/* Copyright (C) 2007-2022 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.

 */

#include "suricata-common.h"

#include "runmode-pcap.h"

#include "runmodes.h"

#include "output.h"

#include "util-conf.h"

#include "util-debug.h"

#include "util-time.h"

#include "util-cpu.h"

#include "util-device-private.h"

#include "util-runmodes.h"

#include "util-misc.h"

#include "util-byte.h"

const char *RunModeIdsGetDefaultMode(void)

{

    return "autofp";

}

int RunModeIdsPcapWorkers(void);

void RunModeIdsPcapRegister(void)

{

    RunModeRegisterNewRunMode(RUNMODE_PCAP_DEV, "single", "Single threaded pcap live mode",

            RunModeIdsPcapSingle, NULL);

    RunModeRegisterNewRunMode(RUNMODE_PCAP_DEV, "autofp",

            "Multi-threaded pcap live mode. Packets from each flow are assigned to a consistent "

            "detection thread",

            RunModeIdsPcapAutoFp, NULL);

    RunModeRegisterNewRunMode(RUNMODE_PCAP_DEV, "workers",

            "Workers pcap live mode, each thread does all"

            " tasks from acquisition to logging",

            RunModeIdsPcapWorkers, NULL);

}

static void PcapDerefConfig(void *conf)

{

    PcapIfaceConfig *pfp = (PcapIfaceConfig *)conf;

    /* Pcap config is used only once but cost of this low. */

    if (SC_ATOMIC_SUB(pfp->ref, 1) == 1) {

        SCFree(pfp);

    }

}

static void *ParsePcapConfig(const char *iface)

{

    const char *threadsstr = NULL;

    SCConfNode *if_root;

    SCConfNode *if_default = NULL;

    SCConfNode *pcap_node;

    PcapIfaceConfig *aconf = SCMalloc(sizeof(*aconf));

    const char *tmpbpf;

    const char *tmpctype;

    intmax_t value;

    int promisc = 0;

    intmax_t snaplen = 0;

    if (unlikely(aconf == NULL)) {

        return NULL;

    }

    if (iface == NULL) {

        SCFree(aconf);

        return NULL;

    }

    memset(aconf, 0x00, sizeof(*aconf));

    strlcpy(aconf->iface, iface, sizeof(aconf->iface));

    aconf->buffer_size = 0;

    /* If set command line option has precedence over config */

    if ((SCConfGetInt("pcap.buffer-size", &value)) == 1) {

        if (value >= 0 && value <= INT_MAX) {

            SCLogInfo("Pcap will use %d buffer size", (int)value);

            aconf->buffer_size = (int)value;

        } else {

            SCLogWarning("pcap.buffer-size "

                         "value of %" PRIiMAX " is invalid. Valid range is "

                         "0-2147483647",

                    value);

        }

    }

    aconf->checksum_mode = CHECKSUM_VALIDATION_AUTO;

    aconf->bpf_filter = NULL;

    if ((SCConfGet("bpf-filter", &tmpbpf)) == 1) {

        aconf->bpf_filter = tmpbpf;

    }

    SC_ATOMIC_INIT(aconf->ref);

    aconf->DerefFunc = PcapDerefConfig;

    aconf->threads = 1;

    /* Find initial node */

    pcap_node = SCConfGetNode("pcap");

    if (pcap_node == NULL) {

        SCLogInfo("Unable to find pcap config using default value");

        return aconf;

    }

    if_root = ConfFindDeviceConfig(pcap_node, iface);

    if_default = ConfFindDeviceConfig(pcap_node, "default");

    if (if_root == NULL && if_default == NULL) {

        SCLogInfo("Unable to find pcap config for "

                  "interface %s, using default value",

                  iface);

        return aconf;

    }

    /* If there is no setting for current interface use default one as main iface */

    if (if_root == NULL) {

        if_root = if_default;

        if_default = NULL;

    }

    if (SCConfGetChildValueWithDefault(if_root, if_default, "threads", &threadsstr) != 1) {

        aconf->threads = 1;

    } else {

        if (threadsstr != NULL) {

            if (StringParseUint16(&aconf->threads, 10, 0, (const char *)threadsstr) < 0) {

                SCLogWarning("Invalid value for "

                             "pcap.threads: %s, resetting to 1",

                        threadsstr);

                aconf->threads = 1;

            }

        }

    }

    if (aconf->threads == 0) {

        aconf->threads = 1;

    }

    (void) SC_ATOMIC_ADD(aconf->ref, aconf->threads);

    if (aconf->buffer_size == 0) {

        const char *s_limit = NULL;

        int ret;

        ret = SCConfGetChildValueWithDefault(if_root, if_default, "buffer-size", &s_limit);

        if (ret == 1 && s_limit) {

            uint64_t bsize = 0;

            if (ParseSizeStringU64(s_limit, &bsize) < 0) {

                SCLogError("Failed to parse pcap buffer size: %s", s_limit);

            } else {

                /* the string 2gb returns 2147483648 which is 1 to high

                 * for a int. */

                if (bsize == (uint64_t)((uint64_t)INT_MAX + (uint64_t)1))

                    bsize = (uint64_t)INT_MAX;

                if (bsize > INT_MAX) {

                    SCLogError("Failed to set pcap buffer size: 2gb max. %" PRIu64 " > %d", bsize,

                            INT_MAX);

                } else {

                    aconf->buffer_size = (int)bsize;

                }

            }

        }

    }

    if (aconf->bpf_filter == NULL) {

        /* set bpf filter if we have one */

        if (SCConfGetChildValueWithDefault(if_root, if_default, "bpf-filter", &tmpbpf) != 1) {

            SCLogDebug("could not get bpf or none specified");

        } else {

            aconf->bpf_filter = tmpbpf;

        }

    } else {

        SCLogInfo("BPF filter set from command line or via old 'bpf-filter' option.");

    }

    if (SCConfGetChildValueWithDefault(if_root, if_default, "checksum-checks", &tmpctype) == 1) {

        if (strcmp(tmpctype, "auto") == 0) {

            aconf->checksum_mode = CHECKSUM_VALIDATION_AUTO;

        } else if (SCConfValIsTrue(tmpctype)) {

            aconf->checksum_mode = CHECKSUM_VALIDATION_ENABLE;

        } else if (SCConfValIsFalse(tmpctype)) {

            aconf->checksum_mode = CHECKSUM_VALIDATION_DISABLE;

        } else {

            SCLogError("Invalid value for checksum-checks for %s", aconf->iface);

        }

    }

    aconf->promisc = LIBPCAP_PROMISC;

    if (SCConfGetChildValueBoolWithDefault(if_root, if_default, "promisc", &promisc) != 1) {

        SCLogDebug("could not get promisc or none specified");

    } else {

        aconf->promisc = promisc;

    }

    aconf->snaplen = 0;

    if (SCConfGetChildValueIntWithDefault(if_root, if_default, "snaplen", &snaplen) != 1) {

        SCLogDebug("could not get snaplen or none specified");

    } else if (snaplen < INT_MIN || snaplen > INT_MAX) {

        SCLogDebug("snaplen value is not in the accepted range");

    } else {

        aconf->snaplen = (int)snaplen;

    }

    return aconf;

}

static uint16_t PcapConfigGeThreadsCount(void *conf)

{

    PcapIfaceConfig *pfp = (PcapIfaceConfig *)conf;

    return pfp->threads;

}

/**

 * \brief Single thread version of the Pcap live processing.

 */

int RunModeIdsPcapSingle(void)

{

    int ret;

    const char *live_dev = NULL;

    SCEnter();

    TimeModeSetLive();

    (void)SCConfGet("pcap.single-pcap-dev", &live_dev);

    ret = RunModeSetLiveCaptureSingle(ParsePcapConfig,

                                    PcapConfigGeThreadsCount,

                                    "ReceivePcap",

                                    "DecodePcap", thread_name_single,

                                    live_dev);

    if (ret != 0) {

        FatalError("Runmode start failed");

    }

    SCLogDebug("RunModeIdsPcapSingle initialised");

    SCReturnInt(0);

}

/**

 * \brief RunModIdsPcapAutoFp set up the following thread packet handlers:

 *        - Receive thread (from pcap device)

 *        - Decode thread

 *        - Stream thread

 *        - Detect: If we have only 1 cpu, it will setup one Detect thread

 *                  If we have more than one, it will setup num_cpus - 1

 *                  starting from the second cpu available.

 *        - Outputs thread

 *        By default the threads will use the first cpu available

 *        except the Detection threads if we have more than one cpu.

 *

 * \retval 0 If all goes well. (If any problem is detected the engine will

 *           exit()).

 */

int RunModeIdsPcapAutoFp(void)

{

    int ret;

    const char *live_dev = NULL;

    SCEnter();

    TimeModeSetLive();

    (void)SCConfGet("pcap.single-pcap-dev", &live_dev);

    ret = RunModeSetLiveCaptureAutoFp(ParsePcapConfig, PcapConfigGeThreadsCount, "ReceivePcap",

            "DecodePcap", thread_name_autofp, live_dev);

    if (ret != 0) {

        FatalError("Runmode start failed");

    }

    SCLogDebug("RunModeIdsPcapAutoFp initialised");

    SCReturnInt(0);

}

/**

 * \brief Workers version of the PCAP LIVE processing.

 *

 * Start N threads with each thread doing all the work.

 *

 */

int RunModeIdsPcapWorkers(void)

{

    int ret;

    const char *live_dev = NULL;

    SCEnter();

    TimeModeSetLive();

    (void)SCConfGet("pcap.single-pcap-dev", &live_dev);

    ret = RunModeSetLiveCaptureWorkers(ParsePcapConfig, PcapConfigGeThreadsCount, "ReceivePcap",

            "DecodePcap", thread_name_workers, live_dev);

    if (ret != 0) {

        FatalError("Unable to start runmode");

    }

    SCLogDebug("RunModeIdsPcapWorkers initialised");

    SCReturnInt(0);

}