#include <stdio.h>

#include <errno.h>

#include <string.h>

#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"

struct linebuf {

char bytes[LINE_MAX];

size_t size;

size_t len;

};

static void linebuf_init(struct linebuf *buf) {

buf->size = 0;

buf->len = 0;

}

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;

}

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;

}

static void linebuf_rem(struct linebuf *buf, size_t count) {

assert(buf->len >= count);

buf->len -= count;

}

static void linebuf_rem_char(struct linebuf *buf) {

linebuf_rem(buf, 1);

}

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;

};

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));

}

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;

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 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));

}

static const char *trie_string(struct trie_f *trie, le64_t off) {

return trie->map + le64toh(off);

}

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;

return n1->c - n2->c;

}

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;

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;

}

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;

prefix = trie_string(trie, node->prefix_off);

len = strlen(prefix + p);

linebuf_add(buf, prefix + p, len);

for (i = 0; i < node->children_count; i++) {

const struct trie_child_entry_f *child = &trie_node_children(trie, node)[i];

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 (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));

linebuf_rem(buf, len);

}

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;

linebuf_init(&buf);

node = trie_node_from_off(trie, trie->head->nodes_root_off);

while (node) {

const struct trie_node_f *child;

size_t p = 0;

if (node->prefix_off) {

uint8_t c;

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;

}

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);

}

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);

}

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 (search[i] == '\0') {

size_t n;

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++;

}

}

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);

}

static struct trie_f trie;

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;

/* 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);

/* look only at devices of a specific subsystem */

if (subsys && dsubsys && !streq(dsubsys, subsys))

continue;

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;

}

}

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;

for (;;) {

int option;

option = getopt_long(argc, argv, "s", options, NULL);

if (option == -1)

break;

switch (option) {

case 's':

subsys = optarg;

break;

}

}

trie.dev = dev;

trie.test = test;

if (hwdb_lookup(dev, subsys) < 0)

return EXIT_FAILURE;

return EXIT_SUCCESS;

}

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;

}

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;

}

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 void builtin_hwdb_exit(struct udev *udev)

{

if (!trie.f)

return;

munmap((void *)trie.map, trie.map_size);

fclose(trie.f);

zero(trie);

}

static bool builtin_hwdb_validate(struct udev *udev)

{

struct stat st;

if (!trie.f)

return 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_hwdb = {

.name = "hwdb",

.cmd = builtin_hwdb,

.init = builtin_hwdb_init,

.exit = builtin_hwdb_exit,

.validate = builtin_hwdb_validate,

.help = "hardware database",

};