#include?
#include?

#include?“protocol.h“
#include?“datalink.h“

#define?MAX_SEQ?31
#define?DATA_TIMER?3800//calculagraph?timer
#define?ACK_TIMER?1100
#define?NR_BUFS?16???//windows?number
#define?inc（k）if（k
typedef?enum{falsetrue}bool;
typedef?unsigned?char?seq_nr;//sequence?or?ack?number
typedef?struct{
	unsigned?char?info[PKT_LEN];
}packet;//packet?definition

static?int?phl_ready?=?0;

bool?no_nak=true;

typedef?struct?frame?{?
????unsigned?char?kind;?//?frame_DATA?
????seq_nr?ack;//acknowledgement?number
????seq_nr??seq;//sequence?number
????packet?data;?//the?network?layer?packet
????unsigned?int??padding;
}frame;

static?int?between（seq_nr?aseq_nr?bseq_nr?c）{
??????if（（a?<=?b?&&?b???????????return?true;
??????else
??????????return?false;?
}
//add?crc
static?void?put_frame（unsigned?char?*frame?int?len）
{
????*（unsigned?int?*）（frame?+?len）?=?crc32（frame?len）;
????send_frame（frame?len?+?4）;
????phl_ready?=?0;
}
//send?data?to?physical?layer
static?void?send_data（unsigned?char?fkseq_nr?frame_nrseq_nr?frame_expectedpacket?buffer[]）
{
????frame?s;
????s.kind?=?fk;
????s.seq?=?frame_nr;//insert?sequence?number?into?frame
????s.ack?=?（frame_expected+?MAX_SEQ）%（MAX_SEQ+1）;//piggyback?ack

	if（fk?==?frame_DATA）
		memcpy（s.data.info?buffer[frame_nr%NR_BUFS].info?PKT_LEN）;//insert?packet?into?frame
	
	if（fk?==?frame_NAK）
		no_nak?=?false;??//one?nak?per?frameplease

????dbg_frame（“Send?DATA?%d?%d?ID?%d\n“?s.seq?s.ack?*（short?*）s.data.info）;
	if?（fk?==?frame_DATA）
?????	put_frame（（unsigned?char?*）&s?3?+?PKT_LEN）;//put?CRC?following?the?frame	
	if（fk?==?frame_NAK||fk==frame_ACK）
		put_frame（（unsigned?char?*）&s?2）;//put?CRC?following?the?frame
????if（fk?==?frame_DATA）
		start_timer（frame_nr%NR_BUFS?DATA_TIMER）;
	stop_ack_timer（）;//no?need?for?separate?ack?frame
}

int?main（int?argc?char?**argv）{
????
	int?eventarglen=0;
????int?i;//contol?the?number?of?circle?of?arrived
????frame?r;//scratch?variable
????seq_nr?next_frame_to_send;//the?upper?of?the?send‘s?window
????seq_nr?ack_expected;//the?lower?of?the?send‘s?window
????seq_nr?frame_expected;//the?lower?of?the?reciver‘s?window
????seq_nr?too_far;//the?upper?of?the?reciver‘s?window
????seq_nr?nbuffered;//currently?window
????packet?out_buf[NR_BUFS];//buffer?for?the?outbound?stream
????packet?in_buf[NR_BUFS];//buffer?for?the?in?stream
????bool?arrived[NR_BUFS];
????
????enable_network_layer（）;
????//disable_network_layer（）;//allow?netword_layer_ready?events
????ack_expected?=?0;
????next_frame_to_send?=?0;
????frame_expected?=?0;
????too_far?=?NR_BUFS;
????nbuffered?=?0;??
????for（i?=?0;i?????????arrived[i]?=?false;

	protocol_init（argc?argv）;?
????lprintf（“Designed?by?chenchen_07415_071419?build:?“?__DATE__“??“__TIME__“\n\n“）;

????while（true）{
????????event?=?wait_for_event（&arg）;
?

?屬性????????????大小?????日期????時(shí)間???名稱
-----------?---------??----------?-----??----

?????文件??????47509??2009-12-01?14:32??數(shù)據(jù)鏈路層—選擇性重傳協(xié)議\datalink-A.log

?????文件??????59499??2009-12-01?14:32??數(shù)據(jù)鏈路層—選擇性重傳協(xié)議\datalink-B.log

?????文件???????6264??2009-12-01?19:03??數(shù)據(jù)鏈路層—選擇性重傳協(xié)議\datalink.c

?????文件???????3476??2009-10-19?16:46??數(shù)據(jù)鏈路層—選擇性重傳協(xié)議\datalink.dsp

?????文件????????524??2009-10-16?10:23??數(shù)據(jù)鏈路層—選擇性重傳協(xié)議\datalink.dsw

?????文件?????176162??2009-12-01?14:02??數(shù)據(jù)鏈路層—選擇性重傳協(xié)議\datalink.exe

?????文件????????518??2009-10-16?12:34??數(shù)據(jù)鏈路層—選擇性重傳協(xié)議\datalink.h

?????文件?????199324??2009-12-01?14:02??數(shù)據(jù)鏈路層—選擇性重傳協(xié)議\datalink.ilk

?????文件??????50176??2009-12-01?14:27??數(shù)據(jù)鏈路層—選擇性重傳協(xié)議\datalink.ncb

?????文件??????48640??2009-12-01?14:27??數(shù)據(jù)鏈路層—選擇性重傳協(xié)議\datalink.opt

?????文件?????427008??2009-12-01?14:02??數(shù)據(jù)鏈路層—選擇性重傳協(xié)議\datalink.pdb

?????文件???????1516??2009-12-01?14:02??數(shù)據(jù)鏈路層—選擇性重傳協(xié)議\datalink.plg

?????文件??????94208??2009-10-19?22:57??數(shù)據(jù)鏈路層—選擇性重傳協(xié)議\Protocol.dll

?????文件???????1831??2009-10-19?16:46??數(shù)據(jù)鏈路層—選擇性重傳協(xié)議\protocol.h

?????文件???????5932??2009-10-19?22:57??數(shù)據(jù)鏈路層—選擇性重傳協(xié)議\Protocol.lib

?????目錄??????????0??2010-01-02?12:54??數(shù)據(jù)鏈路層—選擇性重傳協(xié)議

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??????????????1122587????????????????????16