fre. 20. des. 2024, 11:35 skrev Eelco Chaudron <[email protected]>:

>
>
> On 18 Dec 2024, at 20:21, Frode Nordahl wrote:
>
> > On Wed, Dec 18, 2024 at 8:12 PM Frode Nordahl <[email protected]>
> wrote:
> >>
> >> In preparation for adding support for parsing routes with multiple
> >> next hops per destination, we need dynamic storage for them.
> >>
> >> Storage for the primary next hop is set aside in struct route_data
> >> to avoid unnecessary memory allocations for the common case of one
> >> next hop.
> >>
> >> The ovs-router module does not support storing multiple next hop
> >> information, and the existing parser does not understand them, so
> >> we retain this behavior by only passing single next hop routes for
> >> storage in ovs-router.
> >>
> >> This patch makes this change in isolation so that it is easier to
> >> review subsequent patches.
> >>
> >> Signed-off-by: Frode Nordahl <[email protected]>
> >> ---
> >>  lib/route-table.c | 94 ++++++++++++++++++++++++++++++++++++++++-------
> >>  1 file changed, 81 insertions(+), 13 deletions(-)
> >>
> >> diff --git a/lib/route-table.c b/lib/route-table.c
> >> index 4e8f35199..b6f0223c0 100644
> >> --- a/lib/route-table.c
> >> +++ b/lib/route-table.c
> >> @@ -32,6 +32,7 @@
> >>  #include "netlink.h"
> >>  #include "netlink-notifier.h"
> >>  #include "netlink-socket.h"
> >> +#include "openvswitch/list.h"
> >>  #include "openvswitch/ofpbuf.h"
> >>  #include "ovs-router.h"
> >>  #include "packets.h"
> >> @@ -47,7 +48,34 @@ VLOG_DEFINE_THIS_MODULE(route_table);
> >>
> >>  COVERAGE_DEFINE(route_table_dump);
> >>
> >> +struct route_data_nexthop {
> >> +    struct ovs_list nexthop_node;
> >> +
> >> +    struct in6_addr addr;
> >> +    char ifname[IFNAMSIZ]; /* Interface name. */
> >> +};
> >> +
> >>  struct route_data {
> >> +    /* Routes can have multiple next hops per destination.
> >> +     *
> >> +     * Each next hop has its own set of attributes such as address
> family,
> >> +     * interface and IP address.
> >> +     *
> >> +     * When retrieving information about a route from the kernel, in
> the case
> >> +     * of multiple next hops, information is provided as nested
> attributes.
> >> +     *
> >> +     * A linked list with struct route_data_nexthop entries is used to
> store
> >> +     * this information as we parse each attribute.
> >> +     *
> >> +     * For the common case of one next hop, the nexthops list will
> contain a
> >> +     * single entry pointing to the struct route_data _primary_next_hop
> >> +     * element.
> >> +     *
> >> +     * Any dynamically allocated list elements can be freed with a
> call to the
> >> +     * route_data_destroy function. */
> >> +    struct ovs_list nexthops;
> >> +    struct route_data_nexthop _primary_next_hop;
> >> +
> >>      /* Copied from struct rtmsg. */
> >>      unsigned char rtm_dst_len;
> >>      unsigned char rtm_protocol;
> >> @@ -56,8 +84,6 @@ struct route_data {
> >>      /* Extracted from Netlink attributes. */
> >>      struct in6_addr rta_dst; /* 0 if missing. */
> >>      struct in6_addr rta_prefsrc; /* 0 if missing. */
> >> -    struct in6_addr rta_gw;
> >> -    char ifname[IFNAMSIZ]; /* Interface name. */
> >>      uint32_t mark;
> >>      uint32_t rta_table_id; /* 0 if missing. */
> >>      uint32_t rta_priority; /* 0 if missing. */
> >> @@ -89,12 +115,24 @@ static bool route_table_valid = false;
> >>  static void route_table_reset(void);
> >>  static void route_table_handle_msg(const struct route_table_msg *);
> >>  static int route_table_parse(struct ofpbuf *, void *change);
> >> -static void route_table_change(const struct route_table_msg *, void *);
> >> +static void route_table_change(struct route_table_msg *, void *aux);
> >>  static void route_map_clear(void);
> >>
> >>  static void name_table_init(void);
> >>  static void name_table_change(const struct rtnetlink_change *, void *);
> >>
> >> +static void
> >> +route_data_destroy(struct route_data *rd)
> >> +{
> >> +    struct route_data_nexthop *rdnh;
> >> +
> >> +    LIST_FOR_EACH_POP (rdnh, nexthop_node, &rd->nexthops) {
> >> +        if (rdnh && rdnh != &rd->_primary_next_hop) {
> >> +            free(rdnh);
> >> +        }
> >> +    }
> >> +}
> >> +
> >>  uint64_t
> >>  route_table_get_change_seq(void)
> >>  {
> >> @@ -190,6 +228,7 @@ route_table_dump_one_table(unsigned char id)
> >>                  filtered = false;
> >>              }
> >>              route_table_handle_msg(&msg);
> >> +            route_data_destroy(&msg.rd);
> >>          }
> >>      }
> >>      ofpbuf_uninit(&buf);
> >> @@ -222,13 +261,12 @@ route_table_reset(void)
> >>      }
> >>  }
> >>
> >> -/* Return RTNLGRP_IPV4_ROUTE or RTNLGRP_IPV6_ROUTE on success, 0 on
> parse
> >> - * error. */
> >>  static int
> >>  route_table_parse__(struct ofpbuf *buf, size_t ofs,
> >>                      const struct nlmsghdr *nlmsg,
> >>                      const struct rtmsg *rtm, struct route_table_msg
> *change)
> >>  {
> >> +    struct route_data_nexthop *rdnh = NULL;
> >>      bool parsed, ipv4 = false;
> >>
> >>      static const struct nl_policy policy[] = {
> >> @@ -269,6 +307,12 @@ route_table_parse__(struct ofpbuf *buf, size_t ofs,
> >>          int rta_oif;      /* Output interface index. */
> >>
> >>          memset(change, 0, sizeof *change);
> >> +
> >> +        /* ovs_list_init / ovs_list_insert does not allocate any
> memory */
> >> +        ovs_list_init(&change->rd.nexthops);
> >> +        rdnh = &change->rd._primary_next_hop;
> >> +        ovs_list_insert(&change->rd.nexthops, &rdnh->nexthop_node);
> >> +
> >>          change->relevant = true;
> >>
> >>          if (rtm->rtm_scope == RT_SCOPE_NOWHERE) {
> >> @@ -292,7 +336,7 @@ route_table_parse__(struct ofpbuf *buf, size_t ofs,
> >>          if (attrs[RTA_OIF]) {
> >>              rta_oif = nl_attr_get_u32(attrs[RTA_OIF]);
> >>
> >> -            if (!if_indextoname(rta_oif, change->rd.ifname)) {
> >> +            if (!if_indextoname(rta_oif, rdnh->ifname)) {
> >>                  int error = errno;
> >>
> >>                  VLOG_DBG_RL(&rl, "Could not find interface name[%u]:
> %s",
> >> @@ -300,7 +344,7 @@ route_table_parse__(struct ofpbuf *buf, size_t ofs,
> >>                  if (error == ENXIO) {
> >>                      change->relevant = false;
> >>                  } else {
> >> -                    return 0;
> >> +                    goto error_out;
> >>                  }
> >>              }
> >>          }
> >> @@ -330,9 +374,9 @@ route_table_parse__(struct ofpbuf *buf, size_t ofs,
> >>              if (ipv4) {
> >>                  ovs_be32 gw;
> >>                  gw = nl_attr_get_be32(attrs[RTA_GATEWAY]);
> >> -                in6_addr_set_mapped_ipv4(&change->rd.rta_gw, gw);
> >> +                in6_addr_set_mapped_ipv4(&rdnh->addr, gw);
> >>              } else {
> >> -                change->rd.rta_gw =
> nl_attr_get_in6_addr(attrs[RTA_GATEWAY]);
> >> +                rdnh->addr = nl_attr_get_in6_addr(attrs[RTA_GATEWAY]);
> >>              }
> >>          }
> >>          if (attrs[RTA_MARK]) {
> >> @@ -343,13 +387,27 @@ route_table_parse__(struct ofpbuf *buf, size_t
> ofs,
> >>          }
> >>      } else {
> >>          VLOG_DBG_RL(&rl, "received unparseable rtnetlink route
> message");
> >> -        return 0;
> >> +        goto error_out;
> >>      }
> >>
> >>      /* Success. */
> >>      return ipv4 ? RTNLGRP_IPV4_ROUTE : RTNLGRP_IPV6_ROUTE;
> >> +
> >> +error_out:
> >> +    route_data_destroy(&change->rd);
> >> +    return 0;
> >>  }
> >>
> >> +/* Parse Netlink message in buf, which is expected to contain UAPI
> rtmsg
> >> + * header and associated route attributes.
> >> + *
> >> + * Return RTNLGRP_IPV4_ROUTE or RTNLGRP_IPV6_ROUTE on success, 0 on
> parse
> >> + * error.
> >> + *
> >> + * On success, memory may have be allocated, and it is the callers
> >> + * responsibility to free it with a call to route_data_destroy.
> >> + *
> >> + * In case of error, any allocated memory will be freed before return.
> */
> >>  static int
> >>  route_table_parse(struct ofpbuf *buf, void *change)
> >>  {
> >> @@ -373,7 +431,7 @@ route_table_standard_table(uint32_t table_id)
> >>  }
> >>
> >>  static void
> >> -route_table_change(const struct route_table_msg *change OVS_UNUSED,
> >> +route_table_change(struct route_table_msg *change,
> >>                     void *aux OVS_UNUSED)
> >>  {
> >>      if (!change
> >> @@ -381,16 +439,26 @@ route_table_change(const struct route_table_msg
> *change OVS_UNUSED,
> >>              && route_table_standard_table(change->rd.rta_table_id))) {
> >>          route_table_valid = false;
> >>      }
> >> +    if (change) {
> >> +        route_data_destroy(&change->rd);
> >> +    }
> >>  }
> >>
> >>  static void
> >>  route_table_handle_msg(const struct route_table_msg *change)
> >>  {
> >> -    if (change->relevant && change->nlmsg_type == RTM_NEWROUTE) {
> >> +    if (change->relevant && change->nlmsg_type == RTM_NEWROUTE
> >> +            && ovs_list_is_singleton(&change->rd.nexthops)) {
> >
> > Note that this is changed to !ovs_list_is_empty(&change->rd.nexthops)
> > in patch 15.
> >
> > I missed that I touched this in both patches, hope that's OK.
>
> I guess this needs to be fixed in this patch.


Ok, I'll hold off a bit in case there are other comments.

However, please look at the robot page, as some patches (4, 6, and 7) are
> failing CI.
>
> https://patchwork.ozlabs.org/project/openvswitch/list/?series=437419


>
I did take a look, and it looks like flaky tests to me, subsequent patches
have no such failures.

--
Frode Nordahl


>
> >>          const struct route_data *rd = &change->rd;
> >> +        const struct route_data_nexthop *rdnh;
> >> +
> >> +        /* The ovs-router module does currently not implement lookup
> nor
> >> +         * storage for routes with multiple next hops. */
> >> +        rdnh = CONTAINER_OF(ovs_list_front(&change->rd.nexthops),
> >> +                            const struct route_data_nexthop,
> nexthop_node);
> >>
> >>          ovs_router_insert(rd->mark, &rd->rta_dst, rd->rtm_dst_len,
> >> -                          rd->local, rd->ifname, &rd->rta_gw,
> >> +                          rd->local, rdnh->ifname, &rdnh->addr,
> >>                            &rd->rta_prefsrc);
> >>      }
> >>  }
> >> --
> >> 2.45.2
> >>
>
>
_______________________________________________
dev mailing list
[email protected]
https://mail.openvswitch.org/mailman/listinfo/ovs-dev

Reply via email to