Mercurial > hg > nginx-quic
view src/core/ngx_resolver.c @ 5885:5a042519bfe7
Upstream: limited next_upstream time and tries when resolving DNS.
When got multiple upstream IP addresses using DNS resolving, the number of
upstreams tries and the maxinum time spent for these tries were not affected.
This patch fixed it.
author | Gu Feng <flygoast@126.com> |
---|---|
date | Mon, 27 Oct 2014 19:52:03 +0800 |
parents | 3377f9459e99 |
children | 7420068c4d4b |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #define NGX_RESOLVER_UDP_SIZE 4096 typedef struct { u_char ident_hi; u_char ident_lo; u_char flags_hi; u_char flags_lo; u_char nqs_hi; u_char nqs_lo; u_char nan_hi; u_char nan_lo; u_char nns_hi; u_char nns_lo; u_char nar_hi; u_char nar_lo; } ngx_resolver_hdr_t; typedef struct { u_char type_hi; u_char type_lo; u_char class_hi; u_char class_lo; } ngx_resolver_qs_t; typedef struct { u_char type_hi; u_char type_lo; u_char class_hi; u_char class_lo; u_char ttl[4]; u_char len_hi; u_char len_lo; } ngx_resolver_an_t; 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 qtype, ngx_uint_t nan, ngx_uint_t ans); static void ngx_resolver_process_ptr(ngx_resolver_t *r, u_char *buf, size_t n, ngx_uint_t ident, ngx_uint_t code, ngx_uint_t nan); static ngx_resolver_node_t *ngx_resolver_lookup_name(ngx_resolver_t *r, ngx_str_t *name, uint32_t hash); static ngx_resolver_node_t *ngx_resolver_lookup_addr(ngx_resolver_t *r, in_addr_t addr); static void ngx_resolver_rbtree_insert_value(ngx_rbtree_node_t *temp, ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel); static ngx_int_t ngx_resolver_copy(ngx_resolver_t *r, ngx_str_t *name, u_char *buf, u_char *src, u_char *last); static void ngx_resolver_timeout_handler(ngx_event_t *ev); static void ngx_resolver_free_node(ngx_resolver_t *r, ngx_resolver_node_t *rn); static void *ngx_resolver_alloc(ngx_resolver_t *r, size_t size); static void *ngx_resolver_calloc(ngx_resolver_t *r, size_t size); static void ngx_resolver_free(ngx_resolver_t *r, void *p); static void ngx_resolver_free_locked(ngx_resolver_t *r, void *p); static void *ngx_resolver_dup(ngx_resolver_t *r, void *src, size_t size); static ngx_addr_t *ngx_resolver_export(ngx_resolver_t *r, ngx_resolver_node_t *rn, ngx_uint_t rotate); static u_char *ngx_resolver_log_error(ngx_log_t *log, u_char *buf, size_t len); #if (NGX_HAVE_INET6) static void ngx_resolver_rbtree_insert_addr6_value(ngx_rbtree_node_t *temp, ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel); static ngx_resolver_node_t *ngx_resolver_lookup_addr6(ngx_resolver_t *r, struct in6_addr *addr, uint32_t hash); #endif ngx_resolver_t * ngx_resolver_create(ngx_conf_t *cf, ngx_str_t *names, ngx_uint_t n) { ngx_str_t s; ngx_url_t u; ngx_uint_t i, j; ngx_resolver_t *r; ngx_pool_cleanup_t *cln; ngx_udp_connection_t *uc; cln = ngx_pool_cleanup_add(cf->pool, 0); if (cln == NULL) { return NULL; } cln->handler = ngx_resolver_cleanup; r = ngx_calloc(sizeof(ngx_resolver_t), cf->log); if (r == NULL) { return NULL; } cln->data = r; r->event = ngx_calloc(sizeof(ngx_event_t), cf->log); if (r->event == NULL) { return NULL; } ngx_rbtree_init(&r->name_rbtree, &r->name_sentinel, ngx_resolver_rbtree_insert_value); ngx_rbtree_init(&r->addr_rbtree, &r->addr_sentinel, ngx_rbtree_insert_value); ngx_queue_init(&r->name_resend_queue); ngx_queue_init(&r->addr_resend_queue); ngx_queue_init(&r->name_expire_queue); ngx_queue_init(&r->addr_expire_queue); #if (NGX_HAVE_INET6) r->ipv6 = 1; ngx_rbtree_init(&r->addr6_rbtree, &r->addr6_sentinel, ngx_resolver_rbtree_insert_addr6_value); ngx_queue_init(&r->addr6_resend_queue); ngx_queue_init(&r->addr6_expire_queue); #endif r->event->handler = ngx_resolver_resend_handler; r->event->data = r; r->event->log = &cf->cycle->new_log; r->ident = -1; r->resend_timeout = 5; r->expire = 30; r->valid = 0; r->log = &cf->cycle->new_log; r->log_level = NGX_LOG_ERR; if (n) { if (ngx_array_init(&r->udp_connections, cf->pool, n, sizeof(ngx_udp_connection_t)) != NGX_OK) { return NULL; } } for (i = 0; i < n; i++) { if (ngx_strncmp(names[i].data, "valid=", 6) == 0) { s.len = names[i].len - 6; s.data = names[i].data + 6; r->valid = ngx_parse_time(&s, 1); if (r->valid == (time_t) NGX_ERROR) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid parameter: %V", &names[i]); return NULL; } continue; } #if (NGX_HAVE_INET6) if (ngx_strncmp(names[i].data, "ipv6=", 5) == 0) { if (ngx_strcmp(&names[i].data[5], "on") == 0) { r->ipv6 = 1; } else if (ngx_strcmp(&names[i].data[5], "off") == 0) { r->ipv6 = 0; } else { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid parameter: %V", &names[i]); return NULL; } continue; } #endif ngx_memzero(&u, sizeof(ngx_url_t)); u.url = names[i]; u.default_port = 53; if (ngx_parse_url(cf->pool, &u) != NGX_OK) { if (u.err) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "%s in resolver \"%V\"", u.err, &u.url); } return NULL; } uc = ngx_array_push_n(&r->udp_connections, u.naddrs); if (uc == NULL) { return NULL; } ngx_memzero(uc, u.naddrs * sizeof(ngx_udp_connection_t)); for (j = 0; j < u.naddrs; j++) { uc[j].sockaddr = u.addrs[j].sockaddr; uc[j].socklen = u.addrs[j].socklen; uc[j].server = u.addrs[j].name; } } return r; } static void ngx_resolver_cleanup(void *data) { ngx_resolver_t *r = data; ngx_uint_t i; ngx_udp_connection_t *uc; if (r) { ngx_log_debug0(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0, "cleanup resolver"); ngx_resolver_cleanup_tree(r, &r->name_rbtree); ngx_resolver_cleanup_tree(r, &r->addr_rbtree); #if (NGX_HAVE_INET6) ngx_resolver_cleanup_tree(r, &r->addr6_rbtree); #endif if (r->event) { ngx_free(r->event); } uc = r->udp_connections.elts; for (i = 0; i < r->udp_connections.nelts; i++) { if (uc[i].connection) { ngx_close_connection(uc[i].connection); } } ngx_free(r); } } static void ngx_resolver_cleanup_tree(ngx_resolver_t *r, ngx_rbtree_t *tree) { ngx_resolver_ctx_t *ctx, *next; ngx_resolver_node_t *rn; while (tree->root != tree->sentinel) { rn = (ngx_resolver_node_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.sockaddr = (struct sockaddr *) &temp->sin; temp->addr.socklen = sizeof(struct sockaddr_in); ngx_memzero(&temp->sin, sizeof(struct sockaddr_in)); temp->sin.sin_family = AF_INET; temp->sin.sin_addr.s_addr = addr; temp->quick = 1; return temp; } } if (r->udp_connections.nelts == 0) { return NGX_NO_RESOLVER; } ctx = ngx_resolver_calloc(r, sizeof(ngx_resolver_ctx_t)); if (ctx) { ctx->resolver = r; } return ctx; } ngx_int_t ngx_resolve_name(ngx_resolver_ctx_t *ctx) { ngx_int_t rc; ngx_resolver_t *r; r = ctx->resolver; if (ctx->name.len > 0 && ctx->name.data[ctx->name.len - 1] == '.') { ctx->name.len--; } ngx_log_debug1(NGX_LOG_DEBUG_CORE, r->log, 0, "resolve: \"%V\"", &ctx->name); if (ctx->quick) { ctx->handler(ctx); return NGX_OK; } /* lock name mutex */ rc = ngx_resolve_name_locked(r, ctx); if (rc == NGX_OK) { return NGX_OK; } /* unlock name mutex */ if (rc == NGX_AGAIN) { return NGX_OK; } /* NGX_ERROR */ if (ctx->event) { ngx_resolver_free(r, ctx->event); } ngx_resolver_free(r, ctx); return NGX_ERROR; } void ngx_resolve_name_done(ngx_resolver_ctx_t *ctx) { uint32_t hash; ngx_resolver_t *r; ngx_resolver_ctx_t *w, **p; ngx_resolver_node_t *rn; r = ctx->resolver; ngx_log_debug1(NGX_LOG_DEBUG_CORE, r->log, 0, "resolve name done: %i", ctx->state); if (ctx->quick) { return; } if (ctx->event && ctx->event->timer_set) { ngx_del_timer(ctx->event); } /* lock name mutex */ if (ctx->state == NGX_AGAIN) { hash = ngx_crc32_short(ctx->name.data, ctx->name.len); rn = ngx_resolver_lookup_name(r, &ctx->name, hash); if (rn) { p = &rn->waiting; w = rn->waiting; while (w) { if (w == ctx) { *p = w->next; goto done; } p = &w->next; w = w->next; } } ngx_log_error(NGX_LOG_ALERT, r->log, 0, "could not cancel %V resolving", &ctx->name); } done: ngx_resolver_expire(r, &r->name_rbtree, &r->name_expire_queue); /* unlock name mutex */ /* lock alloc mutex */ if (ctx->event) { ngx_resolver_free_locked(r, ctx->event); } ngx_resolver_free_locked(r, ctx); /* unlock alloc mutex */ } static ngx_int_t ngx_resolve_name_locked(ngx_resolver_t *r, ngx_resolver_ctx_t *ctx) { uint32_t hash; ngx_int_t rc; ngx_uint_t naddrs; ngx_addr_t *addrs; ngx_resolver_ctx_t *next; ngx_resolver_node_t *rn; ngx_strlow(ctx->name.data, ctx->name.data, ctx->name.len); hash = ngx_crc32_short(ctx->name.data, ctx->name.len); rn = ngx_resolver_lookup_name(r, &ctx->name, hash); if (rn) { if (rn->valid >= ngx_time()) { ngx_log_debug0(NGX_LOG_DEBUG_CORE, r->log, 0, "resolve cached"); ngx_queue_remove(&rn->queue); rn->expire = ngx_time() + r->expire; ngx_queue_insert_head(&r->name_expire_queue, &rn->queue); naddrs = (rn->naddrs == (u_short) -1) ? 0 : rn->naddrs; #if (NGX_HAVE_INET6) naddrs += (rn->naddrs6 == (u_short) -1) ? 0 : rn->naddrs6; #endif if (naddrs) { if (naddrs == 1 && rn->naddrs == 1) { addrs = NULL; } else { addrs = ngx_resolver_export(r, rn, 1); if (addrs == NULL) { return NGX_ERROR; } } ctx->next = rn->waiting; rn->waiting = NULL; /* unlock name mutex */ do { ctx->state = NGX_OK; ctx->naddrs = naddrs; if (addrs == NULL) { ctx->addrs = &ctx->addr; ctx->addr.sockaddr = (struct sockaddr *) &ctx->sin; ctx->addr.socklen = sizeof(struct sockaddr_in); ngx_memzero(&ctx->sin, sizeof(struct sockaddr_in)); ctx->sin.sin_family = AF_INET; ctx->sin.sin_addr.s_addr = rn->u.addr; } else { ctx->addrs = addrs; } next = ctx->next; ctx->handler(ctx); ctx = next; } while (ctx); if (addrs != NULL) { ngx_resolver_free(r, addrs->sockaddr); ngx_resolver_free(r, addrs); } return NGX_OK; } /* NGX_RESOLVE_CNAME */ if (ctx->recursion++ < NGX_RESOLVER_MAX_RECURSION) { ctx->name.len = rn->cnlen; ctx->name.data = rn->u.cname; return ngx_resolve_name_locked(r, ctx); } ctx->next = rn->waiting; rn->waiting = NULL; /* unlock name mutex */ do { ctx->state = NGX_RESOLVE_NXDOMAIN; next = ctx->next; ctx->handler(ctx); ctx = next; } while (ctx); return NGX_OK; } if (rn->waiting) { ctx->next = rn->waiting; rn->waiting = ctx; ctx->state = NGX_AGAIN; return NGX_AGAIN; } ngx_queue_remove(&rn->queue); /* lock alloc mutex */ if (rn->query) { ngx_resolver_free_locked(r, rn->query); rn->query = NULL; #if (NGX_HAVE_INET6) rn->query6 = NULL; #endif } if (rn->cnlen) { ngx_resolver_free_locked(r, rn->u.cname); } if (rn->naddrs > 1 && rn->naddrs != (u_short) -1) { ngx_resolver_free_locked(r, rn->u.addrs); } #if (NGX_HAVE_INET6) if (rn->naddrs6 > 1 && rn->naddrs6 != (u_short) -1) { ngx_resolver_free_locked(r, rn->u6.addrs6); } #endif /* unlock alloc mutex */ } else { rn = ngx_resolver_alloc(r, sizeof(ngx_resolver_node_t)); if (rn == NULL) { return NGX_ERROR; } rn->name = ngx_resolver_dup(r, ctx->name.data, ctx->name.len); if (rn->name == NULL) { ngx_resolver_free(r, rn); return NGX_ERROR; } rn->node.key = hash; rn->nlen = (u_short) ctx->name.len; rn->query = NULL; #if (NGX_HAVE_INET6) rn->query6 = NULL; #endif ngx_rbtree_insert(&r->name_rbtree, &rn->node); } rc = ngx_resolver_create_name_query(rn, ctx); if (rc == NGX_ERROR) { goto failed; } if (rc == NGX_DECLINED) { ngx_rbtree_delete(&r->name_rbtree, &rn->node); ngx_resolver_free(r, rn->query); ngx_resolver_free(r, rn->name); ngx_resolver_free(r, rn); ctx->state = NGX_RESOLVE_NXDOMAIN; ctx->handler(ctx); return NGX_OK; } rn->naddrs = (u_short) -1; #if (NGX_HAVE_INET6) rn->naddrs6 = r->ipv6 ? (u_short) -1 : 0; #endif if (ngx_resolver_send_query(r, rn) != NGX_OK) { goto failed; } if (ctx->event == NULL) { ctx->event = ngx_resolver_calloc(r, sizeof(ngx_event_t)); if (ctx->event == NULL) { goto failed; } ctx->event->handler = ngx_resolver_timeout_handler; ctx->event->data = rn; ctx->event->log = r->log; 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->code = 0; rn->cnlen = 0; rn->valid = 0; rn->ttl = NGX_MAX_UINT32_VALUE; rn->waiting = ctx; ctx->state = NGX_AGAIN; return NGX_AGAIN; failed: ngx_rbtree_delete(&r->name_rbtree, &rn->node); if (rn->query) { ngx_resolver_free(r, rn->query); } ngx_resolver_free(r, rn->name); ngx_resolver_free(r, rn); return NGX_ERROR; } ngx_int_t ngx_resolve_addr(ngx_resolver_ctx_t *ctx) { u_char *name; in_addr_t addr; ngx_queue_t *resend_queue, *expire_queue; ngx_rbtree_t *tree; ngx_resolver_t *r; struct sockaddr_in *sin; ngx_resolver_node_t *rn; #if (NGX_HAVE_INET6) uint32_t hash; struct sockaddr_in6 *sin6; #endif #if (NGX_SUPPRESS_WARN) addr = 0; #if (NGX_HAVE_INET6) hash = 0; sin6 = NULL; #endif #endif r = ctx->resolver; switch (ctx->addr.sockaddr->sa_family) { #if (NGX_HAVE_INET6) case AF_INET6: sin6 = (struct sockaddr_in6 *) ctx->addr.sockaddr; hash = ngx_crc32_short(sin6->sin6_addr.s6_addr, 16); /* lock addr mutex */ rn = ngx_resolver_lookup_addr6(r, &sin6->sin6_addr, hash); tree = &r->addr6_rbtree; resend_queue = &r->addr6_resend_queue; expire_queue = &r->addr6_expire_queue; break; #endif default: /* AF_INET */ sin = (struct sockaddr_in *) ctx->addr.sockaddr; addr = ntohl(sin->sin_addr.s_addr); /* lock addr mutex */ rn = ngx_resolver_lookup_addr(r, addr); tree = &r->addr_rbtree; resend_queue = &r->addr_resend_queue; expire_queue = &r->addr_expire_queue; } if (rn) { if (rn->valid >= ngx_time()) { ngx_log_debug0(NGX_LOG_DEBUG_CORE, r->log, 0, "resolve cached"); ngx_queue_remove(&rn->queue); rn->expire = ngx_time() + r->expire; ngx_queue_insert_head(expire_queue, &rn->queue); name = ngx_resolver_dup(r, rn->name, rn->nlen); if (name == NULL) { goto failed; } ctx->name.len = rn->nlen; ctx->name.data = name; /* unlock addr mutex */ ctx->state = NGX_OK; ctx->handler(ctx); ngx_resolver_free(r, name); return NGX_OK; } if (rn->waiting) { ctx->next = rn->waiting; rn->waiting = ctx; ctx->state = NGX_AGAIN; /* unlock addr mutex */ return NGX_OK; } ngx_queue_remove(&rn->queue); ngx_resolver_free(r, rn->query); rn->query = NULL; #if (NGX_HAVE_INET6) rn->query6 = NULL; #endif } else { rn = ngx_resolver_alloc(r, sizeof(ngx_resolver_node_t)); if (rn == NULL) { goto failed; } switch (ctx->addr.sockaddr->sa_family) { #if (NGX_HAVE_INET6) case AF_INET6: rn->addr6 = sin6->sin6_addr; rn->node.key = hash; break; #endif default: /* AF_INET */ rn->node.key = addr; } rn->query = NULL; #if (NGX_HAVE_INET6) rn->query6 = NULL; #endif ngx_rbtree_insert(tree, &rn->node); } if (ngx_resolver_create_addr_query(rn, ctx) != NGX_OK) { goto failed; } rn->naddrs = (u_short) -1; #if (NGX_HAVE_INET6) rn->naddrs6 = (u_short) -1; #endif if (ngx_resolver_send_query(r, rn) != NGX_OK) { goto failed; } ctx->event = ngx_resolver_calloc(r, sizeof(ngx_event_t)); if (ctx->event == NULL) { goto failed; } ctx->event->handler = ngx_resolver_timeout_handler; ctx->event->data = rn; ctx->event->log = r->log; ctx->ident = -1; ngx_add_timer(ctx->event, ctx->timeout); if (ngx_queue_empty(resend_queue)) { ngx_add_timer(r->event, (ngx_msec_t) (r->resend_timeout * 1000)); } rn->expire = ngx_time() + r->resend_timeout; ngx_queue_insert_head(resend_queue, &rn->queue); rn->code = 0; rn->cnlen = 0; rn->name = NULL; rn->nlen = 0; rn->valid = 0; rn->ttl = NGX_MAX_UINT32_VALUE; rn->waiting = ctx; /* unlock addr mutex */ ctx->state = NGX_AGAIN; return NGX_OK; failed: if (rn) { ngx_rbtree_delete(tree, &rn->node); if (rn->query) { ngx_resolver_free(r, rn->query); } ngx_resolver_free(r, rn); } /* unlock addr mutex */ if (ctx->event) { ngx_resolver_free(r, ctx->event); } ngx_resolver_free(r, ctx); return NGX_ERROR; } void ngx_resolve_addr_done(ngx_resolver_ctx_t *ctx) { in_addr_t addr; ngx_queue_t *expire_queue; ngx_rbtree_t *tree; ngx_resolver_t *r; ngx_resolver_ctx_t *w, **p; struct sockaddr_in *sin; ngx_resolver_node_t *rn; #if (NGX_HAVE_INET6) uint32_t hash; struct sockaddr_in6 *sin6; #endif r = ctx->resolver; switch (ctx->addr.sockaddr->sa_family) { #if (NGX_HAVE_INET6) case AF_INET6: tree = &r->addr6_rbtree; expire_queue = &r->addr6_expire_queue; break; #endif default: /* AF_INET */ tree = &r->addr_rbtree; expire_queue = &r->addr_expire_queue; } ngx_log_debug1(NGX_LOG_DEBUG_CORE, r->log, 0, "resolve addr done: %i", ctx->state); if (ctx->event && ctx->event->timer_set) { ngx_del_timer(ctx->event); } /* lock addr mutex */ if (ctx->state == NGX_AGAIN) { switch (ctx->addr.sockaddr->sa_family) { #if (NGX_HAVE_INET6) case AF_INET6: sin6 = (struct sockaddr_in6 *) ctx->addr.sockaddr; hash = ngx_crc32_short(sin6->sin6_addr.s6_addr, 16); rn = ngx_resolver_lookup_addr6(r, &sin6->sin6_addr, hash); break; #endif default: /* AF_INET */ sin = (struct sockaddr_in *) ctx->addr.sockaddr; addr = ntohl(sin->sin_addr.s_addr); rn = ngx_resolver_lookup_addr(r, addr); } if (rn) { p = &rn->waiting; w = rn->waiting; while (w) { if (w == ctx) { *p = w->next; goto done; } p = &w->next; w = w->next; } } { u_char text[NGX_SOCKADDR_STRLEN]; ngx_str_t addrtext; addrtext.data = text; addrtext.len = ngx_sock_ntop(ctx->addr.sockaddr, ctx->addr.socklen, text, NGX_SOCKADDR_STRLEN, 0); ngx_log_error(NGX_LOG_ALERT, r->log, 0, "could not cancel %V resolving", &addrtext); } } done: ngx_resolver_expire(r, tree, expire_queue); /* unlock addr mutex */ /* lock alloc mutex */ if (ctx->event) { ngx_resolver_free_locked(r, ctx->event); } ngx_resolver_free_locked(r, ctx); /* unlock alloc mutex */ } static void ngx_resolver_expire(ngx_resolver_t *r, ngx_rbtree_t *tree, ngx_queue_t *queue) { time_t now; ngx_uint_t i; ngx_queue_t *q; ngx_resolver_node_t *rn; ngx_log_debug0(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver expire"); now = ngx_time(); for (i = 0; i < 2; i++) { if (ngx_queue_empty(queue)) { return; } q = ngx_queue_last(queue); rn = ngx_queue_data(q, ngx_resolver_node_t, queue); if (now <= rn->expire) { return; } ngx_log_debug2(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver expire \"%*s\"", (size_t) rn->nlen, rn->name); ngx_queue_remove(q); ngx_rbtree_delete(tree, &rn->node); ngx_resolver_free_node(r, rn); } } static ngx_int_t ngx_resolver_send_query(ngx_resolver_t *r, ngx_resolver_node_t *rn) { ssize_t n; ngx_udp_connection_t *uc; uc = r->udp_connections.elts; uc = &uc[r->last_connection++]; if (r->last_connection == r->udp_connections.nelts) { r->last_connection = 0; } if (uc->connection == NULL) { uc->log = *r->log; uc->log.handler = ngx_resolver_log_error; uc->log.data = uc; uc->log.action = "resolving"; if (ngx_udp_connect(uc) != NGX_OK) { return NGX_ERROR; } uc->connection->data = r; uc->connection->read->handler = ngx_resolver_read_response; uc->connection->read->resolver = 1; } if (rn->naddrs == (u_short) -1) { n = ngx_send(uc->connection, rn->query, rn->qlen); if (n == -1) { return NGX_ERROR; } if ((size_t) n != (size_t) rn->qlen) { ngx_log_error(NGX_LOG_CRIT, &uc->log, 0, "send() incomplete"); return NGX_ERROR; } } #if (NGX_HAVE_INET6) if (rn->query6 && rn->naddrs6 == (u_short) -1) { n = ngx_send(uc->connection, rn->query6, rn->qlen); if (n == -1) { return NGX_ERROR; } if ((size_t) n != (size_t) rn->qlen) { ngx_log_error(NGX_LOG_CRIT, &uc->log, 0, "send() incomplete"); return NGX_ERROR; } } #endif return NGX_OK; } static void ngx_resolver_resend_handler(ngx_event_t *ev) { time_t timer, atimer, ntimer; #if (NGX_HAVE_INET6) time_t a6timer; #endif ngx_resolver_t *r; r = ev->data; ngx_log_debug0(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver resend handler"); /* lock name mutex */ ntimer = ngx_resolver_resend(r, &r->name_rbtree, &r->name_resend_queue); /* unlock name mutex */ /* lock addr mutex */ atimer = ngx_resolver_resend(r, &r->addr_rbtree, &r->addr_resend_queue); /* unlock addr mutex */ #if (NGX_HAVE_INET6) /* lock addr6 mutex */ a6timer = ngx_resolver_resend(r, &r->addr6_rbtree, &r->addr6_resend_queue); /* unlock addr6 mutex */ #endif timer = ntimer; if (timer == 0) { timer = atimer; } else if (atimer) { timer = ngx_min(timer, atimer); } #if (NGX_HAVE_INET6) if (timer == 0) { timer = a6timer; } else if (a6timer) { timer = ngx_min(timer, a6timer); } #endif if (timer) { ngx_add_timer(r->event, (ngx_msec_t) (timer * 1000)); } } static time_t ngx_resolver_resend(ngx_resolver_t *r, ngx_rbtree_t *tree, ngx_queue_t *queue) { time_t now; ngx_queue_t *q; ngx_resolver_node_t *rn; now = ngx_time(); for ( ;; ) { if (ngx_queue_empty(queue)) { return 0; } q = ngx_queue_last(queue); rn = ngx_queue_data(q, ngx_resolver_node_t, queue); if (now < rn->expire) { return rn->expire - now; } ngx_log_debug3(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver resend \"%*s\" %p", (size_t) rn->nlen, rn->name, rn->waiting); ngx_queue_remove(q); if (rn->waiting) { (void) ngx_resolver_send_query(r, rn); rn->expire = now + r->resend_timeout; ngx_queue_insert_head(queue, q); continue; } ngx_rbtree_delete(tree, &rn->node); ngx_resolver_free_node(r, rn); } } static void ngx_resolver_read_response(ngx_event_t *rev) { ssize_t n; ngx_connection_t *c; u_char buf[NGX_RESOLVER_UDP_SIZE]; c = rev->data; do { n = ngx_udp_recv(c, buf, NGX_RESOLVER_UDP_SIZE); if (n < 0) { return; } ngx_resolver_process_response(c->data, buf, n); } while (rev->ready); } static void ngx_resolver_process_response(ngx_resolver_t *r, u_char *buf, size_t n) { char *err; ngx_uint_t i, times, ident, qident, flags, code, nqs, nan, qtype, qclass; #if (NGX_HAVE_INET6) ngx_uint_t qident6; #endif ngx_queue_t *q; ngx_resolver_qs_t *qs; ngx_resolver_hdr_t *response; ngx_resolver_node_t *rn; if (n < sizeof(ngx_resolver_hdr_t)) { goto short_response; } response = (ngx_resolver_hdr_t *) buf; ident = (response->ident_hi << 8) + response->ident_lo; flags = (response->flags_hi << 8) + response->flags_lo; nqs = (response->nqs_hi << 8) + response->nqs_lo; nan = (response->nan_hi << 8) + response->nan_lo; ngx_log_debug6(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver DNS response %ui fl:%04Xui %ui/%ui/%ud/%ud", ident, flags, nqs, nan, (response->nns_hi << 8) + response->nns_lo, (response->nar_hi << 8) + response->nar_lo); /* response to a standard query */ if ((flags & 0xf870) != 0x8000) { ngx_log_error(r->log_level, r->log, 0, "invalid DNS response %ui fl:%04Xui", ident, flags); return; } code = flags & 0xf; if (code == NGX_RESOLVE_FORMERR) { times = 0; for (q = ngx_queue_head(&r->name_resend_queue); q != ngx_queue_sentinel(&r->name_resend_queue) || times++ < 100; q = ngx_queue_next(q)) { rn = ngx_queue_data(q, ngx_resolver_node_t, queue); qident = (rn->query[0] << 8) + rn->query[1]; if (qident == ident) { goto dns_error_name; } #if (NGX_HAVE_INET6) if (rn->query6) { qident6 = (rn->query6[0] << 8) + rn->query6[1]; if (qident6 == ident) { goto dns_error_name; } } #endif } goto dns_error; } if (code > NGX_RESOLVE_REFUSED) { goto dns_error; } if (nqs != 1) { err = "invalid number of questions in DNS response"; goto done; } i = sizeof(ngx_resolver_hdr_t); while (i < (ngx_uint_t) n) { if (buf[i] == '\0') { goto found; } i += 1 + buf[i]; } goto short_response; found: if (i++ == sizeof(ngx_resolver_hdr_t)) { err = "zero-length domain name in DNS response"; goto done; } if (i + sizeof(ngx_resolver_qs_t) + nan * (2 + sizeof(ngx_resolver_an_t)) > (ngx_uint_t) n) { goto short_response; } qs = (ngx_resolver_qs_t *) &buf[i]; qtype = (qs->type_hi << 8) + qs->type_lo; qclass = (qs->class_hi << 8) + qs->class_lo; ngx_log_debug2(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver DNS response qt:%ui cl:%ui", qtype, qclass); if (qclass != 1) { ngx_log_error(r->log_level, r->log, 0, "unknown query class %ui in DNS response", qclass); return; } switch (qtype) { case NGX_RESOLVE_A: #if (NGX_HAVE_INET6) case NGX_RESOLVE_AAAA: #endif ngx_resolver_process_a(r, buf, n, ident, code, qtype, nan, i + sizeof(ngx_resolver_qs_t)); break; case NGX_RESOLVE_PTR: ngx_resolver_process_ptr(r, buf, n, ident, code, nan); break; default: ngx_log_error(r->log_level, r->log, 0, "unknown query type %ui in DNS response", qtype); return; } return; short_response: err = "short DNS response"; done: ngx_log_error(r->log_level, r->log, 0, err); return; dns_error_name: ngx_log_error(r->log_level, r->log, 0, "DNS error (%ui: %s), query id:%ui, name:\"%*s\"", code, ngx_resolver_strerror(code), ident, rn->nlen, rn->name); return; dns_error: ngx_log_error(r->log_level, r->log, 0, "DNS error (%ui: %s), query id:%ui", code, ngx_resolver_strerror(code), ident); return; } static void ngx_resolver_process_a(ngx_resolver_t *r, u_char *buf, size_t last, ngx_uint_t ident, ngx_uint_t code, ngx_uint_t qtype, ngx_uint_t nan, ngx_uint_t ans) { char *err; u_char *cname; size_t len; int32_t ttl; uint32_t hash; in_addr_t *addr; ngx_str_t name; ngx_addr_t *addrs; ngx_uint_t type, class, qident, naddrs, a, i, n, start; #if (NGX_HAVE_INET6) struct in6_addr *addr6; #endif ngx_resolver_an_t *an; ngx_resolver_ctx_t *ctx, *next; ngx_resolver_node_t *rn; if (ngx_resolver_copy(r, &name, buf, buf + sizeof(ngx_resolver_hdr_t), buf + last) != NGX_OK) { return; } ngx_log_debug1(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver qs:%V", &name); hash = ngx_crc32_short(name.data, name.len); /* lock name mutex */ rn = ngx_resolver_lookup_name(r, &name, hash); if (rn == NULL) { ngx_log_error(r->log_level, r->log, 0, "unexpected response for %V", &name); ngx_resolver_free(r, name.data); goto failed; } switch (qtype) { #if (NGX_HAVE_INET6) case NGX_RESOLVE_AAAA: if (rn->query6 == NULL || rn->naddrs6 != (u_short) -1) { ngx_log_error(r->log_level, r->log, 0, "unexpected response for %V", &name); ngx_resolver_free(r, name.data); goto failed; } qident = (rn->query6[0] << 8) + rn->query6[1]; break; #endif default: /* NGX_RESOLVE_A */ if (rn->query == NULL || rn->naddrs != (u_short) -1) { ngx_log_error(r->log_level, r->log, 0, "unexpected response for %V", &name); ngx_resolver_free(r, name.data); goto failed; } qident = (rn->query[0] << 8) + rn->query[1]; } if (ident != qident) { ngx_log_error(r->log_level, r->log, 0, "wrong ident %ui response for %V, expect %ui", ident, &name, qident); ngx_resolver_free(r, name.data); goto failed; } ngx_resolver_free(r, name.data); if (code == 0 && rn->code) { code = rn->code; } if (code == 0 && nan == 0) { #if (NGX_HAVE_INET6) switch (qtype) { case NGX_RESOLVE_AAAA: rn->naddrs6 = 0; if (rn->naddrs == (u_short) -1) { goto next; } if (rn->naddrs) { goto export; } break; default: /* NGX_RESOLVE_A */ rn->naddrs = 0; if (rn->naddrs6 == (u_short) -1) { goto next; } if (rn->naddrs6) { goto export; } } #endif code = NGX_RESOLVE_NXDOMAIN; } if (code) { #if (NGX_HAVE_INET6) switch (qtype) { case NGX_RESOLVE_AAAA: rn->naddrs6 = 0; if (rn->naddrs == (u_short) -1) { rn->code = (u_char) code; goto next; } break; default: /* NGX_RESOLVE_A */ rn->naddrs = 0; if (rn->naddrs6 == (u_short) -1) { rn->code = (u_char) code; goto next; } } #endif next = rn->waiting; rn->waiting = NULL; ngx_queue_remove(&rn->queue); ngx_rbtree_delete(&r->name_rbtree, &rn->node); 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; cname = NULL; for (a = 0; a < nan; a++) { start = i; while (i < last) { if (buf[i] & 0xc0) { i += 2; goto found; } if (buf[i] == 0) { i++; goto test_length; } i += 1 + buf[i]; } goto short_response; test_length: if (i - start < 2) { err = "invalid name in DNS response"; goto invalid; } found: if (i + sizeof(ngx_resolver_an_t) >= last) { goto short_response; } an = (ngx_resolver_an_t *) &buf[i]; type = (an->type_hi << 8) + an->type_lo; class = (an->class_hi << 8) + an->class_lo; len = (an->len_hi << 8) + an->len_lo; ttl = (an->ttl[0] << 24) + (an->ttl[1] << 16) + (an->ttl[2] << 8) + (an->ttl[3]); if (class != 1) { ngx_log_error(r->log_level, r->log, 0, "unexpected RR class %ui", class); goto failed; } if (ttl < 0) { ttl = 0; } rn->ttl = ngx_min(rn->ttl, (uint32_t) ttl); i += sizeof(ngx_resolver_an_t); switch (type) { case NGX_RESOLVE_A: if (qtype != NGX_RESOLVE_A) { err = "unexpected A record in DNS response"; goto invalid; } if (len != 4) { err = "invalid A record in DNS response"; goto invalid; } if (i + 4 > last) { goto short_response; } naddrs++; break; #if (NGX_HAVE_INET6) case NGX_RESOLVE_AAAA: if (qtype != NGX_RESOLVE_AAAA) { err = "unexpected AAAA record in DNS response"; goto invalid; } if (len != 16) { err = "invalid AAAA record in DNS response"; goto invalid; } if (i + 16 > last) { goto short_response; } naddrs++; break; #endif case NGX_RESOLVE_CNAME: cname = &buf[i]; break; case NGX_RESOLVE_DNAME: break; default: ngx_log_error(r->log_level, r->log, 0, "unexpected RR type %ui", type); } i += len; } ngx_log_debug3(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver naddrs:%ui cname:%p ttl:%uD", naddrs, cname, rn->ttl); if (naddrs) { switch (qtype) { #if (NGX_HAVE_INET6) case NGX_RESOLVE_AAAA: if (naddrs == 1) { addr6 = &rn->u6.addr6; rn->naddrs6 = 1; } else { addr6 = ngx_resolver_alloc(r, naddrs * sizeof(struct in6_addr)); if (addr6 == NULL) { goto failed; } rn->u6.addrs6 = addr6; rn->naddrs6 = (u_short) naddrs; } #if (NGX_SUPPRESS_WARN) addr = NULL; #endif break; #endif default: /* NGX_RESOLVE_A */ if (naddrs == 1) { addr = &rn->u.addr; rn->naddrs = 1; } else { addr = ngx_resolver_alloc(r, naddrs * sizeof(in_addr_t)); if (addr == NULL) { goto failed; } rn->u.addrs = addr; rn->naddrs = (u_short) naddrs; } #if (NGX_HAVE_INET6 && NGX_SUPPRESS_WARN) addr6 = NULL; #endif } n = 0; i = ans; for (a = 0; a < nan; a++) { for ( ;; ) { if (buf[i] & 0xc0) { i += 2; break; } if (buf[i] == 0) { i++; break; } i += 1 + buf[i]; } an = (ngx_resolver_an_t *) &buf[i]; type = (an->type_hi << 8) + an->type_lo; len = (an->len_hi << 8) + an->len_lo; i += sizeof(ngx_resolver_an_t); if (type == NGX_RESOLVE_A) { addr[n] = htonl((buf[i] << 24) + (buf[i + 1] << 16) + (buf[i + 2] << 8) + (buf[i + 3])); if (++n == naddrs) { #if (NGX_HAVE_INET6) if (rn->naddrs6 == (u_short) -1) { goto next; } #endif break; } } #if (NGX_HAVE_INET6) else if (type == NGX_RESOLVE_AAAA) { ngx_memcpy(addr6[n].s6_addr, &buf[i], 16); if (++n == naddrs) { if (rn->naddrs == (u_short) -1) { goto next; } break; } } #endif i += len; } } switch (qtype) { #if (NGX_HAVE_INET6) case NGX_RESOLVE_AAAA: if (rn->naddrs6 == (u_short) -1) { rn->naddrs6 = 0; } break; #endif default: /* NGX_RESOLVE_A */ if (rn->naddrs == (u_short) -1) { rn->naddrs = 0; } } if (rn->naddrs != (u_short) -1 #if (NGX_HAVE_INET6) && rn->naddrs6 != (u_short) -1 #endif && rn->naddrs #if (NGX_HAVE_INET6) + rn->naddrs6 #endif > 0) { #if (NGX_HAVE_INET6) export: #endif naddrs = rn->naddrs; #if (NGX_HAVE_INET6) naddrs += rn->naddrs6; #endif if (naddrs == 1 && rn->naddrs == 1) { addrs = NULL; } else { addrs = ngx_resolver_export(r, rn, 0); if (addrs == NULL) { goto failed; } } ngx_queue_remove(&rn->queue); rn->valid = ngx_time() + (r->valid ? r->valid : (time_t) rn->ttl); rn->expire = ngx_time() + r->expire; ngx_queue_insert_head(&r->name_expire_queue, &rn->queue); next = rn->waiting; rn->waiting = NULL; /* unlock name mutex */ while (next) { ctx = next; ctx->state = NGX_OK; ctx->naddrs = naddrs; if (addrs == NULL) { ctx->addrs = &ctx->addr; ctx->addr.sockaddr = (struct sockaddr *) &ctx->sin; ctx->addr.socklen = sizeof(struct sockaddr_in); ngx_memzero(&ctx->sin, sizeof(struct sockaddr_in)); ctx->sin.sin_family = AF_INET; ctx->sin.sin_addr.s_addr = rn->u.addr; } else { ctx->addrs = addrs; } next = ctx->next; ctx->handler(ctx); } if (addrs != NULL) { ngx_resolver_free(r, addrs->sockaddr); ngx_resolver_free(r, addrs); } ngx_resolver_free(r, rn->query); rn->query = NULL; #if (NGX_HAVE_INET6) rn->query6 = NULL; #endif return; } if (cname) { /* CNAME only */ if (rn->naddrs == (u_short) -1 #if (NGX_HAVE_INET6) || rn->naddrs6 == (u_short) -1 #endif ) { goto next; } if (ngx_resolver_copy(r, &name, buf, cname, buf + last) != NGX_OK) { goto failed; } ngx_log_debug1(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver cname:\"%V\"", &name); ngx_queue_remove(&rn->queue); rn->cnlen = (u_short) name.len; rn->u.cname = name.data; rn->valid = ngx_time() + (r->valid ? r->valid : (time_t) rn->ttl); rn->expire = ngx_time() + r->expire; ngx_queue_insert_head(&r->name_expire_queue, &rn->queue); ctx = rn->waiting; rn->waiting = NULL; if (ctx) { ctx->name = name; (void) ngx_resolve_name_locked(r, ctx); } ngx_resolver_free(r, rn->query); rn->query = NULL; #if (NGX_HAVE_INET6) rn->query6 = NULL; #endif /* unlock name mutex */ return; } ngx_log_error(r->log_level, r->log, 0, "no A or CNAME types in DNS response"); return; short_response: err = "short DNS response"; invalid: /* unlock name mutex */ ngx_log_error(r->log_level, r->log, 0, err); return; failed: next: /* unlock name mutex */ return; } static void ngx_resolver_process_ptr(ngx_resolver_t *r, u_char *buf, size_t n, ngx_uint_t ident, ngx_uint_t code, ngx_uint_t nan) { char *err; size_t len; u_char text[NGX_SOCKADDR_STRLEN]; in_addr_t addr; int32_t ttl; ngx_int_t octet; ngx_str_t name; ngx_uint_t i, mask, qident, class; ngx_queue_t *expire_queue; ngx_rbtree_t *tree; ngx_resolver_an_t *an; ngx_resolver_ctx_t *ctx, *next; ngx_resolver_node_t *rn; #if (NGX_HAVE_INET6) uint32_t hash; ngx_int_t digit; struct in6_addr addr6; #endif if (ngx_resolver_copy(r, NULL, buf, buf + sizeof(ngx_resolver_hdr_t), buf + n) != NGX_OK) { return; } /* AF_INET */ addr = 0; i = sizeof(ngx_resolver_hdr_t); for (mask = 0; mask < 32; mask += 8) { len = buf[i++]; octet = ngx_atoi(&buf[i], len); if (octet == NGX_ERROR || octet > 255) { goto invalid_in_addr_arpa; } addr += octet << mask; i += len; } if (ngx_strcasecmp(&buf[i], (u_char *) "\7in-addr\4arpa") == 0) { i += sizeof("\7in-addr\4arpa"); /* lock addr mutex */ rn = ngx_resolver_lookup_addr(r, addr); tree = &r->addr_rbtree; expire_queue = &r->addr_expire_queue; addr = htonl(addr); name.len = ngx_inet_ntop(AF_INET, &addr, text, NGX_SOCKADDR_STRLEN); name.data = text; goto valid; } invalid_in_addr_arpa: #if (NGX_HAVE_INET6) i = sizeof(ngx_resolver_hdr_t); for (octet = 15; octet >= 0; octet--) { if (buf[i++] != '\1') { goto invalid_ip6_arpa; } digit = ngx_hextoi(&buf[i++], 1); if (digit == NGX_ERROR) { goto invalid_ip6_arpa; } addr6.s6_addr[octet] = (u_char) digit; if (buf[i++] != '\1') { goto invalid_ip6_arpa; } digit = ngx_hextoi(&buf[i++], 1); if (digit == NGX_ERROR) { goto invalid_ip6_arpa; } addr6.s6_addr[octet] += (u_char) (digit * 16); } if (ngx_strcasecmp(&buf[i], (u_char *) "\3ip6\4arpa") == 0) { i += sizeof("\3ip6\4arpa"); /* lock addr mutex */ hash = ngx_crc32_short(addr6.s6_addr, 16); rn = ngx_resolver_lookup_addr6(r, &addr6, hash); tree = &r->addr6_rbtree; expire_queue = &r->addr6_expire_queue; name.len = ngx_inet6_ntop(addr6.s6_addr, text, NGX_SOCKADDR_STRLEN); name.data = text; goto valid; } invalid_ip6_arpa: #endif ngx_log_error(r->log_level, r->log, 0, "invalid in-addr.arpa or ip6.arpa name in DNS response"); return; valid: if (rn == NULL || rn->query == NULL) { ngx_log_error(r->log_level, r->log, 0, "unexpected response for %V", &name); goto failed; } qident = (rn->query[0] << 8) + rn->query[1]; if (ident != qident) { ngx_log_error(r->log_level, r->log, 0, "wrong ident %ui response for %V, expect %ui", ident, &name, qident); goto failed; } if (code == 0 && nan == 0) { code = NGX_RESOLVE_NXDOMAIN; } if (code) { next = rn->waiting; rn->waiting = NULL; ngx_queue_remove(&rn->queue); ngx_rbtree_delete(tree, &rn->node); 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(ngx_resolver_qs_t); if (i + 2 + sizeof(ngx_resolver_an_t) >= n) { goto short_response; } /* compression pointer to *.arpa */ if (buf[i] != 0xc0 || buf[i + 1] != sizeof(ngx_resolver_hdr_t)) { err = "invalid in-addr.arpa or ip6.arpa name in DNS response"; goto invalid; } an = (ngx_resolver_an_t *) &buf[i + 2]; class = (an->class_hi << 8) + an->class_lo; len = (an->len_hi << 8) + an->len_lo; ttl = (an->ttl[0] << 24) + (an->ttl[1] << 16) + (an->ttl[2] << 8) + (an->ttl[3]); if (class != 1) { ngx_log_error(r->log_level, r->log, 0, "unexpected RR class %ui", class); goto failed; } if (ttl < 0) { ttl = 0; } ngx_log_debug3(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver qt:%ui cl:%ui len:%uz", (an->type_hi << 8) + an->type_lo, class, len); i += 2 + sizeof(ngx_resolver_an_t); if (i + len > n) { goto short_response; } if (ngx_resolver_copy(r, &name, buf, buf + i, buf + n) != NGX_OK) { goto failed; } ngx_log_debug1(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver an:%V", &name); if (name.len != (size_t) rn->nlen || ngx_strncmp(name.data, rn->name, name.len) != 0) { if (rn->nlen) { ngx_resolver_free(r, rn->name); } rn->nlen = (u_short) name.len; rn->name = name.data; name.data = ngx_resolver_dup(r, rn->name, name.len); if (name.data == NULL) { goto failed; } } ngx_queue_remove(&rn->queue); rn->valid = ngx_time() + (r->valid ? r->valid : ttl); rn->expire = ngx_time() + r->expire; ngx_queue_insert_head(expire_queue, &rn->queue); next = rn->waiting; rn->waiting = NULL; /* unlock addr mutex */ while (next) { ctx = next; ctx->state = NGX_OK; ctx->name = name; next = ctx->next; ctx->handler(ctx); } ngx_resolver_free(r, name.data); return; short_response: err = "short DNS response"; invalid: /* unlock addr mutex */ ngx_log_error(r->log_level, r->log, 0, err); return; failed: /* unlock addr mutex */ return; } static ngx_resolver_node_t * ngx_resolver_lookup_name(ngx_resolver_t *r, ngx_str_t *name, uint32_t hash) { ngx_int_t rc; ngx_rbtree_node_t *node, *sentinel; ngx_resolver_node_t *rn; node = r->name_rbtree.root; sentinel = r->name_rbtree.sentinel; while (node != sentinel) { if (hash < node->key) { node = node->left; continue; } if (hash > node->key) { node = node->right; continue; } /* hash == node->key */ rn = (ngx_resolver_node_t *) node; rc = ngx_memn2cmp(name->data, rn->name, name->len, rn->nlen); if (rc == 0) { return rn; } node = (rc < 0) ? node->left : node->right; } /* not found */ return NULL; } static ngx_resolver_node_t * ngx_resolver_lookup_addr(ngx_resolver_t *r, in_addr_t addr) { ngx_rbtree_node_t *node, *sentinel; node = r->addr_rbtree.root; sentinel = r->addr_rbtree.sentinel; while (node != sentinel) { if (addr < node->key) { node = node->left; continue; } if (addr > node->key) { node = node->right; continue; } /* addr == node->key */ return (ngx_resolver_node_t *) node; } /* not found */ return NULL; } #if (NGX_HAVE_INET6) static ngx_resolver_node_t * ngx_resolver_lookup_addr6(ngx_resolver_t *r, struct in6_addr *addr, uint32_t hash) { ngx_int_t rc; ngx_rbtree_node_t *node, *sentinel; ngx_resolver_node_t *rn; node = r->addr6_rbtree.root; sentinel = r->addr6_rbtree.sentinel; while (node != sentinel) { if (hash < node->key) { node = node->left; continue; } if (hash > node->key) { node = node->right; continue; } /* hash == node->key */ rn = (ngx_resolver_node_t *) node; rc = ngx_memcmp(addr, &rn->addr6, 16); if (rc == 0) { return rn; } node = (rc < 0) ? node->left : node->right; } /* not found */ return NULL; } #endif static void ngx_resolver_rbtree_insert_value(ngx_rbtree_node_t *temp, ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel) { ngx_rbtree_node_t **p; ngx_resolver_node_t *rn, *rn_temp; for ( ;; ) { if (node->key < temp->key) { p = &temp->left; } else if (node->key > temp->key) { p = &temp->right; } else { /* node->key == temp->key */ rn = (ngx_resolver_node_t *) node; rn_temp = (ngx_resolver_node_t *) temp; p = (ngx_memn2cmp(rn->name, rn_temp->name, rn->nlen, rn_temp->nlen) < 0) ? &temp->left : &temp->right; } if (*p == sentinel) { break; } temp = *p; } *p = node; node->parent = temp; node->left = sentinel; node->right = sentinel; ngx_rbt_red(node); } #if (NGX_HAVE_INET6) static void ngx_resolver_rbtree_insert_addr6_value(ngx_rbtree_node_t *temp, ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel) { ngx_rbtree_node_t **p; ngx_resolver_node_t *rn, *rn_temp; for ( ;; ) { if (node->key < temp->key) { p = &temp->left; } else if (node->key > temp->key) { p = &temp->right; } else { /* node->key == temp->key */ rn = (ngx_resolver_node_t *) node; rn_temp = (ngx_resolver_node_t *) temp; p = (ngx_memcmp(&rn->addr6, &rn_temp->addr6, 16) < 0) ? &temp->left : &temp->right; } if (*p == sentinel) { break; } temp = *p; } *p = node; node->parent = temp; node->left = sentinel; node->right = sentinel; ngx_rbt_red(node); } #endif static ngx_int_t ngx_resolver_create_name_query(ngx_resolver_node_t *rn, ngx_resolver_ctx_t *ctx) { u_char *p, *s; size_t len, nlen; ngx_uint_t ident; #if (NGX_HAVE_INET6) ngx_resolver_t *r; #endif ngx_resolver_qs_t *qs; ngx_resolver_hdr_t *query; nlen = ctx->name.len ? (1 + ctx->name.len + 1) : 1; len = sizeof(ngx_resolver_hdr_t) + nlen + sizeof(ngx_resolver_qs_t); #if (NGX_HAVE_INET6) r = ctx->resolver; p = ngx_resolver_alloc(ctx->resolver, r->ipv6 ? len * 2 : len); #else p = ngx_resolver_alloc(ctx->resolver, len); #endif if (p == NULL) { return NGX_ERROR; } rn->qlen = (u_short) len; rn->query = p; #if (NGX_HAVE_INET6) if (r->ipv6) { rn->query6 = p + len; } #endif query = (ngx_resolver_hdr_t *) p; ident = ngx_random(); ngx_log_debug2(NGX_LOG_DEBUG_CORE, ctx->resolver->log, 0, "resolve: \"%V\" A %i", &ctx->name, ident & 0xffff); query->ident_hi = (u_char) ((ident >> 8) & 0xff); query->ident_lo = (u_char) (ident & 0xff); /* recursion query */ query->flags_hi = 1; query->flags_lo = 0; /* one question */ query->nqs_hi = 0; query->nqs_lo = 1; query->nan_hi = 0; query->nan_lo = 0; query->nns_hi = 0; query->nns_lo = 0; query->nar_hi = 0; query->nar_lo = 0; p += sizeof(ngx_resolver_hdr_t) + nlen; qs = (ngx_resolver_qs_t *) p; /* query type */ qs->type_hi = 0; qs->type_lo = NGX_RESOLVE_A; /* IN query class */ qs->class_hi = 0; qs->class_lo = 1; /* convert "www.example.com" to "\3www\7example\3com\0" */ len = 0; p--; *p-- = '\0'; if (ctx->name.len == 0) { return NGX_DECLINED; } for (s = ctx->name.data + ctx->name.len - 1; s >= ctx->name.data; s--) { if (*s != '.') { *p = *s; len++; } else { if (len == 0 || len > 255) { return NGX_DECLINED; } *p = (u_char) len; len = 0; } p--; } if (len == 0 || len > 255) { return NGX_DECLINED; } *p = (u_char) len; #if (NGX_HAVE_INET6) if (!r->ipv6) { return NGX_OK; } p = rn->query6; ngx_memcpy(p, rn->query, rn->qlen); query = (ngx_resolver_hdr_t *) p; ident = ngx_random(); ngx_log_debug2(NGX_LOG_DEBUG_CORE, ctx->resolver->log, 0, "resolve: \"%V\" AAAA %i", &ctx->name, ident & 0xffff); query->ident_hi = (u_char) ((ident >> 8) & 0xff); query->ident_lo = (u_char) (ident & 0xff); p += sizeof(ngx_resolver_hdr_t) + nlen; qs = (ngx_resolver_qs_t *) p; qs->type_lo = NGX_RESOLVE_AAAA; #endif return NGX_OK; } static ngx_int_t ngx_resolver_create_addr_query(ngx_resolver_node_t *rn, ngx_resolver_ctx_t *ctx) { u_char *p, *d; size_t len; in_addr_t addr; ngx_int_t n; ngx_uint_t ident; ngx_resolver_hdr_t *query; struct sockaddr_in *sin; #if (NGX_HAVE_INET6) struct sockaddr_in6 *sin6; #endif switch (ctx->addr.sockaddr->sa_family) { #if (NGX_HAVE_INET6) case AF_INET6: len = sizeof(ngx_resolver_hdr_t) + 64 + sizeof(".ip6.arpa.") - 1 + sizeof(ngx_resolver_qs_t); break; #endif default: /* AF_INET */ len = sizeof(ngx_resolver_hdr_t) + sizeof(".255.255.255.255.in-addr.arpa.") - 1 + sizeof(ngx_resolver_qs_t); } p = ngx_resolver_alloc(ctx->resolver, len); if (p == NULL) { return NGX_ERROR; } rn->query = p; query = (ngx_resolver_hdr_t *) p; ident = ngx_random(); query->ident_hi = (u_char) ((ident >> 8) & 0xff); query->ident_lo = (u_char) (ident & 0xff); /* recursion query */ query->flags_hi = 1; query->flags_lo = 0; /* one question */ query->nqs_hi = 0; query->nqs_lo = 1; query->nan_hi = 0; query->nan_lo = 0; query->nns_hi = 0; query->nns_lo = 0; query->nar_hi = 0; query->nar_lo = 0; p += sizeof(ngx_resolver_hdr_t); switch (ctx->addr.sockaddr->sa_family) { #if (NGX_HAVE_INET6) case AF_INET6: sin6 = (struct sockaddr_in6 *) ctx->addr.sockaddr; for (n = 15; n >= 0; n--) { p = ngx_sprintf(p, "\1%xd\1%xd", sin6->sin6_addr.s6_addr[n] & 0xf, (sin6->sin6_addr.s6_addr[n] >> 4) & 0xf); } p = ngx_cpymem(p, "\3ip6\4arpa\0", 10); break; #endif default: /* AF_INET */ sin = (struct sockaddr_in *) ctx->addr.sockaddr; addr = ntohl(sin->sin_addr.s_addr); for (n = 0; n < 32; n += 8) { d = ngx_sprintf(&p[1], "%ud", (addr >> n) & 0xff); *p = (u_char) (d - &p[1]); p = d; } p = ngx_cpymem(p, "\7in-addr\4arpa\0", 14); } /* query type "PTR", IN query class */ p = ngx_cpymem(p, "\0\14\0\1", 4); rn->qlen = (u_short) (p - rn->query); return NGX_OK; } static ngx_int_t ngx_resolver_copy(ngx_resolver_t *r, ngx_str_t *name, u_char *buf, u_char *src, u_char *last) { char *err; u_char *p, *dst; ssize_t len; ngx_uint_t i, n; p = src; len = -1; /* * compression pointers allow to create endless loop, so we set limit; * 128 pointers should be enough to store 255-byte name */ for (i = 0; i < 128; i++) { n = *p++; if (n == 0) { goto done; } if (n & 0xc0) { n = ((n & 0x3f) << 8) + *p; p = &buf[n]; } else { len += 1 + n; p = &p[n]; } if (p >= last) { err = "name is out of response"; goto invalid; } } err = "compression pointers loop"; invalid: ngx_log_error(r->log_level, r->log, 0, err); return NGX_ERROR; done: if (name == NULL) { return NGX_OK; } if (len == -1) { ngx_str_null(name); return NGX_OK; } dst = ngx_resolver_alloc(r, len); if (dst == NULL) { return NGX_ERROR; } name->data = dst; n = *src++; for ( ;; ) { if (n & 0xc0) { n = ((n & 0x3f) << 8) + *src; src = &buf[n]; n = *src++; } else { ngx_strlow(dst, src, n); dst += n; src += n; n = *src++; if (n != 0) { *dst++ = '.'; } } if (n == 0) { name->len = dst - name->data; return NGX_OK; } } } static void ngx_resolver_timeout_handler(ngx_event_t *ev) { ngx_resolver_ctx_t *ctx, *next; ngx_resolver_node_t *rn; rn = ev->data; ctx = rn->waiting; rn->waiting = NULL; do { ctx->state = NGX_RESOLVE_TIMEDOUT; next = ctx->next; ctx->handler(ctx); ctx = next; } while (ctx); } static void ngx_resolver_free_node(ngx_resolver_t *r, ngx_resolver_node_t *rn) { /* lock alloc mutex */ if (rn->query) { ngx_resolver_free_locked(r, rn->query); } if (rn->name) { ngx_resolver_free_locked(r, rn->name); } if (rn->cnlen) { ngx_resolver_free_locked(r, rn->u.cname); } if (rn->naddrs > 1 && rn->naddrs != (u_short) -1) { ngx_resolver_free_locked(r, rn->u.addrs); } #if (NGX_HAVE_INET6) if (rn->naddrs6 > 1 && rn->naddrs6 != (u_short) -1) { ngx_resolver_free_locked(r, rn->u6.addrs6); } #endif ngx_resolver_free_locked(r, rn); /* unlock alloc mutex */ } static void * ngx_resolver_alloc(ngx_resolver_t *r, size_t size) { u_char *p; /* lock alloc mutex */ p = ngx_alloc(size, r->log); /* unlock alloc mutex */ return p; } static void * ngx_resolver_calloc(ngx_resolver_t *r, size_t size) { u_char *p; p = ngx_resolver_alloc(r, size); if (p) { ngx_memzero(p, size); } return p; } static void ngx_resolver_free(ngx_resolver_t *r, void *p) { /* lock alloc mutex */ ngx_free(p); /* unlock alloc mutex */ } static void ngx_resolver_free_locked(ngx_resolver_t *r, void *p) { ngx_free(p); } static void * ngx_resolver_dup(ngx_resolver_t *r, void *src, size_t size) { void *dst; dst = ngx_resolver_alloc(r, size); if (dst == NULL) { return dst; } ngx_memcpy(dst, src, size); return dst; } static ngx_addr_t * ngx_resolver_export(ngx_resolver_t *r, ngx_resolver_node_t *rn, ngx_uint_t rotate) { ngx_addr_t *dst; ngx_uint_t d, i, j, n; u_char (*sockaddr)[NGX_SOCKADDRLEN]; in_addr_t *addr; struct sockaddr_in *sin; #if (NGX_HAVE_INET6) struct in6_addr *addr6; struct sockaddr_in6 *sin6; #endif n = rn->naddrs; #if (NGX_HAVE_INET6) n += rn->naddrs6; #endif dst = ngx_resolver_calloc(r, n * sizeof(ngx_addr_t)); if (dst == NULL) { return NULL; } sockaddr = ngx_resolver_calloc(r, n * NGX_SOCKADDRLEN); if (sockaddr == NULL) { ngx_resolver_free(r, dst); return NULL; } i = 0; d = rotate ? ngx_random() % n : 0; if (rn->naddrs) { j = rotate ? ngx_random() % rn->naddrs : 0; addr = (rn->naddrs == 1) ? &rn->u.addr : rn->u.addrs; do { sin = (struct sockaddr_in *) sockaddr[d]; sin->sin_family = AF_INET; sin->sin_addr.s_addr = addr[j++]; dst[d].sockaddr = (struct sockaddr *) sin; dst[d++].socklen = sizeof(struct sockaddr_in); if (d == n) { d = 0; } if (j == rn->naddrs) { j = 0; } } while (++i < rn->naddrs); } #if (NGX_HAVE_INET6) if (rn->naddrs6) { j = rotate ? ngx_random() % rn->naddrs6 : 0; addr6 = (rn->naddrs6 == 1) ? &rn->u6.addr6 : rn->u6.addrs6; do { sin6 = (struct sockaddr_in6 *) sockaddr[d]; sin6->sin6_family = AF_INET6; ngx_memcpy(sin6->sin6_addr.s6_addr, addr6[j++].s6_addr, 16); dst[d].sockaddr = (struct sockaddr *) sin6; dst[d++].socklen = sizeof(struct sockaddr_in6); if (d == n) { d = 0; } if (j == rn->naddrs6) { j = 0; } } while (++i < n); } #endif return dst; } char * ngx_resolver_strerror(ngx_int_t err) { static char *errors[] = { "Format error", /* FORMERR */ "Server failure", /* SERVFAIL */ "Host not found", /* NXDOMAIN */ "Unimplemented", /* NOTIMP */ "Operation refused" /* REFUSED */ }; if (err > 0 && err < 6) { return errors[err - 1]; } if (err == NGX_RESOLVE_TIMEDOUT) { return "Operation timed out"; } return "Unknown error"; } static u_char * ngx_resolver_log_error(ngx_log_t *log, u_char *buf, size_t len) { u_char *p; ngx_udp_connection_t *uc; p = buf; if (log->action) { p = ngx_snprintf(buf, len, " while %s", log->action); len -= p - buf; } uc = log->data; if (uc) { p = ngx_snprintf(p, len, ", resolver: %V", &uc->server); } return p; } ngx_int_t ngx_udp_connect(ngx_udp_connection_t *uc) { int rc; ngx_int_t event; ngx_event_t *rev, *wev; ngx_socket_t s; ngx_connection_t *c; s = ngx_socket(uc->sockaddr->sa_family, SOCK_DGRAM, 0); ngx_log_debug1(NGX_LOG_DEBUG_EVENT, &uc->log, 0, "UDP socket %d", s); if (s == (ngx_socket_t) -1) { ngx_log_error(NGX_LOG_ALERT, &uc->log, ngx_socket_errno, ngx_socket_n " failed"); return NGX_ERROR; } c = ngx_get_connection(s, &uc->log); if (c == NULL) { if (ngx_close_socket(s) == -1) { ngx_log_error(NGX_LOG_ALERT, &uc->log, ngx_socket_errno, ngx_close_socket_n "failed"); } return NGX_ERROR; } if (ngx_nonblocking(s) == -1) { ngx_log_error(NGX_LOG_ALERT, &uc->log, ngx_socket_errno, ngx_nonblocking_n " failed"); goto failed; } rev = c->read; wev = c->write; rev->log = &uc->log; wev->log = &uc->log; uc->connection = c; c->number = ngx_atomic_fetch_add(ngx_connection_counter, 1); ngx_log_debug3(NGX_LOG_DEBUG_EVENT, &uc->log, 0, "connect to %V, fd:%d #%uA", &uc->server, s, c->number); rc = connect(s, uc->sockaddr, uc->socklen); /* TODO: aio, iocp */ if (rc == -1) { ngx_log_error(NGX_LOG_CRIT, &uc->log, ngx_socket_errno, "connect() failed"); goto failed; } /* UDP sockets are always ready to write */ wev->ready = 1; 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) { goto failed; } } else { /* rtsig */ if (ngx_add_conn(c) == NGX_ERROR) { goto failed; } } return NGX_OK; failed: ngx_close_connection(c); uc->connection = NULL; return NGX_ERROR; }