| /* Utilities for reading/writing fstab, mtab, etc. |
| Copyright (C) 1995-2016 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <alloca.h> |
| #include <mntent.h> |
| #include <stdio.h> |
| #include <stdio_ext.h> |
| #include <string.h> |
| #include <sys/types.h> |
| |
| #define flockfile(s) _IO_flockfile (s) |
| #define funlockfile(s) _IO_funlockfile (s) |
| |
| #undef __setmntent |
| #undef __endmntent |
| #undef __getmntent_r |
| |
| /* Prepare to begin reading and/or writing mount table entries from the |
| beginning of FILE. MODE is as for `fopen'. */ |
| FILE * |
| __setmntent (const char *file, const char *mode) |
| { |
| /* Extend the mode parameter with "c" to disable cancellation in the |
| I/O functions and "e" to set FD_CLOEXEC. */ |
| size_t modelen = strlen (mode); |
| char newmode[modelen + 3]; |
| memcpy (mempcpy (newmode, mode, modelen), "ce", 3); |
| FILE *result = fopen (file, newmode); |
| |
| if (result != NULL) |
| /* We do the locking ourselves. */ |
| __fsetlocking (result, FSETLOCKING_BYCALLER); |
| |
| return result; |
| } |
| libc_hidden_def (__setmntent) |
| weak_alias (__setmntent, setmntent) |
| |
| |
| /* Close a stream opened with `setmntent'. */ |
| int |
| __endmntent (FILE *stream) |
| { |
| if (stream) /* SunOS 4.x allows for NULL stream */ |
| fclose (stream); |
| return 1; /* SunOS 4.x says to always return 1 */ |
| } |
| libc_hidden_def (__endmntent) |
| weak_alias (__endmntent, endmntent) |
| |
| |
| /* Since the values in a line are separated by spaces, a name cannot |
| contain a space. Therefore some programs encode spaces in names |
| by the strings "\040". We undo the encoding when reading an entry. |
| The decoding happens in place. */ |
| static char * |
| decode_name (char *buf) |
| { |
| char *rp = buf; |
| char *wp = buf; |
| |
| do |
| if (rp[0] == '\\' && rp[1] == '0' && rp[2] == '4' && rp[3] == '0') |
| { |
| /* \040 is a SPACE. */ |
| *wp++ = ' '; |
| rp += 3; |
| } |
| else if (rp[0] == '\\' && rp[1] == '0' && rp[2] == '1' && rp[3] == '1') |
| { |
| /* \011 is a TAB. */ |
| *wp++ = '\t'; |
| rp += 3; |
| } |
| else if (rp[0] == '\\' && rp[1] == '0' && rp[2] == '1' && rp[3] == '2') |
| { |
| /* \012 is a NEWLINE. */ |
| *wp++ = '\n'; |
| rp += 3; |
| } |
| else if (rp[0] == '\\' && rp[1] == '\\') |
| { |
| /* We have to escape \\ to be able to represent all characters. */ |
| *wp++ = '\\'; |
| rp += 1; |
| } |
| else if (rp[0] == '\\' && rp[1] == '1' && rp[2] == '3' && rp[3] == '4') |
| { |
| /* \134 is also \\. */ |
| *wp++ = '\\'; |
| rp += 3; |
| } |
| else |
| *wp++ = *rp; |
| while (*rp++ != '\0'); |
| |
| return buf; |
| } |
| |
| |
| /* Read one mount table entry from STREAM. Returns a pointer to storage |
| reused on the next call, or null for EOF or error (use feof/ferror to |
| check). */ |
| struct mntent * |
| __getmntent_r (FILE *stream, struct mntent *mp, char *buffer, int bufsiz) |
| { |
| char *cp; |
| char *head; |
| |
| flockfile (stream); |
| do |
| { |
| char *end_ptr; |
| |
| if (__fgets_unlocked (buffer, bufsiz, stream) == NULL) |
| { |
| funlockfile (stream); |
| return NULL; |
| } |
| |
| end_ptr = strchr (buffer, '\n'); |
| if (end_ptr != NULL) /* chop newline */ |
| { |
| /* Do not walk past the start of buffer if it's all whitespace. */ |
| while (end_ptr != buffer |
| && (end_ptr[-1] == ' ' || end_ptr[-1] == '\t')) |
| end_ptr--; |
| *end_ptr = '\0'; |
| } |
| else |
| { |
| /* Not the whole line was read. Do it now but forget it. */ |
| char tmp[1024]; |
| while (__fgets_unlocked (tmp, sizeof tmp, stream) != NULL) |
| if (strchr (tmp, '\n') != NULL) |
| break; |
| } |
| |
| head = buffer + strspn (buffer, " \t"); |
| /* skip empty lines and comment lines: */ |
| } |
| while (head[0] == '\0' || head[0] == '#'); |
| |
| cp = __strsep (&head, " \t"); |
| mp->mnt_fsname = cp != NULL ? decode_name (cp) : (char *) ""; |
| if (head) |
| head += strspn (head, " \t"); |
| cp = __strsep (&head, " \t"); |
| mp->mnt_dir = cp != NULL ? decode_name (cp) : (char *) ""; |
| if (head) |
| head += strspn (head, " \t"); |
| cp = __strsep (&head, " \t"); |
| mp->mnt_type = cp != NULL ? decode_name (cp) : (char *) ""; |
| if (head) |
| head += strspn (head, " \t"); |
| cp = __strsep (&head, " \t"); |
| mp->mnt_opts = cp != NULL ? decode_name (cp) : (char *) ""; |
| switch (head ? sscanf (head, " %d %d ", &mp->mnt_freq, &mp->mnt_passno) : 0) |
| { |
| case 0: |
| mp->mnt_freq = 0; |
| case 1: |
| mp->mnt_passno = 0; |
| case 2: |
| break; |
| } |
| funlockfile (stream); |
| |
| return mp; |
| } |
| libc_hidden_def (__getmntent_r) |
| weak_alias (__getmntent_r, getmntent_r) |
| |
| |
| /* We have to use an encoding for names if they contain spaces or tabs. |
| To be able to represent all characters we also have to escape the |
| backslash itself. This "function" must be a macro since we use |
| `alloca'. */ |
| #define encode_name(name) \ |
| do { \ |
| const char *rp = name; \ |
| \ |
| while (*rp != '\0') \ |
| if (*rp == ' ' || *rp == '\t' || *rp == '\n' || *rp == '\\') \ |
| break; \ |
| else \ |
| ++rp; \ |
| \ |
| if (*rp != '\0') \ |
| { \ |
| /* In the worst case the length of the string can increase to \ |
| four times the current length. */ \ |
| char *wp; \ |
| \ |
| rp = name; \ |
| name = wp = (char *) alloca (strlen (name) * 4 + 1); \ |
| \ |
| do \ |
| if (*rp == ' ') \ |
| { \ |
| *wp++ = '\\'; \ |
| *wp++ = '0'; \ |
| *wp++ = '4'; \ |
| *wp++ = '0'; \ |
| } \ |
| else if (*rp == '\t') \ |
| { \ |
| *wp++ = '\\'; \ |
| *wp++ = '0'; \ |
| *wp++ = '1'; \ |
| *wp++ = '1'; \ |
| } \ |
| else if (*rp == '\n') \ |
| { \ |
| *wp++ = '\\'; \ |
| *wp++ = '0'; \ |
| *wp++ = '1'; \ |
| *wp++ = '2'; \ |
| } \ |
| else if (*rp == '\\') \ |
| { \ |
| *wp++ = '\\'; \ |
| *wp++ = '\\'; \ |
| } \ |
| else \ |
| *wp++ = *rp; \ |
| while (*rp++ != '\0'); \ |
| } \ |
| } while (0) |
| |
| |
| /* Write the mount table entry described by MNT to STREAM. |
| Return zero on success, nonzero on failure. */ |
| int |
| __addmntent (FILE *stream, const struct mntent *mnt) |
| { |
| struct mntent mntcopy = *mnt; |
| if (fseek (stream, 0, SEEK_END)) |
| return 1; |
| |
| /* Encode spaces and tabs in the names. */ |
| encode_name (mntcopy.mnt_fsname); |
| encode_name (mntcopy.mnt_dir); |
| encode_name (mntcopy.mnt_type); |
| encode_name (mntcopy.mnt_opts); |
| |
| return (fprintf (stream, "%s %s %s %s %d %d\n", |
| mntcopy.mnt_fsname, |
| mntcopy.mnt_dir, |
| mntcopy.mnt_type, |
| mntcopy.mnt_opts, |
| mntcopy.mnt_freq, |
| mntcopy.mnt_passno) < 0 |
| || fflush (stream) != 0); |
| } |
| weak_alias (__addmntent, addmntent) |
| |
| |
| /* Search MNT->mnt_opts for an option matching OPT. |
| Returns the address of the substring, or null if none found. */ |
| char * |
| __hasmntopt (const struct mntent *mnt, const char *opt) |
| { |
| const size_t optlen = strlen (opt); |
| char *rest = mnt->mnt_opts, *p; |
| |
| while ((p = strstr (rest, opt)) != NULL) |
| { |
| if ((p == rest || p[-1] == ',') |
| && (p[optlen] == '\0' || p[optlen] == '=' || p[optlen] == ',')) |
| return p; |
| |
| rest = strchr (p, ','); |
| if (rest == NULL) |
| break; |
| ++rest; |
| } |
| |
| return NULL; |
| } |
| weak_alias (__hasmntopt, hasmntopt) |