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authorGuillaume Nault <gnault@redhat.com>2023-12-01 17:49:52 +0300
committerJakub Kicinski <kuba@kernel.org>2023-12-05 01:45:26 +0300
commit91051f003948432f83b5d2766eeb83b2b4993649 (patch)
tree81d4fce457617cee61630705f9411364f4dc1aca /net/ipv4/inet_diag.c
parente4b5e96d9c197524543bd522b3d5714d1eebcefb (diff)
downloadlinux-91051f003948432f83b5d2766eeb83b2b4993649.tar.xz
tcp: Dump bound-only sockets in inet_diag.
Walk the hashinfo->bhash2 table so that inet_diag can dump TCP sockets that are bound but haven't yet called connect() or listen(). The code is inspired by the ->lhash2 loop. However there's no manual test of the source port, since this kind of filtering is already handled by inet_diag_bc_sk(). Also, a maximum of 16 sockets are dumped at a time, to avoid running with bh disabled for too long. There's no TCP state for bound but otherwise inactive sockets. Such sockets normally map to TCP_CLOSE. However, "ss -l", which is supposed to only dump listening sockets, actually requests the kernel to dump sockets in either the TCP_LISTEN or TCP_CLOSE states. To avoid dumping bound-only sockets with "ss -l", we therefore need to define a new pseudo-state (TCP_BOUND_INACTIVE) that user space will be able to set explicitly. With an IPv4, an IPv6 and an IPv6-only socket, bound respectively to 40000, 64000, 60000, an updated version of iproute2 could work as follow: $ ss -t state bound-inactive Recv-Q Send-Q Local Address:Port Peer Address:Port Process 0 0 0.0.0.0:40000 0.0.0.0:* 0 0 [::]:60000 [::]:* 0 0 *:64000 *:* Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/b3a84ae61e19c06806eea9c602b3b66e8f0cfc81.1701362867.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv4/inet_diag.c')
-rw-r--r--net/ipv4/inet_diag.c86
1 files changed, 85 insertions, 1 deletions
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 7d0e7aaa71e0..46b13962ad02 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -1077,10 +1077,94 @@ skip_listen_ht:
s_i = num = s_num = 0;
}
+/* Process a maximum of SKARR_SZ sockets at a time when walking hash buckets
+ * with bh disabled.
+ */
+#define SKARR_SZ 16
+
+ /* Dump bound but inactive (not listening, connecting, etc.) sockets */
+ if (cb->args[0] == 1) {
+ if (!(idiag_states & TCPF_BOUND_INACTIVE))
+ goto skip_bind_ht;
+
+ for (i = s_i; i < hashinfo->bhash_size; i++) {
+ struct inet_bind_hashbucket *ibb;
+ struct inet_bind2_bucket *tb2;
+ struct sock *sk_arr[SKARR_SZ];
+ int num_arr[SKARR_SZ];
+ int idx, accum, res;
+
+resume_bind_walk:
+ num = 0;
+ accum = 0;
+ ibb = &hashinfo->bhash2[i];
+
+ spin_lock_bh(&ibb->lock);
+ inet_bind_bucket_for_each(tb2, &ibb->chain) {
+ if (!net_eq(ib2_net(tb2), net))
+ continue;
+
+ sk_for_each_bound_bhash2(sk, &tb2->owners) {
+ struct inet_sock *inet = inet_sk(sk);
+
+ if (num < s_num)
+ goto next_bind;
+
+ if (sk->sk_state != TCP_CLOSE ||
+ !inet->inet_num)
+ goto next_bind;
+
+ if (r->sdiag_family != AF_UNSPEC &&
+ r->sdiag_family != sk->sk_family)
+ goto next_bind;
+
+ if (!inet_diag_bc_sk(bc, sk))
+ goto next_bind;
+
+ sock_hold(sk);
+ num_arr[accum] = num;
+ sk_arr[accum] = sk;
+ if (++accum == SKARR_SZ)
+ goto pause_bind_walk;
+next_bind:
+ num++;
+ }
+ }
+pause_bind_walk:
+ spin_unlock_bh(&ibb->lock);
+
+ res = 0;
+ for (idx = 0; idx < accum; idx++) {
+ if (res >= 0) {
+ res = inet_sk_diag_fill(sk_arr[idx],
+ NULL, skb, cb,
+ r, NLM_F_MULTI,
+ net_admin);
+ if (res < 0)
+ num = num_arr[idx];
+ }
+ sock_put(sk_arr[idx]);
+ }
+ if (res < 0)
+ goto done;
+
+ cond_resched();
+
+ if (accum == SKARR_SZ) {
+ s_num = num + 1;
+ goto resume_bind_walk;
+ }
+
+ s_num = 0;
+ }
+skip_bind_ht:
+ cb->args[0] = 2;
+ s_i = num = s_num = 0;
+ }
+
if (!(idiag_states & ~TCPF_LISTEN))
goto out;
-#define SKARR_SZ 16
for (i = s_i; i <= hashinfo->ehash_mask; i++) {
struct inet_ehash_bucket *head = &hashinfo->ehash[i];
spinlock_t *lock = inet_ehash_lockp(hashinfo, i);