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 "libfstools.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 /*
  40  * Find path of a device mounted to the given point.
  41  */
  42 char*
  43 find_mount(char *mp)
  44 {
  45         FILE *fp = fopen("/proc/mounts", "r");
  46         static char line[256];
  47         char *point = NULL;
  48
  49         if(!fp)
  50                 return NULL;
  51
  52         while (fgets(line, sizeof(line), fp)) {
  53                 char *s, *t = strstr(line, " ");
  54
  55                 if (!t) {
  56                         fclose(fp);
  57                         return NULL;
  58                 }
  59                 *t = '\0';
  60                 t++;
  61                 s = strstr(t, " ");
  62                 if (!s) {
  63                         fclose(fp);
  64                         return NULL;
  65                 }
  66                 *s = '\0';
  67
  68                 if (!strcmp(t, mp)) {
  69                         fclose(fp);
  70                         return line;
  71                 }
  72         }
  73
  74         fclose(fp);
  75
  76         return point;
  77 }
  78
  79 char*
  80 find_mount_point(char *block, int mtd_only)
  81 {
  82         FILE *fp = fopen("/proc/mounts", "r");
  83         static char line[256];
  84         int len = strlen(block);
  85         char *point = NULL;
  86
  87         if(!fp)
  88                 return NULL;
  89
  90         while (fgets(line, sizeof(line), fp)) {
  91                 if (!strncmp(line, block, len)) {
  92                         char *p = &line[len + 1];
  93                         char *t = strstr(p, " ");
  94
  95                         if (!t) {
  96                                 fclose(fp);
  97                                 return NULL;
  98                         }
  99
 100                         *t = '\0';
 101                         t++;
 102
 103                         if (mtd_only &&
 104                             strncmp(t, "jffs2", 5) &&
 105                             strncmp(t, "ubifs", 5) &&
 106                             strncmp(t, "ext4", 4)) {
 107                                 fclose(fp);
 108                                 ULOG_ERR("block is mounted with wrong fs\n");
 109                                 return NULL;
 110                         }
 111                         point = p;
 112
 113                         break;
 114                 }
 115         }
 116
 117         fclose(fp);
 118
 119         return point;
 120 }
 121
 122 int
 123 find_filesystem(char *fs)
 124 {
 125         FILE *fp = fopen("/proc/filesystems", "r");
 126         static char line[256];
 127         int ret = -1;
 128
 129         if (!fp) {
 130                 ULOG_ERR("opening /proc/filesystems failed: %s\n", strerror(errno));
 131                 goto out;
 132         }
 133
 134         while (ret && fgets(line, sizeof(line), fp))
 135                 if (strstr(line, fs))
 136                         ret = 0;
 137
 138         fclose(fp);
 139
 140 out:
 141         return ret;
 142 }