/* FUSE: Filesystem in Userspace Copyright (C) 2001-2007 Miklos Szeredi 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_opt.h" #include "mount_util.h" #include #include #include #include #include #include #include #include #include #include #include #include #ifdef __SOLARIS__ #define FUSERMOUNT_PROG "fusermount" #define FUSE_COMMFD_ENV "_FUSE_COMMFD" #ifndef FUSERMOUNT_DIR #define FUSERMOUNT_DIR "/usr" #endif /* FUSERMOUNT_DIR */ #ifndef HAVE_FORK #define fork() vfork() #endif #endif /* __SOLARIS__ */ #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; #ifdef __SOLARIS__ int nonempty; int blkdev; char *fsname; char *subtype; char *subtype_opt; #else int blkdev; char *fsname; #endif 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[] = { #ifdef __SOLARIS__ 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("-g", KEY_KERN_FLAG), FUSE_OPT_KEY("-m", KEY_KERN_FLAG), FUSE_OPT_KEY("-O", KEY_KERN_FLAG), FUSE_OPT_KEY("setuid", KEY_KERN_OPT), FUSE_OPT_KEY("nosetuid", KEY_KERN_OPT), FUSE_OPT_KEY("devices", KEY_KERN_OPT), FUSE_OPT_KEY("nodevices", KEY_KERN_OPT), FUSE_OPT_KEY("exec", KEY_KERN_OPT), FUSE_OPT_KEY("noexec", KEY_KERN_OPT), FUSE_OPT_KEY("nbmand", KEY_KERN_OPT), FUSE_OPT_KEY("nonbmand", KEY_KERN_OPT), #else /* __SOLARIS__ */ FUSE_MOUNT_OPT("allow_other", allow_other), FUSE_MOUNT_OPT("allow_root", allow_root), FUSE_MOUNT_OPT("blkdev", blkdev), FUSE_MOUNT_OPT("fsname=%s", fsname), FUSE_OPT_KEY("allow_other", KEY_KERN_OPT), FUSE_OPT_KEY("allow_root", KEY_ALLOW_ROOT), FUSE_OPT_KEY("blkdev", KEY_FUSERMOUNT_OPT), FUSE_OPT_KEY("fsname=", KEY_FUSERMOUNT_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("context=", 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), #endif /* __SOLARIS__ */ 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 }; #ifdef __SOLARIS__ 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" ); } 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); } #endif /* __SOLARIS__ */ 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}, #ifndef __SOLARIS__ {"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}, #else /* __SOLARIS__ */ {"-g", MS_GLOBAL, 1}, /* 1eaf4 */ {"-m", MS_NOMNTTAB, 1}, /* 1eb00 */ {"-O", MS_OVERLAY, 1}, /* 1eb0c */ #endif /* __SOLARIS__ */ {NULL, 0, 0} }; #ifdef __SOLARIS__ /* * See comments in fuse_kern_mount() */ struct solaris_mount_opts { int nosuid; int setuid; int nosetuid; int devices; int nodevices; }; #define SOLARIS_MOUNT_OPT(t, p, n) \ { t, offsetof(struct solaris_mount_opts, p), n } static const struct fuse_opt solaris_mnt_opts[] = { SOLARIS_MOUNT_OPT("suid", setuid, 1), SOLARIS_MOUNT_OPT("suid", devices, 1), SOLARIS_MOUNT_OPT("nosuid", nosuid, 1), SOLARIS_MOUNT_OPT("setuid", setuid, 1), SOLARIS_MOUNT_OPT("nosetuid", nosetuid, 1), SOLARIS_MOUNT_OPT("devices", devices, 1), SOLARIS_MOUNT_OPT("nodevices", nodevices, 1), FUSE_OPT_END }; #endif /* __SOLARIS__ */ 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(&mo->fusermount_opts, arg); #ifdef __SOLARIS__ case KEY_SUBTYPE_OPT: return fuse_opt_add_opt(&mo->subtype_opt, arg); #endif /* __SOLARIS__ */ case KEY_MTAB_OPT: return fuse_opt_add_opt(&mo->mtab_opts, arg); case KEY_HELP: #ifdef __SOLARIS__ mount_help(); #endif /* __SOLARIS__ */ mo->ishelp = 1; break; case KEY_VERSION: #ifdef __SOLARIS__ mount_version(); #endif /* __SOLARIS__ */ mo->ishelp = 1; break; } return 1; } #ifdef __SOLARIS__ /* 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); } #endif /* __SOLARIS__ */ void fuse_kern_unmount(const char *mountpoint, int fd) { int res; #ifdef __SOLARIS__ int pid; #endif /* __SOLARIS__ */ 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); } #ifndef __SOLARIS__ fusermount(1, 0, 1, "", mountpoint); #else /* __SOLARIS__ */ if (geteuid() == 0) { fuse_mnt_umount("fuse", 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); #endif /* __SOLARIS__ */ } #ifdef __SOLARIS__ 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\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; } 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\n"); return -1; } res = lstat(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)); /* JPA added two final zeroes */ res = mount(source, mnt, MS_OPTIONSTR|mo->flags, type, NULL, 0, mo->kernel_opts, MAX_MNTOPT_STR, 0, 0); if (res == -1 && errno == EINVAL && 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); } /* JPA two null args added */ res = mount(source, mnt, MS_OPTIONSTR|mo->flags, type, NULL, 0, mo->kernel_opts, MAX_MNTOPT_STR, 0, 0); } 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; } return fd; out_umount: umount2(mnt, 2); /* lazy umount */ out_close: free(type); free(source); close(fd); return res; } #endif /* __SOLARIS__ */ 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; #ifdef __SOLARIS__ struct solaris_mount_opts smo; struct fuse_args sa = FUSE_ARGS_INIT(0, NULL); #endif /* __SOLARIS__ */ memset(&mo, 0, sizeof(mo)); #ifndef __SOLARIS__ if (getuid()) mo.flags = MS_NOSUID | MS_NODEV; #else /* __SOLARIS__ */ mo.flags = 0; memset(&smo, 0, sizeof(smo)); if (args != NULL) { while (args->argv[sa.argc] != NULL) fuse_opt_add_arg(&sa, args->argv[sa.argc]); } #endif /* __SOLARIS__ */ if (args && fuse_opt_parse(args, &mo, fuse_mount_opts, fuse_mount_opt_proc) == -1) #ifndef __SOLARIS__ return -1; #else /* __SOLARIS__ */ goto out; /* if SOLARIS, clean up 'sa' */ /* * In Solaris, nosuid is equivalent to nosetuid + nodevices. We only * have MS_NOSUID for mount flags (no MS_(NO)SETUID, etc.). But if * we set that as a default, it restricts specifying just nosetuid * or nodevices; there is no way for the user to specify setuid + * nodevices or vice-verse. So we parse the existing options, then * add restrictive defaults if needed. */ if (fuse_opt_parse(&sa, &smo, solaris_mnt_opts, NULL) == -1) goto out; if (smo.nosuid || (!smo.nodevices && !smo.devices && !smo.nosetuid && !smo.setuid)) { mo.flags |= MS_NOSUID; } else { /* * Defaults; if neither nodevices|devices,nosetuid|setuid has * been specified, add the default negative option string. If * both have been specified (i.e., -osuid,nosuid), leave them * alone; the last option will have precedence. */ if (!smo.nodevices && !smo.devices) if (fuse_opt_add_opt(&mo.kernel_opts, "nodevices") == -1) goto out; if (!smo.nosetuid && !smo.setuid) if (fuse_opt_add_opt(&mo.kernel_opts, "nosetuid") == -1) goto out; } #endif /* __SOLARIS__ */ 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; #ifndef __SOLARIS__ if (!(mo.flags & MS_NODEV) && fuse_opt_add_opt(&mnt_opts, "dev") == -1) goto out; if (!(mo.flags & MS_NOSUID) && fuse_opt_add_opt(&mnt_opts, "suid") == -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; if (mo.fusermount_opts && fuse_opt_add_opt(&mnt_opts, mo.fusermount_opts) < 0) goto out; res = fusermount(0, 0, 0, mnt_opts ? mnt_opts : "", mountpoint); #else /* __SOLARIS__ */ 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); } } #endif /* __SOLARIS__ */ out: free(mnt_opts); #ifdef __SOLARIS__ fuse_opt_free_args(&sa); free(mo.subtype); free(mo.subtype_opt); #endif /* __SOLARIS__ */ free(mo.fsname); free(mo.fusermount_opts); free(mo.kernel_opts); free(mo.mtab_opts); return res; }