diff --git a/serial_link/protocol/byte_stuffer.c b/serial_link/protocol/byte_stuffer.c index 7ce01a96..e578f88d 100644 --- a/serial_link/protocol/byte_stuffer.c +++ b/serial_link/protocol/byte_stuffer.c @@ -41,6 +41,7 @@ void init_byte_stuffer_state(byte_stuffer_state_t* state) { } void recv_byte(byte_stuffer_state_t* state, uint8_t data) { + // Start of a new frame if (state->next_zero == 0) { state->next_zero = data; state->data_pos = 0; @@ -49,10 +50,19 @@ void recv_byte(byte_stuffer_state_t* state, uint8_t data) { state->next_zero--; if (data == 0) { - recv_frame(state->data, state->data_pos); + if (state->next_zero == 0) { + // The frame is completed + recv_frame(state->data, state->data_pos); + } + else { + // The frame is invalid, so reset + state->next_zero = 0; + state->data_pos = 0; + } } else { if (state->next_zero == 0) { + // Special case for zeroes state->next_zero = data; state->data[state->data_pos++] = 0; } diff --git a/serial_link/tests/byte_stuffer_tests.c b/serial_link/tests/byte_stuffer_tests.c index 2fc7a0b2..74a349b1 100644 --- a/serial_link/tests/byte_stuffer_tests.c +++ b/serial_link/tests/byte_stuffer_tests.c @@ -72,7 +72,7 @@ Ensure(ByteStuffer, receives_three_bytes_valid_frame) { when(size, is_equal_to(3)), when(data, is_equal_to_contents_of(expected, 3)) ); - recv_byte(&state, 5); + recv_byte(&state, 4); recv_byte(&state, 0x37); recv_byte(&state, 0x99); recv_byte(&state, 0xFF); @@ -103,3 +103,54 @@ Ensure(ByteStuffer, receives_valid_frame_with_zeroes) { recv_byte(&state, 1); recv_byte(&state, 0); } + +Ensure(ByteStuffer, receives_two_valid_frames) { + uint8_t expected1[] = {5, 0}; + uint8_t expected2[] = {3}; + expect(recv_frame, + when(size, is_equal_to(2)), + when(data, is_equal_to_contents_of(expected1, 2)) + ); + expect(recv_frame, + when(size, is_equal_to(1)), + when(data, is_equal_to_contents_of(expected2, 1)) + ); + recv_byte(&state, 2); + recv_byte(&state, 5); + recv_byte(&state, 1); + recv_byte(&state, 0); + recv_byte(&state, 2); + recv_byte(&state, 3); + recv_byte(&state, 0); +} + +Ensure(ByteStuffer, receives_valid_frame_after_unexpected_zero) { + uint8_t expected[] = {5, 7}; + expect(recv_frame, + when(size, is_equal_to(2)), + when(data, is_equal_to_contents_of(expected, 2)) + ); + recv_byte(&state, 3); + recv_byte(&state, 1); + recv_byte(&state, 0); + recv_byte(&state, 3); + recv_byte(&state, 5); + recv_byte(&state, 7); + recv_byte(&state, 0); +} + +Ensure(ByteStuffer, receives_valid_frame_after_unexpected_non_zero) { + uint8_t expected[] = {5, 7}; + expect(recv_frame, + when(size, is_equal_to(2)), + when(data, is_equal_to_contents_of(expected, 2)) + ); + recv_byte(&state, 2); + recv_byte(&state, 9); + recv_byte(&state, 4); // This should have been zero + recv_byte(&state, 0); + recv_byte(&state, 3); + recv_byte(&state, 5); + recv_byte(&state, 7); + recv_byte(&state, 0); +}