libfstools/find.c

   1 /*
   2  * Copyright (C) 2014 John Crispin <blogic@openwrt.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU Lesser General Public License version 2.1
   6  * as published by the Free Software Foundation
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <errno.h>
  15 #include <stdio.h>
  16 #include <string.h>
  17
  18 #include "../fs-state.h"
  19
  20 int
  21 find_overlay_mount(char *overlay)
  22 {
  23         FILE *fp = fopen("/proc/mounts", "r");
  24         static char line[256];
  25         int ret = -1;
  26
  27         if(!fp)
  28                 return ret;
  29
  30         while (ret && fgets(line, sizeof(line), fp))
  31                 if (!strncmp(line, overlay, strlen(overlay)))
  32                         ret = 0;
  33
  34         fclose(fp);
  35
  36         return ret;
  37 }
  38
  39 char*
  40 find_mount(char *mp)
  41 {
  42         FILE *fp = fopen("/proc/mounts", "r");
  43         static char line[256];
  44         char *point = NULL;
  45
  46         if(!fp)
  47                 return NULL;
  48
  49         while (fgets(line, sizeof(line), fp)) {
  50                 char *s, *t = strstr(line, " ");
  51
  52                 if (!t) {
  53                         fclose(fp);
  54                         return NULL;
  55                 }
  56                 t++;
  57                 s = strstr(t, " ");
  58                 if (!s) {
  59                         fclose(fp);
  60                         return NULL;
  61                 }
  62                 *s = '\0';
  63
  64                 if (!strcmp(t, mp)) {
  65                         fclose(fp);
  66                         return t;
  67                 }
  68         }
  69
  70         fclose(fp);
  71
  72         return point;
  73 }
  74
  75 char*
  76 find_mount_point(char *block, char *fs)
  77 {
  78         FILE *fp = fopen("/proc/mounts", "r");
  79         static char line[256];
  80         int len = strlen(block);
  81         char *point = NULL;
  82
  83         if(!fp)
  84                 return NULL;
  85
  86         while (fgets(line, sizeof(line), fp)) {
  87                 if (!strncmp(line, block, len)) {
  88                         char *p = &line[len + 1];
  89                         char *t = strstr(p, " ");
  90
  91                         if (!t) {
  92                                 fclose(fp);
  93                                 return NULL;
  94                         }
  95
  96                         *t = '\0';
  97                         t++;
  98
  99                         if (fs && strncmp(t, fs, strlen(fs))) {
 100                                 fclose(fp);
 101                                 fprintf(stderr, "block is mounted with wrong fs\n");
 102                                 return NULL;
 103                         }
 104                         point = p;
 105
 106                         break;
 107                 }
 108         }
 109
 110         fclose(fp);
 111
 112         return point;
 113 }
 114
 115 int
 116 find_filesystem(char *fs)
 117 {
 118         FILE *fp = fopen("/proc/filesystems", "r");
 119         static char line[256];
 120         int ret = -1;
 121
 122         if (!fp) {
 123                 fprintf(stderr, "opening /proc/filesystems failed: %s\n", strerror(errno));
 124                 goto out;
 125         }
 126
 127         while (ret && fgets(line, sizeof(line), fp))
 128                 if (strstr(line, fs))
 129                         ret = 0;
 130
 131         fclose(fp);
 132
 133 out:
 134         return ret;
 135 }