Fix up guid
GUIDs have some cases where they might not be representable as a string,
due to an overflow. To handle this previously, the existing
implementation just allocated extra space.
To ensure that we are always publishing correct guids, break this
function down into an add_guid method that we can call anytime we add a
guid to json. This function can use the appropriate guid string length,
and if we go over, we can make sure that we don't publish the string at
all, by handling the appropriate error codes.
Change-Id: I98239b7d5ba7567cea1b016579d7566e292b6e81
Signed-off-by: Ed Tanous <ed@tanous.net>
diff --git a/cper-parse.c b/cper-parse.c
index 8b62ef6..12eb464 100644
--- a/cper-parse.c
+++ b/cper-parse.c
@@ -221,37 +221,22 @@
//If a platform ID exists according to the validation bits, then add it.
if (header->ValidationBits & 0x1) {
- char platform_string[GUID_STRING_LENGTH];
- guid_to_string(platform_string, &header->PlatformID);
- json_object_object_add(header_ir, "platformID",
- json_object_new_string(platform_string));
+ add_guid(header_ir, "platformID", &header->PlatformID);
}
//If a partition ID exists according to the validation bits, then add it.
if (header->ValidationBits & 0x4) {
- char partition_string[GUID_STRING_LENGTH];
- guid_to_string(partition_string, &header->PartitionID);
- json_object_object_add(
- header_ir, "partitionID",
- json_object_new_string(partition_string));
+ add_guid(header_ir, "partitionID", &header->PartitionID);
}
//Creator ID of the header.
- char creator_string[GUID_STRING_LENGTH];
- guid_to_string(creator_string, &header->CreatorID);
- json_object_object_add(header_ir, "creatorID",
- json_object_new_string(creator_string));
-
+ add_guid(header_ir, "creatorID", &header->CreatorID);
//Notification type for the header. Some defined types are available.
json_object *notification_type = json_object_new_object();
- char notification_type_string[GUID_STRING_LENGTH];
- guid_to_string(notification_type_string, &header->NotificationType);
- json_object_object_add(
- notification_type, "guid",
- json_object_new_string(notification_type_string));
+ add_guid(notification_type, "guid", &header->NotificationType);
//Add the human readable notification type if possible.
- char *notification_type_readable = "Unknown";
+ const char *notification_type_readable = "Unknown";
if (guid_equal(&header->NotificationType,
&gEfiEventNotificationTypeCmcGuid)) {
notification_type_readable = "CMC";
@@ -343,11 +328,8 @@
//Section type (GUID).
json_object *section_type = json_object_new_object();
- char section_type_string[GUID_STRING_LENGTH];
- guid_to_string(section_type_string, §ion_descriptor->SectionType);
- json_object_object_add(section_type, "data",
- json_object_new_string(section_type_string));
+ add_guid(section_type, "data", §ion_descriptor->SectionType);
//Readable section type, if possible.
const char *section_type_readable = "Unknown";
for (size_t i = 0; i < section_definitions_len; i++) {
@@ -366,10 +348,8 @@
//If validation bits indicate it exists, add FRU ID.
if (section_descriptor->SecValidMask & 0x1) {
- char fru_id_string[GUID_STRING_LENGTH];
- guid_to_string(fru_id_string, §ion_descriptor->FruId);
- json_object_object_add(section_descriptor_ir, "fruID",
- json_object_new_string(fru_id_string));
+ add_guid(section_descriptor_ir, "fruID",
+ §ion_descriptor->FruId);
}
//If validation bits indicate it exists, add FRU text.
diff --git a/cper-utils.c b/cper-utils.c
index 11fdbcb..c37796d 100644
--- a/cper-utils.c
+++ b/cper-utils.c
@@ -384,12 +384,18 @@
}
//Helper function to convert an EDK EFI GUID into a string for intermediate use.
-void guid_to_string(char *out, EFI_GUID *guid)
+int guid_to_string(char *out, size_t out_len, EFI_GUID *guid)
{
- sprintf(out, "%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",
- guid->Data1, guid->Data2, guid->Data3, guid->Data4[0],
- guid->Data4[1], guid->Data4[2], guid->Data4[3], guid->Data4[4],
- guid->Data4[5], guid->Data4[6], guid->Data4[7]);
+ size_t len = snprintf(
+ out, out_len,
+ "%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x", guid->Data1,
+ guid->Data2, guid->Data3, guid->Data4[0], guid->Data4[1],
+ guid->Data4[2], guid->Data4[3], guid->Data4[4], guid->Data4[5],
+ guid->Data4[6], guid->Data4[7]);
+ if (len != out_len) {
+ return -1;
+ }
+ return len;
}
//Helper function to convert a string into an EDK EFI GUID.
@@ -446,3 +452,15 @@
json_object_new_string_len(str, fru_text_len));
}
}
+
+void add_guid(json_object *ir, const char *field_name, EFI_GUID *guid)
+{
+ char platform_string[GUID_STRING_LENGTH + 1];
+ if (!guid_to_string(platform_string, sizeof(platform_string), guid)) {
+ return;
+ }
+ json_object_object_add(
+ ir, field_name,
+ json_object_new_string_len(platform_string,
+ sizeof(platform_string) - 1));
+}
diff --git a/include/libcper/cper-utils.h b/include/libcper/cper-utils.h
index 1003c38..e5ec8d4 100644
--- a/include/libcper/cper-utils.h
+++ b/include/libcper/cper-utils.h
@@ -1,7 +1,7 @@
#ifndef CPER_UTILS_H
#define CPER_UTILS_H
-#define GUID_STRING_LENGTH 48
+#define GUID_STRING_LENGTH 36
#define TIMESTAMP_LENGTH 26
#ifdef __cplusplus
@@ -57,13 +57,15 @@
int timestamp_to_string(char *out, int out_len,
EFI_ERROR_TIME_STAMP *timestamp);
void string_to_timestamp(EFI_ERROR_TIME_STAMP *out, const char *timestamp);
-void guid_to_string(char *out, EFI_GUID *guid);
+int guid_to_string(char *out, size_t out_len, EFI_GUID *guid);
void string_to_guid(EFI_GUID *out, const char *guid);
int guid_equal(EFI_GUID *a, EFI_GUID *b);
void add_untrusted_string(json_object *ir, const char *field_name,
const char *str, int len);
+void add_guid(json_object *ir, const char *field_name, EFI_GUID *guid);
+
//The available severity types for CPER.
extern const char *CPER_SEVERITY_TYPES[4];
diff --git a/sections/cper-section-firmware.c b/sections/cper-section-firmware.c
index 78f04d0..327d70b 100644
--- a/sections/cper-section-firmware.c
+++ b/sections/cper-section-firmware.c
@@ -35,10 +35,7 @@
json_object_new_uint64(firmware_error->RecordId));
//Record GUID.
- char record_id_guid[GUID_STRING_LENGTH];
- guid_to_string(record_id_guid, &firmware_error->RecordIdGuid);
- json_object_object_add(section_ir, "recordIDGUID",
- json_object_new_string(record_id_guid));
+ add_guid(section_ir, "recordIDGUID", &firmware_error->RecordIdGuid);
return section_ir;
}
diff --git a/sections/cper-section-ia32x64.c b/sections/cper-section-ia32x64.c
index c127e93..c04bed1 100644
--- a/sections/cper-section-ia32x64.c
+++ b/sections/cper-section-ia32x64.c
@@ -148,13 +148,10 @@
EFI_IA32_X64_PROCESS_ERROR_INFO *error_info)
{
json_object *error_info_ir = json_object_new_object();
+ json_object *type = json_object_new_object();
//Error structure type (as GUID).
- char error_type[GUID_STRING_LENGTH];
- guid_to_string(error_type, &error_info->ErrorType);
- json_object *type = json_object_new_object();
- json_object_object_add(type, "guid",
- json_object_new_string(error_type));
+ add_guid(type, "guid", &error_info->ErrorType);
//Get the error structure type as a readable string.
const char *readable_type = "Unknown";