From owner-freebsd-arch@freebsd.org Mon Mar 29 14:03:53 2021 Return-Path: Delivered-To: freebsd-arch@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id A3818578719; Mon, 29 Mar 2021 14:03:53 +0000 (UTC) (envelope-from cy.schubert@cschubert.com) Received: from smtp-out-so.shaw.ca (smtp-out-so.shaw.ca [64.59.136.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "Client", Issuer "CA" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4F8Dp03SPcz3RCX; Mon, 29 Mar 2021 14:03:51 +0000 (UTC) (envelope-from cy.schubert@cschubert.com) Received: from spqr.komquats.com ([70.66.148.124]) by shaw.ca with ESMTPA id QsURlPdAJHmS3QsUSlmu8x; Mon, 29 Mar 2021 08:03:47 -0600 X-Authority-Analysis: v=2.4 cv=MaypB7zf c=1 sm=1 tr=0 ts=6061de43 a=Cwc3rblV8FOMdVN/wOAqyQ==:117 a=Cwc3rblV8FOMdVN/wOAqyQ==:17 a=xqWC_Br6kY4A:10 a=8nJEP1OIZ-IA:10 a=dESyimp9J3IA:10 a=6I5d2MoRAAAA:8 a=YxBL1-UpAAAA:8 a=EkcXrb_YAAAA:8 a=6fP0Wl_uBWtMcdXx8xYA:9 a=wPNLvfGTeEIA:10 a=IjZwj45LgO3ly-622nXo:22 a=Ia-lj3WSrqcvXOmTRaiG:22 a=LK5xJRSDVpKd5WXXoEvA:22 a=RBBcRewTFc8P4JkPnay6:22 Received: from slippy.cwsent.com (slippy [IPv6:fc00:1:1:1::5b]) by spqr.komquats.com (Postfix) with ESMTPS id B57298D0; Mon, 29 Mar 2021 07:03:34 -0700 (PDT) Received: from slippy (localhost [127.0.0.1]) by slippy.cwsent.com (8.16.1/8.16.1) with ESMTP id 12TE3Y2H094131; Mon, 29 Mar 2021 07:03:34 -0700 (PDT) (envelope-from Cy.Schubert@cschubert.com) Message-Id: <202103291403.12TE3Y2H094131@slippy.cwsent.com> X-Mailer: exmh version 2.9.0 11/07/2018 with nmh-1.7.1 Reply-to: Cy Schubert From: Cy Schubert X-os: FreeBSD X-Sender: cy@cwsent.com X-URL: http://www.cschubert.com/ To: "Kristof Provost" cc: "FreeBSD pf" , freebsd-arch@freebsd.org Subject: Re: [RFC] pf ioctl changes In-reply-to: <24E09373-EBCD-4ED1-8B59-A44E687F287E@FreeBSD.org> References: <24E09373-EBCD-4ED1-8B59-A44E687F287E@FreeBSD.org> Comments: In-reply-to "Kristof Provost" message dated "Sat, 27 Mar 2021 12:54:28 +0100." Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Date: Mon, 29 Mar 2021 07:03:34 -0700 X-CMAE-Envelope: MS4xfFKcENIMkskoHVgzpRCsxACpuWR3pzFJNLMWZUc1GHdRyeS/vKuaKb06r2JbgL8YSDKuvnpnFIwwGCNFH7riq6x406XjtiYc7nCpORvSV1RkodTJln3u GffcTr7ud+xIxI2TAOf3u580XkB6Ui1SG9NBZY/NX1RpN5PPMkIOq3Ffy2SGl6e+eWTfMVbMsLevN+uej+6bWXPR3dpvvWmwS2cC6WPCeRc/zLBVDg5QEx6x U4HqtZGHzmKm6hnp0QfB2j0QxKsyC+7t6pTJLpjvOnA= X-Rspamd-Queue-Id: 4F8Dp03SPcz3RCX X-Spamd-Bar: - Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=none (mx1.freebsd.org: domain of cy.schubert@cschubert.com has no SPF policy when checking 64.59.136.137) smtp.mailfrom=cy.schubert@cschubert.com X-Spamd-Result: default: False [-1.70 / 15.00]; HAS_REPLYTO(0.00)[Cy.Schubert@cschubert.com]; RCVD_VIA_SMTP_AUTH(0.00)[]; TO_DN_SOME(0.00)[]; MV_CASE(0.50)[]; RWL_MAILSPIKE_GOOD(0.00)[64.59.136.137:from]; RCVD_COUNT_THREE(0.00)[4]; NEURAL_HAM_SHORT(-1.00)[-1.000]; RECEIVED_SPAMHAUS_PBL(0.00)[70.66.148.124:received]; MIME_TRACE(0.00)[0:+]; RBL_DBL_DONT_QUERY_IPS(0.00)[64.59.136.137:from]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; ASN(0.00)[asn:6327, ipnet:64.59.128.0/20, country:CA]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; REPLYTO_EQ_FROM(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; TO_MATCH_ENVRCPT_ALL(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[cschubert.com: no valid DMARC record]; AUTH_NA(1.00)[]; SPAMHAUS_ZRD(0.00)[64.59.136.137:from:127.0.2.255]; RCVD_IN_DNSWL_LOW(-0.10)[64.59.136.137:from]; RCVD_TLS_LAST(0.00)[]; R_SPF_NA(0.00)[no SPF record]; MAILMAN_DEST(0.00)[freebsd-arch,freebsd-pf] X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 29 Mar 2021 14:03:53 -0000 In message <24E09373-EBCD-4ED1-8B59-A44E687F287E@FreeBSD.org>, "Kristof Provost " writes: > Hi, > > There are several patches in the pipeline that require changes in pf’s > interface between kernel and userspace. > In the past these have been handled in multiple ways. Either by simply > making the change, breaking binary compatibility, or by introducing a v2 > ioctl (e.g. DIOCADDALTQV1). > > While one is better than the other neither is wholly satisfying. New > versions of calls constitute a maintenance burden after all. > > I’d like to change the ioctl interface to use nvlists, which would > make such extensions much easier, because fields can be optional. > That is, if userspace doesn’t supply the ‘shinynewfeature’ field > the kernel can assume the default value and things just work. Similarly, > if the kernel supplies a ’shinynewfeature’ which userspace doesn’t > know about it’s simply ignored. > > The rough plan is to introduce nvlist versions of the get/add rules > calls for now. Others will follow as the need presents itself. > As these are new ioctls it is safe to MFC them to stable/12 and > stable/13. > The old interface will remain supported in those branches, but I’d > like to remove it from main (and thus FreeBSD 14). > > As part of this effort I may end up splitting off the ioctl interface > code from pfctl into libpfctl, which should make reuse of that code > easier. > > I hope to post preliminary patches in the coming week. > > Thoughts? Objections? Kernel and userland should be, I'd say must be, kept in sync. We have many examples of userland and kernel not being in sync over the years. For ipfilter, I've made incompatible changes to data structures requiring userand and kernel be in sync. These are few and far between. I've gotten away with this because there is no third party software that relies on the ipfilter kernel interfaces. I could be wrong but I doubt there may be third party software requiring pf ABI compatibility. But if there is then verstioned library interfaces are required. Given that the advice is to keep kernel and userland in sync there probably is no requirement for an UPDATING entry but that would be your call. -- Cheers, Cy Schubert FreeBSD UNIX: Web: https://FreeBSD.org NTP: Web: https://nwtime.org The need of the many outweighs the greed of the few. From owner-freebsd-arch@freebsd.org Mon Mar 29 14:55:33 2021 Return-Path: Delivered-To: freebsd-arch@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id C9B3A5799CC; Mon, 29 Mar 2021 14:55:33 +0000 (UTC) (envelope-from kp@FreeBSD.org) Received: from smtp.freebsd.org (smtp.freebsd.org [96.47.72.83]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4F8Fxd5SKjz3l8N; Mon, 29 Mar 2021 14:55:33 +0000 (UTC) (envelope-from kp@FreeBSD.org) Received: from venus.codepro.be (venus.codepro.be [5.9.86.228]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mx1.codepro.be", Issuer "R3" (verified OK)) (Authenticated sender: kp) by smtp.freebsd.org (Postfix) with ESMTPSA id 948DE29D4B; Mon, 29 Mar 2021 14:55:33 +0000 (UTC) (envelope-from kp@FreeBSD.org) Received: by venus.codepro.be (Postfix, authenticated sender kp) id C447D1243C; Mon, 29 Mar 2021 16:55:30 +0200 (CEST) From: "Kristof Provost" To: "Cy Schubert" Cc: "FreeBSD pf" , freebsd-arch@freebsd.org Subject: Re: [RFC] pf ioctl changes Date: Mon, 29 Mar 2021 16:55:29 +0200 X-Mailer: MailMate (1.13.2r5673) Message-ID: <18DC1EA9-ABFC-4A06-8710-A3068370EC52@FreeBSD.org> In-Reply-To: <202103291403.12TE3Y2H094131@slippy.cwsent.com> References: <24E09373-EBCD-4ED1-8B59-A44E687F287E@FreeBSD.org> <202103291403.12TE3Y2H094131@slippy.cwsent.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 29 Mar 2021 14:55:33 -0000 On 29 Mar 2021, at 16:03, Cy Schubert wrote: > In message <24E09373-EBCD-4ED1-8B59-A44E687F287E@FreeBSD.org>, > "Kristof > Provost > " writes: >> Hi, >> >> There are several patches in the pipeline that require changes in >> pf’s >> interface between kernel and userspace. >> In the past these have been handled in multiple ways. Either by >> simply >> making the change, breaking binary compatibility, or by introducing a >> v2 >> ioctl (e.g. DIOCADDALTQV1). >> >> While one is better than the other neither is wholly satisfying. New >> versions of calls constitute a maintenance burden after all. >> >> I’d like to change the ioctl interface to use nvlists, which >> would >> make such extensions much easier, because fields can be optional. >> That is, if userspace doesn’t supply the >> ‘shinynewfeature’ field >> the kernel can assume the default value and things just work. >> Similarly, >> if the kernel supplies a ’shinynewfeature’ which userspace >> doesn’t >> know about it’s simply ignored. >> >> The rough plan is to introduce nvlist versions of the get/add rules >> calls for now. Others will follow as the need presents itself. >> As these are new ioctls it is safe to MFC them to stable/12 and >> stable/13. >> The old interface will remain supported in those branches, but >> I’d >> like to remove it from main (and thus FreeBSD 14). >> >> As part of this effort I may end up splitting off the ioctl interface >> code from pfctl into libpfctl, which should make reuse of that code >> easier. >> >> I hope to post preliminary patches in the coming week. >> >> Thoughts? Objections? > > Kernel and userland should be, I'd say must be, kept in sync. We have > many > examples of userland and kernel not being in sync over the years. For > ipfilter, I've made incompatible changes to data structures requiring > userand and kernel be in sync. These are few and far between. > > I've gotten away with this because there is no third party software > that > relies on the ipfilter kernel interfaces. I could be wrong but I doubt > there may be third party software requiring pf ABI compatibility. But > if > there is then verstioned library interfaces are required. > > Given that the advice is to keep kernel and userland in sync there > probably > is no requirement for an UPDATING entry but that would be your call. > There are out-of-tree users of the pf ioctl interface. security/expiretable[1] for example. security/snort2pfcd appears to as well. sysutils/pfstat and sysutils/pftop use the ioctl interface as well, although not the three specific calls of immediate interest. I’m trying to work out how many examples there are, because one way or the other they’re going to have to cope with changes. So, I’d prefer to not just change the definitions of structs, even if we’ve done that in the past. struct pf_rule contains a few peculiarities from historical mistakes that I hope to correct now. Best regards, Kristof [1] Perhaps not the greatest example, because its use of struct pf_state was incorrect, so it couldn’t actually have worked correctly before it stopped building. See PR #253547 for details. From owner-freebsd-arch@freebsd.org Mon Mar 29 15:16:50 2021 Return-Path: Delivered-To: freebsd-arch@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 49F2257A6EE; Mon, 29 Mar 2021 15:16:50 +0000 (UTC) (envelope-from cy.schubert@cschubert.com) Received: from smtp-out-no.shaw.ca (smtp-out-no.shaw.ca [64.59.134.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "Client", Issuer "CA" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4F8GQ96cZTz3nvW; Mon, 29 Mar 2021 15:16:49 +0000 (UTC) (envelope-from cy.schubert@cschubert.com) Received: from spqr.komquats.com ([70.66.148.124]) by shaw.ca with ESMTPA id QtdGlpLzf2SWTQtdHlPeLf; Mon, 29 Mar 2021 09:16:47 -0600 X-Authority-Analysis: v=2.4 cv=fdJod2cF c=1 sm=1 tr=0 ts=6061ef5f a=Cwc3rblV8FOMdVN/wOAqyQ==:117 a=Cwc3rblV8FOMdVN/wOAqyQ==:17 a=xqWC_Br6kY4A:10 a=8nJEP1OIZ-IA:10 a=dESyimp9J3IA:10 a=6I5d2MoRAAAA:8 a=YxBL1-UpAAAA:8 a=EkcXrb_YAAAA:8 a=XSbsiAr4RLdZVirN8WEA:9 a=wPNLvfGTeEIA:10 a=IjZwj45LgO3ly-622nXo:22 a=Ia-lj3WSrqcvXOmTRaiG:22 a=LK5xJRSDVpKd5WXXoEvA:22 a=RBBcRewTFc8P4JkPnay6:22 Received: from slippy.cwsent.com (slippy [IPv6:fc00:1:1:1::5b]) by spqr.komquats.com (Postfix) with ESMTPS id 80AC518A; Mon, 29 Mar 2021 08:16:45 -0700 (PDT) Received: from slippy (localhost [127.0.0.1]) by slippy.cwsent.com (8.16.1/8.16.1) with ESMTP id 12TFGjTi004433; Mon, 29 Mar 2021 08:16:45 -0700 (PDT) (envelope-from Cy.Schubert@cschubert.com) Message-Id: <202103291516.12TFGjTi004433@slippy.cwsent.com> X-Mailer: exmh version 2.9.0 11/07/2018 with nmh-1.7.1 Reply-to: Cy Schubert From: Cy Schubert X-os: FreeBSD X-Sender: cy@cwsent.com X-URL: http://www.cschubert.com/ To: "Kristof Provost" cc: "Cy Schubert" , "FreeBSD pf" , freebsd-arch@freebsd.org Subject: Re: [RFC] pf ioctl changes In-reply-to: <18DC1EA9-ABFC-4A06-8710-A3068370EC52@FreeBSD.org> References: <24E09373-EBCD-4ED1-8B59-A44E687F287E@FreeBSD.org> <202103291403.12TE3Y2H094131@slippy.cwsent.com> <18DC1EA9-ABFC-4A06-8710-A3068370EC52@FreeBSD.org> Comments: In-reply-to "Kristof Provost" message dated "Mon, 29 Mar 2021 16:55:29 +0200." Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Date: Mon, 29 Mar 2021 08:16:45 -0700 X-CMAE-Envelope: MS4xfLa1KfqDIepTI3eJZkcB2BRJ9L3xywlsyfx5NBlF8+0/8A8cllRBWXLjC0TG1yEbtQ9Hbu/kbaJWLRbSZa5/CpR7jnd8x4Yoprc4kXljsWfbahB2UmNq +TpQdvwyrHuuUS1UAKbqwBFgF79NdGlKWqIYdDQXJecPfRfKQCaJu3bLK+YE8ygRu9J/GdwsoJ++bs8zu/JEvjFNXIeIlM44tHFLE50/eNS+zkiH9Gur6nBI 6pNrLdDZRa9a+PeVF6st51DzERV2J+7XxoFvwJiDREY= X-Rspamd-Queue-Id: 4F8GQ96cZTz3nvW X-Spamd-Bar: ---- Authentication-Results: mx1.freebsd.org; none X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[] X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 29 Mar 2021 15:16:50 -0000 In message <18DC1EA9-ABFC-4A06-8710-A3068370EC52@FreeBSD.org>, "Kristof Provost " writes: > On 29 Mar 2021, at 16:03, Cy Schubert wrote: > > In message <24E09373-EBCD-4ED1-8B59-A44E687F287E@FreeBSD.org>, > > "Kristof > > Provost > > " writes: > >> Hi, > >> > >> There are several patches in the pipeline that require changes in > >> pf’s > >> interface between kernel and userspace. > >> In the past these have been handled in multiple ways. Either by > >> simply > >> making the change, breaking binary compatibility, or by introducing a > >> v2 > >> ioctl (e.g. DIOCADDALTQV1). > >> > >> While one is better than the other neither is wholly satisfying. New > >> versions of calls constitute a maintenance burden after all. > >> > >> I’d like to change the ioctl interface to use nvlists, which > >> would > >> make such extensions much easier, because fields can be optional. > >> That is, if userspace doesn’t supply the > >> ‘shinynewfeature’ field > >> the kernel can assume the default value and things just work. > >> Similarly, > >> if the kernel supplies a ’shinynewfeature’ which userspace > >> doesn’t > >> know about it’s simply ignored. > >> > >> The rough plan is to introduce nvlist versions of the get/add rules > >> calls for now. Others will follow as the need presents itself. > >> As these are new ioctls it is safe to MFC them to stable/12 and > >> stable/13. > >> The old interface will remain supported in those branches, but > >> I’d > >> like to remove it from main (and thus FreeBSD 14). > >> > >> As part of this effort I may end up splitting off the ioctl interface > >> code from pfctl into libpfctl, which should make reuse of that code > >> easier. > >> > >> I hope to post preliminary patches in the coming week. > >> > >> Thoughts? Objections? > > > > Kernel and userland should be, I'd say must be, kept in sync. We have > > many > > examples of userland and kernel not being in sync over the years. For > > ipfilter, I've made incompatible changes to data structures requiring > > userand and kernel be in sync. These are few and far between. > > > > I've gotten away with this because there is no third party software > > that > > relies on the ipfilter kernel interfaces. I could be wrong but I doubt > > there may be third party software requiring pf ABI compatibility. But > > if > > there is then verstioned library interfaces are required. > > > > Given that the advice is to keep kernel and userland in sync there > > probably > > is no requirement for an UPDATING entry but that would be your call. > > > There are out-of-tree users of the pf ioctl interface. > security/expiretable[1] for example. > security/snort2pfcd appears to as well. > sysutils/pfstat and sysutils/pftop use the ioctl interface as well, > although not the three specific calls of immediate interest. This complicates things. IMO you'll probably need versioned function calls for at least 13-STABLE EOL. Or, versioning the data structures passed into the kernel such that the new fields are at the tail of the existing structures. > > I’m trying to work out how many examples there are, because one way or > the other they’re going to have to cope with changes. > > So, I’d prefer to not just change the definitions of structs, even if > we’ve done that in the past. struct pf_rule contains a few > peculiarities from historical mistakes that I hope to correct now. Technical debt is difficult to eliminate. We either fix it, paying it off in one lump sum or we pay it off through aggravation and design limitations, with interest, over time. Given that pf uses ioctl, versioned function calls won't help. A new ioctl may be the only answer. If you do choose this, add an identifier and version number to the head of each new struct to future proof pf. > > Best regards, > Kristof > > [1] Perhaps not the greatest example, because its use of struct pf_state > was incorrect, so it couldn’t actually have worked correctly before it > stopped building. See PR #253547 for details. -- Cheers, Cy Schubert FreeBSD UNIX: Web: https://FreeBSD.org NTP: Web: https://nwtime.org The need of the many outweighs the greed of the few. From owner-freebsd-arch@freebsd.org Mon Mar 29 15:25:58 2021 Return-Path: Delivered-To: freebsd-arch@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id B306A57AC3E; Mon, 29 Mar 2021 15:25:58 +0000 (UTC) (envelope-from kp@FreeBSD.org) Received: from smtp.freebsd.org (smtp.freebsd.org [96.47.72.83]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4F8Gck4kMlz3p7f; Mon, 29 Mar 2021 15:25:58 +0000 (UTC) (envelope-from kp@FreeBSD.org) Received: from venus.codepro.be (venus.codepro.be [5.9.86.228]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mx1.codepro.be", Issuer "R3" (verified OK)) (Authenticated sender: kp) by smtp.freebsd.org (Postfix) with ESMTPSA id 64F4F2A32F; Mon, 29 Mar 2021 15:25:58 +0000 (UTC) (envelope-from kp@FreeBSD.org) Received: by venus.codepro.be (Postfix, authenticated sender kp) id C3AE012464; Mon, 29 Mar 2021 17:25:56 +0200 (CEST) From: "Kristof Provost" To: "Cy Schubert" Cc: "FreeBSD pf" , freebsd-arch@freebsd.org Subject: Re: [RFC] pf ioctl changes Date: Mon, 29 Mar 2021 17:25:55 +0200 X-Mailer: MailMate (1.13.2r5673) Message-ID: <75FA4097-ED2A-4B96-9C90-E82F49F7764B@FreeBSD.org> In-Reply-To: <202103291516.12TFGjTi004433@slippy.cwsent.com> References: <24E09373-EBCD-4ED1-8B59-A44E687F287E@FreeBSD.org> <202103291403.12TE3Y2H094131@slippy.cwsent.com> <18DC1EA9-ABFC-4A06-8710-A3068370EC52@FreeBSD.org> <202103291516.12TFGjTi004433@slippy.cwsent.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 29 Mar 2021 15:25:58 -0000 On 29 Mar 2021, at 17:16, Cy Schubert wrote: > In message <18DC1EA9-ABFC-4A06-8710-A3068370EC52@FreeBSD.org>, > "Kristof > Provost > " writes: >> On 29 Mar 2021, at 16:03, Cy Schubert wrote: >>> In message <24E09373-EBCD-4ED1-8B59-A44E687F287E@FreeBSD.org>, >>> "Kristof >>> Provost >>> " writes: >>>> Hi, >>>> >>>> There are several patches in the pipeline that require changes in >>>> pf’s >>>> interface between kernel and userspace. >>>> In the past these have been handled in multiple ways. Either by >>>> simply >>>> making the change, breaking binary compatibility, or by introducing >>>> a >>>> v2 >>>> ioctl (e.g. DIOCADDALTQV1). >>>> >>>> While one is better than the other neither is wholly satisfying. >>>> New >>>> versions of calls constitute a maintenance burden after all. >>>> >>>> I’d like to change the ioctl interface to use nvlists, >>>> which >>>> would >>>> make such extensions much easier, because fields can be optional. >>>> That is, if userspace doesn’t supply the >>>> ‘shinynewfeature’ field >>>> the kernel can assume the default value and things just work. >>>> Similarly, >>>> if the kernel supplies a ’shinynewfeature’ >>>> which userspace >>>> doesn’t >>>> know about it’s simply ignored. >>>> >>>> The rough plan is to introduce nvlist versions of the get/add rules >>>> calls for now. Others will follow as the need presents itself. >>>> As these are new ioctls it is safe to MFC them to stable/12 and >>>> stable/13. >>>> The old interface will remain supported in those branches, but >>>> I’d >>>> like to remove it from main (and thus FreeBSD 14). >>>> >>>> As part of this effort I may end up splitting off the ioctl >>>> interface >>>> code from pfctl into libpfctl, which should make reuse of that code >>>> easier. >>>> >>>> I hope to post preliminary patches in the coming week. >>>> >>>> Thoughts? Objections? >>> >>> Kernel and userland should be, I'd say must be, kept in sync. We >>> have >>> many >>> examples of userland and kernel not being in sync over the years. >>> For >>> ipfilter, I've made incompatible changes to data structures >>> requiring >>> userand and kernel be in sync. These are few and far between. >>> >>> I've gotten away with this because there is no third party software >>> that >>> relies on the ipfilter kernel interfaces. I could be wrong but I >>> doubt >>> there may be third party software requiring pf ABI compatibility. >>> But >>> if >>> there is then verstioned library interfaces are required. >>> >>> Given that the advice is to keep kernel and userland in sync there >>> probably >>> is no requirement for an UPDATING entry but that would be your call. >>> >> There are out-of-tree users of the pf ioctl interface. >> security/expiretable[1] for example. >> security/snort2pfcd appears to as well. >> sysutils/pfstat and sysutils/pftop use the ioctl interface as well, >> although not the three specific calls of immediate interest. > > This complicates things. IMO you'll probably need versioned function > calls > for at least 13-STABLE EOL. Or, versioning the data structures passed > into > the kernel such that the new fields are at the tail of the existing > structures. > That’s essentially the plan. I plan to keep the existing definitions (of both structure and ioctl numbers) in stable/12 and stable/13. They’ll disappear in main (i.e. 14). Alongside we’ll introduce new nvlist variants for those calls, which will have the new features. >> I’m trying to work out how many examples there are, because one >> way or >> the other they’re going to have to cope with changes. >> >> So, I’d prefer to not just change the definitions of structs, >> even if >> we’ve done that in the past. struct pf_rule contains a few >> peculiarities from historical mistakes that I hope to correct now. > > Technical debt is difficult to eliminate. We either fix it, paying it > off > in one lump sum or we pay it off through aggravation and design > limitations, with interest, over time. > Indeed. To take struct pf_rule as an example: it contains counter_u64’s, which don’t really work for userspace, so we’ve added uint64_t versions of those variables. Now the struct has two version of the same field. That can be cleaned up once the ioctls which use the struct have been removed (so on main only). My plan is to remove the struct definition from the kernel’s headers (again, once there are alternative ioctls and only in main), moving it into libpfctl. Then there will be nothing to stop us from removing the counter_u64 versions of those fields, cleaning up the struct. > Given that pf uses ioctl, versioned function calls won't help. A new > ioctl > may be the only answer. If you do choose this, add an identifier and > version number to the head of each new struct to future proof pf. > The nvlist versions will be much more flexible, so embedding a version number seem redundant. Best regards, Kristof From owner-freebsd-arch@freebsd.org Mon Mar 29 16:16:19 2021 Return-Path: Delivered-To: freebsd-arch@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 77E3157C426; Mon, 29 Mar 2021 16:16:19 +0000 (UTC) (envelope-from cy.schubert@cschubert.com) Received: from smtp-out-so.shaw.ca (smtp-out-so.shaw.ca [64.59.136.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "Client", Issuer "CA" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4F8Hkq0tsRz3sTF; Mon, 29 Mar 2021 16:16:18 +0000 (UTC) (envelope-from cy.schubert@cschubert.com) Received: from spqr.komquats.com ([70.66.148.124]) by shaw.ca with ESMTPA id QuYflQZRXHmS3QuYglnPLd; Mon, 29 Mar 2021 10:16:17 -0600 X-Authority-Analysis: v=2.4 cv=MaypB7zf c=1 sm=1 tr=0 ts=6061fd51 a=Cwc3rblV8FOMdVN/wOAqyQ==:117 a=Cwc3rblV8FOMdVN/wOAqyQ==:17 a=xqWC_Br6kY4A:10 a=8nJEP1OIZ-IA:10 a=dESyimp9J3IA:10 a=6I5d2MoRAAAA:8 a=YxBL1-UpAAAA:8 a=EkcXrb_YAAAA:8 a=T-UDMwMZcZjofG2IphkA:9 a=wPNLvfGTeEIA:10 a=IjZwj45LgO3ly-622nXo:22 a=Ia-lj3WSrqcvXOmTRaiG:22 a=LK5xJRSDVpKd5WXXoEvA:22 a=RBBcRewTFc8P4JkPnay6:22 Received: from slippy.cwsent.com (slippy [IPv6:fc00:1:1:1::5b]) by spqr.komquats.com (Postfix) with ESMTPS id 0BEBD218; Mon, 29 Mar 2021 09:16:04 -0700 (PDT) Received: from slippy (localhost [127.0.0.1]) by slippy.cwsent.com (8.16.1/8.16.1) with ESMTP id 12TGG3IL005274; Mon, 29 Mar 2021 09:16:03 -0700 (PDT) (envelope-from Cy.Schubert@cschubert.com) Message-Id: <202103291616.12TGG3IL005274@slippy.cwsent.com> X-Mailer: exmh version 2.9.0 11/07/2018 with nmh-1.7.1 Reply-to: Cy Schubert From: Cy Schubert X-os: FreeBSD X-Sender: cy@cwsent.com X-URL: http://www.cschubert.com/ To: "Kristof Provost" cc: "Cy Schubert" , "FreeBSD pf" , freebsd-arch@freebsd.org Subject: Re: [RFC] pf ioctl changes In-reply-to: <75FA4097-ED2A-4B96-9C90-E82F49F7764B@FreeBSD.org> References: <24E09373-EBCD-4ED1-8B59-A44E687F287E@FreeBSD.org> <202103291403.12TE3Y2H094131@slippy.cwsent.com> <18DC1EA9-ABFC-4A06-8710-A3068370EC52@FreeBSD.org> <202103291516.12TFGjTi004433@slippy.cwsent.com> <75FA4097-ED2A-4B96-9C90-E82F49F7764B@FreeBSD.org> Comments: In-reply-to "Kristof Provost" message dated "Mon, 29 Mar 2021 17:25:55 +0200." Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Date: Mon, 29 Mar 2021 09:16:03 -0700 X-CMAE-Envelope: MS4xfJOEuTOA14hIp35c38ebBKeIOm9E3yWSo/9VEgmcA3yUmVrSHvFaIMI+xqViwqt7QvzzM7Xx5seMQGnFk4t881DsHynJPAuIc8mxYsMp7NDlHTw+hkKe 8xFClUsiLEKjMaX2lL+4/9fSOGWMA1K68S6hHe8ef6kDmnN158vgP+aATWUkl5xYgc5juyMStNBAAY8d4ZZhYh5PZmZO7EvDETG2oiSN36uShAAFj/ISna27 5L3lIx4cGxwSK9rrqmPnt/0eS7bf2aABIQLGup6lA0E= X-Rspamd-Queue-Id: 4F8Hkq0tsRz3sTF X-Spamd-Bar: ---- Authentication-Results: mx1.freebsd.org; none X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[] X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 29 Mar 2021 16:16:19 -0000 In message <75FA4097-ED2A-4B96-9C90-E82F49F7764B@FreeBSD.org>, "Kristof Provost " writes: > On 29 Mar 2021, at 17:16, Cy Schubert wrote: > > In message <18DC1EA9-ABFC-4A06-8710-A3068370EC52@FreeBSD.org>, > > "Kristof > > Provost > > " writes: > >> On 29 Mar 2021, at 16:03, Cy Schubert wrote: > >>> In message <24E09373-EBCD-4ED1-8B59-A44E687F287E@FreeBSD.org>, > >>> "Kristof > >>> Provost > >>> " writes: > >>>> Hi, > >>>> > >>>> There are several patches in the pipeline that require changes in > >>>> pf’s > >>>> interface between kernel and userspace. > >>>> In the past these have been handled in multiple ways. Either by > >>>> simply > >>>> making the change, breaking binary compatibility, or by introducing > >>>> a > >>>> v2 > >>>> ioctl (e.g. DIOCADDALTQV1). > >>>> > >>>> While one is better than the other neither is wholly satisfying. > >>>> New > >>>> versions of calls constitute a maintenance burden after all. > >>>> > >>>> I’d like to change the ioctl interface to use nvlists, > >>>> which > >>>> would > >>>> make such extensions much easier, because fields can be optional. > >>>> That is, if userspace doesn’t supply the > >>>> ‘shinynewfeature’ field > >>>> the kernel can assume the default value and things just work. > >>>> Similarly, > >>>> if the kernel supplies a ’shinynewfeature’ > >>>> which userspace > >>>> doesn’t > >>>> know about it’s simply ignored. > >>>> > >>>> The rough plan is to introduce nvlist versions of the get/add rules > >>>> calls for now. Others will follow as the need presents itself. > >>>> As these are new ioctls it is safe to MFC them to stable/12 and > >>>> stable/13. > >>>> The old interface will remain supported in those branches, but > >>>> I’d > >>>> like to remove it from main (and thus FreeBSD 14). > >>>> > >>>> As part of this effort I may end up splitting off the ioctl > >>>> interface > >>>> code from pfctl into libpfctl, which should make reuse of that code > >>>> easier. > >>>> > >>>> I hope to post preliminary patches in the coming week. > >>>> > >>>> Thoughts? Objections? > >>> > >>> Kernel and userland should be, I'd say must be, kept in sync. We > >>> have > >>> many > >>> examples of userland and kernel not being in sync over the years. > >>> For > >>> ipfilter, I've made incompatible changes to data structures > >>> requiring > >>> userand and kernel be in sync. These are few and far between. > >>> > >>> I've gotten away with this because there is no third party software > >>> that > >>> relies on the ipfilter kernel interfaces. I could be wrong but I > >>> doubt > >>> there may be third party software requiring pf ABI compatibility. > >>> But > >>> if > >>> there is then verstioned library interfaces are required. > >>> > >>> Given that the advice is to keep kernel and userland in sync there > >>> probably > >>> is no requirement for an UPDATING entry but that would be your call. > >>> > >> There are out-of-tree users of the pf ioctl interface. > >> security/expiretable[1] for example. > >> security/snort2pfcd appears to as well. > >> sysutils/pfstat and sysutils/pftop use the ioctl interface as well, > >> although not the three specific calls of immediate interest. > > > > This complicates things. IMO you'll probably need versioned function > > calls > > for at least 13-STABLE EOL. Or, versioning the data structures passed > > into > > the kernel such that the new fields are at the tail of the existing > > structures. > > > That’s essentially the plan. I plan to keep the existing definitions > (of both structure and ioctl numbers) in stable/12 and stable/13. > They’ll disappear in main (i.e. 14). > > Alongside we’ll introduce new nvlist variants for those calls, which > will have the new features. > > >> I’m trying to work out how many examples there are, because one > >> way or > >> the other they’re going to have to cope with changes. > >> > >> So, I’d prefer to not just change the definitions of structs, > >> even if > >> we’ve done that in the past. struct pf_rule contains a few > >> peculiarities from historical mistakes that I hope to correct now. > > > > Technical debt is difficult to eliminate. We either fix it, paying it > > off > > in one lump sum or we pay it off through aggravation and design > > limitations, with interest, over time. > > > Indeed. > > To take struct pf_rule as an example: it contains counter_u64’s, which > don’t really work for userspace, so we’ve added uint64_t versions of > those variables. Now the struct has two version of the same field. > That can be cleaned up once the ioctls which use the struct have been > removed (so on main only). My plan is to remove the struct definition > from the kernel’s headers (again, once there are alternative ioctls > and only in main), moving it into libpfctl. > Then there will be nothing to stop us from removing the counter_u64 > versions of those fields, cleaning up the struct. > > > Given that pf uses ioctl, versioned function calls won't help. A new > > ioctl > > may be the only answer. If you do choose this, add an identifier and > > version number to the head of each new struct to future proof pf. > > > The nvlist versions will be much more flexible, so embedding a version > number seem redundant. This is probably the best plan. It of course adds some MFC pain or the requirement to commit directly to -STABLE when fixing serious bugs but it's manageable. -- Cheers, Cy Schubert FreeBSD UNIX: Web: https://FreeBSD.org NTP: Web: https://nwtime.org The need of the many outweighs the greed of the few. From owner-freebsd-arch@freebsd.org Fri Apr 2 18:59:55 2021 Return-Path: Delivered-To: freebsd-arch@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 0F56B57EF87; Fri, 2 Apr 2021 18:59:55 +0000 (UTC) (envelope-from kp@FreeBSD.org) Received: from smtp.freebsd.org (smtp.freebsd.org [96.47.72.83]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4FBq9l02BSz3mDY; Fri, 2 Apr 2021 18:59:55 +0000 (UTC) (envelope-from kp@FreeBSD.org) Received: from venus.codepro.be (venus.codepro.be [5.9.86.228]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mx1.codepro.be", Issuer "R3" (verified OK)) (Authenticated sender: kp) by smtp.freebsd.org (Postfix) with ESMTPSA id CA6551BD1; Fri, 2 Apr 2021 18:59:54 +0000 (UTC) (envelope-from kp@FreeBSD.org) Received: by venus.codepro.be (Postfix, authenticated sender kp) id A653422ED5; Fri, 2 Apr 2021 20:59:52 +0200 (CEST) From: "Kristof Provost" To: "FreeBSD pf" Cc: freebsd-arch@freebsd.org Subject: Re: [RFC] pf ioctl changes Date: Fri, 02 Apr 2021 20:59:51 +0200 X-Mailer: MailMate (1.13.2r5673) Message-ID: <4E521EB3-7D64-4292-B4F6-8E10AC2B0937@FreeBSD.org> In-Reply-To: <24E09373-EBCD-4ED1-8B59-A44E687F287E@FreeBSD.org> References: <24E09373-EBCD-4ED1-8B59-A44E687F287E@FreeBSD.org> MIME-Version: 1.0 Content-Type: text/plain X-Content-Filtered-By: Mailman/MimeDel 2.1.34 X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 02 Apr 2021 18:59:55 -0000 On 27 Mar 2021, at 12:54, Kristof Provost wrote: > I hope to post preliminary patches in the coming week. > - https://reviews.freebsd.org/D29556 - https://reviews.freebsd.org/D29557 - https://reviews.freebsd.org/D29558 - https://reviews.freebsd.org/D29559 - https://reviews.freebsd.org/D29560 - https://reviews.freebsd.org/D29561 - https://reviews.freebsd.org/D29562 Best regards, Kristof