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        NETLINK_SKB_DST         = 0x8,  /* Dst set in sendto or sendmsg */
  23};
  24
  25struct netlink_skb_parms {
  26        struct scm_creds        creds;          /* Skb credentials      */
  27        __u32                   portid;
  28        __u32                   dst_group;
  29        __u32                   flags;
  30        struct sock             *sk;
  31};
  32
  33#define NETLINK_CB(skb)         (*(struct netlink_skb_parms*)&((skb)->cb))
  34#define NETLINK_CREDS(skb)      (&NETLINK_CB((skb)).creds)
  35
  36
  37extern void netlink_table_grab(void);
  38extern void netlink_table_ungrab(void);
  39
  40#define NL_CFG_F_NONROOT_RECV   (1 << 0)
  41#define NL_CFG_F_NONROOT_SEND   (1 << 1)
  42
  43/* optional Netlink kernel configuration parameters */
  44struct netlink_kernel_cfg {
  45        unsigned int    groups;
  46        unsigned int    flags;
  47        void            (*input)(struct sk_buff *skb);
  48        struct mutex    *cb_mutex;
  49        int             (*bind)(int group);
  50        void            (*unbind)(int group);
  51        bool            (*compare)(struct net *net, struct sock *sk);
  52};
  53
  54extern struct sock *__netlink_kernel_create(struct net *net, int unit,
  55                                            struct module *module,
  56                                            struct netlink_kernel_cfg *cfg);
  57static inline struct sock *
  58netlink_kernel_create(struct net *net, int unit, struct netlink_kernel_cfg *cfg)
  59{
  60        return __netlink_kernel_create(net, unit, THIS_MODULE, cfg);
  61}
  62
  63extern void netlink_kernel_release(struct sock *sk);
  64extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
  65extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
  66extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
  67extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);
  68extern int netlink_has_listeners(struct sock *sk, unsigned int group);
  69extern struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size,
  70                                         u32 dst_portid, gfp_t gfp_mask);
  71extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock);
  72extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid,
  73                             __u32 group, gfp_t allocation);
  74extern int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
  75        __u32 portid, __u32 group, gfp_t allocation,
  76        int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
  77        void *filter_data);
  78extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code);
  79extern int netlink_register_notifier(struct notifier_block *nb);
  80extern int netlink_unregister_notifier(struct notifier_block *nb);
  81
  82/* finegrained unicast helpers: */
  83struct sock *netlink_getsockbyfilp(struct file *filp);
  84int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
  85                      long *timeo, struct sock *ssk);
  86void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
  87int netlink_sendskb(struct sock *sk, struct sk_buff *skb);
  88
  89static inline struct sk_buff *
  90netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
  91{
  92        struct sk_buff *nskb;
  93
  94        nskb = skb_clone(skb, gfp_mask);
  95        if (!nskb)
  96                return NULL;
  97
  98        /* This is a large skb, set destructor callback to release head */
  99        if (is_vmalloc_addr(skb->head))
 100                nskb->destructor = skb->destructor;
 101
 102        return nskb;
 103}
 104
 105/*
 106 *      skb should fit one page. This choice is good for headerless malloc.
 107 *      But we should limit to 8K so that userspace does not have to
 108 *      use enormous buffer sizes on recvmsg() calls just to avoid
 109 *      MSG_TRUNC when PAGE_SIZE is very large.
 110 */
 111#if PAGE_SIZE < 8192UL
 112#define NLMSG_GOODSIZE  SKB_WITH_OVERHEAD(PAGE_SIZE)
 113#else
 114#define NLMSG_GOODSIZE  SKB_WITH_OVERHEAD(8192UL)
 115#endif
 116
 117#define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
 118
 119
 120struct netlink_callback {
 121        struct sk_buff          *skb;
 122        const struct nlmsghdr   *nlh;
 123        int                     (*dump)(struct sk_buff * skb,
 124                                        struct netlink_callback *cb);
 125        int                     (*done)(struct netlink_callback *cb);
 126        void                    *data;
 127        /* the module that dump function belong to */
 128        struct module           *module;
 129        u16                     family;
 130        u16                     min_dump_alloc;
 131        unsigned int            prev_seq, seq;
 132        long                    args[6];
 133};
 134
 135struct netlink_notify {
 136        struct net *net;
 137        int portid;
 138        int protocol;
 139};
 140
 141struct nlmsghdr *
 142__nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags);
 143
 144struct netlink_dump_control {
 145        int (*dump)(struct sk_buff *skb, struct netlink_callback *);
 146        int (*done)(struct netlink_callback *);
 147        void *data;
 148        struct module *module;
 149        u16 min_dump_alloc;
 150};
 151
 152extern int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
 153                                const struct nlmsghdr *nlh,
 154                                struct netlink_dump_control *control);
 155static inline int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
 156                                     const struct nlmsghdr *nlh,
 157                                     struct netlink_dump_control *control)
 158{
 159        if (!control->module)
 160                control->module = THIS_MODULE;
 161
 162        return __netlink_dump_start(ssk, skb, nlh, control);
 163}
 164
 165struct netlink_tap {
 166        struct net_device *dev;
 167        struct module *module;
 168        struct list_head list;
 169};
 170
 171extern int netlink_add_tap(struct netlink_tap *nt);
 172extern int netlink_remove_tap(struct netlink_tap *nt);
 173
 174bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
 175                          struct user_namespace *ns, int cap);
 176bool netlink_ns_capable(const struct sk_buff *skb,
 177                        struct user_namespace *ns, int cap);
 178bool netlink_capable(const struct sk_buff *skb, int cap);
 179bool netlink_net_capable(const struct sk_buff *skb, int cap);
 180
 181#endif  /* __LINUX_NETLINK_H */
 182