/*-
* 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 <sys/cdefs.h>
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_route.h"
#include <sys/param.h>
#include <sys/eventhandler.h>
#include <sys/kernel.h>
#include <sys/sbuf.h>
#include <sys/lock.h>
#include <sys/rmlock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/kernel.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/queue.h>
#include <net/vnet.h>
#include <net/if.h>
#include <net/if_var.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#ifdef INET6
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#endif
#include <net/route.h>
#include <net/route/nhop.h>
#include <net/route/route_ctl.h>
#include <net/route/route_var.h>
#include <net/route/fib_algo.h>
#include <machine/stdarg.h>
/*
* Fib lookup framework.
*
* This framework enables accelerated longest-prefix-match lookups for the
* routing tables by adding the ability to dynamically attach/detach lookup
* algorithms implementation to/from the datapath.
*
* flm - fib lookup modules - implementation of particular lookup algorithm
* fd - fib data - instance of an flm bound to specific routing table
*
* This file provides main framework functionality.
*
* The following are the features provided by the framework
*
* 1) nexhops abstraction -> provides transparent referencing, indexing
* and efficient idx->ptr mappings for nexthop and nexthop groups.
* 2) Routing table synchronisation
* 3) dataplane attachment points
* 4) automatic algorithm selection based on the provided preference.
*
*
* DATAPATH
* For each supported address family, there is a an allocated array of fib_dp
* structures, indexed by fib number. Each array entry contains callback function
* and its argument. This function will be called with a family-specific lookup key,
* scope and provided argument. This array gets re-created every time when new algo
* instance gets created. Please take a look at the replace_rtables_family() function
* for more details.
*
*/
SYSCTL_DECL(_net_route);
SYSCTL_NODE(_net_route, OID_AUTO, algo, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Fib algorithm lookups");
/* Algorithm sync policy */
/* Time interval to bucket updates */
VNET_DEFINE_STATIC(unsigned int, update_bucket_time_ms) = 50;
#define V_update_bucket_time_ms VNET(update_bucket_time_ms)
SYSCTL_UINT(_net_route_algo, OID_AUTO, bucket_time_ms, CTLFLAG_RW | CTLFLAG_VNET,
&VNET_NAME(update_bucket_time_ms), 0, "Time interval to calculate update rate");
/* Minimum update rate to delay sync */
VNET_DEFINE_STATIC(unsigned int, bucket_change_threshold_rate) = 500;
#define V_bucket_change_threshold_rate VNET(bucket_change_threshold_rate)
SYSCTL_UINT(_net_route_algo, OID_AUTO, bucket_change_threshold_rate, CTLFLAG_RW | CTLFLAG_VNET,
&VNET_NAME(bucket_change_threshold_rate), 0, "Minimum update rate to delay sync");
/* Max allowed delay to sync */
VNET_DEFINE_STATIC(unsigned int, fib_max_sync_delay_ms) = 1000;
#define V_fib_max_sync_delay_ms VNET(fib_max_sync_delay_ms)
SYSCTL_UINT(_net_route_algo, OID_AUTO, fib_max_sync_delay_ms, CTLFLAG_RW | CTLFLAG_VNET,
&VNET_NAME(fib_max_sync_delay_ms), 0, "Maximum time to delay sync (ms)");
#ifdef INET6
VNET_DEFINE_STATIC(bool, algo_fixed_inet6) = false;
#define V_algo_fixed_inet6 VNET(algo_fixed_inet6)
SYSCTL_NODE(_net_route_algo, OID_AUTO, inet6, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"IPv6 longest prefix match lookups");
#endif
#ifdef INET
VNET_DEFINE_STATIC(bool, algo_fixed_inet) = false;
#define V_algo_fixed_inet VNET(algo_fixed_inet)
SYSCTL_NODE(_net_route_algo, OID_AUTO, inet, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"IPv4 longest prefix match lookups");
#endif
/* Fib instance counter */
static uint32_t fib_gen = 0;
struct nhop_ref_table {
uint32_t count;
int32_t refcnt[0];
};
enum fib_callout_action {
FDA_NONE, /* No callout scheduled */
FDA_REBUILD, /* Asks to rebuild algo instance */
FDA_EVAL, /* Asks to evaluate if the current algo is still be best */
FDA_BATCH, /* Asks to submit batch of updates to the algo */
};
struct fib_sync_status {
struct timeval diverge_time; /* ts when diverged */
uint32_t num_changes; /* number of changes since sync */
uint32_t bucket_changes; /* num changes within the current bucket */
uint64_t bucket_id; /* 50ms bucket # */
struct fib_change_queue fd_change_queue;/* list of scheduled entries */
};
/*
* Data structure for the fib lookup instance tied to the particular rib.
*/
struct fib_data {
uint32_t number_nhops; /* current # of nhops */
uint8_t hit_nhops; /* true if out of nhop limit */
uint8_t init_done; /* true if init is competed */
uint32_t fd_dead:1; /* Scheduled for deletion */
uint32_t fd_linked:1; /* true if linked */
uint32_t fd_need_rebuild:1; /* true if rebuild scheduled */
uint32_t fd_batch:1; /* true if batched notification scheduled */
uint8_t fd_family; /* family */
uint32_t fd_fibnum; /* fibnum */
uint32_t fd_failed_rebuilds; /* stat: failed rebuilds */
uint32_t fd_gen; /* instance gen# */
struct callout fd_callout; /* rebuild callout */
enum fib_callout_action fd_callout_action; /* Callout action to take */
void *fd_algo_data; /* algorithm data */
struct nhop_object **nh_idx; /* nhop idx->ptr array */
struct nhop_ref_table *nh_ref_table; /* array with # of nhop references */
struct rib_head *fd_rh; /* RIB table we're attached to */
struct rib_subscription *fd_rs; /* storing table subscription */
struct fib_dp fd_dp; /* fib datapath data */
struct vnet *fd_vnet; /* vnet fib belongs to */
struct epoch_context fd_epoch_ctx; /* epoch context for deletion */
struct fib_lookup_module *fd_flm;/* pointer to the lookup module */
struct fib_sync_status fd_ss; /* State relevant to the rib sync */
uint32_t fd_num_changes; /* number of changes since last callout */
TAILQ_ENTRY(fib_data) entries; /* list of all fds in vnet */
};
static bool rebuild_fd(struct fib_data *fd, const char *reason);
static bool rebuild_fd_flm(struct fib_data *fd, struct fib_lookup_module *flm_new);
static void handle_fd_callout(void *_data);
static void destroy_fd_instance_epoch(epoch_context_t ctx);
static bool is_idx_free(struct fib_data *fd, uint32_t index);
static void set_algo_fixed(struct rib_head *rh);
static bool is_algo_fixed(struct rib_head *rh);
static uint32_t fib_ref_nhop(struct fib_data *fd, struct nhop_object *nh);
static void fib_unref_nhop(struct fib_data *fd, struct nhop_object *nh);
static struct fib_lookup_module *fib_check_best_algo(struct rib_head *rh,
struct fib_lookup_module *orig_flm);
static void fib_unref_algo(struct fib_lookup_module *flm);
static bool flm_error_check(const struct fib_lookup_module *flm, uint32_t fibnum);
struct mtx fib_mtx;
#define FIB_MOD_LOCK() mtx_lock(&fib_mtx)
#define FIB_MOD_UNLOCK() mtx_unlock(&fib_mtx)
#define FIB_MOD_LOCK_ASSERT() mtx_assert(&fib_mtx, MA_OWNED)
MTX_SYSINIT(fib_mtx, &fib_mtx, "algo list mutex", MTX_DEF);
/* Algorithm has to be this percent better than the current to switch */
#define BEST_DIFF_PERCENT (5 * 256 / 100)
/* Schedule algo re-evaluation X seconds after a change */
#define ALGO_EVAL_DELAY_MS 30000
/* Force algo re-evaluation after X changes */
#define ALGO_EVAL_NUM_ROUTES 100
/* Try to setup algorithm X times */
#define FIB_MAX_TRIES 32
/* Max amount of supported nexthops */
#define FIB_MAX_NHOPS 262144
#define FIB_CALLOUT_DELAY_MS 50
/* Debug */
static int flm_debug_level = LOG_NOTICE;
SYSCTL_INT(_net_route_algo, OID_AUTO, debug_level, CTLFLAG_RW | CTLFLAG_RWTUN,
&flm_debug_level, 0, "debuglevel");
#define FLM_MAX_DEBUG_LEVEL LOG_DEBUG
#ifndef LOG_DEBUG2
#define LOG_DEBUG2 8
#endif
#define _PASS_MSG(_l) (flm_debug_level >= (_l))
#define ALGO_PRINTF(_l, _fmt, ...) if (_PASS_MSG(_l)) { \
printf("[fib_algo] %s: " _fmt "\n", __func__, ##__VA_ARGS__); \
}
#define _ALGO_PRINTF(_fib, _fam, _aname, _gen, _func, _fmt, ...) \
printf("[fib_algo] %s.%u (%s#%u) %s: " _fmt "\n",\
print_family(_fam), _fib, _aname, _gen, _func, ## __VA_ARGS__)
#define _RH_PRINTF(_fib, _fam, _func, _fmt, ...) \
printf("[fib_algo] %s.%u %s: " _fmt "\n", print_family(_fam), _fib, _func, ## __VA_ARGS__)
#define RH_PRINTF(_l, _rh, _fmt, ...) if (_PASS_MSG(_l)) { \
_RH_PRINTF(_rh->rib_fibnum, _rh->rib_family, __func__, _fmt, ## __VA_ARGS__);\
}
#define FD_PRINTF(_l, _fd, _fmt, ...) FD_PRINTF_##_l(_l, _fd, _fmt, ## __VA_ARGS__)
#define _FD_PRINTF(_l, _fd, _fmt, ...) if (_PASS_MSG(_l)) { \
_ALGO_PRINTF(_fd->fd_fibnum, _fd->fd_family, _fd->fd_flm->flm_name, \
_fd->fd_gen, __func__, _fmt, ## __VA_ARGS__); \
}
#if FLM_MAX_DEBUG_LEVEL>=LOG_DEBUG2
#define FD_PRINTF_LOG_DEBUG2 _FD_PRINTF
#else
#define FD_PRINTF_LOG_DEBUG2(_l, _fd, _fmt, ...)
#endif
#if FLM_MAX_DEBUG_LEVEL>=LOG_DEBUG
#define FD_PRINTF_LOG_DEBUG _FD_PRINTF
#else
#define FD_PRINTF_LOG_DEBUG()
#endif
#if FLM_MAX_DEBUG_LEVEL>=LOG_INFO
#define FD_PRINTF_LOG_INFO _FD_PRINTF
#else
#define FD_PRINTF_LOG_INFO()
#endif
#define FD_PRINTF_LOG_NOTICE _FD_PRINTF
#define FD_PRINTF_LOG_ERR _FD_PRINTF
#define FD_PRINTF_LOG_WARNING _FD_PRINTF
/* List of all registered lookup algorithms */
static TAILQ_HEAD(, fib_lookup_module) all_algo_list = TAILQ_HEAD_INITIALIZER(all_algo_list);
/* List of all fib lookup instances in the vnet */
VNET_DEFINE_STATIC(TAILQ_HEAD(fib_data_head, fib_data), fib_data_list);
#define V_fib_data_list VNET(fib_data_list)
/* Datastructure for storing non-transient fib lookup module failures */
struct fib_error {
int fe_family;
uint32_t fe_fibnum; /* failed rtable */
struct fib_lookup_module *fe_flm; /* failed module */
TAILQ_ENTRY(fib_error) entries;/* list of all errored entries */
};
VNET_DEFINE_STATIC(TAILQ_HEAD(fib_error_head, fib_error), fib_error_list);
#define V_fib_error_list VNET(fib_error_list)
/* Per-family array of fibnum -> {func, arg} mappings used in datapath */
struct fib_dp_header {
struct epoch_context fdh_epoch_ctx;
uint32_t fdh_num_tables;
struct fib_dp fdh_idx[0];
};
/*
* Tries to add new non-transient algorithm error to the list of
* errors.
* Returns true on success.
*/
static bool
flm_error_add(struct fib_lookup_module *flm, uint32_t fibnum)
{
struct fib_error *fe;
fe = malloc(sizeof(struct fib_error), M_TEMP, M_NOWAIT | M_ZERO);
if (fe == NULL)
return (false);
fe->fe_flm = flm;
fe->fe_family = flm->flm_family;
fe->fe_fibnum = fibnum;
FIB_MOD_LOCK();
/* Avoid duplicates by checking if error already exists first */
if (flm_error_check(flm, fibnum)) {
FIB_MOD_UNLOCK();
free(fe, M_TEMP);
return (true);
}
TAILQ_INSERT_HEAD(&V_fib_error_list, fe, entries);
FIB_MOD_UNLOCK();
return (true);
}
/*
* True if non-transient error has been registered for @flm in @fibnum.
*/
static bool
flm_error_check(const struct fib_lookup_module *flm, uint32_t fibnum)
{
const struct fib_error *fe;
TAILQ_FOREACH(fe, &V_fib_error_list, entries) {
if ((fe->fe_flm == flm) && (fe->fe_fibnum == fibnum))
return (true);
}
return (false);
}
/*
* Clear all errors of algo specified by @flm.
*/
static void
fib_error_clear_flm(struct fib_lookup_module *flm)
{
struct fib_error *fe, *fe_tmp;
FIB_MOD_LOCK_ASSERT();
TAILQ_FOREACH_SAFE(fe, &V_fib_error_list, entries, fe_tmp) {
if (fe->fe_flm == flm) {
TAILQ_REMOVE(&V_fib_error_list, fe, entries);
free(fe, M_TEMP);
}
}
}
/*
* Clears all errors in current VNET.
*/
static void
fib_error_clear(void)
{
struct fib_error *fe, *fe_tmp;
FIB_MOD_LOCK_ASSERT();
TAILQ_FOREACH_SAFE(fe, &V_fib_error_list, entries, fe_tmp) {
TAILQ_REMOVE(&V_fib_error_list, fe, entries);
free(fe, M_TEMP);
}
}
static const char *
print_op_result(enum flm_op_result result)
{
switch (result) {
case FLM_SUCCESS:
return "success";
case FLM_REBUILD:
return "rebuild";
case FLM_BATCH:
return "batch";
case FLM_ERROR:
return "error";
}
return "unknown";
}
static const char *
print_family(int family)
{
if (family == AF_INET)
return ("inet");
else if (family == AF_INET6)
return ("inet6");
else
return ("unknown");
}
/*
* Debug function used by lookup algorithms.
* Outputs message denoted by @fmt, prepended by "[fib_algo] inetX.Y (algo) "
*/
void
fib_printf(int level, struct fib_data *fd, const char *func, char *fmt, ...)
{
char buf[128];
va_list ap;
if (level > flm_debug_level)
return;
va_start(ap, fmt);
vsnprintf(buf, sizeof(buf), fmt, ap);
va_end(ap);
_ALGO_PRINTF(fd->fd_fibnum, fd->fd_family, fd->fd_flm->flm_name,
fd->fd_gen, func, "%s", buf);
}
/*
* Outputs list of algorithms supported by the provided address family.
*/
static int
print_algos_sysctl(struct sysctl_req *req, int family)
{
struct fib_lookup_module *flm;
struct sbuf sbuf;
int error, count = 0;
error = sysctl_wire_old_buffer(req, 0);
if (error == 0) {
sbuf_new_for_sysctl(&sbuf, NULL, 512, req);
TAILQ_FOREACH(flm, &all_algo_list, entries) {
if (flm->flm_family == family) {
if (count++ > 0)
sbuf_cat(&sbuf, ", ");
sbuf_cat(&sbuf, flm->flm_name);
}
}
error = sbuf_finish(&sbuf);
sbuf_delete(&sbuf);
}
return (error);
}
#ifdef INET6
static int
print_algos_sysctl_inet6(SYSCTL_HANDLER_ARGS)
{
return (print_algos_sysctl(req, AF_INET6));
}
SYSCTL_PROC(_net_route_algo_inet6, OID_AUTO, algo_list,
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
print_algos_sysctl_inet6, "A", "List of IPv6 lookup algorithms");
#endif
#ifdef INET
static int
print_algos_sysctl_inet(SYSCTL_HANDLER_ARGS)
{
return (print_algos_sysctl(req, AF_INET));
}
SYSCTL_PROC(_net_route_algo_inet, OID_AUTO, algo_list,
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
print_algos_sysctl_inet, "A", "List of IPv4 lookup algorithms");
#endif
/*
* Calculate delay between repeated failures.
* Returns current delay in milliseconds.
*/
static uint32_t
callout_calc_delay_ms(struct fib_data *fd)
{
uint32_t shift;
if (fd->fd_failed_rebuilds > 10)
shift = 10;
else
shift = fd->fd_failed_rebuilds;
return ((1 << shift) * FIB_CALLOUT_DELAY_MS);
}
static void
schedule_callout(struct fib_data *fd, enum fib_callout_action action, int delay_ms)
{
FD_PRINTF(LOG_DEBUG, fd, "delay=%d action=%d", delay_ms, action);
fd->fd_callout_action = action;
callout_reset_sbt(&fd->fd_callout, SBT_1MS * delay_ms, 0,
handle_fd_callout, fd, 0);
}
static void
schedule_fd_rebuild(struct fib_data *fd, const char *reason)
{
RIB_WLOCK_ASSERT(fd->fd_rh);
if (!fd->fd_need_rebuild) {
fd->fd_need_rebuild = true;
/* Stop batch updates */
fd->fd_batch = false;
/*
* Potentially re-schedules pending callout
* initiated by schedule_algo_eval.
*/
FD_PRINTF(LOG_INFO, fd, "Scheduling rebuild: %s (failures=%d)",
reason, fd->fd_failed_rebuilds);
schedule_callout(fd, FDA_REBUILD, callout_calc_delay_ms(fd));
}
}
static void
sync_rib_gen(struct fib_data *fd)
{
FD_PRINTF(LOG_DEBUG, fd, "Sync gen %u -> %u", fd->fd_rh->rnh_gen, fd->fd_rh->rnh_gen_rib);
fd->fd_rh->rnh_gen = fd->fd_rh->rnh_gen_rib;
}
static int64_t
get_tv_diff_ms(const struct timeval *old_tv, const struct timeval *new_tv)
{
int64_t diff = 0;
diff = ((int64_t)(new_tv->tv_sec - old_tv->tv_sec)) * 1000;
diff += (new_tv->tv_usec - old_tv->tv_usec) / 1000;
return (diff);
}
static void
add_tv_diff_ms(struct timeval *tv, int ms)
{
tv->tv_sec += ms / 1000;
ms = ms % 1000;
if (ms * 1000 + tv->tv_usec < 1000000)
tv->tv_usec += ms * 1000;
else {
tv->tv_sec += 1;
tv->tv_usec = ms * 1000 + tv->tv_usec - 1000000;
}
}
/*
* Marks the time when algo state diverges from the rib state.
*/
static void
mark_diverge_time(struct fib_data *fd)
{
struct fib_sync_status *fd_ss = &fd->fd_ss;
getmicrouptime(&fd_ss->diverge_time);
fd_ss->bucket_id = 0;
fd_ss->bucket_changes = 0;
}
/*
* Calculates and updates the next algorithm sync time, based on the current activity.
*
* The intent is to provide reasonable balance between the update
* latency and efficient batching when changing large amount of routes.
*
* High-level algorithm looks the following:
* 1) all changes are bucketed in 50ms intervals
* 2) If amount of changes within the bucket is greater than the threshold,
* the update gets delayed, up to maximum delay threshold.
*/
static void
update_rebuild_delay(struct fib_data *fd, enum fib_callout_action action)
{
uint32_t bucket_id, new_delay = 0;
struct timeval tv;
/* Fetch all variables at once to ensure consistent reads */
uint32_t bucket_time_ms = V_update_bucket_time_ms;
uint32_t threshold_rate = V_bucket_change_threshold_rate;
uint32_t max_delay_ms = V_fib_max_sync_delay_ms;
if (bucket_time_ms == 0)
bucket_time_ms = 50;
/* calculate per-bucket threshold rate */
threshold_rate = threshold_rate * bucket_time_ms / 1000;
getmicrouptime(&tv);
struct fib_sync_status *fd_ss = &fd->fd_ss;
bucket_id = get_tv_diff_ms(&fd_ss->diverge_time, &tv) / bucket_time_ms;
if (fd_ss->bucket_id == bucket_id) {
fd_ss->bucket_changes++;
if (fd_ss->bucket_changes == threshold_rate) {
new_delay = (bucket_id + 2) * bucket_time_ms;
if (new_delay <= max_delay_ms) {
FD_PRINTF(LOG_DEBUG, fd,
"hit threshold of %u routes, delay update,"
"bucket: %u, total delay: %u",
threshold_rate, bucket_id + 1, new_delay);
} else {
new_delay = 0;
FD_PRINTF(LOG_DEBUG, fd,
"maximum sync delay (%u ms) reached", max_delay_ms);
}
} else if ((bucket_id == 0) && (fd_ss->bucket_changes == 1))
new_delay = bucket_time_ms;
} else {
fd_ss->bucket_id = bucket_id;
fd_ss->bucket_changes = 1;
}
if (new_delay > 0) {
/* Calculated time has been updated */
struct timeval new_tv = fd_ss->diverge_time;
add_tv_diff_ms(&new_tv, new_delay);
int32_t delay_ms = get_tv_diff_ms(&tv, &new_tv);
schedule_callout(fd, action, delay_ms);
}
}
static void
update_algo_state(struct fib_data *fd)
{
RIB_WLOCK_ASSERT(fd->fd_rh);
if (fd->fd_batch || fd->fd_need_rebuild) {
enum fib_callout_action action = fd->fd_need_rebuild ? FDA_REBUILD : FDA_BATCH;
update_rebuild_delay(fd, action);
return;
}
if (fd->fd_num_changes++ == 0) {
/* Start callout to consider switch */
if (!callout_pending(&fd->fd_callout))
schedule_callout(fd, FDA_EVAL, ALGO_EVAL_DELAY_MS);
} else if (fd->fd_num_changes == ALGO_EVAL_NUM_ROUTES) {
/* Reset callout to exec immediately */
if (fd->fd_callout_action == FDA_EVAL)
schedule_callout(fd, FDA_EVAL, 1);
}
}
static bool
need_immediate_sync(struct fib_data *fd, struct rib_cmd_info *rc)
{
struct nhop_object *nh;
/* Sync addition/removal of interface routes */
switch (rc->rc_cmd) {
case RTM_ADD:
nh = rc->rc_nh_new;
if (!NH_IS_NHGRP(nh)) {
if (!(nh->nh_flags & NHF_GATEWAY))
return (true);
if (nhop_get_rtflags(nh) & RTF_STATIC)
return (true);
}
break;
case RTM_DELETE:
nh = rc->rc_nh_old;
if (!NH_IS_NHGRP(nh)) {
if (!(nh->nh_flags & NHF_GATEWAY))
return (true);
if (nhop_get_rtflags(nh) & RTF_STATIC)
return (true);
}
break;
}
return (false);
}
static bool
apply_rtable_changes(struct fib_data *fd)
{
enum flm_op_result result;
struct fib_change_queue *q = &fd->fd_ss.fd_change_queue;
result = fd->fd_flm->flm_change_rib_items_cb(fd->fd_rh, q, fd->fd_algo_data);
if (result == FLM_SUCCESS) {
sync_rib_gen(fd);
for (int i = 0; i < q->count; i++)
if (q->entries[i].nh_old)
fib_unref_nhop(fd, q->entries[i].nh_old);
q->count = 0;
}
fd->fd_batch = false;
return (result == FLM_SUCCESS);
}
static bool
fill_change_entry(struct fib_data *fd, struct fib_change_entry *ce, struct rib_cmd_info *rc)
{
int plen = 0;
switch (fd->fd_family) {
#ifdef INET
case AF_INET:
rt_get_inet_prefix_plen(rc->rc_rt, &ce->addr4, &plen, &ce->scopeid);
break;
#endif
#ifdef INET6
case AF_INET6:
rt_get_inet6_prefix_plen(rc->rc_rt, &ce->addr6, &plen, &ce->scopeid);
break;
#endif
}
ce->plen = plen;
ce->nh_old = rc->rc_nh_old;
ce->nh_new = rc->rc_nh_new;
if (ce->nh_new != NULL) {
if (fib_ref_nhop(fd, ce->nh_new) == 0)
return (false);
}
return (true);
}
static bool
queue_rtable_change(struct fib_data *fd, struct rib_cmd_info *rc)
{
struct fib_change_queue *q = &fd->fd_ss.fd_change_queue;
if (q->count >= q->size) {
uint32_t q_size;
if (q->size == 0)
q_size = 256; /* ~18k memory */
else
q_size = q->size * 2;
size_t size = q_size * sizeof(struct fib_change_entry);
void *a = realloc(q->entries, size, M_TEMP, M_NOWAIT | M_ZERO);
if (a == NULL) {
FD_PRINTF(LOG_INFO, fd, "Unable to realloc queue for %u elements",
q_size);
return (false);
}
q->entries = a;
q->size = q_size;
}
return (fill_change_entry(fd, &q->entries[q->count++], rc));
}
/*
* Rib subscription handler. Checks if the algorithm is ready to
* receive updates, handles nexthop refcounting and passes change
* data to the algorithm callback.
*/
static void
handle_rtable_change_cb(struct rib_head *rnh, struct rib_cmd_info *rc,
void *_data)
{
struct fib_data *fd = (struct fib_data *)_data;
enum flm_op_result result;
RIB_WLOCK_ASSERT(rnh);
/*
* There is a small gap between subscribing for route changes
* and initiating rtable dump. Avoid receiving route changes
* prior to finishing rtable dump by checking `init_done`.
*/
if (!fd->init_done)
return;
bool immediate_sync = need_immediate_sync(fd, rc);
/* Consider scheduling algorithm re-evaluation */
update_algo_state(fd);
/*
* If algo requested rebuild, stop sending updates by default.
* This simplifies nexthop refcount handling logic.
*/
if (fd->fd_need_rebuild) {
if (immediate_sync)
rebuild_fd(fd, "rtable change type enforced sync");
return;
}
/*
* Algo requested updates to be delivered in batches.
* Add the current change to the queue and return.
*/
if (fd->fd_batch) {
if (immediate_sync) {
if (!queue_rtable_change(fd, rc) || !apply_rtable_changes(fd))
rebuild_fd(fd, "batch sync failed");
} else {
if (!queue_rtable_change(fd, rc))
schedule_fd_rebuild(fd, "batch queue failed");
}
return;
}
/*
* Maintain guarantee that every nexthop returned by the dataplane
* lookup has > 0 refcount, so can be safely referenced within current
* epoch.
*/
if (rc->rc_nh_new != NULL) {
if (fib_ref_nhop(fd, rc->rc_nh_new) == 0) {
/* ran out of indexes */
schedule_fd_rebuild(fd, "ran out of nhop indexes");
return;
}
}
result = fd->fd_flm->flm_change_rib_item_cb(rnh, rc, fd->fd_algo_data);
switch (result) {
case FLM_SUCCESS:
sync_rib_gen(fd);
/* Unref old nexthop on success */
if (rc->rc_nh_old != NULL)
fib_unref_nhop(fd, rc->rc_nh_old);
break;
case FLM_BATCH:
/*
* Algo asks to batch the changes.
*/
if (queue_rtable_change(fd, rc)) {
if (!immediate_sync) {
fd->fd_batch = true;
mark_diverge_time(fd);
update_rebuild_delay(fd, FDA_BATCH);
break;
}
if (apply_rtable_changes(fd))
break;
}
FD_PRINTF(LOG_ERR, fd, "batched sync failed, force the rebuild");
case FLM_REBUILD:
/*
* Algo is not able to apply the update.
* Schedule algo rebuild.
*/
if (!immediate_sync) {
mark_diverge_time(fd);
schedule_fd_rebuild(fd, "algo requested rebuild");
break;
}
FD_PRINTF(LOG_INFO, fd, "running sync rebuild");
rebuild_fd(fd, "rtable change type enforced sync");
break;
case FLM_ERROR:
/*
* Algo reported a non-recoverable error.
* Record the error and schedule rebuild, which will
* trigger best algo selection.
*/
FD_PRINTF(LOG_ERR, fd, "algo reported non-recoverable error");
if (!flm_error_add(fd->fd_flm, fd->fd_fibnum))
FD_PRINTF(LOG_ERR, fd, "failed to ban algo");
schedule_fd_rebuild(fd, "algo reported non-recoverable error");
}
}
static void
estimate_nhop_scale(const struct fib_data *old_fd, struct fib_data *fd)
{
if (old_fd == NULL) {
// TODO: read from rtable
fd->number_nhops = 16;
return;
}
if (old_fd->hit_nhops && old_fd->number_nhops < FIB_MAX_NHOPS)
fd->number_nhops = 2 * old_fd->number_nhops;
else
fd->number_nhops = old_fd->number_nhops;
}
struct walk_cbdata {
struct fib_data *fd;
flm_dump_t *func;
enum flm_op_result result;
};
/*
* Handler called after all rtenties have been dumped.
* Performs post-dump framework checks and calls
* algo:flm_dump_end_cb().
*
* Updates walk_cbdata result.
*/
static void
sync_algo_end_cb(struct rib_head *rnh, enum rib_walk_hook stage, void *_data)
{
struct walk_cbdata *w = (struct walk_cbdata *)_data;
struct fib_data *fd = w->fd;
RIB_WLOCK_ASSERT(w->fd->fd_rh);
if (rnh->rib_dying) {
w->result = FLM_ERROR;
return;
}
if (fd->hit_nhops) {
FD_PRINTF(LOG_INFO, fd, "ran out of nexthops at %u nhops",
fd->nh_ref_table->count);
if (w->result == FLM_SUCCESS)
w->result = FLM_REBUILD;
return;
}
if (stage != RIB_WALK_HOOK_POST || w->result != FLM_SUCCESS)
return;
/* Post-dump hook, dump successful */
w->result = fd->fd_flm->flm_dump_end_cb(fd->fd_algo_data, &fd->fd_dp);
if (w->result == FLM_SUCCESS) {
/* Mark init as done to allow routing updates */
fd->init_done = 1;
}
}
/*
* Callback for each entry in rib.
* Calls algo:flm_dump_rib_item_cb func as a part of initial
* route table synchronisation.
*/
static int
sync_algo_cb(struct rtentry *rt, void *_data)
{
struct walk_cbdata *w = (struct walk_cbdata *)_data;
RIB_WLOCK_ASSERT(w->fd->fd_rh);
if (w->result == FLM_SUCCESS && w->func) {
/*
* Reference nexthops to maintain guarantee that
* each nexthop returned by datapath has > 0 references
* and can be safely referenced within current epoch.
*/
struct nhop_object *nh = rt_get_raw_nhop(rt);
if (fib_ref_nhop(w->fd, nh) != 0)
w->result = w->func(rt, w->fd->fd_algo_data);
else
w->result = FLM_REBUILD;
}
return (0);
}
/*
* Dump all routing table state to the algo instance.
*/
static enum flm_op_result
sync_algo(struct fib_data *fd)
{
struct walk_cbdata w = {
.fd = fd,
.func = fd->fd_flm->flm_dump_rib_item_cb,
.result = FLM_SUCCESS,
};
rib_walk_ext_locked(fd->fd_rh, sync_algo_cb, sync_algo_end_cb, &w);
FD_PRINTF(LOG_INFO, fd,
"initial dump completed (rtable version: %d), result: %s",
fd->fd_rh->rnh_gen, print_op_result(w.result));
return (w.result);
}
/*
* Schedules epoch-backed @fd instance deletion.
* * Unlinks @fd from the list of active algo instances.
* * Removes rib subscription.
* * Stops callout.
* * Schedules actual deletion.
*
* Assume @fd is already unlinked from the datapath.
*/
static int
schedule_destroy_fd_instance(struct fib_data *fd, bool in_callout)
{
bool is_dead;
NET_EPOCH_ASSERT();
RIB_WLOCK_ASSERT(fd->fd_rh);
FIB_MOD_LOCK();
is_dead = fd->fd_dead;
if (!is_dead)
fd->fd_dead = true;
if (fd->fd_linked) {
TAILQ_REMOVE(&V_fib_data_list, fd, entries);
fd->fd_linked = false;
}
FIB_MOD_UNLOCK();
if (is_dead)
return (0);
FD_PRINTF(LOG_INFO, fd, "DETACH");
if (fd->fd_rs != NULL)
rib_unsubscribe_locked(fd->fd_rs);
/*
* After rib_unsubscribe() no _new_ handle_rtable_change_cb() calls
* will be executed, hence no _new_ callout schedules will happen.
*/
callout_stop(&fd->fd_callout);
fib_epoch_call(destroy_fd_instance_epoch, &fd->fd_epoch_ctx);
return (0);
}
/*
* Wipe all fd instances from the list matching rib specified by @rh.
* If @keep_first is set, remove all but the first record.
*/
static void
fib_cleanup_algo(struct rib_head *rh, bool keep_first, bool in_callout)
{
struct fib_data_head tmp_head = TAILQ_HEAD_INITIALIZER(tmp_head);
struct fib_data *fd, *fd_tmp;
struct epoch_tracker et;
FIB_MOD_LOCK();
TAILQ_FOREACH_SAFE(fd, &V_fib_data_list, entries, fd_tmp) {
if (fd->fd_rh == rh) {
if (keep_first) {
keep_first = false;
continue;
}
TAILQ_REMOVE(&V_fib_data_list, fd, entries);
fd->fd_linked = false;
TAILQ_INSERT_TAIL(&tmp_head, fd, entries);
}
}
FIB_MOD_UNLOCK();
/* Pass 2: remove each entry */
NET_EPOCH_ENTER(et);
TAILQ_FOREACH_SAFE(fd, &tmp_head, entries, fd_tmp) {
if (!in_callout)
RIB_WLOCK(fd->fd_rh);
schedule_destroy_fd_instance(fd, in_callout);
if (!in_callout)
RIB_WUNLOCK(fd->fd_rh);
}
NET_EPOCH_EXIT(et);
}
void
fib_destroy_rib(struct rib_head *rh)
{
/*
* rnh has `is_dying` flag set, so setup of new fd's will fail at
* sync_algo() stage, preventing new entries to be added to the list
* of active algos. Remove all existing entries for the particular rib.
*/
fib_cleanup_algo(rh, false, false);
}
/*
* Finalises fd destruction by freeing all fd resources.
*/
static void
destroy_fd_instance(struct fib_data *fd)
{
FD_PRINTF(LOG_INFO, fd, "destroy fd %p", fd);
/* Call destroy callback first */
if (fd->fd_algo_data != NULL)
fd->fd_flm->flm_destroy_cb(fd->fd_algo_data);
/* Nhop table */
if ((fd->nh_idx != NULL) && (fd->nh_ref_table != NULL)) {
for (int i = 0; i < fd->number_nhops; i++) {
if (!is_idx_free(fd, i)) {
FD_PRINTF(LOG_DEBUG2, fd, " FREE nhop %d %p",
i, fd->nh_idx[i]);
nhop_free_any(fd->nh_idx[i]);
}
}
free(fd->nh_idx, M_RTABLE);
}
if (fd->nh_ref_table != NULL)
free(fd->nh_ref_table, M_RTABLE);
if (fd->fd_ss.fd_change_queue.entries != NULL)
free(fd->fd_ss.fd_change_queue.entries, M_TEMP);
fib_unref_algo(fd->fd_flm);
free(fd, M_RTABLE);
}
/*
* Epoch callback indicating fd is safe to destroy
*/
static void
destroy_fd_instance_epoch(epoch_context_t ctx)
{
struct fib_data *fd;
fd = __containerof(ctx, struct fib_data, fd_epoch_ctx);
CURVNET_SET(fd->fd_vnet);
destroy_fd_instance(fd);
CURVNET_RESTORE();
}
/*
* Tries to setup fd instance.
* - Allocates fd/nhop table
* - Runs algo:flm_init_cb algo init
* - Subscribes fd to the rib
* - Runs rtable dump
* - Adds instance to the list of active instances.
*
* Returns: operation result. Fills in @pfd with resulting fd on success.
*
*/
static enum flm_op_result
try_setup_fd_instance(struct fib_lookup_module *flm, struct rib_head *rh,
struct fib_data *old_fd, struct fib_data **pfd)
{
struct fib_data *fd;
size_t size;
enum flm_op_result result;
/* Allocate */
fd = malloc(sizeof(struct fib_data), M_RTABLE, M_NOWAIT | M_ZERO);
if (fd == NULL) {
*pfd = NULL;
RH_PRINTF(LOG_INFO, rh, "Unable to allocate fib_data structure");
return (FLM_REBUILD);
}
*pfd = fd;
estimate_nhop_scale(old_fd, fd);
fd->fd_rh = rh;
fd->fd_family = rh->rib_family;
fd->fd_fibnum = rh->rib_fibnum;
callout_init_rm(&fd->fd_callout, &rh->rib_lock, 0);
fd->fd_vnet = curvnet;
fd->fd_flm = flm;
FIB_MOD_LOCK();
flm->flm_refcount++;
fd->fd_gen = ++fib_gen;
FIB_MOD_UNLOCK();
FD_PRINTF(LOG_DEBUG, fd, "allocated fd %p", fd);
/* Allocate nhidx -> nhop_ptr table */
size = fd->number_nhops * sizeof(void *);
fd->nh_idx = malloc(size, M_RTABLE, M_NOWAIT | M_ZERO);
if (fd->nh_idx == NULL) {
FD_PRINTF(LOG_INFO, fd, "Unable to allocate nhop table idx (sz:%zu)", size);
return (FLM_REBUILD);
}
/* Allocate nhop index refcount table */
size = sizeof(struct nhop_ref_table);
size += fd->number_nhops * sizeof(uint32_t);
fd->nh_ref_table = malloc(size, M_RTABLE, M_NOWAIT | M_ZERO);
if (fd->nh_ref_table == NULL) {
FD_PRINTF(LOG_INFO, fd, "Unable to allocate nhop refcount table (sz:%zu)", size);
return (FLM_REBUILD);
}
FD_PRINTF(LOG_DEBUG, fd, "Allocated %u nhop indexes", fd->number_nhops);
/* Okay, we're ready for algo init */
void *old_algo_data = (old_fd != NULL) ? old_fd->fd_algo_data : NULL;
result = flm->flm_init_cb(fd->fd_fibnum, fd, old_algo_data, &fd->fd_algo_data);
if (result != FLM_SUCCESS) {
FD_PRINTF(LOG_INFO, fd, "%s algo init failed", flm->flm_name);
return (result);
}
/* Try to subscribe */
if (flm->flm_change_rib_item_cb != NULL) {
fd->fd_rs = rib_subscribe_locked(fd->fd_rh,
handle_rtable_change_cb, fd, RIB_NOTIFY_IMMEDIATE);
if (fd->fd_rs == NULL) {
FD_PRINTF(LOG_INFO, fd, "failed to subscribe to the rib changes");
return (FLM_REBUILD);
}
}
/* Dump */
result = sync_algo(fd);
if (result != FLM_SUCCESS) {
FD_PRINTF(LOG_INFO, fd, "rib sync failed");
return (result);
}
FD_PRINTF(LOG_INFO, fd, "DUMP completed successfully.");
FIB_MOD_LOCK();
/*
* Insert fd in the beginning of a list, to maintain invariant
* that first matching entry for the AF/fib is always the active
* one.
*/
TAILQ_INSERT_HEAD(&V_fib_data_list, fd, entries);
fd->fd_linked = true;
FIB_MOD_UNLOCK();
return (FLM_SUCCESS);
}
/*
* Sets up algo @flm for table @rh and links it to the datapath.
*
*/
static enum flm_op_result
setup_fd_instance(struct fib_lookup_module *flm, struct rib_head *rh,
struct fib_data *orig_fd, struct fib_data **pfd, bool attach)
{
struct fib_data *prev_fd, *new_fd;
enum flm_op_result result;
NET_EPOCH_ASSERT();
RIB_WLOCK_ASSERT(rh);
prev_fd = orig_fd;
new_fd = NULL;
for (int i = 0; i < FIB_MAX_TRIES; i++) {
result = try_setup_fd_instance(flm, rh, prev_fd, &new_fd);
if ((result == FLM_SUCCESS) && attach) {
if (fib_set_datapath_ptr(new_fd, &new_fd->fd_dp))
sync_rib_gen(new_fd);
else
result = FLM_REBUILD;
}
if ((prev_fd != NULL) && (prev_fd != orig_fd)) {
schedule_destroy_fd_instance(prev_fd, false);
prev_fd = NULL;
}
RH_PRINTF(LOG_INFO, rh, "try %d: fib algo result: %s", i,
print_op_result(result));
if (result == FLM_REBUILD) {
prev_fd = new_fd;
new_fd = NULL;
continue;
}
break;
}
if (result != FLM_SUCCESS) {
RH_PRINTF(LOG_WARNING, rh,
"%s algo instance setup failed, failures=%d", flm->flm_name,
orig_fd ? orig_fd->fd_failed_rebuilds + 1 : 0);
/* update failure count */
FIB_MOD_LOCK();
if (orig_fd != NULL)
orig_fd->fd_failed_rebuilds++;
FIB_MOD_UNLOCK();
/* Ban algo on non-recoverable error */
if (result == FLM_ERROR)
flm_error_add(flm, rh->rib_fibnum);
if ((prev_fd != NULL) && (prev_fd != orig_fd))
schedule_destroy_fd_instance(prev_fd, false);
if (new_fd != NULL) {
schedule_destroy_fd_instance(new_fd, false);
new_fd = NULL;
}
}
*pfd = new_fd;
return (result);
}
/*
* Tries to sync algo with the current rtable state, either
* by executing batch update or rebuilding.
* Returns true on success.
*/
static bool
execute_callout_action(struct fib_data *fd)
{
enum fib_callout_action action = fd->fd_callout_action;
struct fib_lookup_module *flm_new = NULL;
bool result = true;
NET_EPOCH_ASSERT();
RIB_WLOCK_ASSERT(fd->fd_rh);
fd->fd_need_rebuild = false;
fd->fd_batch = false;
fd->fd_num_changes = 0;
/* First, check if we're still OK to use this algo */
if (!is_algo_fixed(fd->fd_rh))
flm_new = fib_check_best_algo(fd->fd_rh, fd->fd_flm);
if (flm_new != NULL)
action = FDA_REBUILD;
if (action == FDA_BATCH) {
/* Try to sync */
if (!apply_rtable_changes(fd))
action = FDA_REBUILD;
}
if (action == FDA_REBUILD)
result = rebuild_fd_flm(fd, flm_new != NULL ? flm_new : fd->fd_flm);
if (flm_new != NULL)
fib_unref_algo(flm_new);
return (result);
}
/*
* Callout for all scheduled fd-related work.
* - Checks if the current algo is still the best algo
* - Synchronises algo instance to the rtable (batch usecase)
* - Creates a new instance of an algo for af/fib if desired.
*/
static void
handle_fd_callout(void *_data)
{
struct fib_data *fd = (struct fib_data *)_data;
struct epoch_tracker et;
FD_PRINTF(LOG_INFO, fd, "running callout type=%d", fd->fd_callout_action);
NET_EPOCH_ENTER(et);
CURVNET_SET(fd->fd_vnet);
execute_callout_action(fd);
CURVNET_RESTORE();
NET_EPOCH_EXIT(et);
}
/*
* Tries to create new algo instance based on @fd data.
* Returns true on success.
*/
static bool
rebuild_fd_flm(struct fib_data *fd, struct fib_lookup_module *flm_new)
{
struct fib_data *fd_new, *fd_tmp = NULL;
bool result;
if (flm_new == fd->fd_flm)
fd_tmp = fd;
else
FD_PRINTF(LOG_NOTICE, fd, "switching algo to %s", flm_new->flm_name);
result = setup_fd_instance(flm_new, fd->fd_rh, fd_tmp, &fd_new, true);
if (result != FLM_SUCCESS) {
FD_PRINTF(LOG_NOTICE, fd, "table rebuild failed");
return (false);
}
FD_PRINTF(LOG_INFO, fd_new, "switched to new instance");
/* Remove old instance */
schedule_destroy_fd_instance(fd, true);
return (true);
}
static bool
rebuild_fd(struct fib_data *fd, const char *reason)
{
struct fib_lookup_module *flm_new = NULL;
bool result;
if (!is_algo_fixed(fd->fd_rh))
flm_new = fib_check_best_algo(fd->fd_rh, fd->fd_flm);
FD_PRINTF(LOG_INFO, fd, "running sync rebuild: %s", reason);
result = rebuild_fd_flm(fd, flm_new != NULL ? flm_new : fd->fd_flm);
if (flm_new != NULL)
fib_unref_algo(flm_new);
if (!result) {
FD_PRINTF(LOG_ERR, fd, "sync rebuild failed");
schedule_fd_rebuild(fd, "sync rebuild failed");
}
return (result);
}
/*
* Finds algo by name/family.
* Returns referenced algo or NULL.
*/
static struct fib_lookup_module *
fib_find_algo(const char *algo_name, int family)
{
struct fib_lookup_module *flm;
FIB_MOD_LOCK();
TAILQ_FOREACH(flm, &all_algo_list, entries) {
if ((strcmp(flm->flm_name, algo_name) == 0) &&
(family == flm->flm_family)) {
flm->flm_refcount++;
FIB_MOD_UNLOCK();
return (flm);
}
}
FIB_MOD_UNLOCK();
return (NULL);
}
static void
fib_unref_algo(struct fib_lookup_module *flm)
{
FIB_MOD_LOCK();
flm->flm_refcount--;
FIB_MOD_UNLOCK();
}
static int
set_fib_algo(uint32_t fibnum, int family, struct sysctl_oid *oidp, struct sysctl_req *req)
{
struct fib_lookup_module *flm = NULL;
struct fib_data *fd = NULL;
char old_algo_name[32], algo_name[32];
struct rib_head *rh = NULL;
enum flm_op_result result;
struct epoch_tracker et;
int error;
/* Fetch current algo/rib for af/family */
FIB_MOD_LOCK();
TAILQ_FOREACH(fd, &V_fib_data_list, entries) {
if ((fd->fd_family == family) && (fd->fd_fibnum == fibnum))
break;
}
if (fd == NULL) {
FIB_MOD_UNLOCK();
return (ENOENT);
}
rh = fd->fd_rh;
strlcpy(old_algo_name, fd->fd_flm->flm_name,
sizeof(old_algo_name));
FIB_MOD_UNLOCK();
strlcpy(algo_name, old_algo_name, sizeof(algo_name));
error = sysctl_handle_string(oidp, algo_name, sizeof(algo_name), req);
if (error != 0 || req->newptr == NULL)
return (error);
if (strcmp(algo_name, old_algo_name) == 0)
return (0);
/* New algorithm name is different */
flm = fib_find_algo(algo_name, family);
if (flm == NULL) {
RH_PRINTF(LOG_INFO, rh, "unable to find algo %s", algo_name);
return (ESRCH);
}
fd = NULL;
NET_EPOCH_ENTER(et);
RIB_WLOCK(rh);
result = setup_fd_instance(flm, rh, NULL, &fd, true);
RIB_WUNLOCK(rh);
NET_EPOCH_EXIT(et);
fib_unref_algo(flm);
if (result != FLM_SUCCESS)
return (EINVAL);
/* Disable automated jumping between algos */
FIB_MOD_LOCK();
set_algo_fixed(rh);
FIB_MOD_UNLOCK();
/* Remove old instance(s) */
fib_cleanup_algo(rh, true, false);
/* Drain cb so user can unload the module after userret if so desired */
NET_EPOCH_DRAIN_CALLBACKS();
return (0);
}
#ifdef INET
static int
set_algo_inet_sysctl_handler(SYSCTL_HANDLER_ARGS)
{
return (set_fib_algo(curthread->td_proc->p_fibnum, AF_INET, oidp, req));
}
SYSCTL_PROC(_net_route_algo_inet, OID_AUTO, algo,
CTLFLAG_VNET | CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_MPSAFE, NULL, 0,
set_algo_inet_sysctl_handler, "A", "Set IPv4 lookup algo");
#endif
#ifdef INET6
static int
set_algo_inet6_sysctl_handler(SYSCTL_HANDLER_ARGS)
{
return (set_fib_algo(curthread->td_proc->p_fibnum, AF_INET6, oidp, req));
}
SYSCTL_PROC(_net_route_algo_inet6, OID_AUTO, algo,
CTLFLAG_VNET | CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_MPSAFE, NULL, 0,
set_algo_inet6_sysctl_handler, "A", "Set IPv6 lookup algo");
#endif
static struct nhop_object *
dummy_lookup(void *algo_data, const struct flm_lookup_key key, uint32_t scopeid)
{
return (NULL);
}
static void
destroy_fdh_epoch(epoch_context_t ctx)
{
struct fib_dp_header *fdh;
fdh = __containerof(ctx, struct fib_dp_header, fdh_epoch_ctx);
free(fdh, M_RTABLE);
}
static struct fib_dp_header *
alloc_fib_dp_array(uint32_t num_tables, bool waitok)
{
size_t sz;
struct fib_dp_header *fdh;
sz = sizeof(struct fib_dp_header);
sz += sizeof(struct fib_dp) * num_tables;
fdh = malloc(sz, M_RTABLE, (waitok ? M_WAITOK : M_NOWAIT) | M_ZERO);
if (fdh != NULL) {
fdh->fdh_num_tables = num_tables;
/*
* Set dummy lookup function ptr always returning NULL, so
* we can delay algo init.
*/
for (uint32_t i = 0; i < num_tables; i++)
fdh->fdh_idx[i].f = dummy_lookup;
}
return (fdh);
}
static struct fib_dp_header *
get_fib_dp_header(struct fib_dp *dp)
{
return (__containerof((void *)dp, struct fib_dp_header, fdh_idx));
}
/*
* Replace per-family index pool @pdp with a new one which
* contains updated callback/algo data from @fd.
* Returns true on success.
*/
static bool
replace_rtables_family(struct fib_dp **pdp, struct fib_data *fd, struct fib_dp *dp)
{
struct fib_dp_header *new_fdh, *old_fdh;
NET_EPOCH_ASSERT();
FD_PRINTF(LOG_DEBUG, fd, "[vnet %p] replace with f:%p arg:%p",
curvnet, dp->f, dp->arg);
FIB_MOD_LOCK();
old_fdh = get_fib_dp_header(*pdp);
if (old_fdh->fdh_idx[fd->fd_fibnum].f == dp->f) {
/*
* Function is the same, data pointer needs update.
* Perform in-line replace without reallocation.
*/
old_fdh->fdh_idx[fd->fd_fibnum].arg = dp->arg;
FD_PRINTF(LOG_DEBUG, fd, "FDH %p inline update", old_fdh);
FIB_MOD_UNLOCK();
return (true);
}
new_fdh = alloc_fib_dp_array(old_fdh->fdh_num_tables, false);
FD_PRINTF(LOG_DEBUG, fd, "OLD FDH: %p NEW FDH: %p", old_fdh, new_fdh);
if (new_fdh == NULL) {
FIB_MOD_UNLOCK();
FD_PRINTF(LOG_WARNING, fd, "error attaching datapath");
return (false);
}
memcpy(&new_fdh->fdh_idx[0], &old_fdh->fdh_idx[0],
old_fdh->fdh_num_tables * sizeof(struct fib_dp));
/* Update relevant data structure for @fd */
new_fdh->fdh_idx[fd->fd_fibnum] = *dp;
/* Ensure memcpy() writes have completed */
atomic_thread_fence_rel();
/* Set new datapath pointer */
*pdp = &new_fdh->fdh_idx[0];
FIB_MOD_UNLOCK();
FD_PRINTF(LOG_DEBUG, fd, "update %p -> %p", old_fdh, new_fdh);
fib_epoch_call(destroy_fdh_epoch, &old_fdh->fdh_epoch_ctx);
return (true);
}
static struct fib_dp **
get_family_dp_ptr(int family)
{
switch (family) {
#ifdef INET
case AF_INET:
return (&V_inet_dp);
#endif
#ifdef INET6
case AF_INET6:
return (&V_inet6_dp);
#endif
}
return (NULL);
}
/*
* Make datapath use fib instance @fd
*/
bool
fib_set_datapath_ptr(struct fib_data *fd, struct fib_dp *dp)
{
struct fib_dp **pdp;
pdp = get_family_dp_ptr(fd->fd_family);
return (replace_rtables_family(pdp, fd, dp));
}
/*
* Grow datapath pointers array.
* Called from sysctl handler on growing number of routing tables.
*/
static void
grow_rtables_family(struct fib_dp **pdp, uint32_t new_num_tables)
{
struct fib_dp_header *new_fdh, *old_fdh = NULL;
new_fdh = alloc_fib_dp_array(new_num_tables, true);
FIB_MOD_LOCK();
if (*pdp != NULL) {
old_fdh = get_fib_dp_header(*pdp);
memcpy(&new_fdh->fdh_idx[0], &old_fdh->fdh_idx[0],
old_fdh->fdh_num_tables * sizeof(struct fib_dp));
}
/* Wait till all writes completed */
atomic_thread_fence_rel();
*pdp = &new_fdh->fdh_idx[0];
FIB_MOD_UNLOCK();
if (old_fdh != NULL)
fib_epoch_call(destroy_fdh_epoch, &old_fdh->fdh_epoch_ctx);
}
/*
* Grows per-AF arrays of datapath pointers for each supported family.
* Called from fibs resize sysctl handler.
*/
void
fib_grow_rtables(uint32_t new_num_tables)
{
#ifdef INET
grow_rtables_family(get_family_dp_ptr(AF_INET), new_num_tables);
#endif
#ifdef INET6
grow_rtables_family(get_family_dp_ptr(AF_INET6), new_num_tables);
#endif
}
void
fib_get_rtable_info(struct rib_head *rh, struct rib_rtable_info *rinfo)
{
bzero(rinfo, sizeof(struct rib_rtable_info));
rinfo->num_prefixes = rh->rnh_prefixes;
rinfo->num_nhops = nhops_get_count(rh);
#ifdef ROUTE_MPATH
rinfo->num_nhgrp = nhgrp_get_count(rh);
#endif
}
/*
* Updates pointer to the algo data for the @fd.
*/
void
fib_set_algo_ptr(struct fib_data *fd, void *algo_data)
{
RIB_WLOCK_ASSERT(fd->fd_rh);
fd->fd_algo_data = algo_data;
}
/*
* Calls @callback with @ctx after the end of a current epoch.
*/
void
fib_epoch_call(epoch_callback_t callback, epoch_context_t ctx)
{
NET_EPOCH_CALL(callback, ctx);
}
/*
* Accessor to get rib instance @fd is attached to.
*/
struct rib_head *
fib_get_rh(struct fib_data *fd)
{
return (fd->fd_rh);
}
/*
* Accessor to export idx->nhop array
*/
struct nhop_object **
fib_get_nhop_array(struct fib_data *fd)
{
return (fd->nh_idx);
}
static uint32_t
get_nhop_idx(struct nhop_object *nh)
{
#ifdef ROUTE_MPATH
if (NH_IS_NHGRP(nh))
return (nhgrp_get_idx((struct nhgrp_object *)nh));
else
#endif
return (nhop_get_idx(nh));
}
uint32_t
fib_get_nhop_idx(struct fib_data *fd, struct nhop_object *nh)
{
return (get_nhop_idx(nh));
}
static bool
is_idx_free(struct fib_data *fd, uint32_t index)
{
return (fd->nh_ref_table->refcnt[index] == 0);
}
static uint32_t
fib_ref_nhop(struct fib_data *fd, struct nhop_object *nh)
{
uint32_t idx = get_nhop_idx(nh);
if (idx >= fd->number_nhops) {
fd->hit_nhops = 1;
return (0);
}
if (is_idx_free(fd, idx)) {
nhop_ref_any(nh);
fd->nh_idx[idx] = nh;
fd->nh_ref_table->count++;
FD_PRINTF(LOG_DEBUG2, fd, " REF nhop %u %p", idx, fd->nh_idx[idx]);
}
fd->nh_ref_table->refcnt[idx]++;
return (idx);
}
struct nhop_release_data {
struct nhop_object *nh;
struct epoch_context ctx;
};
static void
release_nhop_epoch(epoch_context_t ctx)
{
struct nhop_release_data *nrd;
nrd = __containerof(ctx, struct nhop_release_data, ctx);
nhop_free_any(nrd->nh);
free(nrd, M_TEMP);
}
/*
* Delays nexthop refcount release.
* Datapath may have the datastructures not updated yet, so the old
* nexthop may still be returned till the end of current epoch. Delay
* refcount removal, as we may be removing the last instance, which will
* trigger nexthop deletion, rendering returned nexthop invalid.
*/
static void
fib_schedule_release_nhop(struct fib_data *fd, struct nhop_object *nh)
{
struct nhop_release_data *nrd;
nrd = malloc(sizeof(struct nhop_release_data), M_TEMP, M_NOWAIT | M_ZERO);
if (nrd != NULL) {
nrd->nh = nh;
fib_epoch_call(release_nhop_epoch, &nrd->ctx);
} else {
/*
* Unable to allocate memory. Leak nexthop to maintain guarantee
* that each nhop can be referenced.
*/
FD_PRINTF(LOG_ERR, fd, "unable to schedule nhop %p deletion", nh);
}
}
static void
fib_unref_nhop(struct fib_data *fd, struct nhop_object *nh)
{
uint32_t idx = get_nhop_idx(nh);
KASSERT((idx < fd->number_nhops), ("invalid nhop index"));
KASSERT((nh == fd->nh_idx[idx]), ("index table contains whong nh"));
fd->nh_ref_table->refcnt[idx]--;
if (fd->nh_ref_table->refcnt[idx] == 0) {
FD_PRINTF(LOG_DEBUG, fd, " FREE nhop %d %p", idx, fd->nh_idx[idx]);
fib_schedule_release_nhop(fd, fd->nh_idx[idx]);
}
}
static void
set_algo_fixed(struct rib_head *rh)
{
switch (rh->rib_family) {
#ifdef INET
case AF_INET:
V_algo_fixed_inet = true;
break;
#endif
#ifdef INET6
case AF_INET6:
V_algo_fixed_inet6 = true;
break;
#endif
}
}
static bool
is_algo_fixed(struct rib_head *rh)
{
switch (rh->rib_family) {
#ifdef INET
case AF_INET:
return (V_algo_fixed_inet);
#endif
#ifdef INET6
case AF_INET6:
return (V_algo_fixed_inet6);
#endif
}
return (false);
}
/*
* Runs the check on what would be the best algo for rib @rh, assuming
* that the current algo is the one specified by @orig_flm. Note that
* it can be NULL for initial selection.
*
* Returns referenced new algo or NULL if the current one is the best.
*/
static struct fib_lookup_module *
fib_check_best_algo(struct rib_head *rh, struct fib_lookup_module *orig_flm)
{
uint8_t preference, curr_preference = 0, best_preference = 0;
struct fib_lookup_module *flm, *best_flm = NULL;
struct rib_rtable_info rinfo;
int candidate_algos = 0;
fib_get_rtable_info(rh, &rinfo);
FIB_MOD_LOCK();
TAILQ_FOREACH(flm, &all_algo_list, entries) {
if (flm->flm_family != rh->rib_family)
continue;
candidate_algos++;
preference = flm->flm_get_pref(&rinfo);
if (preference > best_preference) {
if (!flm_error_check(flm, rh->rib_fibnum)) {
best_preference = preference;
best_flm = flm;
}
}
if (flm == orig_flm)
curr_preference = preference;
}
if ((best_flm != NULL) && (curr_preference + BEST_DIFF_PERCENT < best_preference))
best_flm->flm_refcount++;
else
best_flm = NULL;
FIB_MOD_UNLOCK();
RH_PRINTF(LOG_DEBUG, rh, "candidate_algos: %d, curr: %s(%d) result: %s(%d)",
candidate_algos, orig_flm ? orig_flm->flm_name : "NULL", curr_preference,
best_flm ? best_flm->flm_name : (orig_flm ? orig_flm->flm_name : "NULL"),
best_preference);
return (best_flm);
}
/*
* Called when new route table is created.
* Selects, allocates and attaches fib algo for the table.
*/
static bool
fib_select_algo_initial(struct rib_head *rh, struct fib_dp *dp)
{
struct fib_lookup_module *flm;
struct fib_data *fd = NULL;
enum flm_op_result result;
struct epoch_tracker et;
flm = fib_check_best_algo(rh, NULL);
if (flm == NULL) {
RH_PRINTF(LOG_CRIT, rh, "no algo selected");
return (false);
}
RH_PRINTF(LOG_INFO, rh, "selected algo %s", flm->flm_name);
NET_EPOCH_ENTER(et);
RIB_WLOCK(rh);
result = setup_fd_instance(flm, rh, NULL, &fd, false);
RIB_WUNLOCK(rh);
NET_EPOCH_EXIT(et);
RH_PRINTF(LOG_DEBUG, rh, "result=%d fd=%p", result, fd);
if (result == FLM_SUCCESS)
*dp = fd->fd_dp;
else
RH_PRINTF(LOG_CRIT, rh, "unable to setup algo %s", flm->flm_name);
fib_unref_algo(flm);
return (result == FLM_SUCCESS);
}
/*
* Sets up fib algo instances for the non-initialized RIBs in the @family.
* Allocates temporary datapath index to amortize datapaint index updates
* with large @num_tables.
*/
void
fib_setup_family(int family, uint32_t num_tables)
{
struct fib_dp_header *new_fdh = alloc_fib_dp_array(num_tables, false);
if (new_fdh == NULL) {
ALGO_PRINTF(LOG_CRIT, "Unable to setup framework for %s", print_family(family));
return;
}
for (int i = 0; i < num_tables; i++) {
struct rib_head *rh = rt_tables_get_rnh(i, family);
if (rh->rib_algo_init)
continue;
if (!fib_select_algo_initial(rh, &new_fdh->fdh_idx[i]))
continue;
rh->rib_algo_init = true;
}
FIB_MOD_LOCK();
struct fib_dp **pdp = get_family_dp_ptr(family);
struct fib_dp_header *old_fdh = get_fib_dp_header(*pdp);
/* Update the items not touched by the new init, from the old data pointer */
for (int i = 0; i < num_tables; i++) {
if (new_fdh->fdh_idx[i].f == dummy_lookup)
new_fdh->fdh_idx[i] = old_fdh->fdh_idx[i];
}
/* Ensure all index writes have completed */
atomic_thread_fence_rel();
/* Set new datapath pointer */
*pdp = &new_fdh->fdh_idx[0];
FIB_MOD_UNLOCK();
fib_epoch_call(destroy_fdh_epoch, &old_fdh->fdh_epoch_ctx);
}
/*
* Registers fib lookup module within the subsystem.
*/
int
fib_module_register(struct fib_lookup_module *flm)
{
FIB_MOD_LOCK();
ALGO_PRINTF(LOG_INFO, "attaching %s to %s", flm->flm_name,
print_family(flm->flm_family));
TAILQ_INSERT_TAIL(&all_algo_list, flm, entries);
FIB_MOD_UNLOCK();
return (0);
}
/*
* Tries to unregister fib lookup module.
*
* Returns 0 on success, EBUSY if module is still used
* by some of the tables.
*/
int
fib_module_unregister(struct fib_lookup_module *flm)
{
FIB_MOD_LOCK();
if (flm->flm_refcount > 0) {
FIB_MOD_UNLOCK();
return (EBUSY);
}
fib_error_clear_flm(flm);
ALGO_PRINTF(LOG_INFO, "detaching %s from %s", flm->flm_name,
print_family(flm->flm_family));
TAILQ_REMOVE(&all_algo_list, flm, entries);
FIB_MOD_UNLOCK();
return (0);
}
void
vnet_fib_init(void)
{
TAILQ_INIT(&V_fib_data_list);
}
void
vnet_fib_destroy(void)
{
FIB_MOD_LOCK();
fib_error_clear();
FIB_MOD_UNLOCK();
}
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