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 72 extern struct sk_buff *__netlink_alloc_skb(struct sock *ssk, unsigned int size, 73 unsigned int ldiff, u32 dst_portid, 74 gfp_t gfp_mask); 75 static inline struct sk_buff * 76 netlink_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 82 extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock); 83 extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid, 84 __u32 group, gfp_t allocation); 85 extern 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); 89 extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code); 90 extern int netlink_register_notifier(struct notifier_block *nb); 91 extern int netlink_unregister_notifier(struct notifier_block *nb); 92 93 /* finegrained unicast helpers: */ 94 struct sock *netlink_getsockbyfilp(struct file *filp); 95 int netlink_attachskb(struct sock *sk, struct sk_buff *skb, 96 long *timeo, struct sock *ssk); 97 void netlink_detachskb(struct sock *sk, struct sk_buff *skb); 98 int netlink_sendskb(struct sock *sk, struct sk_buff *skb); 99 100 static inline struct sk_buff * 101 netlink_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) 129 130 131 struct 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 }; 146 147 struct netlink_notify { 148 struct net *net; 149 u32 portid; 150 int protocol; 151 }; 152 153 struct nlmsghdr * 154 __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags); 155 156 struct 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 }; 164 165 extern int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, 166 const struct nlmsghdr *nlh, 167 struct netlink_dump_control *control); 168 static 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 } 177 178 struct netlink_tap { 179 struct net_device *dev; 180 struct module *module; 181 struct list_head list; 182 }; 183 184 extern int netlink_add_tap(struct netlink_tap *nt); 185 extern int netlink_remove_tap(struct netlink_tap *nt); 186 187 bool __netlink_ns_capable(const struct netlink_skb_parms *nsp, 188 struct user_namespace *ns, int cap); 189 bool netlink_ns_capable(const struct sk_buff *skb, 190 struct user_namespace *ns, int cap); 191 bool netlink_capable(const struct sk_buff *skb, int cap); 192 bool netlink_net_capable(const struct sk_buff *skb, int cap); 193 194 #endif /* __LINUX_NETLINK_H */ 195