1/*
2 * Copyright (C) 2016 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *  * Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *  * Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in
12 *    the documentation and/or other materials provided with the
13 *    distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include "private/icu.h"
30
31#include <dirent.h>
32#include <dlfcn.h>
33#include <pthread.h>
34#include <stdlib.h>
35#include <string.h>
36
37#include <async_safe/log.h>
38
39// Allowed icu4c version numbers are in the range [44, 999].
40// Gingerbread's icu4c 4.4 is the minimum supported ICU version.
41static constexpr auto ICUDATA_VERSION_MIN_LENGTH = 2;
42static constexpr auto ICUDATA_VERSION_MAX_LENGTH = 3;
43static constexpr auto ICUDATA_VERSION_MIN = 44;
44
45static char g_icudata_version[ICUDATA_VERSION_MAX_LENGTH + 1];
46
47static void* g_libicuuc_handle = nullptr;
48
49static int __icu_dat_file_filter(const dirent* dirp) {
50  const char* name = dirp->d_name;
51
52  // Is the name the right length to match 'icudt(\d\d\d)l.dat'?
53  const size_t len = strlen(name);
54  if (len < 10 + ICUDATA_VERSION_MIN_LENGTH || len > 10 + ICUDATA_VERSION_MAX_LENGTH) return 0;
55
56  return !strncmp(name, "icudt", 5) && !strncmp(&name[len - 5], "l.dat", 5);
57}
58
59static bool __find_icu() {
60  dirent** namelist = nullptr;
61  int n = scandir("/system/usr/icu", &namelist, &__icu_dat_file_filter, alphasort);
62  int max_version = -1;
63  while (n--) {
64    // We prefer the latest version available.
65    int version = atoi(&namelist[n]->d_name[strlen("icudt")]);
66    if (version != 0 && version > max_version) max_version = version;
67    free(namelist[n]);
68  }
69  free(namelist);
70
71  if (max_version < ICUDATA_VERSION_MIN) {
72    async_safe_write_log(ANDROID_LOG_ERROR, "bionic-icu", "couldn't find an ICU .dat file");
73    return false;
74  }
75
76  snprintf(g_icudata_version, sizeof(g_icudata_version), "_%d", max_version);
77
78  g_libicuuc_handle = dlopen("libicuuc.so", RTLD_LOCAL);
79  if (g_libicuuc_handle == nullptr) {
80    async_safe_format_log(ANDROID_LOG_ERROR, "bionic-icu", "couldn't open libicuuc.so: %s",
81                          dlerror());
82    return false;
83  }
84
85  return true;
86}
87
88void* __find_icu_symbol(const char* symbol_name) {
89  static bool found_icu = __find_icu();
90  if (!found_icu) return nullptr;
91
92  char versioned_symbol_name[strlen(symbol_name) + sizeof(g_icudata_version)];
93  snprintf(versioned_symbol_name, sizeof(versioned_symbol_name), "%s%s",
94           symbol_name, g_icudata_version);
95
96  void* symbol = dlsym(g_libicuuc_handle, versioned_symbol_name);
97  if (symbol == nullptr) {
98    async_safe_format_log(ANDROID_LOG_ERROR, "bionic-icu", "couldn't find %s",
99                          versioned_symbol_name);
100  }
101  return symbol;
102}
103