diff options
Diffstat (limited to '')
-rw-r--r-- | src/VBox/Additions/linux/sharedfolders/vfsmod.c | 683 |
1 files changed, 683 insertions, 0 deletions
diff --git a/src/VBox/Additions/linux/sharedfolders/vfsmod.c b/src/VBox/Additions/linux/sharedfolders/vfsmod.c new file mode 100644 index 00000000..209424a6 --- /dev/null +++ b/src/VBox/Additions/linux/sharedfolders/vfsmod.c @@ -0,0 +1,683 @@ +/* $Id: vfsmod.c $ */ +/** @file + * vboxsf - VBox Linux Shared Folders VFS, module init/term, super block management. + */ + +/* + * Copyright (C) 2006-2019 Oracle Corporation + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, + * copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following + * conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES + * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT + * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, + * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + */ + +/** + * @note Anyone wishing to make changes here might wish to take a look at + * https://github.com/torvalds/linux/blob/master/Documentation/filesystems/vfs.txt + * which seems to be the closest there is to official documentation on + * writing filesystem drivers for Linux. + */ + +#include "vfsmod.h" +#include "version-generated.h" +#include "revision-generated.h" +#include "product-generated.h" +#include "VBoxGuestR0LibInternal.h" +#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 3, 0) +# include <linux/mount.h> +#endif +#include <linux/seq_file.h> + +MODULE_DESCRIPTION(VBOX_PRODUCT " VFS Module for Host File System Access"); +MODULE_AUTHOR(VBOX_VENDOR); +MODULE_LICENSE("GPL and additional rights"); +#ifdef MODULE_ALIAS_FS +MODULE_ALIAS_FS("vboxsf"); +#endif +#ifdef MODULE_VERSION +MODULE_VERSION(VBOX_VERSION_STRING " r" RT_XSTR(VBOX_SVN_REV)); +#endif + +/* globals */ +VBGLSFCLIENT client_handle; + +/* forward declarations */ +static struct super_operations sf_super_ops; + +/* allocate global info, try to map host share */ +static int sf_glob_alloc(struct vbsf_mount_info_new *info, + struct sf_glob_info **sf_gp) +{ + int err, rc; + SHFLSTRING *str_name; + size_t name_len, str_len; + struct sf_glob_info *sf_g; + + TRACE(); + sf_g = kmalloc(sizeof(*sf_g), GFP_KERNEL); + if (!sf_g) { + err = -ENOMEM; + LogRelFunc(("could not allocate memory for global info\n")); + goto fail0; + } + + RT_ZERO(*sf_g); + + if (info->nullchar != '\0' + || info->signature[0] != VBSF_MOUNT_SIGNATURE_BYTE_0 + || info->signature[1] != VBSF_MOUNT_SIGNATURE_BYTE_1 + || info->signature[2] != VBSF_MOUNT_SIGNATURE_BYTE_2) { + err = -EINVAL; + goto fail1; + } + + info->name[sizeof(info->name) - 1] = 0; + info->nls_name[sizeof(info->nls_name) - 1] = 0; + + name_len = strlen(info->name); + str_len = offsetof(SHFLSTRING, String.utf8) + name_len + 1; + str_name = kmalloc(str_len, GFP_KERNEL); + if (!str_name) { + err = -ENOMEM; + LogRelFunc(("could not allocate memory for host name\n")); + goto fail1; + } + + str_name->u16Length = name_len; + str_name->u16Size = name_len + 1; + memcpy(str_name->String.utf8, info->name, name_len + 1); + +#define _IS_UTF8(_str) \ + (strcmp(_str, "utf8") == 0) +#define _IS_EMPTY(_str) \ + (strcmp(_str, "") == 0) + + /* Check if NLS charset is valid and not points to UTF8 table */ + if (info->nls_name[0]) { + if (_IS_UTF8(info->nls_name)) + sf_g->nls = NULL; + else { + sf_g->nls = load_nls(info->nls_name); + if (!sf_g->nls) { + err = -EINVAL; + LogFunc(("failed to load nls %s\n", + info->nls_name)); + kfree(str_name); + goto fail1; + } + } + } else { +#ifdef CONFIG_NLS_DEFAULT + /* If no NLS charset specified, try to load the default + * one if it's not points to UTF8. */ + if (!_IS_UTF8(CONFIG_NLS_DEFAULT) + && !_IS_EMPTY(CONFIG_NLS_DEFAULT)) + sf_g->nls = load_nls_default(); + else + sf_g->nls = NULL; +#else + sf_g->nls = NULL; +#endif + +#undef _IS_UTF8 +#undef _IS_EMPTY + } + + rc = VbglR0SfMapFolder(&client_handle, str_name, &sf_g->map); + kfree(str_name); + + if (RT_FAILURE(rc)) { + err = -EPROTO; + LogFunc(("VbglR0SfMapFolder failed rc=%d\n", rc)); + goto fail2; + } + + sf_g->ttl = info->ttl; + sf_g->uid = info->uid; + sf_g->gid = info->gid; + + if ((unsigned)info->length >= RT_UOFFSETOF(struct vbsf_mount_info_new, tag)) { + /* new fields */ + sf_g->dmode = info->dmode; + sf_g->fmode = info->fmode; + sf_g->dmask = info->dmask; + sf_g->fmask = info->fmask; + } else { + sf_g->dmode = ~0; + sf_g->fmode = ~0; + } + + if ((unsigned)info->length >= sizeof(struct vbsf_mount_info_new)) { + AssertCompile(sizeof(sf_g->tag) >= sizeof(info->tag)); + memcpy(sf_g->tag, info->tag, sizeof(info->tag)); + sf_g->tag[sizeof(sf_g->tag) - 1] = '\0'; + } else { + sf_g->tag[0] = '\0'; + } + + *sf_gp = sf_g; + return 0; + + fail2: + if (sf_g->nls) + unload_nls(sf_g->nls); + + fail1: + kfree(sf_g); + + fail0: + return err; +} + +/* unmap the share and free global info [sf_g] */ +static void sf_glob_free(struct sf_glob_info *sf_g) +{ + int rc; + + TRACE(); + rc = VbglR0SfUnmapFolder(&client_handle, &sf_g->map); + if (RT_FAILURE(rc)) + LogFunc(("VbglR0SfUnmapFolder failed rc=%d\n", rc)); + + if (sf_g->nls) + unload_nls(sf_g->nls); + + kfree(sf_g); +} + +/** + * This is called (by sf_read_super_[24|26] when vfs mounts the fs and + * wants to read super_block. + * + * calls [sf_glob_alloc] to map the folder and allocate global + * information structure. + * + * initializes [sb], initializes root inode and dentry. + * + * should respect [flags] + */ +static int sf_read_super_aux(struct super_block *sb, void *data, int flags) +{ + int err; + struct dentry *droot; + struct inode *iroot; + struct sf_inode_info *sf_i; + struct sf_glob_info *sf_g; + SHFLFSOBJINFO fsinfo; + struct vbsf_mount_info_new *info; + bool fInodePut = true; + + TRACE(); + if (!data) { + LogFunc(("no mount info specified\n")); + return -EINVAL; + } + + info = data; + + if (flags & MS_REMOUNT) { + LogFunc(("remounting is not supported\n")); + return -ENOSYS; + } + + err = sf_glob_alloc(info, &sf_g); + if (err) + goto fail0; + + sf_i = kmalloc(sizeof(*sf_i), GFP_KERNEL); + if (!sf_i) { + err = -ENOMEM; + LogRelFunc(("could not allocate memory for root inode info\n")); + goto fail1; + } + + sf_i->handle = SHFL_HANDLE_NIL; + sf_i->path = kmalloc(sizeof(SHFLSTRING) + 1, GFP_KERNEL); + if (!sf_i->path) { + err = -ENOMEM; + LogRelFunc(("could not allocate memory for root inode path\n")); + goto fail2; + } + + sf_i->path->u16Length = 1; + sf_i->path->u16Size = 2; + sf_i->path->String.utf8[0] = '/'; + sf_i->path->String.utf8[1] = 0; + sf_i->force_reread = 0; + + err = sf_stat(__func__, sf_g, sf_i->path, &fsinfo, 0); + if (err) { + LogFunc(("could not stat root of share\n")); + goto fail3; + } + + sb->s_magic = 0xface; + sb->s_blocksize = 1024; +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 4, 3) + /* Required for seek/sendfile. + * + * Must by less than or equal to INT64_MAX despite the fact that the + * declaration of this variable is unsigned long long. See determination + * of 'loff_t max' in fs/read_write.c / do_sendfile(). I don't know the + * correct limit but MAX_LFS_FILESIZE (8TB-1 on 32-bit boxes) takes the + * page cache into account and is the suggested limit. */ +# if defined MAX_LFS_FILESIZE + sb->s_maxbytes = MAX_LFS_FILESIZE; +# else + sb->s_maxbytes = 0x7fffffffffffffffULL; +# endif +#endif + sb->s_op = &sf_super_ops; + +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 4, 25) + iroot = iget_locked(sb, 0); +#else + iroot = iget(sb, 0); +#endif + if (!iroot) { + err = -ENOMEM; /* XXX */ + LogFunc(("could not get root inode\n")); + goto fail3; + } + + if (sf_init_backing_dev(sf_g)) { + err = -EINVAL; + LogFunc(("could not init bdi\n")); +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 4, 25) + unlock_new_inode(iroot); +#endif + goto fail4; + } + + sf_init_inode(sf_g, iroot, &fsinfo); + SET_INODE_INFO(iroot, sf_i); + +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 4, 25) + unlock_new_inode(iroot); +#endif + +#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 4, 0) + droot = d_make_root(iroot); +#else + droot = d_alloc_root(iroot); +#endif + if (!droot) { + err = -ENOMEM; /* XXX */ + LogFunc(("d_alloc_root failed\n")); +#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 4, 0) + fInodePut = false; +#endif + goto fail5; + } + + sb->s_root = droot; + SET_GLOB_INFO(sb, sf_g); + return 0; + + fail5: + sf_done_backing_dev(sf_g); + + fail4: + if (fInodePut) + iput(iroot); + + fail3: + kfree(sf_i->path); + + fail2: + kfree(sf_i); + + fail1: + sf_glob_free(sf_g); + + fail0: + return err; +} + +#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 0) +static struct super_block *sf_read_super_24(struct super_block *sb, void *data, + int flags) +{ + int err; + + TRACE(); + err = sf_read_super_aux(sb, data, flags); + if (err) + return NULL; + + return sb; +} +#endif + +/* this is called when vfs is about to destroy the [inode]. all + resources associated with this [inode] must be cleared here */ +#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 36) +static void sf_clear_inode(struct inode *inode) +{ + struct sf_inode_info *sf_i; + + TRACE(); + sf_i = GET_INODE_INFO(inode); + if (!sf_i) + return; + + BUG_ON(!sf_i->path); + kfree(sf_i->path); + kfree(sf_i); + SET_INODE_INFO(inode, NULL); +} +#else /* LINUX_VERSION_CODE >= 2.6.36 */ +static void sf_evict_inode(struct inode *inode) +{ + struct sf_inode_info *sf_i; + + TRACE(); + truncate_inode_pages(&inode->i_data, 0); +# if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 5, 0) + clear_inode(inode); +# else + end_writeback(inode); +# endif + + sf_i = GET_INODE_INFO(inode); + if (!sf_i) + return; + + BUG_ON(!sf_i->path); + kfree(sf_i->path); + kfree(sf_i); + SET_INODE_INFO(inode, NULL); +} +#endif /* LINUX_VERSION_CODE >= 2.6.36 */ + +/* this is called by vfs when it wants to populate [inode] with data. + the only thing that is known about inode at this point is its index + hence we can't do anything here, and let lookup/whatever with the + job to properly fill then [inode] */ +#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 25) +static void sf_read_inode(struct inode *inode) +{ +} +#endif + +/* vfs is done with [sb] (umount called) call [sf_glob_free] to unmap + the folder and free [sf_g] */ +static void sf_put_super(struct super_block *sb) +{ + struct sf_glob_info *sf_g; + + sf_g = GET_GLOB_INFO(sb); + BUG_ON(!sf_g); + sf_done_backing_dev(sf_g); + sf_glob_free(sf_g); +} + +#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 18) +static int sf_statfs(struct super_block *sb, STRUCT_STATFS * stat) +{ + return sf_get_volume_info(sb, stat); +} +#else +static int sf_statfs(struct dentry *dentry, STRUCT_STATFS * stat) +{ + struct super_block *sb = dentry->d_inode->i_sb; + return sf_get_volume_info(sb, stat); +} +#endif + +static int sf_remount_fs(struct super_block *sb, int *flags, char *data) +{ +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 4, 23) + struct sf_glob_info *sf_g; + struct sf_inode_info *sf_i; + struct inode *iroot; + SHFLFSOBJINFO fsinfo; + int err; + + sf_g = GET_GLOB_INFO(sb); + BUG_ON(!sf_g); + if (data && data[0] != 0) { + struct vbsf_mount_info_new *info = + (struct vbsf_mount_info_new *)data; + if (info->signature[0] == VBSF_MOUNT_SIGNATURE_BYTE_0 + && info->signature[1] == VBSF_MOUNT_SIGNATURE_BYTE_1 + && info->signature[2] == VBSF_MOUNT_SIGNATURE_BYTE_2) { + sf_g->uid = info->uid; + sf_g->gid = info->gid; + sf_g->ttl = info->ttl; + if ((unsigned)info->length >= RT_UOFFSETOF(struct vbsf_mount_info_new, tag)) { + sf_g->dmode = info->dmode; + sf_g->fmode = info->fmode; + sf_g->dmask = info->dmask; + sf_g->fmask = info->fmask; + } else { + sf_g->dmode = ~0; + sf_g->fmode = ~0; + } + if ((unsigned)info->length >= sizeof(struct vbsf_mount_info_new)) { + AssertCompile(sizeof(sf_g->tag) >= sizeof(info->tag)); + memcpy(sf_g->tag, info->tag, sizeof(info->tag)); + sf_g->tag[sizeof(sf_g->tag) - 1] = '\0'; + } else { + sf_g->tag[0] = '\0'; + } + } + } + + iroot = ilookup(sb, 0); + if (!iroot) + return -ENOSYS; + + sf_i = GET_INODE_INFO(iroot); + err = sf_stat(__func__, sf_g, sf_i->path, &fsinfo, 0); + BUG_ON(err != 0); + sf_init_inode(sf_g, iroot, &fsinfo); + /*unlock_new_inode(iroot); */ + return 0; +#else /* LINUX_VERSION_CODE < 2.4.23 */ + return -ENOSYS; +#endif /* LINUX_VERSION_CODE < 2.4.23 */ +} + +/** Show mount options. */ +#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 3, 0) +static int sf_show_options(struct seq_file *m, struct vfsmount *mnt) +#else +static int sf_show_options(struct seq_file *m, struct dentry *root) +#endif +{ +#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 3, 0) + struct super_block *sb = mnt->mnt_sb; +#else + struct super_block *sb = root->d_sb; +#endif + struct sf_glob_info *sf_g = GET_GLOB_INFO(sb); + if (sf_g) { + seq_printf(m, ",uid=%u,gid=%u,ttl=%u,dmode=0%o,fmode=0%o,dmask=0%o,fmask=0%o", + sf_g->uid, sf_g->gid, sf_g->ttl, sf_g->dmode, sf_g->fmode, sf_g->dmask, sf_g->fmask); + if (sf_g->tag[0] != '\0') { + seq_puts(m, ",tag="); + seq_escape(m, sf_g->tag, " \t\n\\"); + } + } + + return 0; +} + +static struct super_operations sf_super_ops = { +#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 36) + .clear_inode = sf_clear_inode, +#else + .evict_inode = sf_evict_inode, +#endif +#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 25) + .read_inode = sf_read_inode, +#endif + .put_super = sf_put_super, + .statfs = sf_statfs, + .remount_fs = sf_remount_fs, + .show_options = sf_show_options +}; + +#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 0) +static DECLARE_FSTYPE(vboxsf_fs_type, "vboxsf", sf_read_super_24, 0); +#else +static int sf_read_super_26(struct super_block *sb, void *data, int flags) +{ + int err; + + TRACE(); + err = sf_read_super_aux(sb, data, flags); + if (err) + printk(KERN_DEBUG "sf_read_super_aux err=%d\n", err); + + return err; +} + +# if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 18) +static struct super_block *sf_get_sb(struct file_system_type *fs_type, + int flags, const char *dev_name, + void *data) +{ + TRACE(); + return get_sb_nodev(fs_type, flags, data, sf_read_super_26); +} +# elif LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 39) +static int sf_get_sb(struct file_system_type *fs_type, int flags, + const char *dev_name, void *data, struct vfsmount *mnt) +{ + TRACE(); + return get_sb_nodev(fs_type, flags, data, sf_read_super_26, mnt); +} +# else /* LINUX_VERSION_CODE >= 2.6.39 */ +static struct dentry *sf_mount(struct file_system_type *fs_type, int flags, + const char *dev_name, void *data) +{ + TRACE(); + return mount_nodev(fs_type, flags, data, sf_read_super_26); +} +# endif /* LINUX_VERSION_CODE >= 2.6.39 */ + +static struct file_system_type vboxsf_fs_type = { + .owner = THIS_MODULE, + .name = "vboxsf", +# if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 39) + .get_sb = sf_get_sb, +# else + .mount = sf_mount, +# endif + .kill_sb = kill_anon_super +}; + +#endif /* LINUX_VERSION_CODE >= 2.6.0 */ + +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 0) +static int follow_symlinks = 0; +module_param(follow_symlinks, int, 0); +MODULE_PARM_DESC(follow_symlinks, + "Let host resolve symlinks rather than showing them"); +#endif + +/* Module initialization/finalization handlers */ +static int __init init(void) +{ + int rcVBox; + int rcRet = 0; + int err; + + TRACE(); + + if (sizeof(struct vbsf_mount_info_new) > PAGE_SIZE) { + printk(KERN_ERR + "Mount information structure is too large %lu\n" + "Must be less than or equal to %lu\n", + (unsigned long)sizeof(struct vbsf_mount_info_new), + (unsigned long)PAGE_SIZE); + return -EINVAL; + } + + err = register_filesystem(&vboxsf_fs_type); + if (err) { + LogFunc(("register_filesystem err=%d\n", err)); + return err; + } + + rcVBox = VbglR0HGCMInit(); + if (RT_FAILURE(rcVBox)) { + LogRelFunc(("VbglR0HGCMInit failed, rc=%d\n", rcVBox)); + rcRet = -EPROTO; + goto fail0; + } + + rcVBox = VbglR0SfConnect(&client_handle); + if (RT_FAILURE(rcVBox)) { + LogRelFunc(("VbglR0SfConnect failed, rc=%d\n", rcVBox)); + rcRet = -EPROTO; + goto fail1; + } + + rcVBox = VbglR0SfSetUtf8(&client_handle); + if (RT_FAILURE(rcVBox)) { + LogRelFunc(("VbglR0SfSetUtf8 failed, rc=%d\n", rcVBox)); + rcRet = -EPROTO; + goto fail2; + } +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 0) + if (!follow_symlinks) { + rcVBox = VbglR0SfSetSymlinks(&client_handle); + if (RT_FAILURE(rcVBox)) { + printk(KERN_WARNING + "vboxsf: Host unable to show symlinks, rc=%d\n", + rcVBox); + } + } +#endif + + printk(KERN_DEBUG + "vboxsf: Successfully loaded version " VBOX_VERSION_STRING + " (interface " RT_XSTR(VMMDEV_VERSION) ")\n"); + + return 0; + + fail2: + VbglR0SfDisconnect(&client_handle); + + fail1: + VbglR0HGCMTerminate(); + + fail0: + unregister_filesystem(&vboxsf_fs_type); + return rcRet; +} + +static void __exit fini(void) +{ + TRACE(); + + VbglR0SfDisconnect(&client_handle); + VbglR0HGCMTerminate(); + unregister_filesystem(&vboxsf_fs_type); +} + +module_init(init); +module_exit(fini); + +/* C++ hack */ +int __gxx_personality_v0 = 0xdeadbeef; |