media-sound/netease-cloud-music/files/patch.c

   1 // SPDX-License-Identifier: BSD-3-Clause
   2 /**
   3  * Copyright (c) 2021 kXuan. All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
   6  * following conditions are met:
   7  *
   8  * 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following
   9  * disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
  11  * following disclaimer in the documentation and/or other materials provided with the distribution.
  12  * 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote
  13  * products derived from this software without specific prior written permission.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
  16  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  17  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  18  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  19  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  20  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  21  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  22  *
  23  */
  24 #define _GNU_SOURCE
  25
  26 #include <dlfcn.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <strings.h>
  30 #include <unistd.h>
  31 #include <vlc/vlc.h>
  32 #include <vlc/plugins/vlc_common.h>
  33 #include <vlc/plugins/vlc_stream.h>
  34
  35 static void *load_sym(void *override_func, const char *name)
  36 {
  37     void *ptr = dlsym(RTLD_NEXT, name);
  38     if (ptr == NULL) {
  39         fprintf(stderr, "Cannot load symbol '%s' %s. Please report bug on AUR.\n", name, dlerror());
  40         exit(1);
  41     }
  42     if (ptr == override_func) {
  43         fprintf(stderr, "circular reference '%s'. Please report bug on AUR.\n", name);
  44         exit(1);
  45     }
  46     return ptr;
  47 }
  48
  49 static int is_flac(const char *url)
  50 {
  51     static const char suffix[] = ".flac";
  52     if (!url) {
  53         return 0;
  54     }
  55     size_t len = strlen(url);
  56     if (len < sizeof(suffix)) {
  57         return 0;
  58     }
  59
  60     return strcasecmp(url + len - sizeof(suffix) + 1, suffix) == 0;
  61 }
  62
  63 /**
  64  * The netease cloud music server set the Content-Type of .flac format to mpeg/audio, which results vlc unable to decode
  65  * the music and play.
  66  *
  67  * To make vlc works correctly, we rewrite the Content-Type to audio/flac.
  68  *
  69  * @param s
  70  * @param query
  71  * @param args
  72  * @return
  73  */
  74 int vlc_stream_vaControl(stream_t *s, int query, va_list args)
  75 {
  76     static typeof(vlc_stream_vaControl) *orig_fn;
  77     if (orig_fn == NULL) {
  78         orig_fn = load_sym(vlc_stream_vaControl, __func__);
  79     }
  80     if (query == STREAM_GET_CONTENT_TYPE && is_flac(s->psz_url)) {
  81         *va_arg(args, char **) = strdup("audio/flac");
  82         return VLC_SUCCESS;
  83     } else {
  84         return orig_fn(s, query, args);
  85     }
  86 }
  87
  88 struct string_with_len {
  89     const char *s;
  90     size_t len;
  91 };
  92 #define STRING_WITH_LEN_INIT(s) {s, sizeof(s)-1}
  93
  94 /**
  95  * drop all library fixes.
  96  *
  97  * Library fixes should only be applied to the netease-cloud-music main process. Sometime, netease-cloud-music execute
  98  * external program, such as `xdg-open`, `kde-open5`. Those external programs use newer version qt and other new
  99  * libraries. If we don't drop these environment variables, those programs may not work, because some symbol may not
 100  * exist in the bundled old library.
 101  *
 102  * @param path
 103  * @param argv
 104  * @param envp
 105  * @return
 106  */
 107 int execve(const char *path, char *const argv[], char *const envp[])
 108 {
 109     static typeof(execve) *orig_fn;
 110     if (orig_fn == NULL) {
 111         orig_fn = load_sym(execve, "execve");
 112     }
 113
 114     static struct string_with_len drop_env[] = {
 115         STRING_WITH_LEN_INIT("LD_LIBRARY_PATH="),
 116         STRING_WITH_LEN_INIT("LD_PRELOAD="),
 117         STRING_WITH_LEN_INIT("QT_PLUGIN_PATH="),
 118         STRING_WITH_LEN_INIT("QT_QPA_PLATFORM_PLUGIN_PATH="),
 119         STRING_WITH_LEN_INIT("QT_QPA_PLATFORM="),
 120     };
 121
 122     size_t nenv;
 123     for (nenv = 0; envp[nenv]; nenv++);
 124
 125     char *new_envp[nenv + 1];
 126     char *const *src = envp;
 127     char **dst = new_envp;
 128
 129     while (*src) {
 130         for (int i = 0; i < sizeof(drop_env) / sizeof(*drop_env); ++i) {
 131             if (strncmp(drop_env[i].s, *src, drop_env[i].len) == 0) {
 132                 goto next_env;
 133             }
 134         }
 135         *dst = *src;
 136         ++dst;
 137 next_env:
 138         ++src;
 139     }
 140
 141     *dst = NULL;
 142     return orig_fn(path, argv, new_envp);
 143 }