package/libs/libnl-tiny/src/include/netlink/handlers.h

   1 /*
   2  * netlink/handlers.c   default netlink message handlers
   3  *
   4  *      This library is free software; you can redistribute it and/or
   5  *      modify it under the terms of the GNU Lesser General Public
   6  *      License as published by the Free Software Foundation version 2.1
   7  *      of the License.
   8  *
   9  * Copyright (c) 2003-2006 Thomas Graf <tgraf@suug.ch>
  10  */
  11
  12 #ifndef NETLINK_HANDLERS_H_
  13 #define NETLINK_HANDLERS_H_
  14
  15 #include <stdio.h>
  16 #include <stdint.h>
  17 #include <sys/socket.h>
  18 #include <sys/types.h>
  19 #include <netlink/netlink-compat.h>
  20 #include <netlink/netlink-kernel.h>
  21 #include <netlink/types.h>
  22
  23 #ifdef __cplusplus
  24 extern "C" {
  25 #endif
  26
  27 struct nl_sock;
  28 struct nl_msg;
  29 struct nl_cb;
  30 /**
  31  * @name Callback Typedefs
  32  * @{
  33  */
  34
  35 /**
  36  * nl_recvmsgs() callback for message processing customization
  37  * @ingroup cb
  38  * @arg msg             netlink message being processed
  39  * @arg arg             argument passwd on through caller
  40  */
  41 typedef int (*nl_recvmsg_msg_cb_t)(struct nl_msg *msg, void *arg);
  42
  43 /**
  44  * nl_recvmsgs() callback for error message processing customization
  45  * @ingroup cb
  46  * @arg nla             netlink address of the peer
  47  * @arg nlerr           netlink error message being processed
  48  * @arg arg             argument passed on through caller
  49  */
  50 typedef int (*nl_recvmsg_err_cb_t)(struct sockaddr_nl *nla,
  51                                    struct nlmsgerr *nlerr, void *arg);
  52
  53 /** @} */
  54
  55 /**
  56  * Callback actions
  57  * @ingroup cb
  58  */
  59 enum nl_cb_action {
  60         /** Proceed with wathever would come next */
  61         NL_OK,
  62         /** Skip this message */
  63         NL_SKIP,
  64         /** Stop parsing altogether and discard remaining messages */
  65         NL_STOP,
  66 };
  67
  68 /**
  69  * Callback kinds
  70  * @ingroup cb
  71  */
  72 enum nl_cb_kind {
  73         /** Default handlers (quiet) */
  74         NL_CB_DEFAULT,
  75         /** Verbose default handlers (error messages printed) */
  76         NL_CB_VERBOSE,
  77         /** Debug handlers for debugging */
  78         NL_CB_DEBUG,
  79         /** Customized handler specified by the user */
  80         NL_CB_CUSTOM,
  81         __NL_CB_KIND_MAX,
  82 };
  83
  84 #define NL_CB_KIND_MAX (__NL_CB_KIND_MAX - 1)
  85
  86 /**
  87  * Callback types
  88  * @ingroup cb
  89  */
  90 enum nl_cb_type {
  91         /** Message is valid */
  92         NL_CB_VALID,
  93         /** Last message in a series of multi part messages received */
  94         NL_CB_FINISH,
  95         /** Report received that data was lost */
  96         NL_CB_OVERRUN,
  97         /** Message wants to be skipped */
  98         NL_CB_SKIPPED,
  99         /** Message is an acknowledge */
 100         NL_CB_ACK,
 101         /** Called for every message received */
 102         NL_CB_MSG_IN,
 103         /** Called for every message sent out except for nl_sendto() */
 104         NL_CB_MSG_OUT,
 105         /** Message is malformed and invalid */
 106         NL_CB_INVALID,
 107         /** Called instead of internal sequence number checking */
 108         NL_CB_SEQ_CHECK,
 109         /** Sending of an acknowledge message has been requested */
 110         NL_CB_SEND_ACK,
 111         __NL_CB_TYPE_MAX,
 112 };
 113
 114 #define NL_CB_TYPE_MAX (__NL_CB_TYPE_MAX - 1)
 115
 116 struct nl_cb
 117 {
 118         nl_recvmsg_msg_cb_t     cb_set[NL_CB_TYPE_MAX+1];
 119         void *                  cb_args[NL_CB_TYPE_MAX+1];
 120
 121         nl_recvmsg_err_cb_t     cb_err;
 122         void *                  cb_err_arg;
 123
 124         /** May be used to replace nl_recvmsgs with your own implementation
 125          * in all internal calls to nl_recvmsgs. */
 126         int                     (*cb_recvmsgs_ow)(struct nl_sock *,
 127                                                   struct nl_cb *);
 128
 129         /** Overwrite internal calls to nl_recv, must return the number of
 130          * octets read and allocate a buffer for the received data. */
 131         int                     (*cb_recv_ow)(struct nl_sock *,
 132                                               struct sockaddr_nl *,
 133                                               unsigned char **,
 134                                               struct ucred **);
 135
 136         /** Overwrites internal calls to nl_send, must send the netlink
 137          * message. */
 138         int                     (*cb_send_ow)(struct nl_sock *,
 139                                               struct nl_msg *);
 140
 141         int                     cb_refcnt;
 142 };
 143
 144
 145 extern struct nl_cb *   nl_cb_alloc(enum nl_cb_kind);
 146 extern struct nl_cb *   nl_cb_clone(struct nl_cb *);
 147 extern void             nl_cb_put(struct nl_cb *);
 148
 149 extern int  nl_cb_set(struct nl_cb *, enum nl_cb_type, enum nl_cb_kind,
 150                       nl_recvmsg_msg_cb_t, void *);
 151 extern int  nl_cb_err(struct nl_cb *, enum nl_cb_kind, nl_recvmsg_err_cb_t,
 152                       void *);
 153
 154 static inline struct nl_cb *nl_cb_get(struct nl_cb *cb)
 155 {
 156         cb->cb_refcnt++;
 157
 158         return cb;
 159 }
 160
 161 /**
 162  * Set up a all callbacks
 163  * @arg cb              callback set
 164  * @arg kind            kind of callback
 165  * @arg func            callback function
 166  * @arg arg             argument to be passwd to callback function
 167  *
 168  * @return 0 on success or a negative error code
 169  */
 170 static inline int nl_cb_set_all(struct nl_cb *cb, enum nl_cb_kind kind,
 171                   nl_recvmsg_msg_cb_t func, void *arg)
 172 {
 173         int i, err;
 174
 175         for (i = 0; i <= NL_CB_TYPE_MAX; i++) {
 176                 err = nl_cb_set(cb,(enum nl_cb_type)i, kind, func, arg);
 177                 if (err < 0)
 178                         return err;
 179         }
 180
 181         return 0;
 182 }
 183
 184
 185 /**
 186  * @name Overwriting
 187  * @{
 188  */
 189
 190 /**
 191  * Overwrite internal calls to nl_recvmsgs()
 192  * @arg cb              callback set
 193  * @arg func            replacement callback for nl_recvmsgs()
 194  */
 195 static inline void nl_cb_overwrite_recvmsgs(struct nl_cb *cb,
 196                               int (*func)(struct nl_sock *, struct nl_cb *))
 197 {
 198         cb->cb_recvmsgs_ow = func;
 199 }
 200
 201 /**
 202  * Overwrite internal calls to nl_recv()
 203  * @arg cb              callback set
 204  * @arg func            replacement callback for nl_recv()
 205  */
 206 static inline void nl_cb_overwrite_recv(struct nl_cb *cb,
 207                           int (*func)(struct nl_sock *, struct sockaddr_nl *,
 208                                       unsigned char **, struct ucred **))
 209 {
 210         cb->cb_recv_ow = func;
 211 }
 212
 213 /**
 214  * Overwrite internal calls to nl_send()
 215  * @arg cb              callback set
 216  * @arg func            replacement callback for nl_send()
 217  */
 218 static inline void nl_cb_overwrite_send(struct nl_cb *cb,
 219                           int (*func)(struct nl_sock *, struct nl_msg *))
 220 {
 221         cb->cb_send_ow = func;
 222 }
 223
 224 /** @} */
 225
 226
 227 #ifdef __cplusplus
 228 }
 229 #endif
 230
 231 #endif