From 68e1093028185cde31dcacf34a59f6c08848d3d4 Mon Sep 17 00:00:00 2001 From: Jeff Sharkey Date: Mon, 8 Jan 2018 11:22:38 -0700 Subject: [PATCH] Remove FUSE logic; it's only a sdcardfs wrapper. Leaving the FUSE logic intact was confusing to OEMs, who expected that it would still work and pass CTS. Remove all the FUSE logic and leave a comment block about why the wrapper exists. Also use new Android.bp makefile format. Test: builds, boots Bug: 63524725 Change-Id: I8b2a4fa0227109d65689c43302dc6fa40394ff58 --- sdcard/Android.bp | 17 + sdcard/Android.mk | 12 - sdcard/fuse.cpp | 1476 --------------------------------------------- sdcard/fuse.h | 209 ------- sdcard/sdcard.cpp | 309 +--------- 5 files changed, 22 insertions(+), 2001 deletions(-) create mode 100644 sdcard/Android.bp delete mode 100644 sdcard/Android.mk delete mode 100644 sdcard/fuse.cpp delete mode 100644 sdcard/fuse.h diff --git a/sdcard/Android.bp b/sdcard/Android.bp new file mode 100644 index 000000000..c096587ba --- /dev/null +++ b/sdcard/Android.bp @@ -0,0 +1,17 @@ +cc_binary { + srcs: ["sdcard.cpp"], + name: "sdcard", + cflags: [ + "-Wall", + "-Wno-unused-parameter", + "-Werror", + ], + shared_libs: [ + "libbase", + "libcutils", + "libminijail", + ], + sanitize: { + misc_undefined: ["integer"], + }, +} diff --git a/sdcard/Android.mk b/sdcard/Android.mk deleted file mode 100644 index 5b4dc5841..000000000 --- a/sdcard/Android.mk +++ /dev/null @@ -1,12 +0,0 @@ -LOCAL_PATH := $(call my-dir) - -include $(CLEAR_VARS) - -LOCAL_SRC_FILES := sdcard.cpp fuse.cpp -LOCAL_MODULE := sdcard -LOCAL_CFLAGS := -Wall -Wno-unused-parameter -Werror -LOCAL_SHARED_LIBRARIES := libbase libcutils libminijail libpackagelistparser - -LOCAL_SANITIZE := integer - -include $(BUILD_EXECUTABLE) diff --git a/sdcard/fuse.cpp b/sdcard/fuse.cpp deleted file mode 100644 index 10d0f0418..000000000 --- a/sdcard/fuse.cpp +++ /dev/null @@ -1,1476 +0,0 @@ -/* - * Copyright (C) 2010 The Android Open Source Project - * - * Licensed under the Apache License, Version 2.0 (the "License"); - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - */ - -#include -#include -#include - -#define LOG_TAG "sdcard" - -#include "fuse.h" - -#include - -/* FUSE_CANONICAL_PATH is not currently upstreamed */ -#define FUSE_CANONICAL_PATH 2016 - -#define FUSE_UNKNOWN_INO 0xffffffff - -/* Pseudo-error constant used to indicate that no fuse status is needed - * or that a reply has already been written. */ -#define NO_STATUS 1 - -static inline void *id_to_ptr(__u64 nid) -{ - return (void *) (uintptr_t) nid; -} - -static inline __u64 ptr_to_id(void *ptr) -{ - return (__u64) (uintptr_t) ptr; -} - -static void acquire_node_locked(struct node* node) -{ - node->refcount++; - DLOG(INFO) << "ACQUIRE " << std::hex << node << std::dec - << " (" << node->name << ") rc=" << node->refcount; -} - -static void remove_node_from_parent_locked(struct node* node); - -static void release_node_locked(struct node* node) -{ - DLOG(INFO) << "RELEASE " << std::hex << node << std::dec - << " (" << node->name << ") rc=" << node->refcount; - if (node->refcount > 0) { - node->refcount--; - if (!node->refcount) { - DLOG(INFO) << "DESTROY " << std::hex << node << std::dec << " (" << node->name << ")"; - remove_node_from_parent_locked(node); - - /* TODO: remove debugging - poison memory */ - memset(node->name, 0xef, node->namelen); - free(node->name); - free(node->actual_name); - memset(node, 0xfc, sizeof(*node)); - free(node); - } - } else { - LOG(ERROR) << std::hex << node << std::dec << " refcount=0"; - } -} - -static void add_node_to_parent_locked(struct node *node, struct node *parent) { - node->parent = parent; - node->next = parent->child; - parent->child = node; - acquire_node_locked(parent); -} - -static void remove_node_from_parent_locked(struct node* node) -{ - if (node->parent) { - if (node->parent->child == node) { - node->parent->child = node->parent->child->next; - } else { - struct node *node2; - node2 = node->parent->child; - while (node2->next != node) - node2 = node2->next; - node2->next = node->next; - } - release_node_locked(node->parent); - node->parent = NULL; - node->next = NULL; - } -} - -/* Gets the absolute path to a node into the provided buffer. - * - * Populates 'buf' with the path and returns the length of the path on success, - * or returns -1 if the path is too long for the provided buffer. - */ -static ssize_t get_node_path_locked(struct node* node, char* buf, size_t bufsize) { - const char* name; - size_t namelen; - if (node->graft_path) { - name = node->graft_path; - namelen = node->graft_pathlen; - } else if (node->actual_name) { - name = node->actual_name; - namelen = node->namelen; - } else { - name = node->name; - namelen = node->namelen; - } - - if (bufsize < namelen + 1) { - return -1; - } - - ssize_t pathlen = 0; - if (node->parent && node->graft_path == NULL) { - pathlen = get_node_path_locked(node->parent, buf, bufsize - namelen - 1); - if (pathlen < 0) { - return -1; - } - buf[pathlen++] = '/'; - } - - memcpy(buf + pathlen, name, namelen + 1); /* include trailing \0 */ - return pathlen + namelen; -} - -/* Finds the absolute path of a file within a given directory. - * Performs a case-insensitive search for the file and sets the buffer to the path - * of the first matching file. If 'search' is zero or if no match is found, sets - * the buffer to the path that the file would have, assuming the name were case-sensitive. - * - * Populates 'buf' with the path and returns the actual name (within 'buf') on success, - * or returns NULL if the path is too long for the provided buffer. - */ -static char* find_file_within(const char* path, const char* name, - char* buf, size_t bufsize, int search) -{ - size_t pathlen = strlen(path); - size_t namelen = strlen(name); - size_t childlen = pathlen + namelen + 1; - char* actual; - - if (bufsize <= childlen) { - return NULL; - } - - memcpy(buf, path, pathlen); - buf[pathlen] = '/'; - actual = buf + pathlen + 1; - memcpy(actual, name, namelen + 1); - - if (search && access(buf, F_OK)) { - struct dirent* entry; - DIR* dir = opendir(path); - if (!dir) { - PLOG(ERROR) << "opendir(" << path << ") failed"; - return actual; - } - while ((entry = readdir(dir))) { - if (!strcasecmp(entry->d_name, name)) { - /* we have a match - replace the name, don't need to copy the null again */ - memcpy(actual, entry->d_name, namelen); - break; - } - } - closedir(dir); - } - return actual; -} - -static void attr_from_stat(struct fuse* fuse, struct fuse_attr *attr, - const struct stat *s, const struct node* node) { - attr->ino = node->ino; - attr->size = s->st_size; - attr->blocks = s->st_blocks; - attr->atime = s->st_atim.tv_sec; - attr->mtime = s->st_mtim.tv_sec; - attr->ctime = s->st_ctim.tv_sec; - attr->atimensec = s->st_atim.tv_nsec; - attr->mtimensec = s->st_mtim.tv_nsec; - attr->ctimensec = s->st_ctim.tv_nsec; - attr->mode = s->st_mode; - attr->nlink = s->st_nlink; - - attr->uid = node->uid; - - if (fuse->gid == AID_SDCARD_RW) { - /* As an optimization, certain trusted system components only run - * as owner but operate across all users. Since we're now handing - * out the sdcard_rw GID only to trusted apps, we're okay relaxing - * the user boundary enforcement for the default view. The UIDs - * assigned to app directories are still multiuser aware. */ - attr->gid = AID_SDCARD_RW; - } else { - attr->gid = multiuser_get_uid(node->userid, fuse->gid); - } - - int visible_mode = 0775 & ~fuse->mask; - if (node->perm == PERM_PRE_ROOT) { - /* Top of multi-user view should always be visible to ensure - * secondary users can traverse inside. */ - visible_mode = 0711; - } else if (node->under_android) { - /* Block "other" access to Android directories, since only apps - * belonging to a specific user should be in there; we still - * leave +x open for the default view. */ - if (fuse->gid == AID_SDCARD_RW) { - visible_mode = visible_mode & ~0006; - } else { - visible_mode = visible_mode & ~0007; - } - } - int owner_mode = s->st_mode & 0700; - int filtered_mode = visible_mode & (owner_mode | (owner_mode >> 3) | (owner_mode >> 6)); - attr->mode = (attr->mode & S_IFMT) | filtered_mode; -} - -static int touch(char* path, mode_t mode) { - int fd = TEMP_FAILURE_RETRY(open(path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW | O_CLOEXEC, - mode)); - if (fd == -1) { - if (errno == EEXIST) { - return 0; - } else { - PLOG(ERROR) << "open(" << path << ") failed"; - return -1; - } - } - close(fd); - return 0; -} - -static void derive_permissions_locked(struct fuse* fuse, struct node *parent, - struct node *node) { - appid_t appid; - - /* By default, each node inherits from its parent */ - node->perm = PERM_INHERIT; - node->userid = parent->userid; - node->uid = parent->uid; - node->under_android = parent->under_android; - - /* Derive custom permissions based on parent and current node */ - switch (parent->perm) { - case PERM_INHERIT: - /* Already inherited above */ - break; - case PERM_PRE_ROOT: - /* Legacy internal layout places users at top level */ - node->perm = PERM_ROOT; - node->userid = strtoul(node->name, NULL, 10); - break; - case PERM_ROOT: - /* Assume masked off by default. */ - if (!strcasecmp(node->name, "Android")) { - /* App-specific directories inside; let anyone traverse */ - node->perm = PERM_ANDROID; - node->under_android = true; - } - break; - case PERM_ANDROID: - if (!strcasecmp(node->name, "data")) { - /* App-specific directories inside; let anyone traverse */ - node->perm = PERM_ANDROID_DATA; - } else if (!strcasecmp(node->name, "obb")) { - /* App-specific directories inside; let anyone traverse */ - node->perm = PERM_ANDROID_OBB; - /* Single OBB directory is always shared */ - node->graft_path = fuse->global->obb_path; - node->graft_pathlen = strlen(fuse->global->obb_path); - } else if (!strcasecmp(node->name, "media")) { - /* App-specific directories inside; let anyone traverse */ - node->perm = PERM_ANDROID_MEDIA; - } - break; - case PERM_ANDROID_DATA: - case PERM_ANDROID_OBB: - case PERM_ANDROID_MEDIA: - const auto& iter = fuse->global->package_to_appid->find(node->name); - if (iter != fuse->global->package_to_appid->end()) { - appid = iter->second; - node->uid = multiuser_get_uid(parent->userid, appid); - } - break; - } -} - -void derive_permissions_recursive_locked(struct fuse* fuse, struct node *parent) { - struct node *node; - for (node = parent->child; node; node = node->next) { - derive_permissions_locked(fuse, parent, node); - if (node->child) { - derive_permissions_recursive_locked(fuse, node); - } - } -} - -/* Kernel has already enforced everything we returned through - * derive_permissions_locked(), so this is used to lock down access - * even further, such as enforcing that apps hold sdcard_rw. */ -static bool check_caller_access_to_name(struct fuse* fuse, - const struct fuse_in_header *hdr, const struct node* parent_node, - const char* name, int mode) { - /* Always block security-sensitive files at root */ - if (parent_node && parent_node->perm == PERM_ROOT) { - if (!strcasecmp(name, "autorun.inf") - || !strcasecmp(name, ".android_secure") - || !strcasecmp(name, "android_secure")) { - return false; - } - } - - /* Root always has access; access for any other UIDs should always - * be controlled through packages.list. */ - if (hdr->uid == AID_ROOT) { - return true; - } - - /* No extra permissions to enforce */ - return true; -} - -static bool check_caller_access_to_node(struct fuse* fuse, - const struct fuse_in_header *hdr, const struct node* node, int mode) { - return check_caller_access_to_name(fuse, hdr, node->parent, node->name, mode); -} - -struct node *create_node_locked(struct fuse* fuse, - struct node *parent, const char *name, const char* actual_name) -{ - struct node *node; - size_t namelen = strlen(name); - - // Detect overflows in the inode counter. "4 billion nodes should be enough - // for everybody". - if (fuse->global->inode_ctr == 0) { - LOG(ERROR) << "No more inode numbers available"; - return NULL; - } - - node = static_cast(calloc(1, sizeof(struct node))); - if (!node) { - return NULL; - } - node->name = static_cast(malloc(namelen + 1)); - if (!node->name) { - free(node); - return NULL; - } - memcpy(node->name, name, namelen + 1); - if (strcmp(name, actual_name)) { - node->actual_name = static_cast(malloc(namelen + 1)); - if (!node->actual_name) { - free(node->name); - free(node); - return NULL; - } - memcpy(node->actual_name, actual_name, namelen + 1); - } - node->namelen = namelen; - node->nid = ptr_to_id(node); - node->ino = fuse->global->inode_ctr++; - node->gen = fuse->global->next_generation++; - - node->deleted = false; - - derive_permissions_locked(fuse, parent, node); - acquire_node_locked(node); - add_node_to_parent_locked(node, parent); - return node; -} - -static int rename_node_locked(struct node *node, const char *name, - const char* actual_name) -{ - size_t namelen = strlen(name); - int need_actual_name = strcmp(name, actual_name); - - /* make the storage bigger without actually changing the name - * in case an error occurs part way */ - if (namelen > node->namelen) { - char* new_name = static_cast(realloc(node->name, namelen + 1)); - if (!new_name) { - return -ENOMEM; - } - node->name = new_name; - if (need_actual_name && node->actual_name) { - char* new_actual_name = static_cast(realloc(node->actual_name, namelen + 1)); - if (!new_actual_name) { - return -ENOMEM; - } - node->actual_name = new_actual_name; - } - } - - /* update the name, taking care to allocate storage before overwriting the old name */ - if (need_actual_name) { - if (!node->actual_name) { - node->actual_name = static_cast(malloc(namelen + 1)); - if (!node->actual_name) { - return -ENOMEM; - } - } - memcpy(node->actual_name, actual_name, namelen + 1); - } else { - free(node->actual_name); - node->actual_name = NULL; - } - memcpy(node->name, name, namelen + 1); - node->namelen = namelen; - return 0; -} - -static struct node *lookup_node_by_id_locked(struct fuse *fuse, __u64 nid) -{ - if (nid == FUSE_ROOT_ID) { - return &fuse->global->root; - } else { - return static_cast(id_to_ptr(nid)); - } -} - -static struct node* lookup_node_and_path_by_id_locked(struct fuse* fuse, __u64 nid, - char* buf, size_t bufsize) -{ - struct node* node = lookup_node_by_id_locked(fuse, nid); - if (node && get_node_path_locked(node, buf, bufsize) < 0) { - node = NULL; - } - return node; -} - -static struct node *lookup_child_by_name_locked(struct node *node, const char *name) -{ - for (node = node->child; node; node = node->next) { - /* use exact string comparison, nodes that differ by case - * must be considered distinct even if they refer to the same - * underlying file as otherwise operations such as "mv x x" - * will not work because the source and target nodes are the same. */ - if (!strcmp(name, node->name) && !node->deleted) { - return node; - } - } - return 0; -} - -static struct node* acquire_or_create_child_locked( - struct fuse* fuse, struct node* parent, - const char* name, const char* actual_name) -{ - struct node* child = lookup_child_by_name_locked(parent, name); - if (child) { - acquire_node_locked(child); - } else { - child = create_node_locked(fuse, parent, name, actual_name); - } - return child; -} - -static void fuse_status(struct fuse *fuse, __u64 unique, int err) -{ - struct fuse_out_header hdr; - hdr.len = sizeof(hdr); - hdr.error = err; - hdr.unique = unique; - ssize_t ret = TEMP_FAILURE_RETRY(write(fuse->fd, &hdr, sizeof(hdr))); - if (ret == -1) { - PLOG(ERROR) << "*** STATUS FAILED ***"; - } else if (static_cast(ret) != sizeof(hdr)) { - LOG(ERROR) << "*** STATUS FAILED: written " << ret << " expected " - << sizeof(hdr) << " ***"; - } -} - -static void fuse_reply(struct fuse *fuse, __u64 unique, void *data, int len) -{ - struct fuse_out_header hdr; - hdr.len = len + sizeof(hdr); - hdr.error = 0; - hdr.unique = unique; - - struct iovec vec[2]; - vec[0].iov_base = &hdr; - vec[0].iov_len = sizeof(hdr); - vec[1].iov_base = data; - vec[1].iov_len = len; - - ssize_t ret = TEMP_FAILURE_RETRY(writev(fuse->fd, vec, 2)); - if (ret == -1) { - PLOG(ERROR) << "*** REPLY FAILED ***"; - } else if (static_cast(ret) != sizeof(hdr) + len) { - LOG(ERROR) << "*** REPLY FAILED: written " << ret << " expected " - << sizeof(hdr) + len << " ***"; - } -} - -static int fuse_reply_entry(struct fuse* fuse, __u64 unique, - struct node* parent, const char* name, const char* actual_name, - const char* path) -{ - struct node* node; - struct fuse_entry_out out; - struct stat s; - - if (lstat(path, &s) == -1) { - return -errno; - } - - pthread_mutex_lock(&fuse->global->lock); - node = acquire_or_create_child_locked(fuse, parent, name, actual_name); - if (!node) { - pthread_mutex_unlock(&fuse->global->lock); - return -ENOMEM; - } - memset(&out, 0, sizeof(out)); - attr_from_stat(fuse, &out.attr, &s, node); - out.attr_valid = 10; - out.entry_valid = 10; - out.nodeid = node->nid; - out.generation = node->gen; - pthread_mutex_unlock(&fuse->global->lock); - fuse_reply(fuse, unique, &out, sizeof(out)); - return NO_STATUS; -} - -static int fuse_reply_attr(struct fuse* fuse, __u64 unique, const struct node* node, - const char* path) -{ - struct fuse_attr_out out; - struct stat s; - - if (lstat(path, &s) == -1) { - return -errno; - } - memset(&out, 0, sizeof(out)); - attr_from_stat(fuse, &out.attr, &s, node); - out.attr_valid = 10; - fuse_reply(fuse, unique, &out, sizeof(out)); - return NO_STATUS; -} - -static void fuse_notify_delete(struct fuse* fuse, const __u64 parent, - const __u64 child, const char* name) { - struct fuse_out_header hdr; - struct fuse_notify_delete_out data; - size_t namelen = strlen(name); - hdr.len = sizeof(hdr) + sizeof(data) + namelen + 1; - hdr.error = FUSE_NOTIFY_DELETE; - hdr.unique = 0; - - data.parent = parent; - data.child = child; - data.namelen = namelen; - data.padding = 0; - - struct iovec vec[3]; - vec[0].iov_base = &hdr; - vec[0].iov_len = sizeof(hdr); - vec[1].iov_base = &data; - vec[1].iov_len = sizeof(data); - vec[2].iov_base = (void*) name; - vec[2].iov_len = namelen + 1; - - ssize_t ret = TEMP_FAILURE_RETRY(writev(fuse->fd, vec, 3)); - /* Ignore ENOENT, since other views may not have seen the entry */ - if (ret == -1) { - if (errno != ENOENT) { - PLOG(ERROR) << "*** NOTIFY FAILED ***"; - } - } else if (static_cast(ret) != sizeof(hdr) + sizeof(data) + namelen + 1) { - LOG(ERROR) << "*** NOTIFY FAILED: written " << ret << " expected " - << sizeof(hdr) + sizeof(data) + namelen + 1 << " ***"; - } -} - -static int handle_lookup(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header *hdr, const char* name) -{ - struct node* parent_node; - char parent_path[PATH_MAX]; - char child_path[PATH_MAX]; - const char* actual_name; - - pthread_mutex_lock(&fuse->global->lock); - parent_node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid, - parent_path, sizeof(parent_path)); - DLOG(INFO) << "[" << handler->token << "] LOOKUP " << name << " @ " << hdr->nodeid - << " (" << (parent_node ? parent_node->name : "?") << ")"; - pthread_mutex_unlock(&fuse->global->lock); - - if (!parent_node || !(actual_name = find_file_within(parent_path, name, - child_path, sizeof(child_path), 1))) { - return -ENOENT; - } - if (!check_caller_access_to_name(fuse, hdr, parent_node, name, R_OK)) { - return -EACCES; - } - - return fuse_reply_entry(fuse, hdr->unique, parent_node, name, actual_name, child_path); -} - -static int handle_forget(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header *hdr, const struct fuse_forget_in *req) -{ - struct node* node; - - pthread_mutex_lock(&fuse->global->lock); - node = lookup_node_by_id_locked(fuse, hdr->nodeid); - DLOG(INFO) << "[" << handler->token << "] FORGET #" << req->nlookup - << " @ " << std::hex << hdr->nodeid - << " (" << (node ? node->name : "?") << ")"; - if (node) { - __u64 n = req->nlookup; - while (n) { - n--; - release_node_locked(node); - } - } - pthread_mutex_unlock(&fuse->global->lock); - return NO_STATUS; /* no reply */ -} - -static int handle_getattr(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header *hdr, const struct fuse_getattr_in *req) -{ - struct node* node; - char path[PATH_MAX]; - - pthread_mutex_lock(&fuse->global->lock); - node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid, path, sizeof(path)); - DLOG(INFO) << "[" << handler->token << "] GETATTR flags=" << req->getattr_flags - << " fh=" << std::hex << req->fh << " @ " << hdr->nodeid << std::dec - << " (" << (node ? node->name : "?") << ")"; - pthread_mutex_unlock(&fuse->global->lock); - - if (!node) { - return -ENOENT; - } - if (!check_caller_access_to_node(fuse, hdr, node, R_OK)) { - return -EACCES; - } - - return fuse_reply_attr(fuse, hdr->unique, node, path); -} - -static int handle_setattr(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header *hdr, const struct fuse_setattr_in *req) -{ - struct node* node; - char path[PATH_MAX]; - struct timespec times[2]; - - pthread_mutex_lock(&fuse->global->lock); - node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid, path, sizeof(path)); - DLOG(INFO) << "[" << handler->token << "] SETATTR fh=" << std::hex << req->fh - << " valid=" << std::hex << req->valid << " @ " << hdr->nodeid << std::dec - << " (" << (node ? node->name : "?") << ")"; - pthread_mutex_unlock(&fuse->global->lock); - - if (!node) { - return -ENOENT; - } - - if (!(req->valid & FATTR_FH) && - !check_caller_access_to_node(fuse, hdr, node, W_OK)) { - return -EACCES; - } - - /* XXX: incomplete implementation on purpose. - * chmod/chown should NEVER be implemented.*/ - - if ((req->valid & FATTR_SIZE) && TEMP_FAILURE_RETRY(truncate64(path, req->size)) == -1) { - return -errno; - } - - /* Handle changing atime and mtime. If FATTR_ATIME_and FATTR_ATIME_NOW - * are both set, then set it to the current time. Else, set it to the - * time specified in the request. Same goes for mtime. Use utimensat(2) - * as it allows ATIME and MTIME to be changed independently, and has - * nanosecond resolution which fuse also has. - */ - if (req->valid & (FATTR_ATIME | FATTR_MTIME)) { - times[0].tv_nsec = UTIME_OMIT; - times[1].tv_nsec = UTIME_OMIT; - if (req->valid & FATTR_ATIME) { - if (req->valid & FATTR_ATIME_NOW) { - times[0].tv_nsec = UTIME_NOW; - } else { - times[0].tv_sec = req->atime; - times[0].tv_nsec = req->atimensec; - } - } - if (req->valid & FATTR_MTIME) { - if (req->valid & FATTR_MTIME_NOW) { - times[1].tv_nsec = UTIME_NOW; - } else { - times[1].tv_sec = req->mtime; - times[1].tv_nsec = req->mtimensec; - } - } - DLOG(INFO) << "[" << handler->token << "] Calling utimensat on " << path - << " with atime " << times[0].tv_sec << ", mtime=" << times[1].tv_sec; - if (utimensat(-1, path, times, 0) < 0) { - return -errno; - } - } - return fuse_reply_attr(fuse, hdr->unique, node, path); -} - -static int handle_mknod(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header* hdr, const struct fuse_mknod_in* req, const char* name) -{ - struct node* parent_node; - char parent_path[PATH_MAX]; - char child_path[PATH_MAX]; - const char* actual_name; - - pthread_mutex_lock(&fuse->global->lock); - parent_node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid, - parent_path, sizeof(parent_path)); - DLOG(INFO) << "[" << handler->token << "] MKNOD " << name << " 0" << std::oct << req->mode - << " @ " << std::hex << hdr->nodeid - << " (" << (parent_node ? parent_node->name : "?") << ")"; - pthread_mutex_unlock(&fuse->global->lock); - - if (!parent_node || !(actual_name = find_file_within(parent_path, name, - child_path, sizeof(child_path), 1))) { - return -ENOENT; - } - if (!check_caller_access_to_name(fuse, hdr, parent_node, name, W_OK)) { - return -EACCES; - } - __u32 mode = (req->mode & (~0777)) | 0664; - if (mknod(child_path, mode, req->rdev) == -1) { - return -errno; - } - return fuse_reply_entry(fuse, hdr->unique, parent_node, name, actual_name, child_path); -} - -static int handle_mkdir(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header* hdr, const struct fuse_mkdir_in* req, const char* name) -{ - struct node* parent_node; - char parent_path[PATH_MAX]; - char child_path[PATH_MAX]; - const char* actual_name; - - pthread_mutex_lock(&fuse->global->lock); - parent_node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid, - parent_path, sizeof(parent_path)); - DLOG(INFO) << "[" << handler->token << "] MKDIR " << name << " 0" << std::oct << req->mode - << " @ " << std::hex << hdr->nodeid - << " (" << (parent_node ? parent_node->name : "?") << ")"; - pthread_mutex_unlock(&fuse->global->lock); - - if (!parent_node || !(actual_name = find_file_within(parent_path, name, - child_path, sizeof(child_path), 1))) { - return -ENOENT; - } - if (!check_caller_access_to_name(fuse, hdr, parent_node, name, W_OK)) { - return -EACCES; - } - __u32 mode = (req->mode & (~0777)) | 0775; - if (mkdir(child_path, mode) == -1) { - return -errno; - } - - /* When creating /Android/data and /Android/obb, mark them as .nomedia */ - if (parent_node->perm == PERM_ANDROID && !strcasecmp(name, "data")) { - char nomedia[PATH_MAX]; - snprintf(nomedia, PATH_MAX, "%s/.nomedia", child_path); - if (touch(nomedia, 0664) != 0) { - PLOG(ERROR) << "touch(" << nomedia << ") failed"; - return -ENOENT; - } - } - if (parent_node->perm == PERM_ANDROID && !strcasecmp(name, "obb")) { - char nomedia[PATH_MAX]; - snprintf(nomedia, PATH_MAX, "%s/.nomedia", fuse->global->obb_path); - if (touch(nomedia, 0664) != 0) { - PLOG(ERROR) << "touch(" << nomedia << ") failed"; - return -ENOENT; - } - } - - return fuse_reply_entry(fuse, hdr->unique, parent_node, name, actual_name, child_path); -} - -static int handle_unlink(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header* hdr, const char* name) -{ - struct node* parent_node; - struct node* child_node; - char parent_path[PATH_MAX]; - char child_path[PATH_MAX]; - - pthread_mutex_lock(&fuse->global->lock); - parent_node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid, - parent_path, sizeof(parent_path)); - DLOG(INFO) << "[" << handler->token << "] UNLINK " << name << " @ " << std::hex << hdr->nodeid - << " (" << (parent_node ? parent_node->name : "?") << ")"; - pthread_mutex_unlock(&fuse->global->lock); - - if (!parent_node || !find_file_within(parent_path, name, - child_path, sizeof(child_path), 1)) { - return -ENOENT; - } - if (!check_caller_access_to_name(fuse, hdr, parent_node, name, W_OK)) { - return -EACCES; - } - if (unlink(child_path) == -1) { - return -errno; - } - pthread_mutex_lock(&fuse->global->lock); - child_node = lookup_child_by_name_locked(parent_node, name); - if (child_node) { - child_node->deleted = true; - } - pthread_mutex_unlock(&fuse->global->lock); - if (parent_node && child_node) { - /* Tell all other views that node is gone */ - DLOG(INFO) << "[" << handler->token << "] fuse_notify_delete" - << " parent=" << std::hex << parent_node->nid - << ", child=" << std::hex << child_node->nid << std::dec - << ", name=" << name; - if (fuse != fuse->global->fuse_default) { - fuse_notify_delete(fuse->global->fuse_default, parent_node->nid, child_node->nid, name); - } - if (fuse != fuse->global->fuse_read) { - fuse_notify_delete(fuse->global->fuse_read, parent_node->nid, child_node->nid, name); - } - if (fuse != fuse->global->fuse_write) { - fuse_notify_delete(fuse->global->fuse_write, parent_node->nid, child_node->nid, name); - } - } - return 0; -} - -static int handle_rmdir(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header* hdr, const char* name) -{ - struct node* child_node; - struct node* parent_node; - char parent_path[PATH_MAX]; - char child_path[PATH_MAX]; - - pthread_mutex_lock(&fuse->global->lock); - parent_node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid, - parent_path, sizeof(parent_path)); - DLOG(INFO) << "[" << handler->token << "] UNLINK " << name << " @ " << std::hex << hdr->nodeid - << " (" << (parent_node ? parent_node->name : "?") << ")"; - pthread_mutex_unlock(&fuse->global->lock); - - if (!parent_node || !find_file_within(parent_path, name, - child_path, sizeof(child_path), 1)) { - return -ENOENT; - } - if (!check_caller_access_to_name(fuse, hdr, parent_node, name, W_OK)) { - return -EACCES; - } - if (rmdir(child_path) == -1) { - return -errno; - } - pthread_mutex_lock(&fuse->global->lock); - child_node = lookup_child_by_name_locked(parent_node, name); - if (child_node) { - child_node->deleted = true; - } - pthread_mutex_unlock(&fuse->global->lock); - if (parent_node && child_node) { - /* Tell all other views that node is gone */ - DLOG(INFO) << "[" << handler->token << "] fuse_notify_delete" - << " parent=" << std::hex << parent_node->nid - << ", child=" << std::hex << child_node->nid << std::dec - << ", name=" << name; - if (fuse != fuse->global->fuse_default) { - fuse_notify_delete(fuse->global->fuse_default, parent_node->nid, child_node->nid, name); - } - if (fuse != fuse->global->fuse_read) { - fuse_notify_delete(fuse->global->fuse_read, parent_node->nid, child_node->nid, name); - } - if (fuse != fuse->global->fuse_write) { - fuse_notify_delete(fuse->global->fuse_write, parent_node->nid, child_node->nid, name); - } - } - return 0; -} - -static int handle_rename(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header* hdr, const struct fuse_rename_in* req, - const char* old_name, const char* new_name) -{ - struct node* old_parent_node; - struct node* new_parent_node; - struct node* child_node; - char old_parent_path[PATH_MAX]; - char new_parent_path[PATH_MAX]; - char old_child_path[PATH_MAX]; - char new_child_path[PATH_MAX]; - const char* new_actual_name; - int search; - int res; - - pthread_mutex_lock(&fuse->global->lock); - old_parent_node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid, - old_parent_path, sizeof(old_parent_path)); - new_parent_node = lookup_node_and_path_by_id_locked(fuse, req->newdir, - new_parent_path, sizeof(new_parent_path)); - DLOG(INFO) << "[" << handler->token << "] RENAME " << old_name << "->" << new_name - << " @ " << std::hex << hdr->nodeid - << " (" << (old_parent_node ? old_parent_node->name : "?") << ") -> " - << std::hex << req->newdir - << " (" << (new_parent_node ? new_parent_node->name : "?") << ")"; - if (!old_parent_node || !new_parent_node) { - res = -ENOENT; - goto lookup_error; - } - if (!check_caller_access_to_name(fuse, hdr, old_parent_node, old_name, W_OK)) { - res = -EACCES; - goto lookup_error; - } - if (!check_caller_access_to_name(fuse, hdr, new_parent_node, new_name, W_OK)) { - res = -EACCES; - goto lookup_error; - } - child_node = lookup_child_by_name_locked(old_parent_node, old_name); - if (!child_node || get_node_path_locked(child_node, - old_child_path, sizeof(old_child_path)) < 0) { - res = -ENOENT; - goto lookup_error; - } - acquire_node_locked(child_node); - pthread_mutex_unlock(&fuse->global->lock); - - /* Special case for renaming a file where destination is same path - * differing only by case. In this case we don't want to look for a case - * insensitive match. This allows commands like "mv foo FOO" to work as expected. - */ - search = old_parent_node != new_parent_node - || strcasecmp(old_name, new_name); - if (!(new_actual_name = find_file_within(new_parent_path, new_name, - new_child_path, sizeof(new_child_path), search))) { - res = -ENOENT; - goto io_error; - } - - DLOG(INFO) << "[" << handler->token << "] RENAME " << old_child_path << "->" << new_child_path; - res = rename(old_child_path, new_child_path); - if (res == -1) { - res = -errno; - goto io_error; - } - - pthread_mutex_lock(&fuse->global->lock); - res = rename_node_locked(child_node, new_name, new_actual_name); - if (!res) { - remove_node_from_parent_locked(child_node); - derive_permissions_locked(fuse, new_parent_node, child_node); - derive_permissions_recursive_locked(fuse, child_node); - add_node_to_parent_locked(child_node, new_parent_node); - } - goto done; - -io_error: - pthread_mutex_lock(&fuse->global->lock); -done: - release_node_locked(child_node); -lookup_error: - pthread_mutex_unlock(&fuse->global->lock); - return res; -} - -static int open_flags_to_access_mode(int open_flags) { - if ((open_flags & O_ACCMODE) == O_RDONLY) { - return R_OK; - } else if ((open_flags & O_ACCMODE) == O_WRONLY) { - return W_OK; - } else { - /* Probably O_RDRW, but treat as default to be safe */ - return R_OK | W_OK; - } -} - -static int handle_open(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header* hdr, const struct fuse_open_in* req) -{ - struct node* node; - char path[PATH_MAX]; - struct fuse_open_out out = {}; - struct handle *h; - - pthread_mutex_lock(&fuse->global->lock); - node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid, path, sizeof(path)); - DLOG(INFO) << "[" << handler->token << "] OPEN 0" << std::oct << req->flags - << " @ " << std::hex << hdr->nodeid << std::dec - << " (" << (node ? node->name : "?") << ")"; - pthread_mutex_unlock(&fuse->global->lock); - - if (!node) { - return -ENOENT; - } - if (!check_caller_access_to_node(fuse, hdr, node, - open_flags_to_access_mode(req->flags))) { - return -EACCES; - } - h = static_cast(malloc(sizeof(*h))); - if (!h) { - return -ENOMEM; - } - DLOG(INFO) << "[" << handler->token << "] OPEN " << path; - h->fd = TEMP_FAILURE_RETRY(open(path, req->flags)); - if (h->fd == -1) { - free(h); - return -errno; - } - out.fh = ptr_to_id(h); - out.open_flags = 0; - fuse_reply(fuse, hdr->unique, &out, sizeof(out)); - return NO_STATUS; -} - -static int handle_read(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header* hdr, const struct fuse_read_in* req) -{ - struct handle *h = static_cast(id_to_ptr(req->fh)); - __u64 unique = hdr->unique; - __u32 size = req->size; - __u64 offset = req->offset; - int res; - __u8 *read_buffer = (__u8 *) ((uintptr_t)(handler->read_buffer + PAGE_SIZE) & ~((uintptr_t)PAGE_SIZE-1)); - - /* Don't access any other fields of hdr or req beyond this point, the read buffer - * overlaps the request buffer and will clobber data in the request. This - * saves us 128KB per request handler thread at the cost of this scary comment. */ - - DLOG(INFO) << "[" << handler->token << "] READ " << std::hex << h << std::dec - << "(" << h->fd << ") " << size << "@" << offset; - if (size > MAX_READ) { - return -EINVAL; - } - res = TEMP_FAILURE_RETRY(pread64(h->fd, read_buffer, size, offset)); - if (res == -1) { - return -errno; - } - fuse_reply(fuse, unique, read_buffer, res); - return NO_STATUS; -} - -static int handle_write(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header* hdr, const struct fuse_write_in* req, - const void* buffer) -{ - struct fuse_write_out out; - struct handle *h = static_cast(id_to_ptr(req->fh)); - int res; - __u8 aligned_buffer[req->size] __attribute__((__aligned__(PAGE_SIZE))); - - if (req->flags & O_DIRECT) { - memcpy(aligned_buffer, buffer, req->size); - buffer = (const __u8*) aligned_buffer; - } - - DLOG(INFO) << "[" << handler->token << "] WRITE " << std::hex << h << std::dec - << "(" << h->fd << ") " << req->size << "@" << req->offset; - res = TEMP_FAILURE_RETRY(pwrite64(h->fd, buffer, req->size, req->offset)); - if (res == -1) { - return -errno; - } - out.size = res; - out.padding = 0; - fuse_reply(fuse, hdr->unique, &out, sizeof(out)); - return NO_STATUS; -} - -static int handle_statfs(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header* hdr) -{ - char path[PATH_MAX]; - struct statfs stat; - struct fuse_statfs_out out; - int res; - - pthread_mutex_lock(&fuse->global->lock); - DLOG(INFO) << "[" << handler->token << "] STATFS"; - res = get_node_path_locked(&fuse->global->root, path, sizeof(path)); - pthread_mutex_unlock(&fuse->global->lock); - if (res < 0) { - return -ENOENT; - } - if (TEMP_FAILURE_RETRY(statfs(fuse->global->root.name, &stat)) == -1) { - return -errno; - } - memset(&out, 0, sizeof(out)); - out.st.blocks = stat.f_blocks; - out.st.bfree = stat.f_bfree; - out.st.bavail = stat.f_bavail; - out.st.files = stat.f_files; - out.st.ffree = stat.f_ffree; - out.st.bsize = stat.f_bsize; - out.st.namelen = stat.f_namelen; - out.st.frsize = stat.f_frsize; - fuse_reply(fuse, hdr->unique, &out, sizeof(out)); - return NO_STATUS; -} - -static int handle_release(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header* hdr, const struct fuse_release_in* req) -{ - struct handle *h = static_cast(id_to_ptr(req->fh)); - - DLOG(INFO) << "[" << handler->token << "] RELEASE " << std::hex << h << std::dec - << "(" << h->fd << ")"; - close(h->fd); - free(h); - return 0; -} - -static int handle_fsync(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header* hdr, const struct fuse_fsync_in* req) -{ - bool is_dir = (hdr->opcode == FUSE_FSYNCDIR); - bool is_data_sync = req->fsync_flags & 1; - - int fd = -1; - if (is_dir) { - struct dirhandle *dh = static_cast(id_to_ptr(req->fh)); - fd = dirfd(dh->d); - } else { - struct handle *h = static_cast(id_to_ptr(req->fh)); - fd = h->fd; - } - - DLOG(INFO) << "[" << handler->token << "] " << (is_dir ? "FSYNCDIR" : "FSYNC") << " " - << std::hex << req->fh << std::dec << "(" << fd << ") is_data_sync=" << is_data_sync; - int res = is_data_sync ? fdatasync(fd) : fsync(fd); - if (res == -1) { - return -errno; - } - return 0; -} - -static int handle_flush(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header* hdr) -{ - DLOG(INFO) << "[" << handler->token << "] FLUSH"; - return 0; -} - -static int handle_opendir(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header* hdr, const struct fuse_open_in* req) -{ - struct node* node; - char path[PATH_MAX]; - struct fuse_open_out out = {}; - struct dirhandle *h; - - pthread_mutex_lock(&fuse->global->lock); - node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid, path, sizeof(path)); - DLOG(INFO) << "[" << handler->token << "] OPENDIR @ " << std::hex << hdr->nodeid - << " (" << (node ? node->name : "?") << ")"; - pthread_mutex_unlock(&fuse->global->lock); - - if (!node) { - return -ENOENT; - } - if (!check_caller_access_to_node(fuse, hdr, node, R_OK)) { - return -EACCES; - } - h = static_cast(malloc(sizeof(*h))); - if (!h) { - return -ENOMEM; - } - DLOG(INFO) << "[" << handler->token << "] OPENDIR " << path; - h->d = opendir(path); - if (!h->d) { - free(h); - return -errno; - } - out.fh = ptr_to_id(h); - out.open_flags = 0; - fuse_reply(fuse, hdr->unique, &out, sizeof(out)); - return NO_STATUS; -} - -static int handle_readdir(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header* hdr, const struct fuse_read_in* req) -{ - char buffer[8192]; - struct fuse_dirent *fde = (struct fuse_dirent*) buffer; - struct dirent *de; - struct dirhandle *h = static_cast(id_to_ptr(req->fh)); - - DLOG(INFO) << "[" << handler->token << "] READDIR " << h; - if (req->offset == 0) { - /* rewinddir() might have been called above us, so rewind here too */ - DLOG(INFO) << "[" << handler->token << "] calling rewinddir()"; - rewinddir(h->d); - } - de = readdir(h->d); - if (!de) { - return 0; - } - fde->ino = FUSE_UNKNOWN_INO; - /* increment the offset so we can detect when rewinddir() seeks back to the beginning */ - fde->off = req->offset + 1; - fde->type = de->d_type; - fde->namelen = strlen(de->d_name); - memcpy(fde->name, de->d_name, fde->namelen + 1); - fuse_reply(fuse, hdr->unique, fde, - FUSE_DIRENT_ALIGN(sizeof(struct fuse_dirent) + fde->namelen)); - return NO_STATUS; -} - -static int handle_releasedir(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header* hdr, const struct fuse_release_in* req) -{ - struct dirhandle *h = static_cast(id_to_ptr(req->fh)); - - DLOG(INFO) << "[" << handler->token << "] RELEASEDIR " << h; - closedir(h->d); - free(h); - return 0; -} - -static int handle_init(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header* hdr, const struct fuse_init_in* req) -{ - struct fuse_init_out out; - size_t fuse_struct_size; - - DLOG(INFO) << "[" << handler->token << "] INIT ver=" << req->major << "." << req->minor - << " maxread=" << req->max_readahead << " flags=" << std::hex << req->flags; - - /* Kernel 2.6.16 is the first stable kernel with struct fuse_init_out - * defined (fuse version 7.6). The structure is the same from 7.6 through - * 7.22. Beginning with 7.23, the structure increased in size and added - * new parameters. - */ - if (req->major != FUSE_KERNEL_VERSION || req->minor < 6) { - LOG(ERROR) << "Fuse kernel version mismatch: Kernel version " - << req->major << "." << req->minor - << ", Expected at least " << FUSE_KERNEL_VERSION << ".6"; - return -1; - } - - /* We limit ourselves to 15 because we don't handle BATCH_FORGET yet */ - out.minor = MIN(req->minor, 15); - fuse_struct_size = sizeof(out); -#if defined(FUSE_COMPAT_22_INIT_OUT_SIZE) - /* FUSE_KERNEL_VERSION >= 23. */ - - /* Since we return minor version 15, the kernel does not accept the latest - * fuse_init_out size. We need to use FUSE_COMPAT_22_INIT_OUT_SIZE always.*/ - fuse_struct_size = FUSE_COMPAT_22_INIT_OUT_SIZE; -#endif - - out.major = FUSE_KERNEL_VERSION; - out.max_readahead = req->max_readahead; - out.flags = FUSE_ATOMIC_O_TRUNC | FUSE_BIG_WRITES; - out.max_background = 32; - out.congestion_threshold = 32; - out.max_write = MAX_WRITE; - fuse_reply(fuse, hdr->unique, &out, fuse_struct_size); - return NO_STATUS; -} - -static int handle_canonical_path(struct fuse* fuse, struct fuse_handler* handler, - const struct fuse_in_header *hdr) -{ - struct node* node; - char path[PATH_MAX]; - int len; - - pthread_mutex_lock(&fuse->global->lock); - node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid, - path, sizeof(path)); - DLOG(INFO) << "[" << handler->token << "] CANONICAL_PATH @ " << std::hex << hdr->nodeid - << std::dec << " (" << (node ? node->name : "?") << ")"; - pthread_mutex_unlock(&fuse->global->lock); - - if (!node) { - return -ENOENT; - } - if (!check_caller_access_to_node(fuse, hdr, node, R_OK)) { - return -EACCES; - } - len = strlen(path); - if (len + 1 > PATH_MAX) - len = PATH_MAX - 1; - path[PATH_MAX - 1] = 0; - fuse_reply(fuse, hdr->unique, path, len + 1); - return NO_STATUS; -} - -static int handle_fuse_request(struct fuse *fuse, struct fuse_handler* handler, - const struct fuse_in_header *hdr, const void *data, size_t data_len) -{ - switch (hdr->opcode) { - case FUSE_LOOKUP: { /* bytez[] -> entry_out */ - const char *name = static_cast(data); - return handle_lookup(fuse, handler, hdr, name); - } - - case FUSE_FORGET: { - const struct fuse_forget_in *req = static_cast(data); - return handle_forget(fuse, handler, hdr, req); - } - - case FUSE_GETATTR: { /* getattr_in -> attr_out */ - const struct fuse_getattr_in *req = static_cast(data); - return handle_getattr(fuse, handler, hdr, req); - } - - case FUSE_SETATTR: { /* setattr_in -> attr_out */ - const struct fuse_setattr_in *req = static_cast(data); - return handle_setattr(fuse, handler, hdr, req); - } - -// case FUSE_READLINK: -// case FUSE_SYMLINK: - case FUSE_MKNOD: { /* mknod_in, bytez[] -> entry_out */ - const struct fuse_mknod_in *req = static_cast(data); - const char *name = ((const char*) data) + sizeof(*req); - return handle_mknod(fuse, handler, hdr, req, name); - } - - case FUSE_MKDIR: { /* mkdir_in, bytez[] -> entry_out */ - const struct fuse_mkdir_in *req = static_cast(data); - const char *name = ((const char*) data) + sizeof(*req); - return handle_mkdir(fuse, handler, hdr, req, name); - } - - case FUSE_UNLINK: { /* bytez[] -> */ - const char *name = static_cast(data); - return handle_unlink(fuse, handler, hdr, name); - } - - case FUSE_RMDIR: { /* bytez[] -> */ - const char *name = static_cast(data); - return handle_rmdir(fuse, handler, hdr, name); - } - - case FUSE_RENAME: { /* rename_in, oldname, newname -> */ - const struct fuse_rename_in *req = static_cast(data); - const char *old_name = ((const char*) data) + sizeof(*req); - const char *new_name = old_name + strlen(old_name) + 1; - return handle_rename(fuse, handler, hdr, req, old_name, new_name); - } - -// case FUSE_LINK: - case FUSE_OPEN: { /* open_in -> open_out */ - const struct fuse_open_in *req = static_cast(data); - return handle_open(fuse, handler, hdr, req); - } - - case FUSE_READ: { /* read_in -> byte[] */ - const struct fuse_read_in *req = static_cast(data); - return handle_read(fuse, handler, hdr, req); - } - - case FUSE_WRITE: { /* write_in, byte[write_in.size] -> write_out */ - const struct fuse_write_in *req = static_cast(data); - const void* buffer = (const __u8*)data + sizeof(*req); - return handle_write(fuse, handler, hdr, req, buffer); - } - - case FUSE_STATFS: { /* getattr_in -> attr_out */ - return handle_statfs(fuse, handler, hdr); - } - - case FUSE_RELEASE: { /* release_in -> */ - const struct fuse_release_in *req = static_cast(data); - return handle_release(fuse, handler, hdr, req); - } - - case FUSE_FSYNC: - case FUSE_FSYNCDIR: { - const struct fuse_fsync_in *req = static_cast(data); - return handle_fsync(fuse, handler, hdr, req); - } - -// case FUSE_SETXATTR: -// case FUSE_GETXATTR: -// case FUSE_LISTXATTR: -// case FUSE_REMOVEXATTR: - case FUSE_FLUSH: { - return handle_flush(fuse, handler, hdr); - } - - case FUSE_OPENDIR: { /* open_in -> open_out */ - const struct fuse_open_in *req = static_cast(data); - return handle_opendir(fuse, handler, hdr, req); - } - - case FUSE_READDIR: { - const struct fuse_read_in *req = static_cast(data); - return handle_readdir(fuse, handler, hdr, req); - } - - case FUSE_RELEASEDIR: { /* release_in -> */ - const struct fuse_release_in *req = static_cast(data); - return handle_releasedir(fuse, handler, hdr, req); - } - - case FUSE_INIT: { /* init_in -> init_out */ - const struct fuse_init_in *req = static_cast(data); - return handle_init(fuse, handler, hdr, req); - } - - case FUSE_CANONICAL_PATH: { /* nodeid -> bytez[] */ - return handle_canonical_path(fuse, handler, hdr); - } - - default: { - DLOG(INFO) << "[" << handler->token << "] NOTIMPL op=" << hdr->opcode - << "uniq=" << std::hex << hdr->unique << "nid=" << hdr->nodeid << std::dec; - return -ENOSYS; - } - } -} - -void handle_fuse_requests(struct fuse_handler* handler) -{ - struct fuse* fuse = handler->fuse; - for (;;) { - ssize_t len = TEMP_FAILURE_RETRY(read(fuse->fd, - handler->request_buffer, sizeof(handler->request_buffer))); - if (len == -1) { - if (errno == ENODEV) { - LOG(ERROR) << "[" << handler->token << "] someone stole our marbles!"; - exit(2); - } - PLOG(ERROR) << "[" << handler->token << "] handle_fuse_requests"; - continue; - } - - if (static_cast(len) < sizeof(struct fuse_in_header)) { - LOG(ERROR) << "[" << handler->token << "] request too short: len=" << len; - continue; - } - - const struct fuse_in_header* hdr = - reinterpret_cast(handler->request_buffer); - if (hdr->len != static_cast(len)) { - LOG(ERROR) << "[" << handler->token << "] malformed header: len=" << len - << ", hdr->len=" << hdr->len; - continue; - } - - const void *data = handler->request_buffer + sizeof(struct fuse_in_header); - size_t data_len = len - sizeof(struct fuse_in_header); - __u64 unique = hdr->unique; - int res = handle_fuse_request(fuse, handler, hdr, data, data_len); - - /* We do not access the request again after this point because the underlying - * buffer storage may have been reused while processing the request. */ - - if (res != NO_STATUS) { - if (res) { - DLOG(INFO) << "[" << handler->token << "] ERROR " << res; - } - fuse_status(fuse, unique, res); - } - } -} diff --git a/sdcard/fuse.h b/sdcard/fuse.h deleted file mode 100644 index 9ccd21dc4..000000000 --- a/sdcard/fuse.h +++ /dev/null @@ -1,209 +0,0 @@ -/* - * Copyright (C) 2016 The Android Open Source Project - * - * Licensed under the Apache License, Version 2.0 (the "License"); - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - */ - -#ifndef FUSE_H_ -#define FUSE_H_ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include -#include - -#include -#include -#include -#include - -#include - -#define FUSE_TRACE 0 - -#if FUSE_TRACE -static constexpr bool kEnableDLog = true; -#else // FUSE_TRACE == 0 -static constexpr bool kEnableDLog = false; -#endif - -// Use same strategy as DCHECK(). -#define DLOG(x) \ - if (kEnableDLog) LOG(x) - -/* Maximum number of bytes to write in one request. */ -#define MAX_WRITE (256 * 1024) - -/* Maximum number of bytes to read in one request. */ -#define MAX_READ (128 * 1024) - -/* Largest possible request. - * The request size is bounded by the maximum size of a FUSE_WRITE request because it has - * the largest possible data payload. */ -#define MAX_REQUEST_SIZE (sizeof(struct fuse_in_header) + sizeof(struct fuse_write_in) + MAX_WRITE) - -namespace { -struct CaseInsensitiveCompare { - bool operator()(const std::string& lhs, const std::string& rhs) const { - return strcasecmp(lhs.c_str(), rhs.c_str()) < 0; - } -}; -} - -using AppIdMap = std::map; - -/* Permission mode for a specific node. Controls how file permissions - * are derived for children nodes. */ -typedef enum { - /* Nothing special; this node should just inherit from its parent. */ - PERM_INHERIT, - /* This node is one level above a normal root; used for legacy layouts - * which use the first level to represent user_id. */ - PERM_PRE_ROOT, - /* This node is "/" */ - PERM_ROOT, - /* This node is "/Android" */ - PERM_ANDROID, - /* This node is "/Android/data" */ - PERM_ANDROID_DATA, - /* This node is "/Android/obb" */ - PERM_ANDROID_OBB, - /* This node is "/Android/media" */ - PERM_ANDROID_MEDIA, -} perm_t; - -struct handle { - int fd; -}; - -struct dirhandle { - DIR *d; -}; - -struct node { - __u32 refcount; - __u64 nid; - __u64 gen; - /* - * The inode number for this FUSE node. Note that this isn't stable across - * multiple invocations of the FUSE daemon. - */ - __u32 ino; - - /* State derived based on current position in hierarchy. */ - perm_t perm; - userid_t userid; - uid_t uid; - bool under_android; - - struct node *next; /* per-dir sibling list */ - struct node *child; /* first contained file by this dir */ - struct node *parent; /* containing directory */ - - size_t namelen; - char *name; - /* If non-null, this is the real name of the file in the underlying storage. - * This may differ from the field "name" only by case. - * strlen(actual_name) will always equal strlen(name), so it is safe to use - * namelen for both fields. - */ - char *actual_name; - - /* If non-null, an exact underlying path that should be grafted into this - * position. Used to support things like OBB. */ - char* graft_path; - size_t graft_pathlen; - - bool deleted; -}; - -/* Global data for all FUSE mounts */ -struct fuse_global { - pthread_mutex_t lock; - - uid_t uid; - gid_t gid; - bool multi_user; - - char source_path[PATH_MAX]; - char obb_path[PATH_MAX]; - - AppIdMap* package_to_appid; - - __u64 next_generation; - struct node root; - - /* Used to allocate unique inode numbers for fuse nodes. We use - * a simple counter based scheme where inode numbers from deleted - * nodes aren't reused. Note that inode allocations are not stable - * across multiple invocation of the sdcard daemon, but that shouldn't - * be a huge problem in practice. - * - * Note that we restrict inodes to 32 bit unsigned integers to prevent - * truncation on 32 bit processes when unsigned long long stat.st_ino is - * assigned to an unsigned long ino_t type in an LP32 process. - * - * Also note that fuse_attr and fuse_dirent inode values are 64 bits wide - * on both LP32 and LP64, but the fuse kernel code doesn't squash 64 bit - * inode numbers into 32 bit values on 64 bit kernels (see fuse_squash_ino - * in fs/fuse/inode.c). - * - * Accesses must be guarded by |lock|. - */ - __u32 inode_ctr; - - struct fuse* fuse_default; - struct fuse* fuse_read; - struct fuse* fuse_write; -}; - -/* Single FUSE mount */ -struct fuse { - struct fuse_global* global; - - char dest_path[PATH_MAX]; - - int fd; - - gid_t gid; - mode_t mask; -}; - -/* Private data used by a single FUSE handler */ -struct fuse_handler { - struct fuse* fuse; - int token; - - /* To save memory, we never use the contents of the request buffer and the read - * buffer at the same time. This allows us to share the underlying storage. */ - union { - __u8 request_buffer[MAX_REQUEST_SIZE]; - __u8 read_buffer[MAX_READ + PAGE_SIZE]; - }; -}; - -void handle_fuse_requests(struct fuse_handler* handler); -void derive_permissions_recursive_locked(struct fuse* fuse, struct node *parent); - -#endif /* FUSE_H_ */ diff --git a/sdcard/sdcard.cpp b/sdcard/sdcard.cpp index 0d5e5aff6..574bbfee9 100644 --- a/sdcard/sdcard.cpp +++ b/sdcard/sdcard.cpp @@ -38,164 +38,18 @@ #include #include -#include - #include #include #include -// README -// -// What is this? -// -// sdcard is a program that uses FUSE to emulate FAT-on-sdcard style -// directory permissions (all files are given fixed owner, group, and -// permissions at creation, owner, group, and permissions are not -// changeable, symlinks and hardlinks are not createable, etc. -// -// See usage() for command line options. -// -// It must be run as root, but will drop to requested UID/GID as soon as it -// mounts a filesystem. It will refuse to run if requested UID/GID are zero. -// -// Things I believe to be true: -// -// - ops that return a fuse_entry (LOOKUP, MKNOD, MKDIR, LINK, SYMLINK, -// CREAT) must bump that node's refcount -// - don't forget that FORGET can forget multiple references (req->nlookup) -// - if an op that returns a fuse_entry fails writing the reply to the -// kernel, you must rollback the refcount to reflect the reference the -// kernel did not actually acquire -// -// This daemon can also derive custom filesystem permissions based on directory -// structure when requested. These custom permissions support several features: -// -// - Apps can access their own files in /Android/data/com.example/ without -// requiring any additional GIDs. -// - Separate permissions for protecting directories like Pictures and Music. -// - Multi-user separation on the same physical device. - -#include "fuse.h" - -#define PROP_SDCARDFS_DEVICE "ro.sys.sdcardfs" -#define PROP_SDCARDFS_USER "persist.sys.sdcardfs" +// NOTE: This is a vestigial program that simply exists to mount the in-kernel +// sdcardfs filesystem. The older FUSE-based design that used to live here has +// been completely removed to avoid confusion. /* Supplementary groups to execute with. */ static const gid_t kGroups[1] = { AID_PACKAGE_INFO }; -static bool package_parse_callback(pkg_info *info, void *userdata) { - struct fuse_global *global = (struct fuse_global *)userdata; - bool res = global->package_to_appid->emplace(info->name, info->uid).second; - packagelist_free(info); - return res; -} - -static bool read_package_list(struct fuse_global* global) { - pthread_mutex_lock(&global->lock); - - global->package_to_appid->clear(); - bool rc = packagelist_parse(package_parse_callback, global); - DLOG(INFO) << "read_package_list: found " << global->package_to_appid->size() << " packages"; - - // Regenerate ownership details using newly loaded mapping. - derive_permissions_recursive_locked(global->fuse_default, &global->root); - - pthread_mutex_unlock(&global->lock); - - return rc; -} - -static void watch_package_list(struct fuse_global* global) { - struct inotify_event *event; - char event_buf[512]; - - int nfd = inotify_init(); - if (nfd == -1) { - PLOG(ERROR) << "inotify_init failed"; - return; - } - - bool active = false; - while (1) { - if (!active) { - int res = inotify_add_watch(nfd, PACKAGES_LIST_FILE, IN_DELETE_SELF); - if (res == -1) { - if (errno == ENOENT || errno == EACCES) { - /* Framework may not have created the file yet, sleep and retry. */ - LOG(ERROR) << "missing \"" << PACKAGES_LIST_FILE << "\"; retrying..."; - sleep(3); - continue; - } else { - PLOG(ERROR) << "inotify_add_watch failed"; - return; - } - } - - /* Watch above will tell us about any future changes, so - * read the current state. */ - if (read_package_list(global) == false) { - LOG(ERROR) << "read_package_list failed"; - return; - } - active = true; - } - - int event_pos = 0; - ssize_t res = TEMP_FAILURE_RETRY(read(nfd, event_buf, sizeof(event_buf))); - if (res == -1) { - PLOG(ERROR) << "failed to read inotify event"; - return; - } else if (static_cast(res) < sizeof(*event)) { - LOG(ERROR) << "failed to read inotify event: read " << res << " expected " - << sizeof(event_buf); - return; - } - - while (res >= static_cast(sizeof(*event))) { - int event_size; - event = reinterpret_cast(event_buf + event_pos); - - DLOG(INFO) << "inotify event: " << std::hex << event->mask << std::dec; - if ((event->mask & IN_IGNORED) == IN_IGNORED) { - /* Previously watched file was deleted, probably due to move - * that swapped in new data; re-arm the watch and read. */ - active = false; - } - - event_size = sizeof(*event) + event->len; - res -= event_size; - event_pos += event_size; - } - } -} - -static int fuse_setup(struct fuse* fuse, gid_t gid, mode_t mask) { - char opts[256]; - - fuse->fd = TEMP_FAILURE_RETRY(open("/dev/fuse", O_RDWR | O_CLOEXEC)); - if (fuse->fd == -1) { - PLOG(ERROR) << "failed to open fuse device"; - return -1; - } - - umount2(fuse->dest_path, MNT_DETACH); - - snprintf(opts, sizeof(opts), - "fd=%i,rootmode=40000,default_permissions,allow_other,user_id=%d,group_id=%d", - fuse->fd, fuse->global->uid, fuse->global->gid); - if (mount("/dev/fuse", fuse->dest_path, "fuse", MS_NOSUID | MS_NODEV | MS_NOEXEC | MS_NOATIME, - opts) == -1) { - PLOG(ERROR) << "failed to mount fuse filesystem"; - return -1; - } - - fuse->gid = gid; - fuse->mask = mask; - - return 0; -} - static void drop_privs(uid_t uid, gid_t gid) { ScopedMinijail j(minijail_new()); minijail_set_supplementary_gids(j.get(), arraysize(kGroups), kGroups); @@ -205,120 +59,6 @@ static void drop_privs(uid_t uid, gid_t gid) { minijail_enter(j.get()); } -static void* start_handler(void* data) { - struct fuse_handler* handler = static_cast(data); - handle_fuse_requests(handler); - return NULL; -} - -static void run(const char* source_path, const char* label, uid_t uid, - gid_t gid, userid_t userid, bool multi_user, bool full_write) { - struct fuse_global global; - struct fuse fuse_default; - struct fuse fuse_read; - struct fuse fuse_write; - struct fuse_handler handler_default; - struct fuse_handler handler_read; - struct fuse_handler handler_write; - pthread_t thread_default; - pthread_t thread_read; - pthread_t thread_write; - - memset(&global, 0, sizeof(global)); - memset(&fuse_default, 0, sizeof(fuse_default)); - memset(&fuse_read, 0, sizeof(fuse_read)); - memset(&fuse_write, 0, sizeof(fuse_write)); - memset(&handler_default, 0, sizeof(handler_default)); - memset(&handler_read, 0, sizeof(handler_read)); - memset(&handler_write, 0, sizeof(handler_write)); - - pthread_mutex_init(&global.lock, NULL); - global.package_to_appid = new AppIdMap; - global.uid = uid; - global.gid = gid; - global.multi_user = multi_user; - global.next_generation = 0; - global.inode_ctr = 1; - - memset(&global.root, 0, sizeof(global.root)); - global.root.nid = FUSE_ROOT_ID; /* 1 */ - global.root.refcount = 2; - global.root.namelen = strlen(source_path); - global.root.name = strdup(source_path); - global.root.userid = userid; - global.root.uid = AID_ROOT; - global.root.under_android = false; - - // Clang static analyzer think strcpy potentially overwrites other fields - // in global. Use snprintf() to mute the false warning. - snprintf(global.source_path, sizeof(global.source_path), "%s", source_path); - - if (multi_user) { - global.root.perm = PERM_PRE_ROOT; - snprintf(global.obb_path, sizeof(global.obb_path), "%s/obb", source_path); - } else { - global.root.perm = PERM_ROOT; - snprintf(global.obb_path, sizeof(global.obb_path), "%s/Android/obb", source_path); - } - - fuse_default.global = &global; - fuse_read.global = &global; - fuse_write.global = &global; - - global.fuse_default = &fuse_default; - global.fuse_read = &fuse_read; - global.fuse_write = &fuse_write; - - snprintf(fuse_default.dest_path, PATH_MAX, "/mnt/runtime/default/%s", label); - snprintf(fuse_read.dest_path, PATH_MAX, "/mnt/runtime/read/%s", label); - snprintf(fuse_write.dest_path, PATH_MAX, "/mnt/runtime/write/%s", label); - - handler_default.fuse = &fuse_default; - handler_read.fuse = &fuse_read; - handler_write.fuse = &fuse_write; - - handler_default.token = 0; - handler_read.token = 1; - handler_write.token = 2; - - umask(0); - - if (multi_user) { - /* Multi-user storage is fully isolated per user, so "other" - * permissions are completely masked off. */ - if (fuse_setup(&fuse_default, AID_SDCARD_RW, 0006) - || fuse_setup(&fuse_read, AID_EVERYBODY, 0027) - || fuse_setup(&fuse_write, AID_EVERYBODY, full_write ? 0007 : 0027)) { - PLOG(FATAL) << "failed to fuse_setup"; - } - } else { - /* Physical storage is readable by all users on device, but - * the Android directories are masked off to a single user - * deep inside attr_from_stat(). */ - if (fuse_setup(&fuse_default, AID_SDCARD_RW, 0006) - || fuse_setup(&fuse_read, AID_EVERYBODY, full_write ? 0027 : 0022) - || fuse_setup(&fuse_write, AID_EVERYBODY, full_write ? 0007 : 0022)) { - PLOG(FATAL) << "failed to fuse_setup"; - } - } - - // Will abort if priv-dropping fails. - drop_privs(uid, gid); - - if (multi_user) { - fs_prepare_dir(global.obb_path, 0775, uid, gid); - } - - if (pthread_create(&thread_default, NULL, start_handler, &handler_default) - || pthread_create(&thread_read, NULL, start_handler, &handler_read) - || pthread_create(&thread_write, NULL, start_handler, &handler_write)) { - LOG(FATAL) << "failed to pthread_create"; - } - - watch_package_list(&global); - LOG(FATAL) << "terminated prematurely"; -} - static bool sdcardfs_setup(const std::string& source_path, const std::string& dest_path, uid_t fsuid, gid_t fsgid, bool multi_user, userid_t userid, gid_t gid, mode_t mask, bool derive_gid, bool default_normal) { @@ -407,41 +147,6 @@ static void run_sdcardfs(const std::string& source_path, const std::string& labe exit(0); } -static bool supports_sdcardfs(void) { - std::string filesystems; - if (!android::base::ReadFileToString("/proc/filesystems", &filesystems)) { - PLOG(ERROR) << "Could not read /proc/filesystems"; - return false; - } - for (const auto& fs : android::base::Split(filesystems, "\n")) { - if (fs.find("sdcardfs") != std::string::npos) return true; - } - return false; -} - -static bool should_use_sdcardfs(void) { - char property[PROPERTY_VALUE_MAX]; - - // Allow user to have a strong opinion about state - property_get(PROP_SDCARDFS_USER, property, ""); - if (!strcmp(property, "force_on")) { - LOG(WARNING) << "User explicitly enabled sdcardfs"; - return supports_sdcardfs(); - } else if (!strcmp(property, "force_off")) { - LOG(WARNING) << "User explicitly disabled sdcardfs"; - return false; - } - - // Fall back to device opinion about state - if (property_get_bool(PROP_SDCARDFS_DEVICE, true)) { - LOG(WARNING) << "Device explicitly enabled sdcardfs"; - return supports_sdcardfs(); - } else { - LOG(WARNING) << "Device explicitly disabled sdcardfs"; - return false; - } -} - static int usage() { LOG(ERROR) << "usage: sdcard [OPTIONS]