From f62231a54abff6566415ea82aa8773e61f5688d6 Mon Sep 17 00:00:00 2001
From: Michal Sekletar <msekleta@redhat.com>
Date: Tue, 15 Mar 2022 19:02:05 +0100
Subject: [PATCH] core: shorten long unit names that are based on paths and
append path hash at the end
Fixes #18077
(cherry picked from commit 1d0727e76fd5e9a07cc9991ec9a10ea1d78a99c7)
Resolves: #1940973
---
src/basic/string-util.h | 23 +++++-----
src/basic/unit-name.c | 88 ++++++++++++++++++++++++++++++++++++++-
src/basic/unit-name.h | 3 ++
src/core/mount.c | 3 ++
src/test/test-unit-name.c | 25 ++++++++++-
5 files changed, 129 insertions(+), 13 deletions(-)
diff --git a/src/basic/string-util.h b/src/basic/string-util.h
index 742b566932..0d406ff64a 100644
--- a/src/basic/string-util.h
+++ b/src/basic/string-util.h
@@ -9,17 +9,18 @@
#include "macro.h"
/* What is interpreted as whitespace? */
-#define WHITESPACE " \t\n\r"
-#define NEWLINE "\n\r"
-#define QUOTES "\"\'"
-#define COMMENTS "#;"
-#define GLOB_CHARS "*?["
-#define DIGITS "0123456789"
-#define LOWERCASE_LETTERS "abcdefghijklmnopqrstuvwxyz"
-#define UPPERCASE_LETTERS "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
-#define LETTERS LOWERCASE_LETTERS UPPERCASE_LETTERS
-#define ALPHANUMERICAL LETTERS DIGITS
-#define HEXDIGITS DIGITS "abcdefABCDEF"
+#define WHITESPACE " \t\n\r"
+#define NEWLINE "\n\r"
+#define QUOTES "\"\'"
+#define COMMENTS "#;"
+#define GLOB_CHARS "*?["
+#define DIGITS "0123456789"
+#define LOWERCASE_LETTERS "abcdefghijklmnopqrstuvwxyz"
+#define UPPERCASE_LETTERS "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+#define LETTERS LOWERCASE_LETTERS UPPERCASE_LETTERS
+#define ALPHANUMERICAL LETTERS DIGITS
+#define HEXDIGITS DIGITS "abcdefABCDEF"
+#define LOWERCASE_HEXDIGITS DIGITS "abcdef"
#define streq(a,b) (strcmp((a),(b)) == 0)
#define strneq(a, b, n) (strncmp((a), (b), (n)) == 0)
diff --git a/src/basic/unit-name.c b/src/basic/unit-name.c
index f9b3fafd4d..65ed979e39 100644
--- a/src/basic/unit-name.c
+++ b/src/basic/unit-name.c
@@ -6,11 +6,17 @@
#include <stdlib.h>
#include <string.h>
+#include "sd-id128.h"
+
#include "alloc-util.h"
#include "glob-util.h"
#include "hexdecoct.h"
#include "path-util.h"
+#include "random-util.h"
+#include "siphash24.h"
+#include "sparse-endian.h"
#include "special.h"
+#include "stdio-util.h"
#include "string-util.h"
#include "strv.h"
#include "unit-name.h"
@@ -31,6 +37,9 @@
VALID_CHARS_WITH_AT \
"[]!-*?"
+#define LONG_UNIT_NAME_HASH_KEY SD_ID128_MAKE(ec,f2,37,fb,58,32,4a,32,84,9f,06,9b,0d,21,eb,9a)
+#define UNIT_NAME_HASH_LENGTH_CHARS 16
+
bool unit_name_is_valid(const char *n, UnitNameFlags flags) {
const char *e, *i, *at;
@@ -513,6 +522,68 @@ int unit_name_template(const char *f, char **ret) {
return 0;
}
+bool unit_name_is_hashed(const char *name) {
+ char *s;
+
+ if (!unit_name_is_valid(name, UNIT_NAME_PLAIN))
+ return false;
+
+ assert_se(s = strrchr(name, '.'));
+
+ if (s - name < UNIT_NAME_HASH_LENGTH_CHARS + 1)
+ return false;
+
+ s -= UNIT_NAME_HASH_LENGTH_CHARS;
+ if (s[-1] != '_')
+ return false;
+
+ for (size_t i = 0; i < UNIT_NAME_HASH_LENGTH_CHARS; i++)
+ if (!strchr(LOWERCASE_HEXDIGITS, s[i]))
+ return false;
+
+ return true;
+}
+
+int unit_name_hash_long(const char *name, char **ret) {
+ _cleanup_free_ char *n = NULL, *hash = NULL;
+ char *suffix;
+ le64_t h;
+ size_t len;
+
+ if (strlen(name) < UNIT_NAME_MAX)
+ return -EMSGSIZE;
+
+ suffix = strrchr(name, '.');
+ if (!suffix)
+ return -EINVAL;
+
+ if (unit_type_from_string(suffix+1) < 0)
+ return -EINVAL;
+
+ h = htole64(siphash24(name, strlen(name) + 1, LONG_UNIT_NAME_HASH_KEY.bytes));
+
+ hash = hexmem(&h, sizeof(h));
+ if (!hash)
+ return -ENOMEM;
+
+ assert_se(strlen(hash) == UNIT_NAME_HASH_LENGTH_CHARS);
+
+ len = UNIT_NAME_MAX - 1 - strlen(suffix+1) - UNIT_NAME_HASH_LENGTH_CHARS - 2;
+ assert(len > 0 && len < UNIT_NAME_MAX);
+
+ n = strndup(name, len);
+ if (!n)
+ return -ENOMEM;
+
+ if (!strextend(&n, "_", hash, suffix, NULL))
+ return -ENOMEM;
+ assert_se(unit_name_is_valid(n, UNIT_NAME_PLAIN));
+
+ *ret = TAKE_PTR(n);
+
+ return 0;
+}
+
int unit_name_from_path(const char *path, const char *suffix, char **ret) {
_cleanup_free_ char *p = NULL, *s = NULL;
int r;
@@ -532,7 +603,19 @@ int unit_name_from_path(const char *path, const char *suffix, char **ret) {
if (!s)
return -ENOMEM;
- /* Refuse this if this got too long or for some other reason didn't result in a valid name */
+ if (strlen(s) >= UNIT_NAME_MAX) {
+ _cleanup_free_ char *n = NULL;
+
+ log_debug("Unit name \"%s\" too long, falling back to hashed unit name.", s);
+
+ r = unit_name_hash_long(s, &n);
+ if (r < 0)
+ return r;
+
+ free_and_replace(s, n);
+ }
+
+ /* Refuse if this for some other reason didn't result in a valid name */
if (!unit_name_is_valid(s, UNIT_NAME_PLAIN))
return -EINVAL;
@@ -582,6 +665,9 @@ int unit_name_to_path(const char *name, char **ret) {
if (r < 0)
return r;
+ if (unit_name_is_hashed(name))
+ return -ENAMETOOLONG;
+
return unit_name_path_unescape(prefix, ret);
}
diff --git a/src/basic/unit-name.h b/src/basic/unit-name.h
index 61abcd585b..602295af8f 100644
--- a/src/basic/unit-name.h
+++ b/src/basic/unit-name.h
@@ -45,6 +45,9 @@ int unit_name_replace_instance(const char *f, const char *i, char **ret);
int unit_name_template(const char *f, char **ret);
+int unit_name_hash_long(const char *name, char **ret);
+bool unit_name_is_hashed(const char *name);
+
int unit_name_from_path(const char *path, const char *suffix, char **ret);
int unit_name_from_path_instance(const char *prefix, const char *path, const char *suffix, char **ret);
int unit_name_to_path(const char *name, char **ret);
diff --git a/src/core/mount.c b/src/core/mount.c
index d37b5731f8..e69ecb7ce3 100644
--- a/src/core/mount.c
+++ b/src/core/mount.c
@@ -572,6 +572,9 @@ static int mount_add_extras(Mount *m) {
if (!m->where) {
r = unit_name_to_path(u->id, &m->where);
+ if (r == -ENAMETOOLONG)
+ log_unit_error_errno(u, r, "Failed to derive mount point path from unit name, because unit name is hashed. "
+ "Set \"Where=\" in the unit file explicitly.");
if (r < 0)
return r;
}
diff --git a/src/test/test-unit-name.c b/src/test/test-unit-name.c
index 2b00ef8cb7..35cfaafd30 100644
--- a/src/test/test-unit-name.c
+++ b/src/test/test-unit-name.c
@@ -82,6 +82,7 @@ static void test_unit_name_replace_instance(void) {
static void test_unit_name_from_path_one(const char *path, const char *suffix, const char *expected, int ret) {
_cleanup_free_ char *t = NULL;
+ int r;
assert_se(unit_name_from_path(path, suffix, &t) == ret);
puts(strna(t));
@@ -89,12 +90,31 @@ static void test_unit_name_from_path_one(const char *path, const char *suffix, c
if (t) {
_cleanup_free_ char *k = NULL;
- assert_se(unit_name_to_path(t, &k) == 0);
+
+ /* We don't support converting hashed unit names back to paths */
+ r = unit_name_to_path(t, &k);
+ if (r == -ENAMETOOLONG)
+ return;
+ assert(r == 0);
+
puts(strna(k));
assert_se(path_equal(k, empty_to_root(path)));
}
}
+static void test_unit_name_is_hashed(void) {
+ assert_se(!unit_name_is_hashed(""));
+ assert_se(!unit_name_is_hashed("foo@bar.service"));
+ assert_se(!unit_name_is_hashed("foo@.service"));
+ assert_se(unit_name_is_hashed("waldoaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa_7736d9ed33c2ec55.mount"));
+ assert_se(!unit_name_is_hashed("waldoaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa_7736D9ED33C2EC55.mount"));
+ assert_se(!unit_name_is_hashed("waldoaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa!7736d9ed33c2ec55.mount"));
+ assert_se(!unit_name_is_hashed("waldoaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa_7736d9gd33c2ec55.mount"));
+ assert_se(!unit_name_is_hashed("waldoaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa_.mount"));
+ assert_se(!unit_name_is_hashed("waldoaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa_2103e1466b87f7f7@waldo.mount"));
+ assert_se(!unit_name_is_hashed("waldoaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa_2103e1466b87f7f7@.mount"));
+}
+
static void test_unit_name_from_path(void) {
puts("-------------------------------------------------");
test_unit_name_from_path_one("/waldo", ".mount", "waldo.mount", 0);
@@ -105,6 +125,8 @@ static void test_unit_name_from_path(void) {
test_unit_name_from_path_one("///", ".mount", "-.mount", 0);
test_unit_name_from_path_one("/foo/../bar", ".mount", NULL, -EINVAL);
test_unit_name_from_path_one("/foo/./bar", ".mount", NULL, -EINVAL);
+ test_unit_name_from_path_one("/waldoaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", ".mount",
+ "waldoaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa_7736d9ed33c2ec55.mount", 0);
}
static void test_unit_name_from_path_instance_one(const char *pattern, const char *path, const char *suffix, const char *expected, int ret) {
@@ -824,6 +846,7 @@ int main(int argc, char* argv[]) {
test_unit_name_is_valid();
test_unit_name_replace_instance();
+ test_unit_name_is_hashed();
test_unit_name_from_path();
test_unit_name_from_path_instance();
test_unit_name_mangle();