From b73db54750482cf3910046c82a84ce8c1684dfbe Mon Sep 17 00:00:00 2001 From: Rashika Kheria 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 Signed-off-by: Greg Kroah-Hartman --- 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 @@ done: 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; /* -- 2.30.2