tests: Add bootstrapping of faux legacy environment

We now create the relevant GPT structure to allow CBM to detect a legacy
boot device. Currently this is only used for the syslinux bootloader, but
in future will be extended to permit GRUB too.

Signed-off-by: Ikey Doherty <michael.i.doherty@intel.com>

tests/check-legacy.c

@@ -29,6 +29,33 @@
 #include "harness.h"
 #include "system-harness.h"
 
+/**
+ * Coerce legacy lookup
+ */
+static inline int legacy_devno_to_wholedisk(__cbm_unused__ dev_t dev, __cbm_unused__ char *diskname,
+                                            __cbm_unused__ size_t len,
+                                            __cbm_unused__ dev_t *diskdevno)
+{
+        *diskdevno = makedev(8, 8);
+        return 0;
+}
+
+/**
+ * Forces detection of GPT legacy boot partition
+ */
+static inline unsigned long long legacy_partition_get_flags(__cbm_unused__ blkid_partition par)
+{
+        return (1ULL << 2);
+}
+
+/**
+ * Force the detection of a boot partition GPT UUID
+ */
+static inline const char *legacy_partition_get_uuid(__cbm_unused__ blkid_partition par)
+{
+        return DEFAULT_PART_UUID;
+}
+
 static PlaygroundKernel legacy_kernels[] = { { "4.2.1", "kvm", 121, false },
                                              { "4.2.3", "kvm", 124, true },
                                              { "4.2.1", "native", 137, false },
@@ -44,13 +71,22 @@ static PlaygroundConfig legacy_config = { "4.2.1-121.kvm",
 START_TEST(bootman_legacy_get_boot_device)
 {
         autofree(char) *boot_device = NULL;
-        prepare_playground(&legacy_config);
+        autofree(BootManager) *m = NULL;
+        autofree(char) *exp = NULL;
+
+        /* Ensure cleanup */
+        m = prepare_playground(&legacy_config);
 
         boot_device = get_boot_device();
         fail_if(boot_device != NULL, "Found incorrect UEFI device for Legacy Boot");
 
         boot_device = get_legacy_boot_device(PLAYGROUND_ROOT);
         fail_if(!boot_device, "Failed to determine legacy boot device");
+
+        if (asprintf(&exp, "%s/dev/disk/by-partuuid/Test-PartUUID", PLAYGROUND_ROOT) < 0) {
+                abort();
+        }
+        fail_if(!streq(exp, boot_device), "Boot device does not match expected result");
 }
 END_TEST
 
@@ -72,6 +108,11 @@ int main(void)
         Suite *s;
         SRunner *sr;
         int fail;
+        /* override test ops for legacy testing */
+        CbmBlkidOps blkid_ops = BlkidTestOps;
+        blkid_ops.devno_to_wholedisk = legacy_devno_to_wholedisk;
+        blkid_ops.partition_get_flags = legacy_partition_get_flags;
+        blkid_ops.partition_get_uuid = legacy_partition_get_uuid;
 
         /* syncing can be problematic during test suite runs */
         cbm_set_sync_filesystems(false);
@@ -80,7 +121,7 @@ int main(void)
         setenv("CBM_DEBUG", "1", 1);
         cbm_log_init(stderr);
 
-        cbm_blkid_set_vtable(&BlkidTestOps);
+        cbm_blkid_set_vtable(&blkid_ops);
         cbm_system_set_vtable(&SystemTestOps);
 
         s = core_suite();

tests/harness.c

@@ -377,9 +377,11 @@ BootManager *prepare_playground(PlaygroundConfig *config)
                 goto fail;
         }
 
-        /* Pending: Add support for legacy boot */
+        /* Initialise the root devfs/sysfs */
         if (config->uefi) {
                 set_test_system_uefi();
+        } else {
+                set_test_system_legacy();
         }
 
         /* Construct kernel config directory */
@@ -554,6 +556,58 @@ mem_fail:
         abort();
 }
 
+void set_test_system_legacy(void)
+{
+        autofree(char) *ddir = NULL;
+        autofree(char) *diskdir = NULL;
+        autofree(char) *diskfile = NULL;
+        autofree(char) *dfile = NULL;
+        autofree(char) *dlink = NULL;
+        const char *devfs_path = cbm_system_get_devfs_path();
+
+        /* dev tree */
+        if (asprintf(&ddir, "%s/block", devfs_path) < 0) {
+                goto mem_fail;
+        }
+
+        /* dev/block link */
+        if (asprintf(&dlink, "%s/block/%u:%u", devfs_path, 8, 8) < 0) {
+                goto mem_fail;
+        }
+
+        /* "real" dev file for realpath()ing */
+        if (asprintf(&dfile, "%s/leRootDevice", devfs_path) < 0) {
+                goto mem_fail;
+        }
+
+        nc_mkdir_p(ddir, 00755);
+        if (!file_set_text(dfile, "le-root-device")) {
+                goto mem_fail;
+        }
+
+        if (symlink("../leRootDevice", dlink) != 0) {
+                fprintf(stderr, "Cannot create symlink: %s", strerror(errno));
+                abort();
+        }
+
+        /* Create /dev/disk/by-partuuid portions */
+        if (asprintf(&diskdir, "%s/disk/by-partuuid", cbm_system_get_devfs_path()) < 0) {
+                goto mem_fail;
+        }
+        if (asprintf(&diskfile, "%s/%s", diskdir, "Test-PartUUID") < 0) {
+                goto mem_fail;
+        }
+        nc_mkdir_p(diskdir, 00755);
+        if (!file_set_text(diskfile, "clr-boot-manager Legacy testing")) {
+                goto mem_fail;
+        }
+        return;
+
+mem_fail:
+        DECLARE_OOM();
+        abort();
+}
+
 /*
  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
  *

tests/harness.h

@@ -99,6 +99,11 @@ bool create_timeout_conf(void);
  */
 void set_test_system_uefi(void);
 
+/**
+ * Set up the test harness to emulate legacy boot
+ */
+void set_test_system_legacy(void);
+
 /*
  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
  *