diff options
Diffstat (limited to 'app/nginx/src/core/ngx_resolver.c')
| -rw-r--r-- | app/nginx/src/core/ngx_resolver.c | 4662 |
1 files changed, 4662 insertions, 0 deletions
diff --git a/app/nginx/src/core/ngx_resolver.c b/app/nginx/src/core/ngx_resolver.c new file mode 100644 index 0000000..e140ab6 --- /dev/null +++ b/app/nginx/src/core/ngx_resolver.c @@ -0,0 +1,4662 @@ + +/* + * 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 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; + + 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->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->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; + } + } + + return r; +} + + +static void +ngx_resolver_cleanup(void *data) +{ + ngx_resolver_t *r = data; + + ngx_uint_t i; + ngx_resolver_connection_t *rec; + + 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->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) { + if (r->event->timer_set) { + ngx_del_timer(r->event); + } + + ngx_free(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); + } + } + + ngx_free(r); + } +} + + +static void +ngx_resolver_cleanup_tree(ngx_resolver_t *r, ngx_rbtree_t *tree) +{ + ngx_resolver_ctx_t *ctx, *next; + ngx_resolver_node_t *rn; + + while (tree->root != tree->sentinel) { + + rn = ngx_resolver_node(ngx_rbtree_min(tree->root, tree->sentinel)); + + ngx_queue_remove(&rn->queue); + + for (ctx = rn->waiting; ctx; ctx = next) { + next = ctx->next; + + if (ctx->event) { + 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) { + return NGX_ERROR; + } + + 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); + } + + 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 (ctx->event == NULL && ctx->timeout) { + 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->ident = -1; + + ngx_add_timer(ctx->event, ctx->timeout); + } + + last->next = rn->waiting; + rn->waiting = ctx; + ctx->state = NGX_AGAIN; + + 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) { + goto failed; + } + + if (ctx->event == NULL && ctx->timeout) { + ctx->event = ngx_resolver_calloc(r, sizeof(ngx_event_t)); + if (ctx->event == NULL) { + goto failed; + } + + ctx->event->handler = ngx_resolver_timeout_handler; + ctx->event->data = ctx; + ctx->event->log = r->log; + ctx->ident = -1; + + ngx_add_timer(ctx->event, ctx->timeout); + } + + if (ngx_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; + + 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) { + goto failed; + } + + 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 (ctx->event == NULL && ctx->timeout) { + 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->ident = -1; + + ngx_add_timer(ctx->event, ctx->timeout); + } + + ctx->next = rn->waiting; + rn->waiting = ctx; + ctx->state = NGX_AGAIN; + 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) { + goto failed; + } + + if (ctx->event == NULL && ctx->timeout) { + ctx->event = ngx_resolver_calloc(r, sizeof(ngx_event_t)); + if (ctx->event == NULL) { + goto failed; + } + + ctx->event->handler = ngx_resolver_timeout_handler; + ctx->event->data = ctx; + ctx->event->log = r->log; + ctx->ident = -1; + + ngx_add_timer(ctx->event, ctx->timeout); + } + + if (ngx_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->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 == -1) { + return NGX_ERROR; + } + + if ((size_t) n != (size_t) qlen) { + ngx_log_error(NGX_LOG_CRIT, &rec->log, 0, "send() incomplete"); + return NGX_ERROR; + } + + return NGX_OK; +} + + +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--; + + 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) { + ngx_resolve_name_done(cctx); + + ctx->state = NGX_ERROR; + ctx->valid = ngx_time() + (r->valid ? r->valid : 10); + + ctx->handler(ctx); + return; + } + + sockaddr = ngx_resolver_alloc(r, cctx->naddrs * sizeof(ngx_sockaddr_t)); + if (sockaddr == NULL) { + ngx_resolver_free(r, addrs); + ngx_resolve_name_done(cctx); + + ctx->state = NGX_ERROR; + ctx->valid = ngx_time() + (r->valid ? r->valid : 10); + + ctx->handler(ctx); + return; + } + + 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; + } + + 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 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; + + naddrs = 0; + + for (i = 0; i < ctx->nsrvs; i++) { + naddrs += ctx->srvs[i].naddrs; + } + + if (naddrs == 0) { + ctx->state = NGX_RESOLVE_NXDOMAIN; + 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; + } + + srvs = ctx->srvs; + nsrvs = ctx->nsrvs; + + 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, c->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; +} |