/* packet-vsock.c

 * Routines for AF_VSOCK dissection

 * Copyright 2016, Gerard Garcia <ggarcia@deic.uab.cat>

 *

 * Header definition:

 * https://github.com/GerardGarcia/linux/blob/vsockmon/include/uapi/linux/vsockmon.h

 *

 * Wireshark - Network traffic analyzer

 * By Gerald Combs <gerald@wireshark.org>

 * Copyright 1998 Gerald Combs

 *

 * SPDX-License-Identifier: GPL-2.0-or-later

 */

/*

 * The AF_VSOCK socket allows zero-configuration communication between guests

 * and hypervisors using the standard socket API.

 */

#include <config.h>

#include <epan/packet.h>

#include <wsutil/pint.h>

#include <epan/address_types.h>

#include <wiretap/wtap.h>

void proto_register_vsock(void);

void proto_reg_handoff_vsock(void);

static int proto_vsock;

static int vsock_address_type = -1;

static dissector_handle_t vsock_handle;

/* Generic header related fields */

static int hf_vsock_src_cid;

static int hf_vsock_src_port;

static int hf_vsock_dst_cid;

static int hf_vsock_dst_port;

static int hf_vsock_op;

static int hf_vsock_t;

static int hf_vsock_t_len;

static int hf_vsock_reserved;

static int hf_vsock_payload;

/* Virtio related fields */

static int hf_virtio_src_cid;

static int hf_virtio_dst_cid;

static int hf_virtio_src_port;

static int hf_virtio_dst_port;

static int hf_virtio_len;

static int hf_virtio_type;

static int hf_virtio_op;

static int hf_virtio_flags;

static int hf_virtio_buf_alloc;

static int hf_virtio_fwd_cnt;

static int ett_vsock;

static int ett_virtio;

static const value_string af_vsockmon_op_names[] = {

    { 0, "Unknown" },

    { 1, "Connect" },

    { 2, "Disconnect" },

    { 3, "Control" },

    { 4, "Payload" },

    { 0, NULL }

};

enum af_vsockmon_t {

    AF_VSOCK_T_UNKNOWN = 0,

    AF_VSOCK_T_NO_INFO = 1,

    AF_VSOCK_T_VIRTIO = 2

};

static const value_string af_vsockmon_t_names[] = {

    { 0, "Unknown" },

    { 1, "No info" },

    { 2, "Virtio" },

    { 0 , NULL }

};

static const value_string virtio_vsock_type_names[] = {

    { 1, "Stream"},

    { 0, NULL }

};

static const value_string virtio_vsock_op_names[] = {

    { 0, "Invalid" },

    { 1, "Request" },

    { 2, "Response" },

    { 3, "Rst" },

    { 4, "Shutdown" },

    { 5, "RW" },

    { 6, "Credit update" },

    { 7, "Credit response" },

    { 0 , NULL }

};

#define VSOCK_MIN_LENGTH 32

static int vsock_addr_to_str(const address* addr, char *buf, int buf_len)

{

    const uint8_t *addrp = (const uint8_t *)addr->data;

    if(pletohu64(&addrp[0])==2){

        (void) g_strlcpy(buf, "host", buf_len);

    } else {

        snprintf(buf, buf_len, "%" PRIu64, pletohu64(&addrp[0]));

    }

    return (int)(strlen(buf)+1);

}

static int vsock_addr_str_len(const address* addr _U_)

{

    /* 2^64 unsigned int len */

    return 19;

}

static int

dissect_vsock(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,

        void *data _U_)

{

    proto_item *ti, *virtio_ti;

    proto_tree *vsock_tree, *virtio_tree;

    uint32_t t_len, payload_len, virtio_buf_alloc, op, type,

            virtio_fwd_cnt, virtio_op, virtio_type;

    uint16_t payload_offset = 0, offset = 0;

    char *op_name, *t_name;

    if (tvb_reported_length(tvb) < VSOCK_MIN_LENGTH)

        return 0;

    /* Clear column information before start parsing */

    col_clear(pinfo->cinfo, COL_INFO);

    /* Create top tree */

    ti = proto_tree_add_item(tree, proto_vsock, tvb, 0, -1, ENC_NA);

    vsock_tree = proto_item_add_subtree(ti, ett_vsock);

    /* Parse generic header part */

    proto_tree_add_item(vsock_tree, hf_vsock_src_cid, tvb, offset, 8, ENC_LITTLE_ENDIAN);

    set_address_tvb(&pinfo->src, vsock_address_type, 8, tvb, offset);

    offset += 8;

    proto_tree_add_item(vsock_tree, hf_vsock_dst_cid, tvb, offset, 8, ENC_LITTLE_ENDIAN);

    set_address_tvb(&pinfo->dst, vsock_address_type, 8, tvb, offset);

    offset += 8;

    proto_tree_add_item_ret_uint(vsock_tree, hf_vsock_src_port, tvb, offset, 4, ENC_LITTLE_ENDIAN, &pinfo->srcport);

    offset += 4;

    proto_tree_add_item_ret_uint(vsock_tree, hf_vsock_dst_port, tvb, offset, 4, ENC_LITTLE_ENDIAN, &pinfo->destport);

    offset += 4;

    proto_tree_add_item_ret_uint(vsock_tree, hf_vsock_op, tvb, offset, 2, ENC_LITTLE_ENDIAN, &op);

    offset += 2;

    proto_tree_add_item_ret_uint(vsock_tree, hf_vsock_t, tvb, offset, 2, ENC_LITTLE_ENDIAN, &type);

    offset += 2;

    proto_tree_add_item_ret_uint(vsock_tree, hf_vsock_t_len, tvb, offset, 2, ENC_LITTLE_ENDIAN, &t_len);

    offset += 2;

    proto_tree_add_item(vsock_tree, hf_vsock_reserved, tvb, offset, 2, ENC_NA);

    offset += 2;

    payload_offset = offset + t_len;

    op_name = val_to_str(pinfo->pool, op, af_vsockmon_op_names, "Unknown (%d)");

    t_name = val_to_str(pinfo->pool, type, af_vsockmon_t_names, "Unknown (%d)");

    /* Append summary information to top tree */

    proto_item_append_text(ti, ", Op: %s, Transport: %s", op_name, t_name);

    /* Fill columns */

    col_add_fstr(pinfo->cinfo, COL_INFO, "[%s] %s", op_name, t_name);

    col_set_str(pinfo->cinfo, COL_PROTOCOL, "vSocket");

    /* Create subtree if there is transport information */

    switch (type) {

        case AF_VSOCK_T_UNKNOWN:

        case AF_VSOCK_T_NO_INFO:

            break;

        case AF_VSOCK_T_VIRTIO:

            virtio_tree = proto_tree_add_subtree(vsock_tree, tvb, offset, 44, ett_virtio, &virtio_ti, "Virtio transport header");

            proto_tree_add_item(virtio_tree, hf_virtio_src_cid, tvb, offset, 8, ENC_LITTLE_ENDIAN);

            offset += 8;

            proto_tree_add_item(virtio_tree, hf_virtio_dst_cid, tvb, offset, 8, ENC_LITTLE_ENDIAN);

            offset += 8;

            proto_tree_add_item(virtio_tree, hf_virtio_src_port, tvb, offset, 4, ENC_LITTLE_ENDIAN);

            offset += 4;

            proto_tree_add_item(virtio_tree, hf_virtio_dst_port, tvb, offset, 4, ENC_LITTLE_ENDIAN);

            offset += 4;

            proto_tree_add_item(virtio_tree, hf_virtio_len, tvb, offset, 4, ENC_LITTLE_ENDIAN);

            offset += 4;

            proto_tree_add_item_ret_uint(virtio_tree, hf_virtio_type, tvb, offset, 2, ENC_LITTLE_ENDIAN, &virtio_type);

            offset += 2;

            proto_tree_add_item_ret_uint(virtio_tree, hf_virtio_op, tvb, offset, 2, ENC_LITTLE_ENDIAN, &virtio_op);

            offset += 2;

            proto_tree_add_item(virtio_tree, hf_virtio_flags, tvb, offset, 4, ENC_LITTLE_ENDIAN);

            offset += 4;

            proto_tree_add_item_ret_uint(virtio_tree, hf_virtio_buf_alloc, tvb, offset, 4, ENC_LITTLE_ENDIAN, &virtio_buf_alloc);

            offset += 4;

            proto_tree_add_item_ret_uint(virtio_tree, hf_virtio_fwd_cnt, tvb, offset, 4, ENC_LITTLE_ENDIAN, &virtio_fwd_cnt);

            /*offset += 4;*/

            /* Append virtio information */

            col_append_fstr(pinfo->cinfo, COL_INFO, ": %s, Op: %s, Buf alloc: %u, Fwd cnt: %u",

                    val_to_str(pinfo->pool, virtio_type, virtio_vsock_type_names, "Unknown (%d)"),

                    val_to_str(pinfo->pool, virtio_op, virtio_vsock_op_names, "Unknown (%d)"),

                    virtio_buf_alloc, virtio_fwd_cnt);

            break;

    }

    /* Append payload */

    payload_len = tvb_reported_length_remaining(tvb, payload_offset);

    if (payload_len)

        proto_tree_add_bytes_format(vsock_tree, hf_vsock_payload, tvb, payload_offset, payload_len,

                NULL, "Payload (%uB)", payload_len);

    return tvb_reported_length(tvb);

}

void

proto_register_vsock(void)

{

    static hf_register_info hf[] = {

        { &hf_vsock_src_cid,

            {"Source cid", "vsock.src_cid", FT_UINT64, BASE_DEC, NULL,

                0x0, NULL, HFILL }},

        { &hf_vsock_dst_cid,

            {"Destination cid", "vsock.dst_cid", FT_UINT64, BASE_DEC, NULL,

                0x0, NULL, HFILL }},

        { &hf_vsock_src_port,

            {"Source port", "vsock.src_port", FT_UINT32, BASE_DEC, NULL,

                0x0, NULL, HFILL }},

        { &hf_vsock_dst_port,

            {"Destination port", "vsock.dst_port", FT_UINT32, BASE_DEC, NULL,

                0x0, NULL, HFILL }},

        { &hf_vsock_op,

            {"Operation", "vsock.op", FT_UINT16, BASE_DEC, VALS(af_vsockmon_op_names),

                0x0, NULL, HFILL }},

        { &hf_vsock_t,

            {"Transport", "vsock.trans", FT_UINT16, BASE_DEC, VALS(af_vsockmon_t_names),

                0x0, NULL, HFILL }},

        { &hf_vsock_t_len,

            {"Transport length", "vsock.trans_len", FT_UINT16, BASE_DEC, NULL,

                0x0, NULL, HFILL }},

        { &hf_vsock_reserved,

            {"Reserved", "vsock.reserved", FT_BYTES, BASE_NONE, NULL,

                0x0, NULL, HFILL }},

        { &hf_vsock_payload,

            { "Payload", "vsock.payload", FT_BYTES, BASE_NONE, NULL,

                0x0, NULL, HFILL}},

        { &hf_virtio_src_cid,

            {"Source cid", "vsock.virtio.src_cid", FT_UINT64, BASE_DEC, NULL,

                0x0, NULL, HFILL }},

        { &hf_virtio_dst_cid,

            {"Destination cid", "vsock.virtio.dst_cid", FT_UINT64, BASE_DEC, NULL,

                0x0, NULL, HFILL }},

        { &hf_virtio_src_port,

            {"Source port", "vsock.virtio.src_prot", FT_UINT32, BASE_DEC, NULL,

                0x0, NULL, HFILL }},

        { &hf_virtio_dst_port,

            {"Destination port", "vsock.virtio.dst_prot", FT_UINT32, BASE_DEC, NULL,

                0x0, NULL, HFILL }},

        { &hf_virtio_len,

            {"Length", "vsock.virtio.len", FT_UINT32, BASE_DEC, NULL,

                0x0, NULL, HFILL }},

        { &hf_virtio_type,

            {"Type", "vsock.virtio.type", FT_UINT16, BASE_DEC, VALS(virtio_vsock_type_names),

                0x0, NULL, HFILL }},

        { &hf_virtio_op,

            {"Operation", "vsock.virtio.op", FT_UINT16, BASE_DEC, VALS(virtio_vsock_op_names),

                0x0, NULL, HFILL }},

        { &hf_virtio_flags,

            {"Flags", "vsock.virtio.flags", FT_UINT32, BASE_HEX, NULL,

                0x0, NULL, HFILL }},

        { &hf_virtio_buf_alloc,

            {"Buf alloc", "vsock.virtio.buf_alloc", FT_UINT32, BASE_DEC, NULL,

                0x0, NULL, HFILL }},

        { &hf_virtio_fwd_cnt,

            {"Fwd cnt", "vsock.virtio.fwd_cnt", FT_UINT32, BASE_DEC, NULL,

                0x0, NULL, HFILL }}

    };

    static int *ett[] = {

        &ett_vsock,

        &ett_virtio

    };

    vsock_address_type = address_type_dissector_register("AT_VSOCK", "vSocket Address",

            vsock_addr_to_str, vsock_addr_str_len, NULL, NULL, NULL, NULL, NULL);

    proto_vsock = proto_register_protocol("vSocket", "vsock", "vsock");

    proto_register_field_array(proto_vsock, hf, array_length(hf));

    proto_register_subtree_array(ett, array_length(ett));

    vsock_handle = register_dissector("vsock", dissect_vsock, proto_vsock);

}

void

proto_reg_handoff_vsock(void)

{

    dissector_add_uint("wtap_encap", WTAP_ENCAP_VSOCK, vsock_handle);

}

/*

 * Editor modelines  -  https://www.wireshark.org/tools/modelines.html

 *

 * Local variables:

 * c-basic-offset: 4

 * tab-width: 8

 * indent-tabs-mode: nil

 * End:

 *

 * vi: set shiftwidth=4 tabstop=8 expandtab:

 * :indentSize=4:tabSize=8:noTabs=true:

 */