diff options
Diffstat (limited to 'libfshelp')
| -rw-r--r-- | libfshelp/fshelp.h | 180 |
1 files changed, 99 insertions, 81 deletions
diff --git a/libfshelp/fshelp.h b/libfshelp/fshelp.h index 926b0ced..d5942e97 100644 --- a/libfshelp/fshelp.h +++ b/libfshelp/fshelp.h @@ -1,5 +1,5 @@ /* FS helper library definitions - Copyright (C) 1994 Free Software Foundation + Copyright (C) 1994, 1995 Free Software Foundation This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as @@ -23,93 +23,111 @@ presumes that you are using the iohelp library as well. It is divided into separate facilities which may be used independently. */ + +/* Passive translator linkage */ +/* These routines are self-contained and start passive translators, + returning the control port. They do not require multi threading + or the ports library. */ + +/* Start a passive translator NAME with arguments ARGZ (length + ARGZ_LEN). Initialize the initports to PORTS (length PORTS_LEN), + the initints to INTS (length INTS_LEN), and the file descriptor + table to FDS (length FDS_LEN). Return the control port in + *CONTROL. If the translator doesn't respond or die in TIMEOUT + milliseconds (if TIMEOUT > 0), return an appropriate error. If the + translator dies before responding, return EDIED. */ +error_t +fshelp_start_translator_long (mach_port_t underlying, + mach_msg_type_name_t underlying_type, + char *name, char *argz, int argz_len, + mach_port_t *ports, int ports_len, + mach_msg_type_name_t ports_type, + int *ints, int ints_len, + mach_port_t *fds, int fds_len, + mach_msg_type_name_t fds_type, + int timeout, fsys_t *control); + + +/* Same as fshelp_start_translator_long, except the initports and ints + are copied from our own state, fd[2] is copied from our own stderr, + and the other fds are cleared. */ +error_t +fshelp_start_translator (mach_port_t underlying, + char *name, char *argz, int argz_len, + int timeout, fsys_t *control); -/* Translator linkage. These routines only work for multi-threaded - servers, and assume you are using the ports library. */ - -/* Define one of these structures as part of every disk node. */ -struct trans_link -{ - /* control port for the child filesystem */ - fsys_t control; + +/* Active translator linkage */ - /* this is woken up when fsys_startup is receieved - from the child filesystem. */ - struct condition initwait; +/* These routines implement the linkage to active translators needed + by any filesystem which supports them. They require cthreads and + use the passive translator routines above, but they don't require + the ports library at all. */ - /* Lock of this structure's contents */ - struct mutex lock; +struct transbox +{ + fsys_t active; + struct mutex *lock; + struct mutex innerlock; + void *cookie; +}; - /* This indicates that someone has already started up the translator */ - int starting; +/* This interface is complex, because creating the ports and state + necessary for start_translator_long is expensive. The caller to + fshelp_fetch_root should not need to create them on every call, since + usually there will be an existing active translator. */ + +/* Fetch the root from TRANSBOX. DOTDOT is an unauthenticated port + for the directory in which we are looking; UIDS (length UIDS_LEN) + and GIDS (length GIDS_LEN) are the ids of the user responsible for + the call. FLAGS are as for dir_pathtrans (but O_CREAT and O_EXCL + are not meaningful and are ignored). The trasnbox lock (as + set by fshelp_transbox_init) must be held before the call, and will + be held upon return, but may be released during the operation of + the call. */ +error_t +fshelp_fetch_root (struct transbox *transbox, file_t dotdot, + uid_t uids, int uids_len, + uid_t gids, int gids_len, + int flags, fshelp_callback_t callback, + mach_port_t *root); + +void +fshelp_transbox_init (struct transbox *transbox, + struct mutex *lock, + void *cookie); + +/* This routine is called by fshelp_fetch_root to fetch more + information. Return the owner and group of the underlying + translated file in *UID and *GID; return an unauthenticated + node for the file itself in *UNDERLYING, and point *ARGZ at + the entire passive translator spec for the file (setting + *ARGZ_LEN to the length.) If there is no passive + translator, then return ENOENT. */ +typedef void (*fshelp_callback_t) (void *cookie, + mach_port_t *underlying, + uid_t *uid, gid_t *gid, + char **argz, int *argz_len); + +/* Return true iff there is an active translator on this box */ +extern inline int +fshelp_translated (struct transbox *box) +{ + return (box->active != MACH_PORT_NULL); +} - /* Error to return to user */ - error_t error; +/* Atomically replace the existing active translator port for this box + with NEWACTIVE. */ +error_t fshelp_set_active (struct transbox *box, + fsys_t newactive); - /* Linked list of all translators */ - struct trans_link *next, **prevp; -}; +/* Fetch the control port to make a request on it. It's a bad idea + to do fsys_getroot with the result; use fetch_root instead. */ +error_t fshelp_fetch_control (struct transbox *box, + mach_port_t *control); -/* The user must define this variable. This is the libports type for - bootstrap ports given to newly started translators. */ -extern int fshelp_transboot_port_type; - -/* Call this before calling any of the other translator linkage routines, - normally from your main node initialization routine. */ -void fshelp_init_trans_link (struct trans_link *LINK); - -/* Call to set the control field of translator LINK to CTL - directly. */ -void fshelp_set_control (struct trans_link *link, mach_port_t ctl); - -/* Call this when the control field of a translator is null and you - want to have the translator started so you can talk to it. LINK is - the trans_link structure for this node; NAME is the file to execute - as the translator (*NAME may be modified). DIR and NODE should be - send rights; DIR will be reauthenticated before being given to the - translator and NODE should already be authenticated properly. Both - send-rights will be consumed by this call, whatever its exit value. DIR - should refer to the directory holding the node being translater, - and will be provided as the cwdir of the process. NODE should - refer to the node being translated, and will be provided as the - realnode return value from fsys_startup. UID and GID are the uid - and gid of the process to be started. */ -error_t fshelp_start_translator (struct trans_link *link, char *name, - int namelen, file_t dir, file_t node, - uid_t uid, gid_t gid); - -/* Call this when you receive a fsys_startup message on a port of type - fshelp_transboot_port_type. PORTSTRUCT is the result of - ports_check_port_type/ports_get_port; this routine does not call - ports_done_with_port so the caller normally should. CTL, REAL, and - REALPOLY, are copied from the fsys_startup message; CTL will be - installed as the control field of the translator making this call, - *REAL will be set to be the underlying port (by calling the - MAKE_PORT function set at fshelp_start_translator time with the - NODE argument to that call). *REALPOLY will be set to the Mach - message transmission types for that. If this routine returns an - error, then the CTL port must be deallocated by the caller. */ -error_t fshelp_handle_fsys_startup (void *portstruct, mach_port_t ctl, - mach_port_t *real, - mach_msg_type_name_t *realpoly); - -/* Install this routine as the ports library type-specific clean routine - for ports of type fshelp_transboot_port_type. */ -void fshelp_transboot_clean (void *arg); - -/* Call function FUNC for each translator that has completed its - startup. The arguments to FUNC are the translator and ARG - respectively. */ -void fshelp_translator_iterate (void (*func)(struct trans_link *, void *), - void *arg); - -/* Set the active translator port to null and clear state. Deallocate - our send right on the translator control port. */ -void fshelp_translator_drop (struct trans_link *link); - -/* A trans_link structure is being deallocated; clean up any state - we need to. */ -void fshelp_kill_translator (struct trans_link *link); +/* A transbox is being deallocated, clean associated state. */ +void fshelp_drop_transbox (struct transbox *box); |