From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from gandalf.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by passt.top (Postfix) with ESMTPS id 468DC5A0275 for ; Thu, 10 Aug 2023 04:33:27 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gibson.dropbear.id.au; s=201602; t=1691634801; bh=fkOP0ChdQ0WgaM02Uqbe6EGG3wkO9JwVwAoG87Zf+lc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NzFztSVzx1nVds+FLxzQME85xBFUeIzY6XYhrmo3cI28EgjSkZrM3/uvpMyIFgSCr 77w4HYiqwhWDLh3MO3VUB+8FNqZ2QF+KdcWBBXf9exexyADfH56ol6NWFVPAWErAHO B9hW3sFis1tGyNvoNOxYk/LaKDyX8sTDRFyJpDTU= Received: by gandalf.ozlabs.org (Postfix, from userid 1007) id 4RLrZT264Kz4wjG; Thu, 10 Aug 2023 12:33:21 +1000 (AEST) From: David Gibson To: passt-dev@passt.top, Stefano Brivio Subject: [PATCH v2 01/13] tap: Clean up tap reset path Date: Thu, 10 Aug 2023 12:33:03 +1000 Message-ID: <20230810023315.684784-2-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230810023315.684784-1-david@gibson.dropbear.id.au> References: <20230810023315.684784-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-ID-Hash: QYS5LAZ2NLFTFD2KO5GP2MMF2CG5OFSA X-Message-ID-Hash: QYS5LAZ2NLFTFD2KO5GP2MMF2CG5OFSA X-MailFrom: dgibson@gandalf.ozlabs.org X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: David Gibson X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: In tap_handler() if we get an error on the tap device or socket, we use tap_sock_init() to re-initialise it. However, what we actually need for this reset case has remarkably little in common with the case where we're initialising for the first time: * Re-initialising the packet pools is unnecessary * The case of a passed in fd (--fd) isn't relevant * We don't even call this for pasta mode * We will never re-call tap_sock_unix_init() because we never clear fd_tap_listen In fact the only thing we do in tap_sock_init() relevant to the reset case is to remove the fd from the epoll and close it... which isn't used in the first initialisation case. So make a new tap_sock_reset() function just for this case, and simplify tap_sock_init() slightly as being used only for the first time case. Signed-off-by: David Gibson --- tap.c | 52 +++++++++++++++++++++++++++++----------------------- 1 file changed, 29 insertions(+), 23 deletions(-) diff --git a/tap.c b/tap.c index e034f94..b4967d0 100644 --- a/tap.c +++ b/tap.c @@ -1236,19 +1236,14 @@ void tap_sock_init(struct ctx *c) tap6_l4[i].p = PACKET_INIT(pool_l4, TAP_SEQS, pkt_buf, sz); } - if (c->fd_tap != -1) { - if (c->one_off) { /* Passed as --fd */ - struct epoll_event ev = { 0 }; - - ev.data.fd = c->fd_tap; - ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP; - epoll_ctl(c->epollfd, EPOLL_CTL_ADD, c->fd_tap, &ev); - return; - } + if (c->fd_tap != -1) { /* Passed as --fd */ + struct epoll_event ev = { 0 }; + ASSERT(c->one_off); - epoll_ctl(c->epollfd, EPOLL_CTL_DEL, c->fd_tap, NULL); - close(c->fd_tap); - c->fd_tap = -1; + ev.data.fd = c->fd_tap; + ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP; + epoll_ctl(c->epollfd, EPOLL_CTL_ADD, c->fd_tap, &ev); + return; } if (c->mode == MODE_PASST) { @@ -1259,6 +1254,26 @@ void tap_sock_init(struct ctx *c) } } +/** + * tap_sock_reset() - Handle closing or failure of connect AF_UNIX socket + * @c: Execution context + */ +static void tap_sock_reset(struct ctx *c) +{ + if (c->one_off) { + info("Client closed connection, exiting"); + exit(EXIT_SUCCESS); + } + + if (c->mode == MODE_PASTA) + die("Error on tap device, exiting"); + + /* Close the connected socket, wait for a new connection */ + epoll_ctl(c->epollfd, EPOLL_CTL_DEL, c->fd_tap, NULL); + close(c->fd_tap); + c->fd_tap = -1; +} + /** * tap_handler() - Packet handler for AF_UNIX or tuntap file descriptor * @c: Execution context @@ -1276,15 +1291,6 @@ void tap_handler(struct ctx *c, int fd, uint32_t events, if ((c->mode == MODE_PASST && tap_handler_passt(c, now)) || (c->mode == MODE_PASTA && tap_handler_pasta(c, now)) || - (events & (EPOLLRDHUP | EPOLLHUP | EPOLLERR))) { - if (c->one_off) { - info("Client closed connection, exiting"); - exit(EXIT_SUCCESS); - } - - if (c->mode == MODE_PASTA) - die("Error on tap device, exiting"); - - tap_sock_init(c); - } + (events & (EPOLLRDHUP | EPOLLHUP | EPOLLERR))) + tap_sock_reset(c); } -- 2.41.0