/* Copyright (C) 2007-2013 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 Victor Julien <victor@inliniac.net>

 *

 * Flow utility functions

 */

#include "suricata-common.h"

#include "threads.h"

#include "flow.h"

#include "flow-private.h"

#include "flow-util.h"

#include "flow-var.h"

#include "app-layer.h"

#include "util-var.h"

#include "util-debug.h"

#include "util-macset.h"

#include "flow-storage.h"

#include "detect.h"

#include "detect-engine-state.h"

#include "decode-icmpv4.h"

#include "util-validate.h"

/** \brief allocate a flow

 *

 *  We check against the memuse counter. If it passes that check we increment

 *  the counter first, then we try to alloc.

 *

 *  \retval f the flow or NULL on out of memory

 */

Flow *FlowAlloc(void)

{

    Flow *f;

    size_t size = sizeof(Flow) + FlowStorageSize();

    if (!(FLOW_CHECK_MEMCAP(size))) {

        return NULL;

    }

    (void) SC_ATOMIC_ADD(flow_memuse, size);

    f = SCMalloc(size);

    if (unlikely(f == NULL)) {

        (void)SC_ATOMIC_SUB(flow_memuse, size);

        return NULL;

    }

    memset(f, 0, size);

    /* coverity[missing_lock] */

    FLOW_INITIALIZE(f);

    return f;

}

/**

 *  \brief cleanup & free the memory of a flow

 *

 *  \param f flow to clear & destroy

 */

void FlowFree(Flow *f)

{

    FLOW_DESTROY(f);

    SCFree(f);

    size_t size = sizeof(Flow) + FlowStorageSize();

    (void) SC_ATOMIC_SUB(flow_memuse, size);

}

/**

 *  \brief   Function to map the protocol to the defined FLOW_PROTO_* enumeration.

 *

 *  \param   proto  protocol which is needed to be mapped

 */

uint8_t FlowGetProtoMapping(uint8_t proto)

{

    switch (proto) {

        case IPPROTO_TCP:

            return FLOW_PROTO_TCP;

        case IPPROTO_UDP:

            return FLOW_PROTO_UDP;

        case IPPROTO_ICMP:

            return FLOW_PROTO_ICMP;

        default:

            return FLOW_PROTO_DEFAULT;

    }

}

uint8_t FlowGetReverseProtoMapping(uint8_t rproto)

{

    switch (rproto) {

        case FLOW_PROTO_TCP:

            return IPPROTO_TCP;

        case FLOW_PROTO_UDP:

            return IPPROTO_UDP;

        case FLOW_PROTO_ICMP:

            return IPPROTO_ICMP;

        default:

            exit(EXIT_FAILURE);

    }

}

static inline void FlowSetICMPv4CounterPart(Flow *f)

{

    int ctype = ICMPv4GetCounterpart(f->icmp_s.type);

    if (ctype == -1)

        return;

    f->icmp_d.type = (uint8_t)ctype;

}

static inline void FlowSetICMPv6CounterPart(Flow *f)

{

    int ctype = ICMPv6GetCounterpart(f->icmp_s.type);

    if (ctype == -1)

        return;

    f->icmp_d.type = (uint8_t)ctype;

}

/* initialize the flow from the first packet

 * we see from it. */

void FlowInit(ThreadVars *tv, Flow *f, const Packet *p)

{

    SCEnter();

    SCLogDebug("flow %p", f);

    f->proto = p->proto;

    f->recursion_level = p->recursion_level;

    memcpy(&f->vlan_id[0], &p->vlan_id[0], sizeof(f->vlan_id));

    f->vlan_idx = p->vlan_idx;

    f->thread_id[0] = (FlowThreadId)tv->id;

    f->livedev = p->livedev;

    if (PKT_IS_IPV4(p)) {

        FLOW_SET_IPV4_SRC_ADDR_FROM_PACKET(p, &f->src);

        FLOW_SET_IPV4_DST_ADDR_FROM_PACKET(p, &f->dst);

        f->min_ttl_toserver = f->max_ttl_toserver = IPV4_GET_IPTTL((p));

        f->flags |= FLOW_IPV4;

    } else if (PKT_IS_IPV6(p)) {

        FLOW_SET_IPV6_SRC_ADDR_FROM_PACKET(p, &f->src);

        FLOW_SET_IPV6_DST_ADDR_FROM_PACKET(p, &f->dst);

        f->min_ttl_toserver = f->max_ttl_toserver = IPV6_GET_HLIM((p));

        f->flags |= FLOW_IPV6;

    } else {

        SCLogDebug("neither IPv4 or IPv6, weird");

        DEBUG_VALIDATE_BUG_ON(1);

    }

    if (p->tcph != NULL) { /* XXX MACRO */

        SET_TCP_SRC_PORT(p,&f->sp);

        SET_TCP_DST_PORT(p,&f->dp);

    } else if (p->udph != NULL) { /* XXX MACRO */

        SET_UDP_SRC_PORT(p,&f->sp);

        SET_UDP_DST_PORT(p,&f->dp);

    } else if (p->icmpv4h != NULL) {

        f->icmp_s.type = p->icmp_s.type;

        f->icmp_s.code = p->icmp_s.code;

        FlowSetICMPv4CounterPart(f);

    } else if (p->icmpv6h != NULL) {

        f->icmp_s.type = p->icmp_s.type;

        f->icmp_s.code = p->icmp_s.code;

        FlowSetICMPv6CounterPart(f);

    } else if (p->sctph != NULL) { /* XXX MACRO */

        SET_SCTP_SRC_PORT(p,&f->sp);

        SET_SCTP_DST_PORT(p,&f->dp);

    } else if (p->esph != NULL) {

        f->esp.spi = ESP_GET_SPI(p);

    } else {

        /* nothing to do for this IP proto. */

        SCLogDebug("no special setup for IP proto %u", p->proto);

    }

    f->startts = p->ts;

    f->protomap = FlowGetProtoMapping(f->proto);

    f->timeout_policy = FlowGetTimeoutPolicy(f);

    const uint32_t timeout_at = (uint32_t)SCTIME_SECS(f->startts) + f->timeout_policy;

    f->timeout_at = timeout_at;

    if (MacSetFlowStorageEnabled()) {

        DEBUG_VALIDATE_BUG_ON(FlowGetStorageById(f, MacSetGetFlowStorageID()) != NULL);

        MacSet *ms = MacSetInit(10);

        FlowSetStorageById(f, MacSetGetFlowStorageID(), ms);

    }

    SCReturn;

}

FlowStorageId g_bypass_info_id = { .id = -1 };

FlowStorageId GetFlowBypassInfoID(void)

{

    return g_bypass_info_id;

}

static void FlowBypassFree(void *x)

{

    FlowBypassInfo *fb = (FlowBypassInfo *) x;

    if (fb == NULL)

        return;

    if (fb->bypass_data && fb->BypassFree) {

        fb->BypassFree(fb->bypass_data);

    }

    SCFree(fb);

}

void RegisterFlowBypassInfo(void)

{

    g_bypass_info_id = FlowStorageRegister("bypass_counters", sizeof(void *),

                                              NULL, FlowBypassFree);

}

void FlowEndCountersRegister(ThreadVars *t, FlowEndCounters *fec)

{

    for (int i = 0; i < FLOW_STATE_SIZE; i++) {

        const char *name = NULL;

        if (i == FLOW_STATE_NEW) {

            name = "flow.end.state.new";

        } else if (i == FLOW_STATE_ESTABLISHED) {

            name = "flow.end.state.established";

        } else if (i == FLOW_STATE_CLOSED) {

            name = "flow.end.state.closed";

        } else if (i == FLOW_STATE_LOCAL_BYPASSED) {

            name = "flow.end.state.local_bypassed";

#ifdef CAPTURE_OFFLOAD

        } else if (i == FLOW_STATE_CAPTURE_BYPASSED) {

            name = "flow.end.state.capture_bypassed";

#endif

        }

        if (name) {

            fec->flow_state[i] = StatsRegisterCounter(name, t);

        }

    }

    for (enum TcpState i = TCP_NONE; i <= TCP_CLOSED; i++) {

        const char *name = NULL;

        switch (i) {

            case TCP_NONE:

                name = "flow.end.tcp_state.none";

                break;

            case TCP_SYN_SENT:

                name = "flow.end.tcp_state.syn_sent";

                break;

            case TCP_SYN_RECV:

                name = "flow.end.tcp_state.syn_recv";

                break;

            case TCP_ESTABLISHED:

                name = "flow.end.tcp_state.established";

                break;

            case TCP_FIN_WAIT1:

                name = "flow.end.tcp_state.fin_wait1";

                break;

            case TCP_FIN_WAIT2:

                name = "flow.end.tcp_state.fin_wait2";

                break;

            case TCP_TIME_WAIT:

                name = "flow.end.tcp_state.time_wait";

                break;

            case TCP_LAST_ACK:

                name = "flow.end.tcp_state.last_ack";

                break;

            case TCP_CLOSE_WAIT:

                name = "flow.end.tcp_state.close_wait";

                break;

            case TCP_CLOSING:

                name = "flow.end.tcp_state.closing";

                break;

            case TCP_CLOSED:

                name = "flow.end.tcp_state.closed";

                break;

        }

        fec->flow_tcp_state[i] = StatsRegisterCounter(name, t);

    }

    fec->flow_tcp_liberal = StatsRegisterCounter("flow.end.tcp_liberal", t);

}