| 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 int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock); |
| 73 | extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid, |
| 74 | __u32 group, gfp_t allocation); |
| 75 | extern int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, |
| 76 | __u32 portid, __u32 group, gfp_t allocation, |
| 77 | int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data), |
| 78 | void *filter_data); |
| 79 | extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code); |
| 80 | extern int netlink_register_notifier(struct notifier_block *nb); |
| 81 | extern int netlink_unregister_notifier(struct notifier_block *nb); |
| 82 | |
| 83 | /* finegrained unicast helpers: */ |
| 84 | struct sock *netlink_getsockbyfilp(struct file *filp); |
| 85 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, |
| 86 | long *timeo, struct sock *ssk); |
| 87 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb); |
| 88 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb); |
| 89 | |
| 90 | static inline struct sk_buff * |
| 91 | netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask) |
| 92 | { |
| 93 | struct sk_buff *nskb; |
| 94 | |
| 95 | nskb = skb_clone(skb, gfp_mask); |
| 96 | if (!nskb) |
| 97 | return NULL; |
| 98 | |
| 99 | /* This is a large skb, set destructor callback to release head */ |
| 100 | if (is_vmalloc_addr(skb->head)) |
| 101 | nskb->destructor = skb->destructor; |
| 102 | |
| 103 | return nskb; |
| 104 | } |
| 105 | |
| 106 | /* |
| 107 | * skb should fit one page. This choice is good for headerless malloc. |
| 108 | * But we should limit to 8K so that userspace does not have to |
| 109 | * use enormous buffer sizes on recvmsg() calls just to avoid |
| 110 | * MSG_TRUNC when PAGE_SIZE is very large. |
| 111 | */ |
| 112 | #if PAGE_SIZE < 8192UL |
| 113 | #define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(PAGE_SIZE) |
| 114 | #else |
| 115 | #define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(8192UL) |
| 116 | #endif |
| 117 | |
| 118 | #define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN) |
| 119 | |
| 120 | |
| 121 | struct netlink_callback { |
| 122 | struct sk_buff *skb; |
| 123 | const struct nlmsghdr *nlh; |
| 124 | int (*start)(struct netlink_callback *); |
| 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 (*start)(struct netlink_callback *); |
| 148 | int (*dump)(struct sk_buff *skb, struct netlink_callback *); |
| 149 | int (*done)(struct netlink_callback *); |
| 150 | void *data; |
| 151 | struct module *module; |
| 152 | u16 min_dump_alloc; |
| 153 | }; |
| 154 | |
| 155 | extern int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, |
| 156 | const struct nlmsghdr *nlh, |
| 157 | struct netlink_dump_control *control); |
| 158 | static inline int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, |
| 159 | const struct nlmsghdr *nlh, |
| 160 | struct netlink_dump_control *control) |
| 161 | { |
| 162 | if (!control->module) |
| 163 | control->module = THIS_MODULE; |
| 164 | |
| 165 | return __netlink_dump_start(ssk, skb, nlh, control); |
| 166 | } |
| 167 | |
| 168 | struct netlink_tap { |
| 169 | struct net_device *dev; |
| 170 | struct module *module; |
| 171 | struct list_head list; |
| 172 | }; |
| 173 | |
| 174 | extern int netlink_add_tap(struct netlink_tap *nt); |
| 175 | extern int netlink_remove_tap(struct netlink_tap *nt); |
| 176 | |
| 177 | bool __netlink_ns_capable(const struct netlink_skb_parms *nsp, |
| 178 | struct user_namespace *ns, int cap); |
| 179 | bool netlink_ns_capable(const struct sk_buff *skb, |
| 180 | struct user_namespace *ns, int cap); |
| 181 | bool netlink_capable(const struct sk_buff *skb, int cap); |
| 182 | bool netlink_net_capable(const struct sk_buff *skb, int cap); |
| 183 | |
| 184 | #endif /* __LINUX_NETLINK_H */ |