/*发送请求函数，一次一般发送５个请求*/
void sendRequest(peer_t *peer,ReqState* state)
{
int i=0;
int r;
char sendbuf[MAXLINE];
//pthread_mutex_lock(&g_isSeed_lock); //做种后不需要再存分片
//i=g_isSeed;
//pthread_mutex_unlock(&g_isSeed_lock);
//if(i==2)return;
//int size=0;
while(i<1)
{
memset(sendbuf,0,MAXLINE);
if(state->index<0) //还未分配给该连接需要发送分片
{
state->index=getIndex(peer); //选择分片，该连接负责该分片，直到该分片完成
if(state->index<0)
{
//printf("没有请求可以发送\n");
break; //没有需要发送请求的分片
}
if(state->index==g_num_pieces-1) //最后一片，需要特殊处理
state->len=g_filelen-(g_num_pieces-1)*g_torrentmeta->piece_len;
else
state->len=g_torrentmeta->piece_len;
state->offset=0;
printf("请求分片：index:%d len:%d\n",state->index,state->len);
}
Head* h=(Head*)sendbuf;
h->len=reverse_byte_orderi(13);
h->id=0x06;
Request * req=(Request*)(sendbuf+HEAD_SIZE);
req->index=reverse_byte_orderi(state->index);
req->offset=reverse_byte_orderi(state->offset);
req->len=16384; //16k
if(state->offset+req->len>g_piece_state[state->index].len) //最后一片
req->len=g_piece_state[state->index].len-state->offset;
printf("send request sock:%d :index: %d offset: %d len:%d\n",peer->sockfd,state->index,state->offset,req->len);
state->offset+=req->len;
req->len=reverse_byte_orderi(req->len);
//printf("%d\n",req->len);
r=sendme(peer->sockfd,sendbuf,17);
if(r<=0)
printf("req send error\n");
if(state->offset>=g_piece_state[state->index].len) //该分片请求已经发完
state->index=-1;
i++;
}
}
/*告诉所有人我有了某个分片*/
void showPiece(int index)
{
char temp[9];
int len=reverse_byte_orderi(5);
char id=0x04;
int ind=reverse_byte_orderi(index);
memcpy(temp,&len,sizeof(int));
memcpy(temp+sizeof(int),&id,1);
memcpy(temp+sizeof(int)+1,&ind,sizeof(int));
pthread_mutex_lock(&all_peer_lock);
int i;
for(i=0;i<MAXPEER;i++)
{
if(myPeer[i].sockfd>=0)
sendme(myPeer[i].sockfd,temp,9);
}
pthread_mutex_unlock(&all_peer_lock);
}
/*向所有人发送某个分片的cancel*/
void publicCancel(int index){
char temp[17];
int len = reverse_byte_orderi(13);
char id = 0x08;
int ind = reverse_byte_orderi(index);
int begin = reverse_byte_orderi(0);
int length = reverse_byte_orderi(0);
memcpy(temp,&len,4);
memcpy(temp+4,&id,1);
memcpy(temp+5,&ind,4);
memcpy(temp+9,&begin,4);
memcpy(temp+13,&length,4);
pthread_mutex_lock(&all_peer_lock);
peer_t *p = all_peer;
while(p != NULL)
{
sendme(p->sockfd,temp,17);
p = p->next;
}
pthread_mutex_unlock(&all_peer_lock);
}
void sendPiece(int sockfd,int index,int offset,int len)
{
int i=reverse_byte_orderi(index);
int o=reverse_byte_orderi(offset);
int l=reverse_byte_orderi(len);
int size=l+HEAD_SIZE+2*sizeof(int);
char sendline[MAXLINE];
Head *head=(Head*)sendline;
head->len=reverse_byte_orderi(size-sizeof(int));
head->id=0x07;
Request *req=(Request*)(sendline+HEAD_SIZE);
req->index=index;
req->offset=offset;
pthread_mutex_lock(&g_f_lock);
fseek(g_f,i*g_torrentmeta->piece_len+o,SEEK_SET);
fread(sendline+HEAD_SIZE+2*sizeof(int),l,1,g_f);
pthread_mutex_unlock(&g_f_lock);
//memcpy(sendline+HEAD_SIZE+2*sizeof(int),g_filedata+i*g_torrentmeta->piece_len+o,l);
printf("send piece:sock:%d index %d offset %d len %d\n",sockfd,i,o,l);
int r=sendme(sockfd,sendline,size);
g_uploaded+=l;
if(r<=0)return;
}
void sendshkhdmsg(int sockfd)
{
printf("\033[34m""I will send shkhdmsg to somebody\n""\033[m");
unsigned char *shkhdmsg1;
unsigned char *current;
int msglen = 0;
shkhdmsg1 = (unsigned char* )malloc(HANDSHAKE_LEN);
current = shkhdmsg1;
int pstrlen = strlen(BT_PROTOCOL);
memcpy(current, (unsigned char*)&pstrlen, sizeof(int));
current += sizeof(int);
strncpy(current, BT_PROTOCOL, pstrlen);
current += pstrlen;
memset(current, 0, 8);
current += 8;
int i = 0;
for(; i < 5; i ++)
{
int j = 0;
int part = reverse_byte_orderi(g_infohash[i]);
unsigned char *p = (unsigned char*)∂
for(; j < 4; j ++)
{
*current++ = p[j];
}
}
for(i = 0; i < 20; i ++)
{
*current = g_my_id[i];
current ++;
}
msglen = current - shkhdmsg1;
send(sockfd, shkhdmsg1, msglen, 0);
free(shkhdmsg1);
shkhdmsg1 = NULL;
current = NULL;
}
// 制作一个发送给Tracker的HTTP请求. 使用一些全局变量来填充请求中的参数,
// 如info_hash, peer_id以及有多少字节已上传和下载, 等等.
//
// 事件: 0 - started, 1 - stopped, 2 - completed
// 这些宏的定义见头文件btdata.h
// 这个函数返回HTTP请求消息, 消息的长度写入mlen
char* make_tracker_request(int event, int* mlen)
{
// 分配一个很大的空间给MESG, 并填充它
char *MESG;
char* cur;
int i;
MESG = (char*)malloc(4096*sizeof(char));
cur = MESG;
strcpy(cur,"GET /announce?");
cur += strlen("GET /announce?");
// 填入info_hash
//char hexdigs[16] = {'0', '1', '2', '3', '4', '5', '6', '7',
// '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
strcpy(cur,"info_hash=");
cur += strlen("info_hash=");
for(i=0; i<5; i++)
{
int j;
int part = reverse_byte_orderi(g_infohash[i]);
unsigned char* p = (unsigned char*)∂
for(j=0; j<4; j++)
{
if((p[j] > 0x2F && p[j] < 0x3A) || (p[j] > 0x41 && p[j] < 0x5B) ||
(p[j] > 0x60 && p[j] < 0x7B))
{
*cur++ = p[j];
}
else
{
*cur++ = '%';
cur += sprintf(cur,"%02X",p[j]);
}
}
}
// Peer id
strcpy(cur,"&peer_id=");
cur += strlen("&peer_id=");
for(i=0; i<20; i++)
{
*cur++ = '%';
cur += sprintf(cur,"%02X",(unsigned char)g_my_id[i]);
}
// port
strcpy(cur,"&port=");
cur += strlen("&port=");
cur += sprintf(cur,"%d",g_peerport);
// ip
strcpy(cur,"&ip=");
cur += strlen("&ip=");
strcpy(cur,g_my_ip);
cur += strlen(g_my_ip);
// uploaded
strcpy(cur,"&uploaded=");
cur += strlen("&uploaded=");
cur += sprintf(cur,"%d",g_uploaded);
// downloaded
strcpy(cur,"&downloaded=");
cur += strlen("&downloaded=");
cur += sprintf(cur,"%d",g_downloaded);
// left
strcpy(cur,"&left=");
cur += strlen("&left=");
cur += sprintf(cur,"%d",g_left);
switch(event) {
case BT_STARTED:
strcpy(cur,"&event=");
cur += strlen("&event=");
strcpy(cur,"started");
cur += strlen("started");
break;
case BT_STOPPED:
strcpy(cur,"&event=");
cur += strlen("&event=");
strcpy(cur,"stopped");
cur += strlen("stopped");
break;
case BT_COMPLETED:
strcpy(cur,"&event=");
cur += strlen("&event=");
strcpy(cur,"completed");
cur += strlen("completed");
break;
// 除了上述情况以外, 不发送event参数
}
strcpy(cur," HTTP/1.1\r\n\r\n");
cur += strlen(" HTTP/1.1\r\n\r\n");
*cur = '\0';
*mlen = cur - MESG;
return MESG;
}
void *PToP(void *arg)
{
Head* head;
peer_t * peer=(peer_t *)arg;
peer->bitmap=malloc(mapcount); //记录该peer的bitfield
memset(peer->bitmap,0,mapcount);
int sockfd=peer->sockfd;
int i;
char rcvline[MAXLINE];
char sendline[MAXLINE];
char templine[MAXLINE];
char c;
memset(rcvline,0,MAXLINE);
memset(sendline,0,MAXLINE);
//啥话不说，先来一发
Hand* hk=(Hand*)sendline;
hk->len=0x13;
strcpy(hk->name,"BitTorrent protocol");
memset(hk->reserve,0,8);
int hash[5];
for(i=0;i<5;i++)
hash[i]=reverse_byte_orderi(g_infohash[i]);
memcpy(hk->sha,hash,20);
memcpy(hk->id,g_my_id,20);
sendme(sockfd,sendline,sizeof(Hand));
if(recvme(sockfd,rcvline,sizeof(Hand))<=0)
{
printf("握手失败\n");
{
shutdown(sockfd,SHUT_RDWR);
close(sockfd);
peer->sockfd=-1;
return NULL;
}
}
hk=(Hand*)rcvline;
/*if(memcmp(hash,hk->sha,20)!=0){
printf("hash 不匹配\n");
shutdown(sockfd,SHUT_RDWR);
close(sockfd);
peer->sockfd=-1;
return NULL;
}*/
memcpy(peer->name,hk->id,20);
//bitfield
pthread_mutex_lock(&g_isSeed_lock);
i=g_isSeed;
pthread_mutex_unlock(&g_isSeed_lock);
if(i==2)
{
memset(sendline,0,MAXLINE);
head=(Head*)sendline;
head->len=reverse_byte_orderi(mapcount+1);
head->id=0x05;
pthread_mutex_lock(&g_bitmap_lock);
memcpy(&sendline[HEAD_SIZE],g_bitmap,mapcount);
pthread_mutex_unlock(&g_bitmap_lock);
sendme(sockfd,sendline,HEAD_SIZE+mapcount);
}
Request* req;
int temp;
ReqState reqState;
reqState.index=-1;
reqState.offset=-1;
reqState.len=-1;
SaveState saveState;
saveState.index=-1;
saveState.offset=0;
int cancel=-1;
int errcount=0;
while(!g_done)
{
req=NULL;
memset(rcvline,0,MAXLINE);
memset(sendline,0,MAXLINE);
memset(templine,0,MAXLINE);
head=NULL;
i=recvme(sockfd,rcvline,sizeof(int));
if(peer->state||i<=0)
{
errcount++;
if(errcount>1)
{
printf("接受信息错误%d\n",peer->state);
shutdown(sockfd,SHUT_RDWR);
close(sockfd);
peer->sockfd=-1;
return NULL;
}
continue;
}
errcount=0;
head=(Head*)rcvline;
if(reverse_byte_orderi(head->len)<=0)continue; //keep alive
if(recvme(sockfd,rcvline+sizeof(int),1)<0)continue;
int load_len=reverse_byte_orderi(head->len)-1;
//printf("状态:%02X\n",head->id);
switch(head->id)
{
case 0x00: //choke
printf("被阻塞!\n");
head=(Head*)sendline;
head->len=reverse_byte_orderi(1);
head->id=0x02;
peer->have_interest=1;
sendme(sockfd,sendline,HEAD_SIZE);
break;
case 0x01: //unchoke
if(!peer->have_interest)break;
peer->choked=0;
sendRequest(peer,&reqState); //send request
break;
case 0x02: //interest
if(peer->choking)break;
cancel=-1;
peer->interested=1;
head=(Head*)sendline;
head->len=reverse_byte_orderi(1);
head->id=0x01; //unchoke
sendme(sockfd,sendline,HEAD_SIZE);
//等待对方的request
break;
case 0x03: //not interested
cancel=-1;
break;
case 0x04: //have
if(recvme(sockfd,templine,load_len)<=0)
continue;
memcpy(&temp,templine,sizeof(int));
temp=reverse_byte_orderi(temp);
pthread_mutex_lock(&g_bitmap_lock);
c=g_bitmap[temp/8];
pthread_mutex_unlock(&g_bitmap_lock);
if(isSet(c,8-temp%8))continue;
head=(Head*)sendline;
head->len=reverse_byte_orderi(1);
head->id=0x02;
sendme(sockfd,sendline,HEAD_SIZE);
break;
case 0x05: //bitfield
if(recvme(sockfd,templine,load_len)<=0)
continue;
if(load_len!=mapcount)
{
shutdown(sockfd,SHUT_RDWR);
close(sockfd);
peer->sockfd=-1;
return NULL;
}
memcpy(peer->bitmap,templine,mapcount);
i=needThis(peer->bitmap); //判断是否有需要该用户,需要记录该用户提供了那些分片
//printf("是否需要该用户%d\n",i);
if(i==0)
{
shutdown(sockfd,SHUT_RDWR);
close(sockfd);
peer->sockfd=-1;
return NULL;
}
else if(i==1)break; //不感兴趣
//send interest
head=(Head*)sendline;
head->len=reverse_byte_orderi(1);
head->id=0x02;
peer->have_interest=1;
sendme(sockfd,sendline,HEAD_SIZE);
break;
case 0x06: //request
if(recvme(sockfd,templine,load_len)<=0)
continue;
req=(Request *)templine;
if(reverse_byte_orderi(req->len)>131072) //2^17
{
shutdown(sockfd,SHUT_RDWR);
close(sockfd);
peer->sockfd=-1;
return NULL;
}
if(cancel==reverse_byte_orderi(req->index)){
cancel=-1;
continue;
}
sendPiece(sockfd,req->index,req->offset,req->len); //发送子分片
break;
case 0x07: //piece
if(recvme(sockfd,templine,load_len)<=0)
continue;
//printf("load len :%d\n",i);
req=(Request *)templine;
/*for(i=0;i<8;i++)
{
for(temp=0;temp<8;temp++)
printf("%02X ",templine[i*8+temp]);
printf("\n");
}*/
savePiece(reverse_byte_orderi(req->index),reverse_byte_orderi(req->offset),templine+2*sizeof(int),load_len-2*sizeof(int),&saveState); //存储分片:w
sendRequest(peer,&reqState);
break;
case 0x08: //cancel
if(recvme(sockfd,templine,load_len)<=0)continue;
req=(Request*)templine;
cancel=reverse_byte_orderi(req->index);
break;
default:
;//printf("没有该状态%02X\n",head->id);return NULL;
}
}
shutdown(sockfd,SHUT_RDWR);
close(sockfd);
peer->sockfd=-1;
return NULL;
}
void *peer_deal(void *i)
{
struct param_list *my_param = (struct param_list *)i;
int sockfd = my_param->sockfd;
int close_bit = 1;
printf("Child created for dealing with client request\n");
char *buf = (char *)malloc(HANDSHAKE_LEN);
memset(buf,0,HANDSHAKE_LEN);
int n;
while(n=recv(sockfd,buf,HANDSHAKE_LEN,0) > 0)
{
struct handshake_packet *my_packet = (struct handshake_packet *)buf;
if(my_packet->len != strlen(BT_PROTOCOL))
{
printf("len is not match\n");
break;
}
if(strncmp(my_packet->name,BT_PROTOCOL,strlen(BT_PROTOCOL)) != 0)
{
printf("BT_PROTOCOL is not match\n");
break;
}
int i = 0,flag = 1;
unsigned char *buf_info = my_packet->info_hash;
for(; i<5; i++)
{
int j = 0;
int part = reverse_byte_orderi(g_infohash[i]);
unsigned char *p = (unsigned char *)∂
for(; j<4; j++)
{
if(*buf_info != p[j])
{
printf("buf_info is %x and p[j] is %x\n",*buf_info,p[j]);
flag = 0;
goto END;
}
buf_info ++;
}
}
END:
if(flag != 1)
{
printf("\033[33m buf_info is not match\n \033[m");
break;
}
printf("waiting client get info\n");
//sleep(10); //这里是为了等客户端向tracker服务器发送更新请求报文
//这里需要上锁
pthread_mutex_lock(&g_mutex);
for(i=0; i<MAXPEERS; i++)
{
//printf("peers_pool[i].id is %s and my_packet->peer_id is %s\n",peers_pool[i].id,my_packet->peer_id);
if(peers_pool[i].used == 1 && strncmp(peers_pool[i].ip,my_param->ip,strlen(my_param->ip)) == 0)
{
printf("find you\n");
break;
}
}
pthread_mutex_unlock(&g_mutex);
if(i == MAXPEERS || peers_pool[i].sockfd > 0)
{
printf("not you\n");
break;
}
printf("i is %d\n",i);
pthread_mutex_lock(&peers_pool[i].sock_mutex);
if(peers_pool[i].status == 1)
{
pthread_mutex_unlock(&peers_pool[i].sock_mutex);
printf("I already some shake hand to peer\n");
break;
}
peers_pool[i].status = 2;
peers_pool[i].sockfd = sockfd;
memcpy(peers_pool[i].id,my_packet->peer_id,20);
printf("peers_pool 0 status is %d in listen_peers\n",peers_pool[0].status);
pthread_mutex_unlock(&peers_pool[i].sock_mutex);
//这里开始向对方返回握手信息
printf("send handshake packet return \n");
memcpy(my_packet->peer_id,g_my_id,20);
send(sockfd,buf,HANDSHAKE_LEN,0);
close_bit = 0;
pthread_t thread;
int rc = pthread_create(&thread, NULL, recv_from_peer, (void *)i);
if(rc)
{
printf("Error, return code from pthread_create() is %d\n", rc);
exit(-1);
}
printf("shake hands succeed\n");
//sleep(10); //等一会
sendBitField(sockfd);
pthread_t thread_1;
pthread_create(&thread_1, NULL, check_and_keepalive, (void*)i);
break;
}
if(n<0)
{
printf("%s\n",strerror(errno));
}
if(close_bit)
close(sockfd);
free(buf);
}