/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2020 Alexander V. Chernikov
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "opt_inet.h"
#include "opt_route.h"
#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/rmlock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/refcount.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/kernel.h>
#include <sys/epoch.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_private.h>
#include <net/route.h>
#include <net/route/route_ctl.h>
#include <net/route/route_var.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_fib.h>
#include <net/route/nhop_utils.h>
#include <net/route/nhop.h>
#include <net/route/nhop_var.h>
#include <net/route/nhgrp_var.h>
#define DEBUG_MOD_NAME nhgrp_ctl
#define DEBUG_MAX_LEVEL LOG_DEBUG
#include <net/route/route_debug.h>
_DECLARE_DEBUG(LOG_INFO);
/*
* This file contains the supporting functions for creating multipath groups
* and compiling their dataplane parts.
*/
/* MPF_MULTIPATH must be the same as NHF_MULTIPATH for nhop selection to work */
_Static_assert(MPF_MULTIPATH == NHF_MULTIPATH,
"MPF_MULTIPATH must be the same as NHF_MULTIPATH");
/* Offset and size of flags field has to be the same for nhop/nhop groups */
CHK_STRUCT_FIELD_GENERIC(struct nhop_object, nh_flags, struct nhgrp_object, nhg_flags);
/* Cap multipath to 64, as the larger values would break rib_cmd_info bmasks */
CTASSERT(RIB_MAX_MPATH_WIDTH <= 64);
static int wn_cmp_idx(const void *a, const void *b);
static void sort_weightened_nhops(struct weightened_nhop *wn, int num_nhops);
static struct nhgrp_priv *get_nhgrp(struct nh_control *ctl,
struct weightened_nhop *wn, int num_nhops, uint32_t uidx, int *perror);
static void destroy_nhgrp(struct nhgrp_priv *nhg_priv);
static void destroy_nhgrp_epoch(epoch_context_t ctx);
static void free_nhgrp_nhops(struct nhgrp_priv *nhg_priv);
static int
wn_cmp_idx(const void *a, const void *b)
{
const struct weightened_nhop *w_a = a;
const struct weightened_nhop *w_b = b;
uint32_t a_idx = w_a->nh->nh_priv->nh_idx;
uint32_t b_idx = w_b->nh->nh_priv->nh_idx;
if (a_idx < b_idx)
return (-1);
else if (a_idx > b_idx)
return (1);
else
return (0);
}
/*
* Perform in-place sorting for array of nexthops in @wn.
* Sort by nexthop index ascending.
*/
static void
sort_weightened_nhops(struct weightened_nhop *wn, int num_nhops)
{
qsort(wn, num_nhops, sizeof(struct weightened_nhop), wn_cmp_idx);
}
/*
* In order to determine the minimum weight difference in the array
* of weights, create a sorted array of weights, using spare "storage"
* field in the `struct weightened_nhop`.
* Assume weights to be (mostly) the same and use insertion sort to
* make it sorted.
*/
static void
sort_weightened_nhops_weights(struct weightened_nhop *wn, int num_items)
{
wn[0].storage = wn[0].weight;
for (int i = 1, j = 0; i < num_items; i++) {
uint32_t weight = wn[i].weight; // read from 'weight' as it's not reordered
/* Move all weights > weight 1 position right */
for (j = i - 1; j >= 0 && wn[j].storage > weight; j--)
wn[j + 1].storage = wn[j].storage;
wn[j + 1].storage = weight;
}
}
/*
* Calculate minimum number of slots required to fit the existing
* set of weights in the common use case where weights are "easily"
* comparable.
* Assumes @wn is sorted by weight ascending and each weight is > 0.
* Returns number of slots or 0 if precise calculation failed.
*
* Some examples:
* note: (i, X) pair means (nhop=i, weight=X):
* (1, 1) (2, 2) -> 3 slots [1, 2, 2]
* (1, 100), (2, 200) -> 3 slots [1, 2, 2]
* (1, 100), (2, 200), (3, 400) -> 7 slots [1, 2, 2, 3, 3, 3]
*/
static uint32_t
calc_min_mpath_slots_fast(struct weightened_nhop *wn, size_t num_items,
uint64_t *ptotal)
{
uint32_t i, last, xmin;
uint64_t total = 0;
// Get sorted array of weights in .storage field
sort_weightened_nhops_weights(wn, num_items);
last = 0;
xmin = wn[0].storage;
for (i = 0; i < num_items; i++) {
total += wn[i].storage;
if ((wn[i].storage != last) &&
((wn[i].storage - last < xmin) || xmin == 0)) {
xmin = wn[i].storage - last;
}
last = wn[i].storage;
}
*ptotal = total;
/* xmin is the minimum unit of desired capacity */
if ((total % xmin) != 0)
return (0);
for (i = 0; i < num_items; i++) {
if ((wn[i].weight % xmin) != 0)
return (0);
}
return ((uint32_t)(total / xmin));
}
/*
* Calculate minimum number of slots required to fit the existing
* set of weights while maintaining weight coefficients.
*
* Assume @wn is sorted by weight ascending and each weight is > 0.
*
* Tries to find simple precise solution first and falls back to
* RIB_MAX_MPATH_WIDTH in case of any failure.
*/
static uint32_t
calc_min_mpath_slots(struct weightened_nhop *wn, size_t num_items)
{
uint32_t v;
uint64_t total;
v = calc_min_mpath_slots_fast(wn, num_items, &total);
if (total == 0)
return (0);
if ((v == 0) || (v > RIB_MAX_MPATH_WIDTH))
v = RIB_MAX_MPATH_WIDTH;
return (v);
}
/*
* Nexthop group data consists of
* 1) dataplane part, with nhgrp_object as a header followed by an
* arbitrary number of nexthop pointers.
* 2) control plane part, with nhgrp_priv as a header, followed by
* an arbirtrary number of 'struct weightened_nhop' object.
*
* Given nexthop groups are (mostly) immutable, allocate all data
* in one go.
*
*/
__noinline static size_t
get_nhgrp_alloc_size(uint32_t nhg_size, uint32_t num_nhops)
{
size_t sz;
sz = sizeof(struct nhgrp_object);
sz += nhg_size * sizeof(struct nhop_object *);
sz += sizeof(struct nhgrp_priv);
sz += num_nhops * sizeof(struct weightened_nhop);
return (sz);
}
/*
* Compile actual list of nexthops to be used by datapath from
* the nexthop group @dst.
*
* For example, compiling control plane list of 2 nexthops
* [(200, A), (100, B)] would result in the datapath array
* [A, A, B]
*/
static void
compile_nhgrp(struct nhgrp_priv *dst_priv, const struct weightened_nhop *x,
uint32_t num_slots)
{
struct nhgrp_object *dst;
int i, slot_idx, remaining_slots;
uint64_t remaining_sum, nh_weight, nh_slots;
slot_idx = 0;
dst = dst_priv->nhg;
/* Calculate sum of all weights */
remaining_sum = 0;
for (i = 0; i < dst_priv->nhg_nh_count; i++)
remaining_sum += x[i].weight;
remaining_slots = num_slots;
FIB_NH_LOG(LOG_DEBUG3, x[0].nh, "sum: %lu, slots: %d",
remaining_sum, remaining_slots);
for (i = 0; i < dst_priv->nhg_nh_count; i++) {
/* Calculate number of slots for the current nexthop */
if (remaining_sum > 0) {
nh_weight = (uint64_t)x[i].weight;
nh_slots = (nh_weight * remaining_slots / remaining_sum);
} else
nh_slots = 0;
remaining_sum -= x[i].weight;
remaining_slots -= nh_slots;
FIB_NH_LOG(LOG_DEBUG3, x[0].nh,
" rem_sum: %lu, rem_slots: %d nh_slots: %d, slot_idx: %d",
remaining_sum, remaining_slots, (int)nh_slots, slot_idx);
KASSERT((slot_idx + nh_slots <= num_slots),
("index overflow during nhg compilation"));
while (nh_slots-- > 0)
dst->nhops[slot_idx++] = x[i].nh;
}
}
/*
* Allocates new nexthop group for the list of weightened nexthops.
* Assume sorted list.
* Does NOT reference any nexthops in the group.
* Returns group with refcount=1 or NULL.
*/
static struct nhgrp_priv *
alloc_nhgrp(struct weightened_nhop *wn, int num_nhops)
{
uint32_t nhgrp_size;
struct nhgrp_object *nhg;
struct nhgrp_priv *nhg_priv;
nhgrp_size = calc_min_mpath_slots(wn, num_nhops);
if (nhgrp_size == 0) {
/* Zero weights, abort */
return (NULL);
}
size_t sz = get_nhgrp_alloc_size(nhgrp_size, num_nhops);
nhg = malloc(sz, M_NHOP, M_NOWAIT | M_ZERO);
if (nhg == NULL) {
FIB_NH_LOG(LOG_INFO, wn[0].nh,
"unable to allocate group with num_nhops %d (compiled %u)",
num_nhops, nhgrp_size);
return (NULL);
}
/* Has to be the first to make NHGRP_PRIV() work */
nhg->nhg_size = nhgrp_size;
nhg->nhg_flags = MPF_MULTIPATH;
nhg_priv = NHGRP_PRIV(nhg);
nhg_priv->nhg_nh_count = num_nhops;
refcount_init(&nhg_priv->nhg_refcount, 1);
/* Please see nhgrp_free() comments on the initial value */
refcount_init(&nhg_priv->nhg_linked, 2);
nhg_priv->nhg = nhg;
memcpy(&nhg_priv->nhg_nh_weights[0], wn,
num_nhops * sizeof(struct weightened_nhop));
FIB_NH_LOG(LOG_DEBUG, wn[0].nh, "num_nhops: %d, compiled_nhop: %u",
num_nhops, nhgrp_size);
compile_nhgrp(nhg_priv, wn, nhg->nhg_size);
return (nhg_priv);
}
void
nhgrp_ref_object(struct nhgrp_object *nhg)
{
struct nhgrp_priv *nhg_priv;
u_int old __diagused;
nhg_priv = NHGRP_PRIV(nhg);
old = refcount_acquire(&nhg_priv->nhg_refcount);
KASSERT(old > 0, ("%s: nhgrp object %p has 0 refs", __func__, nhg));
}
void
nhgrp_free(struct nhgrp_object *nhg)
{
struct nhgrp_priv *nhg_priv;
struct nh_control *ctl;
struct epoch_tracker et;
nhg_priv = NHGRP_PRIV(nhg);
if (!refcount_release(&nhg_priv->nhg_refcount))
return;
/*
* group objects don't have an explicit lock attached to it.
* As groups are reclaimed based on reference count, it is possible
* that some groups will persist after vnet destruction callback
* called. Given that, handle scenario with nhgrp_free_group() being
* called either after or simultaneously with nhgrp_ctl_unlink_all()
* by using another reference counter: nhg_linked.
*
* There are only 2 places, where nhg_linked can be decreased:
* rib destroy (nhgrp_ctl_unlink_all) and this function.
* nhg_link can never be increased.
*
* Hence, use initial value of 2 to make use of
* refcount_release_if_not_last().
*
* There can be two scenarious when calling this function:
*
* 1) nhg_linked value is 2. This means that either
* nhgrp_ctl_unlink_all() has not been called OR it is running,
* but we are guaranteed that nh_control won't be freed in
* this epoch. Hence, nexthop can be safely unlinked.
*
* 2) nh_linked value is 1. In that case, nhgrp_ctl_unlink_all()
* has been called and nhgrp unlink can be skipped.
*/
NET_EPOCH_ENTER(et);
if (refcount_release_if_not_last(&nhg_priv->nhg_linked)) {
ctl = nhg_priv->nh_control;
if (unlink_nhgrp(ctl, nhg_priv) == NULL) {
/* Do not try to reclaim */
RT_LOG(LOG_INFO, "Failed to unlink nexhop group %p",
nhg_priv);
NET_EPOCH_EXIT(et);
return;
}
MPASS((nhg_priv->nhg_idx == 0));
MPASS((nhg_priv->nhg_refcount == 0));
}
NET_EPOCH_EXIT(et);
NET_EPOCH_CALL(destroy_nhgrp_epoch, &nhg_priv->nhg_epoch_ctx);
}
/*
* Destroys all local resources belonging to @nhg_priv.
*/
__noinline static void
destroy_nhgrp_int(struct nhgrp_priv *nhg_priv)
{
free(nhg_priv->nhg, M_NHOP);
}
__noinline static void
destroy_nhgrp(struct nhgrp_priv *nhg_priv)
{
IF_DEBUG_LEVEL(LOG_DEBUG2) {
char nhgbuf[NHOP_PRINT_BUFSIZE] __unused;
FIB_NH_LOG(LOG_DEBUG2, nhg_priv->nhg_nh_weights[0].nh,
"destroying %s", nhgrp_print_buf(nhg_priv->nhg,
nhgbuf, sizeof(nhgbuf)));
}
free_nhgrp_nhops(nhg_priv);
destroy_nhgrp_int(nhg_priv);
}
/*
* Epoch callback indicating group is safe to destroy
*/
static void
destroy_nhgrp_epoch(epoch_context_t ctx)
{
struct nhgrp_priv *nhg_priv;
nhg_priv = __containerof(ctx, struct nhgrp_priv, nhg_epoch_ctx);
destroy_nhgrp(nhg_priv);
}
static bool
ref_nhgrp_nhops(struct nhgrp_priv *nhg_priv)
{
for (int i = 0; i < nhg_priv->nhg_nh_count; i++) {
if (nhop_try_ref_object(nhg_priv->nhg_nh_weights[i].nh) != 0)
continue;
/*
* Failed to ref the nexthop, b/c it's deleted.
* Need to rollback references back.
*/
for (int j = 0; j < i; j++)
nhop_free(nhg_priv->nhg_nh_weights[j].nh);
return (false);
}
return (true);
}
static void
free_nhgrp_nhops(struct nhgrp_priv *nhg_priv)
{
for (int i = 0; i < nhg_priv->nhg_nh_count; i++)
nhop_free(nhg_priv->nhg_nh_weights[i].nh);
}
/*
* Allocate nexthop group of size @num_nhops with nexthops specified by
* @wn. Nexthops have to be unique and match the fibnum/family of the group.
* Returns unlinked nhgrp object on success or NULL and non-zero perror.
*/
struct nhgrp_object *
nhgrp_alloc(uint32_t fibnum, int family, struct weightened_nhop *wn, int num_nhops,
int *perror)
{
struct rib_head *rh = rt_tables_get_rnh(fibnum, family);
struct nhgrp_priv *nhg_priv;
struct nh_control *ctl;
if (rh == NULL) {
*perror = E2BIG;
return (NULL);
}
ctl = rh->nh_control;
if (num_nhops > RIB_MAX_MPATH_WIDTH) {
*perror = E2BIG;
return (NULL);
}
if (ctl->gr_head.hash_size == 0) {
/* First multipath request. Bootstrap mpath datastructures. */
if (nhgrp_ctl_alloc_default(ctl, M_NOWAIT) == 0) {
*perror = ENOMEM;
return (NULL);
}
}
/* Sort nexthops & check there are no duplicates */
sort_weightened_nhops(wn, num_nhops);
uint32_t last_id = 0;
for (int i = 0; i < num_nhops; i++) {
if (wn[i].nh->nh_priv->nh_control != ctl) {
*perror = EINVAL;
return (NULL);
}
if (wn[i].nh->nh_priv->nh_idx == last_id) {
*perror = EEXIST;
return (NULL);
}
last_id = wn[i].nh->nh_priv->nh_idx;
}
if ((nhg_priv = alloc_nhgrp(wn, num_nhops)) == NULL) {
*perror = ENOMEM;
return (NULL);
}
nhg_priv->nh_control = ctl;
*perror = 0;
return (nhg_priv->nhg);
}
/*
* Finds an existing group matching @nhg or links @nhg to the tree.
* Returns the referenced group or NULL and non-zero @perror.
*/
struct nhgrp_object *
nhgrp_get_nhgrp(struct nhgrp_object *nhg, int *perror)
{
struct nhgrp_priv *nhg_priv, *key = NHGRP_PRIV(nhg);
struct nh_control *ctl = key->nh_control;
nhg_priv = find_nhgrp(ctl, key);
if (nhg_priv != NULL) {
/*
* Free originally-created group. As it hasn't been linked
* and the dependent nexhops haven't been referenced, just free
* the group.
*/
destroy_nhgrp_int(key);
*perror = 0;
return (nhg_priv->nhg);
} else {
/* No existing group, try to link the new one */
if (!ref_nhgrp_nhops(key)) {
/*
* Some of the nexthops have been scheduled for deletion.
* As the group hasn't been linked / no nexhops have been
* referenced, call the final destructor immediately.
*/
destroy_nhgrp_int(key);
*perror = EAGAIN;
return (NULL);
}
if (link_nhgrp(ctl, key) == 0) {
/* Unable to allocate index? */
*perror = EAGAIN;
free_nhgrp_nhops(key);
destroy_nhgrp_int(key);
return (NULL);
}
*perror = 0;
return (nhg);
}
/* NOTREACHED */
}
/*
* Creates or looks up an existing nexthop group based on @wn and @num_nhops.
*
* Returns referenced nhop group or NULL, passing error code in @perror.
*/
struct nhgrp_priv *
get_nhgrp(struct nh_control *ctl, struct weightened_nhop *wn, int num_nhops,
uint32_t uidx, int *perror)
{
struct nhgrp_object *nhg;
nhg = nhgrp_alloc(ctl->ctl_rh->rib_fibnum, ctl->ctl_rh->rib_family,
wn, num_nhops, perror);
if (nhg == NULL)
return (NULL);
nhgrp_set_uidx(nhg, uidx);
nhg = nhgrp_get_nhgrp(nhg, perror);
if (nhg != NULL)
return (NHGRP_PRIV(nhg));
return (NULL);
}
/*
* Appends one or more nexthops denoted by @wm to the nexthop group @gr_orig.
*
* Returns referenced nexthop group or NULL. In the latter case, @perror is
* filled with an error code.
* Note that function does NOT care if the next nexthops already exists
* in the @gr_orig. As a result, they will be added, resulting in the
* same nexthop being present multiple times in the new group.
*/
static struct nhgrp_priv *
append_nhops(struct nh_control *ctl, const struct nhgrp_object *gr_orig,
struct weightened_nhop *wn, int num_nhops, int *perror)
{
char storage[64];
struct weightened_nhop *pnhops;
struct nhgrp_priv *nhg_priv;
const struct nhgrp_priv *src_priv;
size_t sz;
int curr_nhops;
src_priv = NHGRP_PRIV_CONST(gr_orig);
curr_nhops = src_priv->nhg_nh_count;
*perror = 0;
sz = (src_priv->nhg_nh_count + num_nhops) * (sizeof(struct weightened_nhop));
/* optimize for <= 4 paths, each path=16 bytes */
if (sz <= sizeof(storage))
pnhops = (struct weightened_nhop *)&storage[0];
else {
pnhops = malloc(sz, M_TEMP, M_NOWAIT);
if (pnhops == NULL) {
*perror = ENOMEM;
return (NULL);
}
}
/* Copy nhops from original group first */
memcpy(pnhops, src_priv->nhg_nh_weights,
curr_nhops * sizeof(struct weightened_nhop));
memcpy(&pnhops[curr_nhops], wn, num_nhops * sizeof(struct weightened_nhop));
curr_nhops += num_nhops;
nhg_priv = get_nhgrp(ctl, pnhops, curr_nhops, 0, perror);
if (pnhops != (struct weightened_nhop *)&storage[0])
free(pnhops, M_TEMP);
if (nhg_priv == NULL)
return (NULL);
return (nhg_priv);
}
/*
* Creates/finds nexthop group based on @wn and @num_nhops.
* Returns 0 on success with referenced group in @rnd, or
* errno.
*
* If the error is EAGAIN, then the operation can be retried.
*/
int
nhgrp_get_group(struct rib_head *rh, struct weightened_nhop *wn, int num_nhops,
uint32_t uidx, struct nhgrp_object **pnhg)
{
struct nh_control *ctl = rh->nh_control;
struct nhgrp_priv *nhg_priv;
int error;
nhg_priv = get_nhgrp(ctl, wn, num_nhops, uidx, &error);
if (nhg_priv != NULL)
*pnhg = nhg_priv->nhg;
return (error);
}
/*
* Creates new nexthop group based on @src group without the nexthops
* chosen by @flt_func.
* Returns 0 on success, storring the reference nhop group/object in @rnd.
*/
int
nhgrp_get_filtered_group(struct rib_head *rh, const struct rtentry *rt,
const struct nhgrp_object *src, rib_filter_f_t flt_func, void *flt_data,
struct route_nhop_data *rnd)
{
char storage[64];
struct nh_control *ctl = rh->nh_control;
struct weightened_nhop *pnhops;
const struct nhgrp_priv *mp_priv, *src_priv;
size_t sz;
int error, i, num_nhops;
src_priv = NHGRP_PRIV_CONST(src);
sz = src_priv->nhg_nh_count * (sizeof(struct weightened_nhop));
/* optimize for <= 4 paths, each path=16 bytes */
if (sz <= sizeof(storage))
pnhops = (struct weightened_nhop *)&storage[0];
else {
if ((pnhops = malloc(sz, M_TEMP, M_NOWAIT)) == NULL)
return (ENOMEM);
}
/* Filter nexthops */
error = 0;
num_nhops = 0;
for (i = 0; i < src_priv->nhg_nh_count; i++) {
if (flt_func(rt, src_priv->nhg_nh_weights[i].nh, flt_data))
continue;
memcpy(&pnhops[num_nhops++], &src_priv->nhg_nh_weights[i],
sizeof(struct weightened_nhop));
}
if (num_nhops == 0) {
rnd->rnd_nhgrp = NULL;
rnd->rnd_weight = 0;
} else if (num_nhops == 1) {
rnd->rnd_nhop = pnhops[0].nh;
rnd->rnd_weight = pnhops[0].weight;
if (nhop_try_ref_object(rnd->rnd_nhop) == 0)
error = EAGAIN;
} else {
mp_priv = get_nhgrp(ctl, pnhops, num_nhops, 0, &error);
if (mp_priv != NULL)
rnd->rnd_nhgrp = mp_priv->nhg;
rnd->rnd_weight = 0;
}
if (pnhops != (struct weightened_nhop *)&storage[0])
free(pnhops, M_TEMP);
return (error);
}
/*
* Creates new multipath group based on existing group/nhop in @rnd_orig and
* to-be-added nhop @wn_add.
* Returns 0 on success and stores result in @rnd_new.
*/
int
nhgrp_get_addition_group(struct rib_head *rh, struct route_nhop_data *rnd_orig,
struct route_nhop_data *rnd_add, struct route_nhop_data *rnd_new)
{
struct nh_control *ctl = rh->nh_control;
struct nhgrp_priv *nhg_priv;
struct weightened_nhop wn[2] = {};
int error;
if (rnd_orig->rnd_nhop == NULL) {
/* No paths to add to, just reference current nhop */
*rnd_new = *rnd_add;
if (nhop_try_ref_object(rnd_new->rnd_nhop) == 0)
return (EAGAIN);
return (0);
}
wn[0].nh = rnd_add->rnd_nhop;
wn[0].weight = rnd_add->rnd_weight;
if (!NH_IS_NHGRP(rnd_orig->rnd_nhop)) {
/* Simple merge of 2 non-multipath nexthops */
wn[1].nh = rnd_orig->rnd_nhop;
wn[1].weight = rnd_orig->rnd_weight;
nhg_priv = get_nhgrp(ctl, wn, 2, 0, &error);
} else {
/* Get new nhop group with @rt->rt_nhop as an additional nhop */
nhg_priv = append_nhops(ctl, rnd_orig->rnd_nhgrp, &wn[0], 1,
&error);
}
if (nhg_priv == NULL)
return (error);
rnd_new->rnd_nhgrp = nhg_priv->nhg;
rnd_new->rnd_weight = 0;
return (0);
}
/*
* Returns pointer to array of nexthops with weights for
* given @nhg. Stores number of items in the array into @pnum_nhops.
*/
const struct weightened_nhop *
nhgrp_get_nhops(const struct nhgrp_object *nhg, uint32_t *pnum_nhops)
{
const struct nhgrp_priv *nhg_priv;
KASSERT(((nhg->nhg_flags & MPF_MULTIPATH) != 0), ("nhop is not mpath"));
nhg_priv = NHGRP_PRIV_CONST(nhg);
*pnum_nhops = nhg_priv->nhg_nh_count;
return (nhg_priv->nhg_nh_weights);
}
void
nhgrp_set_uidx(struct nhgrp_object *nhg, uint32_t uidx)
{
struct nhgrp_priv *nhg_priv;
KASSERT(((nhg->nhg_flags & MPF_MULTIPATH) != 0), ("nhop is not mpath"));
nhg_priv = NHGRP_PRIV(nhg);
nhg_priv->nhg_uidx = uidx;
}
uint32_t
nhgrp_get_uidx(const struct nhgrp_object *nhg)
{
const struct nhgrp_priv *nhg_priv;
KASSERT(((nhg->nhg_flags & MPF_MULTIPATH) != 0), ("nhop is not mpath"));
nhg_priv = NHGRP_PRIV_CONST(nhg);
return (nhg_priv->nhg_uidx);
}
/*
* Prints nexhop group @nhg data in the provided @buf.
* Example: nhg#33/sz=3:[#1:100,#2:100,#3:100]
* Example: nhg#33/sz=5:[#1:100,#2:100,..]
*/
char *
nhgrp_print_buf(const struct nhgrp_object *nhg, char *buf, size_t bufsize)
{
const struct nhgrp_priv *nhg_priv = NHGRP_PRIV_CONST(nhg);
int off = snprintf(buf, bufsize, "nhg#%u/sz=%u:[", nhg_priv->nhg_idx,
nhg_priv->nhg_nh_count);
for (int i = 0; i < nhg_priv->nhg_nh_count; i++) {
const struct weightened_nhop *wn = &nhg_priv->nhg_nh_weights[i];
int len = snprintf(&buf[off], bufsize - off, "#%u:%u,",
wn->nh->nh_priv->nh_idx, wn->weight);
if (len + off + 3 >= bufsize) {
int len = snprintf(&buf[off], bufsize - off, "...");
off += len;
break;
}
off += len;
}
if (off > 0)
off--; // remove last ","
if (off + 1 < bufsize)
snprintf(&buf[off], bufsize - off, "]");
return buf;
}
__noinline static int
dump_nhgrp_entry(struct rib_head *rh, const struct nhgrp_priv *nhg_priv,
char *buffer, size_t buffer_size, struct sysctl_req *w)
{
struct rt_msghdr *rtm;
struct nhgrp_external *nhge;
struct nhgrp_container *nhgc;
const struct nhgrp_object *nhg;
struct nhgrp_nhop_external *ext;
int error;
size_t sz;
nhg = nhg_priv->nhg;
sz = sizeof(struct rt_msghdr) + sizeof(struct nhgrp_external);
/* controlplane nexthops */
sz += sizeof(struct nhgrp_container);
sz += sizeof(struct nhgrp_nhop_external) * nhg_priv->nhg_nh_count;
/* dataplane nexthops */
sz += sizeof(struct nhgrp_container);
sz += sizeof(struct nhgrp_nhop_external) * nhg->nhg_size;
KASSERT(sz <= buffer_size, ("increase nhgrp buffer size"));
bzero(buffer, sz);
rtm = (struct rt_msghdr *)buffer;
rtm->rtm_msglen = sz;
rtm->rtm_version = RTM_VERSION;
rtm->rtm_type = RTM_GET;
nhge = (struct nhgrp_external *)(rtm + 1);
nhge->nhg_idx = nhg_priv->nhg_idx;
nhge->nhg_refcount = nhg_priv->nhg_refcount;
/* fill in control plane nexthops firs */
nhgc = (struct nhgrp_container *)(nhge + 1);
nhgc->nhgc_type = NHG_C_TYPE_CNHOPS;
nhgc->nhgc_subtype = 0;
nhgc->nhgc_len = sizeof(struct nhgrp_container);
nhgc->nhgc_len += sizeof(struct nhgrp_nhop_external) * nhg_priv->nhg_nh_count;
nhgc->nhgc_count = nhg_priv->nhg_nh_count;
ext = (struct nhgrp_nhop_external *)(nhgc + 1);
for (int i = 0; i < nhg_priv->nhg_nh_count; i++) {
ext[i].nh_idx = nhg_priv->nhg_nh_weights[i].nh->nh_priv->nh_idx;
ext[i].nh_weight = nhg_priv->nhg_nh_weights[i].weight;
}
/* fill in dataplane nexthops */
nhgc = (struct nhgrp_container *)(&ext[nhg_priv->nhg_nh_count]);
nhgc->nhgc_type = NHG_C_TYPE_DNHOPS;
nhgc->nhgc_subtype = 0;
nhgc->nhgc_len = sizeof(struct nhgrp_container);
nhgc->nhgc_len += sizeof(struct nhgrp_nhop_external) * nhg->nhg_size;
nhgc->nhgc_count = nhg->nhg_size;
ext = (struct nhgrp_nhop_external *)(nhgc + 1);
for (int i = 0; i < nhg->nhg_size; i++) {
ext[i].nh_idx = nhg->nhops[i]->nh_priv->nh_idx;
ext[i].nh_weight = 0;
}
error = SYSCTL_OUT(w, buffer, sz);
return (error);
}
uint32_t
nhgrp_get_idx(const struct nhgrp_object *nhg)
{
const struct nhgrp_priv *nhg_priv;
nhg_priv = NHGRP_PRIV_CONST(nhg);
return (nhg_priv->nhg_idx);
}
uint8_t
nhgrp_get_origin(const struct nhgrp_object *nhg)
{
return (NHGRP_PRIV_CONST(nhg)->nhg_origin);
}
void
nhgrp_set_origin(struct nhgrp_object *nhg, uint8_t origin)
{
NHGRP_PRIV(nhg)->nhg_origin = origin;
}
uint32_t
nhgrp_get_count(struct rib_head *rh)
{
struct nh_control *ctl;
uint32_t count;
ctl = rh->nh_control;
NHOPS_RLOCK(ctl);
count = ctl->gr_head.items_count;
NHOPS_RUNLOCK(ctl);
return (count);
}
int
nhgrp_dump_sysctl(struct rib_head *rh, struct sysctl_req *w)
{
struct nh_control *ctl = rh->nh_control;
struct epoch_tracker et;
struct nhgrp_priv *nhg_priv;
char *buffer;
size_t sz;
int error = 0;
if (ctl->gr_head.items_count == 0)
return (0);
/* Calculate the maximum nhop group size in bytes */
sz = sizeof(struct rt_msghdr) + sizeof(struct nhgrp_external);
sz += 2 * sizeof(struct nhgrp_container);
sz += 2 * sizeof(struct nhgrp_nhop_external) * RIB_MAX_MPATH_WIDTH;
buffer = malloc(sz, M_TEMP, M_NOWAIT);
if (buffer == NULL)
return (ENOMEM);
NET_EPOCH_ENTER(et);
NHOPS_RLOCK(ctl);
CHT_SLIST_FOREACH(&ctl->gr_head, mpath, nhg_priv) {
error = dump_nhgrp_entry(rh, nhg_priv, buffer, sz, w);
if (error != 0)
break;
} CHT_SLIST_FOREACH_END;
NHOPS_RUNLOCK(ctl);
NET_EPOCH_EXIT(et);
free(buffer, M_TEMP);
return (error);
}
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