git: 0d60e88b41fe - main - routing: refactor control cmds #1
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Date: Wed, 10 Aug 2022 18:20:29 UTC
The branch main has been updated by melifaro:
URL: https://cgit.FreeBSD.org/src/commit/?id=0d60e88b41fe1c090f9b28ea133d0787827f84fc
commit 0d60e88b41fe1c090f9b28ea133d0787827f84fc
Author: Alexander V. Chernikov <melifaro@FreeBSD.org>
AuthorDate: 2022-08-02 12:44:20 +0000
Commit: Alexander V. Chernikov <melifaro@FreeBSD.org>
CommitDate: 2022-08-10 18:20:20 +0000
routing: refactor control cmds #1
This and the follow-up routing-related changes target to remove or
reduce `struct rt_addrinfo` usage and use recently-landed nhop(9)
KPI instead.
Traditionally `rt_addrinfo` structure has been used to propagate all necessary
information between the protocol/rtsock and a routing layer. Many
functions inside routing subsystem uses it internally. However, using
this structure became somewhat complicated, as there are too many ways
of specifying a single state and verifying data consistency is hard.
For example, arerouting flgs consistent with mask/gateway sockaddr pointers?
Is mask really a host mask? Are sockaddr "valid" (e.g. properly zeroed, masked,
have proper length)? Are they mutable? Is the suggested interface specified
by the interface index embedded into the sockadd_dl gateway, or passed
as RTAX_IFP parameter, or directly provided by rti_ifp or it needs to
be derived from the ifa?
These (and other similar) questions have to be considered every time when
a function has `rt_addrinfo` pointer as an argument.
The new approach is to bring more control back to the protocols and
construct the desired routing objects themselves - in the end, it's the
protocol/subsystem who knows the desired outcome.
This specific diff changes the following:
* add explicit basic low-level radix operations:
add_route() (renamed from add_route_nhop())
delete_route() (factored from change_route_nhop())
change_route() (renamed from change_route_nhop)
* remove "info" parameter from change_route_conditional() as a part
of reducing rt_addrinfo usage in the internal KPIs
* add lookup_prefix_rt() wrapper for doing re-lookups after
RIB lock/unlock
Differential Revision: https://reviews.freebsd.org/D36070
MFC after: 2 weeks
---
sys/net/route/mpath_ctl.c | 7 +-
sys/net/route/route_ctl.c | 220 ++++++++++++++++++++++------------------------
sys/net/route/route_var.h | 8 +-
3 files changed, 113 insertions(+), 122 deletions(-)
diff --git a/sys/net/route/mpath_ctl.c b/sys/net/route/mpath_ctl.c
index db3c757e818d..b3f716875fa9 100644
--- a/sys/net/route/mpath_ctl.c
+++ b/sys/net/route/mpath_ctl.c
@@ -117,13 +117,12 @@ add_route_mpath(struct rib_head *rnh, struct rt_addrinfo *info,
* Refresh @rnd_orig data and retry.
*/
RIB_RLOCK(rnh);
- lookup_prefix(rnh, info, rnd_orig);
+ lookup_prefix_rt(rnh, rt, rnd_orig);
RIB_RUNLOCK(rnh);
continue;
}
- error = change_route_conditional(rnh, rt, info, rnd_orig,
- &rnd_new, rc);
+ error = change_route_conditional(rnh, rt, rnd_orig, &rnd_new, rc);
if (error != EAGAIN)
break;
RTSTAT_INC(rts_add_retry);
@@ -188,7 +187,7 @@ del_route_mpath(struct rib_head *rh, struct rt_addrinfo *info,
nhop_free_any(rnd.rnd_nhop);
return (ESRCH);
}
- error = change_route_nhop(rh, rt, &rnd, rc);
+ error = change_route(rh, rt, &rnd, rc);
}
return (error);
}
diff --git a/sys/net/route/route_ctl.c b/sys/net/route/route_ctl.c
index 394260e1421c..133f9d34d854 100644
--- a/sys/net/route/route_ctl.c
+++ b/sys/net/route/route_ctl.c
@@ -77,15 +77,16 @@ struct rib_subscription {
struct epoch_context epoch_ctx;
};
-static int add_route(struct rib_head *rnh, struct rt_addrinfo *info,
+static int add_route_byinfo(struct rib_head *rnh, struct rt_addrinfo *info,
struct rib_cmd_info *rc);
-static int add_route_nhop(struct rib_head *rnh, struct rtentry *rt,
- struct route_nhop_data *rnd, struct rib_cmd_info *rc);
-static int del_route(struct rib_head *rnh, struct rt_addrinfo *info,
+static int change_route_byinfo(struct rib_head *rnh, struct rtentry *rt,
+ struct rt_addrinfo *info, struct route_nhop_data *nhd_orig,
struct rib_cmd_info *rc);
-static int change_route(struct rib_head *rnh, struct rt_addrinfo *info,
- struct route_nhop_data *nhd_orig, struct rib_cmd_info *rc);
+static int add_route(struct rib_head *rnh, struct rtentry *rt,
+ struct route_nhop_data *rnd, struct rib_cmd_info *rc);
+static int delete_route(struct rib_head *rnh, struct rtentry *rt,
+ struct rib_cmd_info *rc);
static int rt_unlinkrte(struct rib_head *rnh, struct rt_addrinfo *info,
struct rib_cmd_info *rc);
@@ -519,8 +520,7 @@ lookup_prefix_bysa(struct rib_head *rnh, const struct sockaddr *dst,
RIB_LOCK_ASSERT(rnh);
- rt = (struct rtentry *)rnh->rnh_lookup(__DECONST(void *, dst),
- __DECONST(void *, netmask), &rnh->head);
+ rt = (struct rtentry *)rnh->rnh_lookup(dst, netmask, &rnh->head);
if (rt != NULL) {
rnd->rnd_nhop = rt->rt_nhop;
rnd->rnd_weight = rt->rt_weight;
@@ -532,6 +532,13 @@ lookup_prefix_bysa(struct rib_head *rnh, const struct sockaddr *dst,
return (rt);
}
+struct rtentry *
+lookup_prefix_rt(struct rib_head *rnh, const struct rtentry *rt,
+ struct route_nhop_data *rnd)
+{
+ return (lookup_prefix_bysa(rnh, rt_key_const(rt), rt_mask_const(rt), rnd));
+}
+
/*
* Runs exact prefix match based on dst/netmask from @info.
* Assumes RIB lock is held.
@@ -583,7 +590,7 @@ rib_add_route(uint32_t fibnum, struct rt_addrinfo *info,
bzero(rc, sizeof(struct rib_cmd_info));
rc->rc_cmd = RTM_ADD;
- error = add_route(rnh, info, rc);
+ error = add_route_byinfo(rnh, info, rc);
if (error == 0)
rib_notify(rnh, RIB_NOTIFY_DELAYED, rc);
@@ -701,7 +708,7 @@ create_rtentry(struct rib_head *rnh, struct rt_addrinfo *info,
}
static int
-add_route(struct rib_head *rnh, struct rt_addrinfo *info,
+add_route_byinfo(struct rib_head *rnh, struct rt_addrinfo *info,
struct rib_cmd_info *rc)
{
struct nhop_object *nh_orig;
@@ -719,7 +726,7 @@ add_route(struct rib_head *rnh, struct rt_addrinfo *info,
nh = rt->rt_nhop;
RIB_WLOCK(rnh);
- error = add_route_nhop(rnh, rt, &rnd_add, rc);
+ error = add_route(rnh, rt, &rnd_add, rc);
if (error == 0) {
RIB_WUNLOCK(rnh);
return (0);
@@ -740,7 +747,7 @@ add_route(struct rib_head *rnh, struct rt_addrinfo *info,
/* 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, &rnd_add, rc);
+ change_route(rnh, rt_orig, &rnd_add, rc);
RIB_WUNLOCK(rnh);
uma_zfree(V_rtzone, rt);
nhop_free(nh_orig);
@@ -808,10 +815,32 @@ rib_del_route(uint32_t fibnum, struct rt_addrinfo *info, struct rib_cmd_info *rc
rt_maskedcopy(dst_orig, (struct sockaddr *)&mdst, netmask);
info->rti_info[RTAX_DST] = (struct sockaddr *)&mdst;
}
- error = del_route(rnh, info, rc);
+
+ RIB_WLOCK(rnh);
+ error = rt_unlinkrte(rnh, info, rc);
+ RIB_WUNLOCK(rnh);
+
info->rti_info[RTAX_DST] = dst_orig;
- return (error);
+ if (error != 0)
+ return (error);
+
+ rib_notify(rnh, RIB_NOTIFY_DELAYED, rc);
+
+ if (rc->rc_cmd == RTM_DELETE)
+ rtfree(rc->rc_rt);
+#ifdef ROUTE_MPATH
+ else {
+ /*
+ * Deleting 1 path may result in RTM_CHANGE to
+ * a different mpath group/nhop.
+ * Free old mpath group.
+ */
+ nhop_free_any(rc->rc_nh_old);
+ }
+#endif
+
+ return (0);
}
/*
@@ -827,7 +856,6 @@ rt_unlinkrte(struct rib_head *rnh, struct rt_addrinfo *info, struct rib_cmd_info
{
struct rtentry *rt;
struct nhop_object *nh;
- struct radix_node *rn;
struct route_nhop_data rnd;
int error;
@@ -850,65 +878,7 @@ rt_unlinkrte(struct rib_head *rnh, struct rt_addrinfo *info, struct rib_cmd_info
if (can_override_nhop(info, nh) < 0)
return (EADDRINUSE);
- /*
- * Remove the item from the tree and return it.
- * Complain if it is not there and do no more processing.
- */
- rn = rnh->rnh_deladdr(rt_key_const(rt), rt_mask_const(rt), &rnh->head);
- if (rn == NULL)
- return (ESRCH);
-
- if (rn->rn_flags & (RNF_ACTIVE | RNF_ROOT))
- panic ("rtrequest delete");
-
- rt = RNTORT(rn);
- rt->rte_flags &= ~RTF_UP;
-
- /* Finalize notification */
- rib_bump_gen(rnh);
- rnh->rnh_prefixes--;
-
- 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 (0);
-}
-
-static int
-del_route(struct rib_head *rnh, struct rt_addrinfo *info,
- struct rib_cmd_info *rc)
-{
- int error;
-
- RIB_WLOCK(rnh);
- error = rt_unlinkrte(rnh, info, rc);
- RIB_WUNLOCK(rnh);
- if (error != 0)
- return (error);
-
- rib_notify(rnh, RIB_NOTIFY_DELAYED, rc);
-
- /*
- * If the caller wants it, then it can have it,
- * the entry will be deleted after the end of the current epoch.
- */
- if (rc->rc_cmd == RTM_DELETE)
- rtfree(rc->rc_rt);
-#ifdef ROUTE_MPATH
- else {
- /*
- * Deleting 1 path may result in RTM_CHANGE to
- * a different mpath group/nhop.
- * Free old mpath group.
- */
- nhop_free_any(rc->rc_nh_old);
- }
-#endif
-
- return (0);
+ return (delete_route(rnh, rt, rc));
}
int
@@ -965,7 +935,7 @@ rib_change_route(uint32_t fibnum, struct rt_addrinfo *info,
RIB_RUNLOCK(rnh);
for (int i = 0; i < RIB_MAX_RETRIES; i++) {
- error = change_route(rnh, info, &rnd_orig, rc);
+ error = change_route_byinfo(rnh, rt, info, &rnd_orig, rc);
if (error != EAGAIN)
break;
}
@@ -1005,8 +975,9 @@ change_nhop(struct rib_head *rnh, struct rt_addrinfo *info,
#ifdef ROUTE_MPATH
static int
-change_mpath_route(struct rib_head *rnh, struct rt_addrinfo *info,
- struct route_nhop_data *rnd_orig, struct rib_cmd_info *rc)
+change_mpath_route(struct rib_head *rnh, struct rtentry *rt,
+ struct rt_addrinfo *info, struct route_nhop_data *rnd_orig,
+ struct rib_cmd_info *rc)
{
int error = 0, found_idx = 0;
struct nhop_object *nh_orig = NULL, *nh_new;
@@ -1049,15 +1020,16 @@ change_mpath_route(struct rib_head *rnh, struct rt_addrinfo *info,
if (error != 0)
return (error);
- error = change_route_conditional(rnh, NULL, info, rnd_orig, &rnd_new, rc);
+ error = change_route_conditional(rnh, rt, rnd_orig, &rnd_new, rc);
return (error);
}
#endif
static int
-change_route(struct rib_head *rnh, struct rt_addrinfo *info,
- struct route_nhop_data *rnd_orig, struct rib_cmd_info *rc)
+change_route_byinfo(struct rib_head *rnh, struct rtentry *rt,
+ struct rt_addrinfo *info, struct route_nhop_data *rnd_orig,
+ struct rib_cmd_info *rc)
{
int error = 0;
struct nhop_object *nh_orig;
@@ -1069,14 +1041,14 @@ change_route(struct rib_head *rnh, struct rt_addrinfo *info,
#ifdef ROUTE_MPATH
if (NH_IS_NHGRP(nh_orig))
- return (change_mpath_route(rnh, info, rnd_orig, rc));
+ return (change_mpath_route(rnh, rt, info, rnd_orig, rc));
#endif
rnd_new.rnd_weight = get_info_weight(info, rnd_orig->rnd_weight);
error = change_nhop(rnh, info, nh_orig, &rnd_new.rnd_nhop);
if (error != 0)
return (error);
- error = change_route_conditional(rnh, NULL, info, rnd_orig, &rnd_new, rc);
+ error = change_route_conditional(rnh, rt, rnd_orig, &rnd_new, rc);
return (error);
}
@@ -1086,11 +1058,10 @@ change_route(struct rib_head *rnh, struct rt_addrinfo *info,
* Returns 0 on success and stores operation results in @rc.
*/
static int
-add_route_nhop(struct rib_head *rnh, struct rtentry *rt,
+add_route(struct rib_head *rnh, struct rtentry *rt,
struct route_nhop_data *rnd, struct rib_cmd_info *rc)
{
struct radix_node *rn;
- int error = 0;
RIB_WLOCK_ASSERT(rnh);
@@ -1113,12 +1084,42 @@ add_route_nhop(struct rib_head *rnh, struct rtentry *rt,
rc->rc_nh_weight = rnd->rnd_weight;
rib_notify(rnh, RIB_NOTIFY_IMMEDIATE, rc);
- } else {
- /* Existing route or memory allocation failure */
- error = EEXIST;
+ return (0);
}
- return (error);
+ /* Existing route or memory allocation failure. */
+ return (EEXIST);
+}
+
+/*
+ * Unconditionally deletes @rt from @rnh.
+ */
+static int
+delete_route(struct rib_head *rnh, struct rtentry *rt, struct rib_cmd_info *rc)
+{
+ RIB_WLOCK_ASSERT(rnh);
+
+ /* Route deletion requested. */
+ struct radix_node *rn;
+
+ rn = rnh->rnh_deladdr(rt_key_const(rt), rt_mask_const(rt), &rnh->head);
+ if (rn == NULL)
+ return (ESRCH);
+ rt = RNTORT(rn);
+ rt->rte_flags &= ~RTF_UP;
+
+ rib_bump_gen(rnh);
+ rnh->rnh_prefixes--;
+
+ rc->rc_cmd = RTM_DELETE;
+ rc->rc_rt = rt;
+ rc->rc_nh_old = rt->rt_nhop;
+ rc->rc_nh_new = NULL;
+ rc->rc_nh_weight = rt->rt_weight;
+
+ rib_notify(rnh, RIB_NOTIFY_IMMEDIATE, rc);
+
+ return (0);
}
/*
@@ -1126,7 +1127,7 @@ add_route_nhop(struct rib_head *rnh, struct rtentry *rt,
* Returns 0 on success.
*/
int
-change_route_nhop(struct rib_head *rnh, struct rtentry *rt,
+change_route(struct rib_head *rnh, struct rtentry *rt,
struct route_nhop_data *rnd, struct rib_cmd_info *rc)
{
struct nhop_object *nh_orig;
@@ -1135,29 +1136,18 @@ change_route_nhop(struct rib_head *rnh, struct rtentry *rt,
nh_orig = rt->rt_nhop;
- if (rnd->rnd_nhop != NULL) {
- /* Changing nexthop & weight to a new one */
- rt->rt_nhop = rnd->rnd_nhop;
- rt->rt_weight = rnd->rnd_weight;
- if (!NH_IS_NHGRP(rnd->rnd_nhop) && nhop_get_expire(rnd->rnd_nhop))
- tmproutes_update(rnh, rt, rnd->rnd_nhop);
- } else {
- /* Route deletion requested. */
- struct radix_node *rn;
-
- rn = rnh->rnh_deladdr(rt_key_const(rt), rt_mask_const(rt), &rnh->head);
- if (rn == NULL)
- return (ESRCH);
- rt = RNTORT(rn);
- rt->rte_flags &= ~RTF_UP;
- }
+ if (rnd->rnd_nhop == NULL)
+ return (delete_route(rnh, rt, rc));
+
+ /* Changing nexthop & weight to a new one */
+ rt->rt_nhop = rnd->rnd_nhop;
+ rt->rt_weight = rnd->rnd_weight;
+ if (!NH_IS_NHGRP(rnd->rnd_nhop) && nhop_get_expire(rnd->rnd_nhop))
+ tmproutes_update(rnh, rt, rnd->rnd_nhop);
/* Finalize notification */
rib_bump_gen(rnh);
- if (rnd->rnd_nhop == NULL)
- rnh->rnh_prefixes--;
-
- rc->rc_cmd = (rnd->rnd_nhop != NULL) ? RTM_CHANGE : RTM_DELETE;
+ rc->rc_cmd = RTM_CHANGE;
rc->rc_rt = rt;
rc->rc_nh_old = nh_orig;
rc->rc_nh_new = rnd->rnd_nhop;
@@ -1175,8 +1165,8 @@ change_route_nhop(struct rib_head *rnh, struct rtentry *rt,
*/
int
change_route_conditional(struct rib_head *rnh, struct rtentry *rt,
- struct rt_addrinfo *info, struct route_nhop_data *rnd_orig,
- struct route_nhop_data *rnd_new, struct rib_cmd_info *rc)
+ struct route_nhop_data *rnd_orig, struct route_nhop_data *rnd_new,
+ struct rib_cmd_info *rc)
{
struct rtentry *rt_new;
int error = 0;
@@ -1192,12 +1182,12 @@ change_route_conditional(struct rib_head *rnh, struct rtentry *rt,
#endif
RIB_WLOCK(rnh);
- rt_new = (struct rtentry *)rnh->rnh_lookup(info->rti_info[RTAX_DST],
- info->rti_info[RTAX_NETMASK], &rnh->head);
+ struct route_nhop_data rnd;
+ rt_new = lookup_prefix_rt(rnh, rt, &rnd);
if (rt_new == NULL) {
if (rnd_orig->rnd_nhop == NULL)
- error = add_route_nhop(rnh, rt, rnd_new, rc);
+ error = add_route(rnh, rt, rnd_new, rc);
else {
/*
* Prefix does not exist, which was not our assumption.
@@ -1214,7 +1204,7 @@ change_route_conditional(struct rib_head *rnh, struct rtentry *rt,
* Nhop/mpath group hasn't changed. Flip
* to the new precalculated one and return
*/
- error = change_route_nhop(rnh, rt_new, rnd_new, rc);
+ error = change_route(rnh, rt_new, rnd_new, rc);
} else {
/* Update and retry */
rnd_orig->rnd_nhop = rt_new->rt_nhop;
diff --git a/sys/net/route/route_var.h b/sys/net/route/route_var.h
index 403e432ea836..12bf1b4093cb 100644
--- a/sys/net/route/route_var.h
+++ b/sys/net/route/route_var.h
@@ -212,13 +212,15 @@ void tmproutes_destroy(struct rib_head *rh);
/* route_ctl.c */
struct route_nhop_data;
-int change_route_nhop(struct rib_head *rnh, struct rtentry *rt,
+int change_route(struct rib_head *rnh, struct rtentry *rt,
struct route_nhop_data *rnd, struct rib_cmd_info *rc);
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 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);
+struct rtentry *lookup_prefix_rt(struct rib_head *rnh, const struct rtentry *rt,
+ struct route_nhop_data *rnd);
bool nhop_can_multipath(const struct nhop_object *nh);
bool match_nhop_gw(const struct nhop_object *nh, const struct sockaddr *gw);