From b73db54750482cf3910046c82a84ce8c1684dfbe Mon Sep 17 00:00:00 2001
From: Rashika Kheria <rashika.kheria@gmail.com>
Date: Mon, 11 Nov 2013 11:52:31 +0530
Subject: [PATCH] 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>
---
drivers/staging/dgrp/dgrp_net_ops.c | 330 +++++++++++++++-------------
1 file changed, 175 insertions(+), 155 deletions(-)
diff --git a/drivers/staging/dgrp/dgrp_net_ops.c b/drivers/staging/dgrp/dgrp_net_ops.c
index 33ac7fb88cbd..1f61b89eca44 100644
--- a/drivers/staging/dgrp/dgrp_net_ops.c
+++ b/drivers/staging/dgrp/dgrp_net_ops.c
@@ -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;
/*