Merge Android 14android-u-rb-dp-10-gplandroid-u-rb-dp-10-gpl

Bug: 298295554
Merged-In: Iefaa6682729600f8804b454bb14f9d1611c6d7a7
Change-Id: I84d5fdd1700f18e2596bab4c0a2f123c7b2385a0

3 files changed, 121 insertions, 3 deletions

diff --git a/include/fuse_kernel.h b/include/fuse_kernel.h
index 7adace0..7928a2f 100644
--- a/include/fuse_kernel.h
+++ b/include/fuse_kernel.h
@@ -716,6 +716,12 @@ struct fuse_read_in {
 	uint32_t	padding;
 };
 
+struct fuse_read_out {
+	uint64_t offset;
+	uint32_t size;
+	uint32_t again;
+};
+
 struct fuse_passthrough_out_v0 {
 	uint32_t	fd;
 	/* For future implementation */
@@ -903,7 +909,7 @@ struct fuse_in_header {
 	uint32_t	uid;
 	uint32_t	gid;
 	uint32_t	pid;
-	uint32_t	padding;
+	uint32_t	error_in;
 };
 
 struct fuse_out_header {
diff --git a/include/fuse_lowlevel.h b/include/fuse_lowlevel.h
index c591f71..92370ea 100644
--- a/include/fuse_lowlevel.h
+++ b/include/fuse_lowlevel.h
@@ -143,6 +143,12 @@ struct fuse_forget_data {
 #define FUSE_SET_ATTR_CTIME	(1 << 10)
 
 /* ----------------------------------------------------------- *
+ * structs from fuse_kernel.h                                  *
+ * ----------------------------------------------------------- */
+struct fuse_entry_out;
+struct fuse_entry_bpf_out;
+
+/* ----------------------------------------------------------- *
  * Request methods and replies				       *
  * ----------------------------------------------------------- */
 
@@ -219,6 +225,25 @@ struct fuse_lowlevel_ops {
 	void (*lookup) (fuse_req_t req, fuse_ino_t parent, const char *name);
 
 	/**
+	 * post filter a lookup
+	 *
+	 * Valid replies:
+	 *   fuse_reply_entry
+	 *   fuse_reply_err
+	 *
+	 * @param req request handle
+	 * @param parent inode number of the parent directory
+	 * @param error_in the error, or 0, of the lookup
+	 * @param name the name that was looked up
+	 * @param feo the fuse entry out struct from the lookup
+	 * @param febo the fuse entry bpf out struct from the lookup
+	 */
+	void (*lookup_postfilter)(fuse_req_t req, fuse_ino_t parent,
+								uint32_t error_in, const char *name,
+								struct fuse_entry_out *feo,
+								struct fuse_entry_bpf_out *febo);
+
+	/**
 	 * Forget about an inode
 	 *
 	 * This function is called when the kernel removes an inode
@@ -743,6 +768,27 @@ struct fuse_lowlevel_ops {
 			 struct fuse_file_info *fi);
 
 	/**
+	 * Read directory postfilter
+	 *
+	 * Valid replies:
+	 *   fuse_reply_buf
+	 *   fuse_reply_data
+	 *   fuse_reply_err
+	 *
+	 * @param req request handle
+	 * @param ino the inode number
+	 * @param error_in the error from the readdir
+	 * @param off_in offset to continue reading the directory stream before backing
+	 * @param off_out offset to continue reading the directory stream after backing
+	 * @param size_out length in bytes of dirents
+	 * @param dirents array of dirents read by backing
+	 * @param fi file information
+	 */
+	void (*readdirpostfilter)(fuse_req_t req, fuse_ino_t ino, uint32_t error_in,
+								off_t off_in, off_t off_out, size_t size_out,
+								const void *dirents, struct fuse_file_info *fi);
+
+	/**
 	 * Release an open directory
 	 *
 	 * For every opendir call there will be exactly one releasedir
diff --git a/lib/fuse_lowlevel.c b/lib/fuse_lowlevel.c
index 51cd412..4c75e3b 100644
--- a/lib/fuse_lowlevel.c
+++ b/lib/fuse_lowlevel.c
@@ -1187,6 +1187,28 @@ static void do_lookup(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
 		fuse_reply_err(req, ENOSYS);
 }
 
+static void do_lookup_postfilter(fuse_req_t req, fuse_ino_t nodeid, uint32_t error_in,
+								 const void *inarg, size_t size)
+{
+	if (req->se->op.lookup_postfilter) {
+		char *name = (char *) inarg;
+		size_t namelen = strlen(name);
+
+		if (size != namelen + 1 + sizeof(struct fuse_entry_out)
+						+ sizeof(struct fuse_entry_bpf_out)) {
+			fuse_log(FUSE_LOG_ERR, "%s: Bad size", __func__);
+			fuse_reply_err(req, EIO);
+		} else {
+			struct fuse_entry_out *feo = (void *) (name + namelen + 1);
+			struct fuse_entry_bpf_out *febo = (char *) feo + sizeof(*feo);
+
+			req->se->op.lookup_postfilter(req, nodeid, error_in, name, feo,
+											febo);
+		}
+	} else
+		fuse_reply_err(req, ENOSYS);
+}
+
 static void do_forget(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
 {
 	struct fuse_forget_in *arg = (struct fuse_forget_in *) inarg;
@@ -1629,6 +1651,26 @@ static void do_readdirplus(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
 		fuse_reply_err(req, ENOSYS);
 }
 
+static void do_readdir_postfilter(fuse_req_t req, fuse_ino_t nodeid,
+									uint32_t error_in, const void *inarg,
+									size_t size) {
+	struct fuse_read_in *fri = (struct fuse_read_in *) inarg;
+	struct fuse_read_out *fro = (struct fuse_read_out *) (fri + 1);
+	struct fuse_dirent *dirents = (struct fuse_dirent *) (fro + 1);
+	struct fuse_file_info fi;
+
+	memset(&fi, 0, sizeof(fi));
+	fi.fh = fri->fh;
+
+	if (req->se->op.readdirpostfilter)
+		req->se->op.readdirpostfilter(req, nodeid, error_in, fri->offset,
+										fro->offset,
+										size - sizeof(*fri) - sizeof(*fro),
+										dirents, &fi);
+	else
+		fuse_reply_err(req, ENOSYS);
+}
+
 static void do_releasedir(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
 {
 	struct fuse_release_in *arg = (struct fuse_release_in *) inarg;
@@ -2605,7 +2647,7 @@ static struct {
 	[FUSE_GETATTR]	   = { do_getattr,     "GETATTR"     },
 	[FUSE_SETATTR]	   = { do_setattr,     "SETATTR"     },
 	[FUSE_READLINK]	   = { do_readlink,    "READLINK"    },
-        [FUSE_CANONICAL_PATH] = { do_canonical_path, "CANONICAL_PATH" },
+	[FUSE_CANONICAL_PATH] = { do_canonical_path, "CANONICAL_PATH" },
 	[FUSE_SYMLINK]	   = { do_symlink,     "SYMLINK"     },
 	[FUSE_MKNOD]	   = { do_mknod,       "MKNOD"	     },
 	[FUSE_MKDIR]	   = { do_mkdir,       "MKDIR"	     },
@@ -2649,6 +2691,18 @@ static struct {
 	[CUSE_INIT]	   = { cuse_lowlevel_init, "CUSE_INIT"   },
 };
 
+static struct {
+	void (*func)( fuse_req_t, fuse_ino_t, const void *);
+	const char *name;
+} fuse_ll_prefilter_ops[] = {};
+
+static struct {
+	void (*func)( fuse_req_t, fuse_ino_t, uint32_t, const void *, size_t size);
+} fuse_ll_postfilter_ops[] = {
+		[FUSE_LOOKUP] = {do_lookup_postfilter},
+		[FUSE_READDIR] = {do_readdir_postfilter},
+};
+
 #define FUSE_MAXOP (sizeof(fuse_ll_ops) / sizeof(fuse_ll_ops[0]))
 
 static const char *opname(enum fuse_opcode opcode)
@@ -2826,8 +2880,20 @@ void fuse_session_process_buf_int(struct fuse_session *se,
 		do_write_buf(req, in->nodeid, inarg, buf);
 	else if (in->opcode == FUSE_NOTIFY_REPLY)
 		do_notify_reply(req, in->nodeid, inarg, buf);
-	else
+	else if (!opcode_filter)
 		fuse_ll_ops[in->opcode].func(req, in->nodeid, inarg);
+	else if (opcode_filter == FUSE_PREFILTER && fuse_ll_prefilter_ops[in->opcode].func)
+	  fuse_ll_prefilter_ops[in->opcode].func(req, in->nodeid, inarg);
+	else if (opcode_filter == FUSE_POSTFILTER
+			&& fuse_ll_postfilter_ops[in->opcode].func)
+		fuse_ll_postfilter_ops[in->opcode].func(
+				req, in->nodeid, in->error_in, inarg,
+				buf->size - sizeof(struct fuse_in_header));
+	else {
+		fuse_log(FUSE_LOG_ERR, "Bad opcode");
+		err = ENOSYS;
+		goto reply_err;
+	}
 
 out_free:
 	free(mbuf);