From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3F4AFC433EF for ; Wed, 8 Dec 2021 13:49:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232761AbhLHNxT (ORCPT ); Wed, 8 Dec 2021 08:53:19 -0500 Received: from dehost.average.org ([88.198.2.197]:47502 "EHLO dehost.average.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232719AbhLHNxT (ORCPT ); Wed, 8 Dec 2021 08:53:19 -0500 Received: from wncross.fkb.profitbricks.net (unknown [IPv6:2a02:8106:1:6800:8b1c:cff2:1ce3:e09b]) by dehost.average.org (Postfix) with ESMTPA id 258D3394DEAB; Wed, 8 Dec 2021 14:49:46 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=average.org; s=mail; t=1638971386; bh=s1fhuSWfF4Cs5J9Br+0mqP+BL0meUj5ax/rruKiXRH0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eoyhlj+xmBvB+/ceUt38bkKAlFdv+zgwXjZPV29F4Blo9DoY98QedS3J5NFNbQT1q iJGvv8PGdnvT1sgUfUWrRQ+kdk6U6T5TjsK2WYTmPUNIKNOAiTsMWkm93Qubl6Sbex RlbPrWPdvfQEQae9ufM/NsSeDHtK9PSmuOiXSerc= From: Eugene Crosser To: netfilter-devel@vger.kernel.org Cc: Eugene Crosser Subject: [PATCH nft 2/2] Handle retriable errors from mnl functions Date: Wed, 8 Dec 2021 14:49:14 +0100 Message-Id: <20211208134914.16365-3-crosser@average.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211208134914.16365-1-crosser@average.org> References: <20211208134914.16365-1-crosser@average.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org rc == -1 and errno == EINTR mean: mnl_socket_recvfrom() - blindly rerun the function mnl_cb_run() - restart dump request from scratch This commit introduces handling of both these conditions Signed-off-by: Eugene Crosser --- src/iface.c | 73 ++++++++++++++++++++++++++++++++--------------------- 1 file changed, 44 insertions(+), 29 deletions(-) diff --git a/src/iface.c b/src/iface.c index d0e1834c..029f6476 100644 --- a/src/iface.c +++ b/src/iface.c @@ -66,39 +66,54 @@ void iface_cache_update(void) struct nlmsghdr *nlh; struct rtgenmsg *rt; uint32_t seq, portid; + bool need_restart; + int retry_count = 5; int ret; - nlh = mnl_nlmsg_put_header(buf); - nlh->nlmsg_type = RTM_GETLINK; - nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP; - nlh->nlmsg_seq = seq = time(NULL); - rt = mnl_nlmsg_put_extra_header(nlh, sizeof(struct rtgenmsg)); - rt->rtgen_family = AF_PACKET; - - nl = mnl_socket_open(NETLINK_ROUTE); - if (nl == NULL) - netlink_init_error(); - - if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) - netlink_init_error(); - - portid = mnl_socket_get_portid(nl); - - if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) - netlink_init_error(); - - ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); - while (ret > 0) { - ret = mnl_cb_run(buf, ret, seq, portid, data_cb, NULL); - if (ret <= MNL_CB_STOP) - break; - ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); - } - if (ret == -1) + do { + nlh = mnl_nlmsg_put_header(buf); + nlh->nlmsg_type = RTM_GETLINK; + nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP; + nlh->nlmsg_seq = seq = time(NULL); + rt = mnl_nlmsg_put_extra_header(nlh, sizeof(struct rtgenmsg)); + rt->rtgen_family = AF_PACKET; + + nl = mnl_socket_open(NETLINK_ROUTE); + if (nl == NULL) + netlink_init_error(); + + if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) + netlink_init_error(); + + portid = mnl_socket_get_portid(nl); + + if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) + netlink_init_error(); + + need_restart = false; + while (true) { + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + if (ret == -1) { + if (errno == EINTR) + continue; + else + netlink_init_error(); + } + ret = mnl_cb_run(buf, ret, seq, portid, data_cb, NULL); + if (ret == MNL_CB_STOP) + break; + if (ret == -1) { + if (errno == EINTR) + need_restart = true; + else + netlink_init_error(); + } + } + mnl_socket_close(nl); + } while (need_restart && retry_count--); + if (need_restart) netlink_init_error(); - mnl_socket_close(nl); - iface_cache_init = true; } -- 2.32.0