linux/include/net/rtnetlink.h
Kees Cook ccf8dbcd06 rtnetlink: Remove VLA usage
In the quest to remove all stack VLA usage from the kernel[1], this
allocates the maximum size expected for all possible types and adds
sanity-checks at both registration and usage to make sure nothing gets
out of sync. This matches the proposed VLA solution for nfnetlink[2]. The
values chosen here were based on finding assignments for .maxtype and
.slave_maxtype and manually counting the enums:

slave_maxtype (max 33):
	IFLA_BRPORT_MAX     33
	IFLA_BOND_SLAVE_MAX  9

maxtype (max 45):
	IFLA_BOND_MAX       28
	IFLA_BR_MAX         45
	__IFLA_CAIF_HSI_MAX  8
	IFLA_CAIF_MAX        4
	IFLA_CAN_MAX        16
	IFLA_GENEVE_MAX     12
	IFLA_GRE_MAX        25
	IFLA_GTP_MAX         5
	IFLA_HSR_MAX         7
	IFLA_IPOIB_MAX       4
	IFLA_IPTUN_MAX      21
	IFLA_IPVLAN_MAX      3
	IFLA_MACSEC_MAX     15
	IFLA_MACVLAN_MAX     7
	IFLA_PPP_MAX         2
	__IFLA_RMNET_MAX     4
	IFLA_VLAN_MAX        6
	IFLA_VRF_MAX         2
	IFLA_VTI_MAX         7
	IFLA_VXLAN_MAX      28
	VETH_INFO_MAX        2
	VXCAN_INFO_MAX       2

This additionally changes maxtype and slave_maxtype fields to unsigned,
since they're only ever using positive values.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com
[2] https://patchwork.kernel.org/patch/10439647/

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-31 22:48:46 -04:00

172 lines
6.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __NET_RTNETLINK_H
#define __NET_RTNETLINK_H
#include <linux/rtnetlink.h>
#include <net/netlink.h>
typedef int (*rtnl_doit_func)(struct sk_buff *, struct nlmsghdr *,
struct netlink_ext_ack *);
typedef int (*rtnl_dumpit_func)(struct sk_buff *, struct netlink_callback *);
enum rtnl_link_flags {
RTNL_FLAG_DOIT_UNLOCKED = 1,
};
void rtnl_register(int protocol, int msgtype,
rtnl_doit_func, rtnl_dumpit_func, unsigned int flags);
int rtnl_register_module(struct module *owner, int protocol, int msgtype,
rtnl_doit_func, rtnl_dumpit_func, unsigned int flags);
int rtnl_unregister(int protocol, int msgtype);
void rtnl_unregister_all(int protocol);
static inline int rtnl_msg_family(const struct nlmsghdr *nlh)
{
if (nlmsg_len(nlh) >= sizeof(struct rtgenmsg))
return ((struct rtgenmsg *) nlmsg_data(nlh))->rtgen_family;
else
return AF_UNSPEC;
}
/**
* struct rtnl_link_ops - rtnetlink link operations
*
* @list: Used internally
* @kind: Identifier
* @maxtype: Highest device specific netlink attribute number
* @policy: Netlink policy for device specific attribute validation
* @validate: Optional validation function for netlink/changelink parameters
* @priv_size: sizeof net_device private space
* @setup: net_device setup function
* @newlink: Function for configuring and registering a new device
* @changelink: Function for changing parameters of an existing device
* @dellink: Function to remove a device
* @get_size: Function to calculate required room for dumping device
* specific netlink attributes
* @fill_info: Function to dump device specific netlink attributes
* @get_xstats_size: Function to calculate required room for dumping device
* specific statistics
* @fill_xstats: Function to dump device specific statistics
* @get_num_tx_queues: Function to determine number of transmit queues
* to create when creating a new device.
* @get_num_rx_queues: Function to determine number of receive queues
* to create when creating a new device.
* @get_link_net: Function to get the i/o netns of the device
* @get_linkxstats_size: Function to calculate the required room for
* dumping device-specific extended link stats
* @fill_linkxstats: Function to dump device-specific extended link stats
*/
struct rtnl_link_ops {
struct list_head list;
const char *kind;
size_t priv_size;
void (*setup)(struct net_device *dev);
unsigned int maxtype;
const struct nla_policy *policy;
int (*validate)(struct nlattr *tb[],
struct nlattr *data[],
struct netlink_ext_ack *extack);
int (*newlink)(struct net *src_net,
struct net_device *dev,
struct nlattr *tb[],
struct nlattr *data[],
struct netlink_ext_ack *extack);
int (*changelink)(struct net_device *dev,
struct nlattr *tb[],
struct nlattr *data[],
struct netlink_ext_ack *extack);
void (*dellink)(struct net_device *dev,
struct list_head *head);
size_t (*get_size)(const struct net_device *dev);
int (*fill_info)(struct sk_buff *skb,
const struct net_device *dev);
size_t (*get_xstats_size)(const struct net_device *dev);
int (*fill_xstats)(struct sk_buff *skb,
const struct net_device *dev);
unsigned int (*get_num_tx_queues)(void);
unsigned int (*get_num_rx_queues)(void);
unsigned int slave_maxtype;
const struct nla_policy *slave_policy;
int (*slave_changelink)(struct net_device *dev,
struct net_device *slave_dev,
struct nlattr *tb[],
struct nlattr *data[],
struct netlink_ext_ack *extack);
size_t (*get_slave_size)(const struct net_device *dev,
const struct net_device *slave_dev);
int (*fill_slave_info)(struct sk_buff *skb,
const struct net_device *dev,
const struct net_device *slave_dev);
struct net *(*get_link_net)(const struct net_device *dev);
size_t (*get_linkxstats_size)(const struct net_device *dev,
int attr);
int (*fill_linkxstats)(struct sk_buff *skb,
const struct net_device *dev,
int *prividx, int attr);
};
int __rtnl_link_register(struct rtnl_link_ops *ops);
void __rtnl_link_unregister(struct rtnl_link_ops *ops);
int rtnl_link_register(struct rtnl_link_ops *ops);
void rtnl_link_unregister(struct rtnl_link_ops *ops);
/**
* struct rtnl_af_ops - rtnetlink address family operations
*
* @list: Used internally
* @family: Address family
* @fill_link_af: Function to fill IFLA_AF_SPEC with address family
* specific netlink attributes.
* @get_link_af_size: Function to calculate size of address family specific
* netlink attributes.
* @validate_link_af: Validate a IFLA_AF_SPEC attribute, must check attr
* for invalid configuration settings.
* @set_link_af: Function to parse a IFLA_AF_SPEC attribute and modify
* net_device accordingly.
*/
struct rtnl_af_ops {
struct list_head list;
int family;
int (*fill_link_af)(struct sk_buff *skb,
const struct net_device *dev,
u32 ext_filter_mask);
size_t (*get_link_af_size)(const struct net_device *dev,
u32 ext_filter_mask);
int (*validate_link_af)(const struct net_device *dev,
const struct nlattr *attr);
int (*set_link_af)(struct net_device *dev,
const struct nlattr *attr);
int (*fill_stats_af)(struct sk_buff *skb,
const struct net_device *dev);
size_t (*get_stats_af_size)(const struct net_device *dev);
};
void rtnl_af_register(struct rtnl_af_ops *ops);
void rtnl_af_unregister(struct rtnl_af_ops *ops);
struct net *rtnl_link_get_net(struct net *src_net, struct nlattr *tb[]);
struct net_device *rtnl_create_link(struct net *net, const char *ifname,
unsigned char name_assign_type,
const struct rtnl_link_ops *ops,
struct nlattr *tb[]);
int rtnl_delete_link(struct net_device *dev);
int rtnl_configure_link(struct net_device *dev, const struct ifinfomsg *ifm);
int rtnl_nla_parse_ifla(struct nlattr **tb, const struct nlattr *head, int len,
struct netlink_ext_ack *exterr);
#define MODULE_ALIAS_RTNL_LINK(kind) MODULE_ALIAS("rtnl-link-" kind)
#endif