| /* vi: set sw=4 ts=4: */ |
| /* |
| * Mini mount implementation for busybox |
| * |
| * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>. |
| * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> |
| * Copyright (C) 2005 by Rob Landley <rob@landley.net> |
| * |
| * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. |
| */ |
| |
| #include <limits.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <errno.h> |
| #include <string.h> |
| #include <stdio.h> |
| #include <mntent.h> |
| #include <ctype.h> |
| #include <sys/mount.h> |
| #include <fcntl.h> // for CONFIG_FEATURE_MOUNT_LOOP |
| #include <sys/ioctl.h> // for CONFIG_FEATURE_MOUNT_LOOP |
| #include "busybox.h" |
| |
| // These two aren't always defined in old headers |
| #ifndef MS_BIND |
| #define MS_BIND 4096 |
| #endif |
| #ifndef MS_MOVE |
| #define MS_MOVE 8192 |
| #endif |
| |
| /* Consume standard mount options (from -o options or --options). |
| * Set appropriate flags and collect unrecognized ones as a comma separated |
| * string to pass to kernel */ |
| |
| struct { |
| const char *name; |
| long flags; |
| } static const mount_options[] = { |
| {"loop", 0}, |
| {"defaults", 0}, |
| {"noauto", 0}, |
| {"ro", MS_RDONLY}, |
| {"rw", ~MS_RDONLY}, |
| {"nosuid", MS_NOSUID}, |
| {"suid", ~MS_NOSUID}, |
| {"dev", ~MS_NODEV}, |
| {"nodev", MS_NODEV}, |
| {"exec", ~MS_NOEXEC}, |
| {"noexec", MS_NOEXEC}, |
| {"sync", MS_SYNCHRONOUS}, |
| {"async", ~MS_SYNCHRONOUS}, |
| {"remount", MS_REMOUNT}, |
| {"atime", ~MS_NOATIME}, |
| {"noatime", MS_NOATIME}, |
| {"diratime", ~MS_NODIRATIME}, |
| {"nodiratime", MS_NODIRATIME}, |
| {"bind", MS_BIND}, |
| {"move", MS_MOVE} |
| }; |
| |
| /* Uses the mount_options list above */ |
| static void parse_mount_options(char *options, int *flags, char **strflags) |
| { |
| // Loop through options |
| for(;;) { |
| int i; |
| char *comma = strchr(options, ','); |
| |
| if(comma) *comma = 0; |
| |
| // Find this option in mount_options |
| for(i = 0; i < (sizeof(mount_options) / sizeof(*mount_options)); i++) { |
| if(!strcasecmp(mount_options[i].name, options)) { |
| long fl = mount_options[i].flags; |
| if(fl < 0) *flags &= fl; |
| else *flags |= fl; |
| break; |
| } |
| } |
| // Unrecognized mount option? |
| if(i == (sizeof(mount_options) / sizeof(*mount_options))) { |
| // Add it to strflags, to pass on to kernel |
| i = *strflags ? strlen(*strflags) : 0; |
| *strflags = xrealloc(*strflags, i+strlen(options)+2); |
| // Comma separated if it's not the first one |
| if(i) (*strflags)[i++] = ','; |
| strcpy((*strflags)+i, options); |
| } |
| // Advance to next option, or finish |
| if(comma) { |
| *comma = ','; |
| options = ++comma; |
| } else break; |
| } |
| } |
| |
| /* This does the work */ |
| |
| extern int mount_main(int argc, char **argv) |
| { |
| char *string_flags = 0, *fsType = 0, *blockDevice = 0, *directory = 0, |
| *loopFile = 0, *buf = 0, |
| *files[] = {"/etc/filesystems", "/proc/filesystems", 0}; |
| int i, opt, all = FALSE, fakeIt = FALSE, allowWrite = FALSE, |
| rc = 1, useMtab = ENABLE_FEATURE_MTAB_SUPPORT; |
| int flags=0xc0ed0000; // Needed for linux 2.2, ignored by 2.4 and 2.6. |
| FILE *file = 0,*f = 0; |
| char path[PATH_MAX*2]; |
| struct mntent m; |
| struct stat statbuf; |
| |
| /* parse long options, like --bind and --move. Note that -o option |
| * and --option are synonymous. Yes, this means --remount,rw works. */ |
| |
| for(i = opt = 0; i < argc; i++) { |
| if(argv[i][0] == '-' && argv[i][1] == '-') |
| parse_mount_options(argv[i]+2, &flags, &string_flags); |
| else argv[opt++] = argv[i]; |
| } |
| argc = opt; |
| |
| // Parse remaining options |
| |
| while((opt = getopt(argc, argv, "o:t:rwafnv")) > 0) { |
| switch (opt) { |
| case 'o': |
| parse_mount_options(optarg, &flags, &string_flags); |
| break; |
| case 't': |
| fsType = optarg; |
| break; |
| case 'r': |
| flags |= MS_RDONLY; |
| break; |
| case 'w': |
| allowWrite=TRUE; |
| break; |
| case 'a': |
| all = TRUE; |
| break; |
| case 'f': |
| fakeIt = TRUE; |
| break; |
| case 'n': |
| useMtab = FALSE; |
| break; |
| case 'v': |
| break; // ignore -v |
| default: |
| bb_show_usage(); |
| } |
| } |
| |
| // If we have no arguments, show currently mounted filesystems |
| |
| if(!all && (optind == argc)) { |
| FILE *mountTable = setmntent(bb_path_mtab_file, "r"); |
| |
| if(!mountTable) bb_perror_msg_and_die(bb_path_mtab_file); |
| |
| while (getmntent_r(mountTable,&m,path,sizeof(path))) { |
| blockDevice = m.mnt_fsname; |
| |
| // Clean up display a little bit regarding root device |
| if(!strcmp(blockDevice, "rootfs")) continue; |
| if(!strcmp(blockDevice, "/dev/root")) |
| blockDevice = find_block_device("/"); |
| |
| if(!fsType || !strcmp(m.mnt_type, fsType)) |
| printf("%s on %s type %s (%s)\n", blockDevice, m.mnt_dir, |
| m.mnt_type, m.mnt_opts); |
| if(ENABLE_FEATURE_CLEAN_UP && blockDevice != m.mnt_fsname) |
| free(blockDevice); |
| } |
| endmntent(mountTable); |
| return EXIT_SUCCESS; |
| } |
| |
| /* The next argument is what to mount. if there's an argument after that |
| * it's where to mount it. If we're not mounting all, and we have both |
| * of these arguments, jump straight to the actual mount. */ |
| |
| statbuf.st_mode=0; |
| if(optind < argc) |
| blockDevice = !stat(argv[optind], &statbuf) ? |
| bb_simplify_path(argv[optind]) : |
| (ENABLE_FEATURE_CLEAN_UP ? strdup(argv[optind]) : argv[optind]); |
| if(optind+1 < argc) directory = bb_simplify_path(argv[optind+1]); |
| |
| // If we don't have to loop through fstab, skip ahead a bit. |
| |
| if(!all && optind+1!=argc) goto singlemount; |
| |
| // Loop through /etc/fstab entries to look up this entry. |
| |
| if(!(file=setmntent("/etc/fstab","r"))) |
| bb_perror_msg_and_die("\nCannot read /etc/fstab"); |
| for(;;) { |
| |
| // Get next fstab entry |
| |
| if(!getmntent_r(file,&m,path,sizeof(path))) { |
| if(!all) |
| bb_perror_msg("Can't find %s in /etc/fstab\n", blockDevice); |
| break; |
| } |
| |
| // If we're mounting all and all doesn't mount this one, skip it. |
| |
| if(all) { |
| if(strstr(m.mnt_opts,"noauto") || strstr(m.mnt_type,"swap")) |
| continue; |
| flags=0; |
| |
| /* If we're mounting something specific and this isn't it, skip it. |
| * Note we must match both the exact text in fstab (ala "proc") or |
| * a full path from root */ |
| |
| } else if(strcmp(blockDevice,m.mnt_fsname) && |
| strcmp(argv[optind],m.mnt_fsname) && |
| strcmp(blockDevice,m.mnt_dir) && |
| strcmp(argv[optind],m.mnt_dir)) continue; |
| |
| /* Parse flags from /etc/fstab (unless this is a single mount |
| * overriding fstab -- note the "all" test above zeroed the flags, |
| * to prevent flags from previous entries affecting this one, so |
| * the only way we could get here with nonzero flags is a single |
| * mount). */ |
| |
| if(!flags) { |
| if(ENABLE_FEATURE_CLEAN_UP) free(string_flags); |
| string_flags=NULL; |
| parse_mount_options(m.mnt_opts, &flags, &string_flags); |
| } |
| |
| /* Fill out remaining fields with info from mtab */ |
| |
| if(ENABLE_FEATURE_CLEAN_UP) { |
| free(blockDevice); |
| blockDevice=strdup(m.mnt_fsname); |
| free(directory); |
| directory=strdup(m.mnt_dir); |
| } else { |
| blockDevice=m.mnt_fsname; |
| directory=m.mnt_dir; |
| } |
| fsType=m.mnt_type; |
| |
| /* Ok, we're ready to actually mount a specific source on a specific |
| * directory now. */ |
| |
| singlemount: |
| |
| // If they said -w, override fstab |
| |
| if(allowWrite) flags&=~MS_RDONLY; |
| |
| // Might this be an NFS filesystem? |
| |
| if(ENABLE_FEATURE_MOUNT_NFS && (!fsType || !strcmp(fsType,"nfs")) && |
| strchr(blockDevice, ':') != NULL) |
| { |
| if(nfsmount(blockDevice, directory, &flags, &string_flags, 1)) |
| bb_perror_msg("nfsmount failed"); |
| else { |
| rc = 0; |
| fsType="nfs"; |
| // Strangely enough, nfsmount() doesn't actually mount() |
| goto mount_it_now; |
| } |
| } else { |
| |
| // Do we need to allocate a loopback device? |
| |
| if(ENABLE_FEATURE_MOUNT_LOOP && !fakeIt && S_ISREG(statbuf.st_mode)) |
| { |
| loopFile = blockDevice; |
| blockDevice = 0; |
| switch(set_loop(&blockDevice, loopFile, 0)) { |
| case 0: |
| case 1: |
| break; |
| default: |
| bb_error_msg_and_die( |
| errno == EPERM || errno == EACCES ? |
| bb_msg_perm_denied_are_you_root : |
| "Couldn't setup loop device"); |
| break; |
| } |
| } |
| |
| /* If we know the fstype (or don't need to), jump straight |
| * to the actual mount. */ |
| |
| if(fsType || (flags & (MS_REMOUNT | MS_BIND | MS_MOVE))) |
| goto mount_it_now; |
| } |
| |
| // Loop through filesystem types until mount succeeds or we run out |
| |
| for(i = 0; files[i] && rc; i++) { |
| f = fopen(files[i], "r"); |
| if(!f) continue; |
| // Get next block device backed filesystem |
| for(buf = 0; (buf = fsType = bb_get_chomped_line_from_file(f)); |
| free(buf)) |
| { |
| // Skip funky entries in /proc |
| if(!strncmp(buf,"nodev",5) && isspace(buf[5])) continue; |
| |
| while(isspace(*fsType)) fsType++; |
| if(*buf=='#' || *buf=='*') continue; |
| if(!*fsType) continue; |
| mount_it_now: |
| // Okay, try to mount |
| |
| if (!fakeIt) { |
| for(;;) { |
| rc = mount(blockDevice, directory, fsType, flags, string_flags); |
| if(!rc || (flags&MS_RDONLY) || (errno!=EACCES && errno!=EROFS)) |
| break; |
| bb_error_msg("%s is write-protected, mounting read-only", blockDevice); |
| flags|=MS_RDONLY; |
| } |
| } |
| if(!rc || !f) break; |
| } |
| if(!f) break; |
| fclose(f); |
| // goto mount_it_now with -a can jump past the initialization |
| f=0; |
| if(!rc) break; |
| } |
| |
| /* If the mount was successful, and we're maintaining an old-style |
| * mtab file by hand, add new entry to it now. */ |
| if((!rc || fakeIt) && useMtab) { |
| FILE *mountTable = setmntent(bb_path_mtab_file, "a+"); |
| |
| if(!mountTable) bb_perror_msg(bb_path_mtab_file); |
| else { |
| // Remove trailing / (if any) from directory we mounted on |
| int length=strlen(directory); |
| if(length>1 && directory[length-1] == '/') |
| directory[length-1]=0; |
| |
| // Fill out structure (should be ok to re-use existing one). |
| m.mnt_fsname=blockDevice; |
| m.mnt_dir=directory; |
| m.mnt_type=fsType ? : "--bind"; |
| m.mnt_opts=string_flags ? : |
| ((flags & MS_RDONLY) ? "ro" : "rw"); |
| m.mnt_freq = 0; |
| m.mnt_passno = 0; |
| |
| // Write and close |
| addmntent(mountTable, &m); |
| endmntent(mountTable); |
| } |
| } else { |
| // Mount failed. Clean up |
| if(loopFile) { |
| del_loop(blockDevice); |
| if(ENABLE_FEATURE_CLEAN_UP) free(loopFile); |
| } |
| // Don't whine about already mounted fs when mounting all. |
| if(rc<0 && errno == EBUSY && all) rc = 0; |
| else if (errno == EPERM) |
| bb_error_msg_and_die(bb_msg_perm_denied_are_you_root); |
| } |
| // We couldn't free this earlier becase fsType could be in buf. |
| if(ENABLE_FEATURE_CLEAN_UP) free(buf); |
| if(!all) break; |
| } |
| |
| if(file) endmntent(file); |
| if(rc) bb_perror_msg("Mounting %s on %s failed", blockDevice, directory); |
| if(ENABLE_FEATURE_CLEAN_UP) { |
| free(blockDevice); |
| free(directory); |
| } |
| |
| return rc; |
| } |