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synfrag.c
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synfrag.c
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/*
* Copyright (c) 2012, Yahoo! Inc All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer. Redistributions
* in binary form must reproduce the above copyright notice, this list
* of conditions and the following disclaimer in the documentation and/or
* other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
* OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*
* Author: John Eaglesham
*/
#define __USE_BSD
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <err.h>
#include <string.h>
#include <netdb.h>
#ifdef __FreeBSD__
#include <netinet/in_systm.h>
#include <ifaddrs.h>
#include <net/if_dl.h>
#endif
#ifdef __linux
#define ETHERTYPE_IPV6 ETH_P_IPV6
#define __FAVOR_BSD
#endif
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/select.h>
#include <sys/time.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip6.h>
#include <netinet/ip_icmp.h>
#include <netinet/icmp6.h>
#include <netinet/tcp.h>
#include <netinet/if_ether.h>
#include <net/if.h>
#include <pcap.h>
#include <signal.h>
#include <sys/wait.h>
#include <getopt.h>
#include "flag_names.h"
#include "packets.h"
#include "constants.h"
#include "checksums.h"
/*
* XXX We don't close the pcap device on failure anywhere. The OS will do it
* for us, but it's impolite.
*/
/*
* This might turn out to be stupid, but lets try having TCP tests be odd
* numbered and ICMP even numbered. IPv4 tests will be <= 10 and IPv6 > 10.
*/
#define IS_TEST_TCP(x) ( x % 2 == 1 )
#define IS_TEST_ICMP(x) ( x % 2 == 0 )
#define IS_TEST_IPV4(x) ( x <= 10 )
#define IS_TEST_IPV6(x) ( x > 10 )
enum TEST_TYPE {
TEST_IPV4_TCP = 1,
TEST_IPV4_FRAG_TCP = 3,
TEST_IPV4_DSTOPT_FRAG_TCP = 5,
TEST_IPV4_FRAG_ICMP = 2,
TEST_IPV4_DSTOPT_FRAG_ICMP = 4,
TEST_IPV6_TCP = 11,
TEST_IPV6_FRAG_TCP = 13,
TEST_IPV6_DSTOPT_FRAG_TCP = 15,
TEST_IPV6_FRAG_DSTOPT_TCP = 17,
TEST_IPV6_FRAG_FRAG_TCP = 19,
TEST_IPV6_FRAG_NOMORE_TCP = 21,
TEST_IPV6_FRAG_ICMP6 = 12,
TEST_IPV6_DSTOPT_FRAG_ICMP6 = 14,
TEST_INVALID = 0
};
/*
* Items and their order in test_indexes needs to match test_names (but not
* enum TEST_TYPE).
*/
enum TEST_TYPE test_indexes[] = {
TEST_IPV4_TCP,
TEST_IPV4_FRAG_TCP,
TEST_IPV4_FRAG_ICMP,
TEST_IPV4_DSTOPT_FRAG_TCP,
TEST_IPV4_DSTOPT_FRAG_ICMP,
TEST_IPV6_TCP,
TEST_IPV6_FRAG_TCP,
TEST_IPV6_FRAG_ICMP6,
TEST_IPV6_DSTOPT_FRAG_TCP,
TEST_IPV6_FRAG_DSTOPT_TCP,
TEST_IPV6_FRAG_FRAG_TCP,
TEST_IPV6_FRAG_NOMORE_TCP,
TEST_IPV6_DSTOPT_FRAG_ICMP6,
0
};
char *test_names[] = {
"v4-tcp",
"v4-frag-tcp",
"v4-frag-icmp",
"v4-dstopt-frag-tcp",
"v4-dstopt-frag-icmp",
"v6-tcp",
"v6-frag-tcp",
"v6-frag-icmp6",
"v6-dstopt-frag-tcp",
"v6-frag-dstopt-tcp",
"v6-frag-frag-tcp",
"v6-frag-nomore-tcp",
"v6-dstopt-frag-icmp6",
NULL
};
pcap_t *pcap;
pid_t listener_pid;
int pfd[2];
#ifdef SIOCGIFHWADDR
char *get_interface_mac( char *interface )
{
int fd;
struct ifreq ifr;
char *dest = malloc( MAC_ADDRESS_STRING_LENGTH + 1 );
if ( dest == NULL ) return NULL;
if ( ( fd = socket( AF_INET, SOCK_DGRAM, 0 ) ) == -1 )
return NULL;
ifr.ifr_addr.sa_family = AF_INET;
strncpy( ifr.ifr_name, interface, IFNAMSIZ - 1 );
if ( ioctl( fd, SIOCGIFHWADDR, &ifr ) == -1 ) {
close( fd );
return NULL;
}
close( fd );
sprintf( dest, "%02X:%02X:%02X:%02X:%02X:%02X",
(unsigned char) ifr.ifr_hwaddr.sa_data[0],
(unsigned char) ifr.ifr_hwaddr.sa_data[1],
(unsigned char) ifr.ifr_hwaddr.sa_data[2],
(unsigned char) ifr.ifr_hwaddr.sa_data[3],
(unsigned char) ifr.ifr_hwaddr.sa_data[4],
(unsigned char) ifr.ifr_hwaddr.sa_data[5]
);
return dest;
}
#elif __FreeBSD__
char *get_interface_mac( char *interface )
{
struct ifaddrs *ifap;
char *dest = malloc( MAC_ADDRESS_STRING_LENGTH + 1 );
if ( dest == NULL ) return NULL;
if ( getifaddrs( &ifap ) == 0 ) {
struct ifaddrs *p;
for ( p = ifap; p; p = p->ifa_next ) {
if ( ( p->ifa_addr->sa_family == AF_LINK ) && ( strcmp( p->ifa_name, interface ) == 0 ) ) {
struct sockaddr_dl* sdp = (struct sockaddr_dl *) p->ifa_addr;
unsigned char *mac_ptr = (unsigned char *) sdp->sdl_data + sdp->sdl_nlen;
sprintf( dest, "%02X:%02X:%02X:%02X:%02X:%02X",
mac_ptr[0],
mac_ptr[1],
mac_ptr[2],
mac_ptr[3],
mac_ptr[4],
mac_ptr[5]
);
freeifaddrs( ifap );
return dest;
}
}
freeifaddrs(ifap);
}
return NULL;
}
#else
#error Do not know how to get MAC address on this platform.
#endif
void *malloc_check( int size )
{
void *r = malloc( size );
if ( r == NULL ) err( 1, "malloc" );
return r;
}
unsigned short fix_up_destination_options_length( unsigned short optlen )
{
/*
* Per RFC 2460, a destination options header must have a payload size
* that is: ( multiple of 8 ) - 2. We fix that up here by only ever
* increasing the size (though the algorithm would be simpler if we were
* willing to decrease it. There's no good reason not to decrease it, I
* just made a decision.
*/
if ( optlen % 8 != 6 ) {
int x = 6 - ( optlen % 8 );
if ( x < 0 ) x += 8;
optlen += x;
}
return optlen;
}
void calc_checksum( void *iph, int protocol, int len )
{
if ( do_checksum( iph, protocol, len ) != 1 ) {
fprintf(
stderr,
"Warning: Failed to calculate checksum for protocol %i. This is probably a bug.\n",
protocol
);
}
}
/*
* I know this is undesirable, but I'm not sure I want to keep the structure
* of the code this way, and until I do this out of place function definition
* will work okay.
*/
char *print_a_packet( char *, int, unsigned short );
void synfrag_send( void *packet, int len )
{
static unsigned int packets_sent = 1;
printf( "Sending packet %u:\n\n", packets_sent++ );
print_a_packet( packet, len, 0 );
putchar( '\n' );
if ( pcap_inject( pcap, packet, len ) != len ) errx( 1, "pcap_inject failed: %s", pcap_geterr( pcap ) );
}
void print_ethh( struct ether_header *ethh )
{
printf( "Ethernet Frame: \n Ethertype: 0x%04X (%s)\n",
ntohs( ethh->ether_type ), ether_protocol_to_name( ntohs( ethh->ether_type ) )
);
printf( " Src MAC: %02X:%02X:%02X:%02X:%02X:%02X\n",
ethh->ether_shost[0],
ethh->ether_shost[1],
ethh->ether_shost[2],
ethh->ether_shost[3],
ethh->ether_shost[4],
ethh->ether_shost[5] );
printf( " Dest MAC: %02X:%02X:%02X:%02X:%02X:%02X\n",
ethh->ether_dhost[0],
ethh->ether_dhost[1],
ethh->ether_dhost[2],
ethh->ether_dhost[3],
ethh->ether_dhost[4],
ethh->ether_dhost[5] );
}
void print_iph( struct ip *iph )
{
char srcbuf[INET_ADDRSTRLEN];
char dstbuf[INET_ADDRSTRLEN];
char *flag_names = ip_flags_to_names( ntohs( iph->ip_off ) >> IP_FLAGS_OFFSET );
if ( inet_ntop( AF_INET, &iph->ip_src, (char *) &srcbuf, INET_ADDRSTRLEN ) == NULL ) errx( 1, "inet_ntop failed" );
if ( inet_ntop( AF_INET, &iph->ip_dst, (char *) &dstbuf, INET_ADDRSTRLEN ) == NULL ) errx( 1, "inet_ntop failed" );
printf( "IPv4 Packet:\n\
Src IP: %s\n\
Dst IP: %s\n\
Protocol: %i (%s)\n\
Frag Offset: %i (%i bytes)\n\
Flags: %i (%s)\n\
Iphl: %i (%i bytes)\n",
(char *) &srcbuf,
(char *) &dstbuf,
iph->ip_p, ip_protocol_to_name( iph->ip_p ),
ntohs( iph->ip_off ) & 0x1FFF, ( ntohs( iph->ip_off ) & 0x1FFF ) * FRAGMENT_OFFSET_TO_BYTES,
ntohs( iph->ip_off ) >> IP_FLAGS_OFFSET, flag_names,
iph->ip_hl, iph->ip_hl * 4
);
free( flag_names );
}
void print_ip6h( struct ip6_hdr *ip6h )
{
char srcbuf[INET6_ADDRSTRLEN];
char dstbuf[INET6_ADDRSTRLEN];
if ( inet_ntop( AF_INET6, &ip6h->ip6_src, (char *) &srcbuf, INET6_ADDRSTRLEN ) == NULL ) err( 1, "inet_ntop failed" );
if ( inet_ntop( AF_INET6, &ip6h->ip6_dst, (char *) &dstbuf, INET6_ADDRSTRLEN ) == NULL ) err( 1, "inet_ntop failed" );
printf( "IPv6 Packet:\n\
Src IP: %s\n\
Dst IP: %s\n\
Protocol: %i (%s)\n\
Payload Len: %i\n",
(char *) &srcbuf,
(char *) &dstbuf,
ip6h->ip6_nxt, ip_protocol_to_name( ip6h->ip6_nxt ),
ntohs( ip6h->ip6_plen )
);
}
void print_icmph( struct icmp *icmph )
{
printf( "ICMP Packet:\n\
Type: %i (%s)\n\
Code: %i (%s)\n",
icmph->icmp_type, icmp_type_to_name( icmph->icmp_type ),
icmph->icmp_code, icmp_code_to_name( icmph->icmp_type, icmph->icmp_code )
);
if ( ( icmph->icmp_type == ICMP_ECHO || icmph->icmp_type == ICMP_ECHOREPLY ) && ( icmph->icmp_code == 0 ) ) {
printf( " Echo id: %i\n", htons( icmph->icmp_id ) );
}
}
void print_icmp6h( struct icmp6_hdr *icmp6h )
{
printf( "ICMPv6 Packet:\n\
Type: %i (%s)\n\
Code: %i (%s)\n",
icmp6h->icmp6_type, icmp6_type_to_name( icmp6h->icmp6_type ),
icmp6h->icmp6_code, icmp6_code_to_name( icmp6h->icmp6_type, icmp6h->icmp6_code )
);
if ( ( icmp6h->icmp6_type == ICMP6_ECHO_REQUEST || icmp6h->icmp6_type == ICMP6_ECHO_REPLY ) && ( icmp6h->icmp6_code == 0 ) ) {
printf( " Echo id: %i\n", htons( icmp6h->icmp6_id ) );
}
}
void print_tcph( struct tcphdr *tcph )
{
char *tcp_flags = tcp_flags_to_names( tcph->th_flags );
printf( "TCP Packet:\n\
Src Port: %u\n\
Dst Port: %u\n\
Seq Num: %u\n\
Ack Num: %u\n\
Flags: 0x%02X (%s)\n",
ntohs( tcph->th_sport ),
ntohs( tcph->th_dport ),
ntohl( tcph->th_seq ),
ntohl( tcph->th_ack ),
tcph->th_flags, tcp_flags
);
free( tcp_flags );
}
void print_fragh( struct ip6_frag *fragh )
{
printf( "Fragment Header:\n\
Next Header: %i (%s)\n\
Ident: %i\n\
Offlg: 0x%04x\n\
Offset: %i (%i bytes)\n\
More Frags: %s\n",
fragh->ip6f_nxt, ip_protocol_to_name( fragh->ip6f_nxt ),
ntohs( fragh->ip6f_ident ),
ntohs( fragh->ip6f_offlg ),
ntohs( fragh->ip6f_offlg ) >> 3, ( ntohs( fragh->ip6f_offlg ) >> 3 ) * 8,
fragh->ip6f_offlg & IP6F_MORE_FRAG ? "Yes" : "No"
);
}
void print_dstopth( struct ip6_dest *desth )
{
printf( "Destination Options Header:\n\
Next Header: %i (%s)\n\
Header Length: %i (%i bytes)\n\
Options Length: %i bytes\n",
desth->ip6d_nxt,
ip_protocol_to_name( desth->ip6d_nxt ),
desth->ip6d_len,
8 + ( desth->ip6d_len * 8 ),
8 - 2 + ( desth->ip6d_len * 8 )
);
}
/* Returns the layer 4 header if we found one. */
char *print_a_packet( char *packet_data, int len, unsigned short wanted_type )
{
struct ip *iph;
struct ip6_hdr *ip6h;
size_t s = SIZEOF_ETHER;
struct ether_header *ethh = (struct ether_header *) packet_data;
int found_type = -1;
char *found_header = NULL;
if ( len < SIZEOF_ETHER ) {
printf( "Ethernet Frame: \nToo short\n" );
return NULL;
}
print_ethh( ethh );
if ( ntohs( ethh->ether_type ) == ETHERTYPE_IP ) {
iph = (struct ip *) ( packet_data + SIZEOF_ETHER );
s += ( iph->ip_hl * 4 );
if ( s > len ) {
printf( "IPv4 Header:\n Too short\n" );
return NULL;
}
print_iph( iph );
if ( ( ntohs( iph->ip_off ) & 0x1FFF ) || ntohs( iph->ip_off ) & ( 1 << IP_FLAGS_OFFSET ) ) {
printf( "(Fragment)\n" );
found_type = -1;
found_header = NULL;
} else if ( iph->ip_p == IPPROTO_TCP ) {
if ( s + SIZEOF_TCP > len ) {
printf( "TCP Header:\n Too short\n" );
return NULL;
}
print_tcph( (struct tcphdr *) ( packet_data + s ) );
found_type = IPPROTO_TCP;
found_header = packet_data + s;
} else if ( iph->ip_p == IPPROTO_ICMP ) {
if ( s + SIZEOF_PING > len ) {
printf( "UDP Header:\n Too short\n" );
return NULL;
}
print_icmph( (struct icmp *) ( packet_data + s ) );
found_type = IPPROTO_ICMP;
found_header = packet_data + s;
} else {
printf( "Unsupported protocol:\n IP Protocol %i (%s)\n", iph->ip_p, ip_protocol_to_name( iph->ip_p ) );
return NULL;
}
} else if ( ntohs( ethh->ether_type ) == ETHERTYPE_IPV6 ) {
int ipv6_next_header_type = IPPROTO_IPV6;
int depth = 0;
while( 1 ) {
if ( depth >= 20 ) {
printf( "Too many headers, stopping parsing after %i.\n", depth );
return NULL;
}
if ( ipv6_next_header_type == IPPROTO_IPV6 ) {
ip6h = (struct ip6_hdr *) ( packet_data + SIZEOF_ETHER );
s += SIZEOF_IPV6;
if ( s > len ) {
printf( "IPv6 Header:\n Too short\n" );
return NULL;
}
print_ip6h( ip6h );
ipv6_next_header_type = ip6h->ip6_nxt;
} else if ( ipv6_next_header_type == IPPROTO_TCP ) {
if ( s + SIZEOF_TCP > len ) {
printf( "TCP Header:\n Too short\n" );
return NULL;
}
print_tcph( (struct tcphdr *) ( packet_data + s ) );
found_type = IPPROTO_TCP;
found_header = packet_data + s;
s += SIZEOF_TCP;
break;
} else if ( ipv6_next_header_type == IPPROTO_ICMPV6 ) {
if ( s + SIZEOF_ICMP6 > len ) {
printf( "ICMP6 Header:\n Too short\n" );
return NULL;
}
print_icmp6h( (struct icmp6_hdr *) ( packet_data + s ) );
found_type = IPPROTO_ICMPV6;
found_header = packet_data + s;
s += SIZEOF_ICMP6;
break;
} else if ( ipv6_next_header_type == IPPROTO_FRAGMENT ) {
if ( s + SIZEOF_FRAG > len ) {
printf( "Fragment Header:\n Too short\n" );
return NULL;
}
print_fragh( (struct ip6_frag *) ( packet_data + s ) );
found_type = IPPROTO_FRAGMENT;
found_header = packet_data + s;
if ( ntohs( ( (struct ip6_frag *) ( packet_data + s ) )->ip6f_offlg ) >> 3 > 0 ) {
printf( "[ Not parsing data fragment. ]\n" );
break;
}
ipv6_next_header_type = ( (struct ip6_frag *) ( packet_data + s ) )->ip6f_nxt;
s += SIZEOF_FRAG;
} else if ( ipv6_next_header_type == IPPROTO_DSTOPTS ) {
/*
* Wow, this is ugly! First check if we have enough room in the
* buffer to read the destopts header, then check we have to check
* again to see if we have the complete header.
*/
if ( s + SIZEOF_DESTOPT > len ) {
printf( "Destination Options Header:\n Too short\n" );
return NULL;
}
if (
(
s
+ 8 /*
* The Destination Options header length field is
* the total header length in 8 byte octets +
* another 8 bytes. See RFC 2460.
*/
+ ( ( (struct ip6_dest *) ( packet_data + s ) )->ip6d_len * 8 )
)
> len ) {
printf( "Destination Options Header:\n Too short (options truncated)\n" );
return NULL;
}
print_dstopth( (struct ip6_dest *) ( packet_data + s ) );
found_type = IPPROTO_DSTOPTS;
found_header = packet_data + s;
ipv6_next_header_type = ( (struct ip6_dest *) ( packet_data + s ) )->ip6d_nxt;
s += 8 + ( ( (struct ip6_dest *) ( packet_data + s ) )->ip6d_len * 8 );
} else {
printf( "Unsupported IPv6 Header:\n Next header: %i (%s)\n",
ipv6_next_header_type,
ip_protocol_to_name( ipv6_next_header_type )
);
return NULL;
}
}
} else { /* ETHERTYPE_IPV6 */
printf( "Unsupported Protocol:\n Ethertype: %i (%s)\n",
ntohs( ethh->ether_type ),
ether_protocol_to_name( ethh->ether_type )
);
return NULL;
}
if ( wanted_type == found_type ) return found_header;
return NULL;
}
int receive_a_packet( const char *filter_str, char **packet_buf, long receive_timeout, int signal_pipe )
{
struct pcap_pkthdr *received_packet_pcap;
struct bpf_program pcap_filter;
unsigned char *received_packet_data;
int r, fd;
fd_set select_me;
struct timeval ts;
if ( pcap_compile( pcap, &pcap_filter, filter_str, 1, 0 ) == -1 )
errx( 1, "pcap_compile failed: %s", pcap_geterr( pcap ) );
if ( pcap_setfilter( pcap, &pcap_filter ) == -1 )
errx( 1, "pcap_setfilter failed: %s", pcap_geterr( pcap ) );
pcap_freecode( &pcap_filter );
if ( ( fd = pcap_fileno( pcap ) ) == -1 )
errx( 1, "pcap_fileno failed" );
FD_ZERO( &select_me );
FD_SET( fd, &select_me );
ts.tv_sec = receive_timeout;
ts.tv_usec = 0;
if ( signal_pipe ) {
/*
* Signal we're ready to go. Still a race condition. I don't see how to
* work around this with pcap.
*/
write( pfd[1], ".", 1 );
}
r = select( fd + 1, &select_me, NULL, NULL, receive_timeout ? &ts : NULL );
/* Timed out */
if ( r == 0 ) return 0;
r = pcap_next_ex( pcap, &received_packet_pcap, (const unsigned char **) &received_packet_data );
/* Error or pcap_next_ex timed out (should never happen) */
if ( r < 1 ) return 0;
if ( received_packet_pcap->len > received_packet_pcap->caplen ) errx( 1, "pcap didn't capture the whole packet." );
*packet_buf = (char *) received_packet_data;
return received_packet_pcap->len;
}
int receive_synfrag_reply( char *srcip, char *dstip, unsigned short srcport, unsigned short dstport, enum TEST_TYPE test_type, char **packet_buf, long receive_timeout )
{
/*
* My back-of-the-napkin for the maximum length for the ipv6 filter string
* below + 1 byte for the trailing NULL
*/
const int FILTER_STR_LEN = 203;
char filter_str[FILTER_STR_LEN];
int r;
/*
* Something prior to now should have validated srcip and dstip are valid
* IP addresses, we hope. Napkin math says we shouldn't even be close to
* overflowing our buffer.
*/
if ( IS_TEST_IPV4( test_type ) ) {
r = snprintf(
(char *) &filter_str,
FILTER_STR_LEN,
"ip src %s and dst %s and (icmp or (tcp and src port %i and dst port %i))",
srcip,
dstip,
srcport,
dstport
);
} else {
r = snprintf(
(char *) &filter_str,
FILTER_STR_LEN,
/* Attempt to ignore ICMP6 neighbor solicitation/advertisement */
"ip6 src %s and dst %s and ((icmp6 and ip6[40] != 135 and ip6[40] != 136) or (tcp and src port %i and dst port %i))",
srcip,
dstip,
srcport,
dstport
);
}
if ( r < 0 || r >= FILTER_STR_LEN ) errx( 1, "snprintf for pcap filter failed" );
return receive_a_packet( filter_str, packet_buf, receive_timeout, 1 );
}
int get_isn_for_replay( char *interface, char *srcip, char *dstip, unsigned short dstport, enum TEST_TYPE test_type, uint32_t *isn, unsigned short *srcport )
{
const int FILTER_STR_LEN = 100;
char filter_str[FILTER_STR_LEN];
int r;
char *packet_buf;
struct tcphdr *tcph;
/*
* Something prior to now should have validated srcip and dstip are valid
* IP addresses, we hope. Napkin math says we shouldn't even be close to
* overflowing our buffer.
*/
if ( IS_TEST_IPV4( test_type ) ) {
r = snprintf(
(char *) &filter_str,
FILTER_STR_LEN,
"ip src %s and dst %s and tcp dst port %i",
srcip,
dstip,
dstport
);
} else {
r = snprintf(
(char *) &filter_str,
FILTER_STR_LEN,
"ip6 src %s and dst %s and tcp dst port %i",
srcip,
dstip,
dstport
);
}
if ( r < 0 || r >= FILTER_STR_LEN ) errx( 1, "snprintf for pcap filter failed" );
r = receive_a_packet( filter_str, &packet_buf, 0, 0 );
if ( !r ) return 0;
printf( "Found a matching outgoing TCP SYN:\n\n" );
tcph = (struct tcphdr *) print_a_packet( (char *) packet_buf, r, IPPROTO_TCP );
if ( !tcph ) return 0;
printf( "\nLooks good, sending replay.\n\n" );
*isn = tcph->th_seq;
*srcport = ntohs( tcph->th_sport );
free( packet_buf );
return 1;
}
int check_received_packet( int buf_len, char *packet_buf, enum TEST_TYPE test_type ) {
struct ether_header *received_packet_data = (struct ether_header *) packet_buf;
struct tcphdr *tcph;
struct icmp *icmph;
struct icmp6_hdr *icmp6h;
printf( "Received packet 1:\n\n" );
if ( IS_TEST_IPV4( test_type ) && IS_TEST_ICMP( test_type ) ) {
icmph = (struct icmp *) print_a_packet( (char *) received_packet_data, buf_len, IPPROTO_ICMP );
if ( !icmph ) return 0;
if ( icmph->icmp_type == ICMP_ECHOREPLY && icmph->icmp_id == htons( ICMP_ID ) ) return 1;
} else if ( IS_TEST_IPV6( test_type ) && IS_TEST_ICMP( test_type ) ) {
icmp6h = (struct icmp6_hdr *) print_a_packet( (char *) received_packet_data, buf_len, IPPROTO_ICMPV6 );
if ( !icmp6h ) return 0;
if ( icmp6h->icmp6_type == ICMP6_ECHO_REPLY && icmp6h->icmp6_id == htons( ICMP_ID ) ) return 1;
} else { /* Assume pcap picked the right address family for our packet. */
tcph = (struct tcphdr *) print_a_packet( (char *) received_packet_data, buf_len, IPPROTO_TCP );
if ( !tcph ) return 0;
if ( ( tcph->th_flags & ( TH_SYN|TH_ACK ) ) && !( tcph->th_flags & TH_RST ) ) {
return 1;
}
}
printf( "\nReceived reply but it wasn't what we were hoping for.\n" );
return 0;
}
/* IPv4 tests. */
void do_ipv4_syn( char *interface, char *srcip, char *dstip, char *srcmac, char *dstmac, unsigned short srcport, unsigned short dstport, uint32_t isn )
{
struct ip *iph;
struct tcphdr *tcph;
struct ether_header *ethh;
int packet_size;
packet_size = SIZEOF_ETHER + SIZEOF_TCP + SIZEOF_IPV4;
ethh = (struct ether_header *) malloc_check( BIG_PACKET_SIZE );
iph = (struct ip *) ( (char *) ethh + SIZEOF_ETHER );
tcph = (struct tcphdr *) ( (char *) iph + SIZEOF_IPV4 );
append_ethernet( ethh, srcmac, dstmac, ETHERTYPE_IP );
append_ipv4( iph, srcip, dstip, IPPROTO_TCP );
append_tcp_syn( tcph, srcport, dstport, isn );
calc_checksum( iph, IPPROTO_TCP, SIZEOF_TCP );
calc_checksum( iph, IPPROTO_IP, SIZEOF_IPV4 );
synfrag_send( ethh, packet_size );
free( ethh );
}
void do_ipv4_frag_tcp( char *interface, char *srcip, char *dstip, char *srcmac, char *dstmac, unsigned short srcport, unsigned short dstport, uint32_t isn )
{
struct ip *iph;
struct tcphdr *tcph;
struct ether_header *ethh;
int packet_size;
unsigned short fragid = rand();
packet_size = SIZEOF_ETHER + SIZEOF_IPV4 + MINIMUM_FRAGMENT_SIZE;
ethh = (struct ether_header *) malloc_check( BIG_PACKET_SIZE );
iph = (struct ip *) ( (char *) ethh + SIZEOF_ETHER );
tcph = (struct tcphdr *) ( (char *) iph + SIZEOF_IPV4 );
append_ethernet( ethh, srcmac, dstmac, ETHERTYPE_IP );
append_ipv4_short_frag1( iph, srcip, dstip, IPPROTO_TCP, fragid );
append_tcp_syn( tcph, srcport, dstport, isn );
calc_checksum( iph, IPPROTO_TCP, SIZEOF_TCP );
calc_checksum( iph, IPPROTO_IP, SIZEOF_IPV4 );
synfrag_send( ethh, packet_size );
packet_size = SIZEOF_ETHER + SIZEOF_IPV4 + SIZEOF_TCP - MINIMUM_FRAGMENT_SIZE;
append_ipv4_frag2( iph, srcip, dstip, IPPROTO_TCP, fragid, SIZEOF_TCP - MINIMUM_FRAGMENT_SIZE );
memmove( tcph, (char *) tcph + MINIMUM_FRAGMENT_SIZE, SIZEOF_TCP - MINIMUM_FRAGMENT_SIZE );
calc_checksum( iph, IPPROTO_IP, SIZEOF_IPV4 );
synfrag_send( ethh, packet_size );
free( ethh );
}
void do_ipv4_frag_icmp( char *interface, char *srcip, char *dstip, char *srcmac, char *dstmac )
{
struct ip *iph;
struct icmp *icmph;
struct ether_header *ethh;
int packet_size;
unsigned short fragid = rand();
unsigned short pinglen = 40;
packet_size = SIZEOF_ETHER + SIZEOF_IPV4 + MINIMUM_FRAGMENT_SIZE;
ethh = (struct ether_header *) malloc_check( BIG_PACKET_SIZE );
iph = (struct ip *) ( (char *) ethh + SIZEOF_ETHER );
icmph = (struct icmp *) ( (char *) iph + SIZEOF_IPV4 );
append_ethernet( ethh, srcmac, dstmac, ETHERTYPE_IP );
append_ipv4_short_frag1( iph, srcip, dstip, IPPROTO_ICMP, fragid );
append_icmp_ping( icmph, pinglen );
calc_checksum( iph, IPPROTO_IP, SIZEOF_IPV4 );
calc_checksum( iph, IPPROTO_ICMP, SIZEOF_PING + pinglen );
synfrag_send( ethh, packet_size );
packet_size = SIZEOF_ETHER + SIZEOF_IPV4 + SIZEOF_PING + pinglen - MINIMUM_FRAGMENT_SIZE;
append_ipv4_frag2( iph, srcip, dstip, IPPROTO_ICMP, fragid, SIZEOF_PING + pinglen - MINIMUM_FRAGMENT_SIZE );
memmove( icmph, (char *) icmph + MINIMUM_FRAGMENT_SIZE, SIZEOF_PING + pinglen - MINIMUM_FRAGMENT_SIZE );
calc_checksum( iph, IPPROTO_IP, SIZEOF_IPV4 );
synfrag_send( ethh, packet_size );
free( ethh );
}
void do_ipv4_options_tcp_frag( char *interface, char *srcip, char *dstip, char *srcmac, char *dstmac, unsigned short srcport, unsigned short dstport, uint32_t isn )
{
struct ip *iph;
struct tcphdr *tcph, *tcph_optioned;
struct ether_header *ethh;
int packet_size;
unsigned short fragid = rand();
unsigned short optlen = 40; /* Multiple of 4. */
packet_size = SIZEOF_ETHER + SIZEOF_IPV4 + optlen + MINIMUM_FRAGMENT_SIZE;
ethh = (struct ether_header *) malloc_check( BIG_PACKET_SIZE );
iph = (struct ip *) ( (char *) ethh + SIZEOF_ETHER );
tcph = (struct tcphdr *) ( (char *) iph + SIZEOF_IPV4 );
tcph_optioned = (struct tcphdr *) ( (char *) tcph + optlen );
append_ethernet( ethh, srcmac, dstmac, ETHERTYPE_IP );
append_ipv4_optioned_frag1( iph, srcip, dstip, IPPROTO_TCP, fragid, optlen );
append_tcp_syn( tcph_optioned, srcport, dstport, isn );
calc_checksum( iph, IPPROTO_TCP, SIZEOF_TCP );
calc_checksum( iph, IPPROTO_IP, SIZEOF_IPV4 + optlen );
synfrag_send( ethh, packet_size );
packet_size = SIZEOF_ETHER + SIZEOF_IPV4 + SIZEOF_TCP - MINIMUM_FRAGMENT_SIZE;
append_ipv4_frag2( iph, srcip, dstip, IPPROTO_TCP, fragid, SIZEOF_TCP - MINIMUM_FRAGMENT_SIZE );
memmove( tcph, (char *) tcph_optioned + MINIMUM_FRAGMENT_SIZE, SIZEOF_TCP - MINIMUM_FRAGMENT_SIZE );
calc_checksum( iph, IPPROTO_IP, SIZEOF_IPV4 );
synfrag_send( ethh, packet_size );
free( ethh );
}
void do_ipv4_options_icmp_frag( char *interface, char *srcip, char *dstip, char *srcmac, char *dstmac )
{
struct ip *iph;
struct icmp *icmph, *icmph_optioned;
struct ether_header *ethh;
int packet_size;
unsigned short fragid = rand();
unsigned short optlen = 40; /* Multiple of 4. */
unsigned short pinglen = 40;
packet_size = SIZEOF_ETHER + SIZEOF_IPV4 + optlen + MINIMUM_FRAGMENT_SIZE;
ethh = (struct ether_header *) malloc_check( BIG_PACKET_SIZE );
iph = (struct ip *) ( (char *) ethh + SIZEOF_ETHER );
icmph = (struct icmp *) ( (char *) iph + SIZEOF_IPV4 );
icmph_optioned = (struct icmp *) ( (char *) icmph + optlen );
append_ethernet( ethh, srcmac, dstmac, ETHERTYPE_IP );
append_ipv4_optioned_frag1( iph, srcip, dstip, IPPROTO_ICMP, fragid, optlen );
append_icmp_ping( icmph_optioned, pinglen );
calc_checksum( iph, IPPROTO_ICMP, SIZEOF_PING + pinglen );
calc_checksum( iph, IPPROTO_IP, SIZEOF_IPV4 + optlen );
synfrag_send( ethh, packet_size );
packet_size = SIZEOF_ETHER + SIZEOF_IPV4 + SIZEOF_PING + pinglen;
append_ipv4_frag2( iph, srcip, dstip, IPPROTO_ICMP, fragid, SIZEOF_PING - MINIMUM_FRAGMENT_SIZE + pinglen );
memmove( icmph, (char *) icmph_optioned + MINIMUM_FRAGMENT_SIZE, SIZEOF_PING + pinglen - MINIMUM_FRAGMENT_SIZE );
calc_checksum( iph, IPPROTO_IP, SIZEOF_IPV4 );
synfrag_send( ethh, packet_size );
free( ethh );
}
/* IPv6 tests. */
void do_ipv6_syn( char *interface, char *srcip, char *dstip, char *srcmac, char *dstmac, unsigned short srcport, unsigned short dstport, uint32_t isn )
{
struct ip6_hdr *ip6h;
struct tcphdr *tcph;
struct ether_header *ethh;
int packet_size;
packet_size = SIZEOF_ETHER + SIZEOF_IPV6 + SIZEOF_TCP;
ethh = (struct ether_header *) malloc_check( BIG_PACKET_SIZE );
ip6h = (struct ip6_hdr *) ( (char *) ethh + SIZEOF_ETHER );
tcph = (struct tcphdr *) ( (char *) ip6h + SIZEOF_IPV6 );
append_ethernet( ethh, srcmac, dstmac, ETHERTYPE_IPV6 );
append_ipv6( ip6h, srcip, dstip, IPPROTO_TCP, SIZEOF_TCP );
append_tcp_syn( tcph, srcport, dstport, isn );
calc_checksum( ip6h, IPPROTO_TCP, SIZEOF_TCP );
synfrag_send( ethh, packet_size );
free( ethh );
}
void do_ipv6_frag_tcp( char *interface, char *srcip, char *dstip, char *srcmac, char *dstmac, unsigned short srcport, unsigned short dstport, uint32_t isn )
{
struct ip6_hdr *ip6h;
struct tcphdr *tcph;
struct ether_header *ethh;
int packet_size;
unsigned short fragid = rand();
void *next;
packet_size = SIZEOF_ETHER + SIZEOF_IPV6 + SIZEOF_FRAG + MINIMUM_FRAGMENT_SIZE;
ethh = (struct ether_header *) malloc_check( BIG_PACKET_SIZE );
ip6h = (struct ip6_hdr *) ( (char *) ethh + SIZEOF_ETHER );
tcph = (struct tcphdr *) ( (char *) ip6h + SIZEOF_IPV6 + SIZEOF_FRAG );
next = append_ethernet( ethh, srcmac, dstmac, ETHERTYPE_IPV6 );
next = append_ipv6( next, srcip, dstip, IPPROTO_FRAGMENT, SIZEOF_FRAG + MINIMUM_FRAGMENT_SIZE );
next = append_frag_first( next, IPPROTO_TCP, fragid );
append_tcp_syn( next, srcport, dstport, isn );
calc_checksum( ip6h, IPPROTO_TCP, SIZEOF_TCP );
synfrag_send( ethh, packet_size );
packet_size = SIZEOF_ETHER + SIZEOF_IPV6 + SIZEOF_FRAG + SIZEOF_TCP - MINIMUM_FRAGMENT_SIZE;
next = append_ipv6( ip6h, srcip, dstip, IPPROTO_FRAGMENT, SIZEOF_FRAG + SIZEOF_TCP - MINIMUM_FRAGMENT_SIZE );
append_frag_last( next, IPPROTO_TCP, MINIMUM_FRAGMENT_SIZE, fragid );
memmove( tcph, (char *) tcph + MINIMUM_FRAGMENT_SIZE, SIZEOF_TCP - MINIMUM_FRAGMENT_SIZE );
synfrag_send( ethh, packet_size );
free( ethh );
}
void do_ipv6_frag_icmp( char *interface, char *srcip, char *dstip, char *srcmac, char *dstmac )
{
struct ip6_hdr *ip6h;
struct icmp6_hdr *icmp6h;
struct ether_header *ethh;
void *next;
int packet_size;
unsigned short fragid = rand();
unsigned short pinglen = 40;
packet_size = SIZEOF_ETHER + SIZEOF_IPV6 + SIZEOF_FRAG + MINIMUM_FRAGMENT_SIZE;
ethh = (struct ether_header *) malloc_check( BIG_PACKET_SIZE );
ip6h = (struct ip6_hdr *) ( (char *) ethh + SIZEOF_ETHER );
icmp6h = (struct icmp6_hdr *) ( (char *) ip6h + SIZEOF_IPV6 + SIZEOF_FRAG );
next = append_ethernet( ethh, srcmac, dstmac, ETHERTYPE_IPV6 );
next = append_ipv6( next, srcip, dstip, IPPROTO_FRAGMENT, SIZEOF_FRAG + MINIMUM_FRAGMENT_SIZE );
next = append_frag_first( next, IPPROTO_ICMPV6, fragid );
append_icmp6_ping( next, pinglen );
calc_checksum( ip6h, IPPROTO_ICMPV6, SIZEOF_ICMP6 + pinglen );
synfrag_send( ethh, packet_size );
packet_size = SIZEOF_ETHER + SIZEOF_IPV6 + SIZEOF_FRAG + SIZEOF_ICMP6 + pinglen - MINIMUM_FRAGMENT_SIZE;
next = append_ipv6( ip6h, srcip, dstip, IPPROTO_FRAGMENT, SIZEOF_FRAG + SIZEOF_ICMP6 + pinglen - MINIMUM_FRAGMENT_SIZE );
next = append_frag_last( next, IPPROTO_ICMPV6, MINIMUM_FRAGMENT_SIZE, fragid );
memmove( icmp6h, (char *) icmp6h + MINIMUM_FRAGMENT_SIZE, SIZEOF_ICMP6 + pinglen - MINIMUM_FRAGMENT_SIZE );
synfrag_send( ethh, packet_size );
free( ethh );
}
void do_ipv6_dstopt_frag_icmp( char *interface, char *srcip, char *dstip, char *srcmac, char *dstmac )
{
struct ip6_hdr *ip6h;
struct icmp6_hdr *icmp6h, *icmp6h_optioned;
struct ether_header *ethh;
void *next;
int packet_size;
unsigned short fragid = rand();
unsigned short optlen = fix_up_destination_options_length(
MINIMUM_PACKET_SIZE - SIZEOF_IPV6 - SIZEOF_DESTOPT - SIZEOF_FRAG - MINIMUM_FRAGMENT_SIZE
);
/*
* pinglen must be > 6 or our first packet will be <= MINIMUM_PACKET_SIZE bytes and
* our second packet empty.
*/
unsigned short pinglen = 40;
packet_size = SIZEOF_ETHER + SIZEOF_IPV6 + SIZEOF_DESTOPT + optlen + SIZEOF_FRAG + MINIMUM_FRAGMENT_SIZE;
ethh = (struct ether_header *) malloc_check( BIG_PACKET_SIZE );
ip6h = (struct ip6_hdr *) ( (char *) ethh + SIZEOF_ETHER );
icmp6h = (struct icmp6_hdr *) ( (char *) ip6h + SIZEOF_IPV6 + SIZEOF_FRAG );
icmp6h_optioned = (struct icmp6_hdr *) ( (char *) ip6h + SIZEOF_IPV6 + SIZEOF_DESTOPT + optlen + SIZEOF_FRAG + MINIMUM_FRAGMENT_SIZE );
next = append_ethernet( ethh, srcmac, dstmac, ETHERTYPE_IPV6 );
next = append_ipv6( next, srcip, dstip, IPPROTO_DSTOPTS, SIZEOF_DESTOPT + optlen + SIZEOF_FRAG + MINIMUM_FRAGMENT_SIZE );
next = append_dest( next, IPPROTO_FRAGMENT, optlen );
next = append_frag_first( next, IPPROTO_ICMPV6, fragid );
append_icmp6_ping( icmp6h_optioned, pinglen );
calc_checksum( ip6h, IPPROTO_ICMPV6, SIZEOF_ICMP6 + pinglen );
synfrag_send( ethh, packet_size );