|  | 
 | /* | 
 |  * 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   4096 | 
 |  | 
 |  | 
 | typedef struct { | 
 |     u_char  ident_hi; | 
 |     u_char  ident_lo; | 
 |     u_char  flags_hi; | 
 |     u_char  flags_lo; | 
 |     u_char  nqs_hi; | 
 |     u_char  nqs_lo; | 
 |     u_char  nan_hi; | 
 |     u_char  nan_lo; | 
 |     u_char  nns_hi; | 
 |     u_char  nns_lo; | 
 |     u_char  nar_hi; | 
 |     u_char  nar_lo; | 
 | } ngx_resolver_hdr_t; | 
 |  | 
 |  | 
 | typedef struct { | 
 |     u_char  type_hi; | 
 |     u_char  type_lo; | 
 |     u_char  class_hi; | 
 |     u_char  class_lo; | 
 | } ngx_resolver_qs_t; | 
 |  | 
 |  | 
 | typedef struct { | 
 |     u_char  type_hi; | 
 |     u_char  type_lo; | 
 |     u_char  class_hi; | 
 |     u_char  class_lo; | 
 |     u_char  ttl[4]; | 
 |     u_char  len_hi; | 
 |     u_char  len_lo; | 
 | } ngx_resolver_an_t; | 
 |  | 
 |  | 
 | #define ngx_resolver_node(n)                                                 \ | 
 |     (ngx_resolver_node_t *)                                                  \ | 
 |         ((u_char *) (n) - offsetof(ngx_resolver_node_t, node)) | 
 |  | 
 |  | 
 | ngx_int_t ngx_udp_connect(ngx_udp_connection_t *uc); | 
 |  | 
 |  | 
 | 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); | 
 | 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_create_name_query(ngx_resolver_node_t *rn, | 
 |     ngx_resolver_ctx_t *ctx); | 
 | static ngx_int_t ngx_resolver_create_addr_query(ngx_resolver_node_t *rn, | 
 |     ngx_resolver_ctx_t *ctx); | 
 | 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_read_response(ngx_event_t *rev); | 
 | static void ngx_resolver_process_response(ngx_resolver_t *r, u_char *buf, | 
 |     size_t n); | 
 | 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 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_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 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_addr_t *ngx_resolver_export(ngx_resolver_t *r, | 
 |     ngx_resolver_node_t *rn, ngx_uint_t rotate); | 
 | static u_char *ngx_resolver_log_error(ngx_log_t *log, u_char *buf, size_t len); | 
 |  | 
 | #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) | 
 | { | 
 |     ngx_str_t              s; | 
 |     ngx_url_t              u; | 
 |     ngx_uint_t             i, j; | 
 |     ngx_resolver_t        *r; | 
 |     ngx_pool_cleanup_t    *cln; | 
 |     ngx_udp_connection_t  *uc; | 
 |  | 
 |     cln = ngx_pool_cleanup_add(cf->pool, 0); | 
 |     if (cln == NULL) { | 
 |         return NULL; | 
 |     } | 
 |  | 
 |     cln->handler = ngx_resolver_cleanup; | 
 |  | 
 |     r = ngx_calloc(sizeof(ngx_resolver_t), cf->log); | 
 |     if (r == NULL) { | 
 |         return NULL; | 
 |     } | 
 |  | 
 |     cln->data = r; | 
 |  | 
 |     r->event = ngx_calloc(sizeof(ngx_event_t), cf->log); | 
 |     if (r->event == NULL) { | 
 |         return NULL; | 
 |     } | 
 |  | 
 |     ngx_rbtree_init(&r->name_rbtree, &r->name_sentinel, | 
 |                     ngx_resolver_rbtree_insert_value); | 
 |  | 
 |     ngx_rbtree_init(&r->addr_rbtree, &r->addr_sentinel, | 
 |                     ngx_rbtree_insert_value); | 
 |  | 
 |     ngx_queue_init(&r->name_resend_queue); | 
 |     ngx_queue_init(&r->addr_resend_queue); | 
 |  | 
 |     ngx_queue_init(&r->name_expire_queue); | 
 |     ngx_queue_init(&r->addr_expire_queue); | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |     r->ipv6 = 1; | 
 |  | 
 |     ngx_rbtree_init(&r->addr6_rbtree, &r->addr6_sentinel, | 
 |                     ngx_resolver_rbtree_insert_addr6_value); | 
 |  | 
 |     ngx_queue_init(&r->addr6_resend_queue); | 
 |  | 
 |     ngx_queue_init(&r->addr6_expire_queue); | 
 | #endif | 
 |  | 
 |     r->event->handler = ngx_resolver_resend_handler; | 
 |     r->event->data = r; | 
 |     r->event->log = &cf->cycle->new_log; | 
 |     r->ident = -1; | 
 |  | 
 |     r->resend_timeout = 5; | 
 |     r->expire = 30; | 
 |     r->valid = 0; | 
 |  | 
 |     r->log = &cf->cycle->new_log; | 
 |     r->log_level = NGX_LOG_ERR; | 
 |  | 
 |     if (n) { | 
 |         if (ngx_array_init(&r->udp_connections, cf->pool, n, | 
 |                            sizeof(ngx_udp_connection_t)) | 
 |             != NGX_OK) | 
 |         { | 
 |             return NULL; | 
 |         } | 
 |     } | 
 |  | 
 |     for (i = 0; i < n; i++) { | 
 |         if (ngx_strncmp(names[i].data, "valid=", 6) == 0) { | 
 |             s.len = names[i].len - 6; | 
 |             s.data = names[i].data + 6; | 
 |  | 
 |             r->valid = ngx_parse_time(&s, 1); | 
 |  | 
 |             if (r->valid == (time_t) NGX_ERROR) { | 
 |                 ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, | 
 |                                    "invalid parameter: %V", &names[i]); | 
 |                 return NULL; | 
 |             } | 
 |  | 
 |             continue; | 
 |         } | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |         if (ngx_strncmp(names[i].data, "ipv6=", 5) == 0) { | 
 |  | 
 |             if (ngx_strcmp(&names[i].data[5], "on") == 0) { | 
 |                 r->ipv6 = 1; | 
 |  | 
 |             } else if (ngx_strcmp(&names[i].data[5], "off") == 0) { | 
 |                 r->ipv6 = 0; | 
 |  | 
 |             } else { | 
 |                 ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, | 
 |                                    "invalid parameter: %V", &names[i]); | 
 |                 return NULL; | 
 |             } | 
 |  | 
 |             continue; | 
 |         } | 
 | #endif | 
 |  | 
 |         ngx_memzero(&u, sizeof(ngx_url_t)); | 
 |  | 
 |         u.url = names[i]; | 
 |         u.default_port = 53; | 
 |  | 
 |         if (ngx_parse_url(cf->pool, &u) != NGX_OK) { | 
 |             if (u.err) { | 
 |                 ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, | 
 |                                    "%s in resolver \"%V\"", | 
 |                                    u.err, &u.url); | 
 |             } | 
 |  | 
 |             return NULL; | 
 |         } | 
 |  | 
 |         uc = ngx_array_push_n(&r->udp_connections, u.naddrs); | 
 |         if (uc == NULL) { | 
 |             return NULL; | 
 |         } | 
 |  | 
 |         ngx_memzero(uc, u.naddrs * sizeof(ngx_udp_connection_t)); | 
 |  | 
 |         for (j = 0; j < u.naddrs; j++) { | 
 |             uc[j].sockaddr = u.addrs[j].sockaddr; | 
 |             uc[j].socklen = u.addrs[j].socklen; | 
 |             uc[j].server = u.addrs[j].name; | 
 |         } | 
 |     } | 
 |  | 
 |     return r; | 
 | } | 
 |  | 
 |  | 
 | static void | 
 | ngx_resolver_cleanup(void *data) | 
 | { | 
 |     ngx_resolver_t  *r = data; | 
 |  | 
 |     ngx_uint_t             i; | 
 |     ngx_udp_connection_t  *uc; | 
 |  | 
 |     if (r) { | 
 |         ngx_log_debug0(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0, | 
 |                        "cleanup resolver"); | 
 |  | 
 |         ngx_resolver_cleanup_tree(r, &r->name_rbtree); | 
 |  | 
 |         ngx_resolver_cleanup_tree(r, &r->addr_rbtree); | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |         ngx_resolver_cleanup_tree(r, &r->addr6_rbtree); | 
 | #endif | 
 |  | 
 |         if (r->event) { | 
 |             ngx_free(r->event); | 
 |         } | 
 |  | 
 |  | 
 |         uc = r->udp_connections.elts; | 
 |  | 
 |         for (i = 0; i < r->udp_connections.nelts; i++) { | 
 |             if (uc[i].connection) { | 
 |                 ngx_close_connection(uc[i].connection); | 
 |             } | 
 |         } | 
 |  | 
 |         ngx_free(r); | 
 |     } | 
 | } | 
 |  | 
 |  | 
 | static void | 
 | ngx_resolver_cleanup_tree(ngx_resolver_t *r, ngx_rbtree_t *tree) | 
 | { | 
 |     ngx_resolver_ctx_t   *ctx, *next; | 
 |     ngx_resolver_node_t  *rn; | 
 |  | 
 |     while (tree->root != tree->sentinel) { | 
 |  | 
 |         rn = ngx_resolver_node(ngx_rbtree_min(tree->root, tree->sentinel)); | 
 |  | 
 |         ngx_queue_remove(&rn->queue); | 
 |  | 
 |         for (ctx = rn->waiting; ctx; ctx = next) { | 
 |             next = ctx->next; | 
 |  | 
 |             if (ctx->event) { | 
 |                 ngx_resolver_free(r, ctx->event); | 
 |             } | 
 |  | 
 |             ngx_resolver_free(r, ctx); | 
 |         } | 
 |  | 
 |         ngx_rbtree_delete(tree, &rn->node); | 
 |  | 
 |         ngx_resolver_free_node(r, rn); | 
 |     } | 
 | } | 
 |  | 
 |  | 
 | ngx_resolver_ctx_t * | 
 | ngx_resolve_start(ngx_resolver_t *r, ngx_resolver_ctx_t *temp) | 
 | { | 
 |     in_addr_t            addr; | 
 |     ngx_resolver_ctx_t  *ctx; | 
 |  | 
 |     if (temp) { | 
 |         addr = ngx_inet_addr(temp->name.data, temp->name.len); | 
 |  | 
 |         if (addr != INADDR_NONE) { | 
 |             temp->resolver = r; | 
 |             temp->state = NGX_OK; | 
 |             temp->naddrs = 1; | 
 |             temp->addrs = &temp->addr; | 
 |             temp->addr.sockaddr = (struct sockaddr *) &temp->sin; | 
 |             temp->addr.socklen = sizeof(struct sockaddr_in); | 
 |             ngx_memzero(&temp->sin, sizeof(struct sockaddr_in)); | 
 |             temp->sin.sin_family = AF_INET; | 
 |             temp->sin.sin_addr.s_addr = addr; | 
 |             temp->quick = 1; | 
 |  | 
 |             return temp; | 
 |         } | 
 |     } | 
 |  | 
 |     if (r->udp_connections.nelts == 0) { | 
 |         return NGX_NO_RESOLVER; | 
 |     } | 
 |  | 
 |     ctx = ngx_resolver_calloc(r, sizeof(ngx_resolver_ctx_t)); | 
 |  | 
 |     if (ctx) { | 
 |         ctx->resolver = r; | 
 |     } | 
 |  | 
 |     return ctx; | 
 | } | 
 |  | 
 |  | 
 | ngx_int_t | 
 | ngx_resolve_name(ngx_resolver_ctx_t *ctx) | 
 | { | 
 |     ngx_int_t        rc; | 
 |     ngx_resolver_t  *r; | 
 |  | 
 |     r = ctx->resolver; | 
 |  | 
 |     if (ctx->name.len > 0 && ctx->name.data[ctx->name.len - 1] == '.') { | 
 |         ctx->name.len--; | 
 |     } | 
 |  | 
 |     ngx_log_debug1(NGX_LOG_DEBUG_CORE, r->log, 0, | 
 |                    "resolve: \"%V\"", &ctx->name); | 
 |  | 
 |     if (ctx->quick) { | 
 |         ctx->handler(ctx); | 
 |         return NGX_OK; | 
 |     } | 
 |  | 
 |     /* lock name mutex */ | 
 |  | 
 |     rc = ngx_resolve_name_locked(r, ctx); | 
 |  | 
 |     if (rc == NGX_OK) { | 
 |         return NGX_OK; | 
 |     } | 
 |  | 
 |     /* unlock name mutex */ | 
 |  | 
 |     if (rc == NGX_AGAIN) { | 
 |         return NGX_OK; | 
 |     } | 
 |  | 
 |     /* NGX_ERROR */ | 
 |  | 
 |     if (ctx->event) { | 
 |         ngx_resolver_free(r, ctx->event); | 
 |     } | 
 |  | 
 |     ngx_resolver_free(r, ctx); | 
 |  | 
 |     return NGX_ERROR; | 
 | } | 
 |  | 
 |  | 
 | void | 
 | ngx_resolve_name_done(ngx_resolver_ctx_t *ctx) | 
 | { | 
 |     uint32_t              hash; | 
 |     ngx_resolver_t       *r; | 
 |     ngx_resolver_ctx_t   *w, **p; | 
 |     ngx_resolver_node_t  *rn; | 
 |  | 
 |     r = ctx->resolver; | 
 |  | 
 |     ngx_log_debug1(NGX_LOG_DEBUG_CORE, r->log, 0, | 
 |                    "resolve name done: %i", ctx->state); | 
 |  | 
 |     if (ctx->quick) { | 
 |         return; | 
 |     } | 
 |  | 
 |     if (ctx->event && ctx->event->timer_set) { | 
 |         ngx_del_timer(ctx->event); | 
 |     } | 
 |  | 
 |     /* lock name mutex */ | 
 |  | 
 |     if (ctx->state == NGX_AGAIN) { | 
 |  | 
 |         hash = ngx_crc32_short(ctx->name.data, ctx->name.len); | 
 |  | 
 |         rn = ngx_resolver_lookup_name(r, &ctx->name, hash); | 
 |  | 
 |         if (rn) { | 
 |             p = &rn->waiting; | 
 |             w = rn->waiting; | 
 |  | 
 |             while (w) { | 
 |                 if (w == ctx) { | 
 |                     *p = w->next; | 
 |  | 
 |                     goto done; | 
 |                 } | 
 |  | 
 |                 p = &w->next; | 
 |                 w = w->next; | 
 |             } | 
 |         } | 
 |  | 
 |         ngx_log_error(NGX_LOG_ALERT, r->log, 0, | 
 |                       "could not cancel %V resolving", &ctx->name); | 
 |     } | 
 |  | 
 | done: | 
 |  | 
 |     ngx_resolver_expire(r, &r->name_rbtree, &r->name_expire_queue); | 
 |  | 
 |     /* unlock name mutex */ | 
 |  | 
 |     /* lock alloc mutex */ | 
 |  | 
 |     if (ctx->event) { | 
 |         ngx_resolver_free_locked(r, ctx->event); | 
 |     } | 
 |  | 
 |     ngx_resolver_free_locked(r, ctx); | 
 |  | 
 |     /* unlock alloc mutex */ | 
 |  | 
 |     if (r->event->timer_set && ngx_resolver_resend_empty(r)) { | 
 |         ngx_del_timer(r->event); | 
 |     } | 
 | } | 
 |  | 
 |  | 
 | static ngx_int_t | 
 | ngx_resolve_name_locked(ngx_resolver_t *r, ngx_resolver_ctx_t *ctx) | 
 | { | 
 |     uint32_t              hash; | 
 |     ngx_int_t             rc; | 
 |     ngx_uint_t            naddrs; | 
 |     ngx_addr_t           *addrs; | 
 |     ngx_resolver_ctx_t   *next; | 
 |     ngx_resolver_node_t  *rn; | 
 |  | 
 |     ngx_strlow(ctx->name.data, ctx->name.data, ctx->name.len); | 
 |  | 
 |     hash = ngx_crc32_short(ctx->name.data, ctx->name.len); | 
 |  | 
 |     rn = ngx_resolver_lookup_name(r, &ctx->name, hash); | 
 |  | 
 |     if (rn) { | 
 |  | 
 |         if (rn->valid >= ngx_time()) { | 
 |  | 
 |             ngx_log_debug0(NGX_LOG_DEBUG_CORE, r->log, 0, "resolve cached"); | 
 |  | 
 |             ngx_queue_remove(&rn->queue); | 
 |  | 
 |             rn->expire = ngx_time() + r->expire; | 
 |  | 
 |             ngx_queue_insert_head(&r->name_expire_queue, &rn->queue); | 
 |  | 
 |             naddrs = (rn->naddrs == (u_short) -1) ? 0 : rn->naddrs; | 
 | #if (NGX_HAVE_INET6) | 
 |             naddrs += (rn->naddrs6 == (u_short) -1) ? 0 : rn->naddrs6; | 
 | #endif | 
 |  | 
 |             if (naddrs) { | 
 |  | 
 |                 if (naddrs == 1 && rn->naddrs == 1) { | 
 |                     addrs = NULL; | 
 |  | 
 |                 } else { | 
 |                     addrs = ngx_resolver_export(r, rn, 1); | 
 |                     if (addrs == NULL) { | 
 |                         return NGX_ERROR; | 
 |                     } | 
 |                 } | 
 |  | 
 |                 ctx->next = rn->waiting; | 
 |                 rn->waiting = NULL; | 
 |  | 
 |                 /* unlock name mutex */ | 
 |  | 
 |                 do { | 
 |                     ctx->state = NGX_OK; | 
 |                     ctx->naddrs = naddrs; | 
 |  | 
 |                     if (addrs == NULL) { | 
 |                         ctx->addrs = &ctx->addr; | 
 |                         ctx->addr.sockaddr = (struct sockaddr *) &ctx->sin; | 
 |                         ctx->addr.socklen = sizeof(struct sockaddr_in); | 
 |                         ngx_memzero(&ctx->sin, sizeof(struct sockaddr_in)); | 
 |                         ctx->sin.sin_family = AF_INET; | 
 |                         ctx->sin.sin_addr.s_addr = rn->u.addr; | 
 |  | 
 |                     } else { | 
 |                         ctx->addrs = addrs; | 
 |                     } | 
 |  | 
 |                     next = ctx->next; | 
 |  | 
 |                     ctx->handler(ctx); | 
 |  | 
 |                     ctx = next; | 
 |                 } while (ctx); | 
 |  | 
 |                 if (addrs != NULL) { | 
 |                     ngx_resolver_free(r, addrs->sockaddr); | 
 |                     ngx_resolver_free(r, addrs); | 
 |                 } | 
 |  | 
 |                 return NGX_OK; | 
 |             } | 
 |  | 
 |             /* NGX_RESOLVE_CNAME */ | 
 |  | 
 |             if (ctx->recursion++ < NGX_RESOLVER_MAX_RECURSION) { | 
 |  | 
 |                 ctx->name.len = rn->cnlen; | 
 |                 ctx->name.data = rn->u.cname; | 
 |  | 
 |                 return ngx_resolve_name_locked(r, ctx); | 
 |             } | 
 |  | 
 |             ctx->next = rn->waiting; | 
 |             rn->waiting = NULL; | 
 |  | 
 |             /* unlock name mutex */ | 
 |  | 
 |             do { | 
 |                 ctx->state = NGX_RESOLVE_NXDOMAIN; | 
 |                 next = ctx->next; | 
 |  | 
 |                 ctx->handler(ctx); | 
 |  | 
 |                 ctx = next; | 
 |             } while (ctx); | 
 |  | 
 |             return NGX_OK; | 
 |         } | 
 |  | 
 |         if (rn->waiting) { | 
 |  | 
 |             ctx->next = rn->waiting; | 
 |             rn->waiting = ctx; | 
 |             ctx->state = NGX_AGAIN; | 
 |  | 
 |             return NGX_AGAIN; | 
 |         } | 
 |  | 
 |         ngx_queue_remove(&rn->queue); | 
 |  | 
 |         /* lock alloc mutex */ | 
 |  | 
 |         if (rn->query) { | 
 |             ngx_resolver_free_locked(r, rn->query); | 
 |             rn->query = NULL; | 
 | #if (NGX_HAVE_INET6) | 
 |             rn->query6 = NULL; | 
 | #endif | 
 |         } | 
 |  | 
 |         if (rn->cnlen) { | 
 |             ngx_resolver_free_locked(r, rn->u.cname); | 
 |         } | 
 |  | 
 |         if (rn->naddrs > 1 && rn->naddrs != (u_short) -1) { | 
 |             ngx_resolver_free_locked(r, rn->u.addrs); | 
 |         } | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |         if (rn->naddrs6 > 1 && rn->naddrs6 != (u_short) -1) { | 
 |             ngx_resolver_free_locked(r, rn->u6.addrs6); | 
 |         } | 
 | #endif | 
 |  | 
 |         /* unlock alloc mutex */ | 
 |  | 
 |     } else { | 
 |  | 
 |         rn = ngx_resolver_alloc(r, sizeof(ngx_resolver_node_t)); | 
 |         if (rn == NULL) { | 
 |             return NGX_ERROR; | 
 |         } | 
 |  | 
 |         rn->name = ngx_resolver_dup(r, ctx->name.data, ctx->name.len); | 
 |         if (rn->name == NULL) { | 
 |             ngx_resolver_free(r, rn); | 
 |             return NGX_ERROR; | 
 |         } | 
 |  | 
 |         rn->node.key = hash; | 
 |         rn->nlen = (u_short) ctx->name.len; | 
 |         rn->query = NULL; | 
 | #if (NGX_HAVE_INET6) | 
 |         rn->query6 = NULL; | 
 | #endif | 
 |  | 
 |         ngx_rbtree_insert(&r->name_rbtree, &rn->node); | 
 |     } | 
 |  | 
 |     rc = ngx_resolver_create_name_query(rn, ctx); | 
 |  | 
 |     if (rc == NGX_ERROR) { | 
 |         goto failed; | 
 |     } | 
 |  | 
 |     if (rc == NGX_DECLINED) { | 
 |         ngx_rbtree_delete(&r->name_rbtree, &rn->node); | 
 |  | 
 |         ngx_resolver_free(r, rn->query); | 
 |         ngx_resolver_free(r, rn->name); | 
 |         ngx_resolver_free(r, rn); | 
 |  | 
 |         ctx->state = NGX_RESOLVE_NXDOMAIN; | 
 |         ctx->handler(ctx); | 
 |  | 
 |         return NGX_OK; | 
 |     } | 
 |  | 
 |     rn->naddrs = (u_short) -1; | 
 | #if (NGX_HAVE_INET6) | 
 |     rn->naddrs6 = r->ipv6 ? (u_short) -1 : 0; | 
 | #endif | 
 |  | 
 |     if (ngx_resolver_send_query(r, rn) != NGX_OK) { | 
 |         goto failed; | 
 |     } | 
 |  | 
 |     if (ctx->event == NULL) { | 
 |         ctx->event = ngx_resolver_calloc(r, sizeof(ngx_event_t)); | 
 |         if (ctx->event == NULL) { | 
 |             goto failed; | 
 |         } | 
 |  | 
 |         ctx->event->handler = ngx_resolver_timeout_handler; | 
 |         ctx->event->data = rn; | 
 |         ctx->event->log = r->log; | 
 |         rn->ident = -1; | 
 |  | 
 |         ngx_add_timer(ctx->event, ctx->timeout); | 
 |     } | 
 |  | 
 |     if (ngx_queue_empty(&r->name_resend_queue)) { | 
 |         ngx_add_timer(r->event, (ngx_msec_t) (r->resend_timeout * 1000)); | 
 |     } | 
 |  | 
 |     rn->expire = ngx_time() + r->resend_timeout; | 
 |  | 
 |     ngx_queue_insert_head(&r->name_resend_queue, &rn->queue); | 
 |  | 
 |     rn->code = 0; | 
 |     rn->cnlen = 0; | 
 |     rn->valid = 0; | 
 |     rn->ttl = NGX_MAX_UINT32_VALUE; | 
 |     rn->waiting = ctx; | 
 |  | 
 |     ctx->state = NGX_AGAIN; | 
 |  | 
 |     return NGX_AGAIN; | 
 |  | 
 | failed: | 
 |  | 
 |     ngx_rbtree_delete(&r->name_rbtree, &rn->node); | 
 |  | 
 |     if (rn->query) { | 
 |         ngx_resolver_free(r, rn->query); | 
 |     } | 
 |  | 
 |     ngx_resolver_free(r, rn->name); | 
 |  | 
 |     ngx_resolver_free(r, rn); | 
 |  | 
 |     return NGX_ERROR; | 
 | } | 
 |  | 
 |  | 
 | ngx_int_t | 
 | ngx_resolve_addr(ngx_resolver_ctx_t *ctx) | 
 | { | 
 |     u_char               *name; | 
 |     in_addr_t             addr; | 
 |     ngx_queue_t          *resend_queue, *expire_queue; | 
 |     ngx_rbtree_t         *tree; | 
 |     ngx_resolver_t       *r; | 
 |     struct sockaddr_in   *sin; | 
 |     ngx_resolver_node_t  *rn; | 
 | #if (NGX_HAVE_INET6) | 
 |     uint32_t              hash; | 
 |     struct sockaddr_in6  *sin6; | 
 | #endif | 
 |  | 
 | #if (NGX_SUPPRESS_WARN) | 
 |     addr = 0; | 
 | #if (NGX_HAVE_INET6) | 
 |     hash = 0; | 
 |     sin6 = NULL; | 
 | #endif | 
 | #endif | 
 |  | 
 |     r = ctx->resolver; | 
 |  | 
 |     switch (ctx->addr.sockaddr->sa_family) { | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |     case AF_INET6: | 
 |         sin6 = (struct sockaddr_in6 *) ctx->addr.sockaddr; | 
 |         hash = ngx_crc32_short(sin6->sin6_addr.s6_addr, 16); | 
 |  | 
 |         /* lock addr mutex */ | 
 |  | 
 |         rn = ngx_resolver_lookup_addr6(r, &sin6->sin6_addr, hash); | 
 |  | 
 |         tree = &r->addr6_rbtree; | 
 |         resend_queue = &r->addr6_resend_queue; | 
 |         expire_queue = &r->addr6_expire_queue; | 
 |  | 
 |         break; | 
 | #endif | 
 |  | 
 |     default: /* AF_INET */ | 
 |         sin = (struct sockaddr_in *) ctx->addr.sockaddr; | 
 |         addr = ntohl(sin->sin_addr.s_addr); | 
 |  | 
 |         /* lock addr mutex */ | 
 |  | 
 |         rn = ngx_resolver_lookup_addr(r, addr); | 
 |  | 
 |         tree = &r->addr_rbtree; | 
 |         resend_queue = &r->addr_resend_queue; | 
 |         expire_queue = &r->addr_expire_queue; | 
 |     } | 
 |  | 
 |     if (rn) { | 
 |  | 
 |         if (rn->valid >= ngx_time()) { | 
 |  | 
 |             ngx_log_debug0(NGX_LOG_DEBUG_CORE, r->log, 0, "resolve cached"); | 
 |  | 
 |             ngx_queue_remove(&rn->queue); | 
 |  | 
 |             rn->expire = ngx_time() + r->expire; | 
 |  | 
 |             ngx_queue_insert_head(expire_queue, &rn->queue); | 
 |  | 
 |             name = ngx_resolver_dup(r, rn->name, rn->nlen); | 
 |             if (name == NULL) { | 
 |                 goto failed; | 
 |             } | 
 |  | 
 |             ctx->name.len = rn->nlen; | 
 |             ctx->name.data = name; | 
 |  | 
 |             /* unlock addr mutex */ | 
 |  | 
 |             ctx->state = NGX_OK; | 
 |  | 
 |             ctx->handler(ctx); | 
 |  | 
 |             ngx_resolver_free(r, name); | 
 |  | 
 |             return NGX_OK; | 
 |         } | 
 |  | 
 |         if (rn->waiting) { | 
 |  | 
 |             ctx->next = rn->waiting; | 
 |             rn->waiting = ctx; | 
 |             ctx->state = NGX_AGAIN; | 
 |  | 
 |             /* unlock addr mutex */ | 
 |  | 
 |             return NGX_OK; | 
 |         } | 
 |  | 
 |         ngx_queue_remove(&rn->queue); | 
 |  | 
 |         ngx_resolver_free(r, rn->query); | 
 |         rn->query = NULL; | 
 | #if (NGX_HAVE_INET6) | 
 |         rn->query6 = NULL; | 
 | #endif | 
 |  | 
 |     } else { | 
 |         rn = ngx_resolver_alloc(r, sizeof(ngx_resolver_node_t)); | 
 |         if (rn == NULL) { | 
 |             goto failed; | 
 |         } | 
 |  | 
 |         switch (ctx->addr.sockaddr->sa_family) { | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |         case AF_INET6: | 
 |             rn->addr6 = sin6->sin6_addr; | 
 |             rn->node.key = hash; | 
 |             break; | 
 | #endif | 
 |  | 
 |         default: /* AF_INET */ | 
 |             rn->node.key = addr; | 
 |         } | 
 |  | 
 |         rn->query = NULL; | 
 | #if (NGX_HAVE_INET6) | 
 |         rn->query6 = NULL; | 
 | #endif | 
 |  | 
 |         ngx_rbtree_insert(tree, &rn->node); | 
 |     } | 
 |  | 
 |     if (ngx_resolver_create_addr_query(rn, ctx) != NGX_OK) { | 
 |         goto failed; | 
 |     } | 
 |  | 
 |     rn->naddrs = (u_short) -1; | 
 | #if (NGX_HAVE_INET6) | 
 |     rn->naddrs6 = (u_short) -1; | 
 | #endif | 
 |  | 
 |     if (ngx_resolver_send_query(r, rn) != NGX_OK) { | 
 |         goto failed; | 
 |     } | 
 |  | 
 |     ctx->event = ngx_resolver_calloc(r, sizeof(ngx_event_t)); | 
 |     if (ctx->event == NULL) { | 
 |         goto failed; | 
 |     } | 
 |  | 
 |     ctx->event->handler = ngx_resolver_timeout_handler; | 
 |     ctx->event->data = rn; | 
 |     ctx->event->log = r->log; | 
 |     rn->ident = -1; | 
 |  | 
 |     ngx_add_timer(ctx->event, ctx->timeout); | 
 |  | 
 |     if (ngx_queue_empty(resend_queue)) { | 
 |         ngx_add_timer(r->event, (ngx_msec_t) (r->resend_timeout * 1000)); | 
 |     } | 
 |  | 
 |     rn->expire = ngx_time() + r->resend_timeout; | 
 |  | 
 |     ngx_queue_insert_head(resend_queue, &rn->queue); | 
 |  | 
 |     rn->code = 0; | 
 |     rn->cnlen = 0; | 
 |     rn->name = NULL; | 
 |     rn->nlen = 0; | 
 |     rn->valid = 0; | 
 |     rn->ttl = NGX_MAX_UINT32_VALUE; | 
 |     rn->waiting = ctx; | 
 |  | 
 |     /* unlock addr mutex */ | 
 |  | 
 |     ctx->state = NGX_AGAIN; | 
 |  | 
 |     return NGX_OK; | 
 |  | 
 | failed: | 
 |  | 
 |     if (rn) { | 
 |         ngx_rbtree_delete(tree, &rn->node); | 
 |  | 
 |         if (rn->query) { | 
 |             ngx_resolver_free(r, rn->query); | 
 |         } | 
 |  | 
 |         ngx_resolver_free(r, rn); | 
 |     } | 
 |  | 
 |     /* unlock addr mutex */ | 
 |  | 
 |     if (ctx->event) { | 
 |         ngx_resolver_free(r, ctx->event); | 
 |     } | 
 |  | 
 |     ngx_resolver_free(r, ctx); | 
 |  | 
 |     return NGX_ERROR; | 
 | } | 
 |  | 
 |  | 
 | void | 
 | ngx_resolve_addr_done(ngx_resolver_ctx_t *ctx) | 
 | { | 
 |     in_addr_t             addr; | 
 |     ngx_queue_t          *expire_queue; | 
 |     ngx_rbtree_t         *tree; | 
 |     ngx_resolver_t       *r; | 
 |     ngx_resolver_ctx_t   *w, **p; | 
 |     struct sockaddr_in   *sin; | 
 |     ngx_resolver_node_t  *rn; | 
 | #if (NGX_HAVE_INET6) | 
 |     uint32_t              hash; | 
 |     struct sockaddr_in6  *sin6; | 
 | #endif | 
 |  | 
 |     r = ctx->resolver; | 
 |  | 
 |     switch (ctx->addr.sockaddr->sa_family) { | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |     case AF_INET6: | 
 |         tree = &r->addr6_rbtree; | 
 |         expire_queue = &r->addr6_expire_queue; | 
 |         break; | 
 | #endif | 
 |  | 
 |     default: /* AF_INET */ | 
 |         tree = &r->addr_rbtree; | 
 |         expire_queue = &r->addr_expire_queue; | 
 |     } | 
 |  | 
 |     ngx_log_debug1(NGX_LOG_DEBUG_CORE, r->log, 0, | 
 |                    "resolve addr done: %i", ctx->state); | 
 |  | 
 |     if (ctx->event && ctx->event->timer_set) { | 
 |         ngx_del_timer(ctx->event); | 
 |     } | 
 |  | 
 |     /* lock addr mutex */ | 
 |  | 
 |     if (ctx->state == NGX_AGAIN) { | 
 |  | 
 |         switch (ctx->addr.sockaddr->sa_family) { | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |         case AF_INET6: | 
 |             sin6 = (struct sockaddr_in6 *) ctx->addr.sockaddr; | 
 |             hash = ngx_crc32_short(sin6->sin6_addr.s6_addr, 16); | 
 |             rn = ngx_resolver_lookup_addr6(r, &sin6->sin6_addr, hash); | 
 |             break; | 
 | #endif | 
 |  | 
 |         default: /* AF_INET */ | 
 |             sin = (struct sockaddr_in *) ctx->addr.sockaddr; | 
 |             addr = ntohl(sin->sin_addr.s_addr); | 
 |             rn = ngx_resolver_lookup_addr(r, addr); | 
 |         } | 
 |  | 
 |         if (rn) { | 
 |             p = &rn->waiting; | 
 |             w = rn->waiting; | 
 |  | 
 |             while (w) { | 
 |                 if (w == ctx) { | 
 |                     *p = w->next; | 
 |  | 
 |                     goto done; | 
 |                 } | 
 |  | 
 |                 p = &w->next; | 
 |                 w = w->next; | 
 |             } | 
 |         } | 
 |  | 
 |         { | 
 |             u_char     text[NGX_SOCKADDR_STRLEN]; | 
 |             ngx_str_t  addrtext; | 
 |  | 
 |             addrtext.data = text; | 
 |             addrtext.len = ngx_sock_ntop(ctx->addr.sockaddr, ctx->addr.socklen, | 
 |                                          text, NGX_SOCKADDR_STRLEN, 0); | 
 |  | 
 |             ngx_log_error(NGX_LOG_ALERT, r->log, 0, | 
 |                           "could not cancel %V resolving", &addrtext); | 
 |         } | 
 |     } | 
 |  | 
 | done: | 
 |  | 
 |     ngx_resolver_expire(r, tree, expire_queue); | 
 |  | 
 |     /* unlock addr mutex */ | 
 |  | 
 |     /* lock alloc mutex */ | 
 |  | 
 |     if (ctx->event) { | 
 |         ngx_resolver_free_locked(r, ctx->event); | 
 |     } | 
 |  | 
 |     ngx_resolver_free_locked(r, ctx); | 
 |  | 
 |     /* unlock alloc mutex */ | 
 |  | 
 |     if (r->event->timer_set && ngx_resolver_resend_empty(r)) { | 
 |         ngx_del_timer(r->event); | 
 |     } | 
 | } | 
 |  | 
 |  | 
 | static void | 
 | ngx_resolver_expire(ngx_resolver_t *r, ngx_rbtree_t *tree, ngx_queue_t *queue) | 
 | { | 
 |     time_t                now; | 
 |     ngx_uint_t            i; | 
 |     ngx_queue_t          *q; | 
 |     ngx_resolver_node_t  *rn; | 
 |  | 
 |     ngx_log_debug0(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver expire"); | 
 |  | 
 |     now = ngx_time(); | 
 |  | 
 |     for (i = 0; i < 2; i++) { | 
 |         if (ngx_queue_empty(queue)) { | 
 |             return; | 
 |         } | 
 |  | 
 |         q = ngx_queue_last(queue); | 
 |  | 
 |         rn = ngx_queue_data(q, ngx_resolver_node_t, queue); | 
 |  | 
 |         if (now <= rn->expire) { | 
 |             return; | 
 |         } | 
 |  | 
 |         ngx_log_debug2(NGX_LOG_DEBUG_CORE, r->log, 0, | 
 |                        "resolver expire \"%*s\"", (size_t) rn->nlen, rn->name); | 
 |  | 
 |         ngx_queue_remove(q); | 
 |  | 
 |         ngx_rbtree_delete(tree, &rn->node); | 
 |  | 
 |         ngx_resolver_free_node(r, rn); | 
 |     } | 
 | } | 
 |  | 
 |  | 
 | static ngx_int_t | 
 | ngx_resolver_send_query(ngx_resolver_t *r, ngx_resolver_node_t *rn) | 
 | { | 
 |     ssize_t                n; | 
 |     ngx_udp_connection_t  *uc; | 
 |  | 
 |     uc = r->udp_connections.elts; | 
 |  | 
 |     uc = &uc[r->last_connection++]; | 
 |     if (r->last_connection == r->udp_connections.nelts) { | 
 |         r->last_connection = 0; | 
 |     } | 
 |  | 
 |     if (uc->connection == NULL) { | 
 |  | 
 |         uc->log = *r->log; | 
 |         uc->log.handler = ngx_resolver_log_error; | 
 |         uc->log.data = uc; | 
 |         uc->log.action = "resolving"; | 
 |  | 
 |         if (ngx_udp_connect(uc) != NGX_OK) { | 
 |             return NGX_ERROR; | 
 |         } | 
 |  | 
 |         uc->connection->data = r; | 
 |         uc->connection->read->handler = ngx_resolver_read_response; | 
 |         uc->connection->read->resolver = 1; | 
 |     } | 
 |  | 
 |     if (rn->naddrs == (u_short) -1) { | 
 |         n = ngx_send(uc->connection, rn->query, rn->qlen); | 
 |  | 
 |         if (n == -1) { | 
 |             return NGX_ERROR; | 
 |         } | 
 |  | 
 |         if ((size_t) n != (size_t) rn->qlen) { | 
 |             ngx_log_error(NGX_LOG_CRIT, &uc->log, 0, "send() incomplete"); | 
 |             return NGX_ERROR; | 
 |         } | 
 |     } | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |     if (rn->query6 && rn->naddrs6 == (u_short) -1) { | 
 |         n = ngx_send(uc->connection, rn->query6, rn->qlen); | 
 |  | 
 |         if (n == -1) { | 
 |             return NGX_ERROR; | 
 |         } | 
 |  | 
 |         if ((size_t) n != (size_t) rn->qlen) { | 
 |             ngx_log_error(NGX_LOG_CRIT, &uc->log, 0, "send() incomplete"); | 
 |             return NGX_ERROR; | 
 |         } | 
 |     } | 
 | #endif | 
 |  | 
 |     return NGX_OK; | 
 | } | 
 |  | 
 |  | 
 | static void | 
 | ngx_resolver_resend_handler(ngx_event_t *ev) | 
 | { | 
 |     time_t           timer, atimer, ntimer; | 
 | #if (NGX_HAVE_INET6) | 
 |     time_t           a6timer; | 
 | #endif | 
 |     ngx_resolver_t  *r; | 
 |  | 
 |     r = ev->data; | 
 |  | 
 |     ngx_log_debug0(NGX_LOG_DEBUG_CORE, r->log, 0, | 
 |                    "resolver resend handler"); | 
 |  | 
 |     /* lock name mutex */ | 
 |  | 
 |     ntimer = ngx_resolver_resend(r, &r->name_rbtree, &r->name_resend_queue); | 
 |  | 
 |     /* unlock name mutex */ | 
 |  | 
 |     /* lock addr mutex */ | 
 |  | 
 |     atimer = ngx_resolver_resend(r, &r->addr_rbtree, &r->addr_resend_queue); | 
 |  | 
 |     /* unlock addr mutex */ | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |  | 
 |     /* lock addr6 mutex */ | 
 |  | 
 |     a6timer = ngx_resolver_resend(r, &r->addr6_rbtree, &r->addr6_resend_queue); | 
 |  | 
 |     /* unlock addr6 mutex */ | 
 |  | 
 | #endif | 
 |  | 
 |     timer = ntimer; | 
 |  | 
 |     if (timer == 0) { | 
 |         timer = atimer; | 
 |  | 
 |     } else if (atimer) { | 
 |         timer = ngx_min(timer, atimer); | 
 |     } | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |  | 
 |     if (timer == 0) { | 
 |         timer = a6timer; | 
 |  | 
 |     } else if (a6timer) { | 
 |         timer = ngx_min(timer, a6timer); | 
 |     } | 
 |  | 
 | #endif | 
 |  | 
 |     if (timer) { | 
 |         ngx_add_timer(r->event, (ngx_msec_t) (timer * 1000)); | 
 |     } | 
 | } | 
 |  | 
 |  | 
 | static time_t | 
 | ngx_resolver_resend(ngx_resolver_t *r, ngx_rbtree_t *tree, ngx_queue_t *queue) | 
 | { | 
 |     time_t                now; | 
 |     ngx_queue_t          *q; | 
 |     ngx_resolver_node_t  *rn; | 
 |  | 
 |     now = ngx_time(); | 
 |  | 
 |     for ( ;; ) { | 
 |         if (ngx_queue_empty(queue)) { | 
 |             return 0; | 
 |         } | 
 |  | 
 |         q = ngx_queue_last(queue); | 
 |  | 
 |         rn = ngx_queue_data(q, ngx_resolver_node_t, queue); | 
 |  | 
 |         if (now < rn->expire) { | 
 |             return rn->expire - now; | 
 |         } | 
 |  | 
 |         ngx_log_debug3(NGX_LOG_DEBUG_CORE, r->log, 0, | 
 |                        "resolver resend \"%*s\" %p", | 
 |                        (size_t) rn->nlen, rn->name, rn->waiting); | 
 |  | 
 |         ngx_queue_remove(q); | 
 |  | 
 |         if (rn->waiting) { | 
 |  | 
 |             (void) ngx_resolver_send_query(r, rn); | 
 |  | 
 |             rn->expire = now + r->resend_timeout; | 
 |  | 
 |             ngx_queue_insert_head(queue, q); | 
 |  | 
 |             continue; | 
 |         } | 
 |  | 
 |         ngx_rbtree_delete(tree, &rn->node); | 
 |  | 
 |         ngx_resolver_free_node(r, rn); | 
 |     } | 
 | } | 
 |  | 
 |  | 
 | static ngx_uint_t | 
 | ngx_resolver_resend_empty(ngx_resolver_t *r) | 
 | { | 
 |     return ngx_queue_empty(&r->name_resend_queue) | 
 | #if (NGX_HAVE_INET6) | 
 |            && ngx_queue_empty(&r->addr6_resend_queue) | 
 | #endif | 
 |            && ngx_queue_empty(&r->addr_resend_queue); | 
 | } | 
 |  | 
 |  | 
 | static void | 
 | ngx_resolver_read_response(ngx_event_t *rev) | 
 | { | 
 |     ssize_t            n; | 
 |     ngx_connection_t  *c; | 
 |     u_char             buf[NGX_RESOLVER_UDP_SIZE]; | 
 |  | 
 |     c = rev->data; | 
 |  | 
 |     do { | 
 |         n = ngx_udp_recv(c, buf, NGX_RESOLVER_UDP_SIZE); | 
 |  | 
 |         if (n < 0) { | 
 |             return; | 
 |         } | 
 |  | 
 |         ngx_resolver_process_response(c->data, buf, n); | 
 |  | 
 |     } while (rev->ready); | 
 | } | 
 |  | 
 |  | 
 | static void | 
 | ngx_resolver_process_response(ngx_resolver_t *r, u_char *buf, size_t n) | 
 | { | 
 |     char                 *err; | 
 |     ngx_uint_t            i, times, ident, qident, flags, code, nqs, nan, | 
 |                           qtype, qclass; | 
 | #if (NGX_HAVE_INET6) | 
 |     ngx_uint_t            qident6; | 
 | #endif | 
 |     ngx_queue_t          *q; | 
 |     ngx_resolver_qs_t    *qs; | 
 |     ngx_resolver_hdr_t   *response; | 
 |     ngx_resolver_node_t  *rn; | 
 |  | 
 |     if (n < sizeof(ngx_resolver_hdr_t)) { | 
 |         goto short_response; | 
 |     } | 
 |  | 
 |     response = (ngx_resolver_hdr_t *) buf; | 
 |  | 
 |     ident = (response->ident_hi << 8) + response->ident_lo; | 
 |     flags = (response->flags_hi << 8) + response->flags_lo; | 
 |     nqs = (response->nqs_hi << 8) + response->nqs_lo; | 
 |     nan = (response->nan_hi << 8) + response->nan_lo; | 
 |  | 
 |     ngx_log_debug6(NGX_LOG_DEBUG_CORE, r->log, 0, | 
 |                    "resolver DNS response %ui fl:%04Xui %ui/%ui/%ud/%ud", | 
 |                    ident, flags, nqs, nan, | 
 |                    (response->nns_hi << 8) + response->nns_lo, | 
 |                    (response->nar_hi << 8) + response->nar_lo); | 
 |  | 
 |     /* response to a standard query */ | 
 |     if ((flags & 0xf870) != 0x8000) { | 
 |         ngx_log_error(r->log_level, r->log, 0, | 
 |                       "invalid DNS response %ui fl:%04Xui", ident, flags); | 
 |         return; | 
 |     } | 
 |  | 
 |     code = flags & 0xf; | 
 |  | 
 |     if (code == NGX_RESOLVE_FORMERR) { | 
 |  | 
 |         times = 0; | 
 |  | 
 |         for (q = ngx_queue_head(&r->name_resend_queue); | 
 |              q != ngx_queue_sentinel(&r->name_resend_queue) || times++ < 100; | 
 |              q = ngx_queue_next(q)) | 
 |         { | 
 |             rn = ngx_queue_data(q, ngx_resolver_node_t, queue); | 
 |             qident = (rn->query[0] << 8) + rn->query[1]; | 
 |  | 
 |             if (qident == ident) { | 
 |                 goto dns_error_name; | 
 |             } | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |             if (rn->query6) { | 
 |                 qident6 = (rn->query6[0] << 8) + rn->query6[1]; | 
 |  | 
 |                 if (qident6 == ident) { | 
 |                     goto dns_error_name; | 
 |                 } | 
 |             } | 
 | #endif | 
 |         } | 
 |  | 
 |         goto dns_error; | 
 |     } | 
 |  | 
 |     if (code > NGX_RESOLVE_REFUSED) { | 
 |         goto dns_error; | 
 |     } | 
 |  | 
 |     if (nqs != 1) { | 
 |         err = "invalid number of questions in DNS response"; | 
 |         goto done; | 
 |     } | 
 |  | 
 |     i = sizeof(ngx_resolver_hdr_t); | 
 |  | 
 |     while (i < (ngx_uint_t) n) { | 
 |         if (buf[i] == '\0') { | 
 |             goto found; | 
 |         } | 
 |  | 
 |         i += 1 + buf[i]; | 
 |     } | 
 |  | 
 |     goto short_response; | 
 |  | 
 | found: | 
 |  | 
 |     if (i++ == sizeof(ngx_resolver_hdr_t)) { | 
 |         err = "zero-length domain name in DNS response"; | 
 |         goto done; | 
 |     } | 
 |  | 
 |     if (i + sizeof(ngx_resolver_qs_t) + nan * (2 + sizeof(ngx_resolver_an_t)) | 
 |         > (ngx_uint_t) n) | 
 |     { | 
 |         goto short_response; | 
 |     } | 
 |  | 
 |     qs = (ngx_resolver_qs_t *) &buf[i]; | 
 |  | 
 |     qtype = (qs->type_hi << 8) + qs->type_lo; | 
 |     qclass = (qs->class_hi << 8) + qs->class_lo; | 
 |  | 
 |     ngx_log_debug2(NGX_LOG_DEBUG_CORE, r->log, 0, | 
 |                    "resolver DNS response qt:%ui cl:%ui", qtype, qclass); | 
 |  | 
 |     if (qclass != 1) { | 
 |         ngx_log_error(r->log_level, r->log, 0, | 
 |                       "unknown query class %ui in DNS response", qclass); | 
 |         return; | 
 |     } | 
 |  | 
 |     switch (qtype) { | 
 |  | 
 |     case NGX_RESOLVE_A: | 
 | #if (NGX_HAVE_INET6) | 
 |     case NGX_RESOLVE_AAAA: | 
 | #endif | 
 |  | 
 |         ngx_resolver_process_a(r, buf, n, ident, code, qtype, nan, | 
 |                                i + sizeof(ngx_resolver_qs_t)); | 
 |  | 
 |         break; | 
 |  | 
 |     case NGX_RESOLVE_PTR: | 
 |  | 
 |         ngx_resolver_process_ptr(r, buf, n, ident, code, nan); | 
 |  | 
 |         break; | 
 |  | 
 |     default: | 
 |         ngx_log_error(r->log_level, r->log, 0, | 
 |                       "unknown query type %ui in DNS response", qtype); | 
 |         return; | 
 |     } | 
 |  | 
 |     return; | 
 |  | 
 | short_response: | 
 |  | 
 |     err = "short DNS response"; | 
 |  | 
 | done: | 
 |  | 
 |     ngx_log_error(r->log_level, r->log, 0, err); | 
 |  | 
 |     return; | 
 |  | 
 | dns_error_name: | 
 |  | 
 |     ngx_log_error(r->log_level, r->log, 0, | 
 |                   "DNS error (%ui: %s), query id:%ui, name:\"%*s\"", | 
 |                   code, ngx_resolver_strerror(code), ident, | 
 |                   rn->nlen, rn->name); | 
 |     return; | 
 |  | 
 | dns_error: | 
 |  | 
 |     ngx_log_error(r->log_level, r->log, 0, | 
 |                   "DNS error (%ui: %s), query id:%ui", | 
 |                   code, ngx_resolver_strerror(code), ident); | 
 |     return; | 
 | } | 
 |  | 
 |  | 
 | static void | 
 | ngx_resolver_process_a(ngx_resolver_t *r, u_char *buf, size_t last, | 
 |     ngx_uint_t ident, ngx_uint_t code, ngx_uint_t qtype, | 
 |     ngx_uint_t nan, ngx_uint_t ans) | 
 | { | 
 |     char                 *err; | 
 |     u_char               *cname; | 
 |     size_t                len; | 
 |     int32_t               ttl; | 
 |     uint32_t              hash; | 
 |     in_addr_t            *addr; | 
 |     ngx_str_t             name; | 
 |     ngx_addr_t           *addrs; | 
 |     ngx_uint_t            type, class, qident, naddrs, a, i, n, start; | 
 | #if (NGX_HAVE_INET6) | 
 |     struct in6_addr      *addr6; | 
 | #endif | 
 |     ngx_resolver_an_t    *an; | 
 |     ngx_resolver_ctx_t   *ctx, *next; | 
 |     ngx_resolver_node_t  *rn; | 
 |  | 
 |     if (ngx_resolver_copy(r, &name, buf, | 
 |                           buf + sizeof(ngx_resolver_hdr_t), buf + last) | 
 |         != NGX_OK) | 
 |     { | 
 |         return; | 
 |     } | 
 |  | 
 |     ngx_log_debug1(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver qs:%V", &name); | 
 |  | 
 |     hash = ngx_crc32_short(name.data, name.len); | 
 |  | 
 |     /* lock name mutex */ | 
 |  | 
 |     rn = ngx_resolver_lookup_name(r, &name, hash); | 
 |  | 
 |     if (rn == NULL) { | 
 |         ngx_log_error(r->log_level, r->log, 0, | 
 |                       "unexpected response for %V", &name); | 
 |         ngx_resolver_free(r, name.data); | 
 |         goto failed; | 
 |     } | 
 |  | 
 |     switch (qtype) { | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |     case NGX_RESOLVE_AAAA: | 
 |  | 
 |         if (rn->query6 == NULL || rn->naddrs6 != (u_short) -1) { | 
 |             ngx_log_error(r->log_level, r->log, 0, | 
 |                           "unexpected response for %V", &name); | 
 |             ngx_resolver_free(r, name.data); | 
 |             goto failed; | 
 |         } | 
 |  | 
 |         qident = (rn->query6[0] << 8) + rn->query6[1]; | 
 |  | 
 |         break; | 
 | #endif | 
 |  | 
 |     default: /* NGX_RESOLVE_A */ | 
 |  | 
 |         if (rn->query == NULL || rn->naddrs != (u_short) -1) { | 
 |             ngx_log_error(r->log_level, r->log, 0, | 
 |                           "unexpected response for %V", &name); | 
 |             ngx_resolver_free(r, name.data); | 
 |             goto failed; | 
 |         } | 
 |  | 
 |         qident = (rn->query[0] << 8) + rn->query[1]; | 
 |     } | 
 |  | 
 |     if (ident != qident) { | 
 |         ngx_log_error(r->log_level, r->log, 0, | 
 |                       "wrong ident %ui response for %V, expect %ui", | 
 |                       ident, &name, qident); | 
 |         ngx_resolver_free(r, name.data); | 
 |         goto failed; | 
 |     } | 
 |  | 
 |     ngx_resolver_free(r, name.data); | 
 |  | 
 |     if (code == 0 && rn->code) { | 
 |         code = rn->code; | 
 |     } | 
 |  | 
 |     if (code == 0 && nan == 0) { | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |         switch (qtype) { | 
 |  | 
 |         case NGX_RESOLVE_AAAA: | 
 |  | 
 |             rn->naddrs6 = 0; | 
 |  | 
 |             if (rn->naddrs == (u_short) -1) { | 
 |                 goto next; | 
 |             } | 
 |  | 
 |             if (rn->naddrs) { | 
 |                 goto export; | 
 |             } | 
 |  | 
 |             break; | 
 |  | 
 |         default: /* NGX_RESOLVE_A */ | 
 |  | 
 |             rn->naddrs = 0; | 
 |  | 
 |             if (rn->naddrs6 == (u_short) -1) { | 
 |                 goto next; | 
 |             } | 
 |  | 
 |             if (rn->naddrs6) { | 
 |                 goto export; | 
 |             } | 
 |         } | 
 | #endif | 
 |  | 
 |         code = NGX_RESOLVE_NXDOMAIN; | 
 |     } | 
 |  | 
 |     if (code) { | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |         switch (qtype) { | 
 |  | 
 |         case NGX_RESOLVE_AAAA: | 
 |  | 
 |             rn->naddrs6 = 0; | 
 |  | 
 |             if (rn->naddrs == (u_short) -1) { | 
 |                 rn->code = (u_char) code; | 
 |                 goto next; | 
 |             } | 
 |  | 
 |             break; | 
 |  | 
 |         default: /* NGX_RESOLVE_A */ | 
 |  | 
 |             rn->naddrs = 0; | 
 |  | 
 |             if (rn->naddrs6 == (u_short) -1) { | 
 |                 rn->code = (u_char) code; | 
 |                 goto next; | 
 |             } | 
 |         } | 
 | #endif | 
 |  | 
 |         next = rn->waiting; | 
 |         rn->waiting = NULL; | 
 |  | 
 |         ngx_queue_remove(&rn->queue); | 
 |  | 
 |         ngx_rbtree_delete(&r->name_rbtree, &rn->node); | 
 |  | 
 |         /* unlock name mutex */ | 
 |  | 
 |         while (next) { | 
 |             ctx = next; | 
 |             ctx->state = code; | 
 |             next = ctx->next; | 
 |  | 
 |             ctx->handler(ctx); | 
 |         } | 
 |  | 
 |         ngx_resolver_free_node(r, rn); | 
 |  | 
 |         return; | 
 |     } | 
 |  | 
 |     i = ans; | 
 |     naddrs = 0; | 
 |     cname = NULL; | 
 |  | 
 |     for (a = 0; a < nan; a++) { | 
 |  | 
 |         start = i; | 
 |  | 
 |         while (i < last) { | 
 |  | 
 |             if (buf[i] & 0xc0) { | 
 |                 i += 2; | 
 |                 goto found; | 
 |             } | 
 |  | 
 |             if (buf[i] == 0) { | 
 |                 i++; | 
 |                 goto test_length; | 
 |             } | 
 |  | 
 |             i += 1 + buf[i]; | 
 |         } | 
 |  | 
 |         goto short_response; | 
 |  | 
 |     test_length: | 
 |  | 
 |         if (i - start < 2) { | 
 |             err = "invalid name in DNS response"; | 
 |             goto invalid; | 
 |         } | 
 |  | 
 |     found: | 
 |  | 
 |         if (i + sizeof(ngx_resolver_an_t) >= last) { | 
 |             goto short_response; | 
 |         } | 
 |  | 
 |         an = (ngx_resolver_an_t *) &buf[i]; | 
 |  | 
 |         type = (an->type_hi << 8) + an->type_lo; | 
 |         class = (an->class_hi << 8) + an->class_lo; | 
 |         len = (an->len_hi << 8) + an->len_lo; | 
 |         ttl = (an->ttl[0] << 24) + (an->ttl[1] << 16) | 
 |             + (an->ttl[2] << 8) + (an->ttl[3]); | 
 |  | 
 |         if (class != 1) { | 
 |             ngx_log_error(r->log_level, r->log, 0, | 
 |                           "unexpected RR class %ui", class); | 
 |             goto failed; | 
 |         } | 
 |  | 
 |         if (ttl < 0) { | 
 |             ttl = 0; | 
 |         } | 
 |  | 
 |         rn->ttl = ngx_min(rn->ttl, (uint32_t) ttl); | 
 |  | 
 |         i += sizeof(ngx_resolver_an_t); | 
 |  | 
 |         switch (type) { | 
 |  | 
 |         case NGX_RESOLVE_A: | 
 |  | 
 |             if (qtype != NGX_RESOLVE_A) { | 
 |                 err = "unexpected A record in DNS response"; | 
 |                 goto invalid; | 
 |             } | 
 |  | 
 |             if (len != 4) { | 
 |                 err = "invalid A record in DNS response"; | 
 |                 goto invalid; | 
 |             } | 
 |  | 
 |             if (i + 4 > last) { | 
 |                 goto short_response; | 
 |             } | 
 |  | 
 |             naddrs++; | 
 |  | 
 |             break; | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |         case NGX_RESOLVE_AAAA: | 
 |  | 
 |             if (qtype != NGX_RESOLVE_AAAA) { | 
 |                 err = "unexpected AAAA record in DNS response"; | 
 |                 goto invalid; | 
 |             } | 
 |  | 
 |             if (len != 16) { | 
 |                 err = "invalid AAAA record in DNS response"; | 
 |                 goto invalid; | 
 |             } | 
 |  | 
 |             if (i + 16 > last) { | 
 |                 goto short_response; | 
 |             } | 
 |  | 
 |             naddrs++; | 
 |  | 
 |             break; | 
 | #endif | 
 |  | 
 |         case NGX_RESOLVE_CNAME: | 
 |  | 
 |             cname = &buf[i]; | 
 |  | 
 |             break; | 
 |  | 
 |         case NGX_RESOLVE_DNAME: | 
 |  | 
 |             break; | 
 |  | 
 |         default: | 
 |  | 
 |             ngx_log_error(r->log_level, r->log, 0, | 
 |                           "unexpected RR type %ui", type); | 
 |         } | 
 |  | 
 |         i += len; | 
 |     } | 
 |  | 
 |     ngx_log_debug3(NGX_LOG_DEBUG_CORE, r->log, 0, | 
 |                    "resolver naddrs:%ui cname:%p ttl:%uD", | 
 |                    naddrs, cname, rn->ttl); | 
 |  | 
 |     if (naddrs) { | 
 |  | 
 |         switch (qtype) { | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |         case NGX_RESOLVE_AAAA: | 
 |  | 
 |             if (naddrs == 1) { | 
 |                 addr6 = &rn->u6.addr6; | 
 |                 rn->naddrs6 = 1; | 
 |  | 
 |             } else { | 
 |                 addr6 = ngx_resolver_alloc(r, naddrs * sizeof(struct in6_addr)); | 
 |                 if (addr6 == NULL) { | 
 |                     goto failed; | 
 |                 } | 
 |  | 
 |                 rn->u6.addrs6 = addr6; | 
 |                 rn->naddrs6 = (u_short) naddrs; | 
 |             } | 
 |  | 
 | #if (NGX_SUPPRESS_WARN) | 
 |             addr = NULL; | 
 | #endif | 
 |  | 
 |             break; | 
 | #endif | 
 |  | 
 |         default: /* NGX_RESOLVE_A */ | 
 |  | 
 |             if (naddrs == 1) { | 
 |                 addr = &rn->u.addr; | 
 |                 rn->naddrs = 1; | 
 |  | 
 |             } else { | 
 |                 addr = ngx_resolver_alloc(r, naddrs * sizeof(in_addr_t)); | 
 |                 if (addr == NULL) { | 
 |                     goto failed; | 
 |                 } | 
 |  | 
 |                 rn->u.addrs = addr; | 
 |                 rn->naddrs = (u_short) naddrs; | 
 |             } | 
 |  | 
 | #if (NGX_HAVE_INET6 && NGX_SUPPRESS_WARN) | 
 |             addr6 = NULL; | 
 | #endif | 
 |         } | 
 |  | 
 |         n = 0; | 
 |         i = ans; | 
 |  | 
 |         for (a = 0; a < nan; a++) { | 
 |  | 
 |             for ( ;; ) { | 
 |  | 
 |                 if (buf[i] & 0xc0) { | 
 |                     i += 2; | 
 |                     break; | 
 |                 } | 
 |  | 
 |                 if (buf[i] == 0) { | 
 |                     i++; | 
 |                     break; | 
 |                 } | 
 |  | 
 |                 i += 1 + buf[i]; | 
 |             } | 
 |  | 
 |             an = (ngx_resolver_an_t *) &buf[i]; | 
 |  | 
 |             type = (an->type_hi << 8) + an->type_lo; | 
 |             len = (an->len_hi << 8) + an->len_lo; | 
 |  | 
 |             i += sizeof(ngx_resolver_an_t); | 
 |  | 
 |             if (type == NGX_RESOLVE_A) { | 
 |  | 
 |                 addr[n] = htonl((buf[i] << 24) + (buf[i + 1] << 16) | 
 |                                 + (buf[i + 2] << 8) + (buf[i + 3])); | 
 |  | 
 |                 if (++n == naddrs) { | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |                     if (rn->naddrs6 == (u_short) -1) { | 
 |                         goto next; | 
 |                     } | 
 | #endif | 
 |  | 
 |                     break; | 
 |                 } | 
 |             } | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |             else if (type == NGX_RESOLVE_AAAA) { | 
 |  | 
 |                 ngx_memcpy(addr6[n].s6_addr, &buf[i], 16); | 
 |  | 
 |                 if (++n == naddrs) { | 
 |  | 
 |                     if (rn->naddrs == (u_short) -1) { | 
 |                         goto next; | 
 |                     } | 
 |  | 
 |                     break; | 
 |                 } | 
 |             } | 
 | #endif | 
 |  | 
 |             i += len; | 
 |         } | 
 |     } | 
 |  | 
 |     switch (qtype) { | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |     case NGX_RESOLVE_AAAA: | 
 |  | 
 |         if (rn->naddrs6 == (u_short) -1) { | 
 |             rn->naddrs6 = 0; | 
 |         } | 
 |  | 
 |         break; | 
 | #endif | 
 |  | 
 |     default: /* NGX_RESOLVE_A */ | 
 |  | 
 |         if (rn->naddrs == (u_short) -1) { | 
 |             rn->naddrs = 0; | 
 |         } | 
 |     } | 
 |  | 
 |     if (rn->naddrs != (u_short) -1 | 
 | #if (NGX_HAVE_INET6) | 
 |         && rn->naddrs6 != (u_short) -1 | 
 | #endif | 
 |         && rn->naddrs | 
 | #if (NGX_HAVE_INET6) | 
 |            + rn->naddrs6 | 
 | #endif | 
 |            > 0) | 
 |     { | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |     export: | 
 | #endif | 
 |  | 
 |         naddrs = rn->naddrs; | 
 | #if (NGX_HAVE_INET6) | 
 |         naddrs += rn->naddrs6; | 
 | #endif | 
 |  | 
 |         if (naddrs == 1 && rn->naddrs == 1) { | 
 |             addrs = NULL; | 
 |  | 
 |         } else { | 
 |             addrs = ngx_resolver_export(r, rn, 0); | 
 |             if (addrs == NULL) { | 
 |                 goto failed; | 
 |             } | 
 |         } | 
 |  | 
 |         ngx_queue_remove(&rn->queue); | 
 |  | 
 |         rn->valid = ngx_time() + (r->valid ? r->valid : (time_t) rn->ttl); | 
 |         rn->expire = ngx_time() + r->expire; | 
 |  | 
 |         ngx_queue_insert_head(&r->name_expire_queue, &rn->queue); | 
 |  | 
 |         next = rn->waiting; | 
 |         rn->waiting = NULL; | 
 |  | 
 |         /* unlock name mutex */ | 
 |  | 
 |         while (next) { | 
 |             ctx = next; | 
 |             ctx->state = NGX_OK; | 
 |             ctx->naddrs = naddrs; | 
 |  | 
 |             if (addrs == NULL) { | 
 |                 ctx->addrs = &ctx->addr; | 
 |                 ctx->addr.sockaddr = (struct sockaddr *) &ctx->sin; | 
 |                 ctx->addr.socklen = sizeof(struct sockaddr_in); | 
 |                 ngx_memzero(&ctx->sin, sizeof(struct sockaddr_in)); | 
 |                 ctx->sin.sin_family = AF_INET; | 
 |                 ctx->sin.sin_addr.s_addr = rn->u.addr; | 
 |  | 
 |             } else { | 
 |                 ctx->addrs = addrs; | 
 |             } | 
 |  | 
 |             next = ctx->next; | 
 |  | 
 |             ctx->handler(ctx); | 
 |         } | 
 |  | 
 |         if (addrs != NULL) { | 
 |             ngx_resolver_free(r, addrs->sockaddr); | 
 |             ngx_resolver_free(r, addrs); | 
 |         } | 
 |  | 
 |         ngx_resolver_free(r, rn->query); | 
 |         rn->query = NULL; | 
 | #if (NGX_HAVE_INET6) | 
 |         rn->query6 = NULL; | 
 | #endif | 
 |  | 
 |         return; | 
 |     } | 
 |  | 
 |     if (cname) { | 
 |  | 
 |         /* CNAME only */ | 
 |  | 
 |         if (rn->naddrs == (u_short) -1 | 
 | #if (NGX_HAVE_INET6) | 
 |             || rn->naddrs6 == (u_short) -1 | 
 | #endif | 
 |             ) | 
 |         { | 
 |             goto next; | 
 |         } | 
 |  | 
 |         if (ngx_resolver_copy(r, &name, buf, cname, buf + last) != NGX_OK) { | 
 |             goto failed; | 
 |         } | 
 |  | 
 |         ngx_log_debug1(NGX_LOG_DEBUG_CORE, r->log, 0, | 
 |                        "resolver cname:\"%V\"", &name); | 
 |  | 
 |         ngx_queue_remove(&rn->queue); | 
 |  | 
 |         rn->cnlen = (u_short) name.len; | 
 |         rn->u.cname = name.data; | 
 |  | 
 |         rn->valid = ngx_time() + (r->valid ? r->valid : (time_t) rn->ttl); | 
 |         rn->expire = ngx_time() + r->expire; | 
 |  | 
 |         ngx_queue_insert_head(&r->name_expire_queue, &rn->queue); | 
 |  | 
 |         ctx = rn->waiting; | 
 |         rn->waiting = NULL; | 
 |  | 
 |         if (ctx) { | 
 |             ctx->name = name; | 
 |  | 
 |             (void) ngx_resolve_name_locked(r, ctx); | 
 |         } | 
 |  | 
 |         ngx_resolver_free(r, rn->query); | 
 |         rn->query = NULL; | 
 | #if (NGX_HAVE_INET6) | 
 |         rn->query6 = NULL; | 
 | #endif | 
 |  | 
 |         /* unlock name mutex */ | 
 |  | 
 |         return; | 
 |     } | 
 |  | 
 |     ngx_log_error(r->log_level, r->log, 0, | 
 |                   "no A or CNAME types in DNS response"); | 
 |     return; | 
 |  | 
 | short_response: | 
 |  | 
 |     err = "short DNS response"; | 
 |  | 
 | invalid: | 
 |  | 
 |     /* unlock name mutex */ | 
 |  | 
 |     ngx_log_error(r->log_level, r->log, 0, err); | 
 |  | 
 |     return; | 
 |  | 
 | failed: | 
 |  | 
 | next: | 
 |  | 
 |     /* unlock name mutex */ | 
 |  | 
 |     return; | 
 | } | 
 |  | 
 |  | 
 | 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) | 
 | { | 
 |     char                 *err; | 
 |     size_t                len; | 
 |     u_char                text[NGX_SOCKADDR_STRLEN]; | 
 |     in_addr_t             addr; | 
 |     int32_t               ttl; | 
 |     ngx_int_t             octet; | 
 |     ngx_str_t             name; | 
 |     ngx_uint_t            i, mask, qident, class; | 
 |     ngx_queue_t          *expire_queue; | 
 |     ngx_rbtree_t         *tree; | 
 |     ngx_resolver_an_t    *an; | 
 |     ngx_resolver_ctx_t   *ctx, *next; | 
 |     ngx_resolver_node_t  *rn; | 
 | #if (NGX_HAVE_INET6) | 
 |     uint32_t              hash; | 
 |     ngx_int_t             digit; | 
 |     struct in6_addr       addr6; | 
 | #endif | 
 |  | 
 |     if (ngx_resolver_copy(r, NULL, buf, | 
 |                           buf + sizeof(ngx_resolver_hdr_t), buf + n) | 
 |         != NGX_OK) | 
 |     { | 
 |         return; | 
 |     } | 
 |  | 
 |     /* AF_INET */ | 
 |  | 
 |     addr = 0; | 
 |     i = sizeof(ngx_resolver_hdr_t); | 
 |  | 
 |     for (mask = 0; mask < 32; mask += 8) { | 
 |         len = buf[i++]; | 
 |  | 
 |         octet = ngx_atoi(&buf[i], len); | 
 |         if (octet == NGX_ERROR || octet > 255) { | 
 |             goto invalid_in_addr_arpa; | 
 |         } | 
 |  | 
 |         addr += octet << mask; | 
 |         i += len; | 
 |     } | 
 |  | 
 |     if (ngx_strcasecmp(&buf[i], (u_char *) "\7in-addr\4arpa") == 0) { | 
 |         i += sizeof("\7in-addr\4arpa"); | 
 |  | 
 |         /* lock addr mutex */ | 
 |  | 
 |         rn = ngx_resolver_lookup_addr(r, addr); | 
 |  | 
 |         tree = &r->addr_rbtree; | 
 |         expire_queue = &r->addr_expire_queue; | 
 |  | 
 |         addr = htonl(addr); | 
 |         name.len = ngx_inet_ntop(AF_INET, &addr, text, NGX_SOCKADDR_STRLEN); | 
 |         name.data = text; | 
 |  | 
 |         goto valid; | 
 |     } | 
 |  | 
 | invalid_in_addr_arpa: | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |  | 
 |     i = sizeof(ngx_resolver_hdr_t); | 
 |  | 
 |     for (octet = 15; octet >= 0; octet--) { | 
 |         if (buf[i++] != '\1') { | 
 |             goto invalid_ip6_arpa; | 
 |         } | 
 |  | 
 |         digit = ngx_hextoi(&buf[i++], 1); | 
 |         if (digit == NGX_ERROR) { | 
 |             goto invalid_ip6_arpa; | 
 |         } | 
 |  | 
 |         addr6.s6_addr[octet] = (u_char) digit; | 
 |  | 
 |         if (buf[i++] != '\1') { | 
 |             goto invalid_ip6_arpa; | 
 |         } | 
 |  | 
 |         digit = ngx_hextoi(&buf[i++], 1); | 
 |         if (digit == NGX_ERROR) { | 
 |             goto invalid_ip6_arpa; | 
 |         } | 
 |  | 
 |         addr6.s6_addr[octet] += (u_char) (digit * 16); | 
 |     } | 
 |  | 
 |     if (ngx_strcasecmp(&buf[i], (u_char *) "\3ip6\4arpa") == 0) { | 
 |         i += sizeof("\3ip6\4arpa"); | 
 |  | 
 |         /* lock addr mutex */ | 
 |  | 
 |         hash = ngx_crc32_short(addr6.s6_addr, 16); | 
 |         rn = ngx_resolver_lookup_addr6(r, &addr6, hash); | 
 |  | 
 |         tree = &r->addr6_rbtree; | 
 |         expire_queue = &r->addr6_expire_queue; | 
 |  | 
 |         name.len = ngx_inet6_ntop(addr6.s6_addr, text, NGX_SOCKADDR_STRLEN); | 
 |         name.data = text; | 
 |  | 
 |         goto valid; | 
 |     } | 
 |  | 
 | invalid_ip6_arpa: | 
 | #endif | 
 |  | 
 |     ngx_log_error(r->log_level, r->log, 0, | 
 |                   "invalid in-addr.arpa or ip6.arpa name in DNS response"); | 
 |     return; | 
 |  | 
 | valid: | 
 |  | 
 |     if (rn == NULL || rn->query == NULL) { | 
 |         ngx_log_error(r->log_level, r->log, 0, | 
 |                       "unexpected response for %V", &name); | 
 |         goto failed; | 
 |     } | 
 |  | 
 |     qident = (rn->query[0] << 8) + rn->query[1]; | 
 |  | 
 |     if (ident != qident) { | 
 |         ngx_log_error(r->log_level, r->log, 0, | 
 |                       "wrong ident %ui response for %V, expect %ui", | 
 |                       ident, &name, qident); | 
 |         goto failed; | 
 |     } | 
 |  | 
 |     if (code == 0 && nan == 0) { | 
 |         code = NGX_RESOLVE_NXDOMAIN; | 
 |     } | 
 |  | 
 |     if (code) { | 
 |         next = rn->waiting; | 
 |         rn->waiting = NULL; | 
 |  | 
 |         ngx_queue_remove(&rn->queue); | 
 |  | 
 |         ngx_rbtree_delete(tree, &rn->node); | 
 |  | 
 |         /* unlock addr mutex */ | 
 |  | 
 |         while (next) { | 
 |             ctx = next; | 
 |             ctx->state = code; | 
 |             next = ctx->next; | 
 |  | 
 |             ctx->handler(ctx); | 
 |         } | 
 |  | 
 |         ngx_resolver_free_node(r, rn); | 
 |  | 
 |         return; | 
 |     } | 
 |  | 
 |     i += sizeof(ngx_resolver_qs_t); | 
 |  | 
 |     if (i + 2 + sizeof(ngx_resolver_an_t) >= n) { | 
 |         goto short_response; | 
 |     } | 
 |  | 
 |     /* compression pointer to *.arpa */ | 
 |  | 
 |     if (buf[i] != 0xc0 || buf[i + 1] != sizeof(ngx_resolver_hdr_t)) { | 
 |         err = "invalid in-addr.arpa or ip6.arpa name in DNS response"; | 
 |         goto invalid; | 
 |     } | 
 |  | 
 |     an = (ngx_resolver_an_t *) &buf[i + 2]; | 
 |  | 
 |     class = (an->class_hi << 8) + an->class_lo; | 
 |     len = (an->len_hi << 8) + an->len_lo; | 
 |     ttl = (an->ttl[0] << 24) + (an->ttl[1] << 16) | 
 |         + (an->ttl[2] << 8) + (an->ttl[3]); | 
 |  | 
 |     if (class != 1) { | 
 |         ngx_log_error(r->log_level, r->log, 0, | 
 |                       "unexpected RR class %ui", class); | 
 |         goto failed; | 
 |     } | 
 |  | 
 |     if (ttl < 0) { | 
 |         ttl = 0; | 
 |     } | 
 |  | 
 |     ngx_log_debug3(NGX_LOG_DEBUG_CORE, r->log, 0, | 
 |                   "resolver qt:%ui cl:%ui len:%uz", | 
 |                   (an->type_hi << 8) + an->type_lo, | 
 |                   class, len); | 
 |  | 
 |     i += 2 + sizeof(ngx_resolver_an_t); | 
 |  | 
 |     if (i + len > n) { | 
 |         goto short_response; | 
 |     } | 
 |  | 
 |     if (ngx_resolver_copy(r, &name, buf, buf + i, buf + n) != NGX_OK) { | 
 |         goto failed; | 
 |     } | 
 |  | 
 |     ngx_log_debug1(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver an:%V", &name); | 
 |  | 
 |     if (name.len != (size_t) rn->nlen | 
 |         || ngx_strncmp(name.data, rn->name, name.len) != 0) | 
 |     { | 
 |         if (rn->nlen) { | 
 |             ngx_resolver_free(r, rn->name); | 
 |         } | 
 |  | 
 |         rn->nlen = (u_short) name.len; | 
 |         rn->name = name.data; | 
 |  | 
 |         name.data = ngx_resolver_dup(r, rn->name, name.len); | 
 |         if (name.data == NULL) { | 
 |             goto failed; | 
 |         } | 
 |     } | 
 |  | 
 |     ngx_queue_remove(&rn->queue); | 
 |  | 
 |     rn->valid = ngx_time() + (r->valid ? r->valid : ttl); | 
 |     rn->expire = ngx_time() + r->expire; | 
 |  | 
 |     ngx_queue_insert_head(expire_queue, &rn->queue); | 
 |  | 
 |     next = rn->waiting; | 
 |     rn->waiting = NULL; | 
 |  | 
 |     /* unlock addr mutex */ | 
 |  | 
 |     while (next) { | 
 |         ctx = next; | 
 |         ctx->state = NGX_OK; | 
 |         ctx->name = name; | 
 |         next = ctx->next; | 
 |  | 
 |         ctx->handler(ctx); | 
 |     } | 
 |  | 
 |     ngx_resolver_free(r, name.data); | 
 |  | 
 |     return; | 
 |  | 
 | short_response: | 
 |  | 
 |     err = "short DNS response"; | 
 |  | 
 | invalid: | 
 |  | 
 |     /* unlock addr mutex */ | 
 |  | 
 |     ngx_log_error(r->log_level, r->log, 0, err); | 
 |  | 
 |     return; | 
 |  | 
 | failed: | 
 |  | 
 |     /* unlock addr mutex */ | 
 |  | 
 |     return; | 
 | } | 
 |  | 
 |  | 
 | static ngx_resolver_node_t * | 
 | ngx_resolver_lookup_name(ngx_resolver_t *r, ngx_str_t *name, uint32_t hash) | 
 | { | 
 |     ngx_int_t             rc; | 
 |     ngx_rbtree_node_t    *node, *sentinel; | 
 |     ngx_resolver_node_t  *rn; | 
 |  | 
 |     node = r->name_rbtree.root; | 
 |     sentinel = r->name_rbtree.sentinel; | 
 |  | 
 |     while (node != sentinel) { | 
 |  | 
 |         if (hash < node->key) { | 
 |             node = node->left; | 
 |             continue; | 
 |         } | 
 |  | 
 |         if (hash > node->key) { | 
 |             node = node->right; | 
 |             continue; | 
 |         } | 
 |  | 
 |         /* hash == node->key */ | 
 |  | 
 |         rn = ngx_resolver_node(node); | 
 |  | 
 |         rc = ngx_memn2cmp(name->data, rn->name, name->len, rn->nlen); | 
 |  | 
 |         if (rc == 0) { | 
 |             return rn; | 
 |         } | 
 |  | 
 |         node = (rc < 0) ? node->left : node->right; | 
 |     } | 
 |  | 
 |     /* not found */ | 
 |  | 
 |     return NULL; | 
 | } | 
 |  | 
 |  | 
 | static ngx_resolver_node_t * | 
 | ngx_resolver_lookup_addr(ngx_resolver_t *r, in_addr_t addr) | 
 | { | 
 |     ngx_rbtree_node_t  *node, *sentinel; | 
 |  | 
 |     node = r->addr_rbtree.root; | 
 |     sentinel = r->addr_rbtree.sentinel; | 
 |  | 
 |     while (node != sentinel) { | 
 |  | 
 |         if (addr < node->key) { | 
 |             node = node->left; | 
 |             continue; | 
 |         } | 
 |  | 
 |         if (addr > node->key) { | 
 |             node = node->right; | 
 |             continue; | 
 |         } | 
 |  | 
 |         /* addr == node->key */ | 
 |  | 
 |         return ngx_resolver_node(node); | 
 |     } | 
 |  | 
 |     /* not found */ | 
 |  | 
 |     return NULL; | 
 | } | 
 |  | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |  | 
 | static ngx_resolver_node_t * | 
 | ngx_resolver_lookup_addr6(ngx_resolver_t *r, struct in6_addr *addr, | 
 |     uint32_t hash) | 
 | { | 
 |     ngx_int_t             rc; | 
 |     ngx_rbtree_node_t    *node, *sentinel; | 
 |     ngx_resolver_node_t  *rn; | 
 |  | 
 |     node = r->addr6_rbtree.root; | 
 |     sentinel = r->addr6_rbtree.sentinel; | 
 |  | 
 |     while (node != sentinel) { | 
 |  | 
 |         if (hash < node->key) { | 
 |             node = node->left; | 
 |             continue; | 
 |         } | 
 |  | 
 |         if (hash > node->key) { | 
 |             node = node->right; | 
 |             continue; | 
 |         } | 
 |  | 
 |         /* hash == node->key */ | 
 |  | 
 |         rn = ngx_resolver_node(node); | 
 |  | 
 |         rc = ngx_memcmp(addr, &rn->addr6, 16); | 
 |  | 
 |         if (rc == 0) { | 
 |             return rn; | 
 |         } | 
 |  | 
 |         node = (rc < 0) ? node->left : node->right; | 
 |     } | 
 |  | 
 |     /* not found */ | 
 |  | 
 |     return NULL; | 
 | } | 
 |  | 
 | #endif | 
 |  | 
 |  | 
 | static void | 
 | ngx_resolver_rbtree_insert_value(ngx_rbtree_node_t *temp, | 
 |     ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel) | 
 | { | 
 |     ngx_rbtree_node_t    **p; | 
 |     ngx_resolver_node_t   *rn, *rn_temp; | 
 |  | 
 |     for ( ;; ) { | 
 |  | 
 |         if (node->key < temp->key) { | 
 |  | 
 |             p = &temp->left; | 
 |  | 
 |         } else if (node->key > temp->key) { | 
 |  | 
 |             p = &temp->right; | 
 |  | 
 |         } else { /* node->key == temp->key */ | 
 |  | 
 |             rn = ngx_resolver_node(node); | 
 |             rn_temp = ngx_resolver_node(temp); | 
 |  | 
 |             p = (ngx_memn2cmp(rn->name, rn_temp->name, rn->nlen, rn_temp->nlen) | 
 |                  < 0) ? &temp->left : &temp->right; | 
 |         } | 
 |  | 
 |         if (*p == sentinel) { | 
 |             break; | 
 |         } | 
 |  | 
 |         temp = *p; | 
 |     } | 
 |  | 
 |     *p = node; | 
 |     node->parent = temp; | 
 |     node->left = sentinel; | 
 |     node->right = sentinel; | 
 |     ngx_rbt_red(node); | 
 | } | 
 |  | 
 |  | 
 | #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) | 
 | { | 
 |     ngx_rbtree_node_t    **p; | 
 |     ngx_resolver_node_t   *rn, *rn_temp; | 
 |  | 
 |     for ( ;; ) { | 
 |  | 
 |         if (node->key < temp->key) { | 
 |  | 
 |             p = &temp->left; | 
 |  | 
 |         } else if (node->key > temp->key) { | 
 |  | 
 |             p = &temp->right; | 
 |  | 
 |         } else { /* node->key == temp->key */ | 
 |  | 
 |             rn = ngx_resolver_node(node); | 
 |             rn_temp = ngx_resolver_node(temp); | 
 |  | 
 |             p = (ngx_memcmp(&rn->addr6, &rn_temp->addr6, 16) | 
 |                  < 0) ? &temp->left : &temp->right; | 
 |         } | 
 |  | 
 |         if (*p == sentinel) { | 
 |             break; | 
 |         } | 
 |  | 
 |         temp = *p; | 
 |     } | 
 |  | 
 |     *p = node; | 
 |     node->parent = temp; | 
 |     node->left = sentinel; | 
 |     node->right = sentinel; | 
 |     ngx_rbt_red(node); | 
 | } | 
 |  | 
 | #endif | 
 |  | 
 |  | 
 | static ngx_int_t | 
 | ngx_resolver_create_name_query(ngx_resolver_node_t *rn, ngx_resolver_ctx_t *ctx) | 
 | { | 
 |     u_char              *p, *s; | 
 |     size_t               len, nlen; | 
 |     ngx_uint_t           ident; | 
 | #if (NGX_HAVE_INET6) | 
 |     ngx_resolver_t      *r; | 
 | #endif | 
 |     ngx_resolver_qs_t   *qs; | 
 |     ngx_resolver_hdr_t  *query; | 
 |  | 
 |     nlen = ctx->name.len ? (1 + ctx->name.len + 1) : 1; | 
 |  | 
 |     len = sizeof(ngx_resolver_hdr_t) + nlen + sizeof(ngx_resolver_qs_t); | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |     r = ctx->resolver; | 
 |  | 
 |     p = ngx_resolver_alloc(ctx->resolver, r->ipv6 ? len * 2 : len); | 
 | #else | 
 |     p = ngx_resolver_alloc(ctx->resolver, len); | 
 | #endif | 
 |     if (p == NULL) { | 
 |         return NGX_ERROR; | 
 |     } | 
 |  | 
 |     rn->qlen = (u_short) len; | 
 |     rn->query = p; | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |     if (r->ipv6) { | 
 |         rn->query6 = p + len; | 
 |     } | 
 | #endif | 
 |  | 
 |     query = (ngx_resolver_hdr_t *) p; | 
 |  | 
 |     ident = ngx_random(); | 
 |  | 
 |     ngx_log_debug2(NGX_LOG_DEBUG_CORE, ctx->resolver->log, 0, | 
 |                    "resolve: \"%V\" A %i", &ctx->name, ident & 0xffff); | 
 |  | 
 |     query->ident_hi = (u_char) ((ident >> 8) & 0xff); | 
 |     query->ident_lo = (u_char) (ident & 0xff); | 
 |  | 
 |     /* recursion query */ | 
 |     query->flags_hi = 1; query->flags_lo = 0; | 
 |  | 
 |     /* one question */ | 
 |     query->nqs_hi = 0; query->nqs_lo = 1; | 
 |     query->nan_hi = 0; query->nan_lo = 0; | 
 |     query->nns_hi = 0; query->nns_lo = 0; | 
 |     query->nar_hi = 0; query->nar_lo = 0; | 
 |  | 
 |     p += sizeof(ngx_resolver_hdr_t) + nlen; | 
 |  | 
 |     qs = (ngx_resolver_qs_t *) p; | 
 |  | 
 |     /* query type */ | 
 |     qs->type_hi = 0; qs->type_lo = NGX_RESOLVE_A; | 
 |  | 
 |     /* IN query class */ | 
 |     qs->class_hi = 0; qs->class_lo = 1; | 
 |  | 
 |     /* convert "www.example.com" to "\3www\7example\3com\0" */ | 
 |  | 
 |     len = 0; | 
 |     p--; | 
 |     *p-- = '\0'; | 
 |  | 
 |     if (ctx->name.len == 0)  { | 
 |         return NGX_DECLINED; | 
 |     } | 
 |  | 
 |     for (s = ctx->name.data + ctx->name.len - 1; s >= ctx->name.data; s--) { | 
 |         if (*s != '.') { | 
 |             *p = *s; | 
 |             len++; | 
 |  | 
 |         } else { | 
 |             if (len == 0 || len > 255) { | 
 |                 return NGX_DECLINED; | 
 |             } | 
 |  | 
 |             *p = (u_char) len; | 
 |             len = 0; | 
 |         } | 
 |  | 
 |         p--; | 
 |     } | 
 |  | 
 |     if (len == 0 || len > 255) { | 
 |         return NGX_DECLINED; | 
 |     } | 
 |  | 
 |     *p = (u_char) len; | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |     if (!r->ipv6) { | 
 |         return NGX_OK; | 
 |     } | 
 |  | 
 |     p = rn->query6; | 
 |  | 
 |     ngx_memcpy(p, rn->query, rn->qlen); | 
 |  | 
 |     query = (ngx_resolver_hdr_t *) p; | 
 |  | 
 |     ident = ngx_random(); | 
 |  | 
 |     ngx_log_debug2(NGX_LOG_DEBUG_CORE, ctx->resolver->log, 0, | 
 |                    "resolve: \"%V\" AAAA %i", &ctx->name, ident & 0xffff); | 
 |  | 
 |     query->ident_hi = (u_char) ((ident >> 8) & 0xff); | 
 |     query->ident_lo = (u_char) (ident & 0xff); | 
 |  | 
 |     p += sizeof(ngx_resolver_hdr_t) + nlen; | 
 |  | 
 |     qs = (ngx_resolver_qs_t *) p; | 
 |  | 
 |     qs->type_lo = NGX_RESOLVE_AAAA; | 
 | #endif | 
 |  | 
 |     return NGX_OK; | 
 | } | 
 |  | 
 |  | 
 | static ngx_int_t | 
 | ngx_resolver_create_addr_query(ngx_resolver_node_t *rn, ngx_resolver_ctx_t *ctx) | 
 | { | 
 |     u_char               *p, *d; | 
 |     size_t                len; | 
 |     in_addr_t             addr; | 
 |     ngx_int_t             n; | 
 |     ngx_uint_t            ident; | 
 |     ngx_resolver_hdr_t   *query; | 
 |     struct sockaddr_in   *sin; | 
 | #if (NGX_HAVE_INET6) | 
 |     struct sockaddr_in6  *sin6; | 
 | #endif | 
 |  | 
 |     switch (ctx->addr.sockaddr->sa_family) { | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |     case AF_INET6: | 
 |         len = sizeof(ngx_resolver_hdr_t) | 
 |               + 64 + sizeof(".ip6.arpa.") - 1 | 
 |               + sizeof(ngx_resolver_qs_t); | 
 |  | 
 |         break; | 
 | #endif | 
 |  | 
 |     default: /* AF_INET */ | 
 |         len = sizeof(ngx_resolver_hdr_t) | 
 |               + sizeof(".255.255.255.255.in-addr.arpa.") - 1 | 
 |               + sizeof(ngx_resolver_qs_t); | 
 |     } | 
 |  | 
 |     p = ngx_resolver_alloc(ctx->resolver, len); | 
 |     if (p == NULL) { | 
 |         return NGX_ERROR; | 
 |     } | 
 |  | 
 |     rn->query = p; | 
 |     query = (ngx_resolver_hdr_t *) p; | 
 |  | 
 |     ident = ngx_random(); | 
 |  | 
 |     query->ident_hi = (u_char) ((ident >> 8) & 0xff); | 
 |     query->ident_lo = (u_char) (ident & 0xff); | 
 |  | 
 |     /* recursion query */ | 
 |     query->flags_hi = 1; query->flags_lo = 0; | 
 |  | 
 |     /* one question */ | 
 |     query->nqs_hi = 0; query->nqs_lo = 1; | 
 |     query->nan_hi = 0; query->nan_lo = 0; | 
 |     query->nns_hi = 0; query->nns_lo = 0; | 
 |     query->nar_hi = 0; query->nar_lo = 0; | 
 |  | 
 |     p += sizeof(ngx_resolver_hdr_t); | 
 |  | 
 |     switch (ctx->addr.sockaddr->sa_family) { | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |     case AF_INET6: | 
 |         sin6 = (struct sockaddr_in6 *) ctx->addr.sockaddr; | 
 |  | 
 |         for (n = 15; n >= 0; n--) { | 
 |             p = ngx_sprintf(p, "\1%xd\1%xd", | 
 |                             sin6->sin6_addr.s6_addr[n] & 0xf, | 
 |                             (sin6->sin6_addr.s6_addr[n] >> 4) & 0xf); | 
 |         } | 
 |  | 
 |         p = ngx_cpymem(p, "\3ip6\4arpa\0", 10); | 
 |  | 
 |         break; | 
 | #endif | 
 |  | 
 |     default: /* AF_INET */ | 
 |  | 
 |         sin = (struct sockaddr_in *) ctx->addr.sockaddr; | 
 |         addr = ntohl(sin->sin_addr.s_addr); | 
 |  | 
 |         for (n = 0; n < 32; n += 8) { | 
 |             d = ngx_sprintf(&p[1], "%ud", (addr >> n) & 0xff); | 
 |             *p = (u_char) (d - &p[1]); | 
 |             p = d; | 
 |         } | 
 |  | 
 |         p = ngx_cpymem(p, "\7in-addr\4arpa\0", 14); | 
 |     } | 
 |  | 
 |     /* query type "PTR", IN query class */ | 
 |     p = ngx_cpymem(p, "\0\14\0\1", 4); | 
 |  | 
 |     rn->qlen = (u_short) (p - rn->query); | 
 |  | 
 |     return NGX_OK; | 
 | } | 
 |  | 
 |  | 
 | static ngx_int_t | 
 | ngx_resolver_copy(ngx_resolver_t *r, ngx_str_t *name, u_char *buf, u_char *src, | 
 |     u_char *last) | 
 | { | 
 |     char        *err; | 
 |     u_char      *p, *dst; | 
 |     ssize_t      len; | 
 |     ngx_uint_t   i, n; | 
 |  | 
 |     p = src; | 
 |     len = -1; | 
 |  | 
 |     /* | 
 |      * compression pointers allow to create endless loop, so we set limit; | 
 |      * 128 pointers should be enough to store 255-byte name | 
 |      */ | 
 |  | 
 |     for (i = 0; i < 128; i++) { | 
 |         n = *p++; | 
 |  | 
 |         if (n == 0) { | 
 |             goto done; | 
 |         } | 
 |  | 
 |         if (n & 0xc0) { | 
 |             n = ((n & 0x3f) << 8) + *p; | 
 |             p = &buf[n]; | 
 |  | 
 |         } else { | 
 |             len += 1 + n; | 
 |             p = &p[n]; | 
 |         } | 
 |  | 
 |         if (p >= last) { | 
 |             err = "name is out of response"; | 
 |             goto invalid; | 
 |         } | 
 |     } | 
 |  | 
 |     err = "compression pointers loop"; | 
 |  | 
 | invalid: | 
 |  | 
 |     ngx_log_error(r->log_level, r->log, 0, err); | 
 |  | 
 |     return NGX_ERROR; | 
 |  | 
 | done: | 
 |  | 
 |     if (name == NULL) { | 
 |         return NGX_OK; | 
 |     } | 
 |  | 
 |     if (len == -1) { | 
 |         ngx_str_null(name); | 
 |         return NGX_OK; | 
 |     } | 
 |  | 
 |     dst = ngx_resolver_alloc(r, len); | 
 |     if (dst == NULL) { | 
 |         return NGX_ERROR; | 
 |     } | 
 |  | 
 |     name->data = dst; | 
 |  | 
 |     n = *src++; | 
 |  | 
 |     for ( ;; ) { | 
 |         if (n & 0xc0) { | 
 |             n = ((n & 0x3f) << 8) + *src; | 
 |             src = &buf[n]; | 
 |  | 
 |             n = *src++; | 
 |  | 
 |         } else { | 
 |             ngx_strlow(dst, src, n); | 
 |             dst += n; | 
 |             src += n; | 
 |  | 
 |             n = *src++; | 
 |  | 
 |             if (n != 0) { | 
 |                 *dst++ = '.'; | 
 |             } | 
 |         } | 
 |  | 
 |         if (n == 0) { | 
 |             name->len = dst - name->data; | 
 |             return NGX_OK; | 
 |         } | 
 |     } | 
 | } | 
 |  | 
 |  | 
 | static void | 
 | ngx_resolver_timeout_handler(ngx_event_t *ev) | 
 | { | 
 |     ngx_resolver_ctx_t   *ctx, *next; | 
 |     ngx_resolver_node_t  *rn; | 
 |  | 
 |     rn = ev->data; | 
 |     ctx = rn->waiting; | 
 |     rn->waiting = NULL; | 
 |  | 
 |     do { | 
 |         ctx->state = NGX_RESOLVE_TIMEDOUT; | 
 |         next = ctx->next; | 
 |  | 
 |         ctx->handler(ctx); | 
 |  | 
 |         ctx = next; | 
 |     } while (ctx); | 
 | } | 
 |  | 
 |  | 
 | static void | 
 | ngx_resolver_free_node(ngx_resolver_t *r, ngx_resolver_node_t *rn) | 
 | { | 
 |     /* lock alloc mutex */ | 
 |  | 
 |     if (rn->query) { | 
 |         ngx_resolver_free_locked(r, rn->query); | 
 |     } | 
 |  | 
 |     if (rn->name) { | 
 |         ngx_resolver_free_locked(r, rn->name); | 
 |     } | 
 |  | 
 |     if (rn->cnlen) { | 
 |         ngx_resolver_free_locked(r, rn->u.cname); | 
 |     } | 
 |  | 
 |     if (rn->naddrs > 1 && rn->naddrs != (u_short) -1) { | 
 |         ngx_resolver_free_locked(r, rn->u.addrs); | 
 |     } | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |     if (rn->naddrs6 > 1 && rn->naddrs6 != (u_short) -1) { | 
 |         ngx_resolver_free_locked(r, rn->u6.addrs6); | 
 |     } | 
 | #endif | 
 |  | 
 |     ngx_resolver_free_locked(r, rn); | 
 |  | 
 |     /* unlock alloc mutex */ | 
 | } | 
 |  | 
 |  | 
 | static void * | 
 | ngx_resolver_alloc(ngx_resolver_t *r, size_t size) | 
 | { | 
 |     u_char  *p; | 
 |  | 
 |     /* lock alloc mutex */ | 
 |  | 
 |     p = ngx_alloc(size, r->log); | 
 |  | 
 |     /* unlock alloc mutex */ | 
 |  | 
 |     return p; | 
 | } | 
 |  | 
 |  | 
 | static void * | 
 | ngx_resolver_calloc(ngx_resolver_t *r, size_t size) | 
 | { | 
 |     u_char  *p; | 
 |  | 
 |     p = ngx_resolver_alloc(r, size); | 
 |  | 
 |     if (p) { | 
 |         ngx_memzero(p, size); | 
 |     } | 
 |  | 
 |     return p; | 
 | } | 
 |  | 
 |  | 
 | static void | 
 | ngx_resolver_free(ngx_resolver_t *r, void *p) | 
 | { | 
 |     /* lock alloc mutex */ | 
 |  | 
 |     ngx_free(p); | 
 |  | 
 |     /* unlock alloc mutex */ | 
 | } | 
 |  | 
 |  | 
 | static void | 
 | ngx_resolver_free_locked(ngx_resolver_t *r, void *p) | 
 | { | 
 |     ngx_free(p); | 
 | } | 
 |  | 
 |  | 
 | static void * | 
 | ngx_resolver_dup(ngx_resolver_t *r, void *src, size_t size) | 
 | { | 
 |     void  *dst; | 
 |  | 
 |     dst = ngx_resolver_alloc(r, size); | 
 |  | 
 |     if (dst == NULL) { | 
 |         return dst; | 
 |     } | 
 |  | 
 |     ngx_memcpy(dst, src, size); | 
 |  | 
 |     return dst; | 
 | } | 
 |  | 
 |  | 
 | static ngx_addr_t * | 
 | ngx_resolver_export(ngx_resolver_t *r, ngx_resolver_node_t *rn, | 
 |     ngx_uint_t rotate) | 
 | { | 
 |     ngx_addr_t            *dst; | 
 |     ngx_uint_t             d, i, j, n; | 
 |     u_char               (*sockaddr)[NGX_SOCKADDRLEN]; | 
 |     in_addr_t             *addr; | 
 |     struct sockaddr_in    *sin; | 
 | #if (NGX_HAVE_INET6) | 
 |     struct in6_addr       *addr6; | 
 |     struct sockaddr_in6   *sin6; | 
 | #endif | 
 |  | 
 |     n = rn->naddrs; | 
 | #if (NGX_HAVE_INET6) | 
 |     n += rn->naddrs6; | 
 | #endif | 
 |  | 
 |     dst = ngx_resolver_calloc(r, n * sizeof(ngx_addr_t)); | 
 |     if (dst == NULL) { | 
 |         return NULL; | 
 |     } | 
 |  | 
 |     sockaddr = ngx_resolver_calloc(r, n * NGX_SOCKADDRLEN); | 
 |     if (sockaddr == NULL) { | 
 |         ngx_resolver_free(r, dst); | 
 |         return NULL; | 
 |     } | 
 |  | 
 |     i = 0; | 
 |     d = rotate ? ngx_random() % n : 0; | 
 |  | 
 |     if (rn->naddrs) { | 
 |         j = rotate ? ngx_random() % rn->naddrs : 0; | 
 |  | 
 |         addr = (rn->naddrs == 1) ? &rn->u.addr : rn->u.addrs; | 
 |  | 
 |         do { | 
 |             sin = (struct sockaddr_in *) sockaddr[d]; | 
 |             sin->sin_family = AF_INET; | 
 |             sin->sin_addr.s_addr = addr[j++]; | 
 |             dst[d].sockaddr = (struct sockaddr *) sin; | 
 |             dst[d++].socklen = sizeof(struct sockaddr_in); | 
 |  | 
 |             if (d == n) { | 
 |                 d = 0; | 
 |             } | 
 |  | 
 |             if (j == rn->naddrs) { | 
 |                 j = 0; | 
 |             } | 
 |         } while (++i < rn->naddrs); | 
 |     } | 
 |  | 
 | #if (NGX_HAVE_INET6) | 
 |     if (rn->naddrs6) { | 
 |         j = rotate ? ngx_random() % rn->naddrs6 : 0; | 
 |  | 
 |         addr6 = (rn->naddrs6 == 1) ? &rn->u6.addr6 : rn->u6.addrs6; | 
 |  | 
 |         do { | 
 |             sin6 = (struct sockaddr_in6 *) sockaddr[d]; | 
 |             sin6->sin6_family = AF_INET6; | 
 |             ngx_memcpy(sin6->sin6_addr.s6_addr, addr6[j++].s6_addr, 16); | 
 |             dst[d].sockaddr = (struct sockaddr *) sin6; | 
 |             dst[d++].socklen = sizeof(struct sockaddr_in6); | 
 |  | 
 |             if (d == n) { | 
 |                 d = 0; | 
 |             } | 
 |  | 
 |             if (j == rn->naddrs6) { | 
 |                 j = 0; | 
 |             } | 
 |         } while (++i < n); | 
 |     } | 
 | #endif | 
 |  | 
 |     return dst; | 
 | } | 
 |  | 
 |  | 
 | char * | 
 | ngx_resolver_strerror(ngx_int_t err) | 
 | { | 
 |     static char *errors[] = { | 
 |         "Format error",     /* FORMERR */ | 
 |         "Server failure",   /* SERVFAIL */ | 
 |         "Host not found",   /* NXDOMAIN */ | 
 |         "Unimplemented",    /* NOTIMP */ | 
 |         "Operation refused" /* REFUSED */ | 
 |     }; | 
 |  | 
 |     if (err > 0 && err < 6) { | 
 |         return errors[err - 1]; | 
 |     } | 
 |  | 
 |     if (err == NGX_RESOLVE_TIMEDOUT) { | 
 |         return "Operation timed out"; | 
 |     } | 
 |  | 
 |     return "Unknown error"; | 
 | } | 
 |  | 
 |  | 
 | static u_char * | 
 | ngx_resolver_log_error(ngx_log_t *log, u_char *buf, size_t len) | 
 | { | 
 |     u_char                *p; | 
 |     ngx_udp_connection_t  *uc; | 
 |  | 
 |     p = buf; | 
 |  | 
 |     if (log->action) { | 
 |         p = ngx_snprintf(buf, len, " while %s", log->action); | 
 |         len -= p - buf; | 
 |     } | 
 |  | 
 |     uc = log->data; | 
 |  | 
 |     if (uc) { | 
 |         p = ngx_snprintf(p, len, ", resolver: %V", &uc->server); | 
 |     } | 
 |  | 
 |     return p; | 
 | } | 
 |  | 
 |  | 
 | ngx_int_t | 
 | ngx_udp_connect(ngx_udp_connection_t *uc) | 
 | { | 
 |     int                rc; | 
 |     ngx_int_t          event; | 
 |     ngx_event_t       *rev, *wev; | 
 |     ngx_socket_t       s; | 
 |     ngx_connection_t  *c; | 
 |  | 
 |     s = ngx_socket(uc->sockaddr->sa_family, SOCK_DGRAM, 0); | 
 |  | 
 |     ngx_log_debug1(NGX_LOG_DEBUG_EVENT, &uc->log, 0, "UDP socket %d", s); | 
 |  | 
 |     if (s == (ngx_socket_t) -1) { | 
 |         ngx_log_error(NGX_LOG_ALERT, &uc->log, ngx_socket_errno, | 
 |                       ngx_socket_n " failed"); | 
 |         return NGX_ERROR; | 
 |     } | 
 |  | 
 |     c = ngx_get_connection(s, &uc->log); | 
 |  | 
 |     if (c == NULL) { | 
 |         if (ngx_close_socket(s) == -1) { | 
 |             ngx_log_error(NGX_LOG_ALERT, &uc->log, ngx_socket_errno, | 
 |                           ngx_close_socket_n "failed"); | 
 |         } | 
 |  | 
 |         return NGX_ERROR; | 
 |     } | 
 |  | 
 |     if (ngx_nonblocking(s) == -1) { | 
 |         ngx_log_error(NGX_LOG_ALERT, &uc->log, ngx_socket_errno, | 
 |                       ngx_nonblocking_n " failed"); | 
 |  | 
 |         goto failed; | 
 |     } | 
 |  | 
 |     rev = c->read; | 
 |     wev = c->write; | 
 |  | 
 |     rev->log = &uc->log; | 
 |     wev->log = &uc->log; | 
 |  | 
 |     uc->connection = c; | 
 |  | 
 |     c->number = ngx_atomic_fetch_add(ngx_connection_counter, 1); | 
 |  | 
 |     ngx_log_debug3(NGX_LOG_DEBUG_EVENT, &uc->log, 0, | 
 |                    "connect to %V, fd:%d #%uA", &uc->server, s, c->number); | 
 |  | 
 |     rc = connect(s, uc->sockaddr, uc->socklen); | 
 |  | 
 |     /* TODO: iocp */ | 
 |  | 
 |     if (rc == -1) { | 
 |         ngx_log_error(NGX_LOG_CRIT, &uc->log, ngx_socket_errno, | 
 |                       "connect() failed"); | 
 |  | 
 |         goto failed; | 
 |     } | 
 |  | 
 |     /* UDP sockets are always ready to write */ | 
 |     wev->ready = 1; | 
 |  | 
 |     event = (ngx_event_flags & NGX_USE_CLEAR_EVENT) ? | 
 |                 /* kqueue, epoll */                 NGX_CLEAR_EVENT: | 
 |                 /* select, poll, /dev/poll */       NGX_LEVEL_EVENT; | 
 |                 /* eventport event type has no meaning: oneshot only */ | 
 |  | 
 |     if (ngx_add_event(rev, NGX_READ_EVENT, event) != NGX_OK) { | 
 |         goto failed; | 
 |     } | 
 |  | 
 |     return NGX_OK; | 
 |  | 
 | failed: | 
 |  | 
 |     ngx_close_connection(c); | 
 |     uc->connection = NULL; | 
 |  | 
 |     return NGX_ERROR; | 
 | } |