nginx/src/core/ngx_resolver.h

   1
   2 /*
   3  * Copyright (C) Igor Sysoev
   4  */
   5
   6
   7 #include <ngx_config.h>
   8 #include <ngx_core.h>
   9
  10
  11 #ifndef _NGX_RESOLVER_H_INCLUDED_
  12 #define _NGX_RESOLVER_H_INCLUDED_
  13
  14
  15 #define NGX_RESOLVE_A         1
  16 #define NGX_RESOLVE_CNAME     5
  17 #define NGX_RESOLVE_PTR       12
  18 #define NGX_RESOLVE_MX        15
  19 #define NGX_RESOLVE_TXT       16
  20 #define NGX_RESOLVE_DNAME     39
  21
  22 #define NGX_RESOLVE_FORMERR   1
  23 #define NGX_RESOLVE_SERVFAIL  2
  24 #define NGX_RESOLVE_NXDOMAIN  3
  25 #define NGX_RESOLVE_NOTIMP    4
  26 #define NGX_RESOLVE_REFUSED   5
  27 #define NGX_RESOLVE_TIMEDOUT  NGX_ETIMEDOUT
  28
  29
  30 #define NGX_NO_RESOLVER       (void *) -1
  31
  32 #define NGX_RESOLVER_MAX_RECURSION    50
  33
  34
  35 typedef struct {
  36     ngx_connection_t         *connection;
  37     struct sockaddr          *sockaddr;
  38     socklen_t                 socklen;
  39     ngx_str_t                 server;
  40     ngx_log_t                *log;
  41 } ngx_udp_connection_t;
  42
  43
  44 typedef struct ngx_resolver_ctx_s  ngx_resolver_ctx_t;
  45
  46 typedef void (*ngx_resolver_handler_pt)(ngx_resolver_ctx_t *ctx);
  47
  48
  49 typedef struct {
  50     ngx_rbtree_node_t         node;
  51     ngx_queue_t               queue;
  52
  53     /* PTR: resolved name, A: name to resolve */
  54     u_char                   *name;
  55
  56     u_short                   nlen;
  57     u_short                   qlen;
  58
  59     u_char                   *query;
  60
  61     union {
  62         in_addr_t             addr;
  63         in_addr_t            *addrs;
  64         u_char               *cname;
  65     } u;
  66
  67     u_short                   naddrs;
  68     u_short                   cnlen;
  69
  70     time_t                    expire;
  71     time_t                    valid;
  72
  73     ngx_resolver_ctx_t       *waiting;
  74 } ngx_resolver_node_t;
  75
  76
  77 typedef struct {
  78     /* has to be pointer because of "incomplete type" */
  79     ngx_event_t              *event;
  80
  81     /* TODO: DNS peers balancer */
  82     /* STUB */
  83     ngx_udp_connection_t     *udp_connection;
  84
  85     ngx_log_t                *log;
  86
  87     /* ident must be after 3 pointers */
  88     ngx_int_t                 ident;
  89
  90     ngx_rbtree_t              name_rbtree;
  91     ngx_rbtree_node_t         name_sentinel;
  92
  93     ngx_rbtree_t              addr_rbtree;
  94     ngx_rbtree_node_t         addr_sentinel;
  95
  96     ngx_queue_t               name_resend_queue;
  97     ngx_queue_t               addr_resend_queue;
  98
  99     ngx_queue_t               name_expire_queue;
 100     ngx_queue_t               addr_expire_queue;
 101
 102     time_t                    resend_timeout;
 103     time_t                    expire;
 104     time_t                    valid;
 105
 106     ngx_uint_t                log_level;
 107 } ngx_resolver_t;
 108
 109
 110 struct ngx_resolver_ctx_s {
 111     ngx_resolver_ctx_t       *next;
 112     ngx_resolver_t           *resolver;
 113     ngx_udp_connection_t     *udp_connection;
 114
 115     /* ident must be after 3 pointers */
 116     ngx_int_t                 ident;
 117
 118     ngx_int_t                 state;
 119     ngx_int_t                 type;
 120     ngx_str_t                 name;
 121
 122     ngx_uint_t                naddrs;
 123     in_addr_t                *addrs;
 124     in_addr_t                 addr;
 125
 126     /* TODO: DNS peers balancer ctx */
 127
 128     ngx_resolver_handler_pt   handler;
 129     void                     *data;
 130     ngx_msec_t                timeout;
 131
 132     ngx_uint_t                quick;  /* unsigned  quick:1; */
 133     ngx_uint_t                recursion;
 134     ngx_event_t              *event;
 135 };
 136
 137
 138 ngx_resolver_t *ngx_resolver_create(ngx_conf_t *cf, ngx_peer_addr_t *addr);
 139 ngx_resolver_ctx_t *ngx_resolve_start(ngx_resolver_t *r,
 140     ngx_resolver_ctx_t *temp);
 141 ngx_int_t ngx_resolve_name(ngx_resolver_ctx_t *ctx);
 142 void ngx_resolve_name_done(ngx_resolver_ctx_t *ctx);
 143 ngx_int_t ngx_resolve_addr(ngx_resolver_ctx_t *ctx);
 144 void ngx_resolve_addr_done(ngx_resolver_ctx_t *ctx);
 145 char *ngx_resolver_strerror(ngx_int_t err);
 146
 147
 148 #endif /* _NGX_RESOLVER_H_INCLUDED_ */