The function http_send_response() did too much. It not only took
the request fields and built them together into a response, it
delegated too little and many functions were "hacked" into it, for
instance shady directory-changes for vhosts and hand-construction
of response structs.
The preparations for a rework were already made in previous commits,
including a tighter focus on the response-struct itself. Instead of
doing everything locally in the http_send_response() function, the
new http_prepare_response() only really takes the request-struct and
builds a response-struct. The response-struct is expanded such that
it's possible to do the data-sending simply with the response-struct
itself and not any other magic parameters that just drop out of the
function.
Another matter are the http_send_status()-calls. Because the
aforementioned function is so central, this refactoring has included
many areas. Instead of calling http_send_status() in every error-case,
which makes little sense now given we first delegate everything through
a response struct, errors are just sent as a return value and caught
centrally (in serve() in main.c), which centralizes the error handling
a bit.
It might look a bit strange now and it might not be clear in which
direction this is going, but subsequent commits will hopefully give
clarity in this regard.
Signed-off-by: Laslo Hunhold <dev@frign.de>
The function has become too long and basically did two things: Receiving
the header and parsing it. To better reflect this, we split it up into
the two functions http_recv_header() and http_parse_header(). This way,
we also obtain a better separation of concerns and can further reduce
the scope of each parameter-list.
http_recv_header() has been written in such a way that it can be
reentered and fill up the header-buffer bit by bit using a pointer to
an offset value.
The error handling was improved by only returning the immediate error
status codes and letting the caller do the error-handling with
http_send_status().
Signed-off-by: Laslo Hunhold <dev@frign.de>
The server-struct variable s was global, which made it readable and
modifiable from any point in the code. Making it a local variable in
main() instead and passing it as a pointer to constant memory to each
function needing it makes much more sense and allows the compiler to
warn us if we do try to modify it, which it wouldn't have before.
Signed-off-by: Laslo Hunhold <dev@frign.de>
I know that the effect of 'const' on compiler optimizations is smaller
than many believe, but it provides a good insight to the caller which
parameters are not modified and simplifies parallelization, in case
that is desired at a later point.
Throughout processing, the big structs mostly remained unmodified, with
the exception of parse_range(), which added a null-byte in the "Range"-
header to simplify its parsing. This commit refactors parse_range()
such that it won't modify this string anymore.
Additionally, the parser was made even stricter: Usually, strtoll()
(which is wrapped by strtonum()) allows whitespace and plus and minus
signs before the number, which is not part of the specification. The
stricter parser also better differentiates now between invalid requests
and range-lists. In that context, the switch in http_send_response()
was replaced for better readability.
Signed-off-by: Laslo Hunhold <dev@frign.de>
The named constants for header fields of the response struct all
pretty much matched the actual header name, which I think improves
readability for everyone familiar with the HTTP-spec.
The request header fields named constants followed the rule, except
the "If-Modified-Since"-header, which is addressed in this commit.
Signed-off-by: Laslo Hunhold <dev@frign.de>
I wasn't happy with how responses were generated. HTTP-headers were
handled by hand and it was duplicated in multiple parts of the code.
Due to the duplication, some functions like timestamp() had really
ugly semantics.
The HTTP requests are parsed much better: We have an enum of fields
we care about that are automatically read into our request struct. This
commit adapts this idea to the response: We have an enum of fields
we might put into our response, and a response-struct holds the
content of these fields. A function http_send_header() automatically
sends a header based on the entries in response. In case we don't
use a field, we just leave the field in the response-struct empty.
With this commit, some logical changes came with it:
- timestamp() now has a sane signature, TIMESTAMP_LEN is no more and
it can now return proper errors and is also reentrant by using
gmtime_r() instead of gmtime()
- No more use of a static timestamp-array, making all the methods
also reentrant
- Better internal-error-reporting: Because the fields are filled
before and not during sending the response-headers, we can better
report any internal errors as status 500 instead of sending a
partial non-500-header and then dying.
These improved data structures make it easier to read and hack the code
and implement new features, if desired.
Signed-off-by: Laslo Hunhold <dev@frign.de>
And many other things, too many to list here. For example, it now
properly logs uds instead of erroring out.
Separating concerns in many places definitely improves the readability.
