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

   1
   2 #define _GNU_SOURCE
   3
   4 #include <assert.h>
   5 #include <stdbool.h>
   6 #include <string.h>
   7
   8 #include <url/url.h>
   9 #include <talloc/talloc.h>
  10
  11 #include "device-handler.h"
  12 #include "resource.h"
  13 #include "paths.h"
  14
  15 static int is_prefix_ignorecase(const char *str, const char *prefix)
  16 {
  17         return !strncasecmp(str, prefix, strlen(prefix));
  18 }
  19
  20 struct devpath_resource_info {
  21         char    *dev, *path;
  22 };
  23
  24 static struct discover_device *parse_device_string(
  25                 struct device_handler *handler, const char *devstr)
  26 {
  27         if (is_prefix_ignorecase(devstr, "uuid="))
  28                 return device_lookup_by_uuid(handler, devstr + strlen("uuid"));
  29
  30         if (is_prefix_ignorecase(devstr, "label="))
  31                 return device_lookup_by_label(handler,
  32                                         devstr + strlen("label="));
  33
  34         return device_lookup_by_name(handler, devstr);
  35 }
  36 static void resolve_devpath_against_device(struct resource *res,
  37         struct discover_device *dev, const char *path)
  38 {
  39         char *resolved_path = join_paths(res, dev->mount_path, path);
  40         res->url = pb_url_parse(res, resolved_path);
  41         res->resolved = true;
  42 }
  43
  44 struct resource *create_devpath_resource(void *ctx,
  45         struct discover_device *orig_device,
  46         const char *devpath)
  47 {
  48         struct devpath_resource_info *info;
  49         char *pos, *devstr, *path;
  50         struct resource *res;
  51         struct pb_url *url;
  52
  53         res = talloc(ctx, struct resource);
  54
  55         pos = strchr(devpath, ':');
  56
  57         /* do we have a "://" scheme separator? */
  58         if (pos && pos[1] && pos[1] == '/' && pos[2] && pos[2] == '/') {
  59                 url = pb_url_parse(res, devpath);
  60
  61                 if (url->scheme != pb_url_file) {
  62                         /* not a file? we're ready to go */
  63                         res->resolved = true;
  64                         res->url = url;
  65                 } else {
  66                         /* we've been passed a file:// URL, which has no device
  67                          * specifier. We can resolve against the original
  68                          * device */
  69                         resolve_devpath_against_device(res, orig_device,
  70                                         url->path);
  71                         talloc_free(url);
  72                 }
  73                 return res;
  74         }
  75
  76         /* if there was no device specified, we can resolve now */
  77         if (!pos) {
  78                 resolve_devpath_against_device(res, orig_device, devpath);
  79                 return res;
  80         }
  81
  82         devstr = talloc_strndup(res, devpath, pos - devpath);
  83         path = talloc_strdup(res, pos + 1);
  84
  85         /* defer resolution until we can find a suitable matching device */
  86         info = talloc(res, struct devpath_resource_info);
  87         info->dev = devstr;
  88         info->path = path;
  89
  90         res->resolved = false;
  91         res->info = info;
  92
  93         return res;
  94 }
  95
  96 bool resolve_devpath_resource(struct device_handler *handler,
  97                 struct resource *res)
  98 {
  99         struct devpath_resource_info *info = res->info;
 100         struct discover_device *dev;
 101
 102         assert(!res->resolved);
 103
 104         dev = parse_device_string(handler, info->dev);
 105
 106         if (!dev)
 107                 return false;
 108
 109         resolve_devpath_against_device(res, dev, info->path);
 110         talloc_free(info);
 111
 112         return true;
 113 }
 114
 115 struct resource *create_url_resource(void *ctx, struct pb_url *url)
 116 {
 117         struct resource *res;
 118
 119         res = talloc(ctx, struct resource);
 120         res->url = url;
 121         res->resolved = true;
 122
 123         return res;
 124 }