src/proc_self_mountinfo.c

   1 #ifdef HAVE_CONFIG_H
   2 #include <config.h>
   3 #endif
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7 #include <sys/types.h>
   8 #include <sys/stat.h>
   9 #include <fcntl.h>
  10
  11 #include "common.h"
  12 #include "log.h"
  13 #include "appconfig.h"
  14
  15 #include "proc_self_mountinfo.h"
  16
  17 // find the mount info with the given major:minor
  18 // in the supplied linked list of mountinfo structures
  19 struct mountinfo *mountinfo_find(struct mountinfo *root, unsigned long major, unsigned long minor) {
  20         struct mountinfo *mi;
  21
  22         for(mi = root; mi ; mi = mi->next)
  23                 if(mi->major == major && mi->minor == minor)
  24                         return mi;
  25
  26         return NULL;
  27 }
  28
  29 // free a linked list of mountinfo structures
  30 void mountinfo_free(struct mountinfo *mi) {
  31         if(unlikely(!mi))
  32                 return;
  33
  34         if(likely(mi->next))
  35                 mountinfo_free(mi->next);
  36
  37         free(mi->root);
  38         free(mi->mount_point);
  39         free(mi->mount_options);
  40
  41         if(mi->optional_fields_count) {
  42                 int i;
  43                 for(i = 0; i < mi->optional_fields_count ; i++)
  44                         free(mi->optional_fields[i]);
  45         }
  46         free(mi->optional_fields);
  47
  48         free(mi->filesystem);
  49         free(mi->mount_source);
  50         free(mi->super_options);
  51         free(mi);
  52 }
  53
  54 // read the whole mountinfo into a linked list
  55 struct mountinfo *mountinfo_read() {
  56         procfile *ff = NULL;
  57
  58         char filename[FILENAME_MAX + 1];
  59         snprintf(filename, FILENAME_MAX, "%s/proc/self/mountinfo", global_host_prefix);
  60         ff = procfile_open(filename, " \t", PROCFILE_FLAG_DEFAULT);
  61         if(!ff) {
  62                 snprintf(filename, FILENAME_MAX, "%s/proc/1/mountinfo", global_host_prefix);
  63                 ff = procfile_open(filename, " \t", PROCFILE_FLAG_DEFAULT);
  64                 if(!ff) return NULL;
  65         }
  66
  67         ff = procfile_readall(ff);
  68         if(!ff) return NULL;
  69
  70         struct mountinfo *root = NULL, *last = NULL, *mi = NULL;
  71
  72         unsigned long l, lines = procfile_lines(ff);
  73         error("MOUNTINFO: file has %u lines", lines);
  74         for(l = 0; l < lines ;l++) {
  75                 if(procfile_linewords(ff, l) < 5)
  76                         continue;
  77
  78                 mi = malloc(sizeof(struct mountinfo));
  79                 if(unlikely(!mi)) fatal("Cannot allocate memory for mountinfo");
  80
  81                 if(unlikely(!root))
  82                         root = last = mi;
  83                 else
  84                         last->next = mi;
  85
  86                 last = mi;
  87                 mi->next = NULL;
  88
  89                 unsigned long w = 0;
  90                 mi->id = strtoul(procfile_lineword(ff, l, w), NULL, 10); w++;
  91                 mi->parentid = strtoul(procfile_lineword(ff, l, w), NULL, 10); w++;
  92
  93                 char *major = procfile_lineword(ff, l, w), *minor; w++;
  94                 for(minor = major; *minor && *minor != ':' ;minor++) ;
  95                 *minor = '\0';
  96                 minor++;
  97
  98                 mi->major = strtoul(major, NULL, 10);
  99                 mi->minor = strtoul(minor, NULL, 10);
 100
 101                 mi->root = strdup(procfile_lineword(ff, l, w)); w++;
 102                 if(unlikely(!mi->root)) fatal("Cannot allocate memory");
 103
 104                 mi->mount_point = strdup(procfile_lineword(ff, l, w)); w++;
 105                 if(unlikely(!mi->mount_point)) fatal("Cannot allocate memory");
 106
 107                 mi->mount_options = strdup(procfile_lineword(ff, l, w)); w++;
 108                 if(unlikely(!mi->mount_options)) fatal("Cannot allocate memory");
 109
 110                 // count the optional fields
 111                 unsigned long wo = w;
 112                 mi->optional_fields_count = 0;
 113                 char *s = procfile_lineword(ff, l, w);
 114                 while(*s && *s != '-') {
 115                         w++;
 116                         s = procfile_lineword(ff, l, w);
 117                         mi->optional_fields_count++;
 118                 }
 119
 120                 if(unlikely(mi->optional_fields_count)) {
 121                         // we have some optional fields
 122                         // read them into a new array of pointers;
 123
 124                         mi->optional_fields = malloc(mi->optional_fields_count * sizeof(char *));
 125                         if(unlikely(!mi->optional_fields))
 126                                 fatal("Cannot allocate memory for %d mountinfo optional fields", mi->optional_fields_count);
 127
 128                         int i;
 129                         for(i = 0; i < mi->optional_fields_count ; i++) {
 130                                 mi->optional_fields[wo] = strdup(procfile_lineword(ff, l, w));
 131                                 if(!mi->optional_fields[wo]) fatal("Cannot allocate memory");
 132                                 wo++;
 133                         }
 134                 }
 135                 else
 136                         mi->optional_fields = NULL;
 137
 138                 if(likely(*s == '-')) {
 139                         mi->filesystem = strdup(procfile_lineword(ff, l, w)); w++;
 140                         if(!mi->filesystem) fatal("Cannot allocate memory");
 141
 142                         mi->mount_source = strdup(procfile_lineword(ff, l, w)); w++;
 143                         if(!mi->mount_source) fatal("Cannot allocate memory");
 144
 145                         mi->super_options = strdup(procfile_lineword(ff, l, w)); w++;
 146                         if(!mi->super_options) fatal("Cannot allocate memory");
 147                 }
 148                 else {
 149                         mi->filesystem = NULL;
 150                         mi->mount_source = NULL;
 151                         mi->super_options = NULL;
 152                 }
 153
 154                 //info("MOUNTINFO: %u %u %u:%u root '%s', mount point '%s', mount options '%s', filesystem '%s', mount source '%s', super options '%s'",
 155                 //     mi->id,
 156                 //     mi->parentid,
 157                 //     mi->major,
 158                 //     mi->minor,
 159                 //     mi->root,
 160                 //     mi->mount_point,
 161                 //     mi->mount_options,
 162                 //     mi->filesystem,
 163                 //     mi->mount_source,
 164                 //     mi->super_options
 165                 //);
 166         }
 167
 168         procfile_close(ff);
 169         return root;
 170 }