mirror of
https://github.com/nginx/nginx.git
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2011 lines
43 KiB
C
2011 lines
43 KiB
C
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/*
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* Copyright (C) Igor Sysoev
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*/
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#include <ngx_config.h>
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#include <ngx_core.h>
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#include <ngx_event.h>
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#define NGX_RESOLVER_UDP_SIZE 4096
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typedef struct {
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u_char ident_hi;
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u_char ident_lo;
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u_char flags_hi;
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u_char flags_lo;
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u_char nqs_hi;
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u_char nqs_lo;
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u_char nan_hi;
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u_char nan_lo;
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u_char nns_hi;
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u_char nns_lo;
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u_char nar_hi;
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u_char nar_lo;
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} ngx_resolver_query_t;
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typedef struct {
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u_char type_hi;
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u_char type_lo;
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u_char class_hi;
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u_char class_lo;
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} ngx_resolver_qs_t;
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typedef struct {
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u_char type_hi;
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u_char type_lo;
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u_char class_hi;
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u_char class_lo;
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u_char ttl[4];
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u_char len_hi;
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u_char len_lo;
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} ngx_resolver_an_t;
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ngx_int_t ngx_udp_connect(ngx_udp_connection_t *uc);
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static ngx_int_t ngx_resolve_name_locked(ngx_resolver_t *r,
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ngx_resolver_ctx_t *ctx);
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static void ngx_resolver_expire(ngx_resolver_t *r, ngx_rbtree_t *tree,
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ngx_queue_t *queue);
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static ngx_int_t ngx_resolver_send_query(ngx_resolver_t *r,
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ngx_resolver_node_t *rn);
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static ngx_int_t ngx_resolver_create_name_query(ngx_resolver_node_t *rn,
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ngx_resolver_ctx_t *ctx);
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static ngx_int_t ngx_resolver_create_addr_query(ngx_resolver_node_t *rn,
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ngx_resolver_ctx_t *ctx);
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static void ngx_resolver_resend_handler(ngx_event_t *ev);
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static time_t ngx_resolver_resend(ngx_resolver_t *r, ngx_rbtree_t *tree,
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ngx_queue_t *queue);
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static void ngx_resolver_read_response(ngx_event_t *rev);
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static void ngx_resolver_process_response(ngx_resolver_t *r, u_char *buf,
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size_t n);
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static void ngx_resolver_process_a(ngx_resolver_t *r, u_char *buf, size_t n,
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ngx_uint_t ident, ngx_uint_t code, ngx_uint_t nan, ngx_uint_t i);
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static void ngx_resolver_process_ptr(ngx_resolver_t *r, u_char *buf, size_t n,
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ngx_uint_t ident, ngx_uint_t code);
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static ngx_resolver_node_t *ngx_resolver_lookup_name(ngx_resolver_t *r,
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ngx_str_t *name, uint32_t hash);
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static ngx_resolver_node_t *ngx_resolver_lookup_addr(ngx_resolver_t *r,
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in_addr_t addr);
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static void ngx_resolver_rbtree_insert_value(ngx_rbtree_node_t *temp,
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ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel);
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static ngx_int_t ngx_resolver_copy(ngx_resolver_t *r, ngx_str_t *name,
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u_char *buf, u_char *src, u_char *last);
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static void ngx_resolver_timeout_handler(ngx_event_t *ev);
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static void ngx_resolver_free_node(ngx_resolver_t *r, ngx_resolver_node_t *rn);
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static void *ngx_resolver_alloc(ngx_resolver_t *r, size_t size);
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static void ngx_resolver_free(ngx_resolver_t *r, void *p);
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static void ngx_resolver_free_locked(ngx_resolver_t *r, void *p);
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static void *ngx_resolver_dup(ngx_resolver_t *r, void *src, size_t size);
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/* STUB: ngx_peer_addr_t * */
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ngx_resolver_t *
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ngx_resolver_create(ngx_peer_addr_t *addr, ngx_log_t *log)
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{
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ngx_resolver_t *r;
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ngx_udp_connection_t *uc;
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r = ngx_calloc(sizeof(ngx_resolver_t), log);
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if (r == NULL) {
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return NULL;
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}
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uc = ngx_calloc(sizeof(ngx_udp_connection_t), log);
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if (uc == NULL) {
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return NULL;
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}
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r->event = ngx_calloc(sizeof(ngx_event_t), log);
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if (r->event == NULL) {
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return NULL;
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}
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ngx_rbtree_sentinel_init(&r->name_sentinel);
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r->name_rbtree.root = &r->name_sentinel;
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r->name_rbtree.sentinel = &r->name_sentinel;
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r->name_rbtree.insert = ngx_resolver_rbtree_insert_value;
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ngx_rbtree_sentinel_init(&r->addr_sentinel);
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r->addr_rbtree.root = &r->addr_sentinel;
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r->addr_rbtree.sentinel = &r->addr_sentinel;
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r->addr_rbtree.insert = ngx_rbtree_insert_value;
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r->name_resend_queue.prev = &r->name_resend_queue;
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r->name_resend_queue.next = &r->name_resend_queue;
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r->addr_resend_queue.prev = &r->addr_resend_queue;
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r->addr_resend_queue.next = &r->addr_resend_queue;
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r->name_expire_queue.prev = &r->name_expire_queue;
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r->name_expire_queue.next = &r->name_expire_queue;
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r->addr_expire_queue.prev = &r->addr_expire_queue;
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r->addr_expire_queue.next = &r->addr_expire_queue;
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r->event->handler = ngx_resolver_resend_handler;
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r->event->data = r;
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r->event->log = log;
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r->ident = -1;
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r->udp_connection = uc;
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r->resend_timeout = 5;
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r->expire = 30;
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r->valid = 300;
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r->log = log;
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r->log_level = NGX_LOG_ALERT;
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uc->sockaddr = addr->sockaddr;
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uc->socklen = addr->socklen;
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uc->server = addr->name;
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uc->log = log;
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return r;
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}
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ngx_resolver_ctx_t *
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ngx_resolve_start(ngx_resolver_t *r, ngx_resolver_ctx_t *temp)
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{
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in_addr_t addr;
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ngx_resolver_ctx_t *ctx;
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if (temp) {
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addr = ngx_inet_addr(temp->name.data, temp->name.len);
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if (addr != INADDR_NONE) {
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temp->resolver = r;
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temp->state = NGX_OK;
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temp->naddrs = 1;
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temp->addrs = &temp->addr;
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temp->addr = addr;
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temp->quick = 1;
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return temp;
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}
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}
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ctx = ngx_resolver_calloc(r, sizeof(ngx_resolver_ctx_t));
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if (ctx) {
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ctx->resolver = r;
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}
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return ctx;
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}
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ngx_int_t
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ngx_resolve_name(ngx_resolver_ctx_t *ctx)
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{
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ngx_int_t rc;
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ngx_resolver_t *r;
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r = ctx->resolver;
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ngx_log_debug1(NGX_LOG_DEBUG_CORE, r->log, 0,
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"resolve: \"%V\"", &ctx->name);
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if (ctx->quick) {
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ctx->handler(ctx);
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return NGX_OK;
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}
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/* lock name mutex */
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rc = ngx_resolve_name_locked(r, ctx);
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if (rc == NGX_OK) {
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return NGX_OK;
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}
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/* unlock name mutex */
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if (rc == NGX_AGAIN) {
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return NGX_OK;
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}
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/* lock alloc mutex */
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if (ctx->event) {
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ngx_resolver_free_locked(r, ctx->event);
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}
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ngx_resolver_free_locked(r, ctx);
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/* unlock alloc mutex */
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return NGX_ERROR;
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}
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void
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ngx_resolve_name_done(ngx_resolver_ctx_t *ctx)
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{
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uint32_t hash;
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ngx_resolver_t *r;
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ngx_resolver_ctx_t *w, **p;
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ngx_resolver_node_t *rn;
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r = ctx->resolver;
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ngx_log_debug1(NGX_LOG_DEBUG_CORE, r->log, 0,
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"resolve name done: %i", ctx->state);
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if (ctx->quick) {
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return;
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}
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if (ctx->event && ctx->event->timer_set) {
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ngx_del_timer(ctx->event);
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}
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/* lock name mutex */
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if (ctx->state == NGX_AGAIN || ctx->state == NGX_RESOLVE_TIMEDOUT) {
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hash = ngx_crc32_short(ctx->name.data, ctx->name.len);
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rn = ngx_resolver_lookup_name(r, &ctx->name, hash);
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if (rn) {
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p = &rn->waiting;
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w = rn->waiting;
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while (w) {
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if (w == ctx) {
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*p = w->next;
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goto done;
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}
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p = &w->next;
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w = w->next;
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}
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}
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ngx_log_error(NGX_LOG_ALERT, r->log, 0,
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"could not cancel %V resolving", &ctx->name);
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}
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done:
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ngx_resolver_expire(r, &r->name_rbtree, &r->name_expire_queue);
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/* unlock name mutex */
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ngx_resolver_free(r, ctx);
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}
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/* NGX_RESOLVE_A only */
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static ngx_int_t
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ngx_resolve_name_locked(ngx_resolver_t *r, ngx_resolver_ctx_t *ctx)
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{
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uint32_t hash;
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in_addr_t addr, *addrs;
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ngx_uint_t naddrs;
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ngx_resolver_ctx_t *next;
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ngx_resolver_node_t *rn;
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hash = ngx_crc32_short(ctx->name.data, ctx->name.len);
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rn = ngx_resolver_lookup_name(r, &ctx->name, hash);
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if (rn) {
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if (rn->valid >= ngx_time()) {
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ngx_log_debug0(NGX_LOG_DEBUG_CORE, r->log, 0, "resolve cached");
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ngx_queue_remove(&rn->queue);
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rn->expire = ngx_time() + r->expire;
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ngx_queue_insert_head(&r->name_expire_queue, &rn->queue);
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naddrs = rn->naddrs;
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if (naddrs) {
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/* NGX_RESOLVE_A answer */
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if (naddrs != 1) {
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addr = 0;
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addrs = ngx_resolver_dup(r, rn->u.addrs,
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naddrs * sizeof(in_addr_t));
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if (addrs == NULL) {
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return NGX_ERROR;
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}
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} else {
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addr = rn->u.addr;
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addrs = NULL;
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}
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ctx->next = rn->waiting;
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rn->waiting = NULL;
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/* unlock name mutex */
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do {
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ctx->state = NGX_OK;
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ctx->naddrs = naddrs;
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ctx->addrs = (naddrs == 1) ? &ctx->addr : addrs;
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ctx->addr = addr;
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next = ctx->next;
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ctx->handler(ctx);
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ctx = next;
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} while (ctx);
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if (addrs) {
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ngx_resolver_free(r, addrs);
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}
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return NGX_OK;
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}
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/* NGX_RESOLVE_CNAME */
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ctx->name.len = rn->cnlen;
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ctx->name.data = rn->u.cname;
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return ngx_resolve_name_locked(r, ctx);
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}
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if (rn->waiting) {
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ctx->next = rn->waiting;
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rn->waiting = ctx;
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return NGX_AGAIN;
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}
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ngx_queue_remove(&rn->queue);
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/* lock alloc mutex */
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ngx_resolver_free_locked(r, rn->query);
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if (rn->cnlen) {
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ngx_resolver_free_locked(r, rn->u.cname);
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}
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if (rn->naddrs > 1) {
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ngx_resolver_free_locked(r, rn->u.addrs);
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}
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/* unlock alloc mutex */
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} else {
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rn = ngx_resolver_alloc(r, sizeof(ngx_resolver_node_t));
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if (rn == NULL) {
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return NGX_ERROR;
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}
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rn->name = ngx_resolver_dup(r, ctx->name.data, ctx->name.len);
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if (rn->name == NULL) {
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ngx_resolver_free(r, rn);
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return NGX_ERROR;
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}
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rn->node.key = hash;
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rn->nlen = (u_short) ctx->name.len;
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ngx_rbtree_insert(&r->name_rbtree, &rn->node);
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}
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if (ngx_resolver_create_name_query(rn, ctx) != NGX_OK) {
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goto failed;
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}
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if (ngx_resolver_send_query(r, rn) != NGX_OK) {
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goto failed;
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}
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if (ctx->event == NULL) {
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ctx->event = ngx_resolver_calloc(r, sizeof(ngx_event_t));
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if (ctx->event == NULL) {
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goto failed;
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}
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ctx->event->handler = ngx_resolver_timeout_handler;
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ctx->event->data = ctx;
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ctx->event->log = r->log;
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ctx->ident = -1;
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ngx_add_timer(ctx->event, ctx->timeout);
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}
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if (ngx_queue_empty(&r->name_resend_queue)) {
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ngx_add_timer(r->event, (ngx_msec_t) (r->resend_timeout * 1000));
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}
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rn->expire = ngx_time() + r->resend_timeout;
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ngx_queue_insert_head(&r->name_resend_queue, &rn->queue);
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rn->cnlen = 0;
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rn->naddrs = 0;
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rn->valid = 0;
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rn->waiting = ctx;
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ctx->state = NGX_AGAIN;
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return NGX_AGAIN;
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failed:
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ngx_rbtree_delete(&r->name_rbtree, &rn->node);
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ngx_resolver_free(r, rn->name);
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ngx_resolver_free(r, rn);
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return NGX_ERROR;
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}
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ngx_int_t
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ngx_resolve_addr(ngx_resolver_ctx_t *ctx)
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{
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ngx_resolver_t *r;
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ngx_resolver_node_t *rn;
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r = ctx->resolver;
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ctx->addr = ntohl(ctx->addr);
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/* lock addr mutex */
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rn = ngx_resolver_lookup_addr(r, ctx->addr);
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if (rn) {
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if (rn->valid >= ngx_time()) {
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ngx_log_debug0(NGX_LOG_DEBUG_CORE, r->log, 0, "resolve cached");
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ngx_queue_remove(&rn->queue);
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rn->expire = ngx_time() + r->expire;
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ngx_queue_insert_head(&r->addr_expire_queue, &rn->queue);
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ctx->name.len = rn->nlen;
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ctx->name.data = ngx_resolver_dup(r, rn->name, rn->nlen);
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if (ctx->name.data == NULL) {
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goto failed;
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}
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/* unlock addr mutex */
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ctx->state = NGX_OK;
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ctx->handler(ctx);
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ngx_resolver_free(r, ctx->name.data);
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return NGX_OK;
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}
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if (rn->waiting) {
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ctx->next = rn->waiting;
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rn->waiting = ctx;
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return NGX_AGAIN;
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}
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ngx_queue_remove(&rn->queue);
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ngx_resolver_free(r, rn->query);
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} else {
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rn = ngx_resolver_alloc(r, sizeof(ngx_resolver_node_t));
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if (rn == NULL) {
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goto failed;
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}
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rn->node.key = ctx->addr;
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ngx_rbtree_insert(&r->addr_rbtree, &rn->node);
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}
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if (ngx_resolver_create_addr_query(rn, ctx) != NGX_OK) {
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goto failed;
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}
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if (ngx_resolver_send_query(r, rn) != NGX_OK) {
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goto failed;
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}
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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 = ctx;
|
|
ctx->event->log = r->log;
|
|
ctx->ident = -1;
|
|
|
|
ngx_add_timer(ctx->event, ctx->timeout);
|
|
|
|
if (ngx_queue_empty(&r->addr_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->addr_resend_queue, &rn->queue);
|
|
|
|
rn->cnlen = 0;
|
|
rn->naddrs = 0;
|
|
rn->name = NULL;
|
|
rn->nlen = 0;
|
|
rn->valid = 0;
|
|
rn->waiting = ctx;
|
|
|
|
/* unlock addr mutex */
|
|
|
|
ctx->state = NGX_AGAIN;
|
|
|
|
return NGX_OK;
|
|
|
|
failed:
|
|
|
|
if (rn) {
|
|
ngx_rbtree_delete(&r->addr_rbtree, &rn->node);
|
|
|
|
ngx_resolver_free(r, rn);
|
|
}
|
|
|
|
/* 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 */
|
|
|
|
return NGX_ERROR;
|
|
}
|
|
|
|
|
|
void
|
|
ngx_resolve_addr_done(ngx_resolver_ctx_t *ctx)
|
|
{
|
|
in_addr_t addr;
|
|
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 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 || ctx->state == NGX_RESOLVE_TIMEDOUT) {
|
|
|
|
rn = ngx_resolver_lookup_addr(r, ctx->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;
|
|
}
|
|
}
|
|
|
|
addr = ntohl(ctx->addr);
|
|
|
|
ngx_log_error(NGX_LOG_ALERT, r->log, 0,
|
|
"could not cancel %ud.%ud.%ud.%ud resolving",
|
|
(addr >> 24) & 0xff, (addr >> 16) & 0xff,
|
|
(addr >> 8) & 0xff, addr & 0xff);
|
|
}
|
|
|
|
done:
|
|
|
|
ngx_resolver_expire(r, &r->addr_rbtree, &r->addr_expire_queue);
|
|
|
|
/* unlock addr mutex */
|
|
|
|
ngx_resolver_free(r, ctx);
|
|
}
|
|
|
|
|
|
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;
|
|
}
|
|
|
|
#if (NGX_DEBUG)
|
|
{
|
|
ngx_str_t s;
|
|
|
|
s.len = rn->nlen;
|
|
s.data = rn->name;
|
|
|
|
ngx_log_debug1(NGX_LOG_DEBUG_CORE, r->log, 0,
|
|
"resolver expire \"%V\"", &s);
|
|
}
|
|
#endif
|
|
|
|
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_connection;
|
|
|
|
if (uc->connection == NULL) {
|
|
if (ngx_udp_connect(uc) != NGX_OK) {
|
|
return NGX_ERROR;
|
|
}
|
|
|
|
uc->connection->data = r;
|
|
uc->connection->read->handler = ngx_resolver_read_response;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
return NGX_OK;
|
|
}
|
|
|
|
|
|
static void
|
|
ngx_resolver_resend_handler(ngx_event_t *ev)
|
|
{
|
|
time_t timer, atimer, ntimer;
|
|
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 (ntimer == 0) {
|
|
timer = atimer;
|
|
|
|
} else if (atimer == 0) {
|
|
timer = ntimer;
|
|
|
|
} else {
|
|
timer = (atimer < ntimer) ? atimer : ntimer;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
#if (NGX_DEBUG)
|
|
{
|
|
ngx_str_t s;
|
|
|
|
s.len = rn->nlen;
|
|
s.data = rn->name;
|
|
|
|
ngx_log_debug2(NGX_LOG_DEBUG_CORE, r->log, 0,
|
|
"resolver resend \"%V\" %p", &s, rn->waiting);
|
|
}
|
|
#endif
|
|
|
|
ngx_queue_remove(q);
|
|
|
|
if (rn->waiting) {
|
|
|
|
if (ngx_resolver_send_query(r, rn) == NGX_OK) {
|
|
|
|
rn->expire = now + r->resend_timeout;
|
|
|
|
ngx_queue_insert_head(queue, &rn->queue);
|
|
|
|
continue;
|
|
}
|
|
}
|
|
|
|
ngx_rbtree_delete(tree, &rn->node);
|
|
|
|
ngx_resolver_free_node(r, rn);
|
|
}
|
|
}
|
|
|
|
|
|
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_recv(c, buf, NGX_RESOLVER_UDP_SIZE);
|
|
|
|
if (n == -1) {
|
|
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;
|
|
size_t len;
|
|
ngx_uint_t i, ident, flags, code, nqs, nan, qtype, qclass;
|
|
ngx_resolver_qs_t *qs;
|
|
ngx_resolver_query_t *query;
|
|
|
|
if ((size_t) n < sizeof(ngx_resolver_query_t) + 1) {
|
|
goto short_response;
|
|
}
|
|
|
|
query = (ngx_resolver_query_t *) buf;
|
|
|
|
ident = (query->ident_hi << 8) + query->ident_lo;
|
|
flags = (query->flags_hi << 8) + query->flags_lo;
|
|
nqs = (query->nqs_hi << 8) + query->nqs_lo;
|
|
nan = (query->nan_hi << 8) + query->nan_lo;
|
|
|
|
ngx_log_debug6(NGX_LOG_DEBUG_CORE, r->log, 0,
|
|
"resolver DNS response %d fl:%04Xud %d/%d/%d/%d",
|
|
ident, flags, nqs, nan,
|
|
(query->nns_hi << 8) + query->nns_lo,
|
|
(query->nar_hi << 8) + query->nar_lo);
|
|
|
|
if (!(flags & 0x8000)) {
|
|
ngx_log_error(r->log_level, r->log, 0,
|
|
"invalid DNS response %d fl:%04Xud", ident, flags);
|
|
return;
|
|
}
|
|
|
|
code = flags & 0x7f;
|
|
|
|
if (code == NGX_RESOLVE_FORMERR || code > NGX_RESOLVE_REFUSED) {
|
|
ngx_log_error(r->log_level, r->log, 0,
|
|
"DNS error (%d: %s), query id:%d",
|
|
code, ngx_resolver_strerror(code), ident);
|
|
return;
|
|
}
|
|
|
|
if (nqs != 1) {
|
|
err = "invalid number of questions in DNS response";
|
|
goto done;
|
|
}
|
|
|
|
if (code == 0 && nan == 0) {
|
|
err = "no answers in DNS response";
|
|
goto done;
|
|
}
|
|
|
|
i = sizeof(ngx_resolver_query_t);
|
|
|
|
while (i < (ngx_uint_t) n) {
|
|
if (buf[i] == '\0') {
|
|
goto found;
|
|
}
|
|
|
|
len = buf[i];
|
|
i += 1 + len;
|
|
}
|
|
|
|
goto short_response;
|
|
|
|
found:
|
|
|
|
if (i++ == 0) {
|
|
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:%d cl:%d", qtype, qclass);
|
|
|
|
if (qclass != 1) {
|
|
ngx_log_error(r->log_level, r->log, 0,
|
|
"unknown query class %d in DNS response", qclass);
|
|
return;
|
|
}
|
|
|
|
switch (qtype) {
|
|
|
|
case NGX_RESOLVE_A:
|
|
|
|
ngx_resolver_process_a(r, buf, n, ident, code, nan,
|
|
i + sizeof(ngx_resolver_qs_t));
|
|
|
|
break;
|
|
|
|
case NGX_RESOLVE_PTR:
|
|
|
|
ngx_resolver_process_ptr(r, buf, n, ident, code);
|
|
|
|
break;
|
|
|
|
default:
|
|
ngx_log_error(r->log_level, r->log, 0,
|
|
"unknown query type %d in DNS response", qtype);
|
|
return;
|
|
}
|
|
|
|
return;
|
|
|
|
short_response:
|
|
|
|
err = "short dns response";
|
|
|
|
done:
|
|
|
|
ngx_log_error(r->log_level, r->log, 0, err);
|
|
|
|
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 nan, ngx_uint_t ans)
|
|
{
|
|
char *err;
|
|
u_char *cname;
|
|
size_t len;
|
|
uint32_t hash;
|
|
in_addr_t addr, *addrs;
|
|
ngx_str_t name;
|
|
ngx_uint_t qtype, qident, naddrs, a, i, n, start;
|
|
ngx_resolver_an_t *an;
|
|
ngx_resolver_ctx_t *ctx, *next;
|
|
ngx_resolver_node_t *rn;
|
|
|
|
if (ngx_resolver_copy(r, &name, buf, &buf[12], &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 || 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 %d response for %V, expect %d",
|
|
ident, &name, qident);
|
|
goto failed;
|
|
}
|
|
|
|
if (code) {
|
|
next = rn->waiting;
|
|
rn->waiting = NULL;
|
|
|
|
ngx_queue_remove(&rn->queue);
|
|
|
|
ngx_rbtree_delete(&r->name_rbtree, &rn->node);
|
|
|
|
ngx_resolver_free_node(r, rn);
|
|
|
|
/* unlock name mutex */
|
|
|
|
while (next) {
|
|
ctx = next;
|
|
ctx->state = code;
|
|
next = ctx->next;
|
|
|
|
ctx->handler(ctx);
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
i = ans;
|
|
naddrs = 0;
|
|
addr = 0;
|
|
addrs = NULL;
|
|
cname = NULL;
|
|
qtype = 0;
|
|
|
|
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];
|
|
|
|
qtype = (an->type_hi << 8) + an->type_lo;
|
|
len = (an->len_hi << 8) + an->len_lo;
|
|
|
|
if (qtype == NGX_RESOLVE_A) {
|
|
|
|
i += sizeof(ngx_resolver_an_t);
|
|
|
|
if (i + len > last) {
|
|
goto short_response;
|
|
}
|
|
|
|
addr = htonl((buf[i] << 24) + (buf[i + 1] << 16)
|
|
+ (buf[i + 2] << 8) + (buf[i + 3]));
|
|
|
|
naddrs++;
|
|
|
|
i += len;
|
|
|
|
} else if (qtype == NGX_RESOLVE_CNAME) {
|
|
cname = &buf[i] + sizeof(ngx_resolver_an_t);
|
|
i += sizeof(ngx_resolver_an_t) + len;
|
|
}
|
|
}
|
|
|
|
ngx_log_debug2(NGX_LOG_DEBUG_CORE, r->log, 0,
|
|
"resolver naddrs:%ui cname:%p", naddrs, cname);
|
|
|
|
if (naddrs) {
|
|
|
|
if (naddrs == 1) {
|
|
rn->u.addr = addr;
|
|
|
|
} else {
|
|
|
|
addrs = ngx_resolver_alloc(r, naddrs * sizeof(in_addr_t));
|
|
if (addrs == NULL) {
|
|
return;
|
|
}
|
|
|
|
n = 0;
|
|
i = ans;
|
|
|
|
for (a = 0; a < nan; a++) {
|
|
|
|
for ( ;; ) {
|
|
|
|
if (buf[i] & 0xc0) {
|
|
i += 2;
|
|
goto ok;
|
|
}
|
|
|
|
if (buf[i] == 0) {
|
|
i++;
|
|
goto ok;
|
|
}
|
|
|
|
i += 1 + buf[i];
|
|
}
|
|
|
|
ok:
|
|
|
|
an = (ngx_resolver_an_t *) &buf[i];
|
|
|
|
qtype = (an->type_hi << 8) + an->type_lo;
|
|
len = (an->len_hi << 8) + an->len_lo;
|
|
|
|
i += sizeof(ngx_resolver_an_t);
|
|
|
|
if (qtype == NGX_RESOLVE_A) {
|
|
|
|
addrs[n++] = htonl((buf[i] << 24) + (buf[i + 1] << 16)
|
|
+ (buf[i + 2] << 8) + (buf[i + 3]));
|
|
|
|
if (n == naddrs) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
i += len;
|
|
}
|
|
|
|
rn->u.addrs = addrs;
|
|
|
|
addrs = ngx_resolver_dup(r, rn->u.addrs,
|
|
naddrs * sizeof(in_addr_t));
|
|
if (addrs == NULL) {
|
|
return;
|
|
}
|
|
}
|
|
|
|
rn->naddrs = (u_short) naddrs;
|
|
|
|
ngx_queue_remove(&rn->queue);
|
|
|
|
rn->valid = ngx_time() + r->valid;
|
|
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;
|
|
ctx->addrs = (naddrs == 1) ? &ctx->addr : addrs;
|
|
ctx->addr = addr;
|
|
next = ctx->next;
|
|
|
|
ctx->handler(ctx);
|
|
}
|
|
|
|
if (naddrs) {
|
|
ngx_resolver_free(r, addrs);
|
|
}
|
|
|
|
return;
|
|
|
|
} else if (cname) {
|
|
|
|
/* CNAME only */
|
|
|
|
if (ngx_resolver_copy(r, &name, buf, cname, &buf[last]) != NGX_OK) {
|
|
return;
|
|
}
|
|
|
|
ngx_log_debug1(NGX_LOG_DEBUG_CORE, r->log, 0,
|
|
"resolver cname:\"%V\"", &name);
|
|
|
|
rn->cnlen = (u_short) name.len;
|
|
rn->u.cname = name.data;
|
|
rn->valid = ngx_time() + r->valid;
|
|
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);
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
ngx_log_error(r->log_level, r->log, 0,
|
|
"no A or CNAME types in DNS responses, unknown query type: %d",
|
|
qtype);
|
|
return;
|
|
|
|
short_response:
|
|
|
|
err = "short dns response";
|
|
|
|
invalid:
|
|
|
|
/* unlock name mutex */
|
|
|
|
ngx_log_error(r->log_level, r->log, 0, err);
|
|
|
|
return;
|
|
|
|
failed:
|
|
|
|
/* 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)
|
|
{
|
|
char *err;
|
|
size_t len;
|
|
in_addr_t addr;
|
|
ngx_int_t digit;
|
|
ngx_str_t name;
|
|
ngx_uint_t i, mask, qtype, qclass, qident;
|
|
ngx_resolver_an_t *an;
|
|
ngx_resolver_ctx_t *ctx, *next;
|
|
ngx_resolver_node_t *rn;
|
|
|
|
if (ngx_resolver_copy(r, NULL, buf, &buf[12], &buf[n]) != NGX_OK) {
|
|
goto invalid_in_addr_arpa;
|
|
}
|
|
|
|
addr = 0;
|
|
i = 12;
|
|
|
|
for (mask = 0; mask < 32; mask += 8) {
|
|
len = buf[i++];
|
|
|
|
digit = ngx_atoi(&buf[i], len);
|
|
if (digit == NGX_ERROR || digit > 255) {
|
|
goto invalid_in_addr_arpa;
|
|
}
|
|
|
|
addr += digit << mask;
|
|
i += len;
|
|
}
|
|
|
|
if (ngx_strcmp(&buf[i], "\7in-addr\4arpa") != 0) {
|
|
goto invalid_in_addr_arpa;
|
|
}
|
|
|
|
/* lock addr mutex */
|
|
|
|
rn = ngx_resolver_lookup_addr(r, addr);
|
|
|
|
if (rn == NULL || rn->query == NULL) {
|
|
ngx_log_error(r->log_level, r->log, 0,
|
|
"unexpected response for %ud.%ud.%ud.%ud",
|
|
(addr >> 24) & 0xff, (addr >> 16) & 0xff,
|
|
(addr >> 8) & 0xff, addr & 0xff);
|
|
goto failed;
|
|
}
|
|
|
|
qident = (rn->query[0] << 8) + rn->query[1];
|
|
|
|
if (ident != qident) {
|
|
ngx_log_error(r->log_level, r->log, 0,
|
|
"wrong ident %d response for %ud.%ud.%ud.%ud, expect %d",
|
|
ident, (addr >> 24) & 0xff, (addr >> 16) & 0xff,
|
|
(addr >> 8) & 0xff, addr & 0xff, qident);
|
|
goto failed;
|
|
}
|
|
|
|
if (code) {
|
|
next = rn->waiting;
|
|
rn->waiting = NULL;
|
|
|
|
ngx_queue_remove(&rn->queue);
|
|
|
|
ngx_rbtree_delete(&r->addr_rbtree, &rn->node);
|
|
|
|
ngx_resolver_free_node(r, rn);
|
|
|
|
/* unlock addr mutex */
|
|
|
|
while (next) {
|
|
ctx = next;
|
|
ctx->state = code;
|
|
next = ctx->next;
|
|
|
|
ctx->handler(ctx);
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
i += sizeof("\7in-addr\4arpa") + sizeof(ngx_resolver_qs_t);
|
|
|
|
if (i + 2 + sizeof(ngx_resolver_an_t) > (ngx_uint_t) n) {
|
|
goto short_response;
|
|
}
|
|
|
|
/* compression pointer to "XX.XX.XX.XX.in-addr.arpa */
|
|
|
|
if (buf[i] != 0xc0 || buf[i + 1] != 0x0c) {
|
|
err = "invalid in-addr.arpa name in DNS response";
|
|
goto invalid;
|
|
}
|
|
|
|
an = (ngx_resolver_an_t *) &buf[i + 2];
|
|
|
|
qtype = (an->type_hi << 8) + an->type_lo;
|
|
qclass = (an->class_hi << 8) + an->class_lo;
|
|
len = (an->len_hi << 8) + an->len_lo;
|
|
|
|
ngx_log_debug3(NGX_LOG_DEBUG_CORE, r->log, 0,
|
|
"resolver qt:%d cl:%d len:%uz", qtype, qclass, len);
|
|
|
|
i += 2 + sizeof(ngx_resolver_an_t);
|
|
|
|
if (i + len > (ngx_uint_t) n) {
|
|
goto short_response;
|
|
}
|
|
|
|
len -= 2;
|
|
|
|
if (ngx_resolver_copy(r, &name, buf, &buf[i], &buf[n]) != NGX_OK) {
|
|
return;
|
|
}
|
|
|
|
ngx_log_debug1(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver an:%V", &name);
|
|
|
|
if (len != (size_t) rn->nlen || ngx_strncmp(name.data, rn->name, len) != 0)
|
|
{
|
|
ngx_resolver_free(r, rn->name);
|
|
rn->name = name.data;
|
|
|
|
name.data = ngx_resolver_dup(r, rn->name, len);
|
|
if (name.data == NULL) {
|
|
goto failed;
|
|
}
|
|
}
|
|
|
|
ngx_queue_remove(&rn->queue);
|
|
|
|
rn->valid = ngx_time() + r->valid;
|
|
rn->expire = ngx_time() + r->expire;
|
|
|
|
ngx_queue_insert_head(&r->addr_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;
|
|
|
|
invalid_in_addr_arpa:
|
|
|
|
ngx_log_error(r->log_level, r->log, 0,
|
|
"invalid in-addr.arpa name in DNS response");
|
|
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;
|
|
size_t len;
|
|
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 */
|
|
|
|
do {
|
|
rn = (ngx_resolver_node_t *) node;
|
|
|
|
len = (name->len > (size_t) rn->nlen) ? rn->nlen : name->len;
|
|
|
|
rc = ngx_strncmp(name->data, rn->name, len);
|
|
|
|
if (rc == 0) {
|
|
return rn;
|
|
}
|
|
|
|
node = (rc < 0) ? node->left : node->right;
|
|
|
|
} while (node != sentinel && hash == node->key);
|
|
|
|
break;
|
|
}
|
|
|
|
/* 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_t *) node;
|
|
}
|
|
|
|
/* not found */
|
|
|
|
return NULL;
|
|
}
|
|
|
|
|
|
static void
|
|
ngx_resolver_rbtree_insert_value(ngx_rbtree_node_t *temp,
|
|
ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel)
|
|
{
|
|
size_t len;
|
|
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_t *) node;
|
|
rn_temp = (ngx_resolver_node_t *) temp;
|
|
|
|
len = (rn->nlen > rn_temp->nlen) ? rn_temp->nlen : rn->nlen;
|
|
|
|
p = (ngx_strncmp(rn->name, rn_temp->name, len) < 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);
|
|
}
|
|
|
|
|
|
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;
|
|
ngx_uint_t ident;
|
|
ngx_resolver_qs_t *qs;
|
|
ngx_resolver_query_t *query;
|
|
|
|
len = sizeof(ngx_resolver_query_t)
|
|
+ 1 + ctx->name.len + 1 + sizeof(ngx_resolver_qs_t);
|
|
|
|
p = ngx_resolver_calloc(ctx->resolver, len);
|
|
if (p == NULL) {
|
|
return NGX_ERROR;
|
|
}
|
|
|
|
rn->qlen = (u_short) len;
|
|
rn->query = p;
|
|
|
|
query = (ngx_resolver_query_t *) p;
|
|
|
|
ident = ngx_random();
|
|
|
|
ngx_log_debug2(NGX_LOG_DEBUG_CORE, ctx->resolver->log, 0,
|
|
"resolve: \"%V\" %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_query_t) + 1 + ctx->name.len + 1;
|
|
|
|
qs = (ngx_resolver_qs_t *) p;
|
|
|
|
/* query type */
|
|
qs->type_hi = 0; qs->type_lo = (u_char) ctx->type;
|
|
|
|
/* IP query class */
|
|
qs->class_hi = 0; qs->class_lo = 1;
|
|
|
|
/* convert "www.example.com" to "\3www\7example\3com\0" */
|
|
|
|
len = 0;
|
|
p--;
|
|
*p-- = '\0';
|
|
|
|
for (s = ctx->name.data + ctx->name.len - 1; s >= ctx->name.data; s--) {
|
|
if (*s != '.') {
|
|
*p = *s;
|
|
len++;
|
|
|
|
} else {
|
|
*p = (u_char) len;
|
|
len = 0;
|
|
}
|
|
|
|
p--;
|
|
}
|
|
|
|
*p = (u_char) len;
|
|
|
|
return NGX_OK;
|
|
}
|
|
|
|
|
|
/* AF_INET only */
|
|
|
|
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;
|
|
ngx_int_t n;
|
|
ngx_uint_t ident;
|
|
ngx_resolver_query_t *query;
|
|
|
|
len = sizeof(ngx_resolver_query_t)
|
|
+ sizeof(".255.255.255.255.in-addr.arpa.") - 1
|
|
+ sizeof(ngx_resolver_qs_t);
|
|
|
|
p = ngx_resolver_calloc(ctx->resolver, len);
|
|
if (p == NULL) {
|
|
return NGX_ERROR;
|
|
}
|
|
|
|
rn->query = p;
|
|
query = (ngx_resolver_query_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_query_t);
|
|
|
|
for (n = 0; n < 32; n += 8){
|
|
d = ngx_sprintf(&p[1], "%ud", (ctx->addr >> n) & 0xff);
|
|
*p = (u_char) (d - &p[1]);
|
|
p = d;
|
|
}
|
|
|
|
/* query type "PTR", IP query class */
|
|
ngx_memcpy(p, "\7in-addr\4arpa\0\0\14\0\1", 18);
|
|
|
|
rn->qlen = (u_short)
|
|
(p + sizeof("\7in-addr\4arpa") + sizeof(ngx_resolver_qs_t)
|
|
- 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;
|
|
}
|
|
|
|
dst = ngx_resolver_alloc(r, len);
|
|
if (dst == NULL) {
|
|
return NGX_ERROR;
|
|
}
|
|
|
|
name->data = dst;
|
|
|
|
n = *src++;
|
|
|
|
for ( ;; ) {
|
|
if (n != 0xc0) {
|
|
ngx_memcpy(dst, src, n);
|
|
dst += n;
|
|
src += n;
|
|
|
|
n = *src++;
|
|
|
|
if (n != 0) {
|
|
*dst++ = '.';
|
|
}
|
|
|
|
} else {
|
|
n = (n & 0x3f << 8) + *src;
|
|
src = &buf[n];
|
|
|
|
n = *src++;
|
|
}
|
|
|
|
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;
|
|
|
|
ctx = ev->data;
|
|
|
|
ctx->state = NGX_RESOLVE_TIMEDOUT;
|
|
|
|
ctx->handler(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) {
|
|
ngx_resolver_free_locked(r, rn->u.addrs);
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
|
|
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;
|
|
}
|
|
|
|
|
|
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";
|
|
}
|
|
|
|
|
|
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(AF_INET, SOCK_DGRAM, 0);
|
|
|
|
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, uc->log, 0, "UDP socket %d", s);
|
|
|
|
if (s == -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");
|
|
|
|
ngx_free_connection(c);
|
|
|
|
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;
|
|
}
|
|
|
|
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);
|
|
|
|
#if (NGX_THREADS)
|
|
|
|
/* TODO: lock event when call completion handler */
|
|
|
|
rev->lock = &c->lock;
|
|
wev->lock = &c->lock;
|
|
rev->own_lock = &c->lock;
|
|
wev->own_lock = &c->lock;
|
|
|
|
#endif
|
|
|
|
ngx_log_debug3(NGX_LOG_DEBUG_EVENT, uc->log, 0,
|
|
"connect to %V, fd:%d #%d", &uc->server, s, c->number);
|
|
|
|
rc = connect(s, uc->sockaddr, uc->socklen);
|
|
|
|
/* TODO: aio, iocp */
|
|
|
|
if (rc == -1) {
|
|
ngx_log_error(NGX_LOG_CRIT, uc->log, ngx_socket_errno,
|
|
"connect() to %V failed", &uc->server);
|
|
|
|
return NGX_ERROR;
|
|
}
|
|
|
|
/* UDP sockets are always ready to write */
|
|
wev->ready = 1;
|
|
|
|
if (ngx_add_event) {
|
|
|
|
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) {
|
|
return NGX_ERROR;
|
|
}
|
|
|
|
} else {
|
|
/* rtsig */
|
|
|
|
if (ngx_add_conn(c) == NGX_ERROR) {
|
|
return NGX_ERROR;
|
|
}
|
|
}
|
|
|
|
return NGX_OK;
|
|
}
|