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 bool (*compare)(struct net *net, struct sock *sk); 50 }; 51 52 extern struct sock *__netlink_kernel_create(struct net *net, int unit, 53 struct module *module, 54 struct netlink_kernel_cfg *cfg); 55 static inline struct sock * 56 netlink_kernel_create(struct net *net, int unit, struct netlink_kernel_cfg *cfg) 57 { 58 return __netlink_kernel_create(net, unit, THIS_MODULE, cfg); 59 } 60 61 extern void netlink_kernel_release(struct sock *sk); 62 extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups); 63 extern int netlink_change_ngroups(struct sock *sk, unsigned int groups); 64 extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group); 65 extern void netlink_clear_multicast_users(struct sock *sk, unsigned int group); 66 extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err); 67 extern int netlink_has_listeners(struct sock *sk, unsigned int group); 68 extern struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size, 69 u32 dst_portid, gfp_t gfp_mask); 70 extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock); 71 extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid, 72 __u32 group, gfp_t allocation); 73 extern 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); 77 extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code); 78 extern int netlink_register_notifier(struct notifier_block *nb); 79 extern int netlink_unregister_notifier(struct notifier_block *nb); 80 81 /* finegrained unicast helpers: */ 82 struct sock *netlink_getsockbyfilp(struct file *filp); 83 int netlink_attachskb(struct sock *sk, struct sk_buff *skb, 84 long *timeo, struct sock *ssk); 85 void netlink_detachskb(struct sock *sk, struct sk_buff *skb); 86 int netlink_sendskb(struct sock *sk, struct sk_buff *skb); 87 88 static inline struct sk_buff * 89 netlink_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) 117 118 119 struct 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 }; 133 134 struct netlink_notify { 135 struct net *net; 136 int portid; 137 int protocol; 138 }; 139 140 struct nlmsghdr * 141 __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags); 142 143 struct 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 }; 150 151 extern int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, 152 const struct nlmsghdr *nlh, 153 struct netlink_dump_control *control); 154 static 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 } 163 164 struct netlink_tap { 165 struct net_device *dev; 166 struct module *module; 167 struct list_head list; 168 }; 169 170 extern int netlink_add_tap(struct netlink_tap *nt); 171 extern int __netlink_remove_tap(struct netlink_tap *nt); 172 extern int netlink_remove_tap(struct netlink_tap *nt); 173 174 #endif /* __LINUX_NETLINK_H */ 175