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diff --git a/Documentation/networking/lapb-module.txt b/Documentation/networking/lapb-module.txt deleted file mode 100644 index d4fc8f221559..000000000000 --- a/Documentation/networking/lapb-module.txt +++ /dev/null @@ -1,263 +0,0 @@ - The Linux LAPB Module Interface 1.3 - - Jonathan Naylor 29.12.96 - -Changed (Henner Eisen, 2000-10-29): int return value for data_indication() - -The LAPB module will be a separately compiled module for use by any parts of -the Linux operating system that require a LAPB service. This document -defines the interfaces to, and the services provided by this module. The -term module in this context does not imply that the LAPB module is a -separately loadable module, although it may be. The term module is used in -its more standard meaning. - -The interface to the LAPB module consists of functions to the module, -callbacks from the module to indicate important state changes, and -structures for getting and setting information about the module. - -Structures ----------- - -Probably the most important structure is the skbuff structure for holding -received and transmitted data, however it is beyond the scope of this -document. - -The two LAPB specific structures are the LAPB initialisation structure and -the LAPB parameter structure. These will be defined in a standard header -file, <linux/lapb.h>. The header file <net/lapb.h> is internal to the LAPB -module and is not for use. - -LAPB Initialisation Structure ------------------------------ - -This structure is used only once, in the call to lapb_register (see below). -It contains information about the device driver that requires the services -of the LAPB module. - -struct lapb_register_struct { - void (*connect_confirmation)(int token, int reason); - void (*connect_indication)(int token, int reason); - void (*disconnect_confirmation)(int token, int reason); - void (*disconnect_indication)(int token, int reason); - int (*data_indication)(int token, struct sk_buff *skb); - void (*data_transmit)(int token, struct sk_buff *skb); -}; - -Each member of this structure corresponds to a function in the device driver -that is called when a particular event in the LAPB module occurs. These will -be described in detail below. If a callback is not required (!!) then a NULL -may be substituted. - - -LAPB Parameter Structure ------------------------- - -This structure is used with the lapb_getparms and lapb_setparms functions -(see below). They are used to allow the device driver to get and set the -operational parameters of the LAPB implementation for a given connection. - -struct lapb_parms_struct { - unsigned int t1; - unsigned int t1timer; - unsigned int t2; - unsigned int t2timer; - unsigned int n2; - unsigned int n2count; - unsigned int window; - unsigned int state; - unsigned int mode; -}; - -T1 and T2 are protocol timing parameters and are given in units of 100ms. N2 -is the maximum number of tries on the link before it is declared a failure. -The window size is the maximum number of outstanding data packets allowed to -be unacknowledged by the remote end, the value of the window is between 1 -and 7 for a standard LAPB link, and between 1 and 127 for an extended LAPB -link. - -The mode variable is a bit field used for setting (at present) three values. -The bit fields have the following meanings: - -Bit Meaning -0 LAPB operation (0=LAPB_STANDARD 1=LAPB_EXTENDED). -1 [SM]LP operation (0=LAPB_SLP 1=LAPB=MLP). -2 DTE/DCE operation (0=LAPB_DTE 1=LAPB_DCE) -3-31 Reserved, must be 0. - -Extended LAPB operation indicates the use of extended sequence numbers and -consequently larger window sizes, the default is standard LAPB operation. -MLP operation is the same as SLP operation except that the addresses used by -LAPB are different to indicate the mode of operation, the default is Single -Link Procedure. The difference between DCE and DTE operation is (i) the -addresses used for commands and responses, and (ii) when the DCE is not -connected, it sends DM without polls set, every T1. The upper case constant -names will be defined in the public LAPB header file. - - -Functions ---------- - -The LAPB module provides a number of function entry points. - - -int lapb_register(void *token, struct lapb_register_struct); - -This must be called before the LAPB module may be used. If the call is -successful then LAPB_OK is returned. The token must be a unique identifier -generated by the device driver to allow for the unique identification of the -instance of the LAPB link. It is returned by the LAPB module in all of the -callbacks, and is used by the device driver in all calls to the LAPB module. -For multiple LAPB links in a single device driver, multiple calls to -lapb_register must be made. The format of the lapb_register_struct is given -above. The return values are: - -LAPB_OK LAPB registered successfully. -LAPB_BADTOKEN Token is already registered. -LAPB_NOMEM Out of memory - - -int lapb_unregister(void *token); - -This releases all the resources associated with a LAPB link. Any current -LAPB link will be abandoned without further messages being passed. After -this call, the value of token is no longer valid for any calls to the LAPB -function. The valid return values are: - -LAPB_OK LAPB unregistered successfully. -LAPB_BADTOKEN Invalid/unknown LAPB token. - - -int lapb_getparms(void *token, struct lapb_parms_struct *parms); - -This allows the device driver to get the values of the current LAPB -variables, the lapb_parms_struct is described above. The valid return values -are: - -LAPB_OK LAPB getparms was successful. -LAPB_BADTOKEN Invalid/unknown LAPB token. - - -int lapb_setparms(void *token, struct lapb_parms_struct *parms); - -This allows the device driver to set the values of the current LAPB -variables, the lapb_parms_struct is described above. The values of t1timer, -t2timer and n2count are ignored, likewise changing the mode bits when -connected will be ignored. An error implies that none of the values have -been changed. The valid return values are: - -LAPB_OK LAPB getparms was successful. -LAPB_BADTOKEN Invalid/unknown LAPB token. -LAPB_INVALUE One of the values was out of its allowable range. - - -int lapb_connect_request(void *token); - -Initiate a connect using the current parameter settings. The valid return -values are: - -LAPB_OK LAPB is starting to connect. -LAPB_BADTOKEN Invalid/unknown LAPB token. -LAPB_CONNECTED LAPB module is already connected. - - -int lapb_disconnect_request(void *token); - -Initiate a disconnect. The valid return values are: - -LAPB_OK LAPB is starting to disconnect. -LAPB_BADTOKEN Invalid/unknown LAPB token. -LAPB_NOTCONNECTED LAPB module is not connected. - - -int lapb_data_request(void *token, struct sk_buff *skb); - -Queue data with the LAPB module for transmitting over the link. If the call -is successful then the skbuff is owned by the LAPB module and may not be -used by the device driver again. The valid return values are: - -LAPB_OK LAPB has accepted the data. -LAPB_BADTOKEN Invalid/unknown LAPB token. -LAPB_NOTCONNECTED LAPB module is not connected. - - -int lapb_data_received(void *token, struct sk_buff *skb); - -Queue data with the LAPB module which has been received from the device. It -is expected that the data passed to the LAPB module has skb->data pointing -to the beginning of the LAPB data. If the call is successful then the skbuff -is owned by the LAPB module and may not be used by the device driver again. -The valid return values are: - -LAPB_OK LAPB has accepted the data. -LAPB_BADTOKEN Invalid/unknown LAPB token. - - -Callbacks ---------- - -These callbacks are functions provided by the device driver for the LAPB -module to call when an event occurs. They are registered with the LAPB -module with lapb_register (see above) in the structure lapb_register_struct -(see above). - - -void (*connect_confirmation)(void *token, int reason); - -This is called by the LAPB module when a connection is established after -being requested by a call to lapb_connect_request (see above). The reason is -always LAPB_OK. - - -void (*connect_indication)(void *token, int reason); - -This is called by the LAPB module when the link is established by the remote -system. The value of reason is always LAPB_OK. - - -void (*disconnect_confirmation)(void *token, int reason); - -This is called by the LAPB module when an event occurs after the device -driver has called lapb_disconnect_request (see above). The reason indicates -what has happened. In all cases the LAPB link can be regarded as being -terminated. The values for reason are: - -LAPB_OK The LAPB link was terminated normally. -LAPB_NOTCONNECTED The remote system was not connected. -LAPB_TIMEDOUT No response was received in N2 tries from the remote - system. - - -void (*disconnect_indication)(void *token, int reason); - -This is called by the LAPB module when the link is terminated by the remote -system or another event has occurred to terminate the link. This may be -returned in response to a lapb_connect_request (see above) if the remote -system refused the request. The values for reason are: - -LAPB_OK The LAPB link was terminated normally by the remote - system. -LAPB_REFUSED The remote system refused the connect request. -LAPB_NOTCONNECTED The remote system was not connected. -LAPB_TIMEDOUT No response was received in N2 tries from the remote - system. - - -int (*data_indication)(void *token, struct sk_buff *skb); - -This is called by the LAPB module when data has been received from the -remote system that should be passed onto the next layer in the protocol -stack. The skbuff becomes the property of the device driver and the LAPB -module will not perform any more actions on it. The skb->data pointer will -be pointing to the first byte of data after the LAPB header. - -This method should return NET_RX_DROP (as defined in the header -file include/linux/netdevice.h) if and only if the frame was dropped -before it could be delivered to the upper layer. - - -void (*data_transmit)(void *token, struct sk_buff *skb); - -This is called by the LAPB module when data is to be transmitted to the -remote system by the device driver. The skbuff becomes the property of the -device driver and the LAPB module will not perform any more actions on it. -The skb->data pointer will be pointing to the first byte of the LAPB header. |