print-l2tp.c

Windump3.6.2源代码

	print_octets(dat, 16);		/* XXX length should be 16? */
}

static void
l2tp_assnd_sess_id_print(const u_char *dat, u_int length)
{
	print_short((u_short *)dat);
}

static void
l2tp_call_ser_num_print(const u_char *dat, u_int length)
{
	print_int((u_int *)dat);
}

static void
l2tp_minimum_bps_print(const u_char *dat, u_int length)
{
	print_int((u_int *)dat);
}

static void
l2tp_maximum_bps_print(const u_char *dat, u_int length)
{
	print_int((u_int *)dat);
}

static void
l2tp_bearer_type_print(const u_char *dat, u_int length)
{
	u_int *ptr = (u_int *)dat;

	if (ntohl(*ptr) &  L2TP_BEARER_TYPE_ANALOG_MASK) {
		printf("A");
	}
	if (ntohl(*ptr) &  L2TP_BEARER_TYPE_DIGITAL_MASK) {
		printf("D");
	}
}

static void
l2tp_framing_type_print(const u_char *dat, u_int length)
{
	u_int *ptr = (u_int *)dat;

	if (ntohl(*ptr) &  L2TP_FRAMING_TYPE_ASYNC_MASK) {
		printf("A");
	}
	if (ntohl(*ptr) &  L2TP_FRAMING_TYPE_SYNC_MASK) {
		printf("S");
	}
}

static void
l2tp_packet_proc_delay_print(const u_char *dat, u_int length)
{
	printf("obsolete");
}

static void
l2tp_called_number_print(const u_char *dat, u_int length)
{
	print_string(dat, length);
}

static void
l2tp_calling_number_print(const u_char *dat, u_int length)
{
	print_string(dat, length);
}

static void
l2tp_sub_address_print(const u_char *dat, u_int length)
{
	print_string(dat, length);
}

static void
l2tp_tx_conn_speed_print(const u_char *dat, u_int length)
{
	print_int((u_int *)dat);
}

static void
l2tp_phy_channel_id_print(const u_char *dat, u_int length)
{
	print_int((u_int *)dat);
}

static void
l2tp_ini_recv_lcp_print(const u_char *dat, u_int length)
{
	print_octets(dat, length);
}

static void
l2tp_last_sent_lcp_print(const u_char *dat, u_int length)
{
	print_octets(dat, length);
}

static void
l2tp_last_recv_lcp_print(const u_char *dat, u_int length)
{
	print_octets(dat, length);
}

static void
l2tp_proxy_auth_type_print(const u_char *dat, u_int length)
{
	u_short *ptr = (u_short *)dat;

	switch (ntohs(*ptr)) {
	case L2TP_AUTHEN_TYPE_RESERVED:
		printf("Reserved");
		break;
	case L2TP_AUTHEN_TYPE_TEXTUAL:
		printf("Textual");
		break;
	case L2TP_AUTHEN_TYPE_CHAP:
		printf("CHAP");
		break;
	case L2TP_AUTHEN_TYPE_PAP:
		printf("PAP");
		break;
	case L2TP_AUTHEN_TYPE_NO_AUTH:
		printf("No Auth");
		break;
	case L2TP_AUTHEN_TYPE_MSCHAP:
		printf("MS-CHAP");
		break;
	default:
		printf("unknown");
	}
}

static void
l2tp_proxy_auth_name_print(const u_char *dat, u_int length)
{
	print_octets(dat, length);
}

static void
l2tp_proxy_auth_chal_print(const u_char *dat, u_int length)
{
	print_octets(dat, length);
}

static void
l2tp_proxy_auth_id_print(const u_char *dat, u_int length)
{
	u_short *ptr = (u_short *)dat;

	printf("%u", ntohs(*ptr) & L2TP_PROXY_AUTH_ID_MASK);
}

static void
l2tp_proxy_auth_resp_print(const u_char *dat, u_int length)
{
	print_octets(dat, length);
}

static void
l2tp_call_errors_print(const u_char *dat, u_int length)
{
	struct l2tp_call_errors *ptr = (struct l2tp_call_errors *)dat;

	printf("CRCErr=%d FrameErr=%d HardOver=%d BufOver=%d ",
	       ptr->crc_errs,
	       ptr->framing_errs,
	       ptr->hardware_overruns,
	       ptr->buffer_overruns);
	printf("Timeout=%d AlingErr=%d",
	       ptr->timeout_errs,
	       ptr->alignment_errs);
}

static void
l2tp_accm_print(const u_char *dat, u_int length)
{
	struct l2tp_accm *ptr = (struct l2tp_accm *)dat;

	printf("send=%x recv=%x", ptr->send_accm, ptr->recv_accm);
}

static void
l2tp_random_vector_print(const u_char *dat, u_int length)
{
	print_octets(dat, length);
}

static void
l2tp_private_grp_id_print(const u_char *dat, u_int length)
{
	print_string(dat, length);	
	/* XXX print_octets is more appropriate?? */
}

static void
l2tp_rx_conn_speed_print(const u_char *dat, u_int length)
{
	print_int((u_int *)dat);
}

static void
l2tp_seq_required_print(const u_char *dat, u_int length)
{
	return;
}

static void
l2tp_avp_print(const u_char *dat, u_int length)
{
	u_int len;
	const u_short *ptr = (u_short *)dat;
	int hidden = FALSE;

	printf(" ");
	if (length > 0 && (snapend - dat) >= 2) {
		/* there must be at least two octets for the length
		   to be decoded */
		if ((len = (ntohs(*ptr) & L2TP_AVP_HDR_LEN_MASK)) <=
		    (snapend - dat)) {
			if (ntohs(*ptr) & L2TP_AVP_HDR_FLAG_MANDATORY) {
				printf("*");
			}
			if (ntohs(*ptr) & L2TP_AVP_HDR_FLAG_HIDDEN) {
				hidden = TRUE;
				printf("?");
			}
		} else {
			printf("|...");
			return;
		}
		ptr++;

		if (ntohs(*ptr)) {
			/* Vendor Specific Attribute */
			printf("VENDOR%04x:", ntohs(*ptr));
			ptr++;
			printf("ATTR%04x", ntohs(*ptr));
			printf("(");
			print_octets((u_char *)ptr+2, len-6);
			printf(")");
		} else {
			/* IETF-defined Attribute */ 
			ptr++;
			if (ntohs(*ptr) < L2TP_MAX_AVP_INDEX) {
				printf("%s", l2tp_avp[ntohs(*ptr)].name);
				printf("(");
				if (!hidden) {
					(l2tp_avp[ntohs(*ptr)].print)
						((u_char *)ptr+2, len-6);
				} else {
					printf("???");
				}
				printf(")");
			} else {
				printf(" invalid AVP %u", ntohs(*ptr));
			}
		}

		l2tp_avp_print(dat + len, length - len);
	} else if (length == 0) {
		return;
	} else {
		printf("|...");
	}
}


void
l2tp_print(const u_char *dat, u_int length)
{
	const u_short *ptr = (u_short *)dat;
	u_int cnt = 0;			/* total octets consumed */
	u_short pad;
	int flag_t, flag_l, flag_s, flag_o, flag_p;
	u_short l2tp_len;

	flag_t = flag_l = flag_s = flag_o = flag_p = FALSE;

	if (min(length, snapend - dat) - 6 < 0) { 
		/* flag/ver, tunnel_id, session_id must be present for
		   this packet to be properly decoded */
		printf("%s", tstr);
		return;
	}

	if ((ntohs(*ptr) & L2TP_VERSION_MASK) == L2TP_VERSION_L2TP) {
		printf(" l2tp:");
	} else if ((ntohs(*ptr) & L2TP_VERSION_MASK) == L2TP_VERSION_L2F) {
		printf(" l2f:");
		return;		/* nothing to do */
	} else {
		printf(" Unknown Version, neither L2F(1) nor L2TP(2)");
		return;		/* nothing we can do */
	}

	printf("[");
	if (ntohs(*ptr) & L2TP_FLAG_TYPE) {
		flag_t = TRUE;
		printf("T");
	}
	if (ntohs(*ptr) & L2TP_FLAG_LENGTH) {
		flag_l = TRUE;
		printf("L");
	}
	if (ntohs(*ptr) & L2TP_FLAG_SEQUENCE) {
		flag_s = TRUE;
		printf("S");
	}
	if (ntohs(*ptr) & L2TP_FLAG_OFFSET) {
		flag_o = TRUE;
		printf("O");
	}
	if (ntohs(*ptr) & L2TP_FLAG_PRIORITY) {
		flag_p = TRUE;
		printf("P");
	}
	printf("]");

	ptr++;
	cnt += 2;
	
	if (flag_l) {
		l2tp_len = ntohs(*ptr++);	/* XXX need to consider 
						   truncation ?? */
		cnt += 2;
	} else {
		l2tp_len = 0;
	}

	printf("(%u/", ntohs(*ptr++));		/* Tunnel ID */
	printf("%u)",  ntohs(*ptr++));		/* Session ID */
	cnt += 4;

	if (flag_s) {
		printf("Ns=%u,", ntohs(*ptr++));
		printf("Nr=%u",  ntohs(*ptr++));
		cnt += 4;
	}

	if (flag_o) {
		pad =  ntohs(*ptr++);
		ptr += pad / sizeof(*ptr);
		cnt += (2 + pad);
	}

	if (flag_t) {
		if (length - cnt == 0) {
			printf(" ZLB");
		} else {
			l2tp_avp_print((u_char *)ptr, length - cnt);
		}
	} else {
		printf(" {");
		ppp_print((u_char *)ptr, length - cnt);
		printf("}");
	}
}