Commit 59348b19 authored by Gerrit Renker's avatar Gerrit Renker Committed by David S. Miller
Browse files

[DCCP]: Simplified conditions due to use of enum:8 states 



This reaps the benefit of the earlier patch, which changed the type of
CCID 3 states to use enums, in that many conditions are now simplified
and the number of possible (unexpected) values is greatly reduced.

In a few instances, this also allowed to simplify pre-conditions; where
care has been taken to retain logical equivalence.

[DCCP]: Introduce a consistent BUG/WARN message scheme

This refines the existing set of DCCP messages so that
 * BUG(), BUG_ON(), WARN_ON() have meaningful DCCP-specific counterparts
 * DCCP_CRIT (for severe warnings) is not rate-limited
 * DCCP_WARN() is introduced as rate-limited wrapper

Using these allows a faster and cleaner transition to their original
counterparts once the code has matured into a full DCCP implementation.

Signed-off-by: default avatarGerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@mandriva.com>
parent b1308dc0

net/dccp/ackvec.c

+1 −4
Original line number Diff line number Diff line
@@ -461,9 +461,6 @@ int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb, 
	return 0;

}



static char dccp_ackvec_slab_msg[] __initdata =

	KERN_CRIT "DCCP: Unable to create ack vectors slab caches\n";



int __init dccp_ackvec_init(void)

{

	dccp_ackvec_slab = kmem_cache_create("dccp_ackvec",
@@ -485,7 +482,7 @@ int __init dccp_ackvec_init(void) 
	kmem_cache_destroy(dccp_ackvec_slab);

	dccp_ackvec_slab = NULL;

out_err:

	printk(dccp_ackvec_slab_msg);

	DCCP_CRIT("Unable to create Ack Vector slab cache");

	return -ENOBUFS;

}

net/dccp/ccids/ccid2.c

+1 −1
Original line number Diff line number Diff line
@@ -420,7 +420,7 @@ static int ccid2_ackvector(struct sock *sk, struct sk_buff *skb, int offset, 
	return -1;



out_invalid_option:

	BUG_ON(1); /* should never happen... options were previously parsed ! */

	DCCP_BUG("Invalid option - this should not happen (previous parsing)!");

	return -1;

}

net/dccp/ccids/ccid3.c

+55 −77
Original line number Diff line number Diff line
@@ -176,8 +176,6 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data) 
		       ccid3_tx_state_name(hctx->ccid3hctx_state));

	

	switch (hctx->ccid3hctx_state) {

	case TFRC_SSTATE_TERM:

		goto out;

	case TFRC_SSTATE_NO_FBACK:

		/* Halve send rate */

		hctx->ccid3hctx_x /= 2;
@@ -240,9 +238,10 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data) 
					2 * usecs_div(hctx->ccid3hctx_s,

						      hctx->ccid3hctx_x));

		break;

	default:

		DCCP_BUG("%s, sk=%p, Illegal state (%d)!", dccp_role(sk), sk,

			 hctx->ccid3hctx_state);

	case TFRC_SSTATE_NO_SENT:

		DCCP_BUG("Illegal %s state NO_SENT, sk=%p", dccp_role(sk), sk);

		/* fall through */

	case TFRC_SSTATE_TERM:

		goto out;

	}
@@ -264,7 +263,7 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, 
	long delay;

	int rc = -ENOTCONN;



	BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM);

	BUG_ON(hctx == NULL);



	/* Check if pure ACK or Terminating*/

	/*
@@ -282,9 +281,8 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, 


		rc = -ENOBUFS;

		if (unlikely(new_packet == NULL)) {

			LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, not enough "

				       "mem to add to history, send refused\n",

				       __FUNCTION__, dccp_role(sk), sk);

			DCCP_WARN("%s, sk=%p, not enough mem to add to history,"

				  "send refused\n", dccp_role(sk), sk);

			goto out;

		}
@@ -317,9 +315,8 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, 
		/* divide by -1000 is to convert to ms and get sign right */

		rc = delay > 0 ? delay : 0;

		break;

	default:

		DCCP_BUG("%s, sk=%p, Illegal state (%d)!", dccp_role(sk), sk,

			 hctx->ccid3hctx_state);

	case TFRC_SSTATE_TERM:

		DCCP_BUG("Illegal %s state TERM, sk=%p", dccp_role(sk), sk);

		rc = -EINVAL;

		break;

	}
@@ -343,7 +340,7 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, int len) 
	struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);

	struct timeval now;



	BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM);

	BUG_ON(hctx == NULL);



	dccp_timestamp(sk, &now);
@@ -354,13 +351,11 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, int len) 


		packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist);

		if (unlikely(packet == NULL)) {

			LIMIT_NETDEBUG(KERN_WARNING "%s: packet doesn't "

				       "exists in history!\n", __FUNCTION__);

			DCCP_WARN("packet doesn't exist in history!\n");

			return;

		}

		if (unlikely(packet->dccphtx_sent)) {

			LIMIT_NETDEBUG(KERN_WARNING "%s: no unsent packet in "

				       "history!\n", __FUNCTION__);

			DCCP_WARN("no unsent packet in history!\n");

			return;

		}

		packet->dccphtx_tstamp = now;
@@ -395,9 +390,8 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, int len) 
	case TFRC_SSTATE_NO_SENT:

		/* if first wasn't pure ack */

		if (len != 0)

			printk(KERN_CRIT "%s: %s, First packet sent is noted "

					 "as a data packet\n",

			       __FUNCTION__, dccp_role(sk));

			DCCP_CRIT("%s, First packet sent is noted "

				  "as a data packet",  dccp_role(sk));

		return;

	case TFRC_SSTATE_NO_FBACK:

	case TFRC_SSTATE_FBACK:
@@ -410,9 +404,8 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, int len) 
					  hctx->ccid3hctx_t_ipi);

		}

		break;

	default:

		DCCP_BUG("%s, sk=%p, Illegal state (%d)!", dccp_role(sk), sk,

			 hctx->ccid3hctx_state);

	case TFRC_SSTATE_TERM:

		DCCP_BUG("Illegal %s state TERM, sk=%p", dccp_role(sk), sk);

		break;

	}

}
@@ -430,7 +423,7 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) 
	u32 x_recv;

	u32 r_sample;



	BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM);

	BUG_ON(hctx == NULL);



	/* we are only interested in ACKs */

	if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK ||
@@ -455,9 +448,8 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) 
		packet = dccp_tx_hist_find_entry(&hctx->ccid3hctx_hist,

						 DCCP_SKB_CB(skb)->dccpd_ack_seq);

		if (unlikely(packet == NULL)) {

			LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, seqno "

				       "%llu(%s) does't exist in history!\n",

				       __FUNCTION__, dccp_role(sk), sk,

			DCCP_WARN("%s, sk=%p, seqno %llu(%s) does't exist "

				  "in history!\n",  dccp_role(sk), sk,

			    (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq,

				  dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type));

			return;
@@ -467,9 +459,8 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) 
		dccp_timestamp(sk, &now);

		r_sample = timeval_delta(&now, &packet->dccphtx_tstamp);

		if (unlikely(r_sample <= t_elapsed))

			LIMIT_NETDEBUG(KERN_WARNING "%s: r_sample=%uus, "

				       "t_elapsed=%uus\n",

				       __FUNCTION__, r_sample, t_elapsed);

			DCCP_WARN("r_sample=%uus,t_elapsed=%uus\n",

				  r_sample, t_elapsed);

		else

			r_sample -= t_elapsed;
@@ -554,9 +545,8 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) 
		/* set idle flag */

		hctx->ccid3hctx_idle = 1;   

		break;

	default:

		DCCP_BUG("%s, sk=%p, Illegal state (%d)!", dccp_role(sk), sk,

			 hctx->ccid3hctx_state);

	case TFRC_SSTATE_TERM:

		DCCP_BUG("Illegal %s state TERM, sk=%p", dccp_role(sk), sk);

		break;

	}

}
@@ -596,9 +586,9 @@ static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option, 
	switch (option) {

	case TFRC_OPT_LOSS_EVENT_RATE:

		if (unlikely(len != 4)) {

			LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, invalid "

				       "len for TFRC_OPT_LOSS_EVENT_RATE\n",

				       __FUNCTION__, dccp_role(sk), sk);

			DCCP_WARN("%s, sk=%p, invalid len %d "

				  "for TFRC_OPT_LOSS_EVENT_RATE\n",

				  dccp_role(sk), sk, len);

			rc = -EINVAL;

		} else {

			opt_recv->ccid3or_loss_event_rate = ntohl(*(__be32 *)value);
@@ -617,9 +607,9 @@ static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option, 
		break;

	case TFRC_OPT_RECEIVE_RATE:

		if (unlikely(len != 4)) {

			LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, invalid "

				       "len for TFRC_OPT_RECEIVE_RATE\n",

				       __FUNCTION__, dccp_role(sk), sk);

			DCCP_WARN("%s, sk=%p, invalid len %d "

				  "for TFRC_OPT_RECEIVE_RATE\n",

				  dccp_role(sk), sk, len);

			rc = -EINVAL;

		} else {

			opt_recv->ccid3or_receive_rate = ntohl(*(__be32 *)value);
@@ -722,17 +712,15 @@ static void ccid3_hc_rx_send_feedback(struct sock *sk) 
						   delta);

	}

		break;

	default:

		DCCP_BUG("%s, sk=%p, Illegal state (%d)!", dccp_role(sk), sk,

			 hcrx->ccid3hcrx_state);

	case TFRC_RSTATE_TERM:

		DCCP_BUG("Illegal %s state TERM, sk=%p", dccp_role(sk), sk);

		return;

	}



	packet = dccp_rx_hist_find_data_packet(&hcrx->ccid3hcrx_hist);

	if (unlikely(packet == NULL)) {

		LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, no data packet "

			       "in history!\n",

			       __FUNCTION__, dccp_role(sk), sk);

		DCCP_WARN("%s, sk=%p, no data packet in history!\n",

			  dccp_role(sk), sk);

		return;

	}
@@ -820,29 +808,29 @@ static u32 ccid3_hc_rx_calc_first_li(struct sock *sk) 
	}



	if (unlikely(step == 0)) {

		LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, packet history "

			       "contains no data packets!\n",

			       __FUNCTION__, dccp_role(sk), sk);

		DCCP_WARN("%s, sk=%p, packet history has no data packets!\n",

			  dccp_role(sk), sk);

		return ~0;

	}



	if (unlikely(interval == 0)) {

		LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, Could not find a "

			       "win_count interval > 0. Defaulting to 1\n",

			       __FUNCTION__, dccp_role(sk), sk);

		DCCP_WARN("%s, sk=%p, Could not find a win_count interval > 0."

			  "Defaulting to 1\n", dccp_role(sk), sk);

		interval = 1;

	}

found:

	if (!tail) {

		LIMIT_NETDEBUG(KERN_WARNING "%s: tail is null\n",

		   __FUNCTION__);

		DCCP_CRIT("tail is null\n");

		return ~0;

	}

	rtt = timeval_delta(&tstamp, &tail->dccphrx_tstamp) * 4 / interval;

	ccid3_pr_debug("%s, sk=%p, approximated RTT to %uus\n",

		       dccp_role(sk), sk, rtt);

	if (rtt == 0)



	if (rtt == 0) {

		DCCP_WARN("RTT==0, setting to 1\n");

 		rtt = 1;

	}



	dccp_timestamp(sk, &tstamp);

	delta = timeval_delta(&tstamp, &hcrx->ccid3hcrx_tstamp_last_feedback);
@@ -856,9 +844,7 @@ static u32 ccid3_hc_rx_calc_first_li(struct sock *sk) 
	tmp2 = (u32)tmp1;



	if (!tmp2) {

		LIMIT_NETDEBUG(KERN_WARNING "tmp2 = 0 "

		   "%s: x_recv = %u, rtt =%u\n",

		   __FUNCTION__, x_recv, rtt);

		DCCP_CRIT("tmp2 = 0, x_recv = %u, rtt =%u\n", x_recv, rtt);

		return ~0;

	}
@@ -904,8 +890,7 @@ static void ccid3_hc_rx_update_li(struct sock *sk, u64 seq_loss, u8 win_loss) 
		entry = dccp_li_hist_entry_new(ccid3_li_hist, SLAB_ATOMIC);



		if (entry == NULL) {

			printk(KERN_CRIT "%s: out of memory\n",__FUNCTION__);

			dump_stack();

			DCCP_BUG("out of memory - can not allocate entry");

			return;

		}
@@ -984,9 +969,7 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) 
	u32 p_prev, rtt_prev, r_sample, t_elapsed;

	int loss;



	BUG_ON(hcrx == NULL ||

	       !(hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA ||

		 hcrx->ccid3hcrx_state == TFRC_RSTATE_DATA));

	BUG_ON(hcrx == NULL);



	opt_recv = &dccp_sk(sk)->dccps_options_received;
@@ -1004,9 +987,8 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) 
		t_elapsed = opt_recv->dccpor_elapsed_time * 10;



		if (unlikely(r_sample <= t_elapsed))

			LIMIT_NETDEBUG(KERN_WARNING "%s: r_sample=%uus, "

				       "t_elapsed=%uus\n",

				       __FUNCTION__, r_sample, t_elapsed);

			DCCP_WARN("r_sample=%uus, t_elapsed=%uus\n",

				  r_sample, t_elapsed);

		else

			r_sample -= t_elapsed;
@@ -1030,9 +1012,8 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) 
	packet = dccp_rx_hist_entry_new(ccid3_rx_hist, sk, opt_recv->dccpor_ndp,

					skb, SLAB_ATOMIC);

	if (unlikely(packet == NULL)) {

		LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, Not enough mem to "

				"add rx packet to history, consider it lost!\n",

			       __FUNCTION__, dccp_role(sk), sk);

		DCCP_WARN("%s, sk=%p, Not enough mem to add rx packet "

			  "to history, consider it lost!\n", dccp_role(sk), sk);

		return;

	}
@@ -1065,9 +1046,8 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) 
			ccid3_hc_rx_send_feedback(sk);

		}

		return;

	default:

		DCCP_BUG("%s, sk=%p, Illegal state (%d)!",  dccp_role(sk), sk,

			 hcrx->ccid3hcrx_state);

	case TFRC_RSTATE_TERM:

		DCCP_BUG("Illegal %s state TERM, sk=%p", dccp_role(sk), sk);

		return;

	}
@@ -1084,10 +1064,8 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) 
		/* Scaling up by 1000000 as fixed decimal */

		if (i_mean != 0)

			hcrx->ccid3hcrx_p = 1000000 / i_mean;

	} else {

		printk(KERN_CRIT "%s: empty loss hist\n",__FUNCTION__);

		dump_stack();

	}

	} else

		DCCP_BUG("empty loss history");



	if (hcrx->ccid3hcrx_p > p_prev) {

		ccid3_hc_rx_send_feedback(sk);

net/dccp/ccids/lib/loss_interval.c

+3 −3
Original line number Diff line number Diff line
@@ -13,7 +13,7 @@ 


#include <linux/module.h>

#include <net/sock.h>



#include "../../dccp.h"

#include "loss_interval.h"



struct dccp_li_hist *dccp_li_hist_new(const char *name)
@@ -109,7 +109,7 @@ u32 dccp_li_hist_calc_i_mean(struct list_head *list) 
	i_tot = max(i_tot0, i_tot1);



	if (!w_tot) {

		LIMIT_NETDEBUG(KERN_WARNING "%s: w_tot = 0\n", __FUNCTION__);

		DCCP_WARN("w_tot = 0\n");

		return 1;

	}
@@ -128,7 +128,7 @@ int dccp_li_hist_interval_new(struct dccp_li_hist *hist, 
		entry = dccp_li_hist_entry_new(hist, SLAB_ATOMIC);

		if (entry == NULL) {

			dccp_li_hist_purge(hist, list);

			dump_stack();

			DCCP_BUG("loss interval list entry is NULL");

			return 0;

		}

		entry->dccplih_interval = ~0;

net/dccp/ccids/lib/tfrc_equation.c

+4 −3
Original line number Diff line number Diff line
@@ -13,9 +13,8 @@ 
 */



#include <linux/module.h>



#include <asm/div64.h>



#include "../../dccp.h"

#include "tfrc.h"



#define TFRC_CALC_X_ARRSIZE 500
@@ -588,8 +587,10 @@ u32 tfrc_calc_x(u16 s, u32 R, u32 p) 
		/* p should be 0 unless there is a bug in my code */

		index = 0;



	if (R == 0)

	if (R == 0) {

		DCCP_WARN("RTT==0, setting to 1\n");

		R = 1; /* RTT can't be zero or else divide by zero */

	}



	BUG_ON(index >= TFRC_CALC_X_ARRSIZE);