TEST_ASSERT_REL(IP_Checksum(IP_CHECKSUM_START, sizeof(hdr), &hdr), ==, 0);
TEST_ASSERT_REL(ntohs(hdr.TotalLength), <=, len - ofs);
TEST_ASSERT_REL(IP_Checksum(IP_CHECKSUM_START, sizeof(hdr), &hdr), ==, 0);
TEST_ASSERT_REL(ntohs(hdr.TotalLength), <=, len - ofs);