1 files changed, 596 insertions, 0 deletions

diff --git a/fuse/mount.c b/fuse/mount.c
new file mode 100644
index 000000000..88ab59721
--- /dev/null
+++ b/fuse/mount.c
@@ -0,0 +1,596 @@
+/*
+  FUSE: Filesystem in Userspace
+  Copyright (C) 2001-2007  Miklos Szeredi <miklos@szeredi.hu>
+
+  This program can be distributed under the terms of the GNU LGPLv2.
+  See the file COPYING.LIB.
+*/
+
+#include "config.h"
+#include "fuse_i.h"
+#include "fuse_misc.h"
+#include "fuse_opt.h"
+#include "fuse_common_compat.h"
+#include "mount_util.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stddef.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/poll.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/wait.h>
+#include <sys/mount.h>
+
+#define FUSERMOUNT_PROG		"fusermount"
+#define FUSE_COMMFD_ENV		"_FUSE_COMMFD"
+
+#ifndef HAVE_FORK
+#define fork() vfork()
+#endif
+
+#ifndef MS_DIRSYNC
+#define MS_DIRSYNC 128
+#endif
+
+enum {
+	KEY_KERN_FLAG,
+	KEY_KERN_OPT,
+	KEY_FUSERMOUNT_OPT,
+	KEY_SUBTYPE_OPT,
+	KEY_MTAB_OPT,
+	KEY_ALLOW_ROOT,
+	KEY_RO,
+	KEY_HELP,
+	KEY_VERSION,
+};
+
+struct mount_opts {
+	int allow_other;
+	int allow_root;
+	int ishelp;
+	int flags;
+	int nonempty;
+	int blkdev;
+	char *fsname;
+	char *subtype;
+	char *subtype_opt;
+	char *mtab_opts;
+	char *fusermount_opts;
+	char *kernel_opts;
+};
+
+#define FUSE_MOUNT_OPT(t, p) { t, offsetof(struct mount_opts, p), 1 }
+
+static const struct fuse_opt fuse_mount_opts[] = {
+	FUSE_MOUNT_OPT("allow_other",		allow_other),
+	FUSE_MOUNT_OPT("allow_root",		allow_root),
+	FUSE_MOUNT_OPT("nonempty",		nonempty),
+	FUSE_MOUNT_OPT("blkdev",		blkdev),
+	FUSE_MOUNT_OPT("fsname=%s",		fsname),
+	FUSE_MOUNT_OPT("subtype=%s",		subtype),
+	FUSE_OPT_KEY("allow_other",		KEY_KERN_OPT),
+	FUSE_OPT_KEY("allow_root",		KEY_ALLOW_ROOT),
+	FUSE_OPT_KEY("nonempty",		KEY_FUSERMOUNT_OPT),
+	FUSE_OPT_KEY("blkdev",			KEY_FUSERMOUNT_OPT),
+	FUSE_OPT_KEY("fsname=",			KEY_FUSERMOUNT_OPT),
+	FUSE_OPT_KEY("subtype=",		KEY_SUBTYPE_OPT),
+	FUSE_OPT_KEY("large_read",		KEY_KERN_OPT),
+	FUSE_OPT_KEY("blksize=",		KEY_KERN_OPT),
+	FUSE_OPT_KEY("default_permissions",	KEY_KERN_OPT),
+	FUSE_OPT_KEY("max_read=",		KEY_KERN_OPT),
+	FUSE_OPT_KEY("max_read=",		FUSE_OPT_KEY_KEEP),
+	FUSE_OPT_KEY("user=",			KEY_MTAB_OPT),
+	FUSE_OPT_KEY("-r",			KEY_RO),
+	FUSE_OPT_KEY("ro",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("rw",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("suid",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("nosuid",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("dev",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("nodev",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("exec",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("noexec",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("async",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("sync",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("dirsync",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("atime",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("noatime",			KEY_KERN_FLAG),
+	FUSE_OPT_KEY("-h",			KEY_HELP),
+	FUSE_OPT_KEY("--help",			KEY_HELP),
+	FUSE_OPT_KEY("-V",			KEY_VERSION),
+	FUSE_OPT_KEY("--version",		KEY_VERSION),
+	FUSE_OPT_END
+};
+
+static void mount_help(void)
+{
+	fprintf(stderr,
+"    -o allow_other         allow access to other users\n"
+"    -o allow_root          allow access to root\n"
+"    -o nonempty            allow mounts over non-empty file/dir\n"
+"    -o default_permissions enable permission checking by kernel\n"
+"    -o fsname=NAME         set filesystem name\n"
+"    -o subtype=NAME        set filesystem type\n"
+"    -o large_read          issue large read requests (2.4 only)\n"
+"    -o max_read=N          set maximum size of read requests\n"
+"\n");
+}
+
+#define FUSERMOUNT_DIR "/usr/bin"
+
+static void exec_fusermount(const char *argv[])
+{
+	execv(FUSERMOUNT_DIR "/" FUSERMOUNT_PROG, (char **) argv);
+	execvp(FUSERMOUNT_PROG, (char **) argv);
+}
+
+static void mount_version(void)
+{
+	int pid = fork();
+	if (!pid) {
+		const char *argv[] = { FUSERMOUNT_PROG, "--version", NULL };
+		exec_fusermount(argv);
+		_exit(1);
+	} else if (pid != -1)
+		waitpid(pid, NULL, 0);
+}
+
+struct mount_flags {
+	const char *opt;
+	unsigned long flag;
+	int on;
+};
+
+static struct mount_flags mount_flags[] = {
+	{"rw",	    MS_RDONLY,	    0},
+	{"ro",	    MS_RDONLY,	    1},
+	{"suid",    MS_NOSUID,	    0},
+	{"nosuid",  MS_NOSUID,	    1},
+	{"dev",	    MS_NODEV,	    0},
+	{"nodev",   MS_NODEV,	    1},
+	{"exec",    MS_NOEXEC,	    0},
+	{"noexec",  MS_NOEXEC,	    1},
+	{"async",   MS_SYNCHRONOUS, 0},
+	{"sync",    MS_SYNCHRONOUS, 1},
+	{"atime",   MS_NOATIME,	    0},
+	{"noatime", MS_NOATIME,	    1},
+	{"dirsync", MS_DIRSYNC,	    1},
+	{NULL,	    0,		    0}
+};
+
+static void set_mount_flag(const char *s, int *flags)
+{
+	int i;
+
+	for (i = 0; mount_flags[i].opt != NULL; i++) {
+		const char *opt = mount_flags[i].opt;
+		if (strcmp(opt, s) == 0) {
+			if (mount_flags[i].on)
+				*flags |= mount_flags[i].flag;
+			else
+				*flags &= ~mount_flags[i].flag;
+			return;
+		}
+	}
+	fprintf(stderr, "fuse: internal error, can't find mount flag\n");
+	abort();
+}
+
+static int fuse_mount_opt_proc(void *data, const char *arg, int key,
+			       struct fuse_args *outargs)
+{
+	struct mount_opts *mo = data;
+
+	switch (key) {
+	case KEY_ALLOW_ROOT:
+		if (fuse_opt_add_opt(&mo->kernel_opts, "allow_other") == -1 ||
+		    fuse_opt_add_arg(outargs, "-oallow_root") == -1)
+			return -1;
+		return 0;
+
+	case KEY_RO:
+		arg = "ro";
+		/* fall through */
+	case KEY_KERN_FLAG:
+		set_mount_flag(arg, &mo->flags);
+		return 0;
+
+	case KEY_KERN_OPT:
+		return fuse_opt_add_opt(&mo->kernel_opts, arg);
+
+	case KEY_FUSERMOUNT_OPT:
+		return fuse_opt_add_opt_escaped(&mo->fusermount_opts, arg);
+
+	case KEY_SUBTYPE_OPT:
+		return fuse_opt_add_opt(&mo->subtype_opt, arg);
+
+	case KEY_MTAB_OPT:
+		return fuse_opt_add_opt(&mo->mtab_opts, arg);
+
+	case KEY_HELP:
+		mount_help();
+		mo->ishelp = 1;
+		break;
+
+	case KEY_VERSION:
+		mount_version();
+		mo->ishelp = 1;
+		break;
+	}
+	return 1;
+}
+
+/* return value:
+ * >= 0	 => fd
+ * -1	 => error
+ */
+static int receive_fd(int fd)
+{
+	struct msghdr msg;
+	struct iovec iov;
+	char buf[1];
+	int rv;
+	size_t ccmsg[CMSG_SPACE(sizeof(int)) / sizeof(size_t)];
+	struct cmsghdr *cmsg;
+
+	iov.iov_base = buf;
+	iov.iov_len = 1;
+
+	msg.msg_name = 0;
+	msg.msg_namelen = 0;
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+	/* old BSD implementations should use msg_accrights instead of
+	 * msg_control; the interface is different. */
+	msg.msg_control = ccmsg;
+	msg.msg_controllen = sizeof(ccmsg);
+
+	while(((rv = recvmsg(fd, &msg, 0)) == -1) && errno == EINTR);
+	if (rv == -1) {
+		perror("recvmsg");
+		return -1;
+	}
+	if(!rv) {
+		/* EOF */
+		return -1;
+	}
+
+	cmsg = CMSG_FIRSTHDR(&msg);
+	if (!cmsg->cmsg_type == SCM_RIGHTS) {
+		fprintf(stderr, "got control message of unknown type %d\n",
+			cmsg->cmsg_type);
+		return -1;
+	}
+	return *(int*)CMSG_DATA(cmsg);
+}
+
+void fuse_kern_unmount(const char *mountpoint, int fd)
+{
+	int res;
+	int pid;
+
+	if (!mountpoint)
+		return;
+
+	if (fd != -1) {
+		struct pollfd pfd;
+
+		pfd.fd = fd;
+		pfd.events = 0;
+		res = poll(&pfd, 1, 0);
+		/* If file poll returns POLLERR on the device file descriptor,
+		   then the filesystem is already unmounted */
+		if (res == 1 && (pfd.revents & POLLERR))
+			return;
+
+		/* Need to close file descriptor, otherwise synchronous umount
+		   would recurse into filesystem, and deadlock */
+		close(fd);
+	}
+
+	if (geteuid() == 0) {
+		fuse_mnt_umount("fuse", mountpoint, mountpoint,  1);
+		return;
+	}
+
+	res = umount2(mountpoint, 2);
+	if (res == 0)
+		return;
+
+	pid = fork();
+	if(pid == -1)
+		return;
+
+	if(pid == 0) {
+		const char *argv[] = { FUSERMOUNT_PROG, "-u", "-q", "-z",
+				       "--", mountpoint, NULL };
+
+		exec_fusermount(argv);
+		_exit(1);
+	}
+	waitpid(pid, NULL, 0);
+}
+
+void fuse_unmount_compat22(const char *mountpoint)
+{
+	fuse_kern_unmount(mountpoint, -1);
+}
+
+static int fuse_mount_fusermount(const char *mountpoint, const char *opts,
+				 int quiet)
+{
+	int fds[2], pid;
+	int res;
+	int rv;
+
+	if (!mountpoint) {
+		fprintf(stderr, "fuse: missing mountpoint parameter\n");
+		return -1;
+	}
+
+	res = socketpair(PF_UNIX, SOCK_STREAM, 0, fds);
+	if(res == -1) {
+		perror("fuse: socketpair() failed");
+		return -1;
+	}
+
+	pid = fork();
+	if(pid == -1) {
+		perror("fuse: fork() failed");
+		close(fds[0]);
+		close(fds[1]);
+		return -1;
+	}
+
+	if(pid == 0) {
+		char env[10];
+		const char *argv[32];
+		int a = 0;
+
+		if (quiet) {
+			int fd = open("/dev/null", O_RDONLY);
+			dup2(fd, 1);
+			dup2(fd, 2);
+		}
+
+		argv[a++] = FUSERMOUNT_PROG;
+		if (opts) {
+			argv[a++] = "-o";
+			argv[a++] = opts;
+		}
+		argv[a++] = "--";
+		argv[a++] = mountpoint;
+		argv[a++] = NULL;
+
+		close(fds[1]);
+		fcntl(fds[0], F_SETFD, 0);
+		snprintf(env, sizeof(env), "%i", fds[0]);
+		setenv(FUSE_COMMFD_ENV, env, 1);
+		exec_fusermount(argv);
+		perror("fuse: failed to exec fusermount");
+		_exit(1);
+	}
+
+	close(fds[0]);
+	rv = receive_fd(fds[1]);
+	close(fds[1]);
+	waitpid(pid, NULL, 0); /* bury zombie */
+
+	return rv;
+}
+
+int fuse_mount_compat22(const char *mountpoint, const char *opts)
+{
+	return fuse_mount_fusermount(mountpoint, opts, 0);
+}
+
+static int fuse_mount_sys(const char *mnt, struct mount_opts *mo,
+			  const char *mnt_opts)
+{
+	char tmp[128];
+	const char *devname = "/dev/fuse";
+	char *source = NULL;
+	char *type = NULL;
+	struct stat stbuf;
+	int fd;
+	int res;
+
+	if (!mnt) {
+		fprintf(stderr, "fuse: missing mountpoint parameter\n");
+		return -1;
+	}
+
+	res = stat(mnt, &stbuf);
+	if (res == -1) {
+		fprintf(stderr ,"fuse: failed to access mountpoint %s: %s\n",
+			mnt, strerror(errno));
+		return -1;
+	}
+
+	if (!mo->nonempty) {
+		res = fuse_mnt_check_empty("fuse", mnt, stbuf.st_mode,
+					   stbuf.st_size);
+		if (res == -1)
+			return -1;
+	}
+
+	fd = open(devname, O_RDWR);
+	if (fd == -1) {
+		if (errno == ENODEV || errno == ENOENT)
+			fprintf(stderr, "fuse: device not found, try 'modprobe fuse' first\n");
+		else
+			fprintf(stderr, "fuse: failed to open %s: %s\n",
+				devname, strerror(errno));
+		return -1;
+	}
+
+	snprintf(tmp, sizeof(tmp),  "fd=%i,rootmode=%o,user_id=%i,group_id=%i",
+		 fd, stbuf.st_mode & S_IFMT, getuid(), getgid());
+
+	res = fuse_opt_add_opt(&mo->kernel_opts, tmp);
+	if (res == -1)
+		goto out_close;
+
+	source = malloc((mo->fsname ? strlen(mo->fsname) : 0) +
+			(mo->subtype ? strlen(mo->subtype) : 0) +
+			strlen(devname) + 32);
+
+	type = malloc((mo->subtype ? strlen(mo->subtype) : 0) + 32);
+	if (!type || !source) {
+		fprintf(stderr, "fuse: failed to allocate memory\n");
+		goto out_close;
+	}
+
+	strcpy(type, mo->blkdev ? "fuseblk" : "fuse");
+	if (mo->subtype) {
+		strcat(type, ".");
+		strcat(type, mo->subtype);
+	}
+	strcpy(source,
+	       mo->fsname ? mo->fsname : (mo->subtype ? mo->subtype : devname));
+
+	res = mount(source, mnt, type, mo->flags, mo->kernel_opts);
+	if (res == -1 && errno == ENODEV && mo->subtype) {
+		/* Probably missing subtype support */
+		strcpy(type, mo->blkdev ? "fuseblk" : "fuse");
+		if (mo->fsname) {
+			if (!mo->blkdev)
+				sprintf(source, "%s#%s", mo->subtype,
+					mo->fsname);
+		} else {
+			strcpy(source, type);
+		}
+		res = mount(source, mnt, type, mo->flags, mo->kernel_opts);
+	}
+	if (res == -1) {
+		/*
+		 * Maybe kernel doesn't support unprivileged mounts, in this
+		 * case try falling back to fusermount
+		 */
+		if (errno == EPERM) {
+			res = -2;
+		} else {
+			int errno_save = errno;
+			if (mo->blkdev && errno == ENODEV &&
+			    !fuse_mnt_check_fuseblk())
+				fprintf(stderr,
+					"fuse: 'fuseblk' support missing\n");
+			else
+				fprintf(stderr, "fuse: mount failed: %s\n",
+					strerror(errno_save));
+		}
+
+		goto out_close;
+	}
+
+	if (geteuid() == 0) {
+		char *newmnt = fuse_mnt_resolve_path("fuse", mnt);
+		res = -1;
+		if (!newmnt)
+			goto out_umount;
+
+		res = fuse_mnt_add_mount("fuse", source, newmnt, type,
+					 mnt_opts);
+		free(newmnt);
+		if (res == -1)
+			goto out_umount;
+	}
+	free(type);
+	free(source);
+
+	return fd;
+
+out_umount:
+	umount2(mnt, 2); /* lazy umount */
+out_close:
+	free(type);
+	free(source);
+	close(fd);
+	return res;
+}
+
+static int get_mnt_flag_opts(char **mnt_optsp, int flags)
+{
+	int i;
+
+	if (!(flags & MS_RDONLY) && fuse_opt_add_opt(mnt_optsp, "rw") == -1)
+		return -1;
+
+	for (i = 0; mount_flags[i].opt != NULL; i++) {
+		if (mount_flags[i].on && (flags & mount_flags[i].flag) &&
+		    fuse_opt_add_opt(mnt_optsp, mount_flags[i].opt) == -1)
+			return -1;
+	}
+	return 0;
+}
+
+int fuse_kern_mount(const char *mountpoint, struct fuse_args *args)
+{
+	struct mount_opts mo;
+	int res = -1;
+	char *mnt_opts = NULL;
+
+	memset(&mo, 0, sizeof(mo));
+	mo.flags = MS_NOSUID | MS_NODEV;
+
+	if (args &&
+	    fuse_opt_parse(args, &mo, fuse_mount_opts, fuse_mount_opt_proc) == -1)
+		return -1;
+
+	if (mo.allow_other && mo.allow_root) {
+		fprintf(stderr, "fuse: 'allow_other' and 'allow_root' options are mutually exclusive\n");
+		goto out;
+	}
+	res = 0;
+	if (mo.ishelp)
+		goto out;
+
+	res = -1;
+	if (get_mnt_flag_opts(&mnt_opts, mo.flags) == -1)
+		goto out;
+	if (mo.kernel_opts && fuse_opt_add_opt(&mnt_opts, mo.kernel_opts) == -1)
+		goto out;
+	if (mo.mtab_opts &&  fuse_opt_add_opt(&mnt_opts, mo.mtab_opts) == -1)
+		goto out;
+
+	res = fuse_mount_sys(mountpoint, &mo, mnt_opts);
+	if (res == -2) {
+		if (mo.fusermount_opts &&
+		    fuse_opt_add_opt(&mnt_opts, mo.fusermount_opts) == -1)
+			goto out;
+
+		if (mo.subtype) {
+			char *tmp_opts = NULL;
+
+			res = -1;
+			if (fuse_opt_add_opt(&tmp_opts, mnt_opts) == -1 ||
+			    fuse_opt_add_opt(&tmp_opts, mo.subtype_opt) == -1) {
+				free(tmp_opts);
+				goto out;
+			}
+
+			res = fuse_mount_fusermount(mountpoint, tmp_opts, 1);
+			free(tmp_opts);
+			if (res == -1)
+				res = fuse_mount_fusermount(mountpoint,
+							    mnt_opts, 0);
+		} else {
+			res = fuse_mount_fusermount(mountpoint, mnt_opts, 0);
+		}
+	}
+out:
+	free(mnt_opts);
+	free(mo.fsname);
+	free(mo.subtype);
+	free(mo.fusermount_opts);
+	free(mo.subtype_opt);
+	free(mo.kernel_opts);
+	free(mo.mtab_opts);
+	return res;
+}
+
+FUSE_SYMVER(".symver fuse_mount_compat22,fuse_mount@FUSE_2.2");
+FUSE_SYMVER(".symver fuse_unmount_compat22,fuse_unmount@FUSE_2.2");