linux/net/netlink/af_netlink.h
Richard Guy Briggs 4f52090052 netlink: have netlink per-protocol bind function return an error code.
Have the netlink per-protocol optional bind function return an int error code
rather than void to signal a failure.

This will enable netlink protocols to perform extra checks including
capabilities and permissions verifications when updating memberships in
multicast groups.

In netlink_bind() and netlink_setsockopt() the call to the per-protocol bind
function was moved above the multicast group update to prevent any access to
the multicast socket groups before checking with the per-protocol bind
function.  This will enable the per-protocol bind function to be used to check
permissions which could be denied before making them available, and to avoid
the messy job of undoing the addition should the per-protocol bind function
fail.

The netfilter subsystem seems to be the only one currently using the
per-protocol bind function.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-22 21:42:26 -04:00

88 lines
1.9 KiB
C

#ifndef _AF_NETLINK_H
#define _AF_NETLINK_H
#include <net/sock.h>
#define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8)
#define NLGRPLONGS(x) (NLGRPSZ(x)/sizeof(unsigned long))
struct netlink_ring {
void **pg_vec;
unsigned int head;
unsigned int frames_per_block;
unsigned int frame_size;
unsigned int frame_max;
unsigned int pg_vec_order;
unsigned int pg_vec_pages;
unsigned int pg_vec_len;
atomic_t pending;
};
struct netlink_sock {
/* struct sock has to be the first member of netlink_sock */
struct sock sk;
u32 portid;
u32 dst_portid;
u32 dst_group;
u32 flags;
u32 subscriptions;
u32 ngroups;
unsigned long *groups;
unsigned long state;
size_t max_recvmsg_len;
wait_queue_head_t wait;
bool cb_running;
struct netlink_callback cb;
struct mutex *cb_mutex;
struct mutex cb_def_mutex;
void (*netlink_rcv)(struct sk_buff *skb);
int (*netlink_bind)(int group);
void (*netlink_unbind)(int group);
struct module *module;
#ifdef CONFIG_NETLINK_MMAP
struct mutex pg_vec_lock;
struct netlink_ring rx_ring;
struct netlink_ring tx_ring;
atomic_t mapped;
#endif /* CONFIG_NETLINK_MMAP */
};
static inline struct netlink_sock *nlk_sk(struct sock *sk)
{
return container_of(sk, struct netlink_sock, sk);
}
struct nl_portid_hash {
struct hlist_head *table;
unsigned long rehash_time;
unsigned int mask;
unsigned int shift;
unsigned int entries;
unsigned int max_shift;
u32 rnd;
};
struct netlink_table {
struct nl_portid_hash hash;
struct hlist_head mc_list;
struct listeners __rcu *listeners;
unsigned int flags;
unsigned int groups;
struct mutex *cb_mutex;
struct module *module;
int (*bind)(int group);
void (*unbind)(int group);
bool (*compare)(struct net *net, struct sock *sock);
int registered;
};
extern struct netlink_table *nl_table;
extern rwlock_t nl_table_lock;
#endif