1#include <stdio.h>
2#include <string.h>
3#include <mntent.h>
4#include <errno.h>
5#include <limits.h>
6
7static char *internal_buf;
8static size_t internal_bufsize;
9
10#define SENTINEL (char *)&internal_buf
11
12FILE *setmntent(const char *name, const char *mode)
13{
14 return fopen(name, mode);
15}
16
17int endmntent(FILE *f)
18{
19 if (f) fclose(f);
20 return 1;
21}
22
23static char *unescape_ent(char *beg)
24{
25 char *dest = beg;
26 const char *src = beg;
27 while (*src) {
28 const char *val;
29 unsigned char cval = 0;
30 if (*src != '\\') {
31 *dest++ = *src++;
32 continue;
33 }
34 if (src[1] == '\\') {
35 ++src;
36 *dest++ = *src++;
37 continue;
38 }
39 val = src + 1;
40 for (int i = 0; i < 3; ++i) {
41 if (*val >= '0' && *val <= '7') {
42 cval <<= 3;
43 cval += *val++ - '0';
44 } else {
45 break;
46 }
47 }
48 if (cval) {
49 *dest++ = cval;
50 src = val;
51 } else {
52 *dest++ = *src++;
53 }
54 }
55 *dest = 0;
56 return beg;
57}
58
59struct mntent *getmntent_r(FILE *f, struct mntent *mnt, char *linebuf, int buflen)
60{
61 int n[8], use_internal = (linebuf == SENTINEL);
62 size_t len, i;
63
64 mnt->mnt_freq = 0;
65 mnt->mnt_passno = 0;
66
67 do {
68 if (use_internal) {
69 getline(&internal_buf, &internal_bufsize, f);
70 linebuf = internal_buf;
71 } else {
72 fgets(linebuf, buflen, f);
73 }
74 if (feof(f) || ferror(f)) return 0;
75 if (!strchr(linebuf, '\n')) {
76 fscanf(f, "%*[^\n]%*[\n]");
77 errno = ERANGE;
78 return 0;
79 }
80
81 len = strlen(linebuf);
82 if (len > INT_MAX) continue;
83 for (i = 0; i < sizeof n / sizeof *n; i++) n[i] = len;
84 sscanf(linebuf, " %n%*[^ \t]%n %n%*[^ \t]%n %n%*[^ \t]%n %n%*[^ \t]%n %d %d",
85 n, n+1, n+2, n+3, n+4, n+5, n+6, n+7,
86 &mnt->mnt_freq, &mnt->mnt_passno);
87 } while (linebuf[n[0]] == '#' || n[1]==len);
88
89 linebuf[n[1]] = 0;
90 linebuf[n[3]] = 0;
91 linebuf[n[5]] = 0;
92 linebuf[n[7]] = 0;
93
94 mnt->mnt_fsname = unescape_ent(linebuf+n[0]);
95 mnt->mnt_dir = unescape_ent(linebuf+n[2]);
96 mnt->mnt_type = unescape_ent(linebuf+n[4]);
97 mnt->mnt_opts = unescape_ent(linebuf+n[6]);
98
99 return mnt;
100}
101
102struct mntent *getmntent(FILE *f)
103{
104 static struct mntent mnt;
105 return getmntent_r(f, &mnt, SENTINEL, 0);
106}
107
108int addmntent(FILE *f, const struct mntent *mnt)
109{
110 if (fseek(f, 0, SEEK_END)) return 1;
111 return fprintf(f, "%s\t%s\t%s\t%s\t%d\t%d\n",
112 mnt->mnt_fsname, mnt->mnt_dir, mnt->mnt_type, mnt->mnt_opts,
113 mnt->mnt_freq, mnt->mnt_passno) < 0;
114}
115
116char *hasmntopt(const struct mntent *mnt, const char *opt)
117{
118 return strstr(mnt->mnt_opts, opt);
119}