/* Copyright (C) CZ.NIC, z.s.p.o. * SPDX-License-Identifier: GPL-3.0-or-later */ #include "kresconfig.h" #include "daemon/worker.h" #include #include #include #include #include #include #include #include #if defined(__GLIBC__) && defined(_GNU_SOURCE) #include #endif #include #include #include #if ENABLE_XDP #include #endif #include "daemon/bindings/api.h" #include "daemon/engine.h" #include "daemon/io.h" #include "daemon/proxyv2.h" #include "daemon/session.h" #include "daemon/tls.h" #include "daemon/http.h" #include "daemon/udp_queue.h" #include "lib/layer.h" #include "lib/utils.h" /* Magic defaults for the worker. */ #ifndef MAX_PIPELINED #define MAX_PIPELINED 100 #endif #define VERBOSE_MSG(qry, ...) kr_log_q(qry, WORKER, __VA_ARGS__) /** Client request state. */ struct request_ctx { struct kr_request req; struct worker_ctx *worker; struct qr_task *task; struct { /** NULL if the request didn't come over network. */ struct session *session; /** Requestor's address; separate because of UDP session "sharing". */ union kr_sockaddr addr; /** Request communication address; if not from a proxy, same as addr. */ union kr_sockaddr comm_addr; /** Local address. For AF_XDP we couldn't use session's, * as the address might be different every time. */ union kr_sockaddr dst_addr; /** MAC addresses - ours [0] and router's [1], in case of AF_XDP socket. */ uint8_t eth_addrs[2][6]; } source; }; /** 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 timeouts; uint16_t iter_count; uint32_t refs; bool finished : 1; bool leading : 1; uint64_t creation_time; uint64_t send_time; uint64_t recv_time; struct kr_transport *transport; }; /* Convenience macros */ #define qr_task_ref(task) \ do { ++(task)->refs; } while(0) #define qr_task_unref(task) \ do { \ if (task) \ kr_require((task)->refs > 0); \ if ((task) && --(task)->refs == 0) \ qr_task_free((task)); \ } while (0) /* 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, const 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); 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); struct session* worker_find_tcp_waiting(struct worker_ctx *worker, const struct sockaddr *addr); static void on_tcp_connect_timeout(uv_timer_t *timer); static void on_udp_timeout(uv_timer_t *timer); static void subreq_finalize(struct qr_task *task, const struct sockaddr *packet_source, knot_pkt_t *pkt); struct worker_ctx the_worker_value; /**< Static allocation is suitable for the singleton. */ struct worker_ctx *the_worker = NULL; /*! @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 has_http) { bool precond = (socktype == SOCK_DGRAM || socktype == SOCK_STREAM) && (family == AF_INET || family == AF_INET6); if (kr_fails_assert(precond)) { kr_log_debug(WORKER, "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, has_http); 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 kr_sockaddr *addr; if (family == AF_INET) { addr = (union kr_sockaddr *)&worker->out_addr4; } else { addr = (union kr_sockaddr *)&worker->out_addr6; } if (addr->ip.sa_family != AF_UNSPEC) { if (kr_fails_assert(addr->ip.sa_family == family)) { io_free(handle); return NULL; } 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_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; } /** Get a mempool. */ static inline struct mempool *pool_borrow(struct worker_ctx *worker) { /* The implementation used to have extra caching layer, * but it didn't work well. Now it's very simple. */ return mp_new(16 * 1024); } /** Return a mempool. */ static inline void pool_release(struct worker_ctx *worker, struct mempool *mp) { 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) { kr_require(pkt); return kr_rrkey(dst, knot_pkt_qclass(pkt), knot_pkt_qname(pkt), knot_pkt_qtype(pkt), knot_pkt_qtype(pkt)); } #if ENABLE_XDP static uint8_t *alloc_wire_cb(struct kr_request *req, uint16_t *maxlen) { if (kr_fails_assert(maxlen)) return NULL; struct request_ctx *ctx = (struct request_ctx *)req; /* We know it's an AF_XDP socket; otherwise this CB isn't assigned. */ uv_handle_t *handle = session_get_handle(ctx->source.session); if (kr_fails_assert(handle->type == UV_POLL)) return NULL; xdp_handle_data_t *xhd = handle->data; knot_xdp_msg_t out; bool ipv6 = ctx->source.comm_addr.ip.sa_family == AF_INET6; int ret = knot_xdp_send_alloc(xhd->socket, #if KNOT_VERSION_HEX >= 0x030100 ipv6 ? KNOT_XDP_MSG_IPV6 : 0, &out); #else ipv6, &out, NULL); #endif if (ret != KNOT_EOK) { kr_assert(ret == KNOT_ENOMEM); *maxlen = 0; return NULL; } *maxlen = MIN(*maxlen, out.payload.iov_len); #if KNOT_VERSION_HEX < 0x030100 /* It's most convenient to fill the MAC addresses at this point. */ memcpy(out.eth_from, &ctx->source.eth_addrs[0], 6); memcpy(out.eth_to, &ctx->source.eth_addrs[1], 6); #endif return out.payload.iov_base; } static void free_wire(const struct request_ctx *ctx) { if (kr_fails_assert(ctx->req.alloc_wire_cb == alloc_wire_cb)) return; knot_pkt_t *ans = ctx->req.answer; if (unlikely(ans == NULL)) /* dropped */ return; if (likely(ans->wire == NULL)) /* sent most likely */ return; /* We know it's an AF_XDP socket; otherwise alloc_wire_cb isn't assigned. */ uv_handle_t *handle = session_get_handle(ctx->source.session); if (kr_fails_assert(handle->type == UV_POLL)) return; xdp_handle_data_t *xhd = handle->data; /* Freeing is done by sending an empty packet (the API won't really send it). */ knot_xdp_msg_t out; out.payload.iov_base = ans->wire; out.payload.iov_len = 0; uint32_t sent = 0; #if KNOT_VERSION_HEX >= 0x030100 int ret = 0; knot_xdp_send_free(xhd->socket, &out, 1); #else int ret = knot_xdp_send(xhd->socket, &out, 1, &sent); #endif kr_assert(ret == KNOT_EOK && sent == 0); kr_log_debug(XDP, "freed unsent buffer, ret = %d\n", ret); } #endif /* Helper functions for transport selection */ static inline bool is_tls_capable(struct sockaddr *address) { tls_client_param_t *tls_entry = tls_client_param_get(the_worker->engine->net.tls_client_params, address); return tls_entry; } static inline bool is_tcp_connected(struct sockaddr *address) { return worker_find_tcp_connected(the_worker, address); } static inline bool is_tcp_waiting(struct sockaddr *address) { return worker_find_tcp_waiting(the_worker, address); } /** Create and initialize a request_ctx (on a fresh mempool). * * session 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, struct session *session, struct io_comm_data *comm, const uint8_t *eth_from, const uint8_t *eth_to, 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_calloc(&pool, 1, sizeof(*ctx)); if (!ctx) { pool_release(worker, pool.ctx); return NULL; } /* TODO Relocate pool to struct request */ ctx->worker = worker; if (session && kr_fails_assert(session_flags(session)->outgoing == false)) { pool_release(worker, pool.ctx); return NULL; } ctx->source.session = session; if (kr_fails_assert(!!eth_to == !!eth_from)) { pool_release(worker, pool.ctx); return NULL; } const bool is_xdp = eth_to != NULL; if (is_xdp) { #if ENABLE_XDP if (kr_fails_assert(session)) { pool_release(worker, pool.ctx); return NULL; } memcpy(&ctx->source.eth_addrs[0], eth_to, sizeof(ctx->source.eth_addrs[0])); memcpy(&ctx->source.eth_addrs[1], eth_from, sizeof(ctx->source.eth_addrs[1])); ctx->req.alloc_wire_cb = alloc_wire_cb; #else kr_assert(!EINVAL); pool_release(worker, pool.ctx); return NULL; #endif } struct kr_request *req = &ctx->req; req->pool = pool; req->vars_ref = LUA_NOREF; req->uid = uid; req->qsource.comm_flags.xdp = is_xdp; kr_request_set_extended_error(req, KNOT_EDNS_EDE_NONE, NULL); array_init(req->qsource.headers); if (session) { kr_require(comm); const struct sockaddr *src_addr = comm->src_addr; const struct sockaddr *comm_addr = comm->comm_addr; const struct sockaddr *dst_addr = comm->dst_addr; const struct proxy_result *proxy = comm->proxy; req->qsource.comm_flags.tcp = session_get_handle(session)->type == UV_TCP; req->qsource.comm_flags.tls = session_flags(session)->has_tls; req->qsource.comm_flags.http = session_flags(session)->has_http; req->qsource.flags = req->qsource.comm_flags; if (proxy) { req->qsource.flags.tcp = proxy->protocol == SOCK_STREAM; req->qsource.flags.tls = proxy->has_tls; } req->qsource.stream_id = -1; #if ENABLE_DOH2 if (req->qsource.comm_flags.http) { struct http_ctx *http_ctx = session_http_get_server_ctx(session); struct http_stream stream = queue_head(http_ctx->streams); req->qsource.stream_id = stream.id; if (stream.headers) { req->qsource.headers = *stream.headers; free(stream.headers); stream.headers = NULL; } } #endif /* We need to store a copy of peer address. */ memcpy(&ctx->source.addr.ip, src_addr, kr_sockaddr_len(src_addr)); req->qsource.addr = &ctx->source.addr.ip; if (!comm_addr) comm_addr = src_addr; memcpy(&ctx->source.comm_addr.ip, comm_addr, kr_sockaddr_len(comm_addr)); req->qsource.comm_addr = &ctx->source.comm_addr.ip; if (!dst_addr) /* We wouldn't have to copy in this case, but for consistency. */ dst_addr = session_get_sockname(session); memcpy(&ctx->source.dst_addr.ip, dst_addr, kr_sockaddr_len(dst_addr)); req->qsource.dst_addr = &ctx->source.dst_addr.ip; } req->selection_context.is_tls_capable = is_tls_capable; req->selection_context.is_tcp_connected = is_tcp_connected; req->selection_context.is_tcp_waiting = is_tcp_waiting; array_init(req->selection_context.forwarding_targets); array_reserve_mm(req->selection_context.forwarding_targets, 1, kr_memreserve, &req->pool); worker->stats.rconcurrent += 1; return ctx; } /** More initialization, related to the particular incoming query/packet. */ static int request_start(struct request_ctx *ctx, knot_pkt_t *query) { if (kr_fails_assert(query && ctx)) return kr_error(EINVAL); struct kr_request *req = &ctx->req; req->qsource.size = query->size; if (knot_pkt_has_tsig(query)) { req->qsource.size += query->tsig_wire.len; } 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); worker->stats.queries += 1; 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; } /* Free HTTP/2 headers for DoH requests. */ for(int i = 0; i < ctx->req.qsource.headers.len; i++) { free(ctx->req.qsource.headers.at[i].name); free(ctx->req.qsource.headers.at[i].value); } array_clear(ctx->req.qsource.headers); /* Make sure to free XDP buffer in case it wasn't sent. */ if (ctx->req.alloc_wire_cb) { #if ENABLE_XDP free_wire(ctx); #else kr_assert(!EINVAL); #endif } /* 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. */ worker->stats.rconcurrent -= 1; } static struct qr_task *qr_task_create(struct request_ctx *ctx) { /* Choose (initial) pktbuf size. As it is now, pktbuf can be used * for UDP answers from upstream *and* from cache * and for sending queries upstream */ uint16_t pktbuf_max = KR_EDNS_PAYLOAD; const knot_rrset_t *opt_our = ctx->worker->engine->resolver.upstream_opt_rr; if (opt_our) { pktbuf_max = MAX(pktbuf_max, knot_edns_get_payload(opt_our)); } /* Create resolution task */ struct qr_task *task = mm_calloc(&ctx->req.pool, 1, sizeof(*task)); if (!task) { return NULL; } /* 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; kr_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; if (kr_fails_assert(ctx)) return; 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) { if (kr_fails_assert(!session_flags(session)->outgoing && session_get_handle(session)->type == UV_TCP)) return kr_error(EINVAL); session_tasklist_add(session, task); struct request_ctx *ctx = task->ctx; if (kr_fails_assert(ctx && (ctx->source.session == NULL || ctx->source.session == session))) return kr_error(EINVAL); 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); kr_require(task->waiting.len == 0); kr_require(task->leading == false); struct session *s = ctx->source.session; if (s) { kr_require(!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 */ int qr_task_on_send(struct qr_task *task, const uv_handle_t *handle, int status) { if (task->finished) { kr_require(task->leading == false); qr_task_complete(task); } if (!handle || kr_fails_assert(handle->data)) return status; struct session* s = handle->data; if (handle->type == UV_UDP && session_flags(s)->outgoing) { // This should ensure that we are only dealing with our question to upstream if (kr_fails_assert(!knot_wire_get_qr(task->pktbuf->wire))) return status; // start the timer struct kr_query *qry = array_tail(task->ctx->req.rplan.pending); if (kr_fails_assert(qry && task->transport)) return status; size_t timeout = task->transport->timeout; int ret = session_timer_start(s, on_udp_timeout, timeout, 0); /* Start next step with timeout, fatal if can't start a timer. */ if (ret != 0) { subreq_finalize(task, &task->transport->address.ip, task->pktbuf); qr_task_finalize(task, KR_STATE_FAIL); } } if (handle->type == UV_TCP) { if (status != 0) { // session probably not usable anymore; typically: ECONNRESET const struct kr_request *req = &task->ctx->req; if (kr_log_is_debug(WORKER, req)) { const char *peer_str = NULL; if (!session_flags(s)->outgoing) { peer_str = "hidden"; // avoid logging downstream IPs } else if (task->transport) { peer_str = kr_straddr(&task->transport->address.ip); } if (!peer_str) peer_str = "unknown"; // probably shouldn't happen kr_log_req(req, 0, 0, WORKER, "=> disconnected from '%s': %s\n", peer_str, uv_strerror(status)); } worker_end_tcp(s); return status; } 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, const 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); if (kr_fails_assert(handle && handle->data == session)) return qr_task_on_send(task, NULL, kr_error(EINVAL)); const bool is_stream = handle->type == UV_TCP; kr_require(is_stream || handle->type == UV_UDP); 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); } struct worker_ctx *worker = ctx->worker; /* Note time for upstream RTT */ task->send_time = kr_now(); task->recv_time = 0; // task structure is being reused so we have to zero this out here /* Send using given protocol */ if (kr_fails_assert(!session_flags(session)->closing)) return qr_task_on_send(task, NULL, kr_error(EIO)); 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); if (session_flags(session)->has_http) { #if ENABLE_DOH2 uv_write_t *write_req = (uv_write_t *)ioreq; write_req->data = task; ret = http_write(write_req, handle, pkt, ctx->req.qsource.stream_id, &on_write); #else ret = kr_error(ENOPROTOOPT); #endif } else 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; /* We need to write message length in native byte order, * but we don't have a convenient place to store those bytes. * The problem is that all memory referenced from buf[] MUST retain * its contents at least until on_write() is called, and I currently * can't see any convenient place outside the `pkt` structure. * So we use directly the *individual* bytes in pkt->size. * The call to htonl() and the condition will probably be inlinable. */ int lsbi, slsbi; /* (second) least significant byte index */ if (htonl(1) == 1) { /* big endian */ lsbi = sizeof(pkt->size) - 1; slsbi = sizeof(pkt->size) - 2; } else { lsbi = 0; slsbi = 1; } uv_buf_t buf[3] = { { (char *)&pkt->size + slsbi, 1 }, { (char *)&pkt->size + lsbi, 1 }, { (char *)pkt->wire, pkt->size }, }; write_req->data = task; ret = uv_write(write_req, (uv_stream_t *)handle, buf, 3, &on_write); } else { kr_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); } if (session_flags(session)->has_http) worker->stats.err_http += 1; else if (session_flags(session)->has_tls) worker->stats.err_tls += 1; else if (handle->type == UV_UDP) worker->stats.err_udp += 1; else worker->stats.err_tcp += 1; } /* Update outgoing query 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) { if (kr_fails_assert(session_flags(session)->outgoing)) return kr_error(EINVAL); struct sockaddr *peer = session_get_peer(session); int deletion_res = worker_del_tcp_waiting(the_worker, peer); int ret = kr_ok(); if (status) { struct qr_task *task = session_waitinglist_get(session); if (task) { // TLS handshake failed, report it to server selection struct kr_query *qry = array_tail(task->ctx->req.rplan.pending); qry->server_selection.error(qry, task->transport, KR_SELECTION_TLS_HANDSHAKE_FAILED); } #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. */ kr_require(deletion_res != 0); struct kr_sockaddr_key_storage key; ssize_t keylen = kr_sockaddr_key(&key, peer); if (keylen < 0) return keylen; trie_val_t *val; kr_require((val = trie_get_try(the_worker->tcp_connected, key.bytes, keylen)) && *val); } #endif return ret; } /* handshake was completed successfully */ struct tls_client_ctx *tls_client_ctx = session_tls_get_client_ctx(session); tls_client_param_t *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_debug(TLSCLIENT, "TLS session has resumed\n"); } else { kr_log_debug(TLSCLIENT, "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(the_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(the_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 timed out * 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(the_worker, peer); session_waitinglist_finalize(session, KR_STATE_FAIL); session_tasklist_finalize(session, KR_STATE_FAIL); 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 = the_worker; kr_require(worker); uv_stream_t *handle = req->handle; struct session *session = handle->data; struct sockaddr *peer = session_get_peer(session); free(req); if (kr_fails_assert(session_flags(session)->outgoing)) return; if (session_flags(session)->closing) { worker_del_tcp_waiting(worker, peer); kr_assert(session_is_empty(session)); return; } const bool log_debug = kr_log_is_debug(WORKER, NULL); /* Check if the connection is in the waiting list. * If no, most likely this is timed out 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 timed out session. */ if (log_debug) { const char *peer_str = kr_straddr(peer); kr_log_debug(WORKER, "=> connected to '%s', but session " "is already timed out, close\n", peer_str ? peer_str : ""); } kr_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 (log_debug) { const char *peer_str = kr_straddr(peer); kr_log_debug(WORKER, "=> connected to '%s', but peer " "is already connected, close\n", peer_str ? peer_str : ""); } kr_assert(session_tasklist_is_empty(session)); session_waitinglist_retry(session, false); session_close(session); return; } if (status != 0) { if (log_debug) { const char *peer_str = kr_straddr(peer); kr_log_debug(WORKER, "=> 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_query *qry = array_tail(task->ctx->req.rplan.pending); qry->server_selection.error(qry, task->transport, KR_SELECTION_TCP_CONNECT_FAILED); } kr_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); kr_assert(session_tasklist_is_empty(session)); session_close(session); return; } } if (log_debug) { const char *peer_str = kr_straddr(peer); kr_log_debug(WORKER, "=> 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 *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 = the_worker; kr_require(worker); kr_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); if (kr_log_is_debug_qry(WORKER, qry)) { const char *peer_str = kr_straddr(peer); VERBOSE_MSG(qry, "=> connection to '%s' failed (internal timeout)\n", peer_str ? peer_str : ""); } qry->server_selection.error(qry, task->transport, KR_SELECTION_TCP_CONNECT_TIMEOUT); worker->stats.timeout += session_waitinglist_get_len(session); session_waitinglist_retry(session, true); kr_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 timed out 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; kr_assert(session_get_handle(session)->data == session); kr_assert(session_tasklist_get_len(session) == 1); kr_assert(session_waitinglist_is_empty(session)); uv_timer_stop(timer); struct qr_task *task = session_tasklist_get_first(session); if (!task) return; 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); qry->server_selection.error(qry, task->transport, KR_SELECTION_QUERY_TIMEOUT); } task->timeouts += 1; worker->stats.timeout += 1; qr_task_step(task, NULL, NULL); } static uv_handle_t *transmit(struct qr_task *task) { uv_handle_t *ret = NULL; if (task) { struct kr_transport* transport = task->transport; struct sockaddr_in6 *choice = (struct sockaddr_in6 *)&transport->address; 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, transport, task->pktbuf) != 0) { return ret; } ret = ioreq_spawn(ctx->worker, SOCK_DGRAM, choice->sin6_family, false, false); if (!ret) { return ret; } struct sockaddr *addr = (struct sockaddr *)choice; struct session *session = ret->data; struct sockaddr *peer = session_get_peer(session); kr_assert(peer->sa_family == AF_UNSPEC && session_flags(session)->outgoing); kr_require(addr->sa_family == AF_INET || addr->sa_family == AF_INET6); 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; session_start_read(session); /* Start reading answer */ } } return ret; } 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); kr_assert(ret == KNOT_EOK && val_deleted == task); } /* 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; // Note that this transport may not be present in `leader_qry`'s server selection follower->transport = task->transport; if(follower->transport) { follower->transport->deduplicated = true; } 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) { if (kr_fails_assert(task)) return; 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 (kr_fails_assert(*tvp == NULL)) return; *tvp = task; task->leading = true; } static bool subreq_enqueue(struct qr_task *task) { if (kr_fails_assert(task)) return false; 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; } #if ENABLE_XDP static void xdp_tx_waker(uv_idle_t *handle) { int ret = knot_xdp_send_finish(handle->data); if (ret != KNOT_EAGAIN && ret != KNOT_EOK) kr_log_error(XDP, "check: ret = %d, %s\n", ret, knot_strerror(ret)); /* Apparently some drivers need many explicit wake-up calls * even if we push no additional packets (in case they accumulated a lot) */ if (ret != KNOT_EAGAIN) uv_idle_stop(handle); knot_xdp_send_prepare(handle->data); /* LATER(opt.): it _might_ be better for performance to do these two steps * at different points in time */ } #endif /** Send an answer packet over XDP. */ static int xdp_push(struct qr_task *task, const uv_handle_t *src_handle) { #if ENABLE_XDP struct request_ctx *ctx = task->ctx; xdp_handle_data_t *xhd = src_handle->data; if (kr_fails_assert(xhd && xhd->socket && xhd->session == ctx->source.session)) return qr_task_on_send(task, src_handle, kr_error(EINVAL)); knot_xdp_msg_t msg; #if KNOT_VERSION_HEX >= 0x030100 /* We don't have a nice way of preserving the _msg_t from frame allocation, * so we manually redo all other parts of knot_xdp_send_alloc() */ memset(&msg, 0, sizeof(msg)); bool ipv6 = ctx->source.addr.ip.sa_family == AF_INET6; msg.flags = ipv6 ? KNOT_XDP_MSG_IPV6 : 0; memcpy(msg.eth_from, &ctx->source.eth_addrs[0], 6); memcpy(msg.eth_to, &ctx->source.eth_addrs[1], 6); #endif const struct sockaddr *ip_from = &ctx->source.dst_addr.ip; const struct sockaddr *ip_to = &ctx->source.comm_addr.ip; memcpy(&msg.ip_from, ip_from, kr_sockaddr_len(ip_from)); memcpy(&msg.ip_to, ip_to, kr_sockaddr_len(ip_to)); msg.payload.iov_base = ctx->req.answer->wire; msg.payload.iov_len = ctx->req.answer->size; uint32_t sent; int ret = knot_xdp_send(xhd->socket, &msg, 1, &sent); ctx->req.answer->wire = NULL; /* it's been freed */ uv_idle_start(&xhd->tx_waker, xdp_tx_waker); kr_log_debug(XDP, "pushed a packet, ret = %d\n", ret); return qr_task_on_send(task, src_handle, ret); #else kr_assert(!EINVAL); return kr_error(EINVAL); #endif } static int qr_task_finalize(struct qr_task *task, int state) { kr_require(task && task->leading == false); if (task->finished) { return kr_ok(); } 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 ? kr_ok() : kr_error(EIO); } /* meant to be dropped */ if (unlikely(ctx->req.answer == NULL || ctx->req.options.NO_ANSWER)) { /* For NO_ANSWER, a well-behaved layer should set the state to FAIL */ kr_assert(!ctx->req.options.NO_ANSWER || (ctx->req.state & KR_STATE_FAIL)); (void) qr_task_on_send(task, NULL, kr_ok()); return kr_ok(); } if (session_flags(source_session)->closing || ctx->source.addr.ip.sa_family == AF_UNSPEC) return kr_error(EINVAL); /* Reference task as the callback handler can close it */ qr_task_ref(task); /* Send back answer */ int ret; const uv_handle_t *src_handle = session_get_handle(source_session); if (kr_fails_assert(src_handle->type == UV_UDP || src_handle->type == UV_TCP || src_handle->type == UV_POLL)) { ret = kr_error(EINVAL); } else if (src_handle->type == UV_POLL) { ret = xdp_push(task, src_handle); } else if (src_handle->type == UV_UDP && ENABLE_SENDMMSG) { int fd; ret = uv_fileno(src_handle, &fd); if (ret == 0) udp_queue_push(fd, &ctx->req, task); else kr_assert(false); } else { ret = qr_task_send(task, source_session, &ctx->source.comm_addr.ip, ctx->req.answer); } if (ret != 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; kr_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); if (ret != kr_ok() || state != KR_STATE_DONE) return kr_error(EIO); return kr_ok(); } static int udp_task_step(struct qr_task *task, const struct sockaddr *packet_source, knot_pkt_t *packet) { /* 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 = transmit(task); if (handle == NULL) { subreq_finalize(task, packet_source, packet); return qr_task_finalize(task, KR_STATE_FAIL); } /* Announce and start subrequest. * @note Only UDP can lead I/O as it doesn't touch 'task->pktbuf' for reassembly. */ subreq_lead(task); return kr_ok(); } static int tcp_task_waiting_connection(struct session *session, struct qr_task *task) { if (kr_fails_assert(session_flags(session)->outgoing && !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) { if (kr_fails_assert(session_flags(session)->outgoing && !session_flags(session)->closing)) return kr_error(EINVAL); struct request_ctx *ctx = task->ctx; struct worker_ctx *worker = ctx->worker; /* 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 SERVFAIL, */ 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 tls_client_ctx *tls_ctx = NULL; struct network *net = &worker->engine->net; tls_client_param_t *entry = tls_client_param_get(net->tls_client_params, addr); 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_http = false; bool has_tls = (tls_ctx != NULL); uv_handle_t *client = ioreq_spawn(worker, SOCK_STREAM, addr->sa_family, has_tls, has_http); if (!client) { tls_client_ctx_free(tls_ctx); free(conn); return kr_error(EINVAL); } struct session *session = client->data; if (kr_fails_assert(session_flags(session)->has_tls == has_tls)) { tls_client_ctx_free(tls_ctx); free(conn); return kr_error(EINVAL); } 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(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(worker, addr); free(conn); session_close(session); return kr_error(EINVAL); } struct kr_query *qry = task_get_last_pending_query(task); if (kr_log_is_debug_qry(WORKER, 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(worker, addr); free(conn); session_close(session); qry->server_selection.error(qry, task->transport, KR_SELECTION_TCP_CONNECT_FAILED); 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(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) { if (kr_fails_assert(task->pending_count == 0)) { subreq_finalize(task, packet_source, packet); return qr_task_finalize(task, KR_STATE_FAIL); } /* target */ const struct sockaddr *addr = &task->transport->address.ip; 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, task->transport, 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) { struct kr_request *req = worker_task_request(task); if (!kr_fails_assert(req)) kr_query_inform_timeout(req, req->current_query); return qr_task_finalize(task, KR_STATE_FAIL); } /* Consume input and produce next query */ struct request_ctx *ctx = task->ctx; if (kr_fails_assert(ctx)) return qr_task_finalize(task, KR_STATE_FAIL); struct kr_request *req = &ctx->req; struct worker_ctx *worker = ctx->worker; 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, &task->transport, packet); } return qr_task_finalize(task, KR_STATE_FAIL); } } // Report network RTT back to server selection if (packet && task->send_time && task->recv_time) { struct kr_query *qry = array_tail(req->rplan.pending); qry->server_selection.update_rtt(qry, task->transport, task->recv_time - task->send_time); } int state = kr_resolve_consume(req, &task->transport, packet); task->transport = NULL; while (state == KR_STATE_PRODUCE) { state = kr_resolve_produce(req, &task->transport, task->pktbuf); if (unlikely(++task->iter_count > KR_ITER_LIMIT || task->timeouts >= KR_TIMEOUT_LIMIT)) { struct kr_rplan *rplan = &req->rplan; struct kr_query *last = kr_rplan_last(rplan); if (task->iter_count > KR_ITER_LIMIT) { char *msg = "cancelling query due to exceeded iteration count limit"; VERBOSE_MSG(last, "%s of %d\n", msg, KR_ITER_LIMIT); kr_request_set_extended_error(req, KNOT_EDNS_EDE_OTHER, "OGHD: exceeded iteration count limit"); } if (task->timeouts >= KR_TIMEOUT_LIMIT) { char *msg = "cancelling query due to exceeded timeout retries limit"; VERBOSE_MSG(last, "%s of %d\n", msg, KR_TIMEOUT_LIMIT); kr_request_set_extended_error(req, KNOT_EDNS_EDE_NREACH_AUTH, "QLPL"); } 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->transport || !task->transport->protocol) { return qr_task_step(task, NULL, NULL); } switch (task->transport->protocol) { case KR_TRANSPORT_UDP: return udp_task_step(task, packet_source, packet); case KR_TRANSPORT_TCP: // fall through case KR_TRANSPORT_TLS: return tcp_task_step(task, packet_source, packet); default: kr_assert(!EINVAL); return kr_error(EINVAL); } } int worker_submit(struct session *session, struct io_comm_data *comm, const uint8_t *eth_from, const uint8_t *eth_to, knot_pkt_t *pkt) { if (!session || !pkt) return kr_error(EINVAL); uv_handle_t *handle = session_get_handle(session); if (!handle || !handle->loop->data) return kr_error(EINVAL); const bool is_query = pkt->size > KNOT_WIRE_OFFSET_FLAGS1 && knot_wire_get_qr(pkt->wire) == 0; const bool is_outgoing = session_flags(session)->outgoing; int ret = 0; if (is_query == is_outgoing) ret = KNOT_ENOENT; // For responses from upstream, try to find associated task and query. // In case of errors, at least try to guess. struct qr_task *task = NULL; bool task_matched_id = false; if (is_outgoing && pkt->size >= 2) { const uint16_t id = knot_wire_get_id(pkt->wire); task = session_tasklist_del_msgid(session, id); task_matched_id = task != NULL; if (task_matched_id) // Note receive time for RTT calculation task->recv_time = kr_now(); if (!task_matched_id) { ret = KNOT_ENOENT; VERBOSE_MSG(NULL, "=> DNS message with mismatching ID %d\n", (int)id); } } if (!task && is_outgoing && handle->type == UV_TCP) { // Source address of the reply got somewhat validated, // so we try to at least guess which query, for error reporting. task = session_tasklist_get_first(session); } struct kr_query *qry = NULL; if (task) qry = array_tail(task->ctx->req.rplan.pending); // Parse the packet, unless it's useless anyway. if (ret == 0) { ret = knot_pkt_parse(pkt, 0); if (ret == KNOT_ETRAIL && is_outgoing && !kr_fails_assert(pkt->parsed < pkt->size)) { // We deal with this later, so that RCODE takes priority. ret = 0; } if (ret && kr_log_is_debug_qry(WORKER, qry)) { VERBOSE_MSG(qry, "=> DNS message failed to parse, %s\n", knot_strerror(ret)); } } struct http_ctx *http_ctx = NULL; #if ENABLE_DOH2 http_ctx = session_http_get_server_ctx(session); /* Badly formed query when using DoH leads to a Bad Request */ if (http_ctx && !is_outgoing && ret) { http_send_status(session, HTTP_STATUS_BAD_REQUEST); return kr_error(ret); } #endif if (!is_outgoing && http_ctx && queue_len(http_ctx->streams) <= 0) return kr_error(ENOENT); const struct sockaddr *addr = comm ? comm->src_addr : NULL; /* Ignore badly formed queries. */ if (ret) { if (is_outgoing && qry) // unusuable response from somewhat validated IP qry->server_selection.error(qry, task->transport, KR_SELECTION_MALFORMED); if (!is_outgoing) the_worker->stats.dropped += 1; if (task_matched_id) // notify task that answer won't be coming anymore qr_task_step(task, addr, NULL); return kr_error(EILSEQ); } /* Start new task on listening sockets, * or resume if this is subrequest */ if (!is_outgoing) { /* request from a client */ struct request_ctx *ctx = request_create(the_worker, session, comm, eth_from, eth_to, knot_wire_get_id(pkt->wire)); if (http_ctx) queue_pop(http_ctx->streams); if (!ctx) return kr_error(ENOMEM); ret = request_start(ctx, pkt); 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 { /* response from upstream */ if (task == NULL) { return kr_error(ENOENT); } if (kr_fails_assert(!session_flags(session)->closing)) return kr_error(EINVAL); } if (kr_fails_assert(!uv_is_closing(session_get_handle(session)))) return kr_error(EINVAL); /* Packet was successfully parsed. * Task was created (found). */ session_touch(session); /* Consume input and produce next message */ return qr_task_step(task, addr, pkt); } static int trie_add_tcp_session(trie_t *trie, const struct sockaddr *addr, struct session *session) { if (kr_fails_assert(trie && addr)) return kr_error(EINVAL); struct kr_sockaddr_key_storage key; ssize_t keylen = kr_sockaddr_key(&key, addr); if (keylen < 0) return keylen; trie_val_t *val = trie_get_ins(trie, key.bytes, keylen); if (kr_fails_assert(*val == NULL)) return kr_error(EINVAL); *val = session; return kr_ok(); } static int trie_del_tcp_session(trie_t *trie, const struct sockaddr *addr) { if (kr_fails_assert(trie && addr)) return kr_error(EINVAL); struct kr_sockaddr_key_storage key; ssize_t keylen = kr_sockaddr_key(&key, addr); if (keylen < 0) return keylen; int ret = trie_del(trie, key.bytes, keylen, NULL); return ret ? kr_error(ENOENT) : kr_ok(); } static struct session *trie_find_tcp_session(trie_t *trie, const struct sockaddr *addr) { if (kr_fails_assert(trie && addr)) return NULL; struct kr_sockaddr_key_storage key; ssize_t keylen = kr_sockaddr_key(&key, addr); if (keylen < 0) return NULL; trie_val_t *val = trie_get_try(trie, key.bytes, keylen); return val ? *val : NULL; } int worker_add_tcp_connected(struct worker_ctx *worker, const struct sockaddr* addr, struct session *session) { return trie_add_tcp_session(worker->tcp_connected, addr, session); } int worker_del_tcp_connected(struct worker_ctx *worker, const struct sockaddr* addr) { return trie_del_tcp_session(worker->tcp_connected, addr); } struct session* worker_find_tcp_connected(struct worker_ctx *worker, const struct sockaddr* addr) { return trie_find_tcp_session(worker->tcp_connected, addr); } static int worker_add_tcp_waiting(struct worker_ctx *worker, const struct sockaddr* addr, struct session *session) { return trie_add_tcp_session(worker->tcp_waiting, addr, session); } int worker_del_tcp_waiting(struct worker_ctx *worker, const struct sockaddr* addr) { return trie_del_tcp_session(worker->tcp_waiting, addr); } struct session* worker_find_tcp_waiting(struct worker_ctx *worker, const struct sockaddr* addr) { return trie_find_tcp_session(worker->tcp_waiting, addr); } int worker_end_tcp(struct session *session) { if (!session) return kr_error(EINVAL); session_timer_stop(session); struct sockaddr *peer = session_get_peer(session); worker_del_tcp_waiting(the_worker, peer); worker_del_tcp_connected(the_worker, peer); session_flags(session)->connected = false; struct tls_client_ctx *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 *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); kr_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 { kr_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 { kr_assert(task->ctx->source.session == session); task->ctx->source.session = NULL; } worker_task_unref(task); } session_close(session); return kr_ok(); } knot_pkt_t *worker_resolve_mk_pkt_dname(knot_dname_t *qname, uint16_t qtype, uint16_t qclass, const struct kr_qflags *options) { knot_pkt_t *pkt = knot_pkt_new(NULL, KNOT_EDNS_MAX_UDP_PAYLOAD, NULL); if (!pkt) return NULL; knot_pkt_put_question(pkt, qname, qclass, qtype); knot_wire_set_rd(pkt->wire); knot_wire_set_ad(pkt->wire); /* Add OPT RR, including wire format so modules can see both representations. * knot_pkt_put() copies the outside; we need to duplicate the inside manually. */ knot_rrset_t *opt = knot_rrset_copy(the_worker->engine->resolver.downstream_opt_rr, NULL); if (!opt) { knot_pkt_free(pkt); return NULL; } if (options->DNSSEC_WANT) { knot_edns_set_do(opt); } knot_pkt_begin(pkt, KNOT_ADDITIONAL); int ret = knot_pkt_put(pkt, KNOT_COMPR_HINT_NONE, opt, KNOT_PF_FREE); if (ret == KNOT_EOK) { free(opt); /* inside is owned by pkt now */ } else { knot_rrset_free(opt, NULL); knot_pkt_free(pkt); return NULL; } if (options->DNSSEC_CD) { knot_wire_set_cd(pkt->wire); } return pkt; } knot_pkt_t *worker_resolve_mk_pkt(const char *qname_str, uint16_t qtype, uint16_t qclass, const struct kr_qflags *options) { uint8_t qname[KNOT_DNAME_MAXLEN]; if (!knot_dname_from_str(qname, qname_str, sizeof(qname))) return NULL; return worker_resolve_mk_pkt_dname(qname, qtype, qclass, options); } struct qr_task *worker_resolve_start(knot_pkt_t *query, struct kr_qflags options) { struct worker_ctx *worker = the_worker; if (kr_fails_assert(worker && query)) return NULL; struct request_ctx *ctx = request_create(worker, NULL, NULL, 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 kr_transport *worker_task_get_transport(struct qr_task *task) { return task->transport; } struct session *worker_request_get_source_session(const struct kr_request *req) { static_assert(offsetof(struct request_ctx, req) == 0, "Bad struct request_ctx definition."); return ((struct request_ctx *)req)->source.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. We assume worker's been zeroed. */ static int worker_reserve(struct worker_ctx *worker) { worker->tcp_connected = trie_create(NULL); worker->tcp_waiting = trie_create(NULL); worker->subreq_out = trie_create(NULL); mm_ctx_mempool(&worker->pkt_pool, 4 * sizeof(knot_pkt_t)); return kr_ok(); } void worker_deinit(void) { struct worker_ctx *worker = the_worker; if (kr_fails_assert(worker)) return; trie_free(worker->tcp_connected); trie_free(worker->tcp_waiting); trie_free(worker->subreq_out); worker->subreq_out = NULL; for (int i = 0; i < worker->doh_qry_headers.len; i++) free((void *)worker->doh_qry_headers.at[i]); array_clear(worker->doh_qry_headers); mp_delete(worker->pkt_pool.ctx); worker->pkt_pool.ctx = NULL; the_worker = NULL; } int worker_init(struct engine *engine, int worker_count) { if (kr_fails_assert(engine && engine->L && the_worker == NULL)) return kr_error(EINVAL); kr_bindings_register(engine->L); /* Create main worker. */ struct worker_ctx *worker = &the_worker_value; memset(worker, 0, sizeof(*worker)); worker->engine = engine; uv_loop_t *loop = uv_default_loop(); worker->loop = loop; worker->count = worker_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); worker->tcp_pipeline_max = MAX_PIPELINED; worker->out_addr4.sin_family = AF_UNSPEC; worker->out_addr6.sin6_family = AF_UNSPEC; array_init(worker->doh_qry_headers); int ret = worker_reserve(worker); if (ret) return ret; worker->next_request_uid = UINT16_MAX + 1; /* Set some worker.* fields in Lua */ lua_getglobal(engine->L, "worker"); pid_t pid = getpid(); auto_free char *pid_str = NULL; const char *inst_name = getenv("SYSTEMD_INSTANCE"); if (inst_name) { lua_pushstring(engine->L, inst_name); } else { ret = asprintf(&pid_str, "%ld", (long)pid); kr_assert(ret > 0); lua_pushstring(engine->L, pid_str); } lua_setfield(engine->L, -2, "id"); lua_pushnumber(engine->L, pid); lua_setfield(engine->L, -2, "pid"); lua_pushnumber(engine->L, worker_count); lua_setfield(engine->L, -2, "count"); char cwd[PATH_MAX]; get_workdir(cwd, sizeof(cwd)); lua_pushstring(engine->L, cwd); lua_setfield(engine->L, -2, "cwd"); the_worker = worker; loop->data = the_worker; /* ^^^^ Now this shouldn't be used anymore, but it's hard to be 100% sure. */ return kr_ok(); } #undef VERBOSE_MSG