diff options
Diffstat (limited to 'daemon/session.c')
| -rw-r--r-- | daemon/session.c | 767 |
1 files changed, 767 insertions, 0 deletions
diff --git a/daemon/session.c b/daemon/session.c new file mode 100644 index 0000000..c870d8c --- /dev/null +++ b/daemon/session.c @@ -0,0 +1,767 @@ +/* Copyright (C) 2018 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 <assert.h> + +#include <libknot/packet/pkt.h> + +#include "lib/defines.h" +#include "daemon/session.h" +#include "daemon/engine.h" +#include "daemon/tls.h" +#include "daemon/worker.h" +#include "daemon/io.h" +#include "lib/generic/queue.h" + +#define TLS_CHUNK_SIZE (16 * 1024) + +/* Per-session (TCP or UDP) persistent structure, + * that exists between remote counterpart and a local socket. + */ +struct session { + struct session_flags sflags; /**< miscellaneous flags. */ + union inaddr peer; /**< address of peer; is not set for client's UDP sessions. */ + uv_handle_t *handle; /**< libuv handle for IO operations. */ + uv_timer_t timeout; /**< libuv handle for timer. */ + + struct tls_ctx_t *tls_ctx; /**< server side tls-related data. */ + struct tls_client_ctx_t *tls_client_ctx; /**< client side tls-related data. */ + + trie_t *tasks; /**< list of tasks assotiated with given session. */ + queue_t(struct qr_task *) waiting; /**< list of tasks waiting for sending to upstream. */ + + uint8_t *wire_buf; /**< Buffer for DNS message. */ + ssize_t wire_buf_size; /**< Buffer size. */ + ssize_t wire_buf_start_idx; /**< Data start offset in wire_buf. */ + ssize_t wire_buf_end_idx; /**< Data end offset in wire_buf. */ + uint64_t last_activity; /**< Time of last IO activity (if any occurs). + * Otherwise session creation time. */ +}; + +static void on_session_close(uv_handle_t *handle) +{ + struct session *session = handle->data; + assert(session->handle == handle); (void)session; + io_free(handle); +} + +static void on_session_timer_close(uv_handle_t *timer) +{ + struct session *session = timer->data; + uv_handle_t *handle = session->handle; + assert(handle && handle->data == session); + assert (session->sflags.outgoing || handle->type == UV_TCP); + if (!uv_is_closing(handle)) { + uv_close(handle, on_session_close); + } +} + +void session_free(struct session *session) +{ + if (session) { + assert(session_is_empty(session)); + session_clear(session); + free(session); + } +} + +void session_clear(struct session *session) +{ + assert(session_is_empty(session)); + if (session->handle && session->handle->type == UV_TCP) { + free(session->wire_buf); + } + trie_clear(session->tasks); + trie_free(session->tasks); + queue_deinit(session->waiting); + tls_free(session->tls_ctx); + tls_client_ctx_free(session->tls_client_ctx); + memset(session, 0, sizeof(*session)); +} + +void session_close(struct session *session) +{ + assert(session_is_empty(session)); + if (session->sflags.closing) { + return; + } + + uv_handle_t *handle = session->handle; + io_stop_read(handle); + session->sflags.closing = true; + + if (!uv_is_closing((uv_handle_t *)&session->timeout)) { + uv_timer_stop(&session->timeout); + if (session->tls_client_ctx) { + tls_close(&session->tls_client_ctx->c); + } + if (session->tls_ctx) { + tls_close(&session->tls_ctx->c); + } + + session->timeout.data = session; + uv_close((uv_handle_t *)&session->timeout, on_session_timer_close); + } +} + +int session_start_read(struct session *session) +{ + return io_start_read(session->handle); +} + +int session_stop_read(struct session *session) +{ + return io_stop_read(session->handle); +} + +int session_waitinglist_push(struct session *session, struct qr_task *task) +{ + queue_push(session->waiting, task); + worker_task_ref(task); + return kr_ok(); +} + +struct qr_task *session_waitinglist_get(const struct session *session) +{ + return (queue_len(session->waiting) > 0) ? (queue_head(session->waiting)) : NULL; +} + +struct qr_task *session_waitinglist_pop(struct session *session, bool deref) +{ + struct qr_task *t = session_waitinglist_get(session); + queue_pop(session->waiting); + if (deref) { + worker_task_unref(t); + } + return t; +} + +int session_tasklist_add(struct session *session, struct qr_task *task) +{ + trie_t *t = session->tasks; + uint16_t task_msg_id = 0; + const char *key = NULL; + size_t key_len = 0; + if (session->sflags.outgoing) { + knot_pkt_t *pktbuf = worker_task_get_pktbuf(task); + task_msg_id = knot_wire_get_id(pktbuf->wire); + key = (const char *)&task_msg_id; + key_len = sizeof(task_msg_id); + } else { + key = (const char *)&task; + key_len = sizeof(char *); + } + trie_val_t *v = trie_get_ins(t, key, key_len); + if (unlikely(!v)) { + assert(false); + return kr_error(ENOMEM); + } + if (*v == NULL) { + *v = task; + worker_task_ref(task); + } else if (*v != task) { + assert(false); + return kr_error(EINVAL); + } + return kr_ok(); +} + +int session_tasklist_del(struct session *session, struct qr_task *task) +{ + trie_t *t = session->tasks; + uint16_t task_msg_id = 0; + const char *key = NULL; + size_t key_len = 0; + trie_val_t val; + if (session->sflags.outgoing) { + knot_pkt_t *pktbuf = worker_task_get_pktbuf(task); + task_msg_id = knot_wire_get_id(pktbuf->wire); + key = (const char *)&task_msg_id; + key_len = sizeof(task_msg_id); + } else { + key = (const char *)&task; + key_len = sizeof(char *); + } + int ret = trie_del(t, key, key_len, &val); + if (ret == kr_ok()) { + assert(val == task); + worker_task_unref(val); + } + return ret; +} + +struct qr_task *session_tasklist_get_first(struct session *session) +{ + trie_val_t *val = trie_get_first(session->tasks, NULL, NULL); + return val ? (struct qr_task *) *val : NULL; +} + +struct qr_task *session_tasklist_del_first(struct session *session, bool deref) +{ + trie_val_t val = NULL; + int res = trie_del_first(session->tasks, NULL, NULL, &val); + if (res != kr_ok()) { + val = NULL; + } else if (deref) { + worker_task_unref(val); + } + return (struct qr_task *)val; +} +struct qr_task* session_tasklist_del_msgid(const struct session *session, uint16_t msg_id) +{ + trie_t *t = session->tasks; + assert(session->sflags.outgoing); + struct qr_task *ret = NULL; + const char *key = (const char *)&msg_id; + size_t key_len = sizeof(msg_id); + trie_val_t val; + int res = trie_del(t, key, key_len, &val); + if (res == kr_ok()) { + if (worker_task_numrefs(val) > 1) { + ret = val; + } + worker_task_unref(val); + } + return ret; +} + +struct qr_task* session_tasklist_find_msgid(const struct session *session, uint16_t msg_id) +{ + trie_t *t = session->tasks; + assert(session->sflags.outgoing); + struct qr_task *ret = NULL; + trie_val_t *val = trie_get_try(t, (char *)&msg_id, sizeof(msg_id)); + if (val) { + ret = *val; + } + return ret; +} + +struct session_flags *session_flags(struct session *session) +{ + return &session->sflags; +} + +struct sockaddr *session_get_peer(struct session *session) +{ + return &session->peer.ip; +} + +struct tls_ctx_t *session_tls_get_server_ctx(const struct session *session) +{ + return session->tls_ctx; +} + +void session_tls_set_server_ctx(struct session *session, struct tls_ctx_t *ctx) +{ + session->tls_ctx = ctx; +} + +struct tls_client_ctx_t *session_tls_get_client_ctx(const struct session *session) +{ + return session->tls_client_ctx; +} + +void session_tls_set_client_ctx(struct session *session, struct tls_client_ctx_t *ctx) +{ + session->tls_client_ctx = ctx; +} + +struct tls_common_ctx *session_tls_get_common_ctx(const struct session *session) +{ + struct tls_common_ctx *tls_ctx = session->sflags.outgoing ? &session->tls_client_ctx->c : + &session->tls_ctx->c; + return tls_ctx; +} + +uv_handle_t *session_get_handle(struct session *session) +{ + return session->handle; +} + +struct session *session_get(uv_handle_t *h) +{ + return h->data; +} + +struct session *session_new(uv_handle_t *handle, bool has_tls) +{ + if (!handle) { + return NULL; + } + struct session *session = calloc(1, sizeof(struct session)); + if (!session) { + return NULL; + } + + queue_init(session->waiting); + session->tasks = trie_create(NULL); + if (handle->type == UV_TCP) { + size_t wire_buffer_size = KNOT_WIRE_MAX_PKTSIZE; + if (has_tls) { + /* When decoding large packets, + * gnutls gives the application chunks of size 16 kb each. */ + wire_buffer_size += TLS_CHUNK_SIZE; + session->sflags.has_tls = true; + } + uint8_t *wire_buf = malloc(wire_buffer_size); + if (!wire_buf) { + free(session); + return NULL; + } + session->wire_buf = wire_buf; + session->wire_buf_size = wire_buffer_size; + } else if (handle->type == UV_UDP) { + /* We use the singleton buffer from worker for all UDP (!) + * libuv documentation doesn't really guarantee this is OK, + * but the implementation for unix systems does not hold + * the buffer (both UDP and TCP) - always makes a NON-blocking + * syscall that fills the buffer and immediately calls + * the callback, whatever the result of the operation. + * We still need to keep in mind to only touch the buffer + * in this callback... */ + assert(handle->loop->data); + struct worker_ctx *worker = handle->loop->data; + session->wire_buf = worker->wire_buf; + session->wire_buf_size = sizeof(worker->wire_buf); + } + + uv_timer_init(handle->loop, &session->timeout); + + session->handle = handle; + handle->data = session; + session->timeout.data = session; + session_touch(session); + + return session; +} + +size_t session_tasklist_get_len(const struct session *session) +{ + return trie_weight(session->tasks); +} + +size_t session_waitinglist_get_len(const struct session *session) +{ + return queue_len(session->waiting); +} + +bool session_tasklist_is_empty(const struct session *session) +{ + return session_tasklist_get_len(session) == 0; +} + +bool session_waitinglist_is_empty(const struct session *session) +{ + return session_waitinglist_get_len(session) == 0; +} + +bool session_is_empty(const struct session *session) +{ + return session_tasklist_is_empty(session) && + session_waitinglist_is_empty(session); +} + +bool session_has_tls(const struct session *session) +{ + return session->sflags.has_tls; +} + +void session_set_has_tls(struct session *session, bool has_tls) +{ + session->sflags.has_tls = has_tls; +} + +void session_waitinglist_retry(struct session *session, bool increase_timeout_cnt) +{ + while (!session_waitinglist_is_empty(session)) { + struct qr_task *task = session_waitinglist_pop(session, false); + if (increase_timeout_cnt) { + worker_task_timeout_inc(task); + } + worker_task_step(task, &session->peer.ip, NULL); + worker_task_unref(task); + } +} + +void session_waitinglist_finalize(struct session *session, int status) +{ + while (!session_waitinglist_is_empty(session)) { + struct qr_task *t = session_waitinglist_pop(session, false); + worker_task_finalize(t, status); + worker_task_unref(t); + } +} + +void session_tasklist_finalize(struct session *session, int status) +{ + while (session_tasklist_get_len(session) > 0) { + struct qr_task *t = session_tasklist_del_first(session, false); + assert(worker_task_numrefs(t) > 0); + worker_task_finalize(t, status); + worker_task_unref(t); + } +} + +int session_tasklist_finalize_expired(struct session *session) +{ + int ret = 0; + queue_t(struct qr_task *) q; + uint64_t now = kr_now(); + trie_t *t = session->tasks; + trie_it_t *it; + queue_init(q); + for (it = trie_it_begin(t); !trie_it_finished(it); trie_it_next(it)) { + trie_val_t *v = trie_it_val(it); + struct qr_task *task = (struct qr_task *)*v; + if ((now - worker_task_creation_time(task)) >= KR_RESOLVE_TIME_LIMIT) { + queue_push(q, task); + worker_task_ref(task); + } + } + trie_it_free(it); + + struct qr_task *task = NULL; + uint16_t msg_id = 0; + char *key = (char *)&task; + int32_t keylen = sizeof(struct qr_task *); + if (session->sflags.outgoing) { + key = (char *)&msg_id; + keylen = sizeof(msg_id); + } + while (queue_len(q) > 0) { + task = queue_head(q); + if (session->sflags.outgoing) { + knot_pkt_t *pktbuf = worker_task_get_pktbuf(task); + msg_id = knot_wire_get_id(pktbuf->wire); + } + int res = trie_del(t, key, keylen, NULL); + if (!worker_task_finished(task)) { + /* task->pending_count must be zero, + * but there are can be followers, + * so run worker_task_subreq_finalize() to ensure retrying + * for all the followers. */ + worker_task_subreq_finalize(task); + worker_task_finalize(task, KR_STATE_FAIL); + } + if (res == KNOT_EOK) { + worker_task_unref(task); + } + queue_pop(q); + worker_task_unref(task); + ++ret; + } + + queue_deinit(q); + return ret; +} + +int session_timer_start(struct session *session, uv_timer_cb cb, + uint64_t timeout, uint64_t repeat) +{ + uv_timer_t *timer = &session->timeout; + assert(timer->data == session); + int ret = uv_timer_start(timer, cb, timeout, repeat); + if (ret != 0) { + uv_timer_stop(timer); + return kr_error(ENOMEM); + } + return 0; +} + +int session_timer_restart(struct session *session) +{ + return uv_timer_again(&session->timeout); +} + +int session_timer_stop(struct session *session) +{ + return uv_timer_stop(&session->timeout); +} + +ssize_t session_wirebuf_consume(struct session *session, const uint8_t *data, ssize_t len) +{ + if (data != &session->wire_buf[session->wire_buf_end_idx]) { + /* shouldn't happen */ + return kr_error(EINVAL); + } + + if (len < 0) { + /* shouldn't happen */ + return kr_error(EINVAL); + } + + if (session->wire_buf_end_idx + len > session->wire_buf_size) { + /* shouldn't happen */ + return kr_error(EINVAL); + } + + session->wire_buf_end_idx += len; + return len; +} + +knot_pkt_t *session_produce_packet(struct session *session, knot_mm_t *mm) +{ + session->sflags.wirebuf_error = false; + if (session->wire_buf_end_idx == 0) { + return NULL; + } + + if (session->wire_buf_start_idx == session->wire_buf_end_idx) { + session->wire_buf_start_idx = 0; + session->wire_buf_end_idx = 0; + return NULL; + } + + if (session->wire_buf_start_idx > session->wire_buf_end_idx) { + session->sflags.wirebuf_error = true; + session->wire_buf_start_idx = 0; + session->wire_buf_end_idx = 0; + return NULL; + } + + const uv_handle_t *handle = session->handle; + uint8_t *msg_start = &session->wire_buf[session->wire_buf_start_idx]; + ssize_t wirebuf_msg_data_size = session->wire_buf_end_idx - session->wire_buf_start_idx; + uint16_t msg_size = 0; + + if (!handle) { + session->sflags.wirebuf_error = true; + return NULL; + } else if (handle->type == UV_TCP) { + if (wirebuf_msg_data_size < 2) { + return NULL; + } + msg_size = knot_wire_read_u16(msg_start); + if (msg_size >= session->wire_buf_size) { + session->sflags.wirebuf_error = true; + return NULL; + } + if (msg_size + 2 > wirebuf_msg_data_size) { + return NULL; + } + if (msg_size == 0) { + session->sflags.wirebuf_error = true; + return NULL; + } + msg_start += 2; + } else if (wirebuf_msg_data_size < UINT16_MAX) { + msg_size = wirebuf_msg_data_size; + } else { + session->sflags.wirebuf_error = true; + return NULL; + } + + + knot_pkt_t *pkt = knot_pkt_new(msg_start, msg_size, mm); + session->sflags.wirebuf_error = (pkt == NULL); + return pkt; +} + +int session_discard_packet(struct session *session, const knot_pkt_t *pkt) +{ + uv_handle_t *handle = session->handle; + /* Pointer to data start in wire_buf */ + uint8_t *wirebuf_data_start = &session->wire_buf[session->wire_buf_start_idx]; + /* Number of data bytes in wire_buf */ + size_t wirebuf_data_size = session->wire_buf_end_idx - session->wire_buf_start_idx; + /* Pointer to message start in wire_buf */ + uint8_t *wirebuf_msg_start = wirebuf_data_start; + /* Number of message bytes in wire_buf. + * For UDP it is the same number as wirebuf_data_size. */ + size_t wirebuf_msg_size = wirebuf_data_size; + /* Wire data from parsed packet. */ + uint8_t *pkt_msg_start = pkt->wire; + /* Number of bytes in packet wire buffer. */ + size_t pkt_msg_size = pkt->size; + if (knot_pkt_has_tsig(pkt)) { + pkt_msg_size += pkt->tsig_wire.len; + } + + session->sflags.wirebuf_error = true; + + if (!handle) { + return kr_error(EINVAL); + } else if (handle->type == UV_TCP) { + /* wire_buf contains TCP DNS message. */ + if (wirebuf_data_size < 2) { + /* TCP message length field isn't in buffer, must not happen. */ + assert(0); + session->wire_buf_start_idx = 0; + session->wire_buf_end_idx = 0; + return kr_error(EINVAL); + } + wirebuf_msg_size = knot_wire_read_u16(wirebuf_msg_start); + wirebuf_msg_start += 2; + if (wirebuf_msg_size + 2 > wirebuf_data_size) { + /* TCP message length field is greater then + * number of bytes in buffer, must not happen. */ + assert(0); + session->wire_buf_start_idx = 0; + session->wire_buf_end_idx = 0; + return kr_error(EINVAL); + } + } + + if (wirebuf_msg_start != pkt_msg_start) { + /* packet wirebuf must be located at the beginning + * of the session wirebuf, must not happen. */ + assert(0); + session->wire_buf_start_idx = 0; + session->wire_buf_end_idx = 0; + return kr_error(EINVAL); + } + + if (wirebuf_msg_size < pkt_msg_size) { + /* Message length field is lesser then packet size, + * must not happen. */ + assert(0); + session->wire_buf_start_idx = 0; + session->wire_buf_end_idx = 0; + return kr_error(EINVAL); + } + + if (handle->type == UV_TCP) { + session->wire_buf_start_idx += wirebuf_msg_size + 2; + } else { + session->wire_buf_start_idx += pkt_msg_size; + } + session->sflags.wirebuf_error = false; + + wirebuf_data_size = session->wire_buf_end_idx - session->wire_buf_start_idx; + if (wirebuf_data_size == 0) { + session_wirebuf_discard(session); + } else if (wirebuf_data_size < KNOT_WIRE_HEADER_SIZE) { + session_wirebuf_compress(session); + } + + return kr_ok(); +} + +void session_wirebuf_discard(struct session *session) +{ + session->wire_buf_start_idx = 0; + session->wire_buf_end_idx = 0; +} + +void session_wirebuf_compress(struct session *session) +{ + if (session->wire_buf_start_idx == 0) { + return; + } + uint8_t *wirebuf_data_start = &session->wire_buf[session->wire_buf_start_idx]; + size_t wirebuf_data_size = session->wire_buf_end_idx - session->wire_buf_start_idx; + if (session->wire_buf_start_idx < wirebuf_data_size) { + memmove(session->wire_buf, wirebuf_data_start, wirebuf_data_size); + } else { + memcpy(session->wire_buf, wirebuf_data_start, wirebuf_data_size); + } + session->wire_buf_start_idx = 0; + session->wire_buf_end_idx = wirebuf_data_size; +} + +bool session_wirebuf_error(struct session *session) +{ + return session->sflags.wirebuf_error; +} + +uint8_t *session_wirebuf_get_start(struct session *session) +{ + return session->wire_buf; +} + +size_t session_wirebuf_get_size(struct session *session) +{ + return session->wire_buf_size; +} + +uint8_t *session_wirebuf_get_free_start(struct session *session) +{ + return &session->wire_buf[session->wire_buf_end_idx]; +} + +size_t session_wirebuf_get_free_size(struct session *session) +{ + return session->wire_buf_size - session->wire_buf_end_idx; +} + +void session_poison(struct session *session) +{ + kr_asan_poison(session, sizeof(*session)); +} + +void session_unpoison(struct session *session) +{ + kr_asan_unpoison(session, sizeof(*session)); +} + +int session_wirebuf_process(struct session *session) +{ + int ret = 0; + if (session->wire_buf_start_idx == session->wire_buf_end_idx) { + return ret; + } + struct worker_ctx *worker = session_get_handle(session)->loop->data; + size_t wirebuf_data_size = session->wire_buf_end_idx - session->wire_buf_start_idx; + uint32_t max_iterations = (wirebuf_data_size / (KNOT_WIRE_HEADER_SIZE + KNOT_WIRE_QUESTION_MIN_SIZE)) + 1; + knot_pkt_t *query = NULL; + while (((query = session_produce_packet(session, &worker->pkt_pool)) != NULL) && + (ret < max_iterations)) { + assert (!session_wirebuf_error(session)); + int res = worker_submit(session, query); + if (res != kr_error(EILSEQ)) { + /* Packet has been successfully parsed. */ + ret += 1; + } + if (session_discard_packet(session, query) < 0) { + /* Packet data isn't stored in memory as expected. + something went wrong, normally should not happen. */ + break; + } + } + if (session_wirebuf_error(session)) { + ret = -1; + } + return ret; +} + +void session_kill_ioreq(struct session *s, struct qr_task *task) +{ + if (!s) { + return; + } + assert(s->sflags.outgoing && s->handle); + if (s->sflags.closing) { + return; + } + session_tasklist_del(s, task); + if (s->handle->type == UV_UDP) { + assert(session_tasklist_is_empty(s)); + session_close(s); + return; + } +} + +/** Update timestamp */ +void session_touch(struct session *s) +{ + s->last_activity = kr_now(); +} + +uint64_t session_last_activity(struct session *s) +{ + return s->last_activity; +} |