/* * IrNET protocol module : Synchronous PPP over an IrDA socket. * * Jean II - HPL `00 - * * 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 #include #include #include #include #include #include #include #include #include /* isspace() */ #include /* skip_spaces() */ #include #include #include #include #include #include #include #include #include #include #include /***************************** 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 */