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
  11 struct net;
  12
  13 static inline struct nlmsghdr *nlmsg_hdr(const struct sk_buff *skb)
  14 {
  15         return (struct nlmsghdr *)skb->data;
  16 }
  17
  18 enum 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
  24 struct 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
  36 extern void netlink_table_grab(void);
  37 extern 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 */
  43 struct 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
  51 extern struct sock *__netlink_kernel_create(struct net *net, int unit,
  52                                             struct module *module,
  53                                             struct netlink_kernel_cfg *cfg);
  54 static inline struct sock *
  55 netlink_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
  60 extern void netlink_kernel_release(struct sock *sk);
  61 extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
  62 extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
  63 extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
  64 extern void netlink_clear_multicast_users(struct sock *sk, unsigned int group);
  65 extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);
  66 extern int netlink_has_listeners(struct sock *sk, unsigned int group);
  67 extern struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size,
  68                                          u32 dst_portid, gfp_t gfp_mask);
  69 extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock);
  70 extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid,
  71                              __u32 group, gfp_t allocation);
  72 extern 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);
  76 extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code);
  77 extern int netlink_register_notifier(struct notifier_block *nb);
  78 extern int netlink_unregister_notifier(struct notifier_block *nb);
  79
  80 /* finegrained unicast helpers: */
  81 struct sock *netlink_getsockbyfilp(struct file *filp);
  82 int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
  83                       long *timeo, struct sock *ssk);
  84 void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
  85 int 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
 102 struct 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
 117 struct netlink_notify {
 118         struct net *net;
 119         int portid;
 120         int protocol;
 121 };
 122
 123 struct nlmsghdr *
 124 __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags);
 125
 126 struct 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
 134 extern int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
 135                                 const struct nlmsghdr *nlh,
 136                                 struct netlink_dump_control *control);
 137 static 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 */