From 92388b2c470dd4b01bf47902132349319b8f0cd6 Mon Sep 17 00:00:00 2001
From: Kasun Athukorala <kasunath@google.com>
Date: Fri, 5 Sep 2025 18:50:26 +0000
Subject: [PATCH] dsp: base: Fix MultipartReceive Request decoding

This fix is based on DSP0240 v1.2.0 section 9.6.5 MultipartReceive.

- 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, when using MultipartReceive to read a file,
the client has to send transfer handle 0 with XFER_FIRST_PART.

Change-Id: I06428556f9dee341de97f72b015ed0347adc9454
Signed-off-by: Kasun Athukorala <kasunath@google.com>
---
 CHANGELOG.md       |  4 ++++
 src/dsp/base.c     | 11 ++++-------
 tests/dsp/base.cpp | 37 -------------------------------------
 3 files changed, 8 insertions(+), 44 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9f28c0d..b28a4fc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -96,6 +96,10 @@ Change categories:
 - 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
diff --git a/src/dsp/base.c b/src/dsp/base.c
index cc805df..eb0aaa4 100644
--- a/src/dsp/base.c
+++ b/src/dsp/base.c
@@ -569,13 +569,10 @@ int decode_multipart_receive_req(const struct pldm_msg *msg,
 		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) {
+	// Transfer handle can be 0 only if the transfer flag is one of XFER_FIRST_PART,
+	// PLDM_XFER_CURRENT_PART, XFER_ABORT or XFER_COMPLETE.
+	if ((*transfer_handle == 0) &&
+	    (*transfer_opflag == PLDM_XFER_NEXT_PART)) {
 		return PLDM_ERROR_INVALID_DATA;
 	}
 
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 @@ TEST(DecodeMultipartReceiveRequest, testDecodeRequestFailBadTransferFlag)
               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;
-- 
2.51.0.536.g15c5d4f767-goog