/* * mountopts.c --- convert between default mount options and strings * * Copyright (C) 2002 Theodore Ts'o <tytso@mit.edu> * * This file can be redistributed under the terms of the GNU Library General * Public License * */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <ctype.h> #include <errno.h> #include "e2p.h" struct mntopt { unsigned int mask; const char *string; }; static const struct mntopt mntopt_list[] = { { EXT2_DEFM_DEBUG, "debug" }, { EXT2_DEFM_BSDGROUPS, "bsdgroups" }, { EXT2_DEFM_XATTR_USER, "user_xattr" }, { EXT2_DEFM_ACL, "acl" }, { EXT2_DEFM_UID16, "uid16" }, { EXT3_DEFM_JMODE_DATA, "journal_data" }, { EXT3_DEFM_JMODE_ORDERED, "journal_data_ordered" }, { EXT3_DEFM_JMODE_WBACK, "journal_data_writeback" }, { 0, 0 }, }; const char *e2p_mntopt2string(unsigned int mask) { const struct mntopt *f; static char buf[20]; int fnum; for (f = mntopt_list; f->string; f++) { if (mask == f->mask) return f->string; } for (fnum = 0; mask >>= 1; fnum++); sprintf(buf, "MNTOPT_%d", fnum); return buf; } int e2p_string2mntopt(char *string, unsigned int *mask) { const struct mntopt *f; char *eptr; int num; for (f = mntopt_list; f->string; f++) { if (!strcasecmp(string, f->string)) { *mask = f->mask; return 0; } } if (strncasecmp(string, "MNTOPT_", 8)) return 1; if (string[8] == 0) return 1; num = strtol(string+8, &eptr, 10); if (num > 32 || num < 0) return 1; if (*eptr) return 1; *mask = 1 << num; return 0; } static char *skip_over_blanks(char *cp) { while (*cp && isspace(*cp)) cp++; return cp; } static char *skip_over_word(char *cp) { while (*cp && !isspace(*cp) && *cp != ',') cp++; return cp; } /* * Edit a mntopt set array as requested by the user. The ok * parameter, if non-zero, allows the application to limit what * mntopts the user is allowed to set or clear using this function. */ int e2p_edit_mntopts(const char *str, __u32 *mntopts, __u32 ok) { char *cp, *buf, *next; int neg; unsigned int mask; buf = bb_xstrdup(str); cp = buf; while (cp && *cp) { neg = 0; cp = skip_over_blanks(cp); next = skip_over_word(cp); if (*next == 0) next = 0; else *next = 0; switch (*cp) { case '-': case '^': neg++; case '+': cp++; break; } if (e2p_string2mntopt(cp, &mask)) return 1; if (ok && !(ok & mask)) return 1; if (mask & EXT3_DEFM_JMODE) *mntopts &= ~EXT3_DEFM_JMODE; if (neg) *mntopts &= ~mask; else *mntopts |= mask; cp = next ? next+1 : 0; } return 0; }