Significant edit pass over ICMPv6 code.

Matti, more per mail.
This commit is contained in:
Robin Sommer 2011-01-25 17:54:20 -08:00
parent cb64bb6874
commit 50181edd84
10 changed files with 424 additions and 719 deletions

View file

@ -28,6 +28,8 @@ type icmp_conn: record {
itype: count;
icode: count;
len: count;
v6: bool; # true if it's an ICMPv6 packet.
};
type icmp_hdr: record {
@ -38,12 +40,11 @@ type icmp_context: record {
id: conn_id;
len: count;
proto: count;
frag_offset: count &optional; #no frag offset for IPv6
bad_hdr_len: bool &optional;
bad_checksum: bool &optional; #no checksum in IPv6 header
MF: bool &optional; #no MF for IPv6
DF: bool &optional; #no DF for IPv6
ICMP6Flag: bool;
bad_hdr_len: bool;
bad_checksum: bool; # always true for ICMPv6.
frag_offset: count; # always 0 for IMCPv6.
MF: bool; # always false for IMCPv6.
DF: bool; # always true for ICMPv6.
};
type addr_set: set[addr];

View file

@ -1,5 +1,4 @@
# $Id: icmp.bro 6883 2009-08-19 21:08:09Z vern $
# While using this script, please notice that the last F/T value is the IPv6 Flag
@load hot
@load weird
@ -18,6 +17,7 @@ export {
ICMPAsymPayload, # payload in echo req-resp not the same
ICMPConnectionPair, # too many ICMPs between hosts
ICMPAddressScan,
ICMPRogueRouter, # v6 advertisement from unknown router
# The following isn't presently sufficiently useful due
# to cold start and packet drops.
@ -35,6 +35,12 @@ export {
const detect_conn_pairs = F &redef; # switch for connection pair
const detect_payload_asym = F &redef; # switch for echo payload
const conn_pair_threshold = 200 &redef;
# If the IPv6 routers in a network are all known, they can be
# whitelisted here. If so, any other router seen sending an
# announcement will be reported. If this set remains empty, no such
# detection will be done.
const router_whitelist: set[addr] &redef;
}
global conn_pair:table[addr] of set[addr] &create_expire = 1 day;
@ -56,12 +62,6 @@ type flow_info: record {
payload: string;
};
#Insert whitelisted routers here, Router advertisements from other
#routers will be logged as possible rogue router attacks
const routers_whitelist: table[string] of bool = {
#["fe80::260:97ff:fe07:69ea"] = T, #an example
} &redef &default = F;
const names: table[count] of string = {
[0] = "echo_reply",
[1] = "unreach", # icmpv6
@ -116,8 +116,8 @@ const IP_proto_name: table[count] of string = {
[2] = "IGMP",
[6] = "TCP",
[17] = "UDP",
[41] = "IP6",
[58] = "ICMP6",
[41] = "IPV6",
[58] = "ICMPV6",
} &default = function(n: count): string { return fmt("%s", n); }
&redef;
@ -160,13 +160,38 @@ global flows: table[flow_id] of flow_info
&read_expire = 45 sec
&expire_func = flush_flow;
event icmp_sent(c: connection, icmp: icmp_conn, ICMP6: bool)
function print_log(c: connection, icmp: icmp_conn, addl: string)
{
if ( ! log_details )
return;
print icmp_file, fmt("%.6f %.6f %s %s %s %s %s %s %s %s %s %s",
print icmp_file, fmt("%.6f %.6f %s %s %s %s %s %s %s %s",
network_time(), 0.0, icmp$orig_h, icmp$resp_h,
names[icmp$itype], icmp$itype, icmp$icode, "icmp",
icmp$len, "0", "SH", ICMP6);
names[icmp$itype], icmp$itype, icmp$icode,
icmp$v6 ? "icmp6" : "icmp", icmp$len, addl);
}
function print_log_with_context(c: connection, icmp: icmp_conn, context: icmp_context, addl: string)
{
# Due to the connection data contained *within*
# them, each log line will contain two connections' worth
# of data. The initial ICMP connection info is the same
# as logged for connections.
local ctx = fmt("0 EncapPkt: %s %s %s %s %s %s %s %s %s",
context$id$orig_h, context$id$orig_p,
context$id$resp_h, context$id$resp_p,
context$len, IP_proto_name[context$proto],
context$len, context$bad_hdr_len,
context$bad_checksum);
print_log(c, icmp, ctx);
}
event icmp_sent(c: connection, icmp: icmp_conn)
{
print_log(c, icmp, "0 SH");
}
event flow_summary(flow: flow_id, last_time: time)
@ -212,63 +237,18 @@ function update_flow(icmp: icmp_conn, id: count, is_orig: bool, payload: string)
}
event icmp_error_message(c: connection, icmp: icmp_conn, code: count, context: icmp_context) #for other but the unreach types, which is preserved
event icmp_error_message(c: connection, icmp: icmp_conn, code: count, context: icmp_context)
{
if ( active_connection(context$id) )
{
# This section allows Bro to act on ICMP error message packets
# that happen in the context of an active connection. It is
# not currently used.
local c2 = connection_record(context$id);
local os = c2$orig$state;
local rs = c2$resp$state;
local is_attempt =
is_tcp_port(c2$id$orig_p) ?
(os == TCP_SYN_SENT && rs == TCP_INACTIVE) :
(os == UDP_ACTIVE && rs == UDP_INACTIVE);
# Insert action here.
print_log_with_context(c, icmp, context, "");
}
if ( log_details )
{
# ICMP error message packets are logged here.
# Due to the connection data contained *within*
# them, each log line will contain two connections' worth
# of data. The initial ICMP connection info is the same
# as logged for connections.
print icmp_file, fmt("%.6f %.6f %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s",
network_time(), 0.0, icmp$orig_h, icmp$resp_h,
names[icmp$itype], icmp$itype, icmp$icode, "icmp",
icmp$len, "0", "EncapPkt:",
# This is the encapsulated packet:
context$id$orig_h, context$id$orig_p,
context$id$resp_h, context$id$resp_p,
context$len, IP_proto_name[context$proto],
context$len, context$bad_hdr_len,
context$bad_checksum, context$ICMP6Flag);
}
}
event icmp6_placeholder(c: connection, icmp: icmp_conn, ICMP6: bool) #just for testing
{
print "icmp6_placeholder triggered";
}
event icmp_echo_request(c: connection, icmp: icmp_conn, id: count, seq: count, payload: string, ICMP6: bool)
event icmp_echo_request(c: connection, icmp: icmp_conn, id: count, seq: count, payload: string)
{
update_flow(icmp, id, T, payload);
local orig = icmp$orig_h;
local resp = icmp$resp_h;
# Simple ping scan detector.
if ( detect_scans &&
(orig !in Scan::distinct_peers ||
@ -320,7 +300,7 @@ event icmp_echo_request(c: connection, icmp: icmp_conn, id: count, seq: count, p
}
event icmp_echo_reply(c: connection, icmp: icmp_conn, id: count,
seq: count, payload: string, ICMP6: bool)
seq: count, payload: string)
{
# Check payload with the associated flow.
@ -329,8 +309,6 @@ event icmp_echo_reply(c: connection, icmp: icmp_conn, id: count,
fid$resp_h = icmp$orig_h; # it's an echo reply.
fid$id = id;
if ( fid !in flows )
{
# NOTICE([$note=ICMPUnpairedEchoReply,
@ -357,78 +335,19 @@ event icmp_echo_reply(c: connection, icmp: icmp_conn, id: count,
update_flow(icmp, id, F, payload);
}
event icmp_unreachable(c: connection, icmp: icmp_conn, code: count,
context: icmp_context)
{
print_log_with_context(c, icmp, context, "");
}
if ( active_connection(context$id) )
event icmp_router_advertisement(c: connection, icmp: icmp_conn)
{
# This section allows Bro to act on ICMP-unreachable packets
# that happen in the context of an active connection. It is
# not currently used.
local c2 = connection_record(context$id);
local os = c2$orig$state;
local rs = c2$resp$state;
local is_attempt =
is_tcp_port(c2$id$orig_p) ?
(os == TCP_SYN_SENT && rs == TCP_INACTIVE) :
(os == UDP_ACTIVE && rs == UDP_INACTIVE);
print_log(c, icmp, "");
# Insert action here.
if ( |router_whitelist| == 0 || icmp$orig_h in router_whitelist )
return;
NOTICE([$note=ICMPRogueRouter,
$msg=fmt("rouge router advertisement from %s", icmp$orig_h)]);
}
if ( log_details )
{
# ICMP unreachable packets are the only ones currently
# logged. Due to the connection data contained *within*
# them, each log line will contain two connections' worth
# of data. The initial ICMP connection info is the same
# as logged for connections.
print icmp_file, fmt("%.6f %.6f %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s",
network_time(), 0.0, icmp$orig_h, icmp$resp_h,
names[icmp$itype], icmp$itype, icmp$icode, "icmp",
icmp$len, "0", "EncapPkt:",
# This is the encapsulated packet:
context$id$orig_h, context$id$orig_p,
context$id$resp_h, context$id$resp_p,
context$len, IP_proto_name[context$proto],
context$len, context$bad_hdr_len,
context$bad_checksum, context$ICMP6Flag);
}
}
event icmp_router_advertisement(c: connection, icmp: icmp_conn, ICMP6: bool)
{
if ( routers_whitelist[ fmt("%s",icmp$orig_h) ] )
{
print icmp_file, fmt("%.6f %.6f %s %s %s %s %s %s %s %s %s %s",
network_time(), 0.0, icmp$orig_h, icmp$resp_h,
names[icmp$itype], icmp$itype, icmp$icode, "icmp",
icmp$len, "0", "SH", ICMP6);
}
else
{
print icmp_file, fmt("%.6f %.6f %s %s %s %s %s %s %s %s",
network_time(), 0.0, icmp$orig_h, icmp$resp_h,
names[icmp$itype], "Possible Rogue Router Detected", icmp$itype, icmp$icode,
icmp$len, ICMP6);
}
}

View file

@ -48,20 +48,6 @@ const Analyzer::Config Analyzer::analyzer_configs[] = {
{ AnalyzerTag::ICMP, "ICMP", ICMP_Analyzer::InstantiateAnalyzer,
ICMP_Analyzer::Available, 0, false },
/*{ AnalyzerTag::ICMP_TimeExceeded, "ICMP_TIMEEXCEEDED",
ICMP_TimeExceeded_Analyzer::InstantiateAnalyzer,
ICMP_TimeExceeded_Analyzer::Available, 0, false },
{ AnalyzerTag::ICMP_Unreachable, "ICMP_UNREACHABLE",
ICMP_Unreachable_Analyzer::InstantiateAnalyzer,
ICMP_Unreachable_Analyzer::Available, 0, false },
{ AnalyzerTag::ICMP_Echo, "ICMP_ECHO",
ICMP_Echo_Analyzer::InstantiateAnalyzer,
ICMP_Echo_Analyzer::Available, 0, false },*/
{ AnalyzerTag::TCP, "TCP", TCP_Analyzer::InstantiateAnalyzer,
TCP_Analyzer::Available, 0, false },
{ AnalyzerTag::UDP, "UDP", UDP_Analyzer::InstantiateAnalyzer,

View file

@ -22,7 +22,7 @@ namespace AnalyzerTag {
PIA_TCP, PIA_UDP,
// Transport-layer analyzers.
ICMP,/* ICMP_TimeExceeded, ICMP_Unreachable, ICMP_Echo*/ TCP, UDP,
ICMP, TCP, UDP,
// Application-layer analyzers (hand-written).
BitTorrent, BitTorrentTracker,

View file

@ -214,42 +214,8 @@ bool DPM::BuildInitialAnalyzerTree(TransportProto proto, Connection* conn,
break;
case TRANSPORT_ICMP: {
const struct icmp* icmpp = (const struct icmp *) data;
//Old code, moving to having only one ICMP analyzer
/*switch ( icmpp->icmp_type ) {
case ICMP_ECHO:
case ICMP_ECHOREPLY:
if ( ICMP_Echo_Analyzer::Available() )
{
root = new ICMP_Echo_Analyzer(conn);
DBG_DPD(conn, "activated ICMP Echo analyzer");
}
break;
case ICMP_UNREACH:
if ( ICMP_Unreachable_Analyzer::Available() )
{
root = new ICMP_Unreachable_Analyzer(conn);
DBG_DPD(conn, "activated ICMP Unreachable analyzer");
}
break;
case ICMP_TIMXCEED:
if ( ICMP_TimeExceeded_Analyzer::Available() )
{
root = new ICMP_TimeExceeded_Analyzer(conn);
DBG_DPD(conn, "activated ICMP Time Exceeded analyzer");
}
break;
}*/
//if ( ! root )
root = new ICMP_Analyzer(conn);
DBG_DPD(conn, "activated ICMP analyzer");
analyzed = true;
break;
}

View file

@ -11,15 +11,12 @@
#include <netinet/icmp6.h>
ICMP_Analyzer::ICMP_Analyzer(Connection* c)
: TransportLayerAnalyzer(AnalyzerTag::ICMP, c)
{
icmp_conn_val = 0;
c->SetInactivityTimeout(icmp_inactivity_timeout);
request_len = reply_len = -1;
}
ICMP_Analyzer::ICMP_Analyzer(AnalyzerTag::Tag tag, Connection* c)
@ -37,7 +34,7 @@ void ICMP_Analyzer::Done()
matcher_state.FinishEndpointMatcher();
}
void ICMP_Analyzer::DeliverPacket(int arg_len, const u_char* data,
void ICMP_Analyzer::DeliverPacket(int len, const u_char* data,
bool is_orig, int seq, const IP_Hdr* ip, int caplen)
{
assert(ip);
@ -50,43 +47,40 @@ void ICMP_Analyzer::DeliverPacket(int arg_len, const u_char* data,
// Subtract off the common part of ICMP header.
PacketContents(data + 8, min(len, caplen) - 8);
const struct icmp* icmpp = (const struct icmp*) data;
len = arg_len;
assert(caplen >= len); // Should have been caught earlier already.
if ( ! ignore_checksums )
{
int chksum;
//We need a separate calculation for ICMP6 checksums, pseudoheader is appended to the
//ICMP6 checksum calculation, which is different from ICMP4
#ifdef BROv6
switch ( ip->NextProto() )
{
case IPPROTO_ICMP:
chksum = icmp_checksum(icmpp, len);
break;
case IPPROTO_ICMPV6:
chksum = icmp6_checksum(icmpp, ip->IP6_Hdr(), len);
break;
if (ip->NextProto() == IPPROTO_ICMPV6 && ! ignore_checksums &&
caplen >= len && icmp6_checksum(icmpp,ip->IP6_Hdr(),len )!= 0xffff )
default:
internal_error("unexpected IP proto in ICMP analyzer");
}
#else
# Classic v4 version.
chksum = icmp_checksum(icmpp, len);
#endif
if ( chksum != 0xffff )
{
Weird("bad_ICMP6_checksum");
return;
}
else if (ip->NextProto() != IPPROTO_ICMPV6 && ! ignore_checksums &&
caplen >= len && icmp_checksum(icmpp, len) != 0xffff )
{
Weird("bad_ICMP_checksum");
return;
}
#else
if ( ! ignore_checksums && caplen >= len &&
icmp_checksum(icmpp, len) != 0xffff )
{
Weird("bad_ICMP_checksum");
return;
}
#endif
Conn()->SetLastTime(current_timestamp);
if ( rule_matcher )
@ -95,89 +89,26 @@ void ICMP_Analyzer::DeliverPacket(int arg_len, const u_char* data,
matcher_state.InitEndpointMatcher(this, ip, len, is_orig, 0);
}
type = icmpp->icmp_type;
code = icmpp->icmp_code;
// Move past common portion of ICMP header. //OK for ICMPv6?
// Move past common portion of ICMP header.
data += 8;
caplen -= 8;
len -= 8;
int& len_stat = is_orig ? request_len : reply_len;
if ( len_stat < 0 )
len_stat = len;
if ( ip->NextProto() == IPPROTO_ICMP )
NextICMP4(current_timestamp, icmpp, len, caplen, data, ip);
else
len_stat += len;
NextICMP6(current_timestamp, icmpp, len, caplen, data, ip);
NextICMP(current_timestamp, icmpp, len, caplen, data, ip);
if ( rule_matcher )
matcher_state.Match(Rule::PAYLOAD, data, len, is_orig,
false, false, true);
}
/********************Generic analyzer for all ICMP4/ICMP6******************************/
void ICMP_Analyzer::NextICMP(double t , const struct icmp* icmpp , int len , int caplen,
void ICMP_Analyzer::NextICMP4(double t, const struct icmp* icmpp, int len, int caplen,
const u_char*& data, const IP_Hdr* ip_hdr )
{
int ICMP6Flag = 0;
//printf("Executing: ICMP_Analyzer::NextICMP\n");
//printf("New analyzer structure\n");
if ( ip_hdr->NextProto() == IPPROTO_ICMPV6 )
{
//printf("ICMP6!\n");
ICMP6Flag = 1;
switch (type) //Add new ICMP6 functions here, you can also use codes to narrow the area of single functions.
{
//All the echo stuff here
case ICMP6_ECHO_REQUEST:
case ICMP6_ECHO_REPLY:
Echo(t, icmpp, len, caplen, data, ip_hdr);
break;
//Error messages all have the same structure for their context, and are handled by the same function.
case ICMP6_PARAM_PROB:
case ICMP6_TIME_EXCEEDED:
case ICMP6_PACKET_TOO_BIG:
case ICMP6_DST_UNREACH:
Context(t, icmpp, len, caplen, data, ip_hdr);
break;
//All router related stuff should eventually be handled by the Router()
case ND_REDIRECT:
case ND_ROUTER_SOLICIT:
case ICMP6_ROUTER_RENUMBERING:
case ND_ROUTER_ADVERT:
Router(t, icmpp, len, caplen, data, ip_hdr); //currently only logs the router stuff for other than router_advert
break;
/* listed for convenience
case ICMP6_PARAM_PROB: break;
case MLD_LISTENER_QUERY: break;
case MLD_LISTENER_REPORT: break;
case MLD_LISTENER_REDUCTION: break;
case ND_NEIGHBOR_SOLICIT: break;
case ND_NEIGHBOR_ADVERT: break;
case ND_REDIRECT: break;
case ICMP6_ROUTER_RENUMBERING: break;
case ND_NEIGHBOR_SOLICIT: break;
case ND_NEIGHBOR_ADVERT: break;
case ICMP6_TIME_EXCEEDED: break;
*/
default: ICMPEvent(icmp_sent, ICMP6Flag); break;
}
}
else if ( ip_hdr->NextProto() == IPPROTO_ICMP )
{
switch (type) //Add new ICMP4 functions here
switch ( icmpp->icmp_type )
{
case ICMP_ECHO:
case ICMP_ECHOREPLY:
@ -186,36 +117,76 @@ void ICMP_Analyzer::NextICMP(double t , const struct icmp* icmpp , int len , i
case ICMP_UNREACH:
case ICMP_TIMXCEED:
Context(t, icmpp, len, caplen, data, ip_hdr);
Context4(t, icmpp, len, caplen, data, ip_hdr);
break;
default: ICMPEvent(icmp_sent, ICMP6Flag); break;
default:
ICMPEvent(icmp_sent, icmpp, len, 0); break;
}
}
#ifdef BROv6
void ICMP_Analyzer::NextICMP6(double t, const struct icmp* icmpp, int len, int caplen,
const u_char*& data, const IP_Hdr* ip_hdr )
{
switch ( icmpp->icmp_type )
{
// Echo types.
case ICMP6_ECHO_REQUEST:
case ICMP6_ECHO_REPLY:
Echo(t, icmpp, len, caplen, data, ip_hdr);
break;
// Error messages all have the same structure for their context,
// and are handled by the same function.
case ICMP6_PARAM_PROB:
case ICMP6_TIME_EXCEEDED:
case ICMP6_PACKET_TOO_BIG:
case ICMP6_DST_UNREACH:
Context6(t, icmpp, len, caplen, data, ip_hdr);
break;
// Router related messages.
case ND_REDIRECT:
case ND_ROUTER_SOLICIT:
case ICMP6_ROUTER_RENUMBERING:
case ND_ROUTER_ADVERT:
Router(t, icmpp, len, caplen, data, ip_hdr);
break;
#if 0
// Currently not specifically implemented.
case ICMP6_PARAM_PROB:
case MLD_LISTENER_QUERY:
case MLD_LISTENER_REPORT:
case MLD_LISTENER_REDUCTION:
case ND_NEIGHBOR_SOLICIT:
case ND_NEIGHBOR_ADVERT:
case ND_REDIRECT:
case ICMP6_ROUTER_RENUMBERING:
case ND_NEIGHBOR_SOLICIT:
case ND_NEIGHBOR_ADVERT:
case ICMP6_TIME_EXCEEDED:
#endif
default:
ICMPEvent(icmp_sent, icmpp, len, 1);
break;
}
else
Weird("Malformed ip header");
}
#endif
void ICMP_Analyzer::ICMPEvent(EventHandlerPtr f, int ICMP6Flag)
void ICMP_Analyzer::ICMPEvent(EventHandlerPtr f, const struct icmp* icmpp, int len, int icmpv6)
{
if ( ! f )
return;
val_list* vl = new val_list;
vl->append(BuildConnVal());
vl->append(BuildICMPVal(ICMP6Flag));
//if ( f == icmp_sent ) //for now, testing purposes
vl->append(new Val(ICMP6Flag, TYPE_BOOL));
vl->append(BuildICMPVal(icmpp, len, icmpv6));
ConnectionEvent(f, vl);
}
RecordVal* ICMP_Analyzer::BuildICMPVal(int ICMP6Flag)
RecordVal* ICMP_Analyzer::BuildICMPVal(const struct icmp* icmpp, int len, int icmpv6)
{
if ( ! icmp_conn_val )
{
@ -223,15 +194,10 @@ RecordVal* ICMP_Analyzer::BuildICMPVal(int ICMP6Flag)
icmp_conn_val->Assign(0, new AddrVal(Conn()->OrigAddr()));
icmp_conn_val->Assign(1, new AddrVal(Conn()->RespAddr()));
if ( ICMP6Flag == 1 )
icmp_conn_val->Assign(2, new Val(Type6to4(type), TYPE_COUNT)); //to avoid errors in getting the message type *name* right on the scripting level, type number will be different from true ipv6
else
icmp_conn_val->Assign(2, new Val(type, TYPE_COUNT));
icmp_conn_val->Assign(3, new Val(code, TYPE_COUNT));
icmp_conn_val->Assign(2, new Val(icmpp->icmp_type, TYPE_COUNT));
icmp_conn_val->Assign(3, new Val(icmpp->icmp_code, TYPE_COUNT));
icmp_conn_val->Assign(4, new Val(len, TYPE_COUNT));
icmp_conn_val->Assign(5, new Val(icmpv6, TYPE_BOOL));
}
Ref(icmp_conn_val);
@ -239,15 +205,74 @@ RecordVal* ICMP_Analyzer::BuildICMPVal(int ICMP6Flag)
return icmp_conn_val;
}
TransportProto ICMP_Analyzer::GetContextProtocol(const IP_Hdr* ip_hdr, uint32* src_port, uint32* dst_port)
{
const u_char* transport_hdr;
uint32 ip_hdr_len = ip_hdr->HdrLen();
bool ip4 = ip_hdr->IP4_Hdr();
if ( ip4 )
transport_hdr = ((u_char *) ip_hdr->IP4_Hdr() + ip_hdr_len);
else
transport_hdr = ((u_char *) ip_hdr->IP6_Hdr() + ip_hdr_len);
TransportProto proto;
switch ( ip_hdr->NextProto() ) {
case 1: proto = TRANSPORT_ICMP; break;
case 6: proto = TRANSPORT_TCP; break;
case 17: proto = TRANSPORT_UDP; break;
case 58: proto = TRANSPORT_ICMP; //TransportProto Hack // XXX What's this?
default: proto = TRANSPORT_UNKNOWN; break;
}
switch ( proto ) {
case TRANSPORT_ICMP:
{
const struct icmp* icmpp =
(const struct icmp *) transport_hdr;
bool is_one_way; // dummy
*src_port = ntohs(icmpp->icmp_type);
if ( ip4 )
*dst_port = ntohs(ICMP4_counterpart(icmpp->icmp_type,
icmpp->icmp_code, is_one_way));
else
*dst_port = ntohs(ICMP6_counterpart(icmpp->icmp_type,
icmpp->icmp_code, is_one_way));
break;
}
case TRANSPORT_TCP:
{
const struct tcphdr* tp =
(const struct tcphdr *) transport_hdr;
*src_port = ntohs(tp->th_sport);
*dst_port = ntohs(tp->th_dport);
break;
}
case TRANSPORT_UDP:
{
const struct udphdr* up =
(const struct udphdr *) transport_hdr;
*src_port = ntohs(up->uh_sport);
*dst_port = ntohs(up->uh_dport);
break;
}
default:
*src_port = *dst_port = ntohs(0);
}
return proto;
}
RecordVal* ICMP_Analyzer::ExtractICMP4Context(int len, const u_char*& data)
{
/**
* For use only with ICMP4, ICMPV6 context extraction is still non-functional
*/
const IP_Hdr ip_hdr_data((const struct ip*) data);
const IP_Hdr* ip_hdr = &ip_hdr_data;
int ICMP6Flag = 0;
uint32 ip_hdr_len = ip_hdr->HdrLen();
@ -258,7 +283,8 @@ RecordVal* ICMP_Analyzer::ExtractICMP4Context(int len, const u_char*& data)
uint32 src_port, dst_port;
if ( ip_hdr_len < sizeof(struct ip) || ip_hdr_len > uint32(len) )
{ // We don't have an entire IP header.
{
// We don't have an entire IP header.
bad_hdr_len = 1;
ip_len = frag_offset = 0;
DF = MF = bad_checksum = 0;
@ -275,62 +301,19 @@ RecordVal* ICMP_Analyzer::ExtractICMP4Context(int len, const u_char*& data)
src_addr = ip_hdr->SrcAddr4();
dst_addr = ip_hdr->DstAddr4();
switch ( ip_hdr->NextProto() ) {
case 1: proto = TRANSPORT_ICMP; break;
case 6: proto = TRANSPORT_TCP; break;
case 17: proto = TRANSPORT_UDP; break;
// Default uses TRANSPORT_UNKNOWN, per initialization above.
}
uint32 frag_field = ip_hdr->FragField();
DF = ip_hdr->DF();
MF = frag_field & 0x2000;
frag_offset = frag_field & /* IP_OFFMASK not portable */ 0x1fff;
const u_char* transport_hdr = ((u_char *) ip_hdr->IP4_Hdr() + ip_hdr_len);
if ( uint32(len) < ip_hdr_len + 4 ) //what is this value for ipv6?
if ( uint32(len) >= ip_hdr_len + 4 )
proto = GetContextProtocol(ip_hdr, &src_port, &dst_port);
else
{
// 4 above is the magic number meaning that both
// port numbers are included in the ICMP.
bad_hdr_len = 1;
src_port = dst_port = 0;
}
switch ( proto ) {
case TRANSPORT_ICMP:
{
const struct icmp* icmpp =
(const struct icmp *) transport_hdr;
bool is_one_way; // dummy
src_port = ntohs(icmpp->icmp_type);
dst_port = ntohs(ICMP4_counterpart(icmpp->icmp_type,
icmpp->icmp_code,
is_one_way));
}
break;
case TRANSPORT_TCP:
{
const struct tcphdr* tp =
(const struct tcphdr *) transport_hdr;
src_port = ntohs(tp->th_sport);
dst_port = ntohs(tp->th_dport);
}
break;
case TRANSPORT_UDP:
{
const struct udphdr* up =
(const struct udphdr *) transport_hdr;
src_port = ntohs(up->uh_sport);
dst_port = ntohs(up->uh_dport);
}
break;
default:
src_port = dst_port = ntohs(0);
bad_hdr_len = 1;
}
}
@ -341,48 +324,40 @@ RecordVal* ICMP_Analyzer::ExtractICMP4Context(int len, const u_char*& data)
id_val->Assign(1, new PortVal(src_port, proto));
id_val->Assign(2, new AddrVal(dst_addr));
id_val->Assign(3, new PortVal(dst_port, proto));
iprec->Assign(0, id_val);
iprec->Assign(0, id_val);
iprec->Assign(1, new Val(ip_len, TYPE_COUNT));
iprec->Assign(2, new Val(proto, TYPE_COUNT));
iprec->Assign(3, new Val(frag_offset, TYPE_COUNT));
iprec->Assign(4, new Val(bad_hdr_len, TYPE_BOOL));
iprec->Assign(5, new Val(bad_checksum, TYPE_BOOL));
iprec->Assign(3, new Val(bad_hdr_len, TYPE_BOOL));
iprec->Assign(4, new Val(bad_checksum, TYPE_BOOL));
iprec->Assign(5, new Val(frag_offset, TYPE_COUNT));
iprec->Assign(6, new Val(MF, TYPE_BOOL));
iprec->Assign(7, new Val(DF, TYPE_BOOL));
iprec->Assign(8, new Val(ICMP6Flag, TYPE_BOOL));
return iprec;
}
RecordVal* ICMP_Analyzer::ExtractICMP6Context(int len, const u_char*& data)
{
/**
* For use with ICMP6 error message context extraction (possibly very frail function)
*/
const IP_Hdr ip_hdr_data((const struct ip6_hdr*) data);
const IP_Hdr* ip_hdr = &ip_hdr_data;
int ICMP6Flag = 1;
int DF = 0, MF = 0, bad_hdr_len = 0, bad_checksum = 0;
TransportProto proto = TRANSPORT_UNKNOWN;
uint32 ip_hdr_len = ip_hdr->HdrLen(); //should always be 40
uint32* src_addr;
uint32* dst_addr;
uint32 ip_len, frag_offset = 0;
TransportProto proto = TRANSPORT_UNKNOWN;
uint32 src_port, dst_port;
if ( ip_hdr_len < sizeof(struct ip6_hdr) || ip_hdr_len != 40 )
if ( ip_hdr_len < sizeof(struct ip6_hdr) || ip_hdr_len != 40 ) // XXX What's the 2nd part doing?
{
bad_hdr_len = 1;
ip_len = 0;
src_addr = dst_addr = 0;
src_port = dst_port = 0;
}
else
{
ip_len = ip_hdr->TotalLen();
@ -390,61 +365,14 @@ RecordVal* ICMP_Analyzer::ExtractICMP6Context(int len, const u_char*& data)
src_addr = (uint32 *) ip_hdr->SrcAddr();
dst_addr = (uint32 *) ip_hdr->DstAddr();
switch ( ip_hdr->NextProto() ) {
case 1: proto = TRANSPORT_ICMP; break;
case 6: proto = TRANSPORT_TCP; break;
case 17: proto = TRANSPORT_UDP; break;
case 58: proto = TRANSPORT_ICMP; break; //TransportProto Hack
// Default uses TRANSPORT_UNKNOWN, per initialization above.
}
const u_char* transport_hdr = ((u_char *)ip_hdr->IP6_Hdr() + ip_hdr_len);
if ( uint32(len) < ip_hdr_len + 4 )
if ( uint32(len) >= ip_hdr_len + 4 )
proto = GetContextProtocol(ip_hdr, &src_port, &dst_port);
else
{
// 4 above is the magic number meaning that both
// port numbers are included in the ICMP.
bad_hdr_len = 1;
src_port = dst_port = 0;
}
switch ( proto ) {
case TRANSPORT_ICMP:
{
const struct icmp* icmpp =
(const struct icmp *) transport_hdr;
bool is_one_way; // dummy
src_port = ntohs(icmpp->icmp_type);
dst_port = ntohs(ICMP6_counterpart(icmpp->icmp_type,
icmpp->icmp_code,
is_one_way));
}
break;
case TRANSPORT_TCP:
{
const struct tcphdr* tp =
(const struct tcphdr *) transport_hdr;
src_port = ntohs(tp->th_sport);
dst_port = ntohs(tp->th_dport);
}
break;
case TRANSPORT_UDP:
{
const struct udphdr* up =
(const struct udphdr *) transport_hdr;
src_port = ntohs(up->uh_sport);
dst_port = ntohs(up->uh_dport);
}
break;
default:
src_port = dst_port = ntohs(0);
bad_hdr_len = 1;
}
}
@ -459,7 +387,7 @@ RecordVal* ICMP_Analyzer::ExtractICMP6Context(int len, const u_char*& data)
iprec->Assign(0, id_val);
iprec->Assign(1, new Val(ip_len, TYPE_COUNT));
//TransportProto Hack
//TransportProto Hack // XXX Likewise.
if ( ip_hdr->NextProto() == 58 || 17 ) //if the encap packet is ICMPv6 we force this... (cause there is no IGMP (by that name) for ICMPv6), rather ugly hack once more
{
iprec->Assign(2, new Val(58, TYPE_COUNT));
@ -469,28 +397,18 @@ RecordVal* ICMP_Analyzer::ExtractICMP6Context(int len, const u_char*& data)
iprec->Assign(2, new Val(proto, TYPE_COUNT));
}
iprec->Assign(3, new Val(frag_offset, TYPE_COUNT)); //NA for ip6
iprec->Assign(4, new Val(bad_hdr_len, TYPE_BOOL));
iprec->Assign(5, new Val(bad_checksum, TYPE_BOOL));
iprec->Assign(6, new Val(MF, TYPE_BOOL)); //NA for ip6
iprec->Assign(7, new Val(DF, TYPE_BOOL)); //NA for ip6
iprec->Assign(8, new Val(ICMP6Flag, TYPE_BOOL)); //ICMP6Flag
iprec->Assign(3, new Val(bad_hdr_len, TYPE_BOOL));
// The following are not available for IPv6.
iprec->Assign(4, new Val(0, TYPE_BOOL)); // bad_checksum
iprec->Assign(5, new Val(frag_offset, TYPE_COUNT)); // frag_offset
iprec->Assign(6, new Val(0, TYPE_BOOL)); // MF
iprec->Assign(7, new Val(1, TYPE_BOOL)); // DF
return iprec;
}
bool ICMP_Analyzer::IsReuse(double /* t */, const u_char* /* pkt */)
{
return 0;
@ -504,10 +422,12 @@ void ICMP_Analyzer::Describe(ODesc* d) const
d->AddSP(")");
d->Add(dotted_addr(Conn()->OrigAddr()));
#if 0
d->Add(".");
d->Add(type);
d->Add(".");
d->Add(code);
#endif
d->SP();
d->AddSP("->");
@ -543,19 +463,16 @@ unsigned int ICMP_Analyzer::MemoryAllocation() const
void ICMP_Analyzer::Echo(double t, const struct icmp* icmpp, int len,
int caplen, const u_char*& data, const IP_Hdr* ip_hdr)
{ //For handling all Echo related ICMP messages
EventHandlerPtr f = 0;
int ICMP6Flag = 0;
//printf("Executing: Echo, NextProto:%d\n",ip_hdr->NextProto());
if ( ip_hdr->NextProto() == IPPROTO_ICMPV6 )
{
f = type == ICMP6_ECHO_REQUEST ? icmp_echo_request : icmp_echo_reply;
ICMP6Flag = 1;
}
// For handling all Echo related ICMP messages
EventHandlerPtr f = 0;
#ifdef BROv6
if ( ip_hdr->NextProto() == IPPROTO_ICMPV6 )
f = (icmpp->icmp_type == ICMP6_ECHO_REQUEST) ? icmp_echo_request : icmp_echo_reply;
else
f = type == ICMP_ECHO ? icmp_echo_request : icmp_echo_reply;
#endif
f = (icmpp->icmp_type == ICMP_ECHO) ? icmp_echo_request : icmp_echo_reply;
if ( ! f )
return;
@ -563,137 +480,110 @@ void ICMP_Analyzer::Echo(double t, const struct icmp* icmpp, int len,
int iid = ntohs(icmpp->icmp_hun.ih_idseq.icd_id);
int iseq = ntohs(icmpp->icmp_hun.ih_idseq.icd_seq);
//printf("Check these values: iid:[%d] iseq:[%d]\n",iid,iseq);
BroString* payload = new BroString(data, caplen, 0);
val_list* vl = new val_list;
vl->append(BuildConnVal());
vl->append(BuildICMPVal(ICMP6Flag));
vl->append(BuildICMPVal(icmpp, len, ip_hdr->NextProto() != IPPROTO_ICMP));
vl->append(new Val(iid, TYPE_COUNT));
vl->append(new Val(iseq, TYPE_COUNT));
vl->append(new StringVal(payload));
vl->append(new Val(ICMP6Flag, TYPE_BOOL));
ConnectionEvent(f, vl);
}
void ICMP_Analyzer::Router(double t, const struct icmp* icmpp, int len,
int caplen, const u_char*& data, const IP_Hdr* /*ip_hdr*/)
//For handling router related ICMP messages,
{
EventHandlerPtr f = 0;
int ICMP6Flag = 1;
switch ( type )
switch ( icmpp->icmp_type )
{
case ND_ROUTER_ADVERT: f = icmp_router_advertisement; break;
case ND_ROUTER_ADVERT:
f = icmp_router_advertisement;
break;
case ND_REDIRECT:
case ND_ROUTER_SOLICIT:
case ICMP6_ROUTER_RENUMBERING:
default: ICMPEvent(icmp_sent,ICMP6Flag); return;
default:
ICMPEvent(icmp_sent, icmpp, len, 1);
return;
}
val_list* vl = new val_list;
vl->append(BuildConnVal());
vl->append(BuildICMPVal(ICMP6Flag));
vl->append(new Val(ICMP6Flag, TYPE_BOOL));
vl->append(BuildICMPVal(icmpp, len, 1));
ConnectionEvent(f, vl);
}
void ICMP_Analyzer::Context(double t, const struct icmp* icmpp,
void ICMP_Analyzer::Context4(double t, const struct icmp* icmpp,
int len, int caplen, const u_char*& data, const IP_Hdr* ip_hdr)
{//For handling the ICMP error messages
{
EventHandlerPtr f = 0;
int ICMP6Flag = 0;
if ( ip_hdr->NextProto() == IPPROTO_ICMPV6 ) //is ip6
switch ( icmpp->icmp_type )
{
case ICMP_UNREACH:
f = icmp_unreachable;
break;
ICMP6Flag = 1;
//printf("Executing: Context for ICMPv6\n");
switch ( type )
{
case ICMP6_DST_UNREACH: f = icmp_unreachable; break;
case ICMP6_PARAM_PROB: f = icmp_error_message; break;
case ICMP6_TIME_EXCEEDED: f = icmp_error_message; break;
case ICMP6_PACKET_TOO_BIG: f = icmp_error_message; break;
}
if ( f )
{
val_list* vl = new val_list;
vl->append(BuildConnVal()); //check for ip6 functionality
vl->append(BuildICMPVal(ICMP6Flag)); //check for ip6 functionality
vl->append(new Val(code, TYPE_COUNT));
vl->append(ExtractICMP6Context(caplen, data));
ConnectionEvent(f, vl);
}
}
else if ( ip_hdr->NextProto() == IPPROTO_ICMP )
{
//printf("Executing: Context for ICMP\n");
switch ( type )
{
case ICMP_UNREACH: f = icmp_unreachable; break;
case ICMP_TIMXCEED: f = icmp_error_message; break;
case ICMP_TIMXCEED:
f = icmp_error_message;
break;
}
if ( f )
{
val_list* vl = new val_list;
vl->append(BuildConnVal());
vl->append(BuildICMPVal(ICMP6Flag));
vl->append(new Val(code, TYPE_COUNT));
vl->append(BuildICMPVal(icmpp, len, 0));
vl->append(new Val(icmpp->icmp_code, TYPE_COUNT));
vl->append(ExtractICMP4Context(caplen, data));
ConnectionEvent(f, vl);
}
}
else
#ifdef BROv6
void ICMP_Analyzer::Context6(double t, const struct icmp* icmpp,
int len, int caplen, const u_char*& data, const IP_Hdr* ip_hdr)
{
Weird("ICMP packet, invalid data\n"); //make this more descriptive
}
EventHandlerPtr f = 0;
switch ( icmpp->icmp_type )
{
case ICMP6_DST_UNREACH:
f = icmp_unreachable;
break;
case ICMP6_PARAM_PROB:
case ICMP6_TIME_EXCEEDED:
case ICMP6_PACKET_TOO_BIG:
f = icmp_error_message;
break;
}
if ( f )
{
val_list* vl = new val_list;
vl->append(BuildConnVal());
vl->append(BuildICMPVal(icmpp, len, 1));
vl->append(new Val(icmpp->icmp_code, TYPE_COUNT));
vl->append(ExtractICMP6Context(caplen, data));
ConnectionEvent(f, vl);
}
}
#endif
int ICMP4_counterpart(int icmp_type, int icmp_code, bool& is_one_way)
{
is_one_way = false;
// return the counterpart type if one exists. This allows us
// Return the counterpart type if one exists. This allows us
// to track corresponding ICMP requests/replies.
// Note that for the two-way ICMP messages, icmp_code is
// always 0 (RFC 792).
@ -720,12 +610,7 @@ int ICMP6_counterpart(int icmp_type, int icmp_code, bool& is_one_way)
{
is_one_way = false;
/**ICMP6 version of the ICMP4_counterpart, under work**/
//not yet used anywhere, for the context class
switch ( icmp_type ) {
case ICMP6_ECHO_REQUEST: return ICMP6_ECHO_REPLY;
case ICMP6_ECHO_REPLY: return ICMP6_ECHO_REQUEST;
@ -738,39 +623,17 @@ int ICMP6_counterpart(int icmp_type, int icmp_code, bool& is_one_way)
case MLD_LISTENER_QUERY: return MLD_LISTENER_REPORT;
case MLD_LISTENER_REPORT: return MLD_LISTENER_QUERY;
case 139: return 140; //ICMP node information query and response respectively (not defined in icmp6.h)
// ICMP node information query and response respectively (not defined in
// icmp6.h)
case 139: return 140;
case 140: return 139;
case 144: return 145; //Home Agent Address Discovery Request Message and reply
// Home Agent Address Discovery Request Message and reply
case 144: return 145;
case 145: return 144;
//check the rest of the counterparts
// TODO: Add further counterparts.
default: is_one_way = true; return icmp_code;
}
}
//For mapping ICMP types and codes of v6 to v4. Because we are using same events for both icmpv4 and icmpv6 there is some overlap
//in ICMP types. If this function is used, the name (checked from a table in the scripts) will be incorrect for the listed
//types, but the names will be correct for all ICMP types.
int Type6to4(int icmp_type)
{
switch ( icmp_type ) //For these three values, the type number will be wrong if this is used!
{ //easy way to disable this is just to comment all the cases out, and leave only the default.
case ICMP6_DST_UNREACH: return ICMP_UNREACH; break;
case ICMP6_TIME_EXCEEDED: return ICMP_TIMXCEED; break;
case ICMP6_PARAM_PROB: return ICMP_PARAMPROB; break;
default: return icmp_type; break;
}
}
int Code6to4(int icmp_code) //not used yet for anything
{
switch ( icmp_code )
{
default: return icmp_code; break;
}
}

View file

@ -34,7 +34,7 @@ protected:
virtual bool IsReuse(double t, const u_char* pkt);
virtual unsigned int MemoryAllocation() const;
void ICMPEvent(EventHandlerPtr f, int ICMP6Flag);
void ICMPEvent(EventHandlerPtr f, const struct icmp* icmpp, int len, int icmpv6);
void Echo(double t, const struct icmp* icmpp, int len,
int caplen, const u_char*& data, const IP_Hdr* ip_hdr);
@ -43,47 +43,40 @@ protected:
void Router(double t, const struct icmp* icmpp, int len,
int caplen, const u_char*& data, const IP_Hdr* ip_hdr);
void Describe(ODesc* d) const;
RecordVal* BuildICMPVal(int ICMP6Flag);
RecordVal* BuildICMPVal(const struct icmp* icmpp, int len, int icmpv6);
virtual void NextICMP(double t, const struct icmp* icmpp,
int len, int caplen, const u_char*& data, const IP_Hdr* ip_hdr);
void NextICMP4(double t, const struct icmp* icmpp, int len, int caplen,
const u_char*& data, const IP_Hdr* ip_hdr );
RecordVal* ExtractICMP4Context(int len, const u_char*& data);
void Context4(double t, const struct icmp* icmpp, int len, int caplen,
const u_char*& data, const IP_Hdr* ip_hdr);
TransportProto GetContextProtocol(const IP_Hdr* ip_hdr, uint32* src_port,
uint32* dst_port);
#ifdef BROv6
void NextICMP6(double t, const struct icmp* icmpp, int len, int caplen,
const u_char*& data, const IP_Hdr* ip_hdr );
RecordVal* ExtractICMP6Context(int len, const u_char*& data);
void Context6(double t, const struct icmp* icmpp, int len, int caplen,
const u_char*& data, const IP_Hdr* ip_hdr);
#endif
RecordVal* icmp_conn_val;
int type;
int code;
int len;
int request_len, reply_len;
RuleMatcherState matcher_state;
};
/*class ICMP4_Analyzer : public ICMP_Analyzer {
};
class ICMP6_Analyzer : public ICMP_Analyzer {
};*/
// Returns the counterpart type to the given type (e.g., the counterpart
// to ICMP_ECHOREPLY is ICMP_ECHO).
//extern int ICMP_counterpart(int icmp_type, int icmp_code, bool& is_one_way);
extern int ICMP4_counterpart(int icmp_type, int icmp_code, bool& is_one_way);
extern int ICMP6_counterpart(int icmp_type, int icmp_code, bool& is_one_way);
extern int Type6to4(int icmp_type);
extern int Code6to4(int icmp_code);
#endif

View file

@ -53,12 +53,12 @@ event udp_reply%(u: connection%);
event udp_contents%(u: connection, is_orig: bool, contents: string%);
event udp_session_done%(u: connection%);
event icmp_sent%(c: connection, icmp: icmp_conn, ICMP6: bool%);
event icmp_echo_request%(c: connection, icmp: icmp_conn, id: count, seq: count, payload: string, ICMP6: bool%);
event icmp_echo_reply%(c: connection, icmp: icmp_conn, id: count, seq: count, payload: string, ICMP6: bool%);
event icmp_sent%(c: connection, icmp: icmp_conn%);
event icmp_echo_request%(c: connection, icmp: icmp_conn, id: count, seq: count, payload: string%);
event icmp_echo_reply%(c: connection, icmp: icmp_conn, id: count, seq: count, payload: string%);
event icmp_unreachable%(c: connection, icmp: icmp_conn, code: count, context: icmp_context%);
event icmp_error_message%(c: connection, icmp: icmp_conn, code: count, context: icmp_context%);
event icmp_router_advertisement%(c: connection, icmp: icmp_conn, ICMP6: bool%);
event icmp_router_advertisement%(c: connection, icmp: icmp_conn%);

View file

@ -86,14 +86,8 @@ int udp_checksum(const struct ip* ip, const struct udphdr* up, int len)
#ifdef BROv6
int udp6_checksum(const struct ip6_hdr* ip6, const struct udphdr* up, int len)
{
/**From RFC for udp4 (same for udp6, except for different pseudoheader which is same as for icmp6)
Computed as the 16-bit one's complement of the one's complement sum of a
pseudo header of information from the IP header, the UDP header, and the
data, padded as needed with zero bytes at the end to make a multiple of
two bytes. If the checksum is cleared to zero, then checksuming is
disabled. If the computed checksum is zero, then this field must be set
to 0xFFFF.
**/
// UDP over IPv6 uses the same checksum function as over IPv4 but a
// different pseuod-header over which it is computed.
uint32 sum;
if ( len % 2 == 1 )
@ -108,23 +102,18 @@ int udp6_checksum(const struct ip6_hdr* ip6, const struct udphdr* up, int len)
uint32 l = htonl(len);
sum = ones_complement_checksum((void*) &l, 4, sum);
uint32 addl_pseudo = htons(IPPROTO_UDP);
sum = ones_complement_checksum((void*) &addl_pseudo, 4, sum);
sum = ones_complement_checksum((void*) up, len, sum);
//printf("checksum, calculated for UDP6: %d\n",sum);
return sum;
}
int icmp6_checksum(const struct icmp* icmpp, const struct ip6_hdr* ip6, int len)
{
/**From RFC
Checksum that covers the ICMPv6 message. This field contains the 16-bit one's
complement of the one's complement sum of the entire ICMPv6 message starting
with the ICMPv6 message type field, prepended with a pseudo-header of IPv6
header fields.
**/
// ICMP6 uses the same checksum function as over ICMP4 but a different
// pseuod-header over which it is computed.
uint32 sum;
if ( len % 2 == 1 )
@ -133,19 +122,17 @@ int icmp6_checksum(const struct icmp* icmpp, const struct ip6_hdr* ip6, int len)
else
sum = 0;
//pseudoheader as in udp6 above
// Pseudo-header as for UDP over IPv6 above.
sum = ones_complement_checksum((void*) ip6->ip6_src.s6_addr, 16, sum);
sum = ones_complement_checksum((void*) ip6->ip6_dst.s6_addr, 16, sum);
uint32 l = htonl(len);
sum = ones_complement_checksum((void*) &l, 4, sum);
uint32 addl_pseudo = htons(IPPROTO_ICMPV6);
sum = ones_complement_checksum((void*) &addl_pseudo, 4, sum);
//pseudoheader complete
sum = ones_complement_checksum((void*) icmpp, len, sum);
//printf("checksum, calculated for ICMP6: %d\n",sum);
return sum;
}
@ -153,12 +140,6 @@ int icmp6_checksum(const struct icmp* icmpp, const struct ip6_hdr* ip6, int len)
int icmp_checksum(const struct icmp* icmpp, int len)
{
/**From RFC
Checksum that covers the ICMP message. This is the 16-bit one's
complement of the one's complement sum of the ICMP message starting
with the Type field. The checksum field should be cleared to zero
before generating the checksum.
**/
uint32 sum;
if ( len % 2 == 1 )
// Add in pad byte.
@ -168,15 +149,9 @@ int icmp_checksum(const struct icmp* icmpp, int len)
sum = ones_complement_checksum((void*) icmpp, len, sum);
//printf("checksum, calculated for ICMP4: %d\n",sum);
return sum;
}
#define CLASS_A 0x00000000
#define CLASS_B 0x80000000
#define CLASS_C 0xc0000000

View file

@ -88,12 +88,14 @@ extern int ones_complement_checksum(const void* p, int b, uint32 sum);
extern int tcp_checksum(const struct ip* ip, const struct tcphdr* tp, int len);
extern int udp_checksum(const struct ip* ip, const struct udphdr* up, int len);
extern int icmp_checksum(const struct icmp* icmpp, int len);
#ifdef BROv6
extern int udp6_checksum(const struct ip6_hdr* ip, const struct udphdr* up,
int len);
extern int icmp6_checksum(const struct icmp* icmpp, const struct ip6_hdr* ip6, int len);
extern int icmp6_checksum(const struct icmp* icmpp, const struct ip6_hdr* ip6,
int len);
#endif
extern int icmp_checksum(const struct icmp* icmpp, int len);
// Given an address in host order, returns its "classical network prefix",
// also in host order.