git.ozlabs.org Git - petitboot/blob - discover/paths.c

   1 #define _GNU_SOURCE
   2
   3 #include <string.h>
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6
   7 #include "paths.h"
   8
   9 static char *mount_base;
  10
  11 struct device_map {
  12         char *dev, *mnt;
  13 };
  14
  15 #define DEVICE_MAP_SIZE 32
  16 static struct device_map device_map[DEVICE_MAP_SIZE];
  17
  18 char *encode_label(const char *label)
  19 {
  20         char *str, *c;
  21         int i;
  22
  23         /* the label can be expanded by up to four times */
  24         str = malloc(strlen(label) * 4 + 1);
  25         c = str;
  26
  27         for (i = 0; i < strlen(label); i++) {
  28
  29                 if (label[i] == '/' || label[i] == '\\') {
  30                         sprintf(c, "\\x%02x", label[i]);
  31                         c += 4;
  32                         continue;
  33                 }
  34
  35                 *(c++) = label[i];
  36         }
  37
  38         *c = '\0';
  39
  40         return str;
  41 }
  42
  43 char *parse_device_path(const char *dev_str, const char *cur_dev)
  44 {
  45         char *dev, tmp[256], *enc;
  46
  47         if (!strncasecmp(dev_str, "uuid=", 5)) {
  48                 asprintf(&dev, "/dev/disk/by-uuid/%s", dev_str + 5);
  49                 return dev;
  50         }
  51
  52         if (!strncasecmp(dev_str, "label=", 6)) {
  53                 enc = encode_label(dev_str + 6);
  54                 asprintf(&dev, "/dev/disk/by-label/%s", enc);
  55                 free(enc);
  56                 return dev;
  57         }
  58
  59         /* normalise '/dev/foo' to 'foo' for easy comparisons, we'll expand
  60          * back before returning.
  61          */
  62         if (!strncmp(dev_str, "/dev/", 5))
  63                 dev_str += 5;
  64
  65         /* PS3 hack: if we're reading from a ps3dx device, and we refer to
  66          * a sdx device, remap to ps3dx */
  67         if (cur_dev && !strncmp(cur_dev, "/dev/ps3d", 9)
  68                         && !strncmp(dev_str, "sd", 2)) {
  69                 snprintf(tmp, 255, "ps3d%s", dev_str + 2);
  70                 dev_str = tmp;
  71         }
  72
  73         return join_paths("/dev", dev_str);
  74 }
  75
  76 const char *mountpoint_for_device(const char *dev)
  77 {
  78         int i;
  79
  80         if (!strncmp(dev, "/dev/", 5))
  81                 dev += 5;
  82
  83         /* check existing entries in the map */
  84         for (i = 0; (i < DEVICE_MAP_SIZE) && device_map[i].dev; i++)
  85                 if (!strcmp(device_map[i].dev, dev))
  86                         return device_map[i].mnt;
  87
  88         if (i == DEVICE_MAP_SIZE)
  89                 return NULL;
  90
  91         device_map[i].dev = strdup(dev);
  92         device_map[i].mnt = join_paths(mount_base, dev);
  93         return device_map[i].mnt;
  94 }
  95
  96 char *resolve_path(const char *path, const char *current_dev)
  97 {
  98         char *ret;
  99         const char *devpath, *sep;
 100
 101         sep = strchr(path, ':');
 102         if (!sep) {
 103                 devpath = mountpoint_for_device(current_dev);
 104                 ret = join_paths(devpath, path);
 105         } else {
 106                 /* parse just the device name into dev */
 107                 char *tmp, *dev;
 108                 tmp = strndup(path, sep - path);
 109                 dev = parse_device_path(tmp, current_dev);
 110
 111                 devpath = mountpoint_for_device(dev);
 112                 ret = join_paths(devpath, sep + 1);
 113
 114                 free(dev);
 115                 free(tmp);
 116         }
 117
 118         return ret;
 119 }
 120
 121 void set_mount_base(const char *path)
 122 {
 123         if (mount_base)
 124                 free(mount_base);
 125         mount_base = strdup(path);
 126 }
 127
 128 char *join_paths(const char *a, const char *b)
 129 {
 130         char *full_path;
 131
 132         full_path = malloc(strlen(a) + strlen(b) + 2);
 133
 134         strcpy(full_path, a);
 135         if (b[0] != '/' && a[strlen(a) - 1] != '/')
 136                 strcat(full_path, "/");
 137         strcat(full_path, b);
 138
 139         return full_path;
 140 }
 141