From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: passt.top; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: passt.top; dkim=pass (2048-bit key; secure) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.a=rsa-sha256 header.s=202408 header.b=VXkeuGJJ; dkim-atps=neutral Received: from mail.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by passt.top (Postfix) with ESMTPS id EDBA95A0275 for ; Fri, 06 Sep 2024 07:17:23 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gibson.dropbear.id.au; s=202408; t=1725599833; bh=Ue4gPtnPnJ3IbPh3M8rOAr6I52SROQzzR2w+BdESrEs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VXkeuGJJUjjyhU69hhVhwq6e0/HIVjeg8lmIt4AX0XHRetQi+RSytbg+89dWPG40X oYNUFwlO2GdkXjeCVsXq4Yeh8wCphK4E7HaBdAfxex7KEJdFXDxCpenhVgrr0M2kNe 6bB27K9lI0U6ucmioovmTrCAGDnlv6nr7pIknvNtpwQJyeav0tNzkhDxB1SmzjuXnM 1zmg9dZVXapBYjmOlIkGl+aQF5+uzO0QV3jcnrFisy66OGXXk5ZIuzjHS2fO39sAu4 9INj0rS+eJybv5I5NzfaFZV6O5gai3w5cIVnr11qvhjYAZDIsRT6PfW4b65POOu2K+ oe7DodrKeHP5w== Received: by gandalf.ozlabs.org (Postfix, from userid 1007) id 4X0Pc94m3bz4x3q; Fri, 6 Sep 2024 15:17:13 +1000 (AEST) From: David Gibson To: passt-dev@passt.top, Stefano Brivio Subject: [PATCH 2/6] udp: Allow UDP flows to be prematurely closed Date: Fri, 6 Sep 2024 15:17:06 +1000 Message-ID: <20240906051710.3863211-3-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240906051710.3863211-1-david@gibson.dropbear.id.au> References: <20240906051710.3863211-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-ID-Hash: CYCIBI4ESDLRR4V7CHGENAXZZ3ESDU62 X-Message-ID-Hash: CYCIBI4ESDLRR4V7CHGENAXZZ3ESDU62 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: Unlike TCP, UDP has no in-band signalling for the end of a flow. So the only way we remove flows is on a timer if they have no activity for 180s. However, we've started to investigate some error conditions in which we want to prematurely abort / abandon a UDP flow. We can call udp_flow_close(), which will make the flow inert (sockets closed, no epoll events, can't be looked up in hash). However it will still wait 3 minutes to clear away the stale entry. Clean this up by adding an explicit 'closed' flag which will cause a flow to be more promptly cleaned up. We also publish udp_flow_close() so it can be called from other places to abort UDP flows(). Signed-off-by: David Gibson --- flow.c | 3 ++- udp_flow.c | 18 +++++++++++++++++- udp_flow.h | 4 ++++ 3 files changed, 23 insertions(+), 2 deletions(-) diff --git a/flow.c b/flow.c index a00e01d1..f2de0414 100644 --- a/flow.c +++ b/flow.c @@ -832,7 +832,8 @@ void flow_defer_handler(const struct ctx *c, const struct timespec *now) closed = icmp_ping_timer(c, &flow->ping, now); break; case FLOW_UDP: - if (timer) + closed = udp_flow_defer(&flow->udp); + if (!closed && timer) closed = udp_flow_timer(c, &flow->udp, now); break; default: diff --git a/udp_flow.c b/udp_flow.c index 1ff59a9b..b81be2cf 100644 --- a/udp_flow.c +++ b/udp_flow.c @@ -39,8 +39,11 @@ struct udp_flow *udp_at_sidx(flow_sidx_t sidx) * @c: Execution context * @uflow: UDP flow */ -static void udp_flow_close(const struct ctx *c, struct udp_flow *uflow) +void udp_flow_close(const struct ctx *c, struct udp_flow *uflow) { + if (uflow->closed) + return; /* Nothing to do */ + if (uflow->s[INISIDE] >= 0) { /* The listening socket needs to stay in epoll */ close(uflow->s[INISIDE]); @@ -56,6 +59,8 @@ static void udp_flow_close(const struct ctx *c, struct udp_flow *uflow) flow_hash_remove(c, FLOW_SIDX(uflow, INISIDE)); if (!pif_is_socket(uflow->f.pif[TGTSIDE])) flow_hash_remove(c, FLOW_SIDX(uflow, TGTSIDE)); + + uflow->closed = true; } /** @@ -256,6 +261,17 @@ flow_sidx_t udp_flow_from_tap(const struct ctx *c, return udp_flow_new(c, flow, -1, now); } +/** + * udp_flow_defer() - Deferred per-flow handling (clean up aborted flows) + * @uflow: Flow to handle + * + * Return: true if the connection is ready to free, false otherwise + */ +bool udp_flow_defer(const struct udp_flow *uflow) +{ + return uflow->closed; +} + /** * udp_flow_timer() - Handler for timed events related to a given flow * @c: Execution context diff --git a/udp_flow.h b/udp_flow.h index 12ddf039..9a1b059c 100644 --- a/udp_flow.h +++ b/udp_flow.h @@ -10,6 +10,7 @@ /** * struct udp - Descriptor for a flow of UDP packets * @f: Generic flow information + * @closed: Flow is already closed * @ts: Activity timestamp * @s: Socket fd (or -1) for each side of the flow */ @@ -17,6 +18,7 @@ struct udp_flow { /* Must be first element */ struct flow_common f; + bool closed :1; time_t ts; int s[SIDES]; }; @@ -30,6 +32,8 @@ flow_sidx_t udp_flow_from_tap(const struct ctx *c, const void *saddr, const void *daddr, in_port_t srcport, in_port_t dstport, const struct timespec *now); +void udp_flow_close(const struct ctx *c, struct udp_flow *uflow); +bool udp_flow_defer(const struct udp_flow *uflow); bool udp_flow_timer(const struct ctx *c, struct udp_flow *uflow, const struct timespec *now); -- 2.46.0