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Merge pull request #15911 from poettering/unit-name-tighten

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pid1: improve logging when we encounter a path that is too long to be converted into a mount unit name
This commit is contained in:
Yu Watanabe
2020-05-29 15:55:38 +09:00
committed by GitHub
parent f6dbcebdc2 8dd7cbce42
commit fac729f811
5 changed files with 111 additions and 28 deletions
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catalog/systemd.catalog.in
+31
View File
@@ -435,3 +435,34 @@ hyphen and otherwise fully numeric.
For further details on strict and relaxed user/group name rules, see:
https://systemd.io/USER_NAMES
-- 1b3bb94037f04bbf81028e135a12d293
Subject: Failed to generate valid unit name from path '@MOUNT_POINT@'.
Defined-By: systemd
Support: %SUPPORT_URL%
The following mount point path could not be converted into a valid .mount
unit name:
@MOUNT_POINT@
Typically this means that the path to the mount point is longer than allowed
for valid unit names.
systemd dynamically synthesizes .mount units for all mount points appearing on
the system. For that a simple escaping algorithm is applied: the absolute path
name is used, with all "/" characters replaced by "-" (the leading one is
removed). Moreover, any non-alphanumeric characters (as well as any of ":",
"-", "_", ".", "\") are replaced by "\xNN" where "NN" is the hexadecimal code
of the character. Finally, ".mount" is suffixed. The resulting string must be
under 256 characters in length to be a valid unit name. This restriction is
made in order for all unit names to also be suitable as file names. If a mount
point appears that — after escaping — is longer than this limit it cannot be
mapped to a unit. In this case systemd will refrain from synthesizing a unit
and cannot be used to manage the mount point. It will not appear in the service
manager's unit table and thus also not be torn down safely and automatically at
system shutdown.
It is generally recommended to avoid such overly long mount point paths, or —
if used anyway – manage them independently of systemd, i.e. establish them as
well as tear them down automatically at system shutdown by other software.
src/basic/unit-name.c
+48 -24
View File
@@ -207,8 +207,9 @@ UnitType unit_name_to_type(const char *n) {
}
int unit_name_change_suffix(const char *n, const char *suffix, char **ret) {
char *e, *s;
_cleanup_free_ char *s = NULL;
size_t a, b;
char *e;
assert(n);
assert(suffix);
@@ -230,8 +231,12 @@ int unit_name_change_suffix(const char *n, const char *suffix, char **ret) {
return -ENOMEM;
strcpy(mempcpy(s, n, a), suffix);
*ret = s;
/* Make sure the name is still valid (i.e. didn't grow too large due to longer suffix) */
if (!unit_name_is_valid(s, UNIT_NAME_ANY))
return -EINVAL;
*ret = TAKE_PTR(s);
return 0;
}
@@ -253,8 +258,8 @@ int unit_name_build(const char *prefix, const char *instance, const char *suffix
}
int unit_name_build_from_type(const char *prefix, const char *instance, UnitType type, char **ret) {
_cleanup_free_ char *s = NULL;
const char *ut;
char *s;
assert(prefix);
assert(type >= 0);
@@ -264,19 +269,23 @@ int unit_name_build_from_type(const char *prefix, const char *instance, UnitType
if (!unit_prefix_is_valid(prefix))
return -EINVAL;
if (instance && !unit_instance_is_valid(instance))
return -EINVAL;
ut = unit_type_to_string(type);
if (!instance)
s = strjoin(prefix, ".", ut);
else
if (instance) {
if (!unit_instance_is_valid(instance))
return -EINVAL;
s = strjoin(prefix, "@", instance, ".", ut);
} else
s = strjoin(prefix, ".", ut);
if (!s)
return -ENOMEM;
*ret = s;
/* Verify that this didn't grow too large (or otherwise is invalid) */
if (!unit_name_is_valid(s, instance ? UNIT_NAME_INSTANCE : UNIT_NAME_PLAIN))
return -EINVAL;
*ret = TAKE_PTR(s);
return 0;
}
@@ -441,8 +450,8 @@ int unit_name_path_unescape(const char *f, char **ret) {
}
int unit_name_replace_instance(const char *f, const char *i, char **ret) {
_cleanup_free_ char *s = NULL;
const char *p, *e;
char *s;
size_t a, b;
assert(f);
@@ -466,7 +475,11 @@ int unit_name_replace_instance(const char *f, const char *i, char **ret) {
strcpy(mempcpy(mempcpy(s, f, a + 1), i, b), e);
*ret = s;
/* Make sure the resulting name still is valid, i.e. didn't grow too large */
if (!unit_name_is_valid(s, UNIT_NAME_INSTANCE))
return -EINVAL;
*ret = TAKE_PTR(s);
return 0;
}
@@ -497,8 +510,7 @@ int unit_name_template(const char *f, char **ret) {
}
int unit_name_from_path(const char *path, const char *suffix, char **ret) {
_cleanup_free_ char *p = NULL;
char *s = NULL;
_cleanup_free_ char *p = NULL, *s = NULL;
int r;
assert(path);
@@ -516,7 +528,11 @@ int unit_name_from_path(const char *path, const char *suffix, char **ret) {
if (!s)
return -ENOMEM;
*ret = s;
/* Refuse this if this got too long or for some other reason didn't result in a valid name */
if (!unit_name_is_valid(s, UNIT_NAME_PLAIN))
return -EINVAL;
*ret = TAKE_PTR(s);
return 0;
}
@@ -544,6 +560,10 @@ int unit_name_from_path_instance(const char *prefix, const char *path, const cha
if (!s)
return -ENOMEM;
/* Refuse this if this got too long or for some other reason didn't result in a valid name */
if (!unit_name_is_valid(s, UNIT_NAME_INSTANCE))
return -EINVAL;
*ret = s;
return 0;
}
@@ -597,9 +617,9 @@ static bool do_escape_mangle(const char *f, bool allow_globs, char *t) {
* If @allow_globs, globs characters are preserved. Otherwise, they are escaped.
*/
int unit_name_mangle_with_suffix(const char *name, const char *operation, UnitNameMangle flags, const char *suffix, char **ret) {
char *s;
int r;
_cleanup_free_ char *s = NULL;
bool mangled, suggest_escape = true;
int r;
assert(name);
assert(suffix);
@@ -657,7 +677,12 @@ int unit_name_mangle_with_suffix(const char *name, const char *operation, UnitNa
if ((!(flags & UNIT_NAME_MANGLE_GLOB) || !string_is_glob(s)) && unit_name_to_type(s) < 0)
strcat(s, suffix);
*ret = s;
/* Make sure mangling didn't grow this too large (but don't do this check if globbing is allowed,
* since globs generally do not qualify as valid unit names) */
if (!FLAGS_SET(flags, UNIT_NAME_MANGLE_GLOB) && !unit_name_is_valid(s, UNIT_NAME_ANY))
return -EINVAL;
*ret = TAKE_PTR(s);
return 1;
good:
@@ -665,12 +690,13 @@ good:
if (!s)
return -ENOMEM;
*ret = s;
*ret = TAKE_PTR(s);
return 0;
}
int slice_build_parent_slice(const char *slice, char **ret) {
char *s, *dash;
_cleanup_free_ char *s = NULL;
char *dash;
int r;
assert(slice);
@@ -693,13 +719,11 @@ int slice_build_parent_slice(const char *slice, char **ret) {
strcpy(dash, ".slice");
else {
r = free_and_strdup(&s, SPECIAL_ROOT_SLICE);
if (r < 0) {
free(s);
if (r < 0)
return r;
}
}
*ret = s;
*ret = TAKE_PTR(s);
return 1;
}
src/core/mount.c
+24 -3
View File
@@ -1674,9 +1674,30 @@ static int mount_setup_unit(
if (!is_path(where))
return 0;
/* Mount unit names have to be (like all other unit names) short enough to fit into file names. This
* means there's a good chance that overly long mount point paths after mangling them to look like a
* unit name would result in unit names we don't actually consider valid. This should be OK however
* as such long mount point paths should not happen on regular systems — and if they appear
* nonetheless they are generally synthesized by software, and thus managed by that other
* software. Having such long names just means you cannot use systemd to manage those specific mount
* points, which should be an OK restriction to make. After all we don't have to be able to manage
* all mount points in the world — as long as we don't choke on them when we encounter them. */
r = unit_name_from_path(where, ".mount", &e);
if (r < 0)
return log_error_errno(r, "Failed to generate unit name from path '%s': %m", where);
if (r < 0) {
static RateLimit rate_limit = { /* Let's log about this at warning level at most once every
* 5s. Given that we generate this whenever we read the file
* otherwise we probably shouldn't flood the logs with
* this */
.interval = 5 * USEC_PER_SEC,
.burst = 1,
};
return log_struct_errno(
ratelimit_below(&rate_limit) ? LOG_WARNING : LOG_DEBUG, r,
"MESSAGE_ID=" SD_MESSAGE_MOUNT_POINT_PATH_NOT_SUITABLE_STR,
"MOUNT_POINT=%s", where,
LOG_MESSAGE("Failed to generate valid unit name from path '%s', ignoring mount point: %m", where));
}
u = manager_get_unit(m, e);
if (u)
@@ -1686,7 +1707,7 @@ static int mount_setup_unit(
* by the sysadmin having called mount(8) directly. */
r = mount_setup_new_unit(m, e, what, where, options, fstype, &flags, &u);
if (r < 0)
return log_warning_errno(r, "Failed to set up mount unit: %m");
return log_warning_errno(r, "Failed to set up mount unit for '%s': %m", where);
/* If the mount changed properties or state, let's notify our clients */
if (flags & (MOUNT_PROC_JUST_CHANGED|MOUNT_PROC_JUST_MOUNTED))
src/journal/sd-journal.c
+3 -1
View File
@@ -45,7 +45,9 @@
#define JOURNAL_FILES_RECHECK_USEC (2 * USEC_PER_SEC)
#define REPLACE_VAR_MAX 256
/* The maximum size of variable values we'll expand in catalog entries. We bind this to PATH_MAX for now, as
* we want to be able to show all officially valid paths at least */
#define REPLACE_VAR_MAX PATH_MAX
#define DEFAULT_DATA_THRESHOLD (64*1024)
src/systemd/sd-messages.h
+5
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@@ -161,6 +161,11 @@ _SD_BEGIN_DECLARATIONS;
#define SD_MESSAGE_UNSAFE_USER_NAME SD_ID128_MAKE(b6,1f,da,c6,12,e9,4b,91,82,28,5b,99,88,43,06,1f)
#define SD_MESSAGE_UNSAFE_USER_NAME_STR SD_ID128_MAKE_STR(b6,1f,da,c6,12,e9,4b,91,82,28,5b,99,88,43,06,1f)
#define SD_MESSAGE_MOUNT_POINT_PATH_NOT_SUITABLE \
SD_ID128_MAKE(1b,3b,b9,40,37,f0,4b,bf,81,02,8e,13,5a,12,d2,93)
#define SD_MESSAGE_MOUNT_POINT_PATH_NOT_SUITABLE_STR \
SD_ID128_MAKE_STR(1b,3b,b9,40,37,f0,4b,bf,81,02,8e,13,5a,12,d2,93)
_SD_END_DECLARATIONS;
#endif