From fba2b544b6c60904ac1818fba44aa86772e40ebf Mon Sep 17 00:00:00 2001 From: Laurent Vivier Date: Thu, 13 Jun 2024 14:36:49 +0200 Subject: tcp: move buffers management functions to their own file Move all the TCP parts using internal buffers to tcp_buf.c and keep generic TCP management functions in tcp.c. Add tcp_internal.h to export needed functions from tcp.c and tcp_buf.h from tcp_buf.c With this change we can use existing TCP functions with a different kind of memory storage as for instance the shared memory provided by the guest via vhost-user. Signed-off-by: Laurent Vivier Signed-off-by: Stefano Brivio --- tcp_internal.h | 96 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 96 insertions(+) create mode 100644 tcp_internal.h (limited to 'tcp_internal.h') diff --git a/tcp_internal.h b/tcp_internal.h new file mode 100644 index 0000000..51aaa16 --- /dev/null +++ b/tcp_internal.h @@ -0,0 +1,96 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later + * Copyright (c) 2021 Red Hat GmbH + * Author: Stefano Brivio + */ + +#ifndef TCP_INTERNAL_H +#define TCP_INTERNAL_H + +#define MAX_WS 8 +#define MAX_WINDOW (1 << (16 + (MAX_WS))) + +#define MSS4 ROUND_DOWN(IP_MAX_MTU - \ + sizeof(struct tcphdr) - \ + sizeof(struct iphdr), \ + sizeof(uint32_t)) +#define MSS6 ROUND_DOWN(IP_MAX_MTU - \ + sizeof(struct tcphdr) - \ + sizeof(struct ipv6hdr), \ + sizeof(uint32_t)) + +#define SEQ_LE(a, b) ((b) - (a) < MAX_WINDOW) +#define SEQ_LT(a, b) ((b) - (a) - 1 < MAX_WINDOW) +#define SEQ_GE(a, b) ((a) - (b) < MAX_WINDOW) +#define SEQ_GT(a, b) ((a) - (b) - 1 < MAX_WINDOW) + +#define FIN (1 << 0) +#define SYN (1 << 1) +#define RST (1 << 2) +#define ACK (1 << 4) + +/* Flags for internal usage */ +#define DUP_ACK (1 << 5) +#define OPT_EOL 0 +#define OPT_NOP 1 +#define OPT_MSS 2 +#define OPT_MSS_LEN 4 +#define OPT_WS 3 +#define OPT_WS_LEN 3 +#define OPT_SACKP 4 +#define OPT_SACK 5 +#define OPT_TS 8 +#define CONN_V4(conn) (!!inany_v4(&(conn)->faddr)) +#define CONN_V6(conn) (!CONN_V4(conn)) + +/* + * enum tcp_iov_parts - I/O vector parts for one TCP frame + * @TCP_IOV_TAP tap backend specific header + * @TCP_IOV_ETH Ethernet header + * @TCP_IOV_IP IP (v4/v6) header + * @TCP_IOV_PAYLOAD IP payload (TCP header + data) + * @TCP_NUM_IOVS the number of entries in the iovec array + */ +enum tcp_iov_parts { + TCP_IOV_TAP = 0, + TCP_IOV_ETH = 1, + TCP_IOV_IP = 2, + TCP_IOV_PAYLOAD = 3, + TCP_NUM_IOVS +}; + +extern char tcp_buf_discard [MAX_WINDOW]; + +void conn_flag_do(const struct ctx *c, struct tcp_tap_conn *conn, + unsigned long flag); +#define conn_flag(c, conn, flag) \ + do { \ + flow_trace(conn, "flag at %s:%i", __func__, __LINE__); \ + conn_flag_do(c, conn, flag); \ + } while (0) + + +void conn_event_do(const struct ctx *c, struct tcp_tap_conn *conn, + unsigned long event); +#define conn_event(c, conn, event) \ + do { \ + flow_trace(conn, "event at %s:%i", __func__, __LINE__); \ + conn_event_do(c, conn, event); \ + } while (0) + +void tcp_rst_do(struct ctx *c, struct tcp_tap_conn *conn); +#define tcp_rst(c, conn) \ + do { \ + flow_dbg((conn), "TCP reset at %s:%i", __func__, __LINE__); \ + tcp_rst_do(c, conn); \ + } while (0) + +size_t tcp_l2_buf_fill_headers(const struct ctx *c, + const struct tcp_tap_conn *conn, + struct iovec *iov, size_t dlen, + const uint16_t *check, uint32_t seq); +int tcp_update_seqack_wnd(const struct ctx *c, struct tcp_tap_conn *conn, + int force_seq, struct tcp_info *tinfo); +int tcp_prepare_flags(struct ctx *c, struct tcp_tap_conn *conn, int flags, + struct tcphdr *th, char *data, size_t *optlen); + +#endif /* TCP_INTERNAL_H */ -- cgit v1.2.3