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Diffstat (limited to 'lwip/src/include/lwip/tcp.h')
| -rw-r--r-- | lwip/src/include/lwip/tcp.h | 500 |
1 files changed, 500 insertions, 0 deletions
diff --git a/lwip/src/include/lwip/tcp.h b/lwip/src/include/lwip/tcp.h new file mode 100644 index 0000000..daf7599 --- /dev/null +++ b/lwip/src/include/lwip/tcp.h @@ -0,0 +1,500 @@ +/** + * @file + * TCP API (to be used from TCPIP thread)\n + * See also @ref tcp_raw + */ + +/* + * Copyright (c) 2001-2004 Swedish Institute of Computer Science. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * This file is part of the lwIP TCP/IP stack. + * + * Author: Adam Dunkels <adam@sics.se> + * + */ +#ifndef LWIP_HDR_TCP_H +#define LWIP_HDR_TCP_H + +#include "lwip/opt.h" + +#if LWIP_TCP /* don't build if not configured for use in lwipopts.h */ + +#include "lwip/tcpbase.h" +#include "lwip/mem.h" +#include "lwip/pbuf.h" +#include "lwip/ip.h" +#include "lwip/icmp.h" +#include "lwip/err.h" +#include "lwip/ip6.h" +#include "lwip/ip6_addr.h" + +#ifdef __cplusplus +extern "C" { +#endif + +struct tcp_pcb; +struct tcp_pcb_listen; + +/** Function prototype for tcp accept callback functions. Called when a new + * connection can be accepted on a listening pcb. + * + * @param arg Additional argument to pass to the callback function (@see tcp_arg()) + * @param newpcb The new connection pcb + * @param err An error code if there has been an error accepting. + * Only return ERR_ABRT if you have called tcp_abort from within the + * callback function! + */ +typedef err_t (*tcp_accept_fn)(void *arg, struct tcp_pcb *newpcb, err_t err); + +/** Function prototype for tcp receive callback functions. Called when data has + * been received. + * + * @param arg Additional argument to pass to the callback function (@see tcp_arg()) + * @param tpcb The connection pcb which received data + * @param p The received data (or NULL when the connection has been closed!) + * @param err An error code if there has been an error receiving + * Only return ERR_ABRT if you have called tcp_abort from within the + * callback function! + */ +typedef err_t (*tcp_recv_fn)(void *arg, struct tcp_pcb *tpcb, + struct pbuf *p, err_t err); + +/** Function prototype for tcp sent callback functions. Called when sent data has + * been acknowledged by the remote side. Use it to free corresponding resources. + * This also means that the pcb has now space available to send new data. + * + * @param arg Additional argument to pass to the callback function (@see tcp_arg()) + * @param tpcb The connection pcb for which data has been acknowledged + * @param len The amount of bytes acknowledged + * @return ERR_OK: try to send some data by calling tcp_output + * Only return ERR_ABRT if you have called tcp_abort from within the + * callback function! + */ +typedef err_t (*tcp_sent_fn)(void *arg, struct tcp_pcb *tpcb, + u16_t len); + +/** Function prototype for tcp poll callback functions. Called periodically as + * specified by @see tcp_poll. + * + * @param arg Additional argument to pass to the callback function (@see tcp_arg()) + * @param tpcb tcp pcb + * @return ERR_OK: try to send some data by calling tcp_output + * Only return ERR_ABRT if you have called tcp_abort from within the + * callback function! + */ +typedef err_t (*tcp_poll_fn)(void *arg, struct tcp_pcb *tpcb); + +/** Function prototype for tcp error callback functions. Called when the pcb + * receives a RST or is unexpectedly closed for any other reason. + * + * @note The corresponding pcb is already freed when this callback is called! + * + * @param arg Additional argument to pass to the callback function (@see tcp_arg()) + * @param err Error code to indicate why the pcb has been closed + * ERR_ABRT: aborted through tcp_abort or by a TCP timer + * ERR_RST: the connection was reset by the remote host + */ +typedef void (*tcp_err_fn)(void *arg, err_t err); + +/** Function prototype for tcp connected callback functions. Called when a pcb + * is connected to the remote side after initiating a connection attempt by + * calling tcp_connect(). + * + * @param arg Additional argument to pass to the callback function (@see tcp_arg()) + * @param tpcb The connection pcb which is connected + * @param err An unused error code, always ERR_OK currently ;-) @todo! + * Only return ERR_ABRT if you have called tcp_abort from within the + * callback function! + * + * @note When a connection attempt fails, the error callback is currently called! + */ +typedef err_t (*tcp_connected_fn)(void *arg, struct tcp_pcb *tpcb, err_t err); + +#if LWIP_WND_SCALE +#define RCV_WND_SCALE(pcb, wnd) (((wnd) >> (pcb)->rcv_scale)) +#define SND_WND_SCALE(pcb, wnd) (((wnd) << (pcb)->snd_scale)) +#define TCPWND16(x) ((u16_t)LWIP_MIN((x), 0xFFFF)) +#define TCP_WND_MAX(pcb) ((tcpwnd_size_t)(((pcb)->flags & TF_WND_SCALE) ? TCP_WND : TCPWND16(TCP_WND))) +#else +#define RCV_WND_SCALE(pcb, wnd) (wnd) +#define SND_WND_SCALE(pcb, wnd) (wnd) +#define TCPWND16(x) (x) +#define TCP_WND_MAX(pcb) TCP_WND +#endif +/* Increments a tcpwnd_size_t and holds at max value rather than rollover */ +#define TCP_WND_INC(wnd, inc) do { \ + if ((tcpwnd_size_t)(wnd + inc) >= wnd) { \ + wnd = (tcpwnd_size_t)(wnd + inc); \ + } else { \ + wnd = (tcpwnd_size_t)-1; \ + } \ + } while(0) + +#if LWIP_TCP_SACK_OUT +/** SACK ranges to include in ACK packets. + * SACK entry is invalid if left==right. */ +struct tcp_sack_range { + /** Left edge of the SACK: the first acknowledged sequence number. */ + u32_t left; + /** Right edge of the SACK: the last acknowledged sequence number +1 (so first NOT acknowledged). */ + u32_t right; +}; +#endif /* LWIP_TCP_SACK_OUT */ + +/** Function prototype for deallocation of arguments. Called *just before* the + * pcb is freed, so don't expect to be able to do anything with this pcb! + * + * @param id ext arg id (allocated via @ref tcp_ext_arg_alloc_id) + * @param data pointer to the data (set via @ref tcp_ext_arg_set before) + */ +typedef void (*tcp_extarg_callback_pcb_destroyed_fn)(u8_t id, void *data); + +/** Function prototype to transition arguments from a listening pcb to an accepted pcb + * + * @param id ext arg id (allocated via @ref tcp_ext_arg_alloc_id) + * @param lpcb the listening pcb accepting a connection + * @param cpcb the newly allocated connection pcb + * @return ERR_OK if OK, any error if connection should be dropped + */ +typedef err_t (*tcp_extarg_callback_passive_open_fn)(u8_t id, struct tcp_pcb_listen *lpcb, struct tcp_pcb *cpcb); + +/** A table of callback functions that is invoked for ext arguments */ +struct tcp_ext_arg_callbacks { + /** @ref tcp_extarg_callback_pcb_destroyed_fn */ + tcp_extarg_callback_pcb_destroyed_fn destroy; + /** @ref tcp_extarg_callback_passive_open_fn */ + tcp_extarg_callback_passive_open_fn passive_open; +}; + +#define LWIP_TCP_PCB_NUM_EXT_ARG_ID_INVALID 0xFF + +#if LWIP_TCP_PCB_NUM_EXT_ARGS +/* This is the structure for ext args in tcp pcbs (used as array) */ +struct tcp_pcb_ext_args { + const struct tcp_ext_arg_callbacks *callbacks; + void *data; +}; +/* This is a helper define to prevent zero size arrays if disabled */ +#define TCP_PCB_EXTARGS struct tcp_pcb_ext_args ext_args[LWIP_TCP_PCB_NUM_EXT_ARGS]; +#else +#define TCP_PCB_EXTARGS +#endif + +typedef u16_t tcpflags_t; +#define TCP_ALLFLAGS 0xffffU + +/** + * members common to struct tcp_pcb and struct tcp_listen_pcb + */ +#define TCP_PCB_COMMON(type) \ + type *next; /* for the linked list */ \ + void *callback_arg; \ + TCP_PCB_EXTARGS \ + enum tcp_state state; /* TCP state */ \ + u8_t prio; \ + /* ports are in host byte order */ \ + u16_t local_port + + +/** the TCP protocol control block for listening pcbs */ +struct tcp_pcb_listen { +/** Common members of all PCB types */ + IP_PCB; +/** Protocol specific PCB members */ + TCP_PCB_COMMON(struct tcp_pcb_listen); + +#if LWIP_CALLBACK_API + /* Function to call when a listener has been connected. */ + tcp_accept_fn accept; +#endif /* LWIP_CALLBACK_API */ + +#if TCP_LISTEN_BACKLOG + u8_t backlog; + u8_t accepts_pending; +#endif /* TCP_LISTEN_BACKLOG */ +}; + + +/** the TCP protocol control block */ +struct tcp_pcb { +/** common PCB members */ + IP_PCB; +/** protocol specific PCB members */ + TCP_PCB_COMMON(struct tcp_pcb); + + /* ports are in host byte order */ + u16_t remote_port; + + tcpflags_t flags; +#define TF_ACK_DELAY 0x01U /* Delayed ACK. */ +#define TF_ACK_NOW 0x02U /* Immediate ACK. */ +#define TF_INFR 0x04U /* In fast recovery. */ +#define TF_CLOSEPEND 0x08U /* If this is set, tcp_close failed to enqueue the FIN (retried in tcp_tmr) */ +#define TF_RXCLOSED 0x10U /* rx closed by tcp_shutdown */ +#define TF_FIN 0x20U /* Connection was closed locally (FIN segment enqueued). */ +#define TF_NODELAY 0x40U /* Disable Nagle algorithm */ +#define TF_NAGLEMEMERR 0x80U /* nagle enabled, memerr, try to output to prevent delayed ACK to happen */ +#if LWIP_WND_SCALE +#define TF_WND_SCALE 0x0100U /* Window Scale option enabled */ +#endif +#if TCP_LISTEN_BACKLOG +#define TF_BACKLOGPEND 0x0200U /* If this is set, a connection pcb has increased the backlog on its listener */ +#endif +#if LWIP_TCP_TIMESTAMPS +#define TF_TIMESTAMP 0x0400U /* Timestamp option enabled */ +#endif +#define TF_RTO 0x0800U /* RTO timer has fired, in-flight data moved to unsent and being retransmitted */ +#if LWIP_TCP_SACK_OUT +#define TF_SACK 0x1000U /* Selective ACKs enabled */ +#endif + + /* the rest of the fields are in host byte order + as we have to do some math with them */ + + /* Timers */ + u8_t polltmr, pollinterval; + u8_t last_timer; + u32_t tmr; + + /* receiver variables */ + u32_t rcv_nxt; /* next seqno expected */ + tcpwnd_size_t rcv_wnd; /* receiver window available */ + tcpwnd_size_t rcv_ann_wnd; /* receiver window to announce */ + u32_t rcv_ann_right_edge; /* announced right edge of window */ + +#if LWIP_TCP_SACK_OUT + /* SACK ranges to include in ACK packets (entry is invalid if left==right) */ + struct tcp_sack_range rcv_sacks[LWIP_TCP_MAX_SACK_NUM]; +#define LWIP_TCP_SACK_VALID(pcb, idx) ((pcb)->rcv_sacks[idx].left != (pcb)->rcv_sacks[idx].right) +#endif /* LWIP_TCP_SACK_OUT */ + + /* Retransmission timer. */ + s16_t rtime; + + u16_t mss; /* maximum segment size */ + + /* RTT (round trip time) estimation variables */ + u32_t rttest; /* RTT estimate in 500ms ticks */ + u32_t rtseq; /* sequence number being timed */ + s16_t sa, sv; /* @see "Congestion Avoidance and Control" by Van Jacobson and Karels */ + + s16_t rto; /* retransmission time-out (in ticks of TCP_SLOW_INTERVAL) */ + u8_t nrtx; /* number of retransmissions */ + + /* fast retransmit/recovery */ + u8_t dupacks; + u32_t lastack; /* Highest acknowledged seqno. */ + + /* congestion avoidance/control variables */ + tcpwnd_size_t cwnd; + tcpwnd_size_t ssthresh; + + /* first byte following last rto byte */ + u32_t rto_end; + + /* sender variables */ + u32_t snd_nxt; /* next new seqno to be sent */ + u32_t snd_wl1, snd_wl2; /* Sequence and acknowledgement numbers of last + window update. */ + u32_t snd_lbb; /* Sequence number of next byte to be buffered. */ + tcpwnd_size_t snd_wnd; /* sender window */ + tcpwnd_size_t snd_wnd_max; /* the maximum sender window announced by the remote host */ + + tcpwnd_size_t snd_buf; /* Available buffer space for sending (in bytes). */ +#define TCP_SNDQUEUELEN_OVERFLOW (0xffffU-3) + u16_t snd_queuelen; /* Number of pbufs currently in the send buffer. */ + +#if TCP_OVERSIZE + /* Extra bytes available at the end of the last pbuf in unsent. */ + u16_t unsent_oversize; +#endif /* TCP_OVERSIZE */ + + tcpwnd_size_t bytes_acked; + + /* These are ordered by sequence number: */ + struct tcp_seg *unsent; /* Unsent (queued) segments. */ + struct tcp_seg *unacked; /* Sent but unacknowledged segments. */ +#if TCP_QUEUE_OOSEQ + struct tcp_seg *ooseq; /* Received out of sequence segments. */ +#endif /* TCP_QUEUE_OOSEQ */ + + struct pbuf *refused_data; /* Data previously received but not yet taken by upper layer */ + +#if LWIP_CALLBACK_API || TCP_LISTEN_BACKLOG + struct tcp_pcb_listen* listener; +#endif /* LWIP_CALLBACK_API || TCP_LISTEN_BACKLOG */ + +#if LWIP_CALLBACK_API + /* Function to be called when more send buffer space is available. */ + tcp_sent_fn sent; + /* Function to be called when (in-sequence) data has arrived. */ + tcp_recv_fn recv; + /* Function to be called when a connection has been set up. */ + tcp_connected_fn connected; + /* Function which is called periodically. */ + tcp_poll_fn poll; + /* Function to be called whenever a fatal error occurs. */ + tcp_err_fn errf; +#endif /* LWIP_CALLBACK_API */ + +#if LWIP_TCP_TIMESTAMPS + u32_t ts_lastacksent; + u32_t ts_recent; +#endif /* LWIP_TCP_TIMESTAMPS */ + + /* idle time before KEEPALIVE is sent */ + u32_t keep_idle; +#if LWIP_TCP_KEEPALIVE + u32_t keep_intvl; + u32_t keep_cnt; +#endif /* LWIP_TCP_KEEPALIVE */ + + /* Persist timer counter */ + u8_t persist_cnt; + /* Persist timer back-off */ + u8_t persist_backoff; + /* Number of persist probes */ + u8_t persist_probe; + + /* KEEPALIVE counter */ + u8_t keep_cnt_sent; + +#if LWIP_WND_SCALE + u8_t snd_scale; + u8_t rcv_scale; +#endif +}; + +#if LWIP_EVENT_API + +enum lwip_event { + LWIP_EVENT_ACCEPT, + LWIP_EVENT_SENT, + LWIP_EVENT_RECV, + LWIP_EVENT_CONNECTED, + LWIP_EVENT_POLL, + LWIP_EVENT_ERR +}; + +err_t lwip_tcp_event(void *arg, struct tcp_pcb *pcb, + enum lwip_event, + struct pbuf *p, + u16_t size, + err_t err); + +#endif /* LWIP_EVENT_API */ + +/* Application program's interface: */ +struct tcp_pcb * tcp_new (void); +struct tcp_pcb * tcp_new_ip_type (u8_t type); + +void tcp_arg (struct tcp_pcb *pcb, void *arg); +#if LWIP_CALLBACK_API +void tcp_recv (struct tcp_pcb *pcb, tcp_recv_fn recv); +void tcp_sent (struct tcp_pcb *pcb, tcp_sent_fn sent); +void tcp_err (struct tcp_pcb *pcb, tcp_err_fn err); +void tcp_accept (struct tcp_pcb *pcb, tcp_accept_fn accept); +#endif /* LWIP_CALLBACK_API */ +void tcp_poll (struct tcp_pcb *pcb, tcp_poll_fn poll, u8_t interval); + +#define tcp_set_flags(pcb, set_flags) do { (pcb)->flags = (tcpflags_t)((pcb)->flags | (set_flags)); } while(0) +#define tcp_clear_flags(pcb, clr_flags) do { (pcb)->flags = (tcpflags_t)((pcb)->flags & (tcpflags_t)(~(clr_flags) & TCP_ALLFLAGS)); } while(0) +#define tcp_is_flag_set(pcb, flag) (((pcb)->flags & (flag)) != 0) + +#if LWIP_TCP_TIMESTAMPS +#define tcp_mss(pcb) (((pcb)->flags & TF_TIMESTAMP) ? ((pcb)->mss - 12) : (pcb)->mss) +#else /* LWIP_TCP_TIMESTAMPS */ +/** @ingroup tcp_raw */ +#define tcp_mss(pcb) ((pcb)->mss) +#endif /* LWIP_TCP_TIMESTAMPS */ +/** @ingroup tcp_raw */ +#define tcp_sndbuf(pcb) (TCPWND16((pcb)->snd_buf)) +/** @ingroup tcp_raw */ +#define tcp_sndqueuelen(pcb) ((pcb)->snd_queuelen) +/** @ingroup tcp_raw */ +#define tcp_nagle_disable(pcb) tcp_set_flags(pcb, TF_NODELAY) +/** @ingroup tcp_raw */ +#define tcp_nagle_enable(pcb) tcp_clear_flags(pcb, TF_NODELAY) +/** @ingroup tcp_raw */ +#define tcp_nagle_disabled(pcb) tcp_is_flag_set(pcb, TF_NODELAY) + +#if TCP_LISTEN_BACKLOG +#define tcp_backlog_set(pcb, new_backlog) do { \ + LWIP_ASSERT("pcb->state == LISTEN (called for wrong pcb?)", (pcb)->state == LISTEN); \ + ((struct tcp_pcb_listen *)(pcb))->backlog = ((new_backlog) ? (new_backlog) : 1); } while(0) +void tcp_backlog_delayed(struct tcp_pcb* pcb); +void tcp_backlog_accepted(struct tcp_pcb* pcb); +#else /* TCP_LISTEN_BACKLOG */ +#define tcp_backlog_set(pcb, new_backlog) +#define tcp_backlog_delayed(pcb) +#define tcp_backlog_accepted(pcb) +#endif /* TCP_LISTEN_BACKLOG */ +#define tcp_accepted(pcb) do { LWIP_UNUSED_ARG(pcb); } while(0) /* compatibility define, not needed any more */ + +void tcp_recved (struct tcp_pcb *pcb, u16_t len); +err_t tcp_bind (struct tcp_pcb *pcb, const ip_addr_t *ipaddr, + u16_t port); +void tcp_bind_netif(struct tcp_pcb *pcb, const struct netif *netif); +err_t tcp_connect (struct tcp_pcb *pcb, const ip_addr_t *ipaddr, + u16_t port, tcp_connected_fn connected); + +struct tcp_pcb * tcp_listen_with_backlog_and_err(struct tcp_pcb *pcb, u8_t backlog, err_t *err); +struct tcp_pcb * tcp_listen_with_backlog(struct tcp_pcb *pcb, u8_t backlog); +/** @ingroup tcp_raw */ +#define tcp_listen(pcb) tcp_listen_with_backlog(pcb, TCP_DEFAULT_LISTEN_BACKLOG) + +void tcp_abort (struct tcp_pcb *pcb); +err_t tcp_close (struct tcp_pcb *pcb); +err_t tcp_shutdown(struct tcp_pcb *pcb, int shut_rx, int shut_tx); + +err_t tcp_write (struct tcp_pcb *pcb, const void *dataptr, u16_t len, + u8_t apiflags); + +void tcp_setprio (struct tcp_pcb *pcb, u8_t prio); + +err_t tcp_output (struct tcp_pcb *pcb); + +err_t tcp_tcp_get_tcp_addrinfo(struct tcp_pcb *pcb, int local, ip_addr_t *addr, u16_t *port); + +#define tcp_dbg_get_tcp_state(pcb) ((pcb)->state) + +/* for compatibility with older implementation */ +#define tcp_new_ip6() tcp_new_ip_type(IPADDR_TYPE_V6) + +#if LWIP_TCP_PCB_NUM_EXT_ARGS +u8_t tcp_ext_arg_alloc_id(void); +void tcp_ext_arg_set_callbacks(struct tcp_pcb *pcb, uint8_t id, const struct tcp_ext_arg_callbacks * const callbacks); +void tcp_ext_arg_set(struct tcp_pcb *pcb, uint8_t id, void *arg); +void *tcp_ext_arg_get(const struct tcp_pcb *pcb, uint8_t id); +#endif + +#ifdef __cplusplus +} +#endif + +#endif /* LWIP_TCP */ + +#endif /* LWIP_HDR_TCP_H */ |