static int early_select_server_ctx(SSL *s, void *arg, int ignore)
{
    const char *servername;
    const unsigned char *p;
    size_t len, remaining;
    HANDSHAKE_EX_DATA *ex_data =
        (HANDSHAKE_EX_DATA*)(SSL_get_ex_data(s, ex_data_idx));
    if (!SSL_early_get0_ext(s, TLSEXT_TYPE_server_name, &p, &remaining) ||
        remaining <= 2)
        return 0;
    len = (*(p++) << 1);
    len += *(p++);
    if (len + 2 != remaining)
        return 0;
    remaining = len;
    if (remaining == 0 || *p++ != TLSEXT_NAMETYPE_host_name)
        return 0;
    remaining--;
    if (remaining <= 2)
        return 0;
    len = (*(p++) << 1);
    len += *(p++);
    if (len + 2 > remaining)
        return 0;
    remaining = len;
    servername = (const char *)p;
    if (len == strlen("server2") && strncmp(servername, "server2", len) == 0) {
        SSL_CTX *new_ctx = arg;
        SSL_set_SSL_CTX(s, new_ctx);
        SSL_clear_options(s, 0xFFFFFFFFL);
        SSL_set_options(s, SSL_CTX_get_options(new_ctx));
        ex_data->servername = SSL_TEST_SERVERNAME_SERVER2;
        return 1;
    } else if (len == strlen("server1") &&
               strncmp(servername, "server1", len) == 0) {
        ex_data->servername = SSL_TEST_SERVERNAME_SERVER1;
        return 1;
    } else if (ignore) {
        ex_data->servername = SSL_TEST_SERVERNAME_SERVER1;
        return 1;
    }
    return 0;
}
['static int early_select_server_ctx(SSL *s, void *arg, int ignore)\n{\n    const char *servername;\n    const unsigned char *p;\n    size_t len, remaining;\n    HANDSHAKE_EX_DATA *ex_data =\n        (HANDSHAKE_EX_DATA*)(SSL_get_ex_data(s, ex_data_idx));\n    if (!SSL_early_get0_ext(s, TLSEXT_TYPE_server_name, &p, &remaining) ||\n        remaining <= 2)\n        return 0;\n    len = (*(p++) << 1);\n    len += *(p++);\n    if (len + 2 != remaining)\n        return 0;\n    remaining = len;\n    if (remaining == 0 || *p++ != TLSEXT_NAMETYPE_host_name)\n        return 0;\n    remaining--;\n    if (remaining <= 2)\n        return 0;\n    len = (*(p++) << 1);\n    len += *(p++);\n    if (len + 2 > remaining)\n        return 0;\n    remaining = len;\n    servername = (const char *)p;\n    if (len == strlen("server2") && strncmp(servername, "server2", len) == 0) {\n        SSL_CTX *new_ctx = arg;\n        SSL_set_SSL_CTX(s, new_ctx);\n        SSL_clear_options(s, 0xFFFFFFFFL);\n        SSL_set_options(s, SSL_CTX_get_options(new_ctx));\n        ex_data->servername = SSL_TEST_SERVERNAME_SERVER2;\n        return 1;\n    } else if (len == strlen("server1") &&\n               strncmp(servername, "server1", len) == 0) {\n        ex_data->servername = SSL_TEST_SERVERNAME_SERVER1;\n        return 1;\n    } else if (ignore) {\n        ex_data->servername = SSL_TEST_SERVERNAME_SERVER1;\n        return 1;\n    }\n    return 0;\n}', 'void *SSL_get_ex_data(const SSL *s, int idx)\n{\n    return (CRYPTO_get_ex_data(&s->ex_data, idx));\n}', 'void *CRYPTO_get_ex_data(const CRYPTO_EX_DATA *ad, int idx)\n{\n    if (ad->sk == NULL || idx >= sk_void_num(ad->sk))\n        return NULL;\n    return sk_void_value(ad->sk, idx);\n}']