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 NETLINK_SKB_DST = 0x8, /* Dst set in sendto or sendmsg */ 23 }; 24 25 struct 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 39 extern void netlink_table_grab(void); 40 extern 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 */ 46 struct 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 56 extern struct sock *__netlink_kernel_create(struct net *net, int unit, 57 struct module *module, 58 struct netlink_kernel_cfg *cfg); 59 static inline struct sock * 60 netlink_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 65 extern void netlink_kernel_release(struct sock *sk); 66 extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups); 67 extern int netlink_change_ngroups(struct sock *sk, unsigned int groups); 68 extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group); 69 extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err); 70 extern int netlink_has_listeners(struct sock *sk, unsigned int group); 71 extern struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size, 72 u32 dst_portid, gfp_t gfp_mask); 73 extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock); 74 extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid, 75 __u32 group, gfp_t allocation); 76 extern 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); 80 extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code); 81 extern int netlink_register_notifier(struct notifier_block *nb); 82 extern int netlink_unregister_notifier(struct notifier_block *nb); 83 84 /* finegrained unicast helpers: */ 85 struct sock *netlink_getsockbyfilp(struct file *filp); 86 int netlink_attachskb(struct sock *sk, struct sk_buff *skb, 87 long *timeo, struct sock *ssk); 88 void netlink_detachskb(struct sock *sk, struct sk_buff *skb); 89 int netlink_sendskb(struct sock *sk, struct sk_buff *skb); 90 91 static inline struct sk_buff * 92 netlink_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) 120 121 122 struct 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 }; 136 137 struct netlink_notify { 138 struct net *net; 139 u32 portid; 140 int protocol; 141 }; 142 143 struct nlmsghdr * 144 __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags); 145 146 struct 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 }; 153 154 extern int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, 155 const struct nlmsghdr *nlh, 156 struct netlink_dump_control *control); 157 static 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 } 166 167 struct netlink_tap { 168 struct net_device *dev; 169 struct module *module; 170 struct list_head list; 171 }; 172 173 extern int netlink_add_tap(struct netlink_tap *nt); 174 extern int netlink_remove_tap(struct netlink_tap *nt); 175 176 bool __netlink_ns_capable(const struct netlink_skb_parms *nsp, 177 struct user_namespace *ns, int cap); 178 bool netlink_ns_capable(const struct sk_buff *skb, 179 struct user_namespace *ns, int cap); 180 bool netlink_capable(const struct sk_buff *skb, int cap); 181 bool netlink_net_capable(const struct sk_buff *skb, int cap); 182 183 #endif /* __LINUX_NETLINK_H */ 184