[PATCH 08/14] discover/grub2: Allow (device)/path references in general script usage
Jeremy Kerr
jk at ozlabs.org
Wed Nov 20 13:43:00 AEDT 2019
Currently, we have support for grub2 (device)/path syntax for boot
resources. This change allows this syntax for general paths in grub2
scripts (for example, -f tests).
This involves exposing grub2_lookup_device, to allow the script
execution code to resolve pathnames.
Signed-off-by: Jeremy Kerr <jk at ozlabs.org>
---
discover/grub2/builtins.c | 50 ++++++++++++++++---
discover/grub2/grub2.c | 4 +-
discover/grub2/grub2.h | 2 +
test/parser/Makefile.am | 1 +
test/parser/test-grub2-devpath-scripting.c | 56 ++++++++++++++++++++++
5 files changed, 104 insertions(+), 9 deletions(-)
create mode 100644 test/parser/test-grub2-devpath-scripting.c
diff --git a/discover/grub2/builtins.c b/discover/grub2/builtins.c
index 765c4d7..c726216 100644
--- a/discover/grub2/builtins.c
+++ b/discover/grub2/builtins.c
@@ -197,6 +197,32 @@ static int builtin_search(struct grub2_script *script,
return 0;
}
+static int parse_to_device_path(struct grub2_script *script,
+ const char *desc, struct discover_device **devp,
+ char **pathp)
+{
+ struct discover_device *dev;
+ struct grub2_file *file;
+
+ file = grub2_parse_file(script, desc);
+ if (!file)
+ return -1;
+
+ dev = script->ctx->device;
+ if (file->dev)
+ dev = grub2_lookup_device(script->ctx->handler, file->dev);
+
+ if (!dev)
+ return -1;
+
+ *devp = dev;
+ *pathp = talloc_strdup(script, file->path);
+
+ talloc_free(file);
+
+ return 0;
+}
+
/* Note that GRUB does not follow symlinks in evaluating all file
* tests but -s, unlike below. However, it seems like a bad idea to
* emulate GRUB's behavior (e.g., it would take extra work), so we
@@ -204,12 +230,17 @@ static int builtin_search(struct grub2_script *script,
static bool builtin_test_op_file(struct grub2_script *script, char op,
const char *file)
{
+ struct discover_device *dev;
+ struct stat statbuf;
bool result;
+ char *path;
int rc;
- struct stat statbuf;
- rc = parser_stat_path(script->ctx, script->ctx->device,
- file, &statbuf);
+ rc = parse_to_device_path(script, file, &dev, &path);
+ if (rc)
+ return false;
+
+ rc = parser_stat_path(script->ctx, dev, path, &statbuf);
if (rc)
return false;
@@ -237,16 +268,21 @@ static bool builtin_test_op_file(struct grub2_script *script, char op,
static bool builtin_test_op_dir(struct grub2_script *script, char op,
const char *dir)
{
- int rc;
+ struct discover_device *dev;
struct stat statbuf;
+ char *path;
+ int rc;
if (op != 'd')
return false;
- rc = parser_stat_path(script->ctx, script->ctx->device, dir, &statbuf);
- if (rc) {
+ rc = parse_to_device_path(script, dir, &dev, &path);
+ if (rc)
+ return false;
+
+ rc = parser_stat_path(script->ctx, dev, path, &statbuf);
+ if (rc)
return false;
- }
return S_ISDIR(statbuf.st_mode);
}
diff --git a/discover/grub2/grub2.c b/discover/grub2/grub2.c
index a08a320..a8d115f 100644
--- a/discover/grub2/grub2.c
+++ b/discover/grub2/grub2.c
@@ -33,8 +33,8 @@ static const char *const grub2_conf_files[] = {
NULL
};
-static struct discover_device *grub2_lookup_device(
- struct device_handler *handler, const char *desc)
+struct discover_device *grub2_lookup_device(struct device_handler *handler,
+ const char *desc)
{
struct discover_device *dev;
diff --git a/discover/grub2/grub2.h b/discover/grub2/grub2.h
index ef32d4b..eabd6d6 100644
--- a/discover/grub2/grub2.h
+++ b/discover/grub2/grub2.h
@@ -200,6 +200,8 @@ bool resolve_grub2_resource(struct device_handler *handler,
/* grub-style device+path parsing */
struct grub2_file *grub2_parse_file(struct grub2_script *script,
const char *str);
+struct discover_device *grub2_lookup_device(struct device_handler *handler,
+ const char *desc);
/* external parser api */
struct grub2_parser *grub2_parser_create(struct discover_context *ctx);
diff --git a/test/parser/Makefile.am b/test/parser/Makefile.am
index 0378317..c8e059b 100644
--- a/test/parser/Makefile.am
+++ b/test/parser/Makefile.am
@@ -33,6 +33,7 @@ parser_TESTS = \
test/parser/test-grub2-search-uuid \
test/parser/test-grub2-search-label \
test/parser/test-grub2-devpath \
+ test/parser/test-grub2-devpath-scripting \
test/parser/test-grub2-load-env \
test/parser/test-grub2-save-env \
test/parser/test-grub2-save-env-dash-f \
diff --git a/test/parser/test-grub2-devpath-scripting.c b/test/parser/test-grub2-devpath-scripting.c
new file mode 100644
index 0000000..9046ab6
--- /dev/null
+++ b/test/parser/test-grub2-devpath-scripting.c
@@ -0,0 +1,56 @@
+/* check grub2 device+path string parsing, as used in scripts */
+
+#include "parser-test.h"
+
+#if 0 /* PARSER_EMBEDDED_CONFIG */
+
+v=
+
+# local device, file present
+if [ -f "/1-present" ]; then v=${v}a; fi
+
+# local device, file absent
+if [ -f "/1-absent" ]; then v=${v}b; fi;
+
+# local device by UUID, file present
+if [ -f "(00000000-0000-0000-0000-000000000001)/1-present" ]; then v=${v}c; fi;
+
+# remote device by UUID, file present
+if [ -f "(00000000-0000-0000-0000-000000000002)/2-present" ]; then v=${v}d; fi;
+
+# non-existent device
+if [ -f "(00000000-0000-0000-0000-000000000003)/present" ]; then v=${v}e; fi;
+
+menuentry $v {
+ linux /vmlinux
+}
+
+#endif
+
+void run_test(struct parser_test *test)
+{
+ struct discover_device *dev1, *dev2;
+ struct discover_boot_option *opt;
+ struct discover_context *ctx;
+
+ ctx = test->ctx;
+
+ /* set local uuid */
+ dev1 = test->ctx->device;
+ dev1->uuid = "00000000-0000-0000-0000-000000000001";
+
+ dev2 = test_create_device(test, "extdev");
+ dev2->uuid = "00000000-0000-0000-0000-000000000002";
+ device_handler_add_device(ctx->handler, dev2);
+
+ test_add_file_data(test, dev1, "/1-present", "x", 1);
+ test_add_file_data(test, dev2, "/2-present", "x", 1);
+
+ test_read_conf_embedded(test, "/grub/grub.cfg");
+
+ test_run_parser(test, "grub2");
+
+ check_boot_option_count(ctx, 1);
+ opt = get_boot_option(ctx, 0);
+ check_name(opt, "acd");
+}
--
2.20.1
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