libvirt/tests/vircgroupmock.c
Peter Krempa 654486bd57 syntax-check: sc_avoid_write: Don't use blanket file exceptions
Adding an exception for the whole file usually defeats the purpose of a
syntax check and is also likely to get forgotten once the file is
removed.

In case of the suggestion of using 'safewrite' instead of write even the
comment for safewrite states that the function needs to be used only in
certain cases.

Remove the blanket exceptions for files and use an exclude string
instead. The only instance where we keep the full file exception is for
src/libvirt-stream.c as there are multiple uses in example code in
comments where I couldn't find a nicer targetted wapproach.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2022-02-15 09:32:23 +01:00

605 lines
18 KiB
C

/*
* Copyright (C) 2013 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#ifdef __linux__
# include "virmock.h"
# include <unistd.h>
# include <fcntl.h>
# include <sys/stat.h>
# include <sys/sysmacros.h>
# include <stdarg.h>
# include "testutilslxc.h"
# include "virstring.h"
# include "virfile.h"
# include "viralloc.h"
# include "vircgroupv2devices.h"
static int (*real_open)(const char *path, int flags, ...);
static FILE *(*real_fopen)(const char *path, const char *mode);
static int (*real_access)(const char *path, int mode);
static int (*real_mkdir)(const char *path, mode_t mode);
/* Don't make static, since it causes problems with clang
* when passed as an arg to asprintf()
* vircgroupmock.c:462:22: error: static variable 'fakesysfsdir' is used in an inline function with external linkage [-Werror,-Wstatic-in-inline]
*/
char *fakerootdir;
char *fakesysfscgroupdir;
const char *fakedevicedir0 = FAKEDEVDIR0;
const char *fakedevicedir1 = FAKEDEVDIR1;
# define SYSFS_CGROUP_PREFIX "/not/really/sys/fs/cgroup"
# define SYSFS_CPU_PRESENT "/sys/devices/system/cpu/present"
# define SYSFS_CPU_PRESENT_MOCKED "devices_system_cpu_present"
/*
* The plan:
*
* We fake out /proc/mounts, so make it look as is cgroups
* are mounted on /not/really/sys/fs/cgroup. We don't
* use /sys/fs/cgroup, because we want to make it easy to
* detect places where we've not mocked enough syscalls.
*
* In any open/access/mkdir calls we look at path and if
* it starts with /not/really/sys/fs/cgroup, we rewrite
* the path to point at a subdirectory of the temporary
* directory referred to by LIBVIRT_FAKE_ROOT_DIR env
* variable that is set by the main test suite
*
* In mkdir() calls, we simulate the cgroups behaviour
* whereby creating the directory auto-creates a bunch
* of files beneath it
*/
static int make_file(const char *path,
const char *name,
const char *value)
{
int fd = -1;
int ret = -1;
char *filepath = NULL;
if (asprintf(&filepath, "%s/%s", path, name) < 0)
return -1;
if ((fd = real_open(filepath, O_CREAT|O_WRONLY, 0600)) < 0)
goto cleanup;
if (write(fd, value, strlen(value)) != strlen(value)) /* sc_avoid_write */
goto cleanup;
ret = 0;
cleanup:
if (fd != -1 && close(fd) < 0)
ret = -1;
free(filepath);
return ret;
}
static int make_controller_v1(const char *path, mode_t mode)
{
const char *controller;
if (!STRPREFIX(path, fakesysfscgroupdir)) {
errno = EINVAL;
return -1;
}
controller = path + strlen(fakesysfscgroupdir) + 1;
if (STREQ(controller, "cpu"))
return symlink("cpu,cpuacct", path);
if (STREQ(controller, "cpuacct"))
return symlink("cpu,cpuacct", path);
if (real_mkdir(path, mode) < 0)
return -1;
# define MAKE_FILE(name, value) \
do { \
if (make_file(path, name, value) < 0) \
return -1; \
} while (0)
if (STRPREFIX(controller, "cpu,cpuacct")) {
MAKE_FILE("cpu.cfs_period_us", "100000\n");
MAKE_FILE("cpu.cfs_quota_us", "-1\n");
MAKE_FILE("cpu.shares", "1024\n");
MAKE_FILE("cpuacct.stat",
"user 216687025\n"
"system 43421396\n");
MAKE_FILE("cpuacct.usage", "2787788855799582\n");
MAKE_FILE("cpuacct.usage_percpu",
"7059492996 0 0 0 0 0 0 0 4180532496 0 0 0 0 0 0 0 "
"1957541268 0 0 0 0 0 0 0 2065932204 0 0 0 0 0 0 0 "
"18228689414 0 0 0 0 0 0 0 4245525148 0 0 0 0 0 0 0 "
"2911161568 0 0 0 0 0 0 0 1407758136 0 0 0 0 0 0 0 "
"1836807700 0 0 0 0 0 0 0 1065296618 0 0 0 0 0 0 0 "
"2046213266 0 0 0 0 0 0 0 747889778 0 0 0 0 0 0 0 "
"709566900 0 0 0 0 0 0 0 444777342 0 0 0 0 0 0 0 "
"5683512916 0 0 0 0 0 0 0 635751356 0 0 0 0 0 0 0\n");
} else if (STRPREFIX(controller, "cpuset")) {
if (STREQ(controller, "cpuset"))
MAKE_FILE("cpuset.cpus", "0-1");
else
MAKE_FILE("cpuset.cpus", ""); /* Values don't inherit */
MAKE_FILE("cpuset.memory_migrate", "0\n");
if (STREQ(controller, "cpuset"))
MAKE_FILE("cpuset.mems", "0");
else
MAKE_FILE("cpuset.mems", ""); /* Values don't inherit */
} else if (STRPREFIX(controller, "memory")) {
MAKE_FILE("memory.limit_in_bytes", "9223372036854775807\n");
MAKE_FILE("memory.memsw.limit_in_bytes", ""); /* Not supported */
MAKE_FILE("memory.memsw.usage_in_bytes", ""); /* Not supported */
MAKE_FILE("memory.soft_limit_in_bytes", "9223372036854775807\n");
MAKE_FILE("memory.stat",
"cache 1336619008\n"
"rss 97792000\n"
"mapped_file 42090496\n"
"pgpgin 13022605027\n"
"pgpgout 13023820533\n"
"pgfault 54429417056\n"
"pgmajfault 315715\n"
"inactive_anon 145887232\n"
"active_anon 67100672\n"
"inactive_file 627400704\n"
"active_file 661872640\n"
"unevictable 3690496\n"
"hierarchical_memory_limit 9223372036854775807\n"
"total_cache 1336635392\n"
"total_rss 118689792\n"
"total_mapped_file 42106880\n"
"total_pgpgin 13022606816\n"
"total_pgpgout 13023820793\n"
"total_pgfault 54429422313\n"
"total_pgmajfault 315715\n"
"total_inactive_anon 145891328\n"
"total_active_anon 88010752\n"
"total_inactive_file 627400704\n"
"total_active_file 661872640\n"
"total_unevictable 3690496\n"
"recent_rotated_anon 112807028\n"
"recent_rotated_file 2547948\n"
"recent_scanned_anon 113796164\n"
"recent_scanned_file 8199863\n");
MAKE_FILE("memory.usage_in_bytes", "1455321088\n");
MAKE_FILE("memory.use_hierarchy", "0\n");
} else if (STRPREFIX(controller, "freezer")) {
MAKE_FILE("freezer.state", "THAWED");
} else if (STRPREFIX(controller, "blkio")) {
MAKE_FILE("blkio.throttle.io_service_bytes",
"8:0 Read 59542107136\n"
"8:0 Write 411440480256\n"
"8:0 Sync 248486822912\n"
"8:0 Async 222495764480\n"
"8:0 Total 470982587392\n"
"9:0 Read 59542107137\n"
"9:0 Write 411440480257\n"
"9:0 Sync 248486822912\n"
"9:0 Async 222495764480\n"
"9:0 Total 470982587392\n");
MAKE_FILE("blkio.throttle.io_serviced",
"8:0 Read 4832583\n"
"8:0 Write 36641903\n"
"8:0 Sync 30723171\n"
"8:0 Async 10751315\n"
"8:0 Total 41474486\n"
"9:0 Read 4832584\n"
"9:0 Write 36641904\n"
"9:0 Sync 30723171\n"
"9:0 Async 10751315\n"
"9:0 Total 41474486\n");
MAKE_FILE("blkio.throttle.read_bps_device", "");
MAKE_FILE("blkio.throttle.read_iops_device", "");
MAKE_FILE("blkio.throttle.write_bps_device", "");
MAKE_FILE("blkio.throttle.write_iops_device", "");
MAKE_FILE("blkio.weight", "1000\n");
MAKE_FILE("blkio.weight_device", "");
} else {
errno = EINVAL;
return -1;
}
# undef MAKE_FILE
return 0;
}
static int make_controller_v2(const char *path, mode_t mode)
{
if (!STRPREFIX(path, fakesysfscgroupdir)) {
errno = EINVAL;
return -1;
}
if (real_mkdir(path, mode) < 0 && errno != EEXIST)
return -1;
# define MAKE_FILE(name, value) \
do { \
if (make_file(path, name, value) < 0) \
return -1; \
} while (0)
MAKE_FILE("cgroup.controllers", "cpu io memory\n");
MAKE_FILE("cgroup.subtree_control", "");
MAKE_FILE("cgroup.type", "domain\n");
MAKE_FILE("cpu.max", "max 100000\n");
MAKE_FILE("cpu.stat",
"usage_usec 0\n"
"user_usec 0\n"
"system_usec 0\n"
"nr_periods 0\n"
"nr_throttled 0\n"
"throttled_usec 0\n");
MAKE_FILE("cpu.weight", "100\n");
MAKE_FILE("memory.current", "1455321088\n");
MAKE_FILE("memory.high", "max\n");
MAKE_FILE("memory.max", "max\n");
MAKE_FILE("memory.stat",
"anon 0\n"
"file 0\n"
"kernel_stack 0\n"
"slab 0\n"
"sock 0\n"
"shmem 0\n"
"file_mapped 0\n"
"file_dirty 0\n"
"file_writeback 0\n"
"inactive_anon 0\n"
"active_anon 0\n"
"inactive_file 0\n"
"active_file 0\n"
"unevictable 0\n"
"slab_reclaimable 0\n"
"slab_unreclaimable 0\n"
"pgfault 0\n"
"pgmajfault 0\n"
"pgrefill 0\n"
"pgscan 0\n"
"pgsteal 0\n"
"pgactivate 0\n"
"pgdeactivate 0\n"
"pglazyfree 0\n"
"pglazyfreed 0\n"
"workingset_refault 0\n"
"workingset_activate 0\n"
"workingset_nodereclaim 0\n");
MAKE_FILE("memory.swap.current", "0\n");
MAKE_FILE("memory.swap.max", "max\n");
MAKE_FILE("io.stat", "8:0 rbytes=26828800 wbytes=77062144 rios=2256 wios=7849 dbytes=0 dios=0\n");
MAKE_FILE("io.max", "");
MAKE_FILE("io.weight", "default 100\n");
# undef MAKE_FILE
return 0;
}
static void init_syms(void)
{
if (real_fopen)
return;
VIR_MOCK_REAL_INIT(fopen);
VIR_MOCK_REAL_INIT(access);
VIR_MOCK_REAL_INIT(mkdir);
VIR_MOCK_REAL_INIT(open);
}
static int make_controller(const char *path, mode_t mode)
{
const char *mock;
bool unified = false;
bool hybrid = false;
mock = getenv("VIR_CGROUP_MOCK_MODE");
if (mock) {
if (STREQ(mock, "unified")) {
unified = true;
} else if (STREQ(mock, "hybrid")) {
hybrid = true;
} else {
fprintf(stderr, "invalid mode '%s'\n", mock);
abort();
}
}
if (unified || (hybrid && strstr(path, "unified"))) {
return make_controller_v2(path, mode);
} else {
return make_controller_v1(path, mode);
}
}
static void init_sysfs(void)
{
const char *mock;
char *newfakerootdir;
bool unified = false;
bool hybrid = false;
if (!(newfakerootdir = getenv("LIBVIRT_FAKE_ROOT_DIR"))) {
fprintf(stderr, "Missing LIBVIRT_FAKE_ROOT_DIR env variable\n");
abort();
}
if (fakerootdir && STREQ(fakerootdir, newfakerootdir))
return;
fakerootdir = newfakerootdir;
mock = getenv("VIR_CGROUP_MOCK_MODE");
if (mock) {
if (STREQ(mock, "unified")) {
unified = true;
} else if (STREQ(mock, "hybrid")) {
hybrid = true;
} else {
fprintf(stderr, "invalid mode '%s'\n", mock);
abort();
}
}
VIR_FREE(fakesysfscgroupdir);
fakesysfscgroupdir = g_strdup_printf("%s%s",
fakerootdir, SYSFS_CGROUP_PREFIX);
if (g_mkdir_with_parents(fakesysfscgroupdir, 0777) < 0) {
fprintf(stderr, "Cannot create %s\n", fakesysfscgroupdir);
abort();
}
# define MAKE_CONTROLLER(subpath) \
do { \
char *path; \
if (asprintf(&path, "%s/%s", fakesysfscgroupdir, subpath) < 0) \
abort(); \
if (make_controller(path, 0755) < 0) { \
fprintf(stderr, "Cannot initialize %s\n", path); \
free(path); \
abort(); \
} \
free(path); \
} while (0)
if (unified) {
MAKE_CONTROLLER("");
} else if (hybrid) {
MAKE_CONTROLLER("unified");
MAKE_CONTROLLER("cpuset");
MAKE_CONTROLLER("freezer");
} else {
MAKE_CONTROLLER("cpu");
MAKE_CONTROLLER("cpuacct");
MAKE_CONTROLLER("cpu,cpuacct");
MAKE_CONTROLLER("cpuset");
MAKE_CONTROLLER("blkio");
MAKE_CONTROLLER("memory");
MAKE_CONTROLLER("freezer");
if (make_file(fakesysfscgroupdir,
SYSFS_CPU_PRESENT_MOCKED, "8-23,48-159\n") < 0)
abort();
}
}
FILE *fopen(const char *path, const char *mode)
{
char *filepath = NULL;
const char *type = NULL;
FILE *rc = NULL;
const char *filename = getenv("VIR_CGROUP_MOCK_FILENAME");
init_syms();
if (STREQ(path, "/proc/mounts")) {
if (STREQ(mode, "r")) {
type = "mounts";
} else {
errno = EACCES;
return NULL;
}
}
if (STREQ(path, "/proc/cgroups")) {
if (STREQ(mode, "r")) {
type = "cgroups";
} else {
errno = EACCES;
return NULL;
}
}
if (STREQ(path, "/proc/self/cgroup")) {
if (STREQ(mode, "r")) {
type = "self.cgroup";
} else {
errno = EACCES;
return NULL;
}
}
if (type) {
if (!filename) {
errno = EACCES;
return NULL;
}
filepath = g_strdup_printf("%s/vircgroupdata/%s.%s",
abs_srcdir, filename, type);
rc = real_fopen(filepath, mode);
free(filepath);
return rc;
}
return real_fopen(path, mode);
}
int access(const char *path, int mode)
{
int ret;
init_syms();
if (STRPREFIX(path, SYSFS_CGROUP_PREFIX)) {
char *newpath;
init_sysfs();
if (asprintf(&newpath, "%s%s",
fakesysfscgroupdir,
path + strlen(SYSFS_CGROUP_PREFIX)) < 0) {
errno = ENOMEM;
return -1;
}
ret = real_access(newpath, mode);
free(newpath);
} else if (STREQ(path, "/proc/cgroups") ||
STREQ(path, "/proc/self/cgroup") ||
STREQ(path, SYSFS_CPU_PRESENT)) {
/* These files are readable for all. */
ret = (mode == F_OK || mode == R_OK) ? 0 : -1;
} else if (STREQ(path, "/proc/mounts")) {
/* This one is accessible anytime for anybody. In fact, it's just
* a symlink to /proc/self/mounts. */
ret = 0;
} else {
ret = real_access(path, mode);
}
return ret;
}
# define VIR_MOCK_STAT_HOOK \
do { \
if (STRPREFIX(path, fakedevicedir0)) { \
sb->st_mode = S_IFBLK; \
sb->st_rdev = makedev(8, 0); \
return 0; \
} else if (STRPREFIX(path, fakedevicedir1)) { \
sb->st_mode = S_IFBLK; \
sb->st_rdev = makedev(9, 0); \
return 0; \
} \
} while (0)
# include "virmockstathelpers.c"
static int
virMockStatRedirect(const char *path, char **newpath)
{
if (STREQ(path, SYSFS_CPU_PRESENT)) {
init_sysfs();
if (asprintf(newpath, "%s/%s",
fakesysfscgroupdir,
SYSFS_CPU_PRESENT_MOCKED) < 0)
return -1;
} else if (STRPREFIX(path, SYSFS_CGROUP_PREFIX)) {
init_sysfs();
if (asprintf(newpath, "%s%s",
fakesysfscgroupdir,
path + strlen(SYSFS_CGROUP_PREFIX)) < 0)
return -1;
}
return 0;
}
int mkdir(const char *path, mode_t mode)
{
int ret;
init_syms();
if (STRPREFIX(path, SYSFS_CGROUP_PREFIX)) {
char *newpath;
init_sysfs();
if (asprintf(&newpath, "%s%s",
fakesysfscgroupdir,
path + strlen(SYSFS_CGROUP_PREFIX)) < 0) {
errno = ENOMEM;
return -1;
}
ret = make_controller(newpath, mode);
free(newpath);
} else {
ret = real_mkdir(path, mode);
}
return ret;
}
int open(const char *path, int flags, ...)
{
int ret;
char *newpath = NULL;
init_syms();
if (STREQ(path, SYSFS_CPU_PRESENT)) {
init_sysfs();
if (asprintf(&newpath, "%s/%s",
fakesysfscgroupdir,
SYSFS_CPU_PRESENT_MOCKED) < 0) {
errno = ENOMEM;
return -1;
}
}
if (STRPREFIX(path, SYSFS_CGROUP_PREFIX)) {
init_sysfs();
if (asprintf(&newpath, "%s%s",
fakesysfscgroupdir,
path + strlen(SYSFS_CGROUP_PREFIX)) < 0) {
errno = ENOMEM;
return -1;
}
}
if (flags & O_CREAT) {
va_list ap;
mode_t mode;
va_start(ap, flags);
mode = (mode_t) va_arg(ap, int);
va_end(ap);
ret = real_open(newpath ? newpath : path, flags, mode);
} else {
ret = real_open(newpath ? newpath : path, flags);
}
free(newpath);
return ret;
}
bool
virCgroupV2DevicesAvailable(virCgroup *group G_GNUC_UNUSED)
{
return true;
}
#else
/* Nothing to override on non-__linux__ platforms */
#endif