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Diffstat (limited to 'include/haproxy/dns-t.h')
| -rw-r--r-- | include/haproxy/dns-t.h | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/include/haproxy/dns-t.h b/include/haproxy/dns-t.h new file mode 100644 index 0000000..1c876e3 --- /dev/null +++ b/include/haproxy/dns-t.h @@ -0,0 +1,179 @@ +/* + * include/haproxy/dns-t.h + * This file provides structures and types for DNS. + * + * Copyright (C) 2014 Baptiste Assmann <bedis9@gmail.com> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation, version 2.1 + * exclusively. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef _HAPROXY_DNS_T_H +#define _HAPROXY_DNS_T_H + +#include <import/ebtree-t.h> + +#include <haproxy/connection-t.h> +#include <haproxy/buf-t.h> +#include <haproxy/dgram-t.h> +#include <haproxy/obj_type-t.h> +#include <haproxy/ring-t.h> +#include <haproxy/stats-t.h> +#include <haproxy/task-t.h> +#include <haproxy/thread.h> + +/* DNS header size */ +#define DNS_HEADER_SIZE ((int)sizeof(struct dns_header)) + +/* max pending requests per stream */ +#define DNS_STREAM_MAX_PIPELINED_REQ 4 + +#define DNS_TCP_MSG_MAX_SIZE 65535 +#define DNS_TCP_MSG_RING_MAX_SIZE (1 + 1 + 3 + DNS_TCP_MSG_MAX_SIZE) // varint_bytes(DNS_TCP_MSG_MAX_SIZE) == 3 + +/* DNS request or response header structure */ +struct dns_header { + uint16_t id; + uint16_t flags; + uint16_t qdcount; + uint16_t ancount; + uint16_t nscount; + uint16_t arcount; +} __attribute__ ((packed)); + +/* short structure to describe a DNS question */ +/* NOTE: big endian structure */ +struct dns_question { + unsigned short qtype; /* question type */ + unsigned short qclass; /* query class */ +} __attribute__ ((packed)); + + +/* NOTE: big endian structure */ +struct dns_additional_record { + uint8_t name; /* domain name, must be 0 (RFC 6891) */ + uint16_t type; /* record type DNS_RTYPE_OPT (41) */ + uint16_t udp_payload_size; /* maximum size accepted for the response */ + uint32_t extension; /* extended rcode and flags, not used for now */ + uint16_t data_length; /* data length */ +/* as of today, we don't support yet edns options, that said I already put a + * placeholder here for this purpose. We may need to define a dns_option_record + * structure which itself should point to different type of data, based on the + * extension set (client subnet, tcp keepalive, etc...)*/ +} __attribute__ ((packed)); + +/* Structure describing a name server used during name resolution. + * A name server belongs to a resolvers section. + */ +struct dns_stream_server { + struct server *srv; + struct ring *ring_req; + int max_slots; + int maxconn; + int idle_conns; + int cur_conns; + int max_active_conns; + size_t ofs_req; // ring buffer reader offset + size_t ofs_rsp; // ring buffer reader offset + struct task *task_req; /* req conn management */ + struct task *task_rsp; /* rsp management */ + struct task *task_idle; /* handle idle sess */ + struct list free_sess; + struct list idle_sess; + struct list wait_sess; + __decl_thread(HA_SPINLOCK_T lock); // lock to protect current struct +}; + +struct dns_dgram_server { + struct dgram_conn conn; /* transport layer */ + struct ring *ring_req; + size_t ofs_req; // ring buffer reader offset +}; + +struct dns_query { + struct eb32_node qid; + uint16_t original_qid; + int expire; + struct list list; +}; + +struct dns_session { + struct appctx *appctx; // appctx of current session + struct dns_stream_server *dss; + uint16_t tx_msg_offset; + int nb_queries; + int onfly_queries; + int query_counter; + struct list list; + struct list waiter; + struct list queries; + struct task *task_exp; + struct eb_root query_ids; /* tree to quickly lookup/retrieve query ids currently in use */ + size_t ofs; // ring buffer reader offset + struct ring ring; + struct { + uint16_t len; + uint16_t offset; + char *area; + } rx_msg; + unsigned char *tx_ring_area; + int shutdown; +}; + +/* Structure describing a name server + */ +struct dns_nameserver { + char *id; /* nameserver unique identifier */ + void *parent; + struct { + const char *file; /* file where the section appears */ + int line; /* line where the section appears */ + } conf; /* config information */ + + int (*process_responses)(struct dns_nameserver *ns); /* callback used to process responses */ + struct dns_dgram_server *dgram; /* used for dgram dns */ + struct dns_stream_server *stream; /* used for tcp dns */ + + EXTRA_COUNTERS(extra_counters); + struct dns_counters *counters; + + struct list list; /* nameserver chained list */ +}; + +/* mixed dns and resolver counters, we will have to split them */ +struct dns_counters { + char *id; + char *pid; + long long sent; /* - queries sent */ + long long snd_error; /* - sending errors */ + union { + struct { + long long valid; /* - valid response */ + long long update; /* - valid response used to update server's IP */ + long long cname; /* - CNAME response requiring new resolution */ + long long cname_error; /* - error when resolving CNAMEs */ + long long any_err; /* - void response (usually because ANY qtype) */ + long long nx; /* - NX response */ + long long timeout; /* - queries which reached timeout */ + long long refused; /* - queries refused */ + long long other; /* - other type of response */ + long long invalid; /* - malformed DNS response */ + long long too_big; /* - too big response */ + long long outdated; /* - outdated response (server slower than the other ones) */ + long long truncated; /* - truncated response */; + } resolver; + } app; /* application specific counteurs */ +}; + +#endif /* _HAPROXY_DNS_T_H */ |