mirror_ubuntu-kernels/net/devlink/netlink.c

377 lines
9.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) 2016 Mellanox Technologies. All rights reserved.
* Copyright (c) 2016 Jiri Pirko <jiri@mellanox.com>
*/
#include <net/genetlink.h>
#include <net/sock.h>
#include "devl_internal.h"
#define DEVLINK_NL_FLAG_NEED_PORT BIT(0)
#define DEVLINK_NL_FLAG_NEED_DEVLINK_OR_PORT BIT(1)
#define DEVLINK_NL_FLAG_NEED_DEV_LOCK BIT(2)
static const struct genl_multicast_group devlink_nl_mcgrps[] = {
[DEVLINK_MCGRP_CONFIG] = { .name = DEVLINK_GENL_MCGRP_CONFIG_NAME },
};
struct devlink_nl_sock_priv {
struct devlink_obj_desc __rcu *flt;
spinlock_t flt_lock; /* Protects flt. */
};
static void devlink_nl_sock_priv_init(void *priv)
{
struct devlink_nl_sock_priv *sk_priv = priv;
spin_lock_init(&sk_priv->flt_lock);
}
static void devlink_nl_sock_priv_destroy(void *priv)
{
struct devlink_nl_sock_priv *sk_priv = priv;
struct devlink_obj_desc *flt;
flt = rcu_dereference_protected(sk_priv->flt, true);
kfree_rcu(flt, rcu);
}
int devlink_nl_notify_filter_set_doit(struct sk_buff *skb,
struct genl_info *info)
{
struct devlink_nl_sock_priv *sk_priv;
struct nlattr **attrs = info->attrs;
struct devlink_obj_desc *flt;
size_t data_offset = 0;
size_t data_size = 0;
char *pos;
if (attrs[DEVLINK_ATTR_BUS_NAME])
data_size = size_add(data_size,
nla_len(attrs[DEVLINK_ATTR_BUS_NAME]) + 1);
if (attrs[DEVLINK_ATTR_DEV_NAME])
data_size = size_add(data_size,
nla_len(attrs[DEVLINK_ATTR_DEV_NAME]) + 1);
flt = kzalloc(size_add(sizeof(*flt), data_size), GFP_KERNEL);
if (!flt)
return -ENOMEM;
pos = (char *) flt->data;
if (attrs[DEVLINK_ATTR_BUS_NAME]) {
data_offset += nla_strscpy(pos,
attrs[DEVLINK_ATTR_BUS_NAME],
data_size) + 1;
flt->bus_name = pos;
pos += data_offset;
}
if (attrs[DEVLINK_ATTR_DEV_NAME]) {
nla_strscpy(pos, attrs[DEVLINK_ATTR_DEV_NAME],
data_size - data_offset);
flt->dev_name = pos;
}
if (attrs[DEVLINK_ATTR_PORT_INDEX]) {
flt->port_index = nla_get_u32(attrs[DEVLINK_ATTR_PORT_INDEX]);
flt->port_index_valid = true;
}
/* Don't attach empty filter. */
if (!flt->bus_name && !flt->dev_name && !flt->port_index_valid) {
kfree(flt);
flt = NULL;
}
sk_priv = genl_sk_priv_get(&devlink_nl_family, NETLINK_CB(skb).sk);
if (IS_ERR(sk_priv)) {
kfree(flt);
return PTR_ERR(sk_priv);
}
spin_lock(&sk_priv->flt_lock);
flt = rcu_replace_pointer(sk_priv->flt, flt,
lockdep_is_held(&sk_priv->flt_lock));
spin_unlock(&sk_priv->flt_lock);
kfree_rcu(flt, rcu);
return 0;
}
static bool devlink_obj_desc_match(const struct devlink_obj_desc *desc,
const struct devlink_obj_desc *flt)
{
if (desc->bus_name && flt->bus_name &&
strcmp(desc->bus_name, flt->bus_name))
return false;
if (desc->dev_name && flt->dev_name &&
strcmp(desc->dev_name, flt->dev_name))
return false;
if (desc->port_index_valid && flt->port_index_valid &&
desc->port_index != flt->port_index)
return false;
return true;
}
int devlink_nl_notify_filter(struct sock *dsk, struct sk_buff *skb, void *data)
{
struct devlink_obj_desc *desc = data;
struct devlink_nl_sock_priv *sk_priv;
struct devlink_obj_desc *flt;
int ret = 0;
rcu_read_lock();
sk_priv = __genl_sk_priv_get(&devlink_nl_family, dsk);
if (!IS_ERR_OR_NULL(sk_priv)) {
flt = rcu_dereference(sk_priv->flt);
if (flt)
ret = !devlink_obj_desc_match(desc, flt);
}
rcu_read_unlock();
return ret;
}
int devlink_nl_put_nested_handle(struct sk_buff *msg, struct net *net,
struct devlink *devlink, int attrtype)
{
struct nlattr *nested_attr;
struct net *devl_net;
nested_attr = nla_nest_start(msg, attrtype);
if (!nested_attr)
return -EMSGSIZE;
if (devlink_nl_put_handle(msg, devlink))
goto nla_put_failure;
rcu_read_lock();
devl_net = read_pnet_rcu(&devlink->_net);
if (!net_eq(net, devl_net)) {
int id = peernet2id_alloc(net, devl_net, GFP_ATOMIC);
rcu_read_unlock();
if (nla_put_s32(msg, DEVLINK_ATTR_NETNS_ID, id))
return -EMSGSIZE;
} else {
rcu_read_unlock();
}
nla_nest_end(msg, nested_attr);
return 0;
nla_put_failure:
nla_nest_cancel(msg, nested_attr);
return -EMSGSIZE;
}
int devlink_nl_msg_reply_and_new(struct sk_buff **msg, struct genl_info *info)
{
int err;
if (*msg) {
err = genlmsg_reply(*msg, info);
if (err)
return err;
}
*msg = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!*msg)
return -ENOMEM;
return 0;
}
struct devlink *
devlink_get_from_attrs_lock(struct net *net, struct nlattr **attrs,
bool dev_lock)
{
struct devlink *devlink;
unsigned long index;
char *busname;
char *devname;
if (!attrs[DEVLINK_ATTR_BUS_NAME] || !attrs[DEVLINK_ATTR_DEV_NAME])
return ERR_PTR(-EINVAL);
busname = nla_data(attrs[DEVLINK_ATTR_BUS_NAME]);
devname = nla_data(attrs[DEVLINK_ATTR_DEV_NAME]);
devlinks_xa_for_each_registered_get(net, index, devlink) {
if (strcmp(devlink->dev->bus->name, busname) == 0 &&
strcmp(dev_name(devlink->dev), devname) == 0) {
devl_dev_lock(devlink, dev_lock);
if (devl_is_registered(devlink))
return devlink;
devl_dev_unlock(devlink, dev_lock);
}
devlink_put(devlink);
}
return ERR_PTR(-ENODEV);
}
static int __devlink_nl_pre_doit(struct sk_buff *skb, struct genl_info *info,
u8 flags)
{
bool dev_lock = flags & DEVLINK_NL_FLAG_NEED_DEV_LOCK;
struct devlink_port *devlink_port;
struct devlink *devlink;
int err;
devlink = devlink_get_from_attrs_lock(genl_info_net(info), info->attrs,
dev_lock);
if (IS_ERR(devlink))
return PTR_ERR(devlink);
info->user_ptr[0] = devlink;
if (flags & DEVLINK_NL_FLAG_NEED_PORT) {
devlink_port = devlink_port_get_from_info(devlink, info);
if (IS_ERR(devlink_port)) {
err = PTR_ERR(devlink_port);
goto unlock;
}
info->user_ptr[1] = devlink_port;
} else if (flags & DEVLINK_NL_FLAG_NEED_DEVLINK_OR_PORT) {
devlink_port = devlink_port_get_from_info(devlink, info);
if (!IS_ERR(devlink_port))
info->user_ptr[1] = devlink_port;
}
return 0;
unlock:
devl_dev_unlock(devlink, dev_lock);
devlink_put(devlink);
return err;
}
int devlink_nl_pre_doit(const struct genl_split_ops *ops,
struct sk_buff *skb, struct genl_info *info)
{
return __devlink_nl_pre_doit(skb, info, 0);
}
int devlink_nl_pre_doit_port(const struct genl_split_ops *ops,
struct sk_buff *skb, struct genl_info *info)
{
return __devlink_nl_pre_doit(skb, info, DEVLINK_NL_FLAG_NEED_PORT);
}
int devlink_nl_pre_doit_dev_lock(const struct genl_split_ops *ops,
struct sk_buff *skb, struct genl_info *info)
{
return __devlink_nl_pre_doit(skb, info, DEVLINK_NL_FLAG_NEED_DEV_LOCK);
}
int devlink_nl_pre_doit_port_optional(const struct genl_split_ops *ops,
struct sk_buff *skb,
struct genl_info *info)
{
return __devlink_nl_pre_doit(skb, info, DEVLINK_NL_FLAG_NEED_DEVLINK_OR_PORT);
}
static void __devlink_nl_post_doit(struct sk_buff *skb, struct genl_info *info,
u8 flags)
{
bool dev_lock = flags & DEVLINK_NL_FLAG_NEED_DEV_LOCK;
struct devlink *devlink;
devlink = info->user_ptr[0];
devl_dev_unlock(devlink, dev_lock);
devlink_put(devlink);
}
void devlink_nl_post_doit(const struct genl_split_ops *ops,
struct sk_buff *skb, struct genl_info *info)
{
__devlink_nl_post_doit(skb, info, 0);
}
void
devlink_nl_post_doit_dev_lock(const struct genl_split_ops *ops,
struct sk_buff *skb, struct genl_info *info)
{
__devlink_nl_post_doit(skb, info, DEVLINK_NL_FLAG_NEED_DEV_LOCK);
}
static int devlink_nl_inst_single_dumpit(struct sk_buff *msg,
struct netlink_callback *cb, int flags,
devlink_nl_dump_one_func_t *dump_one,
struct nlattr **attrs)
{
struct devlink *devlink;
int err;
devlink = devlink_get_from_attrs_lock(sock_net(msg->sk), attrs, false);
if (IS_ERR(devlink))
return PTR_ERR(devlink);
err = dump_one(msg, devlink, cb, flags | NLM_F_DUMP_FILTERED);
devl_unlock(devlink);
devlink_put(devlink);
if (err != -EMSGSIZE)
return err;
return msg->len;
}
static int devlink_nl_inst_iter_dumpit(struct sk_buff *msg,
struct netlink_callback *cb, int flags,
devlink_nl_dump_one_func_t *dump_one)
{
struct devlink_nl_dump_state *state = devlink_dump_state(cb);
struct devlink *devlink;
int err = 0;
while ((devlink = devlinks_xa_find_get(sock_net(msg->sk),
&state->instance))) {
devl_lock(devlink);
if (devl_is_registered(devlink))
err = dump_one(msg, devlink, cb, flags);
else
err = 0;
devl_unlock(devlink);
devlink_put(devlink);
if (err)
break;
state->instance++;
/* restart sub-object walk for the next instance */
state->idx = 0;
}
if (err != -EMSGSIZE)
return err;
return msg->len;
}
int devlink_nl_dumpit(struct sk_buff *msg, struct netlink_callback *cb,
devlink_nl_dump_one_func_t *dump_one)
{
const struct genl_info *info = genl_info_dump(cb);
struct nlattr **attrs = info->attrs;
int flags = NLM_F_MULTI;
if (attrs &&
(attrs[DEVLINK_ATTR_BUS_NAME] || attrs[DEVLINK_ATTR_DEV_NAME]))
return devlink_nl_inst_single_dumpit(msg, cb, flags, dump_one,
attrs);
else
return devlink_nl_inst_iter_dumpit(msg, cb, flags, dump_one);
}
struct genl_family devlink_nl_family __ro_after_init = {
.name = DEVLINK_GENL_NAME,
.version = DEVLINK_GENL_VERSION,
.netnsok = true,
.parallel_ops = true,
.module = THIS_MODULE,
.split_ops = devlink_nl_ops,
.n_split_ops = ARRAY_SIZE(devlink_nl_ops),
.resv_start_op = DEVLINK_CMD_SELFTESTS_RUN + 1,
.mcgrps = devlink_nl_mcgrps,
.n_mcgrps = ARRAY_SIZE(devlink_nl_mcgrps),
.sock_priv_size = sizeof(struct devlink_nl_sock_priv),
.sock_priv_init = devlink_nl_sock_priv_init,
.sock_priv_destroy = devlink_nl_sock_priv_destroy,
};