platform_bionic/libc/bionic/mntent.cpp
Greg Hackmann 3679ade533 Add hasmntopt(3)
bionic has the Linux-specific mntent.h but is missing hasmntopt().

Change-Id: I0ab7b83626c969704add4e64b37a6fc715d4a723
Signed-off-by: Greg Hackmann <ghackmann@google.com>
2016-03-25 14:16:58 -07:00

100 lines
3.3 KiB
C++

/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <mntent.h>
#include <string.h>
#include "private/ThreadLocalBuffer.h"
static ThreadLocalBuffer<mntent> g_getmntent_mntent_tls_buffer;
static ThreadLocalBuffer<char, BUFSIZ> g_getmntent_strings_tls_buffer;
mntent* getmntent(FILE* fp) {
return getmntent_r(fp, g_getmntent_mntent_tls_buffer.get(),
g_getmntent_strings_tls_buffer.get(),
g_getmntent_strings_tls_buffer.size());
}
mntent* getmntent_r(FILE* fp, struct mntent* e, char* buf, int buf_len) {
memset(e, 0, sizeof(*e));
while (fgets(buf, buf_len, fp) != NULL) {
// Entries look like "proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0".
// That is: mnt_fsname mnt_dir mnt_type mnt_opts 0 0.
int fsname0, fsname1, dir0, dir1, type0, type1, opts0, opts1;
if (sscanf(buf, " %n%*s%n %n%*s%n %n%*s%n %n%*s%n %d %d",
&fsname0, &fsname1, &dir0, &dir1, &type0, &type1, &opts0, &opts1,
&e->mnt_freq, &e->mnt_passno) == 2) {
e->mnt_fsname = &buf[fsname0];
buf[fsname1] = '\0';
e->mnt_dir = &buf[dir0];
buf[dir1] = '\0';
e->mnt_type = &buf[type0];
buf[type1] = '\0';
e->mnt_opts = &buf[opts0];
buf[opts1] = '\0';
return e;
}
}
return NULL;
}
FILE* setmntent(const char* path, const char* mode) {
return fopen(path, mode);
}
int endmntent(FILE* fp) {
if (fp != NULL) {
fclose(fp);
}
return 1;
}
char* hasmntopt(const struct mntent* mnt, const char* opt) {
char* token = mnt->mnt_opts;
char* const end = mnt->mnt_opts + strlen(mnt->mnt_opts);
const size_t optLen = strlen(opt);
while (token) {
char* const tokenEnd = token + optLen;
if (tokenEnd > end) break;
if (memcmp(token, opt, optLen) == 0 &&
(*tokenEnd == '\0' || *tokenEnd == ',' || *tokenEnd == '=')) {
return token;
}
token = strchr(token, ',');
if (token) token++;
}
return nullptr;
}