On 1/29/25 12:15 PM, Felix Huettner via dev wrote: > From: Frode Nordahl <fnord...@ubuntu.com> > > Introduce route-exchange-netlink module which implements interface > for maintaining VRFs [0] and routes through Netlink. > > There is a desire to do this without having to (re-)implement > routing protocol state machines in OVN, and to accomplish this we > make use of Netlink. > > Netlink was chosen because: > * Its ubiquitous nature with availability on any Linux system as > as well other platforms. > * Presence of a very good Netlink library implementation in our > sibling project and library, Open vSwitch. > * Popular routing protocol software conveniently already have > support for redistributing routes to/from Netlink. > * Support for interacting with Virtual Routing and Forwarding > domains [0], allowing full isolation between virtual network > resources defined within OVN and the hosting system while > retaining access to all system network interfaces. > > It is important to note that the purpose of this integration is > generic exchange of control plane information, while allowing to > keep the datapath in OVS/OVN, enabling users to leverage its full > range of user-, kernel- and mixed- space datapath implementations. > > 0: https://docs.kernel.org/networking/vrf.html > > Co-Authored-by: Felix Huettner <felix.huettner@stackit.cloud> > Signed-off-by: Felix Huettner <felix.huettner@stackit.cloud> > Signed-off-by: Frode Nordahl <fnord...@ubuntu.com> > ---
Hi Felix, Frode, > v4->v5: fix compile error > v3->v4: > - addressed review comments. > - fix authorship > > configure.ac | 2 + > controller/automake.mk | 6 + > controller/route-exchange-netlink.c | 274 ++++++++++++++++++++++++++++ > controller/route-exchange-netlink.h | 42 +++++ > m4/ovn.m4 | 25 +++ > tests/automake.mk | 5 + > tests/system-common-macros.at | 12 ++ > 7 files changed, 366 insertions(+) > create mode 100644 controller/route-exchange-netlink.c > create mode 100644 controller/route-exchange-netlink.h > > diff --git a/configure.ac b/configure.ac > index 4a63b84d4..cf9b4a6fd 100644 > --- a/configure.ac > +++ b/configure.ac > @@ -87,6 +87,8 @@ OVS_CHECK_WIN32 > OVS_CHECK_VISUAL_STUDIO_DDK > OVN_CHECK_COVERAGE > OVS_CHECK_NDEBUG > +OVS_CHECK_NETLINK > +OVS_CHECK_LINUX_NETLINK > OVS_CHECK_OPENSSL > OVN_CHECK_LOGDIR > OVN_CHECK_PYTHON3 > diff --git a/controller/automake.mk b/controller/automake.mk > index a6a2c517a..39deeb029 100644 > --- a/controller/automake.mk > +++ b/controller/automake.mk > @@ -55,6 +55,12 @@ controller_ovn_controller_SOURCES = \ > controller/route.h \ > controller/route.c > > +if HAVE_NETLINK > +controller_ovn_controller_SOURCES += \ > + controller/route-exchange-netlink.h \ > + controller/route-exchange-netlink.c > +endif > + > controller_ovn_controller_LDADD = lib/libovn.la > $(OVS_LIBDIR)/libopenvswitch.la > man_MANS += controller/ovn-controller.8 > EXTRA_DIST += controller/ovn-controller.8.xml > diff --git a/controller/route-exchange-netlink.c > b/controller/route-exchange-netlink.c > new file mode 100644 > index 000000000..4ba21ecaa > --- /dev/null > +++ b/controller/route-exchange-netlink.c > @@ -0,0 +1,274 @@ > +/* > + * Copyright (c) 2024 Canonical, Ltd. > + * Copyright (c) 2024, STACKIT GmbH & Co. KG 2025 > + * > + * Licensed under the Apache License, Version 2.0 (the "License"); > + * you may not use this file except in compliance with the License. > + * You may obtain a copy of the License at: > + * > + * http://www.apache.org/licenses/LICENSE-2.0 > + * > + * Unless required by applicable law or agreed to in writing, software > + * distributed under the License is distributed on an "AS IS" BASIS, > + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. > + * See the License for the specific language governing permissions and > + * limitations under the License. > + */ > + > +#include <config.h> > + > +#include <errno.h> > +#include <inttypes.h> > +#include <linux/rtnetlink.h> > +#include <net/if.h> > +#include <netinet/in.h> > + > +#include "netlink-socket.h" > +#include "openvswitch/hmap.h" > +#include "hmapx.h" > +#include "openvswitch/ofpbuf.h" > +#include "openvswitch/vlog.h" > +#include "ovn-util.h" > +#include "route-table.h" > +#include "route.h" > + > +#include "route-exchange-netlink.h" > + > +VLOG_DEFINE_THIS_MODULE(route_exchange_netlink); > +static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 20); > + Was the intention to use the same rate limit for all warning logs this module may generate? If that's the case this is fine. However, if we want to rate limit each warning type (e.g., different limit for create_vrf() failure vs route table deletion failure) then we need different vlog_rate_limit structures. I think I'd prefer the latter though. > +#define TABLE_ID_VALID(table_id) (table_id != RT_TABLE_UNSPEC && > \ > + table_id != RT_TABLE_COMPAT && > \ > + table_id != RT_TABLE_DEFAULT && > \ > + table_id != RT_TABLE_MAIN && > \ > + table_id != RT_TABLE_LOCAL && > \ > + table_id != RT_TABLE_MAX) > + > +int > +re_nl_create_vrf(const char *ifname, uint32_t table_id) > +{ > + if (!TABLE_ID_VALID(table_id)) { > + VLOG_WARN_RL(&rl, > + "attempt to create VRF using invalid table id %"PRIu32, > + table_id); > + return EINVAL; > + } > + > + size_t linkinfo_off, infodata_off; > + struct ifinfomsg *ifinfo; > + struct ofpbuf request; > + int err; > + > + ofpbuf_init(&request, 0); > + nl_msg_put_nlmsghdr(&request, 0, RTM_NEWLINK, > + NLM_F_REQUEST | NLM_F_ACK | NLM_F_CREATE | > NLM_F_EXCL); > + ifinfo = ofpbuf_put_zeros(&request, sizeof *ifinfo); > + nl_msg_put_string(&request, IFLA_IFNAME, ifname); > + > + ifinfo->ifi_change = ifinfo->ifi_flags = IFF_UP; > + linkinfo_off = nl_msg_start_nested(&request, IFLA_LINKINFO); > + nl_msg_put_string(&request, IFLA_INFO_KIND, "vrf"); > + infodata_off = nl_msg_start_nested(&request, IFLA_INFO_DATA); > + nl_msg_put_u32(&request, IFLA_VRF_TABLE, table_id); > + nl_msg_end_nested(&request, infodata_off); > + nl_msg_end_nested(&request, linkinfo_off); > + > + err = nl_transact(NETLINK_ROUTE, &request, NULL); > + > + ofpbuf_uninit(&request); > + > + return err; > + > +} > + > +int > +re_nl_delete_vrf(const char *ifname) > +{ > + struct ifinfomsg *ifinfo; > + struct ofpbuf request; > + int err; > + > + ofpbuf_init(&request, 0); > + nl_msg_put_nlmsghdr(&request, 0, RTM_DELLINK, > + NLM_F_REQUEST | NLM_F_ACK); Nit: these fit on the same line. > + ifinfo = ofpbuf_put_zeros(&request, sizeof *ifinfo); > + nl_msg_put_string(&request, IFLA_IFNAME, ifname); > + err = nl_transact(NETLINK_ROUTE, &request, NULL); > + > + ofpbuf_uninit(&request); > + > + return err; > +} > + > +static int > +modify_route(uint32_t type, uint32_t flags_arg, uint32_t table_id, > + const struct in6_addr *dst, unsigned int plen) > +{ > + uint32_t flags = NLM_F_REQUEST | NLM_F_ACK; > + bool is_ipv4 = IN6_IS_ADDR_V4MAPPED(dst); > + struct ofpbuf request; > + struct rtmsg *rt; > + int err; > + > + flags |= flags_arg; > + > + ofpbuf_init(&request, 0); > + nl_msg_put_nlmsghdr(&request, 0, type, flags); > + rt = ofpbuf_put_zeros(&request, sizeof *rt); > + rt->rtm_family = is_ipv4 ? AF_INET : AF_INET6; > + rt->rtm_table = RT_TABLE_UNSPEC; /* RTA_TABLE attribute allows id > 256 > */ > + /* Manage only OVN routes */ > + rt->rtm_protocol = RTPROT_OVN; > + rt->rtm_type = RTN_BLACKHOLE; > + if (type == RTM_DELROUTE) { > + rt->rtm_scope = RT_SCOPE_NOWHERE; > + } else { > + rt->rtm_scope = RT_SCOPE_UNIVERSE; > + } I'm not sure I understand why on delete we need to set the scope to RT_SCOPE_NOWHERE.. I didn't try passing RT_SCOPE_UNIVERSE for both cases but would that cause issues? > + rt->rtm_dst_len = plen; > + > + nl_msg_put_u32(&request, RTA_TABLE, table_id); > + > + if (is_ipv4) { > + nl_msg_put_be32(&request, RTA_DST, in6_addr_get_mapped_ipv4(dst)); > + } else { > + nl_msg_put_in6_addr(&request, RTA_DST, dst); > + } > + > + if (VLOG_IS_DBG_ENABLED()) { > + struct ds msg = DS_EMPTY_INITIALIZER; > + > + if (type == RTM_DELROUTE) { > + ds_put_cstr(&msg, "Removing blackhole route from "); > + } else { > + ds_put_cstr(&msg, "Adding blackhole route to "); > + } > + > + ds_put_format(&msg, "table %"PRIu32 " for prefix ", table_id); > + Nit: I'd remove this empty line. > + if (IN6_IS_ADDR_V4MAPPED(dst)) { > + ds_put_format(&msg, IP_FMT, > + IP_ARGS(in6_addr_get_mapped_ipv4(dst))); > + } else { > + ipv6_format_addr(dst, &msg); > + } > + Nit: I'd remove this empty line. > + ds_put_format(&msg, "/%u", plen); > + > + VLOG_DBG("%s", ds_cstr(&msg)); > + ds_destroy(&msg); > + } > + > + err = nl_transact(NETLINK_ROUTE, &request, NULL); > + ofpbuf_uninit(&request); > + > + return err; > +} > + > +int > +re_nl_add_route(uint32_t table_id, const struct in6_addr *dst, > + unsigned int plen) > +{ > + uint32_t flags = NLM_F_CREATE | NLM_F_EXCL; > + uint32_t type = RTM_NEWROUTE; I'd just pass these directly to modify_route(). > + > + if (!TABLE_ID_VALID(table_id)) { > + VLOG_WARN_RL(&rl, > + "attempt to add route using invalid table id %"PRIu32, > + table_id); > + return EINVAL; > + } > + > + return modify_route(type, flags, table_id, dst, plen); > +} > + > +int > +re_nl_delete_route(uint32_t table_id, const struct in6_addr *dst, > + unsigned int plen) > +{ > + if (!TABLE_ID_VALID(table_id)) { > + VLOG_WARN_RL(&rl, > + "attempt to delete route using invalid table id > %"PRIu32, > + table_id); > + return EINVAL; > + } > + > + return modify_route(RTM_DELROUTE, 0, table_id, dst, plen); > +} > + > +struct route_msg_handle_data { > + struct hmapx *routes_to_advertise; > +}; > + > +static void > +handle_route_msg(const struct route_table_msg *msg, void *data) > +{ > + const struct route_data *rd = &msg->rd; > + struct route_msg_handle_data *handle_data = data; > + struct advertise_route_entry *ar; > + int err; > + > + /* This route is not from us, we should not touch it. */ > + if (rd->rtm_protocol != RTPROT_OVN) { > + return; > + } > + > + struct hmapx_node *hn; > + HMAPX_FOR_EACH_SAFE (hn, handle_data->routes_to_advertise) { This is misleading: we define routes_to_advertise as hmapx but we use it as a linked list. We never do efficient lookups in it. I think you need to pass both the "routes_to_advertise" hmapx and the "routes" hmap to this callback. And here you should probably do a O(1) lookup in "routes". If you find an entry it means we don't need to readvertise so you can do hmapx_delete(routes_to_advertise, <pointer-returned-by-lookup>). Otherwise the complexity for synchronizing advertised routes is O(N ^ 2) while it could easily be O(N). > + ar = hn->data; > + if (ipv6_addr_equals(&ar->addr, &rd->rta_dst) > + && ar->plen == rd->rtm_dst_len) { > + hmapx_delete(handle_data->routes_to_advertise, hn); > + return; > + } > + } > + err = re_nl_delete_route(rd->rta_table_id, &rd->rta_dst, > + rd->rtm_dst_len); > + if (err) { > + char addr_s[INET6_ADDRSTRLEN + 1]; > + VLOG_WARN_RL(&rl, "Delete route table_id=%"PRIu32" dst=%s plen=%d: > %s", > + rd->rta_table_id, > + ipv6_string_mapped( > + addr_s, &rd->rta_dst) ? addr_s : "(invalid)", Should we add the word "failed" somewhere in this warning message? > + rd->rtm_dst_len, > + ovs_strerror(err)); > + } > +} > + > +void > +re_nl_sync_routes(uint32_t table_id, const struct hmap *routes) > +{ > + struct hmapx routes_to_advertise = > HMAPX_INITIALIZER(&routes_to_advertise); > + struct advertise_route_entry *ar; > + HMAP_FOR_EACH (ar, node, routes) { > + hmapx_add(&routes_to_advertise, ar); > + } > + > + /* Remove routes from the system that are not in the routes hmap and > + * remove entries from routes hmap that match routes already installed > + * in the system. */ > + struct route_msg_handle_data data = { > + .routes_to_advertise = &routes_to_advertise, > + }; > + route_table_dump_one_table(table_id, handle_route_msg, > + &data); > + > + /* Add any remaining routes in the host_routes hmap to the system routing > + * table. */ > + struct hmapx_node *hn; > + HMAPX_FOR_EACH (hn, &routes_to_advertise) { > + ar = hn->data; > + int err = re_nl_add_route(table_id, &ar->addr, ar->plen); > + if (err) { > + char addr_s[INET6_ADDRSTRLEN + 1]; > + VLOG_WARN_RL(&rl, "Add route table_id=%"PRIu32" dst=%s " > + "plen=%d: %s", > + table_id, > + ipv6_string_mapped( > + addr_s, &ar->addr) ? addr_s : "(invalid)", > + ar->plen, > + ovs_strerror(err)); > + } > + } > + hmapx_destroy(&routes_to_advertise); > +} > diff --git a/controller/route-exchange-netlink.h > b/controller/route-exchange-netlink.h > new file mode 100644 > index 000000000..93b593ad2 > --- /dev/null > +++ b/controller/route-exchange-netlink.h > @@ -0,0 +1,42 @@ > +/* > + * Copyright (c) 2024 Canonical, Ltd. > + * Copyright (c) 2024, STACKIT GmbH & Co. KG 2025 > + * > + * Licensed under the Apache License, Version 2.0 (the "License"); > + * you may not use this file except in compliance with the License. > + * You may obtain a copy of the License at: > + * > + * http://www.apache.org/licenses/LICENSE-2.0 > + * > + * Unless required by applicable law or agreed to in writing, software > + * distributed under the License is distributed on an "AS IS" BASIS, > + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. > + * See the License for the specific language governing permissions and > + * limitations under the License. > + */ > + > +#ifndef ROUTE_EXCHANGE_NETLINK_H > +#define ROUTE_EXCHANGE_NETLINK_H 1 > + > +#include <stdint.h> > + > +/* This value is arbitrary but currently unused. > + * See https://github.com/iproute2/iproute2/blob/main/etc/iproute2/rt_protos > */ > +#define RTPROT_OVN 84 > + > +struct in6_addr; > +struct hmap; > + > +int re_nl_create_vrf(const char *ifname, uint32_t table_id); > +int re_nl_delete_vrf(const char *ifname); > + > +int re_nl_add_route(uint32_t table_id, const struct in6_addr *dst, > + unsigned int plen); > +int re_nl_delete_route(uint32_t table_id, const struct in6_addr *dst, > + unsigned int plen); > + > +void re_nl_dump(uint32_t table_id); > + > +void re_nl_sync_routes(uint32_t table_id, const struct hmap *routes); > + > +#endif /* route-exchange-netlink.h */ > diff --git a/m4/ovn.m4 b/m4/ovn.m4 > index 8f36b75fc..8ccc1629e 100644 > --- a/m4/ovn.m4 > +++ b/m4/ovn.m4 > @@ -560,3 +560,28 @@ AC_DEFUN([OVN_CHECK_UNBOUND], > fi > AM_CONDITIONAL([HAVE_UNBOUND], [test "$HAVE_UNBOUND" = yes]) > AC_SUBST([HAVE_UNBOUND])]) > + > +dnl Checks for Netlink support. > +AC_DEFUN([OVS_CHECK_NETLINK], > + [AC_CHECK_HEADER([linux/netlink.h], > + [HAVE_NETLINK=yes], > + [HAVE_NETLINK=no], > + [#include <sys/socket.h> > + ]) > + AM_CONDITIONAL([HAVE_NETLINK], [test "$HAVE_NETLINK" = yes]) > + if test "$HAVE_NETLINK" = yes; then > + AC_DEFINE([HAVE_NETLINK], [1], > + [Define to 1 if Netlink protocol is available.]) > + fi]) > + > +dnl OVS_CHECK_LINUX_NETLINK > +dnl > +dnl Configure Linux netlink compat. > +AC_DEFUN([OVS_CHECK_LINUX_NETLINK], [ > + AC_COMPILE_IFELSE([ > + AC_LANG_PROGRAM([#include <linux/netlink.h>], [ > + struct nla_bitfield32 x = { 0 }; > + ])], > + [AC_DEFINE([HAVE_NLA_BITFIELD32], [1], > + [Define to 1 if struct nla_bitfield32 is available.])]) > +]) > diff --git a/tests/automake.mk b/tests/automake.mk > index 9244532fa..11696f159 100644 > --- a/tests/automake.mk > +++ b/tests/automake.mk > @@ -308,6 +308,11 @@ tests_ovstest_LDADD = $(OVS_LIBDIR)/daemon.lo \ > controller/route.$(OBJEXT) \ > northd/ipam.$(OBJEXT) > > +if HAVE_NETLINK > +tests_ovstest_LDADD += \ > + controller/route-exchange-netlink.$(OBJEXT) > +endif > + > # Python tests. > CHECK_PYFILES = \ > tests/test-l7.py \ > diff --git a/tests/system-common-macros.at b/tests/system-common-macros.at > index 968c4028b..bba2597cf 100644 > --- a/tests/system-common-macros.at > +++ b/tests/system-common-macros.at > @@ -530,3 +530,15 @@ OVS_TRAFFIC_VSWITCHD_STOP(["/.*error receiving.*/d > /failed to query port patch-.*/d > /.*terminating with signal 15.*/d"]) > ])) > + > +# CHECK_VRF() > +# > +# Perform a requirements check for running VRF tests. > +# > +m4_define([CHECK_VRF], > +[ > + rc=0 > + modprobe vrf || rc=$? > + AT_SKIP_IF([test $rc -ne 0]) > + on_exit 'modprobe -r vrf' > +]) Thanks, Dumitru _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
