libnet_ptag_t
libnet_build_egre(uint16_t fv, uint16_t type, uint16_t sum,
uint16_t offset, uint32_t key, uint32_t seq, uint16_t len,
const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)
{
return (libnet_build_gre(fv, type, sum, offset, key, seq, len,
payload, payload_s, l, ptag));
}
int libnet_gen_l4_packet( struct packet_desc *packet_vars, libnet_t *l ) {
libnet_ptag_t t;
char *payload;
u_short payload_s;
u_long src_ip, dst_ip;
u_short src_prt, dst_prt;
u_short options = 0;
if (packet_vars->l4_pkt_type == 0) {
/* NO L4 Processing*/
return(1);
}
if ((packet_vars->l3_pkt_type == 0) || (packet_vars->l2_pkt_type == 0)) {
printf(" TEST PROGRAM ERROR !! \n");
return(-1);
}
#if 0
if( /*TCP_OPTIONS*/) {
// Add code here
}
#endif
payload = genPayload(packet_vars->payload.data_type,
packet_vars->payload.data_seed,packet_vars->l4_len);
payload_s = packet_vars->l4_len;
if (packet_vars->l4_pkt_type & L4_PKT_TYPE_TCP) {
printf(" Building TCP Packet!! \n");
t = libnet_build_tcp(
packet_vars->tcp.src_port, /* source port */
packet_vars->tcp.dst_port, /* destination port */
packet_vars->tcp.seq_no, /* sequence number */
packet_vars->tcp.ack_no, /* acknowledgement num */
packet_vars->tcp.tcp_flags, /* control flags */
0, /* window size */
packet_vars->tcp.checksum, /* checksum */
0, /* urgent pointer */
LIBNET_TCP_H + options + payload_s, /* TCP packet size */
payload, /* payload */
payload_s, /* payload size */
l, /* libnet handle */
0); /* libnet id */
if (t == -1)
{
fprintf(stderr, "Can't build TCP header: %s\n", libnet_geterror(l));
return(-1);
}
} else if (packet_vars->l4_pkt_type & L4_PKT_TYPE_UDP) {
printf(" Building UDP Packet!! \n");
t = libnet_build_udp(
packet_vars->udp.src_port, /* source port */
packet_vars->udp.dst_port , /* destination port */
LIBNET_UDP_H + payload_s, /* packet length */
packet_vars->udp.checksum, /* checksum */
payload, /* payload */
payload_s, /* payload size */
l, /* libnet handle */
0); /* libnet id */
if (t == -1)
{
fprintf(stderr, "Can't build UDP header: %s\n", libnet_geterror(l));
return(-1);
}
} else if (packet_vars->l4_pkt_type & L4_PKT_TYPE_AH) {
printf(" Building AH Packet!! \n");
packet_vars->ipsec_ah.nh = 0;
packet_vars->ipsec_ah.len =
packet_vars->ipsec_ah.res = 0;
packet_vars->ipsec_ah.auth = 0xa5a5a5a5;
t = libnet_build_ipsec_ah(
packet_vars->ipsec_ah.nh,
packet_vars->ipsec_ah.len,
packet_vars->ipsec_ah.res,
packet_vars->ipsec_ah.spi,
packet_vars->ipsec_ah.seq,
packet_vars->ipsec_ah.auth,
payload,
payload_s,
l,
0);
if (t == -1)
{
fprintf(stderr, "Can't build IPSEC_AH header: %s\n",
libnet_geterror(l));
return(-1);
}
} else if (packet_vars->l4_pkt_type & L4_PKT_TYPE_ESP) {
printf(" Building ESP Packet!! \n");
t = libnet_build_ipsec_esp_hdr(
packet_vars->ipsec_ah.spi,
packet_vars->ipsec_ah.seq,
0xa5a5a5a5, // TMP - not sure what can be used here
payload,
payload_s,
l,
0);
if (t == -1) {
fprintf(stderr, "Can't build IPSEC_ESP header: %s\n",
libnet_geterror(l));
return(-1);
}
} else if (packet_vars->l4_pkt_type & L4_PKT_TYPE_SCTP) {
printf("---Building SCTP packet\n");
t = libnet_build_sctp(
packet_vars->sctp.src_port, /* source port */
packet_vars->sctp.dst_port, /* dest port */
packet_vars->sctp.vtag, /* verification tag */
packet_vars->sctp.checksum, /* checksum */
payload, /* payload */
payload_s, /* payload size */
l, /* libnet handle */
0); /* libnet id */
if (t == -1) {
fprintf(stderr, "Can't build SCTP header: %s\n", libnet_geterror(l));
return(-1);
}
} else if (packet_vars->l4_pkt_type & L4_PKT_TYPE_ICMP) {
u_int8_t icmp_type;
if (packet_vars->l3_pkt_type & L3_PKT_TYPE_IPV4) {
if (packet_vars->icmp.type == ICMP_TYPE_ECHO_REQ) {
icmp_type = ICMP_ECHO;
} else if (packet_vars->icmp.type == ICMP_TYPE_ECHO_REPLY) {
icmp_type = ICMP_ECHOREPLY;
} else {
fprintf(stderr, "Unsupported ICMP type: %d\n", packet_vars->icmp.type);
return(-1);
}
printf("---Building ICMPv4 packet\n");
} else if (packet_vars->l3_pkt_type & L3_PKT_TYPE_IPV6) {
if (packet_vars->icmp.type == ICMP_TYPE_ECHO_REQ) {
icmp_type = ICMP6_ECHO;
} else if (packet_vars->icmp.type == ICMP_TYPE_ECHO_REPLY) {
icmp_type = ICMP6_ECHOREPLY;
} else {
fprintf(stderr, "Unsupported ICMP type: %d\n", packet_vars->icmp.type);
return(-1);
}
printf("---Building ICMPv6 packet\n");
} else {
fprintf(stderr, "Unsupported L3 type %d for ICMP\n",
packet_vars->l3_pkt_type);
return(-1);
}
t = libnet_build_icmpv4_echo(
icmp_type, /* type */
0, /* code */
packet_vars->icmp.checksum, /* checksum */
packet_vars->icmp.id, /* id */
packet_vars->icmp.seq, /* sequence number */
payload, /* payload */
payload_s, /* payload size */
l, /* libnet handle */
0); /* libnet id */
if (t == -1) {
fprintf(stderr, "Can't build ICMP header: %s\n", libnet_geterror(l));
return(-1);
}
} else if (packet_vars->l4_pkt_type & L4_PKT_TYPE_IGMP) {
printf("---Building IGMP packet\n");
t = libnet_build_igmp(
packet_vars->igmp.type, /* IGMP type */
0, /* IGMP code (unused in v1 and v2) */
packet_vars->igmp.checksum, /* checksum */
packet_vars->igmp.grp_ip, /* Group host IP */
payload, /* payload */
payload_s, /* payload size */
l, /* libnet handle */
0); /* libnet id */
if (t == -1) {
fprintf(stderr, "Can't build IGMP header: %s\n", libnet_geterror(l));
return(-1);
}
} else if (packet_vars->l4_pkt_type & L4_PKT_TYPE_PIM) {
printf("---Building PIM packet\n");
t = libnet_build_pim(
packet_vars->pim.version, /* PIM version */
packet_vars->pim.type, /* PIM type */
packet_vars->pim.checksum, /* checksum */
payload, /* payload */
payload_s, /* payload size */
l, /* libnet handle */
0); /* libnet id */
if (t == -1) {
fprintf(stderr, "Can't build PIM header: %s\n", libnet_geterror(l));
return(-1);
}
} else if (packet_vars->l4_pkt_type & L4_PKT_TYPE_RSVP) {
printf("---Building RSVP packet\n");
t = libnet_build_rsvp(
packet_vars->rsvp.version, /* RSVP version */
packet_vars->rsvp.flags, /* RSVP flags */
packet_vars->rsvp.type, /* RSVP mesg type */
packet_vars->rsvp.do_chksum, /* 1 - pkt is chksummed, 0, its not */
packet_vars->rsvp.checksum, /* checksum */
packet_vars->rsvp.ttl, /* IP TTL */
LIBNET_RSVP_H + payload_s, /* pkt len */
payload, /* payload */
payload_s, /* payload size */
l, /* libnet handle */
0); /* libnet id */
if (t == -1) {
fprintf(stderr, "Can't build RSVP header: %s\n", libnet_geterror(l));
return(-1);
}
} else if (packet_vars->l4_pkt_type & L4_PKT_TYPE_GRE) {
/* update l4_len */
uint16_t flag_ver = 0;
uint16_t type = 0;
uint16_t len = 0;
printf("---Building GRE,v0 packet\n");
if (packet_vars->gre.csum) {
flag_ver |= GRE_CSUM;
}
if (packet_vars->gre.rout) {
flag_ver |= GRE_ROUTING;
}
if (packet_vars->gre.key) {
flag_ver |= GRE_KEY;
}
if (packet_vars->gre.seq) {
flag_ver |= GRE_SEQ;
}
flag_ver |= GRE_VERSION_0;
type = libnet_get_ethernet_proto(packet_vars);
len = libnet_getgre_length(flag_ver);
packet_vars->l4_len += (len - LIBNET_GRE_H);
packet_vars->payload.data_length += (len - LIBNET_GRE_H);
len += payload_s;
t = libnet_build_gre(
flag_ver, /* flags and version fields */
type, /* protocol type */
packet_vars->gre.checksum, /* checksum */
0, /* offset */
packet_vars->gre.key_val, /* key */
packet_vars->gre.seq_num, /* sequence number */
len, /* GRE pkt length */
payload,
payload_s,
l,
0);
if (t == -1) {
fprintf(stderr, "Can't build GRE,v0 header: %s\n", libnet_geterror(l));
return(-1);
}
} else if (packet_vars->l4_pkt_type & L4_PKT_TYPE_EGRE) {
/* update l4_len */
uint16_t flag_ver = 0;
uint16_t len = 0;
printf("---Building GRE,v1 packet\n");
flag_ver |= GRE_KEY;
if (packet_vars->egre.seq) {
flag_ver |= GRE_SEQ;
}
if (packet_vars->egre.ack) {
flag_ver |= GRE_ACK;
}
flag_ver |= GRE_VERSION_1;
len = libnet_getgre_length(flag_ver);
packet_vars->l4_len += (len - LIBNET_GRE_H);
packet_vars->payload.data_length += (len - LIBNET_GRE_H);
len += payload_s;
t = libnet_build_egre(
flag_ver, /* flags and version fields */
0x880b, /* protocol type */
payload_s, /* payload length */
0, /* call ID */
packet_vars->egre.seq_num, /* sequence number */
packet_vars->egre.ack_num, /* ack number */
len, /* GRE pkt length */
payload,
payload_s,
l,
0);
if (t == -1) {
fprintf(stderr, "Can't build GRE,v1 header: %s\n", libnet_geterror(l));
return(-1);
}
} else {/*??*/
printf("UNSUPPORTED PKT_TYPE !! \n");
return(-1);
}
return(1);
}
