Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6

* master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6: (32 commits)
[NETPOLL]: Fix local_bh_enable() warning.
[IPVS]: Make ip_vs_sync.c <= 80col wide.
[IPVS]: Use msleep_interruptable() instead of ssleep() aka msleep()
[HAMRADIO]: Fix baycom_epp.c compile failure.
[DCCP]: Whitespace cleanups
[DCCP] ccid3: Fixup some type conversions related to rtts
[DCCP] ccid3: BUG-FIX - conversion errors
[DCCP] ccid3: Reorder packet history source file
[DCCP] ccid3: Reorder packet history header file
[DCCP] ccid3: Make debug output consistent
[DCCP] ccid3: Perform history operations only after packet has been sent
[DCCP] ccid3: TX history - remove unused field
[DCCP] ccid3: Shift window counter computation
[DCCP] ccid3: Sanity-check RTT samples
[DCCP] ccid3: Initialise RTT values
[DCCP] ccid: Deprecate ccid_hc_tx_insert_options
[DCCP]: Warn when discarding packet due to internal errors
[DCCP]: Only deliver to the CCID rx side in charge
[DCCP]: Simplify TFRC calculation
[DCCP]: Debug timeval operations
...

Documentation/networking/dccp.txt

···
 
 It has a base protocol and pluggable congestion control IDs (CCIDs).
 
-It is at experimental RFC status and the homepage for DCCP as a protocol is at:
+It is at proposed standard RFC status and the homepage for DCCP as a protocol
+is at:
 	http://www.read.cs.ucla.edu/dccp/
 
 Missing features
···
 
 Socket options
 ==============
-
-DCCP_SOCKOPT_PACKET_SIZE is used for CCID3 to set default packet size for
-calculations.
 
 DCCP_SOCKOPT_SERVICE sets the service. The specification mandates use of
 service codes (RFC 4340, sec. 8.1.2); if this socket option is not set,

crypto/sha512.c

···
 
 #define SHA384_DIGEST_SIZE 48
 #define SHA512_DIGEST_SIZE 64
-#define SHA384_HMAC_BLOCK_SIZE  96
+#define SHA384_HMAC_BLOCK_SIZE 128
 #define SHA512_HMAC_BLOCK_SIZE 128
 
 struct sha512_ctx {

drivers/atm/.gitignore

···
 fore200e_mkfirm
 fore200e_pca_fw.c
 pca200e.bin
-
+pca200e_ecd.bin2

drivers/net/hamradio/baycom_epp.c

···
 	dev->mtu = AX25_DEF_PACLEN;        /* eth_mtu is the default */
 	dev->addr_len = AX25_ADDR_LEN;     /* sizeof an ax.25 address */
 	memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
-	memcpy(dev->dev_addr, &ax25_nocall, AX25_ADDR_LEN);
+	memcpy(dev->dev_addr, &null_ax25_address, AX25_ADDR_LEN);
 	dev->tx_queue_len = 16;
 
 	/* New style flags */

drivers/net/wan/Kconfig

···
 
 # Wan router core.
 config WAN_ROUTER_DRIVERS
-	bool "WAN router drivers"
+	tristate "WAN router drivers"
 	depends on WAN && WAN_ROUTER
 	---help---
 	  Connect LAN to WAN via Linux box.
···
 	  <file:Documentation/networking/wan-router.txt>.
 
 	  Note that the answer to this question won't directly affect the
-	  kernel: saying N will just cause the configurator to skip all
+	  kernel except for how subordinate drivers may be built:
+	  saying N will just cause the configurator to skip all
 	  the questions about WAN router drivers.
 
 	  If unsure, say N.

include/linux/dccp.h

···
 };
 
 /* DCCP features (RFC 4340 section 6.4) */
- enum {
- 	DCCPF_RESERVED = 0,
- 	DCCPF_CCID = 1,
+enum {
+	DCCPF_RESERVED = 0,
+	DCCPF_CCID = 1,
 	DCCPF_SHORT_SEQNOS = 2,		/* XXX: not yet implemented */
- 	DCCPF_SEQUENCE_WINDOW = 3,
+	DCCPF_SEQUENCE_WINDOW = 3,
 	DCCPF_ECN_INCAPABLE = 4,	/* XXX: not yet implemented */
- 	DCCPF_ACK_RATIO = 5,
- 	DCCPF_SEND_ACK_VECTOR = 6,
- 	DCCPF_SEND_NDP_COUNT = 7,
+	DCCPF_ACK_RATIO = 5,
+	DCCPF_SEND_ACK_VECTOR = 6,
+	DCCPF_SEND_NDP_COUNT = 7,
 	DCCPF_MIN_CSUM_COVER = 8,
 	DCCPF_DATA_CHECKSUM = 9,	/* XXX: not yet implemented */
- 	/* 10-127 reserved */
- 	DCCPF_MIN_CCID_SPECIFIC = 128,
- 	DCCPF_MAX_CCID_SPECIFIC = 255,
+	/* 10-127 reserved */
+	DCCPF_MIN_CCID_SPECIFIC = 128,
+	DCCPF_MAX_CCID_SPECIFIC = 255,
 };
 
 /* this structure is argument to DCCP_SOCKOPT_CHANGE_X */
···
 };
 
 #define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1)
-#define DCCP_SERVICE_CODE_IS_ABSENT 		 0
+#define DCCP_SERVICE_CODE_IS_ABSENT		0
 
 static inline int dccp_list_has_service(const struct dccp_service_list *sl,
 					const __be32 service)
···
 		u32 i = sl->dccpsl_nr;
 		while (i--)
 			if (sl->dccpsl_list[i] == service)
-				return 1; 
+				return 1;
 	}
 	return 0;
 }
···
 	__u8				dccps_hc_tx_insert_options:1;
 	struct timer_list		dccps_xmit_timer;
 };
- 
+
 static inline struct dccp_sock *dccp_sk(const struct sock *sk)
 {
 	return (struct dccp_sock *)sk;

include/linux/tfrc.h

···
  * 	@tfrctx_p:	current loss event rate (5.4)
  * 	@tfrctx_rto:	estimate of RTO, equals 4*RTT (4.3)
  * 	@tfrctx_ipi:	inter-packet interval (4.6)
+ *
+ *  Note: X and X_recv are both maintained in units of 64 * bytes/second. This
+ *        enables a finer resolution of sending rates and avoids problems with
+ *        integer arithmetic; u32 is not sufficient as scaling consumes 6 bits.
  */
 struct tfrc_tx_info {
-	__u32 tfrctx_x;
-	__u32 tfrctx_x_recv;
+	__u64 tfrctx_x;
+	__u64 tfrctx_x_recv;
 	__u32 tfrctx_x_calc;
 	__u32 tfrctx_rtt;
 	__u32 tfrctx_p;

include/net/ax25.h

···
 extern const ax25_address ax25_bcast;
 extern const ax25_address ax25_defaddr;
 extern const ax25_address null_ax25_address;
+extern char *ax2asc(char *buf, const ax25_address *);
+extern void asc2ax(ax25_address *addr, const char *callsign);
 extern int ax25cmp(const ax25_address *, const ax25_address *);
 extern int ax25digicmp(const ax25_digi *, const ax25_digi *);
 extern const unsigned char *ax25_addr_parse(const unsigned char *, int,

net/ax25/ax25_addr.c

···
  */
 void asc2ax(ax25_address *addr, const char *callsign)
 {
-	char *s;
+	const char *s;
 	int n;
 
 	for (s = callsign, n = 0; n < 6; n++) {

net/core/netpoll.c

···
 
 	/* don't get messages out of order, and no recursion */
 	if (skb_queue_len(&npinfo->txq) == 0 &&
-	    npinfo->poll_owner != smp_processor_id() &&
-	    netif_tx_trylock(dev)) {
-		/* try until next clock tick */
-		for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; tries > 0; --tries) {
-			if (!netif_queue_stopped(dev))
-				status = dev->hard_start_xmit(skb, dev);
+		    npinfo->poll_owner != smp_processor_id()) {
+		unsigned long flags;
 
-			if (status == NETDEV_TX_OK)
-				break;
+		local_irq_save(flags);
+		if (netif_tx_trylock(dev)) {
+			/* try until next clock tick */
+			for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
+					tries > 0; --tries) {
+				if (!netif_queue_stopped(dev))
+					status = dev->hard_start_xmit(skb, dev);
 
-			/* tickle device maybe there is some cleanup */
-			netpoll_poll(np);
+				if (status == NETDEV_TX_OK)
+					break;
 
-			udelay(USEC_PER_POLL);
+				/* tickle device maybe there is some cleanup */
+				netpoll_poll(np);
+
+				udelay(USEC_PER_POLL);
+			}
+			netif_tx_unlock(dev);
 		}
-		netif_tx_unlock(dev);
+		local_irq_restore(flags);
 	}
 
 	if (status != NETDEV_TX_OK) {

net/dccp/ackvec.c

···
 			gap = -new_head;
 		}
 		new_head += DCCP_MAX_ACKVEC_LEN;
-	} 
+	}
 
 	av->dccpav_buf_head = new_head;
 
···
 void dccp_ackvector_print(const u64 ackno, const unsigned char *vector, int len)
 {
 	dccp_pr_debug_cat("ACK vector len=%d, ackno=%llu |", len,
-			 		(unsigned long long)ackno);
+			 (unsigned long long)ackno);
 
 	while (len--) {
 		const u8 state = (*vector & DCCP_ACKVEC_STATE_MASK) >> 6;

net/dccp/ccid.h

···
 						    unsigned char* value);
 	int		(*ccid_hc_rx_insert_options)(struct sock *sk,
 						     struct sk_buff *skb);
-	int		(*ccid_hc_tx_insert_options)(struct sock *sk,
-						     struct sk_buff *skb);
 	void		(*ccid_hc_tx_packet_recv)(struct sock *sk,
 						  struct sk_buff *skb);
 	int		(*ccid_hc_tx_parse_options)(struct sock *sk,
···
 	if (ccid->ccid_ops->ccid_hc_rx_parse_options != NULL)
 		rc = ccid->ccid_ops->ccid_hc_rx_parse_options(sk, option, len, idx, value);
 	return rc;
-}
-
-static inline int ccid_hc_tx_insert_options(struct ccid *ccid, struct sock *sk,
-					    struct sk_buff *skb)
-{
-	if (ccid->ccid_ops->ccid_hc_tx_insert_options != NULL)
-		return ccid->ccid_ops->ccid_hc_tx_insert_options(sk, skb);
-	return 0;
 }
 
 static inline int ccid_hc_rx_insert_options(struct ccid *ccid, struct sock *sk,

net/dccp/ccids/ccid2.c

···
 
 		while (seqp != hctx->ccid2hctx_seqh) {
 			ccid2_pr_debug("out seq=%llu acked=%d time=%lu\n",
-			       	       (unsigned long long)seqp->ccid2s_seq,
+				       (unsigned long long)seqp->ccid2s_seq,
 				       seqp->ccid2s_acked, seqp->ccid2s_sent);
 			seqp = seqp->ccid2s_next;
 		}
···
 		/* first measurement */
 		if (hctx->ccid2hctx_srtt == -1) {
 			ccid2_pr_debug("R: %lu Time=%lu seq=%llu\n",
-			       	       r, jiffies,
+				       r, jiffies,
 				       (unsigned long long)seqp->ccid2s_seq);
 			ccid2_change_srtt(hctx, r);
 			hctx->ccid2hctx_rttvar = r >> 1;
···
 		hctx->ccid2hctx_lastrtt = jiffies;
 
 		ccid2_pr_debug("srtt: %ld rttvar: %ld rto: %ld (HZ=%d) R=%lu\n",
-		       	       hctx->ccid2hctx_srtt, hctx->ccid2hctx_rttvar,
-		       	       hctx->ccid2hctx_rto, HZ, r);
+			       hctx->ccid2hctx_srtt, hctx->ccid2hctx_rttvar,
+			       hctx->ccid2hctx_rto, HZ, r);
 		hctx->ccid2hctx_sent = 0;
 	}
 
···
 				/* new packet received or marked */
 				if (state != DCCP_ACKVEC_STATE_NOT_RECEIVED &&
 				    !seqp->ccid2s_acked) {
-				    	if (state ==
+					if (state ==
 					    DCCP_ACKVEC_STATE_ECN_MARKED) {
-					    	ccid2_congestion_event(hctx,
+						ccid2_congestion_event(hctx,
 								       seqp);
 					} else
 						ccid2_new_ack(sk, seqp,

net/dccp/ccids/ccid3.c

···
 #include "lib/tfrc.h"
 #include "ccid3.h"
 
-/*
- * Reason for maths here is to avoid 32 bit overflow when a is big.
- * With this we get close to the limit.
- */
-static u32 usecs_div(const u32 a, const u32 b)
-{
-	const u32 div = a < (UINT_MAX / (USEC_PER_SEC /    10)) ?    10 :
-			a < (UINT_MAX / (USEC_PER_SEC /    50)) ?    50 :
-			a < (UINT_MAX / (USEC_PER_SEC /   100)) ?   100 :
-			a < (UINT_MAX / (USEC_PER_SEC /   500)) ?   500 :
-			a < (UINT_MAX / (USEC_PER_SEC /  1000)) ?  1000 :
-			a < (UINT_MAX / (USEC_PER_SEC /  5000)) ?  5000 :
-			a < (UINT_MAX / (USEC_PER_SEC / 10000)) ? 10000 :
-			a < (UINT_MAX / (USEC_PER_SEC / 50000)) ? 50000 :
-								 100000;
-	const u32 tmp = a * (USEC_PER_SEC / div);
-	return (b >= 2 * div) ? tmp / (b / div) : tmp;
-}
-
-
-
 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
 static int ccid3_debug;
 #define ccid3_pr_debug(format, a...)	DCCP_PR_DEBUG(ccid3_debug, format, ##a)
···
 {
 	timeval_sub_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi);
 
-	/* Calculate new t_ipi (inter packet interval) by t_ipi = s / X_inst */
-	hctx->ccid3hctx_t_ipi = usecs_div(hctx->ccid3hctx_s, hctx->ccid3hctx_x);
+	/* Calculate new t_ipi = s / X_inst (X_inst is in 64 * bytes/second) */
+	hctx->ccid3hctx_t_ipi = scaled_div(hctx->ccid3hctx_s,
+					   hctx->ccid3hctx_x >> 6);
 
 	/* Update nominal send time with regard to the new t_ipi */
 	timeval_add_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi);
···
  *          X = max(min(2 * X, 2 * X_recv), s / R);
  *          tld = now;
  *
+ * Note: X and X_recv are both stored in units of 64 * bytes/second, to support
+ *       fine-grained resolution of sending rates. This requires scaling by 2^6
+ *       throughout the code. Only X_calc is unscaled (in bytes/second).
+ *
  * If X has changed, we also update the scheduled send time t_now,
  * the inter-packet interval t_ipi, and the delta value.
- */ 
+ */
 static void ccid3_hc_tx_update_x(struct sock *sk, struct timeval *now)
 
 {
 	struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
-	const __u32 old_x = hctx->ccid3hctx_x;
+	const  __u64 old_x = hctx->ccid3hctx_x;
 
 	if (hctx->ccid3hctx_p > 0) {
-		hctx->ccid3hctx_x_calc = tfrc_calc_x(hctx->ccid3hctx_s,
-						     hctx->ccid3hctx_rtt,
-						     hctx->ccid3hctx_p);
-		hctx->ccid3hctx_x = max_t(u32, min(hctx->ccid3hctx_x_calc,
-						   hctx->ccid3hctx_x_recv * 2),
-					       hctx->ccid3hctx_s / TFRC_T_MBI);
 
-	} else if (timeval_delta(now, &hctx->ccid3hctx_t_ld) >=
-							  hctx->ccid3hctx_rtt) {
-		hctx->ccid3hctx_x = max(min(hctx->ccid3hctx_x_recv,
-					    hctx->ccid3hctx_x      ) * 2,
-					usecs_div(hctx->ccid3hctx_s,
-					       	  hctx->ccid3hctx_rtt)   );
+		hctx->ccid3hctx_x = min(((__u64)hctx->ccid3hctx_x_calc) << 6,
+					hctx->ccid3hctx_x_recv * 2);
+		hctx->ccid3hctx_x = max(hctx->ccid3hctx_x,
+					(((__u64)hctx->ccid3hctx_s) << 6) /
+								TFRC_T_MBI);
+
+	} else if (timeval_delta(now, &hctx->ccid3hctx_t_ld) -
+			(suseconds_t)hctx->ccid3hctx_rtt >= 0) {
+
+		hctx->ccid3hctx_x =
+			max(2 * min(hctx->ccid3hctx_x, hctx->ccid3hctx_x_recv),
+			    scaled_div(((__u64)hctx->ccid3hctx_s) << 6,
+				       hctx->ccid3hctx_rtt));
 		hctx->ccid3hctx_t_ld = *now;
-	} else
-		ccid3_pr_debug("Not changing X\n");
+	}
 
 	if (hctx->ccid3hctx_x != old_x)
 		ccid3_update_send_time(hctx);
 }
 
 /*
- * 	Track the mean packet size `s' (cf. RFC 4342, 5.3 and  RFC 3448, 4.1)
- * 	@len: DCCP packet payload size in bytes
+ *	Track the mean packet size `s' (cf. RFC 4342, 5.3 and  RFC 3448, 4.1)
+ *	@len: DCCP packet payload size in bytes
  */
 static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hctx, int len)
 {
···
 	 */
 }
 
+/*
+ *	Update Window Counter using the algorithm from [RFC 4342, 8.1].
+ *	The algorithm is not applicable if RTT < 4 microseconds.
+ */
+static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hctx,
+						struct timeval *now)
+{
+	suseconds_t delta;
+	u32 quarter_rtts;
+
+	if (unlikely(hctx->ccid3hctx_rtt < 4))	/* avoid divide-by-zero */
+		return;
+
+	delta = timeval_delta(now, &hctx->ccid3hctx_t_last_win_count);
+	DCCP_BUG_ON(delta < 0);
+
+	quarter_rtts = (u32)delta / (hctx->ccid3hctx_rtt / 4);
+
+	if (quarter_rtts > 0) {
+		hctx->ccid3hctx_t_last_win_count = *now;
+		hctx->ccid3hctx_last_win_count	+= min_t(u32, quarter_rtts, 5);
+		hctx->ccid3hctx_last_win_count	&= 0xF;		/* mod 16 */
+
+		ccid3_pr_debug("now at %#X\n", hctx->ccid3hctx_last_win_count);
+	}
+}
+
 static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
 {
 	struct sock *sk = (struct sock *)data;
···
 		goto restart_timer;
 	}
 
-	ccid3_pr_debug("%s, sk=%p, state=%s\n", dccp_role(sk), sk,
+	ccid3_pr_debug("%s(%p, state=%s) - entry \n", dccp_role(sk), sk,
 		       ccid3_tx_state_name(hctx->ccid3hctx_state));
-	
+
 	switch (hctx->ccid3hctx_state) {
 	case TFRC_SSTATE_NO_FBACK:
 		/* RFC 3448, 4.4: Halve send rate directly */
-		hctx->ccid3hctx_x = min_t(u32, hctx->ccid3hctx_x / 2,
-					       hctx->ccid3hctx_s / TFRC_T_MBI);
+		hctx->ccid3hctx_x = max(hctx->ccid3hctx_x / 2,
+					(((__u64)hctx->ccid3hctx_s) << 6) /
+								    TFRC_T_MBI);
 
-		ccid3_pr_debug("%s, sk=%p, state=%s, updated tx rate to %d "
-			       "bytes/s\n",
-			       dccp_role(sk), sk,
+		ccid3_pr_debug("%s(%p, state=%s), updated tx rate to %u "
+			       "bytes/s\n", dccp_role(sk), sk,
 			       ccid3_tx_state_name(hctx->ccid3hctx_state),
-			       hctx->ccid3hctx_x);
+			       (unsigned)(hctx->ccid3hctx_x >> 6));
 		/* The value of R is still undefined and so we can not recompute
 		 * the timout value. Keep initial value as per [RFC 4342, 5]. */
 		t_nfb = TFRC_INITIAL_TIMEOUT;
···
 	case TFRC_SSTATE_FBACK:
 		/*
 		 * Check if IDLE since last timeout and recv rate is less than
-		 * 4 packets per RTT
+		 * 4 packets (in units of 64*bytes/sec) per RTT
 		 */
 		if (!hctx->ccid3hctx_idle ||
-		    (hctx->ccid3hctx_x_recv >=
-		     4 * usecs_div(hctx->ccid3hctx_s, hctx->ccid3hctx_rtt))) {
+		    (hctx->ccid3hctx_x_recv >= 4 *
+		     scaled_div(((__u64)hctx->ccid3hctx_s) << 6,
+				hctx->ccid3hctx_rtt))) {
 			struct timeval now;
 
-			ccid3_pr_debug("%s, sk=%p, state=%s, not idle\n",
+			ccid3_pr_debug("%s(%p, state=%s), not idle\n",
 				       dccp_role(sk), sk,
-				       ccid3_tx_state_name(hctx->ccid3hctx_state));
-			/* Halve sending rate */
+				   ccid3_tx_state_name(hctx->ccid3hctx_state));
 
-			/*  If (p == 0 || X_calc > 2 * X_recv)
+			/*
+			 *  Modify the cached value of X_recv [RFC 3448, 4.4]
+			 *
+			 *  If (p == 0 || X_calc > 2 * X_recv)
 			 *    X_recv = max(X_recv / 2, s / (2 * t_mbi));
 			 *  Else
 			 *    X_recv = X_calc / 4;
+			 *
+			 *  Note that X_recv is scaled by 2^6 while X_calc is not
 			 */
 			BUG_ON(hctx->ccid3hctx_p && !hctx->ccid3hctx_x_calc);
 
 			if (hctx->ccid3hctx_p  == 0 ||
-			    hctx->ccid3hctx_x_calc > 2 * hctx->ccid3hctx_x_recv)
-				hctx->ccid3hctx_x_recv = max_t(u32, hctx->ccid3hctx_x_recv / 2,
-								    hctx->ccid3hctx_s / (2 * TFRC_T_MBI));
-			else
-				hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc / 4;
+			    (hctx->ccid3hctx_x_calc >
+			     (hctx->ccid3hctx_x_recv >> 5))) {
 
-			/* Update sending rate */
-			dccp_timestamp(sk, &now);
+				hctx->ccid3hctx_x_recv =
+					max(hctx->ccid3hctx_x_recv / 2,
+					    (((__u64)hctx->ccid3hctx_s) << 6) /
+							  (2 * TFRC_T_MBI));
+
+				if (hctx->ccid3hctx_p == 0)
+					dccp_timestamp(sk, &now);
+			} else {
+				hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc;
+				hctx->ccid3hctx_x_recv <<= 4;
+			}
+			/* Now recalculate X [RFC 3448, 4.3, step (4)] */
 			ccid3_hc_tx_update_x(sk, &now);
 		}
 		/*
···
 		t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
 		break;
 	case TFRC_SSTATE_NO_SENT:
-		DCCP_BUG("Illegal %s state NO_SENT, sk=%p", dccp_role(sk), sk);
+		DCCP_BUG("%s(%p) - Illegal state NO_SENT", dccp_role(sk), sk);
 		/* fall through */
 	case TFRC_SSTATE_TERM:
 		goto out;
···
 {
 	struct dccp_sock *dp = dccp_sk(sk);
 	struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
-	struct dccp_tx_hist_entry *new_packet;
 	struct timeval now;
-	long delay;
+	suseconds_t delay;
 
 	BUG_ON(hctx == NULL);
 
···
 	if (unlikely(skb->len == 0))
 		return -EBADMSG;
 
-	/* See if last packet allocated was not sent */
-	new_packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist);
-	if (new_packet == NULL || new_packet->dccphtx_sent) {
-		new_packet = dccp_tx_hist_entry_new(ccid3_tx_hist,
-						    GFP_ATOMIC);
-
-		if (unlikely(new_packet == NULL)) {
-			DCCP_WARN("%s, sk=%p, not enough mem to add to history,"
-				  "send refused\n", dccp_role(sk), sk);
-			return -ENOBUFS;
-		}
-
-		dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, new_packet);
-	}
-
 	dccp_timestamp(sk, &now);
 
 	switch (hctx->ccid3hctx_state) {
 	case TFRC_SSTATE_NO_SENT:
 		sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
-			       jiffies + usecs_to_jiffies(TFRC_INITIAL_TIMEOUT));
+			       (jiffies +
+			        usecs_to_jiffies(TFRC_INITIAL_TIMEOUT)));
 		hctx->ccid3hctx_last_win_count	 = 0;
 		hctx->ccid3hctx_t_last_win_count = now;
 		ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);
 
-		/* Set initial sending rate to 1 packet per second */
+		/* Set initial sending rate X/s to 1pps (X is scaled by 2^6) */
 		ccid3_hc_tx_update_s(hctx, skb->len);
-		hctx->ccid3hctx_x     = hctx->ccid3hctx_s;
+		hctx->ccid3hctx_x = hctx->ccid3hctx_s;
+		hctx->ccid3hctx_x <<= 6;
 
 		/* First timeout, according to [RFC 3448, 4.2], is 1 second */
 		hctx->ccid3hctx_t_ipi = USEC_PER_SEC;
···
 	case TFRC_SSTATE_FBACK:
 		delay = timeval_delta(&hctx->ccid3hctx_t_nom, &now);
 		/*
-		 * 	Scheduling of packet transmissions [RFC 3448, 4.6]
+		 *	Scheduling of packet transmissions [RFC 3448, 4.6]
 		 *
 		 * if (t_now > t_nom - delta)
 		 *       // send the packet now
 		 * else
 		 *       // send the packet in (t_nom - t_now) milliseconds.
 		 */
-		if (delay - (long)hctx->ccid3hctx_delta >= 0)
+		if (delay - (suseconds_t)hctx->ccid3hctx_delta >= 0)
 			return delay / 1000L;
+
+		ccid3_hc_tx_update_win_count(hctx, &now);
 		break;
 	case TFRC_SSTATE_TERM:
-		DCCP_BUG("Illegal %s state TERM, sk=%p", dccp_role(sk), sk);
+		DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk);
 		return -EINVAL;
 	}
 
 	/* prepare to send now (add options etc.) */
 	dp->dccps_hc_tx_insert_options = 1;
-	new_packet->dccphtx_ccval = DCCP_SKB_CB(skb)->dccpd_ccval =
-				    hctx->ccid3hctx_last_win_count;
+	DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count;
+
+	/* set the nominal send time for the next following packet */
 	timeval_add_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi);
 
 	return 0;
 }
 
-static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, unsigned int len)
+static void ccid3_hc_tx_packet_sent(struct sock *sk, int more,
+				    unsigned int len)
 {
-	const struct dccp_sock *dp = dccp_sk(sk);
 	struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
 	struct timeval now;
-	unsigned long quarter_rtt;
 	struct dccp_tx_hist_entry *packet;
 
 	BUG_ON(hctx == NULL);
 
-	dccp_timestamp(sk, &now);
-
 	ccid3_hc_tx_update_s(hctx, len);
 
-	packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist);
+	packet = dccp_tx_hist_entry_new(ccid3_tx_hist, GFP_ATOMIC);
 	if (unlikely(packet == NULL)) {
-		DCCP_WARN("packet doesn't exist in history!\n");
+		DCCP_CRIT("packet history - out of memory!");
 		return;
 	}
-	if (unlikely(packet->dccphtx_sent)) {
-		DCCP_WARN("no unsent packet in history!\n");
-		return;
-	}
+	dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, packet);
+
+	dccp_timestamp(sk, &now);
 	packet->dccphtx_tstamp = now;
-	packet->dccphtx_seqno  = dp->dccps_gss;
-	/*
-	 * Check if win_count have changed
-	 * Algorithm in "8.1. Window Counter Value" in RFC 4342.
-	 */
-	quarter_rtt = timeval_delta(&now, &hctx->ccid3hctx_t_last_win_count);
-	if (likely(hctx->ccid3hctx_rtt > 8))
-		quarter_rtt /= hctx->ccid3hctx_rtt / 4;
-
-	if (quarter_rtt > 0) {
-		hctx->ccid3hctx_t_last_win_count = now;
-		hctx->ccid3hctx_last_win_count	 = (hctx->ccid3hctx_last_win_count +
-						    min_t(unsigned long, quarter_rtt, 5)) % 16;
-		ccid3_pr_debug("%s, sk=%p, window changed from "
-			       "%u to %u!\n",
-			       dccp_role(sk), sk,
-			       packet->dccphtx_ccval,
-			       hctx->ccid3hctx_last_win_count);
-	}
-
-	hctx->ccid3hctx_idle = 0;
-	packet->dccphtx_rtt  = hctx->ccid3hctx_rtt;
-	packet->dccphtx_sent = 1;
+	packet->dccphtx_seqno  = dccp_sk(sk)->dccps_gss;
+	packet->dccphtx_rtt    = hctx->ccid3hctx_rtt;
+	packet->dccphtx_sent   = 1;
+	hctx->ccid3hctx_idle   = 0;
 }
 
 static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
···
 	struct timeval now;
 	unsigned long t_nfb;
 	u32 pinv;
-	long r_sample, t_elapsed;
+	suseconds_t r_sample, t_elapsed;
 
 	BUG_ON(hctx == NULL);
 
···
 	case TFRC_SSTATE_FBACK:
 		/* get packet from history to look up t_recvdata */
 		packet = dccp_tx_hist_find_entry(&hctx->ccid3hctx_hist,
-						 DCCP_SKB_CB(skb)->dccpd_ack_seq);
+					      DCCP_SKB_CB(skb)->dccpd_ack_seq);
 		if (unlikely(packet == NULL)) {
 			DCCP_WARN("%s(%p), seqno %llu(%s) doesn'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));
+				dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type));
 			return;
 		}
 
-		/* Update receive rate */
+		/* Update receive rate in units of 64 * bytes/second */
 		hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate;
+		hctx->ccid3hctx_x_recv <<= 6;
 
 		/* Update loss event rate */
 		pinv = opt_recv->ccid3or_loss_event_rate;
-		if (pinv == ~0U || pinv == 0)
+		if (pinv == ~0U || pinv == 0)	       /* see RFC 4342, 8.5   */
 			hctx->ccid3hctx_p = 0;
-		else
- 			hctx->ccid3hctx_p = 1000000 / pinv;
+		else				       /* can not exceed 100% */
+			hctx->ccid3hctx_p = 1000000 / pinv;
 
 		dccp_timestamp(sk, &now);
 
 		/*
 		 * Calculate new round trip sample as per [RFC 3448, 4.3] by
-		 * 	R_sample  =  (now - t_recvdata) - t_elapsed
+		 *	R_sample  =  (now - t_recvdata) - t_elapsed
 		 */
 		r_sample  = timeval_delta(&now, &packet->dccphtx_tstamp);
 		t_elapsed = dp->dccps_options_received.dccpor_elapsed_time * 10;
 
-		if (unlikely(r_sample <= 0)) {
-			DCCP_WARN("WARNING: R_sample (%ld) <= 0!\n", r_sample);
-			r_sample = 0;
-		} else if (unlikely(r_sample <= t_elapsed))
-			DCCP_WARN("WARNING: r_sample=%ldus <= t_elapsed=%ldus\n",
-				  r_sample, t_elapsed);
+		DCCP_BUG_ON(r_sample < 0);
+		if (unlikely(r_sample <= t_elapsed))
+			DCCP_WARN("WARNING: r_sample=%dus <= t_elapsed=%dus\n",
+				  (int)r_sample, (int)t_elapsed);
 		else
 			r_sample -= t_elapsed;
+		CCID3_RTT_SANITY_CHECK(r_sample);
 
-		/* Update RTT estimate by 
+		/* Update RTT estimate by
 		 * If (No feedback recv)
 		 *    R = R_sample;
 		 * Else
···
 		 * q is a constant, RFC 3448 recomments 0.9
 		 */
 		if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
-			/* Use Larger Initial Windows [RFC 4342, sec. 5]
-			 * We deviate in that we use `s' instead of `MSS'. */
-			u16 w_init = max(    4 * hctx->ccid3hctx_s,
-					 max(2 * hctx->ccid3hctx_s, 4380));
+			/*
+			 * Larger Initial Windows [RFC 4342, sec. 5]
+			 * We deviate in that we use `s' instead of `MSS'.
+			 */
+			__u64 w_init = min(4 * hctx->ccid3hctx_s,
+					   max(2 * hctx->ccid3hctx_s, 4380));
 			hctx->ccid3hctx_rtt  = r_sample;
-			hctx->ccid3hctx_x    = usecs_div(w_init, r_sample);
+			hctx->ccid3hctx_x    = scaled_div(w_init << 6, r_sample);
 			hctx->ccid3hctx_t_ld = now;
 
 			ccid3_update_send_time(hctx);
 
-			ccid3_pr_debug("%s(%p), s=%u, w_init=%u, "
-				       "R_sample=%ldus, X=%u\n", dccp_role(sk),
-				       sk, hctx->ccid3hctx_s, w_init, r_sample,
-				       hctx->ccid3hctx_x);
+			ccid3_pr_debug("%s(%p), s=%u, w_init=%llu, "
+				       "R_sample=%dus, X=%u\n", dccp_role(sk),
+				       sk, hctx->ccid3hctx_s, w_init,
+				       (int)r_sample,
+				       (unsigned)(hctx->ccid3hctx_x >> 6));
 
 			ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
 		} else {
 			hctx->ccid3hctx_rtt = (9 * hctx->ccid3hctx_rtt +
-					           (u32)r_sample        ) / 10;
+					           (u32)r_sample) / 10;
 
+			/* Update sending rate (step 4 of [RFC 3448, 4.3]) */
+			if (hctx->ccid3hctx_p > 0)
+				hctx->ccid3hctx_x_calc =
+					tfrc_calc_x(hctx->ccid3hctx_s,
+						    hctx->ccid3hctx_rtt,
+						    hctx->ccid3hctx_p);
 			ccid3_hc_tx_update_x(sk, &now);
 
-			ccid3_pr_debug("%s(%p), RTT=%uus (sample=%ldus), s=%u, "
-				       "p=%u, X_calc=%u, X=%u\n", dccp_role(sk),
-				       sk, hctx->ccid3hctx_rtt, r_sample,
+			ccid3_pr_debug("%s(%p), RTT=%uus (sample=%dus), s=%u, "
+				       "p=%u, X_calc=%u, X_recv=%u, X=%u\n",
+				       dccp_role(sk),
+				       sk, hctx->ccid3hctx_rtt, (int)r_sample,
 				       hctx->ccid3hctx_s, hctx->ccid3hctx_p,
 				       hctx->ccid3hctx_x_calc,
-				       hctx->ccid3hctx_x);
+				       (unsigned)(hctx->ccid3hctx_x_recv >> 6),
+				       (unsigned)(hctx->ccid3hctx_x >> 6));
 		}
 
 		/* unschedule no feedback timer */
···
 		dccp_tx_hist_purge_older(ccid3_tx_hist,
 					 &hctx->ccid3hctx_hist, packet);
 		/*
-		 * As we have calculated new ipi, delta, t_nom it is possible that
-		 * we now can send a packet, so wake up dccp_wait_for_ccid
+		 * As we have calculated new ipi, delta, t_nom it is possible
+		 * that we now can send a packet, so wake up dccp_wait_for_ccid
 		 */
 		sk->sk_write_space(sk);
 
 		/*
 		 * Update timeout interval for the nofeedback timer.
 		 * We use a configuration option to increase the lower bound.
-		 * This can help avoid triggering the nofeedback timer too often
-		 * ('spinning') on LANs with small RTTs.
+		 * This can help avoid triggering the nofeedback timer too
+		 * often ('spinning') on LANs with small RTTs.
 		 */
 		hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt,
 						   CONFIG_IP_DCCP_CCID3_RTO *
-						   (USEC_PER_SEC/1000)	     );
+						   (USEC_PER_SEC/1000));
 		/*
 		 * Schedule no feedback timer to expire in
 		 * max(t_RTO, 2 * s/X)  =  max(t_RTO, 2 * t_ipi)
 		 */
 		t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
-			
-		ccid3_pr_debug("%s, sk=%p, Scheduled no feedback timer to "
-			       "expire in %lu jiffies (%luus)\n",
-			       dccp_role(sk), sk,
-			       usecs_to_jiffies(t_nfb), t_nfb);
 
-		sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, 
+		ccid3_pr_debug("%s(%p), Scheduled no feedback timer to "
+			       "expire in %lu jiffies (%luus)\n",
+			       dccp_role(sk),
+			       sk, usecs_to_jiffies(t_nfb), t_nfb);
+
+		sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
 				   jiffies + usecs_to_jiffies(t_nfb));
 
 		/* set idle flag */
-		hctx->ccid3hctx_idle = 1;   
+		hctx->ccid3hctx_idle = 1;
 		break;
 	case TFRC_SSTATE_NO_SENT:
-		if (dccp_sk(sk)->dccps_role == DCCP_ROLE_CLIENT)
-			DCCP_WARN("Illegal ACK received - no packet sent\n");
+		/*
+		 * XXX when implementing bidirectional rx/tx check this again
+		 */
+		DCCP_WARN("Illegal ACK received - no packet sent\n");
 		/* fall through */
 	case TFRC_SSTATE_TERM:		/* ignore feedback when closing */
 		break;
 	}
-}
-
-static int ccid3_hc_tx_insert_options(struct sock *sk, struct sk_buff *skb)
-{
-	const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
-
-	BUG_ON(hctx == NULL);
-
-	if (sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN)
-		DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count;
-	return 0;
 }
 
 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)) {
-			DCCP_WARN("%s, sk=%p, invalid len %d "
+			DCCP_WARN("%s(%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);
-			ccid3_pr_debug("%s, sk=%p, LOSS_EVENT_RATE=%u\n",
+			opt_recv->ccid3or_loss_event_rate =
+						ntohl(*(__be32 *)value);
+			ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n",
 				       dccp_role(sk), sk,
 				       opt_recv->ccid3or_loss_event_rate);
 		}
···
 	case TFRC_OPT_LOSS_INTERVALS:
 		opt_recv->ccid3or_loss_intervals_idx = idx;
 		opt_recv->ccid3or_loss_intervals_len = len;
-		ccid3_pr_debug("%s, sk=%p, LOSS_INTERVALS=(%u, %u)\n",
+		ccid3_pr_debug("%s(%p), LOSS_INTERVALS=(%u, %u)\n",
 			       dccp_role(sk), sk,
 			       opt_recv->ccid3or_loss_intervals_idx,
 			       opt_recv->ccid3or_loss_intervals_len);
 		break;
 	case TFRC_OPT_RECEIVE_RATE:
 		if (unlikely(len != 4)) {
-			DCCP_WARN("%s, sk=%p, invalid len %d "
+			DCCP_WARN("%s(%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);
-			ccid3_pr_debug("%s, sk=%p, RECEIVE_RATE=%u\n",
+			opt_recv->ccid3or_receive_rate =
+						ntohl(*(__be32 *)value);
+			ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n",
 				       dccp_role(sk), sk,
 				       opt_recv->ccid3or_receive_rate);
 		}
···
 	struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid);
 
 	hctx->ccid3hctx_s     = 0;
+	hctx->ccid3hctx_rtt   = 0;
 	hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT;
 	INIT_LIST_HEAD(&hctx->ccid3hctx_hist);
 
-	hctx->ccid3hctx_no_feedback_timer.function = ccid3_hc_tx_no_feedback_timer;
+	hctx->ccid3hctx_no_feedback_timer.function =
+				ccid3_hc_tx_no_feedback_timer;
 	hctx->ccid3hctx_no_feedback_timer.data     = (unsigned long)sk;
 	init_timer(&hctx->ccid3hctx_no_feedback_timer);
 
···
 	struct dccp_sock *dp = dccp_sk(sk);
 	struct dccp_rx_hist_entry *packet;
 	struct timeval now;
+	suseconds_t delta;
 
-	ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
+	ccid3_pr_debug("%s(%p) - entry \n", dccp_role(sk), sk);
 
 	dccp_timestamp(sk, &now);
 
···
 	case TFRC_RSTATE_NO_DATA:
 		hcrx->ccid3hcrx_x_recv = 0;
 		break;
-	case TFRC_RSTATE_DATA: {
-		const u32 delta = timeval_delta(&now,
-					&hcrx->ccid3hcrx_tstamp_last_feedback);
-		hcrx->ccid3hcrx_x_recv = usecs_div(hcrx->ccid3hcrx_bytes_recv,
-						   delta);
-	}
+	case TFRC_RSTATE_DATA:
+		delta = timeval_delta(&now,
+				      &hcrx->ccid3hcrx_tstamp_last_feedback);
+		DCCP_BUG_ON(delta < 0);
+		hcrx->ccid3hcrx_x_recv =
+			scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta);
 		break;
 	case TFRC_RSTATE_TERM:
-		DCCP_BUG("Illegal %s state TERM, sk=%p", dccp_role(sk), sk);
+		DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk);
 		return;
 	}
 
 	packet = dccp_rx_hist_find_data_packet(&hcrx->ccid3hcrx_hist);
 	if (unlikely(packet == NULL)) {
-		DCCP_WARN("%s, sk=%p, no data packet in history!\n",
+		DCCP_WARN("%s(%p), no data packet in history!\n",
 			  dccp_role(sk), sk);
 		return;
 	}
···
 	hcrx->ccid3hcrx_ccval_last_counter   = packet->dccphrx_ccval;
 	hcrx->ccid3hcrx_bytes_recv	     = 0;
 
-	/* Convert to multiples of 10us */
-	hcrx->ccid3hcrx_elapsed_time =
-			timeval_delta(&now, &packet->dccphrx_tstamp) / 10;
+	/* Elapsed time information [RFC 4340, 13.2] in units of 10 * usecs */
+	delta = timeval_delta(&now, &packet->dccphrx_tstamp);
+	DCCP_BUG_ON(delta < 0);
+	hcrx->ccid3hcrx_elapsed_time = delta / 10;
+
 	if (hcrx->ccid3hcrx_p == 0)
-		hcrx->ccid3hcrx_pinv = ~0;
-	else
+		hcrx->ccid3hcrx_pinv = ~0U;	/* see RFC 4342, 8.5 */
+	else if (hcrx->ccid3hcrx_p > 1000000) {
+		DCCP_WARN("p (%u) > 100%%\n", hcrx->ccid3hcrx_p);
+		hcrx->ccid3hcrx_pinv = 1;	/* use 100% in this case */
+	} else
 		hcrx->ccid3hcrx_pinv = 1000000 / hcrx->ccid3hcrx_p;
+
 	dp->dccps_hc_rx_insert_options = 1;
 	dccp_send_ack(sk);
 }
···
 					     hcrx->ccid3hcrx_elapsed_time)) ||
 	    dccp_insert_option_timestamp(sk, skb) ||
 	    dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE,
-		    	       &pinv, sizeof(pinv)) ||
+			       &pinv, sizeof(pinv)) ||
 	    dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE,
-		    	       &x_recv, sizeof(x_recv)))
+			       &x_recv, sizeof(x_recv)))
 		return -1;
 
 	return 0;
···
 {
 	struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
 	struct dccp_rx_hist_entry *entry, *next, *tail = NULL;
-	u32 rtt, delta, x_recv, fval, p, tmp2;
+	u32 x_recv, p;
+	suseconds_t rtt, delta;
 	struct timeval tstamp = { 0, };
 	int interval = 0;
 	int win_count = 0;
 	int step = 0;
-	u64 tmp1;
+	u64 fval;
 
 	list_for_each_entry_safe(entry, next, &hcrx->ccid3hcrx_hist,
 				 dccphrx_node) {
···
 	}
 
 	if (unlikely(step == 0)) {
-		DCCP_WARN("%s, sk=%p, packet history has no data packets!\n",
+		DCCP_WARN("%s(%p), packet history has no data packets!\n",
 			  dccp_role(sk), sk);
 		return ~0;
 	}
 
 	if (unlikely(interval == 0)) {
-		DCCP_WARN("%s, sk=%p, Could not find a win_count interval > 0."
+		DCCP_WARN("%s(%p), Could not find a win_count interval > 0."
 			  "Defaulting to 1\n", dccp_role(sk), sk);
 		interval = 1;
 	}
···
 		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) {
-		DCCP_WARN("RTT==0, setting to 1\n");
- 		rtt = 1;
+	delta = timeval_delta(&tstamp, &tail->dccphrx_tstamp);
+	DCCP_BUG_ON(delta < 0);
+
+	rtt = delta * 4 / interval;
+	ccid3_pr_debug("%s(%p), approximated RTT to %dus\n",
+		       dccp_role(sk), sk, (int)rtt);
+
+	/*
+	 * Determine the length of the first loss interval via inverse lookup.
+	 * Assume that X_recv can be computed by the throughput equation
+	 *		    s
+	 *	X_recv = --------
+	 *		 R * fval
+	 * Find some p such that f(p) = fval; return 1/p [RFC 3448, 6.3.1].
+	 */
+	if (rtt == 0) {			/* would result in divide-by-zero */
+		DCCP_WARN("RTT==0, returning 1/p = 1\n");
+		return 1000000;
 	}
 
 	dccp_timestamp(sk, &tstamp);
 	delta = timeval_delta(&tstamp, &hcrx->ccid3hcrx_tstamp_last_feedback);
-	x_recv = usecs_div(hcrx->ccid3hcrx_bytes_recv, delta);
+	DCCP_BUG_ON(delta <= 0);
 
-	if (x_recv == 0)
-		x_recv = hcrx->ccid3hcrx_x_recv;
-
-	tmp1 = (u64)x_recv * (u64)rtt;
-	do_div(tmp1,10000000);
-	tmp2 = (u32)tmp1;
-
-	if (!tmp2) {
-		DCCP_CRIT("tmp2 = 0, x_recv = %u, rtt =%u\n", x_recv, rtt);
-		return ~0;
+	x_recv = scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta);
+	if (x_recv == 0) {		/* would also trigger divide-by-zero */
+		DCCP_WARN("X_recv==0\n");
+		if ((x_recv = hcrx->ccid3hcrx_x_recv) == 0) {
+			DCCP_BUG("stored value of X_recv is zero");
+			return 1000000;
+		}
 	}
 
-	fval = (hcrx->ccid3hcrx_s * 100000) / tmp2;
-	/* do not alter order above or you will get overflow on 32 bit */
+	fval = scaled_div(hcrx->ccid3hcrx_s, rtt);
+	fval = scaled_div32(fval, x_recv);
 	p = tfrc_calc_x_reverse_lookup(fval);
-	ccid3_pr_debug("%s, sk=%p, receive rate=%u bytes/s, implied "
+
+	ccid3_pr_debug("%s(%p), receive rate=%u bytes/s, implied "
 		       "loss rate=%u\n", dccp_role(sk), sk, x_recv, p);
 
 	if (p == 0)
 		return ~0;
 	else
-		return 1000000 / p; 
+		return 1000000 / p;
 }
 
 static void ccid3_hc_rx_update_li(struct sock *sk, u64 seq_loss, u8 win_loss)
···
                                     struct dccp_rx_hist_entry *packet)
 {
 	struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
-	struct dccp_rx_hist_entry *rx_hist = dccp_rx_hist_head(&hcrx->ccid3hcrx_hist);
+	struct dccp_rx_hist_entry *rx_hist =
+				dccp_rx_hist_head(&hcrx->ccid3hcrx_hist);
 	u64 seqno = packet->dccphrx_seqno;
 	u64 tmp_seqno;
 	int loss = 0;
···
 		dccp_inc_seqno(&tmp_seqno);
 		while (dccp_rx_hist_find_entry(&hcrx->ccid3hcrx_hist,
 		   tmp_seqno, &ccval)) {
-		   	hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno;
+			hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno;
 			hcrx->ccid3hcrx_ccval_nonloss = ccval;
 			dccp_inc_seqno(&tmp_seqno);
 		}
···
 	const struct dccp_options_received *opt_recv;
 	struct dccp_rx_hist_entry *packet;
 	struct timeval now;
-	u32 p_prev, rtt_prev, r_sample, t_elapsed;
+	u32 p_prev, rtt_prev;
+	suseconds_t r_sample, t_elapsed;
 	int loss, payload_size;
 
 	BUG_ON(hcrx == NULL);
···
 		r_sample = timeval_usecs(&now);
 		t_elapsed = opt_recv->dccpor_elapsed_time * 10;
 
+		DCCP_BUG_ON(r_sample < 0);
 		if (unlikely(r_sample <= t_elapsed))
-			DCCP_WARN("r_sample=%uus, t_elapsed=%uus\n",
+			DCCP_WARN("r_sample=%ldus, t_elapsed=%ldus\n",
 				  r_sample, t_elapsed);
 		else
 			r_sample -= t_elapsed;
+		CCID3_RTT_SANITY_CHECK(r_sample);
 
 		if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
 			hcrx->ccid3hcrx_rtt = r_sample;
···
 					      r_sample / 10;
 
 		if (rtt_prev != hcrx->ccid3hcrx_rtt)
-			ccid3_pr_debug("%s, New RTT=%uus, elapsed time=%u\n",
-				       dccp_role(sk), hcrx->ccid3hcrx_rtt,
+			ccid3_pr_debug("%s(%p), New RTT=%uus, elapsed time=%u\n",
+				       dccp_role(sk), sk, hcrx->ccid3hcrx_rtt,
 				       opt_recv->dccpor_elapsed_time);
 		break;
 	case DCCP_PKT_DATA:
···
 	packet = dccp_rx_hist_entry_new(ccid3_rx_hist, sk, opt_recv->dccpor_ndp,
 					skb, GFP_ATOMIC);
 	if (unlikely(packet == NULL)) {
-		DCCP_WARN("%s, sk=%p, Not enough mem to add rx packet "
+		DCCP_WARN("%s(%p), Not enough mem to add rx packet "
 			  "to history, consider it lost!\n", dccp_role(sk), sk);
 		return;
 	}
···
 
 	switch (hcrx->ccid3hcrx_state) {
 	case TFRC_RSTATE_NO_DATA:
-		ccid3_pr_debug("%s, sk=%p(%s), skb=%p, sending initial "
-			       "feedback\n",
-			       dccp_role(sk), sk,
+		ccid3_pr_debug("%s(%p, state=%s), skb=%p, sending initial "
+			       "feedback\n", dccp_role(sk), sk,
 			       dccp_state_name(sk->sk_state), skb);
 		ccid3_hc_rx_send_feedback(sk);
 		ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA);
···
 			break;
 
 		dccp_timestamp(sk, &now);
-		if (timeval_delta(&now, &hcrx->ccid3hcrx_tstamp_last_ack) >=
-		    hcrx->ccid3hcrx_rtt) {
+		if ((timeval_delta(&now, &hcrx->ccid3hcrx_tstamp_last_ack) -
+		     (suseconds_t)hcrx->ccid3hcrx_rtt) >= 0) {
 			hcrx->ccid3hcrx_tstamp_last_ack = now;
 			ccid3_hc_rx_send_feedback(sk);
 		}
 		return;
 	case TFRC_RSTATE_TERM:
-		DCCP_BUG("Illegal %s state TERM, sk=%p", dccp_role(sk), sk);
+		DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk);
 		return;
 	}
 
 	/* Dealing with packet loss */
-	ccid3_pr_debug("%s, sk=%p(%s), data loss! Reacting...\n",
+	ccid3_pr_debug("%s(%p, state=%s), data loss! Reacting...\n",
 		       dccp_role(sk), sk, dccp_state_name(sk->sk_state));
 
 	p_prev = hcrx->ccid3hcrx_p;
···
 {
 	struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid);
 
-	ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
+	ccid3_pr_debug("entry\n");
 
 	hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA;
 	INIT_LIST_HEAD(&hcrx->ccid3hcrx_hist);
···
 	dccp_timestamp(sk, &hcrx->ccid3hcrx_tstamp_last_ack);
 	hcrx->ccid3hcrx_tstamp_last_feedback = hcrx->ccid3hcrx_tstamp_last_ack;
 	hcrx->ccid3hcrx_s   = 0;
-	hcrx->ccid3hcrx_rtt = 5000; /* XXX 5ms for now... */
+	hcrx->ccid3hcrx_rtt = 0;
 	return 0;
 }
 
···
 
 	BUG_ON(hcrx == NULL);
 
-	info->tcpi_ca_state	= hcrx->ccid3hcrx_state;
-	info->tcpi_options	|= TCPI_OPT_TIMESTAMPS;
-	info->tcpi_rcv_rtt	= hcrx->ccid3hcrx_rtt;
+	info->tcpi_ca_state = hcrx->ccid3hcrx_state;
+	info->tcpi_options  |= TCPI_OPT_TIMESTAMPS;
+	info->tcpi_rcv_rtt  = hcrx->ccid3hcrx_rtt;
 }
 
 static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info)
···
 	.ccid_hc_tx_send_packet	   = ccid3_hc_tx_send_packet,
 	.ccid_hc_tx_packet_sent	   = ccid3_hc_tx_packet_sent,
 	.ccid_hc_tx_packet_recv	   = ccid3_hc_tx_packet_recv,
-	.ccid_hc_tx_insert_options = ccid3_hc_tx_insert_options,
 	.ccid_hc_tx_parse_options  = ccid3_hc_tx_parse_options,
 	.ccid_hc_rx_obj_size	   = sizeof(struct ccid3_hc_rx_sock),
 	.ccid_hc_rx_init	   = ccid3_hc_rx_init,
···
 	.ccid_hc_rx_getsockopt	   = ccid3_hc_rx_getsockopt,
 	.ccid_hc_tx_getsockopt	   = ccid3_hc_tx_getsockopt,
 };
- 
+
 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
 module_param(ccid3_debug, int, 0444);
 MODULE_PARM_DESC(ccid3_debug, "Enable debug messages");
···
 		goto out_free_tx;
 
 	rc = ccid_register(&ccid3);
-	if (rc != 0) 
+	if (rc != 0)
 		goto out_free_loss_interval_history;
 out:
 	return rc;

net/dccp/ccids/ccid3.h

···
 /* Parameter t_mbi from [RFC 3448, 4.3]: backoff interval in seconds */
 #define TFRC_T_MBI		   64
 
+/* What we think is a reasonable upper limit on RTT values */
+#define CCID3_SANE_RTT_MAX	   ((suseconds_t)(4 * USEC_PER_SEC))
+
+#define CCID3_RTT_SANITY_CHECK(rtt) 			do {		   \
+		if (rtt > CCID3_SANE_RTT_MAX) {				   \
+			DCCP_CRIT("RTT (%d) too large, substituting %d",   \
+				  (int)rtt, (int)CCID3_SANE_RTT_MAX);	   \
+			rtt = CCID3_SANE_RTT_MAX;			   \
+		} 					} while (0)
+
 enum ccid3_options {
 	TFRC_OPT_LOSS_EVENT_RATE = 192,
 	TFRC_OPT_LOSS_INTERVALS	 = 193,
···
 
 /* TFRC sender states */
 enum ccid3_hc_tx_states {
-       	TFRC_SSTATE_NO_SENT = 1,
+	TFRC_SSTATE_NO_SENT = 1,
 	TFRC_SSTATE_NO_FBACK,
 	TFRC_SSTATE_FBACK,
 	TFRC_SSTATE_TERM,
···
 
 /** struct ccid3_hc_tx_sock - CCID3 sender half-connection socket
  *
- * @ccid3hctx_x - Current sending rate
- * @ccid3hctx_x_recv - Receive rate
- * @ccid3hctx_x_calc - Calculated send rate (RFC 3448, 3.1)
+ * @ccid3hctx_x - Current sending rate in 64 * bytes per second
+ * @ccid3hctx_x_recv - Receive rate    in 64 * bytes per second
+ * @ccid3hctx_x_calc - Calculated rate in bytes per second
  * @ccid3hctx_rtt - Estimate of current round trip time in usecs
  * @ccid3hctx_p - Current loss event rate (0-1) scaled by 1000000
- * @ccid3hctx_s - Packet size
- * @ccid3hctx_t_rto - Retransmission Timeout (RFC 3448, 3.1)
- * @ccid3hctx_t_ipi - Interpacket (send) interval (RFC 3448, 4.6)
+ * @ccid3hctx_s - Packet size in bytes
+ * @ccid3hctx_t_rto - Nofeedback Timer setting in usecs
+ * @ccid3hctx_t_ipi - Interpacket (send) interval (RFC 3448, 4.6) in usecs
  * @ccid3hctx_state - Sender state, one of %ccid3_hc_tx_states
  * @ccid3hctx_last_win_count - Last window counter sent
  * @ccid3hctx_t_last_win_count - Timestamp of earliest packet
- * 				 with last_win_count value sent
+ *				 with last_win_count value sent
  * @ccid3hctx_no_feedback_timer - Handle to no feedback timer
  * @ccid3hctx_idle - Flag indicating that sender is idling
  * @ccid3hctx_t_ld - Time last doubled during slow start
  * @ccid3hctx_t_nom - Nominal send time of next packet
- * @ccid3hctx_delta - Send timer delta
+ * @ccid3hctx_delta - Send timer delta (RFC 3448, 4.6) in usecs
  * @ccid3hctx_hist - Packet history
  * @ccid3hctx_options_received - Parsed set of retrieved options
  */
···
 #define ccid3hctx_t_rto			ccid3hctx_tfrc.tfrctx_rto
 #define ccid3hctx_t_ipi			ccid3hctx_tfrc.tfrctx_ipi
 	u16				ccid3hctx_s;
-  	enum ccid3_hc_tx_states 	ccid3hctx_state:8;
+	enum ccid3_hc_tx_states		ccid3hctx_state:8;
 	u8				ccid3hctx_last_win_count;
 	u8				ccid3hctx_idle;
 	struct timeval			ccid3hctx_t_last_win_count;
···
 
 /* TFRC receiver states */
 enum ccid3_hc_rx_states {
-       	TFRC_RSTATE_NO_DATA = 1,
+	TFRC_RSTATE_NO_DATA = 1,
 	TFRC_RSTATE_DATA,
 	TFRC_RSTATE_TERM    = 127,
 };
···
 #define ccid3hcrx_x_recv		ccid3hcrx_tfrc.tfrcrx_x_recv
 #define ccid3hcrx_rtt			ccid3hcrx_tfrc.tfrcrx_rtt
 #define ccid3hcrx_p			ccid3hcrx_tfrc.tfrcrx_p
-  	u64				ccid3hcrx_seqno_nonloss:48,
+	u64				ccid3hcrx_seqno_nonloss:48,
 					ccid3hcrx_ccval_nonloss:4,
 					ccid3hcrx_ccval_last_counter:4;
 	enum ccid3_hc_rx_states		ccid3hcrx_state:8;
-  	u32				ccid3hcrx_bytes_recv;
-  	struct timeval			ccid3hcrx_tstamp_last_feedback;
-  	struct timeval			ccid3hcrx_tstamp_last_ack;
+	u32				ccid3hcrx_bytes_recv;
+	struct timeval			ccid3hcrx_tstamp_last_feedback;
+	struct timeval			ccid3hcrx_tstamp_last_ack;
 	struct list_head		ccid3hcrx_hist;
 	struct list_head		ccid3hcrx_li_hist;
-  	u16				ccid3hcrx_s;
-  	u32				ccid3hcrx_pinv;
-  	u32				ccid3hcrx_elapsed_time;
+	u16				ccid3hcrx_s;
+	u32				ccid3hcrx_pinv;
+	u32				ccid3hcrx_elapsed_time;
 };
 
 static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk)

net/dccp/ccids/lib/packet_history.c

···
 
 #include <linux/module.h>
 #include <linux/string.h>
-
 #include "packet_history.h"
 
+/*
+ * 	Transmitter History Routines
+ */
+struct dccp_tx_hist *dccp_tx_hist_new(const char *name)
+{
+	struct dccp_tx_hist *hist = kmalloc(sizeof(*hist), GFP_ATOMIC);
+	static const char dccp_tx_hist_mask[] = "tx_hist_%s";
+	char *slab_name;
+
+	if (hist == NULL)
+		goto out;
+
+	slab_name = kmalloc(strlen(name) + sizeof(dccp_tx_hist_mask) - 1,
+			    GFP_ATOMIC);
+	if (slab_name == NULL)
+		goto out_free_hist;
+
+	sprintf(slab_name, dccp_tx_hist_mask, name);
+	hist->dccptxh_slab = kmem_cache_create(slab_name,
+					     sizeof(struct dccp_tx_hist_entry),
+					       0, SLAB_HWCACHE_ALIGN,
+					       NULL, NULL);
+	if (hist->dccptxh_slab == NULL)
+		goto out_free_slab_name;
+out:
+	return hist;
+out_free_slab_name:
+	kfree(slab_name);
+out_free_hist:
+	kfree(hist);
+	hist = NULL;
+	goto out;
+}
+
+EXPORT_SYMBOL_GPL(dccp_tx_hist_new);
+
+void dccp_tx_hist_delete(struct dccp_tx_hist *hist)
+{
+	const char* name = kmem_cache_name(hist->dccptxh_slab);
+
+	kmem_cache_destroy(hist->dccptxh_slab);
+	kfree(name);
+	kfree(hist);
+}
+
+EXPORT_SYMBOL_GPL(dccp_tx_hist_delete);
+
+struct dccp_tx_hist_entry *
+	dccp_tx_hist_find_entry(const struct list_head *list, const u64 seq)
+{
+	struct dccp_tx_hist_entry *packet = NULL, *entry;
+
+	list_for_each_entry(entry, list, dccphtx_node)
+		if (entry->dccphtx_seqno == seq) {
+			packet = entry;
+			break;
+		}
+
+	return packet;
+}
+
+EXPORT_SYMBOL_GPL(dccp_tx_hist_find_entry);
+
+void dccp_tx_hist_purge(struct dccp_tx_hist *hist, struct list_head *list)
+{
+	struct dccp_tx_hist_entry *entry, *next;
+
+	list_for_each_entry_safe(entry, next, list, dccphtx_node) {
+		list_del_init(&entry->dccphtx_node);
+		dccp_tx_hist_entry_delete(hist, entry);
+	}
+}
+
+EXPORT_SYMBOL_GPL(dccp_tx_hist_purge);
+
+void dccp_tx_hist_purge_older(struct dccp_tx_hist *hist,
+			      struct list_head *list,
+			      struct dccp_tx_hist_entry *packet)
+{
+	struct dccp_tx_hist_entry *next;
+
+	list_for_each_entry_safe_continue(packet, next, list, dccphtx_node) {
+		list_del_init(&packet->dccphtx_node);
+		dccp_tx_hist_entry_delete(hist, packet);
+	}
+}
+
+EXPORT_SYMBOL_GPL(dccp_tx_hist_purge_older);
+
+/*
+ * 	Receiver History Routines
+ */
 struct dccp_rx_hist *dccp_rx_hist_new(const char *name)
 {
 	struct dccp_rx_hist *hist = kmalloc(sizeof(*hist), GFP_ATOMIC);
···
 
 EXPORT_SYMBOL_GPL(dccp_rx_hist_delete);
 
-void dccp_rx_hist_purge(struct dccp_rx_hist *hist, struct list_head *list)
+int dccp_rx_hist_find_entry(const struct list_head *list, const u64 seq,
+			    u8 *ccval)
 {
-	struct dccp_rx_hist_entry *entry, *next;
+	struct dccp_rx_hist_entry *packet = NULL, *entry;
 
-	list_for_each_entry_safe(entry, next, list, dccphrx_node) {
-		list_del_init(&entry->dccphrx_node);
-		kmem_cache_free(hist->dccprxh_slab, entry);
-	}
+	list_for_each_entry(entry, list, dccphrx_node)
+		if (entry->dccphrx_seqno == seq) {
+			packet = entry;
+			break;
+		}
+
+	if (packet)
+		*ccval = packet->dccphrx_ccval;
+
+	return packet != NULL;
 }
 
-EXPORT_SYMBOL_GPL(dccp_rx_hist_purge);
-
+EXPORT_SYMBOL_GPL(dccp_rx_hist_find_entry);
 struct dccp_rx_hist_entry *
 		dccp_rx_hist_find_data_packet(const struct list_head *list)
 {
···
 
 EXPORT_SYMBOL_GPL(dccp_rx_hist_add_packet);
 
-struct dccp_tx_hist *dccp_tx_hist_new(const char *name)
+void dccp_rx_hist_purge(struct dccp_rx_hist *hist, struct list_head *list)
 {
-	struct dccp_tx_hist *hist = kmalloc(sizeof(*hist), GFP_ATOMIC);
-	static const char dccp_tx_hist_mask[] = "tx_hist_%s";
-	char *slab_name;
+	struct dccp_rx_hist_entry *entry, *next;
 
-	if (hist == NULL)
-		goto out;
-
-	slab_name = kmalloc(strlen(name) + sizeof(dccp_tx_hist_mask) - 1,
-			    GFP_ATOMIC);
-	if (slab_name == NULL)
-		goto out_free_hist;
-
-	sprintf(slab_name, dccp_tx_hist_mask, name);
-	hist->dccptxh_slab = kmem_cache_create(slab_name,
-					     sizeof(struct dccp_tx_hist_entry),
-					       0, SLAB_HWCACHE_ALIGN,
-					       NULL, NULL);
-	if (hist->dccptxh_slab == NULL)
-		goto out_free_slab_name;
-out:
-	return hist;
-out_free_slab_name:
-	kfree(slab_name);
-out_free_hist:
-	kfree(hist);
-	hist = NULL;
-	goto out;
-}
-
-EXPORT_SYMBOL_GPL(dccp_tx_hist_new);
-
-void dccp_tx_hist_delete(struct dccp_tx_hist *hist)
-{
-	const char* name = kmem_cache_name(hist->dccptxh_slab);
-
-	kmem_cache_destroy(hist->dccptxh_slab);
-	kfree(name);
-	kfree(hist);
-}
-
-EXPORT_SYMBOL_GPL(dccp_tx_hist_delete);
-
-struct dccp_tx_hist_entry *
-	dccp_tx_hist_find_entry(const struct list_head *list, const u64 seq)
-{
-	struct dccp_tx_hist_entry *packet = NULL, *entry;
-
-	list_for_each_entry(entry, list, dccphtx_node)
-		if (entry->dccphtx_seqno == seq) {
-			packet = entry;
-			break;
-		}
-
-	return packet;
-}
-
-EXPORT_SYMBOL_GPL(dccp_tx_hist_find_entry);
-
-int dccp_rx_hist_find_entry(const struct list_head *list, const u64 seq,
-   u8 *ccval)
-{
-	struct dccp_rx_hist_entry *packet = NULL, *entry;
-
-	list_for_each_entry(entry, list, dccphrx_node)
-		if (entry->dccphrx_seqno == seq) {
-			packet = entry;
-			break;
-		}
-
-	if (packet)
-		*ccval = packet->dccphrx_ccval;
-
-	return packet != NULL;
-}
-
-EXPORT_SYMBOL_GPL(dccp_rx_hist_find_entry);
-
-void dccp_tx_hist_purge_older(struct dccp_tx_hist *hist,
-			      struct list_head *list,
-			      struct dccp_tx_hist_entry *packet)
-{
-	struct dccp_tx_hist_entry *next;
-
-	list_for_each_entry_safe_continue(packet, next, list, dccphtx_node) {
-		list_del_init(&packet->dccphtx_node);
-		dccp_tx_hist_entry_delete(hist, packet);
+	list_for_each_entry_safe(entry, next, list, dccphrx_node) {
+		list_del_init(&entry->dccphrx_node);
+		kmem_cache_free(hist->dccprxh_slab, entry);
 	}
 }
 
-EXPORT_SYMBOL_GPL(dccp_tx_hist_purge_older);
+EXPORT_SYMBOL_GPL(dccp_rx_hist_purge);
 
-void dccp_tx_hist_purge(struct dccp_tx_hist *hist, struct list_head *list)
-{
-	struct dccp_tx_hist_entry *entry, *next;
-
-	list_for_each_entry_safe(entry, next, list, dccphtx_node) {
-		list_del_init(&entry->dccphtx_node);
-		dccp_tx_hist_entry_delete(hist, entry);
-	}
-}
-
-EXPORT_SYMBOL_GPL(dccp_tx_hist_purge);
 
 MODULE_AUTHOR("Ian McDonald <[e-mail]>, "
 	      "Arnaldo Carvalho de Melo <[e-mail]>");

net/dccp/ccids/lib/packet_history.h

···
 #define TFRC_WIN_COUNT_PER_RTT	 4
 #define TFRC_WIN_COUNT_LIMIT	16
 
+/*
+ * 	Transmitter History data structures and declarations
+ */
 struct dccp_tx_hist_entry {
 	struct list_head dccphtx_node;
 	u64		 dccphtx_seqno:48,
-			 dccphtx_ccval:4,
 			 dccphtx_sent:1;
 	u32		 dccphtx_rtt;
 	struct timeval	 dccphtx_tstamp;
-};
-
-struct dccp_rx_hist_entry {
-	struct list_head dccphrx_node;
-	u64		 dccphrx_seqno:48,
-			 dccphrx_ccval:4,
-			 dccphrx_type:4;
-	u32		 dccphrx_ndp; /* In fact it is from 8 to 24 bits */
-	struct timeval	 dccphrx_tstamp;
 };
 
 struct dccp_tx_hist {
···
 };
 
 extern struct dccp_tx_hist *dccp_tx_hist_new(const char *name);
-extern void dccp_tx_hist_delete(struct dccp_tx_hist *hist);
-
-struct dccp_rx_hist {
-	struct kmem_cache *dccprxh_slab;
-};
-
-extern struct dccp_rx_hist *dccp_rx_hist_new(const char *name);
-extern void dccp_rx_hist_delete(struct dccp_rx_hist *hist);
-extern struct dccp_rx_hist_entry *
-		dccp_rx_hist_find_data_packet(const struct list_head *list);
+extern void 		    dccp_tx_hist_delete(struct dccp_tx_hist *hist);
 
 static inline struct dccp_tx_hist_entry *
-		dccp_tx_hist_entry_new(struct dccp_tx_hist *hist,
-				       const gfp_t prio)
+			dccp_tx_hist_entry_new(struct dccp_tx_hist *hist,
+					       const gfp_t prio)
 {
 	struct dccp_tx_hist_entry *entry = kmem_cache_alloc(hist->dccptxh_slab,
 							    prio);
···
 	return entry;
 }
 
-static inline void dccp_tx_hist_entry_delete(struct dccp_tx_hist *hist,
-					     struct dccp_tx_hist_entry *entry)
-{
-	if (entry != NULL)
-		kmem_cache_free(hist->dccptxh_slab, entry);
-}
-
-extern struct dccp_tx_hist_entry *
-			dccp_tx_hist_find_entry(const struct list_head *list,
-						const u64 seq);
-extern int dccp_rx_hist_find_entry(const struct list_head *list, const u64 seq,
-   u8 *ccval);
-
-static inline void dccp_tx_hist_add_entry(struct list_head *list,
-					  struct dccp_tx_hist_entry *entry)
-{
-	list_add(&entry->dccphtx_node, list);
-}
-
-extern void dccp_tx_hist_purge_older(struct dccp_tx_hist *hist,
-				     struct list_head *list,
-				     struct dccp_tx_hist_entry *next);
-
-extern void dccp_tx_hist_purge(struct dccp_tx_hist *hist,
-			       struct list_head *list);
-
 static inline struct dccp_tx_hist_entry *
-		dccp_tx_hist_head(struct list_head *list)
+			dccp_tx_hist_head(struct list_head *list)
 {
 	struct dccp_tx_hist_entry *head = NULL;
 
···
 	return head;
 }
 
+extern struct dccp_tx_hist_entry *
+			dccp_tx_hist_find_entry(const struct list_head *list,
+						const u64 seq);
+
+static inline void dccp_tx_hist_add_entry(struct list_head *list,
+					  struct dccp_tx_hist_entry *entry)
+{
+	list_add(&entry->dccphtx_node, list);
+}
+
+static inline void dccp_tx_hist_entry_delete(struct dccp_tx_hist *hist,
+					     struct dccp_tx_hist_entry *entry)
+{
+	if (entry != NULL)
+		kmem_cache_free(hist->dccptxh_slab, entry);
+}
+
+extern void dccp_tx_hist_purge(struct dccp_tx_hist *hist,
+			       struct list_head *list);
+
+extern void dccp_tx_hist_purge_older(struct dccp_tx_hist *hist,
+				     struct list_head *list,
+				     struct dccp_tx_hist_entry *next);
+
+/*
+ * 	Receiver History data structures and declarations
+ */
+struct dccp_rx_hist_entry {
+	struct list_head dccphrx_node;
+	u64		 dccphrx_seqno:48,
+			 dccphrx_ccval:4,
+			 dccphrx_type:4;
+	u32		 dccphrx_ndp; /* In fact it is from 8 to 24 bits */
+	struct timeval	 dccphrx_tstamp;
+};
+
+struct dccp_rx_hist {
+	struct kmem_cache *dccprxh_slab;
+};
+
+extern struct dccp_rx_hist *dccp_rx_hist_new(const char *name);
+extern void 		dccp_rx_hist_delete(struct dccp_rx_hist *hist);
+
 static inline struct dccp_rx_hist_entry *
-		     dccp_rx_hist_entry_new(struct dccp_rx_hist *hist,
-				     	    const struct sock *sk, 
-				     	    const u32 ndp, 
-					    const struct sk_buff *skb,
-					    const gfp_t prio)
+			dccp_rx_hist_entry_new(struct dccp_rx_hist *hist,
+					       const struct sock *sk,
+				     	       const u32 ndp,
+					       const struct sk_buff *skb,
+					       const gfp_t prio)
 {
 	struct dccp_rx_hist_entry *entry = kmem_cache_alloc(hist->dccprxh_slab,
 							    prio);
···
 	return entry;
 }
 
+static inline struct dccp_rx_hist_entry *
+			dccp_rx_hist_head(struct list_head *list)
+{
+	struct dccp_rx_hist_entry *head = NULL;
+
+	if (!list_empty(list))
+		head = list_entry(list->next, struct dccp_rx_hist_entry,
+				  dccphrx_node);
+	return head;
+}
+
+extern int dccp_rx_hist_find_entry(const struct list_head *list, const u64 seq,
+   				   u8 *ccval);
+extern struct dccp_rx_hist_entry *
+		dccp_rx_hist_find_data_packet(const struct list_head *list);
+
+extern void dccp_rx_hist_add_packet(struct dccp_rx_hist *hist,
+				    struct list_head *rx_list,
+				    struct list_head *li_list,
+				    struct dccp_rx_hist_entry *packet,
+				    u64 nonloss_seqno);
+
 static inline void dccp_rx_hist_entry_delete(struct dccp_rx_hist *hist,
 					     struct dccp_rx_hist_entry *entry)
 {
···
 extern void dccp_rx_hist_purge(struct dccp_rx_hist *hist,
 			       struct list_head *list);
 
-static inline struct dccp_rx_hist_entry *
-		dccp_rx_hist_head(struct list_head *list)
-{
-	struct dccp_rx_hist_entry *head = NULL;
-
-	if (!list_empty(list))
-		head = list_entry(list->next, struct dccp_rx_hist_entry,
-				  dccphrx_node);
-	return head;
-}
-
 static inline int
 	dccp_rx_hist_entry_data_packet(const struct dccp_rx_hist_entry *entry)
 {
 	return entry->dccphrx_type == DCCP_PKT_DATA ||
 	       entry->dccphrx_type == DCCP_PKT_DATAACK;
 }
-
-extern void dccp_rx_hist_add_packet(struct dccp_rx_hist *hist,
-				   struct list_head *rx_list,
-				   struct list_head *li_list,
-				   struct dccp_rx_hist_entry *packet,
-				   u64 nonloss_seqno);
 
 extern u64 dccp_rx_hist_detect_loss(struct list_head *rx_list,
 				    struct list_head *li_list, u8 *win_loss);

net/dccp/ccids/lib/tfrc.h

···
  *  the Free Software Foundation; either version 2 of the License, or
  *  (at your option) any later version.
  */
-
 #include <linux/types.h>
+#include <asm/div64.h>
+
+/* integer-arithmetic divisions of type (a * 1000000)/b */
+static inline u64 scaled_div(u64 a, u32 b)
+{
+	BUG_ON(b==0);
+	a *= 1000000;
+	do_div(a, b);
+	return a;
+}
+
+static inline u32 scaled_div32(u64 a, u32 b)
+{
+	u64 result = scaled_div(a, b);
+
+	if (result > UINT_MAX) {
+		DCCP_CRIT("Overflow: a(%llu)/b(%u) > ~0U",
+			  (unsigned long long)a, b);
+		return UINT_MAX;
+	}
+	return result;
+}
 
 extern u32 tfrc_calc_x(u16 s, u32 R, u32 p);
 extern u32 tfrc_calc_x_reverse_lookup(u32 fvalue);

net/dccp/ccids/lib/tfrc_equation.c

···
  */
 
 #include <linux/module.h>
-#include <asm/div64.h>
 #include "../../dccp.h"
 #include "tfrc.h"
 
···
  *  @R: RTT                  scaled by 1000000   (i.e., microseconds)
  *  @p: loss ratio estimate  scaled by 1000000
  *  Returns X_calc           in bytes per second (not scaled).
- *
- * Note: DO NOT alter this code unless you run test cases against it,
- *       as the code has been optimized to stop underflow/overflow.
  */
 u32 tfrc_calc_x(u16 s, u32 R, u32 p)
 {
-	int index;
+	u16 index;
 	u32 f;
-	u64 tmp1, tmp2;
+	u64 result;
 
 	/* check against invalid parameters and divide-by-zero   */
 	BUG_ON(p >  1000000);		/* p must not exceed 100%   */
···
 		f = tfrc_calc_x_lookup[index][0];
 	}
 
-	/* The following computes X = s/(R*f(p)) in bytes per second. Since f(p)
-	 * and R are both scaled by 1000000, we need to multiply by 1000000^2.
-	 * ==> DO NOT alter this unless you test against overflow on 32 bit   */
-	tmp1 = ((u64)s * 100000000);
-	tmp2 = ((u64)R * (u64)f);
-	do_div(tmp2, 10000);
-	do_div(tmp1, tmp2); 
-
-	return (u32)tmp1; 
+	/*
+	 * Compute X = s/(R*f(p)) in bytes per second.
+	 * Since f(p) and R are both scaled by 1000000, we need to multiply by
+	 * 1000000^2. To avoid overflow, the result is computed in two stages.
+	 * This works under almost all reasonable operational conditions, for a
+	 * wide range of parameters. Yet, should some strange combination of
+	 * parameters result in overflow, the use of scaled_div32 will catch
+	 * this and return UINT_MAX - which is a logically adequate consequence.
+	 */
+	result = scaled_div(s, R);
+	return scaled_div32(result, f);
 }
 
 EXPORT_SYMBOL_GPL(tfrc_calc_x);

net/dccp/dccp.h

···
 
 #define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */
 
-#define DCCP_XMIT_TIMEO 30000 /* Time/msecs for blocking transmit per packet */
-
 /* sysctl variables for DCCP */
 extern int  sysctl_dccp_request_retries;
 extern int  sysctl_dccp_retries1;
···
 		tv->tv_sec--;
 		tv->tv_usec += USEC_PER_SEC;
 	}
+	DCCP_BUG_ON(tv->tv_sec < 0);
 }
 
 #ifdef CONFIG_SYSCTL

net/dccp/feat.c

···
 	switch (type) {
 	case DCCPO_CHANGE_L: opt->dccpop_type = DCCPO_CONFIRM_R; break;
 	case DCCPO_CHANGE_R: opt->dccpop_type = DCCPO_CONFIRM_L; break;
-	default: 	     DCCP_WARN("invalid type %d\n", type); return;
+	default:	     DCCP_WARN("invalid type %d\n", type); return;
 
 	}
 	opt->dccpop_feat = feature;
···
 	switch (type) {
 	case DCCPO_CONFIRM_L: t = DCCPO_CHANGE_R; break;
 	case DCCPO_CONFIRM_R: t = DCCPO_CHANGE_L; break;
-	default: 	      DCCP_WARN("invalid type %d\n", type);
+	default:	      DCCP_WARN("invalid type %d\n", type);
 			      return 1;
 
 	}
···
 	case DCCPO_CHANGE_R:  return("ChangeR");
 	case DCCPO_CONFIRM_R: return("ConfirmR");
 	/* the following case must not appear in feature negotation  */
-	default: 	      dccp_pr_debug("unknown type %d [BUG!]\n", type);
+	default:	      dccp_pr_debug("unknown type %d [BUG!]\n", type);
 	}
 	return NULL;
 }

net/dccp/input.c

···
 /*
  *  net/dccp/input.c
- * 
+ *
  *  An implementation of the DCCP protocol
  *  Arnaldo Carvalho de Melo <[e-mail]>
  *
···
 	 *	  Otherwise,
 	 *	     Drop packet and return
 	 */
-	if (dh->dccph_type == DCCP_PKT_SYNC || 
+	if (dh->dccph_type == DCCP_PKT_SYNC ||
 	    dh->dccph_type == DCCP_PKT_SYNCACK) {
 		if (between48(DCCP_SKB_CB(skb)->dccpd_ack_seq,
 			      dp->dccps_awl, dp->dccps_awh) &&
···
 		dccp_rcv_close(sk, skb);
 		return 0;
 	case DCCP_PKT_REQUEST:
-		/* Step 7 
-            	 *   or (S.is_server and P.type == Response)
+		/* Step 7
+		 *   or (S.is_server and P.type == Response)
 		 *   or (S.is_client and P.type == Request)
 		 *   or (S.state >= OPEN and P.type == Request
 		 *	and P.seqno >= S.OSR)
···
 			    DCCP_ACKVEC_STATE_RECEIVED))
 		goto discard;
 
-	ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb);
-	ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb);
+	/*
+	 * Deliver to the CCID module in charge.
+	 * FIXME: Currently DCCP operates one-directional only, i.e. a listening
+	 *        server is not at the same time a connecting client. There is
+	 *        not much sense in delivering to both rx/tx sides at the moment
+	 *        (only one is active at a time); when moving to bidirectional
+	 *        service, this needs to be revised.
+	 */
+	if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER)
+		ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb);
+	else
+		ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb);
 
 	return __dccp_rcv_established(sk, skb, dh, len);
 discard:
···
 					       const struct dccp_hdr *dh,
 					       const unsigned len)
 {
-	/* 
+	/*
 	 *  Step 4: Prepare sequence numbers in REQUEST
 	 *     If S.state == REQUEST,
 	 *	  If (P.type == Response or P.type == Reset)
···
 		 *	      from the Response * /
 		 *	  S.state := PARTOPEN
 		 *	  Set PARTOPEN timer
-		 * 	  Continue with S.state == PARTOPEN
+		 *	  Continue with S.state == PARTOPEN
 		 *	  / * Step 12 will send the Ack completing the
 		 *	      three-way handshake * /
 		 */
···
 			 */
 			__kfree_skb(skb);
 			return 0;
-		} 
+		}
 		dccp_send_ack(sk);
 		return -1;
 	}
···
 out_invalid_packet:
 	/* dccp_v4_do_rcv will send a reset */
 	DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR;
-	return 1; 
+	return 1;
 }
 
 static int dccp_rcv_respond_partopen_state_process(struct sock *sk,
···
 		if (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
 			dccp_event_ack_recv(sk, skb);
 
- 		if (dccp_msk(sk)->dccpms_send_ack_vector &&
+		if (dccp_msk(sk)->dccpms_send_ack_vector &&
 		    dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk,
- 				    DCCP_SKB_CB(skb)->dccpd_seq,
- 				    DCCP_ACKVEC_STATE_RECEIVED))
- 			goto discard;
+				    DCCP_SKB_CB(skb)->dccpd_seq,
+				    DCCP_ACKVEC_STATE_RECEIVED))
+			goto discard;
 
-		ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb);
-		ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb);
+		/* XXX see the comments in dccp_rcv_established about this */
+		if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER)
+			ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb);
+		else
+			ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb);
 	}
 
 	/*
···
 		}
 	}
 
-	if (!queued) { 
+	if (!queued) {
 discard:
 		__kfree_skb(skb);
 	}

net/dccp/ipv4.c

···
 	/* We don't check in the destentry if pmtu discovery is forbidden
 	 * on this route. We just assume that no packet_to_big packets
 	 * are send back when pmtu discovery is not active.
-     	 * There is a small race when the user changes this flag in the
+ 	 * There is a small race when the user changes this flag in the
 	 * route, but I think that's acceptable.
 	 */
 	if ((dst = __sk_dst_check(sk, 0)) == NULL)
···
 			    .uli_u = { .ports =
 				       { .sport = dccp_hdr(skb)->dccph_dport,
 					 .dport = dccp_hdr(skb)->dccph_sport }
-			   	     }
+				     }
 			  };
 
 	security_skb_classify_flow(skb, &fl);
···
 	struct inet_request_sock *ireq;
 	struct request_sock *req;
 	struct dccp_request_sock *dreq;
- 	const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
+	const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
 	struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
 	__u8 reset_code = DCCP_RESET_CODE_TOO_BUSY;
 
···
 	if (dccp_bad_service_code(sk, service)) {
 		reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
 		goto drop;
- 	}
+	}
 	/*
 	 * TW buckets are converted to open requests without
 	 * limitations, they conserve resources and peer is
···
 	ireq->rmt_addr = skb->nh.iph->saddr;
 	ireq->opt	= NULL;
 
-	/* 
+	/*
 	 * Step 3: Process LISTEN state
 	 *
 	 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
···
 	}
 
 	/* Step 2:
-	 * 	Look up flow ID in table and get corresponding socket */
+	 *	Look up flow ID in table and get corresponding socket */
 	sk = __inet_lookup(&dccp_hashinfo,
 			   skb->nh.iph->saddr, dh->dccph_sport,
 			   skb->nh.iph->daddr, dh->dccph_dport,
 			   inet_iif(skb));
 
-	/* 
+	/*
 	 * Step 2:
-	 * 	If no socket ...
+	 *	If no socket ...
 	 */
 	if (sk == NULL) {
 		dccp_pr_debug("failed to look up flow ID in table and "
···
 		goto no_dccp_socket;
 	}
 
-	/* 
+	/*
 	 * Step 2:
-	 * 	... or S.state == TIMEWAIT,
+	 *	... or S.state == TIMEWAIT,
 	 *		Generate Reset(No Connection) unless P.type == Reset
 	 *		Drop packet and return
 	 */
···
 
 	/*
 	 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
-	 * 	o if MinCsCov = 0, only packets with CsCov = 0 are accepted
-	 * 	o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
+	 *	o if MinCsCov = 0, only packets with CsCov = 0 are accepted
+	 *	o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
 	 */
 	min_cov = dccp_sk(sk)->dccps_pcrlen;
 	if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov))  {
···
 		goto discard_it;
 	/*
 	 * Step 2:
-	 * 	If no socket ...
+	 *	If no socket ...
 	 *		Generate Reset(No Connection) unless P.type == Reset
 	 *		Drop packet and return
 	 */

net/dccp/ipv6.c

···
 }
 
 static inline __u32 secure_dccpv6_sequence_number(__be32 *saddr, __be32 *daddr,
-				   		  __be16 sport, __be16 dport   )
+						  __be16 sport, __be16 dport   )
 {
 	return secure_tcpv6_sequence_number(saddr, daddr, sport, dport);
 }
···
 	skb = alloc_skb(dccp_v6_ctl_socket->sk->sk_prot->max_header,
 			GFP_ATOMIC);
 	if (skb == NULL)
-	  	return;
+		return;
 
 	skb_reserve(skb, dccp_v6_ctl_socket->sk->sk_prot->max_header);
 
···
 
 	dccp_csum_outgoing(skb);
 	dh->dccph_checksum = dccp_v6_csum_finish(skb, &rxskb->nh.ipv6h->saddr,
-				   		      &rxskb->nh.ipv6h->daddr);
+						      &rxskb->nh.ipv6h->daddr);
 
 	memset(&fl, 0, sizeof(fl));
 	ipv6_addr_copy(&fl.fl6_dst, &rxskb->nh.ipv6h->saddr);
···
 	struct dccp_request_sock *dreq;
 	struct inet6_request_sock *ireq6;
 	struct ipv6_pinfo *np = inet6_sk(sk);
- 	const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
+	const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
 	struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
 	__u8 reset_code = DCCP_RESET_CODE_TOO_BUSY;
 
···
 	if (dccp_bad_service_code(sk, service)) {
 		reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
 		goto drop;
- 	}
+	}
 	/*
 	 * There are no SYN attacks on IPv6, yet...
 	 */
···
 		 * otherwise we just shortcircuit this and continue with
 		 * the new socket..
 		 */
- 		if (nsk != sk) {
+		if (nsk != sk) {
 			if (dccp_child_process(sk, nsk, skb))
 				goto reset;
 			if (opt_skb != NULL)
···
 		DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
 
 	/* Step 2:
-	 * 	Look up flow ID in table and get corresponding socket */
+	 *	Look up flow ID in table and get corresponding socket */
 	sk = __inet6_lookup(&dccp_hashinfo, &skb->nh.ipv6h->saddr,
 			    dh->dccph_sport,
 			    &skb->nh.ipv6h->daddr, ntohs(dh->dccph_dport),
 			    inet6_iif(skb));
 	/*
 	 * Step 2:
-	 * 	If no socket ...
+	 *	If no socket ...
 	 */
 	if (sk == NULL) {
 		dccp_pr_debug("failed to look up flow ID in table and "
···
 
 	/*
 	 * Step 2:
-	 * 	... or S.state == TIMEWAIT,
+	 *	... or S.state == TIMEWAIT,
 	 *		Generate Reset(No Connection) unless P.type == Reset
 	 *		Drop packet and return
 	 */
···
 
 	/*
 	 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
-	 * 	o if MinCsCov = 0, only packets with CsCov = 0 are accepted
-	 * 	o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
+	 *	o if MinCsCov = 0, only packets with CsCov = 0 are accepted
+	 *	o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
 	 */
 	min_cov = dccp_sk(sk)->dccps_pcrlen;
 	if (dh->dccph_cscov  &&  (min_cov == 0 || dh->dccph_cscov < min_cov))  {
···
 		goto discard_it;
 	/*
 	 * Step 2:
-	 * 	If no socket ...
+	 *	If no socket ...
 	 *		Generate Reset(No Connection) unless P.type == Reset
 	 *		Drop packet and return
 	 */

net/dccp/minisocks.c

···
 
 EXPORT_SYMBOL_GPL(dccp_create_openreq_child);
 
-/* 
+/*
  * Process an incoming packet for RESPOND sockets represented
  * as an request_sock.
  */

net/dccp/options.c

···
 			return -1;
 		dp->dccps_hc_rx_insert_options = 0;
 	}
-	if (dp->dccps_hc_tx_insert_options) {
-		if (ccid_hc_tx_insert_options(dp->dccps_hc_tx_ccid, sk, skb))
-			return -1;
-		dp->dccps_hc_tx_insert_options = 0;
-	}
 
 	/* Feature negotiation */
 	/* Data packets can't do feat negotiation */

net/dccp/output.c

···
 /*
  *  net/dccp/output.c
- * 
+ *
  *  An implementation of the DCCP protocol
  *  Arnaldo Carvalho de Melo <[e-mail]>
  *
···
 /**
  * dccp_wait_for_ccid - Wait for ccid to tell us we can send a packet
  * @sk: socket to wait for
- * @timeo: for how long
  */
-static int dccp_wait_for_ccid(struct sock *sk, struct sk_buff *skb,
-			      long *timeo)
+static int dccp_wait_for_ccid(struct sock *sk, struct sk_buff *skb)
 {
 	struct dccp_sock *dp = dccp_sk(sk);
 	DEFINE_WAIT(wait);
-	long delay;
+	unsigned long delay;
 	int rc;
 
 	while (1) {
···
 
 		if (sk->sk_err)
 			goto do_error;
-		if (!*timeo)
-			goto do_nonblock;
 		if (signal_pending(current))
 			goto do_interrupted;
 
···
 		if (rc <= 0)
 			break;
 		delay = msecs_to_jiffies(rc);
-		if (delay > *timeo || delay < 0)
-			goto do_nonblock;
-
 		sk->sk_write_pending++;
 		release_sock(sk);
-		*timeo -= schedule_timeout(delay);
+		schedule_timeout(delay);
 		lock_sock(sk);
 		sk->sk_write_pending--;
 	}
···
 do_error:
 	rc = -EPIPE;
 	goto out;
-do_nonblock:
-	rc = -EAGAIN;
-	goto out;
 do_interrupted:
-	rc = sock_intr_errno(*timeo);
+	rc = -EINTR;
 	goto out;
 }
 
···
 {
 	struct dccp_sock *dp = dccp_sk(sk);
 	struct sk_buff *skb;
-	long timeo = DCCP_XMIT_TIMEO; 	/* If a packet is taking longer than
-					   this we have other issues */
 
 	while ((skb = skb_peek(&sk->sk_write_queue))) {
 		int err = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb);
···
 				sk_reset_timer(sk, &dp->dccps_xmit_timer,
 						msecs_to_jiffies(err)+jiffies);
 				break;
-			} else {
-				err = dccp_wait_for_ccid(sk, skb, &timeo);
-				timeo = DCCP_XMIT_TIMEO;
-			}
-			if (err)
+			} else
+				err = dccp_wait_for_ccid(sk, skb);
+			if (err && err != -EINTR)
 				DCCP_BUG("err=%d after dccp_wait_for_ccid", err);
 		}
 
···
 			if (err)
 				DCCP_BUG("err=%d after ccid_hc_tx_packet_sent",
 					 err);
-		} else
+		} else {
+			dccp_pr_debug("packet discarded\n");
 			kfree(skb);
+		}
 	}
 }
 
···
 
 static struct sk_buff *dccp_make_reset(struct sock *sk, struct dst_entry *dst,
 				       const enum dccp_reset_codes code)
-				   
 {
 	struct dccp_hdr *dh;
 	struct dccp_sock *dp = dccp_sk(sk);
···
 	
 	dccp_sync_mss(sk, dst_mtu(dst));
 
- 	/*
+	/*
 	 * SWL and AWL are initially adjusted so that they are not less than
 	 * the initial Sequence Numbers received and sent, respectively:
 	 *	SWL := max(GSR + 1 - floor(W/4), ISR),
 	 *	AWL := max(GSS - W' + 1, ISS).
 	 * These adjustments MUST be applied only at the beginning of the
 	 * connection.
- 	 */
+	 */
 	dccp_update_gss(sk, dp->dccps_iss);
 	dccp_set_seqno(&dp->dccps_awl, max48(dp->dccps_awl, dp->dccps_iss));
 

net/dccp/proto.c

···
 						      sk, GFP_KERNEL);
 		dp->dccps_hc_tx_ccid = ccid_hc_tx_new(dmsk->dccpms_tx_ccid,
 						      sk, GFP_KERNEL);
-	    	if (unlikely(dp->dccps_hc_rx_ccid == NULL ||
+		if (unlikely(dp->dccps_hc_rx_ccid == NULL ||
 			     dp->dccps_hc_tx_ccid == NULL)) {
 			ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
 			ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
···
 	struct dccp_sock *dp = dccp_sk(sk);
 	struct dccp_service_list *sl = NULL;
 
-	if (service == DCCP_SERVICE_INVALID_VALUE || 
+	if (service == DCCP_SERVICE_INVALID_VALUE ||
 	    optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
 		return -EINVAL;
 
···
 static const unsigned char dccp_new_state[] = {
 	/* current state:   new state:      action:	*/
 	[0]		  = DCCP_CLOSED,
-	[DCCP_OPEN] 	  = DCCP_CLOSING | DCCP_ACTION_FIN,
+	[DCCP_OPEN]	  = DCCP_CLOSING | DCCP_ACTION_FIN,
 	[DCCP_REQUESTING] = DCCP_CLOSED,
 	[DCCP_PARTOPEN]	  = DCCP_CLOSING | DCCP_ACTION_FIN,
 	[DCCP_LISTEN]	  = DCCP_CLOSED,

net/dccp/timer.c

···
 /*
  *  net/dccp/timer.c
- * 
+ *
  *  An implementation of the DCCP protocol
  *  Arnaldo Carvalho de Melo <[e-mail]>
  *
···
 	 * sk->sk_send_head has to have one skb with
 	 * DCCP_SKB_CB(skb)->dccpd_type set to one of the retransmittable DCCP
 	 * packet types. The only packets eligible for retransmission are:
-	 * 	-- Requests in client-REQUEST  state (sec. 8.1.1)
-	 * 	-- Acks     in client-PARTOPEN state (sec. 8.1.5)
-	 * 	-- CloseReq in server-CLOSEREQ state (sec. 8.3)
-	 * 	-- Close    in   node-CLOSING  state (sec. 8.3)                */
+	 *	-- Requests in client-REQUEST  state (sec. 8.1.1)
+	 *	-- Acks     in client-PARTOPEN state (sec. 8.1.5)
+	 *	-- CloseReq in server-CLOSEREQ state (sec. 8.3)
+	 *	-- Close    in   node-CLOSING  state (sec. 8.3)                */
 	BUG_TRAP(sk->sk_send_head != NULL);
 
-	/* 
+	/*
 	 * More than than 4MSL (8 minutes) has passed, a RESET(aborted) was
 	 * sent, no need to retransmit, this sock is dead.
 	 */
···
 	/* Only process if socket is not in use. */
 	bh_lock_sock(sk);
 	if (sock_owned_by_user(sk)) {
-		/* Try again later. */ 
+		/* Try again later. */
 		inet_csk_reset_keepalive_timer(sk, HZ / 20);
 		goto out;
 	}

net/ipv4/ipvs/ip_vs_sync.c

···
 		if (stop_master_sync)
 			break;
 
-		ssleep(1);
+		msleep_interruptible(1000);
 	}
 
 	/* clean up the sync_buff queue */
···
 		if (stop_backup_sync)
 			break;
 
-		ssleep(1);
+		msleep_interruptible(1000);
 	}
 
 	/* release the sending multicast socket */
···
 	if ((pid = kernel_thread(sync_thread, startup, 0)) < 0) {
 		IP_VS_ERR("could not create sync_thread due to %d... "
 			  "retrying.\n", pid);
-		ssleep(1);
+		msleep_interruptible(1000);
 		goto repeat;
 	}
 
···
 
 	ip_vs_sync_state |= state;
 	if (state == IP_VS_STATE_MASTER) {
-		strlcpy(ip_vs_master_mcast_ifn, mcast_ifn, sizeof(ip_vs_master_mcast_ifn));
+		strlcpy(ip_vs_master_mcast_ifn, mcast_ifn,
+			sizeof(ip_vs_master_mcast_ifn));
 		ip_vs_master_syncid = syncid;
 	} else {
-		strlcpy(ip_vs_backup_mcast_ifn, mcast_ifn, sizeof(ip_vs_backup_mcast_ifn));
+		strlcpy(ip_vs_backup_mcast_ifn, mcast_ifn,
+			sizeof(ip_vs_backup_mcast_ifn));
 		ip_vs_backup_syncid = syncid;
 	}
 
···
 	if ((pid = kernel_thread(fork_sync_thread, &startup, 0)) < 0) {
 		IP_VS_ERR("could not create fork_sync_thread due to %d... "
 			  "retrying.\n", pid);
-		ssleep(1);
+		msleep_interruptible(1000);
 		goto repeat;
 	}
 
···
 
 	IP_VS_DBG(7, "%s: pid %d\n", __FUNCTION__, current->pid);
 	IP_VS_INFO("stopping sync thread %d ...\n",
-		   (state == IP_VS_STATE_MASTER) ? sync_master_pid : sync_backup_pid);
+		   (state == IP_VS_STATE_MASTER) ?
+		   sync_master_pid : sync_backup_pid);
 
 	__set_current_state(TASK_UNINTERRUPTIBLE);
 	add_wait_queue(&stop_sync_wait, &wait);