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 <log/log.h>
  10 #include <talloc/talloc.h>
  11
  12 #include "device-handler.h"
  13 #include "resource.h"
  14 #include "paths.h"
  15
  16 static int is_prefix_ignorecase(const char *str, const char *prefix)
  17 {
  18         return !strncasecmp(str, prefix, strlen(prefix));
  19 }
  20
  21 struct devpath_resource_info {
  22         char    *dev, *path;
  23 };
  24
  25 static struct discover_device *parse_device_string(
  26                 struct device_handler *handler, const char *devstr)
  27 {
  28         if (is_prefix_ignorecase(devstr, "uuid="))
  29                 return device_lookup_by_uuid(handler, devstr + strlen("uuid"));
  30
  31         if (is_prefix_ignorecase(devstr, "label="))
  32                 return device_lookup_by_label(handler,
  33                                         devstr + strlen("label="));
  34
  35         return device_lookup_by_name(handler, devstr);
  36 }
  37 static void resolve_devpath_against_device(struct resource *res,
  38         struct discover_device *dev, const char *path)
  39 {
  40         char *resolved_path = join_paths(res, dev->mount_path, path);
  41         res->url = pb_url_parse(res, resolved_path);
  42         res->resolved = true;
  43 }
  44
  45 struct resource *create_devpath_resource(struct discover_boot_option *opt,
  46         struct discover_device *orig_device,
  47         const char *devpath)
  48 {
  49         struct devpath_resource_info *info;
  50         char *pos, *devstr, *path;
  51         struct resource *res;
  52         struct pb_url *url;
  53
  54         res = talloc(opt, struct resource);
  55
  56         pos = strchr(devpath, ':');
  57
  58         /* do we have a "://" scheme separator? */
  59         if (pos && pos[1] && pos[1] == '/' && pos[2] && pos[2] == '/') {
  60                 url = pb_url_parse(res, devpath);
  61
  62                 if (url->scheme != pb_url_file) {
  63                         /* not a file? we're ready to go */
  64                         res->resolved = true;
  65                         res->url = url;
  66                 } else {
  67                         /* we've been passed a file:// URL, which has no device
  68                          * specifier. We can resolve against the original
  69                          * device */
  70                         resolve_devpath_against_device(res, orig_device,
  71                                         url->path);
  72                         talloc_free(url);
  73                 }
  74                 return res;
  75         }
  76
  77         /* if there was no device specified, we can resolve now */
  78         if (!pos) {
  79                 resolve_devpath_against_device(res, orig_device, devpath);
  80                 return res;
  81         }
  82
  83         devstr = talloc_strndup(res, devpath, pos - devpath);
  84         path = talloc_strdup(res, pos + 1);
  85
  86         pb_log("%s: resource depends on device %s\n", __func__, devstr);
  87
  88         /* defer resolution until we can find a suitable matching device */
  89         info = talloc(res, struct devpath_resource_info);
  90         info->dev = devstr;
  91         info->path = path;
  92
  93         res->resolved = false;
  94         res->info = info;
  95
  96         return res;
  97 }
  98
  99 bool resolve_devpath_resource(struct device_handler *handler,
 100                 struct resource *res)
 101 {
 102         struct devpath_resource_info *info = res->info;
 103         struct discover_device *dev;
 104
 105         assert(!res->resolved);
 106
 107         dev = parse_device_string(handler, info->dev);
 108
 109         if (!dev)
 110                 return false;
 111
 112         resolve_devpath_against_device(res, dev, info->path);
 113         talloc_free(info);
 114
 115         return true;
 116 }
 117
 118 struct resource *create_url_resource(struct discover_boot_option *opt,
 119                 struct pb_url *url)
 120 {
 121         struct resource *res;
 122
 123         res = talloc(opt, struct resource);
 124         res->url = url;
 125         res->resolved = true;
 126
 127         return res;
 128 }