net: lib: lwm2m: block 0 resets prev block transfer for same resource (2f35d11b) · Commits · Wenxi XU / zephyr

As stated in "[RFC7959], Section 2.5": "The Block1 Option provides no way for a single endpoint to perform multiple concurrently proceeding block-wise request payload transfer (e.g., PUT or POST) operations to the same resource. Starting a new block-wise sequence of requests to the same resource (before an old sequence from the same endpoint was finished) simply overwrites the context the server may still be keeping." Signed-off-by:

Marco Argiolas <marco.argiolas@ftpsolutions.com.au>

subsys/net/lib/lwm2m/lwm2m_message_handling.c

+7 −3

Original line number	Diff line number	Diff line
		@@ -2055,11 +2055,15 @@ static int parse_write_op(struct lwm2m_message *msg, uint16_t format)

		block_num = GET_BLOCK_NUM(block_opt);

		/* Try to retrieve existing block context. If one not exists,
		* and we've received first block, allocate new context.
		/*
		* RFC7959: 2.5. Using the Block1 Option
		* If we've received first block, replace old context (if any) with a new one.
		*/
		r = get_block_ctx(&msg->path, &block_ctx);
		if (r < 0 && block_num == 0) {
		if (block_num == 0) {
		/* free block context for previous incomplete transfer */
		free_block_ctx(block_ctx);

		r = init_block_ctx(&msg->path, &block_ctx);
		}

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