lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Thu, 15 Nov 2007 15:37:34 +0200
From:	"Ilpo Järvinen" <ilpo.jarvinen@...sinki.fi>
To:	David Miller <davem@...emloft.net>
Cc:	netdev@...r.kernel.org
Subject: [PATCH 10/10] [TCP]: Track sacktag (DEVEL PATCH)

This is not intented to go to mainline, provided just for those
who are interested enough about the algorithm internals during
a test.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@...sinki.fi>
---
 include/linux/snmp.h |   19 +++++++++++++++++++
 net/ipv4/proc.c      |   19 +++++++++++++++++++
 net/ipv4/tcp_input.c |   50 ++++++++++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 86 insertions(+), 2 deletions(-)

diff --git a/include/linux/snmp.h b/include/linux/snmp.h
index 89f0c2b..fbcd62d 100644
--- a/include/linux/snmp.h
+++ b/include/linux/snmp.h
@@ -214,6 +214,25 @@ enum
 	LINUX_MIB_TCPDSACKIGNOREDOLD,		/* TCPSACKIgnoredOld */
 	LINUX_MIB_TCPDSACKIGNOREDNOUNDO,	/* TCPSACKIgnoredNoUndo */
 	LINUX_MIB_TCPSPURIOUSRTOS,		/* TCPSpuriousRTOs */
+	LINUX_MIB_TCP_SACK0,
+	LINUX_MIB_TCP_SACK1,
+	LINUX_MIB_TCP_SACK2,
+	LINUX_MIB_TCP_SACK3,
+	LINUX_MIB_TCP_SACK4,
+	LINUX_MIB_TCP_WALKEDSKBS,
+	LINUX_MIB_TCP_WALKEDDSACKS,
+	LINUX_MIB_TCP_SKIPPEDSKBS,
+	LINUX_MIB_TCP_NOCACHE,
+	LINUX_MIB_TCP_HEADWALK,
+	LINUX_MIB_TCP_FULLSKIP,
+	LINUX_MIB_TCP_TAILSKIP,
+	LINUX_MIB_TCP_HEADSKIP_TOHIGH,
+	LINUX_MIB_TCP_TAIL_TOHIGH,
+	LINUX_MIB_TCP_HEADSKIP,
+	LINUX_MIB_TCP_NEWSKIP,
+	LINUX_MIB_TCP_FULLWALK,
+	LINUX_MIB_TCP_TAILWALK,
+	LINUX_MIB_TCP_CACHEREMAINING,
 	__LINUX_MIB_MAX
 };
 
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index ce34b28..a5e842d 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -227,6 +227,25 @@ static const struct snmp_mib snmp4_net_list[] = {
 	SNMP_MIB_ITEM("TCPDSACKIgnoredOld", LINUX_MIB_TCPDSACKIGNOREDOLD),
 	SNMP_MIB_ITEM("TCPDSACKIgnoredNoUndo", LINUX_MIB_TCPDSACKIGNOREDNOUNDO),
 	SNMP_MIB_ITEM("TCPSpuriousRTOs", LINUX_MIB_TCPSPURIOUSRTOS),
+	SNMP_MIB_ITEM("TCP_SACK0", LINUX_MIB_TCP_SACK0),
+	SNMP_MIB_ITEM("TCP_SACK1", LINUX_MIB_TCP_SACK1),
+	SNMP_MIB_ITEM("TCP_SACK2", LINUX_MIB_TCP_SACK2),
+	SNMP_MIB_ITEM("TCP_SACK3", LINUX_MIB_TCP_SACK3),
+	SNMP_MIB_ITEM("TCP_SACK4", LINUX_MIB_TCP_SACK4),
+	SNMP_MIB_ITEM("TCP_WALKEDSKBS", LINUX_MIB_TCP_WALKEDSKBS),
+	SNMP_MIB_ITEM("TCP_WALKEDDSACKS", LINUX_MIB_TCP_WALKEDDSACKS),
+	SNMP_MIB_ITEM("TCP_SKIPPEDSKBS", LINUX_MIB_TCP_SKIPPEDSKBS),
+	SNMP_MIB_ITEM("TCP_NOCACHE", LINUX_MIB_TCP_NOCACHE),
+	SNMP_MIB_ITEM("TCP_FULLWALK", LINUX_MIB_TCP_FULLWALK),
+	SNMP_MIB_ITEM("TCP_HEADWALK", LINUX_MIB_TCP_HEADWALK),
+	SNMP_MIB_ITEM("TCP_TAILWALK", LINUX_MIB_TCP_TAILWALK),
+	SNMP_MIB_ITEM("TCP_FULLSKIP", LINUX_MIB_TCP_FULLSKIP),
+	SNMP_MIB_ITEM("TCP_TAILSKIP", LINUX_MIB_TCP_TAILSKIP),
+	SNMP_MIB_ITEM("TCP_HEADSKIP", LINUX_MIB_TCP_HEADSKIP),
+	SNMP_MIB_ITEM("TCP_HEADSKIP_TOHIGH", LINUX_MIB_TCP_HEADSKIP_TOHIGH),
+	SNMP_MIB_ITEM("TCP_TAIL_TOHIGH", LINUX_MIB_TCP_TAIL_TOHIGH),
+	SNMP_MIB_ITEM("TCP_NEWSKIP", LINUX_MIB_TCP_NEWSKIP),
+	SNMP_MIB_ITEM("TCP_CACHEREMAINING", LINUX_MIB_TCP_CACHEREMAINING),
 	SNMP_MIB_SENTINEL
 };
 
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 5833b01..87ab327 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1370,6 +1370,10 @@ static struct sk_buff *tcp_sacktag_walk(struct sk_buff *skb, struct sock *sk,
 			*flag |= tcp_sacktag_one(skb, tp, reord, dup_sack, *fack_count);
 
 		*fack_count += tcp_skb_pcount(skb);
+
+		NET_INC_STATS_BH(LINUX_MIB_TCP_WALKEDSKBS);
+		if (dup_sack)
+			NET_INC_STATS_BH(LINUX_MIB_TCP_WALKEDDSACKS);
 	}
 	return skb;
 }
@@ -1386,6 +1390,8 @@ static struct sk_buff *tcp_sacktag_skip(struct sk_buff *skb, struct sock *sk,
 
 		if (before(TCP_SKB_CB(skb)->end_seq, skip_to_seq))
 			break;
+
+		NET_INC_STATS_BH(LINUX_MIB_TCP_SKIPPEDSKBS);
 	}
 	return skb;
 }
@@ -1434,6 +1440,7 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
 	int fack_count;
 	int i, j;
 	int first_sack_index;
+	int fullwalk = 1;
 
 	if (!tp->sacked_out) {
 		if (WARN_ON(tp->fackets_out))
@@ -1523,6 +1530,17 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
 			cache++;
 	}
 
+	switch (used_sacks) {
+		case 0: NET_INC_STATS_BH(LINUX_MIB_TCP_SACK0); break;
+		case 1: NET_INC_STATS_BH(LINUX_MIB_TCP_SACK1); break;
+		case 2: NET_INC_STATS_BH(LINUX_MIB_TCP_SACK2); break;
+		case 3: NET_INC_STATS_BH(LINUX_MIB_TCP_SACK3); break;
+		case 4: NET_INC_STATS_BH(LINUX_MIB_TCP_SACK4); break;
+	}
+
+	if (!tcp_sack_cache_ok(tp, cache))
+		NET_INC_STATS_BH(LINUX_MIB_TCP_NOCACHE);
+
 	while (i < used_sacks) {
 		u32 start_seq = sp[i].start_seq;
 		u32 end_seq = sp[i].end_seq;
@@ -1544,6 +1562,9 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
 		/* Can skip some work by looking recv_sack_cache? */
 		if (tcp_sack_cache_ok(tp, cache) && !dup_sack &&
 		    after(end_seq, cache->start_seq)) {
+			int headskip = 0;
+
+			fullwalk = 0;
 
 			/* Head todo? */
 			if (before(start_seq, cache->start_seq)) {
@@ -1551,12 +1572,18 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
 				skb = tcp_sacktag_walk(skb, sk, next_dup, start_seq,
 						       cache->start_seq, dup_sack,
 						       &fack_count, &reord, &flag);
-			}
+				NET_INC_STATS_BH(LINUX_MIB_TCP_HEADWALK);
+			} else
+				headskip = 1;
 
 			/* Rest of the block already fully processed? */
 			if (!after(end_seq, cache->end_seq)) {
 				skb = tcp_maybe_skipping_dsack(skb, sk, next_dup, cache->end_seq,
 							       &fack_count, &reord, &flag);
+				if (headskip)
+					NET_INC_STATS_BH(LINUX_MIB_TCP_FULLSKIP);
+				else
+					NET_INC_STATS_BH(LINUX_MIB_TCP_TAILSKIP);
 				goto advance_sp;
 			}
 
@@ -1571,24 +1598,37 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
 				skb = tcp_write_queue_next(sk, tp->highest_sack);
 				fack_count = tp->fackets_out;
 				cache++;
+
+				if (headskip)
+					NET_INC_STATS_BH(LINUX_MIB_TCP_HEADSKIP_TOHIGH);
+				else
+					NET_INC_STATS_BH(LINUX_MIB_TCP_TAIL_TOHIGH);
 				goto walk;
 			}
 
 			skb = tcp_sacktag_skip(skb, sk, cache->end_seq);
 			/* Check overlap against next cached too (past this one already) */
 			cache++;
+
+			if (headskip)
+				NET_INC_STATS_BH(LINUX_MIB_TCP_HEADSKIP);
 			continue;
 		}
 
 		if (!before(start_seq, tcp_highest_sack_seq(tp))) {
 			skb = tcp_write_queue_next(sk, tp->highest_sack);
 			fack_count = tp->fackets_out;
+			NET_INC_STATS_BH(LINUX_MIB_TCP_NEWSKIP);
 		}
 		skb = tcp_sacktag_skip(skb, sk, start_seq);
 
 walk:
 		skb = tcp_sacktag_walk(skb, sk, next_dup, start_seq, end_seq,
 				       dup_sack, &fack_count, &reord, &flag);
+		if (fullwalk)
+			NET_INC_STATS_BH(LINUX_MIB_TCP_FULLWALK);
+		else
+			NET_INC_STATS_BH(LINUX_MIB_TCP_TAILWALK);
 
 advance_sp:
 		/* SACK enhanced FRTO (RFC4138, Appendix B): Clearing correct
@@ -1598,15 +1638,21 @@ advance_sp:
 			flag &= ~FLAG_ONLY_ORIG_SACKED;
 
 		i++;
+		fullwalk = 1;
 	}
 
+	if (tcp_sack_cache_ok(tp, cache))
+		NET_INC_STATS_BH(LINUX_MIB_TCP_CACHEREMAINING);
+
 	/* Clear the head of the cache sack blocks so we can skip it next time */
 	for (i = 0; i < ARRAY_SIZE(tp->recv_sack_cache) - used_sacks; i++) {
 		tp->recv_sack_cache[i].start_seq = 0;
 		tp->recv_sack_cache[i].end_seq = 0;
 	}
-	for (j = 0; j < used_sacks; j++)
+	for (j = 0; j < used_sacks; j++) {
+		WARN_ON(i >= ARRAY_SIZE(tp->recv_sack_cache));
 		tp->recv_sack_cache[i++] = sp[j];
+	}
 
 	flag |= tcp_mark_lost_retrans(sk);
 
-- 
1.5.0.6

-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ