From d71628326d80e623fc9f008fe4ea93edb5592b2e Mon Sep 17 00:00:00 2001
From: Tuan Hoang <tmhoang@linux.ibm.com>
Date: Fri, 4 Oct 2019 19:37:25 +0200
Subject: [PATCH] zipl: add value of target= as search path for BLS case
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In the BLS files, the 'linux' and 'initrd' fields are relative to the
$BOOT directory. If $BOOT is a mount point of boot partition, 'linux'
and 'initrd' fields are relative to boot partition. If not, the paths
are relative to $BOOT directory of root partition.

zipl always starts searching at / regardless of partitions and mount
points.

This commit extends the semantics of target= field in zipl.conf to make
it as a second search path, besides /, for those 2 BLS fields.

See issues #69 for more details.

Fixes: https://github.com/ibm-s390-tools/s390-tools/issues/69
Closes: https://github.com/ibm-s390-tools/s390-tools/pull/74
Signed-off-by: Tuan Hoang <tmhoang@linux.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
---
 zipl/include/scan.h |  1 +
 zipl/src/job.c      |  6 +++++
 zipl/src/scan.c     | 58 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 65 insertions(+)

diff --git a/zipl/include/scan.h b/zipl/include/scan.h
index 4dcee0b0..f39e96ef 100644
--- a/zipl/include/scan.h
+++ b/zipl/include/scan.h
@@ -126,6 +126,7 @@ char* scan_keyword_name(enum scan_keyword_id id);
 int scan_check_defaultboot(struct scan_token* scan);
 struct scan_token* scan_build_automenu(struct scan_token* scan);
 int scan_check(struct scan_token* scan);
+int scan_check_bls(struct scan_token *scan);
 int scan_find_section(struct scan_token* scan, char* name, enum scan_id type,
 		      int offset);
 int scan_check_section_data(char* keyword[], int* line, char* name,
diff --git a/zipl/src/job.c b/zipl/src/job.c
index ccd9bb0d..7d61c842 100644
--- a/zipl/src/job.c
+++ b/zipl/src/job.c
@@ -1853,6 +1853,12 @@ get_job_from_config_file(struct command_line* cmdline, struct job_data* job)
 		scan_free(scan);
 		return rc;
 	}
+	rc = scan_check_bls(scan);
+	if (rc) {
+		error_text("BLS parsing '%s'", blsdir);
+		scan_free(scan);
+		return rc;
+	}
 	/* Get job from config file data */
 	if (cmdline->menu != NULL)
 		rc = get_menu_job(scan, cmdline->menu, job);
diff --git a/zipl/src/scan.c b/zipl/src/scan.c
index 635d41ef..38fa5454 100644
--- a/zipl/src/scan.c
+++ b/zipl/src/scan.c
@@ -1564,6 +1564,64 @@ scan_check(struct scan_token* scan)
 	return 0;
 }
 
+/*
+ * Check if kernel and initrd image paths provided by BLS files are readable.
+ * If not, add value of 'scan_keyword_target' into search path and silently
+ * update scan list.
+ */
+int
+scan_check_bls(struct scan_token *scan)
+{
+	int i, rc;
+	char *target_value = NULL;
+	char *img_value = NULL;
+	char *buffer = NULL;
+	/*
+	 * In the BLS case, each BLS section heading inherits a keyword
+	 * assignment target= from zipl.conf, and they are all the same.
+	 *
+	 */
+	for (i = 0 ; scan[i].id != scan_id_empty; i++) {
+		if (scan[i].id == scan_id_keyword_assignment &&
+		    scan[i].content.keyword.keyword == scan_keyword_target) {
+			target_value = scan[i].content.keyword.value;
+			break;
+		}
+	}
+	if (!target_value)
+		return -1;
+	for (i = 0 ; scan[i].id != scan_id_empty; i++) {
+		if (scan[i].id != scan_id_keyword_assignment)
+			continue;
+		if (scan[i].content.keyword.keyword == scan_keyword_image ||
+		    scan[i].content.keyword.keyword == scan_keyword_ramdisk) {
+
+			rc = misc_check_readable_file(
+				scan[i].content.keyword.value);
+			if (rc) {
+				misc_asprintf(&img_value, "%s%s",
+					      target_value,
+					      scan[i].content.keyword.value);
+				rc = misc_check_readable_file(img_value);
+				if (rc) {
+					error_text(
+						"Image file '%s' is not accessible",
+						scan[i].content.keyword.value);
+					return rc;
+				}
+				buffer = (char *)
+					misc_malloc(strlen(img_value) + 1);
+				if (buffer == NULL)
+					return -1;
+				memcpy(buffer, img_value, strlen(img_value));
+				buffer[strlen(img_value)] = 0;
+				free(scan[i].content.keyword.value);
+				scan[i].content.keyword.value = buffer;
+			}
+		}
+	}
+	return 0;
+}
 
 static int
 scan_get_defaultboot_type(char* keyword[], int line[], int section_line,