1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *  * Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *  * Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in
12 *    the documentation and/or other materials provided with the
13 *    distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <mntent.h>
30#include <string.h>
31
32#include "bionic/pthread_internal.h"
33
34mntent* getmntent(FILE* fp) {
35  auto& tls = __get_bionic_tls();
36  return getmntent_r(fp, &tls.mntent_buf, tls.mntent_strings, sizeof(tls.mntent_strings));
37}
38
39mntent* getmntent_r(FILE* fp, struct mntent* e, char* buf, int buf_len) {
40  memset(e, 0, sizeof(*e));
41  while (fgets(buf, buf_len, fp) != NULL) {
42    // Entries look like "proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0".
43    // That is: mnt_fsname mnt_dir mnt_type mnt_opts 0 0.
44    int fsname0, fsname1, dir0, dir1, type0, type1, opts0, opts1;
45    if (sscanf(buf, " %n%*s%n %n%*s%n %n%*s%n %n%*s%n %d %d",
46               &fsname0, &fsname1, &dir0, &dir1, &type0, &type1, &opts0, &opts1,
47               &e->mnt_freq, &e->mnt_passno) == 2) {
48      e->mnt_fsname = &buf[fsname0];
49      buf[fsname1] = '\0';
50
51      e->mnt_dir = &buf[dir0];
52      buf[dir1] = '\0';
53
54      e->mnt_type = &buf[type0];
55      buf[type1] = '\0';
56
57      e->mnt_opts = &buf[opts0];
58      buf[opts1] = '\0';
59
60      return e;
61    }
62  }
63  return NULL;
64}
65
66FILE* setmntent(const char* path, const char* mode) {
67  return fopen(path, mode);
68}
69
70int endmntent(FILE* fp) {
71  if (fp != NULL) {
72    fclose(fp);
73  }
74  return 1;
75}
76
77char* hasmntopt(const struct mntent* mnt, const char* opt) {
78  char* token = mnt->mnt_opts;
79  char* const end = mnt->mnt_opts + strlen(mnt->mnt_opts);
80  const size_t optLen = strlen(opt);
81
82  while (token) {
83    char* const tokenEnd = token + optLen;
84    if (tokenEnd > end) break;
85
86    if (memcmp(token, opt, optLen) == 0 &&
87        (*tokenEnd == '\0' || *tokenEnd == ',' || *tokenEnd == '=')) {
88      return token;
89    }
90
91    token = strchr(token, ',');
92    if (token) token++;
93  }
94
95  return nullptr;
96}
97