Function hostname2ip

src/butil/endpoint.cpp:188–237

}

int hostname2ip(const char* hostname, ip_t* ip) {
    char buf[256];
    if (NULL == hostname) {
        if (gethostname(buf, sizeof(buf)) < 0) {
            return -1;
        }
        hostname = buf;
    } else {
        // skip heading space
        for (; isspace(*hostname); ++hostname);
    }

#if defined(OS_MACOSX)
    // gethostbyname on MAC is thread-safe (with current usage) since the
    // returned hostent is TLS. Check following link for the ref:
    // https://lists.apple.com/archives/darwin-dev/2006/May/msg00008.html
    struct hostent* result = gethostbyname(hostname);
    if (result == NULL) {
        return -1;
    }
#else
    int aux_buf_len = 1024;
    std::unique_ptr<char[]> aux_buf(new char[aux_buf_len]);
    int ret = 0;
    int error = 0;
    struct hostent ent;
    struct hostent* result = NULL;
    do {
        result = NULL;
        error = 0;
        ret = gethostbyname_r(hostname,
                              &ent,
                              aux_buf.get(),
                              aux_buf_len,
                              &result,
                              &error);
        if (ret != ERANGE) { // aux_buf is not long enough
            break;
        }
        aux_buf_len *= 2;
        aux_buf.reset(new char[aux_buf_len]);
    } while (1);
    if (ret != 0 || result == NULL) {
        return -1;
    }
#endif // defined(OS_MACOSX)
    // Only fetch the first address here
    bcopy((char*)result->h_addr, (char*)ip, result->h_length);
    return 0;
}

struct MyAddressInfo {
    char my_hostname[256];