[NETFITLER]: Add nfnetlink layer.
Introduce "nfnetlink" (netfilter netlink) layer. This layer is used as transport layer for all userspace communication of the new upcoming netfilter subsystems, such as ctnetlink, nfnetlink_queue and some day even the mythical pkttables ;) Signed-off-by: Harald Welte <laforge@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Harald Welte
committed by
David S. Miller
David S. Miller
parent
ac3247baf8
commit
f9e815b376
145
include/linux/netfilter/nfnetlink.h
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145
include/linux/netfilter/nfnetlink.h
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#ifndef _NFNETLINK_H
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#define _NFNETLINK_H
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#include <linux/types.h>
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/* nfnetlink groups: Up to 32 maximum */
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#define NF_NETLINK_CONNTRACK_NEW 0x00000001
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#define NF_NETLINK_CONNTRACK_UPDATE 0x00000002
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#define NF_NETLINK_CONNTRACK_DESTROY 0x00000004
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#define NF_NETLINK_CONNTRACK_EXP_NEW 0x00000008
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#define NF_NETLINK_CONNTRACK_EXP_UPDATE 0x00000010
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#define NF_NETLINK_CONNTRACK_EXP_DESTROY 0x00000020
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/* Generic structure for encapsulation optional netfilter information.
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* It is reminiscent of sockaddr, but with sa_family replaced
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* with attribute type.
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* ! This should someday be put somewhere generic as now rtnetlink and
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* ! nfnetlink use the same attributes methods. - J. Schulist.
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*/
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struct nfattr
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{
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u_int16_t nfa_len;
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u_int16_t nfa_type;
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} __attribute__ ((packed));
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/* FIXME: Shamelessly copy and pasted from rtnetlink.h, it's time
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* to put this in a generic file */
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#define NFA_ALIGNTO 4
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#define NFA_ALIGN(len) (((len) + NFA_ALIGNTO - 1) & ~(NFA_ALIGNTO - 1))
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#define NFA_OK(nfa,len) ((len) > 0 && (nfa)->nfa_len >= sizeof(struct nfattr) \
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&& (nfa)->nfa_len <= (len))
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#define NFA_NEXT(nfa,attrlen) ((attrlen) -= NFA_ALIGN((nfa)->nfa_len), \
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(struct nfattr *)(((char *)(nfa)) + NFA_ALIGN((nfa)->nfa_len)))
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#define NFA_LENGTH(len) (NFA_ALIGN(sizeof(struct nfattr)) + (len))
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#define NFA_SPACE(len) NFA_ALIGN(NFA_LENGTH(len))
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#define NFA_DATA(nfa) ((void *)(((char *)(nfa)) + NFA_LENGTH(0)))
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#define NFA_PAYLOAD(nfa) ((int)((nfa)->nfa_len) - NFA_LENGTH(0))
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#define NFA_NEST(skb, type) \
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({ struct nfattr *__start = (struct nfattr *) (skb)->tail; \
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NFA_PUT(skb, type, 0, NULL); \
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__start; })
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#define NFA_NEST_END(skb, start) \
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({ (start)->nfa_len = ((skb)->tail - (unsigned char *) (start)); \
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(skb)->len; })
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#define NFA_NEST_CANCEL(skb, start) \
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({ if (start) \
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skb_trim(skb, (unsigned char *) (start) - (skb)->data); \
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-1; })
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/* General form of address family dependent message.
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*/
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struct nfgenmsg {
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u_int8_t nfgen_family; /* AF_xxx */
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u_int8_t version; /* nfnetlink version */
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u_int16_t res_id; /* resource id */
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} __attribute__ ((packed));
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#define NFNETLINK_V1 1
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#define NFM_NFA(n) ((struct nfattr *)(((char *)(n)) \
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+ NLMSG_ALIGN(sizeof(struct nfgenmsg))))
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#define NFM_PAYLOAD(n) NLMSG_PAYLOAD(n, sizeof(struct nfgenmsg))
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/* netfilter netlink message types are split in two pieces:
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* 8 bit subsystem, 8bit operation.
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*/
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#define NFNL_SUBSYS_ID(x) ((x & 0xff00) >> 8)
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#define NFNL_MSG_TYPE(x) (x & 0x00ff)
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enum nfnl_subsys_id {
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NFNL_SUBSYS_NONE = 0,
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NFNL_SUBSYS_CTNETLINK,
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NFNL_SUBSYS_CTNETLINK_EXP,
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NFNL_SUBSYS_IPTNETLINK,
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NFNL_SUBSYS_QUEUE,
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NFNL_SUBSYS_ULOG,
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NFNL_SUBSYS_COUNT,
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};
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#ifdef __KERNEL__
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#include <linux/capability.h>
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struct nfnl_callback
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{
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kernel_cap_t cap_required; /* capabilities required for this msg */
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int (*call)(struct sock *nl, struct sk_buff *skb,
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struct nlmsghdr *nlh, struct nfattr *cda[], int *errp);
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};
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struct nfnetlink_subsystem
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{
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const char *name;
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__u8 subsys_id; /* nfnetlink subsystem ID */
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__u8 cb_count; /* number of callbacks */
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u_int32_t attr_count; /* number of nfattr's */
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struct nfnl_callback *cb; /* callback for individual types */
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};
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extern void __nfa_fill(struct sk_buff *skb, int attrtype,
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int attrlen, const void *data);
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#define NFA_PUT(skb, attrtype, attrlen, data) \
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({ if (skb_tailroom(skb) < (int)NFA_SPACE(attrlen)) goto nfattr_failure; \
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__nfa_fill(skb, attrtype, attrlen, data); })
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extern struct semaphore nfnl_sem;
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#define nfnl_shlock() down(&nfnl_sem)
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#define nfnl_shlock_nowait() down_trylock(&nfnl_sem)
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#define nfnl_shunlock() do { up(&nfnl_sem); \
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if(nfnl && nfnl->sk_receive_queue.qlen) \
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nfnl->sk_data_ready(nfnl, 0); \
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} while(0)
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extern void nfnl_lock(void);
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extern void nfnl_unlock(void);
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extern int nfnetlink_subsys_register(struct nfnetlink_subsystem *n);
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extern int nfnetlink_subsys_unregister(struct nfnetlink_subsystem *n);
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extern int nfattr_parse(struct nfattr *tb[], int maxattr,
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struct nfattr *nfa, int len);
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#define nfattr_parse_nested(tb, max, nfa) \
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nfattr_parse((tb), (max), NFA_DATA((nfa)), NFA_PAYLOAD((nfa)))
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#define nfattr_bad_size(tb, max, cta_min) \
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({ int __i, __res = 0; \
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for (__i=0; __i<max; __i++) \
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if (tb[__i] && NFA_PAYLOAD(tb[__i]) < cta_min[__i]){ \
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__res = 1; \
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break; \
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} \
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__res; \
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})
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extern int nfnetlink_send(struct sk_buff *skb, u32 pid, unsigned group,
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int echo);
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extern int nfnetlink_unicast(struct sk_buff *skb, u_int32_t pid, int flags);
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#endif /* __KERNEL__ */
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#endif /* _NFNETLINK_H */
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