| yuezonghe | 824eb0c | 2024-06-27 02:32:26 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * mountopts.c --- convert between default mount options and strings |
| 3 | * |
| 4 | * Copyright (C) 2002 Theodore Ts'o <tytso@mit.edu> |
| 5 | * |
| 6 | * %Begin-Header% |
| 7 | * This file may be redistributed under the terms of the GNU Library |
| 8 | * General Public License, version 2. |
| 9 | * %End-Header% |
| 10 | */ |
| 11 | |
| 12 | #include "config.h" |
| 13 | #include <stdio.h> |
| 14 | #include <stdlib.h> |
| 15 | #include <string.h> |
| 16 | #include <ctype.h> |
| 17 | #include <errno.h> |
| 18 | |
| 19 | #include "e2p.h" |
| 20 | |
| 21 | struct mntopt { |
| 22 | unsigned int mask; |
| 23 | const char *string; |
| 24 | }; |
| 25 | |
| 26 | static struct mntopt mntopt_list[] = { |
| 27 | { EXT2_DEFM_DEBUG, "debug" }, |
| 28 | { EXT2_DEFM_BSDGROUPS, "bsdgroups" }, |
| 29 | { EXT2_DEFM_XATTR_USER, "user_xattr" }, |
| 30 | { EXT2_DEFM_ACL, "acl" }, |
| 31 | { EXT2_DEFM_UID16, "uid16" }, |
| 32 | { EXT3_DEFM_JMODE_DATA, "journal_data" }, |
| 33 | { EXT3_DEFM_JMODE_ORDERED, "journal_data_ordered" }, |
| 34 | { EXT3_DEFM_JMODE_WBACK, "journal_data_writeback" }, |
| 35 | { EXT4_DEFM_NOBARRIER, "nobarrier" }, |
| 36 | { EXT4_DEFM_BLOCK_VALIDITY, "block_validity" }, |
| 37 | { EXT4_DEFM_DISCARD, "discard"}, |
| 38 | { EXT4_DEFM_NODELALLOC, "nodelalloc"}, |
| 39 | { 0, 0 }, |
| 40 | }; |
| 41 | |
| 42 | const char *e2p_mntopt2string(unsigned int mask) |
| 43 | { |
| 44 | struct mntopt *f; |
| 45 | static char buf[20]; |
| 46 | int fnum; |
| 47 | |
| 48 | for (f = mntopt_list; f->string; f++) { |
| 49 | if (mask == f->mask) |
| 50 | return f->string; |
| 51 | } |
| 52 | for (fnum = 0; mask >>= 1; fnum++); |
| 53 | sprintf(buf, "MNTOPT_%d", fnum); |
| 54 | return buf; |
| 55 | } |
| 56 | |
| 57 | int e2p_string2mntopt(char *string, unsigned int *mask) |
| 58 | { |
| 59 | struct mntopt *f; |
| 60 | char *eptr; |
| 61 | int num; |
| 62 | |
| 63 | for (f = mntopt_list; f->string; f++) { |
| 64 | if (!strcasecmp(string, f->string)) { |
| 65 | *mask = f->mask; |
| 66 | return 0; |
| 67 | } |
| 68 | } |
| 69 | if (strncasecmp(string, "MNTOPT_", 7)) |
| 70 | return 1; |
| 71 | |
| 72 | if (string[8] == 0) |
| 73 | return 1; |
| 74 | num = strtol(string+8, &eptr, 10); |
| 75 | if (num > 32 || num < 0) |
| 76 | return 1; |
| 77 | if (*eptr) |
| 78 | return 1; |
| 79 | *mask = 1 << num; |
| 80 | return 0; |
| 81 | } |
| 82 | |
| 83 | static char *skip_over_blanks(char *cp) |
| 84 | { |
| 85 | while (*cp && isspace(*cp)) |
| 86 | cp++; |
| 87 | return cp; |
| 88 | } |
| 89 | |
| 90 | static char *skip_over_word(char *cp) |
| 91 | { |
| 92 | while (*cp && !isspace(*cp) && *cp != ',') |
| 93 | cp++; |
| 94 | return cp; |
| 95 | } |
| 96 | |
| 97 | /* |
| 98 | * Edit a mntopt set array as requested by the user. The ok |
| 99 | * parameter, if non-zero, allows the application to limit what |
| 100 | * mntopts the user is allowed to set or clear using this function. |
| 101 | */ |
| 102 | int e2p_edit_mntopts(const char *str, __u32 *mntopts, __u32 ok) |
| 103 | { |
| 104 | char *cp, *buf, *next; |
| 105 | int neg; |
| 106 | unsigned int mask; |
| 107 | int rc = 0; |
| 108 | |
| 109 | buf = malloc(strlen(str)+1); |
| 110 | if (!buf) |
| 111 | return 1; |
| 112 | strcpy(buf, str); |
| 113 | cp = buf; |
| 114 | while (cp && *cp) { |
| 115 | neg = 0; |
| 116 | cp = skip_over_blanks(cp); |
| 117 | next = skip_over_word(cp); |
| 118 | if (*next == 0) |
| 119 | next = 0; |
| 120 | else |
| 121 | *next = 0; |
| 122 | switch (*cp) { |
| 123 | case '-': |
| 124 | case '^': |
| 125 | neg++; |
| 126 | /* fallthrough */ |
| 127 | case '+': |
| 128 | cp++; |
| 129 | break; |
| 130 | } |
| 131 | if (e2p_string2mntopt(cp, &mask)) { |
| 132 | rc = 1; |
| 133 | break; |
| 134 | } |
| 135 | if (ok && !(ok & mask)) { |
| 136 | rc = 1; |
| 137 | break; |
| 138 | } |
| 139 | if (mask & EXT3_DEFM_JMODE) |
| 140 | *mntopts &= ~EXT3_DEFM_JMODE; |
| 141 | if (neg) |
| 142 | *mntopts &= ~mask; |
| 143 | else |
| 144 | *mntopts |= mask; |
| 145 | cp = next ? next+1 : 0; |
| 146 | } |
| 147 | free(buf); |
| 148 | return rc; |
| 149 | } |