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socket_pcap.c
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socket_pcap.c
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/*
* $Id$
*
* captagent - Homer capture agent. Modular
* Duplicate SIP messages in Homer Encapulate Protocol [HEP] [ipv6 version]
*
* Author: Alexandr Dubovikov <alexandr.dubovikov@gmail.com>
* (C) QXIP BV 2012-2023 (http://qxip.net)
*
* Homer capture agent is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version
*
* Homer capture agent 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <sys/types.h>
#include <stdint.h>
#include <inttypes.h>
#include <ctype.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <fcntl.h>
#include <getopt.h>
#include <unistd.h>
#include <signal.h>
#include <time.h>
#include <pthread.h>
#include <assert.h>
#include <limits.h>
#ifndef __FAVOR_BSD
#define __FAVOR_BSD
#endif
#include <netinet/if_ether.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <netinet/udp.h>
#include <pcap.h>
#include <pcap/sll.h>
#include <captagent/capture.h>
#include <captagent/globals.h>
#include <captagent/api.h>
#include <captagent/proto_sip.h>
#include <captagent/structure.h>
#include <captagent/modules_api.h>
#include <captagent/modules.h>
#include "socket_pcap.h"
#include <captagent/log.h>
#include <captagent/action.h>
#include "ipreasm.h"
#include "tcpreasm.h"
#include "localapi.h"
#include "sctp_support.h"
#if USE_IPv6
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#endif
#include "uthash.h"
/* ### Declaration of HASH TABLE FOR HANDSHAKE FLOWS ### */
extern struct Hash_Table *HT_Flows;
xml_node *module_xml_config = NULL;
uint16_t link_offset = 14;
uint16_t type_datalink = 0;
char *module_name = "socket_pcap";
uint64_t module_serial = 0;
char *module_description;
int debug_socket_pcap_enable = 0;
int websocket_detection = 0;
static socket_pcap_stats_t stats;
static socket_pcap_user_data_t user_data[MAX_SOCKETS];
pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
pthread_t call_thread[MAX_SOCKETS];
pcap_t *sniffer_proto[MAX_SOCKETS];
pthread_t stat_thread;
bool stats_enable = FALSE;
struct pcap_stat last_stat[MAX_SOCKETS];
struct reasm_ip *reasm[MAX_SOCKETS];
struct tcpreasm_ip *tcpreasm[MAX_SOCKETS];
static int load_module(xml_node *config);
static int unload_module(void);
static int description(char *descr);
static int statistic(char *buf, size_t len);
static uint64_t serial_module(void);
static int free_profile(unsigned int idx);
bool websocket_header_detection(uint8_t *p_websock, uint32_t posLen, unsigned char *data, uint32_t hdrLen);
bool websocket_pre_decode(uint8_t *p_websock, unsigned char *decoded, msg_t *_msg);
unsigned int profile_size = 0;
int verbose = 0;
int stats_interval = 300;
int drop_limit = 25;
int ipindex = -1;
char ipcheck_in[10][80] = {{0},{0}};
char ipcheck_out[10][80]= {{0},{0}};
int port_in[10] = {0};
int port_out[10] = {0};
bind_protocol_module_api_t proto_bind_api;
static cmd_export_t cmds[] = {
{ "socket_pcap_bind_api", (cmd_function) bind_api, 1, 0, 0, 0 },
{ "socket_pcap_check", (cmd_function) bind_check_size, 3, 0, 0, 0 },
{ "bind_socket_pcap", (cmd_function) bind_socket_pcap, 0, 0, 0, 0 },
{ "tzsp_payload_extract", (cmd_function) w_tzsp_payload_extract, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0 }
};
struct module_exports exports = {
"socket_pcap",
cmds, /* Exported functions */
load_module, /* module initialization function */
unload_module,
description,
statistic,
serial_module
};
int bind_api(socket_module_api_t* api)
{
api->reload_f = reload_config;
api->apply_filter_f = apply_filter;
api->module_name = module_name;
return 0;
}
int bind_check_size(msg_t *_m, char *param1, char *param2)
{
return 0;
}
int apply_filter(filter_msg_t *filter)
{
return 1;
}
int reload_config(char *erbuf, int erlen) {
char module_config_name[500];
xml_node *config = NULL;
LNOTICE("reloading config for [%s]", module_name);
snprintf(module_config_name, 500, "%s/%s.xml", global_config_path, module_name);
if(xml_parse_with_report(module_config_name, erbuf, erlen)) {
unload_module();
load_module(config);
return 1;
}
return 0;
}
/**
Function to check the ports in the pkts to the port(or portrange) defined in filter
NOTE: this is to trigger correctly the function strip_fcs_end()
@par filter = the BPF filter
@par port_arg1 = the source port from pkt
@par port_arg2 = the destination port from pkt
@return 0 if port matched; -1 if port NOT matched
**/
static int check_port_filter(char *filter, int port_arg1, int port_arg2) {
char port_str[10], port_str_1[10], port_str_2[10];
int len1, ret, port = 0, portrange = 0;
char *space, *dash, *p, *end;
len1 = strlen(filter);
end = filter+len1-1;
p = strstr(filter, "portrange");
if(p) {
portrange = 1;
} else {
p = strstr(filter, "port");
if(p) {
port = 1;
} else {
LERR("error - bad BPF here\n");
return -1;
}
}
space = strchr(filter, ' ');
filter = space + 1;
memcpy(port_str, filter, end - filter + 1);
if(port == 1) { /* Extract port */
int port_int = atoi(port_str);
if(port_int == port_arg1 || port_int == port_arg2) {
LDEBUG("Port match!\n");
ret = 0;
} else {
LDEBUG("Port does not match: [%d] vs [%d][%d]\n", port_int, port_arg1, port_arg2);
ret = -1;
}
} else if(portrange == 1) { /* Extract portrange */
dash = strchr(filter, '-');
memcpy(port_str_1, filter, dash - filter + 1);
int port_int_1 = atoi(port_str_1);
filter = dash + 1;
memcpy(port_str_2, filter, end - filter + 1);
int port_int_2 = atoi(port_str_2);
if((port_arg1 >= port_int_1 && port_arg1 <= port_int_2) ||
(port_arg2 >= port_int_1 && port_arg2 <= port_int_2)) {
LDEBUG("Port match!\n");
ret = 0;
} else {
LDEBUG("Port does not match: [%d][%d] v [%d][%d]\n", port_int_1, port_int_2, port_arg1, port_arg2);
ret = -1;
}
}
return ret;
}
/**
Function to strip out fcs byte in the end of pkts (if exist)
@par data = the payload to parse
@par len = the len of the payload
@return the new len of payload stripped
**/
static int strip_fcs_end(unsigned char *data, int len) {
if(data == NULL || len == 0)
return 0;
do {
if((data[len-1] == 0x0a && data[len-2] == 0x0d) ||
data[len-1] == 0x0d) {
return len;
} else {
len--;
}
} while(data[len-1] != 0x0a);
return len;
}
static void websocket_decode(char *dst, const char *src, size_t len, const char mask[4])
{
int i;
for(i = 0; i < len; i++) {
dst[i] = src[i] ^ mask[i % 4];
}
}
/* Callback function that is passed to pcap_loop() */
void callback_proto(unsigned char *arg, struct pcap_pkthdr *pkthdr, unsigned char *packet) {
/* Check ingress pkt */
if(pkthdr == NULL || packet == NULL ) {
LERR("[SOCKET PCAP] PKT is wrong... discard it!");
return;
}
/* if len or caplen has wrong values */
if((int) pkthdr->len <= 0 || (int) pkthdr->len >= INT_MAX) {
LERR("[SOCKET_PCAP] lenght %d is not correct - discard it\n", (int) pkthdr->len);
return;
}
if((int) pkthdr->caplen <= 0 || (int) pkthdr->caplen >= INT_MAX) {
LERR("[SOCKET_PCAP] capture lenght %d is not correct - discard it\n", (int) pkthdr->caplen);
return;
}
/* Show a warning in case caplen != len */
if(pkthdr->caplen != pkthdr->len) {
LDEBUG("CAPLEN != LEN --> [caplen = %d - len = %d]", (int) pkthdr->caplen, (int) pkthdr->len);
}
msg_t _msg;
struct ether_header* eth = NULL;
struct sll_header* sll = NULL;
struct sll2_header* sll2 = NULL;
struct ip* ip4_pkt = NULL;
#if USE_IPv6
struct ip6_hdr* ip6_pkt = NULL;
#endif
struct run_act_ctx ctx;
char ip_src[INET6_ADDRSTRLEN + 1], ip_dst[INET6_ADDRSTRLEN + 1];
char mac_src[20] = {0}, mac_dst[20] = {0};
uint32_t ip_ver;
int ipip_offset = 0, action_idx = 0;
uint16_t type_ip = 0;
uint8_t hdr_preset = 0, hdr_offset = 0, vlan = 0;
uint8_t ip_proto = 0, erspan_offset = 0;
uint8_t tmp_ip_proto = 0, tmp_ip_len = 0, is_only_gre = 0;
unsigned char* ethaddr = NULL;
unsigned char* mplsaddr = NULL;
uint8_t loc_index = (uint8_t) *arg;
// Check if GRE/ERSPAN filter is setup
if(profile_socket[loc_index].erspan == 1)
{
unsigned char *tmp_pkt = packet;
//unsigned int extra_sll = 0;
/* if (profile_socket[loc_index].link_type == DLT_LINUX_SLL) { */
/* extra_sll = 2; */
/* } */
memcpy(&tmp_ip_proto, (packet + link_offset + IPPROTO_OFFSET /* + extra_sll */), 1);
/* if(tmp_ip_proto != GRE_PROTO && profile_socket[loc_index].link_type == DLT_LINUX_SLL) */
/* { */
/* extra_sll = 6; */
/* memcpy(&tmp_ip_proto, (packet + ETHHDR_SIZE + IPPROTO_OFFSET + extra_sll), 1); */
/* } */
/**
For ERSPAN packets, the "protocol type" field value in the GRE header
is 0x88BE (ERSPAN type II) or 0x22EB (ERSPAN type III).
**/
if(tmp_ip_proto == GRE_PROTO)
{
memcpy(&tmp_ip_len, (packet + link_offset /* + extra_sll */), 1);
tmp_ip_len = (tmp_ip_len & IPLEN_MASK) * 4; // LSB 4 bits: lenght in 32-bit words
tmp_pkt = tmp_pkt + link_offset /* + extra_sll */ + tmp_ip_len ; // GRE Protocol_type field for ERSPAN version
// ERSPAN Type II
if(tmp_pkt[2] == 0x88 && tmp_pkt[3] == 0xbe) {
// 1. Normal GRE header (4 bytes)
if(tmp_pkt[0] == 0x00 && tmp_pkt[1] == 0x00) {
erspan_offset = link_offset /* + extra_sll */ + tmp_ip_len + GREHDR_SIZE; // Ethernet + IP + GRE
// Check if it's ERSPAN Type II (8 bytes of ERSPAN II)
if(tmp_pkt[4]>>4 == 1) {
erspan_offset += ERSPAN_II_OFF; // Ethernet + IP + GRE II (GRE+SeqNum) + ERSPAN II
}
}
// 2. Extended GRE header (4 bytes GRE + 4 Sequence Number)
else if(tmp_pkt[0] == 0x10 && tmp_pkt[1] == 0x00) {
erspan_offset = link_offset /* + extra_sll */ + tmp_ip_len + GREHDR_SIZE_II; // Ethernet + IP + GRE II
// Check if it's ERSPAN Type II (8 bytes of ERSPAN II)
if(tmp_pkt[8]>>4 == 1) {
erspan_offset += ERSPAN_II_OFF; // Ethernet + IP + GRE II (GRE+SeqNum) + ERSPAN II
}
}
}
// ERSPAN Type III
else if(tmp_pkt[2] == 0x22 && tmp_pkt[3] == 0xeb) {
// 1. Normal GRE header (4 bytes)
if(tmp_pkt[0] == 0x00 && tmp_pkt[1] == 0x00) {
erspan_offset = link_offset /* + extra_sll */ + tmp_ip_len + GREHDR_SIZE; // Ethernet + IP + GRE
// Check if it's ERSPAN Type III (12 bytes of ERSPAN II)
if(tmp_pkt[4]>>4 == 2) {
erspan_offset += ERSPAN_III_OFF; // Ethernet + IP + GRE II (GRE+SeqNum) + ERSPAN II
}
}
// 2. Extended GRE header (4 bytes GRE + 4 Sequence Number)
else if(tmp_pkt[0] == 0x10 && tmp_pkt[1] == 0x00) {
erspan_offset = link_offset /* + extra_sll */ + tmp_ip_len + GREHDR_SIZE_II; // Ethernet + IP + GRE II
// Check if it's ERSPAN Type III (12 bytes of ERSPAN II)
if(tmp_pkt[8]>>4 == 2) {
erspan_offset += ERSPAN_III_OFF; // Ethernet + IP + GRE II (GRE+SeqNum) + ERSPAN III
}
}
}
// Only GRE offset
else {
// 1. Normal GRE header (4 bytes)
if(tmp_pkt[0] == 0x00 && tmp_pkt[1] == 0x00) {
erspan_offset = link_offset /* + extra_sll */ + tmp_ip_len + GREHDR_SIZE; // Ethernet + IP + GRE
}
// 2. Extended GRE header (4 bytes GRE + 4 Sequence Number)
else if(tmp_pkt[0] == 0x10 && tmp_pkt[1] == 0x00) {
erspan_offset = link_offset /* + extra_sll */ + tmp_ip_len + GREHDR_SIZE_II; // Ethernet + IP + GRE II
}
// NOTE: if it's only GRE, could be that the following layer is IP instead of Ethernet, so we have to check the protocol type
if(tmp_pkt[2] == 0x08 && tmp_pkt[3] == 0x00) { // Protocol Type 0x0800 == IPv4
pkthdr->len -= erspan_offset;
pkthdr->caplen -= erspan_offset;
packet += erspan_offset;
is_only_gre = 1;
goto ip_hdr_parse;
}
}
pkthdr->len -= erspan_offset;
pkthdr->caplen -= erspan_offset;
packet += erspan_offset;
/* NOTE: We should recall the pcap_datalink function on the datalink inner header layer
* For simplicity we set to Ethernet, as this cover the majority of the cases
*/
type_datalink = DLT_EN10MB; // Re-set the inner datalink type to Ethernet (the outer type could be SLL or SLL2)
link_offset = 14; // Re-set the link_offset to Ethernet header size
}
}
if(type_datalink == DLT_MTP2) {
snprintf(mac_src, sizeof(mac_src), "00-01-02-03-04-05");
snprintf(mac_dst, sizeof(mac_dst), "05-04-03-02-01-00");
snprintf(ip_src, sizeof(ip_src), "127.0.0.1");
snprintf(ip_dst, sizeof(ip_dst), "127.0.0.2");
memset(&_msg, 0, sizeof(msg_t));
memset(&ctx, 0, sizeof(struct run_act_ctx));
_msg.cap_packet = (void *) packet;
_msg.cap_header = (void *) pkthdr;
_msg.hdr_len = link_offset;
_msg.rcinfo.src_ip = ip_src;
_msg.rcinfo.dst_ip = ip_dst;
_msg.rcinfo.src_mac = mac_src;
_msg.rcinfo.dst_mac = mac_dst;
_msg.rcinfo.ip_family = DLT_MTP2;
_msg.rcinfo.ip_proto = DLT_MTP2;
_msg.rcinfo.time_sec = pkthdr->ts.tv_sec;
_msg.rcinfo.time_usec = pkthdr->ts.tv_usec;
_msg.tcpflag = 0;
_msg.parse_it = 1;
_msg.len = pkthdr->len;
_msg.data = packet;
action_idx = profile_socket[loc_index].action;
run_actions(&ctx, main_ct.clist[action_idx], &_msg);
return;
}
/** DATALINK LAYER **/
memcpy(ðaddr, (packet + 12), 2);
memcpy(&mplsaddr, (packet + 16), 2);
if (ntohs((uint16_t)*(ðaddr)) == ETHERTYPE_VLAN) {
if (ntohs((uint16_t)*(&mplsaddr)) == MPLS_UNI) {
hdr_offset = 8;
vlan = 1;
} else {
hdr_offset = 4;
vlan = 2;
}
}
/* Check if ETHER TYPE is Ethernet or Linux Cooked */
if (type_datalink == DLT_LINUX_SLL) {
sll = (struct sll_header *)(packet + hdr_preset);
} else if (type_datalink == DLT_LINUX_SLL2) {
sll2 = (struct sll2_header *)(packet + hdr_preset);
} else {
eth = (struct ether_header *)(packet + hdr_preset);
}
if (eth) {
snprintf(mac_src, sizeof(mac_src), "%.2X-%.2X-%.2X-%.2X-%.2X-%.2X",
eth->ether_shost[0], eth->ether_shost[1], eth->ether_shost[2], eth->ether_shost[3], eth->ether_shost[4], eth->ether_shost[5]);
snprintf(mac_dst, sizeof(mac_dst), "%.2X-%.2X-%.2X-%.2X-%.2X-%.2X",
eth->ether_dhost[0], eth->ether_dhost[1], eth->ether_dhost[2], eth->ether_dhost[3], eth->ether_dhost[4], eth->ether_dhost[5]);
if(vlan == 0 || vlan == 2) {
// IP TYPE = 0x86dd (IPv6) or 0x0800 (IPv4) or (0x8100 VLAN)
type_ip = ntohs(eth->ether_type);
}
}
/* Linux cooked capture (v1 and v2) shows only Source MAC address */
else if (sll) {
snprintf(mac_src, sizeof(mac_src), "%.2X-%.2X-%.2X-%.2X-%.2X-%.2X", sll->sll_addr[0], sll->sll_addr[1], sll->sll_addr[2], sll->sll_addr[3], sll->sll_addr[4], sll->sll_addr[5]);
if(vlan == 0) {
// IP TYPE = 0x86dd (IPv6) or 0x0800 (IPv4)
type_ip = ntohs(sll->sll_protocol);
}
} else if (sll2) {
snprintf(mac_src, sizeof(mac_src), "%.2X-%.2X-%.2X-%.2X-%.2X-%.2X", sll2->sll2_addr[0], sll2->sll2_addr[1], sll2->sll2_addr[2], sll2->sll2_addr[3], sll2->sll2_addr[4], sll2->sll2_addr[5]);
if(vlan == 0) {
// IP TYPE = 0x86dd (IPv6) or 0x0800 (IPv4)
type_ip = ntohs(sll2->sll2_protocol);
}
}
/** IP LAYER **/
ip_hdr_parse:
if(is_only_gre == 1) {
ip4_pkt = (struct ip *)(packet + link_offset + hdr_offset + ipip_offset);
}
else if(type_ip == ETHERTYPE_IP || type_ip == ETHERTYPE_VLAN) {
ip4_pkt = (struct ip *)(packet + link_offset + hdr_offset + ipip_offset);
} else {
#if USE_IPv6
ip6_pkt = (struct ip6_hdr*)(packet + link_offset + hdr_offset + ipip_offset);
#endif
}
uint32_t len = pkthdr->caplen;
uint32_t ip_hl = 0;
uint32_t ip_off = 0;
uint16_t frag_offset = 0;
uint8_t fragmented = 0, psh = 0;
unsigned char *data, *datatcp;
u_char *pack = NULL;
/* stats */
stats.received_packets_total++;
if(profile_socket[loc_index].reasm && reasm[loc_index] != NULL) {
unsigned new_len;
u_char *new_p = malloc(len - link_offset - hdr_offset);
memcpy(new_p, ip4_pkt, len - link_offset - hdr_offset);
pack = reasm_ip_next(reasm[loc_index], new_p, len - link_offset - hdr_offset,
(reasm_time_t) 1000000UL * pkthdr->ts.tv_sec + pkthdr->ts.tv_usec, &new_len);
if (pack == NULL)
return;
len = new_len + link_offset + hdr_offset;
pkthdr->len = new_len;
pkthdr->caplen = new_len;
ip4_pkt = (struct ip *) pack;
#if USE_IPv6
ip6_pkt = (struct ip6_hdr*)pack;
#endif
}
ip_ver = ip4_pkt->ip_v;
memset(&_msg, 0, sizeof(msg_t));
memset(&ctx, 0, sizeof(struct run_act_ctx));
_msg.cap_packet = (void *) packet;
_msg.cap_header = (void *) pkthdr;
switch(ip_ver) {
case 4: {
#if defined(AIX)
#undef ip_hl
ip_hl = ip4_pkt->ip_ff.ip_fhl * 4;
#else
ip_hl = ip4_pkt->ip_hl * 4;
#endif
ip_proto = ip4_pkt->ip_p;
ip_off = ntohs(ip4_pkt->ip_off);
fragmented = ip_off & (IP_MF | IP_OFFMASK);
frag_offset = (fragmented) ? (ip_off & IP_OFFMASK) * 8 : 0;
//frag_id = ntohs(ip4_pkt->ip_id);
inet_ntop(AF_INET, (const void *) &ip4_pkt->ip_src, ip_src, sizeof(ip_src));
inet_ntop(AF_INET, (const void *) &ip4_pkt->ip_dst, ip_dst, sizeof(ip_dst));
}
break;
#if USE_IPv6
case 6: {
ip_hl = sizeof(struct ip6_hdr);
ip_proto = ip6_pkt->ip6_nxt;
if (ip_proto == IPPROTO_FRAGMENT) {
struct ip6_frag *ip6_fraghdr;
ip6_fraghdr = (struct ip6_frag *)((unsigned char *)(ip6_pkt) + ip_hl);
ip_hl += sizeof(struct ip6_frag);
ip_proto = ip6_fraghdr->ip6f_nxt;
fragmented = 1;
frag_offset = ntohs(ip6_fraghdr->ip6f_offlg & IP6F_OFF_MASK);
//frag_id = ntohl(ip6_fraghdr->ip6f_ident);
}
inet_ntop(AF_INET6, (const void *)&ip6_pkt->ip6_src, ip_src, sizeof(ip_src));
inet_ntop(AF_INET6, (const void *)&ip6_pkt->ip6_dst, ip_dst, sizeof(ip_dst));
}
break;
#endif
}
// check IP-to-IP tunnel
if(ip_proto == 0x04) {
LDEBUG("IP-to-IP tunnel detected -> parsing inner IP");
ipip_offset = IPV4_SIZE;
goto ip_hdr_parse;
}
switch (ip_proto) {
case IPPROTO_TCP: {
struct tcphdr *tcp_pkt = (struct tcphdr *) ((unsigned char *) (ip4_pkt) + ip_hl);
//uint16_t tcphdr_offset = (frag_offset) ? 0 : (tcp_pkt->th_off * 4);
uint16_t tcphdr_offset = frag_offset ? 0 : (uint16_t) (tcp_pkt->th_off * 4);
data = (unsigned char *) tcp_pkt + tcphdr_offset;
_msg.hdr_len = link_offset + hdr_offset + ip_hl + tcphdr_offset + ipip_offset;
len -= link_offset + hdr_offset + ip_hl + tcphdr_offset + ipip_offset;
stats.received_tcp_packets++;
#if USE_IPv6
/* if (ip_ver == 6)
{
len -= (ntohs(ip6_pkt->ip6_plen)) + ipip_offset;
_msg.hdr_len += (ntohs(ip6_pkt->ip6_plen)) + ipip_offset;
}
*/
#endif
if ((int32_t) len < 0)
len = 0;
/******************* Check for Websocket layer (skip it) **************************/
int webLen = link_offset + hdr_offset + ip_hl + tcphdr_offset;
uint8_t *p_websock = packet + webLen;
if(tcpreasm[loc_index] != NULL && (len > 0) && (tcp_pkt->th_flags & TH_ACK)) {
unsigned new_len;
u_char *new_p_2 = malloc(len + 10);
memcpy(new_p_2, data, len);
if ((tcp_pkt->th_flags & TH_PUSH))
psh = 1;
if (debug_socket_pcap_enable)
LDEBUG("DEFRAG TCP process: LEN:[%d], ACK:[%d], PSH[%d]\n", len, (tcp_pkt->th_flags & TH_ACK), psh);
datatcp = tcpreasm_ip_next_tcp(tcpreasm[loc_index], new_p_2, len,
(tcpreasm_time_t) 1000000UL * pkthdr->ts.tv_sec + pkthdr->ts.tv_usec, &new_len,
&ip4_pkt->ip_src, &ip4_pkt->ip_dst, ntohs(tcp_pkt->th_sport),
ntohs(tcp_pkt->th_dport), psh);
if (datatcp == NULL) {
return;
}
len = new_len;
if (debug_socket_pcap_enable) {
LDEBUG("COMPLETE TCP DEFRAG: LEN[%d], PACKET:[%s]\n", len, datatcp);
}
/* check websocket */
if(websocket_detection == 1)
{
p_websock = datatcp;
unsigned char decoded[3000];
memset(decoded, 0, 3000);
if(!websocket_header_detection(p_websock, webLen, datatcp, pkthdr->len))
{
/* clear datatcp */
if(datatcp)
free(datatcp);
goto error;
}
/* next position for websock */
p_websock++;
}
// Full packet
if (!profile_socket[profile_size].full_packet) {
_msg.len = len;
if( websocket_detection == 1) {
unsigned char decoded[3000];
memset(decoded, 0, 3000);
if(!websocket_pre_decode(p_websock, decoded, &_msg)) {
_msg.data = sll ? packet + _msg.hdr_len : datatcp;
}
} else {
_msg.data = sll ? packet + _msg.hdr_len : datatcp;
}
}
// Not full packet
else {
_msg.len = len;
if(websocket_detection == 1) {
unsigned char decoded[3000];
memset(decoded, 0, 3000);
if(!websocket_pre_decode(p_websock, decoded, &_msg)) {
_msg.data = sll ? packet + _msg.hdr_len : datatcp;
}
} else {
_msg.data = sll ? packet + _msg.hdr_len : datatcp;
}
}
_msg.rcinfo.src_mac = mac_src;
_msg.rcinfo.dst_mac = mac_dst;
_msg.rcinfo.src_ip = ip_src;
_msg.rcinfo.dst_ip = ip_dst;
_msg.rcinfo.src_port = ntohs(tcp_pkt->th_sport);
_msg.rcinfo.dst_port = ntohs(tcp_pkt->th_dport);
_msg.rcinfo.ip_family = ip_ver == 4 ? AF_INET : AF_INET6;
_msg.rcinfo.ip_proto = ip_proto;
_msg.rcinfo.time_sec = pkthdr->ts.tv_sec;
_msg.rcinfo.time_usec = pkthdr->ts.tv_usec;
_msg.tcpflag = tcp_pkt->th_flags;
_msg.parse_it = 1;
if(ipindex) {
/* src */
check_ip_data(_msg.rcinfo.src_ip, &_msg.rcinfo.src_port);
/* dst */
check_ip_data(_msg.rcinfo.dst_ip, &_msg.rcinfo.dst_port);
}
action_idx = profile_socket[loc_index].action;
run_actions(&ctx, main_ct.clist[action_idx], &_msg);
/* clear datatcp */
free(datatcp);
} else {
/* detect websocket */
if(websocket_detection == 1) {
if(!websocket_header_detection(p_websock, webLen, data, pkthdr->len)) {
/* clear datatcp */
goto error;
}
/* next position for websock */
p_websock++;
}
// full packet
if (!profile_socket[profile_size].full_packet) {
_msg.len = len;
if(websocket_detection == 1) {
unsigned char decoded[3000];
memset(decoded, 0, 3000);
if(!websocket_pre_decode(p_websock, decoded, &_msg)) {
_msg.data = data;
}
} else {
_msg.data = data;
}
}
// Not full packet
else {
_msg.len = pkthdr->caplen - link_offset - hdr_offset;
if(websocket_detection == 1) {
unsigned char decoded[3000];
memset(decoded, 0, 3000);
if(!websocket_pre_decode(p_websock, decoded, &_msg)) {
_msg.data = (packet + link_offset + hdr_offset);
}
} else {
_msg.data = data;
}
}
_msg.rcinfo.src_mac = mac_src;
_msg.rcinfo.dst_mac = mac_dst;
_msg.rcinfo.src_ip = ip_src;
_msg.rcinfo.dst_ip = ip_dst;
_msg.rcinfo.src_port = ntohs(tcp_pkt->th_sport);
_msg.rcinfo.dst_port = ntohs(tcp_pkt->th_dport);
_msg.rcinfo.ip_family = ip_ver == 4 ? AF_INET : AF_INET6;
_msg.rcinfo.ip_proto = ip_proto;
_msg.rcinfo.time_sec = pkthdr->ts.tv_sec;
_msg.rcinfo.time_usec = pkthdr->ts.tv_usec;
_msg.tcpflag = tcp_pkt->th_flags;
_msg.parse_it = 1;
if(ipindex) {
/* src */
check_ip_data(_msg.rcinfo.src_ip, &_msg.rcinfo.src_port);
/* dst */
check_ip_data(_msg.rcinfo.dst_ip, &_msg.rcinfo.dst_port);
}
action_idx = profile_socket[loc_index].action;
run_actions(&ctx, main_ct.clist[action_idx], &_msg);
stats.send_packets++;
}
}
break;
case IPPROTO_UDP: {
struct udphdr *udp_pkt = (struct udphdr *) ((unsigned char *) (ip4_pkt) + ip_hl);
uint16_t udphdr_offset = (frag_offset) ? 0 : sizeof(*udp_pkt);
data = (unsigned char *) (udp_pkt) + udphdr_offset;
_msg.hdr_len = link_offset + ip_hl + hdr_offset + udphdr_offset + ipip_offset;
len -= link_offset + ip_hl + udphdr_offset + hdr_offset + ipip_offset;
#if USE_IPv6
/*if (ip_ver == 6) {
len -= ntohs(ip6_pkt->ip6_plen);
_msg.hdr_len += ntohs(ip6_pkt->ip6_plen);
}
*/
#endif
/* stats */
stats.received_udp_packets++;
if ((int32_t) len < 0)
len = 0;
_msg.rcinfo.src_port = ntohs(udp_pkt->uh_sport);
_msg.rcinfo.dst_port = ntohs(udp_pkt->uh_dport);
_msg.rcinfo.src_ip = ip_src;
_msg.rcinfo.dst_ip = ip_dst;
_msg.rcinfo.src_mac = mac_src;
_msg.rcinfo.dst_mac = mac_dst;
_msg.rcinfo.ip_family = ip_ver == 4 ? AF_INET : AF_INET6;
_msg.rcinfo.ip_proto = ip_proto;
_msg.rcinfo.time_sec = pkthdr->ts.tv_sec;
_msg.rcinfo.time_usec = pkthdr->ts.tv_usec;
_msg.tcpflag = 0;
_msg.parse_it = 1;
if(!profile_socket[profile_size].full_packet) {
_msg.data = data;
_msg.len = len;
} else {
_msg.len = pkthdr->caplen - link_offset - hdr_offset;
_msg.data = (packet + link_offset + hdr_offset);
}
/* replace IP */
if(ipindex) {
/* src */
check_ip_data(_msg.rcinfo.src_ip, &_msg.rcinfo.src_port);
/* dst */
check_ip_data(_msg.rcinfo.dst_ip, &_msg.rcinfo.dst_port);
}
action_idx = profile_socket[loc_index].action;
run_actions(&ctx, main_ct.clist[action_idx], &_msg);
stats.send_packets++;
}
break;
case IPPROTO_SCTP: {
struct sctp_common_hdr *sctp_hdr;
uint8_t *chunk_data;
int plen;
uint32_t chunk_read = 0;
/* attempt at input validation */
if (len <= link_offset + ip_hl + hdr_offset) {
LDEBUG("sctp: offset handling %zu vs. %zu",
len, link_offset + ip_hl + hdr_offset);
goto error;
}
len -= link_offset + ip_hl + hdr_offset;
sctp_hdr = (struct sctp_common_hdr *) ((uint8_t *)(ip4_pkt) + ip_hl);
plen = sctp_parse_common(&_msg, (uint8_t *)sctp_hdr, len);
if (plen < 0)
goto error;
len -= plen;
/* stats */
stats.received_sctp_packets++;
/* I don't understand the frag_offset in other protos */
/* same for the entire package */
_msg.hdr_len = link_offset + hdr_offset + ip_hl + sizeof(struct sctp_common_hdr);
_msg.rcinfo.src_ip = ip_src;
_msg.rcinfo.dst_ip = ip_dst;
_msg.rcinfo.src_mac = mac_src;
_msg.rcinfo.dst_mac = mac_dst;
_msg.rcinfo.ip_family = ip_ver == 4 ? AF_INET : AF_INET6;
_msg.rcinfo.ip_proto = ip_proto;
_msg.rcinfo.time_sec = pkthdr->ts.tv_sec;
_msg.rcinfo.time_usec = pkthdr->ts.tv_usec;
_msg.tcpflag = 0;
_msg.parse_it = 1;
/* replace IP */
if(ipindex) {
/* src */
check_ip_data(_msg.rcinfo.src_ip, &_msg.rcinfo.src_port);
/* dst */
check_ip_data(_msg.rcinfo.dst_ip, &_msg.rcinfo.dst_port);
}
/* default the full packet */
_msg.len = pkthdr->caplen - link_offset - hdr_offset;
_msg.data = (packet + link_offset + hdr_offset);
chunk_data = &sctp_hdr->data[0];
while (chunk_read < len) {
bool send_data;
uint8_t padding;
plen = sctp_parse_chunk(&_msg, chunk_data, len - chunk_read, &send_data);
if (plen < 0)
goto error;
/* a chunk but no data chunk */
if (!send_data)
goto next;
if (!profile_socket[profile_size].full_packet) {
_msg.len = plen - 16;
_msg.data = chunk_data + 16;
}
action_idx = profile_socket[loc_index].action;
run_actions(&ctx, main_ct.clist[action_idx], &_msg);
next:
padding = (4 - (plen % 4)) & 0x3;
chunk_read += plen + padding;
chunk_data += plen + padding;
}
stats.send_packets++;
}
break;
default:
break;
}
error:
if(pack != NULL)
free(pack);
}
bool websocket_header_detection(uint8_t *p_websock, uint32_t posLen, unsigned char *data, uint32_t hdrLen) {
/**
NOTE: in our case, the first byte is valid ONLY if the value is 129 (0x81) or 130 (0x82)
this means the 1st bit FIN == 1 and 4 less-significant bits could be 0x01 (utf-8 text data) or 0x02 (binary data)
Mask 7 to get the 1st most-significant bit (fin check)
Mask 0xF to get the 4 less-significant bit (opcode check)
**/
if ((((*p_websock >> 7) & 1) == 1) && (((*p_websock & 0xF) == 0x01) || ((*p_websock & 0xF) == 0x02))) {
/* TCP without payload */
if (hdrLen == posLen) {
LERR("This is a TCP packet without payload - SKIP IT\n");
return FALSE;
}
/* HTTP pkt */
if ((strncmp((char*)data, "GET", 3) == 0) || (strncmp((char*)data, "HTTP", 4) == 0)) {
LERR("This is a HTTP packet - SKIP IT\n");
return FALSE;
}
LDEBUG("websocket detected\r\n");
return TRUE;