sysroot: Reword comment and use gboolean over bool, error handling

Be more explicit in the comment, and use gboolean over bool. Less header
inclusions when we use gboolean. Although bool is used in some places.
Write a separate _ostree_sysroot_parse_bootlink_aboot function for
aboot. Make is_aboot optional. Handle invalid androidboot karg and no
ostree and androidboot kargs differently.

Co-authored-by: Jonathan Lebon <jonathan@jlebon.com>
Signed-off-by: Eric Curtin <ecurtin@redhat.com>

src/libostree/ostree-impl-system-generator.c

@@ -126,6 +126,34 @@ require_internal_units (const char *normal_dir, const char *early_dir, const cha
 #endif
 }
 
+// Resolve symlink to return osname
+static gboolean
+_ostree_sysroot_parse_bootlink_aboot (const char *bootlink, char **out_osname, GError **error)
+{
+  static gsize regex_initialized;
+  static GRegex *regex;
+  g_autofree char *symlink_val = glnx_readlinkat_malloc (-1, bootlink, NULL, error);
+  if (!symlink_val)
+    return glnx_throw (error, "Failed to read '%s' symlink", bootlink);
+
+  if (g_once_init_enter (&regex_initialized))
+    {
+      regex = g_regex_new ("^deploy/([^/]+)/", 0, 0, NULL);
+      g_assert (regex);
+      g_once_init_leave (&regex_initialized, 1);
+    }
+
+  g_autoptr (GMatchInfo) match = NULL;
+  if (!g_regex_match (regex, symlink_val, 0, &match))
+    return glnx_throw (error,
+                       "Invalid aboot symlink in /ostree, expected symlink to resolve to "
+                       "deploy/OSNAME/... instead it resolves to '%s'",
+                       symlink_val);
+
+  *out_osname = g_match_info_fetch (match, 1);
+  return TRUE;
+}
+
 /* Generate var.mount */
 static gboolean
 fstab_generator (const char *ostree_target, const bool is_aboot, const char *normal_dir,
@@ -144,8 +172,12 @@ fstab_generator (const char *ostree_target, const bool is_aboot, const char *nor
    * mounted yet.
    */
   g_autofree char *stateroot = NULL;
-  if (!_ostree_sysroot_parse_bootlink (ostree_target, is_aboot, NULL, &stateroot, NULL, NULL,
-                                       error))
+  if (is_aboot)
+    {
+      if (!_ostree_sysroot_parse_bootlink_aboot (ostree_target, &stateroot, error))
+        return glnx_prefix_error (error, "Parsing aboot stateroot");
+    }
+  else if (!_ostree_sysroot_parse_bootlink (ostree_target, NULL, &stateroot, NULL, NULL, error))
     return glnx_prefix_error (error, "Parsing stateroot");
 
   /* Load /etc/fstab if it exists, and look for a /var mount */
@@ -262,14 +294,16 @@ _ostree_impl_system_generator (const char *normal_dir, const char *early_dir, co
   if (!cmdline)
     return glnx_throw (error, "Failed to read /proc/cmdline");
 
-  g_autoptr (GError) otcore_get_ostree_target_error = NULL;
   g_autofree char *ostree_target = NULL;
-  bool is_aboot = false;
-  /* This could happen in CoreOS live environments, where we hackily mock
+  gboolean is_aboot = false;
+  if (!otcore_get_ostree_target (cmdline, &is_aboot, &ostree_target, error))
+    errx (EXIT_FAILURE, "Failed to determine ostree target: %s", (*error)->message);
+
+  /* If no `ostree=` karg exists, gracefully no-op.
+   * This could happen in CoreOS live environments, where we hackily mock
    * the `ostree=` karg for `ostree-prepare-root.service` specifically, but
    * otherwise that karg doesn't exist on the real command-line. */
-  if (!otcore_get_ostree_target (cmdline, &is_aboot, &ostree_target,
-                                 &otcore_get_ostree_target_error))
+  if (!ostree_target)
     return TRUE;
 
   if (!require_internal_units (normal_dir, early_dir, late_dir, error))

src/libostree/ostree-sysroot-private.h

@@ -19,8 +19,6 @@
 
 #pragma once
 
-#include <stdbool.h>
-
 #include "libglnx.h"
 #include "ostree-bootloader.h"
 #include "ostree.h"
@@ -179,9 +177,8 @@ gboolean _ostree_sysroot_parse_bootdir_name (const char *name, char **out_osname
 gboolean _ostree_sysroot_list_all_boot_directories (OstreeSysroot *self, char ***out_bootdirs,
                                                     GCancellable *cancellable, GError **error);
 
-gboolean _ostree_sysroot_parse_bootlink (const char *bootlink, const bool is_aboot,
-                                         int *out_entry_bootversion, char **out_osname,
-                                         char **out_bootcsum, int *out_treebootserial,
-                                         GError **error);
+gboolean _ostree_sysroot_parse_bootlink (const char *bootlink, int *out_entry_bootversion,
+                                         char **out_osname, char **out_bootcsum,
+                                         int *out_treebootserial, GError **error);
 
 G_END_DECLS

src/libostree/ostree-sysroot.c

@@ -724,44 +724,24 @@ load_origin (OstreeSysroot *self, OstreeDeployment *deployment, GCancellable *ca
 
 // Parse the kernel argument ostree=
 gboolean
-_ostree_sysroot_parse_bootlink (const char *bootlink, const bool is_aboot,
-                                int *out_entry_bootversion, char **out_osname, char **out_bootcsum,
-                                int *out_treebootserial, GError **error)
+_ostree_sysroot_parse_bootlink (const char *bootlink, int *out_entry_bootversion, char **out_osname,
+                                char **out_bootcsum, int *out_treebootserial, GError **error)
 {
   static gsize regex_initialized;
   static GRegex *regex;
-  const char *to_parse = bootlink;
-  g_autofree char *symlink_val = NULL;
-  if (is_aboot)
-    {
-      symlink_val = glnx_readlinkat_malloc (-1, bootlink, NULL, error);
-      if (!symlink_val)
-        return glnx_throw (error, "Failed to read '%s' symlink", bootlink);
-
-      to_parse = symlink_val;
-    }
-
   if (g_once_init_enter (&regex_initialized))
     {
-      regex = g_regex_new (is_aboot ? "^deploy/([^/]+)/"
-                                    : "^/ostree/boot.([01])/([^/]+)/([^/]+)/([0-9]+)$",
-                           0, 0, NULL);
+      regex = g_regex_new ("^/ostree/boot.([01])/([^/]+)/([^/]+)/([0-9]+)$", 0, 0, NULL);
       g_assert (regex);
       g_once_init_leave (&regex_initialized, 1);
     }
 
   g_autoptr (GMatchInfo) match = NULL;
-  if (!g_regex_match (regex, to_parse, 0, &match))
+  if (!g_regex_match (regex, bootlink, 0, &match))
     return glnx_throw (error,
                        "Invalid ostree= argument '%s', expected "
-                       "ostree=/ostree/boot.BOOTVERSION/OSNAME/BOOTCSUM/TREESERIAL or aboot method",
-                       to_parse);
-
-  if (is_aboot)
-    {
-      *out_osname = g_match_info_fetch (match, 1);
-      return TRUE;
-    }
+                       "ostree=/ostree/boot.BOOTVERSION/OSNAME/BOOTCSUM/TREESERIAL",
+                       bootlink);
 
   g_autofree char *bootversion_str = g_match_info_fetch (match, 1);
   g_autofree char *treebootserial_str = g_match_info_fetch (match, 4);
@@ -798,7 +778,7 @@ parse_deployment (OstreeSysroot *self, const char *boot_link, OstreeDeployment *
 
   // Note is_boot should always be false here, this boot_link is taken from BLS file, not
   // /proc/cmdline, BLS files are present in aboot images
-  if (!_ostree_sysroot_parse_bootlink (boot_link, false, &entry_boot_version, &osname, &bootcsum,
+  if (!_ostree_sysroot_parse_bootlink (boot_link, &entry_boot_version, &osname, &bootcsum,
                                        &treebootserial, error))
     return FALSE;
 

src/libotcore/otcore-prepare-root.c

@@ -75,7 +75,8 @@ otcore_find_proc_cmdline_key (const char *cmdline, const char *key)
 //
 // If invalid data is found, @error will be set.
 gboolean
-otcore_get_ostree_target (const char *cmdline, bool *is_aboot, char **out_target, GError **error)
+otcore_get_ostree_target (const char *cmdline, gboolean *is_aboot, char **out_target,
+                          GError **error)
 {
   g_assert (cmdline);
   g_assert (out_target && *out_target == NULL);
@@ -84,10 +85,14 @@ otcore_get_ostree_target (const char *cmdline, bool *is_aboot, char **out_target
 
   // First, handle the Android boot case
   g_autofree char *slot_suffix = otcore_find_proc_cmdline_key (cmdline, "androidboot.slot_suffix");
-  *is_aboot = false;
+  if (is_aboot)
+    *is_aboot = false;
+
   if (slot_suffix)
     {
-      *is_aboot = true;
+      if (is_aboot)
+        *is_aboot = true;
+
       if (strcmp (slot_suffix, "_a") == 0)
         {
           *out_target = g_strdup (slot_a);

src/libotcore/otcore.h

@@ -44,7 +44,7 @@ gboolean otcore_validate_ed25519_signature (GBytes *data, GBytes *pubkey, GBytes
                                             bool *out_valid, GError **error);
 
 char *otcore_find_proc_cmdline_key (const char *cmdline, const char *key);
-gboolean otcore_get_ostree_target (const char *cmdline, bool *is_aboot, char **out_target,
+gboolean otcore_get_ostree_target (const char *cmdline, gboolean *is_aboot, char **out_target,
                                    GError **error);
 
 GKeyFile *otcore_load_config (int rootfs, const char *filename, GError **error);

src/switchroot/ostree-prepare-root.c

@@ -124,8 +124,7 @@ resolve_deploy_path (const char *root_mountpoint)
 
   g_autoptr (GError) error = NULL;
   g_autofree char *ostree_target = NULL;
-  bool is_aboot = false;
-  if (!otcore_get_ostree_target (kernel_cmdline, &is_aboot, &ostree_target, &error))
+  if (!otcore_get_ostree_target (kernel_cmdline, NULL, &ostree_target, &error))
     errx (EXIT_FAILURE, "Failed to determine ostree target: %s", error->message);
   if (!ostree_target)
     errx (EXIT_FAILURE, "No ostree target found");

tests/test-otcore.c

@@ -36,47 +36,45 @@ test_prepare_root_cmdline (void)
 {
   g_autoptr (GError) error = NULL;
   g_autofree char *target = NULL;
-  bool is_aboot = false;
-
   static const char *notfound_cases[]
       = { "", "foo", "foo=bar baz  sometest", "xostree foo", "xostree=blah bar", NULL };
   for (const char **iter = notfound_cases; iter && *iter; iter++)
     {
       const char *tcase = *iter;
-      g_assert (otcore_get_ostree_target (tcase, &is_aboot, &target, &error));
+      g_assert (otcore_get_ostree_target (tcase, NULL, &target, &error));
       g_assert_no_error (error);
       g_assert (target == NULL);
     }
 
   // Test the default ostree=
-  g_assert (otcore_get_ostree_target ("blah baz=blah ostree=/foo/bar somearg", &is_aboot, &target,
-                                      &error));
+  g_assert (
+      otcore_get_ostree_target ("blah baz=blah ostree=/foo/bar somearg", NULL, &target, &error));
   g_assert_no_error (error);
   g_assert_cmpstr (target, ==, "/foo/bar");
   free (g_steal_pointer (&target));
 
   // Test android boot
-  g_assert (otcore_get_ostree_target ("blah baz=blah androidboot.slot_suffix=_b somearg", &is_aboot,
+  g_assert (otcore_get_ostree_target ("blah baz=blah androidboot.slot_suffix=_b somearg", NULL,
                                       &target, &error));
   g_assert_no_error (error);
   g_assert_cmpstr (target, ==, "/ostree/root.b");
   free (g_steal_pointer (&target));
 
-  g_assert (otcore_get_ostree_target ("blah baz=blah androidboot.slot_suffix=_a somearg", &is_aboot,
+  g_assert (otcore_get_ostree_target ("blah baz=blah androidboot.slot_suffix=_a somearg", NULL,
                                       &target, &error));
   g_assert_no_error (error);
   g_assert_cmpstr (target, ==, "/ostree/root.a");
   free (g_steal_pointer (&target));
 
   // And an expected failure to parse a "c" suffix
-  g_assert (!otcore_get_ostree_target ("blah baz=blah androidboot.slot_suffix=_c somearg",
-                                       &is_aboot, &target, &error));
+  g_assert (!otcore_get_ostree_target ("blah baz=blah androidboot.slot_suffix=_c somearg", NULL,
+                                       &target, &error));
   g_assert (error);
   g_assert (target == NULL);
   g_clear_error (&error);
 
   // And non-A/B androidboot
-  g_assert (otcore_get_ostree_target ("blah baz=blah androidboot.somethingelse somearg", &is_aboot,
+  g_assert (otcore_get_ostree_target ("blah baz=blah androidboot.somethingelse somearg", NULL,
                                       &target, &error));
   g_assert_no_error (error);
   g_assert_cmpstr (target, ==, "/ostree/root.a");