This is the function version of STARTSWITH_SET(). We also move
STARTSWITH_SET() to string-util.h as it fits more there than in
strv.h and reimplement it using startswith_strv().
These combine strndup() + strspn()/strcspn() into one.
There are a bunch of strndupa() calls that could use similar treatment
(or should be converted to strdup[c]spn(), but this commit doesn't
bother with that.
We recently started making more use of malloc_usable_size() and rely on
it (see the string_erase() story). Given that we don't really support
sytems where malloc_usable_size() cannot be trusted beyond statistics
anyway, let's go fully in and rework GREEDY_REALLOC() on top of it:
instead of passing around and maintaining the currenly allocated size
everywhere, let's just derive it automatically from
malloc_usable_size().
I am mostly after this for the simplicity this brings. It also brings
minor efficiency improvements I guess, but things become so much nicer
to look at if we can avoid these allocation size variables everywhere.
Note that the malloc_usable_size() man page says relying on it wasn't
"good programming practice", but I think it does this for reasons that
don't apply here: the greedy realloc logic specifically doesn't rely on
the returned extra size, beyond the fact that it is equal or larger than
what was requested.
(This commit was supposed to be a quick patch btw, but apparently we use
the greedy realloc stuff quite a bit across the codebase, so this ends
up touching *a*lot* of code.)
It's a wrapper around malloc_usable_size() that is supposed to be
compatible with _FORTIFY_SOURCES=1, by taking the
__builtin_object_size() data into account, the same way as the
_FORTIFY_SOURCES=1 logic does.
Fixes: #19203
It's not going to be efficient if called in inner loops, but it's oh so
handy, and we have some code that does this:
asprintf(&p, "%s…", b, …);
free(b);
b = TAKE_PTR(p);
which can now be replaced by the quicker and easier to read:
strextendf(&p, "…", …);
sd-boot has a copy of a subset of codes from libbasic. This makes
sd-boot share the code with libbasic, and dedup the code.
Note, startswith_no_case() is dropped from sd-boot, as
- it is not used,
- the previous implementation is not correct,
- gnu-efi does not have StrniCmp() or so.
This uses GREEDY_ALLOC_ROUND_UP() to grow the allocation size
exponentially. This should speed allocation loops up a bit, given
that we often call strextend() repeatedly in a loop on the same
buffer.
The current overflow checking is broken in the corner case of the strings'
combined length being exactly SIZE_MAX: After the loop, l would be SIZE_MAX,
but we're not testing whether the l+1 expression overflows.
Fix it by simply pre-accounting for the final '\0': initialize l to 1 instead
of 0.
The loops over (x, then all varargs, until a NULL is found) can be written much
simpler with an ordinary for loop. Just initialize the loop variable to x, test
that, and in the increment part, fetch the next va_arg(). That removes a level
of indentation, and avoids doing a separate strlen()/stpcpy() call for x.
While touching this code anyway, change (size_t)-1 to the more readable
SIZE_MAX.
I had to move STRV_MAKE to macro.h. There is a circular dependency between
extract-word.h, strv.h, and string-util.h that makes it hard to define the
inline function otherwise.
split() and FOREACH_WORD really should die, and everything be moved to
extract_first_word() and friends, but let's at least make sure that for
the remaining code using it we can't deadlock by not progressing in the
word iteration.
Fixes: #15305
When showing logs from a container, we would fail to show various lines:
Oct 29 09:50:51 krowka systemd-nspawn[61376]: Detected architecture x86-64.
Oct 29 09:50:51 krowka systemd-nspawn[61376]: [1B blob data]
Oct 29 09:50:51 krowka systemd-nspawn[61376]: Welcome to Fedora 32 (Rawhide)!
Oct 29 09:50:51 krowka systemd-nspawn[61376]: [1B blob data]
Those are only harmless \r characters that trail the line. We already replace
tabs and strip various ansi characters that we deem inconsequential, so let's
also strip trailing carriage returns. Non-trailing ones are different, because
they change what would be displayed.
Let's drop the 'static' logic when a parameter can be NULL.
I think asan/ubsan are right here, judging by the C99 spec language:
"A declaration of a parameter as ‘‘array of type’’ shall be adjusted to
‘‘qualified pointer to type’’, where the type qualifiers (if any) are
those specified within the [ and ] of the array type derivation. If the
keyword static also appears within the [ and ] of the array type
derivation, then for each call to the function, the value of the
corresponding actual argument shall provide access to the first element
of an array with at least as many elements as specified by the size
expression."
If we specify NULL, then we certainly don't pvode access to any valid
array.
Fixes: #13039
https://hamberg.no/erlend/posts/2013-02-18-static-array-indices.html
This only works with clang, unfortunately gcc doesn't seem to implement the check
(tested with gcc-8.2.1-5.fc29.x86_64).
Simulated error:
[2/3] Compiling C object 'systemd-nspawn@exe/src_nspawn_nspawn.c.o'.
../src/nspawn/nspawn.c:3179:45: warning: array argument is too small; contains 15 elements, callee requires at least 16 [-Warray-bounds]
candidate = (uid_t) siphash24(arg_machine, strlen(arg_machine), hash_key);
^ ~~~~~~~~
../src/basic/siphash24.h:24:64: note: callee declares array parameter as static here
uint64_t siphash24(const void *in, size_t inlen, const uint8_t k[static 16]);
^~~~~~~~~~~~
v2: fix error in free_and_strndup()
When the orignal and copied message were the same, but shorter than specified
length l, memory read past the end of the buffer would be performed. A test
case is included: a string that had an embedded NUL ("q\0") is used to replace
"q".
v3: Fix one more bug in free_and_strndup and add tests.
v4: Some style fixed based on review, one more use of free_and_replace, and
make the tests more comprehensive.
Daan De Meyer
Lennart Poettering
Zbigniew Jędrzejewski-Szmek
Yu Watanabe
Antony Deepak Thomas
Susant Sahani
Rasmus Villemoes