参考：

https://zhou-yuxin.github.io/articles/2017/Linux串口网卡（二）——用户态转发程序的实现/index.html

看了一下源码，还真是要写 /etc/ 目录下面的文件：

ubuntu:/opt/D1/tina_d1_open$ grep /etc -r  package/allwinner/wifimanager/ --include *.c
package/allwinner/wifimanager/demo/wifi_longtime_test.c:	wmg_printf(MSG_INFO,"DESCRIPTION:\n\tTest the stability of wifi module(see the test result in file:/etc/test_result).\n");
package/allwinner/wifimanager/demo/wifi_longtime_test.c: *see the test result in file:/etc/test_result
package/allwinner/wifimanager/demo/wifi_longtime_test.c:	wmg_debug_open_file("/etc/wifi_long_time_test.log");
package/allwinner/wifimanager/demo/wifi_longtime_test.c:    sprintf(prt_buf,"echo \"Test Times:%d, Success Times:%d(including get IP timeout times:%d), Failed Times:%d\" > /etc/test_results",i,success_times,timeout_times,fail_times);
package/allwinner/wifimanager/demo/wifi_longtime_test.c:    sprintf(prt_buf,"echo \"Connecting mean time: %llu.%-llu seconds\" >> /etc/test_results",(total_con_microsec/1000000)/i,(total_con_microsec/i)%1000000);
package/allwinner/wifimanager/demo/wifi_longtime_test.c:    wmg_printf(MSG_INFO,prt_buf,"echo \"Disconnecting mean time: %llu.%-llu seconds\" >> /etc/test_results",(total_disc_microsec/1000000)/i,(total_disc_microsec/i)%1000000);
package/allwinner/wifimanager/demo/wifi_longtime_test.c:        sprintf(prt_buf,"echo Congratulations! >> /etc/test_results");
package/allwinner/wifimanager/src/core/wifi_udhcpc.c:    system("/etc/wifi/udhcpc_wlan0 start >/dev/null");
package/allwinner/wifimanager/src/core/wifimanager.c:    system("/etc/wifi/udhcpc_wlan0 stop >/dev/null");
package/allwinner/wifimanager/src/core/wifi.c:static const char IFACE_DIR[]           = "/etc/wifi/sockets";
package/allwinner/wifimanager/src/core/wifi.c:static const char SUPP_CONFIG_TEMPLATE[]= "/etc/wifi/wpa_supplicant_src.conf";
package/allwinner/wifimanager/src/core/wifi.c:static const char SUPP_CONFIG_FILE[]    = "/etc/wifi/wpa_supplicant.conf";
package/allwinner/wifimanager/src/core/wifi.c:static const char CONTROL_IFACE_PATH[]  = "/etc/wifi/sockets";
package/allwinner/wifimanager/src/core/wifi.c:    strncpy(cmd, "/etc/wifi/wifi start", 511);
package/allwinner/wifimanager/src/core/wifi.c:	  system("/etc/wifi/wifi stop");
package/allwinner/wifimanager/src/daemon/wifid_cmd_handle.c:		system("/etc/init.d/wifi_daemon start");
package/allwinner/wifimanager/src/daemon/wifid_cmd_handle.c:	system("/etc/init.d/wifi_daemon stop");
ubuntu:/opt/D1/tina_d1_open$
ubuntu:/opt/D1/tina_d1_open$

电信移动在http网页插广告，这是中间人攻击吗？

请问有C语言接口接口获取eth的网速1Gbps / 100Mbps吗？

@bishe
这是要抛出一个没头没尾的问题让人猜么？

生成密钥对：

openssl genrsa -out private_key.pem 2048
openssl rsa -in private_key.pem -outform PEM -pubout -out public_key.pem

#include <stdio.h>
#include <string.h>
#include <openssl/rsa.h>
#include <openssl/pem.h>

int main() {
    // 加载RSA密钥对
    RSA *rsa_keypair = RSA_new();
    FILE *private_key_file = fopen("private_key.pem", "r");
    PEM_read_RSAPrivateKey(private_key_file, &rsa_keypair, NULL, NULL);
    fclose(private_key_file);

    // 加载公钥
    RSA *rsa_public_key = RSA_new();
    FILE *public_key_file = fopen("public_key.pem", "r");
    PEM_read_RSA_PUBKEY(public_key_file, &rsa_public_key, NULL, NULL);
    fclose(public_key_file);

    // 明文数据
    char *plaintext = "Hello, world!";

    // 分配内存保存加密后的数据
    int plaintext_len = strlen(plaintext);
    int encrypted_len = RSA_size(rsa_public_key);
    unsigned char *encrypted_data = (unsigned char *)malloc(encrypted_len);

    // 加密数据
    int result = RSA_public_encrypt(plaintext_len, (unsigned char *)plaintext,
            encrypted_data, rsa_public_key, RSA_PKCS1_PADDING);
    if (result == -1) {
        printf("Error: RSA_public_encrypt failed!\n");
        return -1;
    }

    // 输出加密后的数据
    printf("Encrypted data: ");
    for (int i = 0; i < result; i++) {
        printf("%02x", encrypted_data[i]);
    }
    printf("\n");

    // 分配内存保存解密后的数据
    int decrypted_len = RSA_size(rsa_keypair);
    unsigned char *decrypted_data = (unsigned char *)malloc(decrypted_len);

    // 解密数据
    result = RSA_private_decrypt(encrypted_len, encrypted_data, decrypted_data,
            rsa_keypair, RSA_PKCS1_PADDING);
    if (result == -1) {
        printf("Error: RSA_private_decrypt failed!\n");
        return -1;
    }

    // 输出解密后的数据
    printf("Decrypted data: %s\n", decrypted_data);

    // 释放内存
    free(encrypted_data);
    free(decrypted_data);
    RSA_free(rsa_keypair);
    RSA_free(rsa_public_key);

    return 0;
}

编译指令：

gcc -o rsa_example rsa_example.c -lcrypto

运行：

./rsa_example
Encrypted data: 831bbcc94a2f5b30b605849d4756273b7d88d4995f2a2688f26aab81ef3ab992e7fcebe0530e8c0d5c4f889313648f319d55e2321d48edec4e1760959ca24b168               2d0e06911c3e1f8e94357f10b88f2fd6a0e3b1978a8ce6252de849d410f36b1123d7a4a66913eb1bd6c8096fb80f15bda150530a77f6aace39008f35bf7873d11a4903fa0d97647a6               18630b7781732a81d72e17771c60cf343b18565f1e49422dcd2de33cb4f18693a1def0c9b029ec6d1b96991bde6e55b3bdd972391df3c403c13fe27b38df75b4aeb963ad34cd0d55b               26f810d0735017c0e93da288c12bcf71a9b08cacee9923843a506585b534b484ef63119fe813dbf90b9c85fd707ef
Decrypted data: Hello, world!

@whycan

请问均方根值的物理意义是什么？

请问如何用C代码判断音量强度，或者有没有声音？

@houxiaoni

内存足够也寄

@ubuntu

$ grep CWA_SetRes -r external/
external/awcast/src/wireless_display.c:        CWA_SetRes(CWA_RES_MID);
external/awcast/src/airplay/include/coolserver.h:int CWA_SetRes(int res);
Binary file external/awcast/src/airplay/lib/lib32/openwrt-arm-musl/libcoolserver.so matches
Binary file external/awcast/src/airplay/lib/lib32/openwrt-arm-musl/libcoolserver_s.a matches

只有 musl 实现了 CWA_SetRes，glibc没有实现。

@h2631436132
请贴出串口日志。

CFLAGS="-Os -pipe -march=armv7-a -mtune=cortex-a7 -mfpu=neon -fno-caller-saves -Wno-unused-result -mfloat-abi=hard  -Wformat -Werror=format-security -fPIC -D_FORTIFY_SOURCE=2 -Wl,-z,now -Wl,-z,relro -DCONF_AWCAST_DLNA_ENABLE -DCONF_AWCAST_MIRACAST_ENABLE -DCONF_AWCAST_AIRPLAY_ENABLE  -I/opt/H133/H133-lianhe/out/h133-p2/staging_dir/target/usr/include -I/opt/H133/H133-lianhe/out/h133-p2/staging_dir/target/include -I/opt/H133/H133-lianhe/prebuilt/gcc/linux-x86/arm/toolchain-sunxi-glibc/toolchain/usr/include -I/opt/H133/H133-lianhe/prebuilt/gcc/linux-x86/arm/toolchain-sunxi-glibc/toolchain/include " CXXFLAGS="-Os -pipe -march=armv7-a -mtune=cortex-a7 -mfpu=neon -fno-caller-saves -Wno-unused-result -mfloat-abi=hard  -Wformat -Werror=format-security -fPIC -D_FORTIFY_SOURCE=2 -Wl,-z,now -Wl,-z,relro -DCONF_AWCAST_DLNA_ENABLE -DCONF_AWCAST_MIRACAST_ENABLE -DCONF_AWCAST_AIRPLAY_ENABLE -Wno-virtual-dtor  -I/opt/H133/H133-lianhe/out/h133-p2/staging_dir/target/usr/include -I/opt/H133/H133-lianhe/out/h133-p2/staging_dir/target/include -I/opt/H133/H133-lianhe/prebuilt/gcc/linux-x86/arm/toolchain-sunxi-glibc/toolchain/usr/include -I/opt/H133/H133-lianhe/prebuilt/gcc/linux-x86/arm/toolchain-sunxi-glibc/toolchain/include " LDFLAGS="-L/opt/H133/H133-lianhe/out/h133-p2/staging_dir/target/usr/lib -L/opt/H133/H133-lianhe/out/h133-p2/staging_dir/target/lib -L/opt/H133/H133-lianhe/prebuilt/gcc/linux-x86/arm/toolchain-sunxi-glibc/toolchain/usr/lib -L/opt/H133/H133-lianhe/prebuilt/gcc/linux-x86/arm/toolchain-sunxi-glibc/toolchain/lib -specs=/opt/H133/H133-lianhe/build/hardened-ld-pie.specs -znow -zrelro " LIBS="" make -j1 -C /opt/H133/H133-lianhe/out/h133-p2/compile_dir/target/awcast/. AR="arm-openwrt-linux-gnueabi-ar" AS="arm-openwrt-linux-gnueabi-gcc -c -Os -pipe -march=armv7-a -mtune=cortex-a7 -mfpu=neon -fno-caller-saves -Wno-unused-result -mfloat-abi=hard  -Wformat -Werror=format-security -fPIC -D_FORTIFY_SOURCE=2 -Wl,-z,now -Wl,-z,relro -DCONF_AWCAST_DLNA_ENABLE -DCONF_AWCAST_MIRACAST_ENABLE -DCONF_AWCAST_AIRPLAY_ENABLE" LD=arm-openwrt-linux-gnueabi-ld NM="arm-openwrt-linux-gnueabi-nm" CC="arm-openwrt-linux-gnueabi-gcc" GCC="arm-openwrt-linux-gnueabi-gcc" CXX="arm-openwrt-linux-gnueabi-g++" RANLIB="arm-openwrt-linux-gnueabi-ranlib" STRIP=arm-openwrt-linux-gnueabi-strip OBJCOPY=arm-openwrt-linux-gnueabi-objcopy OBJDUMP=arm-openwrt-linux-gnueabi-objdump SIZE=arm-openwrt-linux-gnueabi-size CROSS="arm-openwrt-linux-gnueabi-" ARCH="arm" CMAKE_COMMAND='/opt/H133/H133-lianhe/out/host/bin/cmake' CMAKE_DISABLE_cmake_check_build_system=1 ;
make[4]: Entering directory '/opt/H133/H133-lianhe/out/h133-p2/compile_dir/target/awcast'
make[5]: Entering directory '/opt/H133/H133-lianhe/out/h133-p2/compile_dir/target/awcast'
make[6]: Entering directory '/opt/H133/H133-lianhe/out/h133-p2/compile_dir/target/awcast'
make[6]: Leaving directory '/opt/H133/H133-lianhe/out/h133-p2/compile_dir/target/awcast'
[ 28%] Built target tinyui
make[6]: Entering directory '/opt/H133/H133-lianhe/out/h133-p2/compile_dir/target/awcast'
make[6]: Leaving directory '/opt/H133/H133-lianhe/out/h133-p2/compile_dir/target/awcast'
make[6]: Entering directory '/opt/H133/H133-lianhe/out/h133-p2/compile_dir/target/awcast'
[ 35%] Linking C executable awcast
CMakeFiles/awcast.dir/wireless_display.c.o: In function `wd_start_airplay':
wireless_display.c:(.text+0x344): undefined reference to `CWA_SetRes'
collect2: error: ld returned 1 exit status
CMakeFiles/awcast.dir/build.make:303: recipe for target 'awcast' failed
make[6]: *** [awcast] Error 1
make[6]: Leaving directory '/opt/H133/H133-lianhe/out/h133-p2/compile_dir/target/awcast'
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/awcast.dir/all' failed
make[5]: *** [CMakeFiles/awcast.dir/all] Error 2
make[5]: Leaving directory '/opt/H133/H133-lianhe/out/h133-p2/compile_dir/target/awcast'
Makefile:127: recipe for target 'all' failed
make[4]: *** [all] Error 2
make[4]: Leaving directory '/opt/H133/H133-lianhe/out/h133-p2/compile_dir/target/awcast'
Makefile:130: recipe for target '/opt/H133/H133-lianhe/out/h133-p2/compile_dir/target/awcast/.built' failed
make[3]: *** [/opt/H133/H133-lianhe/out/h133-p2/compile_dir/target/awcast/.built] Error 2
make[3]: Leaving directory '/opt/H133/H133-lianhe/package/allwinner/homlet/awcast'
package/Makefile:192: recipe for target 'package/allwinner/homlet/awcast/compile' failed
make[2]: *** [package/allwinner/homlet/awcast/compile] Error 2
make[2]: Leaving directory '/opt/H133/H133-lianhe'
package/Makefile:189: recipe for target '/opt/H133/H133-lianhe/out/h133-p2/staging_dir/target/stamp/.package_compile' failed
make[1]: *** [/opt/H133/H133-lianhe/out/h133-p2/staging_dir/target/stamp/.package_compile] Error 2
make[1]: Leaving directory '/opt/H133/H133-lianhe'
/opt/H133/H133-lianhe/build/toplevel.mk:304: recipe for target 'world' failed
make: *** [world] Error 2
[2]+  Done                    $T/tools/build/buildserver --path $T 2> /dev/null 1>&2

#### make failed to build some targets (02:53 (mm:ss)) ####