udev: add hardware database support

1 files changed, 302 insertions, 174 deletions

diff --git a/src/udev/udev-builtin-hwdb.c b/src/udev/udev-builtin-hwdb.c
index 0db21641b1..5ccd06df04 100644
--- a/src/udev/udev-builtin-hwdb.c
+++ b/src/udev/udev-builtin-hwdb.c
@@ -1,22 +1,22 @@
-/*
- * usb-db, pci-db - lookup vendor/product database
- *
- * Copyright (C) 2009 Lennart Poettering <lennart@poettering.net>
- * Copyright (C) 2011 Kay Sievers <kay.sievers@vrfy.org>
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program 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 General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
+/***
+  This file is part of systemd.
+
+  Copyright 2012 Kay Sievers <kay.sievers@vrfy.org>
+  Copyright 2008 Alan Jenkins <alan.christopher.jenkins@googlemail.com>
+
+  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 <stdio.h>
 #include <errno.h>
@@ -24,224 +24,352 @@
 #include <inttypes.h>
 #include <ctype.h>
 #include <stdlib.h>
+#include <fnmatch.h>
+#include <getopt.h>
+#include <sys/mman.h>
 
 #include "udev.h"
+#include "udev-hwdb.h"
 
-static int get_id_attr(
-        struct udev_device *parent,
-        const char *name,
-        uint16_t *value) {
+struct linebuf {
+        char bytes[LINE_MAX];
+        size_t size;
+        size_t len;
+};
 
-        const char *t;
-        unsigned u;
+static void linebuf_init(struct linebuf *buf) {
+        buf->size = 0;
+        buf->len = 0;
+}
 
-        if (!(t = udev_device_get_sysattr_value(parent, name))) {
-                fprintf(stderr, "%s lacks %s.\n", udev_device_get_syspath(parent), name);
-                return -1;
-        }
+static const char *linebuf_get(struct linebuf *buf) {
+        if (buf->len + 1 >= sizeof(buf->bytes))
+                return NULL;
+        buf->bytes[buf->len] = '\0';
+        return buf->bytes;
+}
+
+static bool linebuf_add(struct linebuf *buf, const char *s, size_t len) {
+        if (buf->len + len >= sizeof(buf->bytes))
+                return false;
+        memcpy(buf->bytes + buf->len, s, len);
+        buf->len += len;
+        return true;
+}
 
-        if (startswith(t, "0x"))
-                t += 2;
+static bool linebuf_add_char(struct linebuf *buf, char c)
+{
+        if (buf->len + 1 >= sizeof(buf->bytes))
+                return false;
+        buf->bytes[buf->len++] = c;
+        return true;
+}
 
-        if (sscanf(t, "%04x", &u) != 1 || u > 0xFFFFU) {
-                fprintf(stderr, "Failed to parse %s on %s.\n", name, udev_device_get_syspath(parent));
-                return -1;
-        }
+static void linebuf_rem(struct linebuf *buf, size_t count) {
+        assert(buf->len >= count);
+        buf->len -= count;
+}
 
-        *value = (uint16_t) u;
-        return 0;
+static void linebuf_rem_char(struct linebuf *buf) {
+        linebuf_rem(buf, 1);
 }
 
-static int get_vid_pid(
-        struct udev_device *parent,
-        const char *vendor_attr,
-        const char *product_attr,
-        uint16_t *vid,
-        uint16_t *pid) {
+struct trie_f {
+        struct udev_device *dev;
+        bool test;
+        FILE *f;
+        uint64_t file_time_usec;
+        union {
+                struct trie_header_f *head;
+                const char *map;
+        };
+        size_t map_size;
+};
 
-        if (get_id_attr(parent, vendor_attr, vid) < 0)
-                return -1;
-        else if (*vid <= 0) {
-                fprintf(stderr, "Invalid vendor id.\n");
-                return -1;
-        }
+static const struct trie_child_entry_f *trie_node_children(struct trie_f *trie, const struct trie_node_f *node) {
+        return (const struct trie_child_entry_f *)((const char *)node + le64toh(trie->head->node_size));
+}
 
-        if (get_id_attr(parent, product_attr, pid) < 0)
-                return -1;
+static const struct trie_value_entry_f *trie_node_values(struct trie_f *trie, const struct trie_node_f *node) {
+        const char *base = (const char *)node;
 
-        return 0;
+        base += le64toh(trie->head->node_size);
+        base += node->children_count * le64toh(trie->head->child_entry_size);
+        return (const struct trie_value_entry_f *)base;
 }
 
-static void rstrip(char *n) {
-        size_t i;
+static const struct trie_node_f *trie_node_from_off(struct trie_f *trie, le64_t off) {
+        return (const struct trie_node_f *)(trie->map + le64toh(off));
+}
 
-        for (i = strlen(n); i > 0 && isspace(n[i-1]); i--)
-                n[i-1] = 0;
+static const char *trie_string(struct trie_f *trie, le64_t off) {
+        return trie->map + le64toh(off);
 }
 
-#define HEXCHARS "0123456789abcdefABCDEF"
-#define WHITESPACE " \t\n\r"
-static int lookup_vid_pid(const char *database,
-                          uint16_t vid, uint16_t pid,
-                          char **vendor, char **product)
-{
+static int trie_children_cmp_f(const void *v1, const void *v2) {
+        const struct trie_child_entry_f *n1 = v1;
+        const struct trie_child_entry_f *n2 = v2;
 
-        FILE *f;
-        int ret = -1;
-        int found_vendor = 0;
-        char *line = NULL;
+        return n1->c - n2->c;
+}
 
-        *vendor = *product = NULL;
+static const struct trie_node_f *node_lookup_f(struct trie_f *trie, const struct trie_node_f *node, uint8_t c) {
+        struct trie_child_entry_f *child;
+        struct trie_child_entry_f search;
 
-        if (!(f = fopen(database, "rme"))) {
-                fprintf(stderr, "Failed to open database file '%s': %s\n", database, strerror(errno));
-                return -1;
-        }
+        search.c = c;
+        child = bsearch(&search, trie_node_children(trie, node), node->children_count,
+                        le64toh(trie->head->child_entry_size), trie_children_cmp_f);
+        if (child)
+                return trie_node_from_off(trie, child->child_off);
+        return NULL;
+}
 
-        for (;;) {
-                size_t n;
+static void trie_fnmatch_f(struct trie_f *trie, const struct trie_node_f *node, size_t p,
+                           struct linebuf *buf, const char *search,
+                           void (*cb)(struct trie_f *trie, const char *key, const char *value)) {
+        size_t len;
+        size_t i;
+        const char *prefix;
 
-                if (getline(&line, &n, f) < 0)
-                        break;
+        prefix = trie_string(trie, node->prefix_off);
+        len = strlen(prefix + p);
+        linebuf_add(buf, prefix + p, len);
 
-                rstrip(line);
+        for (i = 0; i < node->children_count; i++) {
+                const struct trie_child_entry_f *child = &trie_node_children(trie, node)[i];
 
-                if (line[0] == '#' || line[0] == 0)
-                        continue;
+                linebuf_add_char(buf, child->c);
+                trie_fnmatch_f(trie, trie_node_from_off(trie, child->child_off), 0, buf, search, cb);
+                linebuf_rem_char(buf);
+        }
 
-                if (strspn(line, HEXCHARS) == 4) {
-                        unsigned u;
+        if (node->values_count && fnmatch(linebuf_get(buf), search, 0) == 0)
+                for (i = 0; i < node->values_count; i++)
+                        cb(trie, trie_string(trie, trie_node_values(trie, node)[i].key_off),
+                           trie_string(trie, trie_node_values(trie, node)[i].value_off));
 
-                        if (found_vendor)
-                                break;
+        linebuf_rem(buf, len);
+}
 
-                        if (sscanf(line, "%04x", &u) == 1 && u == vid) {
-                                char *t;
+static void trie_search_f(struct trie_f *trie, const char *search,
+                          void (*cb)(struct trie_f *trie, const char *key, const char *value)) {
+        struct linebuf buf;
+        const struct trie_node_f *node;
+        size_t i = 0;
 
-                                t = line+4;
-                                t += strspn(t, WHITESPACE);
+        linebuf_init(&buf);
 
-                                if (!(*vendor = strdup(t))) {
-                                        fprintf(stderr, "Out of memory.\n");
-                                        goto finish;
-                                }
+        node = trie_node_from_off(trie, trie->head->nodes_root_off);
+        while (node) {
+                const struct trie_node_f *child;
+                size_t p = 0;
 
-                                found_vendor = 1;
-                        }
+                if (node->prefix_off) {
+                        uint8_t c;
 
-                        continue;
+                        for (; (c = trie_string(trie, node->prefix_off)[p]); p++) {
+                                if (c == '*' || c == '?' || c == '[') {
+                                        trie_fnmatch_f(trie, node, p, &buf, search + i + p, cb);
+                                        return;
+                                }
+                                if (c != search[i + p])
+                                        return;
+                        }
+                        i += p;
                 }
 
-                if (found_vendor && line[0] == '\t' && strspn(line+1, HEXCHARS) == 4) {
-                        unsigned u;
+                child = node_lookup_f(trie, node, '*');
+                if (child) {
+                        linebuf_add_char(&buf, '*');
+                        trie_fnmatch_f(trie, child, 0, &buf, search + i, cb);
+                        linebuf_rem_char(&buf);
+                }
 
-                        if (sscanf(line+1, "%04x", &u) == 1 && u == pid) {
-                                char *t;
+                child = node_lookup_f(trie, node, '?');
+                if (child) {
+                        linebuf_add_char(&buf, '?');
+                        trie_fnmatch_f(trie, child, 0, &buf, search + i, cb);
+                        linebuf_rem_char(&buf);
+                }
 
-                                t = line+5;
-                                t += strspn(t, WHITESPACE);
+                child = node_lookup_f(trie, node, '[');
+                if (child) {
+                        linebuf_add_char(&buf, '[');
+                        trie_fnmatch_f(trie, child, 0, &buf, search + i, cb);
+                        linebuf_rem_char(&buf);
+                }
 
-                                if (!(*product = strdup(t))) {
-                                        fprintf(stderr, "Out of memory.\n");
-                                        goto finish;
-                                }
+                if (search[i] == '\0') {
+                        size_t n;
 
-                                break;
-                        }
+                        for (n = 0; n < node->values_count; n++)
+                                cb(trie, trie_string(trie, trie_node_values(trie, node)[n].key_off),
+                                   trie_string(trie, trie_node_values(trie, node)[n].value_off));
+                        return;
                 }
+
+                child = node_lookup_f(trie, node, search[i]);
+                node = child;
+                i++;
         }
+}
 
-        ret = 0;
+static void value_cb(struct trie_f *trie, const char *key, const char *value) {
+        /* TODO: add sub-matches (+) against DMI data */
+        if (key[0] == ' ')
+                udev_builtin_add_property(trie->dev, trie->test, key + 1, value);
+}
 
-finish:
-        free(line);
-        fclose(f);
+static struct trie_f trie;
 
-        if (ret < 0) {
-                free(*product);
-                free(*vendor);
+static int hwdb_lookup(struct udev_device *dev, const char *subsys) {
+        struct udev_device *d;
+        const char *modalias;
+        char str[UTIL_NAME_SIZE];
+        int rc = EXIT_SUCCESS;
 
-                *product = *vendor = NULL;
-        }
+        /* search the first parent device with a modalias */
+        for (d = dev; d; d = udev_device_get_parent(d)) {
+                const char *dsubsys = udev_device_get_subsystem(d);
 
-        return ret;
-}
+                /* look only at devices of a specific subsystem */
+                if (subsys && dsubsys && !streq(dsubsys, subsys))
+                        continue;
 
-static struct udev_device *find_device(struct udev_device *dev, const char *subsys, const char *devtype)
-{
-        const char *str;
-
-        str = udev_device_get_subsystem(dev);
-        if (str == NULL)
-                goto try_parent;
-        if (strcmp(str, subsys) != 0)
-                goto try_parent;
-
-        if (devtype != NULL) {
-                str = udev_device_get_devtype(dev);
-                if (str == NULL)
-                        goto try_parent;
-                if (strcmp(str, devtype) != 0)
-                        goto try_parent;
+                modalias = udev_device_get_property_value(d, "MODALIAS");
+                if (modalias)
+                        break;
+
+                /* the usb_device does not have modalias, compose one */
+                if (dsubsys && streq(dsubsys, "usb")) {
+                        const char *v, *p;
+                        int vn, pn;
+
+                        v = udev_device_get_sysattr_value(d, "idVendor");
+                        if (!v)
+                                continue;
+                        p = udev_device_get_sysattr_value(d, "idProduct");
+                        if (!p)
+                                continue;
+                        vn = strtol(v, NULL, 16);
+                        if (vn <= 0)
+                                continue;
+                        pn = strtol(p, NULL, 16);
+                        if (pn <= 0)
+                                continue;
+                        snprintf(str, sizeof(str), "usb:v%04Xp%04X*", vn, pn);
+                        modalias = str;
+                        break;
+                }
         }
-        return dev;
-try_parent:
-        return udev_device_get_parent_with_subsystem_devtype(dev, subsys, devtype);
+        if (!modalias)
+                return EXIT_FAILURE;
+
+        trie_search_f(&trie, modalias, value_cb);
+        return rc;
 }
 
+static int builtin_hwdb(struct udev_device *dev, int argc, char *argv[], bool test) {
+        static const struct option options[] = {
+                { "subsystem", required_argument, NULL, 's' },
+                {}
+        };
+        const char *subsys = NULL;
 
-static int builtin_db(struct udev_device *dev, bool test,
-                      const char *database,
-                      const char *vendor_attr, const char *product_attr,
-                      const char *subsys, const char *devtype)
-{
-        struct udev_device *parent;
-        uint16_t vid = 0, pid = 0;
-        char *vendor = NULL, *product = NULL;
-
-        parent = find_device(dev, subsys, devtype);
-        if (!parent) {
-                fprintf(stderr, "Failed to find device.\n");
-                goto finish;
+        for (;;) {
+                int option;
+
+                option = getopt_long(argc, argv, "s", options, NULL);
+                if (option == -1)
+                        break;
+
+                switch (option) {
+                case 's':
+                        subsys = optarg;
+                        break;
+                }
         }
 
-        if (get_vid_pid(parent, vendor_attr, product_attr, &vid, &pid) < 0)
-                goto finish;
+        trie.dev = dev;
+        trie.test = test;
+        if (hwdb_lookup(dev, subsys) < 0)
+                return EXIT_FAILURE;
+        return EXIT_SUCCESS;
+}
 
-        if (lookup_vid_pid(database, vid, pid, &vendor, &product) < 0)
-                goto finish;
+/* called at udev startup and reload */
+static int builtin_hwdb_init(struct udev *udev)
+{
+        struct stat st;
+        const char sig[] = HWDB_SIG;
+
+        trie.f = fopen(SYSCONFDIR "/udev/hwdb.bin", "re");
+        if (!trie.f)
+                return -errno;
+
+        if (fstat(fileno(trie.f), &st) < 0 || (size_t)st.st_size < offsetof(struct trie_header_f, strings_len) + 8) {
+                log_error("Error reading '%s'.", SYSCONFDIR "/udev/hwdb.bin: %m");
+                fclose(trie.f);
+                zero(trie);
+                return -EINVAL;
+        }
 
-        if (vendor)
-                udev_builtin_add_property(dev, test, "ID_VENDOR_FROM_DATABASE", vendor);
-        if (product)
-                udev_builtin_add_property(dev, test, "ID_MODEL_FROM_DATABASE", product);
+        trie.map = mmap(0, st.st_size, PROT_READ, MAP_SHARED, fileno(trie.f), 0);
+        if (trie.map == MAP_FAILED) {
+                log_error("Error mapping '%s'.", SYSCONFDIR "/udev/hwdb.bin: %m");
+                fclose(trie.f);
+                return -EINVAL;
+        }
+        trie.file_time_usec = ts_usec(&st.st_mtim);
+        trie.map_size = st.st_size;
+
+        if (memcmp(trie.map, sig, sizeof(trie.head->signature)) != 0 || (size_t)st.st_size != le64toh(trie.head->file_size)) {
+                log_error("Unable to recognize the format of '%s'.", SYSCONFDIR "/udev/hwdb.bin");
+                log_error("Please try 'udevadm hwdb --update' to re-create it.");
+                munmap((void *)trie.map, st.st_size);
+                fclose(trie.f);
+                zero(trie);
+                return EINVAL;
+        }
 
-finish:
-        free(vendor);
-        free(product);
+        log_debug("=== trie on-disk ===\n");
+        log_debug("tool version:          %llu", (unsigned long long)le64toh(trie.head->tool_version));
+        log_debug("file size:        %8zi bytes\n", st.st_size);
+        log_debug("header size       %8zu bytes\n", (size_t)le64toh(trie.head->header_size));
+        log_debug("strings           %8zu bytes\n", (size_t)le64toh(trie.head->strings_len));
+        log_debug("nodes             %8zu bytes\n", (size_t)le64toh(trie.head->nodes_len));
         return 0;
 }
 
-static int builtin_usb_db(struct udev_device *dev, int argc, char *argv[], bool test)
+/* called on udev shutdown and reload request */
+static void builtin_hwdb_exit(struct udev *udev)
 {
-        return builtin_db(dev, test, USB_DATABASE, "idVendor", "idProduct", "usb", "usb_device");
+        if (!trie.f)
+                return;
+        munmap((void *)trie.map, trie.map_size);
+        fclose(trie.f);
+        zero(trie);
 }
 
-static int builtin_pci_db(struct udev_device *dev, int argc, char *argv[], bool test)
+/* called every couple of seconds during event activity; 'true' if config has changed */
+static bool builtin_hwdb_validate(struct udev *udev)
 {
-        return builtin_db(dev, test, PCI_DATABASE, "vendor", "device", "pci", NULL);
-}
+        struct stat st;
 
-const struct udev_builtin udev_builtin_usb_db = {
-        .name = "usb-db",
-        .cmd = builtin_usb_db,
-        .help = "USB vendor/product database",
-        .run_once = true,
-};
+        if (fstat(fileno(trie.f), &st) < 0)
+                return true;
+        if (trie.file_time_usec != ts_usec(&st.st_mtim))
+                return true;
+        return false;
+}
 
-const struct udev_builtin udev_builtin_pci_db = {
-        .name = "pci-db",
-        .cmd = builtin_pci_db,
-        .help = "PCI vendor/product database",
+const struct udev_builtin udev_builtin_hwdb = {
+        .name = "hwdb",
+        .cmd = builtin_hwdb,
+        .init = builtin_hwdb_init,
+        .exit = builtin_hwdb_exit,
+        .validate = builtin_hwdb_validate,
+        .help = "hardware database",
         .run_once = true,
 };