/*
* ndpi_util.c
*
* Copyright (C) 2011-16 - ntop.org
*
* This file is part of nDPI, an open source deep packet inspection
* library based on the OpenDPI and PACE technology by ipoque GmbH
*
* 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 nDPI. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include <stdlib.h>
#ifdef WIN32
#include <winsock2.h> /* winsock.h is included automatically */
#include <process.h>
#include <io.h>
#else
#include <unistd.h>
#include <netinet/in.h>
#endif
#ifndef ETH_P_IP
#define ETH_P_IP 0x0800 /* IPv4 */
#endif
#ifndef ETH_P_IPv6
#define ETH_P_IPV6 0x86dd /* IPv6 */
#endif
#define SLARP 0x8035 /* Cisco Slarp */
#define CISCO_D_PROTO 0x2000 /* Cisco Discovery Protocol */
#define VLAN 0x8100
#define MPLS_UNI 0x8847
#define MPLS_MULTI 0x8848
#define PPPoE 0x8864
#define SNAP 0xaa
/* mask for FCF */
#define WIFI_DATA 0x2 /* 0000 0010 */
#define FCF_TYPE(fc) (((fc) >> 2) & 0x3) /* 0000 0011 = 0x3 */
#define FCF_SUBTYPE(fc) (((fc) >> 4) & 0xF) /* 0000 1111 = 0xF */
#define FCF_TO_DS(fc) ((fc) & 0x0100)
#define FCF_FROM_DS(fc) ((fc) & 0x0200)
/* mask for Bad FCF presence */
#define BAD_FCS 0x50 /* 0101 0000 */
#define GTP_U_V1_PORT 2152
#define TZSP_PORT 37008
#define SIZEOF_ID_STRUCT (sizeof(struct ndpi_id_struct))
#define SIZEOF_FLOW_STRUCT (sizeof(struct ndpi_flow_struct))
#include "ndpi_main.h"
#include "ndpi_util.h"
/* ***************************************************** */
void ndpi_free_flow_info_half(struct ndpi_flow_info *flow) {
if(flow->ndpi_flow) { ndpi_free_flow(flow->ndpi_flow); flow->ndpi_flow = NULL; }
if(flow->src_id) { ndpi_free(flow->src_id); flow->src_id = NULL; }
if(flow->dst_id) { ndpi_free(flow->dst_id); flow->dst_id = NULL; }
}
/* ***************************************************** */
static const u_int8_t nDPI_traceLevel = 0;
/* ***************************************************** */
extern u_int32_t current_ndpi_memory, max_ndpi_memory;
/**
* @brief malloc wrapper function
*/
static void *malloc_wrapper(size_t size) {
current_ndpi_memory += size;
if(current_ndpi_memory > max_ndpi_memory)
max_ndpi_memory = current_ndpi_memory;
return malloc(size);
}
/* ***************************************************** */
/**
* @brief free wrapper function
*/
static void free_wrapper(void *freeable) {
free(freeable);
}
/* ***************************************************** */
struct ndpi_workflow * ndpi_workflow_init(const struct ndpi_workflow_prefs * prefs, pcap_t * pcap_handle) {
set_ndpi_malloc(malloc_wrapper), set_ndpi_free(free_wrapper);
/* TODO: just needed here to init ndpi malloc wrapper */
struct ndpi_detection_module_struct * module = ndpi_init_detection_module();
struct ndpi_workflow * workflow = ndpi_calloc(1, sizeof(struct ndpi_workflow));
workflow->pcap_handle = pcap_handle;
workflow->prefs = *prefs;
workflow->ndpi_struct = module;
if(workflow->ndpi_struct == NULL) {
NDPI_LOG(0, NULL, NDPI_LOG_ERROR, "global structure initialization failed\n");
exit(-1);
}
workflow->ndpi_flows_root = ndpi_calloc(workflow->prefs.num_roots, sizeof(void *));
return workflow;
}
/* ***************************************************** */
static void ndpi_flow_info_freer(void *node) {
struct ndpi_flow_info *flow = (struct ndpi_flow_info*)node;
ndpi_free_flow_info_half(flow);
ndpi_free(flow);
}
/* ***************************************************** */
void ndpi_workflow_free(struct ndpi_workflow * workflow) {
int i;
for(i=0; i<workflow->prefs.num_roots; i++)
ndpi_tdestroy(workflow->ndpi_flows_root[i], ndpi_flow_info_freer);
ndpi_exit_detection_module(workflow->ndpi_struct);
free(workflow->ndpi_flows_root);
free(workflow);
}
/* ***************************************************** */
int ndpi_workflow_node_cmp(const void *a, const void *b) {
struct ndpi_flow_info *fa = (struct ndpi_flow_info*)a;
struct ndpi_flow_info *fb = (struct ndpi_flow_info*)b;
if(fa->vlan_id < fb->vlan_id ) return(-1); else { if(fa->vlan_id > fb->vlan_id ) return(1); }
if(fa->lower_ip < fb->lower_ip ) return(-1); else { if(fa->lower_ip > fb->lower_ip ) return(1); }
if(fa->lower_port < fb->lower_port) return(-1); else { if(fa->lower_port > fb->lower_port) return(1); }
if(fa->upper_ip < fb->upper_ip ) return(-1); else { if(fa->upper_ip > fb->upper_ip ) return(1); }
if(fa->upper_port < fb->upper_port) return(-1); else { if(fa->upper_port > fb->upper_port) return(1); }
if(fa->protocol < fb->protocol ) return(-1); else { if(fa->protocol > fb->protocol ) return(1); }
return(0);
}
/* ***************************************************** */
static void patchIPv6Address(char *str) {
int i = 0, j = 0;
while(str[i] != '\0') {
if((str[i] == ':')
&& (str[i+1] == '0')
&& (str[i+2] == ':')) {
str[j++] = ':';
str[j++] = ':';
i += 3;
} else
str[j++] = str[i++];
}
if(str[j] != '\0') str[j] = '\0';
}
/* ***************************************************** */
static struct ndpi_flow_info *get_ndpi_flow_info(struct ndpi_workflow * workflow,
const u_int8_t version,
u_int16_t vlan_id,
const struct ndpi_iphdr *iph,
const struct ndpi_ipv6hdr *iph6,
u_int16_t ip_offset,
u_int16_t ipsize,
u_int16_t l4_packet_len,
struct ndpi_tcphdr **tcph,
struct ndpi_udphdr **udph,
u_int16_t *sport, u_int16_t *dport,
struct ndpi_id_struct **src,
struct ndpi_id_struct **dst,
u_int8_t *proto,
u_int8_t **payload,
u_int16_t *payload_len,
u_int8_t *src_to_dst_direction) {
u_int32_t idx, l4_offset;
u_int32_t lower_ip;
u_int32_t upper_ip;
u_int16_t lower_port;
u_int16_t upper_port;
struct ndpi_flow_info flow;
void *ret;
u_int8_t *l3, *l4;
/*
Note: to keep things simple (ndpiReader is just a demo app)
we handle IPv6 a-la-IPv4.
*/
if(version == 4) {
if(ipsize < 20)
return NULL;
if((iph->ihl * 4) > ipsize || ipsize < ntohs(iph->tot_len)
|| (iph->frag_off & htons(0x1FFF)) != 0)
return NULL;
l4_offset = iph->ihl * 4;
l3 = (u_int8_t*)iph;
} else {
l4_offset = sizeof(struct ndpi_ipv6hdr);
l3 = (u_int8_t*)iph6;
}
if(l4_packet_len < 64)
workflow->stats.packet_len[0]++;
else if(l4_packet_len >= 64 && l4_packet_len < 128)
workflow->stats.packet_len[1]++;
else if(l4_packet_len >= 128 && l4_packet_len < 256)
workflow->stats.packet_len[2]++;
else if(l4_packet_len >= 256 && l4_packet_len < 1024)
workflow->stats.packet_len[3]++;
else if(l4_packet_len >= 1024 && l4_packet_len < 1500)
workflow->stats.packet_len[4]++;
else if(l4_packet_len >= 1500)
workflow->stats.packet_len[5]++;
if(l4_packet_len > workflow->stats.max_packet_len)
workflow->stats.max_packet_len = l4_packet_len;
if(iph->saddr < iph->daddr) {
lower_ip = iph->saddr;
upper_ip = iph->daddr;
} else {
lower_ip = iph->daddr;
upper_ip = iph->saddr;
}
*proto = iph->protocol;
l4 = ((u_int8_t *) l3 + l4_offset);
if(iph->protocol == 6 && l4_packet_len >= 20) {
u_int tcp_len;
workflow->stats.tcp_count++;
// tcp
*tcph = (struct ndpi_tcphdr *)l4;
*sport = ntohs((*tcph)->source), *dport = ntohs((*tcph)->dest);
if(iph->saddr < iph->daddr) {
lower_port = (*tcph)->source, upper_port = (*tcph)->dest;
*src_to_dst_direction = 1;
} else {
lower_port = (*tcph)->dest;
upper_port = (*tcph)->source;
*src_to_dst_direction = 0;
if(iph->saddr == iph->daddr) {
if(lower_port > upper_port) {
u_int16_t p = lower_port;
lower_port = upper_port;
upper_port = p;
}
}
}
tcp_len = ndpi_min(4*(*tcph)->doff, l4_packet_len);
*payload = &l4[tcp_len];
*payload_len = ndpi_max(0, l4_packet_len-4*(*tcph)->doff);
} else if(iph->protocol == 17 && l4_packet_len >= 8) {
// udp
workflow->stats.udp_count++;
*udph = (struct ndpi_udphdr *)l4;
*sport = ntohs((*udph)->source), *dport = ntohs((*udph)->dest);
*payload = &l4[sizeof(struct ndpi_udphdr)];
*payload_len = ndpi_max(0, l4_packet_len-sizeof(struct ndpi_udphdr));
if(iph->saddr < iph->daddr) {
lower_port = (*udph)->source, upper_port = (*udph)->dest;
*src_to_dst_direction = 1;
} else {
lower_port = (*udph)->dest, upper_port = (*udph)->source;
*src_to_dst_direction = 0;
if(iph->saddr == iph->daddr) {
if(lower_port > upper_port) {
u_int16_t p = lower_port;
lower_port = upper_port;
upper_port = p;
}
}
}
*sport = ntohs(lower_port), *dport = ntohs(upper_port);
} else {
// non tcp/udp protocols
lower_port = 0;
upper_port = 0;
}
flow.protocol = iph->protocol, flow.vlan_id = vlan_id;
flow.lower_ip = lower_ip, flow.upper_ip = upper_ip;
flow.lower_port = lower_port, flow.upper_port = upper_port;
if(0)
NDPI_LOG(0, workflow.ndpi_struct, NDPI_LOG_DEBUG, "[NDPI] [%u][%u:%u <-> %u:%u]\n",
iph->protocol, lower_ip, ntohs(lower_port), upper_ip, ntohs(upper_port));
idx = (vlan_id + lower_ip + upper_ip + iph->protocol + lower_port + upper_port) % workflow->prefs.num_roots;
ret = ndpi_tfind(&flow, &workflow->ndpi_flows_root[idx], ndpi_workflow_node_cmp);
if(ret == NULL) {
if(workflow->stats.ndpi_flow_count == workflow->prefs.max_ndpi_flows) {
NDPI_LOG(0, workflow.ndpi_struct, NDPI_LOG_ERROR, "maximum flow count (%u) has been exceeded\n", workflow->prefs.max_ndpi_flows);
exit(-1);
} else {
struct ndpi_flow_info *newflow = (struct ndpi_flow_info*)malloc(sizeof(struct ndpi_flow_info));
if(newflow == NULL) {
NDPI_LOG(0, workflow.ndpi_struct, NDPI_LOG_ERROR, "[NDPI] %s(1): not enough memory\n", __FUNCTION__);
return(NULL);
}
memset(newflow, 0, sizeof(struct ndpi_flow_info));
newflow->protocol = iph->protocol, newflow->vlan_id = vlan_id;
newflow->lower_ip = lower_ip, newflow->upper_ip = upper_ip;
newflow->lower_port = lower_port, newflow->upper_port = upper_port;
newflow->ip_version = version;
if(version == 4) {
inet_ntop(AF_INET, &lower_ip, newflow->lower_name, sizeof(newflow->lower_name));
inet_ntop(AF_INET, &upper_ip, newflow->upper_name, sizeof(newflow->upper_name));
} else {
inet_ntop(AF_INET6, &iph6->ip6_src, newflow->lower_name, sizeof(newflow->lower_name));
inet_ntop(AF_INET6, &iph6->ip6_dst, newflow->upper_name, sizeof(newflow->upper_name));
/* For consistency across platfoms replace :0: with :: */
patchIPv6Address(newflow->lower_name), patchIPv6Address(newflow->upper_name);
}
if((newflow->ndpi_flow = ndpi_malloc(SIZEOF_FLOW_STRUCT)) == NULL) {
NDPI_LOG(0, workflow.ndpi_struct, NDPI_LOG_ERROR, "[NDPI] %s(2): not enough memory\n", __FUNCTION__);
free(newflow);
return(NULL);
} else
memset(newflow->ndpi_flow, 0, SIZEOF_FLOW_STRUCT);
if((newflow->src_id = ndpi_malloc(SIZEOF_ID_STRUCT)) == NULL) {
NDPI_LOG(0, workflow.ndpi_struct, NDPI_LOG_ERROR, "[NDPI] %s(3): not enough memory\n", __FUNCTION__);
free(newflow);
return(NULL);
} else
memset(newflow->src_id, 0, SIZEOF_ID_STRUCT);
if((newflow->dst_id = ndpi_malloc(SIZEOF_ID_STRUCT)) == NULL) {
NDPI_LOG(0, workflow.ndpi_struct, NDPI_LOG_ERROR, "[NDPI] %s(4): not enough memory\n", __FUNCTION__);
free(newflow);
return(NULL);
} else
memset(newflow->dst_id, 0, SIZEOF_ID_STRUCT);
ndpi_tsearch(newflow, &workflow->ndpi_flows_root[idx], ndpi_workflow_node_cmp); /* Add */
workflow->stats.ndpi_flow_count++;
*src = newflow->src_id, *dst = newflow->dst_id;
return newflow;
}
} else {
struct ndpi_flow_info *flow = *(struct ndpi_flow_info**)ret;
if(flow->lower_ip == lower_ip && flow->upper_ip == upper_ip
&& flow->lower_port == lower_port && flow->upper_port == upper_port)
*src = flow->src_id, *dst = flow->dst_id;
else
*src = flow->dst_id, *dst = flow->src_id;
return flow;
}
}
/* ****************************************************** */
static struct ndpi_flow_info *get_ndpi_flow_info6(struct ndpi_workflow * workflow,
u_int16_t vlan_id,
const struct ndpi_ipv6hdr *iph6,
u_int16_t ip_offset,
struct ndpi_tcphdr **tcph,
struct ndpi_udphdr **udph,
u_int16_t *sport, u_int16_t *dport,
struct ndpi_id_struct **src,
struct ndpi_id_struct **dst,
u_int8_t *proto,
u_int8_t **payload,
u_int16_t *payload_len,
u_int8_t *src_to_dst_direction) {
struct ndpi_iphdr iph;
memset(&iph, 0, sizeof(iph));
iph.version = 4;
iph.saddr = iph6->ip6_src.u6_addr.u6_addr32[2] + iph6->ip6_src.u6_addr.u6_addr32[3];
iph.daddr = iph6->ip6_dst.u6_addr.u6_addr32[2] + iph6->ip6_dst.u6_addr.u6_addr32[3];
iph.protocol = iph6->ip6_ctlun.ip6_un1.ip6_un1_nxt;
if(iph.protocol == 0x3C /* IPv6 destination option */) {
u_int8_t *options = (u_int8_t*)iph6 + sizeof(const struct ndpi_ipv6hdr);
iph.protocol = options[0];
}
return(get_ndpi_flow_info(workflow, 6, vlan_id, &iph, iph6, ip_offset,
sizeof(struct ndpi_ipv6hdr),
ntohs(iph6->ip6_ctlun.ip6_un1.ip6_un1_plen),
tcph, udph, sport, dport,
src, dst, proto, payload, payload_len, src_to_dst_direction));
}
/* ****************************************************** */
// ipsize = header->len - ip_offset ; rawsize = header->len
static unsigned int packet_processing(struct ndpi_workflow * workflow,
const u_int64_t time,
u_int16_t vlan_id,
const struct ndpi_iphdr *iph,
struct ndpi_ipv6hdr *iph6,
u_int16_t ip_offset,
u_int16_t ipsize, u_int16_t rawsize) {
struct ndpi_id_struct *src, *dst;
struct ndpi_flow_info *flow;
struct ndpi_flow_struct *ndpi_flow = NULL;
u_int8_t proto;
struct ndpi_tcphdr *tcph = NULL;
struct ndpi_udphdr *udph = NULL;
u_int16_t sport, dport, payload_len;
u_int8_t *payload;
u_int8_t src_to_dst_direction= 1;
if(iph)
flow = get_ndpi_flow_info(workflow, 4, vlan_id, iph, NULL,
ip_offset, ipsize,
ntohs(iph->tot_len) - (iph->ihl * 4),
&tcph, &udph, &sport, &dport,
&src, &dst, &proto,
&payload, &payload_len, &src_to_dst_direction);
else
flow = get_ndpi_flow_info6(workflow, vlan_id, iph6, ip_offset,
&tcph, &udph, &sport, &dport,
&src, &dst, &proto,
&payload, &payload_len, &src_to_dst_direction);
if(flow != NULL) {
workflow->stats.ip_packet_count++;
workflow->stats.total_wire_bytes += rawsize + 24 /* CRC etc */, workflow->stats.total_ip_bytes += rawsize;
ndpi_flow = flow->ndpi_flow;
flow->packets++, flow->bytes += rawsize;
flow->last_seen = time;
} else {
return(0);
}
/* Protocol already detected */
if(flow->detection_completed) return(0);
flow->detected_protocol = ndpi_detection_process_packet(workflow->ndpi_struct, ndpi_flow,
iph ? (uint8_t *)iph : (uint8_t *)iph6,
ipsize, time, src, dst);
if((flow->detected_protocol.protocol != NDPI_PROTOCOL_UNKNOWN)
|| ((proto == IPPROTO_UDP) && (flow->packets > 8))
|| ((proto == IPPROTO_TCP) && (flow->packets > 10))) {
/* New protocol detected or give up */
flow->detection_completed = 1;
if((flow->detected_protocol.protocol == NDPI_PROTOCOL_UNKNOWN) && (ndpi_flow->num_stun_udp_pkts > 0))
ndpi_set_detected_protocol(workflow->ndpi_struct, ndpi_flow, NDPI_PROTOCOL_STUN, NDPI_PROTOCOL_UNKNOWN);
snprintf(flow->host_server_name, sizeof(flow->host_server_name), "%s", flow->ndpi_flow->host_server_name);
if(flow->detected_protocol.protocol == NDPI_PROTOCOL_BITTORRENT) {
int i, j, n = 0;
for(i=0, j = 0; i<20; i++) {
sprintf(&flow->bittorent_hash[j], "%02x", flow->ndpi_flow->bittorent_hash[i]);
j += 2, n += flow->ndpi_flow->bittorent_hash[i];
}
if(n == 0) flow->bittorent_hash[0] = '\0';
}
if((proto == IPPROTO_TCP) && (flow->detected_protocol.protocol != NDPI_PROTOCOL_DNS)) {
snprintf(flow->ssl.client_certificate, sizeof(flow->ssl.client_certificate), "%s", flow->ndpi_flow->protos.ssl.client_certificate);
snprintf(flow->ssl.server_certificate, sizeof(flow->ssl.server_certificate), "%s", flow->ndpi_flow->protos.ssl.server_certificate);
}
if(flow->detected_protocol.protocol == NDPI_PROTOCOL_UNKNOWN) {
flow->detected_protocol = ndpi_detection_giveup(workflow->ndpi_struct, flow->ndpi_flow);
if (workflow->__flow_giveup_callback != NULL)
workflow->__flow_giveup_callback(workflow, flow, workflow->__flow_giveup_udata);
} else {
if (workflow->__flow_detected_callback != NULL)
workflow->__flow_detected_callback(workflow, flow, workflow->__flow_detected_udata);
}
ndpi_free_flow_info_half(flow);
}
return 0;
}
/* ****************************************************** */
void ndpi_workflow_process_packet (struct ndpi_workflow * workflow,
const struct pcap_pkthdr *header,
const u_char *packet) {
/*
* Declare pointers to packet headers
*/
/* --- Ethernet header --- */
const struct ndpi_ethhdr *ethernet;
/* --- Ethernet II header --- */
const struct ndpi_ethhdr *ethernet_2;
/* --- LLC header --- */
const struct ndpi_llc_header *llc;
/* --- Cisco HDLC header --- */
const struct ndpi_chdlc *chdlc;
/* --- SLARP frame --- */
struct ndpi_slarp *slarp;
/* --- CDP --- */
struct ndpi_cdp *cdp;
/* --- Radio Tap header --- */
const struct ndpi_radiotap_header *radiotap;
/* --- Wifi header --- */
const struct ndpi_wifi_header *wifi;
/* --- MPLS header --- */
struct ndpi_mpls_header *mpls;
/** --- IP header --- **/
struct ndpi_iphdr *iph;
/** --- IPv6 header --- **/
struct ndpi_ipv6hdr *iph6;
/* lengths and offsets */
u_int16_t eth_offset = 0;
u_int16_t radio_len;
u_int16_t fc;
u_int16_t type;
int wifi_len = 0;
int llc_off;
int pyld_eth_len = 0;
int check;
u_int64_t time;
u_int16_t ip_offset, ip_len, ip6_offset;
u_int16_t frag_off = 0, vlan_id = 0;
u_int8_t proto = 0;
u_int32_t label;
/* counters */
u_int8_t vlan_packet = 0;
/* Increment raw packet counter */
workflow->stats.raw_packet_count++;
/* setting time */
time = ((uint64_t) header->ts.tv_sec) * TICK_RESOLUTION + header->ts.tv_usec / (1000000 / TICK_RESOLUTION);
/* safety check */
if(workflow->last_time > time) {
/* printf("\nWARNING: timestamp bug in the pcap file (ts delta: %llu, repairing)\n", ndpi_thread_info[thread_id].last_time - time); */
time = workflow->last_time;
}
/* update last time value */
workflow->last_time = time;
/*** check Data Link type ***/
const int datalink_type = pcap_datalink(workflow->pcap_handle);
datalink_check:
switch(datalink_type) {
case DLT_NULL :
if(ntohl(*((u_int32_t*)&packet[eth_offset])) == 2)
type = ETH_P_IP;
else
type = ETH_P_IPV6;
ip_offset = 4 + eth_offset;
break;
/* Cisco PPP in HDLC-like framing - 50 */
case DLT_PPP_SERIAL:
chdlc = (struct ndpi_chdlc *) &packet[eth_offset];
ip_offset = sizeof(struct ndpi_chdlc); /* CHDLC_OFF = 4 */
type = ntohs(chdlc->proto_code);
break;
/* Cisco PPP with HDLC framing - 104 */
case DLT_C_HDLC:
chdlc = (struct ndpi_chdlc *) &packet[eth_offset];
ip_offset = sizeof(struct ndpi_chdlc); /* CHDLC_OFF = 4 */
type = ntohs(chdlc->proto_code);
break;
/* IEEE 802.3 Ethernet - 1 */
case DLT_EN10MB :
ethernet = (struct ndpi_ethhdr *) &packet[eth_offset];
ip_offset = sizeof(struct ndpi_ethhdr) + eth_offset;
check = ntohs(ethernet->h_proto);
if(check <= 1500)
pyld_eth_len = check;
else if (check >= 1536)
type = check;
if(pyld_eth_len != 0) {
/* check for LLC layer with SNAP extension */
if(packet[ip_offset] == SNAP) {
llc = (struct ndpi_llc_header *)(&packet[ip_offset]);
type = llc->snap.proto_ID;
ip_offset += + 8;
}
}
break;
/* Linux Cooked Capture - 113 */
case DLT_LINUX_SLL :
type = (packet[eth_offset+14] << 8) + packet[eth_offset+15];
ip_offset = 16 + eth_offset;
break;
/* Radiotap link-layer - 127 */
case DLT_IEEE802_11_RADIO :
radiotap = (struct ndpi_radiotap_header *) &packet[eth_offset];
radio_len = radiotap->len;
/* Check Bad FCS presence */
if((radiotap->flags & BAD_FCS) == BAD_FCS) {
workflow->stats.total_discarded_bytes += header->len;
return;
}
/* Calculate 802.11 header length (variable) */
wifi = (struct ndpi_wifi_header*)( packet + eth_offset + radio_len);
fc = wifi->fc;
/* check wifi data presence */
if(FCF_TYPE(fc) == WIFI_DATA) {
if((FCF_TO_DS(fc) && FCF_FROM_DS(fc) == 0x0) ||
(FCF_TO_DS(fc) == 0x0 && FCF_FROM_DS(fc)))
wifi_len = 26; /* + 4 byte fcs */
} else /* no data frames */
break;
/* Check ether_type from LLC */
llc = (struct ndpi_llc_header*)(packet + eth_offset + wifi_len + radio_len);
if(llc->dsap == SNAP)
type = ntohs(llc->snap.proto_ID);
/* Set IP header offset */
ip_offset = wifi_len + radio_len + sizeof(struct ndpi_llc_header) + eth_offset;
break;
case DLT_RAW:
ip_offset = eth_offset = 0;
break;
default:
/* printf("Unknown datalink %d\n", datalink_type); */
return;
}
/* check ether type */
switch(type) {
case VLAN:
vlan_id = ((packet[ip_offset] << 8) + packet[ip_offset+1]) & 0xFFF;
type = (packet[ip_offset+2] << 8) + packet[ip_offset+3];
ip_offset += 4;
vlan_packet = 1;
break;
case MPLS_UNI:
case MPLS_MULTI:
mpls = (struct ndpi_mpls_header *) &packet[ip_offset];
label = ntohl(mpls->label);
/* label = ntohl(*((u_int32_t*)&packet[ip_offset])); */
workflow->stats.mpls_count++;
type = ETH_P_IP, ip_offset += 4;
while((label & 0x100) != 0x100) {
ip_offset += 4;
label = ntohl(mpls->label);
}
break;
case PPPoE:
workflow->stats.pppoe_count++;
type = ETH_P_IP;
ip_offset += 8;
break;
default:
break;
}
workflow->stats.vlan_count += vlan_packet;
iph_check:
/* Check and set IP header size and total packet length */
iph = (struct ndpi_iphdr *) &packet[ip_offset];
/* just work on Ethernet packets that contain IP */
if(type == ETH_P_IP && header->caplen >= ip_offset) {
frag_off = ntohs(iph->frag_off);
proto = iph->protocol;
if(header->caplen < header->len) {
static u_int8_t cap_warning_used = 0;
if(cap_warning_used == 0) {
if(!workflow->prefs.quiet_mode)
NDPI_LOG(0, workflow.ndpi_struct, NDPI_LOG_DEBUG, "\n\nWARNING: packet capture size is smaller than packet size, DETECTION MIGHT NOT WORK CORRECTLY\n\n");
cap_warning_used = 1;
}
}
}
if(iph->version == 4) {
ip_len = ((u_short)iph->ihl * 4);
iph6 = NULL;
if(iph->protocol == 41) {
ip_offset += ip_len;
goto iph_check;
}
if((frag_off & 0x1FFF) != 0) {
static u_int8_t ipv4_frags_warning_used = 0;
workflow->stats.fragmented_count++;
if(ipv4_frags_warning_used == 0) {
if(!workflow->prefs.quiet_mode)
NDPI_LOG(0, workflow.ndpi_struct, NDPI_LOG_DEBUG, "\n\nWARNING: IPv4 fragments are not handled by this demo (nDPI supports them)\n");
ipv4_frags_warning_used = 1;
}
workflow->stats.total_discarded_bytes += header->len;
return;
}
} else if(iph->version == 6) {
iph6 = (struct ndpi_ipv6hdr *)&packet[ip_offset];
proto = iph6->ip6_ctlun.ip6_un1.ip6_un1_nxt;
ip_len = sizeof(struct ndpi_ipv6hdr);
if(proto == 0x3C /* IPv6 destination option */) {
u_int8_t *options = (u_int8_t*)&packet[ip_offset+ip_len];
proto = options[0];
ip_len += 8 * (options[1] + 1);
}
iph = NULL;
} else {
static u_int8_t ipv4_warning_used = 0;
v4_warning:
if(ipv4_warning_used == 0) {
if(!workflow->prefs.quiet_mode)
NDPI_LOG(0, workflow.ndpi_struct, NDPI_LOG_DEBUG, "\n\nWARNING: only IPv4/IPv6 packets are supported in this demo (nDPI supports both IPv4 and IPv6), all other packets will be discarded\n\n");
ipv4_warning_used = 1;
}
workflow->stats.total_discarded_bytes += header->len;
return;
}
if(workflow->prefs.decode_tunnels && (proto == IPPROTO_UDP)) {
struct ndpi_udphdr *udp = (struct ndpi_udphdr *)&packet[ip_offset+ip_len];
u_int16_t sport = ntohs(udp->source), dport = ntohs(udp->dest);
if((sport == GTP_U_V1_PORT) || (dport == GTP_U_V1_PORT)) {
/* Check if it's GTPv1 */
u_int offset = ip_offset+ip_len+sizeof(struct ndpi_udphdr);
u_int8_t flags = packet[offset];
u_int8_t message_type = packet[offset+1];
if((((flags & 0xE0) >> 5) == 1 /* GTPv1 */) &&
(message_type == 0xFF /* T-PDU */)) {
ip_offset = ip_offset+ip_len+sizeof(struct ndpi_udphdr)+8; /* GTPv1 header len */
if(flags & 0x04) ip_offset += 1; /* next_ext_header is present */
if(flags & 0x02) ip_offset += 4; /* sequence_number is present (it also includes next_ext_header and pdu_number) */
if(flags & 0x01) ip_offset += 1; /* pdu_number is present */
iph = (struct ndpi_iphdr *) &packet[ip_offset];
if(iph->version != 4) {
// printf("WARNING: not good (packet_id=%u)!\n", (unsigned int)workflow->stats.raw_packet_count);
goto v4_warning;
}
}
} else if((sport == TZSP_PORT) || (dport == TZSP_PORT)) {
/* https://en.wikipedia.org/wiki/TZSP */
u_int offset = ip_offset+ip_len+sizeof(struct ndpi_udphdr);
u_int8_t version = packet[offset];
u_int8_t type = packet[offset+1];
u_int16_t encapsulates = ntohs(*((u_int16_t*)&packet[offset+2]));
if((version == 1) && (type == 0) && (encapsulates == 1)) {
u_int8_t stop = 0;
offset += 4;
while((!stop) && (offset < header->caplen)) {
u_int8_t tag_type = packet[offset];
u_int8_t tag_len;
switch(tag_type) {
case 0: /* PADDING Tag */
tag_len = 1;
break;
case 1: /* END Tag */
tag_len = 1, stop = 1;
break;
default:
tag_len = packet[offset+1];
break;
}
offset += tag_len;
if(offset >= header->caplen)
return; /* Invalid packet */
else {
eth_offset = offset;
goto datalink_check;
}
}
}
}
}
/* process the packet */
packet_processing(workflow, time, vlan_id, iph, iph6,
ip_offset, header->len - ip_offset, header->len);
}