Considering http.h defined HTTP/1.1-only responses such as "303 See
Other", as well as incoming HTTP/1.1-only features (e.g.: byte serving),
it did not make much sense to keep a somewhat broken compatibility
against HTTP/1.0.
Unfortunately, this breaks support with some existing clients such
as lynx(1), even if HTTP/1.0 was already deprecated many years ago.
However, even lynx(1) can be configured to support HTTP/1.1.
select(2) has a number of well-known issues (e.g.: FD_SETSIZE limiting
the maximum amount of file descriptors to watch) that are mostly solved
by poll(2) and thus can be used as a drop-in replacement.
When using HTTP "Content-Disposition: attachment;", users are forced to
download files in order to use them, whereas others might prefer to open
them in the browser.
Therefore, now that URL parameters are supported by http.h, previews can
be forced by adding "preview=1" or "preview=true" (case-insensitive) as
a URL parameters. Any other parameters are ignored by slcl.
For users, a "Preview" link has been added next to the "Share" button
for each file.
Now, http_payload includes a list of human-readable parameters that can
be read (but not modified) by users. Given the following example link:
/test?key1=value1&key2=value2
This will generate two parameters, with the following values:
{
.args =
{
[0] = {.key = "key1", .value = "value1"},
[1] = {.key = "key2", .value = "value2"}
},
.n_args = 2
}
As expected, if any URL parameters are given, struct http_payload member
"resource" is accordingly trimmed so as not to include any parameters.
Therefore, considering the example above:
{.args = {...}, .resource = "/test"}
Limitations:
- Since the definition of struct http_arg is both shared by http.h
(as a read-only pointer within struct http_payload) and http.c
(as a read/write pointer within struct ctx), its members (namely key
and value) must remain as read/write pointers, even if they must not
be modified by users of http.h.
So far, slcl would just close the connection with a client when the
Content-Length of an incoming request exceeded the user quota, without
any meaningful information given back to the user.
Now, slcl responds with a HTML file with meaningful information about
the error.
Limitations:
- While this commits has been successfully tested on ungoogled-chromium,
LibreWolf (and I assume Firefox and any other derivates too) does not
seem to receive the response from the server.
- However, this issue only occurred during local testing, but not
on remote instances.
- When a non-empty username and an empty password was given, slcl would
crash due to a double free(3). This happened because append_form would
grow the form list before sanitizing the input and, since the output
pointer was not updated to the caller function, the latter would attempt
to free a now-old pointer.
- Additionally, some compilers such as clang complained about the
potential use of an uninitialized variable when calling forms_free.
- Also, it was a good opportunity to refactor get_forms and its caller
functions, as get_forms was not differentiate fatal errors from user
input errors.
As otherwise reported by clang 14.0.0:
main.c:679:14: warning: variable 'cur' is used uninitialized whenever '&&' condition is false [-Wsometimes-uninitialized]
else if (available && quota_current(a, username, &cur))
This was a minor issue after all, as pq was not used unless available
were set.
So far, usergen printed a JSON object over standard output that had to
be manually copied into db.json. Now, this step is done automatically,
thanks to jq(1). OTOH, user directory is now also created by usergen.
So far, slcl used the default browser behaviour (i.e.,
Content-Disposition: inline), which means files were typically shown on
the web browser itself. However, this caused two issues:
- Users would have to right-click -> "Save Link As..." to download a
file, which might be inconvenient for some users.
- The original file name would not be retrieved for publicly shared
files.
Now, file download is always requested to the browser, and the original
file path is retrieved via readlink(2).
So far, slcl failed with poorly described error messages when any of the
essential directories were missing. Now, these are created automatically
so that the initial setup is easier.
An HTML form is now added next to each regular file, that generates a
POST request. Then, slcl replies with a HTML document with a link to the
public resource (which are implemented as symlinks).
Limitations:
- For now, only regular files can be shared i.e., sharing directories is
not possible. While feasible, it still requires a larger refactor to
list_dir and resource_layout, so that read-only access to the directory
is provided to anonymous users.
- Error detection against strotul(3) has been improved, as done in other
places.
- New function encode_hex has been implemented, which will be used
by future commits.
Otherwise, slcl would fail to generate the URLs for the elements inside
a directory, because of how cust_dirname worked, which also turned out
to be redundant.
Until now, f->tmpname was removed by move_file when the move
operation succeeded. However, since a HTTP operation can fail before
move_file is called, the temporary file must also be removed.
This feature allows admins to set a specific quota for each user, in
MiB. This feature is particularly useful for shared instances, where
unlimited user storage might be unfeasible or even dangerous for the
server.
Also, a nice HTML5 <progress> element has been added to the site that
shows how much of the quota has been consumed.
If no quota is set, slcl falls back to the default behaviour i.e.,
assume unlimited storage.
Limitations:
- While HTTP does specify a Content-Length, which determines the length
of the whole request, it does not specify how many files are involved
or their individual sizes.
- Because of this, if multiple files are uploaded simultaneously, the
whole request would be dropped if user quota is exceeded, even if not
all files exceeded it.
- Also, Content-Length adds the length of some HTTP boilerplate
(e.g.: boundaries), but slcl must rely on this before accepting the
whole request. In other words, this means some requests might be
rejected by slcl because of the extra bytes caused by such boilerplate.
- When the quota is exceeded, slcl must close the connection so that
the rest of the transfer is cancelled. Unfortunately, this means no
HTML can be sent back to the customer to inform about the situation.
POSIX functions ftw(3) and nftw(3) do not allow passing an opaque
pointer to the callback they call, so it forces the use of statically
allocated data.
ctfw (from "custom ftw") is a custom implementation that solves this,
while also removing unneeded stuff.
This function will be used by future commits.