aboutsummaryrefslogtreecommitdiff
path: root/lib/getmountlist.c
blob: f7d58ab6240134f19b6f7bedb5866ac9bdd4fc9c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
/* getmountlist.c - Get a linked list of mount points, with stat information.
 *
 * Copyright 2006 Rob Landley <rob@landley.net>
 */

#include "toys.h"
#include <mntent.h>

// Traverse arg_list of csv, calling callback on each value
void comma_args(struct arg_list *al, void *data, char *err,
  char *(*callback)(void *data, char *str, int len))
{
  char *next, *arg;
  int len;

  if (CFG_TOYBOX_DEBUG && !err) err = "INTERNAL";

  while (al) {
    arg = al->arg;
    while ((next = comma_iterate(&arg, &len)))
      if ((next = callback(data, next, len)))
        error_exit("%s '%s'\n%*c", err, al->arg,
          (int)(5+strlen(toys.which->name)+strlen(err)+next-al->arg), '^');
    al = al->next;
  }
}

// Realloc *old with oldstring,newstring

void comma_collate(char **old, char *new)
{
  char *temp, *atold = *old;

  // Only add a comma if old string didn't end with one
  if (atold && *atold) {
    char *comma = ",";

    if (atold[strlen(atold)-1] == ',') comma = "";
    temp = xmprintf("%s%s%s", atold, comma, new);
  } else temp = xstrdup(new);
  free (atold);
  *old = temp;
}

// iterate through strings in a comma separated list.
// returns start of next entry or NULL if none
// sets *len to length of entry (not including comma)
// advances *list to start of next entry
char *comma_iterate(char **list, int *len)
{
  char *start = *list, *end;

  if (!*list || !**list) return 0;

  if (!(end = strchr(*list, ','))) {
    *len = strlen(*list);
    *list = 0;
  } else *list += (*len = end-start)+1;

  return start;
}

static void octal_deslash(char *s)
{
  char *o = s;

  while (*s) {
    if (*s == '\\') {
      int i, oct = 0;

      for (i = 1; i < 4; i++) {
        if (!isdigit(s[i])) break;
        oct = (oct<<3)+s[i]-'0';
      }
      if (i == 4) {
        *o++ = oct;
        s += i;
        continue;
      }
    }
    *o++ = *s++;
  }

  *o = 0;
}

// check all instances of opt and "no"opt in optlist, return true if opt
// found and last instance wasn't no. If clean, remove each instance from list.
int comma_scan(char *optlist, char *opt, int clean)
{
  int optlen = strlen(opt), len, no, got = 0;

  if (optlist) for (;;) {
    char *s = comma_iterate(&optlist, &len);

    if (!s) break;
    no = 2*(*s == 'n' && s[1] == 'o');
    if (optlen == len-no && !strncmp(opt, s+no, optlen)) {
      got = !no;
      if (clean) {
        if (optlist) memmove(s, optlist, strlen(optlist)+1);
        else *s = 0;
      }
    }
  }

  return got;
}

// return true if all scanlist options enabled in optlist
int comma_scanall(char *optlist, char *scanlist)
{
  int i = 1;

  while (scanlist && *scanlist) {
    char *opt = comma_iterate(&scanlist, &i), *s = xstrndup(opt, i);

    i = comma_scan(optlist, s, 0);
    free(s);
    if (!i) break;
  }

  return i;
}

// Check if this type matches list.
// Odd syntax: typelist all yes = if any, typelist all no = if none.

int mountlist_istype(struct mtab_list *ml, char *typelist)
{
  int len, skip;
  char *t;

  if (!typelist) return 1;

  skip = strncmp(typelist, "no", 2);

  for (;;) {
    if (!(t = comma_iterate(&typelist, &len))) break;
    if (!skip) {
      // If one -t starts with "no", the rest must too
      if (strncmp(t, "no", 2)) error_exit("bad typelist");
      if (!strncmp(t+2, ml->type, len-2)) {
        skip = 1;
        break;
      }
    } else if (!strncmp(t, ml->type, len) && !ml->type[len]) {
      skip = 0;
      break;
    }
  }

  return !skip;
}

// Get list of mounted filesystems, including stat and statvfs info.
// Returns a reversed list, which is good for finding overmounts and such.

struct mtab_list *xgetmountlist(char *path)
{
  struct mtab_list *mtlist = 0, *mt;
  struct mntent *me;
  FILE *fp;
  char *p = path ? path : "/proc/mounts";

  if (!(fp = setmntent(p, "r"))) perror_exit("bad %s", p);

  // The "test" part of the loop is done before the first time through and
  // again after each "increment", so putting the actual load there avoids
  // duplicating it. If the load was NULL, the loop stops.

  while ((me = getmntent(fp))) {
    mt = xzalloc(sizeof(struct mtab_list) + strlen(me->mnt_fsname) +
      strlen(me->mnt_dir) + strlen(me->mnt_type) + strlen(me->mnt_opts) + 4);
    dlist_add_nomalloc((void *)&mtlist, (void *)mt);

    // Collect details about mounted filesystem
    // Don't report errors, just leave data zeroed
    if (!path) {
      stat(me->mnt_dir, &(mt->stat));
      statvfs(me->mnt_dir, &(mt->statvfs));
    }

    // Remember information from /proc/mounts
    mt->dir = stpcpy(mt->type, me->mnt_type)+1;
    mt->device = stpcpy(mt->dir, me->mnt_dir)+1;
    mt->opts = stpcpy(mt->device, me->mnt_fsname)+1;
    strcpy(mt->opts, me->mnt_opts);

    octal_deslash(mt->dir);
    octal_deslash(mt->device);
  }
  endmntent(fp);

  return mtlist;
}