Add initial code

The inital code is from this patch:
https://gerrit.fd.io/r/#/c/vpp/+/16580/
It is contributed by Intel and Travelping.
Jerome Tollet, Ed Warnicke, Dave Barach, Damjan Marion from Cisco
and other guys have gave lots of useful comments on it.

The initial code is used for identifying layer-7 applications for HTTPS/TLS traffic

- Below is the brief design info.

- Provides a default APPID database for scan.

- Dynamically create new SW mapping has been supported now.

- Support TCP connection state tracking.

- Support TCP segments reassembly on the fly, which handles out-of-order tcp segments and overlapping segments.
  It means that we do not need to reassembly segments first, then dedect applicaion,
  and then fragment segments again, which helps to improve performance.

- Support Hyperscan Stream mode, which can scan rules straddling into different tcp segments.
  It means that if there is a rule "abcde", then "abc" can be in packet 1,
  and "de" can be in packet 2.

- Configure static dpi flows with 5-tuple and VRF-aware, and supports both ipv4 and ipv6 flows.
  These flows will first try to HW offload to NIC based on DPDK rte_flow mechanism
  and vpp/vnet/flow infrastructure.
  If failed, then will create static SW flow mappings.
  Each flow configuration will create two HW or SW flow mappings, i.e. for forward and reverse traffic.
  And both flow mappings will be mapped to the same dpi flow.
  SW entry aging out mechanism will be added later.
        "dpi flow [add | del]  "
        "[src-ip <ip-addr>] [dst-ip <ip-addr>] "
        "[src-port <port>] [dst-port <port>] "
        "[protocol <protocol>] [vrf-id <nn>]",
        "dpi set flow-offload hw <interface-name> rx <flow-id> [del]",
        "dpi set ip4 flow-bypass <interface> [del]",

- When HW flow offload matched, packets will be redirected to DPI plugin with dpi flow_id in packet descriptor.
   If not, packets will be bypassed to DPI plugin from ip-input, and then lookup SW flow mapping table.

- Then will detect layer 7 applications.
   This first patch only detect sub protocls within SSL/TLS.
   1). Identify SSL/TLS certificate message and subsequent segments.
   2). Scan SSL/TLS certificate message through hyperscan, and get application id if matched.
   3). If maximum packets for this flow are checked and not found matched application, the detection will end up.

Ticket:
Type: feature

Signed-off-by: Hongjun Ni <hongjun.ni@intel.com>
Signed-off-by: Andreas Schultz <andreas.schultz@travelping.com>
Signed-off-by: Mathias Gumz <mathias.gumz@travelping.com>
Change-Id: I839cc70ddc80ea594d22a04e2cabf92a7b9c74e7

1 files changed, 247 insertions, 0 deletions

diff --git a/src/protocols/dpi_ssl.c b/src/protocols/dpi_ssl.c
new file mode 100644
index 0000000..7257ca5
--- /dev/null
+++ b/src/protocols/dpi_ssl.c
@@ -0,0 +1,247 @@
+/*
+ * Copyright (c) 2019 Intel and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdint.h>
+#include <string.h>
+#include <net/if.h>
+#include <sys/ioctl.h>
+#include <inttypes.h>
+
+#include <vlib/vlib.h>
+#include <vlib/unix/unix.h>
+
+#include <dpi/dpi.h>
+
+typedef enum
+{
+  State_Initial = 0,
+  State_Client_Hello = 1,
+  State_Server_Hello = 2,
+  State_Certificate = 3,
+} ssl_state;
+
+enum
+{
+  MAJOR_TLS = 0x3,
+};
+
+enum
+{
+  MINOR_SSL30 = 0,
+  MINOR_TLS10 = 0x1,
+  MINOR_TLS11 = 0x2,
+  MINOR_TLS12 = 0x3,
+};
+
+typedef enum
+{
+  change_cipher_spec = 20,
+  alert = 21,
+  handshake = 22,
+  application_data = 23,
+} ContentType;
+
+typedef struct
+{
+  u8 major;
+  u8 minor;
+} ProtocolVersion;
+
+typedef struct
+{
+  u8 type;
+  ProtocolVersion version;
+  u16 length;
+} __attribute__ ((packed)) ssl_header;
+
+typedef enum
+{
+  hello_request = 0,
+  client_hello = 1,
+  server_hello = 2,
+  certificate = 11,
+  server_key_exchange = 12,
+  certificate_request = 13,
+  server_hello_done = 14,
+  certificate_verify = 15,
+  client_key_exchange = 16,
+  finished = 20,
+} HandshakeType;
+
+typedef struct
+{
+  u8 msg_type;			/* handshake type */
+  u8 length[3];			/* bytes in message */
+} Handshake_header;
+
+int dpi_ssl_detect_protocol_from_cert (u8 * payload, u32 payload_len,
+				       dpi_flow_info_t * flow);
+
+#define dpi_isprint(ch) ((ch) >= 0x20 && (ch) <= 0x7e)
+#define dpi_isalpha(ch) (((ch) >= 'a' && (ch) <= 'z') || ((ch) >= 'A' && (ch) <= 'Z'))
+#define dpi_isdigit(ch) ((ch) >= '0' && (ch) <= '9')
+#define dpi_isspace(ch) (((ch) >= '\t' && (ch) <= '\r') || ((ch) == ' '))
+#define dpi_min(a,b)   ((a < b) ? a : b)
+
+static void
+dpi_set_detected_protocol (dpi_flow_info_t * flow,
+			   u32 upper_protocol, u32 lower_protocol)
+{
+
+  if ((upper_protocol == DPI_PROTOCOL_UNKNOWN)
+      && (lower_protocol != DPI_PROTOCOL_UNKNOWN))
+    upper_protocol = lower_protocol;
+
+  if (upper_protocol == lower_protocol)
+    lower_protocol = DPI_PROTOCOL_UNKNOWN;
+
+  if ((upper_protocol != DPI_PROTOCOL_UNKNOWN)
+      && (lower_protocol == DPI_PROTOCOL_UNKNOWN))
+    {
+      if ((flow->guessed_host_protocol_id != DPI_PROTOCOL_UNKNOWN)
+	  && (upper_protocol != flow->guessed_host_protocol_id))
+	{
+	  lower_protocol = upper_protocol;
+	  upper_protocol = flow->guessed_host_protocol_id;
+	}
+    }
+
+  flow->detected_protocol[0] = upper_protocol;
+  flow->detected_protocol[1] = lower_protocol;
+}
+
+static u32
+dpi_ssl_refine_master_protocol (dpi_flow_info_t * flow, u32 protocol)
+{
+
+  if (flow->l4.tcp.ssl_got_server_cert == 1)
+    protocol = DPI_PROTOCOL_SSL;
+  else
+    protocol = DPI_PROTOCOL_SSL_NO_CERT;
+
+  return protocol;
+}
+
+int
+dpi_ssl_detect_protocol_from_cert (u8 * payload, u32 payload_len,
+				   dpi_flow_info_t * flow)
+{
+  u32 host_protocol = DPI_PROTOCOL_UNKNOWN;
+  int rv = 0;
+
+  /* Only check SSL handshake packets.
+   * Check first segment and subsequent segments. */
+  if (((payload_len > (sizeof (ssl_header) + sizeof (Handshake_header)))
+       && (payload[0] == handshake)) || (flow->detect_begin))
+    {
+      if ((flow->detected_protocol[0] == DPI_PROTOCOL_UNKNOWN)
+	  || (flow->detected_protocol[0] == DPI_PROTOCOL_SSL))
+	{
+	  rv = dpi_search_host_protocol (flow, (char *) payload, payload_len,
+					 DPI_PROTOCOL_SSL, &host_protocol);
+
+	  if (host_protocol != DPI_PROTOCOL_UNKNOWN)
+	    {
+	      dpi_set_detected_protocol (flow, host_protocol,
+					 dpi_ssl_refine_master_protocol (flow,
+									 DPI_PROTOCOL_SSL));
+	      return rv;
+	    }
+	}
+    }
+  return 0;
+}
+
+
+void
+dpi_search_tcp_ssl (u8 * payload, u32 payload_len, dpi_flow_info_t * flow)
+{
+  u32 cur_len = payload_len;
+  u32 cur_len2;
+  u8 handshake_type;
+
+  /* Check first segment of SSL Certificate message */
+  if ((payload_len > (sizeof (ssl_header) + sizeof (Handshake_header)))
+      && (payload[0] == handshake))
+    {
+      handshake_type = payload[5];
+
+      if (handshake_type == client_hello)
+	{
+	  flow->l4.tcp.ssl_stage = State_Client_Hello;
+	  return;
+	}
+      else if (handshake_type == server_hello)
+	{
+	  cur_len = ntohs (get_u16_t (payload, 3)) + sizeof (ssl_header);
+
+	  /* This packet only contains Server Hello message */
+	  if (cur_len == payload_len)
+	    {
+	      flow->l4.tcp.ssl_stage = State_Server_Hello;
+	      return;
+	    }
+
+	  /* This packet contains Server Hello, Certificate and more messages */
+	  if (payload_len >= cur_len + sizeof (ssl_header)
+	      && payload[cur_len] == handshake
+	      && payload[cur_len + 1] == MAJOR_TLS)
+	    {
+	      cur_len2 = ntohs (get_u16_t (payload, cur_len + 3))
+		+ sizeof (ssl_header);
+	      if (payload[cur_len + 5] == certificate)
+		{
+		  flow->l4.tcp.ssl_stage = State_Certificate;
+		  flow->detect_begin = 1;
+		  /* Scan segments of certificate message */
+		  if (dpi_ssl_detect_protocol_from_cert (&payload[cur_len],
+							 cur_len2, flow) > 0)
+		    return;
+		}
+	    }
+	}
+      else if (handshake_type == certificate)
+	{
+	  cur_len = ntohs (get_u16_t (payload, 3)) + sizeof (ssl_header);
+
+	  /* This packet contains first segment of certificate message */
+	  if (cur_len == payload_len)
+	    {
+	      flow->l4.tcp.ssl_stage = State_Certificate;
+	      flow->detect_begin = 1;
+	      /* Scan segments of certificate message */
+	      if (dpi_ssl_detect_protocol_from_cert (payload, cur_len, flow) >
+		  0)
+		return;
+	    }
+	}
+      else if (flow->detect_begin)
+	{
+	  /* Check subsequent segments of SSL Certificate message */
+	  if (dpi_ssl_detect_protocol_from_cert (payload, cur_len, flow) > 0)
+	    return;
+	}
+    }
+
+  return;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */