udev: check stats of .link files and their drop-in files

Fixes #23128.

.github/workflows/build_test.yml

@@ -33,6 +33,6 @@ jobs:
     env: ${{ matrix.env }}
     steps:
       - name: Repository checkout
-        uses: actions/checkout@a12a3943b4bdde767164f792f33f40b04645d846
+        uses: actions/checkout@2541b1294d2704b0964813337f33b291d3f8596b
       - name: ${{ format('Build check ({0}-{1}-{2}-{3})', env.COMPILER, env.COMPILER_VERSION, env.LINKER, env.CRYPTOLIB) }}
         run: sudo -E .github/workflows/build_test.sh

.github/workflows/codeql-analysis.yml

@@ -40,7 +40,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@a12a3943b4bdde767164f792f33f40b04645d846
+      uses: actions/checkout@2541b1294d2704b0964813337f33b291d3f8596b
 
     - name: Initialize CodeQL
       uses: github/codeql-action/init@28eead240834b314f7def40f6fcba65d100d99b1

.github/workflows/coverity.yml

@@ -25,7 +25,7 @@ jobs:
       CURRENT_REF:                      "${{ github.ref }}"
     steps:
       - name: Repository checkout
-        uses: actions/checkout@a12a3943b4bdde767164f792f33f40b04645d846
+        uses: actions/checkout@2541b1294d2704b0964813337f33b291d3f8596b
       # https://docs.github.com/en/free-pro-team@latest/actions/reference/workflow-commands-for-github-actions#setting-an-environment-variable
       - name: Set the $COVERITY_SCAN_NOTIFICATION_EMAIL env variable
         run: echo "COVERITY_SCAN_NOTIFICATION_EMAIL=$(git log -1 ${{ github.sha }} --pretty=\"%aE\")" >> "$GITHUB_ENV"

.github/workflows/linter.yml

@@ -23,13 +23,13 @@ jobs:
 
     steps:
       - name: Repo checkout
-        uses: actions/checkout@a12a3943b4bdde767164f792f33f40b04645d846
+        uses: actions/checkout@2541b1294d2704b0964813337f33b291d3f8596b
         with:
           # We need a full repo clone
           fetch-depth: 0
 
       - name: Lint Code Base
-        uses: github/super-linter/slim@3792fe5373cf2f5b22d590fcbbc4533d735c573e
+        uses: github/super-linter/slim@ae4e373c56efad95924d9cc6b89624fdb2333007
         env:
           DEFAULT_BRANCH: main
           MULTI_STATUS: false

.github/workflows/mkosi.yml

@@ -48,7 +48,7 @@ jobs:
             release: 9-stream
 
     steps:
-    - uses: actions/checkout@a12a3943b4bdde767164f792f33f40b04645d846
+    - uses: actions/checkout@2541b1294d2704b0964813337f33b291d3f8596b
     - uses: systemd/mkosi@93098e2406e12ea7f06f962d4808952b8a06d345
 
     - name: Install

.github/workflows/unit_tests.yml

@@ -30,7 +30,7 @@ jobs:
             cryptolib: gcrypt
     steps:
       - name: Repository checkout
-        uses: actions/checkout@a12a3943b4bdde767164f792f33f40b04645d846
+        uses: actions/checkout@2541b1294d2704b0964813337f33b291d3f8596b
       - name: Install build dependencies
         run: sudo -E .github/workflows/unit_tests.sh SETUP
       - name: Build & test (${{ matrix.run_phase }}-${{ matrix.cryptolib }})

src/libsystemd/sd-journal/journal-file.c

@@ -2358,6 +2358,19 @@ static int generic_array_bisect(
                 uint64_t *ret_offset,
                 uint64_t *ret_idx) {
 
+        /* Given an entry array chain, this function finds the object "closest" to the given needle in the
+         * chain, taking into account the provided direction. A function can be provided to determine how
+         * an object is matched against the given needle.
+         *
+         * Given a journal file, the offset of an object and the needle, the test_object() function should
+         * return TEST_LEFT if the needle is located earlier in the entry array chain, TEST_RIGHT if the
+         * needle is located later in the entry array chain and TEST_FOUND if the object matches the needle.
+         * If test_object() returns TEST_FOUND for a specific object, that object's information will be used
+         * to populate the return values of this function. If test_object() never returns TEST_FOUND, the
+         * return values are populated with the details of one of the objects closest to the needle. If the
+         * direction is DIRECTION_UP, the earlier object is used. Otherwise, the later object is used.
+         */
+
         uint64_t a, p, t = 0, i = 0, last_p = 0, last_index = UINT64_MAX;
         bool subtract_one = false;
         Object *array = NULL;

src/libsystemd/sd-journal/sd-journal.c

@@ -493,7 +493,6 @@ static int next_for_match(
 
         int r;
         uint64_t np = 0;
-        Object *n;
 
         assert(j);
         assert(m);
@@ -569,12 +568,12 @@ static int next_for_match(
 
         assert(np > 0);
 
-        r = journal_file_move_to_object(f, OBJECT_ENTRY, np, &n);
+        if (ret) {
+                r = journal_file_move_to_object(f, OBJECT_ENTRY, np, ret);
                 if (r < 0)
                         return r;
+        }
 
-        if (ret)
-                *ret = n;
         if (offset)
                 *offset = np;
 
@@ -633,7 +632,6 @@ static int find_location_for_match(
 
         } else if (m->type == MATCH_OR_TERM) {
                 uint64_t np = 0;
-                Object *n;
 
                 /* Find the earliest match */
 
@@ -652,12 +650,12 @@ static int find_location_for_match(
                 if (np == 0)
                         return 0;
 
-                r = journal_file_move_to_object(f, OBJECT_ENTRY, np, &n);
+                if (ret) {
+                        r = journal_file_move_to_object(f, OBJECT_ENTRY, np, ret);
                         if (r < 0)
                                 return r;
+                }
 
-                if (ret)
-                        *ret = n;
                 if (offset)
                         *offset = np;
 

src/network/networkd-network.c

@@ -591,28 +591,6 @@ int network_load(Manager *manager, OrderedHashmap **networks) {
         return 0;
 }
 
-static bool stats_by_path_equal(Hashmap *a, Hashmap *b) {
-        struct stat *st_a, *st_b;
-        const char *path;
-
-        assert(a);
-        assert(b);
-
-        if (hashmap_size(a) != hashmap_size(b))
-                return false;
-
-        HASHMAP_FOREACH_KEY(st_a, path, a) {
-                st_b = hashmap_get(b, path);
-                if (!st_b)
-                        return false;
-
-                if (!stat_inode_unmodified(st_a, st_b))
-                        return false;
-        }
-
-        return true;
-}
-
 int network_reload(Manager *manager) {
         OrderedHashmap *new_networks = NULL;
         Network *n, *old;

src/shared/conf-parser.c

@@ -34,6 +34,7 @@
 #include "set.h"
 #include "signal-util.h"
 #include "socket-util.h"
+#include "stat-util.h"
 #include "string-util.h"
 #include "strv.h"
 #include "syslog-util.h"
@@ -556,6 +557,27 @@ int config_parse_many_nulstr(
                                        ret_stats_by_path);
 }
 
+static int config_get_dropin_files(
+                const char* const* conf_file_dirs,
+                const char *dropin_dirname,
+                char ***ret) {
+
+        _cleanup_strv_free_ char **dropin_dirs = NULL;
+        const char *suffix;
+        int r;
+
+        assert(conf_file_dirs);
+        assert(dropin_dirname);
+        assert(ret);
+
+        suffix = strjoina("/", dropin_dirname);
+        r = strv_extend_strv_concat(&dropin_dirs, (char**) conf_file_dirs, suffix);
+        if (r < 0)
+                return r;
+
+        return conf_files_list_strv(ret, ".conf", NULL, 0, (const char* const*) dropin_dirs);
+}
+
 /* Parse each config file in the directories specified as strv. */
 int config_parse_many(
                 const char* const* conf_files,
@@ -568,23 +590,128 @@ int config_parse_many(
                 void *userdata,
                 Hashmap **ret_stats_by_path) {
 
-        _cleanup_strv_free_ char **dropin_dirs = NULL;
         _cleanup_strv_free_ char **files = NULL;
-        const char *suffix;
         int r;
 
-        suffix = strjoina("/", dropin_dirname);
-        r = strv_extend_strv_concat(&dropin_dirs, (char**) conf_file_dirs, suffix);
-        if (r < 0)
-                return r;
+        assert(conf_file_dirs);
+        assert(dropin_dirname);
+        assert(sections);
+        assert(table);
 
-        r = conf_files_list_strv(&files, ".conf", NULL, 0, (const char* const*) dropin_dirs);
+        r = config_get_dropin_files(conf_file_dirs, dropin_dirname, &files);
         if (r < 0)
                 return r;
 
         return config_parse_many_files(conf_files, files, sections, lookup, table, flags, userdata, ret_stats_by_path);
 }
 
+static int config_get_stats_by_path_one(
+                const char* conf_file,
+                const char* const* conf_file_dirs,
+                Hashmap *stats_by_path) {
+
+        _cleanup_strv_free_ char **files = NULL;
+        _cleanup_free_ char *dropin_dirname = NULL;
+        struct stat st;
+        int r;
+
+        assert(conf_file);
+        assert(conf_file_dirs);
+        assert(stats_by_path);
+
+        /* Unlike config_parse(), this does not support stream. */
+
+        r = path_extract_filename(conf_file, &dropin_dirname);
+        if (r < 0)
+                return r;
+        if (r == O_DIRECTORY)
+                return -EINVAL;
+
+        if (!strextend(&dropin_dirname, ".d"))
+                return -ENOMEM;
+
+        r = config_get_dropin_files(conf_file_dirs, dropin_dirname, &files);
+        if (r < 0)
+                return r;
+
+        /* First read the main config file. */
+        r = RET_NERRNO(stat(conf_file, &st));
+        if (r >= 0) {
+                r = hashmap_put_stats_by_path(&stats_by_path, conf_file, &st);
+                if (r < 0)
+                        return r;
+        } else if (r != -ENOENT)
+                return r;
+
+        /* Then read all the drop-ins. */
+        STRV_FOREACH(fn, files) {
+                if (stat(*fn, &st) < 0) {
+                        if (errno == ENOENT)
+                                continue;
+
+                        return -errno;
+                }
+
+                r = hashmap_put_stats_by_path(&stats_by_path, *fn, &st);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+int config_get_stats_by_path(
+                const char *suffix,
+                const char *root,
+                unsigned flags,
+                const char* const* dirs,
+                Hashmap **ret) {
+
+        _cleanup_hashmap_free_ Hashmap *stats_by_path = NULL;
+        _cleanup_strv_free_ char **files = NULL;
+        int r;
+
+        assert(suffix);
+        assert(dirs);
+        assert(ret);
+
+        r = conf_files_list_strv(&files, suffix, root, flags, dirs);
+        if (r < 0)
+                return r;
+
+        stats_by_path = hashmap_new(&path_hash_ops_free_free);
+        if (!stats_by_path)
+                return -ENOMEM;
+
+        STRV_FOREACH(f, files) {
+                r = config_get_stats_by_path_one(*f, dirs, stats_by_path);
+                if (r < 0)
+                        return r;
+        }
+
+        *ret = TAKE_PTR(stats_by_path);
+        return 0;
+}
+
+bool stats_by_path_equal(Hashmap *a, Hashmap *b) {
+        struct stat *st_a, *st_b;
+        const char *path;
+
+        if (hashmap_size(a) != hashmap_size(b))
+                return false;
+
+        HASHMAP_FOREACH_KEY(st_a, path, a) {
+                st_b = hashmap_get(b, path);
+                if (!st_b)
+                        return false;
+
+                if (!stat_inode_unmodified(st_a, st_b))
+                        return false;
+        }
+
+        return true;
+}
+
 static void config_section_hash_func(const ConfigSection *c, struct siphash *state) {
         siphash24_compress_string(c->filename, state);
         siphash24_compress(&c->line, sizeof(c->line), state);

src/shared/conf-parser.h

@@ -114,6 +114,15 @@ int config_parse_many(
                 void *userdata,
                 Hashmap **ret_stats_by_path);   /* possibly NULL */
 
+int config_get_stats_by_path(
+                const char *suffix,
+                const char *root,
+                unsigned flags,
+                const char* const* dirs,
+                Hashmap **ret);
+
+bool stats_by_path_equal(Hashmap *a, Hashmap *b);
+
 typedef struct ConfigSection {
         unsigned line;
         bool invalid;

src/udev/net/link-config.c

@@ -40,6 +40,7 @@ struct LinkConfigContext {
         LIST_HEAD(LinkConfig, configs);
         int ethtool_fd;
         usec_t network_dirs_ts_usec;
+        Hashmap *stats_by_path;
 };
 
 static LinkConfig* link_config_free(LinkConfig *config) {
@@ -71,6 +72,8 @@ static void link_configs_free(LinkConfigContext *ctx) {
         if (!ctx)
                 return;
 
+        ctx->stats_by_path = hashmap_free(ctx->stats_by_path);
+
         LIST_FOREACH(configs, config, ctx->configs)
                 link_config_free(config);
 }
@@ -207,6 +210,7 @@ static int link_adjust_wol_options(LinkConfig *config) {
 
 int link_load_one(LinkConfigContext *ctx, const char *filename) {
         _cleanup_(link_config_freep) LinkConfig *config = NULL;
+        _cleanup_hashmap_free_ Hashmap *stats_by_path = NULL;
         _cleanup_free_ char *name = NULL;
         const char *dropin_dirname;
         size_t i;
@@ -254,16 +258,23 @@ int link_load_one(LinkConfigContext *ctx, const char *filename) {
         dropin_dirname = strjoina(basename(filename), ".d");
         r = config_parse_many(
                         STRV_MAKE_CONST(filename),
-                        (const char* const*) CONF_PATHS_STRV("systemd/network"),
+                        NETWORK_DIRS,
                         dropin_dirname,
                         "Match\0"
                         "Link\0"
                         "SR-IOV\0",
                         config_item_perf_lookup, link_config_gperf_lookup,
-                        CONFIG_PARSE_WARN, config, NULL);
+                        CONFIG_PARSE_WARN, config, &stats_by_path);
         if (r < 0)
                 return r; /* config_parse_many() logs internally. */
 
+        if (ctx->stats_by_path) {
+                r = hashmap_move(ctx->stats_by_path, stats_by_path);
+                if (r < 0)
+                        log_warning_errno(r, "Failed to save stats of '%s' and its drop-in configs, ignoring: %m", filename);
+        } else
+                ctx->stats_by_path = TAKE_PTR(stats_by_path);
+
         if (net_match_is_empty(&config->match) && !config->conditions) {
                 log_warning("%s: No valid settings found in the [Match] section, ignoring file. "
                             "To match all interfaces, add OriginalName=* in the [Match] section.",
@@ -316,10 +327,9 @@ int link_config_load(LinkConfigContext *ctx) {
         _cleanup_strv_free_ char **files = NULL;
         int r;
 
-        link_configs_free(ctx);
+        assert(ctx);
 
-        /* update timestamp */
-        paths_check_timestamp(NETWORK_DIRS, &ctx->network_dirs_ts_usec, true);
+        link_configs_free(ctx);
 
         r = conf_files_list_strv(&files, ".link", NULL, 0, NETWORK_DIRS);
         if (r < 0)
@@ -332,7 +342,18 @@ int link_config_load(LinkConfigContext *ctx) {
 }
 
 bool link_config_should_reload(LinkConfigContext *ctx) {
-        return paths_check_timestamp(NETWORK_DIRS, &ctx->network_dirs_ts_usec, false);
+        _cleanup_hashmap_free_ Hashmap *stats_by_path = NULL;
+        int r;
+
+        assert(ctx);
+
+        r = config_get_stats_by_path(".link", NULL, 0, NETWORK_DIRS, &stats_by_path);
+        if (r < 0) {
+                log_warning_errno(r, "Failed to get stats of .link files: %m");
+                return true;
+        }
+
+        return !stats_by_path_equal(ctx->stats_by_path, stats_by_path);
 }
 
 Link *link_free(Link *link) {