From patchwork Tue Mar 5 05:33:08 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jakub Kicinski X-Patchwork-Id: 13581632 X-Patchwork-Delegate: kuba@kernel.org Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F2A024C637 for ; Tue, 5 Mar 2024 05:33:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709616796; cv=none; b=cbaq5O40dSSfGYmG0uGxqRfNUqNw7arvO1oLGUNrXADwOvOYeMP5TrKNh5go+cFHKpXpS6rd7ljVpn727y1KTm0I83RNzpiPrCozr8zB3tYfvIu39dIEbRuEKlCdJz/GpbsHj18mulht1ayb4NlrTnB77gZ4WagQVKbsodOo5vI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709616796; c=relaxed/simple; bh=vlXNscYVmI9A9o6+mBNrH59tYt31nVVZDVGvFZFv1v8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GM6mLw5tKVJFdcAc81YDaugNJr0necbZe/JnLtmZpGT39YEVITYGejRfKA4qXJ+zadd3f90U47duh/F4ZaXKSDHG9js5Eh4M3xqeRcOT/AQg9UZejTuRG7ffcBbsrZvC716FXf98nvEVQnH7FIv+jDoUMNk5t9VATW2AuwJcotc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mvr2UQ9G; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="mvr2UQ9G" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 770ADC43390; Tue, 5 Mar 2024 05:33:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1709616795; bh=vlXNscYVmI9A9o6+mBNrH59tYt31nVVZDVGvFZFv1v8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mvr2UQ9G1LFU5nPesP5/Zbl2LqNWFD3+tqXGzVnn3yY1/GsN+9q52+2NMuA2CEqY9 EB2REYFcr62PmWWKQ+lAQfTfmBHrpb0x0u4y3a2JLeHtHj7IPlJijEAamfGffaGhEw FkuihKQxc2aDPyx0PFmrlyzkKiUMLiPo8OBybLhJTqhb4AxZrOieVB8bBJ/BPeGsaD 5SIKpzJVSiNdmTAWMX0MB6JiRHeMO8tDgazYs1tBUVVEiAAIDaO63QvQfLiQjCFzmY Q/PCmO9+bJR5zZNmP7yYO3yQPmuDV8eHsZDqLHa8hTNqWT6we9l3YXKWerxwgvzNar 20COouxczjm2Q== From: Jakub Kicinski To: davem@davemloft.net Cc: netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, jiri@resnulli.us, donald.hunter@gmail.com, Jakub Kicinski Subject: [PATCH net-next v2 2/4] tools: ynl: allow setting recv() size Date: Mon, 4 Mar 2024 21:33:08 -0800 Message-ID: <20240305053310.815877-3-kuba@kernel.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240305053310.815877-1-kuba@kernel.org> References: <20240305053310.815877-1-kuba@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org Make the size of the buffer we use for recv() configurable. The details of the buffer sizing in netlink are somewhat arcane, we could spend a lot of time polishing this API. Let's just leave some hopefully helpful comments for now. This is a for-developers-only feature, anyway. Signed-off-by: Jakub Kicinski Reviewed-by: Donald Hunter --- v2: - move the handling somewhere a bit more sensible - use 0 as default, and if to set it --- tools/net/ynl/lib/ynl.py | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/tools/net/ynl/lib/ynl.py b/tools/net/ynl/lib/ynl.py index 92ade9105f31..c3ff5be33e4e 100644 --- a/tools/net/ynl/lib/ynl.py +++ b/tools/net/ynl/lib/ynl.py @@ -84,6 +84,10 @@ from .nlspec import SpecFamily return f"Netlink error: {os.strerror(-self.nl_msg.error)}\n{self.nl_msg}" +class ConfigError(Exception): + pass + + class NlAttr: ScalarFormat = namedtuple('ScalarFormat', ['native', 'big', 'little']) type_formats = { @@ -400,7 +404,8 @@ genl_family_name_to_id = None class YnlFamily(SpecFamily): - def __init__(self, def_path, schema=None, process_unknown=False): + def __init__(self, def_path, schema=None, process_unknown=False, + recv_size=0): super().__init__(def_path, schema) self.include_raw = False @@ -415,6 +420,16 @@ genl_family_name_to_id = None except KeyError: raise Exception(f"Family '{self.yaml['name']}' not supported by the kernel") + # Note that netlink will use conservative (min) message size for + # the first dump recv() on the socket, our setting will only matter + # from the second recv() on. + self._recv_size = recv_size if recv_size else 131072 + # Netlink will always allocate at least PAGE_SIZE - sizeof(skb_shinfo) + # for a message, so smaller receive sizes will lead to truncation. + # Note that the min size for other families may be larger than 4k! + if self._recv_size < 4000: + raise ConfigError() + self.sock = socket.socket(socket.AF_NETLINK, socket.SOCK_RAW, self.nlproto.proto_num) self.sock.setsockopt(Netlink.SOL_NETLINK, Netlink.NETLINK_CAP_ACK, 1) self.sock.setsockopt(Netlink.SOL_NETLINK, Netlink.NETLINK_EXT_ACK, 1) @@ -799,7 +814,7 @@ genl_family_name_to_id = None def check_ntf(self): while True: try: - reply = self.sock.recv(128 * 1024, socket.MSG_DONTWAIT) + reply = self.sock.recv(self._recv_size, socket.MSG_DONTWAIT) except BlockingIOError: return @@ -854,7 +869,7 @@ genl_family_name_to_id = None done = False rsp = [] while not done: - reply = self.sock.recv(128 * 1024) + reply = self.sock.recv(self._recv_size) nms = NlMsgs(reply, attr_space=op.attr_set) for nl_msg in nms: if nl_msg.extack: