[CCID3]: Separate most of the packet history code

This also changes the list_for_each_entry_safe_continue behaviour to match its
kerneldoc comment, that is, to start after the pos passed.

Also adds several helper functions from previously open coded fragments, making
the code more clear.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>

include/linux/list.h

@@ -427,7 +427,8 @@ static inline void list_splice_init(struct list_head *list,
  * @member:	the name of the list_struct within the struct.
  */
 #define list_for_each_entry_safe_continue(pos, n, head, member) 		\
-	for (pos = n, n = list_entry(n->member.next, typeof(*n), member);	\
+	for (pos = list_entry(pos->member.next, typeof(*pos), member), 		\
+		n = list_entry(pos->member.next, typeof(*pos), member);		\
 	     &pos->member != (head);						\
 	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
 

net/dccp/Makefile

 obj-$(CONFIG_IP_DCCP) += dccp.o
 
-dccp-y := ccid.o input.o ipv4.o minisocks.o options.o output.o proto.o timer.o
+dccp-y := ccid.o input.o ipv4.o minisocks.o options.o output.o proto.o \
+	  timer.o packet_history.o
 
 obj-y += ccids/

net/dccp/ccids/ccid3.h

@@ -38,15 +38,6 @@
 
 #include <linux/types.h>
 #include <linux/list.h>
-#include <linux/timer.h>
-
-struct ccid3_tx_hist_entry {
-	struct list_head	ccid3htx_node;
-	u64			ccid3htx_seqno:48,
-				ccid3htx_win_count:8,
-				ccid3htx_sent:1;
-	struct timeval		ccid3htx_tstamp;
-};
 
 struct ccid3_options_received {
 	u64 ccid3or_seqno:48,
@@ -102,15 +93,6 @@ struct ccid3_loss_interval_hist_entry {
 	u32			ccid3lih_interval;
 };
 
-struct ccid3_rx_hist_entry {
-	struct list_head	ccid3hrx_node;
-	u64			ccid3hrx_seqno:48,
-				ccid3hrx_win_count:4,
-				ccid3hrx_type:4;
-	u32			ccid3hrx_ndp; /* In fact it is from 8 to 24 bits */
-	struct timeval		ccid3hrx_tstamp;
-};
-
 struct ccid3_hc_rx_sock {
   	u64			ccid3hcrx_seqno_last_counter:48,
 				ccid3hcrx_state:8,

net/dccp/packet_history.c

+/*
+ *  net/dccp/packet_history.h
+ *
+ *  Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
+ *
+ *  An implementation of the DCCP protocol
+ *
+ *  This code has been developed by the University of Waikato WAND
+ *  research group. For further information please see http://www.wand.net.nz/
+ *  or e-mail Ian McDonald - iam4@cs.waikato.ac.nz
+ *
+ *  This code also uses code from Lulea University, rereleased as GPL by its
+ *  authors:
+ *  Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
+ *
+ *  Changes to meet Linux coding standards, to make it meet latest ccid3 draft
+ *  and to make it work as a loadable module in the DCCP stack written by
+ *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>.
+ *
+ *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/config.h>
+#include <linux/string.h>
+
+#include "packet_history.h"
+
+struct dccp_rx_hist *dccp_rx_hist_new(const char *name)
+{
+	struct dccp_rx_hist *hist = kmalloc(sizeof(*hist), GFP_ATOMIC);
+	static const char dccp_rx_hist_mask[] = "rx_hist_%s";
+	char *slab_name;
+
+	if (hist == NULL)
+		goto out;
+
+	slab_name = kmalloc(strlen(name) + sizeof(dccp_rx_hist_mask) - 1,
+			    GFP_ATOMIC);
+	if (slab_name == NULL)
+		goto out_free_hist;
+
+	sprintf(slab_name, dccp_rx_hist_mask, name);
+	hist->dccprxh_slab = kmem_cache_create(slab_name,
+					       sizeof(struct dccp_rx_hist_entry),
+					       0, SLAB_HWCACHE_ALIGN,
+					       NULL, NULL);
+	if (hist->dccprxh_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_rx_hist_new);
+
+void dccp_rx_hist_delete(struct dccp_rx_hist *hist)
+{
+	const char* name = kmem_cache_name(hist->dccprxh_slab);
+
+	kmem_cache_destroy(hist->dccprxh_slab);
+	kfree(name);
+	kfree(hist);
+}
+
+EXPORT_SYMBOL_GPL(dccp_rx_hist_delete);
+
+void dccp_rx_hist_purge(struct dccp_rx_hist *hist, struct list_head *list)
+{
+	struct dccp_rx_hist_entry *entry, *next;
+
+	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_rx_hist_purge);
+
+struct dccp_rx_hist_entry *
+		dccp_rx_hist_find_data_packet(const struct list_head *list)
+{
+	struct dccp_rx_hist_entry *entry, *packet = NULL;
+
+	list_for_each_entry(entry, list, dccphrx_node)
+		if (entry->dccphrx_type == DCCP_PKT_DATA ||
+		    entry->dccphrx_type == DCCP_PKT_DATAACK) {
+			packet = entry;
+			break;
+		}
+
+	return packet;
+}
+
+EXPORT_SYMBOL_GPL(dccp_rx_hist_find_data_packet);
+
+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_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);
+
+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);

net/dccp/packet_history.h

+/*
+ *  net/dccp/packet_history.h
+ *
+ *  Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
+ *
+ *  An implementation of the DCCP protocol
+ *
+ *  This code has been developed by the University of Waikato WAND
+ *  research group. For further information please see http://www.wand.net.nz/
+ *  or e-mail Ian McDonald - iam4@cs.waikato.ac.nz
+ *
+ *  This code also uses code from Lulea University, rereleased as GPL by its
+ *  authors:
+ *  Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
+ *
+ *  Changes to meet Linux coding standards, to make it meet latest ccid3 draft
+ *  and to make it work as a loadable module in the DCCP stack written by
+ *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>.
+ *
+ *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef _DCCP_PKT_HIST_
+#define _DCCP_PKT_HIST_
+
+#include <linux/config.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+
+#include "dccp.h"
+
+struct dccp_tx_hist_entry {
+	struct list_head dccphtx_node;
+	u64		 dccphtx_seqno:48,
+			 dccphtx_win_count:8,
+			 dccphtx_sent:1;
+	struct timeval	 dccphtx_tstamp;
+};
+
+struct dccp_rx_hist_entry {
+	struct list_head dccphrx_node;
+	u64		 dccphrx_seqno:48,
+			 dccphrx_win_count:4,
+			 dccphrx_type:4;
+	u32		 dccphrx_ndp; /* In fact it is from 8 to 24 bits */
+	struct timeval	 dccphrx_tstamp;
+};
+
+struct dccp_tx_hist {
+	kmem_cache_t *dccptxh_slab;
+};
+
+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 {
+	kmem_cache_t *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);
+
+static inline struct dccp_tx_hist_entry *
+			dccp_tx_hist_entry_new(struct dccp_tx_hist *hist,
+					       const int prio)
+{
+	struct dccp_tx_hist_entry *entry = kmem_cache_alloc(hist->dccptxh_slab,
+							    prio);
+
+	if (entry != NULL)
+		entry->dccphtx_sent = 0;
+
+	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);
+
+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)
+{
+	struct dccp_tx_hist_entry *head = NULL;
+
+	if (!list_empty(list))
+		head = list_entry(list->next, struct dccp_tx_hist_entry,
+				  dccphtx_node);
+	return head;
+}
+
+static inline struct dccp_rx_hist_entry *
+			     dccp_rx_hist_entry_new(struct dccp_rx_hist *hist,
+					     	    const u32 ndp, 
+						    const struct sk_buff *skb,
+						    const int prio)
+{
+	struct dccp_rx_hist_entry *entry = kmem_cache_alloc(hist->dccprxh_slab,
+							    prio);
+
+	if (entry != NULL) {
+		const struct dccp_hdr *dh = dccp_hdr(skb);
+
+		entry->dccphrx_seqno	 = DCCP_SKB_CB(skb)->dccpd_seq;
+		entry->dccphrx_win_count = dh->dccph_ccval;
+		entry->dccphrx_type	 = dh->dccph_type;
+		entry->dccphrx_ndp	 = ndp;
+		do_gettimeofday(&(entry->dccphrx_tstamp));
+	}
+
+	return entry;
+}
+
+static inline void dccp_rx_hist_entry_delete(struct dccp_rx_hist *hist,
+					     struct dccp_rx_hist_entry *entry)
+{
+	if (entry != NULL)
+		kmem_cache_free(hist->dccprxh_slab, entry);
+}
+
+extern void dccp_rx_hist_purge(struct dccp_rx_hist *hist,
+			       struct list_head *list);
+
+static inline void dccp_rx_hist_add_entry(struct list_head *list,
+					  struct dccp_rx_hist_entry *entry)
+{
+	list_add(&entry->dccphrx_node, 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;
+}
+
+#endif /* _DCCP_PKT_HIST_ */