suricata
Packet decoding

Code in charge of protocol decoding. More...

Files

file  decode-chdlc.c
 
file  decode-erspan.c
 
file  decode-esp.c
 
file  decode-ethernet.c
 
file  decode-gre.c
 
file  decode-icmpv4.c
 
file  decode-icmpv6.c
 
file  decode-ipv4.c
 
file  decode-ipv6.c
 
file  decode-nsh.c
 
file  decode-null.c
 
file  decode-ppp.c
 
file  decode-pppoe.c
 
file  decode-raw.c
 
file  decode-sctp.c
 
file  decode-sll.c
 
file  decode-tcp.c
 
file  decode-template.c
 
file  decode-teredo.c
 
file  decode-udp.c
 
file  decode-vlan.c
 
file  decode-vntag.c
 
file  decode.c
 

Data Structures

struct  CaptureStats_
 

Typedefs

typedef struct CaptureStats_ CaptureStats
 

Functions

PacketAlertPacketAlertCreate (void)
 Initialize PacketAlerts with dynamic alerts array size. More...
 
void PacketAlertFree (PacketAlert *pa)
 
void PacketFree (Packet *p)
 Return a malloced packet. More...
 
void PacketDecodeFinalize (ThreadVars *tv, DecodeThreadVars *dtv, Packet *p)
 Finalize decoding of a packet. More...
 
void PacketUpdateEngineEventCounters (ThreadVars *tv, DecodeThreadVars *dtv, Packet *p)
 
PacketPacketGetFromAlloc (void)
 Get a malloced packet. More...
 
void PacketFreeOrRelease (Packet *p)
 Return a packet to where it was allocated. More...
 
PacketPacketGetFromQueueOrAlloc (void)
 Get a packet. We try to get a packet from the packetpool first, but if that is empty we alloc a packet that is free'd again after processing. More...
 
int PacketCallocExtPkt (Packet *p, int datalen)
 
int PacketCopyDataOffset (Packet *p, uint32_t offset, const uint8_t *data, uint32_t datalen)
 Copy data to Packet payload at given offset. More...
 
int PacketCopyData (Packet *p, const uint8_t *pktdata, uint32_t pktlen)
 Copy data to Packet payload and set packet length. More...
 
PacketPacketTunnelPktSetup (ThreadVars *tv, DecodeThreadVars *dtv, Packet *parent, const uint8_t *pkt, uint32_t len, enum DecodeTunnelProto proto)
 Setup a pseudo packet (tunnel) More...
 
PacketPacketDefragPktSetup (Packet *parent, const uint8_t *pkt, uint32_t len, uint8_t proto)
 Setup a pseudo packet (reassembled frags) More...
 
void PacketDefragPktSetupParent (Packet *parent)
 inform defrag "parent" that a pseudo packet is now associated to it. More...
 
void PacketBypassCallback (Packet *p)
 
void PacketSwap (Packet *p)
 switch direction of a packet More...
 
void DecodeUnregisterCounters (void)
 
void DecodeRegisterPerfCounters (DecodeThreadVars *dtv, ThreadVars *tv)
 
void DecodeUpdatePacketCounters (ThreadVars *tv, const DecodeThreadVars *dtv, const Packet *p)
 
void AddressDebugPrint (Address *a)
 Debug print function for printing addresses. More...
 
DecodeThreadVarsDecodeThreadVarsAlloc (ThreadVars *tv)
 Alloc and setup DecodeThreadVars. More...
 
void DecodeThreadVarsFree (ThreadVars *tv, DecodeThreadVars *dtv)
 
int PacketSetData (Packet *p, const uint8_t *pktdata, uint32_t pktlen)
 Set data for Packet and set length when zero copy is used. More...
 
const char * PktSrcToString (enum PktSrcEnum pkt_src)
 
const char * PacketDropReasonToString (enum PacketDropReason r)
 
void CaptureStatsUpdate (ThreadVars *tv, const Packet *p)
 
void CaptureStatsSetup (ThreadVars *tv)
 
void DecodeGlobalConfig (void)
 
void PacketAlertGetMaxConfig (void)
 

Variables

uint32_t default_packet_size = 0
 
bool stats_decoder_events
 
const char * stats_decoder_events_prefix
 
bool stats_stream_events
 
uint8_t decoder_max_layers = PKT_DEFAULT_MAX_DECODED_LAYERS
 
uint16_t packet_alert_max = PACKET_ALERT_MAX
 
ExceptionPolicyStatsSetts defrag_memcap_eps_stats
 
ExceptionPolicyStatsSetts flow_memcap_eps_stats
 
thread_local CaptureStats t_capture_stats
 

Detailed Description

Code in charge of protocol decoding.

The task of decoding packets is made in different files and as Suricata is supporting encapsulation there is a potential recursivity in the call.

For each protocol a DecodePROTO function is provided. For example we have DecodeIPV4() for IPv4 and DecodePPP() for PPP.

These functions have all a pkt and a len argument which are respectively a pointer to the protocol data and the length of this protocol data.

Attention
The pkt parameter must point to the effective data because it will be used later to set per protocol pointer like Packet::tcph

Typedef Documentation

◆ CaptureStats

typedef struct CaptureStats_ CaptureStats

Function Documentation

◆ AddressDebugPrint()

void AddressDebugPrint ( Address a)

Debug print function for printing addresses.

Parameters
Addressobject
Todo:
IPv6

Definition at line 756 of file decode.c.

References Address_::family, PrintInet(), and SCLogDebug.

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◆ CaptureStatsSetup()

◆ CaptureStatsUpdate()

◆ DecodeGlobalConfig()

void DecodeGlobalConfig ( void  )

◆ DecodeRegisterPerfCounters()

void DecodeRegisterPerfCounters ( DecodeThreadVars dtv,
ThreadVars tv 
)

Definition at line 602 of file decode.c.

References DecodeThreadVars_::counter_arp, DecodeThreadVars_::counter_avg_pkt_size, DecodeThreadVars_::counter_bytes, DecodeThreadVars_::counter_chdlc, DecodeThreadVars_::counter_erspan, DecodeThreadVars_::counter_esp, DecodeThreadVars_::counter_eth, DecodeThreadVars_::counter_ethertype_unknown, DecodeThreadVars_::counter_flow_memcap, DecodeThreadVars_::counter_flow_memcap_eps, DecodeThreadVars_::counter_geneve, DecodeThreadVars_::counter_gre, DecodeThreadVars_::counter_icmpv4, DecodeThreadVars_::counter_icmpv6, DecodeThreadVars_::counter_ieee8021ah, DecodeThreadVars_::counter_invalid, DecodeThreadVars_::counter_ipv4, DecodeThreadVars_::counter_ipv4inipv6, DecodeThreadVars_::counter_ipv6, DecodeThreadVars_::counter_ipv6inipv6, DecodeThreadVars_::counter_max_mac_addrs_dst, DecodeThreadVars_::counter_max_mac_addrs_src, DecodeThreadVars_::counter_max_pkt_size, DecodeThreadVars_::counter_mpls, DecodeThreadVars_::counter_nsh, DecodeThreadVars_::counter_null, DecodeThreadVars_::counter_pkts, DecodeThreadVars_::counter_ppp, DecodeThreadVars_::counter_pppoe, DecodeThreadVars_::counter_raw, DecodeThreadVars_::counter_sctp, DecodeThreadVars_::counter_sll, DecodeThreadVars_::counter_tcp, DecodeThreadVars_::counter_tcp_rst, DecodeThreadVars_::counter_tcp_syn, DecodeThreadVars_::counter_tcp_synack, DecodeThreadVars_::counter_teredo, DecodeThreadVars_::counter_udp, DecodeThreadVars_::counter_vlan, DecodeThreadVars_::counter_vlan_qinq, DecodeThreadVars_::counter_vlan_qinqinq, DecodeThreadVars_::counter_vntag, DecodeThreadVars_::counter_vxlan, dtv, ExceptionPolicySetStatsCounters(), flow_memcap_eps_stats, FlowGetMemcapExceptionPolicy(), StatsRegisterAvgCounter(), StatsRegisterCounter(), StatsRegisterMaxCounter(), and tv.

Referenced by DecodeErfDagThreadInit(), DecodePfringThreadInit(), and NapatechDecodeThreadInit().

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◆ DecodeThreadVarsAlloc()

DecodeThreadVars* DecodeThreadVarsAlloc ( ThreadVars tv)

Alloc and setup DecodeThreadVars.

Definition at line 773 of file decode.c.

References DecodeThreadVars_::app_tctx, AppLayerGetCtxThread(), DecodeThreadVarsFree(), dtv, DecodeThreadVars_::output_flow_thread_data, OutputFlowLogThreadInit(), SCCalloc, SCLogError, TM_ECODE_OK, and tv.

Referenced by DecodeErfDagThreadInit(), DecodePfringThreadInit(), and NapatechDecodeThreadInit().

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◆ DecodeThreadVarsFree()

void DecodeThreadVarsFree ( ThreadVars tv,
DecodeThreadVars dtv 
)

Definition at line 791 of file decode.c.

References DecodeThreadVars_::app_tctx, AppLayerDestroyCtxThread(), dtv, DecodeThreadVars_::output_flow_thread_data, OutputFlowLogThreadDeinit(), SCFree, and tv.

Referenced by DecodeErfDagThreadDeinit(), DecodePfringThreadDeinit(), DecodeThreadVarsAlloc(), and NapatechDecodeThreadDeinit().

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◆ DecodeUnregisterCounters()

void DecodeUnregisterCounters ( void  )

Definition at line 576 of file decode.c.

References SCMutexLock.

◆ DecodeUpdatePacketCounters()

void DecodeUpdatePacketCounters ( ThreadVars tv,
const DecodeThreadVars dtv,
const Packet p 
)

Definition at line 739 of file decode.c.

References DecodeThreadVars_::counter_avg_pkt_size, DecodeThreadVars_::counter_bytes, DecodeThreadVars_::counter_max_pkt_size, DecodeThreadVars_::counter_pkts, dtv, GET_PKT_LEN, StatsAddUI64(), StatsIncr(), StatsSetUI64(), and tv.

Referenced by DecodeErfDag(), DecodePfring(), and NapatechDecode().

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◆ PacketAlertCreate()

PacketAlert* PacketAlertCreate ( void  )

Initialize PacketAlerts with dynamic alerts array size.

Definition at line 140 of file decode.c.

References BUG_ON, packet_alert_max, and SCCalloc.

Referenced by PacketInit().

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◆ PacketAlertFree()

void PacketAlertFree ( PacketAlert pa)

Definition at line 148 of file decode.c.

References SCFree.

Referenced by PacketDestructor().

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◆ PacketAlertGetMaxConfig()

void PacketAlertGetMaxConfig ( void  )

Definition at line 1016 of file decode.c.

References ConfGetInt(), packet_alert_max, SCLogDebug, and SCLogWarning.

Referenced by DecodeGlobalConfig().

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◆ PacketBypassCallback()

void PacketBypassCallback ( Packet p)
Note
if p->flow is set, the flow is locked

Definition at line 504 of file decode.c.

References Packet_::BypassPacketsFlow, Packet_::flow, Flow_::flow_state, FLOW_STATE_LOCAL_BYPASSED, FlowGetStorageById(), FlowSetStorageById(), FlowUpdateState(), GetFlowBypassInfoID(), PKT_IS_PSEUDOPKT, and SCCalloc.

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◆ PacketCallocExtPkt()

int PacketCallocExtPkt ( Packet p,
int  datalen 
)
inline

Definition at line 283 of file decode.c.

References Packet_::ext_pkt, SCCalloc, SET_PKT_LEN, and unlikely.

◆ PacketCopyData()

int PacketCopyData ( Packet p,
const uint8_t *  pktdata,
uint32_t  pktlen 
)
inline

Copy data to Packet payload and set packet length.

Parameters
Pointerto the Packet to modify
Pointerto the data to copy
Lengthof the data to copy

Definition at line 351 of file decode.c.

References PacketCopyDataOffset(), and SET_PKT_LEN.

Referenced by PacketDefragPktSetup(), and PacketTunnelPktSetup().

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◆ PacketCopyDataOffset()

int PacketCopyDataOffset ( Packet p,
uint32_t  offset,
const uint8_t *  data,
uint32_t  datalen 
)
inline

Copy data to Packet payload at given offset.

This function copies data/payload to a Packet. It uses the space allocated at Packet creation (pointed by Packet::pkt) or allocate some memory (pointed by Packet::ext_pkt) if the data size is to big to fit in initial space (of size default_packet_size).

Parameters
Pointerto the Packet to modify
Offsetof the copy relatively to payload of Packet
Pointerto the data to copy
Lengthof the data to copy

Definition at line 309 of file decode.c.

References default_packet_size, Packet_::ext_pkt, GET_PKT_DIRECT_DATA, GET_PKT_DIRECT_MAX_SIZE, MAX_PAYLOAD_SIZE, offset, SCMalloc, SET_PKT_LEN, and unlikely.

Referenced by PacketCopyData().

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◆ PacketDecodeFinalize()

void PacketDecodeFinalize ( ThreadVars tv,
DecodeThreadVars dtv,
Packet p 
)

Finalize decoding of a packet.

This function needs to be call at the end of decode functions when decoding has been successful.

Definition at line 206 of file decode.c.

References DecodeThreadVars_::counter_invalid, dtv, Packet_::flags, PKT_IS_INVALID, StatsIncr(), and tv.

Referenced by DecodeErfDag(), DecodePfring(), and NapatechDecode().

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◆ PacketDefragPktSetup()

Packet* PacketDefragPktSetup ( Packet parent,
const uint8_t *  pkt,
uint32_t  len,
uint8_t  proto 
)

Setup a pseudo packet (reassembled frags)

Difference with PacketPseudoPktSetup is that this func doesn't increment the recursion level. It needs to be on the same level as the frags because we run the flow engine against this and we need to get the same flow.

Parameters
parentparent packet for this pseudo pkt
pktraw packet data
lenpacket data length
protoprotocol of the tunneled packet
Return values
pthe pseudo packet or NULL if out of memory

Definition at line 447 of file decode.c.

References BUG_ON, len, Packet_::livedev, PacketCopyData(), PacketGetFromQueueOrAlloc(), PacketTunnelChild, Packet_::recursion_level, Packet_::root, SCEnter, SCReturnPtr, Packet_::tenant_id, Packet_::ts, Packet_::ttype, unlikely, Packet_::vlan_id, and Packet_::vlan_idx.

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◆ PacketDefragPktSetupParent()

void PacketDefragPktSetupParent ( Packet parent)

inform defrag "parent" that a pseudo packet is now associated to it.

Definition at line 486 of file decode.c.

References PacketTunnelNone, PacketTunnelRoot, and Packet_::ttype.

◆ PacketDropReasonToString()

◆ PacketFree()

void PacketFree ( Packet p)

Return a malloced packet.

Definition at line 193 of file decode.c.

References PacketDestructor(), and SCFree.

Referenced by PacketFreeOrRelease(), PacketGetFromAlloc(), and UTHFreePacket().

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◆ PacketFreeOrRelease()

void PacketFreeOrRelease ( Packet p)

Return a packet to where it was allocated.

Definition at line 250 of file decode.c.

References likely, PacketFree(), PacketPoolReturnPacket(), Packet_::pool, and Packet_::ReleasePacket.

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◆ PacketGetFromAlloc()

Packet* PacketGetFromAlloc ( void  )

Get a malloced packet.

Return values
ppacket, NULL on error

Definition at line 232 of file decode.c.

References PACKET_PROFILING_START, PacketFree(), PacketInit(), Packet_::ReleasePacket, SCCalloc, SCLogDebug, SIZE_OF_PACKET, and unlikely.

Referenced by PacketGetFromQueueOrAlloc(), UTHBuildPacketFromEth(), UTHBuildPacketIPV6Real(), and UTHBuildPacketReal().

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◆ PacketGetFromQueueOrAlloc()

Packet* PacketGetFromQueueOrAlloc ( void  )

Get a packet. We try to get a packet from the packetpool first, but if that is empty we alloc a packet that is free'd again after processing.

Return values
ppacket, NULL on error

Definition at line 267 of file decode.c.

References DEBUG_VALIDATE_BUG_ON, PACKET_PROFILING_START, PacketGetFromAlloc(), PacketPoolGetPacket(), PacketPoolReturnPacket(), and Packet_::ReleasePacket.

Referenced by PacketDefragPktSetup(), PacketTunnelPktSetup(), ReceiveErfFileLoop(), and ReceivePfringLoop().

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◆ PacketSetData()

int PacketSetData ( Packet p,
const uint8_t *  pktdata,
uint32_t  pktlen 
)
inline

Set data for Packet and set length when zero copy is used.

Parameters
Pointerto the Packet to modify
Pointerto the data
Lengthof the data

Definition at line 811 of file decode.c.

References Packet_::ext_pkt, Packet_::flags, PKT_ZERO_COPY, SET_PKT_LEN, and unlikely.

Referenced by ReceivePfringLoop().

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◆ PacketSwap()

void PacketSwap ( Packet p)

switch direction of a packet

Definition at line 551 of file decode.c.

References FLOW_PKT_TOCLIENT, FLOW_PKT_TOCLIENT_FIRST, FLOW_PKT_TOSERVER, FLOW_PKT_TOSERVER_FIRST, Packet_::flowflags, and PKT_IS_TOSERVER.

◆ PacketTunnelPktSetup()

Packet* PacketTunnelPktSetup ( ThreadVars tv,
DecodeThreadVars dtv,
Packet parent,
const uint8_t *  pkt,
uint32_t  len,
enum DecodeTunnelProto  proto 
)

Setup a pseudo packet (tunnel)

Parameters
parentparent packet for this pseudo pkt
pktraw packet data
lenpacket data length
protoprotocol of the tunneled packet
Return values
pthe pseudo packet or NULL if out of memory

Definition at line 367 of file decode.c.

References BUG_ON, Packet_::datalink, DEBUG_VALIDATE_BUG_ON, decoder_max_layers, DLT_RAW, ENGINE_SET_INVALID_EVENT, GENERIC_TOO_MANY_LAYERS, len, Packet_::livedev, Packet_::nb_decoded_layers, PacketCopyData(), PacketGetFromQueueOrAlloc(), PacketTunnelChild, PacketTunnelRoot, Packet_::recursion_level, Packet_::root, SCEnter, SCReturnPtr, Packet_::tenant_id, Packet_::ts, Packet_::ttype, and unlikely.

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◆ PacketUpdateEngineEventCounters()

void PacketUpdateEngineEventCounters ( ThreadVars tv,
DecodeThreadVars dtv,
Packet p 
)

◆ PktSrcToString()

Variable Documentation

◆ decoder_max_layers

uint8_t decoder_max_layers = PKT_DEFAULT_MAX_DECODED_LAYERS

Definition at line 81 of file decode.c.

Referenced by DecodeGlobalConfig(), and PacketTunnelPktSetup().

◆ default_packet_size

uint32_t default_packet_size = 0

Definition at line 77 of file decode.c.

Referenced by PacketCopyDataOffset(), and RunUnittests().

◆ defrag_memcap_eps_stats

ExceptionPolicyStatsSetts defrag_memcap_eps_stats
Initial value:
= {
.valid_settings_ids = {
false,
false,
true,
false,
true,
false,
false,
true,
},
.valid_settings_ips = {
false,
false,
true,
false,
true,
true,
false,
true,
},
}

Definition at line 86 of file decode.c.

◆ flow_memcap_eps_stats

ExceptionPolicyStatsSetts flow_memcap_eps_stats
Initial value:
= {
.valid_settings_ids = {
false,
false,
true,
false,
true,
false,
false,
true,
},
.valid_settings_ips = {
false,
false,
true,
false,
true,
true,
false,
true,
},
}

Definition at line 112 of file decode.c.

Referenced by DecodeRegisterPerfCounters().

◆ packet_alert_max

uint16_t packet_alert_max = PACKET_ALERT_MAX

Definition at line 82 of file decode.c.

Referenced by AlertQueueInit(), PacketAlertCreate(), and PacketAlertGetMaxConfig().

◆ stats_decoder_events

bool stats_decoder_events

Definition at line 101 of file counters.c.

Referenced by PacketUpdateEngineEventCounters().

◆ stats_decoder_events_prefix

const char* stats_decoder_events_prefix

add stream events as stats? disabled by default

Definition at line 102 of file counters.c.

◆ stats_stream_events

bool stats_stream_events

Definition at line 104 of file counters.c.

Referenced by PacketUpdateEngineEventCounters().

◆ t_capture_stats

thread_local CaptureStats t_capture_stats

Definition at line 961 of file decode.c.

Referenced by CaptureStatsSetup(), and CaptureStatsUpdate().