From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yb1-f201.google.com (mail-yb1-f201.google.com [209.85.219.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A363C4122D for ; Wed, 21 Feb 2024 10:59:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708513178; cv=none; b=szkhsZkWN530+/onpOU9r4xawzPz6i9KoBdnf3AWwg14K5VKgLxXK33dCEI+JCYVHtGewDh1rGrFAfvCYTk2Ng979evQhaHfq/enfpgVFCd5tFpvl0s/leCTYe4LGV/m3CmzONmUVvj7O7jOALEYXfkqnHdzgw4C/2ENKmB6MT8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708513178; c=relaxed/simple; bh=G1IJOOmceYR7xICiTPfem7LMSRPROleAUjq1Nbd84TI=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=GOwcTQE8Ldzm5orUnCpoIQK969lG2D9D3fYcq6rMZJJEcID5AxL5xF/R5E3dmojgCH/F+56mjXlL2v3/k3kJ1hfYq+q5eDpm+sZ8310QPvupVcOboHy9x/LMiU6FunTfIoyaC8DN+BHzpYBD8iaFddKgWTB/ZfTPVjtnYdlSmoM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=MVgip9jP; arc=none smtp.client-ip=209.85.219.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="MVgip9jP" Received: by mail-yb1-f201.google.com with SMTP id 3f1490d57ef6-dc657e9bdc4so8265387276.0 for ; Wed, 21 Feb 2024 02:59:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1708513175; x=1709117975; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=m12SzjdIh/P1Ghw3NNokbVnXbsJrAc4osZEY9shh5Q0=; b=MVgip9jP6cS1bbq3M1XHARrY8aREPoTl4mEZ+yp6vN2uhgtX74Fhel4AXRViPaGRYK BMk5swNlvfGzkINqZjGlQHkfkEDtFaR3pzvmLreZQ7cdHR7bDRu8SdLa15KClraGjjnn MO00Gop3AzTxypQoMsQXNrmbURF/Vso3llYf6KeZ8aHETk1UgFWzMXBTD5QRVTT8xlhk iZbGs65zoRu/vN9xgSuycBzj5sfVeoRsmsAngHEpHGRGoa7Z7k9SB17iXkhl7JUyd+lf hD2EuNkbH2ODp0bZ5ZNToPzkJubNJgGNYsK/thFqDKPxZI3fOCVXgtZha7cOO9i9pDBz fsOA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1708513175; x=1709117975; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=m12SzjdIh/P1Ghw3NNokbVnXbsJrAc4osZEY9shh5Q0=; b=GZT+ItEQyMdtvK/dqHewyTAox+2Lcdgxn6/+7lfZ5iYXfHXGR7sUb/GnVK2NCEdtUV Av1UoU7VGyHzUK3sS7+4F/qSp0ESFhN4GZ4gPC7RkG0Xfy9lHkIkioo7KFyNiF70M9m7 d7O08dnijSlMcbbDH3pi6Tz51SZB3sZcC3yLIboATl44ldhtcKyZ/nOqDD7lm6CBtbdl kYY7sBOel57PXWuutgtDYSPy7HXsMmhyF/9cyLaFJxEmG7dCwUF5MRCwjnFMJrDuEDjR L4Td62P4T3Fww0HmwJ47uHQ9KtZkSw2Kgyn1MqhgpAAw1if6YlX/LcPE8CKtCswdLpl6 sgTw== X-Gm-Message-State: AOJu0Yyon9uXrmmCc7oaCst2Yo247UJpgIKqqswGRf3twSqb+XWEJjmv xrbiMw/yCU9WYvF+lLbzhpmfpZfkbvlVzCHbK30biMuxqHHtqcSSLA4d7IoCCvczliG2AJ0Nubd zkfsc7BzwbA== X-Google-Smtp-Source: AGHT+IFbutcJ8pCtxn+sPOEXZUQTYzgd4ad2Hmuxuo2Gbn4cCIQAZuoUPEl4Gsw+dUrhr+gciekwKuwmVbJgTg== X-Received: from edumazet1.c.googlers.com ([fda3:e722:ac3:cc00:2b:7d90:c0a8:395a]) (user=edumazet job=sendgmr) by 2002:a05:6902:1008:b0:dbe:a0c2:df25 with SMTP id w8-20020a056902100800b00dbea0c2df25mr1027819ybt.8.1708513175672; Wed, 21 Feb 2024 02:59:35 -0800 (PST) Date: Wed, 21 Feb 2024 10:59:13 +0000 In-Reply-To: <20240221105915.829140-1-edumazet@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240221105915.829140-1-edumazet@google.com> X-Mailer: git-send-email 2.44.0.rc0.258.g7320e95886-goog Message-ID: <20240221105915.829140-12-edumazet@google.com> Subject: [PATCH net-next 11/13] inet: switch inet_dump_fib() to RCU protection From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet Content-Type: text/plain; charset="UTF-8" No longer hold RTNL while calling inet_dump_fib(). Also change return value for a completed dump: Returning 0 instead of skb->len allows NLMSG_DONE to be appended to the skb. User space does not have to call us again to get a standalone NLMSG_DONE marker. Signed-off-by: Eric Dumazet --- net/ipv4/fib_frontend.c | 37 ++++++++++++++++++------------------- net/ipv4/fib_trie.c | 4 ++-- 2 files changed, 20 insertions(+), 21 deletions(-) diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index 39f67990e01c19b73a622dced0220a1bba21d5e6..bf3a2214fe29b6f9b494581b293259e6c5ce6f8c 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -990,7 +990,7 @@ static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) struct fib_dump_filter filter = { .dump_routes = true, .dump_exceptions = true, - .rtnl_held = true, + .rtnl_held = false, }; const struct nlmsghdr *nlh = cb->nlh; struct net *net = sock_net(skb->sk); @@ -998,12 +998,13 @@ static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) unsigned int e = 0, s_e; struct fib_table *tb; struct hlist_head *head; - int dumped = 0, err; + int dumped = 0, err = 0; + rcu_read_lock(); if (cb->strict_check) { err = ip_valid_fib_dump_req(net, nlh, &filter, cb); if (err < 0) - return err; + goto unlock; } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { struct rtmsg *rtm = nlmsg_data(nlh); @@ -1012,29 +1013,28 @@ static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) /* ipv4 does not use prefix flag */ if (filter.flags & RTM_F_PREFIX) - return skb->len; + goto unlock; if (filter.table_id) { tb = fib_get_table(net, filter.table_id); if (!tb) { if (rtnl_msg_family(cb->nlh) != PF_INET) - return skb->len; + goto unlock; NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist"); - return -ENOENT; + err = -ENOENT; + goto unlock; } - - rcu_read_lock(); err = fib_table_dump(tb, skb, cb, &filter); - rcu_read_unlock(); - return skb->len ? : err; + if (err < 0 && skb->len) + err = skb->len; + goto unlock; } s_h = cb->args[0]; s_e = cb->args[1]; - rcu_read_lock(); - + err = 0; for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { e = 0; head = &net->ipv4.fib_table_hash[h]; @@ -1047,9 +1047,8 @@ static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) err = fib_table_dump(tb, skb, cb, &filter); if (err < 0) { if (likely(skb->len)) - goto out; - - goto out_err; + err = skb->len; + goto out; } dumped = 1; next: @@ -1057,13 +1056,12 @@ static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) } } out: - err = skb->len; -out_err: - rcu_read_unlock(); cb->args[1] = e; cb->args[0] = h; +unlock: + rcu_read_unlock(); return err; } @@ -1666,5 +1664,6 @@ void __init ip_fib_init(void) rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0); rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0); - rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0); + rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, + RTNL_FLAG_DUMP_UNLOCKED); } diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c index 0fc7ab5832d1ae00e33fdf6fad4ef379c7d0bd4d..f474106464d2f2a52fa6b7ecaf2146977d05eecc 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -2368,7 +2368,7 @@ int fib_table_dump(struct fib_table *tb, struct sk_buff *skb, * and key == 0 means the dump has wrapped around and we are done. */ if (count && !key) - return skb->len; + return 0; while ((l = leaf_walk_rcu(&tp, key)) != NULL) { int err; @@ -2394,7 +2394,7 @@ int fib_table_dump(struct fib_table *tb, struct sk_buff *skb, cb->args[3] = key; cb->args[2] = count; - return skb->len; + return 0; } void __init fib_trie_init(void) -- 2.44.0.rc0.258.g7320e95886-goog