basic: re-sort includes My previous patch to only include what we use accidentially placed the added inlcudes in non-sorted order.

basic: include only what we use This is a cleaned up result of running iwyu but without forward declarations on src/basic.

siphash: minor coding style fixes and modernizations Only cosmetics really, doesn't change any actual logic.

siphash: fix another alignment issue

siphash24: let siphash24_finalize() and siphash24() return the result directly Rather than passing a pointer to return the result, return it directly from the function calls. Also, return the result in native endianess, and let the callers care about the conversion. For hash tables and bloom filters, we don't care, but in order to keep MAC addresses and DHCP client IDs stable, we explicitly convert to LE.

tree-wide: sort includes Sort the includes accoding to the new coding style.

siphash24: change result argument to uint64_t Change the "out" parameter from uint8_t[8] to uint64_t. On architectures which enforce pointer alignment this fixes crashes when we previously cast an unaligned array to uint64_t*, and on others this should at least improve performance as the compiler now aligns these properly. This also simplifies the code in most cases by getting rid of typecasts. The only place which we can't change is struct duid's en.id, as that is _packed_ and public API, so we can't enforce alignment of the "id" field and have to use memcpy instead.

siphash24: fix memory alignment Use unaligned_read_le64() to access input buffer when reading complete 64-bit words. This should fix memory traps on platforms with strict aliasing.

siphash24: coding-style fixes Drop custom types. Drop unnecessary macros. Fix whitespace. Add asserts.

siphash24: unify API Make the API of the new helpers more similar to the old wrapper. In particular we now return the hash as a byte string to avoid any endianness problems.

siphash24: expose the internal helper functions

siphash24: make siphash24_compress decomposable This allows the input to siphash24_compress to be decomposed into smaller chunks and the function to be called on each individual chunk.

siphash24: move last compression iteration from compression step to finalization step The last compression is special as it deals with the length byte, and padding. Move it to the finalization step in preparation for making compression decomposable.

siphash24: split out the compression step

siphash24: split out the finalization step

siphash24: introduce state struct Encapsulate the four state variables in a struct so we can more easily pass them around.

build-sys: split internal basic/ library from shared/ basic/ can be used by everything cannot use anything outside of basic/ libsystemd/ can use basic/ cannot use shared/ shared/ can use libsystemd/