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