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        bool                    nsid_is_set;
  32        int                     nsid;
  33};
  34
  35#define NETLINK_CB(skb)         (*(struct netlink_skb_parms*)&((skb)->cb))
  36#define NETLINK_CREDS(skb)      (&NETLINK_CB((skb)).creds)
  37
  38
  39extern void netlink_table_grab(void);
  40extern void netlink_table_ungrab(void);
  41
  42#define NL_CFG_F_NONROOT_RECV   (1 << 0)
  43#define NL_CFG_F_NONROOT_SEND   (1 << 1)
  44
  45/* optional Netlink kernel configuration parameters */
  46struct netlink_kernel_cfg {
  47        unsigned int    groups;
  48        unsigned int    flags;
  49        void            (*input)(struct sk_buff *skb);
  50        struct mutex    *cb_mutex;
  51        int             (*bind)(struct net *net, int group);
  52        void            (*unbind)(struct net *net, int group);
  53        bool            (*compare)(struct net *net, struct sock *sk);
  54};
  55
  56extern struct sock *__netlink_kernel_create(struct net *net, int unit,
  57                                            struct module *module,
  58                                            struct netlink_kernel_cfg *cfg);
  59static inline struct sock *
  60netlink_kernel_create(struct net *net, int unit, struct netlink_kernel_cfg *cfg)
  61{
  62        return __netlink_kernel_create(net, unit, THIS_MODULE, cfg);
  63}
  64
  65extern void netlink_kernel_release(struct sock *sk);
  66extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
  67extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
  68extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
  69extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);
  70extern int netlink_has_listeners(struct sock *sk, unsigned int group);
  71extern struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size,
  72                                         u32 dst_portid, gfp_t gfp_mask);
  73extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock);
  74extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid,
  75                             __u32 group, gfp_t allocation);
  76extern int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
  77        __u32 portid, __u32 group, gfp_t allocation,
  78        int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
  79        void *filter_data);
  80extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code);
  81extern int netlink_register_notifier(struct notifier_block *nb);
  82extern int netlink_unregister_notifier(struct notifier_block *nb);
  83
  84/* finegrained unicast helpers: */
  85struct sock *netlink_getsockbyfilp(struct file *filp);
  86int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
  87                      long *timeo, struct sock *ssk);
  88void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
  89int netlink_sendskb(struct sock *sk, struct sk_buff *skb);
  90
  91static inline struct sk_buff *
  92netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
  93{
  94        struct sk_buff *nskb;
  95
  96        nskb = skb_clone(skb, gfp_mask);
  97        if (!nskb)
  98                return NULL;
  99
 100        /* This is a large skb, set destructor callback to release head */
 101        if (is_vmalloc_addr(skb->head))
 102                nskb->destructor = skb->destructor;
 103
 104        return nskb;
 105}
 106
 107/*
 108 *      skb should fit one page. This choice is good for headerless malloc.
 109 *      But we should limit to 8K so that userspace does not have to
 110 *      use enormous buffer sizes on recvmsg() calls just to avoid
 111 *      MSG_TRUNC when PAGE_SIZE is very large.
 112 */
 113#if PAGE_SIZE < 8192UL
 114#define NLMSG_GOODSIZE  SKB_WITH_OVERHEAD(PAGE_SIZE)
 115#else
 116#define NLMSG_GOODSIZE  SKB_WITH_OVERHEAD(8192UL)
 117#endif
 118
 119#define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
 120
 121
 122struct netlink_callback {
 123        struct sk_buff          *skb;
 124        const struct nlmsghdr   *nlh;
 125        int                     (*dump)(struct sk_buff * skb,
 126                                        struct netlink_callback *cb);
 127        int                     (*done)(struct netlink_callback *cb);
 128        void                    *data;
 129        /* the module that dump function belong to */
 130        struct module           *module;
 131        u16                     family;
 132        u16                     min_dump_alloc;
 133        unsigned int            prev_seq, seq;
 134        long                    args[6];
 135};
 136
 137struct netlink_notify {
 138        struct net *net;
 139        u32 portid;
 140        int protocol;
 141};
 142
 143struct nlmsghdr *
 144__nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags);
 145
 146struct netlink_dump_control {
 147        int (*dump)(struct sk_buff *skb, struct netlink_callback *);
 148        int (*done)(struct netlink_callback *);
 149        void *data;
 150        struct module *module;
 151        u16 min_dump_alloc;
 152};
 153
 154extern int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
 155                                const struct nlmsghdr *nlh,
 156                                struct netlink_dump_control *control);
 157static inline int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
 158                                     const struct nlmsghdr *nlh,
 159                                     struct netlink_dump_control *control)
 160{
 161        if (!control->module)
 162                control->module = THIS_MODULE;
 163
 164        return __netlink_dump_start(ssk, skb, nlh, control);
 165}
 166
 167struct netlink_tap {
 168        struct net_device *dev;
 169        struct module *module;
 170        struct list_head list;
 171};
 172
 173extern int netlink_add_tap(struct netlink_tap *nt);
 174extern int netlink_remove_tap(struct netlink_tap *nt);
 175
 176bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
 177                          struct user_namespace *ns, int cap);
 178bool netlink_ns_capable(const struct sk_buff *skb,
 179                        struct user_namespace *ns, int cap);
 180bool netlink_capable(const struct sk_buff *skb, int cap);
 181bool netlink_net_capable(const struct sk_buff *skb, int cap);
 182
 183#endif  /* __LINUX_NETLINK_H */
 184