/* libnfnetlink.h: Header file for generic netfilter netlink interface * * (C) 2002 Harald Welte * * 2005-10-29 Pablo Neira Ayuso : * Fix NFNL_HEADER_LEN * 2005-11-13 Pablo Neira Ayuso : * Define NETLINK_NETFILTER if it's undefined */ #ifndef __LIBNFNETLINK_H #define __LIBNFNETLINK_H #ifndef aligned_u64 #define aligned_u64 unsigned long long __attribute__((aligned(8))) #endif #include /* for sa_family_t */ #include #include #include #ifndef NETLINK_NETFILTER #define NETLINK_NETFILTER 12 #endif #ifndef SOL_NETLINK #define SOL_NETLINK 270 #endif #ifndef NETLINK_BROADCAST_SEND_ERROR #define NETLINK_BROADCAST_SEND_ERROR 4 #endif #ifndef NETLINK_NO_ENOBUFS #define NETLINK_NO_ENOBUFS 5 #endif #define NLMSG_TAIL(nlh) \ (((void *) (nlh)) + NLMSG_ALIGN((nlh)->nlmsg_len)) #define NFNL_HEADER_LEN (NLMSG_ALIGN(sizeof(struct nlmsghdr)) \ +NLMSG_ALIGN(sizeof(struct nfgenmsg))) #define NFNL_BUFFSIZE 8192 #ifdef __cplusplus extern "C" { #endif struct nfnlhdr { struct nlmsghdr nlh; struct nfgenmsg nfmsg; }; struct nfnl_callback { int (*call)(struct nlmsghdr *nlh, struct nfattr *nfa[], void *data); void *data; u_int16_t attr_count; }; struct nfnl_handle; struct nfnl_subsys_handle; extern int nfnl_fd(struct nfnl_handle *h); extern unsigned int nfnl_portid(const struct nfnl_handle *h); /* get a new library handle */ extern struct nfnl_handle *nfnl_open(void); extern struct nfnl_handle *nfnl_open2(int fd, bool bind); extern int nfnl_close(struct nfnl_handle *); extern int nfnl_close2(struct nfnl_handle *); extern struct nfnl_subsys_handle *nfnl_subsys_open(struct nfnl_handle *, u_int8_t, u_int8_t, unsigned int); extern struct nfnl_subsys_handle *nfnl_subsys_open2(struct nfnl_handle *, u_int8_t, u_int8_t, unsigned int, bool bind); extern void nfnl_subsys_close(struct nfnl_subsys_handle *); /* set and unset sequence tracking */ void nfnl_set_sequence_tracking(struct nfnl_handle *h); void nfnl_unset_sequence_tracking(struct nfnl_handle *h); /* set receive buffer size (for nfnl_catch) */ extern void nfnl_set_rcv_buffer_size(struct nfnl_handle *h, unsigned int size); /* sending of data */ extern int nfnl_send(struct nfnl_handle *, struct nlmsghdr *); extern int nfnl_sendmsg(const struct nfnl_handle *, const struct msghdr *msg, unsigned int flags); extern int nfnl_sendiov(const struct nfnl_handle *nfnlh, const struct iovec *iov, unsigned int num, unsigned int flags); extern void nfnl_fill_hdr(struct nfnl_subsys_handle *, struct nlmsghdr *, unsigned int, u_int8_t, u_int16_t, u_int16_t, u_int16_t); extern __attribute__((deprecated)) int nfnl_talk(struct nfnl_handle *, struct nlmsghdr *, pid_t, unsigned, struct nlmsghdr *, int (*)(struct sockaddr_nl *, struct nlmsghdr *, void *), void *); /* simple challenge/response */ extern __attribute__((deprecated)) int nfnl_listen(struct nfnl_handle *, int (*)(struct sockaddr_nl *, struct nlmsghdr *, void *), void *); /* receiving */ extern ssize_t nfnl_recv(const struct nfnl_handle *h, unsigned char *buf, size_t len); extern int nfnl_callback_register(struct nfnl_subsys_handle *, u_int8_t type, struct nfnl_callback *cb); extern int nfnl_callback_unregister(struct nfnl_subsys_handle *, u_int8_t type); extern int nfnl_handle_packet(struct nfnl_handle *, char *buf, int len); /* parsing */ extern struct nfattr *nfnl_parse_hdr(const struct nfnl_handle *nfnlh, const struct nlmsghdr *nlh, struct nfgenmsg **genmsg); extern int nfnl_check_attributes(const struct nfnl_handle *nfnlh, const struct nlmsghdr *nlh, struct nfattr *tb[]); extern struct nlmsghdr *nfnl_get_msg_first(struct nfnl_handle *h, const unsigned char *buf, size_t len); extern struct nlmsghdr *nfnl_get_msg_next(struct nfnl_handle *h, const unsigned char *buf, size_t len); /* callback verdict */ enum { NFNL_CB_FAILURE = -1, /* failure */ NFNL_CB_STOP = 0, /* stop the query */ NFNL_CB_CONTINUE = 1, /* keep iterating */ }; /* join a certain netlink multicast group */ extern int nfnl_join(const struct nfnl_handle *nfnlh, unsigned int group); /* process a netlink message */ extern int nfnl_process(struct nfnl_handle *h, const unsigned char *buf, size_t len); /* iterator API */ extern struct nfnl_iterator * nfnl_iterator_create(const struct nfnl_handle *h, const char *buf, size_t len); extern void nfnl_iterator_destroy(struct nfnl_iterator *it); extern int nfnl_iterator_process(struct nfnl_handle *h, struct nfnl_iterator *it); extern int nfnl_iterator_next(const struct nfnl_handle *h, struct nfnl_iterator *it); /* replacement for nfnl_listen */ extern int nfnl_catch(struct nfnl_handle *h); /* replacement for nfnl_talk */ extern int nfnl_query(struct nfnl_handle *h, struct nlmsghdr *nlh); #define nfnl_attr_present(tb, attr) \ (tb[attr-1]) #define nfnl_get_data(tb, attr, type) \ ({ type __ret = 0; \ if (tb[attr-1]) \ __ret = *(type *)NFA_DATA(tb[attr-1]); \ __ret; \ }) #define nfnl_get_pointer_to_data(tb, attr, type) \ ({ type *__ret = NULL; \ if (tb[attr-1]) \ __ret = NFA_DATA(tb[attr-1]); \ __ret; \ }) #ifndef NLA_F_NESTED #define NLA_F_NESTED (1 << 15) #endif /* nfnl attribute handling functions */ extern int nfnl_addattr_l(struct nlmsghdr *, int, int, const void *, int); extern int nfnl_addattr8(struct nlmsghdr *, int, int, u_int8_t); extern int nfnl_addattr16(struct nlmsghdr *, int, int, u_int16_t); extern int nfnl_addattr32(struct nlmsghdr *, int, int, u_int32_t); extern int nfnl_nfa_addattr_l(struct nfattr *, int, int, const void *, int); extern int nfnl_nfa_addattr16(struct nfattr *, int, int, u_int16_t); extern int nfnl_nfa_addattr32(struct nfattr *, int, int, u_int32_t); extern int nfnl_parse_attr(struct nfattr **, int, struct nfattr *, int); #define nfnl_parse_nested(tb, max, nfa) \ nfnl_parse_attr((tb), (max), NFA_DATA((nfa)), NFA_PAYLOAD((nfa))) #define nfnl_nest(nlh, bufsize, type) \ ({ struct nfattr *__start = NLMSG_TAIL(nlh); \ nfnl_addattr_l(nlh, bufsize, (NLA_F_NESTED | type), NULL, 0); \ __start; }) #define nfnl_nest_end(nlh, tail) \ ({ (tail)->nfa_len = (void *) NLMSG_TAIL(nlh) - (void *) tail; }) extern void nfnl_build_nfa_iovec(struct iovec *iov, struct nfattr *nfa, u_int16_t type, u_int32_t len, unsigned char *val); extern unsigned int nfnl_rcvbufsiz(const struct nfnl_handle *h, unsigned int size); extern void nfnl_dump_packet(struct nlmsghdr *, int, char *); /* * index to interface name API */ #ifndef IFNAMSIZ #define IFNAMSIZ 16 #endif struct nlif_handle; struct nlif_handle *nlif_open(void); void nlif_close(struct nlif_handle *orig); int nlif_fd(struct nlif_handle *nlif_handle); int nlif_query(struct nlif_handle *nlif_handle); int nlif_catch(struct nlif_handle *nlif_handle); int nlif_index2name(struct nlif_handle *nlif_handle, unsigned int if_index, char *name); int nlif_get_ifflags(const struct nlif_handle *h, unsigned int index, unsigned int *flags); #ifdef __cplusplus } /* extern "C" */ #endif /* Pablo: What is the equivalence of be64_to_cpu in userspace? * * Harald: Good question. I don't think there's a standard way [yet?], * so I'd suggest manually implementing it by "#if little endian" bitshift * operations in C (at least for now). * * All the payload of any nfattr will always be in network byte order. * This would allow easy transport over a real network in the future * (e.g. jamal's netlink2). * * Pablo: I've called it __be64_to_cpu instead of be64_to_cpu, since maybe * there will one in the userspace headers someday. We don't want to * pollute POSIX space naming, */ #include #if __BYTE_ORDER == __BIG_ENDIAN # ifndef __be64_to_cpu # define __be64_to_cpu(x) (x) # endif # else # if __BYTE_ORDER == __LITTLE_ENDIAN # ifndef __be64_to_cpu # define __be64_to_cpu(x) __bswap_64(x) # endif # endif #endif #endif /* __LIBNFNETLINK_H */