593Smuzhiyun }; 54*4882a593Smuzhiyun 55*4882a593Smuzhiyun /* 56*4882a593Smuzhiyun * Status of record included in DNS resolver payload. 57*4882a593Smuzhiyun */ 58*4882a593Smuzhiyun enum dns_lookup_status { 59*4882a593Smuzhiyun DNS_LOOKUP_NOT_DONE = 0, /* No lookup has been made */ 60*4882a593Smuzhiyun DNS_LOOKUP_GOOD = 1, /* Good records obtained */ 61*4882a593Smuzhiyun DNS_LOOKUP_GOOD_WITH_BAD = 2, /* Good records, some decoding errors */ 62*4882a593Smuzhiyun DNS_LOOKUP_BAD = 3, /* Couldn't decode results */ 63*4882a593Smuzhiyun DNS_LOOKUP_GOT_NOT_FOUND = 4, /* Got a "Not Found" result */ 64*4882a593Smuzhiyun DNS_LOOKUP_GOT_LOCAL_FAILURE = 5, /* Local failure during lookup */ 65*4882a593Smuzhiyun DNS_LOOKUP_GOT_TEMP_FAILURE = 6, /* Temporary failure during lookup */ 66*4882a593Smuzhiyun DNS_LOOKUP_GOT_NS_FAILURE = 7, /* Name server failure */ 67*4882a593Smuzhiyun NR__dns_lookup_status 68*4882a593Smuzhiyun }; 69*4882a593Smuzhiyun 70*4882a593Smuzhiyun /* 71*4882a593Smuzhiyun * Header at the beginning of binary format payload. 72*4882a593Smuzhiyun */ 73*4882a593Smuzhiyun struct dns_payload_header { 74*4882a593Smuzhiyun __u8 zero; /* Zero byte: marks this as not being text */ 75*4882a593Smuzhiyun __u8 content; /* enum dns_payload_content_type */ 76*4882a593Smuzhiyun __u8 version; /* Encoding version */ 77*4882a593Smuzhiyun } __packed; 78*4882a593Smuzhiyun 79*4882a593Smuzhiyun /* 80*4882a593Smuzhiyun * Header at the beginning of a V1 server list. This is followed directly by 81*4882a593Smuzhiyun * the server records. Each server records begins with a struct of type 82*4882a593Smuzhiyun * dns_server_list_v1_server. 83*4882a593Smuzhiyun */ 84*4882a593Smuzhiyun struct dns_server_list_v1_header { 85*4882a593Smuzhiyun struct dns_payload_header hdr; 86*4882a593Smuzhiyun __u8 source; /* enum dns_record_source */ 87*4882a593Smuzhiyun __u8 status; /* enum dns_lookup_status */ 88*4882a593Smuzhiyun __u8 nr_servers; /* Number of server records following this */ 89*4882a593Smuzhiyun } __packed; 90*4882a593Smuzhiyun 91*4882a593Smuzhiyun /* 92*4882a593Smuzhiyun * Header at the beginning of each V1 server record. This is followed by the 93*4882a593Smuzhiyun * characters of the name with no NUL-terminator, followed by the address 94*4882a593Smuzhiyun * records for that server. Each address record begins with a struct of type 95*4882a593Smuzhiyun * struct dns_server_list_v1_address. 96*4882a593Smuzhiyun */ 97*4882a593Smuzhiyun struct dns_server_list_v1_server { 98*4882a593Smuzhiyun __u16 name_len; /* Length of name (LE) */ 99*4882a593Smuzhiyun __u16 priority; /* Priority (as SRV record) (LE) */ 100*4882a593Smuzhiyun __u16 weight; /* Weight (as SRV record) (LE) */ 101*4882a593Smuzhiyun __u16 port; /* UDP/TCP port number (LE) */ 102*4882a593Smuzhiyun __u8 source; /* enum dns_record_source */ 103*4882a593Smuzhiyun __u8 status; /* enum dns_lookup_status */ 104*4882a593Smuzhiyun __u8 protocol; /* enum dns_payload_protocol_type */ 105*4882a593Smuzhiyun __u8 nr_addrs; 106*4882a593Smuzhiyun } __packed; 107*4882a593Smuzhiyun 108*4882a593Smuzhiyun /* 109*4882a593Smuzhiyun * Header at the beginning of each V1 address record. This is followed by the 110*4882a593Smuzhiyun * bytes of the address, 4 for IPV4 and 16 for IPV6. 111*4882a593Smuzhiyun */ 112*4882a593Smuzhiyun struct dns_server_list_v1_address { 113*4882a593Smuzhiyun __u8 address_type; /* enum dns_payload_address_type */ 114*4882a593Smuzhiyun } __packed; 115*4882a593Smuzhiyun 116*4882a593Smuzhiyun #endif /* _UAPI_LINUX_DNS_RESOLVER_H */ 117