From 097290727d6e16aa2e5859e3cd6f0c5ea4c47101 Mon Sep 17 00:00:00 2001
Message-ID: <097290727d6e16aa2e5859e3cd6f0c5ea4c47101.1696060300.git.vivien@planete-kraus.eu>
From: Vivien Kraus <vivien@planete-kraus.eu>
Date: Tue, 26 Sep 2023 18:17:34 +0200
Subject: [PATCH] Improvements for Guix

---
This is the combination of:

  - https://github.com/eudev-project/eudev/pull/262
  - https://github.com/eudev-project/eudev/pull/263
  - https://github.com/eudev-project/eudev/pull/264

 src/libudev/libudev-hwdb.c |  37 +++++++++--
 src/libudev/libudev.h      |   4 +-
 src/udev/udevadm-hwdb.c    | 127 +++++++++++++++++++++++++++++++++----
 3 files changed, 149 insertions(+), 19 deletions(-)

diff --git a/src/libudev/libudev-hwdb.c b/src/libudev/libudev-hwdb.c
index 62029e2b2..f7212c519 100644
--- a/src/libudev/libudev-hwdb.c
+++ b/src/libudev/libudev-hwdb.c
@@ -47,6 +47,7 @@ struct udev_hwdb {
         struct udev *udev;
         int refcount;
 
+        char *bin_paths;
         FILE *f;
         struct stat st;
         union {
@@ -256,10 +257,28 @@ static int trie_search_f(struct udev_hwdb *hwdb, const char *search) {
         return 0;
 }
 
-static const char hwdb_bin_paths[] =
-    "/etc/udev/hwdb.bin\0"
-    UDEV_LIBEXEC_DIR "/hwdb.bin\0";
-
+static char *get_hwdb_bin_paths (void) {
+        static const char default_locations[] =
+          "/etc/udev/hwdb.bin\0"
+          UDEV_LIBEXEC_DIR "/hwdb.bin\0";
+        const char *by_env = getenv("UDEV_HWDB_BIN");
+        if (by_env != NULL) {
+                char *path = malloc(strlen(by_env) + 1
+                                    + sizeof (default_locations));
+                if (path != NULL) {
+                        memcpy(path, by_env, strlen(by_env) + 1);
+                        memcpy(path + strlen(by_env) + 1,
+                               default_locations,
+                               sizeof (default_locations));
+                }
+                return path;
+        }
+        char *path = malloc(sizeof (default_locations));
+        if (path != NULL) {
+                memcpy(path, default_locations, sizeof (default_locations));
+        }
+        return path;
+}
 
 /**
  * udev_hwdb_new:
@@ -282,7 +301,12 @@ _public_ struct udev_hwdb *udev_hwdb_new(struct udev *udev) {
         udev_list_init(udev, &hwdb->properties_list, true);
 
         /* find hwdb.bin in hwdb_bin_paths */
-        NULSTR_FOREACH(hwdb_bin_path, hwdb_bin_paths) {
+        hwdb->bin_paths = get_hwdb_bin_paths();
+        if (hwdb->bin_paths == NULL) {
+                udev_hwdb_unref(hwdb);
+                return NULL;
+        }
+        NULSTR_FOREACH(hwdb_bin_path, hwdb->bin_paths) {
                 hwdb->f = fopen(hwdb_bin_path, "re");
                 if (hwdb->f)
                         break;
@@ -363,6 +387,7 @@ _public_ struct udev_hwdb *udev_hwdb_unref(struct udev_hwdb *hwdb) {
                 return NULL;
         if (hwdb->map)
                 munmap((void *)hwdb->map, hwdb->st.st_size);
+        free(hwdb->bin_paths);
         if (hwdb->f)
                 fclose(hwdb->f);
         udev_list_cleanup(&hwdb->properties_list);
@@ -381,7 +406,7 @@ bool udev_hwdb_validate(struct udev_hwdb *hwdb) {
                 return false;
 
         /* if hwdb.bin doesn't exist anywhere, we need to update */
-        NULSTR_FOREACH(p, hwdb_bin_paths) {
+        NULSTR_FOREACH(p, hwdb->bin_paths) {
                 if (stat(p, &st) >= 0) {
                         found = true;
                         break;
diff --git a/src/libudev/libudev.h b/src/libudev/libudev.h
index 8491d2b81..e4bc18970 100644
--- a/src/libudev/libudev.h
+++ b/src/libudev/libudev.h
@@ -185,7 +185,9 @@ struct udev_list_entry *udev_queue_get_queued_list_entry(struct udev_queue *udev
 /*
  *  udev_hwdb
  *
- *  access to the static hardware properties database
+ *  access to the static hardware properties database; the database to
+ *  use can be overriden by setting the UDEV_HWDB_BIN environment
+ *  variable to its file name
  */
 struct udev_hwdb;
 struct udev_hwdb *udev_hwdb_new(struct udev *udev);
diff --git a/src/udev/udevadm-hwdb.c b/src/udev/udevadm-hwdb.c
index d14a3434f..c2214dc91 100644
--- a/src/udev/udevadm-hwdb.c
+++ b/src/udev/udevadm-hwdb.c
@@ -35,11 +35,69 @@
  * Uses a Patricia/radix trie to index all matches for efficient lookup.
  */
 
-static const char * const conf_file_dirs[] = {
-        UDEV_HWDB_DIR,
-        UDEV_LIBEXEC_DIR "/hwdb.d",
-        NULL
-};
+static ssize_t follow_path (const char *path_variable, char **destination, size_t max) {
+        size_t n = 0;
+        if (path_variable != NULL) {
+                while (path_variable[0] == ':') {
+                      path_variable++;
+                }
+                while (path_variable[0] != '\0') {
+                        const char *end = strchr(path_variable, ':');
+                        if (end == NULL) {
+                                end = path_variable + strlen(path_variable);
+                        }
+                        if (n < max) {
+                                destination[n] = strndup(path_variable, end - path_variable);
+                                if (destination[n] == NULL) {
+                                        return -ENOMEM;
+                                }
+                        }
+                        n++;
+                        path_variable = end;
+                        while (path_variable[0] == ':') {
+                                path_variable++;
+                        }
+                }
+        }
+        if (n < max) {
+                destination[n] = NULL;
+        }
+        return n;
+}
+
+static char ** list_conf_file_dirs (void) {
+        static const char *main_hwdb_dir = UDEV_HWDB_DIR;
+        static const char *libexec_dir = UDEV_LIBEXEC_DIR "/hwdb.d";
+        const char *path_variable = getenv ("UDEV_HWDB_PATH");
+        ssize_t path_length = 0;
+        if (path_variable != NULL) {
+                path_length = follow_path(path_variable, NULL, 0);
+                if (path_length < 0) {
+                      return NULL;
+                }
+        }
+        char **all_dirs = malloc((path_length + 2 + 1) * sizeof (char *));
+        if (all_dirs == NULL) {
+                return NULL;
+        }
+        for (ssize_t i = 0; i < path_length + 2 + 1; i++) {
+                all_dirs[i] = NULL;
+        }
+        ssize_t error = follow_path(path_variable, all_dirs, path_length + 1);
+        all_dirs[path_length] = strdup(main_hwdb_dir);
+        all_dirs[path_length + 1] = strdup(libexec_dir);
+        all_dirs[path_length + 2] = NULL;
+        if (error < 0
+            || all_dirs[path_length] == NULL
+            || all_dirs[path_length + 1] == NULL) {
+                for (ssize_t i = 0; i < path_length + 2 + 1; i++) {
+                        free(all_dirs[i]);
+                }
+                free(all_dirs);
+                all_dirs = NULL;
+        }
+        return all_dirs;
+}
 
 /* in-memory trie objects */
 struct trie {
@@ -564,10 +622,15 @@ static int import_file(struct udev *udev, struct trie *trie, const char *filenam
 static void help(void) {
         printf("Usage: udevadm hwdb OPTIONS\n"
                "  -u,--update          update the hardware database\n"
+               "  -o,--output=.../hwdb.bin generate in .../hwdb.bin instead of /etc/udev/hwdb.bin\n"
                "  --usr                generate in " UDEV_LIBEXEC_DIR " instead of /etc/udev\n"
                "  -t,--test=MODALIAS   query database and print result\n"
                "  -r,--root=PATH       alternative root path in the filesystem\n"
-               "  -h,--help\n\n");
+               "  -h,--help\n"
+               "\n"
+               "The HWDB is searched in the UDEV_HWDB_PATH search path, "
+               UDEV_HWDB_DIR ", and " UDEV_LIBEXEC_DIR "/hwdb.d.\n"
+               "\n");
 }
 
 static int adm_hwdb(struct udev *udev, int argc, char *argv[]) {
@@ -578,6 +641,7 @@ static int adm_hwdb(struct udev *udev, int argc, char *argv[]) {
         static const struct option options[] = {
                 { "update", no_argument,       NULL, 'u' },
                 { "usr",    no_argument,       NULL, ARG_USR },
+                { "output", required_argument, NULL, 'o' },
                 { "test",   required_argument, NULL, 't' },
                 { "root",   required_argument, NULL, 'r' },
                 { "help",   no_argument,       NULL, 'h' },
@@ -585,19 +649,37 @@ static int adm_hwdb(struct udev *udev, int argc, char *argv[]) {
         };
         const char *test = NULL;
         const char *root = "";
-        const char *hwdb_bin_dir = "/etc/udev";
         bool update = false;
         struct trie *trie = NULL;
         int err, c;
         int rc = EXIT_SUCCESS;
 
-        while ((c = getopt_long(argc, argv, "ut:r:h", options, NULL)) >= 0)
+        _cleanup_free_ char *hwdb_bin = strdup("/etc/udev/hwdb.bin");
+        if (hwdb_bin == NULL) {
+                rc = EXIT_FAILURE;
+                goto out;
+        }
+
+        while ((c = getopt_long(argc, argv, "uo:t:r:h", options, NULL)) >= 0)
                 switch(c) {
                 case 'u':
                         update = true;
                         break;
                 case ARG_USR:
-                        hwdb_bin_dir = UDEV_LIBEXEC_DIR;
+                        free(hwdb_bin);
+                        hwdb_bin = strdup(UDEV_LIBEXEC_DIR "/hwdb.bin");
+                        if (hwdb_bin == NULL) {
+                                rc = EXIT_FAILURE;
+                                goto out;
+                        }
+                        break;
+                case 'o':
+                        free(hwdb_bin);
+                        hwdb_bin = strdup(optarg);
+                        if (hwdb_bin == NULL) {
+                                rc = EXIT_FAILURE;
+                                goto out;
+                        }
                         break;
                 case 't':
                         test = optarg;
@@ -619,9 +701,18 @@ static int adm_hwdb(struct udev *udev, int argc, char *argv[]) {
                 return EXIT_FAILURE;
         }
 
+        if (root) {
+                char *full_hwdb_bin = strjoin(root, "/", hwdb_bin, NULL);
+                if (full_hwdb_bin == NULL) {
+                        rc = EXIT_FAILURE;
+                        goto out;
+                }
+                free (hwdb_bin);
+                hwdb_bin = full_hwdb_bin;
+        }
+
         if (update) {
                 char **files, **f;
-                _cleanup_free_ char *hwdb_bin = NULL;
 
                 trie = new0(struct trie, 1);
                 if (!trie) {
@@ -644,7 +735,20 @@ static int adm_hwdb(struct udev *udev, int argc, char *argv[]) {
                 }
                 trie->nodes_count++;
 
-                err = conf_files_list_strv(&files, ".hwdb", root, conf_file_dirs);
+                char **conf_file_dirs = list_conf_file_dirs ();
+                if (conf_file_dirs == NULL) {
+                        rc = EXIT_FAILURE;
+                        goto out;
+                }
+                err = conf_files_list_strv(&files, ".hwdb", root,
+                                           (const char * const*) conf_file_dirs);
+                size_t dir_to_cleanup = 0;
+                for (dir_to_cleanup = 0;
+                     conf_file_dirs[dir_to_cleanup] != NULL;
+                     dir_to_cleanup++) {
+                        free (conf_file_dirs[dir_to_cleanup]);
+                }
+                free (conf_file_dirs);
                 if (err < 0) {
                         log_error_errno(err, "failed to enumerate hwdb files: %m");
                         rc = EXIT_FAILURE;
@@ -672,7 +776,6 @@ static int adm_hwdb(struct udev *udev, int argc, char *argv[]) {
                 log_debug("strings dedup'ed: %8zu bytes (%8zu)",
                           trie->strings->dedup_len, trie->strings->dedup_count);
 
-                hwdb_bin = strjoin(root, "/", hwdb_bin_dir, "/hwdb.bin", NULL);
                 if (!hwdb_bin) {
                         rc = EXIT_FAILURE;
                         goto out;

base-commit: 0d86dd9a2a57d5d0809de6395dc36abe515818b5
-- 
2.41.0