/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2022 Alexander V. Chernikov <melifaro@FreeBSD.org>
*
* 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/types.h>
#include <sys/ck.h>
#include <sys/epoch.h>
#include <sys/eventhandler.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/socket.h>
#include <sys/sx.h>
#include <netlink/netlink.h>
#include <netlink/netlink_ctl.h>
#include <netlink/netlink_generic.h>
#include <netlink/netlink_var.h>
#define DEBUG_MOD_NAME nl_generic_kpi
#define DEBUG_MAX_LEVEL LOG_DEBUG3
#include <netlink/netlink_debug.h>
_DECLARE_DEBUG(LOG_INFO);
/*
* NETLINK_GENERIC families/groups registration logic
*/
#define GENL_LOCK() sx_xlock(&sx_lock)
#define GENL_UNLOCK() sx_xunlock(&sx_lock)
static struct sx sx_lock;
SX_SYSINIT(genl_lock, &sx_lock, "genetlink lock");
static struct genl_family families[MAX_FAMILIES];
static struct genl_group groups[MAX_GROUPS];
static struct genl_family *
find_family(const char *family_name)
{
for (int i = 0; i < MAX_FAMILIES; i++) {
struct genl_family *gf = &families[i];
if (gf->family_name != NULL && !strcmp(gf->family_name, family_name))
return (gf);
}
return (NULL);
}
static struct genl_family *
find_empty_family_id(const char *family_name)
{
struct genl_family *gf = NULL;
if (!strcmp(family_name, CTRL_FAMILY_NAME)) {
gf = &families[0];
gf->family_id = GENL_MIN_ID;
} else {
/* Index 0 is reserved for the control family */
for (int i = 1; i < MAX_FAMILIES; i++) {
gf = &families[i];
if (gf->family_name == NULL) {
gf->family_id = GENL_MIN_ID + i;
break;
}
}
}
return (gf);
}
uint32_t
genl_register_family(const char *family_name, size_t hdrsize, int family_version,
int max_attr_idx)
{
uint32_t family_id = 0;
MPASS(family_name != NULL);
if (find_family(family_name) != NULL)
return (0);
GENL_LOCK();
struct genl_family *gf = find_empty_family_id(family_name);
MPASS(gf != NULL);
gf->family_name = family_name;
gf->family_version = family_version;
gf->family_hdrsize = hdrsize;
gf->family_attr_max = max_attr_idx;
NL_LOG(LOG_DEBUG2, "Registered family %s id %d", gf->family_name, gf->family_id);
family_id = gf->family_id;
EVENTHANDLER_INVOKE(genl_family_event, gf, CTRL_CMD_NEWFAMILY);
GENL_UNLOCK();
return (family_id);
}
static void
free_family(struct genl_family *gf)
{
if (gf->family_cmds != NULL)
free(gf->family_cmds, M_NETLINK);
}
/*
* unregister groups of a given family
*/
static void
unregister_groups(const struct genl_family *gf)
{
for (int i = 0; i < MAX_GROUPS; i++) {
struct genl_group *gg = &groups[i];
if (gg->group_family == gf && gg->group_name != NULL) {
gg->group_family = NULL;
gg->group_name = NULL;
}
}
}
/*
* Can sleep, I guess
*/
bool
genl_unregister_family(const char *family_name)
{
bool found = false;
GENL_LOCK();
struct genl_family *gf = find_family(family_name);
if (gf != NULL) {
EVENTHANDLER_INVOKE(genl_family_event, gf, CTRL_CMD_DELFAMILY);
found = true;
unregister_groups(gf);
/* TODO: zero pointer first */
free_family(gf);
bzero(gf, sizeof(*gf));
}
GENL_UNLOCK();
return (found);
}
bool
genl_register_cmds(const char *family_name, const struct genl_cmd *cmds, int count)
{
GENL_LOCK();
struct genl_family *gf = find_family(family_name);
if (gf == NULL) {
GENL_UNLOCK();
return (false);
}
int cmd_size = gf->family_cmd_size;
for (int i = 0; i < count; i++) {
MPASS(cmds[i].cmd_cb != NULL);
if (cmds[i].cmd_num >= cmd_size)
cmd_size = cmds[i].cmd_num + 1;
}
if (cmd_size > gf->family_cmd_size) {
/* need to realloc */
size_t sz = cmd_size * sizeof(struct genl_cmd);
void *data = malloc(sz, M_NETLINK, M_WAITOK | M_ZERO);
memcpy(data, gf->family_cmds, gf->family_cmd_size * sizeof(struct genl_cmd));
void *old_data = gf->family_cmds;
gf->family_cmds = data;
gf->family_cmd_size = cmd_size;
free(old_data, M_NETLINK);
}
for (int i = 0; i < count; i++) {
const struct genl_cmd *cmd = &cmds[i];
MPASS(gf->family_cmds[cmd->cmd_num].cmd_cb == NULL);
gf->family_cmds[cmd->cmd_num] = cmds[i];
NL_LOG(LOG_DEBUG2, "Adding cmd %s(%d) to family %s",
cmd->cmd_name, cmd->cmd_num, gf->family_name);
}
GENL_UNLOCK();
return (true);
}
static struct genl_group *
find_group(const struct genl_family *gf, const char *group_name)
{
for (int i = 0; i < MAX_GROUPS; i++) {
struct genl_group *gg = &groups[i];
if (gg->group_family == gf && !strcmp(gg->group_name, group_name))
return (gg);
}
return (NULL);
}
uint32_t
genl_register_group(const char *family_name, const char *group_name)
{
uint32_t group_id = 0;
MPASS(family_name != NULL);
MPASS(group_name != NULL);
GENL_LOCK();
struct genl_family *gf = find_family(family_name);
if (gf == NULL || find_group(gf, group_name) != NULL) {
GENL_UNLOCK();
return (0);
}
for (int i = 0; i < MAX_GROUPS; i++) {
struct genl_group *gg = &groups[i];
if (gg->group_family == NULL) {
gf->family_num_groups++;
gg->group_family = gf;
gg->group_name = group_name;
group_id = i + MIN_GROUP_NUM;
break;
}
}
GENL_UNLOCK();
return (group_id);
}
/* accessors */
struct genl_family *
genl_get_family(uint32_t family_id)
{
return ((family_id < MAX_FAMILIES) ? &families[family_id] : NULL);
}
const char *
genl_get_family_name(const struct genl_family *gf)
{
return (gf->family_name);
}
uint32_t
genl_get_family_id(const struct genl_family *gf)
{
return (gf->family_id);
}
struct genl_group *
genl_get_group(uint32_t group_id)
{
return ((group_id < MAX_GROUPS) ? &groups[group_id] : NULL);
}
