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Diffstat (limited to '')
| -rw-r--r-- | daemon/worker.c | 2010 |
1 files changed, 2010 insertions, 0 deletions
diff --git a/daemon/worker.c b/daemon/worker.c new file mode 100644 index 0000000..117cc91 --- /dev/null +++ b/daemon/worker.c @@ -0,0 +1,2010 @@ +/* Copyright (C) 2014-2017 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +#include <uv.h> +#include <lua.h> +#include <libknot/packet/pkt.h> +#include <libknot/descriptor.h> +#include <contrib/ucw/lib.h> +#include <contrib/ucw/mempool.h> +#include <contrib/wire.h> +#if defined(__GLIBC__) && defined(_GNU_SOURCE) +#include <malloc.h> +#endif +#include <assert.h> +#include <sys/types.h> +#include <unistd.h> +#include <gnutls/gnutls.h> +#include "lib/utils.h" +#include "lib/layer.h" +#include "daemon/worker.h" +#include "daemon/bindings.h" +#include "daemon/engine.h" +#include "daemon/io.h" +#include "daemon/tls.h" +#include "daemon/zimport.h" +#include "daemon/session.h" + + +/* Magic defaults for the worker. */ +#ifndef MP_FREELIST_SIZE +# ifdef __clang_analyzer__ +# define MP_FREELIST_SIZE 0 +# else +# define MP_FREELIST_SIZE 64 /**< Maximum length of the worker mempool freelist */ +# endif +#endif +#ifndef QUERY_RATE_THRESHOLD +#define QUERY_RATE_THRESHOLD (2 * MP_FREELIST_SIZE) /**< Nr of parallel queries considered as high rate */ +#endif +#ifndef MAX_PIPELINED +#define MAX_PIPELINED 100 +#endif + +#define VERBOSE_MSG(qry, ...) QRVERBOSE(qry, "wrkr", __VA_ARGS__) + +/** Client request state. */ +struct request_ctx +{ + struct kr_request req; + struct { + union inaddr addr; + union inaddr dst_addr; + /* uv_handle_t *handle; */ + + /** NULL if the request didn't come over network. */ + struct session *session; + } source; + struct worker_ctx *worker; + struct qr_task *task; +}; + +/** Query resolution task. */ +struct qr_task +{ + struct request_ctx *ctx; + knot_pkt_t *pktbuf; + qr_tasklist_t waiting; + struct session *pending[MAX_PENDING]; + uint16_t pending_count; + uint16_t addrlist_count; + uint16_t addrlist_turn; + uint16_t timeouts; + uint16_t iter_count; + struct sockaddr *addrlist; + uint32_t refs; + bool finished : 1; + bool leading : 1; + uint64_t creation_time; +}; + + +/* Convenience macros */ +#define qr_task_ref(task) \ + do { ++(task)->refs; } while(0) +#define qr_task_unref(task) \ + do { if (task && --(task)->refs == 0) { qr_task_free(task); } } while (0) + +/** @internal get key for tcp session + * @note kr_straddr() return pointer to static string + */ +#define tcpsess_key(addr) kr_straddr(addr) + +/* Forward decls */ +static void qr_task_free(struct qr_task *task); +static int qr_task_step(struct qr_task *task, + const struct sockaddr *packet_source, + knot_pkt_t *packet); +static int qr_task_send(struct qr_task *task, struct session *session, + struct sockaddr *addr, knot_pkt_t *pkt); +static int qr_task_finalize(struct qr_task *task, int state); +static void qr_task_complete(struct qr_task *task); +static struct session* worker_find_tcp_connected(struct worker_ctx *worker, + const struct sockaddr *addr); +static int worker_add_tcp_waiting(struct worker_ctx *worker, + const struct sockaddr *addr, + struct session *session); +static struct session* worker_find_tcp_waiting(struct worker_ctx *worker, + const struct sockaddr *addr); +static void on_tcp_connect_timeout(uv_timer_t *timer); + +/** @internal Get singleton worker. */ +static inline struct worker_ctx *get_worker(void) +{ + return uv_default_loop()->data; +} + +/*! @internal Create a UDP/TCP handle for an outgoing AF_INET* connection. + * socktype is SOCK_* */ +static uv_handle_t *ioreq_spawn(struct worker_ctx *worker, + int socktype, sa_family_t family, bool has_tls) +{ + bool precond = (socktype == SOCK_DGRAM || socktype == SOCK_STREAM) + && (family == AF_INET || family == AF_INET6); + if (!precond) { + assert(false); + kr_log_verbose("[work] ioreq_spawn: pre-condition failed\n"); + return NULL; + } + + /* Create connection for iterative query */ + uv_handle_t *handle = malloc(socktype == SOCK_DGRAM + ? sizeof(uv_udp_t) : sizeof(uv_tcp_t)); + if (!handle) { + return NULL; + } + int ret = io_create(worker->loop, handle, socktype, family, has_tls); + if (ret) { + if (ret == UV_EMFILE) { + worker->too_many_open = true; + worker->rconcurrent_highwatermark = worker->stats.rconcurrent; + } + free(handle); + return NULL; + } + + /* Bind to outgoing address, according to IP v4/v6. */ + union inaddr *addr; + if (family == AF_INET) { + addr = (union inaddr *)&worker->out_addr4; + } else { + addr = (union inaddr *)&worker->out_addr6; + } + if (addr->ip.sa_family != AF_UNSPEC) { + assert(addr->ip.sa_family == family); + if (socktype == SOCK_DGRAM) { + uv_udp_t *udp = (uv_udp_t *)handle; + ret = uv_udp_bind(udp, &addr->ip, 0); + } else if (socktype == SOCK_STREAM){ + uv_tcp_t *tcp = (uv_tcp_t *)handle; + ret = uv_tcp_bind(tcp, &addr->ip, 0); + } + } + + if (ret != 0) { + io_deinit(handle); + free(handle); + return NULL; + } + + /* Set current handle as a subrequest type. */ + struct session *session = handle->data; + session_flags(session)->outgoing = true; + /* Connect or issue query datagram */ + return handle; +} + +static void ioreq_kill_pending(struct qr_task *task) +{ + for (uint16_t i = 0; i < task->pending_count; ++i) { + session_kill_ioreq(task->pending[i], task); + } + task->pending_count = 0; +} + +/** @cond This memory layout is internal to mempool.c, use only for debugging. */ +#if defined(__SANITIZE_ADDRESS__) +struct mempool_chunk { + struct mempool_chunk *next; + size_t size; +}; +static void mp_poison(struct mempool *mp, bool poison) +{ + if (!poison) { /* @note mempool is part of the first chunk, unpoison it first */ + kr_asan_unpoison(mp, sizeof(*mp)); + } + struct mempool_chunk *chunk = mp->state.last[0]; + void *chunk_off = (uint8_t *)chunk - chunk->size; + if (poison) { + kr_asan_poison(chunk_off, chunk->size); + } else { + kr_asan_unpoison(chunk_off, chunk->size); + } +} +#else +#define mp_poison(mp, enable) +#endif +/** @endcond */ + +/** Get a mempool. (Recycle if possible.) */ +static inline struct mempool *pool_borrow(struct worker_ctx *worker) +{ + struct mempool *mp = NULL; + if (worker->pool_mp.len > 0) { + mp = array_tail(worker->pool_mp); + array_pop(worker->pool_mp); + mp_poison(mp, 0); + } else { /* No mempool on the freelist, create new one */ + mp = mp_new (4 * CPU_PAGE_SIZE); + } + return mp; +} + +/** Return a mempool. (Cache them up to some count.) */ +static inline void pool_release(struct worker_ctx *worker, struct mempool *mp) +{ + if (worker->pool_mp.len < MP_FREELIST_SIZE) { + mp_flush(mp); + array_push(worker->pool_mp, mp); + mp_poison(mp, 1); + } else { + mp_delete(mp); + } +} + +/** Create a key for an outgoing subrequest: qname, qclass, qtype. + * @param key Destination buffer for key size, MUST be SUBREQ_KEY_LEN or larger. + * @return key length if successful or an error + */ +static const size_t SUBREQ_KEY_LEN = KR_RRKEY_LEN; +static int subreq_key(char *dst, knot_pkt_t *pkt) +{ + assert(pkt); + return kr_rrkey(dst, knot_pkt_qclass(pkt), knot_pkt_qname(pkt), + knot_pkt_qtype(pkt), knot_pkt_qtype(pkt)); +} + +/** Create and initialize a request_ctx (on a fresh mempool). + * + * handle and addr point to the source of the request, and they are NULL + * in case the request didn't come from network. + */ +static struct request_ctx *request_create(struct worker_ctx *worker, + uv_handle_t *handle, + const struct sockaddr *addr, + uint32_t uid) +{ + knot_mm_t pool = { + .ctx = pool_borrow(worker), + .alloc = (knot_mm_alloc_t) mp_alloc + }; + + /* Create request context */ + struct request_ctx *ctx = mm_alloc(&pool, sizeof(*ctx)); + if (!ctx) { + pool_release(worker, pool.ctx); + return NULL; + } + + memset(ctx, 0, sizeof(*ctx)); + + /* TODO Relocate pool to struct request */ + ctx->worker = worker; + struct session *s = handle ? handle->data : NULL; + if (s) { + assert(session_flags(s)->outgoing == false); + } + ctx->source.session = s; + + struct kr_request *req = &ctx->req; + req->pool = pool; + req->vars_ref = LUA_NOREF; + req->uid = uid; + req->daemon_context = worker; + + /* Remember query source addr */ + if (!addr || (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)) { + ctx->source.addr.ip.sa_family = AF_UNSPEC; + } else { + memcpy(&ctx->source.addr, addr, kr_sockaddr_len(addr)); + ctx->req.qsource.addr = &ctx->source.addr.ip; + } + + worker->stats.rconcurrent += 1; + + if (!handle) { + return ctx; + } + + /* Remember the destination address. */ + int addr_len = sizeof(ctx->source.dst_addr); + struct sockaddr *dst_addr = &ctx->source.dst_addr.ip; + ctx->source.dst_addr.ip.sa_family = AF_UNSPEC; + if (handle->type == UV_UDP) { + if (uv_udp_getsockname((uv_udp_t *)handle, dst_addr, &addr_len) == 0) { + req->qsource.dst_addr = dst_addr; + } + req->qsource.flags.tcp = false; + req->qsource.flags.tls = false; + } else if (handle->type == UV_TCP) { + if (uv_tcp_getsockname((uv_tcp_t *)handle, dst_addr, &addr_len) == 0) { + req->qsource.dst_addr = dst_addr; + } + req->qsource.flags.tcp = true; + req->qsource.flags.tls = s && session_flags(s)->has_tls; + } + + return ctx; +} + +/** More initialization, related to the particular incoming query/packet. */ +static int request_start(struct request_ctx *ctx, knot_pkt_t *query) +{ + assert(query && ctx); + size_t answer_max = KNOT_WIRE_MIN_PKTSIZE; + struct kr_request *req = &ctx->req; + + /* source.session can be empty if request was generated by kresd itself */ + struct session *s = ctx->source.session; + if (!s || session_get_handle(s)->type == UV_TCP) { + answer_max = KNOT_WIRE_MAX_PKTSIZE; + } else if (knot_pkt_has_edns(query)) { /* EDNS */ + answer_max = MAX(knot_edns_get_payload(query->opt_rr), + KNOT_WIRE_MIN_PKTSIZE); + } + req->qsource.size = query->size; + if (knot_pkt_has_tsig(query)) { + req->qsource.size += query->tsig_wire.len; + } + + knot_pkt_t *answer = knot_pkt_new(NULL, answer_max, &req->pool); + if (!answer) { /* Failed to allocate answer */ + return kr_error(ENOMEM); + } + + knot_pkt_t *pkt = knot_pkt_new(NULL, req->qsource.size, &req->pool); + if (!pkt) { + return kr_error(ENOMEM); + } + + int ret = knot_pkt_copy(pkt, query); + if (ret != KNOT_EOK && ret != KNOT_ETRAIL) { + return kr_error(ENOMEM); + } + req->qsource.packet = pkt; + + /* Start resolution */ + struct worker_ctx *worker = ctx->worker; + struct engine *engine = worker->engine; + kr_resolve_begin(req, &engine->resolver, answer); + worker->stats.queries += 1; + /* Throttle outbound queries only when high pressure */ + if (worker->stats.concurrent < QUERY_RATE_THRESHOLD) { + req->options.NO_THROTTLE = true; + } + return kr_ok(); +} + +static void request_free(struct request_ctx *ctx) +{ + struct worker_ctx *worker = ctx->worker; + /* Dereference any Lua vars table if exists */ + if (ctx->req.vars_ref != LUA_NOREF) { + lua_State *L = worker->engine->L; + /* Get worker variables table */ + lua_rawgeti(L, LUA_REGISTRYINDEX, worker->vars_table_ref); + /* Get next free element (position 0) and store it under current reference (forming a list) */ + lua_rawgeti(L, -1, 0); + lua_rawseti(L, -2, ctx->req.vars_ref); + /* Set current reference as the next free element */ + lua_pushinteger(L, ctx->req.vars_ref); + lua_rawseti(L, -2, 0); + lua_pop(L, 1); + ctx->req.vars_ref = LUA_NOREF; + } + /* Return mempool to ring or free it if it's full */ + pool_release(worker, ctx->req.pool.ctx); + /* @note The 'task' is invalidated from now on. */ + /* Decommit memory every once in a while */ + static int mp_delete_count = 0; + if (++mp_delete_count == 100000) { + lua_gc(worker->engine->L, LUA_GCCOLLECT, 0); +#if defined(__GLIBC__) && defined(_GNU_SOURCE) + malloc_trim(0); +#endif + mp_delete_count = 0; + } + worker->stats.rconcurrent -= 1; +} + +static struct qr_task *qr_task_create(struct request_ctx *ctx) +{ + /* How much can client handle? */ + struct engine *engine = ctx->worker->engine; + size_t pktbuf_max = KR_EDNS_PAYLOAD; + if (engine->resolver.opt_rr) { + pktbuf_max = MAX(knot_edns_get_payload(engine->resolver.opt_rr), + pktbuf_max); + } + + /* Create resolution task */ + struct qr_task *task = mm_alloc(&ctx->req.pool, sizeof(*task)); + if (!task) { + return NULL; + } + memset(task, 0, sizeof(*task)); /* avoid accidentally unintialized fields */ + + /* Create packet buffers for answer and subrequests */ + knot_pkt_t *pktbuf = knot_pkt_new(NULL, pktbuf_max, &ctx->req.pool); + if (!pktbuf) { + mm_free(&ctx->req.pool, task); + return NULL; + } + pktbuf->size = 0; + + task->ctx = ctx; + task->pktbuf = pktbuf; + array_init(task->waiting); + task->refs = 0; + assert(ctx->task == NULL); + ctx->task = task; + /* Make the primary reference to task. */ + qr_task_ref(task); + task->creation_time = kr_now(); + ctx->worker->stats.concurrent += 1; + return task; +} + +/* This is called when the task refcount is zero, free memory. */ +static void qr_task_free(struct qr_task *task) +{ + struct request_ctx *ctx = task->ctx; + + assert(ctx); + + struct worker_ctx *worker = ctx->worker; + + if (ctx->task == NULL) { + request_free(ctx); + } + + /* Update stats */ + worker->stats.concurrent -= 1; +} + +/*@ Register new qr_task within session. */ +static int qr_task_register(struct qr_task *task, struct session *session) +{ + assert(!session_flags(session)->outgoing && session_get_handle(session)->type == UV_TCP); + + session_tasklist_add(session, task); + + struct request_ctx *ctx = task->ctx; + assert(ctx && (ctx->source.session == NULL || ctx->source.session == session)); + ctx->source.session = session; + /* Soft-limit on parallel queries, there is no "slow down" RCODE + * that we could use to signalize to client, but we can stop reading, + * an in effect shrink TCP window size. To get more precise throttling, + * we would need to copy remainder of the unread buffer and reassemble + * when resuming reading. This is NYI. */ + if (session_tasklist_get_len(session) >= task->ctx->worker->tcp_pipeline_max && + !session_flags(session)->throttled && !session_flags(session)->closing) { + session_stop_read(session); + session_flags(session)->throttled = true; + } + + return 0; +} + +static void qr_task_complete(struct qr_task *task) +{ + struct request_ctx *ctx = task->ctx; + + /* Kill pending I/O requests */ + ioreq_kill_pending(task); + assert(task->waiting.len == 0); + assert(task->leading == false); + + struct session *s = ctx->source.session; + if (s) { + assert(!session_flags(s)->outgoing && session_waitinglist_is_empty(s)); + ctx->source.session = NULL; + session_tasklist_del(s, task); + } + + /* Release primary reference to task. */ + if (ctx->task == task) { + ctx->task = NULL; + qr_task_unref(task); + } +} + +/* This is called when we send subrequest / answer */ +static int qr_task_on_send(struct qr_task *task, uv_handle_t *handle, int status) +{ + + if (task->finished) { + assert(task->leading == false); + qr_task_complete(task); + } + + if (!handle || handle->type != UV_TCP) { + return status; + } + + struct session* s = handle->data; + assert(s); + if (status != 0) { + session_tasklist_del(s, task); + } + + if (session_flags(s)->outgoing || session_flags(s)->closing) { + return status; + } + + struct worker_ctx *worker = task->ctx->worker; + if (session_flags(s)->throttled && + session_tasklist_get_len(s) < worker->tcp_pipeline_max/2) { + /* Start reading again if the session is throttled and + * the number of outgoing requests is below watermark. */ + session_start_read(s); + session_flags(s)->throttled = false; + } + + return status; +} + +static void on_send(uv_udp_send_t *req, int status) +{ + struct qr_task *task = req->data; + uv_handle_t *h = (uv_handle_t *)req->handle; + qr_task_on_send(task, h, status); + qr_task_unref(task); + free(req); +} + +static void on_write(uv_write_t *req, int status) +{ + struct qr_task *task = req->data; + uv_handle_t *h = (uv_handle_t *)req->handle; + qr_task_on_send(task, h, status); + qr_task_unref(task); + free(req); +} + +static int qr_task_send(struct qr_task *task, struct session *session, + struct sockaddr *addr, knot_pkt_t *pkt) +{ + if (!session) { + return qr_task_on_send(task, NULL, kr_error(EIO)); + } + + int ret = 0; + struct request_ctx *ctx = task->ctx; + + uv_handle_t *handle = session_get_handle(session); + assert(handle && handle->data == session); + const bool is_stream = handle->type == UV_TCP; + if (!is_stream && handle->type != UV_UDP) abort(); + + if (addr == NULL) { + addr = session_get_peer(session); + } + + if (pkt == NULL) { + pkt = worker_task_get_pktbuf(task); + } + + if (session_flags(session)->outgoing && handle->type == UV_TCP) { + size_t try_limit = session_tasklist_get_len(session) + 1; + uint16_t msg_id = knot_wire_get_id(pkt->wire); + size_t try_count = 0; + while (session_tasklist_find_msgid(session, msg_id) && + try_count <= try_limit) { + ++msg_id; + ++try_count; + } + if (try_count > try_limit) { + return kr_error(ENOENT); + } + worker_task_pkt_set_msgid(task, msg_id); + } + + uv_handle_t *ioreq = malloc(is_stream ? sizeof(uv_write_t) : sizeof(uv_udp_send_t)); + if (!ioreq) { + return qr_task_on_send(task, handle, kr_error(ENOMEM)); + } + + /* Pending ioreq on current task */ + qr_task_ref(task); + + struct worker_ctx *worker = ctx->worker; + /* Send using given protocol */ + assert(!session_flags(session)->closing); + if (session_flags(session)->has_tls) { + uv_write_t *write_req = (uv_write_t *)ioreq; + write_req->data = task; + ret = tls_write(write_req, handle, pkt, &on_write); + } else if (handle->type == UV_UDP) { + uv_udp_send_t *send_req = (uv_udp_send_t *)ioreq; + uv_buf_t buf = { (char *)pkt->wire, pkt->size }; + send_req->data = task; + ret = uv_udp_send(send_req, (uv_udp_t *)handle, &buf, 1, addr, &on_send); + } else if (handle->type == UV_TCP) { + uv_write_t *write_req = (uv_write_t *)ioreq; + uint16_t pkt_size = htons(pkt->size); + uv_buf_t buf[2] = { + { (char *)&pkt_size, sizeof(pkt_size) }, + { (char *)pkt->wire, pkt->size } + }; + write_req->data = task; + ret = uv_write(write_req, (uv_stream_t *)handle, buf, 2, &on_write); + } else { + assert(false); + } + + if (ret == 0) { + session_touch(session); + if (session_flags(session)->outgoing) { + session_tasklist_add(session, task); + } + if (worker->too_many_open && + worker->stats.rconcurrent < + worker->rconcurrent_highwatermark - 10) { + worker->too_many_open = false; + } + } else { + free(ioreq); + qr_task_unref(task); + if (ret == UV_EMFILE) { + worker->too_many_open = true; + worker->rconcurrent_highwatermark = worker->stats.rconcurrent; + ret = kr_error(UV_EMFILE); + } + } + + /* Update statistics */ + if (session_flags(session)->outgoing && addr) { + if (session_flags(session)->has_tls) + worker->stats.tls += 1; + else if (handle->type == UV_UDP) + worker->stats.udp += 1; + else + worker->stats.tcp += 1; + + if (addr->sa_family == AF_INET6) + worker->stats.ipv6 += 1; + else if (addr->sa_family == AF_INET) + worker->stats.ipv4 += 1; + } + return ret; +} + +static struct kr_query *task_get_last_pending_query(struct qr_task *task) +{ + if (!task || task->ctx->req.rplan.pending.len == 0) { + return NULL; + } + + return array_tail(task->ctx->req.rplan.pending); +} + +static int session_tls_hs_cb(struct session *session, int status) +{ + assert(session_flags(session)->outgoing); + uv_handle_t *handle = session_get_handle(session); + uv_loop_t *loop = handle->loop; + struct worker_ctx *worker = loop->data; + struct sockaddr *peer = session_get_peer(session); + int deletion_res = worker_del_tcp_waiting(worker, peer); + int ret = kr_ok(); + + if (status) { + struct qr_task *task = session_waitinglist_get(session); + if (task) { + struct kr_qflags *options = &task->ctx->req.options; + unsigned score = options->FORWARD || options->STUB ? KR_NS_FWD_DEAD : KR_NS_DEAD; + kr_nsrep_update_rtt(NULL, peer, score, + worker->engine->resolver.cache_rtt, + KR_NS_UPDATE_NORESET); + } +#ifndef NDEBUG + else { + /* Task isn't in the list of tasks + * waiting for connection to upstream. + * So that it MUST be unsuccessful rehandshake. + * Check it. */ + assert(deletion_res != 0); + const char *key = tcpsess_key(peer); + assert(key); + assert(map_contains(&worker->tcp_connected, key) != 0); + } +#endif + return ret; + } + + /* handshake was completed successfully */ + struct tls_client_ctx_t *tls_client_ctx = session_tls_get_client_ctx(session); + struct tls_client_paramlist_entry *tls_params = tls_client_ctx->params; + gnutls_session_t tls_session = tls_client_ctx->c.tls_session; + if (gnutls_session_is_resumed(tls_session) != 0) { + kr_log_verbose("[tls_client] TLS session has resumed\n"); + } else { + kr_log_verbose("[tls_client] TLS session has not resumed\n"); + /* session wasn't resumed, delete old session data ... */ + if (tls_params->session_data.data != NULL) { + gnutls_free(tls_params->session_data.data); + tls_params->session_data.data = NULL; + tls_params->session_data.size = 0; + } + /* ... and get the new session data */ + gnutls_datum_t tls_session_data = { NULL, 0 }; + ret = gnutls_session_get_data2(tls_session, &tls_session_data); + if (ret == 0) { + tls_params->session_data = tls_session_data; + } + } + + struct session *s = worker_find_tcp_connected(worker, peer); + ret = kr_ok(); + if (deletion_res == kr_ok()) { + /* peer was in the waiting list, add to the connected list. */ + if (s) { + /* Something went wrong, + * peer already is in the connected list. */ + ret = kr_error(EINVAL); + } else { + ret = worker_add_tcp_connected(worker, peer, session); + } + } else { + /* peer wasn't in the waiting list. + * It can be + * 1) either successful rehandshake; in this case peer + * must be already in the connected list. + * 2) or successful handshake with session, which was timeouted + * by on_tcp_connect_timeout(); after successful tcp connection; + * in this case peer isn't in the connected list. + **/ + if (!s || s != session) { + ret = kr_error(EINVAL); + } + } + if (ret == kr_ok()) { + while (!session_waitinglist_is_empty(session)) { + struct qr_task *t = session_waitinglist_get(session); + ret = qr_task_send(t, session, NULL, NULL); + if (ret != 0) { + break; + } + session_waitinglist_pop(session, true); + } + } else { + ret = kr_error(EINVAL); + } + + if (ret != kr_ok()) { + /* Something went wrong. + * Either addition to the list of connected sessions + * or write to upstream failed. */ + worker_del_tcp_connected(worker, peer); + session_waitinglist_finalize(session, KR_STATE_FAIL); + assert(session_tasklist_is_empty(session)); + session_close(session); + } else { + session_timer_stop(session); + session_timer_start(session, tcp_timeout_trigger, + MAX_TCP_INACTIVITY, MAX_TCP_INACTIVITY); + } + return kr_ok(); +} + +static int send_waiting(struct session *session) +{ + int ret = 0; + while (!session_waitinglist_is_empty(session)) { + struct qr_task *t = session_waitinglist_get(session); + ret = qr_task_send(t, session, NULL, NULL); + if (ret != 0) { + struct worker_ctx *worker = t->ctx->worker; + struct sockaddr *peer = session_get_peer(session); + session_waitinglist_finalize(session, KR_STATE_FAIL); + session_tasklist_finalize(session, KR_STATE_FAIL); + worker_del_tcp_connected(worker, peer); + session_close(session); + break; + } + session_waitinglist_pop(session, true); + } + return ret; +} + +static void on_connect(uv_connect_t *req, int status) +{ + struct worker_ctx *worker = get_worker(); + uv_stream_t *handle = req->handle; + struct session *session = handle->data; + struct sockaddr *peer = session_get_peer(session); + free(req); + + assert(session_flags(session)->outgoing); + + if (session_flags(session)->closing) { + worker_del_tcp_waiting(worker, peer); + assert(session_is_empty(session)); + return; + } + + /* Check if the connection is in the waiting list. + * If no, most likely this is timeouted connection + * which was removed from waiting list by + * on_tcp_connect_timeout() callback. */ + struct session *s = worker_find_tcp_waiting(worker, peer); + if (!s || s != session) { + /* session isn't on the waiting list. + * it's timeouted session. */ + if (VERBOSE_STATUS) { + const char *peer_str = kr_straddr(peer); + kr_log_verbose( "[wrkr]=> connected to '%s', but session " + "is already timeouted, close\n", + peer_str ? peer_str : ""); + } + assert(session_tasklist_is_empty(session)); + session_waitinglist_retry(session, false); + session_close(session); + return; + } + + s = worker_find_tcp_connected(worker, peer); + if (s) { + /* session already in the connected list. + * Something went wrong, it can be due to races when kresd has tried + * to reconnect to upstream after unsuccessful attempt. */ + if (VERBOSE_STATUS) { + const char *peer_str = kr_straddr(peer); + kr_log_verbose( "[wrkr]=> connected to '%s', but peer " + "is already connected, close\n", + peer_str ? peer_str : ""); + } + assert(session_tasklist_is_empty(session)); + session_waitinglist_retry(session, false); + session_close(session); + return; + } + + if (status != 0) { + if (VERBOSE_STATUS) { + const char *peer_str = kr_straddr(peer); + kr_log_verbose( "[wrkr]=> connection to '%s' failed (%s), flagged as 'bad'\n", + peer_str ? peer_str : "", uv_strerror(status)); + } + worker_del_tcp_waiting(worker, peer); + struct qr_task *task = session_waitinglist_get(session); + if (task && status != UV_ETIMEDOUT) { + /* Penalize upstream. + * In case of UV_ETIMEDOUT upstream has been + * already penalized in on_tcp_connect_timeout() */ + struct kr_qflags *options = &task->ctx->req.options; + unsigned score = options->FORWARD || options->STUB ? KR_NS_FWD_DEAD : KR_NS_DEAD; + kr_nsrep_update_rtt(NULL, peer, score, + worker->engine->resolver.cache_rtt, + KR_NS_UPDATE_NORESET); + } + assert(session_tasklist_is_empty(session)); + session_waitinglist_retry(session, false); + session_close(session); + return; + } + + if (!session_flags(session)->has_tls) { + /* if there is a TLS, session still waiting for handshake, + * otherwise remove it from waiting list */ + if (worker_del_tcp_waiting(worker, peer) != 0) { + /* session isn't in list of waiting queries, * + * something gone wrong */ + session_waitinglist_finalize(session, KR_STATE_FAIL); + assert(session_tasklist_is_empty(session)); + session_close(session); + return; + } + } + + if (VERBOSE_STATUS) { + const char *peer_str = kr_straddr(peer); + kr_log_verbose( "[wrkr]=> connected to '%s'\n", peer_str ? peer_str : ""); + } + + session_flags(session)->connected = true; + session_start_read(session); + + int ret = kr_ok(); + if (session_flags(session)->has_tls) { + struct tls_client_ctx_t *tls_ctx = session_tls_get_client_ctx(session); + ret = tls_client_connect_start(tls_ctx, session, session_tls_hs_cb); + if (ret == kr_error(EAGAIN)) { + session_timer_stop(session); + session_timer_start(session, tcp_timeout_trigger, + MAX_TCP_INACTIVITY, MAX_TCP_INACTIVITY); + return; + } + } else { + worker_add_tcp_connected(worker, peer, session); + } + + ret = send_waiting(session); + if (ret != 0) { + return; + } + + session_timer_stop(session); + session_timer_start(session, tcp_timeout_trigger, + MAX_TCP_INACTIVITY, MAX_TCP_INACTIVITY); +} + +static void on_tcp_connect_timeout(uv_timer_t *timer) +{ + struct session *session = timer->data; + + uv_timer_stop(timer); + struct worker_ctx *worker = get_worker(); + + assert (session_tasklist_is_empty(session)); + + struct sockaddr *peer = session_get_peer(session); + worker_del_tcp_waiting(worker, peer); + + struct qr_task *task = session_waitinglist_get(session); + if (!task) { + /* Normally shouldn't happen. */ + const char *peer_str = kr_straddr(peer); + VERBOSE_MSG(NULL, "=> connection to '%s' failed (internal timeout), empty waitinglist\n", + peer_str ? peer_str : ""); + return; + } + + struct kr_query *qry = task_get_last_pending_query(task); + WITH_VERBOSE (qry) { + const char *peer_str = kr_straddr(peer); + VERBOSE_MSG(qry, "=> connection to '%s' failed (internal timeout)\n", + peer_str ? peer_str : ""); + } + + unsigned score = qry->flags.FORWARD || qry->flags.STUB ? KR_NS_FWD_DEAD : KR_NS_DEAD; + kr_nsrep_update_rtt(NULL, peer, score, + worker->engine->resolver.cache_rtt, + KR_NS_UPDATE_NORESET); + + worker->stats.timeout += session_waitinglist_get_len(session); + session_waitinglist_retry(session, true); + assert (session_tasklist_is_empty(session)); + /* uv_cancel() doesn't support uv_connect_t request, + * so that we can't cancel it. + * There still exists possibility of successful connection + * for this request. + * So connection callback (on_connect()) must check + * if connection is in the list of waiting connection. + * If no, most likely this is timeouted connection even if + * it was successful. */ +} + +/* This is called when I/O timeouts */ +static void on_udp_timeout(uv_timer_t *timer) +{ + struct session *session = timer->data; + assert(session_get_handle(session)->data == session); + assert(session_tasklist_get_len(session) == 1); + assert(session_waitinglist_is_empty(session)); + + uv_timer_stop(timer); + + /* Penalize all tried nameservers with a timeout. */ + struct qr_task *task = session_tasklist_get_first(session); + struct worker_ctx *worker = task->ctx->worker; + if (task->leading && task->pending_count > 0) { + struct kr_query *qry = array_tail(task->ctx->req.rplan.pending); + struct sockaddr_in6 *addrlist = (struct sockaddr_in6 *)task->addrlist; + for (uint16_t i = 0; i < MIN(task->pending_count, task->addrlist_count); ++i) { + struct sockaddr *choice = (struct sockaddr *)(&addrlist[i]); + WITH_VERBOSE(qry) { + char *addr_str = kr_straddr(choice); + VERBOSE_MSG(qry, "=> server: '%s' flagged as 'bad'\n", addr_str ? addr_str : ""); + } + unsigned score = qry->flags.FORWARD || qry->flags.STUB ? KR_NS_FWD_DEAD : KR_NS_DEAD; + kr_nsrep_update_rtt(&qry->ns, choice, score, + worker->engine->resolver.cache_rtt, + KR_NS_UPDATE_NORESET); + } + } + task->timeouts += 1; + worker->stats.timeout += 1; + qr_task_step(task, NULL, NULL); +} + +static uv_handle_t *retransmit(struct qr_task *task) +{ + uv_handle_t *ret = NULL; + if (task && task->addrlist && task->addrlist_count > 0) { + struct sockaddr_in6 *choice = &((struct sockaddr_in6 *)task->addrlist)[task->addrlist_turn]; + if (!choice) { + return ret; + } + if (task->pending_count >= MAX_PENDING) { + return ret; + } + /* Checkout answer before sending it */ + struct request_ctx *ctx = task->ctx; + if (kr_resolve_checkout(&ctx->req, NULL, (struct sockaddr *)choice, SOCK_DGRAM, task->pktbuf) != 0) { + return ret; + } + ret = ioreq_spawn(ctx->worker, SOCK_DGRAM, choice->sin6_family, false); + if (!ret) { + return ret; + } + struct sockaddr *addr = (struct sockaddr *)choice; + struct session *session = ret->data; + struct sockaddr *peer = session_get_peer(session); + assert (peer->sa_family == AF_UNSPEC && session_flags(session)->outgoing); + memcpy(peer, addr, kr_sockaddr_len(addr)); + if (qr_task_send(task, session, (struct sockaddr *)choice, + task->pktbuf) != 0) { + session_close(session); + ret = NULL; + } else { + task->pending[task->pending_count] = session; + task->pending_count += 1; + task->addrlist_turn = (task->addrlist_turn + 1) % + task->addrlist_count; /* Round robin */ + session_start_read(session); /* Start reading answer */ + } + } + return ret; +} + +static void on_retransmit(uv_timer_t *req) +{ + struct session *session = req->data; + assert(session_tasklist_get_len(session) == 1); + + uv_timer_stop(req); + struct qr_task *task = session_tasklist_get_first(session); + if (retransmit(task) == NULL) { + /* Not possible to spawn request, start timeout timer with remaining deadline. */ + struct kr_qflags *options = &task->ctx->req.options; + uint64_t timeout = options->FORWARD || options->STUB ? KR_NS_FWD_TIMEOUT / 2 : + KR_CONN_RTT_MAX - task->pending_count * KR_CONN_RETRY; + uv_timer_start(req, on_udp_timeout, timeout, 0); + } else { + uv_timer_start(req, on_retransmit, KR_CONN_RETRY, 0); + } +} + +static void subreq_finalize(struct qr_task *task, const struct sockaddr *packet_source, knot_pkt_t *pkt) +{ + if (!task || task->finished) { + return; + } + /* Close pending timer */ + ioreq_kill_pending(task); + /* Clear from outgoing table. */ + if (!task->leading) + return; + char key[SUBREQ_KEY_LEN]; + const int klen = subreq_key(key, task->pktbuf); + if (klen > 0) { + void *val_deleted; + int ret = trie_del(task->ctx->worker->subreq_out, key, klen, &val_deleted); + assert(ret == KNOT_EOK && val_deleted == task); (void)ret; + } + /* Notify waiting tasks. */ + struct kr_query *leader_qry = array_tail(task->ctx->req.rplan.pending); + for (size_t i = task->waiting.len; i > 0; i--) { + struct qr_task *follower = task->waiting.at[i - 1]; + /* Reuse MSGID and 0x20 secret */ + if (follower->ctx->req.rplan.pending.len > 0) { + struct kr_query *qry = array_tail(follower->ctx->req.rplan.pending); + qry->id = leader_qry->id; + qry->secret = leader_qry->secret; + leader_qry->secret = 0; /* Next will be already decoded */ + } + qr_task_step(follower, packet_source, pkt); + qr_task_unref(follower); + } + task->waiting.len = 0; + task->leading = false; +} + +static void subreq_lead(struct qr_task *task) +{ + assert(task); + char key[SUBREQ_KEY_LEN]; + const int klen = subreq_key(key, task->pktbuf); + if (klen < 0) + return; + struct qr_task **tvp = (struct qr_task **) + trie_get_ins(task->ctx->worker->subreq_out, key, klen); + if (unlikely(!tvp)) + return; /*ENOMEM*/ + if (unlikely(*tvp != NULL)) { + assert(false); + return; + } + *tvp = task; + task->leading = true; +} + +static bool subreq_enqueue(struct qr_task *task) +{ + assert(task); + char key[SUBREQ_KEY_LEN]; + const int klen = subreq_key(key, task->pktbuf); + if (klen < 0) + return false; + struct qr_task **leader = (struct qr_task **) + trie_get_try(task->ctx->worker->subreq_out, key, klen); + if (!leader /*ENOMEM*/ || !*leader) + return false; + /* Enqueue itself to leader for this subrequest. */ + int ret = array_push_mm((*leader)->waiting, task, + kr_memreserve, &(*leader)->ctx->req.pool); + if (unlikely(ret < 0)) /*ENOMEM*/ + return false; + qr_task_ref(task); + return true; +} + +static int qr_task_finalize(struct qr_task *task, int state) +{ + assert(task && task->leading == false); + if (task->finished) { + return 0; + } + struct request_ctx *ctx = task->ctx; + struct session *source_session = ctx->source.session; + kr_resolve_finish(&ctx->req, state); + + task->finished = true; + if (source_session == NULL) { + (void) qr_task_on_send(task, NULL, kr_error(EIO)); + return state == KR_STATE_DONE ? 0 : kr_error(EIO); + } + + /* Reference task as the callback handler can close it */ + qr_task_ref(task); + + /* Send back answer */ + assert(!session_flags(source_session)->closing); + assert(ctx->source.addr.ip.sa_family != AF_UNSPEC); + int res = qr_task_send(task, source_session, + (struct sockaddr *)&ctx->source.addr, + ctx->req.answer); + if (res != kr_ok()) { + (void) qr_task_on_send(task, NULL, kr_error(EIO)); + /* Since source session is erroneous detach all tasks. */ + while (!session_tasklist_is_empty(source_session)) { + struct qr_task *t = session_tasklist_del_first(source_session, false); + struct request_ctx *c = t->ctx; + assert(c->source.session == source_session); + c->source.session = NULL; + /* Don't finalize them as there can be other tasks + * waiting for answer to this particular task. + * (ie. task->leading is true) */ + worker_task_unref(t); + } + session_close(source_session); + } + + qr_task_unref(task); + + return state == KR_STATE_DONE ? 0 : kr_error(EIO); +} + +static int udp_task_step(struct qr_task *task, + const struct sockaddr *packet_source, knot_pkt_t *packet) +{ + struct request_ctx *ctx = task->ctx; + struct kr_request *req = &ctx->req; + + /* If there is already outgoing query, enqueue to it. */ + if (subreq_enqueue(task)) { + return kr_ok(); /* Will be notified when outgoing query finishes. */ + } + /* Start transmitting */ + uv_handle_t *handle = retransmit(task); + if (handle == NULL) { + subreq_finalize(task, packet_source, packet); + return qr_task_finalize(task, KR_STATE_FAIL); + } + /* Check current query NSLIST */ + struct kr_query *qry = array_tail(req->rplan.pending); + assert(qry != NULL); + /* Retransmit at default interval, or more frequently if the mean + * RTT of the server is better. If the server is glued, use default rate. */ + size_t timeout = qry->ns.score; + if (timeout > KR_NS_GLUED) { + /* We don't have information about variance in RTT, expect +10ms */ + timeout = MIN(qry->ns.score + 10, KR_CONN_RETRY); + } else { + timeout = KR_CONN_RETRY; + } + /* Announce and start subrequest. + * @note Only UDP can lead I/O as it doesn't touch 'task->pktbuf' for reassembly. + */ + subreq_lead(task); + struct session *session = handle->data; + assert(session_get_handle(session) == handle && (handle->type == UV_UDP)); + int ret = session_timer_start(session, on_retransmit, timeout, 0); + /* Start next step with timeout, fatal if can't start a timer. */ + if (ret != 0) { + subreq_finalize(task, packet_source, packet); + return qr_task_finalize(task, KR_STATE_FAIL); + } + return kr_ok(); +} + +static int tcp_task_waiting_connection(struct session *session, struct qr_task *task) +{ + assert(session_flags(session)->outgoing); + if (session_flags(session)->closing) { + /* Something went wrong. Better answer with KR_STATE_FAIL. + * TODO: normally should not happen, + * consider possibility to transform this into + * assert(!session_flags(session)->closing). */ + return kr_error(EINVAL); + } + /* Add task to the end of list of waiting tasks. + * It will be notified in on_connect() or qr_task_on_send(). */ + int ret = session_waitinglist_push(session, task); + if (ret < 0) { + return kr_error(EINVAL); + } + return kr_ok(); +} + +static int tcp_task_existing_connection(struct session *session, struct qr_task *task) +{ + assert(session_flags(session)->outgoing); + struct request_ctx *ctx = task->ctx; + struct worker_ctx *worker = ctx->worker; + + if (session_flags(session)->closing) { + /* Something went wrong. Better answer with KR_STATE_FAIL. + * TODO: normally should not happen, + * consider possibility to transform this into + * assert(!session_flags(session)->closing). */ + return kr_error(EINVAL); + } + + /* If there are any unsent queries, send it first. */ + int ret = send_waiting(session); + if (ret != 0) { + return kr_error(EINVAL); + } + + /* No unsent queries at that point. */ + if (session_tasklist_get_len(session) >= worker->tcp_pipeline_max) { + /* Too many outstanding queries, answer with SERFVAIL, */ + return kr_error(EINVAL); + } + + /* Send query to upstream. */ + ret = qr_task_send(task, session, NULL, NULL); + if (ret != 0) { + /* Error, finalize task with SERVFAIL and + * close connection to upstream. */ + session_tasklist_finalize(session, KR_STATE_FAIL); + worker_del_tcp_connected(worker, session_get_peer(session)); + session_close(session); + return kr_error(EINVAL); + } + + return kr_ok(); +} + +static int tcp_task_make_connection(struct qr_task *task, const struct sockaddr *addr) +{ + struct request_ctx *ctx = task->ctx; + struct worker_ctx *worker = ctx->worker; + + /* Check if there must be TLS */ + struct engine *engine = worker->engine; + struct network *net = &engine->net; + const char *key = tcpsess_key(addr); + struct tls_client_ctx_t *tls_ctx = NULL; + struct tls_client_paramlist_entry *entry = map_get(&net->tls_client_params, key); + if (entry) { + /* Address is configured to be used with TLS. + * We need to allocate auxiliary data structure. */ + tls_ctx = tls_client_ctx_new(entry, worker); + if (!tls_ctx) { + return kr_error(EINVAL); + } + } + + uv_connect_t *conn = malloc(sizeof(uv_connect_t)); + if (!conn) { + tls_client_ctx_free(tls_ctx); + return kr_error(EINVAL); + } + bool has_tls = (tls_ctx != NULL); + uv_handle_t *client = ioreq_spawn(worker, SOCK_STREAM, addr->sa_family, has_tls); + if (!client) { + tls_client_ctx_free(tls_ctx); + free(conn); + return kr_error(EINVAL); + } + struct session *session = client->data; + assert(session_flags(session)->has_tls == has_tls); + if (has_tls) { + tls_client_ctx_set_session(tls_ctx, session); + session_tls_set_client_ctx(session, tls_ctx); + } + + /* Add address to the waiting list. + * Now it "is waiting to be connected to." */ + int ret = worker_add_tcp_waiting(ctx->worker, addr, session); + if (ret < 0) { + free(conn); + session_close(session); + return kr_error(EINVAL); + } + + conn->data = session; + /* Store peer address for the session. */ + struct sockaddr *peer = session_get_peer(session); + memcpy(peer, addr, kr_sockaddr_len(addr)); + + /* Start watchdog to catch eventual connection timeout. */ + ret = session_timer_start(session, on_tcp_connect_timeout, + KR_CONN_RTT_MAX, 0); + if (ret != 0) { + worker_del_tcp_waiting(ctx->worker, addr); + free(conn); + session_close(session); + return kr_error(EINVAL); + } + + struct kr_query *qry = task_get_last_pending_query(task); + WITH_VERBOSE (qry) { + const char *peer_str = kr_straddr(peer); + VERBOSE_MSG(qry, "=> connecting to: '%s'\n", peer_str ? peer_str : ""); + } + + /* Start connection process to upstream. */ + ret = uv_tcp_connect(conn, (uv_tcp_t *)client, addr , on_connect); + if (ret != 0) { + session_timer_stop(session); + worker_del_tcp_waiting(ctx->worker, addr); + free(conn); + session_close(session); + unsigned score = qry->flags.FORWARD || qry->flags.STUB ? KR_NS_FWD_DEAD : KR_NS_DEAD; + kr_nsrep_update_rtt(NULL, peer, score, + worker->engine->resolver.cache_rtt, + KR_NS_UPDATE_NORESET); + WITH_VERBOSE (qry) { + const char *peer_str = kr_straddr(peer); + kr_log_verbose( "[wrkr]=> connect to '%s' failed (%s), flagged as 'bad'\n", + peer_str ? peer_str : "", uv_strerror(ret)); + } + return kr_error(EAGAIN); + } + + /* Add task to the end of list of waiting tasks. + * Will be notified either in on_connect() or in qr_task_on_send(). */ + ret = session_waitinglist_push(session, task); + if (ret < 0) { + session_timer_stop(session); + worker_del_tcp_waiting(ctx->worker, addr); + free(conn); + session_close(session); + return kr_error(EINVAL); + } + + return kr_ok(); +} + +static int tcp_task_step(struct qr_task *task, + const struct sockaddr *packet_source, knot_pkt_t *packet) +{ + assert(task->pending_count == 0); + + /* target */ + const struct sockaddr *addr = task->addrlist; + if (addr->sa_family == AF_UNSPEC) { + /* Target isn't defined. Finalize task with SERVFAIL. + * Although task->pending_count is zero, there are can be followers, + * so we need to call subreq_finalize() to handle them properly. */ + subreq_finalize(task, packet_source, packet); + return qr_task_finalize(task, KR_STATE_FAIL); + } + /* Checkout task before connecting */ + struct request_ctx *ctx = task->ctx; + if (kr_resolve_checkout(&ctx->req, NULL, (struct sockaddr *)addr, + SOCK_STREAM, task->pktbuf) != 0) { + subreq_finalize(task, packet_source, packet); + return qr_task_finalize(task, KR_STATE_FAIL); + } + int ret; + struct session* session = NULL; + if ((session = worker_find_tcp_waiting(ctx->worker, addr)) != NULL) { + /* Connection is in the list of waiting connections. + * It means that connection establishing is coming right now. */ + ret = tcp_task_waiting_connection(session, task); + } else if ((session = worker_find_tcp_connected(ctx->worker, addr)) != NULL) { + /* Connection has been already established. */ + ret = tcp_task_existing_connection(session, task); + } else { + /* Make connection. */ + ret = tcp_task_make_connection(task, addr); + } + + if (ret != kr_ok()) { + subreq_finalize(task, addr, packet); + if (ret == kr_error(EAGAIN)) { + ret = qr_task_step(task, addr, NULL); + } else { + ret = qr_task_finalize(task, KR_STATE_FAIL); + } + } + + return ret; +} + +static int qr_task_step(struct qr_task *task, + const struct sockaddr *packet_source, knot_pkt_t *packet) +{ + /* No more steps after we're finished. */ + if (!task || task->finished) { + return kr_error(ESTALE); + } + + /* Close pending I/O requests */ + subreq_finalize(task, packet_source, packet); + if ((kr_now() - worker_task_creation_time(task)) >= KR_RESOLVE_TIME_LIMIT) { + return qr_task_finalize(task, KR_STATE_FAIL); + } + + /* Consume input and produce next query */ + struct request_ctx *ctx = task->ctx; + assert(ctx); + struct kr_request *req = &ctx->req; + struct worker_ctx *worker = ctx->worker; + int sock_type = -1; + task->addrlist = NULL; + task->addrlist_count = 0; + task->addrlist_turn = 0; + + if (worker->too_many_open) { + /* */ + struct kr_rplan *rplan = &req->rplan; + if (worker->stats.rconcurrent < + worker->rconcurrent_highwatermark - 10) { + worker->too_many_open = false; + } else { + if (packet && kr_rplan_empty(rplan)) { + /* new query; TODO - make this detection more obvious */ + kr_resolve_consume(req, packet_source, packet); + } + return qr_task_finalize(task, KR_STATE_FAIL); + } + } + + int state = kr_resolve_consume(req, packet_source, packet); + while (state == KR_STATE_PRODUCE) { + state = kr_resolve_produce(req, &task->addrlist, + &sock_type, task->pktbuf); + if (unlikely(++task->iter_count > KR_ITER_LIMIT || + task->timeouts >= KR_TIMEOUT_LIMIT)) { + return qr_task_finalize(task, KR_STATE_FAIL); + } + } + + /* We're done, no more iterations needed */ + if (state & (KR_STATE_DONE|KR_STATE_FAIL)) { + return qr_task_finalize(task, state); + } else if (!task->addrlist || sock_type < 0) { + return qr_task_step(task, NULL, NULL); + } + + /* Count available address choices */ + struct sockaddr_in6 *choice = (struct sockaddr_in6 *)task->addrlist; + for (size_t i = 0; i < KR_NSREP_MAXADDR && choice->sin6_family != AF_UNSPEC; ++i) { + task->addrlist_count += 1; + choice += 1; + } + + /* Upgrade to TLS if the upstream address is configured as DoT capable. */ + if (task->addrlist_count > 0 && kr_inaddr_port(task->addrlist) == KR_DNS_PORT) { + /* TODO if there are multiple addresses (task->addrlist_count > 1) + * check all of them. */ + struct engine *engine = worker->engine; + struct network *net = &engine->net; + struct tls_client_paramlist_entry *tls_entry = + tls_client_try_upgrade(&net->tls_client_params, task->addrlist); + if (tls_entry != NULL) { + kr_inaddr_set_port(task->addrlist, KR_DNS_TLS_PORT); + packet_source = NULL; + sock_type = SOCK_STREAM; + /* TODO in this case in tcp_task_make_connection() will be performed + * redundant map_get() call. */ + } + } + + int ret = 0; + if (sock_type == SOCK_DGRAM) { + /* Start fast retransmit with UDP. */ + ret = udp_task_step(task, packet_source, packet); + } else { + /* TCP. Connect to upstream or send the query if connection already exists. */ + assert (sock_type == SOCK_STREAM); + ret = tcp_task_step(task, packet_source, packet); + } + return ret; +} + +static int parse_packet(knot_pkt_t *query) +{ + if (!query){ + return kr_error(EINVAL); + } + + /* Parse query packet. */ + int ret = knot_pkt_parse(query, 0); + if (ret == KNOT_ETRAIL) { + /* Extra data after message end. */ + ret = kr_error(EMSGSIZE); + } else if (ret != KNOT_EOK) { + /* Malformed query. */ + ret = kr_error(EPROTO); + } else { + ret = kr_ok(); + } + + return ret; +} + +int worker_submit(struct session *session, knot_pkt_t *query) +{ + if (!session) { + assert(false); + return kr_error(EINVAL); + } + + uv_handle_t *handle = session_get_handle(session); + bool OK = handle && handle->loop->data; + if (!OK) { + assert(false); + return kr_error(EINVAL); + } + + struct worker_ctx *worker = handle->loop->data; + + /* Parse packet */ + int ret = parse_packet(query); + + const bool is_query = (knot_wire_get_qr(query->wire) == 0); + const bool is_outgoing = session_flags(session)->outgoing; + /* Ignore badly formed queries. */ + if (!query || + (ret != kr_ok() && ret != kr_error(EMSGSIZE)) || + (is_query == is_outgoing)) { + if (query && !is_outgoing) worker->stats.dropped += 1; + return kr_error(EILSEQ); + } + + /* Start new task on listening sockets, + * or resume if this is subrequest */ + struct qr_task *task = NULL; + struct sockaddr *addr = NULL; + if (!is_outgoing) { /* request from a client */ + struct request_ctx *ctx = request_create(worker, handle, + session_get_peer(session), + knot_wire_get_id(query->wire)); + if (!ctx) { + return kr_error(ENOMEM); + } + + ret = request_start(ctx, query); + if (ret != 0) { + request_free(ctx); + return kr_error(ENOMEM); + } + + task = qr_task_create(ctx); + if (!task) { + request_free(ctx); + return kr_error(ENOMEM); + } + + if (handle->type == UV_TCP && qr_task_register(task, session)) { + return kr_error(ENOMEM); + } + } else if (query) { /* response from upstream */ + task = session_tasklist_del_msgid(session, knot_wire_get_id(query->wire)); + if (task == NULL) { + return kr_error(ENOENT); + } + assert(!session_flags(session)->closing); + addr = session_get_peer(session); + } + assert(uv_is_closing(session_get_handle(session)) == false); + + /* Packet was successfully parsed. + * Task was created (found). */ + session_touch(session); + /* Consume input and produce next message */ + return qr_task_step(task, addr, query); +} + +static int map_add_tcp_session(map_t *map, const struct sockaddr* addr, + struct session *session) +{ + assert(map && addr); + const char *key = tcpsess_key(addr); + assert(key); + assert(map_contains(map, key) == 0); + int ret = map_set(map, key, session); + return ret ? kr_error(EINVAL) : kr_ok(); +} + +static int map_del_tcp_session(map_t *map, const struct sockaddr* addr) +{ + assert(map && addr); + const char *key = tcpsess_key(addr); + assert(key); + int ret = map_del(map, key); + return ret ? kr_error(ENOENT) : kr_ok(); +} + +static struct session* map_find_tcp_session(map_t *map, + const struct sockaddr *addr) +{ + assert(map && addr); + const char *key = tcpsess_key(addr); + assert(key); + struct session* ret = map_get(map, key); + return ret; +} + +int worker_add_tcp_connected(struct worker_ctx *worker, + const struct sockaddr* addr, + struct session *session) +{ +#ifndef NDEBUG + assert(addr); + const char *key = tcpsess_key(addr); + assert(key); + assert(map_contains(&worker->tcp_connected, key) == 0); +#endif + return map_add_tcp_session(&worker->tcp_connected, addr, session); +} + +int worker_del_tcp_connected(struct worker_ctx *worker, + const struct sockaddr* addr) +{ + assert(addr && tcpsess_key(addr)); + return map_del_tcp_session(&worker->tcp_connected, addr); +} + +static struct session* worker_find_tcp_connected(struct worker_ctx *worker, + const struct sockaddr* addr) +{ + return map_find_tcp_session(&worker->tcp_connected, addr); +} + +static int worker_add_tcp_waiting(struct worker_ctx *worker, + const struct sockaddr* addr, + struct session *session) +{ +#ifndef NDEBUG + assert(addr); + const char *key = tcpsess_key(addr); + assert(key); + assert(map_contains(&worker->tcp_waiting, key) == 0); +#endif + return map_add_tcp_session(&worker->tcp_waiting, addr, session); +} + +int worker_del_tcp_waiting(struct worker_ctx *worker, + const struct sockaddr* addr) +{ + assert(addr && tcpsess_key(addr)); + return map_del_tcp_session(&worker->tcp_waiting, addr); +} + +static struct session* worker_find_tcp_waiting(struct worker_ctx *worker, + const struct sockaddr* addr) +{ + return map_find_tcp_session(&worker->tcp_waiting, addr); +} + +int worker_end_tcp(struct session *session) +{ + if (!session) { + return kr_error(EINVAL); + } + + session_timer_stop(session); + + uv_handle_t *handle = session_get_handle(session); + struct worker_ctx *worker = handle->loop->data; + struct sockaddr *peer = session_get_peer(session); + + worker_del_tcp_waiting(worker, peer); + worker_del_tcp_connected(worker, peer); + session_flags(session)->connected = false; + + struct tls_client_ctx_t *tls_client_ctx = session_tls_get_client_ctx(session); + if (tls_client_ctx) { + /* Avoid gnutls_bye() call */ + tls_set_hs_state(&tls_client_ctx->c, TLS_HS_NOT_STARTED); + } + + struct tls_ctx_t *tls_ctx = session_tls_get_server_ctx(session); + if (tls_ctx) { + /* Avoid gnutls_bye() call */ + tls_set_hs_state(&tls_ctx->c, TLS_HS_NOT_STARTED); + } + + while (!session_waitinglist_is_empty(session)) { + struct qr_task *task = session_waitinglist_pop(session, false); + assert(task->refs > 1); + session_tasklist_del(session, task); + if (session_flags(session)->outgoing) { + if (task->ctx->req.options.FORWARD) { + /* We are in TCP_FORWARD mode. + * To prevent failing at kr_resolve_consume() + * qry.flags.TCP must be cleared. + * TODO - refactoring is needed. */ + struct kr_request *req = &task->ctx->req; + struct kr_rplan *rplan = &req->rplan; + struct kr_query *qry = array_tail(rplan->pending); + qry->flags.TCP = false; + } + qr_task_step(task, NULL, NULL); + } else { + assert(task->ctx->source.session == session); + task->ctx->source.session = NULL; + } + worker_task_unref(task); + } + while (!session_tasklist_is_empty(session)) { + struct qr_task *task = session_tasklist_del_first(session, false); + if (session_flags(session)->outgoing) { + if (task->ctx->req.options.FORWARD) { + struct kr_request *req = &task->ctx->req; + struct kr_rplan *rplan = &req->rplan; + struct kr_query *qry = array_tail(rplan->pending); + qry->flags.TCP = false; + } + qr_task_step(task, NULL, NULL); + } else { + assert(task->ctx->source.session == session); + task->ctx->source.session = NULL; + } + worker_task_unref(task); + } + session_close(session); + return kr_ok(); +} + +struct qr_task *worker_resolve_start(struct worker_ctx *worker, knot_pkt_t *query, struct kr_qflags options) +{ + if (!worker || !query) { + assert(!EINVAL); + return NULL; + } + + + struct request_ctx *ctx = request_create(worker, NULL, NULL, worker->next_request_uid); + if (!ctx) { + return NULL; + } + + /* Create task */ + struct qr_task *task = qr_task_create(ctx); + if (!task) { + request_free(ctx); + return NULL; + } + + /* Start task */ + int ret = request_start(ctx, query); + if (ret != 0) { + /* task is attached to request context, + * so dereference (and deallocate) it first */ + ctx->task = NULL; + qr_task_unref(task); + request_free(ctx); + return NULL; + } + + worker->next_request_uid += 1; + if (worker->next_request_uid == 0) { + worker->next_request_uid = UINT16_MAX + 1; + } + + /* Set options late, as qr_task_start() -> kr_resolve_begin() rewrite it. */ + kr_qflags_set(&task->ctx->req.options, options); + return task; +} + +int worker_resolve_exec(struct qr_task *task, knot_pkt_t *query) +{ + if (!task) { + return kr_error(EINVAL); + } + return qr_task_step(task, NULL, query); +} + +int worker_task_numrefs(const struct qr_task *task) +{ + return task->refs; +} + +struct kr_request *worker_task_request(struct qr_task *task) +{ + if (!task || !task->ctx) { + return NULL; + } + + return &task->ctx->req; +} + +int worker_task_finalize(struct qr_task *task, int state) +{ + return qr_task_finalize(task, state); +} + + int worker_task_step(struct qr_task *task, const struct sockaddr *packet_source, + knot_pkt_t *packet) + { + return qr_task_step(task, packet_source, packet); + } + +void worker_task_complete(struct qr_task *task) +{ + qr_task_complete(task); +} + +void worker_task_ref(struct qr_task *task) +{ + qr_task_ref(task); +} + +void worker_task_unref(struct qr_task *task) +{ + qr_task_unref(task); +} + +void worker_task_timeout_inc(struct qr_task *task) +{ + task->timeouts += 1; +} + +knot_pkt_t *worker_task_get_pktbuf(const struct qr_task *task) +{ + return task->pktbuf; +} + +struct request_ctx *worker_task_get_request(struct qr_task *task) +{ + return task->ctx; +} + +struct session *worker_request_get_source_session(struct request_ctx *ctx) +{ + return ctx->source.session; +} + +void worker_request_set_source_session(struct request_ctx *ctx, struct session *session) +{ + ctx->source.session = session; +} + +uint16_t worker_task_pkt_get_msgid(struct qr_task *task) +{ + knot_pkt_t *pktbuf = worker_task_get_pktbuf(task); + uint16_t msg_id = knot_wire_get_id(pktbuf->wire); + return msg_id; +} + +void worker_task_pkt_set_msgid(struct qr_task *task, uint16_t msgid) +{ + knot_pkt_t *pktbuf = worker_task_get_pktbuf(task); + knot_wire_set_id(pktbuf->wire, msgid); + struct kr_query *q = task_get_last_pending_query(task); + q->id = msgid; +} + +uint64_t worker_task_creation_time(struct qr_task *task) +{ + return task->creation_time; +} + +void worker_task_subreq_finalize(struct qr_task *task) +{ + subreq_finalize(task, NULL, NULL); +} + +bool worker_task_finished(struct qr_task *task) +{ + return task->finished; +} +/** Reserve worker buffers */ +static int worker_reserve(struct worker_ctx *worker, size_t ring_maxlen) +{ + array_init(worker->pool_mp); + if (array_reserve(worker->pool_mp, ring_maxlen)) { + return kr_error(ENOMEM); + } + memset(&worker->pkt_pool, 0, sizeof(worker->pkt_pool)); + worker->pkt_pool.ctx = mp_new (4 * sizeof(knot_pkt_t)); + worker->pkt_pool.alloc = (knot_mm_alloc_t) mp_alloc; + worker->subreq_out = trie_create(NULL); + worker->tcp_connected = map_make(NULL); + worker->tcp_waiting = map_make(NULL); + worker->tcp_pipeline_max = MAX_PIPELINED; + memset(&worker->stats, 0, sizeof(worker->stats)); + return kr_ok(); +} + +static inline void reclaim_mp_freelist(mp_freelist_t *list) +{ + for (unsigned i = 0; i < list->len; ++i) { + struct mempool *e = list->at[i]; + kr_asan_unpoison(e, sizeof(*e)); + mp_delete(e); + } + array_clear(*list); +} + +void worker_reclaim(struct worker_ctx *worker) +{ + reclaim_mp_freelist(&worker->pool_mp); + mp_delete(worker->pkt_pool.ctx); + worker->pkt_pool.ctx = NULL; + trie_free(worker->subreq_out); + worker->subreq_out = NULL; + map_clear(&worker->tcp_connected); + map_clear(&worker->tcp_waiting); + if (worker->z_import != NULL) { + zi_free(worker->z_import); + worker->z_import = NULL; + } +} + +struct worker_ctx *worker_create(struct engine *engine, knot_mm_t *pool, + int worker_id, int worker_count) +{ + /* Load bindings */ + engine_lualib(engine, "modules", lib_modules); + engine_lualib(engine, "net", lib_net); + engine_lualib(engine, "cache", lib_cache); + engine_lualib(engine, "event", lib_event); + engine_lualib(engine, "worker", lib_worker); + + /* Create main worker. */ + struct worker_ctx *worker = mm_alloc(pool, sizeof(*worker)); + if (!worker) { + return NULL; + } + memset(worker, 0, sizeof(*worker)); + worker->id = worker_id; + worker->count = worker_count; + worker->engine = engine; + worker->next_request_uid = UINT16_MAX + 1; + worker_reserve(worker, MP_FREELIST_SIZE); + worker->out_addr4.sin_family = AF_UNSPEC; + worker->out_addr6.sin6_family = AF_UNSPEC; + /* Register worker in Lua thread */ + lua_pushlightuserdata(engine->L, worker); + lua_setglobal(engine->L, "__worker"); + lua_getglobal(engine->L, "worker"); + lua_pushnumber(engine->L, worker_id); + lua_setfield(engine->L, -2, "id"); + lua_pushnumber(engine->L, getpid()); + lua_setfield(engine->L, -2, "pid"); + lua_pushnumber(engine->L, worker_count); + lua_setfield(engine->L, -2, "count"); + /* Register table for worker per-request variables */ + lua_newtable(engine->L); + lua_setfield(engine->L, -2, "vars"); + lua_getfield(engine->L, -1, "vars"); + worker->vars_table_ref = luaL_ref(engine->L, LUA_REGISTRYINDEX); + lua_pop(engine->L, 1); + return worker; +} + +#undef VERBOSE_MSG |