diff options
Diffstat (limited to 'src/libknot/xdp/tcp.c')
| -rw-r--r-- | src/libknot/xdp/tcp.c | 729 |
1 files changed, 729 insertions, 0 deletions
diff --git a/src/libknot/xdp/tcp.c b/src/libknot/xdp/tcp.c new file mode 100644 index 0000000..752e9ef --- /dev/null +++ b/src/libknot/xdp/tcp.c @@ -0,0 +1,729 @@ +/* Copyright (C) 2022 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 <limits.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> + +#include "libknot/xdp/tcp.h" +#include "libknot/xdp/tcp_iobuf.h" +#include "libknot/attribute.h" +#include "libknot/error.h" +#include "libdnssec/random.h" +#include "contrib/macros.h" +#include "contrib/openbsd/siphash.h" +#include "contrib/ucw/lists.h" + +static uint32_t get_timestamp(void) +{ + struct timespec t; + clock_gettime(CLOCK_MONOTONIC, &t); + uint64_t res = (uint64_t)t.tv_sec * 1000000; + res += (uint64_t)t.tv_nsec / 1000; + return res & 0xffffffff; // overflow does not matter since we are working with differences +} + +static size_t sockaddr_data_len(const struct sockaddr_in6 *rem, const struct sockaddr_in6 *loc) +{ + assert(rem->sin6_family == loc->sin6_family); + if (rem->sin6_family == AF_INET) { + return offsetof(struct sockaddr_in, sin_zero); + } else { + assert(rem->sin6_family == AF_INET6); + return offsetof(struct sockaddr_in6, sin6_scope_id); + } +} + +static uint64_t hash_four_tuple(const struct sockaddr_in6 *rem, const struct sockaddr_in6 *loc, + knot_tcp_table_t *table) +{ + size_t socka_data_len = sockaddr_data_len(rem, loc); + SIPHASH_CTX ctx; + SipHash24_Init(&ctx, (const SIPHASH_KEY *)(table->hash_secret)); + SipHash24_Update(&ctx, rem, socka_data_len); + SipHash24_Update(&ctx, loc, socka_data_len); + return SipHash24_End(&ctx); +} + +static list_t *tcp_table_timeout(knot_tcp_table_t *table) +{ + return (list_t *)&table->conns[table->size]; +} + +static node_t *tcp_conn_node(knot_tcp_conn_t *conn) +{ + return (node_t *)&conn->list_node_placeholder; +} + +static void next_node_ptr(knot_tcp_conn_t **ptr) +{ + if (*ptr != NULL) { + *ptr = (*ptr)->list_node_placeholder.list_node_next; + if ((*ptr)->list_node_placeholder.list_node_next == NULL) { // detected tail of list + *ptr = NULL; + } + } +} + +static void next_ptr_ibuf(knot_tcp_conn_t **ptr) +{ + do { + next_node_ptr(ptr); + } while (*ptr != NULL && (*ptr)->inbuf.iov_len == 0); +} + +static void next_ptr_obuf(knot_tcp_conn_t **ptr) +{ + do { + next_node_ptr(ptr); + } while (*ptr != NULL && knot_tcp_outbufs_usage((*ptr)->outbufs) == 0); +} + +_public_ +knot_tcp_table_t *knot_tcp_table_new(size_t size, knot_tcp_table_t *secret_share) +{ + knot_tcp_table_t *table = calloc(1, sizeof(*table) + sizeof(list_t) + + size * sizeof(table->conns[0])); + if (table == NULL) { + return table; + } + + table->size = size; + init_list(tcp_table_timeout(table)); + + assert(sizeof(table->hash_secret) == sizeof(SIPHASH_KEY)); + if (secret_share == NULL) { + table->hash_secret[0] = dnssec_random_uint64_t(); + table->hash_secret[1] = dnssec_random_uint64_t(); + } else { + table->hash_secret[0] = secret_share->hash_secret[0]; + table->hash_secret[1] = secret_share->hash_secret[1]; + } + + return table; +} + +static void del_conn(knot_tcp_conn_t *conn) +{ + if (conn != NULL) { + free(conn->inbuf.iov_base); + while (conn->outbufs != NULL) { + struct knot_tcp_outbuf *next = conn->outbufs->next; + free(conn->outbufs); + conn->outbufs = next; + } + free(conn); + } +} + +_public_ +void knot_tcp_table_free(knot_tcp_table_t *table) +{ + if (table != NULL) { + knot_tcp_conn_t *conn, *next; + WALK_LIST_DELSAFE(conn, next, *tcp_table_timeout(table)) { + del_conn(conn); + } + free(table); + } +} + +static knot_tcp_conn_t **tcp_table_lookup(const struct sockaddr_in6 *rem, + const struct sockaddr_in6 *loc, + uint64_t *hash, knot_tcp_table_t *table) +{ + if (*hash == 0) { + *hash = hash_four_tuple(rem, loc, table); + } + size_t sdl = sockaddr_data_len(rem, loc); + knot_tcp_conn_t **res = table->conns + (*hash % table->size); + while (*res != NULL) { + if (memcmp(&(*res)->ip_rem, rem, sdl) == 0 && + memcmp(&(*res)->ip_loc, loc, sdl) == 0) { + break; + } + res = &(*res)->next; + } + return res; +} + +static knot_tcp_conn_t **tcp_table_re_lookup(knot_tcp_conn_t *conn, + knot_tcp_table_t *table) +{ + uint64_t unused_hash = 0; + knot_tcp_conn_t **res = tcp_table_lookup(&conn->ip_rem, &conn->ip_loc, + &unused_hash, table); + assert(*res == conn); + return res; +} + +static void rem_align_pointers(knot_tcp_conn_t *to_rem, knot_tcp_table_t *table) +{ + if (to_rem == table->next_close) { + next_node_ptr(&table->next_close); + } + if (to_rem == table->next_ibuf) { + next_ptr_ibuf(&table->next_ibuf); + } + if (to_rem == table->next_obuf) { + next_ptr_obuf(&table->next_obuf); + } + if (to_rem == table->next_resend) { + next_ptr_obuf(&table->next_resend); + } +} + +static void tcp_table_remove_conn(knot_tcp_conn_t **todel) +{ + rem_node(tcp_conn_node(*todel)); // remove from timeout double-linked list + *todel = (*todel)->next; // remove from conn-table linked list +} + +static void tcp_table_remove(knot_tcp_conn_t **todel, knot_tcp_table_t *table) +{ + assert(table->usage > 0); + rem_align_pointers(*todel, table); + table->inbufs_total -= (*todel)->inbuf.iov_len; + table->outbufs_total -= knot_tcp_outbufs_usage((*todel)->outbufs); + tcp_table_remove_conn(todel); + table->usage--; +} + +static void conn_init_from_msg(knot_tcp_conn_t *conn, knot_xdp_msg_t *msg) +{ + memcpy(&conn->ip_rem, &msg->ip_from, sizeof(conn->ip_rem)); + memcpy(&conn->ip_loc, &msg->ip_to, sizeof(conn->ip_loc)); + + memcpy(&conn->last_eth_rem, &msg->eth_from, sizeof(conn->last_eth_rem)); + memcpy(&conn->last_eth_loc, &msg->eth_to, sizeof(conn->last_eth_loc)); + + conn->seqno = msg->seqno; + conn->ackno = msg->ackno; + conn->acked = msg->ackno; + + conn->last_active = get_timestamp(); + conn->state = XDP_TCP_NORMAL; + conn->establish_rtt = 0; + + memset(&conn->inbuf, 0, sizeof(conn->inbuf)); + memset(&conn->outbufs, 0, sizeof(conn->outbufs)); +} + +static void tcp_table_insert(knot_tcp_conn_t *conn, uint64_t hash, + knot_tcp_table_t *table) +{ + knot_tcp_conn_t **addto = table->conns + (hash % table->size); + add_tail(tcp_table_timeout(table), tcp_conn_node(conn)); + if (table->next_close == NULL) { + table->next_close = conn; + } + conn->next = *addto; + *addto = conn; + table->usage++; +} + +// WARNING you shall ensure that it's not in the table already! +static int tcp_table_add(knot_xdp_msg_t *msg, uint64_t hash, knot_tcp_table_t *table, + knot_tcp_conn_t **res) +{ + knot_tcp_conn_t *c = malloc(sizeof(*c)); + if (c == NULL) { + return KNOT_ENOMEM; + } + conn_init_from_msg(c, msg); + tcp_table_insert(c, hash, table); + *res = c; + return KNOT_EOK; +} + +static bool check_seq_ack(const knot_xdp_msg_t *msg, const knot_tcp_conn_t *conn) +{ + if (conn == NULL || conn->seqno != msg->seqno) { + return false; + } + + if (conn->acked <= conn->ackno) { // ackno does not wrap around uint32 + return (msg->ackno >= conn->acked && msg->ackno <= conn->ackno); + } else { // this is more tricky + return (msg->ackno >= conn->acked || msg->ackno <= conn->ackno); + } +} + +static void conn_update(knot_tcp_conn_t *conn, const knot_xdp_msg_t *msg) +{ + conn->seqno = knot_tcp_next_seqno(msg); + memcpy(conn->last_eth_rem, msg->eth_from, sizeof(conn->last_eth_rem)); + memcpy(conn->last_eth_loc, msg->eth_to, sizeof(conn->last_eth_loc)); + conn->window_size = (uint32_t)msg->win * (1LU << conn->window_scale); + + uint32_t now = get_timestamp(); + if (conn->establish_rtt == 0 && conn->last_active != 0) { + conn->establish_rtt = now - conn->last_active; + } + conn->last_active = now; +} + +_public_ +int knot_tcp_recv(knot_tcp_relay_t *relays, knot_xdp_msg_t msgs[], uint32_t msg_count, + knot_tcp_table_t *tcp_table, knot_tcp_table_t *syn_table, + knot_tcp_ignore_t ignore) +{ + if (msg_count == 0) { + return KNOT_EOK; + } + if (relays == NULL || msgs == NULL || tcp_table == NULL) { + return KNOT_EINVAL; + } + memset(relays, 0, msg_count * sizeof(*relays)); + + knot_tcp_relay_t *relay = relays; + int ret = KNOT_EOK; + + for (knot_xdp_msg_t *msg = msgs; msg != msgs + msg_count && ret == KNOT_EOK; msg++) { + if (!(msg->flags & KNOT_XDP_MSG_TCP)) { + continue; + } + + uint64_t conn_hash = 0; + knot_tcp_conn_t **pconn = tcp_table_lookup(&msg->ip_from, &msg->ip_to, + &conn_hash, tcp_table); + knot_tcp_conn_t *conn = *pconn; + bool seq_ack_match = check_seq_ack(msg, conn); + if (seq_ack_match) { + assert(conn->mss != 0); + conn_update(conn, msg); + + rem_align_pointers(conn, tcp_table); + rem_node(tcp_conn_node(conn)); + add_tail(tcp_table_timeout(tcp_table), tcp_conn_node(conn)); + + if (msg->flags & KNOT_XDP_MSG_ACK) { + conn->acked = msg->ackno; + knot_tcp_outbufs_ack(&conn->outbufs, msg->ackno, &tcp_table->outbufs_total); + } + } + + relay->msg = msg; + relay->conn = conn; + + // process incoming data + if (seq_ack_match && (msg->flags & KNOT_XDP_MSG_ACK) && msg->payload.iov_len > 0) { + if (!(ignore & XDP_TCP_IGNORE_DATA_ACK)) { + relay->auto_answer = KNOT_XDP_MSG_ACK; + } + ret = knot_tcp_inbuf_update(&conn->inbuf, msg->payload, &relay->inbufs, + &relay->inbufs_count, &tcp_table->inbufs_total); + if (ret != KNOT_EOK) { + break; + } + if (conn->inbuf.iov_len > 0 && tcp_table->next_ibuf == NULL) { + tcp_table->next_ibuf = conn; + } + } + + // process TCP connection state + switch (msg->flags & (KNOT_XDP_MSG_SYN | KNOT_XDP_MSG_ACK | + KNOT_XDP_MSG_FIN | KNOT_XDP_MSG_RST)) { + case KNOT_XDP_MSG_SYN: + case (KNOT_XDP_MSG_SYN | KNOT_XDP_MSG_ACK): + if (conn == NULL) { + bool synack = (msg->flags & KNOT_XDP_MSG_ACK); + + knot_tcp_table_t *add_table = tcp_table; + if (syn_table != NULL && !synack) { + add_table = syn_table; + if (*tcp_table_lookup(&msg->ip_from, &msg->ip_to, &conn_hash, syn_table) != NULL) { + break; + } + } + + ret = tcp_table_add(msg, conn_hash, add_table, &relay->conn); + if (ret == KNOT_EOK) { + relay->action = synack ? XDP_TCP_ESTABLISH : XDP_TCP_SYN; + if (!(ignore & XDP_TCP_IGNORE_ESTABLISH)) { + relay->auto_answer = synack ? KNOT_XDP_MSG_ACK : (KNOT_XDP_MSG_SYN | KNOT_XDP_MSG_ACK); + } + + conn = relay->conn; + conn->state = synack ? XDP_TCP_NORMAL: XDP_TCP_ESTABLISHING; + conn->mss = MAX(msg->mss, 536); // minimal MSS, most importantly not zero! + conn->window_scale = msg->win_scale; + conn_update(conn, msg); + if (!synack) { + conn->acked = dnssec_random_uint32_t(); + conn->ackno = conn->acked; + } + } + } else { + relay->auto_answer = KNOT_XDP_MSG_ACK; + } + break; + case KNOT_XDP_MSG_ACK: + if (!seq_ack_match) { + if (syn_table != NULL && msg->payload.iov_len == 0 && + (pconn = tcp_table_lookup(&msg->ip_from, &msg->ip_to, &conn_hash, syn_table)) != NULL && + (conn = *pconn) != NULL && check_seq_ack(msg, conn)) { + // move conn from syn_table to tcp_table + tcp_table_remove(pconn, syn_table); + tcp_table_insert(conn, conn_hash, tcp_table); + relay->conn = conn; + relay->action = XDP_TCP_ESTABLISH; + conn->state = XDP_TCP_NORMAL; + conn_update(conn, msg); + } + } else { + switch (conn->state) { + case XDP_TCP_NORMAL: + case XDP_TCP_CLOSING1: // just a mess, ignore + break; + case XDP_TCP_ESTABLISHING: + conn->state = XDP_TCP_NORMAL; + relay->action = XDP_TCP_ESTABLISH; + break; + case XDP_TCP_CLOSING2: + if (msg->payload.iov_len == 0) { // otherwise ignore close + tcp_table_remove(pconn, tcp_table); + relay->answer = XDP_TCP_FREE; + } + break; + } + } + break; + case (KNOT_XDP_MSG_FIN | KNOT_XDP_MSG_ACK): + if (ignore & XDP_TCP_IGNORE_FIN) { + break; + } + if (!seq_ack_match) { + if (conn != NULL) { + relay->auto_answer = KNOT_XDP_MSG_RST; + relay->auto_seqno = msg->ackno; + } // else ignore. It would be better and possible, but no big value for the price of CPU. + } else { + if (conn->state == XDP_TCP_CLOSING1) { + relay->action = XDP_TCP_CLOSE; + relay->auto_answer = KNOT_XDP_MSG_ACK; + relay->answer = XDP_TCP_FREE; + tcp_table_remove(pconn, tcp_table); + } else if (msg->payload.iov_len == 0) { // otherwise ignore FIN + relay->action = XDP_TCP_CLOSE; + relay->auto_answer = KNOT_XDP_MSG_FIN | KNOT_XDP_MSG_ACK; + conn->state = XDP_TCP_CLOSING2; + } + } + break; + case KNOT_XDP_MSG_RST: + if (conn != NULL && msg->seqno == conn->seqno) { + relay->action = XDP_TCP_RESET; + tcp_table_remove(pconn, tcp_table); + relay->answer = XDP_TCP_FREE; + } else if (conn != NULL) { + relay->auto_answer = KNOT_XDP_MSG_ACK; + } + break; + default: + break; + } + + if (!knot_tcp_relay_empty(relay)) { + relay++; + } + } + + return ret; +} + +_public_ +int knot_tcp_reply_data(knot_tcp_relay_t *relay, knot_tcp_table_t *tcp_table, + bool ignore_lastbyte, uint8_t *data, uint32_t len) +{ + if (relay == NULL || tcp_table == NULL || relay->conn == NULL) { + return KNOT_EINVAL; + } + int ret = knot_tcp_outbufs_add(&relay->conn->outbufs, data, len, ignore_lastbyte, + relay->conn->mss, &tcp_table->outbufs_total); + + if (tcp_table->next_obuf == NULL && knot_tcp_outbufs_usage(relay->conn->outbufs) > 0) { + tcp_table->next_obuf = relay->conn; + } + if (tcp_table->next_resend == NULL && knot_tcp_outbufs_usage(relay->conn->outbufs) > 0) { + tcp_table->next_resend = relay->conn; + } + return ret; +} + +static knot_xdp_msg_t *first_msg(knot_xdp_msg_t *msgs, uint32_t n_msgs) +{ + memset(msgs, 0, n_msgs * sizeof(*msgs)); + return msgs - 1; // will be incremented just before first use +} + +static int send_msgs(knot_xdp_msg_t *msgs, uint32_t n_msgs, knot_xdp_socket_t *socket) +{ + assert(socket); + assert(msgs); + + if (n_msgs > 0) { + uint32_t unused; + return knot_xdp_send(socket, msgs, n_msgs, &unused); + } + + return KNOT_EOK; +} + +static void msg_init_from_conn(knot_xdp_msg_t *msg, knot_tcp_conn_t *conn) +{ + memcpy( msg->eth_from, conn->last_eth_loc, sizeof(msg->eth_from)); + memcpy( msg->eth_to, conn->last_eth_rem, sizeof(msg->eth_to)); + memcpy(&msg->ip_from, &conn->ip_loc, sizeof(msg->ip_from)); + memcpy(&msg->ip_to, &conn->ip_rem, sizeof(msg->ip_to)); + + msg->ackno = conn->seqno; + msg->seqno = conn->ackno; + + msg->payload.iov_len = 0; + + msg->win_scale = 14; // maximum possible + msg->win = 0xffff; +} + +static int next_msg(knot_xdp_msg_t *msgs, uint32_t n_msgs, knot_xdp_msg_t **cur, + knot_xdp_socket_t *socket, knot_tcp_relay_t *rl) +{ + (*cur)++; + if (*cur - msgs >= n_msgs) { + int ret = send_msgs(msgs, n_msgs, socket); + if (ret != KNOT_EOK) { + return ret; + } + *cur = first_msg(msgs, n_msgs); + (*cur)++; + } + + knot_xdp_msg_t *msg = *cur; + + knot_xdp_msg_flag_t fl = KNOT_XDP_MSG_TCP; + if (rl->conn->ip_loc.sin6_family == AF_INET6) { + fl |= KNOT_XDP_MSG_IPV6; + } + if (rl->conn->state == XDP_TCP_ESTABLISHING) { + fl |= KNOT_XDP_MSG_MSS | KNOT_XDP_MSG_WSC; + } + + int ret = knot_xdp_send_alloc(socket, fl, msg); + if (ret != KNOT_EOK) { + return ret; + } + + msg_init_from_conn(msg, rl->conn); + + return ret; +} + +_public_ +int knot_tcp_send(knot_xdp_socket_t *socket, knot_tcp_relay_t relays[], + uint32_t relay_count, uint32_t max_at_once) +{ + if (relay_count == 0) { + return KNOT_EOK; + } + if (socket == NULL || relays == NULL) { + return KNOT_EINVAL; + } + + knot_xdp_msg_t msgs[max_at_once], *first = first_msg(msgs, max_at_once), *msg = first; + + for (uint32_t i = 0; i < relay_count; i++) { + knot_tcp_relay_t *rl = &relays[i]; + +#define NEXT_MSG { \ + int ret = next_msg(msgs, max_at_once, &msg, socket, rl); \ + if (ret != KNOT_EOK) { return ret; } \ +} + + if (rl->auto_answer != 0) { + NEXT_MSG + msg->flags |= rl->auto_answer; + if (msg->flags & (KNOT_XDP_MSG_SYN | KNOT_XDP_MSG_FIN)) { + rl->conn->ackno++; + } + if (rl->auto_answer == KNOT_XDP_MSG_RST) { + msg->seqno = rl->auto_seqno; + } + } + + switch (rl->answer & 0x0f) { + case XDP_TCP_ESTABLISH: + NEXT_MSG + msg->flags |= KNOT_XDP_MSG_SYN; + rl->conn->ackno++; + break; + case XDP_TCP_CLOSE: + NEXT_MSG + msg->flags |= (KNOT_XDP_MSG_FIN | KNOT_XDP_MSG_ACK); + rl->conn->ackno++; + rl->conn->state = XDP_TCP_CLOSING1; + break; + case XDP_TCP_RESET: + NEXT_MSG + msg->flags |= KNOT_XDP_MSG_RST; + break; + case XDP_TCP_NOOP: + default: + break; + } + + size_t can_data = 0; + knot_tcp_outbuf_t *ob; + if (rl->conn != NULL) { + knot_tcp_outbufs_can_send(rl->conn->outbufs, rl->conn->window_size, + rl->answer == XDP_TCP_RESEND, &ob, &can_data); + } + while (can_data > 0) { + NEXT_MSG + msg->flags |= KNOT_XDP_MSG_ACK; + msg->payload.iov_len = ob->len; + memcpy(msg->payload.iov_base, ob->bytes, ob->len); + + if (!ob->sent) { + assert(rl->conn->ackno == msg->seqno); + rl->conn->ackno += msg->payload.iov_len; + } else { + msg->seqno = ob->seqno; + } + + ob->sent = true; + ob->seqno = msg->seqno; + + can_data--; + ob = ob->next; + } +#undef NEXT_MSG + } + + return send_msgs(msgs, msg - first, socket); +} + +static void sweep_reset(knot_tcp_table_t *tcp_table, knot_tcp_relay_t *rl, + ssize_t *free_conns, ssize_t *free_inbuf, ssize_t *free_outbuf, + knot_sweep_stats_t *stats, knot_sweep_counter_t counter) +{ + rl->answer = XDP_TCP_RESET | XDP_TCP_FREE; + tcp_table_remove(tcp_table_re_lookup(rl->conn, tcp_table), tcp_table); // also updates tcp_table->next_* + + *free_conns -= 1; + *free_inbuf -= rl->conn->inbuf.iov_len; + *free_outbuf -= knot_tcp_outbufs_usage(rl->conn->outbufs); + + knot_sweep_stats_incr(stats, counter); +} + +_public_ +int knot_tcp_sweep(knot_tcp_table_t *tcp_table, + uint32_t close_timeout, uint32_t reset_timeout, + uint32_t resend_timeout, uint32_t limit_conn_count, + size_t limit_ibuf_size, size_t limit_obuf_size, + knot_tcp_relay_t *relays, uint32_t max_relays, + struct knot_sweep_stats *stats) +{ + if (tcp_table == NULL || relays == NULL || max_relays < 1) { + return KNOT_EINVAL; + } + + uint32_t now = get_timestamp(); + memset(relays, 0, max_relays * sizeof(*relays)); + knot_tcp_relay_t *rl = relays, *rl_max = rl + max_relays; + + ssize_t free_conns = (ssize_t)(tcp_table->usage - limit_conn_count); + ssize_t free_inbuf = (ssize_t)(tcp_table->inbufs_total - MIN(limit_ibuf_size, SSIZE_MAX)); + ssize_t free_outbuf = (ssize_t)(tcp_table->outbufs_total - MIN(limit_obuf_size, SSIZE_MAX)); + + // reset connections to free ibufs + while (free_inbuf > 0 && rl != rl_max) { + if (tcp_table->next_ibuf->inbuf.iov_len == 0) { // this conn might have get rid of ibuf in the meantime + next_ptr_ibuf(&tcp_table->next_ibuf); + } + assert(tcp_table->next_ibuf != NULL); + rl->conn = tcp_table->next_ibuf; + sweep_reset(tcp_table, rl, &free_conns, &free_inbuf, &free_outbuf, + stats, KNOT_SWEEP_CTR_LIMIT_IBUF); + rl++; + } + + // reset connections to free obufs + while (free_outbuf > 0 && rl != rl_max) { + if (knot_tcp_outbufs_usage(tcp_table->next_obuf->outbufs) == 0) { + next_ptr_obuf(&tcp_table->next_obuf); + } + assert(tcp_table->next_obuf != NULL); + rl->conn = tcp_table->next_obuf; + sweep_reset(tcp_table, rl, &free_conns, &free_inbuf, &free_outbuf, + stats, KNOT_SWEEP_CTR_LIMIT_OBUF); + rl++; + } + + // reset connections to free their count, and old ones + knot_tcp_conn_t *conn, *next; + WALK_LIST_DELSAFE(conn, next, *tcp_table_timeout(tcp_table)) { + if ((free_conns <= 0 && now - conn->last_active < reset_timeout) || rl == rl_max) { + break; + } + + rl->conn = conn; + sweep_reset(tcp_table, rl, &free_conns, &free_inbuf, &free_outbuf, + stats, KNOT_SWEEP_CTR_LIMIT_CONN); + rl++; + } + + // close old connections + while (tcp_table->next_close != NULL && + now - tcp_table->next_close->last_active >= close_timeout && + rl != rl_max) { + if (tcp_table->next_close->state != XDP_TCP_CLOSING1) { + rl->conn = tcp_table->next_close; + rl->answer = XDP_TCP_CLOSE; + knot_sweep_stats_incr(stats, KNOT_SWEEP_CTR_TIMEOUT); + rl++; + } + next_node_ptr(&tcp_table->next_close); + } + + // resend unACKed data + while (tcp_table->next_resend != NULL && + now - tcp_table->next_resend->last_active >= resend_timeout && + rl != rl_max) { + rl->conn = tcp_table->next_resend; + rl->answer = XDP_TCP_RESEND; + rl++; + next_ptr_obuf(&tcp_table->next_resend); + } + + return KNOT_EOK; +} + +_public_ +void knot_tcp_cleanup(knot_tcp_table_t *tcp_table, knot_tcp_relay_t relays[], + uint32_t relay_count) +{ + (void)tcp_table; + for (uint32_t i = 0; i < relay_count; i++) { + if (relays[i].answer & XDP_TCP_FREE) { + del_conn(relays[i].conn); + } + free(relays[i].inbufs); + } +} |