| 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
| ||
|
Message-Id: <1228510736-3655-5-git-send-email-ilpo.jarvinen@helsinki.fi>
Date: Fri, 5 Dec 2008 22:58:50 +0200
From: "Ilpo Järvinen" <ilpo.jarvinen@...sinki.fi>
To: David Miller <davem@...emloft.net>
Cc: netdev@...r.kernel.org,
"Ilpo Järvinen" <ilpo.jarvinen@...sinki.fi>
Subject: [PATCH 04/10] tcp: introduce struct tcp_sacktag_state to reduce arg pressure
There are just too many args to some sacktag functions. This
idea was first proposed by David S. Miller around a year ago,
and the current situation is much worse that what it was back
then.
tcp_sacktag_one can be made a bit simpler by returning the
new sacked (it can be achieved with a single variable though
the previous code "caching" sacked into a local variable and
therefore it is not exactly equal but the results will be the
same).
codiff on x86_64
tcp_sacktag_one | -15
tcp_shifted_skb | -50
tcp_match_skb_to_sack | -1
tcp_sacktag_walk | -64
tcp_sacktag_write_queue | -59
tcp_urg | +1
tcp_event_data_recv | -1
7 functions changed, 1 bytes added, 190 bytes removed, diff: -189
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@...sinki.fi>
---
net/ipv4/tcp_input.c | 145 +++++++++++++++++++++++++------------------------
1 files changed, 74 insertions(+), 71 deletions(-)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 21c6701..57134c2 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1237,6 +1237,12 @@ static int tcp_check_dsack(struct sock *sk, struct sk_buff *ack_skb,
return dup_sack;
}
+struct tcp_sacktag_state {
+ int reord;
+ int fack_count;
+ int flag;
+};
+
/* Check if skb is fully within the SACK block. In presence of GSO skbs,
* the incoming SACK may not exactly match but we can find smaller MSS
* aligned portion of it that matches. Therefore we might need to fragment
@@ -1290,25 +1296,25 @@ static int tcp_match_skb_to_sack(struct sock *sk, struct sk_buff *skb,
return in_sack;
}
-static int tcp_sacktag_one(struct sk_buff *skb, struct sock *sk,
- int *reord, int dup_sack, int fack_count,
- u8 *sackedto, int pcount)
+static u8 tcp_sacktag_one(struct sk_buff *skb, struct sock *sk,
+ struct tcp_sacktag_state *state,
+ int dup_sack, int pcount)
{
struct tcp_sock *tp = tcp_sk(sk);
u8 sacked = TCP_SKB_CB(skb)->sacked;
- int flag = 0;
+ int fack_count = state->fack_count;
/* Account D-SACK for retransmitted packet. */
if (dup_sack && (sacked & TCPCB_RETRANS)) {
if (after(TCP_SKB_CB(skb)->end_seq, tp->undo_marker))
tp->undo_retrans--;
if (sacked & TCPCB_SACKED_ACKED)
- *reord = min(fack_count, *reord);
+ state->reord = min(fack_count, state->reord);
}
/* Nothing to do; acked frame is about to be dropped (was ACKed). */
if (!after(TCP_SKB_CB(skb)->end_seq, tp->snd_una))
- return flag;
+ return sacked;
if (!(sacked & TCPCB_SACKED_ACKED)) {
if (sacked & TCPCB_SACKED_RETRANS) {
@@ -1317,7 +1323,7 @@ static int tcp_sacktag_one(struct sk_buff *skb, struct sock *sk,
* that retransmission is still in flight.
*/
if (sacked & TCPCB_LOST) {
- *sackedto &= ~(TCPCB_LOST|TCPCB_SACKED_RETRANS);
+ sacked &= ~(TCPCB_LOST|TCPCB_SACKED_RETRANS);
tp->lost_out -= pcount;
tp->retrans_out -= pcount;
}
@@ -1328,21 +1334,22 @@ static int tcp_sacktag_one(struct sk_buff *skb, struct sock *sk,
*/
if (before(TCP_SKB_CB(skb)->seq,
tcp_highest_sack_seq(tp)))
- *reord = min(fack_count, *reord);
+ state->reord = min(fack_count,
+ state->reord);
/* SACK enhanced F-RTO (RFC4138; Appendix B) */
if (!after(TCP_SKB_CB(skb)->end_seq, tp->frto_highmark))
- flag |= FLAG_ONLY_ORIG_SACKED;
+ state->flag |= FLAG_ONLY_ORIG_SACKED;
}
if (sacked & TCPCB_LOST) {
- *sackedto &= ~TCPCB_LOST;
+ sacked &= ~TCPCB_LOST;
tp->lost_out -= pcount;
}
}
- *sackedto |= TCPCB_SACKED_ACKED;
- flag |= FLAG_DATA_SACKED;
+ sacked |= TCPCB_SACKED_ACKED;
+ state->flag |= FLAG_DATA_SACKED;
tp->sacked_out += pcount;
fack_count += pcount;
@@ -1361,21 +1368,20 @@ static int tcp_sacktag_one(struct sk_buff *skb, struct sock *sk,
* frames and clear it. undo_retrans is decreased above, L|R frames
* are accounted above as well.
*/
- if (dup_sack && (*sackedto & TCPCB_SACKED_RETRANS)) {
- *sackedto &= ~TCPCB_SACKED_RETRANS;
+ if (dup_sack && (sacked & TCPCB_SACKED_RETRANS)) {
+ sacked &= ~TCPCB_SACKED_RETRANS;
tp->retrans_out -= pcount;
}
- return flag;
+ return sacked;
}
static int tcp_shifted_skb(struct sock *sk, struct sk_buff *prev,
- struct sk_buff *skb, unsigned int pcount,
- int shifted, int fack_count, int *reord,
- int *flag, int mss)
+ struct sk_buff *skb,
+ struct tcp_sacktag_state *state,
+ unsigned int pcount, int shifted, int mss)
{
struct tcp_sock *tp = tcp_sk(sk);
- u8 dummy_sacked = TCP_SKB_CB(skb)->sacked; /* We discard results */
BUG_ON(!pcount);
@@ -1407,8 +1413,8 @@ static int tcp_shifted_skb(struct sock *sk, struct sk_buff *prev,
skb_shinfo(skb)->gso_type = 0;
}
- *flag |= tcp_sacktag_one(skb, sk, reord, 0, fack_count, &dummy_sacked,
- pcount);
+ /* We discard results */
+ tcp_sacktag_one(skb, sk, state, 0, pcount);
/* Difference in this won't matter, both ACKed by the same cumul. ACK */
TCP_SKB_CB(prev)->sacked |= (TCP_SKB_CB(skb)->sacked & TCPCB_EVER_RETRANS);
@@ -1460,9 +1466,9 @@ static int skb_can_shift(struct sk_buff *skb)
* skb.
*/
static struct sk_buff *tcp_shift_skb_data(struct sock *sk, struct sk_buff *skb,
+ struct tcp_sacktag_state *state,
u32 start_seq, u32 end_seq,
- int dup_sack, int *fack_count,
- int *reord, int *flag)
+ int dup_sack)
{
struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *prev;
@@ -1559,8 +1565,7 @@ static struct sk_buff *tcp_shift_skb_data(struct sock *sk, struct sk_buff *skb,
if (!skb_shift(prev, skb, len))
goto fallback;
- if (!tcp_shifted_skb(sk, prev, skb, pcount, len, *fack_count, reord,
- flag, mss))
+ if (!tcp_shifted_skb(sk, prev, skb, state, pcount, len, mss))
goto out;
/* Hole filled allows collapsing with the next as well, this is very
@@ -1579,12 +1584,12 @@ static struct sk_buff *tcp_shift_skb_data(struct sock *sk, struct sk_buff *skb,
len = skb->len;
if (skb_shift(prev, skb, len)) {
pcount += tcp_skb_pcount(skb);
- tcp_shifted_skb(sk, prev, skb, tcp_skb_pcount(skb), len,
- *fack_count, reord, flag, mss);
+ tcp_shifted_skb(sk, prev, skb, state, tcp_skb_pcount(skb), len,
+ mss);
}
out:
- *fack_count += pcount;
+ state->fack_count += pcount;
return prev;
noop:
@@ -1597,9 +1602,9 @@ fallback:
static struct sk_buff *tcp_sacktag_walk(struct sk_buff *skb, struct sock *sk,
struct tcp_sack_block *next_dup,
+ struct tcp_sacktag_state *state,
u32 start_seq, u32 end_seq,
- int dup_sack_in, int *fack_count,
- int *reord, int *flag)
+ int dup_sack_in)
{
struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *tmp;
@@ -1629,9 +1634,8 @@ static struct sk_buff *tcp_sacktag_walk(struct sk_buff *skb, struct sock *sk,
* so not even _safe variant of the loop is enough.
*/
if (in_sack <= 0) {
- tmp = tcp_shift_skb_data(sk, skb, start_seq,
- end_seq, dup_sack,
- fack_count, reord, flag);
+ tmp = tcp_shift_skb_data(sk, skb, state,
+ start_seq, end_seq, dup_sack);
if (tmp != NULL) {
if (tmp != skb) {
skb = tmp;
@@ -1650,17 +1654,17 @@ static struct sk_buff *tcp_sacktag_walk(struct sk_buff *skb, struct sock *sk,
break;
if (in_sack) {
- *flag |= tcp_sacktag_one(skb, sk, reord, dup_sack,
- *fack_count,
- &(TCP_SKB_CB(skb)->sacked),
- tcp_skb_pcount(skb));
+ TCP_SKB_CB(skb)->sacked = tcp_sacktag_one(skb, sk,
+ state,
+ dup_sack,
+ tcp_skb_pcount(skb));
if (!before(TCP_SKB_CB(skb)->seq,
tcp_highest_sack_seq(tp)))
tcp_advance_highest_sack(sk, skb);
}
- *fack_count += tcp_skb_pcount(skb);
+ state->fack_count += tcp_skb_pcount(skb);
}
return skb;
}
@@ -1669,7 +1673,8 @@ static struct sk_buff *tcp_sacktag_walk(struct sk_buff *skb, struct sock *sk,
* a normal way
*/
static struct sk_buff *tcp_sacktag_skip(struct sk_buff *skb, struct sock *sk,
- u32 skip_to_seq, int *fack_count)
+ struct tcp_sacktag_state *state,
+ u32 skip_to_seq)
{
tcp_for_write_queue_from(skb, sk) {
if (skb == tcp_send_head(sk))
@@ -1678,7 +1683,7 @@ static struct sk_buff *tcp_sacktag_skip(struct sk_buff *skb, struct sock *sk,
if (after(TCP_SKB_CB(skb)->end_seq, skip_to_seq))
break;
- *fack_count += tcp_skb_pcount(skb);
+ state->fack_count += tcp_skb_pcount(skb);
}
return skb;
}
@@ -1686,18 +1691,17 @@ static struct sk_buff *tcp_sacktag_skip(struct sk_buff *skb, struct sock *sk,
static struct sk_buff *tcp_maybe_skipping_dsack(struct sk_buff *skb,
struct sock *sk,
struct tcp_sack_block *next_dup,
- u32 skip_to_seq,
- int *fack_count, int *reord,
- int *flag)
+ struct tcp_sacktag_state *state,
+ u32 skip_to_seq)
{
if (next_dup == NULL)
return skb;
if (before(next_dup->start_seq, skip_to_seq)) {
- skb = tcp_sacktag_skip(skb, sk, next_dup->start_seq, fack_count);
- skb = tcp_sacktag_walk(skb, sk, NULL,
- next_dup->start_seq, next_dup->end_seq,
- 1, fack_count, reord, flag);
+ skb = tcp_sacktag_skip(skb, sk, state, next_dup->start_seq);
+ skb = tcp_sacktag_walk(skb, sk, NULL, state,
+ next_dup->start_seq, next_dup->end_seq,
+ 1);
}
return skb;
@@ -1719,15 +1723,16 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb,
struct tcp_sack_block_wire *sp_wire = (struct tcp_sack_block_wire *)(ptr+2);
struct tcp_sack_block sp[TCP_NUM_SACKS];
struct tcp_sack_block *cache;
+ struct tcp_sacktag_state state;
struct sk_buff *skb;
int num_sacks = min(TCP_NUM_SACKS, (ptr[1] - TCPOLEN_SACK_BASE) >> 3);
int used_sacks;
- int reord = tp->packets_out;
- int flag = 0;
int found_dup_sack = 0;
- int fack_count;
int i, j;
int first_sack_index;
+
+ state.flag = 0;
+ state.reord = tp->packets_out;
if (!tp->sacked_out) {
if (WARN_ON(tp->fackets_out))
@@ -1738,7 +1743,7 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb,
found_dup_sack = tcp_check_dsack(sk, ack_skb, sp_wire,
num_sacks, prior_snd_una);
if (found_dup_sack)
- flag |= FLAG_DSACKING_ACK;
+ state.flag |= FLAG_DSACKING_ACK;
/* Eliminate too old ACKs, but take into
* account more or less fresh ones, they can
@@ -1807,7 +1812,7 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb,
}
skb = tcp_write_queue_head(sk);
- fack_count = 0;
+ state.fack_count = 0;
i = 0;
if (!tp->sacked_out) {
@@ -1832,7 +1837,7 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb,
/* Event "B" in the comment above. */
if (after(end_seq, tp->high_seq))
- flag |= FLAG_DATA_LOST;
+ state.flag |= FLAG_DATA_LOST;
/* Skip too early cached blocks */
while (tcp_sack_cache_ok(tp, cache) &&
@@ -1845,13 +1850,13 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb,
/* Head todo? */
if (before(start_seq, cache->start_seq)) {
- skb = tcp_sacktag_skip(skb, sk, start_seq,
- &fack_count);
+ skb = tcp_sacktag_skip(skb, sk, &state,
+ start_seq);
skb = tcp_sacktag_walk(skb, sk, next_dup,
+ &state,
start_seq,
cache->start_seq,
- dup_sack, &fack_count,
- &reord, &flag);
+ dup_sack);
}
/* Rest of the block already fully processed? */
@@ -1859,9 +1864,8 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb,
goto advance_sp;
skb = tcp_maybe_skipping_dsack(skb, sk, next_dup,
- cache->end_seq,
- &fack_count, &reord,
- &flag);
+ &state,
+ cache->end_seq);
/* ...tail remains todo... */
if (tcp_highest_sack_seq(tp) == cache->end_seq) {
@@ -1869,13 +1873,12 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb,
skb = tcp_highest_sack(sk);
if (skb == NULL)
break;
- fack_count = tp->fackets_out;
+ state.fack_count = tp->fackets_out;
cache++;
goto walk;
}
- skb = tcp_sacktag_skip(skb, sk, cache->end_seq,
- &fack_count);
+ skb = tcp_sacktag_skip(skb, sk, &state, cache->end_seq);
/* Check overlap against next cached too (past this one already) */
cache++;
continue;
@@ -1885,20 +1888,20 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb,
skb = tcp_highest_sack(sk);
if (skb == NULL)
break;
- fack_count = tp->fackets_out;
+ state.fack_count = tp->fackets_out;
}
- skb = tcp_sacktag_skip(skb, sk, start_seq, &fack_count);
+ skb = tcp_sacktag_skip(skb, sk, &state, start_seq);
walk:
- skb = tcp_sacktag_walk(skb, sk, next_dup, start_seq, end_seq,
- dup_sack, &fack_count, &reord, &flag);
+ skb = tcp_sacktag_walk(skb, sk, next_dup, &state,
+ start_seq, end_seq, dup_sack);
advance_sp:
/* SACK enhanced FRTO (RFC4138, Appendix B): Clearing correct
* due to in-order walk
*/
if (after(end_seq, tp->frto_highmark))
- flag &= ~FLAG_ONLY_ORIG_SACKED;
+ state.flag &= ~FLAG_ONLY_ORIG_SACKED;
i++;
}
@@ -1915,10 +1918,10 @@ advance_sp:
tcp_verify_left_out(tp);
- if ((reord < tp->fackets_out) &&
+ if ((state.reord < tp->fackets_out) &&
((icsk->icsk_ca_state != TCP_CA_Loss) || tp->undo_marker) &&
(!tp->frto_highmark || after(tp->snd_una, tp->frto_highmark)))
- tcp_update_reordering(sk, tp->fackets_out - reord, 0);
+ tcp_update_reordering(sk, tp->fackets_out - state.reord, 0);
out:
@@ -1928,7 +1931,7 @@ out:
WARN_ON((int)tp->retrans_out < 0);
WARN_ON((int)tcp_packets_in_flight(tp) < 0);
#endif
- return flag;
+ return state.flag;
}
/* Limits sacked_out so that sum with lost_out isn't ever larger than
--
1.5.2.2
--
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