nexmon – Rev 1
?pathlinks?
/* packet-pflog.c
* Routines for pflog (OpenBSD Firewall Logging) packet disassembly
*
* Copyright 2001 Mike Frantzen
* 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.
* 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 HOLDERS 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.
*/
/* Specifications... :
http://www.openbsd.org/cgi-bin/cvsweb/src/sys/net/if_pflog.c
http://www.openbsd.org/cgi-bin/cvsweb/src/sys/net/if_pflog.h
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/aftypes.h>
#include <epan/addr_resolv.h>
#include <epan/expert.h>
#include <epan/prefs.h>
void proto_register_pflog(void);
void proto_reg_handoff_pflog(void);
void proto_register_old_pflog(void);
void proto_reg_handoff_old_pflog(void);
static dissector_handle_t ip_handle, ipv6_handle;
/* header fields */
static int proto_pflog = -1;
static int hf_pflog_length = -1;
static int hf_pflog_af = -1;
static int hf_pflog_action = -1;
static int hf_pflog_reason = -1;
static int hf_pflog_ifname = -1;
static int hf_pflog_ruleset = -1;
static int hf_pflog_rulenr = -1;
static int hf_pflog_subrulenr = -1;
static int hf_pflog_uid = -1;
static int hf_pflog_pid = -1;
static int hf_pflog_rule_uid = -1;
static int hf_pflog_rule_pid = -1;
static int hf_pflog_dir = -1;
static int hf_pflog_rewritten = -1;
static int hf_pflog_pad = -1;
static int hf_pflog_saddr_ipv4 = -1;
static int hf_pflog_daddr_ipv4 = -1;
static int hf_pflog_saddr_ipv6 = -1;
static int hf_pflog_daddr_ipv6 = -1;
static int hf_pflog_saddr = -1;
static int hf_pflog_daddr = -1;
static int hf_pflog_sport = -1;
static int hf_pflog_dport = -1;
static gint ett_pflog = -1;
static expert_field ei_pflog_invalid_header_length = EI_INIT;
/* old header */
static int proto_old_pflog = -1;
static int hf_old_pflog_af = -1;
static int hf_old_pflog_ifname = -1;
static int hf_old_pflog_rnr = -1;
static int hf_old_pflog_reason = -1;
static int hf_old_pflog_action = -1;
static int hf_old_pflog_dir = -1;
static gint ett_old_pflog = -1;
static gboolean uid_endian = TRUE;
#define LEN_PFLOG_BSD34 48
#define LEN_PFLOG_BSD38 64
#define LEN_PFLOG_BSD49 100
static const value_string pflog_af_vals[] = {
{ BSD_AF_INET, "IPv4" },
{ BSD_AF_INET6_BSD, "IPv6" },
{ 0, NULL }
};
static const value_string pflog_reason_vals[] = {
{ 0, "match" },
{ 1, "bad-offset" },
{ 2, "fragment" },
{ 3, "short" },
{ 4, "normalize" },
{ 5, "memory" },
{ 6, "timestamp" },
{ 7, "congestion" },
{ 8, "ip-option" },
{ 9, "proto-cksum" },
{ 10, "state-mismatch" },
{ 11, "state-ins-fail" },
{ 12, "max-states" },
{ 13, "srcnode-limit" },
{ 14, "syn-proxy" },
{ 0, NULL }
};
/* Actions */
enum { PF_PASS, PF_DROP, PF_SCRUB, PF_NOSCRUB, PF_NAT, PF_NONAT,
PF_BINAT, PF_NOBINAT, PF_RDR, PF_NORDR, PF_SYNPROXY_DROP, PF_DEFER,
PF_MATCH, PF_DIVERT, PF_RT };
static const value_string pflog_action_vals[] = {
{ PF_MATCH, "match" },
{ PF_SCRUB, "scrub" },
{ PF_PASS, "pass" },
{ PF_DROP, "block" },
{ PF_DIVERT, "divert" },
{ PF_NAT, "nat" },
{ PF_NONAT, "nat" },
{ PF_BINAT, "binat" },
{ PF_NOBINAT, "binat" },
{ PF_RDR, "rdr" },
{ PF_NORDR, "rdr" },
{ 0, NULL }
};
/* Directions */
#define PF_OLD_IN 0
#define PF_OLD_OUT 1
#define PF_INOUT 0
#define PF_IN 1
#define PF_OUT 2
static const value_string pflog_old_dir_vals[] = {
{ PF_OLD_IN, "in" },
{ PF_OLD_OUT, "out" },
{ 0, NULL }
};
static const value_string pflog_dir_vals[] = {
{ PF_INOUT, "inout" },
{ PF_IN, "in" },
{ PF_OUT, "out" },
{ 0, NULL }
};
static int
dissect_pflog(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
tvbuff_t *next_tvb;
proto_tree *pflog_tree;
proto_item *ti = NULL, *ti_len;
int length;
guint8 af, action;
const guint8 *ifname;
guint32 rulenr;
guint8 pad_len = 3;
gint offset = 0;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "PFLOG");
ti = proto_tree_add_item(tree, proto_pflog, tvb, offset, 0, ENC_NA);
pflog_tree = proto_item_add_subtree(ti, ett_pflog);
length = tvb_get_guint8(tvb, offset) + pad_len;
ti_len = proto_tree_add_item(pflog_tree, hf_pflog_length, tvb, offset, 1, ENC_BIG_ENDIAN);
if(length < LEN_PFLOG_BSD34)
{
expert_add_info_format(pinfo, ti_len, &ei_pflog_invalid_header_length, "Invalid header length %u", length);
}
offset += 1;
proto_tree_add_item(pflog_tree, hf_pflog_af, tvb, offset, 1, ENC_BIG_ENDIAN);
af = tvb_get_guint8(tvb, offset);
offset += 1;
proto_tree_add_item(pflog_tree, hf_pflog_action, tvb, offset, 1, ENC_BIG_ENDIAN);
action = tvb_get_guint8(tvb, offset);
offset += 1;
proto_tree_add_item(pflog_tree, hf_pflog_reason, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
proto_tree_add_item_ret_string(pflog_tree, hf_pflog_ifname, tvb, offset, 16, ENC_ASCII|ENC_NA, wmem_packet_scope(), &ifname);
offset += 16;
proto_tree_add_item(pflog_tree, hf_pflog_ruleset, tvb, offset, 16, ENC_ASCII|ENC_NA);
offset += 16;
proto_tree_add_item(pflog_tree, hf_pflog_rulenr, tvb, offset, 4, ENC_BIG_ENDIAN);
rulenr = tvb_get_ntohs(tvb, offset);
offset += 4;
proto_tree_add_item(pflog_tree, hf_pflog_subrulenr, tvb, offset, 4, ENC_BIG_ENDIAN);
offset += 4;
if(length >= LEN_PFLOG_BSD38)
{
int endian = uid_endian ? ENC_BIG_ENDIAN : ENC_LITTLE_ENDIAN;
proto_tree_add_item(pflog_tree, hf_pflog_uid, tvb, offset, 4, endian);
offset += 4;
proto_tree_add_item(pflog_tree, hf_pflog_pid, tvb, offset, 4, endian);
offset += 4;
proto_tree_add_item(pflog_tree, hf_pflog_rule_uid, tvb, offset, 4, endian);
offset += 4;
proto_tree_add_item(pflog_tree, hf_pflog_rule_pid, tvb, offset, 4, endian);
offset += 4;
}
proto_tree_add_item(pflog_tree, hf_pflog_dir, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
if(length >= LEN_PFLOG_BSD49)
{
pad_len = 2;
length -= 3; /* With OpenBSD >= 4.8 the length is the length of full Header (with padding..) */
proto_tree_add_item(pflog_tree, hf_pflog_rewritten, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
}
proto_tree_add_item(pflog_tree, hf_pflog_pad, tvb, offset, pad_len, ENC_NA);
offset += pad_len;
if(length >= LEN_PFLOG_BSD49)
{
switch (af) {
case BSD_AF_INET:
proto_tree_add_item(pflog_tree, hf_pflog_saddr_ipv4, tvb, offset, 4, ENC_BIG_ENDIAN);
offset += 16;
proto_tree_add_item(pflog_tree, hf_pflog_daddr_ipv4, tvb, offset, 4, ENC_BIG_ENDIAN);
offset += 16;
break;
case BSD_AF_INET6_BSD:
proto_tree_add_item(pflog_tree, hf_pflog_saddr_ipv6, tvb, offset, 16, ENC_NA);
offset += 16;
proto_tree_add_item(pflog_tree, hf_pflog_daddr_ipv6, tvb, offset, 16, ENC_NA);
offset += 16;
break;
default:
proto_tree_add_item(pflog_tree, hf_pflog_saddr, tvb, offset, 16, ENC_NA);
offset += 16;
proto_tree_add_item(pflog_tree, hf_pflog_daddr, tvb, offset, 16, ENC_NA);
offset += 16;
break;
}
proto_tree_add_item(pflog_tree, hf_pflog_sport, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
proto_tree_add_item(pflog_tree, hf_pflog_dport, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
}
proto_item_set_text(ti, "PF Log %s %s on %s by rule %u",
val_to_str(af, pflog_af_vals, "unknown (%u)"),
val_to_str(action, pflog_action_vals, "unknown (%u)"),
ifname,
rulenr);
proto_item_set_len(ti, offset);
/* Set the tvbuff for the payload after the header */
next_tvb = tvb_new_subset_remaining(tvb, length);
switch (af) {
case BSD_AF_INET:
call_dissector(ip_handle, next_tvb, pinfo, tree);
break;
case BSD_AF_INET6_BSD:
call_dissector(ipv6_handle, next_tvb, pinfo, tree);
break;
default:
call_data_dissector(next_tvb, pinfo, tree);
break;
}
col_prepend_fstr(pinfo->cinfo, COL_INFO, "[%s %s/%u] ",
val_to_str(action, pflog_action_vals, "unknown (%u)"),
ifname,
rulenr);
return tvb_captured_length(tvb);
}
void
proto_register_pflog(void)
{
static hf_register_info hf[] = {
{ &hf_pflog_length,
{ "Header Length", "pflog.length", FT_UINT8, BASE_DEC, NULL, 0x0,
"Length of Header", HFILL }},
{ &hf_pflog_af,
{ "Address Family", "pflog.af", FT_UINT32, BASE_DEC, VALS(pflog_af_vals), 0x0,
"Protocol (IPv4 vs IPv6)", HFILL }},
{ &hf_pflog_action,
{ "Action", "pflog.action", FT_UINT8, BASE_DEC, VALS(pflog_action_vals), 0x0,
"Action taken by PF on the packet", HFILL }},
{ &hf_pflog_reason,
{ "Reason", "pflog.reason", FT_UINT8, BASE_DEC, VALS(pflog_reason_vals), 0x0,
"Reason for logging the packet", HFILL }},
{ &hf_pflog_ifname,
{ "Interface", "pflog.ifname", FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL }},
{ &hf_pflog_ruleset,
{ "Ruleset", "pflog.ruleset", FT_STRING, BASE_NONE, NULL, 0x0,
"Ruleset name in anchor", HFILL }},
{ &hf_pflog_rulenr,
{ "Rule Number", "pflog.rulenr", FT_INT32, BASE_DEC, NULL, 0x0,
"Last matched firewall main ruleset rule number", HFILL }},
{ &hf_pflog_subrulenr,
{ "Sub Rule Number", "pflog.subrulenr", FT_INT32, BASE_DEC, NULL, 0x0,
"Last matched firewall anchored ruleset rule number", HFILL }},
{ &hf_pflog_uid,
{ "UID", "pflog.uid", FT_INT32, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_pflog_pid,
{ "PID", "pflog.pid", FT_INT32, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_pflog_rule_uid,
{ "Rule UID", "pflog.rule_uid", FT_INT32, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_pflog_rule_pid,
{ "Rule PID", "pflog.rule_pid", FT_INT32, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_pflog_rewritten,
{ "Rewritten", "pflog.rewritten", FT_UINT8, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_pflog_pad,
{ "Padding", "pflog.pad", FT_BYTES, BASE_NONE, NULL, 0x0,
"Must be Zero", HFILL }},
{ &hf_pflog_saddr_ipv4,
{ "Source Address", "pflog.saddr.ipv4", FT_IPv4, BASE_NONE, NULL, 0x0,
NULL, HFILL }},
{ &hf_pflog_daddr_ipv4,
{ "Destination Address", "pflog.daddr.ipv4", FT_IPv4, BASE_NONE, NULL, 0x0,
NULL, HFILL }},
{ &hf_pflog_saddr_ipv6,
{ "Source Address", "pflog.saddr.ipv6", FT_IPv6, BASE_NONE, NULL, 0x0,
NULL, HFILL }},
{ &hf_pflog_daddr_ipv6,
{ "Destination Address", "pflog.daddr.ipv6", FT_IPv6, BASE_NONE, NULL, 0x0,
NULL, HFILL }},
{ &hf_pflog_saddr,
{ "Source Address", "pflog.saddr.bytes", FT_BYTES, BASE_NONE, NULL, 0x0,
NULL, HFILL }},
{ &hf_pflog_daddr,
{ "Destination Address", "pflog.daddr.bytes", FT_BYTES, BASE_NONE, NULL, 0x0,
NULL, HFILL }},
{ &hf_pflog_sport,
{ "Source Port", "pflog.sport", FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_pflog_dport,
{ "Destination Port", "pflog.dport", FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_pflog_dir,
{ "Direction", "pflog.dir", FT_UINT8, BASE_DEC, VALS(pflog_dir_vals), 0x0,
"Direction of packet in stack (inbound versus outbound)", HFILL }},
};
static gint *ett[] = { &ett_pflog };
static ei_register_info ei[] = {
{ &ei_pflog_invalid_header_length, { "pflog.invalid_header_length", PI_MALFORMED, PI_ERROR, "Invalid header length ", EXPFILL }},
};
expert_module_t* expert_pflog;
module_t *pflog_module;
proto_pflog = proto_register_protocol("OpenBSD Packet Filter log file",
"PFLOG", "pflog");
proto_register_field_array(proto_pflog, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
expert_pflog = expert_register_protocol(proto_pflog);
expert_register_field_array(expert_pflog, ei, array_length(ei));
pflog_module = prefs_register_protocol(proto_pflog, NULL);
prefs_register_bool_preference(pflog_module, "uid_endian",
"Display UID as big endian value",
"Whether or not UID and PID fields are dissected in big or little endian",
&uid_endian);
}
void
proto_reg_handoff_pflog(void)
{
dissector_handle_t pflog_handle;
ip_handle = find_dissector_add_dependency("ip", proto_pflog);
ipv6_handle = find_dissector_add_dependency("ipv6", proto_pflog);
pflog_handle = create_dissector_handle(dissect_pflog, proto_pflog);
dissector_add_uint("wtap_encap", WTAP_ENCAP_PFLOG, pflog_handle);
}
static int
dissect_old_pflog(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
tvbuff_t *next_tvb;
proto_tree *pflog_tree;
proto_item *ti;
guint32 af;
const guint8 *ifname;
guint16 rnr, action;
gint offset = 0;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "PFLOG-OLD");
ti = proto_tree_add_item(tree, proto_old_pflog, tvb, 0, 0, ENC_NA);
pflog_tree = proto_item_add_subtree(ti, ett_pflog);
proto_tree_add_item(pflog_tree, hf_old_pflog_af, tvb, offset, 4, ENC_BIG_ENDIAN);
af = tvb_get_ntohl(tvb, offset);
offset +=4;
proto_tree_add_item_ret_string(pflog_tree, hf_old_pflog_ifname, tvb, offset, 16, ENC_ASCII|ENC_NA, wmem_packet_scope(), &ifname);
offset +=16;
proto_tree_add_item(pflog_tree, hf_old_pflog_rnr, tvb, offset, 2, ENC_BIG_ENDIAN);
rnr = tvb_get_ntohs(tvb, offset);
offset +=2;
proto_tree_add_item(pflog_tree, hf_old_pflog_reason, tvb, offset, 2, ENC_BIG_ENDIAN);
offset +=2;
proto_tree_add_item(pflog_tree, hf_old_pflog_action, tvb, offset, 2, ENC_BIG_ENDIAN);
action = tvb_get_ntohs(tvb, offset);
offset +=2;
proto_tree_add_item(pflog_tree, hf_old_pflog_dir, tvb, offset, 2, ENC_BIG_ENDIAN);
offset +=2;
proto_item_set_text(ti, "PF Log (pre 3.4) %s %s on %s by rule %d",
val_to_str(af, pflog_af_vals, "unknown (%u)"),
val_to_str(action, pflog_action_vals, "unknown (%u)"),
ifname,
rnr);
proto_item_set_len(ti, offset);
/* Set the tvbuff for the payload after the header */
next_tvb = tvb_new_subset_remaining(tvb, offset);
switch (af) {
case BSD_AF_INET:
offset += call_dissector(ip_handle, next_tvb, pinfo, tree);
break;
case BSD_AF_INET6_BSD:
offset += call_dissector(ipv6_handle, next_tvb, pinfo, tree);
break;
default:
offset += call_data_dissector(next_tvb, pinfo, tree);
break;
}
col_prepend_fstr(pinfo->cinfo, COL_INFO, "[%s %s/#%d] ",
val_to_str(action, pflog_action_vals, "unknown (%u)"),
ifname,
rnr);
return offset;
}
void
proto_register_old_pflog(void)
{
static hf_register_info hf[] = {
{ &hf_old_pflog_af,
{ "Address Family", "pflog.af", FT_UINT32, BASE_DEC, VALS(pflog_af_vals), 0x0,
"Protocol (IPv4 vs IPv6)", HFILL }},
{ &hf_old_pflog_ifname,
{ "Interface", "pflog.ifname", FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL }},
{ &hf_old_pflog_rnr,
{ "Rule Number", "pflog.rnr", FT_INT16, BASE_DEC, NULL, 0x0,
"Last matched firewall rule number", HFILL }},
{ &hf_old_pflog_reason,
{ "Reason", "pflog.reason", FT_UINT16, BASE_DEC, VALS(pflog_reason_vals), 0x0,
"Reason for logging the packet", HFILL }},
{ &hf_old_pflog_action,
{ "Action", "pflog.action", FT_UINT16, BASE_DEC, VALS(pflog_action_vals), 0x0,
"Action taken by PF on the packet", HFILL }},
{ &hf_old_pflog_dir,
{ "Direction", "pflog.dir", FT_UINT16, BASE_DEC, VALS(pflog_old_dir_vals), 0x0,
"Direction of packet in stack (inbound versus outbound)", HFILL }},
};
static gint *ett[] = { &ett_old_pflog };
proto_old_pflog = proto_register_protocol(
"OpenBSD Packet Filter log file, pre 3.4",
"PFLOG-OLD", "pflog-old");
proto_register_field_array(proto_old_pflog, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}
void
proto_reg_handoff_old_pflog(void)
{
dissector_handle_t pflog_handle;
ip_handle = find_dissector("ip");
ipv6_handle = find_dissector("ipv6");
pflog_handle = create_dissector_handle(dissect_old_pflog, proto_old_pflog);
dissector_add_uint("wtap_encap", WTAP_ENCAP_OLD_PFLOG, pflog_handle);
}
/*
* Editor modelines
*
* Local Variables:
* c-basic-offset: 2
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* ex: set shiftwidth=2 tabstop=8 expandtab:
* :indentSize=2:tabSize=8:noTabs=true:
*/