123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285 |
- /*
- *
- * Copyright (c) 2003 The Regents of the University of California. All
- * rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * - Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * - Neither the name of the University nor the names of its
- * contributors may be used to endorse or promote products derived
- * from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS''
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
- * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
- * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
- * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
- /*
- * FUSD: the Framework for User-Space Devices
- *
- * Public header function for user-space library. This is the API
- * that user-space device drivers should write to.
- */
- #ifndef __FUSD_H__
- #define __FUSD_H__
- #ifndef __KERNEL__
- #include <sys/types.h>
- __BEGIN_DECLS
- #endif
- #include "fusd_msg.h"
- /* FUSD_NOREPLY is a special error code. If a user-space driver
- * implementing a system call returns -FUSD_NOREPLY (note it's
- * negative!), the calling application will be blocked. When
- * conditions enable a response to the system call (e.g. the read or
- * write has completed), the user-space driver must call the
- * fusd_return() function. */
- #define FUSD_NOREPLY 0x1000
- /* FUSD defines several bitmasks for describing which channels of
- * notification are being requested or signaled. These flags are
- * used in the arguments and return value of the notify() callback. */
- #define FUSD_NOTIFY_INPUT 0x1
- #define FUSD_NOTIFY_OUTPUT 0x2
- #define FUSD_NOTIFY_EXCEPT 0x4
- #define FUSD_KOR_HACKED_VERSION
- struct fusd_file_info; /* forward decl */
- typedef
- struct fusd_file_operations {
- int (*open) (struct fusd_file_info *file);
- int (*close) (struct fusd_file_info *file);
- ssize_t (*read) (struct fusd_file_info *file, char *buffer, size_t length,
- loff_t *offset);
- ssize_t (*write) (struct fusd_file_info *file, const char *buffer,
- size_t length, loff_t *offset);
- int (*ioctl) (struct fusd_file_info *file, int request, void *data);
- int (*poll_diff) (struct fusd_file_info *file, unsigned int cached_state);
- int (*unblock) (struct fusd_file_info *file);
- int (*mmap) (struct fusd_file_info *file, int offset, size_t length, int flags, void** addr, size_t* out_length);
- } fusd_file_operations_t;
- /* state-keeping structure passed to device driver callbacks */
- typedef
- struct fusd_file_info {
- void *device_info; /* This is set by the library to
- * whatever you passed to
- * fusd_register. Changing this in a
- * file_operations callback has no
- * effect. */
- void *private_data; /* File-specific data you can change
- * in a file_operations callback.
- * e.g., you can set this in an open()
- * callback, then get it in a
- * corresponding read() callback. */
- unsigned int flags; /* Kept synced with file->f_flags */
- pid_t pid; /* PID of process making the request */
- uid_t uid; /* UID of process making the request */
- gid_t gid; /* GID of process making the request */
- /* other info might be added later, e.g. state needed to complete
- operations... */
- /* request message associated with this call */
- int fd;
- fusd_msg_t *fusd_msg;
- } fusd_file_info_t;
- /*************************** Library Functions ****************************/
- /* fusd_register: create a device file and register callbacks for it
- *
- * Arguments:
- *
- * name - the name of the device file, to be created wherever devfs
- * is mounted (usually dev). example: pass "mydevice" will create
- * /dev/mydevice.
- *
- * As a convenience, passing a string that starts with "/dev/" will
- * automatically skip over that portion of the name.
- *
- * mode - the file protections to be given to the device
- *
- * device_info - you can provide arbitrary data that will later be
- * passed back to your driver's callbacks in file->device_info.
- * value has no effect on FUSD itself.
- *
- * fops - a table of callbacks to be called for this device; see
- * structure above.
- *
- * Return value:
- * On failure, -1 is returned and errno is set to indicate the error.
- *
- * On success, a valid file descriptor is returned which represents
- * the control channel to your new device. You should never read
- * from or write to that control channel directcly, but you can
- * select on it to see when it needs attention (see fusd_run and
- * fusd_dispatch).
- */
- int fusd_register(const char *name, const char* clazz, const char* devname, mode_t mode, void *device_info,
- struct fusd_file_operations *fops);
- /* "simple" interface to fusd_register. */
- #define fusd_simple_register(name, clazz, devname, perms, arg, ops...) do { \
- struct fusd_file_operations f = { ops } ; \
- if (fusd_register(name, clazz, devname, perms, arg, &f) < 0) \
- perror("warning: fusd unavailable"); \
- } while(0)
- /* fusd_unregister: unregister a previously registered device
- *
- * Arguments:
- * fd - the file descriptor previously returned to you by fusd_register.
- *
- * Return value:
- * 0 on success.
- * -1 on failure with errno set to indicate the failure.
- */
- int fusd_unregister(int fd);
- /* fusd_return: unblock a previously blocked system call
- *
- * Arguments:
- * file - the file info struct that was previously blocked
- * retval - the return value that would have been returned by the
- * returning system call
- *
- * Return value:
- * 0 on success.
- * -1 on failure with errno set to indicate the failure
- */
- int fusd_return(struct fusd_file_info *file, ssize_t retval);
- /*
- * fusd_destroy destroys all state associated with a fusd_file_info
- * pointer. (It is implicitly called by fusd_return.) If a driver
- * saves a fusd_file_info pointer by calling -FUSD_NOREPLY in order to
- * block a read, but gets a "close" request on the file before the
- * pointer is returned with fusd_return, it should be thrown away
- * using fusd_destroy.
- */
- void fusd_destroy(struct fusd_file_info *file);
- /* fusd_dispatch: handles an event on a fusd file descriptor
- *
- * Arguments:
- * fd - the file descriptor of the device that received an event
- *
- * Return value:
- * None.
- *
- * Side effects:
- * May (but may not) call a callback function originally passed to
- * fusd_register.
- *
- * Prints an error to stderr in case of a dispatching error.
- */
- void fusd_dispatch(int fd);
- /*
- * fusd_run: convenience function that handles dispatch for all
- * fusd devices
- *
- * No return value; runs forever.
- */
- void fusd_run(void);
- /*
- * fusd_fdset_add: given an FDSET and "max", add the currently valid
- * FUSD fds to the set and update max accordingly.
- */
- void fusd_fdset_add(fd_set *set, int *max);
- /*
- * fusd_dispatch_fdset: given an fd_set full of descriptors, call
- * fusd_dispatch on every descriptor in the set which is a valid FUSD
- * fd.
- */
- void fusd_dispatch_fdset(fd_set *set);
- /********************************************************************
- *
- * Direct access API
- *
- * This API enables a driver implementation to store state about a
- * blocked call more easily, extracting the call arguments directly
- * with no need to store them separately.
- *
- ********************************************************************/
- /* accessors */
- static inline int fusd_get_call_type(struct fusd_file_info *file)
- { return file->fusd_msg->subcmd; }
- static inline char * fusd_get_read_buffer(struct fusd_file_info *file)
- { return file->fusd_msg->data; }
- static inline const char * fusd_get_write_buffer(struct fusd_file_info *file)
- { return (const char *)file->fusd_msg->data; }
- static inline size_t fusd_get_length(struct fusd_file_info *file)
- { return (size_t)file->fusd_msg->datalen; }
- static inline loff_t *fusd_get_offset(struct fusd_file_info *file)
- { return &(file->fusd_msg->parm.fops_msg.offset); }
- static inline int fusd_get_ioctl_request(struct fusd_file_info *file)
- { return file->fusd_msg->parm.fops_msg.cmd; }
- static inline unsigned long fusd_get_ioctl_arg(struct fusd_file_info *file)
- { return file->fusd_msg->parm.fops_msg.arg.arg; }
- static inline void * fusd_get_ioctl_buffer(struct fusd_file_info *file)
- { return (void *)file->fusd_msg->data; }
- static inline int fusd_get_poll_diff_cached_state(struct fusd_file_info *file)
- { return file->fusd_msg->parm.fops_msg.cmd; }
- /* returns static string representing the flagset (e.g. RWE) */
- char *fusd_unparse_flags(int flags);
- #ifndef __KERNEL__
- __END_DECLS
- #endif
- #endif /* __FUSD_H__ */
|