diff mbox series

[net-next,v04,1/3] af_packet: allow fanout_add when socket is not RUNNING

Message ID 4f1a3c37dbef980ef044c4d2adf91c76e2eca14b.1728802323.git.gur.stavi@huawei.com (mailing list archive)
State Accepted
Commit 2cee3e6e2e4b74bec96694169f01cd3feec1f264
Delegated to: Netdev Maintainers
Headers show
Series net: af_packet: allow joining a fanout when link is down | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 5 this patch: 5
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 5 of 5 maintainers
netdev/build_clang success Errors and warnings before: 3 this patch: 3
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 6 this patch: 6
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 26 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-10-14--09-00 (tests: 777)

Commit Message

Gur Stavi Oct. 13, 2024, 7:15 a.m. UTC
PACKET socket can retain its fanout membership through link down and up
and leave a fanout while closed regardless of link state.
However, socket was forbidden from joining a fanout while it was not
RUNNING.

This patch allows PACKET socket to join fanout while not RUNNING.

Socket can be RUNNING if it has a specified protocol. Either directly
from packet_create (being implicitly bound to any interface) or following
a successful bind. Socket RUNNING state is switched off if it is bound to
an interface that went down.

Instead of the test for RUNNING, this patch adds a test that socket can
become RUNNING.

Signed-off-by: Gur Stavi <gur.stavi@huawei.com>
---
 net/packet/af_packet.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

Comments

Willem de Bruijn Oct. 15, 2024, 12:38 a.m. UTC | #1
Gur Stavi wrote:
> PACKET socket can retain its fanout membership through link down and up
> and leave a fanout while closed regardless of link state.
> However, socket was forbidden from joining a fanout while it was not
> RUNNING.
> 
> This patch allows PACKET socket to join fanout while not RUNNING.
> 
> Socket can be RUNNING if it has a specified protocol. Either directly
> from packet_create (being implicitly bound to any interface) or following
> a successful bind. Socket RUNNING state is switched off if it is bound to
> an interface that went down.
> 
> Instead of the test for RUNNING, this patch adds a test that socket can
> become RUNNING.
> 
> Signed-off-by: Gur Stavi <gur.stavi@huawei.com>

Reviewed-by: Willem de Bruijn <willemb@google.com>
diff mbox series

Patch

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index f8942062f776..2ff4b251842d 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1846,21 +1846,22 @@  static int fanout_add(struct sock *sk, struct fanout_args *args)
 	err = -EINVAL;
 
 	spin_lock(&po->bind_lock);
-	if (packet_sock_flag(po, PACKET_SOCK_RUNNING) &&
+	if (po->num &&
 	    match->type == type &&
 	    match->prot_hook.type == po->prot_hook.type &&
 	    match->prot_hook.dev == po->prot_hook.dev) {
 		err = -ENOSPC;
 		if (refcount_read(&match->sk_ref) < match->max_num_members) {
-			__dev_remove_pack(&po->prot_hook);
-
 			/* Paired with packet_setsockopt(PACKET_FANOUT_DATA) */
 			WRITE_ONCE(po->fanout, match);
 
 			po->rollover = rollover;
 			rollover = NULL;
 			refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1);
-			__fanout_link(sk, po);
+			if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) {
+				__dev_remove_pack(&po->prot_hook);
+				__fanout_link(sk, po);
+			}
 			err = 0;
 		}
 	}