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Commit b73db547 authored by Rashika Kheria's avatar Rashika Kheria Committed by Greg Kroah-Hartman
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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: default avatarRashika Kheria <rashika.kheria@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent c79bfed6
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Inline Side-by-side
Showing with 175 additions and 155 deletions
drivers/staging/dgrp/dgrp_net_ops.c
View file @ b73db547
......@@ -2232,6 +2232,177 @@ static ssize_t dgrp_net_read(struct file *file, char __user *buf, size_t count,
return rtn;
}
/*
* Common Packet Handling code
*/
static void handle_data_in_packet(struct nd_struct *nd, struct ch_struct *ch,
long dlen, long plen, int n1, u8 *dbuf)
{
char *error;
long n;
long remain;
u8 *buf;
u8 *b;
remain = nd->nd_remain;
nd->nd_tx_work = 1;
/*
* Otherwise data should appear only when we are
* in the CS_READY state.
*/
if (ch->ch_state < CS_READY) {
error = "Data received before RWIN established";
nd->nd_remain = 0;
nd->nd_state = NS_SEND_ERROR;
nd->nd_error = error;
}
/*
* Assure that the data received is within the
* allowable window.
*/
n = (ch->ch_s_rwin - ch->ch_s_rin) & 0xffff;
if (dlen > n) {
error = "Receive data overrun";
nd->nd_remain = 0;
nd->nd_state = NS_SEND_ERROR;
nd->nd_error = error;
}
/*
* If we received 3 or less characters,
* assume it is a human typing, and set RTIME
* to 10 milliseconds.
*
* If we receive 10 or more characters,
* assume its not a human typing, and set RTIME
* to 100 milliseconds.
*/
if (ch->ch_edelay != DGRP_RTIME) {
if (ch->ch_rtime != ch->ch_edelay) {
ch->ch_rtime = ch->ch_edelay;
ch->ch_flag |= CH_PARAM;
}
} else if (dlen <= 3) {
if (ch->ch_rtime != 10) {
ch->ch_rtime = 10;
ch->ch_flag |= CH_PARAM;
}
} else {
if (ch->ch_rtime != DGRP_RTIME) {
ch->ch_rtime = DGRP_RTIME;
ch->ch_flag |= CH_PARAM;
}
}
/*
* If a portion of the packet is outside the
* buffer, shorten the effective length of the
* data packet to be the amount of data received.
*/
if (remain < plen)
dlen -= plen - remain;
/*
* Detect if receive flush is now complete.
*/
if ((ch->ch_flag & CH_RX_FLUSH) != 0 &&
((ch->ch_flush_seq - nd->nd_seq_out) & SEQ_MASK) >=
((nd->nd_seq_in - nd->nd_seq_out) & SEQ_MASK)) {
ch->ch_flag &= ~CH_RX_FLUSH;
}
/*
* If we are ready to receive, move the data into
* the receive buffer.
*/
ch->ch_s_rin = (ch->ch_s_rin + dlen) & 0xffff;
if (ch->ch_state == CS_READY &&
(ch->ch_tun.un_open_count != 0) &&
(ch->ch_tun.un_flag & UN_CLOSING) == 0 &&
(ch->ch_cflag & CF_CREAD) != 0 &&
(ch->ch_flag & (CH_BAUD0 | CH_RX_FLUSH)) == 0 &&
(ch->ch_send & RR_RX_FLUSH) == 0) {
if (ch->ch_rin + dlen >= RBUF_MAX) {
n = RBUF_MAX - ch->ch_rin;
memcpy(ch->ch_rbuf + ch->ch_rin, dbuf, n);
ch->ch_rin = 0;
dbuf += n;
dlen -= n;
}
memcpy(ch->ch_rbuf + ch->ch_rin, dbuf, dlen);
ch->ch_rin += dlen;
/*
* If we are not in fastcook mode, or
* if there is a fastcook thread
* waiting for data, send the data to
* the line discipline.
*/
if ((ch->ch_flag & CH_FAST_READ) == 0 ||
ch->ch_inwait != 0) {
dgrp_input(ch);
}
/*
* If there is a read thread waiting
* in select, and we are in fastcook
* mode, wake him up.
*/
if (waitqueue_active(&ch->ch_tun.un_tty->read_wait) &&
(ch->ch_flag & CH_FAST_READ) != 0)
wake_up_interruptible(&ch->ch_tun.un_tty->read_wait);
/*
* Wake any thread waiting in the
* fastcook loop.
*/
if ((ch->ch_flag & CH_INPUT) != 0) {
ch->ch_flag &= ~CH_INPUT;
wake_up_interruptible(&ch->ch_flag_wait);
}
}
/*
* Fabricate and insert a data packet header to
* preced the remaining data when it comes in.
*/
if (remain < plen) {
dlen = plen - remain;
b = buf;
b[0] = 0x90 + n1;
put_unaligned_be16(dlen, b + 1);
remain = 3;
if (remain > 0 && b != buf)
memcpy(buf, b, remain);
nd->nd_remain = remain;
return;
}
}
/**
* dgrp_receive() -- decode data packets received from the remote PortServer.
* @nd: pointer to a node structure
......@@ -2306,7 +2477,8 @@ static void dgrp_receive(struct nd_struct *nd)
plen = dlen + 1;
dbuf = b + 1;
goto data;
handle_data_in_packet(nd, ch, dlen, plen, n1, dbuf);
break;
/*
* Process 2-byte header data packet.
......@@ -2320,7 +2492,8 @@ static void dgrp_receive(struct nd_struct *nd)
plen = dlen + 2;
dbuf = b + 2;
goto data;
handle_data_in_packet(nd, ch, dlen, plen, n1, dbuf);
break;
/*
* Process 3-byte header data packet.
......@@ -2335,159 +2508,6 @@ static void dgrp_receive(struct nd_struct *nd)
dbuf = b + 3;
/*
* Common packet handling code.
*/
data:
nd->nd_tx_work = 1;
/*
* Otherwise data should appear only when we are
* in the CS_READY state.
*/
if (ch->ch_state < CS_READY) {
error = "Data received before RWIN established";
goto prot_error;
}
/*
* Assure that the data received is within the
* allowable window.
*/
n = (ch->ch_s_rwin - ch->ch_s_rin) & 0xffff;
if (dlen > n) {
error = "Receive data overrun";
goto prot_error;
}
/*
* If we received 3 or less characters,
* assume it is a human typing, and set RTIME
* to 10 milliseconds.
*
* If we receive 10 or more characters,
* assume its not a human typing, and set RTIME
* to 100 milliseconds.
*/
if (ch->ch_edelay != DGRP_RTIME) {
if (ch->ch_rtime != ch->ch_edelay) {
ch->ch_rtime = ch->ch_edelay;
ch->ch_flag |= CH_PARAM;
}
} else if (dlen <= 3) {
if (ch->ch_rtime != 10) {
ch->ch_rtime = 10;
ch->ch_flag |= CH_PARAM;
}
} else {
if (ch->ch_rtime != DGRP_RTIME) {
ch->ch_rtime = DGRP_RTIME;
ch->ch_flag |= CH_PARAM;
}
}
/*
* If a portion of the packet is outside the
* buffer, shorten the effective length of the
* data packet to be the amount of data received.
*/
if (remain < plen)
dlen -= plen - remain;
/*
* Detect if receive flush is now complete.
*/
if ((ch->ch_flag & CH_RX_FLUSH) != 0 &&
((ch->ch_flush_seq - nd->nd_seq_out) & SEQ_MASK) >=
((nd->nd_seq_in - nd->nd_seq_out) & SEQ_MASK)) {
ch->ch_flag &= ~CH_RX_FLUSH;
}
/*
* If we are ready to receive, move the data into
* the receive buffer.
*/
ch->ch_s_rin = (ch->ch_s_rin + dlen) & 0xffff;
if (ch->ch_state == CS_READY &&
(ch->ch_tun.un_open_count != 0) &&
(ch->ch_tun.un_flag & UN_CLOSING) == 0 &&
(ch->ch_cflag & CF_CREAD) != 0 &&
(ch->ch_flag & (CH_BAUD0 | CH_RX_FLUSH)) == 0 &&
(ch->ch_send & RR_RX_FLUSH) == 0) {
if (ch->ch_rin + dlen >= RBUF_MAX) {
n = RBUF_MAX - ch->ch_rin;
memcpy(ch->ch_rbuf + ch->ch_rin, dbuf, n);
ch->ch_rin = 0;
dbuf += n;
dlen -= n;
}
memcpy(ch->ch_rbuf + ch->ch_rin, dbuf, dlen);
ch->ch_rin += dlen;
/*
* If we are not in fastcook mode, or
* if there is a fastcook thread
* waiting for data, send the data to
* the line discipline.
*/
if ((ch->ch_flag & CH_FAST_READ) == 0 ||
ch->ch_inwait != 0) {
dgrp_input(ch);
}
/*
* If there is a read thread waiting
* in select, and we are in fastcook
* mode, wake him up.
*/
if (waitqueue_active(&ch->ch_tun.un_tty->read_wait) &&
(ch->ch_flag & CH_FAST_READ) != 0)
wake_up_interruptible(&ch->ch_tun.un_tty->read_wait);
/*
* Wake any thread waiting in the
* fastcook loop.
*/
if ((ch->ch_flag & CH_INPUT) != 0) {
ch->ch_flag &= ~CH_INPUT;
wake_up_interruptible(&ch->ch_flag_wait);
}
}
/*
* Fabricate and insert a data packet header to
* preced the remaining data when it comes in.
*/
if (remain < plen) {
dlen = plen - remain;
b = buf;
b[0] = 0x90 + n1;
put_unaligned_be16(dlen, b + 1);
remain = 3;
goto done;
}
break;
/*
......
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