Adding upstream version 3.2.6.upstream/3.2.6upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 227 insertions, 0 deletions

diff --git a/src/libknot/xdp/tcp.h b/src/libknot/xdp/tcp.h
new file mode 100644
index 0000000..da0f1a4
--- /dev/null
+++ b/src/libknot/xdp/tcp.h
@@ -0,0 +1,227 @@
+/*  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/>.
+ */
+
+/*!
+ * \file
+ *
+ * \brief TCP over XDP IO interface.
+ *
+ * \addtogroup xdp
+ * @{
+ */
+
+#pragma once
+
+#include "libknot/xdp/msg.h"
+#include "libknot/xdp/xdp.h"
+
+struct knot_sweep_stats;
+
+typedef enum {
+	XDP_TCP_NOOP      = 0,
+	XDP_TCP_SYN       = 1,
+	XDP_TCP_ESTABLISH = 2,
+	XDP_TCP_CLOSE     = 3,
+	XDP_TCP_RESET     = 4,
+	XDP_TCP_RESEND    = 5,
+
+	XDP_TCP_FREE      = 0x10,
+} knot_tcp_action_t;
+
+typedef enum {
+	XDP_TCP_NORMAL,
+	XDP_TCP_ESTABLISHING,
+	XDP_TCP_CLOSING1, // FIN+ACK sent
+	XDP_TCP_CLOSING2, // FIN+ACK received and sent
+} knot_tcp_state_t;
+
+typedef enum {
+	XDP_TCP_FREE_NONE,
+	XDP_TCP_FREE_DATA,
+	XDP_TCP_FREE_PREFIX,
+} knot_tcp_relay_free_t;
+
+typedef enum {
+	XDP_TCP_IGNORE_NONE        = 0,
+	XDP_TCP_IGNORE_ESTABLISH   = (1 << 0),
+	XDP_TCP_IGNORE_DATA_ACK    = (1 << 1),
+	XDP_TCP_IGNORE_FIN         = (1 << 2),
+} knot_tcp_ignore_t;
+
+typedef struct knot_tcp_conn {
+	struct {
+		struct knot_tcp_conn *list_node_next;
+		struct knot_tcp_conn *list_node_prev;
+	} list_node_placeholder;
+	struct sockaddr_in6 ip_rem;
+	struct sockaddr_in6 ip_loc;
+	uint8_t last_eth_rem[ETH_ALEN];
+	uint8_t last_eth_loc[ETH_ALEN];
+	uint16_t mss;
+	uint8_t window_scale;
+	uint32_t seqno;
+	uint32_t ackno;
+	uint32_t acked;
+	uint32_t window_size;
+	uint32_t last_active;
+	uint32_t establish_rtt; // in microseconds
+	knot_tcp_state_t state;
+	struct iovec inbuf;
+	struct knot_tcp_outbuf *outbufs;
+	struct knot_tcp_conn *next;
+} knot_tcp_conn_t;
+
+typedef struct {
+	size_t size;
+	size_t usage;
+	size_t inbufs_total;
+	size_t outbufs_total;
+	uint64_t hash_secret[2];
+	knot_tcp_conn_t *next_close;
+	knot_tcp_conn_t *next_ibuf;
+	knot_tcp_conn_t *next_obuf;
+	knot_tcp_conn_t *next_resend;
+	knot_tcp_conn_t *conns[];
+} knot_tcp_table_t;
+
+typedef struct {
+	const knot_xdp_msg_t *msg;
+	knot_tcp_action_t action;
+	knot_xdp_msg_flag_t auto_answer;
+	uint32_t auto_seqno;
+	knot_tcp_action_t answer;
+	struct iovec *inbufs;
+	size_t inbufs_count;
+	knot_tcp_conn_t *conn;
+} knot_tcp_relay_t;
+
+/*!
+ * \brief Return next TCP sequence number.
+ */
+inline static uint32_t knot_tcp_next_seqno(const knot_xdp_msg_t *msg)
+{
+	uint32_t res = msg->seqno + msg->payload.iov_len;
+	if (msg->flags & (KNOT_XDP_MSG_SYN | KNOT_XDP_MSG_FIN)) {
+		res++;
+	}
+	return res;
+}
+
+/*!
+ * \brief Check if the relay is empty.
+ */
+inline static bool knot_tcp_relay_empty(const knot_tcp_relay_t *relay)
+{
+	return relay->action == XDP_TCP_NOOP && relay->answer == XDP_TCP_NOOP &&
+	       relay->auto_answer == 0 && relay->inbufs_count == 0;
+}
+
+/*!
+ * \brief Allocate TCP connection-handling hash table.
+ *
+ * \param size           Number of records for the hash table.
+ * \param secret_share   Optional: share the hashing secret with another table.
+ *
+ * \note Hashing conflicts are solved by single-linked-lists in each record.
+ *
+ * \return The table, or NULL.
+ */
+knot_tcp_table_t *knot_tcp_table_new(size_t size, knot_tcp_table_t *secret_share);
+
+/*!
+ * \brief Free TCP connection hash table including all connection records.
+ *
+ * \note The freed connections are not closed nor reset.
+ */
+void knot_tcp_table_free(knot_tcp_table_t *table);
+
+/*!
+ * \brief Process received packets, prepare automatic responses (e.g. ACK), pick incoming data.
+ *
+ * \param relays      Out: relays to be filled with message/connection details.
+ * \param msgs        Packets received by knot_xdp_recv().
+ * \param msg_count   Number of received packets.
+ * \param tcp_table   Table of TCP connections.
+ * \param syn_table   Optional: extra table for handling partially established connections.
+ * \param ignore      Ignore specific TCP packets indication.
+ *
+ * \return KNOT_E*
+ */
+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);
+
+/*!
+ * \brief Prepare data (payload) to be sent as a response on specific relay.
+ *
+ * \param relay            Relay with active connection.
+ * \param tcp_table        TCP table.
+ * \param ignore_lastbyte  Evil mode: drop last byte of the payload.
+ * \param data             Data payload, possibly > MSS and > window.
+ * \param len              Payload length, < 64k.
+ *
+ * \return KNOT_E*
+ */
+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);
+
+/*!
+ * \brief Send TCP packets.
+ *
+ * \param socket       XDP socket to send through.
+ * \param relays       Connection changes and data.
+ * \param relay_count  Number of connection changes and data.
+ * \param max_at_once  Limit of packet batch sent by knot_xdp_send().
+ *
+ * \return KNOT_E*
+ */
+int knot_tcp_send(knot_xdp_socket_t *socket, knot_tcp_relay_t relays[],
+                  uint32_t relay_count, uint32_t max_at_once);
+
+/*!
+ * \brief Cleanup old TCP connections, perform timeout checks.
+ *
+ * \param tcp_table        TCP connection table to clean up.
+ * \param close_timeout    Gracefully close connections older than this (usecs).
+ * \param reset_timeout    Reset connections older than this (usecs).
+ * \param resend_timeout   Resend unAcked data older than this (usecs).
+ * \param limit_conn_count Limit of active connections in TCP table, reset if more.
+ * \param limit_ibuf_size  Limit of memory usage by input buffers, reset if exceeded.
+ * \param limit_obuf_size  Limit of memory usage by output buffers, reset if exceeded.
+ * \param relays           Out: relays to be filled with close/reset instructions for knot_tcp_send().
+ * \param max_relays       Maximum relays to be used.
+ * \param stats            Out: sweeped out connection statistics.
+ *
+ * \return KNOT_E*
+ */
+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);
+
+/*!
+ * \brief Free resources of closed/reset connections.
+ *
+ * \param tcp_table    TCP table with connections.
+ * \param relays       Relays with closed/reset (or other, ignored) connections.
+ * \param relay_count  Number of relays.
+ */
+void knot_tcp_cleanup(knot_tcp_table_t *tcp_table, knot_tcp_relay_t relays[],
+                      uint32_t relay_count);
+
+/*! @} */