| // Copyright (C) 2019 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. |
| |
| #define ATRACE_TAG ATRACE_TAG_APP |
| #define LOG_TAG "FuseDaemon" |
| #define LIBFUSE_LOG_TAG "libfuse" |
| |
| #include "FuseDaemon.h" |
| |
| #include <android-base/logging.h> |
| #include <android-base/properties.h> |
| #include <android/log.h> |
| #include <android/trace.h> |
| #include <ctype.h> |
| #include <dirent.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <fuse_i.h> |
| #include <fuse_log.h> |
| #include <fuse_lowlevel.h> |
| #include <inttypes.h> |
| #include <limits.h> |
| #include <linux/fuse.h> |
| #include <stdbool.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/inotify.h> |
| #include <sys/mman.h> |
| #include <sys/mount.h> |
| #include <sys/param.h> |
| #include <sys/resource.h> |
| #include <sys/stat.h> |
| #include <sys/statfs.h> |
| #include <sys/statvfs.h> |
| #include <sys/time.h> |
| #include <sys/types.h> |
| #include <sys/uio.h> |
| #include <unistd.h> |
| |
| #include <iostream> |
| #include <list> |
| #include <map> |
| #include <mutex> |
| #include <queue> |
| #include <regex> |
| #include <thread> |
| #include <unordered_map> |
| #include <unordered_set> |
| #include <vector> |
| |
| #include "MediaProviderWrapper.h" |
| #include "libfuse_jni/ReaddirHelper.h" |
| #include "libfuse_jni/RedactionInfo.h" |
| #include "node-inl.h" |
| |
| using mediaprovider::fuse::DirectoryEntry; |
| using mediaprovider::fuse::dirhandle; |
| using mediaprovider::fuse::handle; |
| using mediaprovider::fuse::node; |
| using mediaprovider::fuse::RedactionInfo; |
| using std::list; |
| using std::string; |
| using std::vector; |
| |
| // logging macros to avoid duplication. |
| #define TRACE_NODE(__node) \ |
| LOG(VERBOSE) << __FUNCTION__ << " : " << #__node << " = [" << get_name(__node) << "] " |
| |
| #define ATRACE_NAME(name) ScopedTrace ___tracer(name) |
| #define ATRACE_CALL() ATRACE_NAME(__FUNCTION__) |
| |
| class ScopedTrace { |
| public: |
| explicit inline ScopedTrace(const char *name) { |
| ATrace_beginSection(name); |
| } |
| |
| inline ~ScopedTrace() { |
| ATrace_endSection(); |
| } |
| }; |
| |
| const bool IS_OS_DEBUGABLE = android::base::GetIntProperty("ro.debuggable", 0); |
| |
| #define FUSE_UNKNOWN_INO 0xffffffff |
| |
| // Stolen from: android_filesystem_config.h |
| #define AID_APP_START 10000 |
| |
| constexpr size_t MAX_READ_SIZE = 128 * 1024; |
| // Stolen from: UserHandle#getUserId |
| constexpr int PER_USER_RANGE = 100000; |
| |
| // Regex copied from FileUtils.java in MediaProvider, but without media directory. |
| const std::regex PATTERN_OWNED_PATH( |
| "^/storage/[^/]+/(?:[0-9]+/)?Android/(?:data|obb|sandbox)/([^/]+)(/?.*)?", |
| std::regex_constants::icase); |
| |
| /* |
| * In order to avoid double caching with fuse, call fadvise on the file handles |
| * in the underlying file system. However, if this is done on every read/write, |
| * the fadvises cause a very significant slowdown in tests (specifically fio |
| * seq_write). So call fadvise on the file handles with the most reads/writes |
| * only after a threshold is passed. |
| */ |
| class FAdviser { |
| public: |
| FAdviser() : thread_(MessageLoop, this), total_size_(0) {} |
| |
| ~FAdviser() { |
| SendMessage(Message::quit); |
| thread_.join(); |
| } |
| |
| void Record(int fd, size_t size) { SendMessage(Message::record, fd, size); } |
| |
| void Close(int fd) { SendMessage(Message::close, fd); } |
| |
| private: |
| std::thread thread_; |
| |
| struct Message { |
| enum Type { record, close, quit }; |
| Type type; |
| int fd; |
| size_t size; |
| }; |
| |
| void RecordImpl(int fd, size_t size) { |
| total_size_ += size; |
| |
| // Find or create record in files_ |
| // Remove record from sizes_ if it exists, adjusting size appropriately |
| auto file = files_.find(fd); |
| if (file != files_.end()) { |
| auto old_size = file->second; |
| size += old_size->first; |
| sizes_.erase(old_size); |
| } else { |
| file = files_.insert(Files::value_type(fd, sizes_.end())).first; |
| } |
| |
| // Now (re) insert record in sizes_ |
| auto new_size = sizes_.insert(Sizes::value_type(size, fd)); |
| file->second = new_size; |
| |
| if (total_size_ < threshold_) return; |
| |
| LOG(INFO) << "Threshold exceeded - fadvising " << total_size_; |
| while (!sizes_.empty() && total_size_ > target_) { |
| auto size = --sizes_.end(); |
| total_size_ -= size->first; |
| posix_fadvise(size->second, 0, 0, POSIX_FADV_DONTNEED); |
| files_.erase(size->second); |
| sizes_.erase(size); |
| } |
| LOG(INFO) << "Threshold now " << total_size_; |
| } |
| |
| void CloseImpl(int fd) { |
| auto file = files_.find(fd); |
| if (file == files_.end()) return; |
| |
| total_size_ -= file->second->first; |
| sizes_.erase(file->second); |
| files_.erase(file); |
| } |
| |
| void MessageLoopImpl() { |
| while (1) { |
| Message message; |
| |
| { |
| std::unique_lock<std::mutex> lock(mutex_); |
| cv_.wait(lock, [this] { return !queue_.empty(); }); |
| message = queue_.front(); |
| queue_.pop(); |
| } |
| |
| switch (message.type) { |
| case Message::record: |
| RecordImpl(message.fd, message.size); |
| break; |
| |
| case Message::close: |
| CloseImpl(message.fd); |
| break; |
| |
| case Message::quit: |
| return; |
| } |
| } |
| } |
| |
| static int MessageLoop(FAdviser* ptr) { |
| ptr->MessageLoopImpl(); |
| return 0; |
| } |
| |
| void SendMessage(Message::Type type, int fd = -1, size_t size = 0) { |
| { |
| std::unique_lock<std::mutex> lock(mutex_); |
| Message message = {type, fd, size}; |
| queue_.push(message); |
| } |
| cv_.notify_one(); |
| } |
| |
| std::queue<Message> queue_; |
| std::mutex mutex_; |
| std::condition_variable cv_; |
| |
| typedef std::multimap<size_t, int> Sizes; |
| typedef std::map<int, Sizes::iterator> Files; |
| |
| Files files_; |
| Sizes sizes_; |
| size_t total_size_; |
| |
| const size_t threshold_ = 64 * 1024 * 1024; |
| const size_t target_ = 32 * 1024 * 1024; |
| }; |
| |
| /* Single FUSE mount */ |
| struct fuse { |
| explicit fuse(const std::string& _path) |
| : path(_path), |
| tracker(mediaprovider::fuse::NodeTracker(&lock)), |
| root(node::CreateRoot(_path, &lock, &tracker)), |
| mp(0), |
| zero_addr(0) {} |
| |
| inline bool IsRoot(const node* node) const { return node == root; } |
| |
| // Note that these two (FromInode / ToInode) conversion wrappers are required |
| // because fuse_lowlevel_ops documents that the root inode is always one |
| // (see FUSE_ROOT_ID in fuse_lowlevel.h). There are no particular requirements |
| // on any of the other inodes in the FS. |
| // Also, if ctx is not nullptr, it will also check if the path can be accessible |
| // by the caller, and return nullptr if it cannot access. |
| inline node* FromInode(__u64 inode, const struct fuse_ctx* ctx) { |
| if (inode == FUSE_ROOT_ID) { |
| return root; |
| } |
| |
| node* result = node::FromInode(inode, &tracker); |
| if (ctx == nullptr || ctx->uid < AID_APP_START) { |
| return result; |
| } |
| |
| string path = result->BuildPath(); |
| std::smatch match; |
| if (std::regex_match(path, match, PATTERN_OWNED_PATH)) { |
| std::string const & pkg = match[1]; |
| if (!mp->IsUidForPackage(pkg, ctx->uid)) { |
| PLOG(WARNING) << "Invalid file access from " << pkg << ": " << path; |
| return nullptr; |
| } |
| } |
| |
| return result; |
| } |
| |
| inline __u64 ToInode(node* node) const { |
| if (IsRoot(node)) { |
| return FUSE_ROOT_ID; |
| } |
| |
| return node::ToInode(node); |
| } |
| |
| std::recursive_mutex lock; |
| const string path; |
| // The Inode tracker associated with this FUSE instance. |
| mediaprovider::fuse::NodeTracker tracker; |
| node* const root; |
| struct fuse_session* se; |
| |
| /* |
| * Used to make JNI calls to MediaProvider. |
| * Responsibility of freeing this object falls on corresponding |
| * FuseDaemon object. |
| */ |
| mediaprovider::fuse::MediaProviderWrapper* mp; |
| |
| /* |
| * Points to a range of zeroized bytes, used by pf_read to represent redacted ranges. |
| * The memory is read only and should never be modified. |
| */ |
| /* const */ char* zero_addr; |
| |
| FAdviser fadviser; |
| |
| std::atomic_bool* active; |
| }; |
| |
| static inline string get_name(node* n) { |
| if (n) { |
| std::string name("node_path: " + n->BuildSafePath()); |
| if (IS_OS_DEBUGABLE) { |
| name += " real_path: " + n->BuildPath(); |
| } |
| return name; |
| } |
| return "?"; |
| } |
| |
| static inline __u64 ptr_to_id(void* ptr) { |
| return (__u64)(uintptr_t) ptr; |
| } |
| |
| /* |
| * Set an F_RDLCK or F_WRLCKK on fd with fcntl(2). |
| * |
| * This is called before the MediaProvider returns fd from the lower file |
| * system to an app over the ContentResolver interface. This allows us |
| * check with is_file_locked if any reference to that fd is still open. |
| */ |
| static int set_file_lock(int fd, bool for_read, const std::string& path) { |
| std::string lock_str = (for_read ? "read" : "write"); |
| |
| struct flock fl{}; |
| fl.l_type = for_read ? F_RDLCK : F_WRLCK; |
| fl.l_whence = SEEK_SET; |
| |
| int res = fcntl(fd, F_OFD_SETLK, &fl); |
| if (res) { |
| PLOG(WARNING) << "Failed to set lock: " << lock_str; |
| return res; |
| } |
| return res; |
| } |
| |
| /* |
| * Check if an F_RDLCK or F_WRLCK is set on fd with fcntl(2). |
| * |
| * This is used to determine if the MediaProvider has given an fd to the lower fs to an app over |
| * the ContentResolver interface. Before that happens, we always call set_file_lock on the file |
| * allowing us to know if any reference to that fd is still open here. |
| * |
| * Returns true if fd may have a lock, false otherwise |
| */ |
| static bool is_file_locked(int fd, const std::string& path) { |
| struct flock fl{}; |
| fl.l_type = F_WRLCK; |
| fl.l_whence = SEEK_SET; |
| |
| int res = fcntl(fd, F_OFD_GETLK, &fl); |
| if (res) { |
| PLOG(WARNING) << "Failed to check lock"; |
| // Assume worst |
| return true; |
| } |
| bool locked = fl.l_type != F_UNLCK; |
| return locked; |
| } |
| |
| static struct fuse* get_fuse(fuse_req_t req) { |
| return reinterpret_cast<struct fuse*>(fuse_req_userdata(req)); |
| } |
| |
| static bool is_package_owned_path(const string& path, const string& fuse_path) { |
| if (path.rfind(fuse_path, 0) != 0) { |
| return false; |
| } |
| return std::regex_match(path, PATTERN_OWNED_PATH); |
| } |
| |
| static void invalidate_case_insensitive_dentry_matches(struct fuse* fuse, node* parent, |
| const string& name) { |
| vector<string> children = parent->MatchChildrenCaseInsensitive(name); |
| if (children.empty() || (children.size() == 1 && children[0] == name)) { |
| return; |
| } |
| |
| fuse_ino_t parent_ino = fuse->ToInode(parent); |
| std::thread t([=]() { |
| for (const string& child_name : children) { |
| if (fuse_lowlevel_notify_inval_entry(fuse->se, parent_ino, child_name.c_str(), |
| child_name.size())) { |
| LOG(ERROR) << "Failed to invalidate dentry " << child_name; |
| } |
| } |
| }); |
| t.detach(); |
| } |
| |
| static node* make_node_entry(fuse_req_t req, node* parent, const string& name, const string& path, |
| struct fuse_entry_param* e, int* error_code) { |
| struct fuse* fuse = get_fuse(req); |
| const struct fuse_ctx* ctx = fuse_req_ctx(req); |
| node* node; |
| |
| memset(e, 0, sizeof(*e)); |
| if (lstat(path.c_str(), &e->attr) < 0) { |
| *error_code = errno; |
| return NULL; |
| } |
| |
| node = parent->LookupChildByName(name, true /* acquire */); |
| if (!node) { |
| node = ::node::Create(parent, name, &fuse->lock, &fuse->tracker); |
| } |
| |
| TRACE_NODE(node); |
| |
| invalidate_case_insensitive_dentry_matches(fuse, parent, name); |
| |
| // This FS is not being exported via NFS so just a fixed generation number |
| // for now. If we do need this, we need to increment the generation ID each |
| // time the fuse daemon restarts because that's what it takes for us to |
| // reuse inode numbers. |
| e->generation = 0; |
| e->ino = fuse->ToInode(node); |
| e->entry_timeout = is_package_owned_path(path, fuse->path) ? |
| 0 : std::numeric_limits<double>::max(); |
| e->attr_timeout = is_package_owned_path(path, fuse->path) ? |
| 0 : std::numeric_limits<double>::max(); |
| |
| return node; |
| } |
| |
| static inline bool is_requesting_write(int flags) { |
| return flags & (O_WRONLY | O_RDWR); |
| } |
| |
| namespace mediaprovider { |
| namespace fuse { |
| |
| /** |
| * Function implementations |
| * |
| * These implement the various functions in fuse_lowlevel_ops |
| * |
| */ |
| |
| static void pf_init(void* userdata, struct fuse_conn_info* conn) { |
| // We don't want a getattr request with every read request |
| conn->want &= ~FUSE_CAP_AUTO_INVAL_DATA; |
| unsigned mask = (FUSE_CAP_SPLICE_WRITE | FUSE_CAP_SPLICE_MOVE | FUSE_CAP_SPLICE_READ | |
| FUSE_CAP_ASYNC_READ | FUSE_CAP_ATOMIC_O_TRUNC | FUSE_CAP_WRITEBACK_CACHE | |
| FUSE_CAP_EXPORT_SUPPORT | FUSE_CAP_FLOCK_LOCKS); |
| conn->want |= conn->capable & mask; |
| conn->max_read = MAX_READ_SIZE; |
| |
| struct fuse* fuse = reinterpret_cast<struct fuse*>(userdata); |
| fuse->active->store(true, std::memory_order_release); |
| } |
| |
| static void pf_destroy(void* userdata) { |
| struct fuse* fuse = reinterpret_cast<struct fuse*>(userdata); |
| LOG(INFO) << "DESTROY " << fuse->path; |
| |
| node::DeleteTree(fuse->root); |
| } |
| |
| static std::regex storage_emulated_regex("^\\/storage\\/emulated\\/([0-9]+)"); |
| static node* do_lookup(fuse_req_t req, fuse_ino_t parent, const char* name, |
| struct fuse_entry_param* e, int* error_code) { |
| struct fuse* fuse = get_fuse(req); |
| const struct fuse_ctx* ctx = fuse_req_ctx(req); |
| node* parent_node = fuse->FromInode(parent, ctx); |
| if (!parent_node) { |
| *error_code = ENOENT; |
| return nullptr; |
| } |
| string parent_path = parent_node->BuildPath(); |
| string child_path = parent_path + "/" + name; |
| |
| TRACE_NODE(parent_node); |
| |
| std::smatch match; |
| std::regex_search(child_path, match, storage_emulated_regex); |
| if (match.size() == 2 && std::to_string(getuid() / PER_USER_RANGE) != match[1].str()) { |
| // Ensure the FuseDaemon user id matches the user id in requested path |
| *error_code = EPERM; |
| return nullptr; |
| } |
| return make_node_entry(req, parent_node, name, child_path, e, error_code); |
| } |
| |
| static void pf_lookup(fuse_req_t req, fuse_ino_t parent, const char* name) { |
| ATRACE_CALL(); |
| struct fuse_entry_param e; |
| |
| int error_code = 0; |
| if (do_lookup(req, parent, name, &e, &error_code)) { |
| fuse_reply_entry(req, &e); |
| } else { |
| CHECK(error_code != 0); |
| fuse_reply_err(req, error_code); |
| } |
| } |
| |
| static void do_forget(struct fuse* fuse, fuse_ino_t ino, uint64_t nlookup) { |
| // Always allow to forget so we put ctx as nullptr. |
| node* node = fuse->FromInode(ino, nullptr); |
| TRACE_NODE(node); |
| if (node) { |
| // This is a narrowing conversion from an unsigned 64bit to a 32bit value. For |
| // some reason we only keep 32 bit refcounts but the kernel issues |
| // forget requests with a 64 bit counter. |
| node->Release(static_cast<uint32_t>(nlookup)); |
| } |
| } |
| |
| static void pf_forget(fuse_req_t req, fuse_ino_t ino, uint64_t nlookup) { |
| ATRACE_CALL(); |
| node* node; |
| struct fuse* fuse = get_fuse(req); |
| |
| do_forget(fuse, ino, nlookup); |
| fuse_reply_none(req); |
| } |
| |
| static void pf_forget_multi(fuse_req_t req, |
| size_t count, |
| struct fuse_forget_data* forgets) { |
| ATRACE_CALL(); |
| struct fuse* fuse = get_fuse(req); |
| |
| for (int i = 0; i < count; i++) { |
| do_forget(fuse, forgets[i].ino, forgets[i].nlookup); |
| } |
| fuse_reply_none(req); |
| } |
| |
| static void pf_getattr(fuse_req_t req, |
| fuse_ino_t ino, |
| struct fuse_file_info* fi) { |
| ATRACE_CALL(); |
| struct fuse* fuse = get_fuse(req); |
| const struct fuse_ctx* ctx = fuse_req_ctx(req); |
| node* node = fuse->FromInode(ino, ctx); |
| if (!node) { |
| fuse_reply_err(req, ENOENT); |
| return; |
| } |
| string path = node->BuildPath(); |
| TRACE_NODE(node); |
| |
| struct stat s; |
| memset(&s, 0, sizeof(s)); |
| if (lstat(path.c_str(), &s) < 0) { |
| fuse_reply_err(req, errno); |
| } else { |
| fuse_reply_attr(req, &s, is_package_owned_path(path, fuse->path) ? |
| 0 : std::numeric_limits<double>::max()); |
| } |
| } |
| |
| static void pf_setattr(fuse_req_t req, |
| fuse_ino_t ino, |
| struct stat* attr, |
| int to_set, |
| struct fuse_file_info* fi) { |
| ATRACE_CALL(); |
| struct fuse* fuse = get_fuse(req); |
| const struct fuse_ctx* ctx = fuse_req_ctx(req); |
| node* node = fuse->FromInode(ino, ctx); |
| if (!node) { |
| fuse_reply_err(req, ENOENT); |
| return; |
| } |
| string path = node->BuildPath(); |
| struct timespec times[2]; |
| |
| TRACE_NODE(node); |
| |
| /* XXX: incomplete implementation on purpose. |
| * chmod/chown should NEVER be implemented.*/ |
| |
| if ((to_set & FUSE_SET_ATTR_SIZE) |
| && truncate64(path.c_str(), attr->st_size) < 0) { |
| fuse_reply_err(req, errno); |
| return; |
| } |
| |
| /* 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 (to_set & (FATTR_ATIME | FATTR_MTIME)) { |
| times[0].tv_nsec = UTIME_OMIT; |
| times[1].tv_nsec = UTIME_OMIT; |
| if (to_set & FATTR_ATIME) { |
| if (to_set & FATTR_ATIME_NOW) { |
| times[0].tv_nsec = UTIME_NOW; |
| } else { |
| times[0] = attr->st_atim; |
| } |
| } |
| |
| if (to_set & FATTR_MTIME) { |
| if (to_set & FATTR_MTIME_NOW) { |
| times[1].tv_nsec = UTIME_NOW; |
| } else { |
| times[1] = attr->st_mtim; |
| } |
| } |
| |
| TRACE_NODE(node); |
| if (utimensat(-1, path.c_str(), times, 0) < 0) { |
| fuse_reply_err(req, errno); |
| return; |
| } |
| } |
| |
| lstat(path.c_str(), attr); |
| fuse_reply_attr(req, attr, is_package_owned_path(path, fuse->path) ? |
| 0 : std::numeric_limits<double>::max()); |
| } |
| |
| static void pf_canonical_path(fuse_req_t req, fuse_ino_t ino) |
| { |
| node* node = get_fuse(req)->FromInode(ino, fuse_req_ctx(req)); |
| |
| if (node) { |
| // TODO(b/147482155): Check that uid has access to |path| and its contents |
| fuse_reply_canonical_path(req, node->BuildPath().c_str()); |
| return; |
| } |
| fuse_reply_err(req, ENOENT); |
| } |
| |
| static void pf_mknod(fuse_req_t req, |
| fuse_ino_t parent, |
| const char* name, |
| mode_t mode, |
| dev_t rdev) { |
| ATRACE_CALL(); |
| struct fuse* fuse = get_fuse(req); |
| const struct fuse_ctx* ctx = fuse_req_ctx(req); |
| node* parent_node = fuse->FromInode(parent, ctx); |
| if (!parent_node) { |
| fuse_reply_err(req, ENOENT); |
| return; |
| } |
| string parent_path = parent_node->BuildPath(); |
| |
| TRACE_NODE(parent_node); |
| |
| const string child_path = parent_path + "/" + name; |
| |
| mode = (mode & (~0777)) | 0664; |
| if (mknod(child_path.c_str(), mode, rdev) < 0) { |
| fuse_reply_err(req, errno); |
| return; |
| } |
| |
| int error_code = 0; |
| struct fuse_entry_param e; |
| if (make_node_entry(req, parent_node, name, child_path, &e, &error_code)) { |
| fuse_reply_entry(req, &e); |
| } else { |
| CHECK(error_code != 0); |
| fuse_reply_err(req, error_code); |
| } |
| } |
| |
| static void pf_mkdir(fuse_req_t req, |
| fuse_ino_t parent, |
| const char* name, |
| mode_t mode) { |
| ATRACE_CALL(); |
| struct fuse* fuse = get_fuse(req); |
| const struct fuse_ctx* ctx = fuse_req_ctx(req); |
| node* parent_node = fuse->FromInode(parent, ctx); |
| if (!parent_node) { |
| fuse_reply_err(req, ENOENT); |
| return; |
| } |
| const string parent_path = parent_node->BuildPath(); |
| |
| TRACE_NODE(parent_node); |
| |
| const string child_path = parent_path + "/" + name; |
| |
| int status = fuse->mp->IsCreatingDirAllowed(child_path, ctx->uid); |
| if (status) { |
| fuse_reply_err(req, status); |
| return; |
| } |
| |
| mode = (mode & (~0777)) | 0775; |
| if (mkdir(child_path.c_str(), mode) < 0) { |
| fuse_reply_err(req, errno); |
| return; |
| } |
| |
| int error_code = 0; |
| struct fuse_entry_param e; |
| if (make_node_entry(req, parent_node, name, child_path, &e, &error_code)) { |
| fuse_reply_entry(req, &e); |
| } else { |
| CHECK(error_code != 0); |
| fuse_reply_err(req, error_code); |
| } |
| } |
| |
| static void pf_unlink(fuse_req_t req, fuse_ino_t parent, const char* name) { |
| ATRACE_CALL(); |
| struct fuse* fuse = get_fuse(req); |
| const struct fuse_ctx* ctx = fuse_req_ctx(req); |
| node* parent_node = fuse->FromInode(parent, ctx); |
| if (!parent_node) { |
| fuse_reply_err(req, ENOENT); |
| return; |
| } |
| const string parent_path = parent_node->BuildPath(); |
| |
| TRACE_NODE(parent_node); |
| |
| const string child_path = parent_path + "/" + name; |
| |
| int status = fuse->mp->DeleteFile(child_path, ctx->uid); |
| if (status) { |
| fuse_reply_err(req, status); |
| return; |
| } |
| |
| node* child_node = parent_node->LookupChildByName(name, false /* acquire */); |
| TRACE_NODE(child_node); |
| if (child_node) { |
| child_node->SetDeleted(); |
| } |
| |
| fuse_reply_err(req, 0); |
| } |
| |
| static void pf_rmdir(fuse_req_t req, fuse_ino_t parent, const char* name) { |
| ATRACE_CALL(); |
| struct fuse* fuse = get_fuse(req); |
| const struct fuse_ctx* ctx = fuse_req_ctx(req); |
| node* parent_node = fuse->FromInode(parent, ctx); |
| if (!parent_node) { |
| fuse_reply_err(req, ENOENT); |
| return; |
| } |
| const string parent_path = parent_node->BuildPath(); |
| |
| TRACE_NODE(parent_node); |
| |
| const string child_path = parent_path + "/" + name; |
| |
| int status = fuse->mp->IsDeletingDirAllowed(child_path, ctx->uid); |
| if (status) { |
| fuse_reply_err(req, status); |
| return; |
| } |
| |
| if (rmdir(child_path.c_str()) < 0) { |
| fuse_reply_err(req, errno); |
| return; |
| } |
| |
| node* child_node = parent_node->LookupChildByName(name, false /* acquire */); |
| TRACE_NODE(child_node); |
| if (child_node) { |
| child_node->SetDeleted(); |
| } |
| |
| fuse_reply_err(req, 0); |
| } |
| /* |
| static void pf_symlink(fuse_req_t req, const char* link, fuse_ino_t parent, |
| const char* name) |
| { |
| cout << "TODO:" << __func__; |
| } |
| */ |
| static int do_rename(fuse_req_t req, fuse_ino_t parent, const char* name, fuse_ino_t new_parent, |
| const char* new_name, unsigned int flags) { |
| ATRACE_CALL(); |
| struct fuse* fuse = get_fuse(req); |
| const struct fuse_ctx* ctx = fuse_req_ctx(req); |
| |
| if (flags != 0) { |
| return EINVAL; |
| } |
| |
| node* old_parent_node = fuse->FromInode(parent, ctx); |
| if (!old_parent_node) return ENOENT; |
| const string old_parent_path = old_parent_node->BuildPath(); |
| node* new_parent_node = fuse->FromInode(new_parent, ctx); |
| if (!new_parent_node) return ENOENT; |
| const string new_parent_path = new_parent_node->BuildPath(); |
| |
| if (!old_parent_node || !new_parent_node) { |
| return ENOENT; |
| } else if (parent == new_parent && name == new_name) { |
| // No rename required. |
| return 0; |
| } |
| |
| TRACE_NODE(old_parent_node); |
| TRACE_NODE(new_parent_node); |
| |
| node* child_node = old_parent_node->LookupChildByName(name, true /* acquire */); |
| TRACE_NODE(child_node) << "old_child"; |
| |
| const string old_child_path = child_node->BuildPath(); |
| const string new_child_path = new_parent_path + "/" + new_name; |
| |
| // TODO(b/147408834): Check ENOTEMPTY & EEXIST error conditions before JNI call. |
| const int res = fuse->mp->Rename(old_child_path, new_child_path, req->ctx.uid); |
| // TODO(b/145663158): Lookups can go out of sync if file/directory is actually moved but |
| // EFAULT/EIO is reported due to JNI exception. |
| if (res == 0) { |
| child_node->Rename(new_name, new_parent_node); |
| } |
| TRACE_NODE(child_node) << "new_child"; |
| |
| child_node->Release(1); |
| return res; |
| } |
| |
| static void pf_rename(fuse_req_t req, fuse_ino_t parent, const char* name, fuse_ino_t new_parent, |
| const char* new_name, unsigned int flags) { |
| int res = do_rename(req, parent, name, new_parent, new_name, flags); |
| fuse_reply_err(req, res); |
| } |
| |
| /* |
| static void pf_link(fuse_req_t req, fuse_ino_t ino, fuse_ino_t new_parent, |
| const char* new_name) |
| { |
| cout << "TODO:" << __func__; |
| } |
| */ |
| |
| static handle* create_handle_for_node(struct fuse* fuse, const string& path, int fd, node* node, |
| const RedactionInfo* ri) { |
| std::lock_guard<std::recursive_mutex> guard(fuse->lock); |
| // We don't want to use the FUSE VFS cache in two cases: |
| // 1. When redaction is needed because app A with EXIF access might access |
| // a region that should have been redacted for app B without EXIF access, but app B on |
| // a subsequent read, will be able to see the EXIF data because the read request for |
| // that region will be served from cache and not get to the FUSE daemon |
| // 2. When the file has a read or write lock on it. This means that the MediaProvider |
| // has given an fd to the lower file system to an app. There are two cases where using |
| // the cache in this case can be a problem: |
| // a. Writing to a FUSE fd with caching enabled will use the write-back cache and a |
| // subsequent read from the lower fs fd will not see the write. |
| // b. Reading from a FUSE fd with caching enabled may not see the latest writes using |
| // the lower fs fd because those writes did not go through the FUSE layer and reads from |
| // FUSE after that write may be served from cache |
| bool direct_io = ri->isRedactionNeeded() || is_file_locked(fd, path); |
| |
| handle* h = new handle(fd, ri, !direct_io); |
| node->AddHandle(h); |
| return h; |
| } |
| |
| static void pf_open(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info* fi) { |
| ATRACE_CALL(); |
| struct fuse* fuse = get_fuse(req); |
| const struct fuse_ctx* ctx = fuse_req_ctx(req); |
| node* node = fuse->FromInode(ino, ctx); |
| if (!node) { |
| fuse_reply_err(req, ENOENT); |
| return; |
| } |
| const string path = node->BuildPath(); |
| |
| TRACE_NODE(node) << (is_requesting_write(fi->flags) ? "write" : "read"); |
| |
| if (fi->flags & O_DIRECT) { |
| fi->flags &= ~O_DIRECT; |
| fi->direct_io = true; |
| } |
| |
| int status = fuse->mp->IsOpenAllowed(path, ctx->uid, is_requesting_write(fi->flags)); |
| if (status) { |
| fuse_reply_err(req, status); |
| return; |
| } |
| |
| // With the writeback cache enabled, FUSE may generate READ requests even for files that |
| // were opened O_WRONLY; so make sure we open it O_RDWR instead. |
| int open_flags = fi->flags; |
| if (open_flags & O_WRONLY) { |
| open_flags &= ~O_WRONLY; |
| open_flags |= O_RDWR; |
| } |
| |
| const int fd = open(path.c_str(), open_flags); |
| if (fd < 0) { |
| fuse_reply_err(req, errno); |
| return; |
| } |
| |
| // We don't redact if the caller was granted write permission for this file |
| std::unique_ptr<RedactionInfo> ri; |
| if (is_requesting_write(fi->flags)) { |
| ri = std::make_unique<RedactionInfo>(); |
| } else { |
| ri = fuse->mp->GetRedactionInfo(path, req->ctx.uid); |
| } |
| |
| if (!ri) { |
| close(fd); |
| fuse_reply_err(req, EFAULT); |
| return; |
| } |
| |
| handle* h = create_handle_for_node(fuse, path, fd, node, ri.release()); |
| fi->fh = ptr_to_id(h); |
| fi->keep_cache = 1; |
| fi->direct_io = !h->cached; |
| fuse_reply_open(req, fi); |
| } |
| |
| static void do_read(fuse_req_t req, size_t size, off_t off, struct fuse_file_info* fi) { |
| handle* h = reinterpret_cast<handle*>(fi->fh); |
| struct fuse_bufvec buf = FUSE_BUFVEC_INIT(size); |
| |
| buf.buf[0].fd = h->fd; |
| buf.buf[0].pos = off; |
| buf.buf[0].flags = |
| (enum fuse_buf_flags) (FUSE_BUF_IS_FD | FUSE_BUF_FD_SEEK); |
| |
| fuse_reply_data(req, &buf, (enum fuse_buf_copy_flags) 0); |
| } |
| |
| static bool range_contains(const RedactionRange& rr, off_t off) { |
| return rr.first <= off && off <= rr.second; |
| } |
| |
| /** |
| * Sets the parameters for a fuse_buf that reads from memory, including flags. |
| * Makes buf->mem point to an already mapped region of zeroized memory. |
| * This memory is read only. |
| */ |
| static void create_mem_fuse_buf(size_t size, fuse_buf* buf, struct fuse* fuse) { |
| buf->size = size; |
| buf->mem = fuse->zero_addr; |
| buf->flags = static_cast<fuse_buf_flags>(0 /*read from fuse_buf.mem*/); |
| buf->pos = -1; |
| buf->fd = -1; |
| } |
| |
| /** |
| * Sets the parameters for a fuse_buf that reads from file, including flags. |
| */ |
| static void create_file_fuse_buf(size_t size, off_t pos, int fd, fuse_buf* buf) { |
| buf->size = size; |
| buf->fd = fd; |
| buf->pos = pos; |
| buf->flags = static_cast<fuse_buf_flags>(FUSE_BUF_IS_FD | FUSE_BUF_FD_SEEK); |
| buf->mem = nullptr; |
| } |
| |
| static void do_read_with_redaction(fuse_req_t req, size_t size, off_t off, fuse_file_info* fi) { |
| handle* h = reinterpret_cast<handle*>(fi->fh); |
| auto overlapping_rr = h->ri->getOverlappingRedactionRanges(size, off); |
| |
| if (overlapping_rr->size() <= 0) { |
| // no relevant redaction ranges for this request |
| do_read(req, size, off, fi); |
| return; |
| } |
| // the number of buffers we need, if the read doesn't start or end with |
| // a redaction range. |
| int num_bufs = overlapping_rr->size() * 2 + 1; |
| if (overlapping_rr->front().first <= off) { |
| // the beginning of the read request is redacted |
| num_bufs--; |
| } |
| if (overlapping_rr->back().second >= off + size) { |
| // the end of the read request is redacted |
| num_bufs--; |
| } |
| auto bufvec_ptr = std::unique_ptr<fuse_bufvec, decltype(free)*>{ |
| reinterpret_cast<fuse_bufvec*>( |
| malloc(sizeof(fuse_bufvec) + (num_bufs - 1) * sizeof(fuse_buf))), |
| free}; |
| fuse_bufvec& bufvec = *bufvec_ptr; |
| |
| // initialize bufvec |
| bufvec.count = num_bufs; |
| bufvec.idx = 0; |
| bufvec.off = 0; |
| |
| int rr_idx = 0; |
| off_t start = off; |
| // Add a dummy redaction range to make sure we don't go out of vector |
| // limits when computing the end of the last non-redacted range. |
| // This ranges is invalid because its starting point is larger than it's ending point. |
| overlapping_rr->push_back(RedactionRange(LLONG_MAX, LLONG_MAX - 1)); |
| |
| for (int i = 0; i < num_bufs; ++i) { |
| off_t end; |
| if (range_contains(overlapping_rr->at(rr_idx), start)) { |
| // Handle a redacted range |
| // end should be the end of the redacted range, but can't be out of |
| // the read request bounds |
| end = std::min(static_cast<off_t>(off + size - 1), overlapping_rr->at(rr_idx).second); |
| create_mem_fuse_buf(/*size*/ end - start + 1, &(bufvec.buf[i]), get_fuse(req)); |
| ++rr_idx; |
| } else { |
| // Handle a non-redacted range |
| // end should be right before the next redaction range starts or |
| // the end of the read request |
| end = std::min(static_cast<off_t>(off + size - 1), |
| overlapping_rr->at(rr_idx).first - 1); |
| create_file_fuse_buf(/*size*/ end - start + 1, start, h->fd, &(bufvec.buf[i])); |
| } |
| start = end + 1; |
| } |
| |
| fuse_reply_data(req, &bufvec, static_cast<fuse_buf_copy_flags>(0)); |
| } |
| |
| static void pf_read(fuse_req_t req, fuse_ino_t ino, size_t size, off_t off, |
| struct fuse_file_info* fi) { |
| ATRACE_CALL(); |
| handle* h = reinterpret_cast<handle*>(fi->fh); |
| struct fuse* fuse = get_fuse(req); |
| |
| fuse->fadviser.Record(h->fd, size); |
| |
| if (h->ri->isRedactionNeeded()) { |
| do_read_with_redaction(req, size, off, fi); |
| } else { |
| do_read(req, size, off, fi); |
| } |
| } |
| |
| /* |
| static void pf_write(fuse_req_t req, fuse_ino_t ino, const char* buf, |
| size_t size, off_t off, struct fuse_file_info* fi) |
| { |
| cout << "TODO:" << __func__; |
| } |
| */ |
| |
| static void pf_write_buf(fuse_req_t req, |
| fuse_ino_t ino, |
| struct fuse_bufvec* bufv, |
| off_t off, |
| struct fuse_file_info* fi) { |
| ATRACE_CALL(); |
| handle* h = reinterpret_cast<handle*>(fi->fh); |
| struct fuse_bufvec buf = FUSE_BUFVEC_INIT(fuse_buf_size(bufv)); |
| ssize_t size; |
| struct fuse* fuse = get_fuse(req); |
| |
| buf.buf[0].fd = h->fd; |
| buf.buf[0].pos = off; |
| buf.buf[0].flags = |
| (enum fuse_buf_flags) (FUSE_BUF_IS_FD | FUSE_BUF_FD_SEEK); |
| size = fuse_buf_copy(&buf, bufv, (enum fuse_buf_copy_flags) 0); |
| |
| if (size < 0) |
| fuse_reply_err(req, -size); |
| else { |
| fuse_reply_write(req, size); |
| fuse->fadviser.Record(h->fd, size); |
| } |
| } |
| // Haven't tested this one. Not sure what calls it. |
| #if 0 |
| static void pf_copy_file_range(fuse_req_t req, fuse_ino_t ino_in, |
| off_t off_in, struct fuse_file_info* fi_in, |
| fuse_ino_t ino_out, off_t off_out, |
| struct fuse_file_info* fi_out, size_t len, |
| int flags) |
| { |
| handle* h_in = reinterpret_cast<handle *>(fi_in->fh); |
| handle* h_out = reinterpret_cast<handle *>(fi_out->fh); |
| struct fuse_bufvec buf_in = FUSE_BUFVEC_INIT(len); |
| struct fuse_bufvec buf_out = FUSE_BUFVEC_INIT(len); |
| ssize_t size; |
| |
| buf_in.buf[0].fd = h_in->fd; |
| buf_in.buf[0].pos = off_in; |
| buf_in.buf[0].flags = (enum fuse_buf_flags)(FUSE_BUF_IS_FD|FUSE_BUF_FD_SEEK); |
| |
| buf_out.buf[0].fd = h_out->fd; |
| buf_out.buf[0].pos = off_out; |
| buf_out.buf[0].flags = (enum fuse_buf_flags)(FUSE_BUF_IS_FD|FUSE_BUF_FD_SEEK); |
| size = fuse_buf_copy(&buf_out, &buf_in, (enum fuse_buf_copy_flags) 0); |
| |
| if (size < 0) { |
| fuse_reply_err(req, -size); |
| } |
| |
| fuse_reply_write(req, size); |
| } |
| #endif |
| static void pf_flush(fuse_req_t req, |
| fuse_ino_t ino, |
| struct fuse_file_info* fi) { |
| ATRACE_CALL(); |
| struct fuse* fuse = get_fuse(req); |
| TRACE_NODE(nullptr) << "noop"; |
| fuse_reply_err(req, 0); |
| } |
| |
| static void pf_release(fuse_req_t req, |
| fuse_ino_t ino, |
| struct fuse_file_info* fi) { |
| ATRACE_CALL(); |
| struct fuse* fuse = get_fuse(req); |
| |
| node* node = fuse->FromInode(ino, fuse_req_ctx(req)); |
| handle* h = reinterpret_cast<handle*>(fi->fh); |
| TRACE_NODE(node); |
| |
| fuse->fadviser.Close(h->fd); |
| if (node) { |
| node->DestroyHandle(h); |
| } |
| |
| fuse_reply_err(req, 0); |
| } |
| |
| static int do_sync_common(int fd, bool datasync) { |
| int res = datasync ? fdatasync(fd) : fsync(fd); |
| |
| if (res == -1) return errno; |
| return 0; |
| } |
| |
| static void pf_fsync(fuse_req_t req, |
| fuse_ino_t ino, |
| int datasync, |
| struct fuse_file_info* fi) { |
| ATRACE_CALL(); |
| handle* h = reinterpret_cast<handle*>(fi->fh); |
| int err = do_sync_common(h->fd, datasync); |
| |
| fuse_reply_err(req, err); |
| } |
| |
| static void pf_fsyncdir(fuse_req_t req, |
| fuse_ino_t ino, |
| int datasync, |
| struct fuse_file_info* fi) { |
| dirhandle* h = reinterpret_cast<dirhandle*>(fi->fh); |
| int err = do_sync_common(dirfd(h->d), datasync); |
| |
| fuse_reply_err(req, err); |
| } |
| |
| static void pf_opendir(fuse_req_t req, |
| fuse_ino_t ino, |
| struct fuse_file_info* fi) { |
| ATRACE_CALL(); |
| struct fuse* fuse = get_fuse(req); |
| const struct fuse_ctx* ctx = fuse_req_ctx(req); |
| node* node = fuse->FromInode(ino, ctx); |
| if (!node) { |
| fuse_reply_err(req, ENOENT); |
| return; |
| } |
| const string path = node->BuildPath(); |
| |
| TRACE_NODE(node); |
| |
| int status = fuse->mp->IsOpendirAllowed(path, ctx->uid); |
| if (status) { |
| fuse_reply_err(req, status); |
| return; |
| } |
| |
| DIR* dir = opendir(path.c_str()); |
| if (!dir) { |
| fuse_reply_err(req, errno); |
| return; |
| } |
| |
| dirhandle* h = new dirhandle(dir); |
| node->AddDirHandle(h); |
| |
| fi->fh = ptr_to_id(h); |
| fuse_reply_open(req, fi); |
| } |
| |
| #define READDIR_BUF 8192LU |
| |
| static void do_readdir_common(fuse_req_t req, |
| fuse_ino_t ino, |
| size_t size, |
| off_t off, |
| struct fuse_file_info* fi, |
| bool plus) { |
| struct fuse* fuse = get_fuse(req); |
| dirhandle* h = reinterpret_cast<dirhandle*>(fi->fh); |
| size_t len = std::min<size_t>(size, READDIR_BUF); |
| char buf[READDIR_BUF]; |
| size_t used = 0; |
| std::shared_ptr<DirectoryEntry> de; |
| |
| struct fuse_entry_param e; |
| size_t entry_size = 0; |
| |
| node* node = fuse->FromInode(ino, fuse_req_ctx(req)); |
| if (!node) { |
| fuse_reply_err(req, ENOENT); |
| return; |
| } |
| const string path = node->BuildPath(); |
| |
| TRACE_NODE(node); |
| // Get all directory entries from MediaProvider on first readdir() call of |
| // directory handle. h->next_off = 0 indicates that current readdir() call |
| // is first readdir() call for the directory handle, Avoid multiple JNI calls |
| // for single directory handle. |
| if (h->next_off == 0) { |
| h->de = fuse->mp->GetDirectoryEntries(req->ctx.uid, path, h->d); |
| } |
| // If the last entry in the previous readdir() call was rejected due to |
| // buffer capacity constraints, update directory offset to start from |
| // previously rejected entry. Directory offset can also change if there was |
| // a seekdir() on the given directory handle. |
| if (off != h->next_off) { |
| h->next_off = off; |
| } |
| const int num_directory_entries = h->de.size(); |
| // Check for errors. Any error/exception occurred while obtaining directory |
| // entries will be indicated by marking first directory entry name as empty |
| // string. In the erroneous case corresponding d_type will hold error number. |
| if (num_directory_entries && h->de[0]->d_name.empty()) { |
| fuse_reply_err(req, h->de[0]->d_type); |
| return; |
| } |
| |
| while (h->next_off < num_directory_entries) { |
| de = h->de[h->next_off]; |
| entry_size = 0; |
| h->next_off++; |
| if (plus) { |
| int error_code = 0; |
| if (do_lookup(req, ino, de->d_name.c_str(), &e, &error_code)) { |
| entry_size = fuse_add_direntry_plus(req, buf + used, len - used, de->d_name.c_str(), |
| &e, h->next_off); |
| } else { |
| // Ignore lookup errors on |
| // 1. non-existing files returned from MediaProvider database. |
| // 2. path that doesn't match FuseDaemon UID and calling uid. |
| if (error_code == ENOENT || error_code == EPERM) continue; |
| fuse_reply_err(req, error_code); |
| return; |
| } |
| } else { |
| e.attr.st_ino = FUSE_UNKNOWN_INO; |
| e.attr.st_mode = de->d_type; |
| entry_size = fuse_add_direntry(req, buf + used, len - used, de->d_name.c_str(), &e.attr, |
| h->next_off); |
| } |
| // If buffer in fuse_add_direntry[_plus] is not large enough then |
| // the entry is not added to buffer but the size of the entry is still |
| // returned. Check available buffer size + returned entry size is less |
| // than actual buffer size to confirm entry is added to buffer. |
| if (used + entry_size > len) { |
| // When an entry is rejected, lookup called by readdir_plus will not be tracked by |
| // kernel. Call forget on the rejected node to decrement the reference count. |
| if (plus) { |
| do_forget(fuse, e.ino, 1); |
| } |
| break; |
| } |
| used += entry_size; |
| } |
| fuse_reply_buf(req, buf, used); |
| } |
| |
| static void pf_readdir(fuse_req_t req, fuse_ino_t ino, size_t size, off_t off, |
| struct fuse_file_info* fi) { |
| ATRACE_CALL(); |
| do_readdir_common(req, ino, size, off, fi, false); |
| } |
| |
| static void pf_readdirplus(fuse_req_t req, |
| fuse_ino_t ino, |
| size_t size, |
| off_t off, |
| struct fuse_file_info* fi) { |
| ATRACE_CALL(); |
| do_readdir_common(req, ino, size, off, fi, true); |
| } |
| |
| static void pf_releasedir(fuse_req_t req, |
| fuse_ino_t ino, |
| struct fuse_file_info* fi) { |
| ATRACE_CALL(); |
| struct fuse* fuse = get_fuse(req); |
| |
| node* node = fuse->FromInode(ino, fuse_req_ctx(req)); |
| dirhandle* h = reinterpret_cast<dirhandle*>(fi->fh); |
| TRACE_NODE(node); |
| if (node) { |
| node->DestroyDirHandle(h); |
| } |
| |
| fuse_reply_err(req, 0); |
| } |
| |
| static void pf_statfs(fuse_req_t req, fuse_ino_t ino) { |
| ATRACE_CALL(); |
| struct statvfs st; |
| struct fuse* fuse = get_fuse(req); |
| |
| if (statvfs(fuse->root->GetName().c_str(), &st)) |
| fuse_reply_err(req, errno); |
| else |
| fuse_reply_statfs(req, &st); |
| } |
| /* |
| static void pf_setxattr(fuse_req_t req, fuse_ino_t ino, const char* name, |
| const char* value, size_t size, int flags) |
| { |
| cout << "TODO:" << __func__; |
| } |
| |
| static void pf_getxattr(fuse_req_t req, fuse_ino_t ino, const char* name, |
| size_t size) |
| { |
| cout << "TODO:" << __func__; |
| } |
| |
| static void pf_listxattr(fuse_req_t req, fuse_ino_t ino, size_t size) |
| { |
| cout << "TODO:" << __func__; |
| } |
| |
| static void pf_removexattr(fuse_req_t req, fuse_ino_t ino, const char* name) |
| { |
| cout << "TODO:" << __func__; |
| }*/ |
| |
| static void pf_access(fuse_req_t req, fuse_ino_t ino, int mask) { |
| ATRACE_CALL(); |
| struct fuse* fuse = get_fuse(req); |
| const struct fuse_ctx* ctx = fuse_req_ctx(req); |
| |
| node* node = fuse->FromInode(ino, ctx); |
| if (!node) { |
| fuse_reply_err(req, ENOENT); |
| return; |
| } |
| const string path = node->BuildPath(); |
| TRACE_NODE(node); |
| |
| int res = access(path.c_str(), F_OK); |
| fuse_reply_err(req, res ? errno : 0); |
| } |
| |
| static void pf_create(fuse_req_t req, |
| fuse_ino_t parent, |
| const char* name, |
| mode_t mode, |
| struct fuse_file_info* fi) { |
| ATRACE_CALL(); |
| struct fuse* fuse = get_fuse(req); |
| const struct fuse_ctx* ctx = fuse_req_ctx(req); |
| node* parent_node = fuse->FromInode(parent, ctx); |
| if (!parent_node) { |
| fuse_reply_err(req, ENOENT); |
| return; |
| } |
| const string parent_path = parent_node->BuildPath(); |
| |
| TRACE_NODE(parent_node); |
| |
| const string child_path = parent_path + "/" + name; |
| |
| int mp_return_code = fuse->mp->InsertFile(child_path.c_str(), ctx->uid); |
| if (mp_return_code) { |
| fuse_reply_err(req, mp_return_code); |
| return; |
| } |
| |
| // With the writeback cache enabled, FUSE may generate READ requests even for files that |
| // were opened O_WRONLY; so make sure we open it O_RDWR instead. |
| int open_flags = fi->flags; |
| if (open_flags & O_WRONLY) { |
| open_flags &= ~O_WRONLY; |
| open_flags |= O_RDWR; |
| } |
| |
| mode = (mode & (~0777)) | 0664; |
| int fd = open(child_path.c_str(), open_flags, mode); |
| if (fd < 0) { |
| int error_code = errno; |
| // We've already inserted the file into the MP database before the |
| // failed open(), so that needs to be rolled back here. |
| fuse->mp->DeleteFile(child_path.c_str(), ctx->uid); |
| fuse_reply_err(req, error_code); |
| return; |
| } |
| |
| int error_code = 0; |
| struct fuse_entry_param e; |
| node* node = make_node_entry(req, parent_node, name, child_path, &e, &error_code); |
| TRACE_NODE(node); |
| if (!node) { |
| CHECK(error_code != 0); |
| fuse_reply_err(req, error_code); |
| return; |
| } |
| |
| // TODO(b/147274248): Assume there will be no EXIF to redact. |
| // This prevents crashing during reads but can be a security hole if a malicious app opens an fd |
| // to the file before all the EXIF content is written. We could special case reads before the |
| // first close after a file has just been created. |
| handle* h = create_handle_for_node(fuse, child_path, fd, node, new RedactionInfo()); |
| fi->fh = ptr_to_id(h); |
| fi->keep_cache = 1; |
| fi->direct_io = !h->cached; |
| fuse_reply_create(req, &e, fi); |
| } |
| /* |
| static void pf_getlk(fuse_req_t req, fuse_ino_t ino, |
| struct fuse_file_info* fi, struct flock* lock) |
| { |
| cout << "TODO:" << __func__; |
| } |
| |
| static void pf_setlk(fuse_req_t req, fuse_ino_t ino, |
| struct fuse_file_info* fi, |
| struct flock* lock, int sleep) |
| { |
| cout << "TODO:" << __func__; |
| } |
| |
| static void pf_bmap(fuse_req_t req, fuse_ino_t ino, size_t blocksize, |
| uint64_t idx) |
| { |
| cout << "TODO:" << __func__; |
| } |
| |
| static void pf_ioctl(fuse_req_t req, fuse_ino_t ino, unsigned int cmd, |
| void* arg, struct fuse_file_info* fi, unsigned flags, |
| const void* in_buf, size_t in_bufsz, size_t out_bufsz) |
| { |
| cout << "TODO:" << __func__; |
| } |
| |
| static void pf_poll(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info* fi, |
| struct fuse_pollhandle* ph) |
| { |
| cout << "TODO:" << __func__; |
| } |
| |
| static void pf_retrieve_reply(fuse_req_t req, void* cookie, fuse_ino_t ino, |
| off_t offset, struct fuse_bufvec* bufv) |
| { |
| cout << "TODO:" << __func__; |
| } |
| |
| static void pf_flock(fuse_req_t req, fuse_ino_t ino, |
| struct fuse_file_info* fi, int op) |
| { |
| cout << "TODO:" << __func__; |
| } |
| |
| static void pf_fallocate(fuse_req_t req, fuse_ino_t ino, int mode, |
| off_t offset, off_t length, struct fuse_file_info* fi) |
| { |
| cout << "TODO:" << __func__; |
| } |
| */ |
| |
| static struct fuse_lowlevel_ops ops{ |
| .init = pf_init, .destroy = pf_destroy, .lookup = pf_lookup, .forget = pf_forget, |
| .getattr = pf_getattr, .setattr = pf_setattr, .canonical_path = pf_canonical_path, |
| .mknod = pf_mknod, .mkdir = pf_mkdir, .unlink = pf_unlink, .rmdir = pf_rmdir, |
| /*.symlink = pf_symlink,*/ |
| .rename = pf_rename, |
| /*.link = pf_link,*/ |
| .open = pf_open, .read = pf_read, |
| /*.write = pf_write,*/ |
| .flush = pf_flush, |
| .release = pf_release, .fsync = pf_fsync, .opendir = pf_opendir, .readdir = pf_readdir, |
| .releasedir = pf_releasedir, .fsyncdir = pf_fsyncdir, .statfs = pf_statfs, |
| /*.setxattr = pf_setxattr, |
| .getxattr = pf_getxattr, |
| .listxattr = pf_listxattr, |
| .removexattr = pf_removexattr,*/ |
| .access = pf_access, .create = pf_create, |
| /*.getlk = pf_getlk, |
| .setlk = pf_setlk, |
| .bmap = pf_bmap, |
| .ioctl = pf_ioctl, |
| .poll = pf_poll,*/ |
| .write_buf = pf_write_buf, |
| /*.retrieve_reply = pf_retrieve_reply,*/ |
| .forget_multi = pf_forget_multi, |
| /*.flock = pf_flock, |
| .fallocate = pf_fallocate,*/ |
| .readdirplus = pf_readdirplus, |
| /*.copy_file_range = pf_copy_file_range,*/ |
| }; |
| |
| static struct fuse_loop_config config = { |
| .clone_fd = 1, |
| .max_idle_threads = 10, |
| }; |
| |
| static std::unordered_map<enum fuse_log_level, enum android_LogPriority> fuse_to_android_loglevel({ |
| {FUSE_LOG_EMERG, ANDROID_LOG_FATAL}, |
| {FUSE_LOG_ALERT, ANDROID_LOG_ERROR}, |
| {FUSE_LOG_CRIT, ANDROID_LOG_ERROR}, |
| {FUSE_LOG_ERR, ANDROID_LOG_ERROR}, |
| {FUSE_LOG_WARNING, ANDROID_LOG_WARN}, |
| {FUSE_LOG_NOTICE, ANDROID_LOG_INFO}, |
| {FUSE_LOG_INFO, ANDROID_LOG_DEBUG}, |
| {FUSE_LOG_DEBUG, ANDROID_LOG_VERBOSE}, |
| }); |
| |
| static void fuse_logger(enum fuse_log_level level, const char* fmt, va_list ap) { |
| __android_log_vprint(fuse_to_android_loglevel.at(level), LIBFUSE_LOG_TAG, fmt, ap); |
| } |
| |
| bool FuseDaemon::ShouldOpenWithFuse(int fd, bool for_read, const std::string& path) { |
| bool use_fuse = false; |
| |
| if (active.load(std::memory_order_acquire)) { |
| std::lock_guard<std::recursive_mutex> guard(fuse->lock); |
| const node* node = node::LookupAbsolutePath(fuse->root, path); |
| if (node && node->HasCachedHandle()) { |
| use_fuse = true; |
| } else { |
| // If we are unable to set a lock, we should use fuse since we can't track |
| // when all fd references (including dups) are closed. This can happen when |
| // we try to set a write lock twice on the same file |
| use_fuse = set_file_lock(fd, for_read, path); |
| } |
| } else { |
| LOG(WARNING) << "FUSE daemon is inactive. Cannot open file with FUSE"; |
| } |
| |
| return use_fuse; |
| } |
| |
| void FuseDaemon::InvalidateFuseDentryCache(const std::string& path) { |
| LOG(VERBOSE) << "Invalidating FUSE dentry cache"; |
| if (active.load(std::memory_order_acquire)) { |
| string name; |
| fuse_ino_t parent; |
| |
| { |
| std::lock_guard<std::recursive_mutex> guard(fuse->lock); |
| const node* node = node::LookupAbsolutePath(fuse->root, path); |
| if (node) { |
| name = node->GetName(); |
| parent = fuse->ToInode(node->GetParent()); |
| } |
| } |
| |
| if (!name.empty() && |
| fuse_lowlevel_notify_inval_entry(fuse->se, parent, name.c_str(), name.size())) { |
| LOG(WARNING) << "Failed to invalidate dentry for path"; |
| } |
| } else { |
| LOG(WARNING) << "FUSE daemon is inactive. Cannot invalidate dentry"; |
| } |
| } |
| |
| FuseDaemon::FuseDaemon(JNIEnv* env, jobject mediaProvider) : mp(env, mediaProvider), |
| active(false), fuse(nullptr) {} |
| |
| bool FuseDaemon::IsStarted() const { |
| return active.load(std::memory_order_acquire); |
| } |
| |
| void FuseDaemon::Start(android::base::unique_fd fd, const std::string& path) { |
| struct fuse_args args; |
| struct fuse_cmdline_opts opts; |
| |
| SetMinimumLogSeverity(android::base::VERBOSE); |
| |
| struct stat stat; |
| |
| if (lstat(path.c_str(), &stat)) { |
| PLOG(ERROR) << "ERROR: failed to stat source " << path; |
| return; |
| } |
| |
| if (!S_ISDIR(stat.st_mode)) { |
| PLOG(ERROR) << "ERROR: source is not a directory"; |
| return; |
| } |
| |
| args = FUSE_ARGS_INIT(0, nullptr); |
| if (fuse_opt_add_arg(&args, path.c_str()) || fuse_opt_add_arg(&args, "-odebug") || |
| fuse_opt_add_arg(&args, ("-omax_read=" + std::to_string(MAX_READ_SIZE)).c_str())) { |
| LOG(ERROR) << "ERROR: failed to set options"; |
| return; |
| } |
| |
| struct fuse fuse_default(path); |
| fuse_default.mp = ∓ |
| // fuse_default is stack allocated, but it's safe to save it as an instance variable because |
| // this method blocks and FuseDaemon#active tells if we are currently blocking |
| fuse = &fuse_default; |
| |
| // Used by pf_read: redacted ranges are represented by zeroized ranges of bytes, |
| // so we mmap the maximum length of redacted ranges in the beginning and save memory allocations |
| // on each read. |
| fuse_default.zero_addr = static_cast<char*>(mmap( |
| NULL, MAX_READ_SIZE, PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE, /*fd*/ -1, /*off*/ 0)); |
| if (fuse_default.zero_addr == MAP_FAILED) { |
| LOG(FATAL) << "mmap failed - could not start fuse! errno = " << errno; |
| } |
| |
| // Custom logging for libfuse |
| if (android::base::GetBoolProperty("persist.sys.fuse.log", false)) { |
| fuse_set_log_func(fuse_logger); |
| } |
| |
| struct fuse_session |
| * se = fuse_session_new(&args, &ops, sizeof(ops), &fuse_default); |
| if (!se) { |
| PLOG(ERROR) << "Failed to create session "; |
| return; |
| } |
| fuse_default.se = se; |
| fuse_default.active = &active; |
| se->fd = fd; |
| se->mountpoint = strdup(path.c_str()); |
| |
| // Single thread. Useful for debugging |
| // fuse_session_loop(se); |
| // Multi-threaded |
| LOG(INFO) << "Starting fuse..."; |
| fuse_session_loop_mt(se, &config); |
| fuse->active->store(false, std::memory_order_release); |
| LOG(INFO) << "Ending fuse..."; |
| |
| if (munmap(fuse_default.zero_addr, MAX_READ_SIZE)) { |
| PLOG(ERROR) << "munmap failed!"; |
| } |
| |
| fuse_opt_free_args(&args); |
| fuse_session_destroy(se); |
| LOG(INFO) << "Ended fuse"; |
| return; |
| } |
| } //namespace fuse |
| } // namespace mediaprovider |