tcp.c

minix3的源代码

				i<TCP_CONN_NR; i++, tcp_conn++)
			{
				if (!(tcp_conn->tc_flags & TCF_INUSE))
					continue;
				if (tcp_conn->tc_port != tcp_port)
					continue;
				tcp_conn->tc_locaddr= ipaddr;
			}
		}
		else
			DBLOCK(1, printf("tcp_put_pkt: no TCP header\n"));
		bf_afree(data);
		return;
	}
	data->acc_linkC++;
	ip_pack= data;
	ip_pack= bf_align(ip_pack, ip_hdr_len, 4);
	ip_hdr= (ip_hdr_t *)ptr2acc_data(ip_pack);
	data= bf_delhead(data, ip_hdr_len);

	/* Compute the checksum */
	sum= tcp_pack_oneCsum(ip_hdr, data);

	/* Extract the TCP header */
	if (ip_datalen < TCP_MIN_HDR_SIZE)
	{
		DBLOCK(1, printf("truncated TCP header\n"));
		bf_afree(ip_pack);
		bf_afree(data);
		return;
	}
	data= bf_packIffLess(data, TCP_MIN_HDR_SIZE);
	tcp_hdr= (tcp_hdr_t *)ptr2acc_data(data);
	tcp_hdr_len= (tcp_hdr->th_data_off & TH_DO_MASK) >> 2;
		/* actualy (>> 4) << 2 */
	if (ip_datalen < tcp_hdr_len || tcp_hdr_len < TCP_MIN_HDR_SIZE)
	{
		if (tcp_hdr_len < TCP_MIN_HDR_SIZE)
		{
			DBLOCK(1, printf("strange tcp header length %d\n",
				tcp_hdr_len));
		}
		else
		{
			DBLOCK(1, printf("truncated TCP header\n"));
		}
		bf_afree(ip_pack);
		bf_afree(data);
		return;
	}
	data->acc_linkC++;
	tcp_pack= data;
	tcp_pack= bf_align(tcp_pack, tcp_hdr_len, 4);
	tcp_hdr= (tcp_hdr_t *)ptr2acc_data(tcp_pack);
	if (ip_datalen == tcp_hdr_len)
	{
		bf_afree(data);
		data= NULL;
	}
	else
		data= bf_delhead(data, tcp_hdr_len);
	tcp_datalen= ip_datalen-tcp_hdr_len;

	if ((u16_t)~sum)
	{
		DBLOCK(1, printf("checksum error in tcp packet\n");
			printf("tcp_pack_oneCsum(...)= 0x%x length= %d\n", 
			(u16_t)~sum, tcp_datalen);
			printf("src ip_addr= "); writeIpAddr(ip_hdr->ih_src);
			printf("\n"));
		bf_afree(ip_pack);
		bf_afree(tcp_pack);
		bf_afree(data);
		return;
	}

	srcaddr= ip_hdr->ih_src;
	dstaddr= ip_hdr->ih_dst;
	srcport= tcp_hdr->th_srcport;
	dstport= tcp_hdr->th_dstport;
	bits= srcaddr ^ dstaddr ^ srcport ^ dstport;
	bits= (bits >> 16) ^ bits;
	bits= (bits >> 8) ^ bits;
	hash= ((bits >> TCP_CONN_HASH_SHIFT) ^ bits) & (TCP_CONN_HASH_NR-1);
	conn_p= tcp_port->tp_conn_hash[hash];
	if (conn_p[0]->tc_locport == dstport &&
		conn_p[0]->tc_remport == srcport &&
		conn_p[0]->tc_remaddr == srcaddr &&
		conn_p[0]->tc_locaddr == dstaddr)
	{
		tcp_conn= conn_p[0];
	}
	else if (conn_p[1]->tc_locport == dstport &&
		conn_p[1]->tc_remport == srcport &&
		conn_p[1]->tc_remaddr == srcaddr &&
		conn_p[1]->tc_locaddr == dstaddr)
	{
		tcp_conn= conn_p[1];
		conn_p[1]= conn_p[0];
		conn_p[0]= tcp_conn;
	}
	else if (conn_p[2]->tc_locport == dstport &&
		conn_p[2]->tc_remport == srcport &&
		conn_p[2]->tc_remaddr == srcaddr &&
		conn_p[2]->tc_locaddr == dstaddr)
	{
		tcp_conn= conn_p[2];
		conn_p[2]= conn_p[1];
		conn_p[1]= conn_p[0];
		conn_p[0]= tcp_conn;
	}
	else if (conn_p[3]->tc_locport == dstport &&
		conn_p[3]->tc_remport == srcport &&
		conn_p[3]->tc_remaddr == srcaddr &&
		conn_p[3]->tc_locaddr == dstaddr)
	{
		tcp_conn= conn_p[3];
		conn_p[3]= conn_p[2];
		conn_p[2]= conn_p[1];
		conn_p[1]= conn_p[0];
		conn_p[0]= tcp_conn;
	}
	else
		tcp_conn= NULL;
	if ((tcp_conn != NULL && tcp_conn->tc_state == TCS_CLOSED) ||
		(tcp_hdr->th_flags & THF_SYN))
	{
		tcp_conn= NULL;
	}

	if (tcp_conn == NULL)
	{
		tcp_conn= find_best_conn(ip_hdr, tcp_hdr);
		if (!tcp_conn)
		{
			/* listen backlog hack */
			bf_afree(ip_pack);
			bf_afree(tcp_pack);
			bf_afree(data);
			return;
		}
		if (tcp_conn->tc_state != TCS_CLOSED)
		{
			conn_p[3]= conn_p[2];
			conn_p[2]= conn_p[1];
			conn_p[1]= conn_p[0];
			conn_p[0]= tcp_conn;
		}
	}
	assert(tcp_conn->tc_busy == 0);
	tcp_conn->tc_busy++;
	tcp_frag2conn(tcp_conn, ip_hdr, tcp_hdr, data, tcp_datalen);
	tcp_conn->tc_busy--;
	bf_afree(ip_pack);
	bf_afree(tcp_pack);
}


PUBLIC int tcp_open (port, srfd, get_userdata, put_userdata, put_pkt,
	select_res)
int port;
int srfd;
get_userdata_t get_userdata;
put_userdata_t put_userdata;
put_pkt_t put_pkt;
select_res_t select_res;
{
	int i, j;

	tcp_fd_t *tcp_fd;

	for (i=0; i<TCP_FD_NR && (tcp_fd_table[i].tf_flags & TFF_INUSE);
		i++);
	if (i>=TCP_FD_NR)
	{
		return EAGAIN;
	}

	tcp_fd= &tcp_fd_table[i];

	tcp_fd->tf_flags= TFF_INUSE;
	tcp_fd->tf_flags |= TFF_PUSH_DATA;

	tcp_fd->tf_port= &tcp_port_table[port];
	tcp_fd->tf_srfd= srfd;
	tcp_fd->tf_tcpconf.nwtc_flags= TCP_DEF_CONF;
	tcp_fd->tf_tcpconf.nwtc_remaddr= 0;
	tcp_fd->tf_tcpconf.nwtc_remport= 0;
	tcp_fd->tf_tcpopt.nwto_flags= TCP_DEF_OPT;
	tcp_fd->tf_get_userdata= get_userdata;
	tcp_fd->tf_put_userdata= put_userdata;
	tcp_fd->tf_select_res= select_res;
	tcp_fd->tf_conn= 0;
	for (j= 0; j<TFL_LISTEN_MAX; j++)
		tcp_fd->tf_listenq[j]= NULL;
	return i;
}

/*
tcp_ioctl
*/
PUBLIC int tcp_ioctl (fd, req)
int fd;
ioreq_t req;
{
	tcp_fd_t *tcp_fd;
	tcp_port_t *tcp_port;
	tcp_conn_t *tcp_conn;
	nwio_tcpconf_t *tcp_conf;
	nwio_tcpopt_t *tcp_opt;
	tcp_cookie_t *cookiep;
	acc_t *acc, *conf_acc, *opt_acc;
	int result, *bytesp;
	u8_t rndbits[RAND256_BUFSIZE];

	tcp_fd= &tcp_fd_table[fd];

	assert (tcp_fd->tf_flags & TFF_INUSE);

	tcp_port= tcp_fd->tf_port;
	tcp_fd->tf_flags |= TFF_IOCTL_IP;
	tcp_fd->tf_ioreq= req;

	if (tcp_port->tp_state != TPS_MAIN)
	{
		tcp_fd->tf_flags |= TFF_IOC_INIT_SP;
		return NW_SUSPEND;
	}

	switch (req)
	{
	case NWIOSTCPCONF:
		if ((tcp_fd->tf_flags & TFF_CONNECTEDx) ||
			(tcp_fd->tf_flags & TFF_CONNECTING) ||
			(tcp_fd->tf_flags & TFF_LISTENQ))
		{
			tcp_fd->tf_flags &= ~TFF_IOCTL_IP;
			reply_thr_get (tcp_fd, EISCONN, TRUE);
			result= NW_OK;
			break;
		}
		result= tcp_setconf(tcp_fd);
		break;
	case NWIOGTCPCONF:
		conf_acc= bf_memreq(sizeof(*tcp_conf));
assert (conf_acc->acc_length == sizeof(*tcp_conf));
		tcp_conf= (nwio_tcpconf_t *)ptr2acc_data(conf_acc);

		*tcp_conf= tcp_fd->tf_tcpconf;
		if (tcp_fd->tf_flags & TFF_CONNECTEDx)
		{
			tcp_conn= tcp_fd->tf_conn;
			tcp_conf->nwtc_locport= tcp_conn->tc_locport;
			tcp_conf->nwtc_remaddr= tcp_conn->tc_remaddr;
			tcp_conf->nwtc_remport= tcp_conn->tc_remport;
		}
		tcp_conf->nwtc_locaddr= tcp_fd->tf_port->tp_ipaddr;
		result= (*tcp_fd->tf_put_userdata)(tcp_fd->tf_srfd,
			0, conf_acc, TRUE);
		tcp_fd->tf_flags &= ~TFF_IOCTL_IP;
		reply_thr_put(tcp_fd, result, TRUE);
		result= NW_OK;
		break;
	case NWIOSTCPOPT:
		result= tcp_setopt(tcp_fd);
		break;
	case NWIOGTCPOPT:
		opt_acc= bf_memreq(sizeof(*tcp_opt));
		assert (opt_acc->acc_length == sizeof(*tcp_opt));
		tcp_opt= (nwio_tcpopt_t *)ptr2acc_data(opt_acc);

		*tcp_opt= tcp_fd->tf_tcpopt;
		result= (*tcp_fd->tf_put_userdata)(tcp_fd->tf_srfd,
			0, opt_acc, TRUE);
		tcp_fd->tf_flags &= ~TFF_IOCTL_IP;
		reply_thr_put(tcp_fd, result, TRUE);
		result= NW_OK;
		break;
	case NWIOTCPCONN:
		if (tcp_fd->tf_flags & TFF_CONNECTING)
		{
			tcp_fd->tf_flags &= ~TFF_IOCTL_IP;
			reply_thr_get (tcp_fd, EALREADY, TRUE);
			result= NW_OK;
			break;
		}
		if (tcp_fd->tf_flags & TFF_CONNECTEDx)
		{
			tcp_fd->tf_flags &= ~TFF_IOCTL_IP;
			reply_thr_get (tcp_fd, EISCONN, TRUE);
			result= NW_OK;
			break;
		}
		result= tcp_connect(tcp_fd);
		if (result == NW_OK)
			tcp_fd->tf_flags &= ~TFF_IOCTL_IP;
		break;
	case NWIOTCPLISTEN:
	case NWIOTCPLISTENQ:
		if ((tcp_fd->tf_flags & TFF_CONNECTEDx) ||
			(tcp_fd->tf_flags & TFF_LISTENQ) ||
			(tcp_fd->tf_flags & TFF_CONNECTING))
		{
			tcp_fd->tf_flags &= ~TFF_IOCTL_IP;
			reply_thr_get (tcp_fd, EISCONN, TRUE);
			result= NW_OK;
			break;
		}
		result= tcp_listen(tcp_fd, (req == NWIOTCPLISTENQ));
		break;
	case NWIOTCPSHUTDOWN:
		if (!(tcp_fd->tf_flags & TFF_CONNECTEDx))
		{
			tcp_fd->tf_flags &= ~TFF_IOCTL_IP;
			reply_thr_get (tcp_fd, ENOTCONN, TRUE);
			result= NW_OK;
			break;
		}
		tcp_fd->tf_flags |= TFF_IOCTL_IP;
		tcp_fd->tf_ioreq= req;
		tcp_conn= tcp_fd->tf_conn;

		tcp_conn->tc_busy++;
		tcp_fd_write(tcp_conn);
		tcp_conn->tc_busy--;
		tcp_conn_write(tcp_conn, 0);
		if (!(tcp_fd->tf_flags & TFF_IOCTL_IP))
			result= NW_OK;
		else
			result= NW_SUSPEND;
		break;
	case NWIOTCPPUSH:
		if (!(tcp_fd->tf_flags & TFF_CONNECTEDx))
		{
			tcp_fd->tf_flags &= ~TFF_IOCTL_IP;
			reply_thr_get (tcp_fd, ENOTCONN, TRUE);
			result= NW_OK;
			break;
		}
		tcp_conn= tcp_fd->tf_conn;
		tcp_conn->tc_SND_PSH= tcp_conn->tc_SND_NXT;
		tcp_conn->tc_flags &= ~TCF_NO_PUSH;
		tcp_conn->tc_flags |= TCF_PUSH_NOW;

		/* Start the timer (if necessary) */
		if (tcp_conn->tc_SND_TRM == tcp_conn->tc_SND_UNA)
			tcp_set_send_timer(tcp_conn);

		tcp_conn_write(tcp_conn, 0);
		tcp_fd->tf_flags &= ~TFF_IOCTL_IP;
		reply_thr_get (tcp_fd, NW_OK, TRUE);
		result= NW_OK;
		break;
	case NWIOGTCPCOOKIE:
		if (!(tcp_fd->tf_flags & TFF_COOKIE))
		{
			tcp_fd->tf_cookie.tc_ref= fd;
			rand256(rndbits);
			assert(sizeof(tcp_fd->tf_cookie.tc_secret) <=
				RAND256_BUFSIZE);
			memcpy(tcp_fd->tf_cookie.tc_secret, 
				rndbits, sizeof(tcp_fd->tf_cookie.tc_secret));
			tcp_fd->tf_flags |= TFF_COOKIE;
		}
		acc= bf_memreq(sizeof(*cookiep));
		cookiep= (tcp_cookie_t *)ptr2acc_data(acc);

		*cookiep= tcp_fd->tf_cookie;
		result= (*tcp_fd->tf_put_userdata)(tcp_fd->tf_srfd,
			0, acc, TRUE);
		tcp_fd->tf_flags &= ~TFF_IOCTL_IP;
		reply_thr_put(tcp_fd, result, TRUE);
		result= NW_OK;
		break;
	case NWIOTCPACCEPTTO:
		result= tcp_acceptto(tcp_fd);
		break;
	case FIONREAD:
		acc= bf_memreq(sizeof(*bytesp));
		bytesp= (int *)ptr2acc_data(acc);
		tcp_bytesavailable(tcp_fd, bytesp);
		result= (*tcp_fd->tf_put_userdata)(tcp_fd->tf_srfd,
			0, acc, TRUE);
		tcp_fd->tf_flags &= ~TFF_IOCTL_IP;
		reply_thr_put(tcp_fd, result, TRUE);
		result= NW_OK;
		break;

	default:
		tcp_fd->tf_flags &= ~TFF_IOCTL_IP;
		reply_thr_get(tcp_fd, EBADIOCTL, TRUE);
		result= NW_OK;
		break;
	}
	return result;
}


/*
tcp_setconf
*/

PRIVATE int tcp_setconf(tcp_fd)
tcp_fd_t *tcp_fd;
{
	nwio_tcpconf_t *tcpconf;
	nwio_tcpconf_t oldconf, newconf;
	acc_t *data;
	tcp_fd_t *fd_ptr;
	unsigned int new_en_flags, new_di_flags,
		old_en_flags, old_di_flags, all_flags, flags;
	int i;

	data= (*tcp_fd->tf_get_userdata)
		(tcp_fd->tf_srfd, 0,
		sizeof(nwio_tcpconf_t), TRUE);

	if (!data)
		return EFAULT;

	data= bf_packIffLess(data, sizeof(nwio_tcpconf_t));
assert (data->acc_length == sizeof(nwio_tcpconf_t));

	tcpconf= (nwio_tcpconf_t *)ptr2acc_data(data);
	oldconf= tcp_fd->tf_tcpconf;
	newconf= *tcpconf;

	old_en_flags= oldconf.nwtc_flags & 0xffff;
	old_di_flags= (oldconf.nwtc_flags >> 16) &
		0xffff;
	new_en_flags= newconf.nwtc_flags & 0xffff;
	new_di_flags= (newconf.nwtc_flags >> 16) &
		0xffff;
	if (new_en_flags & new_di_flags)
	{
		tcp_fd->tf_flags &= ~TFF_IOCTL_IP;
		reply_thr_get(tcp_fd, EBADMODE, TRUE);
		bf_afree(data);
		return NW_OK;
	}

	/* NWTC_ACC_MASK */
	if (new_di_flags & NWTC_ACC_MASK)
	{
		tcp_fd->tf_flags &= ~TFF_IOCTL_IP;
		reply_thr_get(tcp_fd, EBADMODE, TRUE);
		bf_afree(data);
		return NW_OK;
		/* access modes can't be disabled */
	}

	if (!(new_en_flags & NWTC_ACC_MASK))
		new_en_flags |= (old_en_flags & NWTC_ACC_MASK);
	
	/* NWTC_LOCPORT_MASK */
	if (new_di_flags & NWTC_LOCPORT_MASK)
	{
		tcp_fd->tf_flags &= ~TFF_IOCTL_IP;
		reply_thr_get(tcp_fd, EBADMODE, TRUE);
		bf_afree(data);
		return NW_OK;
		/* the loc ports can't be disabled */
	}
	if (!(new_en_flags & NWTC_LOCPORT_MASK))
	{
		new_en_flags |= (old_en_flags &
			NWTC_LOCPORT_MASK);
		newconf.nwtc_locport= oldconf.nwtc_locport;
	}
	else if ((new_en_flags & NWTC_LOCPORT_MASK) == NWTC_LP_SEL)
	{
		newconf.nwtc_locport= find_unused_port(tcp_fd-
			tcp_fd_table);
	}
	else if ((new_en_flags & NWTC_LOCPORT_MASK) == NWTC_LP_SET)
	{
		if (!newconf.nwtc_locport)
		{
			tcp_fd->tf_flags &= ~TFF_IOCTL_IP;
			reply_thr_get(tcp_fd, EBADMODE, TRUE);
			bf_afree(data);
			return NW_OK;
		}
	}
	
	/* NWTC_REMADDR_MASK */
	if (!((new_en_flags | new_di_flags) &
		NWTC_REMADDR_MASK))
	{
		new_en_flags |= (old_en_flags &
			NWTC_REMADDR_MASK);
		new_di_flags |= (old_di_flags &
			NWTC_REMADDR_MASK);
		newconf.nwtc_remaddr= oldconf.nwtc_remaddr;
	}
	else if (new_en_flags & NWTC_SET_RA)
	{
		if (!newconf.nwtc_remaddr)
		{
			tcp_fd->tf_flags &= ~TFF_IOCTL_IP;
			reply_thr_get(tcp_fd, EBADMODE, TRUE);
			bf_afree(data);
			return NW_OK;
		}
	}
	else
	{
assert (new_di_flags & NWTC_REMADDR_MASK);
		newconf.nwtc_remaddr= 0;
	}

	/* NWTC_REMPORT_MASK */
	if (!((new_en_flags | new_di_flags) & NWTC_REMPORT_MASK))
	{
		new_en_flags |= (old_en_flags &
			NWTC_REMPORT_MASK);
		new_di_flags |= (old_di_flags &
			NWTC_REMPORT_MASK);
		newconf.nwtc_remport=
			oldconf.nwtc_remport;
	}
	else if (new_en_flags & NWTC_SET_RP)
	{
		if (!newconf.nwtc_remport)
		{
			tcp_fd->tf_flags &= ~TFF_IOCTL_IP;
			reply_thr_get(tcp_fd, EBADMODE, TRUE);
			bf_afree(data);
			return NW_OK;
		}
	}
	else
	{
assert (new_di_flags & NWTC_REMPORT_MASK);
		newconf.nwtc_remport= 0;
	}