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/*
* 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_TCP_H__
#define __LWIP_TCP_H__
#include "lwip/sys.h"
#include "lwip/mem.h"
#include "lwip/pbuf.h"
#include "lwip/opt.h"
#include "lwip/ip.h"
#include "lwip/icmp.h"
#include "lwip/err.h"
struct tcp_pcb;
/* Functions for interfacing with TCP: */
/* Lower layer interface to TCP: */
void tcp_init (void); /* Must be called first to
initialize TCP. */
void tcp_tmr (void); /* Must be called every
TCP_TMR_INTERVAL
ms. (Typically 250 ms). */
/* Application program's interface: */
struct tcp_pcb * tcp_new (void);
struct tcp_pcb * tcp_alloc (u8_t prio);
void tcp_arg (struct tcp_pcb *pcb, void *arg);
void tcp_accept (struct tcp_pcb *pcb,
err_t (* accept)(void *arg, struct tcp_pcb *newpcb,
err_t err));
void tcp_recv (struct tcp_pcb *pcb,
err_t (* recv)(void *arg, struct tcp_pcb *tpcb,
struct pbuf *p, err_t err));
void tcp_sent (struct tcp_pcb *pcb,
err_t (* sent)(void *arg, struct tcp_pcb *tpcb,
u16_t len));
void tcp_poll (struct tcp_pcb *pcb,
err_t (* poll)(void *arg, struct tcp_pcb *tpcb),
u8_t interval);
void tcp_err (struct tcp_pcb *pcb,
void (* err)(void *arg, err_t err));
#define tcp_mss(pcb) ((pcb)->mss)
#define tcp_sndbuf(pcb) ((pcb)->snd_buf)
void tcp_recved (struct tcp_pcb *pcb, u16_t len);
err_t tcp_bind (struct tcp_pcb *pcb, struct ip_addr *ipaddr,
u16_t port);
err_t tcp_connect (struct tcp_pcb *pcb, struct ip_addr *ipaddr,
u16_t port, err_t (* connected)(void *arg,
struct tcp_pcb *tpcb,
err_t err));
struct tcp_pcb * tcp_listen (struct tcp_pcb *pcb);
void tcp_abort (struct tcp_pcb *pcb);
err_t tcp_close (struct tcp_pcb *pcb);
err_t tcp_write (struct tcp_pcb *pcb, const void *dataptr, u16_t len,
u8_t copy);
void tcp_setprio (struct tcp_pcb *pcb, u8_t prio);
#define TCP_PRIO_MIN 1
#define TCP_PRIO_NORMAL 64
#define TCP_PRIO_MAX 127
/* It is also possible to call these two functions at the right
intervals (instead of calling tcp_tmr()). */
void tcp_slowtmr (void);
void tcp_fasttmr (void);
/* Only used by IP to pass a TCP segment to TCP: */
void tcp_input (struct pbuf *p, struct netif *inp);
/* Used within the TCP code only: */
err_t tcp_output (struct tcp_pcb *pcb);
void tcp_rexmit (struct tcp_pcb *pcb);
void tcp_rexmit_rto (struct tcp_pcb *pcb);
#define TCP_SEQ_LT(a,b) ((s32_t)((a)-(b)) < 0)
#define TCP_SEQ_LEQ(a,b) ((s32_t)((a)-(b)) <= 0)
#define TCP_SEQ_GT(a,b) ((s32_t)((a)-(b)) > 0)
#define TCP_SEQ_GEQ(a,b) ((s32_t)((a)-(b)) >= 0)
/* is b<=a<=c? */
#if 0 /* see bug #10548 */
#define TCP_SEQ_BETWEEN(a,b,c) ((c)-(b) >= (a)-(b))
#endif
#define TCP_SEQ_BETWEEN(a,b,c) (TCP_SEQ_GEQ(a,b) && TCP_SEQ_LEQ(a,c))
#define TCP_FIN 0x01U
#define TCP_SYN 0x02U
#define TCP_RST 0x04U
#define TCP_PSH 0x08U
#define TCP_ACK 0x10U
#define TCP_URG 0x20U
#define TCP_ECE 0x40U
#define TCP_CWR 0x80U
#define TCP_FLAGS 0x3fU
/* Length of the TCP header, excluding options. */
#define TCP_HLEN 20
#ifndef TCP_TMR_INTERVAL
#define TCP_TMR_INTERVAL 250 /* The TCP timer interval in
milliseconds. */
#endif /* TCP_TMR_INTERVAL */
#ifndef TCP_FAST_INTERVAL
#define TCP_FAST_INTERVAL TCP_TMR_INTERVAL /* the fine grained timeout in
milliseconds */
#endif /* TCP_FAST_INTERVAL */
#ifndef TCP_SLOW_INTERVAL
#define TCP_SLOW_INTERVAL (2*TCP_TMR_INTERVAL) /* the coarse grained timeout in
milliseconds */
#endif /* TCP_SLOW_INTERVAL */
#define TCP_FIN_WAIT_TIMEOUT 20000 /* milliseconds */
#define TCP_SYN_RCVD_TIMEOUT 20000 /* milliseconds */
#define TCP_OOSEQ_TIMEOUT 6 /* x RTO */
#define TCP_MSL 60000 /* The maximum segment lifetime in microseconds */
/*
* User-settable options (used with setsockopt).
*/
#define TCP_NODELAY 0x01 /* don't delay send to coalesce packets */
#define TCP_KEEPALIVE 0x02 /* send KEEPALIVE probes when idle for pcb->keepalive miliseconds */
/* Keepalive values */
#define TCP_KEEPDEFAULT 7200000 /* KEEPALIVE timer in miliseconds */
#define TCP_KEEPINTVL 75000 /* Time between KEEPALIVE probes in miliseconds */
#define TCP_KEEPCNT 9 /* Counter for KEEPALIVE probes */
#define TCP_MAXIDLE TCP_KEEPCNT * TCP_KEEPINTVL /* Maximum KEEPALIVE probe time */
#ifdef PACK_STRUCT_USE_INCLUDES
# include "arch/bpstruct.h"
#endif
PACK_STRUCT_BEGIN
struct tcp_hdr {
PACK_STRUCT_FIELD(u16_t src);
PACK_STRUCT_FIELD(u16_t dest);
PACK_STRUCT_FIELD(u32_t seqno);
PACK_STRUCT_FIELD(u32_t ackno);
PACK_STRUCT_FIELD(u16_t _hdrlen_rsvd_flags);
PACK_STRUCT_FIELD(u16_t wnd);
PACK_STRUCT_FIELD(u16_t chksum);
PACK_STRUCT_FIELD(u16_t urgp);
} PACK_STRUCT_STRUCT;
PACK_STRUCT_END
#ifdef PACK_STRUCT_USE_INCLUDES
# include "arch/epstruct.h"
#endif
#define TCPH_OFFSET(phdr) (ntohs((phdr)->_hdrlen_rsvd_flags) >> 8)
#define TCPH_HDRLEN(phdr) (ntohs((phdr)->_hdrlen_rsvd_flags) >> 12)
#define TCPH_FLAGS(phdr) (ntohs((phdr)->_hdrlen_rsvd_flags) & TCP_FLAGS)
#define TCPH_OFFSET_SET(phdr, offset) (phdr)->_hdrlen_rsvd_flags = htons(((offset) << 8) | TCPH_FLAGS(phdr))
#define TCPH_HDRLEN_SET(phdr, len) (phdr)->_hdrlen_rsvd_flags = htons(((len) << 12) | TCPH_FLAGS(phdr))
#define TCPH_FLAGS_SET(phdr, flags) (phdr)->_hdrlen_rsvd_flags = htons((ntohs((phdr)->_hdrlen_rsvd_flags) & ~TCP_FLAGS) | (flags))
#define TCPH_SET_FLAG(phdr, flags ) (phdr)->_hdrlen_rsvd_flags = htons(ntohs((phdr)->_hdrlen_rsvd_flags) | (flags))
#define TCPH_UNSET_FLAG(phdr, flags) (phdr)->_hdrlen_rsvd_flags = htons(ntohs((phdr)->_hdrlen_rsvd_flags) | (TCPH_FLAGS(phdr) & ~(flags)) )
#define TCP_TCPLEN(seg) ((seg)->len + ((TCPH_FLAGS((seg)->tcphdr) & TCP_FIN || \
TCPH_FLAGS((seg)->tcphdr) & TCP_SYN)? 1: 0))
enum tcp_state {
CLOSED = 0,
LISTEN = 1,
SYN_SENT = 2,
SYN_RCVD = 3,
ESTABLISHED = 4,
FIN_WAIT_1 = 5,
FIN_WAIT_2 = 6,
CLOSE_WAIT = 7,
CLOSING = 8,
LAST_ACK = 9,
TIME_WAIT = 10
};
/* the TCP protocol control block */
struct tcp_pcb {
/** common PCB members */
IP_PCB;
/** protocol specific PCB members */
struct tcp_pcb *next; /* for the linked list */
enum tcp_state state; /* TCP state */
u8_t prio;
void *callback_arg;
u16_t local_port;
u16_t remote_port;
u8_t flags;
#define TF_ACK_DELAY (u8_t)0x01U /* Delayed ACK. */
#define TF_ACK_NOW (u8_t)0x02U /* Immediate ACK. */
#define TF_INFR (u8_t)0x04U /* In fast recovery. */
#define TF_RESET (u8_t)0x08U /* Connection was reset. */
#define TF_CLOSED (u8_t)0x10U /* Connection was sucessfully closed. */
#define TF_GOT_FIN (u8_t)0x20U /* Connection was closed by the remote end. */
#define TF_NODELAY (u8_t)0x40U /* Disable Nagle algorithm */
/* receiver variables */
u32_t rcv_nxt; /* next seqno expected */
u16_t rcv_wnd; /* receiver window */
/* Timers */
u32_t tmr;
u8_t polltmr, pollinterval;
/* Retransmission timer. */
u16_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; /* @todo document this */
u16_t rto; /* retransmission time-out */
u8_t nrtx; /* number of retransmissions */
/* fast retransmit/recovery */
u32_t lastack; /* Highest acknowledged seqno. */
u8_t dupacks;
/* congestion avoidance/control variables */
u16_t cwnd;
u16_t ssthresh;
/* sender variables */
u32_t snd_nxt, /* next seqno to be sent */
snd_max, /* Highest seqno sent. */
snd_wnd, /* sender window */
snd_wl1, snd_wl2, /* Sequence and acknowledgement numbers of last
window update. */
snd_lbb; /* Sequence number of next byte to be buffered. */
u16_t acked;
u16_t snd_buf; /* Available buffer space for sending (in bytes). */
u8_t snd_queuelen; /* Available buffer space for sending (in tcp_segs). */
/* 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 */
#if LWIP_CALLBACK_API
/* Function to be called when more send buffer space is available. */
err_t (* sent)(void *arg, struct tcp_pcb *pcb, u16_t space);
/* Function to be called when (in-sequence) data has arrived. */
err_t (* recv)(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err);
/* Function to be called when a connection has been set up. */
err_t (* connected)(void *arg, struct tcp_pcb *pcb, err_t err);
/* Function to call when a listener has been connected. */
err_t (* accept)(void *arg, struct tcp_pcb *newpcb, err_t err);
/* Function which is called periodically. */
err_t (* poll)(void *arg, struct tcp_pcb *pcb);
/* Function to be called whenever a fatal error occurs. */
void (* errf)(void *arg, err_t err);
#endif /* LWIP_CALLBACK_API */
/* idle time before KEEPALIVE is sent */
u32_t keepalive;
/* KEEPALIVE counter */
u8_t keep_cnt;
};
struct tcp_pcb_listen {
/* Common members of all PCB types */
IP_PCB;
/* Protocol specific PCB members */
struct tcp_pcb_listen *next; /* for the linked list */
/* Even if state is obviously LISTEN this is here for
* field compatibility with tpc_pcb to which it is cast sometimes
* Until a cleaner solution emerges this is here.FIXME
*/
enum tcp_state state; /* TCP state */
u8_t prio;
void *callback_arg;
u16_t local_port;
#if LWIP_CALLBACK_API
/* Function to call when a listener has been connected. */
err_t (* accept)(void *arg, struct tcp_pcb *newpcb, err_t err);
#endif /* LWIP_CALLBACK_API */
};
#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);
#define TCP_EVENT_ACCEPT(pcb,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
LWIP_EVENT_ACCEPT, NULL, 0, err)
#define TCP_EVENT_SENT(pcb,space,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
LWIP_EVENT_SENT, NULL, space, ERR_OK)
#define TCP_EVENT_RECV(pcb,p,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
LWIP_EVENT_RECV, (p), 0, (err))
#define TCP_EVENT_CONNECTED(pcb,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
LWIP_EVENT_CONNECTED, NULL, 0, (err))
#define TCP_EVENT_POLL(pcb,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
LWIP_EVENT_POLL, NULL, 0, ERR_OK)
#define TCP_EVENT_ERR(errf,arg,err) lwip_tcp_event((arg), NULL, \
LWIP_EVENT_ERR, NULL, 0, (err))
#else /* LWIP_EVENT_API */
#define TCP_EVENT_ACCEPT(pcb,err,ret) \
if((pcb)->accept != NULL) \
(ret = (pcb)->accept((pcb)->callback_arg,(pcb),(err)))
#define TCP_EVENT_SENT(pcb,space,ret) \
if((pcb)->sent != NULL) \
(ret = (pcb)->sent((pcb)->callback_arg,(pcb),(space)))
#define TCP_EVENT_RECV(pcb,p,err,ret) \
if((pcb)->recv != NULL) \
{ ret = (pcb)->recv((pcb)->callback_arg,(pcb),(p),(err)); } else { \
if (p) pbuf_free(p); }
#define TCP_EVENT_CONNECTED(pcb,err,ret) \
if((pcb)->connected != NULL) \
(ret = (pcb)->connected((pcb)->callback_arg,(pcb),(err)))
#define TCP_EVENT_POLL(pcb,ret) \
if((pcb)->poll != NULL) \
(ret = (pcb)->poll((pcb)->callback_arg,(pcb)))
#define TCP_EVENT_ERR(errf,arg,err) \
if((errf) != NULL) \
(errf)((arg),(err))
#endif /* LWIP_EVENT_API */
/* This structure represents a TCP segment on the unsent and unacked queues */
struct tcp_seg {
struct tcp_seg *next; /* used when putting segements on a queue */
struct pbuf *p; /* buffer containing data + TCP header */
void *dataptr; /* pointer to the TCP data in the pbuf */
u16_t len; /* the TCP length of this segment */
struct tcp_hdr *tcphdr; /* the TCP header */
};
/* Internal functions and global variables: */
struct tcp_pcb *tcp_pcb_copy(struct tcp_pcb *pcb);
void tcp_pcb_purge(struct tcp_pcb *pcb);
void tcp_pcb_remove(struct tcp_pcb **pcblist, struct tcp_pcb *pcb);
u8_t tcp_segs_free(struct tcp_seg *seg);
u8_t tcp_seg_free(struct tcp_seg *seg);
struct tcp_seg *tcp_seg_copy(struct tcp_seg *seg);
#define tcp_ack(pcb) if((pcb)->flags & TF_ACK_DELAY) { \
(pcb)->flags &= ~TF_ACK_DELAY; \
(pcb)->flags |= TF_ACK_NOW; \
tcp_output(pcb); \
} else { \
(pcb)->flags |= TF_ACK_DELAY; \
}
#define tcp_ack_now(pcb) (pcb)->flags |= TF_ACK_NOW; \
tcp_output(pcb)
err_t tcp_send_ctrl(struct tcp_pcb *pcb, u8_t flags);
err_t tcp_enqueue(struct tcp_pcb *pcb, void *dataptr, u16_t len,
u8_t flags, u8_t copy,
u8_t *optdata, u8_t optlen);
void tcp_rexmit_seg(struct tcp_pcb *pcb, struct tcp_seg *seg);
void tcp_rst(u32_t seqno, u32_t ackno,
struct ip_addr *local_ip, struct ip_addr *remote_ip,
u16_t local_port, u16_t remote_port);
u32_t tcp_next_iss(void);
void tcp_keepalive(struct tcp_pcb *pcb);
extern struct tcp_pcb *tcp_input_pcb;
extern u32_t tcp_ticks;
#if TCP_DEBUG || TCP_INPUT_DEBUG || TCP_OUTPUT_DEBUG
void tcp_debug_print(struct tcp_hdr *tcphdr);
void tcp_debug_print_flags(u8_t flags);
void tcp_debug_print_state(enum tcp_state s);
void tcp_debug_print_pcbs(void);
s16_t tcp_pcbs_sane(void);
#else
# define tcp_debug_print(tcphdr)
# define tcp_debug_print_flags(flags)
# define tcp_debug_print_state(s)
# define tcp_debug_print_pcbs()
# define tcp_pcbs_sane() 1
#endif /* TCP_DEBUG */
#if NO_SYS
#define tcp_timer_needed()
#else
void tcp_timer_needed(void);
#endif
/* The TCP PCB lists. */
union tcp_listen_pcbs_t { /* List of all TCP PCBs in LISTEN state. */
struct tcp_pcb_listen *listen_pcbs;
struct tcp_pcb *pcbs;
};
extern union tcp_listen_pcbs_t tcp_listen_pcbs;
extern struct tcp_pcb *tcp_active_pcbs; /* List of all TCP PCBs that are in a
state in which they accept or send
data. */
extern struct tcp_pcb *tcp_tw_pcbs; /* List of all TCP PCBs in TIME-WAIT. */
extern struct tcp_pcb *tcp_tmp_pcb; /* Only used for temporary storage. */
/* Axioms about the above lists:
1) Every TCP PCB that is not CLOSED is in one of the lists.
2) A PCB is only in one of the lists.
3) All PCBs in the tcp_listen_pcbs list is in LISTEN state.
4) All PCBs in the tcp_tw_pcbs list is in TIME-WAIT state.
*/
/* Define two macros, TCP_REG and TCP_RMV that registers a TCP PCB
with a PCB list or removes a PCB from a list, respectively. */
#if 0
#define TCP_REG(pcbs, npcb) do {\
LWIP_DEBUGF(TCP_DEBUG, ("TCP_REG %p local port %d\n", npcb, npcb->local_port)); \
for(tcp_tmp_pcb = *pcbs; \
tcp_tmp_pcb != NULL; \
tcp_tmp_pcb = tcp_tmp_pcb->next) { \
LWIP_ASSERT("TCP_REG: already registered\n", tcp_tmp_pcb != npcb); \
} \
LWIP_ASSERT("TCP_REG: pcb->state != CLOSED", npcb->state != CLOSED); \
npcb->next = *pcbs; \
LWIP_ASSERT("TCP_REG: npcb->next != npcb", npcb->next != npcb); \
*(pcbs) = npcb; \
LWIP_ASSERT("TCP_RMV: tcp_pcbs sane", tcp_pcbs_sane()); \
tcp_timer_needed(); \
} while(0)
#define TCP_RMV(pcbs, npcb) do { \
LWIP_ASSERT("TCP_RMV: pcbs != NULL", *pcbs != NULL); \
LWIP_DEBUGF(TCP_DEBUG, ("TCP_RMV: removing %p from %p\n", npcb, *pcbs)); \
if(*pcbs == npcb) { \
*pcbs = (*pcbs)->next; \
} else for(tcp_tmp_pcb = *pcbs; tcp_tmp_pcb != NULL; tcp_tmp_pcb = tcp_tmp_pcb->next) { \
if(tcp_tmp_pcb->next != NULL && tcp_tmp_pcb->next == npcb) { \
tcp_tmp_pcb->next = npcb->next; \
break; \
} \
} \
npcb->next = NULL; \
LWIP_ASSERT("TCP_RMV: tcp_pcbs sane", tcp_pcbs_sane()); \
LWIP_DEBUGF(TCP_DEBUG, ("TCP_RMV: removed %p from %p\n", npcb, *pcbs)); \
} while(0)
#else /* LWIP_DEBUG */
#define TCP_REG(pcbs, npcb) do { \
npcb->next = *pcbs; \
*(pcbs) = npcb; \
tcp_timer_needed(); \
} while(0)
#define TCP_RMV(pcbs, npcb) do { \
if(*(pcbs) == npcb) { \
(*(pcbs)) = (*pcbs)->next; \
} else for(tcp_tmp_pcb = *pcbs; tcp_tmp_pcb != NULL; tcp_tmp_pcb = tcp_tmp_pcb->next) { \
if(tcp_tmp_pcb->next != NULL && tcp_tmp_pcb->next == npcb) { \
tcp_tmp_pcb->next = npcb->next; \
break; \
} \
} \
npcb->next = NULL; \
} while(0)
#endif /* LWIP_DEBUG */
#endif /* __LWIP_TCP_H__ */