Staging: dgrp: Refactor the function dgrp_receive() in drrp_net_ops.c
The function dgrp_receive() in dgrp_net_ops.c is too long and can be refactored. It uses various switch statements and goto labels. I have removed a label called data and tried to extract a new function out of it called as handle_data_in_packet(). This helps to make the code more modularize and simple to read and understand. Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Rashika Kheria
Greg Kroah-Hartman
parent
c79bfed605
commit
b73db54750
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@ -2232,6 +2232,177 @@ done:
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return rtn;
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}
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/*
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* Common Packet Handling code
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*/
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static void handle_data_in_packet(struct nd_struct *nd, struct ch_struct *ch,
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long dlen, long plen, int n1, u8 *dbuf)
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{
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char *error;
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long n;
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long remain;
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u8 *buf;
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u8 *b;
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remain = nd->nd_remain;
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nd->nd_tx_work = 1;
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/*
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* Otherwise data should appear only when we are
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* in the CS_READY state.
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*/
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if (ch->ch_state < CS_READY) {
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error = "Data received before RWIN established";
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nd->nd_remain = 0;
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nd->nd_state = NS_SEND_ERROR;
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nd->nd_error = error;
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}
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/*
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* Assure that the data received is within the
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* allowable window.
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*/
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n = (ch->ch_s_rwin - ch->ch_s_rin) & 0xffff;
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if (dlen > n) {
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error = "Receive data overrun";
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nd->nd_remain = 0;
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nd->nd_state = NS_SEND_ERROR;
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nd->nd_error = error;
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}
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/*
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* If we received 3 or less characters,
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* assume it is a human typing, and set RTIME
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* to 10 milliseconds.
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*
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* If we receive 10 or more characters,
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* assume its not a human typing, and set RTIME
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* to 100 milliseconds.
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*/
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if (ch->ch_edelay != DGRP_RTIME) {
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if (ch->ch_rtime != ch->ch_edelay) {
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ch->ch_rtime = ch->ch_edelay;
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ch->ch_flag |= CH_PARAM;
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}
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} else if (dlen <= 3) {
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if (ch->ch_rtime != 10) {
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ch->ch_rtime = 10;
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ch->ch_flag |= CH_PARAM;
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}
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} else {
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if (ch->ch_rtime != DGRP_RTIME) {
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ch->ch_rtime = DGRP_RTIME;
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ch->ch_flag |= CH_PARAM;
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}
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}
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/*
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* If a portion of the packet is outside the
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* buffer, shorten the effective length of the
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* data packet to be the amount of data received.
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*/
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if (remain < plen)
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dlen -= plen - remain;
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/*
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* Detect if receive flush is now complete.
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*/
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if ((ch->ch_flag & CH_RX_FLUSH) != 0 &&
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((ch->ch_flush_seq - nd->nd_seq_out) & SEQ_MASK) >=
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((nd->nd_seq_in - nd->nd_seq_out) & SEQ_MASK)) {
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ch->ch_flag &= ~CH_RX_FLUSH;
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}
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/*
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* If we are ready to receive, move the data into
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* the receive buffer.
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*/
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ch->ch_s_rin = (ch->ch_s_rin + dlen) & 0xffff;
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if (ch->ch_state == CS_READY &&
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(ch->ch_tun.un_open_count != 0) &&
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(ch->ch_tun.un_flag & UN_CLOSING) == 0 &&
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(ch->ch_cflag & CF_CREAD) != 0 &&
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(ch->ch_flag & (CH_BAUD0 | CH_RX_FLUSH)) == 0 &&
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(ch->ch_send & RR_RX_FLUSH) == 0) {
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if (ch->ch_rin + dlen >= RBUF_MAX) {
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n = RBUF_MAX - ch->ch_rin;
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memcpy(ch->ch_rbuf + ch->ch_rin, dbuf, n);
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ch->ch_rin = 0;
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dbuf += n;
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dlen -= n;
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}
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memcpy(ch->ch_rbuf + ch->ch_rin, dbuf, dlen);
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ch->ch_rin += dlen;
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/*
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* If we are not in fastcook mode, or
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* if there is a fastcook thread
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* waiting for data, send the data to
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* the line discipline.
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*/
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if ((ch->ch_flag & CH_FAST_READ) == 0 ||
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ch->ch_inwait != 0) {
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dgrp_input(ch);
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}
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/*
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* If there is a read thread waiting
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* in select, and we are in fastcook
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* mode, wake him up.
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*/
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if (waitqueue_active(&ch->ch_tun.un_tty->read_wait) &&
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(ch->ch_flag & CH_FAST_READ) != 0)
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wake_up_interruptible(&ch->ch_tun.un_tty->read_wait);
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/*
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* Wake any thread waiting in the
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* fastcook loop.
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*/
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if ((ch->ch_flag & CH_INPUT) != 0) {
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ch->ch_flag &= ~CH_INPUT;
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wake_up_interruptible(&ch->ch_flag_wait);
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}
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}
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/*
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* Fabricate and insert a data packet header to
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* preced the remaining data when it comes in.
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*/
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if (remain < plen) {
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dlen = plen - remain;
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b = buf;
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b[0] = 0x90 + n1;
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put_unaligned_be16(dlen, b + 1);
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remain = 3;
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if (remain > 0 && b != buf)
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memcpy(buf, b, remain);
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nd->nd_remain = remain;
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return;
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}
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}
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/**
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* dgrp_receive() -- decode data packets received from the remote PortServer.
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* @nd: pointer to a node structure
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@ -2306,7 +2477,8 @@ static void dgrp_receive(struct nd_struct *nd)
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plen = dlen + 1;
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dbuf = b + 1;
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goto data;
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handle_data_in_packet(nd, ch, dlen, plen, n1, dbuf);
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break;
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/*
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* Process 2-byte header data packet.
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@ -2320,7 +2492,8 @@ static void dgrp_receive(struct nd_struct *nd)
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plen = dlen + 2;
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dbuf = b + 2;
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goto data;
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handle_data_in_packet(nd, ch, dlen, plen, n1, dbuf);
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break;
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/*
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* Process 3-byte header data packet.
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@ -2335,159 +2508,6 @@ static void dgrp_receive(struct nd_struct *nd)
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dbuf = b + 3;
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/*
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* Common packet handling code.
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*/
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data:
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nd->nd_tx_work = 1;
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/*
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* Otherwise data should appear only when we are
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* in the CS_READY state.
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*/
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if (ch->ch_state < CS_READY) {
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error = "Data received before RWIN established";
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goto prot_error;
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}
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/*
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* Assure that the data received is within the
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* allowable window.
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*/
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n = (ch->ch_s_rwin - ch->ch_s_rin) & 0xffff;
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if (dlen > n) {
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error = "Receive data overrun";
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goto prot_error;
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}
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/*
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* If we received 3 or less characters,
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* assume it is a human typing, and set RTIME
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* to 10 milliseconds.
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*
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* If we receive 10 or more characters,
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* assume its not a human typing, and set RTIME
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* to 100 milliseconds.
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*/
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if (ch->ch_edelay != DGRP_RTIME) {
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if (ch->ch_rtime != ch->ch_edelay) {
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ch->ch_rtime = ch->ch_edelay;
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ch->ch_flag |= CH_PARAM;
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}
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} else if (dlen <= 3) {
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if (ch->ch_rtime != 10) {
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ch->ch_rtime = 10;
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ch->ch_flag |= CH_PARAM;
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}
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} else {
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if (ch->ch_rtime != DGRP_RTIME) {
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ch->ch_rtime = DGRP_RTIME;
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ch->ch_flag |= CH_PARAM;
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}
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}
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/*
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* If a portion of the packet is outside the
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* buffer, shorten the effective length of the
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* data packet to be the amount of data received.
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*/
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if (remain < plen)
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dlen -= plen - remain;
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/*
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* Detect if receive flush is now complete.
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*/
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if ((ch->ch_flag & CH_RX_FLUSH) != 0 &&
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((ch->ch_flush_seq - nd->nd_seq_out) & SEQ_MASK) >=
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((nd->nd_seq_in - nd->nd_seq_out) & SEQ_MASK)) {
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ch->ch_flag &= ~CH_RX_FLUSH;
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}
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/*
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* If we are ready to receive, move the data into
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* the receive buffer.
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*/
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ch->ch_s_rin = (ch->ch_s_rin + dlen) & 0xffff;
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if (ch->ch_state == CS_READY &&
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(ch->ch_tun.un_open_count != 0) &&
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(ch->ch_tun.un_flag & UN_CLOSING) == 0 &&
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(ch->ch_cflag & CF_CREAD) != 0 &&
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(ch->ch_flag & (CH_BAUD0 | CH_RX_FLUSH)) == 0 &&
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(ch->ch_send & RR_RX_FLUSH) == 0) {
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if (ch->ch_rin + dlen >= RBUF_MAX) {
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n = RBUF_MAX - ch->ch_rin;
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memcpy(ch->ch_rbuf + ch->ch_rin, dbuf, n);
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ch->ch_rin = 0;
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dbuf += n;
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dlen -= n;
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}
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memcpy(ch->ch_rbuf + ch->ch_rin, dbuf, dlen);
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ch->ch_rin += dlen;
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/*
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* If we are not in fastcook mode, or
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* if there is a fastcook thread
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* waiting for data, send the data to
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* the line discipline.
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*/
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if ((ch->ch_flag & CH_FAST_READ) == 0 ||
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ch->ch_inwait != 0) {
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dgrp_input(ch);
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}
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/*
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* If there is a read thread waiting
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* in select, and we are in fastcook
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* mode, wake him up.
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*/
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if (waitqueue_active(&ch->ch_tun.un_tty->read_wait) &&
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(ch->ch_flag & CH_FAST_READ) != 0)
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wake_up_interruptible(&ch->ch_tun.un_tty->read_wait);
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/*
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* Wake any thread waiting in the
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* fastcook loop.
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*/
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if ((ch->ch_flag & CH_INPUT) != 0) {
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ch->ch_flag &= ~CH_INPUT;
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wake_up_interruptible(&ch->ch_flag_wait);
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}
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}
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/*
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* Fabricate and insert a data packet header to
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* preced the remaining data when it comes in.
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*/
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if (remain < plen) {
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dlen = plen - remain;
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b = buf;
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b[0] = 0x90 + n1;
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put_unaligned_be16(dlen, b + 1);
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remain = 3;
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goto done;
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}
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break;
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/*
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