| |
| /* |
| * Copyright (C) Igor Sysoev |
| */ |
| |
| |
| #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_query_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; |
| |
| |
| 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 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 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); |
| |
| |
| /* STUB: ngx_peer_addr_t * */ |
| |
| ngx_resolver_t * |
| ngx_resolver_create(ngx_conf_t *cf, ngx_peer_addr_t *addr) |
| { |
| 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); |
| |
| 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 = 300; |
| |
| r->log = &cf->cycle->new_log; |
| r->log_level = NGX_LOG_ALERT; |
| |
| if (addr) { |
| uc = ngx_calloc(sizeof(ngx_udp_connection_t), cf->log); |
| if (uc == NULL) { |
| return NULL; |
| } |
| |
| r->udp_connection = uc; |
| |
| uc->sockaddr = addr->sockaddr; |
| uc->socklen = addr->socklen; |
| uc->server = addr->name; |
| uc->log = &cf->cycle->new_log; |
| } |
| |
| return r; |
| } |
| |
| |
| static void |
| ngx_resolver_cleanup(void *data) |
| { |
| ngx_resolver_t *r = data; |
| |
| 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 (r->event) { |
| ngx_free(r->event); |
| } |
| |
| if (r->udp_connection) { |
| if (r->udp_connection->connection) { |
| ngx_close_connection(r->udp_connection->connection); |
| } |
| |
| ngx_free(r->udp_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_t *) 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 = addr; |
| temp->quick = 1; |
| |
| return temp; |
| } |
| } |
| |
| if (r->udp_connection == NULL) { |
| 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; |
| |
| 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 || ctx->state == NGX_RESOLVE_TIMEDOUT) { |
| |
| 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 */ |
| } |
| |
| |
| /* NGX_RESOLVE_A only */ |
| |
| static ngx_int_t |
| ngx_resolve_name_locked(ngx_resolver_t *r, ngx_resolver_ctx_t *ctx) |
| { |
| uint32_t hash; |
| in_addr_t addr, *addrs; |
| ngx_int_t rc; |
| ngx_uint_t naddrs; |
| ngx_resolver_ctx_t *next; |
| ngx_resolver_node_t *rn; |
| |
| 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; |
| |
| if (naddrs) { |
| |
| /* NGX_RESOLVE_A answer */ |
| |
| if (naddrs != 1) { |
| addr = 0; |
| addrs = ngx_resolver_dup(r, rn->u.addrs, |
| naddrs * sizeof(in_addr_t)); |
| if (addrs == NULL) { |
| return NGX_ERROR; |
| } |
| |
| } else { |
| addr = rn->u.addr; |
| addrs = NULL; |
| } |
| |
| ctx->next = rn->waiting; |
| rn->waiting = NULL; |
| |
| /* unlock name mutex */ |
| |
| do { |
| ctx->state = NGX_OK; |
| ctx->naddrs = naddrs; |
| ctx->addrs = (naddrs == 1) ? &ctx->addr : addrs; |
| ctx->addr = addr; |
| next = ctx->next; |
| |
| ctx->handler(ctx); |
| |
| ctx = next; |
| } while (ctx); |
| |
| if (addrs) { |
| 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; |
| |
| return NGX_AGAIN; |
| } |
| |
| ngx_queue_remove(&rn->queue); |
| |
| /* lock alloc mutex */ |
| |
| ngx_resolver_free_locked(r, rn->query); |
| rn->query = NULL; |
| |
| if (rn->cnlen) { |
| ngx_resolver_free_locked(r, rn->u.cname); |
| } |
| |
| if (rn->naddrs > 1) { |
| ngx_resolver_free_locked(r, rn->u.addrs); |
| } |
| |
| /* 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; |
| |
| 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; |
| } |
| |
| 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 = ctx; |
| ctx->event->log = r->log; |
| ctx->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->cnlen = 0; |
| rn->naddrs = 0; |
| rn->valid = 0; |
| 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; |
| ngx_resolver_t *r; |
| ngx_resolver_node_t *rn; |
| |
| r = ctx->resolver; |
| |
| ctx->addr = ntohl(ctx->addr); |
| |
| /* lock addr mutex */ |
| |
| rn = ngx_resolver_lookup_addr(r, ctx->addr); |
| |
| 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->addr_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; |
| |
| /* unlock addr mutex */ |
| |
| return NGX_OK; |
| } |
| |
| ngx_queue_remove(&rn->queue); |
| |
| ngx_resolver_free(r, rn->query); |
| rn->query = NULL; |
| |
| } else { |
| rn = ngx_resolver_alloc(r, sizeof(ngx_resolver_node_t)); |
| if (rn == NULL) { |
| goto failed; |
| } |
| |
| rn->node.key = ctx->addr; |
| rn->query = NULL; |
| |
| ngx_rbtree_insert(&r->addr_rbtree, &rn->node); |
| } |
| |
| if (ngx_resolver_create_addr_query(rn, ctx) != NGX_OK) { |
| goto failed; |
| } |
| |
| 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 = 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); |
| |
| 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_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 */ |
| |
| /* lock alloc mutex */ |
| |
| if (ctx->event) { |
| ngx_resolver_free_locked(r, ctx->event); |
| } |
| |
| ngx_resolver_free_locked(r, ctx); |
| |
| /* unlock alloc mutex */ |
| } |
| |
| |
| 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_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; |
| uc->connection->read->resolver = 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; |
| } |
| |
| 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; |
| } |
| |
| 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) { |
| |
| 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_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; |
| size_t len; |
| ngx_uint_t i, times, ident, qident, flags, code, nqs, nan, |
| qtype, qclass; |
| ngx_queue_t *q; |
| ngx_resolver_qs_t *qs; |
| ngx_resolver_node_t *rn; |
| ngx_resolver_query_t *query; |
| |
| if ((size_t) n < sizeof(ngx_resolver_query_t)) { |
| 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 %ui fl:%04Xui %ui/%ui/%ui/%ui", |
| 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 %ui fl:%04Xui", ident, flags); |
| return; |
| } |
| |
| code = flags & 0x7f; |
| |
| 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) { |
| 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; |
| } |
| } |
| |
| 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_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:%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: |
| |
| 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, 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: |
| |
| 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 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 %ui response for %V, expect %ui", |
| ident, &name, qident); |
| goto failed; |
| } |
| |
| if (code == 0 && nan == 0) { |
| code = 3; /* NXDOMAIN */ |
| } |
| |
| 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; |
| |
| } else if (qtype == NGX_RESOLVE_DNAME) { |
| i += sizeof(ngx_resolver_an_t) + len; |
| |
| } else { |
| ngx_log_error(r->log_level, r->log, 0, |
| "unexpected qtype %ui", qtype); |
| } |
| } |
| |
| 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 > 1) { |
| 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); |
| |
| ngx_queue_remove(&rn->queue); |
| |
| 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: %ui", |
| 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, ngx_uint_t nan) |
| { |
| 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 %ui response for %ud.%ud.%ud.%ud, expect %ui", |
| ident, (addr >> 24) & 0xff, (addr >> 16) & 0xff, |
| (addr >> 8) & 0xff, addr & 0xff, qident); |
| goto failed; |
| } |
| |
| if (code == 0 && nan == 0) { |
| code = 3; /* NXDOMAIN */ |
| } |
| |
| 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:%ui cl:%ui len:%uz", qtype, qclass, len); |
| |
| i += 2 + sizeof(ngx_resolver_an_t); |
| |
| if (i + len > (ngx_uint_t) n) { |
| goto short_response; |
| } |
| |
| 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 (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; |
| 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 { |
| if (len == 0) { |
| return NGX_DECLINED; |
| } |
| |
| *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; |
| } |
| |
| |
| 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; |
| } |
| |
| |
| 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; |
| } |