netdev - [PATCH 6/9] [TCP]: Remove TCPCB_URG & TCPCB_AT

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:	Mon, 31 Dec 2007 12:47:54 +0200
From:	"Ilpo Järvinen" <ilpo.jarvinen@...sinki.fi>
To:	David Miller <davem@...emloft.net>
Cc:	netdev@...r.kernel.org
Subject: [PATCH 6/9] [TCP]: Remove TCPCB_URG & TCPCB_AT_TAIL as unnecessary

The snd_up check should be enough. I suspect this has been
there to provide a minor optimization in clean_rtx_queue which
used to have a small if (!->sacked) block which could skip
snd_up check among the other work.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@...sinki.fi>
---
 include/net/tcp.h     |    4 ----
 net/ipv4/tcp.c        |    1 -
 net/ipv4/tcp_input.c  |    3 +--
 net/ipv4/tcp_output.c |    7 +++----
 4 files changed, 4 insertions(+), 11 deletions(-)

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 6a732d4..48081ad 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -578,10 +578,6 @@ struct tcp_skb_cb {
 #define TCPCB_EVER_RETRANS	0x80	/* Ever retransmitted frame	*/
 #define TCPCB_RETRANS		(TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS)
 
-#define TCPCB_URG		0x20	/* Urgent pointer advanced here	*/
-
-#define TCPCB_AT_TAIL		(TCPCB_URG)
-
 	__u16		urg_ptr;	/* Valid w/URG flags is set.	*/
 	__u32		ack_seq;	/* Sequence number ACK'd	*/
 };
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 2cbfa6d..34085e3 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -497,7 +497,6 @@ static inline void tcp_mark_urg(struct tcp_sock *tp, int flags,
 	if (flags & MSG_OOB) {
 		tp->urg_mode = 1;
 		tp->snd_up = tp->write_seq;
-		TCP_SKB_CB(skb)->sacked |= TCPCB_URG;
 	}
 }
 
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 7bac1fa..1e7fd81 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2821,8 +2821,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets)
 		if (sacked & TCPCB_LOST)
 			tp->lost_out -= acked_pcount;
 
-		if (unlikely((sacked & TCPCB_URG) && tp->urg_mode &&
-			     !before(end_seq, tp->snd_up)))
+		if (unlikely(tp->urg_mode && !before(end_seq, tp->snd_up)))
 			tp->urg_mode = 0;
 
 		tp->packets_out -= acked_pcount;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 202d60c..182ae21 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -711,7 +711,6 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss
 	TCP_SKB_CB(skb)->flags = flags & ~(TCPCB_FLAG_FIN|TCPCB_FLAG_PSH);
 	TCP_SKB_CB(buff)->flags = flags;
 	TCP_SKB_CB(buff)->sacked = TCP_SKB_CB(skb)->sacked;
-	TCP_SKB_CB(skb)->sacked &= ~TCPCB_AT_TAIL;
 
 	if (!skb_shinfo(skb)->nr_frags && skb->ip_summed != CHECKSUM_PARTIAL) {
 		/* Copy and checksum data tail into the new buffer. */
@@ -1721,7 +1720,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, int m
 		/* All done, get rid of second SKB and account for it so
 		 * packet counting does not break.
 		 */
-		TCP_SKB_CB(skb)->sacked |= TCP_SKB_CB(next_skb)->sacked&(TCPCB_EVER_RETRANS|TCPCB_AT_TAIL);
+		TCP_SKB_CB(skb)->sacked |= TCP_SKB_CB(next_skb)->sacked & TCPCB_EVER_RETRANS;
 		if (TCP_SKB_CB(next_skb)->sacked&TCPCB_SACKED_RETRANS)
 			tp->retrans_out -= tcp_skb_pcount(next_skb);
 		if (TCP_SKB_CB(next_skb)->sacked&TCPCB_LOST)
@@ -2470,7 +2469,7 @@ static int tcp_xmit_probe_skb(struct sock *sk, int urgent)
 	skb_reserve(skb, MAX_TCP_HEADER);
 	skb->csum = 0;
 	TCP_SKB_CB(skb)->flags = TCPCB_FLAG_ACK;
-	TCP_SKB_CB(skb)->sacked = urgent;
+	TCP_SKB_CB(skb)->sacked = 0;
 	skb_shinfo(skb)->gso_segs = 1;
 	skb_shinfo(skb)->gso_size = 0;
 	skb_shinfo(skb)->gso_type = 0;
@@ -2522,7 +2521,7 @@ int tcp_write_wakeup(struct sock *sk)
 		} else {
 			if (tp->urg_mode &&
 			    between(tp->snd_up, tp->snd_una+1, tp->snd_una+0xFFFF))
-				tcp_xmit_probe_skb(sk, TCPCB_URG);
+				tcp_xmit_probe_skb(sk, 1);
 			return tcp_xmit_probe_skb(sk, 0);
 		}
 	}
-- 
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