svn commit: r365521 - head/sys/net/route
Alexander V. Chernikov
melifaro at FreeBSD.org
Wed Sep 9 22:07:55 UTC 2020
Author: melifaro
Date: Wed Sep 9 22:07:54 2020
New Revision: 365521
URL: https://svnweb.freebsd.org/changeset/base/365521
Log:
Update nexthop handling for route addition/deletion in preparation for mpath.
Currently kernel requests deletion for the certain routes with specified gateway,
but this gateway is not actually checked. With multipath routes, internal gateway
checking becomes mandatory. Add the logic performing this check.
Generalise RTF_PINNED routes to the generic route priorities, simplifying the logic.
Add lookup_prefix() function to perform exact match search based on data in @info.
Differential Revision: https://reviews.freebsd.org/D26356
Modified:
head/sys/net/route/route_ctl.c
head/sys/net/route/route_var.h
Modified: head/sys/net/route/route_ctl.c
==============================================================================
--- head/sys/net/route/route_ctl.c Wed Sep 9 22:02:30 2020 (r365520)
+++ head/sys/net/route/route_ctl.c Wed Sep 9 22:07:54 2020 (r365521)
@@ -86,6 +86,10 @@ static int change_route(struct rib_head *rnh, struct r
static int change_route_nhop(struct rib_head *rnh, struct rtentry *rt,
struct rt_addrinfo *info, struct route_nhop_data *rnd,
struct rib_cmd_info *rc);
+
+static int rt_unlinkrte(struct rib_head *rnh, struct rt_addrinfo *info,
+ struct rib_cmd_info *rc);
+
static void rib_notify(struct rib_head *rnh, enum rib_subscription_type type,
struct rib_cmd_info *rc);
@@ -172,6 +176,141 @@ get_rnh(uint32_t fibnum, const struct rt_addrinfo *inf
}
/*
+ * Check if specified @gw matches gw data in the nexthop @nh.
+ *
+ * Returns true if matches, false otherwise.
+ */
+static bool
+match_nhop_gw(const struct nhop_object *nh, const struct sockaddr *gw)
+{
+
+ if (nh->gw_sa.sa_family != gw->sa_family)
+ return (false);
+
+ switch (gw->sa_family) {
+ case AF_INET:
+ return (nh->gw4_sa.sin_addr.s_addr ==
+ ((const struct sockaddr_in *)gw)->sin_addr.s_addr);
+ case AF_INET6:
+ {
+ const struct sockaddr_in6 *gw6;
+ gw6 = (const struct sockaddr_in6 *)gw;
+
+ /*
+ * Currently (2020-09) IPv6 gws in kernel have their
+ * scope embedded. Once this becomes false, this code
+ * has to be revisited.
+ */
+ if (IN6_ARE_ADDR_EQUAL(&nh->gw6_sa.sin6_addr,
+ &gw6->sin6_addr))
+ return (true);
+ return (false);
+ }
+ case AF_LINK:
+ {
+ const struct sockaddr_dl *sdl;
+ sdl = (const struct sockaddr_dl *)gw;
+ return (nh->gwl_sa.sdl_index == sdl->sdl_index);
+ }
+ default:
+ return (memcmp(&nh->gw_sa, gw, nh->gw_sa.sa_len) == 0);
+ }
+
+ /* NOTREACHED */
+ return (false);
+}
+
+/*
+ * Checks if data in @info matches nexhop @nh.
+ *
+ * Returns 0 on success,
+ * ESRCH if not matched,
+ * ENOENT if filter function returned false
+ */
+int
+check_info_match_nhop(const struct rt_addrinfo *info, const struct rtentry *rt,
+ const struct nhop_object *nh)
+{
+ const struct sockaddr *gw = info->rti_info[RTAX_GATEWAY];
+
+ if (info->rti_filter != NULL) {
+ if (info->rti_filter(rt, nh, info->rti_filterdata) == 0)
+ return (ENOENT);
+ else
+ return (0);
+ }
+ if ((gw != NULL) && !match_nhop_gw(nh, gw))
+ return (ESRCH);
+
+ return (0);
+}
+
+/*
+ * Checks if nexhop @nh can be rewritten by data in @info because
+ * of higher "priority". Currently the only case for such scenario
+ * is kernel installing interface routes, marked by RTF_PINNED flag.
+ *
+ * Returns:
+ * 1 if @info data has higher priority
+ * 0 if priority is the same
+ * -1 if priority is lower
+ */
+int
+can_override_nhop(const struct rt_addrinfo *info, const struct nhop_object *nh)
+{
+
+ if (info->rti_flags & RTF_PINNED) {
+ return (NH_IS_PINNED(nh)) ? 0 : 1;
+ } else {
+ return (NH_IS_PINNED(nh)) ? -1 : 0;
+ }
+}
+
+/*
+ * Runs exact prefix match based on @dst and @netmask.
+ * Returns matched @rtentry if found or NULL.
+ * If rtentry was found, saves nexthop / weight value into @rnd.
+ */
+static struct rtentry *
+lookup_prefix_bysa(struct rib_head *rnh, const struct sockaddr *dst,
+ const struct sockaddr *netmask, struct route_nhop_data *rnd)
+{
+ struct rtentry *rt;
+
+ RIB_LOCK_ASSERT(rnh);
+
+ rt = (struct rtentry *)rnh->rnh_lookup(__DECONST(void *, dst),
+ __DECONST(void *, netmask), &rnh->head);
+ if (rt != NULL) {
+ rnd->rnd_nhop = rt->rt_nhop;
+ rnd->rnd_weight = rt->rt_weight;
+ } else {
+ rnd->rnd_nhop = NULL;
+ rnd->rnd_weight = 0;
+ }
+
+ return (rt);
+}
+
+/*
+ * Runs exact prefix match based on dst/netmask from @info.
+ * Assumes RIB lock is held.
+ * Returns matched @rtentry if found or NULL.
+ * If rtentry was found, saves nexthop / weight value into @rnd.
+ */
+struct rtentry *
+lookup_prefix(struct rib_head *rnh, const struct rt_addrinfo *info,
+ struct route_nhop_data *rnd)
+{
+ struct rtentry *rt;
+
+ rt = lookup_prefix_bysa(rnh, info->rti_info[RTAX_DST],
+ info->rti_info[RTAX_NETMASK], rnd);
+
+ return (rt);
+}
+
+/*
* Adds route defined by @info into the kernel table specified by @fibnum and
* sa_family in @info->rti_info[RTAX_DST].
*
@@ -182,6 +321,7 @@ rib_add_route(uint32_t fibnum, struct rt_addrinfo *inf
struct rib_cmd_info *rc)
{
struct rib_head *rnh;
+ int error;
NET_EPOCH_ASSERT();
@@ -201,7 +341,11 @@ rib_add_route(uint32_t fibnum, struct rt_addrinfo *inf
bzero(rc, sizeof(struct rib_cmd_info));
rc->rc_cmd = RTM_ADD;
- return (add_route(rnh, info, rc));
+ error = add_route(rnh, info, rc);
+ if (error == 0)
+ rib_notify(rnh, RIB_NOTIFY_DELAYED, rc);
+
+ return (error);
}
/*
@@ -291,10 +435,10 @@ static int
add_route(struct rib_head *rnh, struct rt_addrinfo *info,
struct rib_cmd_info *rc)
{
- struct sockaddr *ndst, *netmask;
+ struct nhop_object *nh_orig;
struct route_nhop_data rnd;
struct nhop_object *nh;
- struct rtentry *rt;
+ struct rtentry *rt, *rt_orig;
int error;
error = create_rtentry(rnh, info, &rt);
@@ -307,6 +451,7 @@ add_route(struct rib_head *rnh, struct rt_addrinfo *in
RIB_WLOCK(rnh);
#ifdef RADIX_MPATH
+ struct sockaddr *netmask;
netmask = info->rti_info[RTAX_NETMASK];
/* do not permit exactly the same dst/mask/gw pair */
if (rt_mpath_capable(rnh) &&
@@ -320,38 +465,39 @@ add_route(struct rib_head *rnh, struct rt_addrinfo *in
#endif
error = add_route_nhop(rnh, rt, info, &rnd, rc);
if (error == 0) {
- rt = NULL;
- nh = NULL;
- } else if ((error == EEXIST) && ((info->rti_flags & RTF_PINNED) != 0)) {
- struct rtentry *rt_orig;
- struct nhop_object *nh_orig;
- struct radix_node *rn;
+ RIB_WUNLOCK(rnh);
+ return (0);
+ }
- ndst = (struct sockaddr *)rt_key(rt);
- netmask = info->rti_info[RTAX_NETMASK];
- rn = rnh->rnh_lookup(ndst, netmask, &rnh->head);
- rt_orig = (struct rtentry *)rn;
- if (rt_orig != NULL) {
- nh_orig = rt_orig->rt_nhop;
- if ((nhop_get_rtflags(nh_orig) & RTF_PINNED) == 0) {
- /* Current nexhop is not PINNED, can update */
- error = change_route_nhop(rnh, rt_orig,
- info, &rnd, rc);
- if (error == 0)
- nh = NULL;
- }
- } else
- error = ENOBUFS;
+ /* addition failed. Lookup prefix in the rib to determine the cause */
+ rt_orig = lookup_prefix(rnh, info, &rnd);
+ if (rt_orig == NULL) {
+ /* No prefix -> rnh_addaddr() failed to allocate memory */
+ RIB_WUNLOCK(rnh);
+ nhop_free(nh);
+ uma_zfree(V_rtzone, rt);
+ return (ENOMEM);
}
+
+ /* We have existing route in the RIB. */
+ nh_orig = rnd.rnd_nhop;
+ /* Check if new route has higher preference */
+ if (can_override_nhop(info, nh_orig) > 0) {
+ /* Update nexthop to the new route */
+ change_route_nhop(rnh, rt_orig, info, &rnd, rc);
+ RIB_WUNLOCK(rnh);
+ uma_zfree(V_rtzone, rt);
+ nhop_free(nh_orig);
+ return (0);
+ }
+
RIB_WUNLOCK(rnh);
- if (error == 0)
- rib_notify(rnh, RIB_NOTIFY_DELAYED, rc);
+ /* Unable to add - another route with the same preference exists */
+ error = EEXIST;
- if (nh != NULL)
- nhop_free(nh);
- if (rt != NULL)
- uma_zfree(V_rtzone, rt);
+ nhop_free(nh);
+ uma_zfree(V_rtzone, rt);
return (error);
}
@@ -366,6 +512,9 @@ int
rib_del_route(uint32_t fibnum, struct rt_addrinfo *info, struct rib_cmd_info *rc)
{
struct rib_head *rnh;
+ struct sockaddr *dst_orig, *netmask;
+ struct sockaddr_storage mdst;
+ int error;
NET_EPOCH_ASSERT();
@@ -376,72 +525,66 @@ rib_del_route(uint32_t fibnum, struct rt_addrinfo *inf
bzero(rc, sizeof(struct rib_cmd_info));
rc->rc_cmd = RTM_DELETE;
- return (del_route(rnh, info, rc));
+ dst_orig = info->rti_info[RTAX_DST];
+ netmask = info->rti_info[RTAX_NETMASK];
+
+ if (netmask != NULL) {
+ /* Ensure @dst is always properly masked */
+ if (dst_orig->sa_len > sizeof(mdst))
+ return (EINVAL);
+ rt_maskedcopy(dst_orig, (struct sockaddr *)&mdst, netmask);
+ info->rti_info[RTAX_DST] = (struct sockaddr *)&mdst;
+ }
+ error = del_route(rnh, info, rc);
+ info->rti_info[RTAX_DST] = dst_orig;
+
+ return (error);
}
/*
* Conditionally unlinks rtentry matching data inside @info from @rnh.
- * Returns unlinked, locked and referenced @rtentry on success,
- * Returns NULL and sets @perror to:
+ * Returns 0 on success with operation result stored in @rc.
+ * On error, returns:
* ESRCH - if prefix was not found,
- * EADDRINUSE - if trying to delete PINNED route without appropriate flag.
+ * EADDRINUSE - if trying to delete higher priority route.
* ENOENT - if supplied filter function returned 0 (not matched).
*/
-struct rtentry *
-rt_unlinkrte(struct rib_head *rnh, struct rt_addrinfo *info, int *perror)
+static int
+rt_unlinkrte(struct rib_head *rnh, struct rt_addrinfo *info, struct rib_cmd_info *rc)
{
- struct sockaddr *dst, *netmask;
struct rtentry *rt;
struct nhop_object *nh;
struct radix_node *rn;
+ struct route_nhop_data rnd;
+ int error;
- dst = info->rti_info[RTAX_DST];
- netmask = info->rti_info[RTAX_NETMASK];
+ rt = lookup_prefix(rnh, info, &rnd);
+ if (rt == NULL)
+ return (ESRCH);
- rt = (struct rtentry *)rnh->rnh_lookup(dst, netmask, &rnh->head);
- if (rt == NULL) {
- *perror = ESRCH;
- return (NULL);
- }
-
nh = rt->rt_nhop;
- if ((info->rti_flags & RTF_PINNED) == 0) {
- /* Check if target route can be deleted */
- if (NH_IS_PINNED(nh)) {
- *perror = EADDRINUSE;
- return (NULL);
- }
- }
+ error = check_info_match_nhop(info, rt, nh);
+ if (error != 0)
+ return (error);
- if (info->rti_filter != NULL) {
- if (info->rti_filter(rt, nh, info->rti_filterdata)==0){
- /* Not matched */
- *perror = ENOENT;
- return (NULL);
- }
+ if (can_override_nhop(info, nh) < 0)
+ return (EADDRINUSE);
- /*
- * Filter function requested rte deletion.
- * Ease the caller work by filling in remaining info
- * from that particular entry.
- */
- info->rti_info[RTAX_GATEWAY] = &nh->gw_sa;
- }
-
/*
* Remove the item from the tree and return it.
* Complain if it is not there and do no more processing.
*/
- *perror = ESRCH;
#ifdef RADIX_MPATH
+ info->rti_info[RTAX_GATEWAY] = &nh->gw_sa;
if (rt_mpath_capable(rnh))
rn = rt_mpath_unlink(rnh, info, rt, perror);
else
#endif
- rn = rnh->rnh_deladdr(dst, netmask, &rnh->head);
+ rn = rnh->rnh_deladdr(info->rti_info[RTAX_DST],
+ info->rti_info[RTAX_NETMASK], &rnh->head);
if (rn == NULL)
- return (NULL);
+ return (ESRCH);
if (rn->rn_flags & (RNF_ACTIVE | RNF_ROOT))
panic ("rtrequest delete");
@@ -449,39 +592,25 @@ rt_unlinkrte(struct rib_head *rnh, struct rt_addrinfo
rt = RNTORT(rn);
rt->rte_flags &= ~RTF_UP;
- *perror = 0;
+ /* Finalize notification */
+ rnh->rnh_gen++;
+ rc->rc_cmd = RTM_DELETE;
+ rc->rc_rt = rt;
+ rc->rc_nh_old = rt->rt_nhop;
+ rc->rc_nh_weight = rt->rt_weight;
+ rib_notify(rnh, RIB_NOTIFY_IMMEDIATE, rc);
- return (rt);
+ return (0);
}
static int
del_route(struct rib_head *rnh, struct rt_addrinfo *info,
struct rib_cmd_info *rc)
{
- struct sockaddr *dst, *netmask;
- struct sockaddr_storage mdst;
- struct rtentry *rt;
int error;
- dst = info->rti_info[RTAX_DST];
- netmask = info->rti_info[RTAX_NETMASK];
-
- if (netmask) {
- if (dst->sa_len > sizeof(mdst))
- return (EINVAL);
- rt_maskedcopy(dst, (struct sockaddr *)&mdst, netmask);
- dst = (struct sockaddr *)&mdst;
- }
-
RIB_WLOCK(rnh);
- rt = rt_unlinkrte(rnh, info, &error);
- if (rt != NULL) {
- /* Finalize notification */
- rnh->rnh_gen++;
- rc->rc_rt = rt;
- rc->rc_nh_old = rt->rt_nhop;
- rib_notify(rnh, RIB_NOTIFY_IMMEDIATE, rc);
- }
+ error = rt_unlinkrte(rnh, info, rc);
RIB_WUNLOCK(rnh);
if (error != 0)
return (error);
@@ -492,7 +621,7 @@ del_route(struct rib_head *rnh, struct rt_addrinfo *in
* If the caller wants it, then it can have it,
* the entry will be deleted after the end of the current epoch.
*/
- rtfree(rt);
+ rtfree(rc->rc_rt);
return (0);
}
@@ -624,7 +753,7 @@ change_route(struct rib_head *rnh, struct rt_addrinfo
/*
* Insert @rt with nhop data from @rnd_new to @rnh.
- * Returns 0 on success.
+ * Returns 0 on success and stores operation results in @rc.
*/
static int
add_route_nhop(struct rib_head *rnh, struct rtentry *rt,
@@ -830,28 +959,26 @@ rt_checkdelroute(struct radix_node *rn, void *arg)
di = (struct rt_delinfo *)arg;
rt = (struct rtentry *)rn;
info = &di->info;
- error = 0;
info->rti_info[RTAX_DST] = rt_key(rt);
info->rti_info[RTAX_NETMASK] = rt_mask(rt);
info->rti_info[RTAX_GATEWAY] = &rt->rt_nhop->gw_sa;
- rt = rt_unlinkrte(di->rnh, info, &error);
- if (rt == NULL) {
- /* Either not allowed or not matched. Skip entry */
- return (0);
+ error = rt_unlinkrte(di->rnh, info, &di->rc);
+
+ /*
+ * Add deleted rtentries to the list to GC them
+ * after dropping the lock.
+ *
+ * XXX: Delayed notifications not implemented
+ * for nexthop updates.
+ */
+ if (error == 0) {
+ /* Add to the list and return */
+ rt->rt_chain = di->head;
+ di->head = rt;
}
- /* Entry was unlinked. Notify subscribers */
- di->rnh->rnh_gen++;
- di->rc.rc_rt = rt;
- di->rc.rc_nh_old = rt->rt_nhop;
- rib_notify(di->rnh, RIB_NOTIFY_IMMEDIATE, &di->rc);
-
- /* Add to the list and return */
- rt->rt_chain = di->head;
- di->head = rt;
-
return (0);
}
@@ -889,6 +1016,8 @@ rib_walk_del(u_int fibnum, int family, rt_filter_f_t *
RIB_WUNLOCK(rnh);
/* We might have something to reclaim. */
+ bzero(&di.rc, sizeof(di.rc));
+ di.rc.rc_cmd = RTM_DELETE;
while (di.head != NULL) {
rt = di.head;
di.head = rt->rt_chain;
Modified: head/sys/net/route/route_var.h
==============================================================================
--- head/sys/net/route/route_var.h Wed Sep 9 22:02:30 2020 (r365520)
+++ head/sys/net/route/route_var.h Wed Sep 9 22:07:54 2020 (r365521)
@@ -224,6 +224,12 @@ struct route_nhop_data {
int change_route_conditional(struct rib_head *rnh, struct rtentry *rt,
struct rt_addrinfo *info, struct route_nhop_data *nhd_orig,
struct route_nhop_data *nhd_new, struct rib_cmd_info *rc);
+struct rtentry *lookup_prefix(struct rib_head *rnh,
+ const struct rt_addrinfo *info, struct route_nhop_data *rnd);
+int check_info_match_nhop(const struct rt_addrinfo *info,
+ const struct rtentry *rt, const struct nhop_object *nh);
+int can_override_nhop(const struct rt_addrinfo *info,
+ const struct nhop_object *nh);
void vnet_rtzone_init(void);
void vnet_rtzone_destroy(void);
@@ -252,8 +258,5 @@ int nhop_create_from_nhop(struct rib_head *rnh, const
void nhops_update_ifmtu(struct rib_head *rh, struct ifnet *ifp, uint32_t mtu);
int nhops_dump_sysctl(struct rib_head *rh, struct sysctl_req *w);
-/* route */
-struct rtentry *rt_unlinkrte(struct rib_head *rnh, struct rt_addrinfo *info,
- int *perror);
#endif
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