These are supposed to be both functions and macros. I'm not sure
how to provide the functions at the same time as the macros,
as they collide with each other and cause compile errors.
However, some ports fully expect them to be functions.
For example, OpenSSH stores them into structures as function
pointers.
When SO_TIMESTAMP is set as an option on a SOCK_DGRAM socket, then
recvmsg() will return a SCM_TIMESTAMP control message that
contains a struct timeval with the system time that was current
when the socket was received.
The implementation only supports a single iovec for now.
Some might say having more than one iovec is the main point of
recvmsg() and sendmsg(), but I'm interested in the control message
bits.
Since the CPU already does almost all necessary validation steps
for us, we don't really need to attempt to do this. Doing it
ourselves doesn't really work very reliably, because we'd have to
account for other processors modifying virtual memory, and we'd
have to account for e.g. pages not being able to be allocated
due to insufficient resources.
So change the copy_to/from_user (and associated helper functions)
to use the new safe_memcpy, which will return whether it succeeded
or not. The only manual validation step needed (which the CPU
can't perform for us) is making sure the pointers provided by user
mode aren't pointing to kernel mappings.
To make it easier to read/write from/to either kernel or user mode
data add the UserOrKernelBuffer helper class, which will internally
either use copy_from/to_user or directly memcpy, or pass the data
through directly using a temporary buffer on the stack.
Last but not least we need to keep syscall params trivial as we
need to copy them from/to user mode using copy_from/to_user.
str{,n}casecmp is supposed to be *only* declared by strings.h, note the
trailing 's' in the filename.
We don't have any implementation for strlcat; using any strcat variants is
a bad idea anyway, given our implementation of AK::String.
TODO: Find a way to lint for declared-but-nowhere-defined functions.
g++ seems to generate calls to __cxa_guard_* functions when we use
non-trivial initialization of local statics.
Requiring these symbols breaks some ports since these symbols are
defined in libcstdc++ which we do not link against when building ports.
This commit turns some local statics into global statics in netdb.cpp so
libc wouldn't need these symbols.
Previously, we were including the whole of <getopt.h> in <unistd.h>.
However according to the posix <unistd.h> doesn't have to contain
everything we had in <getopt.h>.
This fixes some symbol collisions that broke the git port.
And also mark strlcpy() and strlcat() with __attribute__((warn_unused_result)).
Since our code is warning-free, this ensures we never misuse those functions.
(Or are very sure about doing it when turning off the warning for a particular
piece of code.)
In case we know exactly how many bytes we're copying (and not copying a string
while limiting its length to that of a buffer), memcpy() is a more appropriate
function to call.
Also, fix null-terminating the %c pointer.
Before, we had about these occurrence counts:
COPY: 13 without, 33 with
MOVE: 12 without, 28 with
Clearly, 'with' was the preferred way. However, this introduced double-semicolons
all over the place, and caused some warnings to trigger.
This patch *forces* the usage of a semi-colon when calling the macro,
by removing the semi-colon within the macro. (And thus also gets rid
of the double-semicolon.)
The implementation in LibC did a timestamp->day-of-week conversion
which looks like a valuable thing to have. But we only need it in
time_to_tm, where we already computed year/month/day -- so let's
consolidate on the day_of_week function in DateTime (which is
getting extracted to AK).
The JS tests pointed out that the implementation in DateTime
had an off-by-one in the month when doing the leap year check,
so this change fixes that bug.
