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mongodb/tools/sniffer.cpp

410 lines
12 KiB
C++

// sniffer.cpp
/*
TODO:
large messages - need to track what's left and ingore
single object over packet size - can only display begging of object
getmore
delete
killcursors
*/
#include "../util/builder.h"
#include "../util/message.h"
#include "../db/dbmessage.h"
#include "../client/dbclient.h"
#include <pcap.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <iostream>
#include <map>
#include <string>
#include <boost/shared_ptr.hpp>
using namespace std;
using mongo::asserted;
using mongo::Message;
using mongo::MsgData;
using mongo::DbMessage;
using mongo::BSONObj;
using mongo::BufBuilder;
using mongo::DBClientConnection;
#define SNAP_LEN 65535
int captureHeaderSize;
set<int> serverPorts;
string forwardAddress;
/* IP header */
struct sniff_ip {
u_char ip_vhl; /* version << 4 | header length >> 2 */
u_char ip_tos; /* type of service */
u_short ip_len; /* total length */
u_short ip_id; /* identification */
u_short ip_off; /* fragment offset field */
#define IP_RF 0x8000 /* reserved fragment flag */
#define IP_DF 0x4000 /* dont fragment flag */
#define IP_MF 0x2000 /* more fragments flag */
#define IP_OFFMASK 0x1fff /* mask for fragmenting bits */
u_char ip_ttl; /* time to live */
u_char ip_p; /* protocol */
u_short ip_sum; /* checksum */
struct in_addr ip_src,ip_dst; /* source and dest address */
};
#define IP_HL(ip) (((ip)->ip_vhl) & 0x0f)
#define IP_V(ip) (((ip)->ip_vhl) >> 4)
/* TCP header */
typedef u_int32_t tcp_seq;
struct sniff_tcp {
u_short th_sport; /* source port */
u_short th_dport; /* destination port */
tcp_seq th_seq; /* sequence number */
tcp_seq th_ack; /* acknowledgement number */
u_char th_offx2; /* data offset, rsvd */
#define TH_OFF(th) (((th)->th_offx2 & 0xf0) >> 4)
u_char th_flags;
#define TH_FIN 0x01
#define TH_SYN 0x02
#define TH_RST 0x04
#define TH_PUSH 0x08
#define TH_ACK 0x10
#define TH_URG 0x20
#define TH_ECE 0x40
#define TH_CWR 0x80
#define TH_FLAGS (TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG|TH_ECE|TH_CWR)
u_short th_win; /* window */
u_short th_sum; /* checksum */
u_short th_urp; /* urgent pointer */
};
struct Connection {
struct in_addr srcAddr;
u_short srcPort;
struct in_addr dstAddr;
u_short dstPort;
bool operator<( const Connection &other ) const {
int ret;
ret = diff( srcAddr.s_addr, other.srcAddr.s_addr );
if ( ret != 0 )
return ret < 0;
ret = diff( srcPort, other.srcPort );
if ( ret != 0 )
return ret < 0;
ret = diff( dstAddr.s_addr, other.dstAddr.s_addr );
if ( ret != 0 )
return ret < 0;
ret = diff( dstPort, other.dstPort );
return ret < 0;
}
template< class T >
static int diff( T a, T b ) {
if ( a > b ) return 1;
else if ( a < b ) return -1;
return 0;
}
};
map< Connection, bool > seen;
map< Connection, int > bytesRemainingInMessage;
map< Connection, boost::shared_ptr< BufBuilder > > messageBuilder;
map< Connection, unsigned > expectedSeq;
map< Connection, DBClientConnection* > forwarder;
void got_packet(u_char *args, const struct pcap_pkthdr *header, const u_char *packet){
const struct sniff_ip* ip = (struct sniff_ip*)(packet + captureHeaderSize);
int size_ip = IP_HL(ip)*4;
if ( size_ip < 20 ){
cerr << "*** Invalid IP header length: " << size_ip << " bytes" << endl;
return;
}
assert( ip->ip_p == IPPROTO_TCP );
const struct sniff_tcp* tcp = (struct sniff_tcp*)(packet + captureHeaderSize + size_ip);
int size_tcp = TH_OFF(tcp)*4;
if (size_tcp < 20){
cerr << "*** Invalid TCP header length: " << size_tcp << " bytes" << endl;
return;
}
if ( ! ( serverPorts.count( ntohs( tcp->th_sport ) ) ||
serverPorts.count( ntohs( tcp->th_dport ) ) ) ){
return;
}
const u_char * payload = (const u_char*)(packet + captureHeaderSize + size_ip + size_tcp);
unsigned totalSize = ntohs(ip->ip_len);
assert( totalSize <= header->caplen );
int size_payload = totalSize - (size_ip + size_tcp);
if (size_payload <= 0 )
return;
Connection c;
c.srcAddr = ip->ip_src;
c.srcPort = tcp->th_sport;
c.dstAddr = ip->ip_dst;
c.dstPort = tcp->th_dport;
if ( seen[ c ] ) {
if ( expectedSeq[ c ] != ntohl( tcp->th_seq ) ) {
cerr << "Warning: sequence # mismatch, there may be dropped packets" << endl;
}
expectedSeq[ c ] = ntohl( tcp->th_seq ) + size_payload;
} else {
seen[ c ] = true;
expectedSeq[ c ] = ntohl( tcp->th_seq ) + size_payload;
}
expectedSeq[ c ] = ntohl( tcp->th_seq ) + size_payload;
Message m;
if ( bytesRemainingInMessage[ c ] == 0 ) {
m.setData( (MsgData*)payload , false );
if ( !m.data->valid() ) {
cerr << "Invalid message start, skipping packet." << endl;
return;
}
if ( size_payload > m.data->len ) {
cerr << "Multiple messages in packet, skipping packet." << endl;
return;
}
if ( size_payload < m.data->len ) {
bytesRemainingInMessage[ c ] = m.data->len - size_payload;
messageBuilder[ c ].reset( new BufBuilder() );
messageBuilder[ c ]->append( (void*)payload, size_payload );
return;
}
} else {
bytesRemainingInMessage[ c ] -= size_payload;
messageBuilder[ c ]->append( (void*)payload, size_payload );
if ( bytesRemainingInMessage[ c ] < 0 ) {
cerr << "Received too many bytes to complete message, resetting buffer" << endl;
bytesRemainingInMessage[ c ] = 0;
messageBuilder[ c ].reset();
return;
}
if ( bytesRemainingInMessage[ c ] > 0 )
return;
m.setData( (MsgData*)messageBuilder[ c ]->buf(), true );
messageBuilder[ c ]->decouple();
messageBuilder[ c ].reset();
}
DbMessage d( m );
cout << inet_ntoa(ip->ip_src) << ":" << ntohs( tcp->th_sport )
<< ( serverPorts.count( ntohs( tcp->th_dport ) ) ? " -->> " : " <<-- " )
<< inet_ntoa(ip->ip_dst) << ":" << ntohs( tcp->th_dport )
<< " " << d.getns()
<< " " << m.data->len << " bytes "
<< m.data->id;
if ( m.data->operation() == mongo::opReply )
cout << " - " << m.data->responseTo;
cout << endl;
switch( m.data->operation() ){
case mongo::opReply:{
mongo::QueryResult* r = (mongo::QueryResult*)m.data;
cout << "\treply" << " n:" << r->nReturned << endl;
if ( r->nReturned ){
mongo::BSONObj o( r->data() , 0 );
cout << "\t" << o << endl;
}
break;
}
case mongo::dbQuery:{
mongo::QueryMessage q(d);
cout << "\tquery: " << q.query << endl;
break;
}
case mongo::dbUpdate:{
int flags = d.pullInt();
BSONObj q = d.nextJsObj();
BSONObj o = d.nextJsObj();
cout << "\tupdate flags:" << flags << " q:" << q << " o:" << o << endl;
break;
}
case mongo::dbInsert:{
cout << "\tinsert: " << d.nextJsObj() << endl;
while ( d.moreJSObjs() )
cout << "\t\t" << d.nextJsObj() << endl;
break;
}
case mongo::dbGetMore:{
int nToReturn = d.pullInt();
int cursorId = d.pullInt64();
cout << "\tgetMore nToReturn: " << nToReturn << " cursorId: " << cursorId << endl;
break;
}
case mongo::dbDelete:{
int flags = d.pullInt();
BSONObj q = d.nextJsObj();
cout << "\tdelete flags: " << flags << " q: " << q << endl;
break;
}
case mongo::dbKillCursors:{
int *x = (int *) m.data->_data;
x++; // reserved
int n = *x;
cout << "\tkillCursors n: " << n << endl;
break;
}
default:
cerr << "*** CANNOT HANDLE TYPE: " << m.data->operation() << endl;
}
if ( m.data->operation() != mongo::opReply && !forwardAddress.empty() ) {
DBClientConnection *conn = forwarder[ c ];
if ( !conn ) {
// These won't get freed on error, oh well...
conn = new DBClientConnection( true );
conn->connect( forwardAddress );
forwarder[ c ] = conn;
}
if ( m.data->operation() == mongo::dbQuery || m.data->operation() == mongo::dbGetMore ) {
Message response;
conn->port().call( m, response );
} else {
conn->port().say( m );
}
}
}
void usage() {
cout <<
"Usage: mongosniff [--help] [--forward host:port] [--source (NET <interface> | FILE <filename>)] [<port0> <port1> ... ]\n"
"--forward Forward all parsed request messages to mongod instance at \n"
" specified host:port\n"
"--source Source of traffic to sniff, either a network interface or a\n"
" file containing perviously captured packets, in pcap format.\n"
" If no source is specified, mongosniff will attempt to sniff\n"
" from one of the machine's network interfaces.\n"
"<port0>... These parameters are used to filter sniffing. By default, \n"
" only port 27017 is sniffed.\n"
"--help Print this help message.\n"
<< endl;
}
int main(int argc, char **argv){
const char *dev = NULL;
char errbuf[PCAP_ERRBUF_SIZE];
pcap_t *handle;
struct bpf_program fp;
bpf_u_int32 mask;
bpf_u_int32 net;
bool source = false;
bool replay = false;
const char *file;
vector< const char * > args;
for( int i = 1; i < argc; ++i )
args.push_back( argv[ i ] );
try {
for( unsigned i = 0; i < args.size(); ++i ) {
const char *arg = args[ i ];
if ( arg == string( "--help" ) ) {
usage();
return 0;
} else if ( arg == string( "--forward" ) ) {
forwardAddress = args[ ++i ];
} else if ( arg == string( "--source" ) ) {
assert( source == false );
source = true;
replay = ( args[ ++i ] == string( "FILE" ) );
if ( replay )
file = args[ ++i ];
else
dev = args[ ++i ];
} else {
serverPorts.insert( atoi( args[ i ] ) );
}
}
} catch ( ... ) {
usage();
return -1;
}
if ( !serverPorts.size() )
serverPorts.insert( 27017 );
if ( !replay ) {
if ( !dev ) {
dev = pcap_lookupdev(errbuf);
if ( ! dev ) {
cerr << "error finding device" << endl;
return -1;
}
cout << "found device: " << dev << endl;
}
if (pcap_lookupnet(dev, &net, &mask, errbuf) == -1){
cerr << "can't get netmask!" << endl;
return -1;
}
handle = pcap_open_live(dev, SNAP_LEN, 1, 1000, errbuf);
if ( ! handle ){
cerr << "error opening device!" << endl;
return -1;
}
} else {
handle = pcap_open_offline(file, errbuf);
if ( ! handle ){
cerr << "error opening capture file!" << endl;
return -1;
}
}
switch ( pcap_datalink( handle ) ){
case DLT_EN10MB:
captureHeaderSize = 14;
break;
case DLT_NULL:
captureHeaderSize = 4;
break;
default:
cerr << "don't know how to handle datalink type: " << pcap_datalink( handle ) << endl;
}
assert( pcap_compile(handle, &fp, const_cast< char * >( "tcp" ) , 0, net) != -1 );
assert( pcap_setfilter(handle, &fp) != -1 );
cout << "sniffing... ";
for ( set<int>::iterator i = serverPorts.begin(); i != serverPorts.end(); i++ )
cout << *i << " ";
cout << endl;
pcap_loop(handle, 0 , got_packet, NULL);
pcap_freecode(&fp);
pcap_close(handle);
for( map< Connection, DBClientConnection* >::iterator i = forwarder.begin(); i != forwarder.end(); ++i )
free( i->second );
return 0;
}