commit d50035f598d40309c20c0c75024fda73a6d6cb62
author Kasun Athukorala <kasunath@google.com> Fri Sep 05 18:50:26 2025 +0000
committer Andrew Jeffery <andrew@codeconstruct.com.au> Tue Sep 30 10:28:40 2025 +0930
tree 4dbe185928ae680c806263abf90afab3aaa02c2e
parent 9d320cbc2c63115caabd47229f622756cf7aea19

dsp: base: Fix MultipartReceive Request decoding

This fix is based on DSP0240 v1.2.0 section 9.6.6 - Flag usage for
MultipartReceive (paragraph 351) and Table 17 MultipartReceive request
format.

- Removed RequestedSectionOffset check.

The Property can be 0 for any TransferOperation flag.

- Changed DataTransferHandle check.

The property can be 0 except with PLDM_XFER_NEXT_PART. Eg. In DSP0242
v1.0.0 section 9.8.2, Table 19, and DSP0240 v1.2.0 section 9.6.5, Table
17, when using MultipartReceive to read a file, the client has to send
transfer handle 0 with XFER_FIRST_PART.

Change-Id: I06428556f9dee341de97f72b015ed0347adc9454
Fixes: 9c76679224cf ("libpldm: Migrate to subproject")
Signed-off-by: Kasun Athukorala <kasunath@google.com>
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>

CHANGELOG.md

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9f28c0d..b28a4fc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -96,6 +96,10 @@
 - include, tests: Address concerns from -Wsign-compare
 - dsp: base: decode_pldm_base_negotiate_transfer_params_resp() is stable
 
+- base:
+  - Removed RequestedSectionOffset check in decode_multipart_receive_req()
+  - Updated DataTransferHandle check in decode_multipart_receive_req()
+
 ### Security
 
 ## [0.14.0] 2025-08-11

src/dsp/base.c

diff --git a/src/dsp/base.c b/src/dsp/base.c
index cc805df..cd4878c 100644
--- a/src/dsp/base.c
+++ b/src/dsp/base.c
@@ -569,13 +569,14 @@
 		return PLDM_ERROR_UNEXPECTED_TRANSFER_FLAG_OPERATION;
 	}
 
-	// A section offset of 0 is only valid on FIRST_PART or COMPLETE Xfers.
-	if (*section_offset == 0 && (*transfer_opflag != PLDM_XFER_FIRST_PART &&
-				     *transfer_opflag != PLDM_XFER_COMPLETE)) {
-		return PLDM_ERROR_INVALID_DATA;
-	}
-
-	if (*transfer_handle == 0 && *transfer_opflag != PLDM_XFER_COMPLETE) {
+	// By DSP0240 v1.2.0, section 9.6.5, Table 17, transfer handle can be 0 only
+	// if the transfer flag is one of XFER_FIRST_PART, XFER_COMPLETE or
+	// XFER_ABORT. In addition, it must be allowed in PLDM_XFER_CURRENT_PART as
+	// this may be used to retry the first part, in which case the transfer handle
+	// must again be 0. Therefore, the only operation for which it cannot be 0 is
+	// PLDM_XFER_NEXT_PART.
+	if ((*transfer_handle == 0) &&
+	    (*transfer_opflag == PLDM_XFER_NEXT_PART)) {
 		return PLDM_ERROR_INVALID_DATA;
 	}
 

tests/dsp/base.cpp

diff --git a/tests/dsp/base.cpp b/tests/dsp/base.cpp
index f146e7c..b2e9294 100644
--- a/tests/dsp/base.cpp
+++ b/tests/dsp/base.cpp
@@ -674,43 +674,6 @@
               PLDM_ERROR_UNEXPECTED_TRANSFER_FLAG_OPERATION);
 }
 
-TEST(DecodeMultipartReceiveRequest, testDecodeRequestFailBadOffset)
-{
-    constexpr uint8_t kPldmType = PLDM_BASE;
-    constexpr uint8_t kFlag = PLDM_XFER_NEXT_PART;
-    constexpr uint32_t kTransferCtx = 0x01;
-    constexpr uint32_t kTransferHandle = 0x01;
-    constexpr uint32_t kSectionOffset = 0x0;
-
-    PLDM_MSG_DEFINE_P(msg, PLDM_MULTIPART_RECEIVE_REQ_BYTES);
-    PLDM_MSGBUF_RW_DEFINE_P(buf);
-    int rc;
-
-    // Header values don't matter for this test.
-    rc = pldm_msgbuf_init_errno(buf, PLDM_MULTIPART_RECEIVE_REQ_BYTES,
-                                msg->payload, PLDM_MULTIPART_RECEIVE_REQ_BYTES);
-    ASSERT_EQ(rc, 0);
-    pldm_msgbuf_insert_uint8(buf, kPldmType);
-    pldm_msgbuf_insert_uint8(buf, kFlag);
-    pldm_msgbuf_insert_uint32(buf, kTransferCtx);
-    pldm_msgbuf_insert_uint32(buf, kTransferHandle);
-    pldm_msgbuf_insert_uint32(buf, kSectionOffset);
-    rc = pldm_msgbuf_complete(buf);
-    ASSERT_EQ(rc, 0);
-
-    uint8_t pldm_type;
-    uint8_t flag;
-    uint32_t transfer_ctx;
-    uint32_t transfer_handle;
-    uint32_t section_offset;
-    uint32_t section_length;
-    EXPECT_EQ(decode_multipart_receive_req(
-                  msg, PLDM_MULTIPART_RECEIVE_REQ_BYTES, &pldm_type, &flag,
-                  &transfer_ctx, &transfer_handle, &section_offset,
-                  &section_length),
-              PLDM_ERROR_INVALID_DATA);
-}
-
 TEST(DecodeMultipartReceiveRequest, testDecodeRequestFailBadHandle)
 {
     constexpr uint8_t kPldmType = PLDM_BASE;