nginx/src/core/ngx_resolver.c

/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>


#define NGX_RESOLVER_UDP_SIZE …

#define NGX_RESOLVER_TCP_RSIZE …
#define NGX_RESOLVER_TCP_WSIZE …


ngx_resolver_hdr_t;


ngx_resolver_qs_t;


ngx_resolver_an_t;


#define ngx_resolver_node(n) …


static ngx_int_t ngx_udp_connect(ngx_resolver_connection_t *rec);
static ngx_int_t ngx_tcp_connect(ngx_resolver_connection_t *rec);


static void ngx_resolver_cleanup(void *data);
static void ngx_resolver_cleanup_tree(ngx_resolver_t *r, ngx_rbtree_t *tree);
static ngx_int_t ngx_resolve_name_locked(ngx_resolver_t *r,
    ngx_resolver_ctx_t *ctx, ngx_str_t *name);
static void ngx_resolver_expire(ngx_resolver_t *r, ngx_rbtree_t *tree,
    ngx_queue_t *queue);
static ngx_int_t ngx_resolver_send_query(ngx_resolver_t *r,
    ngx_resolver_node_t *rn);
static ngx_int_t ngx_resolver_send_udp_query(ngx_resolver_t *r,
    ngx_resolver_connection_t *rec, u_char *query, u_short qlen);
static ngx_int_t ngx_resolver_send_tcp_query(ngx_resolver_t *r,
    ngx_resolver_connection_t *rec, u_char *query, u_short qlen);
static ngx_int_t ngx_resolver_create_name_query(ngx_resolver_t *r,
    ngx_resolver_node_t *rn, ngx_str_t *name);
static ngx_int_t ngx_resolver_create_srv_query(ngx_resolver_t *r,
    ngx_resolver_node_t *rn, ngx_str_t *name);
static ngx_int_t ngx_resolver_create_addr_query(ngx_resolver_t *r,
    ngx_resolver_node_t *rn, ngx_resolver_addr_t *addr);
static void ngx_resolver_resend_handler(ngx_event_t *ev);
static time_t ngx_resolver_resend(ngx_resolver_t *r, ngx_rbtree_t *tree,
    ngx_queue_t *queue);
static ngx_uint_t ngx_resolver_resend_empty(ngx_resolver_t *r);
static void ngx_resolver_udp_read(ngx_event_t *rev);
static void ngx_resolver_tcp_write(ngx_event_t *wev);
static void ngx_resolver_tcp_read(ngx_event_t *rev);
static void ngx_resolver_process_response(ngx_resolver_t *r, u_char *buf,
    size_t n, ngx_uint_t tcp);
static void ngx_resolver_process_a(ngx_resolver_t *r, u_char *buf, size_t n,
    ngx_uint_t ident, ngx_uint_t code, ngx_uint_t qtype,
    ngx_uint_t nan, ngx_uint_t trunc, ngx_uint_t ans);
static void ngx_resolver_process_srv(ngx_resolver_t *r, u_char *buf, size_t n,
    ngx_uint_t ident, ngx_uint_t code, ngx_uint_t nan,
    ngx_uint_t trunc, ngx_uint_t ans);
static void ngx_resolver_process_ptr(ngx_resolver_t *r, u_char *buf, size_t n,
    ngx_uint_t ident, ngx_uint_t code, ngx_uint_t nan);
static ngx_resolver_node_t *ngx_resolver_lookup_name(ngx_resolver_t *r,
    ngx_str_t *name, uint32_t hash);
static ngx_resolver_node_t *ngx_resolver_lookup_srv(ngx_resolver_t *r,
    ngx_str_t *name, uint32_t hash);
static ngx_resolver_node_t *ngx_resolver_lookup_addr(ngx_resolver_t *r,
    in_addr_t addr);
static void ngx_resolver_rbtree_insert_value(ngx_rbtree_node_t *temp,
    ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel);
static ngx_int_t ngx_resolver_copy(ngx_resolver_t *r, ngx_str_t *name,
    u_char *buf, u_char *src, u_char *last);
static ngx_int_t ngx_resolver_set_timeout(ngx_resolver_t *r,
    ngx_resolver_ctx_t *ctx);
static void ngx_resolver_timeout_handler(ngx_event_t *ev);
static void ngx_resolver_free_node(ngx_resolver_t *r, ngx_resolver_node_t *rn);
static void *ngx_resolver_alloc(ngx_resolver_t *r, size_t size);
static void *ngx_resolver_calloc(ngx_resolver_t *r, size_t size);
static void ngx_resolver_free(ngx_resolver_t *r, void *p);
static void ngx_resolver_free_locked(ngx_resolver_t *r, void *p);
static void *ngx_resolver_dup(ngx_resolver_t *r, void *src, size_t size);
static ngx_resolver_addr_t *ngx_resolver_export(ngx_resolver_t *r,
    ngx_resolver_node_t *rn, ngx_uint_t rotate);
static void ngx_resolver_report_srv(ngx_resolver_t *r, ngx_resolver_ctx_t *ctx);
static u_char *ngx_resolver_log_error(ngx_log_t *log, u_char *buf, size_t len);
static void ngx_resolver_resolve_srv_names(ngx_resolver_ctx_t *ctx,
    ngx_resolver_node_t *rn);
static void ngx_resolver_srv_names_handler(ngx_resolver_ctx_t *ctx);
static ngx_int_t ngx_resolver_cmp_srvs(const void *one, const void *two);

#if (NGX_HAVE_INET6)
static void ngx_resolver_rbtree_insert_addr6_value(ngx_rbtree_node_t *temp,
    ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel);
static ngx_resolver_node_t *ngx_resolver_lookup_addr6(ngx_resolver_t *r,
    struct in6_addr *addr, uint32_t hash);
#endif


ngx_resolver_t *
ngx_resolver_create(ngx_conf_t *cf, ngx_str_t *names, ngx_uint_t n)
{ … }


static void
ngx_resolver_cleanup(void *data)
{ … }


static void
ngx_resolver_cleanup_tree(ngx_resolver_t *r, ngx_rbtree_t *tree)
{ … }


ngx_resolver_ctx_t *
ngx_resolve_start(ngx_resolver_t *r, ngx_resolver_ctx_t *temp)
{ … }


ngx_int_t
ngx_resolve_name(ngx_resolver_ctx_t *ctx)
{ … }


void
ngx_resolve_name_done(ngx_resolver_ctx_t *ctx)
{ … }


static ngx_int_t
ngx_resolve_name_locked(ngx_resolver_t *r, ngx_resolver_ctx_t *ctx,
    ngx_str_t *name)
{ … }


ngx_int_t
ngx_resolve_addr(ngx_resolver_ctx_t *ctx)
{ … }


void
ngx_resolve_addr_done(ngx_resolver_ctx_t *ctx)
{ … }


static void
ngx_resolver_expire(ngx_resolver_t *r, ngx_rbtree_t *tree, ngx_queue_t *queue)
{ … }


static ngx_int_t
ngx_resolver_send_query(ngx_resolver_t *r, ngx_resolver_node_t *rn)
{ … }


static ngx_int_t
ngx_resolver_send_udp_query(ngx_resolver_t *r, ngx_resolver_connection_t  *rec,
    u_char *query, u_short qlen)
{ … }


static ngx_int_t
ngx_resolver_send_tcp_query(ngx_resolver_t *r, ngx_resolver_connection_t *rec,
    u_char *query, u_short qlen)
{ … }


static void
ngx_resolver_resend_handler(ngx_event_t *ev)
{ … }


static time_t
ngx_resolver_resend(ngx_resolver_t *r, ngx_rbtree_t *tree, ngx_queue_t *queue)
{ … }


static ngx_uint_t
ngx_resolver_resend_empty(ngx_resolver_t *r)
{ … }


static void
ngx_resolver_udp_read(ngx_event_t *rev)
{ … }


static void
ngx_resolver_tcp_write(ngx_event_t *wev)
{ … }


static void
ngx_resolver_tcp_read(ngx_event_t *rev)
{ … }


static void
ngx_resolver_process_response(ngx_resolver_t *r, u_char *buf, size_t n,
    ngx_uint_t tcp)
{ … }


static void
ngx_resolver_process_a(ngx_resolver_t *r, u_char *buf, size_t n,
    ngx_uint_t ident, ngx_uint_t code, ngx_uint_t qtype,
    ngx_uint_t nan, ngx_uint_t trunc, ngx_uint_t ans)
{ … }


static void
ngx_resolver_process_srv(ngx_resolver_t *r, u_char *buf, size_t n,
    ngx_uint_t ident, ngx_uint_t code, ngx_uint_t nan,
    ngx_uint_t trunc, ngx_uint_t ans)
{ … }


static void
ngx_resolver_resolve_srv_names(ngx_resolver_ctx_t *ctx, ngx_resolver_node_t *rn)
{ … }


static void
ngx_resolver_srv_names_handler(ngx_resolver_ctx_t *cctx)
{ … }


static void
ngx_resolver_process_ptr(ngx_resolver_t *r, u_char *buf, size_t n,
    ngx_uint_t ident, ngx_uint_t code, ngx_uint_t nan)
{ … }


static ngx_resolver_node_t *
ngx_resolver_lookup_name(ngx_resolver_t *r, ngx_str_t *name, uint32_t hash)
{ … }


static ngx_resolver_node_t *
ngx_resolver_lookup_srv(ngx_resolver_t *r, ngx_str_t *name, uint32_t hash)
{ … }


static ngx_resolver_node_t *
ngx_resolver_lookup_addr(ngx_resolver_t *r, in_addr_t addr)
{ … }


#if (NGX_HAVE_INET6)

static ngx_resolver_node_t *
ngx_resolver_lookup_addr6(ngx_resolver_t *r, struct in6_addr *addr,
    uint32_t hash)
{ … }

#endif


static void
ngx_resolver_rbtree_insert_value(ngx_rbtree_node_t *temp,
    ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel)
{ … }


#if (NGX_HAVE_INET6)

static void
ngx_resolver_rbtree_insert_addr6_value(ngx_rbtree_node_t *temp,
    ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel)
{ … }

#endif


static ngx_int_t
ngx_resolver_create_name_query(ngx_resolver_t *r, ngx_resolver_node_t *rn,
    ngx_str_t *name)
{ … }


static ngx_int_t
ngx_resolver_create_srv_query(ngx_resolver_t *r, ngx_resolver_node_t *rn,
    ngx_str_t *name)
{ … }


static ngx_int_t
ngx_resolver_create_addr_query(ngx_resolver_t *r, ngx_resolver_node_t *rn,
    ngx_resolver_addr_t *addr)
{ … }


static ngx_int_t
ngx_resolver_copy(ngx_resolver_t *r, ngx_str_t *name, u_char *buf, u_char *src,
    u_char *last)
{ … }


static ngx_int_t
ngx_resolver_set_timeout(ngx_resolver_t *r, ngx_resolver_ctx_t *ctx)
{ … }


static void
ngx_resolver_timeout_handler(ngx_event_t *ev)
{ … }


static void
ngx_resolver_free_node(ngx_resolver_t *r, ngx_resolver_node_t *rn)
{ … }


static void *
ngx_resolver_alloc(ngx_resolver_t *r, size_t size)
{ … }


static void *
ngx_resolver_calloc(ngx_resolver_t *r, size_t size)
{ … }


static void
ngx_resolver_free(ngx_resolver_t *r, void *p)
{ … }


static void
ngx_resolver_free_locked(ngx_resolver_t *r, void *p)
{ … }


static void *
ngx_resolver_dup(ngx_resolver_t *r, void *src, size_t size)
{ … }


static ngx_resolver_addr_t *
ngx_resolver_export(ngx_resolver_t *r, ngx_resolver_node_t *rn,
    ngx_uint_t rotate)
{ … }


static void
ngx_resolver_report_srv(ngx_resolver_t *r, ngx_resolver_ctx_t *ctx)
{ … }


char *
ngx_resolver_strerror(ngx_int_t err)
{ … }


static u_char *
ngx_resolver_log_error(ngx_log_t *log, u_char *buf, size_t len)
{ … }


static ngx_int_t
ngx_udp_connect(ngx_resolver_connection_t *rec)
{ … }


static ngx_int_t
ngx_tcp_connect(ngx_resolver_connection_t *rec)
{ … }


static ngx_int_t
ngx_resolver_cmp_srvs(const void *one, const void *two)
{ … }