/* * Copyright (c) 2001-2003 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 * */ #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/sys.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 100 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); #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) #define TCP_FIN 0x01 #define TCP_SYN 0x02 #define TCP_RST 0x04 #define TCP_PSH 0x08 #define TCP_ACK 0x10 #define TCP_URG 0x20 #define TCP_FLAGS 0x3f /* Length of the TCP header, excluding options. */ #define TCP_HLEN 20 #ifndef TCP_TMR_INTERVAL #define TCP_TMR_INTERVAL 100 /* The TCP timer interval in milliseconds. */ #endif /* TCP_TMR_INTERVAL */ #ifndef TCP_FAST_INTERVAL #define TCP_FAST_INTERVAL 200 /* the fine grained timeout in milliseconds */ #endif /* TCP_FAST_INTERVAL */ #ifndef TCP_SLOW_INTERVAL #define TCP_SLOW_INTERVAL 500 /* 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 */ #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 _offset_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(hdr) (ntohs((hdr)->_offset_flags) >> 8) #define TCPH_FLAGS(hdr) (ntohs((hdr)->_offset_flags) & 0xff) #define TCPH_OFFSET_SET(hdr, offset) (hdr)->_offset_flags = htons(((offset) << 8) | TCPH_FLAGS(hdr)) #define TCPH_FLAGS_SET(hdr, flags) (hdr)->_offset_flags = htons((TCPH_OFFSET(hdr) << 8) | (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 { struct tcp_pcb *next; /* for the linked list */ u8_t prio; void *callback_arg; struct ip_addr local_ip; u16_t local_port; enum tcp_state state; /* TCP state */ struct ip_addr remote_ip; u16_t remote_port; /* receiver varables */ 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 */ u8_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_RESET 0x08U /* Connection was reset. */ #define TF_CLOSED 0x10U /* Connection was sucessfully closed. */ #define TF_GOT_FIN 0x20U /* Connection was closed by the remote end. */ /* RTT estimation variables. */ u16_t rttest; /* RTT estimate in 500ms ticks */ u32_t rtseq; /* sequence number being timed */ s16_t sa, sv; 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 */ }; struct tcp_pcb_listen { struct tcp_pcb_listen *next; /* for the linked list */ u8_t prio; void *callback_arg; struct ip_addr local_ip; u16_t local_port; /* 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 */ #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 { \ 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 is used to repressent TCP segments when queued. */ 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); 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); int tcp_pcbs_sane(void); #else #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. */ extern struct tcp_pcb_listen *tcp_listen_pcbs; /* List of all TCP PCBs in LISTEN state. */ 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 {\ 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); \ 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()); \ 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__ */