release/src/router/libnfnetlink/include/libnfnetlink/libnfnetlink.h

   1 /* libnfnetlink.h: Header file for generic netfilter netlink interface
   2  *
   3  * (C) 2002 Harald Welte <laforge@gnumonks.org>
   4  *
   5  * 2005-10-29 Pablo Neira Ayuso <pablo@netfilter.org>:
   6  *      Fix NFNL_HEADER_LEN
   7  * 2005-11-13 Pablo Neira Ayuso <pablo@netfilter.org>:
   8  *      Define NETLINK_NETFILTER if it's undefined
   9  */
  10
  11 #ifndef __LIBNFNETLINK_H
  12 #define __LIBNFNETLINK_H
  13
  14 #ifndef aligned_u64
  15 #define aligned_u64 unsigned long long __attribute__((aligned(8)))
  16 #endif
  17
  18 #include <sys/socket.h> /* for sa_family_t */
  19 #include <linux/netlink.h>
  20 #include <libnfnetlink/linux_nfnetlink.h>
  21
  22 #ifndef NETLINK_NETFILTER
  23 #define NETLINK_NETFILTER 12
  24 #endif
  25
  26 #ifndef SOL_NETLINK
  27 #define SOL_NETLINK     270
  28 #endif
  29
  30 #ifndef NETLINK_BROADCAST_SEND_ERROR
  31 #define NETLINK_BROADCAST_SEND_ERROR 4
  32 #endif
  33
  34 #ifndef NETLINK_NO_ENOBUFS
  35 #define NETLINK_NO_ENOBUFS 5
  36 #endif
  37
  38 #define NLMSG_TAIL(nlh) \
  39         (((void *) (nlh)) + NLMSG_ALIGN((nlh)->nlmsg_len))
  40
  41 #define NFNL_HEADER_LEN (NLMSG_ALIGN(sizeof(struct nlmsghdr))   \
  42                          +NLMSG_ALIGN(sizeof(struct nfgenmsg)))
  43
  44 #define NFNL_BUFFSIZE           8192
  45
  46 #ifdef __cplusplus
  47 extern "C" {
  48 #endif
  49
  50 struct nfnlhdr {
  51         struct nlmsghdr nlh;
  52         struct nfgenmsg nfmsg;
  53 };
  54
  55 struct nfnl_callback {
  56         int (*call)(struct nlmsghdr *nlh, struct nfattr *nfa[], void *data);
  57         void *data;
  58         u_int16_t attr_count;
  59 };
  60
  61 struct nfnl_handle;
  62 struct nfnl_subsys_handle;
  63
  64 extern int nfnl_fd(struct nfnl_handle *h);
  65 extern unsigned int nfnl_portid(const struct nfnl_handle *h);
  66
  67 /* get a new library handle */
  68 extern struct nfnl_handle *nfnl_open(void);
  69 extern int nfnl_close(struct nfnl_handle *);
  70
  71 extern struct nfnl_subsys_handle *nfnl_subsys_open(struct nfnl_handle *,
  72                                                    u_int8_t, u_int8_t,
  73                                                    unsigned int);
  74 extern void nfnl_subsys_close(struct nfnl_subsys_handle *);
  75
  76 /* set and unset sequence tracking */
  77 void nfnl_set_sequence_tracking(struct nfnl_handle *h);
  78 void nfnl_unset_sequence_tracking(struct nfnl_handle *h);
  79
  80 /* set receive buffer size (for nfnl_catch) */
  81 extern void nfnl_set_rcv_buffer_size(struct nfnl_handle *h, unsigned int size);
  82
  83 /* sending of data */
  84 extern int nfnl_send(struct nfnl_handle *, struct nlmsghdr *);
  85 extern int nfnl_sendmsg(const struct nfnl_handle *, const struct msghdr *msg,
  86                         unsigned int flags);
  87 extern int nfnl_sendiov(const struct nfnl_handle *nfnlh,
  88                         const struct iovec *iov, unsigned int num,
  89                         unsigned int flags);
  90 extern void nfnl_fill_hdr(struct nfnl_subsys_handle *, struct nlmsghdr *,
  91                           unsigned int, u_int8_t, u_int16_t, u_int16_t,
  92                           u_int16_t);
  93 extern __attribute__((deprecated)) int
  94 nfnl_talk(struct nfnl_handle *, struct nlmsghdr *, pid_t,
  95           unsigned, struct nlmsghdr *,
  96           int (*)(struct sockaddr_nl *, struct nlmsghdr *, void *), void *);
  97
  98 /* simple challenge/response */
  99 extern __attribute__((deprecated)) int
 100 nfnl_listen(struct nfnl_handle *,
 101             int (*)(struct sockaddr_nl *, struct nlmsghdr *, void *), void *);
 102
 103 /* receiving */
 104 extern ssize_t nfnl_recv(const struct nfnl_handle *h, unsigned char *buf, size_t len);
 105 extern int nfnl_callback_register(struct nfnl_subsys_handle *,
 106                                   u_int8_t type, struct nfnl_callback *cb);
 107 extern int nfnl_callback_unregister(struct nfnl_subsys_handle *, u_int8_t type);
 108 extern int nfnl_handle_packet(struct nfnl_handle *, char *buf, int len);
 109
 110 /* parsing */
 111 extern struct nfattr *nfnl_parse_hdr(const struct nfnl_handle *nfnlh,
 112                                      const struct nlmsghdr *nlh,
 113                                      struct nfgenmsg **genmsg);
 114 extern int nfnl_check_attributes(const struct nfnl_handle *nfnlh,
 115                                  const struct nlmsghdr *nlh,
 116                                  struct nfattr *tb[]);
 117 extern struct nlmsghdr *nfnl_get_msg_first(struct nfnl_handle *h,
 118                                            const unsigned char *buf,
 119                                            size_t len);
 120 extern struct nlmsghdr *nfnl_get_msg_next(struct nfnl_handle *h,
 121                                           const unsigned char *buf,
 122                                           size_t len);
 123
 124 /* callback verdict */
 125 enum {
 126         NFNL_CB_FAILURE = -1,   /* failure */
 127         NFNL_CB_STOP = 0,       /* stop the query */
 128         NFNL_CB_CONTINUE = 1,   /* keep iterating */
 129 };
 130
 131 /* join a certain netlink multicast group */
 132 extern int nfnl_join(const struct nfnl_handle *nfnlh, unsigned int group);
 133
 134 /* process a netlink message */
 135 extern int nfnl_process(struct nfnl_handle *h,
 136                         const unsigned char *buf,
 137                         size_t len);
 138
 139 /* iterator API */
 140
 141 extern struct nfnl_iterator *
 142 nfnl_iterator_create(const struct nfnl_handle *h,
 143                      const char *buf,
 144                      size_t len);
 145
 146 extern void nfnl_iterator_destroy(struct nfnl_iterator *it);
 147
 148 extern int nfnl_iterator_process(struct nfnl_handle *h,
 149                                  struct nfnl_iterator *it);
 150
 151 extern int nfnl_iterator_next(const struct nfnl_handle *h,
 152                               struct nfnl_iterator *it);
 153
 154 /* replacement for nfnl_listen */
 155 extern int nfnl_catch(struct nfnl_handle *h);
 156
 157 /* replacement for nfnl_talk */
 158 extern int nfnl_query(struct nfnl_handle *h, struct nlmsghdr *nlh);
 159
 160 #define nfnl_attr_present(tb, attr)                     \
 161         (tb[attr-1])
 162
 163 #define nfnl_get_data(tb, attr, type)                   \
 164         ({      type __ret = 0;                         \
 165          if (tb[attr-1])                                \
 166          __ret = *(type *)NFA_DATA(tb[attr-1]);         \
 167          __ret;                                         \
 168          })
 169
 170 #define nfnl_get_pointer_to_data(tb, attr, type)        \
 171         ({      type *__ret = NULL;                     \
 172          if (tb[attr-1])                                \
 173          __ret = NFA_DATA(tb[attr-1]);                  \
 174          __ret;                                         \
 175          })
 176
 177 #ifndef NLA_F_NESTED
 178 #define NLA_F_NESTED            (1 << 15)
 179 #endif
 180
 181 /* nfnl attribute handling functions */
 182 extern int nfnl_addattr_l(struct nlmsghdr *, int, int, const void *, int);
 183 extern int nfnl_addattr8(struct nlmsghdr *, int, int, u_int8_t);
 184 extern int nfnl_addattr16(struct nlmsghdr *, int, int, u_int16_t);
 185 extern int nfnl_addattr32(struct nlmsghdr *, int, int, u_int32_t);
 186 extern int nfnl_nfa_addattr_l(struct nfattr *, int, int, const void *, int);
 187 extern int nfnl_nfa_addattr16(struct nfattr *, int, int, u_int16_t);
 188 extern int nfnl_nfa_addattr32(struct nfattr *, int, int, u_int32_t);
 189 extern int nfnl_parse_attr(struct nfattr **, int, struct nfattr *, int);
 190 #define nfnl_parse_nested(tb, max, nfa) \
 191         nfnl_parse_attr((tb), (max), NFA_DATA((nfa)), NFA_PAYLOAD((nfa)))
 192 #define nfnl_nest(nlh, bufsize, type)                           \
 193 ({      struct nfattr *__start = NLMSG_TAIL(nlh);               \
 194         nfnl_addattr_l(nlh, bufsize, (NLA_F_NESTED | type), NULL, 0);   \
 195         __start; })
 196 #define nfnl_nest_end(nlh, tail)                                \
 197 ({      (tail)->nfa_len = (void *) NLMSG_TAIL(nlh) - (void *) tail; })
 198
 199 extern void nfnl_build_nfa_iovec(struct iovec *iov, struct nfattr *nfa,
 200                                  u_int16_t type, u_int32_t len,
 201                                  unsigned char *val);
 202 extern unsigned int nfnl_rcvbufsiz(const struct nfnl_handle *h,
 203                                    unsigned int size);
 204
 205
 206 extern void nfnl_dump_packet(struct nlmsghdr *, int, char *);
 207
 208 /*
 209  * index to interface name API
 210  */
 211
 212 #ifndef IFNAMSIZ
 213 #define IFNAMSIZ 16
 214 #endif
 215
 216 struct nlif_handle;
 217
 218 struct nlif_handle *nlif_open(void);
 219 void nlif_close(struct nlif_handle *orig);
 220 int nlif_fd(struct nlif_handle *nlif_handle);
 221 int nlif_query(struct nlif_handle *nlif_handle);
 222 int nlif_catch(struct nlif_handle *nlif_handle);
 223 int nlif_index2name(struct nlif_handle *nlif_handle,
 224                     unsigned int if_index,
 225                     char *name);
 226 int nlif_get_ifflags(const struct nlif_handle *h,
 227                      unsigned int index,
 228                      unsigned int *flags);
 229
 230 #ifdef __cplusplus
 231 } /* extern "C" */
 232 #endif
 233
 234 /* Pablo: What is the equivalence of be64_to_cpu in userspace?
 235  *
 236  * Harald: Good question.  I don't think there's a standard way [yet?],
 237  * so I'd suggest manually implementing it by "#if little endian" bitshift
 238  * operations in C (at least for now).
 239  *
 240  * All the payload of any nfattr will always be in network byte order.
 241  * This would allow easy transport over a real network in the future
 242  * (e.g. jamal's netlink2).
 243  *
 244  * Pablo: I've called it __be64_to_cpu instead of be64_to_cpu, since maybe
 245  * there will one in the userspace headers someday. We don't want to
 246  * pollute POSIX space naming,
 247  */
 248
 249 #include <byteswap.h>
 250 #if __BYTE_ORDER == __BIG_ENDIAN
 251 #  ifndef __be64_to_cpu
 252 #  define __be64_to_cpu(x)      (x)
 253 #  endif
 254 # else
 255 # if __BYTE_ORDER == __LITTLE_ENDIAN
 256 #  ifndef __be64_to_cpu
 257 #  define __be64_to_cpu(x)      __bswap_64(x)
 258 #  endif
 259 # endif
 260 #endif
 261
 262 #endif /* __LIBNFNETLINK_H */