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+/*
+ * IrNET protocol module : Synchronous PPP over an IrDA socket.
+ *
+ * Jean II - HPL `00 - <jt@hpl.hp.com>
+ *
+ * This file contains definitions and declarations global to the IrNET module,
+ * all grouped in one place...
+ * This file is a *private* header, so other modules don't want to know
+ * what's in there...
+ *
+ * Note : as most part of the Linux kernel, this module is available
+ * under the GNU General Public License (GPL).
+ */
+
+#ifndef IRNET_H
+#define IRNET_H
+
+/************************** DOCUMENTATION ***************************/
+/*
+ * What is IrNET
+ * -------------
+ * IrNET is a protocol allowing to carry TCP/IP traffic between two
+ * IrDA peers in an efficient fashion. It is a thin layer, passing PPP
+ * packets to IrTTP and vice versa. It uses PPP in synchronous mode,
+ * because IrTTP offer a reliable sequenced packet service (as opposed
+ * to a byte stream). In fact, you could see IrNET as carrying TCP/IP
+ * in a IrDA socket, using PPP to provide the glue.
+ *
+ * The main difference with traditional PPP over IrCOMM is that we
+ * avoid the framing and serial emulation which are a performance
+ * bottleneck. It also allows multipoint communications in a sensible
+ * fashion.
+ *
+ * The main difference with IrLAN is that we use PPP for the link
+ * management, which is more standard, interoperable and flexible than
+ * the IrLAN protocol. For example, PPP adds authentication,
+ * encryption, compression, header compression and automated routing
+ * setup. And, as IrNET let PPP do the hard work, the implementation
+ * is much simpler than IrLAN.
+ *
+ * The Linux implementation
+ * ------------------------
+ * IrNET is written on top of the Linux-IrDA stack, and interface with
+ * the generic Linux PPP driver. Because IrNET depend on recent
+ * changes of the PPP driver interface, IrNET will work only with very
+ * recent kernel (2.3.99-pre6 and up).
+ *
+ * The present implementation offer the following features :
+ * o simple user interface using pppd
+ * o efficient implementation (interface directly to PPP and IrTTP)
+ * o addressing (you can specify the name of the IrNET recipient)
+ * o multipoint operation (limited by IrLAP specification)
+ * o information in /proc/net/irda/irnet
+ * o IrNET events on /dev/irnet (for user space daemon)
+ * o IrNET daemon (irnetd) to automatically handle incoming requests
+ * o Windows 2000 compatibility (tested, but need more work)
+ * Currently missing :
+ * o Lot's of testing (that's your job)
+ * o Connection retries (may be too hard to do)
+ * o Check pppd persist mode
+ * o User space daemon (to automatically handle incoming requests)
+ *
+ * The setup is not currently the most easy, but this should get much
+ * better when everything will get integrated...
+ *
+ * Acknowledgements
+ * ----------------
+ * This module is based on :
+ * o The PPP driver (ppp_synctty/ppp_generic) by Paul Mackerras
+ * o The IrLAN protocol (irlan_common/XXX) by Dag Brattli
+ * o The IrSock interface (af_irda) by Dag Brattli
+ * o Some other bits from the kernel and my drivers...
+ * Infinite thanks to those brave souls for providing the infrastructure
+ * upon which IrNET is built.
+ *
+ * Thanks to all my collegues in HP for helping me. In particular,
+ * thanks to Salil Pradhan and Bill Serra for W2k testing...
+ * Thanks to Luiz Magalhaes for irnetd and much testing...
+ *
+ * Thanks to Alan Cox for answering lot's of my stupid questions, and
+ * to Paul Mackerras answering my questions on how to best integrate
+ * IrNET and pppd.
+ *
+ * Jean II
+ *
+ * Note on some implementations choices...
+ * ------------------------------------
+ * 1) Direct interface vs tty/socket
+ * I could have used a tty interface to hook to ppp and use the full
+ * socket API to connect to IrDA. The code would have been easier to
+ * maintain, and maybe the code would have been smaller...
+ * Instead, we hook directly to ppp_generic and to IrTTP, which make
+ * things more complicated...
+ *
+ * The first reason is flexibility : this allow us to create IrNET
+ * instances on demand (no /dev/ircommX crap) and to allow linkname
+ * specification on pppd command line...
+ *
+ * Second reason is speed optimisation. If you look closely at the
+ * transmit and receive paths, you will notice that they are "super lean"
+ * (that's why they look ugly), with no function calls and as little data
+ * copy and modification as I could...
+ *
+ * 2) irnetd in user space
+ * irnetd is implemented in user space, which is necessary to call pppd.
+ * This also give maximum benefits in term of flexibility and customability,
+ * and allow to offer the event channel, useful for other stuff like debug.
+ *
+ * On the other hand, this require a loose coordination between the
+ * present module and irnetd. One critical area is how incoming request
+ * are handled.
+ * When irnet receive an incoming request, it send an event to irnetd and
+ * drop the incoming IrNET socket.
+ * irnetd start a pppd instance, which create a new IrNET socket. This new
+ * socket is then connected in the originating node to the pppd instance.
+ * At this point, in the originating node, the first socket is closed.
+ *
+ * I admit, this is a bit messy and waste some resources. The alternative
+ * is caching incoming socket, and that's also quite messy and waste
+ * resources.
+ * We also make connection time slower. For example, on a 115 kb/s link it
+ * adds 60ms to the connection time (770 ms). However, this is slower than
+ * the time it takes to fire up pppd on my P133...
+ *
+ *
+ * History :
+ * -------
+ *
+ * v1 - 15.5.00 - Jean II
+ * o Basic IrNET (hook to ppp_generic & IrTTP - incl. multipoint)
+ * o control channel on /dev/irnet (set name/address)
+ * o event channel on /dev/irnet (for user space daemon)
+ *
+ * v2 - 5.6.00 - Jean II
+ * o Enable DROP_NOT_READY to avoid PPP timeouts & other weirdness...
+ * o Add DISCONNECT_TO event and rename DISCONNECT_FROM.
+ * o Set official device number alloaction on /dev/irnet
+ *
+ * v3 - 30.8.00 - Jean II
+ * o Update to latest Linux-IrDA changes :
+ * - queue_t => irda_queue_t
+ * o Update to ppp-2.4.0 :
+ * - move irda_irnet_connect from PPPIOCATTACH to TIOCSETD
+ * o Add EXPIRE event (depend on new IrDA-Linux patch)
+ * o Switch from `hashbin_remove' to `hashbin_remove_this' to fix
+ * a multilink bug... (depend on new IrDA-Linux patch)
+ * o fix a self->daddr to self->raddr in irda_irnet_connect to fix
+ * another multilink bug (darn !)
+ * o Remove LINKNAME_IOCTL cruft
+ *
+ * v3b - 31.8.00 - Jean II
+ * o Dump discovery log at event channel startup
+ *
+ * v4 - 28.9.00 - Jean II
+ * o Fix interaction between poll/select and dump discovery log
+ * o Add IRNET_BLOCKED_LINK event (depend on new IrDA-Linux patch)
+ * o Add IRNET_NOANSWER_FROM event (mostly to help support)
+ * o Release flow control in disconnect_indication
+ * o Block packets while connecting (speed up connections)
+ *
+ * v5 - 11.01.01 - Jean II
+ * o Init self->max_header_size, just in case...
+ * o Set up ap->chan.hdrlen, to get zero copy on tx side working.
+ * o avoid tx->ttp->flow->ppp->tx->... loop, by checking flow state
+ * Thanks to Christian Gennerat for finding this bug !
+ * ---
+ * o Declare the proper MTU/MRU that we can support
+ * (but PPP doesn't read the MTU value :-()
+ * o Declare hashbin HB_NOLOCK instead of HB_LOCAL to avoid
+ * disabling and enabling irq twice
+ *
+ * v6 - 31.05.01 - Jean II
+ * o Print source address in Found, Discovery, Expiry & Request events
+ * o Print requested source address in /proc/net/irnet
+ * o Change control channel input. Allow multiple commands in one line.
+ * o Add saddr command to change ap->rsaddr (and use that in IrDA)
+ * ---
+ * o Make the IrDA connection procedure totally asynchronous.
+ * Heavy rewrite of the IAS query code and the whole connection
+ * procedure. Now, irnet_connect() no longer need to be called from
+ * a process context...
+ * o Enable IrDA connect retries in ppp_irnet_send(). The good thing
+ * is that IrDA connect retries are directly driven by PPP LCP
+ * retries (we retry for each LCP packet), so that everything
+ * is transparently controlled from pppd lcp-max-configure.
+ * o Add ttp_connect flag to prevent rentry on the connect procedure
+ * o Test and fixups to eliminate side effects of retries
+ *
+ * v7 - 22.08.01 - Jean II
+ * o Cleanup : Change "saddr = 0x0" to "saddr = DEV_ADDR_ANY"
+ * o Fix bug in BLOCK_WHEN_CONNECT introduced in v6 : due to the
+ * asynchronous IAS query, self->tsap is NULL when PPP send the
+ * first packet. This was preventing "connect-delay 0" to work.
+ * Change the test in ppp_irnet_send() to self->ttp_connect.
+ *
+ * v8 - 1.11.01 - Jean II
+ * o Tighten the use of self->ttp_connect and self->ttp_open to
+ * prevent various race conditions.
+ * o Avoid leaking discovery log and skb
+ * o Replace "self" with "server" in irnet_connect_indication() to
+ * better detect cut'n'paste error ;-)
+ *
+ * v9 - 29.11.01 - Jean II
+ * o Fix event generation in disconnect indication that I broke in v8
+ * It was always generation "No-Answer" because I was testing ttp_open
+ * just after clearing it. *blush*.
+ * o Use newly created irttp_listen() to fix potential crash when LAP
+ * destroyed before irnet module removed.
+ *
+ * v10 - 4.3.2 - Jean II
+ * o When receiving a disconnect indication, don't reenable the
+ * PPP Tx queue, this will trigger a reconnect. Instead, close
+ * the channel, which will kill pppd...
+ *
+ * v11 - 20.3.02 - Jean II
+ * o Oops ! v10 fix disabled IrNET retries and passive behaviour.
+ * Better fix in irnet_disconnect_indication() :
+ * - if connected, kill pppd via hangup.
+ * - if not connected, reenable ppp Tx, which trigger IrNET retry.
+ *
+ * v12 - 10.4.02 - Jean II
+ * o Fix race condition in irnet_connect_indication().
+ * If the socket was already trying to connect, drop old connection
+ * and use new one only if acting as primary. See comments.
+ *
+ * v13 - 30.5.02 - Jean II
+ * o Update module init code
+ *
+ * v14 - 20.2.03 - Jean II
+ * o Add discovery hint bits in the control channel.
+ * o Remove obsolete MOD_INC/DEC_USE_COUNT in favor of .owner
+ *
+ * v15 - 7.4.03 - Jean II
+ * o Replace spin_lock_irqsave() with spin_lock_bh() so that we can
+ * use ppp_unit_number(). It's probably also better overall...
+ * o Disable call to ppp_unregister_channel(), because we can't do it.
+ */
+
+/***************************** INCLUDES *****************************/
+
+#include <linux/module.h>
+
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/tty.h>
+#include <linux/proc_fs.h>
+#include <linux/devfs_fs_kernel.h>
+#include <linux/netdevice.h>
+#include <linux/miscdevice.h>
+#include <linux/poll.h>
+#include <linux/config.h>
+#include <linux/ctype.h> /* isspace() */
+#include <asm/uaccess.h>
+#include <linux/init.h>
+
+#include <linux/ppp_defs.h>
+#include <linux/if_ppp.h>
+#include <linux/ppp_channel.h>
+
+#include <net/irda/irda.h>
+#include <net/irda/iriap.h>
+#include <net/irda/irias_object.h>
+#include <net/irda/irlmp.h>
+#include <net/irda/irttp.h>
+#include <net/irda/discovery.h>
+
+/***************************** OPTIONS *****************************/
+/*
+ * Define or undefine to compile or not some optional part of the
+ * IrNET driver...
+ * Note : the present defaults make sense, play with that at your
+ * own risk...
+ */
+/* IrDA side of the business... */
+#define DISCOVERY_NOMASK /* To enable W2k compatibility... */
+#define ADVERTISE_HINT /* Advertise IrLAN hint bit */
+#define ALLOW_SIMULT_CONNECT /* This seem to work, cross fingers... */
+#define DISCOVERY_EVENTS /* Query the discovery log to post events */
+#define INITIAL_DISCOVERY /* Dump current discovery log as events */
+#undef STREAM_COMPAT /* Not needed - potentially messy */
+#undef CONNECT_INDIC_KICK /* Might mess IrDA, not needed */
+#undef FAIL_SEND_DISCONNECT /* Might mess IrDA, not needed */
+#undef PASS_CONNECT_PACKETS /* Not needed ? Safe */
+#undef MISSING_PPP_API /* Stuff I wish I could do */
+
+/* PPP side of the business */
+#define BLOCK_WHEN_CONNECT /* Block packets when connecting */
+#define CONNECT_IN_SEND /* Retry IrDA connection procedure */
+#undef FLUSH_TO_PPP /* Not sure about this one, let's play safe */
+#undef SECURE_DEVIRNET /* Bah... */
+
+/****************************** DEBUG ******************************/
+
+/*
+ * This set of flags enable and disable all the various warning,
+ * error and debug message of this driver.
+ * Each section can be enabled and disabled independently
+ */
+/* In the PPP part */
+#define DEBUG_CTRL_TRACE 0 /* Control channel */
+#define DEBUG_CTRL_INFO 0 /* various info */
+#define DEBUG_CTRL_ERROR 1 /* problems */
+#define DEBUG_FS_TRACE 0 /* filesystem callbacks */
+#define DEBUG_FS_INFO 0 /* various info */
+#define DEBUG_FS_ERROR 1 /* problems */
+#define DEBUG_PPP_TRACE 0 /* PPP related functions */
+#define DEBUG_PPP_INFO 0 /* various info */
+#define DEBUG_PPP_ERROR 1 /* problems */
+#define DEBUG_MODULE_TRACE 0 /* module insertion/removal */
+#define DEBUG_MODULE_ERROR 1 /* problems */
+
+/* In the IrDA part */
+#define DEBUG_IRDA_SR_TRACE 0 /* IRDA subroutines */
+#define DEBUG_IRDA_SR_INFO 0 /* various info */
+#define DEBUG_IRDA_SR_ERROR 1 /* problems */
+#define DEBUG_IRDA_SOCK_TRACE 0 /* IRDA main socket functions */
+#define DEBUG_IRDA_SOCK_INFO 0 /* various info */
+#define DEBUG_IRDA_SOCK_ERROR 1 /* problems */
+#define DEBUG_IRDA_SERV_TRACE 0 /* The IrNET server */
+#define DEBUG_IRDA_SERV_INFO 0 /* various info */
+#define DEBUG_IRDA_SERV_ERROR 1 /* problems */
+#define DEBUG_IRDA_TCB_TRACE 0 /* IRDA IrTTP callbacks */
+#define DEBUG_IRDA_CB_INFO 0 /* various info */
+#define DEBUG_IRDA_CB_ERROR 1 /* problems */
+#define DEBUG_IRDA_OCB_TRACE 0 /* IRDA other callbacks */
+#define DEBUG_IRDA_OCB_INFO 0 /* various info */
+#define DEBUG_IRDA_OCB_ERROR 1 /* problems */
+
+#define DEBUG_ASSERT 0 /* Verify all assertions */
+
+/*
+ * These are the macros we are using to actually print the debug
+ * statements. Don't look at it, it's ugly...
+ *
+ * One of the trick is that, as the DEBUG_XXX are constant, the
+ * compiler will optimise away the if() in all cases.
+ */
+/* All error messages (will show up in the normal logs) */
+#define DERROR(dbg, format, args...) \
+ {if(DEBUG_##dbg) \
+ printk(KERN_INFO "irnet: %s(): " format, __FUNCTION__ , ##args);}
+
+/* Normal debug message (will show up in /var/log/debug) */
+#define DEBUG(dbg, format, args...) \
+ {if(DEBUG_##dbg) \
+ printk(KERN_DEBUG "irnet: %s(): " format, __FUNCTION__ , ##args);}
+
+/* Entering a function (trace) */
+#define DENTER(dbg, format, args...) \
+ {if(DEBUG_##dbg) \
+ printk(KERN_DEBUG "irnet: -> %s" format, __FUNCTION__ , ##args);}
+
+/* Entering and exiting a function in one go (trace) */
+#define DPASS(dbg, format, args...) \
+ {if(DEBUG_##dbg) \
+ printk(KERN_DEBUG "irnet: <>%s" format, __FUNCTION__ , ##args);}
+
+/* Exiting a function (trace) */
+#define DEXIT(dbg, format, args...) \
+ {if(DEBUG_##dbg) \
+ printk(KERN_DEBUG "irnet: <-%s()" format, __FUNCTION__ , ##args);}
+
+/* Exit a function with debug */
+#define DRETURN(ret, dbg, args...) \
+ {DEXIT(dbg, ": " args);\
+ return ret; }
+
+/* Exit a function on failed condition */
+#define DABORT(cond, ret, dbg, args...) \
+ {if(cond) {\
+ DERROR(dbg, args);\
+ return ret; }}
+
+/* Invalid assertion, print out an error and exit... */
+#define DASSERT(cond, ret, dbg, args...) \
+ {if((DEBUG_ASSERT) && !(cond)) {\
+ DERROR(dbg, "Invalid assertion: " args);\
+ return ret; }}
+
+/************************ CONSTANTS & MACROS ************************/
+
+/* Paranoia */
+#define IRNET_MAGIC 0xB00754
+
+/* Number of control events in the control channel buffer... */
+#define IRNET_MAX_EVENTS 8 /* Should be more than enough... */
+
+/****************************** TYPES ******************************/
+
+/*
+ * This is the main structure where we store all the data pertaining to
+ * one instance of irnet.
+ * Note : in irnet functions, a pointer this structure is usually called
+ * "ap" or "self". If the code is borrowed from the IrDA stack, it tend
+ * to be called "self", and if it is borrowed from the PPP driver it is
+ * "ap". Apart from that, it's exactly the same structure ;-)
+ */
+typedef struct irnet_socket
+{
+ /* ------------------- Instance management ------------------- */
+ /* We manage a linked list of IrNET socket instances */
+ irda_queue_t q; /* Must be first - for hasbin */
+ int magic; /* Paranoia */
+
+ /* --------------------- FileSystem part --------------------- */
+ /* "pppd" interact directly with us on a /dev/ file */
+ struct file * file; /* File descriptor of this instance */
+ /* TTY stuff - to keep "pppd" happy */
+ struct termios termios; /* Various tty flags */
+ /* Stuff for the control channel */
+ int event_index; /* Last read in the event log */
+
+ /* ------------------------- PPP part ------------------------- */
+ /* We interface directly to the ppp_generic driver in the kernel */
+ int ppp_open; /* registered with ppp_generic */
+ struct ppp_channel chan; /* Interface to generic ppp layer */
+
+ int mru; /* Max size of PPP payload */
+ u32 xaccm[8]; /* Asynchronous character map (just */
+ u32 raccm; /* to please pppd - dummy) */
+ unsigned int flags; /* PPP flags (compression, ...) */
+ unsigned int rbits; /* Unused receive flags ??? */
+
+ /* ------------------------ IrTTP part ------------------------ */
+ /* We create a pseudo "socket" over the IrDA tranport */
+ unsigned long ttp_open; /* Set when IrTTP is ready */
+ unsigned long ttp_connect; /* Set when IrTTP is connecting */
+ struct tsap_cb * tsap; /* IrTTP instance (the connection) */
+
+ char rname[NICKNAME_MAX_LEN + 1];
+ /* IrDA nickname of destination */
+ __u32 rdaddr; /* Requested peer IrDA address */
+ __u32 rsaddr; /* Requested local IrDA address */
+ __u32 daddr; /* actual peer IrDA address */
+ __u32 saddr; /* my local IrDA address */
+ __u8 dtsap_sel; /* Remote TSAP selector */
+ __u8 stsap_sel; /* Local TSAP selector */
+
+ __u32 max_sdu_size_rx;/* Socket parameters used for IrTTP */
+ __u32 max_sdu_size_tx;
+ __u32 max_data_size;
+ __u8 max_header_size;
+ LOCAL_FLOW tx_flow; /* State of the Tx path in IrTTP */
+
+ /* ------------------- IrLMP and IrIAS part ------------------- */
+ /* Used for IrDA Discovery and socket name resolution */
+ void * ckey; /* IrLMP client handle */
+ __u16 mask; /* Hint bits mask (filter discov.)*/
+ int nslots; /* Number of slots for discovery */
+
+ struct iriap_cb * iriap; /* Used to query remote IAS */
+ int errno; /* status of the IAS query */
+
+ /* -------------------- Discovery log part -------------------- */
+ /* Used by initial discovery on the control channel
+ * and by irnet_discover_daddr_and_lsap_sel() */
+ struct irda_device_info *discoveries; /* Copy of the discovery log */
+ int disco_index; /* Last read in the discovery log */
+ int disco_number; /* Size of the discovery log */
+
+} irnet_socket;
+
+/*
+ * This is the various event that we will generate on the control channel
+ */
+typedef enum irnet_event
+{
+ IRNET_DISCOVER, /* New IrNET node discovered */
+ IRNET_EXPIRE, /* IrNET node expired */
+ IRNET_CONNECT_TO, /* IrNET socket has connected to other node */
+ IRNET_CONNECT_FROM, /* Other node has connected to IrNET socket */
+ IRNET_REQUEST_FROM, /* Non satisfied connection request */
+ IRNET_NOANSWER_FROM, /* Failed connection request */
+ IRNET_BLOCKED_LINK, /* Link (IrLAP) is blocked for > 3s */
+ IRNET_DISCONNECT_FROM, /* IrNET socket has disconnected */
+ IRNET_DISCONNECT_TO /* Closing IrNET socket */
+} irnet_event;
+
+/*
+ * This is the storage for an event and its arguments
+ */
+typedef struct irnet_log
+{
+ irnet_event event;
+ int unit;
+ __u32 saddr;
+ __u32 daddr;
+ char name[NICKNAME_MAX_LEN + 1]; /* 21 + 1 */
+ __u16_host_order hints; /* Discovery hint bits */
+} irnet_log;
+
+/*
+ * This is the storage for all events and related stuff...
+ */
+typedef struct irnet_ctrl_channel
+{
+ irnet_log log[IRNET_MAX_EVENTS]; /* Event log */
+ int index; /* Current index in log */
+ spinlock_t spinlock; /* Serialize access to the event log */
+ wait_queue_head_t rwait; /* processes blocked on read (or poll) */
+} irnet_ctrl_channel;
+
+/**************************** PROTOTYPES ****************************/
+/*
+ * Global functions of the IrNET module
+ * Note : we list here also functions called from one file to the other.
+ */
+
+/* -------------------------- IRDA PART -------------------------- */
+extern int
+ irda_irnet_create(irnet_socket *); /* Initialise a IrNET socket */
+extern int
+ irda_irnet_connect(irnet_socket *); /* Try to connect over IrDA */
+extern void
+ irda_irnet_destroy(irnet_socket *); /* Teardown a IrNET socket */
+extern int
+ irda_irnet_init(void); /* Initialise IrDA part of IrNET */
+extern void
+ irda_irnet_cleanup(void); /* Teardown IrDA part of IrNET */
+/* ---------------------------- MODULE ---------------------------- */
+extern int
+ irnet_init(void); /* Initialise IrNET module */
+
+/**************************** VARIABLES ****************************/
+
+/* Control channel stuff - allocated in irnet_irda.h */
+extern struct irnet_ctrl_channel irnet_events;
+
+#endif /* IRNET_H */