- 根目录:
- net
- irda
- irnet
- irnet.h
/*
* 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 colleagues 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/netdevice.h>
#include <linux/miscdevice.h>
#include <linux/poll.h>
#include <linux/capability.h>
#include <linux/ctype.h> /* isspace() */
#include <linux/string.h> /* skip_spaces() */
#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, __func__ , ##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, __func__ , ##args);}
/* Entering a function (trace) */
#define DENTER(dbg, format, args...) \
{if(DEBUG_##dbg) \
printk(KERN_DEBUG "irnet: -> %s" format, __func__ , ##args);}
/* Entering and exiting a function in one go (trace) */
#define DPASS(dbg, format, args...) \
{if(DEBUG_##dbg) \
printk(KERN_DEBUG "irnet: <>%s" format, __func__ , ##args);}
/* Exiting a function (trace) */
#define DEXIT(dbg, format, args...) \
{if(DEBUG_##dbg) \
printk(KERN_DEBUG "irnet: <-%s()" format, __func__ , ##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 ktermios 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 ??? */
struct work_struct disconnect_work; /* Process context disconnection */
/* ------------------------ 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 */
struct mutex lock;
} 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 */
/**************************** VARIABLES ****************************/
/* Control channel stuff - allocated in irnet_irda.h */
extern struct irnet_ctrl_channel irnet_events;
#endif /* IRNET_H */