nDPI/python/ndpi/ndpi_build.py
Ivan Nardi 83d85775a8
Provide an explicit state for the flow classification process (#2942)
Application should keep calling nDPI until flow state became
`NDPI_STATE_CLASSIFIED`.

The main loop in the application is simplified to something like:
```
res = ndpi_detection_process_packet(...);
if(res->state == NDPI_STATE_CLASSIFIED) {
  /* Done: you can get finale classification and all metadata.
     nDPI doesn't need more packets for this flow */
} else {
  /* nDPI needs more packets for this flow. The provided
     classification is not final and more metadata might be
     extracted.
     If `res->state` is `NDPI_STATE_PARTIAL`, partial/initial
     classification is available in `res->proto`
     as usual but it can be updated later.
  */
}

/*
    Example A (QUIC flow):
     pkt 1: proto QUIC state NDPI_STATE_PARTIAL
     pkt 2: proto QUIC/Youtube  state NDPI_STATE_CLASSIFIED
    Example B (GoogleMeet call):
     pkt 1:   proto STUN state NDPI_STATE_PARTIAL
     pkt N:   proto DTLS state NDPI_STATE_PARTIAL
     pkt N+M: proto DTLS/GoogleCall state NDPI_STATE_CLASSIFIED
    Example C (standard TLS flow):
     pkt 1:   proto Unknown state NDPI_STATE_INSPECTING
     pkt 2:   proto Unknown state NDPI_STATE_INSPECTING
     pkt 3:   proto Unknown state NDPI_STATE_INSPECTING
     pkt 4:   proto TLS/Facebook state NDPI_STATE_PARTIAL
     pkt N:   proto TLS/Facebook state NDPI_STATE_CLASSIFIED
 */
}
```
You can take a look at `ndpiReader` for a slightly more complex example.

API changes:
* remove the third parameter from `ndpi_detection_giveup()`. If you need
to know if the classification flow has been guessed, you can access
`flow->protocol_was_guessed`
* remove `ndpi_extra_dissection_possible()`
* change some prototypes from accepting `ndpi_protocol foo` to
`ndpi_master_app_protocol bar`. The update is trivial: from `foo` to
`foo.proto`
2025-11-03 12:08:15 +01:00

130 lines
5 KiB
Python

"""
------------------------------------------------------------------------------------------------------------------------
ndpi_build.py
Copyright (C) 2011-22 - ntop.org
This file is part of nDPI, an open source deep packet inspection library.
nDPI is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later
version.
nDPI is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along with NFStream.
If not, see <http://www.gnu.org/licenses/>.
------------------------------------------------------------------------------------------------------------------------
"""
from cffi import FFI
import subprocess
import pathlib
NDPI_INCLUDES = """
#include "ndpi_main.h"
#include "ndpi_typedefs.h"
#include "ndpi_api.h"
"""
NDPI_HELPERS = """
// nDPI cffi helper functions (function naming convention ndpi_py_*)
void ndpi_py_setup_detection_module(struct ndpi_detection_module_struct *mod) {
if (mod == NULL) {
return;
} else {
ndpi_finalize_initialization(mod);
}
};
struct ndpi_flow_struct * ndpi_py_initialize_flow(void) {
struct ndpi_flow_struct * ndpi_flow = NULL;
ndpi_flow = (struct ndpi_flow_struct *)ndpi_flow_malloc(SIZEOF_FLOW_STRUCT);
memset(ndpi_flow, 0, SIZEOF_FLOW_STRUCT);
return ndpi_flow;
};
"""
NDPI_APIS = """
u_int16_t ndpi_get_api_version(void);
char* ndpi_revision(void);
struct ndpi_detection_module_struct *ndpi_init_detection_module(struct ndpi_global_context *g_ctx);
void ndpi_exit_detection_module(struct ndpi_detection_module_struct *ndpi_struct);
void ndpi_flow_free(void *ptr);
ndpi_protocol ndpi_detection_process_packet(struct ndpi_detection_module_struct *ndpi_struct,
struct ndpi_flow_struct *flow,
const unsigned char *packet,
const unsigned short packetlen,
const u_int64_t packet_time_ms,
struct ndpi_flow_input_info *input_info);
ndpi_protocol ndpi_detection_giveup(struct ndpi_detection_module_struct *ndpi_struct,
struct ndpi_flow_struct *flow);
void ndpi_py_setup_detection_module(struct ndpi_detection_module_struct *mod);
struct ndpi_flow_struct * ndpi_py_initialize_flow(void);
char* ndpi_protocol2name(struct ndpi_detection_module_struct *ndpi_mod, ndpi_master_app_protocol proto, char *buf, u_int buf_len);
const char* ndpi_category_get_name(struct ndpi_detection_module_struct *ndpi_mod, ndpi_protocol_category_t category);
const char* ndpi_confidence_get_name(ndpi_confidence_t confidence);
"""
ffi_builder = FFI()
INCLUDE_DIR = pathlib.Path(__file__)\
.parent.resolve().parent.resolve().parent.resolve().\
joinpath("src").joinpath("include")
LIBRARY_DIR = pathlib.Path(__file__)\
.parent.resolve().parent.resolve().parent.resolve().\
joinpath("src").joinpath("lib")
NDPI_CDEF = subprocess.run(["gcc",
"-DNDPI_LIB_COMPILATION",
"-DNDPI_CFFI_PREPROCESSING",
"-DNDPI_CFFI_PREPROCESSING_EXCLUDE_PACKED",
"-E", "-x", "c", "-P", "-C",
str(INCLUDE_DIR.joinpath("ndpi_typedefs.h"))],
capture_output=True
).stdout.decode('utf-8',
errors='ignore')
NDPI_PACKED = subprocess.run(["gcc",
"-DNDPI_LIB_COMPILATION", "-DNDPI_CFFI_PREPROCESSING",
"-E", "-x", "c", "-P", "-C",
str(INCLUDE_DIR.joinpath("ndpi_typedefs.h"))],
capture_output=True
).stdout.decode('utf-8',
errors='ignore')
NDPI_PACKED_STRUCTURES = NDPI_PACKED.split("//CFFI.NDPI_PACKED_STRUCTURES")[1]
NDPI_SOURCE = NDPI_INCLUDES + NDPI_HELPERS
ffi_builder.set_source("_ndpi",
NDPI_SOURCE,
libraries=["ndpi"],
library_dirs=[str(LIBRARY_DIR)],
include_dirs=[str(INCLUDE_DIR)])
ffi_builder.cdef("""
typedef uint64_t u_int64_t;
typedef uint32_t u_int32_t;
typedef uint16_t u_int16_t;
typedef uint8_t u_int8_t;
typedef uint8_t u_char;
typedef unsigned u_int;
struct in_addr {
unsigned long s_addr;
};
struct in6_addr {
unsigned char s6_addr[16];
};
""")
ffi_builder.cdef(NDPI_PACKED_STRUCTURES, packed=True)
ffi_builder.cdef(NDPI_CDEF)
ffi_builder.cdef(NDPI_APIS)
if __name__ == "__main__":
ffi_builder.compile(verbose=True)