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