If you have a C99 compiler and can use the "new" fixed-width types: make an array of uint8_t and do the separation in members yourself.
uint8_t data[8];
x1 = data[0];
len = data[1];
host = data[2] * 256 + data[3]; /* big endian */
content[0] = data[4];
content[1] = data[5];
content[2] = data[6];
content[3] = data[7];
/* ... */
You can follow the same procedure in C89 if you can rely on CHAR_BIT being 8.
