static void msproxy_sub_dissector( tvbuff_t *tvb, packet_info *pinfo,
proto_tree *tree) {
/* Conversation dissector called from TCP or UDP dissector. Decode and */
/* display the msproxy header, the pass the rest of the data to the tcp */
/* or udp port decode routine to handle the payload. */
guint32 *ptr;
redirect_entry_t *redirect_info;
conversation_t *conversation;
proto_tree *msp_tree;
proto_item *ti;
conversation = find_conversation( pinfo->fd->num, &pinfo->src, &pinfo->dst,
pinfo->ptype, pinfo->srcport, pinfo->destport, 0);
DISSECTOR_ASSERT( conversation); /* should always find a conversation */
redirect_info = conversation_get_proto_data(conversation,
proto_msproxy);
col_set_str(pinfo->cinfo, COL_PROTOCOL, "MS Proxy");
if (check_col(pinfo->cinfo, COL_INFO))
col_set_str(pinfo->cinfo, COL_INFO,
(( redirect_info->proto == PT_TCP) ? "TCP stream" :
"UDP packets"));
if ( tree) {
ti = proto_tree_add_item( tree, proto_msproxy, tvb, 0, 0,
FALSE );
msp_tree = proto_item_add_subtree(ti, ett_msproxy);
proto_tree_add_uint( msp_tree, hf_msproxy_dstport, tvb, 0, 0,
redirect_info->remote_port);
proto_tree_add_ipv4( msp_tree, hf_msproxy_dstaddr, tvb, 0, 0,
redirect_info->remote_addr);
}
/* set pinfo->{src/dst port} and call the UDP sub-dissector lookup */
if ( pinfo->srcport == redirect_info->clnt_port)
ptr = &pinfo->destport;
else
ptr = &pinfo->srcport;
*ptr = redirect_info->remote_port;
if ( redirect_info->proto == PT_TCP)
decode_tcp_ports( tvb, 0, pinfo, tree, pinfo->srcport,
pinfo->destport, NULL);
else
decode_udp_ports( tvb, 0, pinfo, tree, pinfo->srcport,
pinfo->destport, -1);
*ptr = redirect_info->server_int_port;
}
static void
socks_udp_dissector(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
/* Conversation dissector called from UDP dissector. Decode and display */
/* the socks header, the pass the rest of the data to the udp port */
/* decode routine to handle the payload. */
int offset = 0;
guint32 *ptr;
socks_hash_entry_t *hash_info;
conversation_t *conversation;
proto_tree *socks_tree;
proto_item *ti;
conversation = find_conversation( pinfo->fd->num, &pinfo->src, &pinfo->dst, pinfo->ptype,
pinfo->srcport, pinfo->destport, 0);
DISSECTOR_ASSERT( conversation); /* should always find a conversation */
hash_info = (socks_hash_entry_t *)conversation_get_proto_data(conversation, proto_socks);
col_set_str(pinfo->cinfo, COL_PROTOCOL, "Socks");
col_set_str(pinfo->cinfo, COL_INFO, "Version: 5, UDP Associated packet");
if ( tree) {
ti = proto_tree_add_protocol_format( tree, proto_socks, tvb, offset, -1, "Socks" );
socks_tree = proto_item_add_subtree(ti, ett_socks);
proto_tree_add_item(socks_tree, hf_socks_reserved2, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
proto_tree_add_item(socks_tree, hf_socks_fragment_number, tvb, offset, 1, ENC_NA);
offset += 1;
offset = display_address( tvb, offset, socks_tree);
hash_info->udp_remote_port = tvb_get_ntohs(tvb, offset);
proto_tree_add_uint( socks_tree, hf_socks_dstport, tvb,
offset, 2, hash_info->udp_remote_port);
offset += 2;
}
else { /* no tree, skip past the socks header */
offset += 3;
offset = get_address_v5( tvb, offset, 0) + 2;
}
/* set pi src/dst port and call the udp sub-dissector lookup */
if ( pinfo->srcport == hash_info->port)
ptr = &pinfo->destport;
else
ptr = &pinfo->srcport;
*ptr = hash_info->udp_remote_port;
decode_udp_ports( tvb, offset, pinfo, tree, pinfo->srcport, pinfo->destport, -1);
*ptr = hash_info->udp_port;
}
static void
dissect(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 ip_proto)
{
proto_tree *udp_tree = NULL;
proto_item *ti, *hidden_item, *port_item;
guint len;
guint reported_len;
vec_t cksum_vec[4];
guint32 phdr[2];
guint16 computed_cksum;
int offset = 0;
e_udphdr *udph;
proto_tree *checksum_tree;
proto_item *item;
conversation_t *conv = NULL;
struct udp_analysis *udpd = NULL;
proto_tree *process_tree;
udph=ep_new(e_udphdr);
SET_ADDRESS(&udph->ip_src, pinfo->src.type, pinfo->src.len, pinfo->src.data);
SET_ADDRESS(&udph->ip_dst, pinfo->dst.type, pinfo->dst.len, pinfo->dst.data);
col_set_str(pinfo->cinfo, COL_PROTOCOL, (ip_proto == IP_PROTO_UDP) ? "UDP" : "UDPlite");
col_clear(pinfo->cinfo, COL_INFO);
udph->uh_sport=tvb_get_ntohs(tvb, offset);
udph->uh_dport=tvb_get_ntohs(tvb, offset+2);
col_add_fstr(pinfo->cinfo, COL_INFO, "Source port: %s Destination port: %s",
get_udp_port(udph->uh_sport), get_udp_port(udph->uh_dport));
if (tree) {
if (udp_summary_in_tree) {
if (ip_proto == IP_PROTO_UDP) {
ti = proto_tree_add_protocol_format(tree, proto_udp, tvb, offset, 8,
"User Datagram Protocol, Src Port: %s (%u), Dst Port: %s (%u)",
get_udp_port(udph->uh_sport), udph->uh_sport, get_udp_port(udph->uh_dport), udph->uh_dport);
} else {
ti = proto_tree_add_protocol_format(tree, proto_udplite, tvb, offset, 8,
"Lightweight User Datagram Protocol, Src Port: %s (%u), Dst Port: %s (%u)",
get_udp_port(udph->uh_sport), udph->uh_sport, get_udp_port(udph->uh_dport), udph->uh_dport);
}
} else {
ti = proto_tree_add_item(tree, (ip_proto == IP_PROTO_UDP) ? proto_udp : proto_udplite, tvb, offset, 8, ENC_NA);
}
udp_tree = proto_item_add_subtree(ti, ett_udp);
port_item = proto_tree_add_uint_format(udp_tree, hf_udp_srcport, tvb, offset, 2, udph->uh_sport,
"Source port: %s (%u)", get_udp_port(udph->uh_sport), udph->uh_sport);
/* The beginning port number, 32768 + 666 (33434), is from LBL's traceroute.c source code and this code
* further assumes that 3 attempts are made per hop */
if(udph->uh_sport > 32768 + 666 && udph->uh_sport <= 32768 + 666 + 30)
expert_add_info_format(pinfo, port_item, PI_SEQUENCE, PI_CHAT, "Possible traceroute: hop #%u, attempt #%u",
((udph->uh_sport - 32768 - 666 - 1) / 3) + 1,
((udph->uh_sport - 32768 - 666 - 1) % 3) + 1
);
port_item = proto_tree_add_uint_format(udp_tree, hf_udp_dstport, tvb, offset + 2, 2, udph->uh_dport,
"Destination port: %s (%u)", get_udp_port(udph->uh_dport), udph->uh_dport);
if(udph->uh_dport > 32768 + 666 && udph->uh_dport <= 32768 + 666 + 30)
expert_add_info_format(pinfo, port_item, PI_SEQUENCE, PI_CHAT, "Possible traceroute: hop #%u, attempt #%u",
((udph->uh_dport - 32768 - 666 - 1) / 3) + 1,
((udph->uh_dport - 32768 - 666 - 1) % 3) + 1
);
hidden_item = proto_tree_add_uint(udp_tree, hf_udp_port, tvb, offset, 2, udph->uh_sport);
PROTO_ITEM_SET_HIDDEN(hidden_item);
hidden_item = proto_tree_add_uint(udp_tree, hf_udp_port, tvb, offset+2, 2, udph->uh_dport);
PROTO_ITEM_SET_HIDDEN(hidden_item);
}
if (ip_proto == IP_PROTO_UDP) {
udph->uh_ulen = udph->uh_sum_cov = tvb_get_ntohs(tvb, offset+4);
if (udph->uh_ulen < 8) {
/* Bogus length - it includes the header, so it must be >= 8. */
/* XXX - should handle IPv6 UDP jumbograms (RFC 2675), where the length is zero */
item = proto_tree_add_uint_format(udp_tree, hf_udp_length, tvb, offset + 4, 2,
udph->uh_ulen, "Length: %u (bogus, must be >= 8)", udph->uh_ulen);
expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR, "Bad length value %u < 8", udph->uh_ulen);
col_append_fstr(pinfo->cinfo, COL_INFO, " [BAD UDP LENGTH %u < 8]", udph->uh_ulen);
return;
}
if ((udph->uh_ulen > tvb_reported_length(tvb)) && ! pinfo->fragmented && ! pinfo->flags.in_error_pkt) {
/* Bogus length - it goes past the end of the IP payload */
item = proto_tree_add_uint_format(udp_tree, hf_udp_length, tvb, offset + 4, 2,
udph->uh_ulen, "Length: %u (bogus, payload length %u)", udph->uh_ulen, tvb_reported_length(tvb));
expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR, "Bad length value %u > IP payload length", udph->uh_ulen);
col_append_fstr(pinfo->cinfo, COL_INFO, " [BAD UDP LENGTH %u > IP PAYLOAD LENGTH]", udph->uh_ulen);
} else {
if (tree) {
proto_tree_add_uint(udp_tree, hf_udp_length, tvb, offset + 4, 2, udph->uh_ulen);
/* XXX - why is this here, given that this is UDP, not Lightweight UDP? */
hidden_item = proto_tree_add_uint(udp_tree, hf_udplite_checksum_coverage, tvb, offset + 4,
0, udph->uh_sum_cov);
PROTO_ITEM_SET_HIDDEN(hidden_item);
}
}
} else {
udph->uh_ulen = pinfo->iplen - pinfo->iphdrlen;
udph->uh_sum_cov = tvb_get_ntohs(tvb, offset+4);
if (((udph->uh_sum_cov > 0) && (udph->uh_sum_cov < 8)) || (udph->uh_sum_cov > udph->uh_ulen)) {
/* Bogus length - it includes the header, so it must be >= 8, and no larger then the IP payload size. */
if (tree) {
hidden_item = proto_tree_add_boolean(udp_tree, hf_udplite_checksum_coverage_bad, tvb, offset + 4, 2, TRUE);
PROTO_ITEM_SET_HIDDEN(hidden_item);
hidden_item = proto_tree_add_uint(udp_tree, hf_udp_length, tvb, offset + 4, 0, udph->uh_ulen);
PROTO_ITEM_SET_HIDDEN(hidden_item);
}
item = proto_tree_add_uint_format(udp_tree, hf_udplite_checksum_coverage, tvb, offset + 4, 2,
udph->uh_sum_cov, "Checksum coverage: %u (bogus, must be >= 8 and <= %u (ip.len-ip.hdr_len))",
udph->uh_sum_cov, udph->uh_ulen);
expert_add_info_format(pinfo, item, PI_MALFORMED, PI_ERROR, "Bad checksum coverage length value %u < 8 or > %u",
udph->uh_sum_cov, udph->uh_ulen);
col_append_fstr(pinfo->cinfo, COL_INFO, " [BAD LIGHTWEIGHT UDP CHECKSUM COVERAGE LENGTH %u < 8 or > %u]",
udph->uh_sum_cov, udph->uh_ulen);
if (!udplite_ignore_checksum_coverage)
return;
} else {
if (tree) {
hidden_item = proto_tree_add_uint(udp_tree, hf_udp_length, tvb, offset + 4, 0, udph->uh_ulen);
PROTO_ITEM_SET_HIDDEN(hidden_item);
proto_tree_add_uint(udp_tree, hf_udplite_checksum_coverage, tvb, offset + 4, 2, udph->uh_sum_cov);
}
}
}
udph->uh_sum_cov = (udph->uh_sum_cov) ? udph->uh_sum_cov : udph->uh_ulen;
udph->uh_sum = tvb_get_ntohs(tvb, offset+6);
reported_len = tvb_reported_length(tvb);
len = tvb_length(tvb);
if (udph->uh_sum == 0) {
/* No checksum supplied in the packet. */
if ((ip_proto == IP_PROTO_UDP) && (pinfo->src.type == AT_IPv4)) {
item = proto_tree_add_uint_format(udp_tree, hf_udp_checksum, tvb, offset + 6, 2, 0,
"Checksum: 0x%04x (none)", 0);
checksum_tree = proto_item_add_subtree(item, ett_udp_checksum);
item = proto_tree_add_boolean(checksum_tree, hf_udp_checksum_good, tvb,
offset + 6, 2, FALSE);
PROTO_ITEM_SET_GENERATED(item);
item = proto_tree_add_boolean(checksum_tree, hf_udp_checksum_bad, tvb,
offset + 6, 2, FALSE);
PROTO_ITEM_SET_GENERATED(item);
} else {
item = proto_tree_add_uint_format(udp_tree, hf_udp_checksum, tvb, offset + 6, 2, 0,
"Checksum: 0x%04x (Illegal)", 0);
expert_add_info_format(pinfo, item, PI_CHECKSUM, PI_ERROR, "Illegal Checksum value (0)");
col_append_fstr(pinfo->cinfo, COL_INFO, " [ILLEGAL CHECKSUM (0)]");
checksum_tree = proto_item_add_subtree(item, ett_udp_checksum);
item = proto_tree_add_boolean(checksum_tree, hf_udp_checksum_good, tvb,
offset + 6, 2, FALSE);
PROTO_ITEM_SET_GENERATED(item);
item = proto_tree_add_boolean(checksum_tree, hf_udp_checksum_bad, tvb,
offset + 6, 2, TRUE);
PROTO_ITEM_SET_GENERATED(item);
}
} else if (!pinfo->fragmented && len >= reported_len &&
len >= udph->uh_sum_cov && reported_len >= udph->uh_sum_cov &&
udph->uh_sum_cov >=8) {
/* The packet isn't part of a fragmented datagram and isn't
truncated, so we can checksum it.
XXX - make a bigger scatter-gather list once we do fragment
reassembly? */
if (((ip_proto == IP_PROTO_UDP) && (udp_check_checksum)) ||
((ip_proto == IP_PROTO_UDPLITE) && (udplite_check_checksum))) {
/* Set up the fields of the pseudo-header. */
cksum_vec[0].ptr = (const guint8 *)pinfo->src.data;
cksum_vec[0].len = pinfo->src.len;
cksum_vec[1].ptr = (const guint8 *)pinfo->dst.data;
cksum_vec[1].len = pinfo->dst.len;
cksum_vec[2].ptr = (const guint8 *)&phdr;
switch (pinfo->src.type) {
case AT_IPv4:
if (ip_proto == IP_PROTO_UDP)
phdr[0] = g_htonl((ip_proto<<16) | udph->uh_ulen);
else
phdr[0] = g_htonl((ip_proto<<16) | reported_len);
cksum_vec[2].len = 4;
break;
case AT_IPv6:
if (ip_proto == IP_PROTO_UDP)
phdr[0] = g_htonl(udph->uh_ulen);
else
phdr[0] = g_htonl(reported_len);
phdr[1] = g_htonl(ip_proto);
cksum_vec[2].len = 8;
break;
default:
/* UDP runs only atop IPv4 and IPv6.... */
DISSECTOR_ASSERT_NOT_REACHED();
break;
}
cksum_vec[3].ptr = tvb_get_ptr(tvb, offset, udph->uh_sum_cov);
cksum_vec[3].len = udph->uh_sum_cov;
computed_cksum = in_cksum(&cksum_vec[0], 4);
if (computed_cksum == 0) {
item = proto_tree_add_uint_format(udp_tree, hf_udp_checksum, tvb,
offset + 6, 2, udph->uh_sum, "Checksum: 0x%04x [correct]", udph->uh_sum);
checksum_tree = proto_item_add_subtree(item, ett_udp_checksum);
item = proto_tree_add_boolean(checksum_tree, hf_udp_checksum_good, tvb,
offset + 6, 2, TRUE);
PROTO_ITEM_SET_GENERATED(item);
item = proto_tree_add_boolean(checksum_tree, hf_udp_checksum_bad, tvb,
offset + 6, 2, FALSE);
PROTO_ITEM_SET_GENERATED(item);
} else {
item = proto_tree_add_uint_format(udp_tree, hf_udp_checksum, tvb,
offset + 6, 2, udph->uh_sum,
"Checksum: 0x%04x [incorrect, should be 0x%04x (maybe caused by \"UDP checksum offload\"?)]", udph->uh_sum,
in_cksum_shouldbe(udph->uh_sum, computed_cksum));
checksum_tree = proto_item_add_subtree(item, ett_udp_checksum);
item = proto_tree_add_boolean(checksum_tree, hf_udp_checksum_good, tvb,
offset + 6, 2, FALSE);
PROTO_ITEM_SET_GENERATED(item);
item = proto_tree_add_boolean(checksum_tree, hf_udp_checksum_bad, tvb,
offset + 6, 2, TRUE);
PROTO_ITEM_SET_GENERATED(item);
expert_add_info_format(pinfo, item, PI_CHECKSUM, PI_ERROR, "Bad checksum");
col_append_fstr(pinfo->cinfo, COL_INFO, " [UDP CHECKSUM INCORRECT]");
}
} else {
item = proto_tree_add_uint_format(udp_tree, hf_udp_checksum, tvb,
offset + 6, 2, udph->uh_sum, "Checksum: 0x%04x [validation disabled]", udph->uh_sum);
checksum_tree = proto_item_add_subtree(item, ett_udp_checksum);
item = proto_tree_add_boolean(checksum_tree, hf_udp_checksum_good, tvb,
offset + 6, 2, FALSE);
PROTO_ITEM_SET_GENERATED(item);
item = proto_tree_add_boolean(checksum_tree, hf_udp_checksum_bad, tvb,
offset + 6, 2, FALSE);
PROTO_ITEM_SET_GENERATED(item);
}
} else {
item = proto_tree_add_uint_format(udp_tree, hf_udp_checksum, tvb,
offset + 6, 2, udph->uh_sum, "Checksum: 0x%04x [unchecked, not all data available]", udph->uh_sum);
checksum_tree = proto_item_add_subtree(item, ett_udp_checksum);
item = proto_tree_add_boolean(checksum_tree, hf_udp_checksum_good, tvb,
offset + 6, 2, FALSE);
PROTO_ITEM_SET_GENERATED(item);
item = proto_tree_add_boolean(checksum_tree, hf_udp_checksum_bad, tvb,
offset + 6, 2, FALSE);
PROTO_ITEM_SET_GENERATED(item);
}
/* Skip over header */
offset += 8;
pinfo->ptype = PT_UDP;
pinfo->srcport = udph->uh_sport;
pinfo->destport = udph->uh_dport;
tap_queue_packet(udp_tap, pinfo, udph);
/* find(or create if needed) the conversation for this udp session */
if (udp_process_info) {
conv=find_or_create_conversation(pinfo);
udpd=get_udp_conversation_data(conv,pinfo);
}
if (udpd && ((udpd->fwd && udpd->fwd->command) || (udpd->rev && udpd->rev->command))) {
ti = proto_tree_add_text(udp_tree, tvb, offset, 0, "Process Information");
PROTO_ITEM_SET_GENERATED(ti);
process_tree = proto_item_add_subtree(ti, ett_udp_process_info);
if (udpd->fwd && udpd->fwd->command) {
proto_tree_add_uint_format_value(process_tree, hf_udp_proc_dst_uid, tvb, 0, 0,
udpd->fwd->process_uid, "%u", udpd->fwd->process_uid);
proto_tree_add_uint_format_value(process_tree, hf_udp_proc_dst_pid, tvb, 0, 0,
udpd->fwd->process_pid, "%u", udpd->fwd->process_pid);
proto_tree_add_string_format_value(process_tree, hf_udp_proc_dst_uname, tvb, 0, 0,
udpd->fwd->username, "%s", udpd->fwd->username);
proto_tree_add_string_format_value(process_tree, hf_udp_proc_dst_cmd, tvb, 0, 0,
udpd->fwd->command, "%s", udpd->fwd->command);
}
if (udpd->rev->command) {
proto_tree_add_uint_format_value(process_tree, hf_udp_proc_src_uid, tvb, 0, 0,
udpd->rev->process_uid, "%u", udpd->rev->process_uid);
proto_tree_add_uint_format_value(process_tree, hf_udp_proc_src_pid, tvb, 0, 0,
udpd->rev->process_pid, "%u", udpd->rev->process_pid);
proto_tree_add_string_format_value(process_tree, hf_udp_proc_src_uname, tvb, 0, 0,
udpd->rev->username, "%s", udpd->rev->username);
proto_tree_add_string_format_value(process_tree, hf_udp_proc_src_cmd, tvb, 0, 0,
udpd->rev->command, "%s", udpd->rev->command);
}
}
/*
* Call sub-dissectors.
*
* XXX - should we do this if this is included in an error packet?
* It might be nice to see the details of the packet that caused the
* ICMP error, but it might not be nice to have the dissector update
* state based on it.
* Also, we probably don't want to run UDP taps on those packets.
*
* We definitely don't want to do it for an error packet if there's
* nothing left in the packet.
*/
if (!pinfo->flags.in_error_pkt || tvb_length_remaining(tvb, offset) > 0)
decode_udp_ports(tvb, offset, pinfo, tree, udph->uh_sport, udph->uh_dport,
udph->uh_ulen);
}