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Diffstat (limited to 'filter.c')
| -rw-r--r-- | filter.c | 726 |
1 files changed, 726 insertions, 0 deletions
diff --git a/filter.c b/filter.c new file mode 100644 index 000000000..09a409cb2 --- /dev/null +++ b/filter.c @@ -0,0 +1,726 @@ +/*----------------------------------------------------------------------------*/ +/*filter.c*/ +/*----------------------------------------------------------------------------*/ +/*The filtering translator*/ +/*----------------------------------------------------------------------------*/ +/*Based on the code of unionfs translator.*/ +/*----------------------------------------------------------------------------*/ +/*Copyright (C) 2001, 2002, 2005, 2008 Free Software Foundation, Inc. + Written by Sergiu Ivanov <unlimitedscolobb@gmail.com>. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License as + published by the Free Software Foundation; either version 2 of the + License, or * (at your option) any later version. + + This program is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 + USA.*/ +/*----------------------------------------------------------------------------*/ + +/*----------------------------------------------------------------------------*/ +#define _GNU_SOURCE 1 +/*----------------------------------------------------------------------------*/ +#include "filter.h" +/*----------------------------------------------------------------------------*/ +#include <error.h> +#include <argp.h> +#include <argz.h> +#include <hurd/netfs.h> +#include <fcntl.h> +/*----------------------------------------------------------------------------*/ +#include "debug.h" +#include "options.h" +/*----------------------------------------------------------------------------*/ + +/*----------------------------------------------------------------------------*/ +/*--------Global Variables----------------------------------------------------*/ +/*The name of the server*/ +char * netfs_server_name = "filter"; +/*----------------------------------------------------------------------------*/ +/*The version of the server*/ +char * netfs_server_version = "0.0"; +/*----------------------------------------------------------------------------*/ +/*The maximal length of a chain of symbolic links*/ +int netfs_maxsymlinks = 12; +/*----------------------------------------------------------------------------*/ +/*A port to the underlying node*/ +mach_port_t underlying_node; +/*----------------------------------------------------------------------------*/ +/*Status information for the underlying node*/ +io_statbuf_t underlying_node_stat; +/*----------------------------------------------------------------------------*/ +/*Mapped time used for updating node information*/ +volatile struct mapped_time_value * maptime; +/*----------------------------------------------------------------------------*/ +/*The filesystem ID*/ +pid_t fsid; +/*----------------------------------------------------------------------------*/ +/*The port from which we will read (TODO: and write) the data*/ +mach_port_t target; +/*----------------------------------------------------------------------------*/ +/*The file to print debug messages to*/ +FILE * filter_dbg; +/*----------------------------------------------------------------------------*/ + +/*----------------------------------------------------------------------------*/ +/*--------Functions-----------------------------------------------------------*/ +/*Attempts to create a file named `name` in `dir` for `user` with mode `mode`*/ +error_t +netfs_attempt_create_file + ( + struct iouser * user, + struct node * dir, + char * name, + mode_t mode, + struct node ** node + ) + { + LOG_MSG("netfs_attempt_create_file"); + + /*Unlock `dir` and say that we can do nothing else here*/ + mutex_unlock(&dir->lock); + return EOPNOTSUPP; + }/*netfs_attempt_create_file*/ +/*----------------------------------------------------------------------------*/ +/*Return an error if the process of opening a file should not be allowed + to complete because of insufficient permissions*/ +error_t +netfs_check_open_permissions + ( + struct iouser * user, + struct node * np, + int flags, + int newnode + ) + { + LOG_MSG("netfs_check_open_permissions"); + + error_t err = 0; + + /*Cheks user's permissions*/ + if(flags & O_READ) + err = fshelp_access(&np->nn_stat, S_IREAD, user); + if(!err && (flags & O_WRITE)) + err = fshelp_access(&np->nn_stat, S_IWRITE, user); + if(!err && (flags & O_EXEC)) + err = fshelp_access(&np->nn_stat, S_IEXEC, user); + + /*Return the result of the check*/ + return err; + }/*netfs_check_open_permissions*/ +/*----------------------------------------------------------------------------*/ +/*Attempts an utimes call for the user `cred` on node `node`*/ +error_t +netfs_attempt_utimes + ( + struct iouser * cred, + struct node * node, + struct timespec * atime, + struct timespec * mtime + ) + { + LOG_MSG("netfs_attempt_utimes"); + + error_t err = 0; + + /*See what information is to be updated*/ + int flags = TOUCH_CTIME; + + /*Check if the user is indeed the owner of the node*/ + err = fshelp_isowner(&node->nn_stat, cred); + + /*If the user is allowed to do utimes*/ + if(!err) + { + /*If atime is to be updated*/ + if(atime) + /*update the atime*/ + node->nn_stat.st_atim = *atime; + else + /*the current time will be set as the atime*/ + flags |= TOUCH_ATIME; + + /*If mtime is to be updated*/ + if(mtime) + /*update the mtime*/ + node->nn_stat.st_mtim = *mtime; + else + /*the current time will be set as mtime*/ + flags |= TOUCH_MTIME; + + /*touch the file*/ + fshelp_touch(&node->nn_stat, flags, maptime); + } + + /*Return the result of operations*/ + return err; + }/*netfs_attempt_utimes*/ +/*----------------------------------------------------------------------------*/ +/*Returns the valid access types for file `node` and user `cred`*/ +error_t +netfs_report_access + ( + struct iouser * cred, + struct node * np, + int * types + ) + { + LOG_MSG("netfs_report_access"); + + /*No access at first*/ + *types = 0; + + /*Check the access and set the required bits*/ + if(fshelp_access(&np->nn_stat, S_IREAD, cred) == 0) + *types |= O_READ; + if(fshelp_access(&np->nn_stat, S_IWRITE, cred) == 0) + *types |= O_WRITE; + if(fshelp_access(&np->nn_stat, S_IEXEC, cred) == 0) + *types |= O_EXEC; + + /*Everything OK*/ + return 0; + }/*netfs_report_access*/ +/*----------------------------------------------------------------------------*/ +/*Validates the stat data for the node*/ +error_t +netfs_validate_stat + ( + struct node * np, + struct iouser * cred + ) + { + LOG_MSG("netfs_validate_stat"); + + error_t err = 0; + + /*Validate the stat information about the node*/ + err = io_stat(np->nn->port, &np->nn_stat); + + /*Return the result of operations*/ + return err; + }/*netfs_validate_stat*/ +/*----------------------------------------------------------------------------*/ +/*Syncs `node` completely to disk*/ +error_t +netfs_attempt_sync + ( + struct iouser * cred, + struct node * node, + int wait + ) + { + LOG_MSG("netfs_attempt_sync"); + + /*Operation is not supported*/ + return EOPNOTSUPP; + }/*netfs_attempt_sync*/ +/*----------------------------------------------------------------------------*/ +/*Fetches a directory*/ +error_t +netfs_get_dirents + ( + struct iouser * cred, + struct node * dir, + int first_entry, + int num_entries, + char ** data, + mach_msg_type_number_t * data_len, + vm_size_t max_data_len, + int * data_entries + ) + { + LOG_MSG("netfs_get_dirents"); + + /*This node is not a directory*/ + return ENOTDIR; + }/*netfs_get_dirents*/ +/*----------------------------------------------------------------------------*/ +/*Looks up `name` under `dir` for `user`*/ +error_t +netfs_attempt_lookup + ( + struct iouser * user, + struct node * dir, + char * name, + struct node ** node + ) + { + LOG_MSG("netfs_attempt_lookup: '%s'", name); + + /*Unlock the mutexes in `dir`*/ + mutex_unlock(&dir->lock); + return EOPNOTSUPP; + }/*netfs_attempt_lookup*/ +/*----------------------------------------------------------------------------*/ +/*Deletes `name` in `dir` for `user`*/ +error_t +netfs_attempt_unlink + ( + struct iouser * user, + struct node * dir, + char * name + ) + { + LOG_MSG("netfs_attempt_unlink"); + + return 0; + }/*netfs_attempt_unlink*/ +/*----------------------------------------------------------------------------*/ +/*Attempts to rename `fromdir`/`fromname` to `todir`/`toname`*/ +error_t +netfs_attempt_rename + ( + struct iouser * user, + struct node * fromdir, + char * fromname, + struct node * todir, + char * toname, + int excl + ) + { + LOG_MSG("netfs_attempt_rename"); + + /*Operation not supported*/ + return EOPNOTSUPP; + }/*netfs_attempt_rename*/ +/*----------------------------------------------------------------------------*/ +/*Attempts to create a new directory*/ +error_t +netfs_attempt_mkdir + ( + struct iouser * user, + struct node * dir, + char * name, + mode_t mode + ) + { + LOG_MSG("netfs_attempt_mkdir"); + + return 0; + }/*netfs_attempt_mkdir*/ +/*----------------------------------------------------------------------------*/ +/*Attempts to remove directory `name` in `dir` for `user`*/ +error_t +netfs_attempt_rmdir + ( + struct iouser * user, + struct node * dir, + char * name + ) + { + LOG_MSG("netfs_attempt_rmdir"); + + return 0; + }/*netfs_attempt_rmdir*/ +/*----------------------------------------------------------------------------*/ +/*Attempts to change the mode of `node` for user `cred` to `uid`:`gid`*/ +error_t +netfs_attempt_chown + ( + struct iouser * cred, + struct node * node, + uid_t uid, + uid_t gid + ) + { + LOG_MSG("netfs_attempt_chown"); + + /*Operation is not supported*/ + return EOPNOTSUPP; + }/*netfs_attempt_chown*/ +/*----------------------------------------------------------------------------*/ +/*Attempts to change the author of `node` to `author`*/ +error_t +netfs_attempt_chauthor + ( + struct iouser * cred, + struct node * node, + uid_t author + ) + { + LOG_MSG("netfs_attempt_chauthor"); + + /*Operation is not supported*/ + return EOPNOTSUPP; + }/*netfs_attempt_chauthor*/ +/*----------------------------------------------------------------------------*/ +/*Attempts to change the mode of `node` to `mode` for `cred`*/ +error_t +netfs_attempt_chmod + ( + struct iouser * user, + struct node * node, + mode_t mode + ) + { + LOG_MSG("netfs_attempt_chmod"); + + /*Operation is not supported*/ + return EOPNOTSUPP; + }/*netfs_attempt_chmod*/ +/*----------------------------------------------------------------------------*/ +/*Attempts to turn `node` into a symlink targetting `name`*/ +error_t +netfs_attempt_mksymlink + ( + struct iouser * cred, + struct node * node, + char * name + ) + { + LOG_MSG("netfs_attempt_mksymlink"); + + /*Operation is not supported*/ + return EOPNOTSUPP; + }/*netfs_attempt_mksymlink*/ +/*----------------------------------------------------------------------------*/ +/*Attempts to turn `node` into a device; type can be either S_IFBLK or S_IFCHR*/ +error_t +netfs_attempt_mkdev + ( + struct iouser * cred, + struct node * node, + mode_t type, + dev_t indexes + ) + { + LOG_MSG("netfs_attempt_mkdev"); + + /*Operation is not supported*/ + return EOPNOTSUPP; + }/*netfs_attempt_mkdev*/ +/*----------------------------------------------------------------------------*/ +/*Attempts to set the passive translator record for `file` passing `argz`*/ +error_t +netfs_set_translator + ( + struct iouser * cred, + struct node * node, + char * argz, + size_t arglen + ) + { + LOG_MSG("netfs_set_translator"); + + /*Operation is not supported*/ + return EOPNOTSUPP; + }/*netfs_set_translator */ +/*----------------------------------------------------------------------------*/ +/*Attempts to call chflags for `node`*/ +error_t +netfs_attempt_chflags + ( + struct iouser * cred, + struct node * node, + int flags + ) + { + LOG_MSG("netfs_attempt_chflags"); + + /*Operation is not supported*/ + return EOPNOTSUPP; + }/*netfs_attempt_chflags*/ +/*----------------------------------------------------------------------------*/ +/*Attempts to set the size of file `node`*/ +error_t +netfs_attempt_set_size + ( + struct iouser * cred, + struct node * node, + loff_t size + ) + { + LOG_MSG("netfs_attempt_set_size"); + + /*Operation is not supported*/ + return EOPNOTSUPP; + }/*netfs_attempt_set_size*/ +/*----------------------------------------------------------------------------*/ +/*Fetches the filesystem status information*/ +error_t +netfs_attempt_statfs + ( + struct iouser * cred, + struct node * node, + fsys_statfsbuf_t * st + ) + { + LOG_MSG("netfs_attempt_statfs"); + + /*Operation is not supported*/ + return EOPNOTSUPP; + }/*netfs_attempt_statfs*/ +/*----------------------------------------------------------------------------*/ +/*Syncs the filesystem*/ +error_t +netfs_attempt_syncfs + ( + struct iouser * cred, + int wait + ) + { + LOG_MSG("netfs_attempt_syncfs"); + + /*Everythin OK*/ + return 0; + }/*netfs_attempt_syncfs*/ +/*----------------------------------------------------------------------------*/ +/*Creates a link in `dir` with `name` to `file`*/ +error_t +netfs_attempt_link + ( + struct iouser * user, + struct node * dir, + struct node * file, + char * name, + int excl + ) + { + LOG_MSG("netfs_attempt_link"); + + /*Operation not supported*/ + return EOPNOTSUPP; + }/*netfs_attempt_link*/ +/*----------------------------------------------------------------------------*/ +/*Attempts to create an anonymous file related to `dir` with `mode`*/ +error_t +netfs_attempt_mkfile + ( + struct iouser * user, + struct node * dir, + mode_t mode, + struct node ** node + ) + { + LOG_MSG("netfs_attempt_mkfile"); + + /*Unlock the directory*/ + mutex_unlock(&dir->lock); + + /*Operation not supported*/ + return EOPNOTSUPP; + }/*netfs_attempt_mkfile*/ +/*----------------------------------------------------------------------------*/ +/*Reads the contents of symlink `node` into `buf`*/ +error_t +netfs_attempt_readlink + ( + struct iouser * user, + struct node * node, + char * buf + ) + { + LOG_MSG("netfs_attempt_readlink"); + + /*Operation not supported (why?..)*/ + return EOPNOTSUPP; + }/*netfs_attempt_readlink*/ +/*----------------------------------------------------------------------------*/ +/*Reads from file `node` up to `len` bytes from `offset` into `data`*/ +error_t +netfs_attempt_read + ( + struct iouser * cred, + struct node * np, + loff_t offset, + size_t * len, + void * data + ) + { + LOG_MSG("netfs_attempt_read"); + + error_t err = 0; + + /*Obtain a pointer to the first byte of the supplied buffer*/ + char * buf = data; + + /*Try to read the requested information from the file*/ + err = io_read(np->nn->port, &buf, len, offset, *len); + + /*If some data has been read successfully*/ + if(!err && (buf != data)) + { + /*copy the data from the buffer into which it has just been read into + the supplied receiver*/ + memcpy(data, buf, *len); + + /*unmap the new buffer*/ + munmap(buf, *len); + } + + /*Return the result of reading*/ + return err; + }/*netfs_attempt_read*/ +/*----------------------------------------------------------------------------*/ +/*Writes to file `node` up to `len` bytes from offset from `data`*/ +error_t +netfs_attempt_write + ( + struct iouser * cred, + struct node * node, + loff_t offset, + size_t * len, + void * data + ) + { + LOG_MSG("netfs_attempt_write"); + + return 0; + }/*netfs_attempt_write*/ +/*----------------------------------------------------------------------------*/ +/*Frees all storage associated with the node*/ +void +netfs_node_norefs + ( + struct node * np + ) + { + /*Destroy the node*/ + node_destroy(np); + }/*netfs_node_norefs*/ +/*----------------------------------------------------------------------------*/ +/*Implements file_get_translator_cntl as described in <hurd/fs.defs> + (according to diskfs_S_file_get_translator_cntl)*/ +kern_return_t +netfs_S_file_get_translator_cntl + ( + struct protid * user, + mach_port_t * cntl, + mach_msg_type_name_t * cntltype + ) + { + /*If the information about the user is missing*/ + if(!user) + return EOPNOTSUPP; + + error_t err = 0; + + /*Obtain the node for which we are called*/ + node_t * np = user->po->np; + + /*Lock the node*/ + mutex_lock(&np->lock); + + /*Check if the user is the owner of this node*/ + err = fshelp_isowner(&np->nn_stat, user->user); + + /*If no errors have happened*/ + if(!err) + /*try to fetch the control port*/ + err = fshelp_fetch_control(&np->transbox, cntl); + + /*If no errors have occurred, but no port has been returned*/ + if(!err && (cntl == MACH_PORT_NULL)) + /*set the error accordingly*/ + err = ENXIO; + + /*If no errors have occurred so far*/ + if(!err) + /*set the control port type*/ + *cntltype = MACH_MSG_TYPE_MOVE_SEND; + + /*Unlock the node*/ + mutex_unlock(&np->lock); + + /*Return the result of operations*/ + return err; + }/*netfs_S_file_get_translator_cntl*/ +/*----------------------------------------------------------------------------*/ +int +netfs_demuxer + ( + mach_msg_header_t * ing, + mach_msg_header_t * outp + ); +/*----------------------------------------------------------------------------*/ +/*Entry point*/ +int +main + ( + int argc, + char ** argv + ) + { + /*Start logging*/ + INIT_LOG(); + LOG_MSG(">> Starting initialization..."); + + /*The port on which this translator will be set upon*/ + mach_port_t bootstrap_port; + + error_t err = 0; + + /*Parse the command line arguments*/ + argp_parse(&argp_startup, argc, argv, ARGP_IN_ORDER, 0, 0); + LOG_MSG("Command line arguments parsed."); + + /*Try to create the root node*/ + err = node_create_root(&netfs_root_node); + if(err) + error(EXIT_FAILURE, err, "Failed to create the root node"); + LOG_MSG("Root node created."); + + /*Obtain the bootstrap port*/ + task_get_bootstrap_port(mach_task_self(), &bootstrap_port); + + /*Initialize the translator*/ + netfs_init(); + + /*Obtain a port to the underlying node opened as O_NOTRANS*/ + underlying_node = netfs_startup(bootstrap_port, O_READ | O_NOTRANS); + LOG_MSG("netfs initialization complete."); + + /*Initialize the root node*/ + err = node_init_root(underlying_node, netfs_root_node); + if(err) + error(EXIT_FAILURE, err, "Failed to initialize the root node"); + LOG_MSG("Root node initialized."); + LOG_MSG("\tRoot node address: 0x%lX", (unsigned long)netfs_root_node); + + /*Map the time for updating node information*/ + err = maptime_map(0, 0, &maptime); + if(err) + error(EXIT_FAILURE, err, "Failed to map the time"); + LOG_MSG("Time mapped."); + + /*Obtain stat information about the underlying node*/ + err = io_stat(underlying_node, &underlying_node_stat); + if(err) + error(EXIT_FAILURE, err, + "Cannot obtain stat information about the underlying node"); + LOG_MSG("Stat information for undelying node obtained."); + + /*Obtain the ID of the current process*/ + fsid = getpid(); + + /*Setup the stat information for the root node*/ + netfs_root_node->nn_stat = underlying_node_stat; + + netfs_root_node->nn_stat.st_ino = FILTER_ROOT_INODE; + netfs_root_node->nn_stat.st_fsid = fsid; + netfs_root_node->nn_stat.st_mode = underlying_node_stat.st_mode; + + netfs_root_node->nn_translated = netfs_root_node->nn_stat.st_mode; + + netfs_root_node->nn->port = target; + + /*Update the timestamps of the root node*/ + fshelp_touch + (&netfs_root_node->nn_stat, TOUCH_ATIME | TOUCH_MTIME | TOUCH_CTIME, + maptime); + + LOG_MSG(">> Initialization complete. Entering netfs server loop..."); + + /*Start serving clients*/ + for(;;) + netfs_server_loop(); + }/*main*/ +/*----------------------------------------------------------------------------*/ |