Date: Thu, 9 Mar 2023 17:45:50 +0000 From: Alexander Chernikov <melifaro@freebsd.org> To: Kristof Provost <kp@FreeBSD.org> Cc: "src-committers@freebsd.org" <src-committers@FreeBSD.org>, "dev-commits-src-all@freebsd.org" <dev-commits-src-all@FreeBSD.org>, "dev-commits-src-main@freebsd.org" <dev-commits-src-main@FreeBSD.org> Subject: Re: git: 7e5bf68495cc - main - netlink: add netlink support Message-ID: <2F410705-A141-49B4-8395-3B39D3EF1C3E@freebsd.org> In-Reply-To: <3D3095AE-60CC-4CCD-8C8A-A6E53EEB6A8A@FreeBSD.org> References: <202210011419.291EJ3aa000309@gitrepo.freebsd.org> <3D3095AE-60CC-4CCD-8C8A-A6E53EEB6A8A@FreeBSD.org>
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[-- Attachment #1 --] > On 9 Mar 2023, at 15:38, Kristof Provost <kp@FreeBSD.org> wrote: > > On 1 Oct 2022, at 16:19, Alexander V. Chernikov wrote: > > The branch main has been updated by melifaro: > > URL: https://cgit.FreeBSD.org/src/commit/?id=7e5bf68495cc0a8c9793a338a8a02009a7f6dbb6 <https://cgit.freebsd.org/src/commit/?id=7e5bf68495cc0a8c9793a338a8a02009a7f6dbb6>; > commit 7e5bf68495cc0a8c9793a338a8a02009a7f6dbb6 > Author: Alexander V. Chernikov <melifaro@FreeBSD.org> > AuthorDate: 2022-01-20 21:39:21 +0000 > Commit: Alexander V. Chernikov <melifaro@FreeBSD.org> > CommitDate: 2022-10-01 14:15:35 +0000 > > netlink: add netlink support > ... > + > +/* > + * Defition of numbers assigned to the netlink subsystems. > + */ > +#define NETLINK_ROUTE 0 /* Routing/device hook */ > +#define NETLINK_UNUSED 1 /* not supported */ > +#define NETLINK_USERSOCK 2 /* not supported */ > +#define NETLINK_FIREWALL 3 /* not supported */ > +#define NETLINK_SOCK_DIAG 4 /* not supported */ > +#define NETLINK_NFLOG 5 /* not supported */ > +#define NETLINK_XFRM 6 /* (not supported) PF_SETKEY */ > +#define NETLINK_SELINUX 7 /* not supported */ > +#define NETLINK_ISCSI 8 /* not supported */ > +#define NETLINK_AUDIT 9 /* not supported */ > +#define NETLINK_FIB_LOOKUP 10 /* not supported */ > +#define NETLINK_CONNECTOR 11 /* not supported */ > +#define NETLINK_NETFILTER 12 /* not supported */ > +#define NETLINK_IP6_FW 13 /* not supported */ > +#define NETLINK_DNRTMSG 14 /* not supported */ > +#define NETLINK_KOBJECT_UEVENT 15 /* not supported */ > +#define NETLINK_GENERIC 16 /* Generic netlink (dynamic families) */ > + > > So, really fun thing here, we also have #define NETLINK_GENERIC 0 in sys/net/if_mib.h. (And that’s exposed to userspace, and used there, so we can’t just change that.) > Wow. Thanks for pointing it out - it wasn’t defined in the kernel headers so I missed it. That looks like something FreeBSD-specific. Both NetBSD / OpenBSD doesn’t have it. It seem to provide: - iteration over the list of the interfaces - some basic interface traffic statistics - copy of the ’struct ifdata’ (basic interface properties and some interface traffic statistics) - Link-specific data (IFDATA_LINKSPECIFIC), not used by anything in base - Original “driver name” (IFDATA_DRIVERNAME) Most of this is already provided by either getifaddr(3) or netlink or even rtsock. I’m thinking of deprecating it in mid-term in favour of Netlink. I see the following options: 1) Remove usage of if_mib.h from ifconfig 2) Add compat layer: *) Rename NETLINK_GENERIC to NET_LINK_GENERIC (which is the right name de-facto) *) Add conditional define for NETLINK_GENERIC to if_mib and set it to 16 *) Define another tree in if_mib.c under net.link <http://net.link/>.generic16 with value 16 Personally I’m more thinking of starting from (1), then slowly replace the remaining bsnmp usages, and then declare it deprecated after 14.0. /Alexander > Which leads to much fun if we decided to do something like including the netlink_generic header in other headers, so we can define messages that contain the genlmsghdr struct. > > I ran into that experimenting with netlink for carp(4). I think I can work around it by adding a separate ip_carp_nl.h header for the netlink stuff, but sooner or later this is going to bite us. > > Kristof > [-- Attachment #2 --] <html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><meta http-equiv="content-type" content="text/html; charset=utf-8"><div style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><br><div><br><blockquote type="cite"><div>On 9 Mar 2023, at 15:38, Kristof Provost <kp@FreeBSD.org> wrote:</div><br class="Apple-interchange-newline"><div> <meta http-equiv="Content-Type" content="text/xhtml; charset=utf-8"> <div><div style="font-family: sans-serif;"><div class="markdown" style="white-space: normal;"><p dir="auto">On 1 Oct 2022, at 16:19, Alexander V. Chernikov wrote:</p> </div><div class="plaintext" style="white-space: normal;"><blockquote style="margin: 0 0 5px; padding-left: 5px; border-left: 2px solid #136BCE; color: #136BCE;"><p dir="auto">The branch main has been updated by melifaro:</p><p dir="auto">URL: <a href="https://cgit.freebsd.org/src/commit/?id=7e5bf68495cc0a8c9793a338a8a02009a7f6dbb6">https://cgit.FreeBSD.org/src/commit/?id=7e5bf68495cc0a8c9793a338a8a02009a7f6dbb6</a></p><p dir="auto">commit 7e5bf68495cc0a8c9793a338a8a02009a7f6dbb6 <br> Author: Alexander V. Chernikov <melifaro@FreeBSD.org> <br> AuthorDate: 2022-01-20 21:39:21 +0000 <br> Commit: Alexander V. Chernikov <melifaro@FreeBSD.org> <br> CommitDate: 2022-10-01 14:15:35 +0000</p><p dir="auto"> netlink: add netlink support</p></blockquote></div></div></div></div></blockquote>...<br><blockquote type="cite"><div><div><div style="font-family: sans-serif;"><div class="plaintext" style="white-space: normal;"><blockquote style="margin: 0 0 5px; padding-left: 5px; border-left: 2px solid #136BCE; color: #136BCE;"><p dir="auto"> + <br> +/* <br> + * Defition of numbers assigned to the netlink subsystems. <br> + */ <br> +#define NETLINK_ROUTE 0 /* Routing/device hook */ <br> +#define NETLINK_UNUSED 1 /* not supported */ <br> +#define NETLINK_USERSOCK 2 /* not supported */ <br> +#define NETLINK_FIREWALL 3 /* not supported */ <br> +#define NETLINK_SOCK_DIAG 4 /* not supported */ <br> +#define NETLINK_NFLOG 5 /* not supported */ <br> +#define NETLINK_XFRM 6 /* (not supported) PF_SETKEY */ <br> +#define NETLINK_SELINUX 7 /* not supported */ <br> +#define NETLINK_ISCSI 8 /* not supported */ <br> +#define NETLINK_AUDIT 9 /* not supported */ <br> +#define NETLINK_FIB_LOOKUP 10 /* not supported */ <br> +#define NETLINK_CONNECTOR 11 /* not supported */ <br> +#define NETLINK_NETFILTER 12 /* not supported */ <br> +#define NETLINK_IP6_FW 13 /* not supported */ <br> +#define NETLINK_DNRTMSG 14 /* not supported */ <br> +#define NETLINK_KOBJECT_UEVENT 15 /* not supported */ <br> +#define NETLINK_GENERIC 16 /* Generic netlink (dynamic families) */ <br> +</p> </blockquote></div> <div class="markdown" style="white-space: normal;"><p dir="auto">So, really fun thing here, we also have <code style="padding: 0 0.25em; background-color: #E4E4E4;">#define NETLINK_GENERIC 0</code> in sys/net/if_mib.h. (And that’s exposed to userspace, and used there, so we can’t just change that.)</p></div></div></div></div></blockquote><div>Wow. Thanks for pointing it out - it wasn’t defined in the kernel headers so I missed it.</div>That looks like something FreeBSD-specific. Both NetBSD / OpenBSD doesn’t have it.</div><div>It seem to provide:</div><div>- iteration over the list of the interfaces</div><div>- some basic interface traffic statistics</div><div>- copy of the ’struct ifdata’ (basic interface properties and some interface traffic statistics)</div><div>- Link-specific data (IFDATA_LINKSPECIFIC), not used by anything in base</div><div>- Original “driver name” (IFDATA_DRIVERNAME)</div><div><br></div><div>Most of this is already provided by either getifaddr(3) or netlink or even rtsock. I’m thinking of deprecating it in mid-term in favour of Netlink.</div><div><br></div><div>I see the following options:</div><div>1) Remove usage of if_mib.h from ifconfig</div><div><br></div><div>2) Add compat layer:</div><div>*) Rename NETLINK_GENERIC to NET_LINK_GENERIC (which is the right name de-facto)</div><div>*) Add conditional define for NETLINK_GENERIC to if_mib and set it to 16</div><div>*) Define another tree in if_mib.c under <a href="http://net.link/">net.link</a>.generic16 with value 16</div><div><br></div><div>Personally I’m more thinking of starting from (1), then slowly replace the remaining bsnmp usages, and then declare it deprecated after 14.0.</div><div>/Alexander</div><div><blockquote type="cite"><div><div><div style="font-family: sans-serif;"><div class="markdown" style="white-space: normal;"><p dir="auto">Which leads to much fun if we decided to do something like including the netlink_generic header in other headers, so we can define messages that contain the genlmsghdr struct.</p><p dir="auto">I ran into that experimenting with netlink for carp(4). I think I can work around it by adding a separate ip_carp_nl.h header for the netlink stuff, but sooner or later this is going to bite us.</p><p dir="auto">Kristof</p> </div> </div> </div> </div></blockquote></div><br></div></body></html>
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