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| | #include <assert.h>
#include <stdio.h>
#include <string.h>
#include <mntent.h>
#include <errno.h>
#include <limits.h>
#include "stdio_impl.h"
static char *internal_buf;
static size_t internal_bufsize;
#define SENTINEL (char *)&internal_buf
FILE *setmntent(const char *name, const char *mode)
{
return fopen(name, mode);
}
int endmntent(FILE *f)
{
if (f) fclose(f);
return 1;
}
static char* decode(char* buf) {
assert(buf != NULL);
char* src = buf;
char* dest = buf;
while (1) {
char* next_src = __strchrnul(src, '\\');
int offset = next_src - src;
memmove(dest, src, offset);
src = next_src;
dest += offset;
if(*src == '\0') {
*dest = *src;
return buf;
}
assert (*src == '\\');
src++;
const char *replacements =
"\040" "040" "\0" // space
"\011" "011" "\0" // tab
"\012" "012" "\0" // newline
"\134" "134" "\0" // backslash
"\\" "\\" "\0"
// Fallback for unrecognized escape sequence,
// copy literally:
"\\" "";
while(1) {
char c = *replacements++;
size_t n = strlen(replacements);
if (strncmp(src, replacements, n) == 0) {
*dest++ = c;
src += n;
break;
}
replacements += n+1;
}
}
}
struct mntent *getmntent_r(FILE *f, struct mntent *mnt, char *linebuf, int buflen)
{
int n[8], use_internal = (linebuf == SENTINEL);
size_t len, i;
mnt->mnt_freq = 0;
mnt->mnt_passno = 0;
do {
if (use_internal) {
getline(&internal_buf, &internal_bufsize, f);
linebuf = internal_buf;
} else {
fgets(linebuf, buflen, f);
}
if (feof(f) || ferror(f)) return 0;
if (!strchr(linebuf, '\n')) {
fscanf(f, "%*[^\n]%*[\n]");
errno = ERANGE;
return 0;
}
len = strlen(linebuf);
if (len > INT_MAX) continue;
for (i = 0; i < sizeof n / sizeof *n; i++) n[i] = len;
sscanf(linebuf, " %n%*s%n %n%*s%n %n%*s%n %n%*s%n %d %d",
n, n+1, n+2, n+3, n+4, n+5, n+6, n+7,
&mnt->mnt_freq, &mnt->mnt_passno);
} while (linebuf[n[0]] == '#' || n[1]==len);
linebuf[n[1]] = 0;
linebuf[n[3]] = 0;
linebuf[n[5]] = 0;
linebuf[n[7]] = 0;
mnt->mnt_fsname = decode(linebuf+n[0]);
mnt->mnt_dir = decode(linebuf+n[2]);
mnt->mnt_type = decode(linebuf+n[4]);
mnt->mnt_opts = decode(linebuf+n[6]);
return mnt;
}
struct mntent *getmntent(FILE *f)
{
static struct mntent mnt;
return getmntent_r(f, &mnt, SENTINEL, 0);
}
static int escape_and_write_string(FILE *f, const char* str)
{
char c;
int error_occured = 0;
while(str && !error_occured && (c = *str++) != 0) {
if(c == '\040') // space
error_occured = fputs("\\040", f) < 0;
else if (c == '\011') // tab
error_occured = fputs("\\011", f) < 0;
else if (c == '\012') // newline
error_occured = fputs("\\012", f) < 0;
else if (c == '\\')
error_occured = fputs("\\\\", f) < 0;
else
error_occured = putc_unlocked(c, f) < 0;
}
return error_occured;
}
int addmntent(FILE *f, const struct mntent *mnt)
{
if (fseek(f, 0, SEEK_END)) return 1;
FLOCK(f);
int error_occured =
escape_and_write_string(f, mnt->mnt_fsname)
|| (0 > putc_unlocked('\t', f))
|| escape_and_write_string(f, mnt->mnt_dir)
|| (0 > putc_unlocked('\t', f))
|| escape_and_write_string(f, mnt->mnt_type)
|| (0 > putc_unlocked('\t', f))
|| escape_and_write_string(f, mnt->mnt_opts)
|| (0 > fprintf(f, "\t%d\t%d\n",
mnt->mnt_freq, mnt->mnt_passno));
FUNLOCK(f);
return error_occured;
}
char *hasmntopt(const struct mntent *mnt, const char *opt)
{
return strstr(mnt->mnt_opts, opt);
}
|