zephyr/subsys/net/ip/tcp_internal.h

790 lines
18 KiB
C

/** @file
@brief TCP data handler
This is not to be included by the application.
*/
/*
* Copyright (c) 2016 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef __TCP_INTERNAL_H
#define __TCP_INTERNAL_H
#include <zephyr/types.h>
#include <net/net_core.h>
#include <net/net_ip.h>
#include <net/net_pkt.h>
#include <net/net_context.h>
#include "connection.h"
#ifdef __cplusplus
extern "C" {
#endif
/** Is this TCP context/socket used or not */
#define NET_TCP_IN_USE BIT(0)
/* BIT(1), BIT(2) are unused and available */
/** Is the socket shutdown for read/write */
#define NET_TCP_IS_SHUTDOWN BIT(3)
/** A retransmitted packet has been sent and not yet ack'd */
#define NET_TCP_RETRYING BIT(4)
/** MSS option has been set already */
#define NET_TCP_RECV_MSS_SET BIT(5)
/*
* TCP connection states
*/
enum net_tcp_state {
NET_TCP_CLOSED = 0,
NET_TCP_LISTEN,
NET_TCP_SYN_SENT,
NET_TCP_SYN_RCVD,
NET_TCP_ESTABLISHED,
NET_TCP_CLOSE_WAIT,
NET_TCP_LAST_ACK,
NET_TCP_FIN_WAIT_1,
NET_TCP_FIN_WAIT_2,
NET_TCP_TIME_WAIT,
NET_TCP_CLOSING,
};
/* TCP packet types */
#define NET_TCP_FIN 0x01
#define NET_TCP_SYN 0x02
#define NET_TCP_RST 0x04
#define NET_TCP_PSH 0x08
#define NET_TCP_ACK 0x10
#define NET_TCP_URG 0x20
#define NET_TCP_CTL 0x3f
#define NET_TCP_FLAGS(hdr) (hdr->flags & NET_TCP_CTL)
/* Length of TCP header, including options */
/* "offset": 4-bit field in high nibble, units of dwords */
#define NET_TCP_HDR_LEN(hdr) (4 * ((hdr)->offset >> 4))
/* RFC 1122 4.2.2.6 "If an MSS option is not received at connection
* setup, TCP MUST assume a default send MSS of 536"
*/
#define NET_TCP_DEFAULT_MSS 536
/* TCP max window size */
#define NET_TCP_MAX_WIN (4 * 1024)
/* Maximal value of the sequence number */
#define NET_TCP_MAX_SEQ 0xffffffff
#define NET_TCP_MAX_OPT_SIZE 8
/* TCP Option codes */
#define NET_TCP_END_OPT 0
#define NET_TCP_NOP_OPT 1
#define NET_TCP_MSS_OPT 2
#define NET_TCP_WINDOW_SCALE_OPT 3
/* TCP Option sizes */
#define NET_TCP_END_SIZE 1
#define NET_TCP_NOP_SIZE 1
#define NET_TCP_MSS_SIZE 4
#define NET_TCP_WINDOW_SCALE_SIZE 3
/** Parsed TCP option values for net_tcp_parse_opts() */
struct net_tcp_options {
u16_t mss;
};
/* Max received bytes to buffer internally */
#define NET_TCP_BUF_MAX_LEN 1280
/* Max segment lifetime, in seconds */
#define NET_TCP_MAX_SEG_LIFETIME 60
struct net_context;
struct net_tcp {
/** Network context back pointer. */
struct net_context *context;
/** Cookie pointer passed to net_context_recv() */
void *recv_user_data;
/** ACK message timer */
struct k_delayed_work ack_timer;
/** Timer for doing active close in case the peer FIN is lost. */
struct k_delayed_work fin_timer;
/** Retransmit timer */
struct k_delayed_work retry_timer;
/** TIME_WAIT timer */
struct k_delayed_work timewait_timer;
/** List pointer used for TCP retransmit buffering */
sys_slist_t sent_list;
/** Current sequence number. */
u32_t send_seq;
/** Acknowledgment number to send in next packet. */
u32_t send_ack;
/** Last ACK value sent */
u32_t sent_ack;
/** Accept callback to be called when the connection has been
* established.
*/
net_tcp_accept_cb_t accept_cb;
/**
* Semaphore to signal TCP connection completion
*/
struct k_sem connect_wait;
/**
* Current TCP receive window for our side
*/
u16_t recv_wnd;
/**
* Send MSS for the peer
*/
u16_t send_mss;
/** Current retransmit period */
u32_t retry_timeout_shift : 5;
/** Flags for the TCP */
u32_t flags : 8;
/** Current TCP state */
u32_t state : 4;
/* An outbound FIN packet has been sent */
u32_t fin_sent : 1;
/* An inbound FIN packet has been received */
u32_t fin_rcvd : 1;
/** Remaining bits in this u32_t */
u32_t _padding : 13;
};
typedef void (*net_tcp_cb_t)(struct net_tcp *tcp, void *user_data);
static inline bool net_tcp_is_used(struct net_tcp *tcp)
{
NET_ASSERT(tcp);
return tcp->flags & NET_TCP_IN_USE;
}
/**
* @brief Register a callback to be called when TCP packet
* is received corresponding to received packet.
*
* @param remote_addr Remote address of the connection end point.
* @param local_addr Local address of the connection end point.
* @param remote_port Remote port of the connection end point.
* @param local_port Local port of the connection end point.
* @param cb Callback to be called
* @param user_data User data supplied by caller.
* @param handle TCP handle that can be used when unregistering
*
* @return Return 0 if the registration succeed, <0 otherwise.
*/
static inline int net_tcp_register(const struct sockaddr *remote_addr,
const struct sockaddr *local_addr,
u16_t remote_port,
u16_t local_port,
net_conn_cb_t cb,
void *user_data,
struct net_conn_handle **handle)
{
return net_conn_register(IPPROTO_TCP, remote_addr, local_addr,
remote_port, local_port, cb, user_data,
handle);
}
/**
* @brief Unregister TCP handler.
*
* @param handle Handle from registering.
*
* @return Return 0 if the unregistration succeed, <0 otherwise.
*/
static inline int net_tcp_unregister(struct net_conn_handle *handle)
{
return net_conn_unregister(handle);
}
/*
* @brief Generate initial TCP sequence number
*
* @return Return a random TCP sequence number
*/
static inline u32_t tcp_init_isn(void)
{
/* Randomise initial seq number */
return sys_rand32_get();
}
const char *net_tcp_state_str(enum net_tcp_state state);
#if defined(CONFIG_NET_TCP)
void net_tcp_change_state(struct net_tcp *tcp, enum net_tcp_state new_state);
#else
#define net_tcp_change_state(...)
#endif
#if defined(CONFIG_NET_TCP)
/**
* @brief Allocate TCP connection context.
*
* @param context Pointer to net_context that is tied to this TCP
* context.
*
* @return Pointer TCP connection context. NULL if no available
* context can be found.
*/
struct net_tcp *net_tcp_alloc(struct net_context *context);
/**
* @brief Release TCP connection context.
*
* @param tcp Pointer to net_tcp context.
*
* @return 0 if ok, < 0 if error
*/
int net_tcp_release(struct net_tcp *tcp);
/**
* @brief Send a TCP segment without any data. The returned buffer
* is a ready made packet that can be sent via net_send_data()
* function.
*
* @param tcp TCP context
* @param flags TCP flags
* @param options Pointer TCP options, NULL if no options.
* @param optlen Length of the options.
* @param local Source address, or NULL to use the local address of
* the TCP context
* @param remote Peer address
* @param send_pkt Full IP + TCP header that is to be sent.
*
* @return 0 if ok, < 0 if error
*/
int net_tcp_prepare_segment(struct net_tcp *tcp, u8_t flags,
void *options, size_t optlen,
const struct sockaddr_ptr *local,
const struct sockaddr *remote,
struct net_pkt **send_pkt);
/**
* @brief Prepare a TCP ACK message that can be send to peer.
*
* @param tcp TCP context
* @param remote Peer address
* @param pkt Network buffer
*
* @return 0 if ok, < 0 if error
*/
int net_tcp_prepare_ack(struct net_tcp *tcp, const struct sockaddr *remote,
struct net_pkt **pkt);
/**
* @brief Prepare a TCP RST message that can be send to peer.
*
* @param tcp TCP context
* @param local Source address
* @param remote Peer address
* @param pkt Network buffer
*
* @return 0 if ok, < 0 if error
*/
int net_tcp_prepare_reset(struct net_tcp *tcp,
const struct sockaddr *local,
const struct sockaddr *remote,
struct net_pkt **pkt);
/**
* @brief Go through all the TCP connections and call callback
* for each of them.
*
* @param cb User supplied callback function to call.
* @param user_data User specified data.
*/
void net_tcp_foreach(net_tcp_cb_t cb, void *user_data);
/**
* @brief Send available queued data over TCP connection
*
* @param context TCP context
* @param cb TCP callback function
* @param token TCP token
* @param user_data User specified data
*
* @return 0 if ok, < 0 if error
*/
int net_tcp_send_data(struct net_context *context, net_context_send_cb_t cb,
void *token, void *user_data);
/**
* @brief Enqueue a single packet for transmission
*
* @param context TCP context
* @param pkt Packet
*
* @return 0 if ok, < 0 if error
*/
int net_tcp_queue_data(struct net_context *context, struct net_pkt *pkt);
/**
* @brief Sends one TCP packet initialized with the _prepare_*()
* family of functions.
*
* @param pkt Packet
*/
int net_tcp_send_pkt(struct net_pkt *pkt);
/**
* @brief Handle a received TCP ACK
*
* @param cts Context
* @param seq Received ACK sequence number
* @return False if ACK sequence number is invalid, true otherwise
*/
bool net_tcp_ack_received(struct net_context *ctx, u32_t ack);
/**
* @brief Calculates and returns the MSS for a given TCP context
*
* @param tcp TCP context
*
* @return Maximum Segment Size
*/
u16_t net_tcp_get_recv_mss(const struct net_tcp *tcp);
/**
* @brief Returns the receive window for a given TCP context
*
* @param tcp TCP context
*
* @return Current TCP receive window
*/
u32_t net_tcp_get_recv_wnd(const struct net_tcp *tcp);
/**
* @brief Obtains the state for a TCP context
*
* @param tcp TCP context
*/
static inline enum net_tcp_state net_tcp_get_state(const struct net_tcp *tcp)
{
return (enum net_tcp_state)tcp->state;
}
/**
* @brief Check if the sequence number is valid i.e., it is inside the window.
*
* @param tcp TCP context
* @param pkt Network packet
*
* @return true if network packet sequence number is valid, false otherwise
*/
bool net_tcp_validate_seq(struct net_tcp *tcp, struct net_pkt *pkt);
/**
* @brief Set TCP checksum in network packet.
*
* @param pkt Network packet
* @param frag Fragment where to start calculating the offset.
* Typically this is set to pkt->frags by the caller.
*
* @return Return the actual fragment where the checksum was written.
*/
struct net_buf *net_tcp_set_chksum(struct net_pkt *pkt, struct net_buf *frag);
/**
* @brief Get TCP checksum from network packet.
*
* @param pkt Network packet
* @param frag Fragment where to start calculating the offset.
* Typically this is set to pkt->frags by the caller.
*
* @return Return the checksum in host byte order.
*/
u16_t net_tcp_get_chksum(struct net_pkt *pkt, struct net_buf *frag);
/**
* @brief Parse TCP options from network packet.
*
* Parse TCP options, returning MSS value (as that the only one we
* handle so far).
*
* @param pkt Network packet
* @param opt_totlen Total length of options to parse
* @param opts Pointer to TCP options structure. (Each option is updated
* only if present, so the structure must be initialized with the default
* values.)
*
* @return 0 if no error, <0 in case of error
*/
int net_tcp_parse_opts(struct net_pkt *pkt, int opt_totlen,
struct net_tcp_options *opts);
/**
* @brief Get TCP header length
*
* @param pkt Network packet
*
* @return TCP header length
*/
int tcp_hdr_len(struct net_pkt *pkt);
/**
* @brief TCP receive function
*
* @param context Network context
* @param cb TCP receive callback function
* @param user_data TCP receive callback user data
*
* @return 0 if no erro, < 0 in case of error
*/
int net_tcp_recv(struct net_context *context, net_context_recv_cb_t cb,
void *user_data);
/**
* @brief Queue a TCP FIN packet if needed to close the socket
*
* @param context Network context
*
* @return 0 on success where a TCP FIN packet has been queueed, -ENOTCONN
* in case the socket was not connected or listening, -EOPNOTSUPP
* in case it was not a TCP socket or -EPROTONOSUPPORT if TCP is not
* supported
*/
int net_tcp_put(struct net_context *context);
/**
* @brief Set TCP socket into listening state
*
* @param context Network context
*
* @return 0 if successful, -EOPNOTSUPP if the context was not for TCP,
* -EPROTONOSUPPORT if TCP is not supported
*/
int net_tcp_listen(struct net_context *context);
/**
* @brief Update TCP receive window
*
* @param context Network context
* @param delta Receive window delta
*
* @return 0 on success, -EPROTOTYPE if there is no TCP context, -EINVAL
* if the receive window delta is out of bounds, -EPROTONOSUPPORT
* if TCP is not supported
*/
int net_tcp_update_recv_wnd(struct net_context *context, s32_t delta);
/**
* @brief Initialize TCP parts of a context
*
* @param context Network context
*
* @return 0 if successful, < 0 on error
*/
int net_tcp_get(struct net_context *context);
/**
* @brief Unref TCP parts of a context
*
* @param context Network context
*
* @return 0 if successful, < 0 on error
*/
int net_tcp_unref(struct net_context *context);
/**
* @brief Accept TCP connection
*
* @param context Network context
* @param cb Accept callback
* @param user_data Accept callback user data
*
* @return 0 on success, < 0 on error
*/
int net_tcp_accept(struct net_context *context, net_tcp_accept_cb_t cb,
void *user_data);
/**
* @brief Connect TCP connection
*
* @param context Network context
* @param addr Remote address
* @param laddr Local address
* @param rport Remote port
* @param lport Local port
* @param timeout Connect timeout
* @param cb Connect callback
* @param user_data Connect callback user data
*
* @return 0 on success, < 0 on error
*/
int net_tcp_connect(struct net_context *context,
const struct sockaddr *addr,
struct sockaddr *laddr,
u16_t rport,
u16_t lport,
s32_t timeout,
net_context_connect_cb_t cb,
void *user_data);
#else
static inline struct net_tcp *net_tcp_alloc(struct net_context *context)
{
ARG_UNUSED(context);
return NULL;
}
static inline int net_tcp_release(struct net_tcp *tcp)
{
ARG_UNUSED(tcp);
return 0;
}
static inline int net_tcp_prepare_segment(struct net_tcp *tcp, u8_t flags,
void *options, size_t optlen,
const struct sockaddr_ptr *local,
const struct sockaddr *remote,
struct net_pkt **send_pkt)
{
ARG_UNUSED(tcp);
ARG_UNUSED(flags);
ARG_UNUSED(options);
ARG_UNUSED(optlen);
ARG_UNUSED(local);
ARG_UNUSED(remote);
ARG_UNUSED(send_pkt);
return 0;
}
static inline int net_tcp_prepare_ack(struct net_tcp *tcp,
const struct sockaddr *remote,
struct net_pkt **pkt)
{
ARG_UNUSED(tcp);
ARG_UNUSED(remote);
ARG_UNUSED(pkt);
return 0;
}
static inline int net_tcp_prepare_reset(struct net_tcp *tcp,
const struct sockaddr *remote,
struct net_pkt **pkt)
{
ARG_UNUSED(tcp);
ARG_UNUSED(remote);
ARG_UNUSED(pkt);
return 0;
}
static inline void net_tcp_foreach(net_tcp_cb_t cb, void *user_data)
{
ARG_UNUSED(cb);
ARG_UNUSED(user_data);
}
static inline int net_tcp_send_data(struct net_context *context,
net_context_send_cb_t cb, void *token,
void *user_data)
{
ARG_UNUSED(context);
ARG_UNUSED(cb);
ARG_UNUSED(token);
ARG_UNUSED(user_data);
return 0;
}
static inline int net_tcp_queue_data(struct net_context *context,
struct net_pkt *pkt)
{
ARG_UNUSED(context);
ARG_UNUSED(pkt);
return -EPROTONOSUPPORT;
}
static inline int net_tcp_send_pkt(struct net_pkt *pkt)
{
ARG_UNUSED(pkt);
return 0;
}
static inline bool net_tcp_ack_received(struct net_context *ctx, u32_t ack)
{
ARG_UNUSED(ctx);
ARG_UNUSED(ack);
return false;
}
static inline u16_t net_tcp_get_recv_mss(const struct net_tcp *tcp)
{
ARG_UNUSED(tcp);
return 0;
}
static inline u32_t net_tcp_get_recv_wnd(const struct net_tcp *tcp)
{
ARG_UNUSED(tcp);
return 0;
}
static inline enum net_tcp_state net_tcp_get_state(const struct net_tcp *tcp)
{
ARG_UNUSED(tcp);
return NET_TCP_CLOSED;
}
static inline bool net_tcp_validate_seq(struct net_tcp *tcp,
struct net_pkt *pkt)
{
ARG_UNUSED(tcp);
ARG_UNUSED(pkt);
return false;
}
static inline u16_t net_tcp_get_chksum(struct net_pkt *pkt,
struct net_buf *frag)
{
ARG_UNUSED(pkt);
ARG_UNUSED(frag);
return 0;
}
static inline struct net_buf *net_tcp_set_chksum(struct net_pkt *pkt,
struct net_buf *frag)
{
ARG_UNUSED(pkt);
ARG_UNUSED(frag);
return NULL;
}
static inline struct net_tcp_hdr *net_tcp_get_hdr(struct net_pkt *pkt,
struct net_tcp_hdr *hdr)
{
ARG_UNUSED(pkt);
ARG_UNUSED(hdr);
return NULL;
}
static inline struct net_tcp_hdr *net_tcp_set_hdr(struct net_pkt *pkt,
struct net_tcp_hdr *hdr)
{
ARG_UNUSED(pkt);
ARG_UNUSED(hdr);
return NULL;
}
static inline int tcp_hdr_len(struct net_pkt *pkt)
{
ARG_UNUSED(pkt);
return 0;
}
static inline int net_tcp_recv(struct net_context *context,
net_context_recv_cb_t cb, void *user_data)
{
ARG_UNUSED(context);
ARG_UNUSED(cb);
ARG_UNUSED(user_data);
return -EPROTOTYPE;
}
static inline int net_tcp_put(struct net_context *context)
{
ARG_UNUSED(context);
return -EPROTONOSUPPORT;
}
static inline int net_tcp_listen(struct net_context *context)
{
ARG_UNUSED(context);
return -EPROTONOSUPPORT;
}
static inline int net_tcp_update_recv_wnd(struct net_context *context,
s32_t delta)
{
ARG_UNUSED(context);
ARG_UNUSED(delta);
return -EPROTONOSUPPORT;
}
static inline int net_tcp_get(struct net_context *context)
{
ARG_UNUSED(context);
return -EPROTONOSUPPORT;
}
static inline int net_tcp_unref(struct net_context *context)
{
ARG_UNUSED(context);
return -EPROTONOSUPPORT;
}
static inline int net_tcp_accept(struct net_context *context,
net_tcp_accept_cb_t cb, void *user_data)
{
ARG_UNUSED(context);
ARG_UNUSED(cb);
ARG_UNUSED(user_data);
return -EPROTONOSUPPORT;
}
static inline int net_tcp_connect(struct net_context *context,
const struct sockaddr *addr,
struct sockaddr *laddr,
u16_t rport, u16_t lport, s32_t timeout,
net_context_connect_cb_t cb, void *user_data)
{
ARG_UNUSED(context);
ARG_UNUSED(addr);
ARG_UNUSED(laddr);
ARG_UNUSED(rport);
ARG_UNUSED(lport);
ARG_UNUSED(cb);
ARG_UNUSED(user_data);
return -EPROTONOSUPPORT;
}
#endif
#if defined(CONFIG_NET_TCP)
void net_tcp_init(void);
#else
#define net_tcp_init(...)
#endif
#ifdef __cplusplus
}
#endif
#endif /* __TCP_INTERNAL_H */