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);
  71
  72extern struct sk_buff *__netlink_alloc_skb(struct sock *ssk, unsigned int size,
  73                                           unsigned int ldiff, u32 dst_portid,
  74                                           gfp_t gfp_mask);
  75static inline struct sk_buff *
  76netlink_alloc_skb(struct sock *ssk, unsigned int size, u32 dst_portid,
  77                  gfp_t gfp_mask)
  78{
  79        return __netlink_alloc_skb(ssk, size, 0, dst_portid, gfp_mask);
  80}
  81
  82extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock);
  83extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid,
  84                             __u32 group, gfp_t allocation);
  85extern int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
  86        __u32 portid, __u32 group, gfp_t allocation,
  87        int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
  88        void *filter_data);
  89extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code);
  90extern int netlink_register_notifier(struct notifier_block *nb);
  91extern int netlink_unregister_notifier(struct notifier_block *nb);
  92
  93/* finegrained unicast helpers: */
  94struct sock *netlink_getsockbyfilp(struct file *filp);
  95int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
  96                      long *timeo, struct sock *ssk);
  97void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
  98int netlink_sendskb(struct sock *sk, struct sk_buff *skb);
  99
 100static inline struct sk_buff *
 101netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
 102{
 103        struct sk_buff *nskb;
 104
 105        nskb = skb_clone(skb, gfp_mask);
 106        if (!nskb)
 107                return NULL;
 108
 109        /* This is a large skb, set destructor callback to release head */
 110        if (is_vmalloc_addr(skb->head))
 111                nskb->destructor = skb->destructor;
 112
 113        return nskb;
 114}
 115
 116/*
 117 *      skb should fit one page. This choice is good for headerless malloc.
 118 *      But we should limit to 8K so that userspace does not have to
 119 *      use enormous buffer sizes on recvmsg() calls just to avoid
 120 *      MSG_TRUNC when PAGE_SIZE is very large.
 121 */
 122#if PAGE_SIZE < 8192UL
 123#define NLMSG_GOODSIZE  SKB_WITH_OVERHEAD(PAGE_SIZE)
 124#else
 125#define NLMSG_GOODSIZE  SKB_WITH_OVERHEAD(8192UL)
 126#endif
 127
 128#define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
 129
 130
 131struct netlink_callback {
 132        struct sk_buff          *skb;
 133        const struct nlmsghdr   *nlh;
 134        int                     (*start)(struct netlink_callback *);
 135        int                     (*dump)(struct sk_buff * skb,
 136                                        struct netlink_callback *cb);
 137        int                     (*done)(struct netlink_callback *cb);
 138        void                    *data;
 139        /* the module that dump function belong to */
 140        struct module           *module;
 141        u16                     family;
 142        u16                     min_dump_alloc;
 143        unsigned int            prev_seq, seq;
 144        long                    args[6];
 145};
 146
 147struct netlink_notify {
 148        struct net *net;
 149        u32 portid;
 150        int protocol;
 151};
 152
 153struct nlmsghdr *
 154__nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags);
 155
 156struct netlink_dump_control {
 157        int (*start)(struct netlink_callback *);
 158        int (*dump)(struct sk_buff *skb, struct netlink_callback *);
 159        int (*done)(struct netlink_callback *);
 160        void *data;
 161        struct module *module;
 162        u16 min_dump_alloc;
 163};
 164
 165extern int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
 166                                const struct nlmsghdr *nlh,
 167                                struct netlink_dump_control *control);
 168static inline int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
 169                                     const struct nlmsghdr *nlh,
 170                                     struct netlink_dump_control *control)
 171{
 172        if (!control->module)
 173                control->module = THIS_MODULE;
 174
 175        return __netlink_dump_start(ssk, skb, nlh, control);
 176}
 177
 178struct netlink_tap {
 179        struct net_device *dev;
 180        struct module *module;
 181        struct list_head list;
 182};
 183
 184extern int netlink_add_tap(struct netlink_tap *nt);
 185extern int netlink_remove_tap(struct netlink_tap *nt);
 186
 187bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
 188                          struct user_namespace *ns, int cap);
 189bool netlink_ns_capable(const struct sk_buff *skb,
 190                        struct user_namespace *ns, int cap);
 191bool netlink_capable(const struct sk_buff *skb, int cap);
 192bool netlink_net_capable(const struct sk_buff *skb, int cap);
 193
 194#endif  /* __LINUX_NETLINK_H */
 195