Re: [musl] [PATCH libc-test v3] functional: add mntent test

[Szabolcs Nagy <nsz@port70.net>]

* Alyssa Ross <hi@alyssa.is> [2024-10-19 20:16:39 +0200]:
> This only checks reading an fstab from an stream.  I haven't written
> tests for setmntent(), addmntent(), or hasmntnent().
> 
> test_getmntent exposes a bug in musl 1.2.3 where lines omitting the
> final two fields, which are supposed to be optional according to
> fstab(5), are not accepted.  It also exposes a current bug, where if
> the numeric fields are omitted, the last field seen will have a
> newline appended to its value.  The tests all pass on Glibc.
> ---
> v3: updated description for current musl
> v2: https://inbox.vuxu.org/musl/20210821085420.474615-3-hi@alyssa.is/
> 
> Previously I had a second, optional patch, that would have tested the 
> behavior of a single-field mntent entry.  I've dropped that one, because
> musl chose not to match Glibc in accepting it.
> 

patch looks ok. it fails with

src/functional/mntent.c:47: !strcmp(m->mnt_opts, "defaults") failed
FAIL src/functional/mntent-static.exe [status 1]
src/functional/mntent.c:47: !strcmp(m->mnt_opts, "defaults") failed
FAIL src/functional/mntent.exe [status 1]

i guess this should be fixed

i'd factor the test slightly differently but it is also ok as is.
i wait a bit before applyin it, to see if it gets fixed in musl.

(e.g. it could have

	static struct mntent *t_getmntent(char *fstab, int use_r);

and then

	for (i=0; i<2; i++) {
		m = t_getmntent("\n", i);
		ASSERT(!m);
		m = t_getmntent("none /proc proc defaults\n", i);
		ASSERT(m);
		ASSERT(!strcmp(m->mnt_fsname, "none"));
		...
		m = t_getmntent("/dev/sda\t/\text4\trw,nosuid\t2\t1\n", i);
		...
	}

and normally i avoid exitin early on failure if continuing the tests
is possible, so then multiple failures are all reported. t_error sets
t_status so you can just return t_status at the end of main.)



>  AUTHORS                 |  1 +
>  src/functional/mntent.c | 76 +++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 77 insertions(+)
>  create mode 100644 src/functional/mntent.c
> 
> diff --git a/AUTHORS b/AUTHORS
> index ff99471..cf2a394 100644
> --- a/AUTHORS
> +++ b/AUTHORS
> @@ -5,3 +5,4 @@ John Spencer
>  Jens Gustedt
>  Alexander Monakov
>  Julien Ramseier
> +Alyssa Ross
> diff --git a/src/functional/mntent.c b/src/functional/mntent.c
> new file mode 100644
> index 0000000..59d816a
> --- /dev/null
> +++ b/src/functional/mntent.c
> @@ -0,0 +1,76 @@
> +// SPDX-License-Identifier: MIT
> +
> +#define _DEFAULT_SOURCE // for getmntent_r
> +
> +#include <mntent.h>
> +#include <stdlib.h>
> +#include <stdio.h>
> +#include <string.h>
> +#include <errno.h>
> +
> +#include "test.h"
> +
> +#define ASSERT(x) do {				 \
> +		if (!(x)) {			 \
> +			t_error(#x " failed\n"); \
> +			exit(EXIT_FAILURE);	 \
> +		}				 \
> +	} while (0);
> +
> +#define ERR(fmt, ...) do {					       \
> +		t_error(fmt ": %s\n", ##__VA_ARGS__, strerror(errno)); \
> +		exit(EXIT_FAILURE);				       \
> +	} while (0)
> +
> +void test_getmntent_empty(void)
> +{
> +	char fstab[] = "\n";
> +	FILE *f = fmemopen((void *)fstab, sizeof fstab - 1, "r");
> +	if (!f) ERR("fmemopen");
> +	ASSERT(!getmntent(f));
> +	ASSERT(endmntent(f) == 1);
> +}
> +
> +void test_getmntent(void)
> +{
> +	// Checks that the fifth and sixth fields default to 0.
> +	char fstab[] = "none /proc proc defaults\n";
> +	FILE *f = fmemopen((void *)fstab, sizeof fstab - 1, "r");
> +	if (!f) ERR("fmemopen");
> +	struct mntent *m = getmntent(f);
> +	ASSERT(m);
> +	ASSERT(!strcmp(m->mnt_fsname, "none"));
> +	ASSERT(!strcmp(m->mnt_dir, "/proc"));
> +	ASSERT(!strcmp(m->mnt_type, "proc"));
> +	ASSERT(!strcmp(m->mnt_opts, "defaults"));
> +	ASSERT(m->mnt_freq == 0);
> +	ASSERT(m->mnt_passno == 0);
> +	ASSERT(endmntent(f) == 1);
> +}
> +
> +void test_getmntent_r(void)
> +{
> +	struct mntent m, *r;
> +	char fstab[] = "/dev/sda\t/\text4\trw,nosuid\t2\t1\n";
> +	char buf[sizeof(fstab)];
> +
> +	FILE *f = fmemopen((void *)fstab, sizeof fstab - 1, "r");
> +	if (!f) ERR("fmemopen");
> +
> +	r = getmntent_r(f, &m, buf, sizeof buf);
> +	ASSERT(r == &m);
> +	ASSERT(!strcmp(m.mnt_fsname, "/dev/sda"));
> +	ASSERT(!strcmp(m.mnt_dir, "/"));
> +	ASSERT(!strcmp(m.mnt_type, "ext4"));
> +	ASSERT(!strcmp(m.mnt_opts, "rw,nosuid"));
> +	ASSERT(m.mnt_freq == 2);
> +	ASSERT(m.mnt_passno == 1);
> +	ASSERT(endmntent(f) == 1);
> +}
> +
> +int main(void)
> +{
> +	test_getmntent_empty();
> +	test_getmntent();
> +	test_getmntent_r();
> +}
> 
> base-commit: a07fb60c4996955216ef9a331dae124374984b3a
> -- 
> 2.46.0