patch-1.3.69 linux/Documentation/isdn/INTERFACE
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- Lines: 610
- Date:
Mon Feb 26 11:58:03 1996
- Orig file:
v1.3.68/linux/Documentation/isdn/INTERFACE
- Orig date:
Thu Jan 1 02:00:00 1970
diff -u --recursive --new-file v1.3.68/linux/Documentation/isdn/INTERFACE linux/Documentation/isdn/INTERFACE
@@ -0,0 +1,609 @@
+
+Description of the Interface between Linklevel an Harwarelevel
+ of isdn4linux:
+
+
+ The Communication between Linklevel (LL) and Hardwarelevel (HL)
+ is based on the struct isdn_if (defined in isdnif.h).
+
+ An HL-driver can register itself at LL by calling the function
+ register_isdn() with a pointer to that struct. Prior to that, it has
+ to preset some of the fields of isdn_if. The LL sets the rest of
+ the fields. All further communication is done via callbacks using
+ the funtion-pointers defined in isdn_if.
+
+ ATTENTION, CHANGES since version 0.6 are marked with "***CHANGE0.6"!
+ ATTENTION, CHANGES since version 0.7 are marked with "***CHANGE0.7"!
+ ATTENTION, CHANGES since version 0.71 are marked with "***CHANGE0.7.1"!
+
+1. Description of the fields of isdn_if:
+
+ int channels;
+
+ This field has to be set by the HL-driver to the number of channels
+ supported prior to calling register_isdn(). Upon return of the call,
+ the LL puts an id there, which has to be used by the HL-driver when
+ invoking the other callbacks.
+
+ int maxbufsize;
+
+ ***CHANGE0.6: New since this version.
+
+ Also to be preset by the HL-driver. With this value the HL-driver
+ tells to the LL the maximum size of a data-packet it will accept.
+
+ unsigned long features;
+
+ To be preset by the HL-driver. Using this field, the HL-driver
+ announces the features supported. At the moment this is limited to
+ report the supported layer2 and layer3-protocols. For setting this
+ field the constants ISDN_FEATURE..., declared in isdnif.h have to be
+ used.
+
+ ***CHANGE0.7.1: The line type (1TR6, EDSS1) has to be set.
+
+ unsigned short hl_hdrlen;
+
+ ***CHANGED.7.4: New field.
+
+ To be preset by the HL-driver, if it supports sk_buff's. The driver
+ should put here the amount of additional space needed in sk-buff's for
+ it's internal purposes. Drivers not supporting sk_buff's should put
+ initialize this field to 0.
+
+ void (*rcvcallb)(int, int, u_char*, int);
+
+ This field will be set by LL. The HL-driver delivers received data-
+ packets by calling this function.
+
+ Parameter:
+ int driver-Id
+ int Channel-number locally to the driver. (starting with 0)
+ u_char Pointer to received data. (in kernel-space)
+ int length of data-packet.
+
+ void (*rcvcallb_skb)(int, int, struct sk_buff *)
+
+ ***CHANGED.7.4: New field.
+
+ This field will be set by LL. The HL-driver delivers received data-
+ packets by calling this function. Upon calling, the HL-driver must
+ already have it's private data pulled off the head of the sk_buff.
+
+ Parameter:
+ int driver-Id
+ int Channel-number locally to the driver. (starting with 0)
+ struct sk_buff * Pointer to sk_buff, containing received data.
+
+ int (*statcallb)(isdn_ctrl*);
+
+ This field will be set by LL. This function has to be called by the
+ HL-driver for signaling status-changes or other events to the LL.
+
+ Parameter:
+ isdn_ctrl*
+
+ The struct isdn_ctrl also defined in isdn_if. The exact meaning of it's
+ fields is described together with the descriptions of the possible
+ events. Here is only a short description of the fields:
+
+ driver = driver Id.
+ command = event-type. (one of the constants ISDN_STAT_...)
+ arg = depends on event-type.
+ num = depends on event-type.
+
+ Returnvalue:
+ 0 on success, else -1
+
+ int (*command)(isdn_ctrl*);
+
+ This field has to be preset by the HL-driver. It points to a function,
+ to be called by LL to perform functions like dialing, B-channel
+ setup, etc. The exact meaning of the parameters is described with the
+ descriptions of the possible commands.
+
+ Parameter:
+ isdn_ctrl*
+ driver = driver-Id
+ command = command to perform. (one of the constants ISDN_CMD_...)
+ arg = depends on command.
+ num = depends on command.
+
+ Returnvalue:
+ >=0 on success, else error-code (-ENODEV etc.)
+
+ int (*writebuf)(int, int, u_char*, int, int);
+
+ This field has to be preset by the HL-driver. The given funtion will
+ be called by the LL for delivering data to be send via B-Channel.
+
+ Parameter:
+ int driver-Id ***CHANGE.7.4: New parameter.
+ int channel-number locally to the HL-driver. (starts with 0)
+ u_char* pointer to data.
+ int length of data-packet.
+ int flag: 0 = call from within kernel-space. (HL-driver must use
+ memcpy, may NOT use schedule())
+ 1 = call from user-space. (HL-driver must use
+ memcpy_fromfs, use of schedule() allowed)
+
+ Returnvalue:
+ Length of data accepted on success, else error-code (-EINVAL on
+ oversized packets etc.)
+
+ int (*writebuf_skb)(int, int, struct sk_buff *)
+
+ ***CHANGED.7.4: New field.
+
+ This field has to be preset by the HL-driver. The given function will
+ be called by the LL for delivering data to be send via B-Channel.
+
+
+ Parameter:
+ int driver-Id ***CHANGE.7.4: New parameter.
+ int channel-number locally to the HL-driver. (starts with 0)
+ struct sk_buff * Pointer to sk_buff containing data to be send via
+ B-channel.
+
+ Returnvalue:
+ Length of data accepted on success, else error-code (-EINVAL on
+ oversized packets etc.)
+
+NOTE on writebuf and writebuf_skb:
+ The HL-driver may initialize one of the field's to NULL, in which case
+ the LL will call the non-NULL function only.
+
+ int (*writecmd)(u_char*, int, int);
+
+ This field has to be preset by the HL-driver. The given function will be
+ called to perform write-requests on /dev/isdnctrl (i.e. sending commands
+ to the card) The data-format is hardware-specific. This function is
+ intended for debugging only. It is not necessary for normal operation
+ and never will be called by the tty-emulation- or network-code. If
+ this functin is not supported, the driver has to set NULL here.
+
+ Parameter:
+ u_char* pointer to data.
+ int length of data.
+ int flag: 0 = call from within kernel-space. (HL-driver must use
+ memcpy, may NOT use schedule())
+ 1 = call from user-space. (HL-driver must use
+ memcpy_fromfs, use of schedule() allowed)
+
+ Returnvalue:
+ Length of data accepted on success, else error-code (-EINVAL etc.)
+
+ int (*readstat)(u_char*, int, int);
+
+ This field has to be preset by the HL-driver. The given function will be
+ called to perform read-requests on /dev/isdnctrl (i.e. reading repies
+ from the card) The data-format is hardware-specific. This function is
+ intended for debugging only. It is not necessary for normal operation
+ and never will be called by the tty-emulation- or network-code. If
+ this functin is not supported, the driver has to set NULL here.
+
+ Parameter:
+ u_char* pointer to data.
+ int length of data.
+ int flag: 0 = call from within kernel-space. (HL-driver must use
+ memcpy, may NOT use schedule())
+ 1 = call from user-space. (HL-driver must use
+ memcpy_fromfs, use of schedule() allowed)
+
+ Returnvalue:
+ Length of data on success, else error-code (-EINVAL etc.)
+
+ char id[20];
+ ***CHANGE0.7: New since this version.
+
+ This string has to be preset by the HL-driver. It's purpose is for
+ identification of the driver by the user. Eg.: it is shown in the
+ status-info of /dev/isdninfo. Furthermore it is used as Id for binding
+ net-interfaces to a specific channel. If a string of length zero is
+ given, upon return, isdn4linux will replace it by a generic name. (line0,
+ line1 etc.) It is recommended, to make this string configurabele during
+ module-load-time. (copy a global variable to this string.) For doing that,
+ modules 1.2.8 or newer are necessary.
+
+2. Description of the commands, a HL-driver has to support:
+
+ All commands will be performed by calling the funtion command() described
+ above from within the LL. The field command of the struct-parameter will
+ contain the desired command, the field driver always is set to the
+ apropriate driver-Id.
+
+ Until now, the following commands are defined:
+
+
+ ISDN_CMD_IOCTL:
+
+ This command is intended for performing ioctl-calls for configuring
+ hardware or similar purposes (setting port-adresses, loading firmware
+ etc.) For this purpose, in the LL all ioctl-calls with an argument
+ >= ISDN_IOCTL_DRVIOCTL (0x100) will be handed transparently to this
+ function after substracting 0x100 and placing the result in arg.
+ Example:
+ If a userlevel-program calls ioctl(0x101,...) the function gets
+ called with the field command set to 1.
+
+ Parameter:
+ driver = driver-Id.
+ command = ISDN_CMD_IOCTL
+ arg = Original ioctl-cmd - ISDN_IOCTL_DRVIOCTL
+ num = first bytes filled with (unsigned long)arg
+
+ Returnvalue:
+ Depending on driver.
+
+
+ ISDN_CMD_DIAL:
+
+ This command is used to tell the HL-driver it should dial a given
+ number.
+
+ Parameter:
+ driver = driver-Id.
+ command = ISDN_CMD_DIAL
+ arg = channel-number locally to the driver. (starting with 0)
+ num = An ASCII-String containing the number to dial, the own
+ EAZ or MSN, the Service-Indicator and the Additional
+ Info. Format:
+ "%s,%s,%d,%d" RemotePhoneNumber,EazOrMsn,SI,AI
+ If the Line has been designed as SPV (a special german
+ feature, meaning semi-leased-line) the number has to
+ start with an "S".
+ ***CHANGE0.6: In previous versions the EAZ has been given in the
+ highbyte of arg.
+ ***CHANGE0.7.1: New since this version: ServiceIndicator and AddInfo.
+
+ ISDN_CMD_ACCEPTD:
+
+ With this command, the HL-driver is told to accept a D-Channel-setup.
+ (Response to an incoming call)
+
+ Parameter:
+ driver = driver-Id.
+ command = ISDN_CMD_ACCEPTD
+ arg = channel-number locally to the driver. (starting with 0)
+ num = unused.
+
+ ISDN_CMD_ACCEPTB:
+
+ With this command, the HL-driver is told to perform a B-Channel-setup.
+ (after establishing D-Channel-Connection)
+
+ Parameter:
+ driver = driver-Id.
+ command = ISDN_CMD_ACCEPTB
+ arg = channel-number locally to the driver. (starting with 0)
+ num = unused.
+
+ ISDN_CMD_HANGUP:
+
+ With this command, the HL-driver is told to hangup (B-Channel if
+ established first, then D-Channel). This command is also used for
+ actively rejecting an incoming call.
+
+ Parameter:
+ driver = driver-Id.
+ command = ISDN_CMD_HANGUP
+ arg = channel-number locally to the driver. (starting with 0)
+ num = unused.
+
+ ISDN_CMD_CLREAZ:
+
+ With this command, the HL-driver is told not to signal incoming
+ calls to the LL.
+
+ Parameter:
+ driver = driver-Id.
+ command = ISDN_CMD_CLREAZ
+ arg = channel-number locally to the driver. (starting with 0)
+ num = unused.
+
+ ISDN_CMD_SETEAZ:
+
+ With this command, the HL-driver is told to signal incoming calls for
+ the given EAZs/MSNs to the LL.
+
+ Parameter:
+ driver = driver-Id.
+ command = ISDN_CMD_SETEAZ
+ arg = channel-number locally to the driver. (starting with 0)
+ num = ASCII-String, containing the desired EAZ's/MSN's
+ (comma-separated). If an empty String is given, the
+ HL-driver should respond to ALL incoming calls,
+ regardless of the destination-adress.
+ ***CHANGE0.6: New since this version the "empty-string"-feature.
+
+ ISDN_CMD_GETEAZ: (currently unused)
+
+ With this command, the HL-driver is told to report the current setting
+ given with ISDN_CMD_SETEAZ.
+
+ Parameter:
+ driver = driver-Id.
+ command = ISDN_CMD_GETEAZ
+ arg = channel-number locally to the driver. (starting with 0)
+ num = ASCII-String, containing the current EAZ's/MSN's
+
+ ISDN_CMD_SETSIL: (currently unused)
+
+ With this command, the HL-driver is told to signal only incoming
+ calls with the given Service-Indicators.
+
+ Parameter:
+ driver = driver-Id.
+ command = ISDN_CMD_SETSIL
+ arg = channel-number locally to the driver. (starting with 0)
+ num = ASCII-String, containing the desired Service-Indicators.
+
+ ISDN_CMD_GETSIL: (currently unused)
+
+ With this command, the HL-driver is told to return the current
+ Service-Indicators it will respond to.
+
+ Parameter:
+ driver = driver-Id.
+ command = ISDN_CMD_SETSIL
+ arg = channel-number locally to the driver. (starting with 0)
+ num = ASCII-String, containing the current Service-Indicators.
+
+ ISDN_CMD_SETL2:
+
+ With this command, the HL-driver is told to select the given Layer-2-
+ protocol. This command is issued by the LL prior to ISDN_CMD_DIAL or
+ ISDN_CMD_ACCEPTD.
+
+
+ Parameter:
+ driver = driver-Id.
+ command = ISDN_CMD_SETL2
+ arg = channel-number locally to the driver. (starting with 0)
+ logical or'ed with (protocol-Id << 8)
+ protocol-Id is one of the constants ISDN_PROTO_L2...
+ num = unused.
+
+ ISDN_CMD_GETL2: (currently unused)
+
+ With this command, the HL-driver is told to return the current
+ setting of the Layer-2-protocol.
+
+ Parameter:
+ driver = driver-Id.
+ command = ISDN_CMD_GETL2
+ arg = channel-number locally to the driver. (starting with 0)
+ num = unused.
+ Returnvalue:
+ current protocol-Id (one of the constants ISDN_L2_PROTO)
+
+ ISDN_CMD_SETL3:
+
+ With this command, the HL-driver is told to select the given Layer-3-
+ protocol. This command is issued by the LL prior to ISDN_CMD_DIAL or
+ ISDN_CMD_ACCEPTD.
+
+
+ Parameter:
+ driver = driver-Id.
+ command = ISDN_CMD_SETL3
+ arg = channel-number locally to the driver. (starting with 0)
+ logical or'ed with (protocol-Id << 8)
+ protocol-Id is one of the constants ISDN_PROTO_L3...
+ num = unused.
+
+ ISDN_CMD_GETL2: (currently unused)
+
+ With this command, the HL-driver is told to return the current
+ setting of the Layer-3-protocol.
+
+ Parameter:
+ driver = driver-Id.
+ command = ISDN_CMD_GETL3
+ arg = channel-number locally to the driver. (starting with 0)
+ num = unused.
+ Returnvalue:
+ current protocol-Id (one of the constants ISDN_L3_PROTO)
+
+ ISDN_CMD_LOCK:
+
+ With this command the HL-driver is told, that it will be used by the
+ LL and therefore may not be unloaded. The HL-driver should use
+ MOD_INC_USE_COUNT to tell that to the kernel.
+
+ Parameter:
+ driver = driver-Id.
+ command = ISDN_CMD_LOCK
+ arg = unused.
+ num = unused.
+
+ ISDN_CMD_UNLOCK:
+
+ With this command the HL-driver is told, that it is no more used by the
+ LL and therefore may be unloaded. The HL-driver should use
+ DEC_INC_USE_COUNT to tell that to the kernel.
+
+ Parameter:
+ driver = driver-Id.
+ command = ISDN_CMD_UNLOCK
+ arg = unused.
+ num = unused.
+
+3. Description of the events to be signaled by the HL-driver to th LL.
+
+ All status-changes are signaled via calling the previously described
+ function statcallb(). The field command of the struct isdn_cmd has
+ to be set by the HL-driver with the apropriate Status-Id (event-number).
+ The field arg has to be set to the channel-number (locally to the driver,
+ starting with 0) to which this event applies. (Exception: STAVAIL-event)
+
+ Until now, the following Status-Ids are defined:
+
+ ISDN_STAT_AVAIL:
+
+ With this call, the HL-driver signals the availability of new data
+ for readstat(). Used only for debugging-purposes, see description
+ of readstat().
+
+ Parameter:
+ driver = driver-Id
+ command = ISDN_STAT_STAVAIL
+ arg = length of available data.
+ num = unused.
+
+ ISDN_STAT_ICALL:
+
+ With this call, the HL-driver signals an incoming call to the LL.
+
+ Parameter:
+ driver = driver-Id
+ command = ISDN_STAT_ICALL
+ arg = channel-number, locally to the driver. (starting with 0)
+ num = ASCII-String in the following format:
+ "%s,%d,%d,%s",CallerNumber,ServiceIndicator,AddInfo,
+ CalledNumber.
+
+ ISDN_STAT_RUN:
+
+ With this call, the HL-driver signals availability of the ISDN-card.
+ (after initializing, loading firmware)
+
+ Parameter:
+ driver = driver-Id
+ command = ISDN_STAT_RUN
+ arg = unused.
+ num = unused.
+
+ ISDN_STAT_STOP:
+
+ With this call, the HL-driver signals unavailability of the ISDN-card.
+ (before unloading, while resetting/reconfiguring the card)
+
+ Parameter:
+ driver = driver-Id
+ command = ISDN_STAT_STOP
+ arg = unused.
+ num = unused.
+
+ ISDN_STAT_DCONN:
+
+ With this call, the HL-driver signals the successful establishement of
+ a D-Channel-connection. (Response to ISDN_CMD_ACCEPTD or ISDN_CMD_DIAL)
+
+ Parameter:
+ driver = driver-Id
+ command = ISDN_STAT_DCONN
+ arg = channel-number, locally to the driver. (starting with 0)
+ num = unused.
+
+ ISDN_STAT_BCONN:
+
+ With this call, the HL-driver signals the successful establishement of
+ a B-Channel-connection. (Response to ISDN_CMD_ACCEPTB or because the
+ remote-station has initiated establishement)
+
+ Parameter:
+ driver = driver-Id
+ command = ISDN_STAT_BCONN
+ arg = channel-number, locally to the driver. (starting with 0)
+ num = unused.
+
+ ISDN_STAT_DHUP:
+
+ With this call, the HL-driver signals the shutdown of a
+ D-Channel-connection. This could be a response to a prior ISDN_CMD_HANGUP,
+ or caused by a remote-hangup or if the remote-station has actively
+ rejected a call.
+
+ Parameter:
+ driver = driver-Id
+ command = ISDN_STAT_DHUP
+ arg = channel-number, locally to the driver. (starting with 0)
+ num = unused.
+
+ ISDN_STAT_BHUP:
+
+ With this call, the HL-driver signals the shutdown of a
+ B-Channel-connection. This could be a response to a prior ISDN_CMD_HANGUP,
+ or caused by a remote-hangup.
+
+ Parameter:
+ driver = driver-Id
+ command = ISDN_STAT_BHUP
+ arg = channel-number, locally to the driver. (starting with 0)
+ num = unused.
+
+ ISDN_STAT_CINF:
+
+ With this call, the HL-driver delivers charge-unit information to the
+ LL.
+
+ Parameter:
+ driver = driver-Id
+ command = ISDN_STAT_CINF
+ arg = channel-number, locally to the driver. (starting with 0)
+ num = ASCII string containing charge-units (digits only).
+
+ ISDN_STAT_LOAD: (currently unused)
+
+ ISDN_STAT_UNLOAD:
+
+ With this call, the HL-driver signals that it will be unloaded now. This
+ tells the LL to release all corresponding data-structures.
+
+ Parameter:
+ driver = driver-Id
+ command = ISDN_STAT_UNLOAD
+ arg = unused.
+ num = unused.
+
+ ISDN_STAT_BSENT:
+
+ With this call the HL-driver signals the delivery of a data-packet.
+ This callback is used by the network-interfaces only, tty-Emulation
+ does not need this call.
+
+ Parameter:
+ driver = driver-Id
+ command = ISDN_STAT_BSENT
+ arg = channel-number, locally to the driver. (starting with 0)
+ num = unused.
+
+ ISDN_STAT_NODCH:
+
+ With this call, the driver has to respond to a prior ISDN_CMD_DIAL, if
+ no D-Channel is available.
+
+ Parameter:
+ driver = driver-Id
+ command = ISDN_STAT_NODCH
+ arg = channel-number, locally to the driver. (starting with 0)
+ num = unused.
+
+ ISDN_STAT_ADDCH: (currently unused)
+
+ This call is planned for HL-drivers, which are unable to check card-type
+ or numbers of supported channels before they have loaded any firmware
+ using ioctl. Those HL-driver simply set the channel-parameter to zero
+ or a minimum channel-number when registering, and later if they know
+ the real amount, perform this call, allocating additional channels.
+
+ Parameter:
+ driver = driver-Id
+ command = ISDN_STAT_ADDCH
+ arg = to be defined.
+ num = to be defined.
+
+ ISDN_STAT_CAUSE:
+
+ With this call, the HL-driver delivers CAUSE-messages to the LL.
+ Currently the LL does not use this messages. Their contents is simply
+ logged via kernel-messages. Therefore, currently the format of the
+ messages is currently completely free. However they should be printable.
+
+ Parameter:
+ driver = driver-Id
+ command = ISDN_STAT_NODCH
+ arg = channel-number, locally to the driver. (starting with 0)
+ num = ASCII string containing CAUSE-message.
+
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen, slshen@lbl.gov
with Sam's (original) version of this