chiark / gitweb /
systemd-hwdb: introduce new tool
[elogind.git] / src / hwdb / hwdb.c
diff --git a/src/hwdb/hwdb.c b/src/hwdb/hwdb.c
new file mode 100644 (file)
index 0000000..9f8cbf6
--- /dev/null
@@ -0,0 +1,787 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2012 Kay Sievers <kay@vrfy.org>
+
+  systemd 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.
+
+  systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <string.h>
+#include <ctype.h>
+
+#include "util.h"
+#include "strbuf.h"
+#include "conf-files.h"
+#include "strv.h"
+#include "mkdir.h"
+#include "fileio.h"
+
+#include "hwdb-internal.h"
+#include "hwdb-util.h"
+
+/*
+ * Generic udev properties, key/value database based on modalias strings.
+ * Uses a Patricia/radix trie to index all matches for efficient lookup.
+ */
+
+static const char *arg_hwdb_bin_dir = "/etc/udev";
+static const char *arg_root = "";
+
+static const char * const conf_file_dirs[] = {
+        "/etc/udev/hwdb.d",
+        UDEVLIBEXECDIR "/hwdb.d",
+        NULL
+};
+
+/* in-memory trie objects */
+struct trie {
+        struct trie_node *root;
+        struct strbuf *strings;
+
+        size_t nodes_count;
+        size_t children_count;
+        size_t values_count;
+};
+
+struct trie_node {
+        /* prefix, common part for all children of this node */
+        size_t prefix_off;
+
+        /* sorted array of pointers to children nodes */
+        struct trie_child_entry *children;
+        uint8_t children_count;
+
+        /* sorted array of key/value pairs */
+        struct trie_value_entry *values;
+        size_t values_count;
+};
+
+/* children array item with char (0-255) index */
+struct trie_child_entry {
+        uint8_t c;
+        struct trie_node *child;
+};
+
+/* value array item with key/value pairs */
+struct trie_value_entry {
+        size_t key_off;
+        size_t value_off;
+};
+
+static int trie_children_cmp(const void *v1, const void *v2) {
+        const struct trie_child_entry *n1 = v1;
+        const struct trie_child_entry *n2 = v2;
+
+        return n1->c - n2->c;
+}
+
+static int node_add_child(struct trie *trie, struct trie_node *node, struct trie_node *node_child, uint8_t c) {
+        struct trie_child_entry *child;
+
+        /* extend array, add new entry, sort for bisection */
+        child = realloc(node->children, (node->children_count + 1) * sizeof(struct trie_child_entry));
+        if (!child)
+                return -ENOMEM;
+
+        node->children = child;
+        trie->children_count++;
+        node->children[node->children_count].c = c;
+        node->children[node->children_count].child = node_child;
+        node->children_count++;
+        qsort(node->children, node->children_count, sizeof(struct trie_child_entry), trie_children_cmp);
+        trie->nodes_count++;
+
+        return 0;
+}
+
+static struct trie_node *node_lookup(const struct trie_node *node, uint8_t c) {
+        struct trie_child_entry *child;
+        struct trie_child_entry search;
+
+        search.c = c;
+        child = bsearch(&search, node->children, node->children_count, sizeof(struct trie_child_entry), trie_children_cmp);
+        if (child)
+                return child->child;
+        return NULL;
+}
+
+static void trie_node_cleanup(struct trie_node *node) {
+        size_t i;
+
+        for (i = 0; i < node->children_count; i++)
+                trie_node_cleanup(node->children[i].child);
+        free(node->children);
+        free(node->values);
+        free(node);
+}
+
+static void trie_free(struct trie *trie) {
+        if (!trie)
+                return;
+
+        if (trie->root)
+                trie_node_cleanup(trie->root);
+
+        strbuf_cleanup(trie->strings);
+        free(trie);
+}
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(struct trie*, trie_free);
+
+static int trie_values_cmp(const void *v1, const void *v2, void *arg) {
+        const struct trie_value_entry *val1 = v1;
+        const struct trie_value_entry *val2 = v2;
+        struct trie *trie = arg;
+
+        return strcmp(trie->strings->buf + val1->key_off,
+                      trie->strings->buf + val2->key_off);
+}
+
+static int trie_node_add_value(struct trie *trie, struct trie_node *node,
+                          const char *key, const char *value) {
+        ssize_t k, v;
+        struct trie_value_entry *val;
+
+        k = strbuf_add_string(trie->strings, key, strlen(key));
+        if (k < 0)
+                return k;
+        v = strbuf_add_string(trie->strings, value, strlen(value));
+        if (v < 0)
+                return v;
+
+        if (node->values_count) {
+                struct trie_value_entry search = {
+                        .key_off = k,
+                        .value_off = v,
+                };
+
+                val = xbsearch_r(&search, node->values, node->values_count, sizeof(struct trie_value_entry), trie_values_cmp, trie);
+                if (val) {
+                        /* replace existing earlier key with new value */
+                        val->value_off = v;
+                        return 0;
+                }
+        }
+
+        /* extend array, add new entry, sort for bisection */
+        val = realloc(node->values, (node->values_count + 1) * sizeof(struct trie_value_entry));
+        if (!val)
+                return -ENOMEM;
+        trie->values_count++;
+        node->values = val;
+        node->values[node->values_count].key_off = k;
+        node->values[node->values_count].value_off = v;
+        node->values_count++;
+        qsort_r(node->values, node->values_count, sizeof(struct trie_value_entry), trie_values_cmp, trie);
+        return 0;
+}
+
+static int trie_insert(struct trie *trie, struct trie_node *node, const char *search,
+                       const char *key, const char *value) {
+        size_t i = 0;
+        int err = 0;
+
+        for (;;) {
+                size_t p;
+                uint8_t c;
+                struct trie_node *child;
+
+                for (p = 0; (c = trie->strings->buf[node->prefix_off + p]); p++) {
+                        _cleanup_free_ char *s = NULL;
+                        ssize_t off;
+                        _cleanup_free_ struct trie_node *new_child = NULL;
+
+                        if (c == search[i + p])
+                                continue;
+
+                        /* split node */
+                        new_child = new0(struct trie_node, 1);
+                        if (!new_child)
+                                return -ENOMEM;
+
+                        /* move values from parent to child */
+                        new_child->prefix_off = node->prefix_off + p+1;
+                        new_child->children = node->children;
+                        new_child->children_count = node->children_count;
+                        new_child->values = node->values;
+                        new_child->values_count = node->values_count;
+
+                        /* update parent; use strdup() because the source gets realloc()d */
+                        s = strndup(trie->strings->buf + node->prefix_off, p);
+                        if (!s)
+                                return -ENOMEM;
+
+                        off = strbuf_add_string(trie->strings, s, p);
+                        if (off < 0)
+                                return off;
+
+                        node->prefix_off = off;
+                        node->children = NULL;
+                        node->children_count = 0;
+                        node->values = NULL;
+                        node->values_count = 0;
+                        err = node_add_child(trie, node, new_child, c);
+                        if (err < 0)
+                                return err;
+
+                        new_child = NULL; /* avoid cleanup */
+                        break;
+                }
+                i += p;
+
+                c = search[i];
+                if (c == '\0')
+                        return trie_node_add_value(trie, node, key, value);
+
+                child = node_lookup(node, c);
+                if (!child) {
+                        ssize_t off;
+
+                        /* new child */
+                        child = new0(struct trie_node, 1);
+                        if (!child)
+                                return -ENOMEM;
+
+                        off = strbuf_add_string(trie->strings, search + i+1, strlen(search + i+1));
+                        if (off < 0) {
+                                free(child);
+                                return off;
+                        }
+
+                        child->prefix_off = off;
+                        err = node_add_child(trie, node, child, c);
+                        if (err < 0) {
+                                free(child);
+                                return err;
+                        }
+
+                        return trie_node_add_value(trie, child, key, value);
+                }
+
+                node = child;
+                i++;
+        }
+}
+
+struct trie_f {
+        FILE *f;
+        struct trie *trie;
+        uint64_t strings_off;
+
+        uint64_t nodes_count;
+        uint64_t children_count;
+        uint64_t values_count;
+};
+
+/* calculate the storage space for the nodes, children arrays, value arrays */
+static void trie_store_nodes_size(struct trie_f *trie, struct trie_node *node) {
+        uint64_t i;
+
+        for (i = 0; i < node->children_count; i++)
+                trie_store_nodes_size(trie, node->children[i].child);
+
+        trie->strings_off += sizeof(struct trie_node_f);
+        for (i = 0; i < node->children_count; i++)
+                trie->strings_off += sizeof(struct trie_child_entry_f);
+        for (i = 0; i < node->values_count; i++)
+                trie->strings_off += sizeof(struct trie_value_entry_f);
+}
+
+static int64_t trie_store_nodes(struct trie_f *trie, struct trie_node *node) {
+        uint64_t i;
+        struct trie_node_f n = {
+                .prefix_off = htole64(trie->strings_off + node->prefix_off),
+                .children_count = node->children_count,
+                .values_count = htole64(node->values_count),
+        };
+        struct trie_child_entry_f *children = NULL;
+        int64_t node_off;
+
+        if (node->children_count) {
+                children = new0(struct trie_child_entry_f, node->children_count);
+                if (!children)
+                        return -ENOMEM;
+        }
+
+        /* post-order recursion */
+        for (i = 0; i < node->children_count; i++) {
+                int64_t child_off;
+
+                child_off = trie_store_nodes(trie, node->children[i].child);
+                if (child_off < 0) {
+                        free(children);
+                        return child_off;
+                }
+                children[i].c = node->children[i].c;
+                children[i].child_off = htole64(child_off);
+        }
+
+        /* write node */
+        node_off = ftello(trie->f);
+        fwrite(&n, sizeof(struct trie_node_f), 1, trie->f);
+        trie->nodes_count++;
+
+        /* append children array */
+        if (node->children_count) {
+                fwrite(children, sizeof(struct trie_child_entry_f), node->children_count, trie->f);
+                trie->children_count += node->children_count;
+                free(children);
+        }
+
+        /* append values array */
+        for (i = 0; i < node->values_count; i++) {
+                struct trie_value_entry_f v = {
+                        .key_off = htole64(trie->strings_off + node->values[i].key_off),
+                        .value_off = htole64(trie->strings_off + node->values[i].value_off),
+                };
+
+                fwrite(&v, sizeof(struct trie_value_entry_f), 1, trie->f);
+                trie->values_count++;
+        }
+
+        return node_off;
+}
+
+static int trie_store(struct trie *trie, const char *filename) {
+        struct trie_f t = {
+                .trie = trie,
+        };
+        _cleanup_free_ char *filename_tmp = NULL;
+        int64_t pos;
+        int64_t root_off;
+        int64_t size;
+        struct trie_header_f h = {
+                .signature = HWDB_SIG,
+                .tool_version = htole64(atoi(VERSION)),
+                .header_size = htole64(sizeof(struct trie_header_f)),
+                .node_size = htole64(sizeof(struct trie_node_f)),
+                .child_entry_size = htole64(sizeof(struct trie_child_entry_f)),
+                .value_entry_size = htole64(sizeof(struct trie_value_entry_f)),
+        };
+        int err;
+
+        /* calculate size of header, nodes, children entries, value entries */
+        t.strings_off = sizeof(struct trie_header_f);
+        trie_store_nodes_size(&t, trie->root);
+
+        err = fopen_temporary(filename , &t.f, &filename_tmp);
+        if (err < 0)
+                return err;
+        fchmod(fileno(t.f), 0444);
+
+        /* write nodes */
+        err = fseeko(t.f, sizeof(struct trie_header_f), SEEK_SET);
+        if (err < 0) {
+                fclose(t.f);
+                unlink_noerrno(filename_tmp);
+                return -errno;
+        }
+        root_off = trie_store_nodes(&t, trie->root);
+        h.nodes_root_off = htole64(root_off);
+        pos = ftello(t.f);
+        h.nodes_len = htole64(pos - sizeof(struct trie_header_f));
+
+        /* write string buffer */
+        fwrite(trie->strings->buf, trie->strings->len, 1, t.f);
+        h.strings_len = htole64(trie->strings->len);
+
+        /* write header */
+        size = ftello(t.f);
+        h.file_size = htole64(size);
+        err = fseeko(t.f, 0, SEEK_SET);
+        if (err < 0) {
+                fclose(t.f);
+                unlink_noerrno(filename_tmp);
+                return -errno;
+        }
+        fwrite(&h, sizeof(struct trie_header_f), 1, t.f);
+        err = ferror(t.f);
+        if (err)
+                err = -errno;
+        fclose(t.f);
+        if (err < 0 || rename(filename_tmp, filename) < 0) {
+                unlink_noerrno(filename_tmp);
+                return err < 0 ? err : -errno;
+        }
+
+        log_debug("=== trie on-disk ===");
+        log_debug("size:             %8"PRIu64" bytes", size);
+        log_debug("header:           %8zu bytes", sizeof(struct trie_header_f));
+        log_debug("nodes:            %8"PRIu64" bytes (%8"PRIu64")",
+                  t.nodes_count * sizeof(struct trie_node_f), t.nodes_count);
+        log_debug("child pointers:   %8"PRIu64" bytes (%8"PRIu64")",
+                  t.children_count * sizeof(struct trie_child_entry_f), t.children_count);
+        log_debug("value pointers:   %8"PRIu64" bytes (%8"PRIu64")",
+                  t.values_count * sizeof(struct trie_value_entry_f), t.values_count);
+        log_debug("string store:     %8zu bytes", trie->strings->len);
+        log_debug("strings start:    %8"PRIu64, t.strings_off);
+
+        return 0;
+}
+
+static int insert_data(struct trie *trie, char **match_list, char *line, const char *filename) {
+        char *value, **entry;
+
+        value = strchr(line, '=');
+        if (!value) {
+                log_error("Error, key/value pair expected but got '%s' in '%s':", line, filename);
+                return -EINVAL;
+        }
+
+        value[0] = '\0';
+        value++;
+
+        /* libudev requires properties to start with a space */
+        while (isblank(line[0]) && isblank(line[1]))
+                line++;
+
+        if (line[0] == '\0' || value[0] == '\0') {
+                log_error("Error, empty key or value '%s' in '%s':", line, filename);
+                return -EINVAL;
+        }
+
+        STRV_FOREACH(entry, match_list)
+                trie_insert(trie, trie->root, *entry, line, value);
+
+        return 0;
+}
+
+static int import_file(struct trie *trie, const char *filename) {
+        enum {
+                HW_NONE,
+                HW_MATCH,
+                HW_DATA,
+        } state = HW_NONE;
+        _cleanup_fclose_ FILE *f = NULL;
+        char line[LINE_MAX];
+        _cleanup_strv_free_ char **match_list = NULL;
+        char *match = NULL;
+        int r;
+
+        f = fopen(filename, "re");
+        if (!f)
+                return -errno;
+
+        while (fgets(line, sizeof(line), f)) {
+                size_t len;
+                char *pos;
+
+                /* comment line */
+                if (line[0] == '#')
+                        continue;
+
+                /* strip trailing comment */
+                pos = strchr(line, '#');
+                if (pos)
+                        pos[0] = '\0';
+
+                /* strip trailing whitespace */
+                len = strlen(line);
+                while (len > 0 && isspace(line[len-1]))
+                        len--;
+                line[len] = '\0';
+
+                switch (state) {
+                case HW_NONE:
+                        if (len == 0)
+                                break;
+
+                        if (line[0] == ' ') {
+                                log_error("Error, MATCH expected but got '%s' in '%s':", line, filename);
+                                break;
+                        }
+
+                        /* start of record, first match */
+                        state = HW_MATCH;
+
+                        match = strdup(line);
+                        if (!match)
+                                return -ENOMEM;
+
+                        r = strv_consume(&match_list, match);
+                        if (r < 0)
+                                return r;
+
+                        break;
+
+                case HW_MATCH:
+                        if (len == 0) {
+                                log_error("Error, DATA expected but got empty line in '%s':", filename);
+                                state = HW_NONE;
+                                strv_clear(match_list);
+                                break;
+                        }
+
+                        /* another match */
+                        if (line[0] != ' ') {
+                                match = strdup(line);
+                                if (!match)
+                                        return -ENOMEM;
+
+                                r = strv_consume(&match_list, match);
+                                if (r < 0)
+                                        return r;
+
+                                break;
+                        }
+
+                        /* first data */
+                        state = HW_DATA;
+                        insert_data(trie, match_list, line, filename);
+                        break;
+
+                case HW_DATA:
+                        /* end of record */
+                        if (len == 0) {
+                                state = HW_NONE;
+                                strv_clear(match_list);
+                                break;
+                        }
+
+                        if (line[0] != ' ') {
+                                log_error("Error, DATA expected but got '%s' in '%s':", line, filename);
+                                state = HW_NONE;
+                                strv_clear(match_list);
+                                break;
+                        }
+
+                        insert_data(trie, match_list, line, filename);
+                        break;
+                };
+        }
+
+        return 0;
+}
+
+static int hwdb_query(char **args, unsigned n) {
+        _cleanup_hwdb_unref_ sd_hwdb *hwdb = NULL;
+        const char *key, *value;
+        const char *modalias;
+        int r;
+
+        assert(args);
+        assert(n == 2);
+
+        modalias = args[1];
+
+        r = sd_hwdb_new(&hwdb);
+        if (r < 0)
+                return r;
+
+        SD_HWDB_FOREACH_PROPERTY(hwdb, modalias, key, value)
+                printf("%s=%s\n", key, value);
+
+        return 0;
+}
+
+static int hwdb_update(char **args, unsigned n) {
+        _cleanup_free_ char *hwdb_bin = NULL;
+        _cleanup_(trie_freep) struct trie *trie = NULL;
+        char **files, **f;
+        int r;
+
+        trie = new0(struct trie, 1);
+        if (!trie)
+                return -ENOMEM;
+
+        /* string store */
+        trie->strings = strbuf_new();
+        if (!trie->strings)
+                return -ENOMEM;
+
+        /* index */
+        trie->root = new0(struct trie_node, 1);
+        if (!trie->root)
+                return -ENOMEM;
+
+        trie->nodes_count++;
+
+        r = conf_files_list_strv(&files, ".hwdb", arg_root, conf_file_dirs);
+        if (r < 0)
+                return log_error_errno(r, "failed to enumerate hwdb files: %m");
+
+        STRV_FOREACH(f, files) {
+                log_debug("reading file '%s'", *f);
+                import_file(trie, *f);
+        }
+        strv_free(files);
+
+        strbuf_complete(trie->strings);
+
+        log_debug("=== trie in-memory ===");
+        log_debug("nodes:            %8zu bytes (%8zu)",
+                  trie->nodes_count * sizeof(struct trie_node), trie->nodes_count);
+        log_debug("children arrays:  %8zu bytes (%8zu)",
+                  trie->children_count * sizeof(struct trie_child_entry), trie->children_count);
+        log_debug("values arrays:    %8zu bytes (%8zu)",
+                  trie->values_count * sizeof(struct trie_value_entry), trie->values_count);
+        log_debug("strings:          %8zu bytes",
+                  trie->strings->len);
+        log_debug("strings incoming: %8zu bytes (%8zu)",
+                  trie->strings->in_len, trie->strings->in_count);
+        log_debug("strings dedup'ed: %8zu bytes (%8zu)",
+                  trie->strings->dedup_len, trie->strings->dedup_count);
+
+        hwdb_bin = strjoin(arg_root, "/", arg_hwdb_bin_dir, "/hwdb.bin", NULL);
+        if (!hwdb_bin)
+                return -ENOMEM;
+
+        mkdir_parents(hwdb_bin, 0755);
+        r = trie_store(trie, hwdb_bin);
+        if (r < 0)
+                return log_error_errno(r, "Failure writing database %s: %m", hwdb_bin);
+
+        return 0;
+}
+
+static void help(void) {
+        printf("Usage: %s OPTIONS COMMAND\n\n"
+               "Options:\n"
+               "  --usr                generate in " UDEVLIBEXECDIR " instead of /etc/udev\n"
+               "  -r,--root=PATH       alternative root path in the filesystem\n"
+               "  -h,--help\n\n"
+               "Commands:\n"
+               "  update               update the hwdb database\n"
+               "  query MODALIAS       query database and print result\n\n",
+               program_invocation_short_name);
+}
+
+static int parse_argv(int argc, char *argv[]) {
+        enum {
+                ARG_USR = 0x100,
+        };
+
+        static const struct option options[] = {
+                { "usr",    no_argument,       NULL, ARG_USR },
+                { "root",   required_argument, NULL, 'r' },
+                { "help",   no_argument,       NULL, 'h' },
+                {}
+        };
+
+        int c;
+
+        assert(argc >= 0);
+        assert(argv);
+
+        while ((c = getopt_long(argc, argv, "ut:r:h", options, NULL)) >= 0) {
+                switch(c) {
+                case ARG_USR:
+                        arg_hwdb_bin_dir = UDEVLIBEXECDIR;
+                        break;
+                case 'r':
+                        arg_root = optarg;
+                        break;
+                case 'h':
+                        help();
+                        return 0;
+                case '?':
+                        return -EINVAL;
+                default:
+                        assert_not_reached("Unknown option");
+                }
+        }
+
+        return 1;
+}
+
+static int hwdb_main(int argc, char *argv[]) {
+        static const struct {
+                const char *verb;
+                const enum {
+                        MORE,
+                        LESS,
+                        EQUAL,
+                } argc_cmp;
+                const int argc;
+                int (*const dispatch)(char **args, unsigned n);
+        } verbs[] = {
+                { "update", EQUAL, 1, hwdb_update },
+                { "query", EQUAL, 2, hwdb_query },
+        };
+
+        int left;
+        unsigned i;
+
+        assert(argc >= 0);
+        assert(argv);
+
+        left = argc - optind;
+
+        if (left <= 0) {
+                log_error("Missing command.");
+                help();
+                return -EINVAL;
+        }
+
+        for (i = 0; i < ELEMENTSOF(verbs); i++)
+                if (streq(argv[optind], verbs[i].verb))
+                        break;
+
+        if (i >= ELEMENTSOF(verbs)) {
+                log_error("Unknown command %s.", argv[optind]);
+                help();
+                return -EINVAL;
+        }
+
+        switch (verbs[i].argc_cmp) {
+        case EQUAL:
+                if (left != verbs[i].argc) {
+                        log_error("Invalid number of arguments.");
+                        help();
+                        return -EINVAL;
+                }
+
+                break;
+
+        case MORE:
+                if (left < verbs[i].argc) {
+                        log_error("Too few arguments.");
+                        help();
+                        return -EINVAL;
+                }
+
+                break;
+        case LESS:
+                if (left > verbs[i].argc) {
+                        log_error("Too many arguments.");
+                        help();
+                        return -EINVAL;
+                }
+
+                break;
+        default:
+                assert_not_reached("Unknown comparison operator.");
+        }
+
+        return verbs[i].dispatch(argv + optind, left);
+}
+
+int main (int argc, char *argv[]) {
+        int r;
+
+        log_parse_environment();
+        log_open();
+
+        r = parse_argv(argc, argv);
+        if (r <= 0)
+                goto finish;
+
+        r = hwdb_main(argc, argv);
+
+finish:
+        return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
+}