f9c2288837
Add support for mmap'ed recvmsg(). To allow the kernel to construct messages into the mapped area, a dataless skb is allocated and the data pointer is set to point into the ring frame. This means frames will be delivered to userspace in order of allocation instead of order of transmission. This usually doesn't matter since the order is either not determinable by userspace or message creation/transmission is serialized. The only case where this can have a visible difference is nfnetlink_queue. Userspace can't assume mmap'ed messages have ordered IDs anymore and needs to check this if using batched verdicts. For non-mapped sockets, nothing changes. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
148 lines
4.6 KiB
C
148 lines
4.6 KiB
C
#ifndef __LINUX_NETLINK_H
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#define __LINUX_NETLINK_H
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#include <linux/capability.h>
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#include <linux/skbuff.h>
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#include <linux/export.h>
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#include <net/scm.h>
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#include <uapi/linux/netlink.h>
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struct net;
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static inline struct nlmsghdr *nlmsg_hdr(const struct sk_buff *skb)
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{
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return (struct nlmsghdr *)skb->data;
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}
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enum netlink_skb_flags {
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NETLINK_SKB_MMAPED = 0x1, /* Packet data is mmaped */
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NETLINK_SKB_TX = 0x2, /* Packet was sent by userspace */
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NETLINK_SKB_DELIVERED = 0x4, /* Packet was delivered */
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};
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struct netlink_skb_parms {
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struct scm_creds creds; /* Skb credentials */
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__u32 portid;
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__u32 dst_group;
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__u32 flags;
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struct sock *sk;
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};
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#define NETLINK_CB(skb) (*(struct netlink_skb_parms*)&((skb)->cb))
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#define NETLINK_CREDS(skb) (&NETLINK_CB((skb)).creds)
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extern void netlink_table_grab(void);
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extern void netlink_table_ungrab(void);
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#define NL_CFG_F_NONROOT_RECV (1 << 0)
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#define NL_CFG_F_NONROOT_SEND (1 << 1)
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/* optional Netlink kernel configuration parameters */
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struct netlink_kernel_cfg {
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unsigned int groups;
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unsigned int flags;
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void (*input)(struct sk_buff *skb);
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struct mutex *cb_mutex;
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void (*bind)(int group);
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};
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extern struct sock *__netlink_kernel_create(struct net *net, int unit,
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struct module *module,
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struct netlink_kernel_cfg *cfg);
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static inline struct sock *
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netlink_kernel_create(struct net *net, int unit, struct netlink_kernel_cfg *cfg)
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{
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return __netlink_kernel_create(net, unit, THIS_MODULE, cfg);
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}
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extern void netlink_kernel_release(struct sock *sk);
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extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
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extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
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extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
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extern void netlink_clear_multicast_users(struct sock *sk, unsigned int group);
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extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);
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extern int netlink_has_listeners(struct sock *sk, unsigned int group);
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extern struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size,
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u32 dst_portid, gfp_t gfp_mask);
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extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock);
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extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid,
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__u32 group, gfp_t allocation);
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extern int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
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__u32 portid, __u32 group, gfp_t allocation,
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int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
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void *filter_data);
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extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code);
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extern int netlink_register_notifier(struct notifier_block *nb);
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extern int netlink_unregister_notifier(struct notifier_block *nb);
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/* finegrained unicast helpers: */
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struct sock *netlink_getsockbyfilp(struct file *filp);
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int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
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long *timeo, struct sock *ssk);
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void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
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int netlink_sendskb(struct sock *sk, struct sk_buff *skb);
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/*
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* skb should fit one page. This choice is good for headerless malloc.
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* But we should limit to 8K so that userspace does not have to
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* use enormous buffer sizes on recvmsg() calls just to avoid
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* MSG_TRUNC when PAGE_SIZE is very large.
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*/
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#if PAGE_SIZE < 8192UL
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#define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(PAGE_SIZE)
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#else
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#define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(8192UL)
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#endif
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#define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
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struct netlink_callback {
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struct sk_buff *skb;
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const struct nlmsghdr *nlh;
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int (*dump)(struct sk_buff * skb,
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struct netlink_callback *cb);
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int (*done)(struct netlink_callback *cb);
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void *data;
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/* the module that dump function belong to */
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struct module *module;
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u16 family;
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u16 min_dump_alloc;
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unsigned int prev_seq, seq;
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long args[6];
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};
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struct netlink_notify {
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struct net *net;
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int portid;
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int protocol;
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};
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struct nlmsghdr *
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__nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags);
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struct netlink_dump_control {
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int (*dump)(struct sk_buff *skb, struct netlink_callback *);
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int (*done)(struct netlink_callback *);
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void *data;
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struct module *module;
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u16 min_dump_alloc;
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};
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extern int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
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const struct nlmsghdr *nlh,
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struct netlink_dump_control *control);
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static inline int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
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const struct nlmsghdr *nlh,
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struct netlink_dump_control *control)
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{
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if (!control->module)
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control->module = THIS_MODULE;
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return __netlink_dump_start(ssk, skb, nlh, control);
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}
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#endif /* __LINUX_NETLINK_H */
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