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suricata/src/flow-timeout.c

577 lines
18 KiB
C

/* Copyright (C) 2007-2012 Open Information Security Foundation
*
* You can copy, redistribute or modify this Program under the terms of
* the GNU General Public License version 2 as published by the Free
* Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* version 2 along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
/**
* \file
*
* \author Anoop Saldanha <anoopsaldanha@gmail.com>
*/
#include "suricata-common.h"
#include "suricata.h"
#include "decode.h"
#include "conf.h"
#include "threadvars.h"
#include "tm-threads.h"
#include "runmodes.h"
#include "util-random.h"
#include "util-time.h"
#include "flow.h"
#include "flow-queue.h"
#include "flow-hash.h"
#include "flow-util.h"
#include "flow-var.h"
#include "flow-private.h"
#include "flow-manager.h"
#include "pkt-var.h"
#include "host.h"
#include "stream-tcp-private.h"
#include "stream-tcp-reassemble.h"
#include "stream-tcp.h"
#include "util-unittest.h"
#include "util-unittest-helper.h"
#include "util-byte.h"
#include "util-debug.h"
#include "util-privs.h"
#include "detect.h"
#include "detect-engine-state.h"
#include "stream.h"
#include "app-layer-parser.h"
#include "app-layer.h"
#include "util-profiling.h"
/**
* \internal
* \brief Pseudo packet setup for flow forced reassembly.
*
* \param direction Direction of the packet. 0 indicates toserver and 1
* indicates toclient.
* \param f Pointer to the flow.
* \param ssn Pointer to the tcp session.
* \param dummy Indicates to create a dummy pseudo packet. Not all pseudo
* packets need to force reassembly, in which case we just
* set dummy ack/seq values.
*/
static inline Packet *FlowForceReassemblyPseudoPacketSetup(Packet *p,
int direction,
Flow *f,
TcpSession *ssn,
int dummy)
{
p->tenant_id = f->tenant_id;
p->datalink = DLT_RAW;
p->proto = IPPROTO_TCP;
FlowReference(&p->flow, f);
p->flags |= PKT_STREAM_EST;
p->flags |= PKT_STREAM_EOF;
p->flags |= PKT_HAS_FLOW;
p->flags |= PKT_PSEUDO_STREAM_END;
if (f->flags & FLOW_NOPACKET_INSPECTION) {
DecodeSetNoPacketInspectionFlag(p);
}
if (f->flags & FLOW_NOPAYLOAD_INSPECTION) {
DecodeSetNoPayloadInspectionFlag(p);
}
if (direction == 0)
p->flowflags |= FLOW_PKT_TOSERVER;
else
p->flowflags |= FLOW_PKT_TOCLIENT;
p->flowflags |= FLOW_PKT_ESTABLISHED;
p->payload = NULL;
p->payload_len = 0;
if (FLOW_IS_IPV4(f)) {
if (direction == 0) {
FLOW_COPY_IPV4_ADDR_TO_PACKET(&f->src, &p->src);
FLOW_COPY_IPV4_ADDR_TO_PACKET(&f->dst, &p->dst);
p->sp = f->sp;
p->dp = f->dp;
} else {
FLOW_COPY_IPV4_ADDR_TO_PACKET(&f->src, &p->dst);
FLOW_COPY_IPV4_ADDR_TO_PACKET(&f->dst, &p->src);
p->sp = f->dp;
p->dp = f->sp;
}
/* Check if we have enough room in direct data. We need ipv4 hdr + tcp hdr.
* Force an allocation if it is not the case.
*/
if (GET_PKT_DIRECT_MAX_SIZE(p) < 40) {
if (PacketCallocExtPkt(p, 40) == -1) {
goto error;
}
}
/* set the ip header */
p->ip4h = (IPV4Hdr *)GET_PKT_DATA(p);
/* version 4 and length 20 bytes for the tcp header */
p->ip4h->ip_verhl = 0x45;
p->ip4h->ip_tos = 0;
p->ip4h->ip_len = htons(40);
p->ip4h->ip_id = 0;
p->ip4h->ip_off = 0;
p->ip4h->ip_ttl = 64;
p->ip4h->ip_proto = IPPROTO_TCP;
//p->ip4h->ip_csum =
if (direction == 0) {
p->ip4h->s_ip_src.s_addr = f->src.addr_data32[0];
p->ip4h->s_ip_dst.s_addr = f->dst.addr_data32[0];
} else {
p->ip4h->s_ip_src.s_addr = f->dst.addr_data32[0];
p->ip4h->s_ip_dst.s_addr = f->src.addr_data32[0];
}
/* set the tcp header */
p->tcph = (TCPHdr *)((uint8_t *)GET_PKT_DATA(p) + 20);
SET_PKT_LEN(p, 40); /* ipv4 hdr + tcp hdr */
} else if (FLOW_IS_IPV6(f)) {
if (direction == 0) {
FLOW_COPY_IPV6_ADDR_TO_PACKET(&f->src, &p->src);
FLOW_COPY_IPV6_ADDR_TO_PACKET(&f->dst, &p->dst);
p->sp = f->sp;
p->dp = f->dp;
} else {
FLOW_COPY_IPV6_ADDR_TO_PACKET(&f->src, &p->dst);
FLOW_COPY_IPV6_ADDR_TO_PACKET(&f->dst, &p->src);
p->sp = f->dp;
p->dp = f->sp;
}
/* Check if we have enough room in direct data. We need ipv6 hdr + tcp hdr.
* Force an allocation if it is not the case.
*/
if (GET_PKT_DIRECT_MAX_SIZE(p) < 60) {
if (PacketCallocExtPkt(p, 60) == -1) {
goto error;
}
}
/* set the ip header */
p->ip6h = (IPV6Hdr *)GET_PKT_DATA(p);
/* version 6 */
p->ip6h->s_ip6_vfc = 0x60;
p->ip6h->s_ip6_flow = 0;
p->ip6h->s_ip6_nxt = IPPROTO_TCP;
p->ip6h->s_ip6_plen = htons(20);
p->ip6h->s_ip6_hlim = 64;
if (direction == 0) {
p->ip6h->s_ip6_src[0] = f->src.addr_data32[0];
p->ip6h->s_ip6_src[1] = f->src.addr_data32[1];
p->ip6h->s_ip6_src[2] = f->src.addr_data32[2];
p->ip6h->s_ip6_src[3] = f->src.addr_data32[3];
p->ip6h->s_ip6_dst[0] = f->dst.addr_data32[0];
p->ip6h->s_ip6_dst[1] = f->dst.addr_data32[1];
p->ip6h->s_ip6_dst[2] = f->dst.addr_data32[2];
p->ip6h->s_ip6_dst[3] = f->dst.addr_data32[3];
} else {
p->ip6h->s_ip6_src[0] = f->dst.addr_data32[0];
p->ip6h->s_ip6_src[1] = f->dst.addr_data32[1];
p->ip6h->s_ip6_src[2] = f->dst.addr_data32[2];
p->ip6h->s_ip6_src[3] = f->dst.addr_data32[3];
p->ip6h->s_ip6_dst[0] = f->src.addr_data32[0];
p->ip6h->s_ip6_dst[1] = f->src.addr_data32[1];
p->ip6h->s_ip6_dst[2] = f->src.addr_data32[2];
p->ip6h->s_ip6_dst[3] = f->src.addr_data32[3];
}
/* set the tcp header */
p->tcph = (TCPHdr *)((uint8_t *)GET_PKT_DATA(p) + 40);
SET_PKT_LEN(p, 60); /* ipv6 hdr + tcp hdr */
}
p->tcph->th_offx2 = 0x50;
p->tcph->th_flags |= TH_ACK;
p->tcph->th_win = 10;
p->tcph->th_urp = 0;
/* to server */
if (direction == 0) {
p->tcph->th_sport = htons(f->sp);
p->tcph->th_dport = htons(f->dp);
if (dummy) {
p->tcph->th_seq = htonl(ssn->client.next_seq);
p->tcph->th_ack = htonl(ssn->server.last_ack);
} else {
p->tcph->th_seq = htonl(ssn->client.next_seq);
p->tcph->th_ack = htonl(ssn->server.seg_list_tail->seq +
ssn->server.seg_list_tail->payload_len);
}
/* to client */
} else {
p->tcph->th_sport = htons(f->dp);
p->tcph->th_dport = htons(f->sp);
if (dummy) {
p->tcph->th_seq = htonl(ssn->server.next_seq);
p->tcph->th_ack = htonl(ssn->client.last_ack);
} else {
p->tcph->th_seq = htonl(ssn->server.next_seq);
p->tcph->th_ack = htonl(ssn->client.seg_list_tail->seq +
ssn->client.seg_list_tail->payload_len);
}
}
if (FLOW_IS_IPV4(f)) {
p->tcph->th_sum = TCPCalculateChecksum(p->ip4h->s_ip_addrs,
(uint16_t *)p->tcph, 20);
/* calc ipv4 csum as we may log it and barnyard might reject
* a wrong checksum */
p->ip4h->ip_csum = IPV4CalculateChecksum((uint16_t *)p->ip4h,
IPV4_GET_RAW_HLEN(p->ip4h));
} else if (FLOW_IS_IPV6(f)) {
p->tcph->th_sum = TCPCalculateChecksum(p->ip6h->s_ip6_addrs,
(uint16_t *)p->tcph, 20);
}
memset(&p->ts, 0, sizeof(struct timeval));
TimeGet(&p->ts);
AppLayerParserSetEOF(f->alparser);
return p;
error:
FlowDeReference(&p->flow);
return NULL;
}
static inline Packet *FlowForceReassemblyPseudoPacketGet(int direction,
Flow *f,
TcpSession *ssn,
int dummy)
{
PacketPoolWait();
Packet *p = PacketPoolGetPacket();
if (p == NULL) {
return NULL;
}
PACKET_PROFILING_START(p);
return FlowForceReassemblyPseudoPacketSetup(p, direction, f, ssn, dummy);
}
/**
* \brief Check if a flow needs forced reassembly, or any other processing
*
* \param f *LOCKED* flow
* \param server ptr to int that should be set to 1 or 2 if we return 1
* \param client ptr to int that should be set to 1 or 2 if we return 1
*
* \retval 0 no
* \retval 1 yes
*/
int FlowForceReassemblyNeedReassembly(Flow *f, int *server, int *client)
{
TcpSession *ssn;
if (f == NULL) {
*server = *client = STREAM_HAS_UNPROCESSED_SEGMENTS_NONE;
SCReturnInt(0);
}
/* Get the tcp session for the flow */
ssn = (TcpSession *)f->protoctx;
if (ssn == NULL) {
*server = *client = STREAM_HAS_UNPROCESSED_SEGMENTS_NONE;
SCReturnInt(0);
}
*client = StreamNeedsReassembly(ssn, 0);
*server = StreamNeedsReassembly(ssn, 1);
/* if state is not fully closed we assume that we haven't fully
* inspected the app layer state yet */
if (ssn->state >= TCP_ESTABLISHED && ssn->state != TCP_CLOSED)
{
if (*client != STREAM_HAS_UNPROCESSED_SEGMENTS_NEED_REASSEMBLY)
*client = STREAM_HAS_UNPROCESSED_SEGMENTS_NEED_ONLY_DETECTION;
if (*server != STREAM_HAS_UNPROCESSED_SEGMENTS_NEED_REASSEMBLY)
*server = STREAM_HAS_UNPROCESSED_SEGMENTS_NEED_ONLY_DETECTION;
}
/* if app layer still needs some love, push through */
if (f->alproto != ALPROTO_UNKNOWN && f->alstate != NULL &&
AppLayerParserProtocolSupportsTxs(f->proto, f->alproto))
{
uint64_t total_txs = AppLayerParserGetTxCnt(f->proto, f->alproto, f->alstate);
if (AppLayerParserGetTransactionActive(f->proto, f->alproto,
f->alparser, STREAM_TOCLIENT) < total_txs)
{
if (*server != STREAM_HAS_UNPROCESSED_SEGMENTS_NEED_REASSEMBLY)
*server = STREAM_HAS_UNPROCESSED_SEGMENTS_NEED_ONLY_DETECTION;
}
if (AppLayerParserGetTransactionActive(f->proto, f->alproto,
f->alparser, STREAM_TOSERVER) < total_txs)
{
if (*client != STREAM_HAS_UNPROCESSED_SEGMENTS_NEED_REASSEMBLY)
*client = STREAM_HAS_UNPROCESSED_SEGMENTS_NEED_ONLY_DETECTION;
}
}
/* nothing to do */
if (*client == STREAM_HAS_UNPROCESSED_SEGMENTS_NONE &&
*server == STREAM_HAS_UNPROCESSED_SEGMENTS_NONE) {
SCReturnInt(0);
}
SCReturnInt(1);
}
/**
* \internal
* \brief Forces reassembly for flow if it needs it.
*
* The function requires flow to be locked beforehand.
*
* \param f Pointer to the flow.
* \param server action required for server: 1 or 2
* \param client action required for client: 1 or 2
*
* \retval 0 This flow doesn't need any reassembly processing; 1 otherwise.
*/
int FlowForceReassemblyForFlow(Flow *f, int server, int client)
{
Packet *p1 = NULL, *p2 = NULL, *p3 = NULL;
TcpSession *ssn;
/* looks like we have no flows in this queue */
if (f == NULL) {
return 0;
}
/* Get the tcp session for the flow */
ssn = (TcpSession *)f->protoctx;
if (ssn == NULL) {
return 0;
}
/* The packets we use are based on what segments in what direction are
* unprocessed.
* p1 if we have client segments for reassembly purpose only. If we
* have no server segments p2 can be a toserver packet with dummy
* seq/ack, and if we have server segments p2 has to carry out reassembly
* for server segment as well, in which case we will also need a p3 in the
* toclient which is now dummy since all we need it for is detection */
/* insert a pseudo packet in the toserver direction */
if (client == STREAM_HAS_UNPROCESSED_SEGMENTS_NEED_REASSEMBLY) {
p1 = FlowForceReassemblyPseudoPacketGet(1, f, ssn, 0);
if (p1 == NULL) {
goto done;
}
PKT_SET_SRC(p1, PKT_SRC_FFR);
if (server == STREAM_HAS_UNPROCESSED_SEGMENTS_NEED_REASSEMBLY) {
p2 = FlowForceReassemblyPseudoPacketGet(0, f, ssn, 0);
if (p2 == NULL) {
FlowDeReference(&p1->flow);
TmqhOutputPacketpool(NULL, p1);
goto done;
}
PKT_SET_SRC(p2, PKT_SRC_FFR);
p3 = FlowForceReassemblyPseudoPacketGet(1, f, ssn, 1);
if (p3 == NULL) {
FlowDeReference(&p1->flow);
TmqhOutputPacketpool(NULL, p1);
FlowDeReference(&p2->flow);
TmqhOutputPacketpool(NULL, p2);
goto done;
}
PKT_SET_SRC(p3, PKT_SRC_FFR);
} else {
p2 = FlowForceReassemblyPseudoPacketGet(0, f, ssn, 1);
if (p2 == NULL) {
FlowDeReference(&p1->flow);
TmqhOutputPacketpool(NULL, p1);
goto done;
}
PKT_SET_SRC(p2, PKT_SRC_FFR);
}
} else if (client == STREAM_HAS_UNPROCESSED_SEGMENTS_NEED_ONLY_DETECTION) {
if (server == STREAM_HAS_UNPROCESSED_SEGMENTS_NEED_REASSEMBLY) {
p1 = FlowForceReassemblyPseudoPacketGet(0, f, ssn, 0);
if (p1 == NULL) {
goto done;
}
PKT_SET_SRC(p1, PKT_SRC_FFR);
p2 = FlowForceReassemblyPseudoPacketGet(1, f, ssn, 1);
if (p2 == NULL) {
FlowDeReference(&p1->flow);
TmqhOutputPacketpool(NULL, p1);
goto done;
}
PKT_SET_SRC(p2, PKT_SRC_FFR);
} else {
p1 = FlowForceReassemblyPseudoPacketGet(0, f, ssn, 1);
if (p1 == NULL) {
goto done;
}
PKT_SET_SRC(p1, PKT_SRC_FFR);
if (server == STREAM_HAS_UNPROCESSED_SEGMENTS_NEED_ONLY_DETECTION) {
p2 = FlowForceReassemblyPseudoPacketGet(1, f, ssn, 1);
if (p2 == NULL) {
FlowDeReference(&p1->flow);
TmqhOutputPacketpool(NULL, p1);
goto done;
}
PKT_SET_SRC(p2, PKT_SRC_FFR);
}
}
} else {
if (server == STREAM_HAS_UNPROCESSED_SEGMENTS_NEED_REASSEMBLY) {
p1 = FlowForceReassemblyPseudoPacketGet(0, f, ssn, 0);
if (p1 == NULL) {
goto done;
}
PKT_SET_SRC(p1, PKT_SRC_FFR);
p2 = FlowForceReassemblyPseudoPacketGet(1, f, ssn, 1);
if (p2 == NULL) {
FlowDeReference(&p1->flow);
TmqhOutputPacketpool(NULL, p1);
goto done;
}
PKT_SET_SRC(p2, PKT_SRC_FFR);
} else if (server == STREAM_HAS_UNPROCESSED_SEGMENTS_NEED_ONLY_DETECTION) {
p1 = FlowForceReassemblyPseudoPacketGet(1, f, ssn, 1);
if (p1 == NULL) {
goto done;
}
PKT_SET_SRC(p1, PKT_SRC_FFR);
} else {
/* impossible */
BUG_ON(1);
}
}
/* inject the packet(s) into the appropriate thread */
int thread_id = (int)f->thread_id;
Packet *packets[4] = { p1, p2 ? p2 : p3, p2 ? p3 : NULL, NULL }; /**< null terminated array of packets */
if (unlikely(!(TmThreadsInjectPacketsById(packets, thread_id)))) {
FlowDeReference(&p1->flow);
TmqhOutputPacketpool(NULL, p1);
if (p2) {
FlowDeReference(&p2->flow);
TmqhOutputPacketpool(NULL, p2);
}
if (p3) {
FlowDeReference(&p3->flow);
TmqhOutputPacketpool(NULL, p3);
}
}
/* done, in case of error (no packet) we still tag flow as complete
* as we're probably resource stress if we couldn't get packets */
done:
f->flags |= FLOW_TIMEOUT_REASSEMBLY_DONE;
return 1;
}
/**
* \internal
* \brief Forces reassembly for flows that need it.
*
* When this function is called we're running in virtually dead engine,
* so locking the flows is not strictly required. The reasons it is still
* done are:
* - code consistency
* - silence complaining profilers
* - allow us to aggressively check using debug valdation assertions
* - be robust in case of future changes
* - locking overhead if neglectable when no other thread fights us
*
* \param q The queue to process flows from.
*/
static inline void FlowForceReassemblyForHash(void)
{
Flow *f;
TcpSession *ssn;
int client_ok = 0;
int server_ok = 0;
uint32_t idx = 0;
for (idx = 0; idx < flow_config.hash_size; idx++) {
FlowBucket *fb = &flow_hash[idx];
PacketPoolWaitForN(9);
FBLOCK_LOCK(fb);
/* get the topmost flow from the QUEUE */
f = fb->head;
/* we need to loop through all the flows in the queue */
while (f != NULL) {
PacketPoolWaitForN(3);
FLOWLOCK_WRLOCK(f);
/* Get the tcp session for the flow */
ssn = (TcpSession *)f->protoctx;
/* \todo Also skip flows that shouldn't be inspected */
if (ssn == NULL) {
FLOWLOCK_UNLOCK(f);
f = f->hnext;
continue;
}
if (FlowForceReassemblyNeedReassembly(f, &server_ok, &client_ok) == 1) {
FlowForceReassemblyForFlow(f, server_ok, client_ok);
}
FLOWLOCK_UNLOCK(f);
/* next flow in the queue */
f = f->hnext;
}
FBLOCK_UNLOCK(fb);
}
return;
}
/**
* \brief Force reassembly for all the flows that have unprocessed segments.
*/
void FlowForceReassembly(void)
{
/* Carry out flow reassembly for unattended flows */
FlowForceReassemblyForHash();
return;
}