[1.0.15] Regression test broken due to test_1_to_1_sockopt - SO_SNDBUF

lksctp-tools Matija Glavinic Pecotic 2 participants 3 messages Jan 3, 2014 SCTP protocol

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Matija Glavinic Pecotic

author

2014-01-03 15:33 UTC #0 lore raw

Hello sctp folks,

sctp regression suite is currently broken due to test_1_to_1_sockopt.

Problem is following:

TEST17 sets SO_SNDBUF to 2048

TEST18 gets SO_SNDBUF, expected is 2x2048, but obtained value is 4480

Quoted 3 lines

test_1_to_1_sockopt.c 17 PASS : setsockopt() SO_SNDBUF - SUCCESS
test_1_to_1_sockopt.c 18 PASS : getsockopt() SO_SNDBUF - SUCCESS
test_1_to_1_sockopt.c 19 BROK : Comparison failed:Set value and got value differs Set Value@96 Get ValueD80

reason lies is net/core/sock.c

Quoted 10 lines

	case SO_SNDBUF:
		/* Don't error on this BSD doesn't and if you think
		 * about it this is right. Otherwise apps have to
		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
		 * are treated in BSD as hints
		 */
		val = min_t(u32, val, sysctl_wmem_max);
set_sndbuf:
		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
		sk->sk_sndbuf = max_t(u32, val * 2, SOCK_MIN_SNDBUF);

since SOCK_MIN_SNDBUF is defined as:

include/net/sock.h

Quoted 9 lines

/* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
* need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
* Note: for send buffers, TCP works better if we can build two skbs at
* minimum.
*/
#define TCP_SKB_MIN_TRUESIZE (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
#define SOCK_MIN_SNDBUF (TCP_SKB_MIN_TRUESIZE * 2)
#define SOCK_MIN_RCVBUF TCP_SKB_MIN_TRUESIZE

we can observe that value for which we set SO_SNDBUF in TEST17 in test_1_to_1_sockopt.c needs to be increased

Version is visible in subject, 1.0.15, I hope http://sourceforge.net/projects/lksctp/files/ is still valid place to get it.

Best regards,

Matija

PS: happy new year!

Daniel Borkmann

2014-01-03 15:47 UTC #1 lore raw

Quoted 37 lines · Matija Glavinic Pecotic

Hello sctp folks,
sctp regression suite is currently broken due to test_1_to_1_sockopt.
Problem is following:
TEST17 sets SO_SNDBUF to 2048
TEST18 gets SO_SNDBUF, expected is 2x2048, but obtained value is 4480
Quoted 3 lines
test_1_to_1_sockopt.c 17 PASS : setsockopt() SO_SNDBUF - SUCCESS
test_1_to_1_sockopt.c 18 PASS : getsockopt() SO_SNDBUF - SUCCESS
test_1_to_1_sockopt.c 19 BROK : Comparison failed:Set value and got value differs Set Value@96 Get ValueD80
reason lies is net/core/sock.c
Quoted 10 lines
	case SO_SNDBUF:
		/* Don't error on this BSD doesn't and if you think
		 * about it this is right. Otherwise apps have to
		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
		 * are treated in BSD as hints
		 */
		val = min_t(u32, val, sysctl_wmem_max);
set_sndbuf:
		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
		sk->sk_sndbuf = max_t(u32, val * 2, SOCK_MIN_SNDBUF);
since SOCK_MIN_SNDBUF is defined as:
include/net/sock.h
Quoted 7 lines
/* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
* need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
* Note: for send buffers, TCP works better if we can build two skbs at
* minimum.
*/
#define TCP_SKB_MIN_TRUESIZE (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))

Quoted 6 lines

Quoted 2 lines
#define SOCK_MIN_SNDBUF (TCP_SKB_MIN_TRUESIZE * 2)
#define SOCK_MIN_RCVBUF TCP_SKB_MIN_TRUESIZE
we can observe that value for which we set SO_SNDBUF in TEST17 in test_1_to_1_sockopt.c needs to be increased
Version is visible in subject, 1.0.15, I hope http://sourceforge.net/projects/lksctp/files/ is still valid place to get it.

Already fixed in the current git tree (see lksctp.org) under b7ad1afc16cb0c5 ("tests: fix test_1_to_1_sockopt sock buff test case".) Will do a release some time next week.

Quoted 10 lines

Best regards,
Matija
PS: happy new year!
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Matija Glavinic Pecotic

author

2014-01-03 15:55 UTC #2 lore raw

In reply to Matija Glavinic Pecotic

Quoted 41 lines · ext Daniel Borkmann

Quoted 40 lines · Matija Glavinic Pecotic
Hello sctp folks,
sctp regression suite is currently broken due to test_1_to_1_sockopt.
Problem is following:
TEST17 sets SO_SNDBUF to 2048
TEST18 gets SO_SNDBUF, expected is 2x2048, but obtained value is 4480
Quoted 3 lines
test_1_to_1_sockopt.c 17 PASS : setsockopt() SO_SNDBUF - SUCCESS
test_1_to_1_sockopt.c 18 PASS : getsockopt() SO_SNDBUF - SUCCESS
test_1_to_1_sockopt.c 19 BROK : Comparison failed:Set value and got value differs Set Value@96 Get ValueD80
reason lies is net/core/sock.c
Quoted 10 lines
case SO_SNDBUF:
/* Don't error on this BSD doesn't and if you think
* about it this is right. Otherwise apps have to
* play 'guess the biggest size' games. RCVBUF/SNDBUF
* are treated in BSD as hints
*/
val = min_t(u32, val, sysctl_wmem_max);
set_sndbuf:
        sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
        sk->sk_sndbuf = max_t(u32, val * 2, SOCK_MIN_SNDBUF);
since SOCK_MIN_SNDBUF is defined as:
include/net/sock.h
Quoted 9 lines
/* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
* need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
* Note: for send buffers, TCP works better if we can build two skbs at
* minimum.
*/
#define TCP_SKB_MIN_TRUESIZE (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
#define SOCK_MIN_SNDBUF (TCP_SKB_MIN_TRUESIZE * 2)
#define SOCK_MIN_RCVBUF TCP_SKB_MIN_TRUESIZE

Quoted 7 lines

Quoted 3 lines
we can observe that value for which we set SO_SNDBUF in TEST17 in test_1_to_1_sockopt.c needs to be increased
Version is visible in subject, 1.0.15, I hope http://sourceforge.net/projects/lksctp/files/ is still valid place to get it.
Already fixed in the current git tree (see lksctp.org) under b7ad1afc16cb0c5 ("tests: fix test_1_to_1_sockopt sock buff test case".) Will do a release some time next week.

I see, thanks, I will check it next time before reporting.

Quoted 10 lines

Best regards,

Matija

PS: happy new year!

Signature · 3 lines

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