LXR linux/include/linux/netlink.h

   1#ifndef __LINUX_NETLINK_H
   2#define __LINUX_NETLINK_H
   3
   4
   5#include <linux/capability.h>
   6#include <linux/skbuff.h>
   7#include <linux/export.h>
   8#include <net/scm.h>
   9#include <uapi/linux/netlink.h>
  10
  11struct net;
  12
  13static inline struct nlmsghdr *nlmsg_hdr(const struct sk_buff *skb)
  14{
  15        return (struct nlmsghdr *)skb->data;
  16}
  17
  18enum netlink_skb_flags {
  19        NETLINK_SKB_MMAPED      = 0x1,          /* Packet data is mmaped */
  20        NETLINK_SKB_TX          = 0x2,          /* Packet was sent by userspace */
  21        NETLINK_SKB_DELIVERED   = 0x4,          /* Packet was delivered */
  22};
  23
  24struct netlink_skb_parms {
  25        struct scm_creds        creds;          /* Skb credentials      */
  26        __u32                   portid;
  27        __u32                   dst_group;
  28        __u32                   flags;
  29        struct sock             *sk;
  30};
  31
  32#define NETLINK_CB(skb)         (*(struct netlink_skb_parms*)&((skb)->cb))
  33#define NETLINK_CREDS(skb)      (&NETLINK_CB((skb)).creds)
  34
  35
  36extern void netlink_table_grab(void);
  37extern void netlink_table_ungrab(void);
  38
  39#define NL_CFG_F_NONROOT_RECV   (1 << 0)
  40#define NL_CFG_F_NONROOT_SEND   (1 << 1)
  41
  42/* optional Netlink kernel configuration parameters */
  43struct netlink_kernel_cfg {
  44        unsigned int    groups;
  45        unsigned int    flags;
  46        void            (*input)(struct sk_buff *skb);
  47        struct mutex    *cb_mutex;
  48        void            (*bind)(int group);
  49};
  50
  51extern struct sock *__netlink_kernel_create(struct net *net, int unit,
  52                                            struct module *module,
  53                                            struct netlink_kernel_cfg *cfg);
  54static inline struct sock *
  55netlink_kernel_create(struct net *net, int unit, struct netlink_kernel_cfg *cfg)
  56{
  57        return __netlink_kernel_create(net, unit, THIS_MODULE, cfg);
  58}
  59
  60extern void netlink_kernel_release(struct sock *sk);
  61extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
  62extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
  63extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
  64extern void netlink_clear_multicast_users(struct sock *sk, unsigned int group);
  65extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);
  66extern int netlink_has_listeners(struct sock *sk, unsigned int group);
  67extern struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size,
  68                                         u32 dst_portid, gfp_t gfp_mask);
  69extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock);
  70extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid,
  71                             __u32 group, gfp_t allocation);
  72extern int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
  73        __u32 portid, __u32 group, gfp_t allocation,
  74        int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
  75        void *filter_data);
  76extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code);
  77extern int netlink_register_notifier(struct notifier_block *nb);
  78extern int netlink_unregister_notifier(struct notifier_block *nb);
  79
  80/* finegrained unicast helpers: */
  81struct sock *netlink_getsockbyfilp(struct file *filp);
  82int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
  83                      long *timeo, struct sock *ssk);
  84void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
  85int netlink_sendskb(struct sock *sk, struct sk_buff *skb);
  86
  87/*
  88 *      skb should fit one page. This choice is good for headerless malloc.
  89 *      But we should limit to 8K so that userspace does not have to
  90 *      use enormous buffer sizes on recvmsg() calls just to avoid
  91 *      MSG_TRUNC when PAGE_SIZE is very large.
  92 */
  93#if PAGE_SIZE < 8192UL
  94#define NLMSG_GOODSIZE  SKB_WITH_OVERHEAD(PAGE_SIZE)
  95#else
  96#define NLMSG_GOODSIZE  SKB_WITH_OVERHEAD(8192UL)
  97#endif
  98
  99#define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
 100
 101
 102struct netlink_callback {
 103        struct sk_buff          *skb;
 104        const struct nlmsghdr   *nlh;
 105        int                     (*dump)(struct sk_buff * skb,
 106                                        struct netlink_callback *cb);
 107        int                     (*done)(struct netlink_callback *cb);
 108        void                    *data;
 109        /* the module that dump function belong to */
 110        struct module           *module;
 111        u16                     family;
 112        u16                     min_dump_alloc;
 113        unsigned int            prev_seq, seq;
 114        long                    args[6];
 115};
 116
 117struct netlink_notify {
 118        struct net *net;
 119        int portid;
 120        int protocol;
 121};
 122
 123struct nlmsghdr *
 124__nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags);
 125
 126struct netlink_dump_control {
 127        int (*dump)(struct sk_buff *skb, struct netlink_callback *);
 128        int (*done)(struct netlink_callback *);
 129        void *data;
 130        struct module *module;
 131        u16 min_dump_alloc;
 132};
 133
 134extern int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
 135                                const struct nlmsghdr *nlh,
 136                                struct netlink_dump_control *control);
 137static inline int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
 138                                     const struct nlmsghdr *nlh,
 139                                     struct netlink_dump_control *control)
 140{
 141        if (!control->module)
 142                control->module = THIS_MODULE;
 143
 144        return __netlink_dump_start(ssk, skb, nlh, control);
 145}
 146
 147#endif  /* __LINUX_NETLINK_H */
 148