Mercurial > hg > nginx
view src/core/ngx_resolver.c @ 7660:d33e17499088
Version bump.
| author | Maxim Dounin <mdounin@mdounin.ru> |
|---|---|
| date | Tue, 26 May 2020 22:03:00 +0300 |
| parents | 571383f75a9a |
| children | 8fe7ebe5adc4 |
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/* * 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 #define NGX_RESOLVER_TCP_RSIZE (2 + 65535) #define NGX_RESOLVER_TCP_WSIZE 8192 typedef struct { u_char ident_hi; u_char ident_lo; u_char flags_hi; u_char flags_lo; u_char nqs_hi; u_char nqs_lo; u_char nan_hi; u_char nan_lo; u_char nns_hi; u_char nns_lo; u_char nar_hi; u_char nar_lo; } ngx_resolver_hdr_t; typedef struct { u_char type_hi; u_char type_lo; u_char class_hi; u_char class_lo; } ngx_resolver_qs_t; typedef struct { u_char type_hi; u_char type_lo; u_char class_hi; u_char class_lo; u_char ttl[4]; u_char len_hi; u_char len_lo; } ngx_resolver_an_t; #define ngx_resolver_node(n) \ (ngx_resolver_node_t *) \ ((u_char *) (n) - offsetof(ngx_resolver_node_t, node)) static ngx_int_t ngx_udp_connect(ngx_resolver_connection_t *rec); static ngx_int_t ngx_tcp_connect(ngx_resolver_connection_t *rec); static void ngx_resolver_cleanup(void *data); static void ngx_resolver_cleanup_tree(ngx_resolver_t *r, ngx_rbtree_t *tree); static ngx_int_t ngx_resolve_name_locked(ngx_resolver_t *r, ngx_resolver_ctx_t *ctx, ngx_str_t *name); static void ngx_resolver_expire(ngx_resolver_t *r, ngx_rbtree_t *tree, ngx_queue_t *queue); static ngx_int_t ngx_resolver_send_query(ngx_resolver_t *r, ngx_resolver_node_t *rn); static ngx_int_t ngx_resolver_send_udp_query(ngx_resolver_t *r, ngx_resolver_connection_t *rec, u_char *query, u_short qlen); static ngx_int_t ngx_resolver_send_tcp_query(ngx_resolver_t *r, ngx_resolver_connection_t *rec, u_char *query, u_short qlen); static ngx_int_t ngx_resolver_create_name_query(ngx_resolver_t *r, ngx_resolver_node_t *rn, ngx_str_t *name); static ngx_int_t ngx_resolver_create_srv_query(ngx_resolver_t *r, ngx_resolver_node_t *rn, ngx_str_t *name); static ngx_int_t ngx_resolver_create_addr_query(ngx_resolver_t *r, ngx_resolver_node_t *rn, ngx_resolver_addr_t *addr); static void ngx_resolver_resend_handler(ngx_event_t *ev); static time_t ngx_resolver_resend(ngx_resolver_t *r, ngx_rbtree_t *tree, ngx_queue_t *queue); static ngx_uint_t ngx_resolver_resend_empty(ngx_resolver_t *r); static void ngx_resolver_udp_read(ngx_event_t *rev); static void ngx_resolver_tcp_write(ngx_event_t *wev); static void ngx_resolver_tcp_read(ngx_event_t *rev); static void ngx_resolver_process_response(ngx_resolver_t *r, u_char *buf, size_t n, ngx_uint_t tcp); static void ngx_resolver_process_a(ngx_resolver_t *r, u_char *buf, size_t n, ngx_uint_t ident, ngx_uint_t code, ngx_uint_t qtype, ngx_uint_t nan, ngx_uint_t trunc, ngx_uint_t ans); static void ngx_resolver_process_srv(ngx_resolver_t *r, u_char *buf, size_t n, ngx_uint_t ident, ngx_uint_t code, ngx_uint_t nan, ngx_uint_t trunc, ngx_uint_t ans); static void ngx_resolver_process_ptr(ngx_resolver_t *r, u_char *buf, size_t n, ngx_uint_t ident, ngx_uint_t code, ngx_uint_t nan); static ngx_resolver_node_t *ngx_resolver_lookup_name(ngx_resolver_t *r, ngx_str_t *name, uint32_t hash); static ngx_resolver_node_t *ngx_resolver_lookup_srv(ngx_resolver_t *r, ngx_str_t *name, uint32_t hash); static ngx_resolver_node_t *ngx_resolver_lookup_addr(ngx_resolver_t *r, in_addr_t addr); static void ngx_resolver_rbtree_insert_value(ngx_rbtree_node_t *temp, ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel); static ngx_int_t ngx_resolver_copy(ngx_resolver_t *r, ngx_str_t *name, u_char *buf, u_char *src, u_char *last); static ngx_int_t ngx_resolver_set_timeout(ngx_resolver_t *r, ngx_resolver_ctx_t *ctx); static void ngx_resolver_timeout_handler(ngx_event_t *ev); static void ngx_resolver_free_node(ngx_resolver_t *r, ngx_resolver_node_t *rn); static void *ngx_resolver_alloc(ngx_resolver_t *r, size_t size); static void *ngx_resolver_calloc(ngx_resolver_t *r, size_t size); static void ngx_resolver_free(ngx_resolver_t *r, void *p); static void ngx_resolver_free_locked(ngx_resolver_t *r, void *p); static void *ngx_resolver_dup(ngx_resolver_t *r, void *src, size_t size); static ngx_resolver_addr_t *ngx_resolver_export(ngx_resolver_t *r, ngx_resolver_node_t *rn, ngx_uint_t rotate); static void ngx_resolver_report_srv(ngx_resolver_t *r, ngx_resolver_ctx_t *ctx); static u_char *ngx_resolver_log_error(ngx_log_t *log, u_char *buf, size_t len); static void ngx_resolver_resolve_srv_names(ngx_resolver_ctx_t *ctx, ngx_resolver_node_t *rn); static void ngx_resolver_srv_names_handler(ngx_resolver_ctx_t *ctx); static ngx_int_t ngx_resolver_cmp_srvs(const void *one, const void *two); #if (NGX_HAVE_INET6) static void ngx_resolver_rbtree_insert_addr6_value(ngx_rbtree_node_t *temp, ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel); static ngx_resolver_node_t *ngx_resolver_lookup_addr6(ngx_resolver_t *r, struct in6_addr *addr, uint32_t hash); #endif ngx_resolver_t * ngx_resolver_create(ngx_conf_t *cf, ngx_str_t *names, ngx_uint_t n) { ngx_str_t s; ngx_url_t u; ngx_uint_t i, j; ngx_resolver_t *r; ngx_pool_cleanup_t *cln; ngx_resolver_connection_t *rec; r = ngx_pcalloc(cf->pool, sizeof(ngx_resolver_t)); if (r == NULL) { return NULL; } r->event = ngx_pcalloc(cf->pool, sizeof(ngx_event_t)); if (r->event == NULL) { return NULL; } cln = ngx_pool_cleanup_add(cf->pool, 0); if (cln == NULL) { return NULL; } cln->handler = ngx_resolver_cleanup; cln->data = r; ngx_rbtree_init(&r->name_rbtree, &r->name_sentinel, ngx_resolver_rbtree_insert_value); ngx_rbtree_init(&r->srv_rbtree, &r->srv_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->srv_resend_queue); ngx_queue_init(&r->addr_resend_queue); ngx_queue_init(&r->name_expire_queue); ngx_queue_init(&r->srv_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->event->cancelable = 1; r->ident = -1; r->resend_timeout = 5; r->tcp_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->connections, cf->pool, n, sizeof(ngx_resolver_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; } rec = ngx_array_push_n(&r->connections, u.naddrs); if (rec == NULL) { return NULL; } ngx_memzero(rec, u.naddrs * sizeof(ngx_resolver_connection_t)); for (j = 0; j < u.naddrs; j++) { rec[j].sockaddr = u.addrs[j].sockaddr; rec[j].socklen = u.addrs[j].socklen; rec[j].server = u.addrs[j].name; rec[j].resolver = r; } } if (n && r->connections.nelts == 0) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "no name servers defined"); return NULL; } return r; } static void ngx_resolver_cleanup(void *data) { ngx_resolver_t *r = data; ngx_uint_t i; ngx_resolver_connection_t *rec; 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->srv_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->timer_set) { ngx_del_timer(r->event); } rec = r->connections.elts; for (i = 0; i < r->connections.nelts; i++) { if (rec[i].udp) { ngx_close_connection(rec[i].udp); } if (rec[i].tcp) { ngx_close_connection(rec[i].tcp); } if (rec[i].read_buf) { ngx_resolver_free(r, rec[i].read_buf->start); ngx_resolver_free(r, rec[i].read_buf); } if (rec[i].write_buf) { ngx_resolver_free(r, rec[i].write_buf->start); ngx_resolver_free(r, rec[i].write_buf); } } } static void ngx_resolver_cleanup_tree(ngx_resolver_t *r, ngx_rbtree_t *tree) { ngx_resolver_ctx_t *ctx, *next; ngx_resolver_node_t *rn; while (tree->root != tree->sentinel) { rn = ngx_resolver_node(ngx_rbtree_min(tree->root, tree->sentinel)); ngx_queue_remove(&rn->queue); for (ctx = rn->waiting; ctx; ctx = next) { next = ctx->next; if (ctx->event) { if (ctx->event->timer_set) { ngx_del_timer(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->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) { size_t slen; ngx_int_t rc; ngx_str_t name; 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; } if (ctx->service.len) { slen = ctx->service.len; if (ngx_strlchr(ctx->service.data, ctx->service.data + ctx->service.len, '.') == NULL) { slen += sizeof("_._tcp") - 1; } name.len = slen + 1 + ctx->name.len; name.data = ngx_resolver_alloc(r, name.len); if (name.data == NULL) { goto failed; } if (slen == ctx->service.len) { ngx_sprintf(name.data, "%V.%V", &ctx->service, &ctx->name); } else { ngx_sprintf(name.data, "_%V._tcp.%V", &ctx->service, &ctx->name); } /* lock name mutex */ rc = ngx_resolve_name_locked(r, ctx, &name); ngx_resolver_free(r, name.data); } else { /* lock name mutex */ rc = ngx_resolve_name_locked(r, ctx, &ctx->name); } 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); } failed: ngx_resolver_free(r, ctx); return NGX_ERROR; } void ngx_resolve_name_done(ngx_resolver_ctx_t *ctx) { ngx_uint_t i; 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->nsrvs) { for (i = 0; i < ctx->nsrvs; i++) { if (ctx->srvs[i].ctx) { ngx_resolve_name_done(ctx->srvs[i].ctx); } if (ctx->srvs[i].addrs) { ngx_resolver_free(r, ctx->srvs[i].addrs->sockaddr); ngx_resolver_free(r, ctx->srvs[i].addrs); } ngx_resolver_free(r, ctx->srvs[i].name.data); } ngx_resolver_free(r, ctx->srvs); } if (ctx->state == NGX_AGAIN || ctx->state == NGX_RESOLVE_TIMEDOUT) { rn = ctx->node; 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: if (ctx->service.len) { ngx_resolver_expire(r, &r->srv_rbtree, &r->srv_expire_queue); } else { ngx_resolver_expire(r, &r->name_rbtree, &r->name_expire_queue); } /* unlock name mutex */ /* lock alloc mutex */ if (ctx->event) { ngx_resolver_free_locked(r, ctx->event); } ngx_resolver_free_locked(r, ctx); /* unlock alloc mutex */ if (r->event->timer_set && ngx_resolver_resend_empty(r)) { ngx_del_timer(r->event); } } static ngx_int_t ngx_resolve_name_locked(ngx_resolver_t *r, ngx_resolver_ctx_t *ctx, ngx_str_t *name) { uint32_t hash; ngx_int_t rc; ngx_str_t cname; ngx_uint_t i, naddrs; ngx_queue_t *resend_queue, *expire_queue; ngx_rbtree_t *tree; ngx_resolver_ctx_t *next, *last; ngx_resolver_addr_t *addrs; ngx_resolver_node_t *rn; ngx_strlow(name->data, name->data, name->len); hash = ngx_crc32_short(name->data, name->len); if (ctx->service.len) { rn = ngx_resolver_lookup_srv(r, name, hash); tree = &r->srv_rbtree; resend_queue = &r->srv_resend_queue; expire_queue = &r->srv_expire_queue; } else { rn = ngx_resolver_lookup_name(r, name, hash); tree = &r->name_rbtree; resend_queue = &r->name_resend_queue; expire_queue = &r->name_expire_queue; } if (rn) { /* ctx can be a list after NGX_RESOLVE_CNAME */ for (last = ctx; last->next; last = last->next); 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); 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; } } last->next = rn->waiting; rn->waiting = NULL; /* unlock name mutex */ do { ctx->state = NGX_OK; ctx->valid = rn->valid; 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; } if (rn->nsrvs) { last->next = rn->waiting; rn->waiting = NULL; /* unlock name mutex */ do { next = ctx->next; ngx_resolver_resolve_srv_names(ctx, rn); ctx = next; } while (ctx); return NGX_OK; } /* NGX_RESOLVE_CNAME */ if (ctx->recursion++ < NGX_RESOLVER_MAX_RECURSION) { cname.len = rn->cnlen; cname.data = rn->u.cname; return ngx_resolve_name_locked(r, ctx, &cname); } last->next = rn->waiting; rn->waiting = NULL; /* unlock name mutex */ do { ctx->state = NGX_RESOLVE_NXDOMAIN; ctx->valid = ngx_time() + (r->valid ? r->valid : 10); next = ctx->next; ctx->handler(ctx); ctx = next; } while (ctx); return NGX_OK; } if (rn->waiting) { if (ngx_resolver_set_timeout(r, ctx) != NGX_OK) { return NGX_ERROR; } last->next = rn->waiting; rn->waiting = ctx; ctx->state = NGX_AGAIN; ctx->async = 1; do { ctx->node = rn; ctx = ctx->next; } while (ctx); 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 if (rn->nsrvs) { for (i = 0; i < (ngx_uint_t) rn->nsrvs; i++) { if (rn->u.srvs[i].name.data) { ngx_resolver_free_locked(r, rn->u.srvs[i].name.data); } } ngx_resolver_free_locked(r, rn->u.srvs); } /* 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, name->data, name->len); if (rn->name == NULL) { ngx_resolver_free(r, rn); return NGX_ERROR; } rn->node.key = hash; rn->nlen = (u_short) name->len; rn->query = NULL; #if (NGX_HAVE_INET6) rn->query6 = NULL; #endif ngx_rbtree_insert(tree, &rn->node); } if (ctx->service.len) { rc = ngx_resolver_create_srv_query(r, rn, name); } else { rc = ngx_resolver_create_name_query(r, rn, name); } if (rc == NGX_ERROR) { goto failed; } if (rc == NGX_DECLINED) { ngx_rbtree_delete(tree, &rn->node); ngx_resolver_free(r, rn->query); ngx_resolver_free(r, rn->name); ngx_resolver_free(r, rn); do { ctx->state = NGX_RESOLVE_NXDOMAIN; next = ctx->next; ctx->handler(ctx); ctx = next; } while (ctx); return NGX_OK; } rn->last_connection = r->last_connection++; if (r->last_connection == r->connections.nelts) { r->last_connection = 0; } rn->naddrs = (u_short) -1; rn->tcp = 0; #if (NGX_HAVE_INET6) rn->naddrs6 = r->ipv6 ? (u_short) -1 : 0; rn->tcp6 = 0; #endif rn->nsrvs = 0; if (ngx_resolver_send_query(r, rn) != NGX_OK) { /* immediately retry once on failure */ rn->last_connection++; if (rn->last_connection == r->connections.nelts) { rn->last_connection = 0; } (void) ngx_resolver_send_query(r, rn); } if (ngx_resolver_set_timeout(r, ctx) != NGX_OK) { goto failed; } if (ngx_resolver_resend_empty(r)) { 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->valid = 0; rn->ttl = NGX_MAX_UINT32_VALUE; rn->waiting = ctx; ctx->state = NGX_AGAIN; ctx->async = 1; do { ctx->node = rn; ctx = ctx->next; } while (ctx); return NGX_AGAIN; failed: ngx_rbtree_delete(tree, &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) { ngx_resolver_free(r, ctx); return NGX_ERROR; } ctx->name.len = rn->nlen; ctx->name.data = name; /* unlock addr mutex */ ctx->state = NGX_OK; ctx->valid = rn->valid; ctx->handler(ctx); ngx_resolver_free(r, name); return NGX_OK; } if (rn->waiting) { if (ngx_resolver_set_timeout(r, ctx) != NGX_OK) { return NGX_ERROR; } ctx->next = rn->waiting; rn->waiting = ctx; ctx->state = NGX_AGAIN; ctx->async = 1; ctx->node = rn; /* 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(r, rn, &ctx->addr) != NGX_OK) { goto failed; } rn->last_connection = r->last_connection++; if (r->last_connection == r->connections.nelts) { r->last_connection = 0; } rn->naddrs = (u_short) -1; rn->tcp = 0; #if (NGX_HAVE_INET6) rn->naddrs6 = (u_short) -1; rn->tcp6 = 0; #endif rn->nsrvs = 0; if (ngx_resolver_send_query(r, rn) != NGX_OK) { /* immediately retry once on failure */ rn->last_connection++; if (rn->last_connection == r->connections.nelts) { rn->last_connection = 0; } (void) ngx_resolver_send_query(r, rn); } if (ngx_resolver_set_timeout(r, ctx) != NGX_OK) { goto failed; } if (ngx_resolver_resend_empty(r)) { 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; ctx->async = 1; ctx->node = rn; 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) { ngx_queue_t *expire_queue; ngx_rbtree_t *tree; ngx_resolver_t *r; ngx_resolver_ctx_t *w, **p; ngx_resolver_node_t *rn; 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 || ctx->state == NGX_RESOLVE_TIMEDOUT) { rn = ctx->node; if (rn) { p = &rn->waiting; w = rn->waiting; while (w) { if (w == ctx) { *p = w->next; goto done; } p = &w->next; w = w->next; } } { u_char text[NGX_SOCKADDR_STRLEN]; ngx_str_t addrtext; addrtext.data = text; addrtext.len = ngx_sock_ntop(ctx->addr.sockaddr, ctx->addr.socklen, text, NGX_SOCKADDR_STRLEN, 0); ngx_log_error(NGX_LOG_ALERT, r->log, 0, "could not cancel %V resolving", &addrtext); } } done: ngx_resolver_expire(r, tree, expire_queue); /* unlock addr mutex */ /* lock alloc mutex */ if (ctx->event) { ngx_resolver_free_locked(r, ctx->event); } ngx_resolver_free_locked(r, ctx); /* unlock alloc mutex */ if (r->event->timer_set && ngx_resolver_resend_empty(r)) { ngx_del_timer(r->event); } } static void ngx_resolver_expire(ngx_resolver_t *r, ngx_rbtree_t *tree, ngx_queue_t *queue) { time_t now; ngx_uint_t i; ngx_queue_t *q; ngx_resolver_node_t *rn; ngx_log_debug0(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver expire"); now = ngx_time(); for (i = 0; i < 2; i++) { if (ngx_queue_empty(queue)) { return; } q = ngx_queue_last(queue); rn = ngx_queue_data(q, ngx_resolver_node_t, queue); if (now <= rn->expire) { return; } ngx_log_debug2(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver expire \"%*s\"", (size_t) rn->nlen, rn->name); ngx_queue_remove(q); ngx_rbtree_delete(tree, &rn->node); ngx_resolver_free_node(r, rn); } } static ngx_int_t ngx_resolver_send_query(ngx_resolver_t *r, ngx_resolver_node_t *rn) { ngx_int_t rc; ngx_resolver_connection_t *rec; rec = r->connections.elts; rec = &rec[rn->last_connection]; if (rec->log.handler == NULL) { rec->log = *r->log; rec->log.handler = ngx_resolver_log_error; rec->log.data = rec; rec->log.action = "resolving"; } if (rn->naddrs == (u_short) -1) { rc = rn->tcp ? ngx_resolver_send_tcp_query(r, rec, rn->query, rn->qlen) : ngx_resolver_send_udp_query(r, rec, rn->query, rn->qlen); if (rc != NGX_OK) { return rc; } } #if (NGX_HAVE_INET6) if (rn->query6 && rn->naddrs6 == (u_short) -1) { rc = rn->tcp6 ? ngx_resolver_send_tcp_query(r, rec, rn->query6, rn->qlen) : ngx_resolver_send_udp_query(r, rec, rn->query6, rn->qlen); if (rc != NGX_OK) { return rc; } } #endif return NGX_OK; } static ngx_int_t ngx_resolver_send_udp_query(ngx_resolver_t *r, ngx_resolver_connection_t *rec, u_char *query, u_short qlen) { ssize_t n; if (rec->udp == NULL) { if (ngx_udp_connect(rec) != NGX_OK) { return NGX_ERROR; } rec->udp->data = rec; rec->udp->read->handler = ngx_resolver_udp_read; rec->udp->read->resolver = 1; } n = ngx_send(rec->udp, query, qlen); if (n == NGX_ERROR) { goto failed; } if ((size_t) n != (size_t) qlen) { ngx_log_error(NGX_LOG_CRIT, &rec->log, 0, "send() incomplete"); goto failed; } return NGX_OK; failed: ngx_close_connection(rec->udp); rec->udp = NULL; return NGX_ERROR; } static ngx_int_t ngx_resolver_send_tcp_query(ngx_resolver_t *r, ngx_resolver_connection_t *rec, u_char *query, u_short qlen) { ngx_buf_t *b; ngx_int_t rc; rc = NGX_OK; if (rec->tcp == NULL) { b = rec->read_buf; if (b == NULL) { b = ngx_resolver_calloc(r, sizeof(ngx_buf_t)); if (b == NULL) { return NGX_ERROR; } b->start = ngx_resolver_alloc(r, NGX_RESOLVER_TCP_RSIZE); if (b->start == NULL) { ngx_resolver_free(r, b); return NGX_ERROR; } b->end = b->start + NGX_RESOLVER_TCP_RSIZE; rec->read_buf = b; } b->pos = b->start; b->last = b->start; b = rec->write_buf; if (b == NULL) { b = ngx_resolver_calloc(r, sizeof(ngx_buf_t)); if (b == NULL) { return NGX_ERROR; } b->start = ngx_resolver_alloc(r, NGX_RESOLVER_TCP_WSIZE); if (b->start == NULL) { ngx_resolver_free(r, b); return NGX_ERROR; } b->end = b->start + NGX_RESOLVER_TCP_WSIZE; rec->write_buf = b; } b->pos = b->start; b->last = b->start; rc = ngx_tcp_connect(rec); if (rc == NGX_ERROR) { return NGX_ERROR; } rec->tcp->data = rec; rec->tcp->write->handler = ngx_resolver_tcp_write; rec->tcp->read->handler = ngx_resolver_tcp_read; rec->tcp->read->resolver = 1; ngx_add_timer(rec->tcp->write, (ngx_msec_t) (r->tcp_timeout * 1000)); } b = rec->write_buf; if (b->end - b->last < 2 + qlen) { ngx_log_error(NGX_LOG_CRIT, &rec->log, 0, "buffer overflow"); return NGX_ERROR; } *b->last++ = (u_char) (qlen >> 8); *b->last++ = (u_char) qlen; b->last = ngx_cpymem(b->last, query, qlen); if (rc == NGX_OK) { ngx_resolver_tcp_write(rec->tcp->write); } return NGX_OK; } static void ngx_resolver_resend_handler(ngx_event_t *ev) { time_t timer, atimer, stimer, 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); stimer = ngx_resolver_resend(r, &r->srv_rbtree, &r->srv_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 (timer == 0) { timer = stimer; } else if (stimer) { timer = ngx_min(timer, stimer); } #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) { if (++rn->last_connection == r->connections.nelts) { rn->last_connection = 0; } (void) ngx_resolver_send_query(r, rn); rn->expire = now + r->resend_timeout; ngx_queue_insert_head(queue, q); continue; } ngx_rbtree_delete(tree, &rn->node); ngx_resolver_free_node(r, rn); } } static ngx_uint_t ngx_resolver_resend_empty(ngx_resolver_t *r) { return ngx_queue_empty(&r->name_resend_queue) && ngx_queue_empty(&r->srv_resend_queue) #if (NGX_HAVE_INET6) && ngx_queue_empty(&r->addr6_resend_queue) #endif && ngx_queue_empty(&r->addr_resend_queue); } static void ngx_resolver_udp_read(ngx_event_t *rev) { ssize_t n; ngx_connection_t *c; ngx_resolver_connection_t *rec; u_char buf[NGX_RESOLVER_UDP_SIZE]; c = rev->data; rec = c->data; do { n = ngx_udp_recv(c, buf, NGX_RESOLVER_UDP_SIZE); if (n < 0) { return; } ngx_resolver_process_response(rec->resolver, buf, n, 0); } while (rev->ready); } static void ngx_resolver_tcp_write(ngx_event_t *wev) { off_t sent; ssize_t n; ngx_buf_t *b; ngx_resolver_t *r; ngx_connection_t *c; ngx_resolver_connection_t *rec; c = wev->data; rec = c->data; b = rec->write_buf; r = rec->resolver; if (wev->timedout) { goto failed; } sent = c->sent; while (wev->ready && b->pos < b->last) { n = ngx_send(c, b->pos, b->last - b->pos); if (n == NGX_AGAIN) { break; } if (n == NGX_ERROR) { goto failed; } b->pos += n; } if (b->pos != b->start) { b->last = ngx_movemem(b->start, b->pos, b->last - b->pos); b->pos = b->start; } if (c->sent != sent) { ngx_add_timer(wev, (ngx_msec_t) (r->tcp_timeout * 1000)); } if (ngx_handle_write_event(wev, 0) != NGX_OK) { goto failed; } return; failed: ngx_close_connection(c); rec->tcp = NULL; } static void ngx_resolver_tcp_read(ngx_event_t *rev) { u_char *p; size_t size; ssize_t n; u_short qlen; ngx_buf_t *b; ngx_resolver_t *r; ngx_connection_t *c; ngx_resolver_connection_t *rec; c = rev->data; rec = c->data; b = rec->read_buf; r = rec->resolver; while (rev->ready) { n = ngx_recv(c, b->last, b->end - b->last); if (n == NGX_AGAIN) { break; } if (n == NGX_ERROR || n == 0) { goto failed; } b->last += n; for ( ;; ) { p = b->pos; size = b->last - p; if (size < 2) { break; } qlen = (u_short) *p++ << 8; qlen += *p++; if (size < (size_t) (2 + qlen)) { break; } ngx_resolver_process_response(r, p, qlen, 1); b->pos += 2 + qlen; } if (b->pos != b->start) { b->last = ngx_movemem(b->start, b->pos, b->last - b->pos); b->pos = b->start; } } if (ngx_handle_read_event(rev, 0) != NGX_OK) { goto failed; } return; failed: ngx_close_connection(c); rec->tcp = NULL; } static void ngx_resolver_process_response(ngx_resolver_t *r, u_char *buf, size_t n, ngx_uint_t tcp) { char *err; ngx_uint_t i, times, ident, qident, flags, code, nqs, nan, trunc, 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; trunc = flags & 0x0200; ngx_log_debug6(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver DNS response %ui fl:%04Xi %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 || (trunc && tcp)) { ngx_log_error(r->log_level, r->log, 0, "invalid %s DNS response %ui fl:%04Xi", tcp ? "TCP" : "UDP", 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, trunc, i + sizeof(ngx_resolver_qs_t)); break; case NGX_RESOLVE_SRV: ngx_resolver_process_srv(r, buf, n, ident, code, nan, trunc, 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, (size_t) 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 n, ngx_uint_t ident, ngx_uint_t code, ngx_uint_t qtype, ngx_uint_t nan, ngx_uint_t trunc, ngx_uint_t ans) { char *err; u_char *cname; size_t len; int32_t ttl; uint32_t hash; in_addr_t *addr; ngx_str_t name; ngx_uint_t type, class, qident, naddrs, a, i, j, 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; ngx_resolver_addr_t *addrs; ngx_resolver_connection_t *rec; if (ngx_resolver_copy(r, &name, buf, buf + sizeof(ngx_resolver_hdr_t), buf + n) != 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; } if (trunc && rn->tcp6) { 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; } if (trunc && rn->tcp) { 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 (trunc) { ngx_queue_remove(&rn->queue); if (rn->waiting == NULL) { ngx_rbtree_delete(&r->name_rbtree, &rn->node); ngx_resolver_free_node(r, rn); goto next; } rec = r->connections.elts; rec = &rec[rn->last_connection]; switch (qtype) { #if (NGX_HAVE_INET6) case NGX_RESOLVE_AAAA: rn->tcp6 = 1; (void) ngx_resolver_send_tcp_query(r, rec, rn->query6, rn->qlen); break; #endif default: /* NGX_RESOLVE_A */ rn->tcp = 1; (void) ngx_resolver_send_tcp_query(r, rec, rn->query, rn->qlen); } rn->expire = ngx_time() + r->resend_timeout; ngx_queue_insert_head(&r->name_resend_queue, &rn->queue); goto next; } if (code == 0 && rn->code) { code = rn->code; } if (code == 0 && nan == 0) { #if (NGX_HAVE_INET6) switch (qtype) { case NGX_RESOLVE_AAAA: rn->naddrs6 = 0; if (rn->naddrs == (u_short) -1) { goto next; } if (rn->naddrs) { goto export; } break; default: /* NGX_RESOLVE_A */ rn->naddrs = 0; if (rn->naddrs6 == (u_short) -1) { goto next; } if (rn->naddrs6) { goto export; } } #endif code = NGX_RESOLVE_NXDOMAIN; } if (code) { #if (NGX_HAVE_INET6) switch (qtype) { case NGX_RESOLVE_AAAA: rn->naddrs6 = 0; if (rn->naddrs == (u_short) -1) { rn->code = (u_char) code; goto next; } break; default: /* NGX_RESOLVE_A */ rn->naddrs = 0; if (rn->naddrs6 == (u_short) -1) { rn->code = (u_char) code; goto next; } } #endif next = rn->waiting; rn->waiting = NULL; ngx_queue_remove(&rn->queue); ngx_rbtree_delete(&r->name_rbtree, &rn->node); /* unlock name mutex */ while (next) { ctx = next; ctx->state = code; ctx->valid = ngx_time() + (r->valid ? r->valid : 10); next = ctx->next; ctx->handler(ctx); } ngx_resolver_free_node(r, rn); return; } i = ans; naddrs = 0; cname = NULL; for (a = 0; a < nan; a++) { start = i; while (i < n) { 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) >= n) { 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 > n) { 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 > n) { 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 } j = 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[j] = htonl((buf[i] << 24) + (buf[i + 1] << 16) + (buf[i + 2] << 8) + (buf[i + 3])); if (++j == 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[j].s6_addr, &buf[i], 16); if (++j == 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->valid = rn->valid; 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 + n) != 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); ngx_resolver_free(r, rn->query); rn->query = NULL; #if (NGX_HAVE_INET6) rn->query6 = NULL; #endif ctx = rn->waiting; rn->waiting = NULL; if (ctx) { if (ctx->recursion++ >= NGX_RESOLVER_MAX_RECURSION) { /* unlock name mutex */ do { ctx->state = NGX_RESOLVE_NXDOMAIN; next = ctx->next; ctx->handler(ctx); ctx = next; } while (ctx); return; } for (next = ctx; next; next = next->next) { next->node = NULL; } (void) ngx_resolve_name_locked(r, ctx, &name); } /* 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_srv(ngx_resolver_t *r, u_char *buf, size_t n, ngx_uint_t ident, ngx_uint_t code, ngx_uint_t nan, ngx_uint_t trunc, ngx_uint_t ans) { char *err; u_char *cname; size_t len; int32_t ttl; uint32_t hash; ngx_str_t name; ngx_uint_t type, qident, class, start, nsrvs, a, i, j; ngx_resolver_an_t *an; ngx_resolver_ctx_t *ctx, *next; ngx_resolver_srv_t *srvs; ngx_resolver_node_t *rn; ngx_resolver_connection_t *rec; if (ngx_resolver_copy(r, &name, buf, buf + sizeof(ngx_resolver_hdr_t), buf + n) != 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); rn = ngx_resolver_lookup_srv(r, &name, hash); if (rn == NULL || rn->query == NULL) { ngx_log_error(r->log_level, r->log, 0, "unexpected response for %V", &name); ngx_resolver_free(r, name.data); goto failed; } if (trunc && rn->tcp) { 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 (trunc) { ngx_queue_remove(&rn->queue); if (rn->waiting == NULL) { ngx_rbtree_delete(&r->srv_rbtree, &rn->node); ngx_resolver_free_node(r, rn); return; } rec = r->connections.elts; rec = &rec[rn->last_connection]; rn->tcp = 1; (void) ngx_resolver_send_tcp_query(r, rec, rn->query, rn->qlen); rn->expire = ngx_time() + r->resend_timeout; ngx_queue_insert_head(&r->srv_resend_queue, &rn->queue); return; } if (code == 0 && rn->code) { code = rn->code; } 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(&r->srv_rbtree, &rn->node); while (next) { ctx = next; ctx->state = code; ctx->valid = ngx_time() + (r->valid ? r->valid : 10); next = ctx->next; ctx->handler(ctx); } ngx_resolver_free_node(r, rn); return; } i = ans; nsrvs = 0; cname = NULL; for (a = 0; a < nan; a++) { start = i; while (i < n) { 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 DNS response"; goto invalid; } found: if (i + sizeof(ngx_resolver_an_t) >= n) { 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_SRV: if (i + 6 > n) { goto short_response; } if (ngx_resolver_copy(r, NULL, buf, &buf[i + 6], buf + n) != NGX_OK) { goto failed; } nsrvs++; break; 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 nsrvs:%ui cname:%p ttl:%uD", nsrvs, cname, rn->ttl); if (nsrvs) { srvs = ngx_resolver_calloc(r, nsrvs * sizeof(ngx_resolver_srv_t)); if (srvs == NULL) { goto failed; } rn->u.srvs = srvs; rn->nsrvs = (u_short) nsrvs; j = 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_SRV) { srvs[j].priority = (buf[i] << 8) + buf[i + 1]; srvs[j].weight = (buf[i + 2] << 8) + buf[i + 3]; if (srvs[j].weight == 0) { srvs[j].weight = 1; } srvs[j].port = (buf[i + 4] << 8) + buf[i + 5]; if (ngx_resolver_copy(r, &srvs[j].name, buf, &buf[i + 6], buf + n) != NGX_OK) { goto failed; } j++; } i += len; } ngx_sort(srvs, nsrvs, sizeof(ngx_resolver_srv_t), ngx_resolver_cmp_srvs); ngx_resolver_free(r, rn->query); rn->query = NULL; 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->srv_expire_queue, &rn->queue); next = rn->waiting; rn->waiting = NULL; while (next) { ctx = next; next = ctx->next; ngx_resolver_resolve_srv_names(ctx, rn); } return; } rn->nsrvs = 0; if (cname) { /* CNAME only */ if (ngx_resolver_copy(r, &name, buf, cname, buf + n) != 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->srv_expire_queue, &rn->queue); ngx_resolver_free(r, rn->query); rn->query = NULL; #if (NGX_HAVE_INET6) rn->query6 = NULL; #endif ctx = rn->waiting; rn->waiting = NULL; if (ctx) { if (ctx->recursion++ >= NGX_RESOLVER_MAX_RECURSION) { /* unlock name mutex */ do { ctx->state = NGX_RESOLVE_NXDOMAIN; next = ctx->next; ctx->handler(ctx); ctx = next; } while (ctx); return; } for (next = ctx; next; next = next->next) { next->node = NULL; } (void) ngx_resolve_name_locked(r, ctx, &name); } /* unlock name mutex */ return; } ngx_log_error(r->log_level, r->log, 0, "no SRV type 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: /* unlock name mutex */ return; } static void ngx_resolver_resolve_srv_names(ngx_resolver_ctx_t *ctx, ngx_resolver_node_t *rn) { ngx_uint_t i; ngx_resolver_t *r; ngx_resolver_ctx_t *cctx; ngx_resolver_srv_name_t *srvs; r = ctx->resolver; ctx->node = NULL; ctx->state = NGX_OK; ctx->valid = rn->valid; ctx->count = rn->nsrvs; srvs = ngx_resolver_calloc(r, rn->nsrvs * sizeof(ngx_resolver_srv_name_t)); if (srvs == NULL) { goto failed; } ctx->srvs = srvs; ctx->nsrvs = rn->nsrvs; if (ctx->event && ctx->event->timer_set) { ngx_del_timer(ctx->event); } for (i = 0; i < (ngx_uint_t) rn->nsrvs; i++) { srvs[i].name.data = ngx_resolver_alloc(r, rn->u.srvs[i].name.len); if (srvs[i].name.data == NULL) { goto failed; } srvs[i].name.len = rn->u.srvs[i].name.len; ngx_memcpy(srvs[i].name.data, rn->u.srvs[i].name.data, srvs[i].name.len); cctx = ngx_resolve_start(r, NULL); if (cctx == NULL) { goto failed; } cctx->name = srvs[i].name; cctx->handler = ngx_resolver_srv_names_handler; cctx->data = ctx; cctx->srvs = &srvs[i]; cctx->timeout = ctx->timeout; srvs[i].priority = rn->u.srvs[i].priority; srvs[i].weight = rn->u.srvs[i].weight; srvs[i].port = rn->u.srvs[i].port; srvs[i].ctx = cctx; if (ngx_resolve_name(cctx) == NGX_ERROR) { srvs[i].ctx = NULL; goto failed; } } return; failed: ctx->state = NGX_ERROR; ctx->valid = ngx_time() + (r->valid ? r->valid : 10); ctx->handler(ctx); } static void ngx_resolver_srv_names_handler(ngx_resolver_ctx_t *cctx) { ngx_uint_t i; ngx_addr_t *addrs; ngx_resolver_t *r; ngx_sockaddr_t *sockaddr; ngx_resolver_ctx_t *ctx; ngx_resolver_srv_name_t *srv; r = cctx->resolver; ctx = cctx->data; srv = cctx->srvs; ctx->count--; ctx->async |= cctx->async; srv->ctx = NULL; srv->state = cctx->state; if (cctx->naddrs) { ctx->valid = ngx_min(ctx->valid, cctx->valid); addrs = ngx_resolver_calloc(r, cctx->naddrs * sizeof(ngx_addr_t)); if (addrs == NULL) { srv->state = NGX_ERROR; goto done; } sockaddr = ngx_resolver_alloc(r, cctx->naddrs * sizeof(ngx_sockaddr_t)); if (sockaddr == NULL) { ngx_resolver_free(r, addrs); srv->state = NGX_ERROR; goto done; } for (i = 0; i < cctx->naddrs; i++) { addrs[i].sockaddr = &sockaddr[i].sockaddr; addrs[i].socklen = cctx->addrs[i].socklen; ngx_memcpy(&sockaddr[i], cctx->addrs[i].sockaddr, addrs[i].socklen); ngx_inet_set_port(addrs[i].sockaddr, srv->port); } srv->addrs = addrs; srv->naddrs = cctx->naddrs; } done: ngx_resolve_name_done(cctx); if (ctx->count == 0) { ngx_resolver_report_srv(r, ctx); } } 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; int32_t ttl; ngx_int_t octet; ngx_str_t name; ngx_uint_t mask, type, class, qident, a, i, start; 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, &name, buf, buf + sizeof(ngx_resolver_hdr_t), buf + n) != NGX_OK) { return; } ngx_log_debug1(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver qs:%V", &name); /* 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; 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; 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"); ngx_resolver_free(r, name.data); return; valid: if (rn == NULL || rn->query == NULL) { 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 && nan == 0) { code = NGX_RESOLVE_NXDOMAIN; } if (code) { next = rn->waiting; rn->waiting = NULL; ngx_queue_remove(&rn->queue); ngx_rbtree_delete(tree, &rn->node); /* unlock addr mutex */ while (next) { ctx = next; ctx->state = code; ctx->valid = ngx_time() + (r->valid ? r->valid : 10); next = ctx->next; ctx->handler(ctx); } ngx_resolver_free_node(r, rn); return; } i += sizeof(ngx_resolver_qs_t); for (a = 0; a < nan; a++) { start = i; while (i < n) { 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) >= n) { 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; } ngx_log_debug3(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver qt:%ui cl:%ui len:%uz", type, class, len); i += sizeof(ngx_resolver_an_t); switch (type) { case NGX_RESOLVE_PTR: goto ptr; case NGX_RESOLVE_CNAME: break; default: ngx_log_error(r->log_level, r->log, 0, "unexpected RR type %ui", type); } i += len; } /* unlock addr mutex */ ngx_log_error(r->log_level, r->log, 0, "no PTR type in DNS response"); return; ptr: 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->valid = rn->valid; ctx->name = name; next = ctx->next; ctx->handler(ctx); } ngx_resolver_free(r, name.data); return; short_response: err = "short DNS response"; invalid: /* unlock addr mutex */ ngx_log_error(r->log_level, r->log, 0, err); return; failed: /* unlock addr mutex */ return; } static ngx_resolver_node_t * ngx_resolver_lookup_name(ngx_resolver_t *r, ngx_str_t *name, uint32_t hash) { ngx_int_t rc; ngx_rbtree_node_t *node, *sentinel; ngx_resolver_node_t *rn; node = r->name_rbtree.root; sentinel = r->name_rbtree.sentinel; while (node != sentinel) { if (hash < node->key) { node = node->left; continue; } if (hash > node->key) { node = node->right; continue; } /* hash == node->key */ rn = ngx_resolver_node(node); rc = ngx_memn2cmp(name->data, rn->name, name->len, rn->nlen); if (rc == 0) { return rn; } node = (rc < 0) ? node->left : node->right; } /* not found */ return NULL; } static ngx_resolver_node_t * ngx_resolver_lookup_srv(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->srv_rbtree.root; sentinel = r->srv_rbtree.sentinel; while (node != sentinel) { if (hash < node->key) { node = node->left; continue; } if (hash > node->key) { node = node->right; continue; } /* hash == node->key */ rn = ngx_resolver_node(node); rc = ngx_memn2cmp(name->data, rn->name, name->len, rn->nlen); if (rc == 0) { return rn; } node = (rc < 0) ? node->left : node->right; } /* not found */ return NULL; } static ngx_resolver_node_t * ngx_resolver_lookup_addr(ngx_resolver_t *r, in_addr_t addr) { ngx_rbtree_node_t *node, *sentinel; node = r->addr_rbtree.root; sentinel = r->addr_rbtree.sentinel; while (node != sentinel) { if (addr < node->key) { node = node->left; continue; } if (addr > node->key) { node = node->right; continue; } /* addr == node->key */ return ngx_resolver_node(node); } /* not found */ return NULL; } #if (NGX_HAVE_INET6) static ngx_resolver_node_t * ngx_resolver_lookup_addr6(ngx_resolver_t *r, struct in6_addr *addr, uint32_t hash) { ngx_int_t rc; ngx_rbtree_node_t *node, *sentinel; ngx_resolver_node_t *rn; node = r->addr6_rbtree.root; sentinel = r->addr6_rbtree.sentinel; while (node != sentinel) { if (hash < node->key) { node = node->left; continue; } if (hash > node->key) { node = node->right; continue; } /* hash == node->key */ rn = ngx_resolver_node(node); rc = ngx_memcmp(addr, &rn->addr6, 16); if (rc == 0) { return rn; } node = (rc < 0) ? node->left : node->right; } /* not found */ return NULL; } #endif static void ngx_resolver_rbtree_insert_value(ngx_rbtree_node_t *temp, ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel) { ngx_rbtree_node_t **p; ngx_resolver_node_t *rn, *rn_temp; for ( ;; ) { if (node->key < temp->key) { p = &temp->left; } else if (node->key > temp->key) { p = &temp->right; } else { /* node->key == temp->key */ rn = ngx_resolver_node(node); rn_temp = ngx_resolver_node(temp); p = (ngx_memn2cmp(rn->name, rn_temp->name, rn->nlen, rn_temp->nlen) < 0) ? &temp->left : &temp->right; } if (*p == sentinel) { break; } temp = *p; } *p = node; node->parent = temp; node->left = sentinel; node->right = sentinel; ngx_rbt_red(node); } #if (NGX_HAVE_INET6) static void ngx_resolver_rbtree_insert_addr6_value(ngx_rbtree_node_t *temp, ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel) { ngx_rbtree_node_t **p; ngx_resolver_node_t *rn, *rn_temp; for ( ;; ) { if (node->key < temp->key) { p = &temp->left; } else if (node->key > temp->key) { p = &temp->right; } else { /* node->key == temp->key */ rn = ngx_resolver_node(node); rn_temp = ngx_resolver_node(temp); p = (ngx_memcmp(&rn->addr6, &rn_temp->addr6, 16) < 0) ? &temp->left : &temp->right; } if (*p == sentinel) { break; } temp = *p; } *p = node; node->parent = temp; node->left = sentinel; node->right = sentinel; ngx_rbt_red(node); } #endif static ngx_int_t ngx_resolver_create_name_query(ngx_resolver_t *r, ngx_resolver_node_t *rn, ngx_str_t *name) { u_char *p, *s; size_t len, nlen; ngx_uint_t ident; ngx_resolver_qs_t *qs; ngx_resolver_hdr_t *query; nlen = name->len ? (1 + name->len + 1) : 1; len = sizeof(ngx_resolver_hdr_t) + nlen + sizeof(ngx_resolver_qs_t); #if (NGX_HAVE_INET6) p = ngx_resolver_alloc(r, r->ipv6 ? len * 2 : len); #else p = ngx_resolver_alloc(r, 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, r->log, 0, "resolve: \"%V\" A %i", 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 (name->len == 0) { return NGX_DECLINED; } for (s = name->data + name->len - 1; s >= 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, r->log, 0, "resolve: \"%V\" AAAA %i", 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_srv_query(ngx_resolver_t *r, ngx_resolver_node_t *rn, ngx_str_t *name) { u_char *p, *s; size_t len, nlen; ngx_uint_t ident; ngx_resolver_qs_t *qs; ngx_resolver_hdr_t *query; nlen = name->len ? (1 + name->len + 1) : 1; len = sizeof(ngx_resolver_hdr_t) + nlen + sizeof(ngx_resolver_qs_t); p = ngx_resolver_alloc(r, len); if (p == NULL) { return NGX_ERROR; } rn->qlen = (u_short) len; rn->query = p; query = (ngx_resolver_hdr_t *) p; ident = ngx_random(); ngx_log_debug2(NGX_LOG_DEBUG_CORE, r->log, 0, "resolve: \"%V\" SRV %i", 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_SRV; /* IN query class */ qs->class_hi = 0; qs->class_lo = 1; /* converts "www.example.com" to "\3www\7example\3com\0" */ len = 0; p--; *p-- = '\0'; if (name->len == 0) { return NGX_DECLINED; } for (s = name->data + name->len - 1; s >= 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; return NGX_OK; } static ngx_int_t ngx_resolver_create_addr_query(ngx_resolver_t *r, ngx_resolver_node_t *rn, ngx_resolver_addr_t *addr) { u_char *p, *d; size_t len; in_addr_t inaddr; 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 (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(r, 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 (addr->sockaddr->sa_family) { #if (NGX_HAVE_INET6) case AF_INET6: sin6 = (struct sockaddr_in6 *) 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 *) addr->sockaddr; inaddr = ntohl(sin->sin_addr.s_addr); for (n = 0; n < 32; n += 8) { d = ngx_sprintf(&p[1], "%ud", (inaddr >> 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 ngx_int_t ngx_resolver_set_timeout(ngx_resolver_t *r, ngx_resolver_ctx_t *ctx) { if (ctx->event || ctx->timeout == 0) { return NGX_OK; } ctx->event = ngx_resolver_calloc(r, sizeof(ngx_event_t)); if (ctx->event == NULL) { return NGX_ERROR; } ctx->event->handler = ngx_resolver_timeout_handler; ctx->event->data = ctx; ctx->event->log = r->log; ctx->event->cancelable = ctx->cancelable; ctx->ident = -1; ngx_add_timer(ctx->event, ctx->timeout); 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) { ngx_uint_t i; /* 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 if (rn->nsrvs) { for (i = 0; i < (ngx_uint_t) rn->nsrvs; i++) { if (rn->u.srvs[i].name.data) { ngx_resolver_free_locked(r, rn->u.srvs[i].name.data); } } ngx_resolver_free_locked(r, rn->u.srvs); } 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_resolver_addr_t * ngx_resolver_export(ngx_resolver_t *r, ngx_resolver_node_t *rn, ngx_uint_t rotate) { ngx_uint_t d, i, j, n; in_addr_t *addr; ngx_sockaddr_t *sockaddr; struct sockaddr_in *sin; ngx_resolver_addr_t *dst; #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_resolver_addr_t)); if (dst == NULL) { return NULL; } sockaddr = ngx_resolver_calloc(r, n * sizeof(ngx_sockaddr_t)); 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 = &sockaddr[d].sockaddr_in; 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 == (ngx_uint_t) rn->naddrs) { j = 0; } } while (++i < (ngx_uint_t) 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 = &sockaddr[d].sockaddr_in6; 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; } static void ngx_resolver_report_srv(ngx_resolver_t *r, ngx_resolver_ctx_t *ctx) { ngx_uint_t naddrs, nsrvs, nw, i, j, k, l, m, n, w; ngx_resolver_addr_t *addrs; ngx_resolver_srv_name_t *srvs; srvs = ctx->srvs; nsrvs = ctx->nsrvs; naddrs = 0; for (i = 0; i < nsrvs; i++) { if (srvs[i].state == NGX_ERROR) { ctx->state = NGX_ERROR; ctx->valid = ngx_time() + (r->valid ? r->valid : 10); ctx->handler(ctx); return; } naddrs += srvs[i].naddrs; } if (naddrs == 0) { ctx->state = srvs[0].state; for (i = 0; i < nsrvs; i++) { if (srvs[i].state == NGX_RESOLVE_NXDOMAIN) { ctx->state = NGX_RESOLVE_NXDOMAIN; break; } } ctx->valid = ngx_time() + (r->valid ? r->valid : 10); ctx->handler(ctx); return; } addrs = ngx_resolver_calloc(r, naddrs * sizeof(ngx_resolver_addr_t)); if (addrs == NULL) { ctx->state = NGX_ERROR; ctx->valid = ngx_time() + (r->valid ? r->valid : 10); ctx->handler(ctx); return; } i = 0; n = 0; do { nw = 0; for (j = i; j < nsrvs; j++) { if (srvs[j].priority != srvs[i].priority) { break; } nw += srvs[j].naddrs * srvs[j].weight; } if (nw == 0) { goto next_srv; } w = ngx_random() % nw; for (k = i; k < j; k++) { if (w < srvs[k].naddrs * srvs[k].weight) { break; } w -= srvs[k].naddrs * srvs[k].weight; } for (l = i; l < j; l++) { for (m = 0; m < srvs[k].naddrs; m++) { addrs[n].socklen = srvs[k].addrs[m].socklen; addrs[n].sockaddr = srvs[k].addrs[m].sockaddr; addrs[n].name = srvs[k].name; addrs[n].priority = srvs[k].priority; addrs[n].weight = srvs[k].weight; n++; } if (++k == j) { k = i; } } next_srv: i = j; } while (i < ctx->nsrvs); ctx->state = NGX_OK; ctx->addrs = addrs; ctx->naddrs = naddrs; ctx->handler(ctx); ngx_resolver_free(r, addrs); } 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_resolver_connection_t *rec; p = buf; if (log->action) { p = ngx_snprintf(buf, len, " while %s", log->action); len -= p - buf; } rec = log->data; if (rec) { p = ngx_snprintf(p, len, ", resolver: %V", &rec->server); } return p; } static ngx_int_t ngx_udp_connect(ngx_resolver_connection_t *rec) { int rc; ngx_int_t event; ngx_event_t *rev, *wev; ngx_socket_t s; ngx_connection_t *c; s = ngx_socket(rec->sockaddr->sa_family, SOCK_DGRAM, 0); ngx_log_debug1(NGX_LOG_DEBUG_EVENT, &rec->log, 0, "UDP socket %d", s); if (s == (ngx_socket_t) -1) { ngx_log_error(NGX_LOG_ALERT, &rec->log, ngx_socket_errno, ngx_socket_n " failed"); return NGX_ERROR; } c = ngx_get_connection(s, &rec->log); if (c == NULL) { if (ngx_close_socket(s) == -1) { ngx_log_error(NGX_LOG_ALERT, &rec->log, ngx_socket_errno, ngx_close_socket_n " failed"); } return NGX_ERROR; } if (ngx_nonblocking(s) == -1) { ngx_log_error(NGX_LOG_ALERT, &rec->log, ngx_socket_errno, ngx_nonblocking_n " failed"); goto failed; } rev = c->read; wev = c->write; rev->log = &rec->log; wev->log = &rec->log; rec->udp = c; c->number = ngx_atomic_fetch_add(ngx_connection_counter, 1); ngx_log_debug3(NGX_LOG_DEBUG_EVENT, &rec->log, 0, "connect to %V, fd:%d #%uA", &rec->server, s, c->number); rc = connect(s, rec->sockaddr, rec->socklen); /* TODO: iocp */ if (rc == -1) { ngx_log_error(NGX_LOG_CRIT, &rec->log, ngx_socket_errno, "connect() failed"); goto failed; } /* UDP sockets are always ready to write */ wev->ready = 1; event = (ngx_event_flags & NGX_USE_CLEAR_EVENT) ? /* kqueue, epoll */ NGX_CLEAR_EVENT: /* select, poll, /dev/poll */ NGX_LEVEL_EVENT; /* eventport event type has no meaning: oneshot only */ if (ngx_add_event(rev, NGX_READ_EVENT, event) != NGX_OK) { goto failed; } return NGX_OK; failed: ngx_close_connection(c); rec->udp = NULL; return NGX_ERROR; } static ngx_int_t ngx_tcp_connect(ngx_resolver_connection_t *rec) { int rc; ngx_int_t event; ngx_err_t err; ngx_uint_t level; ngx_socket_t s; ngx_event_t *rev, *wev; ngx_connection_t *c; s = ngx_socket(rec->sockaddr->sa_family, SOCK_STREAM, 0); ngx_log_debug1(NGX_LOG_DEBUG_EVENT, &rec->log, 0, "TCP socket %d", s); if (s == (ngx_socket_t) -1) { ngx_log_error(NGX_LOG_ALERT, &rec->log, ngx_socket_errno, ngx_socket_n " failed"); return NGX_ERROR; } c = ngx_get_connection(s, &rec->log); if (c == NULL) { if (ngx_close_socket(s) == -1) { ngx_log_error(NGX_LOG_ALERT, &rec->log, ngx_socket_errno, ngx_close_socket_n " failed"); } return NGX_ERROR; } if (ngx_nonblocking(s) == -1) { ngx_log_error(NGX_LOG_ALERT, &rec->log, ngx_socket_errno, ngx_nonblocking_n " failed"); goto failed; } rev = c->read; wev = c->write; rev->log = &rec->log; wev->log = &rec->log; rec->tcp = c; c->number = ngx_atomic_fetch_add(ngx_connection_counter, 1); if (ngx_add_conn) { if (ngx_add_conn(c) == NGX_ERROR) { goto failed; } } ngx_log_debug3(NGX_LOG_DEBUG_EVENT, &rec->log, 0, "connect to %V, fd:%d #%uA", &rec->server, s, c->number); rc = connect(s, rec->sockaddr, rec->socklen); if (rc == -1) { err = ngx_socket_errno; if (err != NGX_EINPROGRESS #if (NGX_WIN32) /* Winsock returns WSAEWOULDBLOCK (NGX_EAGAIN) */ && err != NGX_EAGAIN #endif ) { if (err == NGX_ECONNREFUSED #if (NGX_LINUX) /* * Linux returns EAGAIN instead of ECONNREFUSED * for unix sockets if listen queue is full */ || err == NGX_EAGAIN #endif || err == NGX_ECONNRESET || err == NGX_ENETDOWN || err == NGX_ENETUNREACH || err == NGX_EHOSTDOWN || err == NGX_EHOSTUNREACH) { level = NGX_LOG_ERR; } else { level = NGX_LOG_CRIT; } ngx_log_error(level, &rec->log, err, "connect() to %V failed", &rec->server); ngx_close_connection(c); rec->tcp = NULL; return NGX_ERROR; } } if (ngx_add_conn) { if (rc == -1) { /* NGX_EINPROGRESS */ return NGX_AGAIN; } ngx_log_debug0(NGX_LOG_DEBUG_EVENT, &rec->log, 0, "connected"); wev->ready = 1; return NGX_OK; } if (ngx_event_flags & NGX_USE_IOCP_EVENT) { ngx_log_debug1(NGX_LOG_DEBUG_EVENT, &rec->log, ngx_socket_errno, "connect(): %d", rc); if (ngx_blocking(s) == -1) { ngx_log_error(NGX_LOG_ALERT, &rec->log, ngx_socket_errno, ngx_blocking_n " failed"); goto failed; } /* * FreeBSD's aio allows to post an operation on non-connected socket. * NT does not support it. * * TODO: check in Win32, etc. As workaround we can use NGX_ONESHOT_EVENT */ rev->ready = 1; wev->ready = 1; return NGX_OK; } if (ngx_event_flags & NGX_USE_CLEAR_EVENT) { /* kqueue */ event = NGX_CLEAR_EVENT; } else { /* select, poll, /dev/poll */ event = NGX_LEVEL_EVENT; } if (ngx_add_event(rev, NGX_READ_EVENT, event) != NGX_OK) { goto failed; } if (rc == -1) { /* NGX_EINPROGRESS */ if (ngx_add_event(wev, NGX_WRITE_EVENT, event) != NGX_OK) { goto failed; } return NGX_AGAIN; } ngx_log_debug0(NGX_LOG_DEBUG_EVENT, &rec->log, 0, "connected"); wev->ready = 1; return NGX_OK; failed: ngx_close_connection(c); rec->tcp = NULL; return NGX_ERROR; } static ngx_int_t ngx_resolver_cmp_srvs(const void *one, const void *two) { ngx_int_t p1, p2; ngx_resolver_srv_t *first, *second; first = (ngx_resolver_srv_t *) one; second = (ngx_resolver_srv_t *) two; p1 = first->priority; p2 = second->priority; return p1 - p2; }