/*
* Copyright (c) 2016 Gerard Garcia <[email protected]>
* Copyright (c) 2017 Red Hat, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
*   1. Redistributions of source code must retain the above copyright
*      notice, this list of conditions and the following disclaimer.
*   2. Redistributions in binary form must reproduce the above copyright
*      notice, this list of conditions and the following disclaimer in
*      the documentation and/or other materials provided with the
*      distribution.
*   3. The names of the authors may not be used to endorse or promote
*      products derived from this software without specific prior
*      written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/

/* \summary: Linux vsock printer */

#include <config.h>

#include "netdissect-stdinc.h"
#include <stddef.h>

#include "netdissect.h"
#include "extract.h"

enum af_vsockmon_transport {
       AF_VSOCK_TRANSPORT_UNKNOWN = 0,
       AF_VSOCK_TRANSPORT_NO_INFO = 1,         /* No transport information */
       AF_VSOCK_TRANSPORT_VIRTIO = 2,          /* Virtio transport header */
};

static const struct tok vsock_transport[] = {
       {AF_VSOCK_TRANSPORT_UNKNOWN, "UNKNOWN"},
       {AF_VSOCK_TRANSPORT_NO_INFO, "NO_INFO"},
       {AF_VSOCK_TRANSPORT_VIRTIO, "VIRTIO"},
       { 0, NULL }
};

enum af_vsockmon_op {
       AF_VSOCK_OP_UNKNOWN = 0,
       AF_VSOCK_OP_CONNECT = 1,
       AF_VSOCK_OP_DISCONNECT = 2,
       AF_VSOCK_OP_CONTROL = 3,
       AF_VSOCK_OP_PAYLOAD = 4,
};

static const struct tok vsock_op[] = {
       {AF_VSOCK_OP_UNKNOWN, "UNKNOWN"},
       {AF_VSOCK_OP_CONNECT, "CONNECT"},
       {AF_VSOCK_OP_DISCONNECT, "DISCONNECT"},
       {AF_VSOCK_OP_CONTROL, "CONTROL"},
       {AF_VSOCK_OP_PAYLOAD, "PAYLOAD"},
       { 0, NULL }
};

enum virtio_vsock_type {
       VIRTIO_VSOCK_TYPE_STREAM = 1,
};

static const struct tok virtio_type[] = {
       {VIRTIO_VSOCK_TYPE_STREAM, "STREAM"},
       { 0, NULL }
};

enum virtio_vsock_op {
       VIRTIO_VSOCK_OP_INVALID = 0,
       VIRTIO_VSOCK_OP_REQUEST = 1,
       VIRTIO_VSOCK_OP_RESPONSE = 2,
       VIRTIO_VSOCK_OP_RST = 3,
       VIRTIO_VSOCK_OP_SHUTDOWN = 4,
       VIRTIO_VSOCK_OP_RW = 5,
       VIRTIO_VSOCK_OP_CREDIT_UPDATE = 6,
       VIRTIO_VSOCK_OP_CREDIT_REQUEST = 7,
};

static const struct tok virtio_op[] = {
       {VIRTIO_VSOCK_OP_INVALID, "INVALID"},
       {VIRTIO_VSOCK_OP_REQUEST, "REQUEST"},
       {VIRTIO_VSOCK_OP_RESPONSE, "RESPONSE"},
       {VIRTIO_VSOCK_OP_RST, "RST"},
       {VIRTIO_VSOCK_OP_SHUTDOWN, "SHUTDOWN"},
       {VIRTIO_VSOCK_OP_RW, "RW"},
       {VIRTIO_VSOCK_OP_CREDIT_UPDATE, "CREDIT UPDATE"},
       {VIRTIO_VSOCK_OP_CREDIT_REQUEST, "CREDIT REQUEST"},
       { 0, NULL }
};

/* All fields are little-endian */

struct virtio_vsock_hdr {
       nd_uint64_t     src_cid;
       nd_uint64_t     dst_cid;
       nd_uint32_t     src_port;
       nd_uint32_t     dst_port;
       nd_uint32_t     len;
       nd_uint16_t     type;           /* enum virtio_vsock_type */
       nd_uint16_t     op;             /* enum virtio_vsock_op */
       nd_uint32_t     flags;
       nd_uint32_t     buf_alloc;
       nd_uint32_t     fwd_cnt;
};

struct af_vsockmon_hdr {
       nd_uint64_t     src_cid;
       nd_uint64_t     dst_cid;
       nd_uint32_t     src_port;
       nd_uint32_t     dst_port;
       nd_uint16_t     op;             /* enum af_vsockmon_op */
       nd_uint16_t     transport;      /* enum af_vosckmon_transport */
       nd_uint16_t     len;            /* size of transport header */
       nd_uint8_t      reserved[2];
};

static void
vsock_virtio_hdr_print(netdissect_options *ndo, const struct virtio_vsock_hdr *hdr)
{
       uint16_t u16_v;
       uint32_t u32_v;

       u32_v = GET_LE_U_4(hdr->len);
       ND_PRINT("len %u", u32_v);

       u16_v = GET_LE_U_2(hdr->type);
       ND_PRINT(", type %s",
                tok2str(virtio_type, "Invalid type (%hu)", u16_v));

       u16_v = GET_LE_U_2(hdr->op);
       ND_PRINT(", op %s",
                tok2str(virtio_op, "Invalid op (%hu)", u16_v));

       u32_v = GET_LE_U_4(hdr->flags);
       ND_PRINT(", flags %x", u32_v);

       u32_v = GET_LE_U_4(hdr->buf_alloc);
       ND_PRINT(", buf_alloc %u", u32_v);

       u32_v = GET_LE_U_4(hdr->fwd_cnt);
       ND_PRINT(", fwd_cnt %u", u32_v);
}

/*
* This size had better fit in a u_int.
*/
static u_int
vsock_transport_hdr_size(uint16_t transport)
{
       switch (transport) {
               case AF_VSOCK_TRANSPORT_VIRTIO:
                       return (u_int)sizeof(struct virtio_vsock_hdr);
               default:
                       return 0;
       }
}

/* Returns 0 on success, -1 on truncation */
static int
vsock_transport_hdr_print(netdissect_options *ndo, uint16_t transport,
                         const u_char *p, const u_int caplen)
{
       u_int transport_size = vsock_transport_hdr_size(transport);
       const void *hdr;

       if (caplen < sizeof(struct af_vsockmon_hdr) + transport_size) {
               return -1;
       }

       hdr = p + sizeof(struct af_vsockmon_hdr);
       switch (transport) {
               case AF_VSOCK_TRANSPORT_VIRTIO:
                       ND_PRINT(" (");
                       vsock_virtio_hdr_print(ndo, hdr);
                       ND_PRINT(")");
                       break;
               default:
                       break;
       }
       return 0;
}

static void
vsock_hdr_print(netdissect_options *ndo, const u_char *p, const u_int caplen)
{
       const struct af_vsockmon_hdr *hdr = (const struct af_vsockmon_hdr *)p;
       uint16_t hdr_transport, hdr_op;
       uint32_t hdr_src_port, hdr_dst_port;
       uint64_t hdr_src_cid, hdr_dst_cid;
       u_int total_hdr_size;
       int ret = 0;

       hdr_transport = GET_LE_U_2(hdr->transport);
       ND_PRINT("%s",
                tok2str(vsock_transport, "Invalid transport (%u)",
                         hdr_transport));

       /* If verbose level is more than 0 print transport details */
       if (ndo->ndo_vflag) {
               ret = vsock_transport_hdr_print(ndo, hdr_transport, p, caplen);
               if (ret == 0)
                       ND_PRINT("\n\t");
       } else
               ND_PRINT(" ");

       hdr_src_cid = GET_LE_U_8(hdr->src_cid);
       hdr_dst_cid = GET_LE_U_8(hdr->dst_cid);
       hdr_src_port = GET_LE_U_4(hdr->src_port);
       hdr_dst_port = GET_LE_U_4(hdr->dst_port);
       hdr_op = GET_LE_U_2(hdr->op);
       ND_PRINT("%" PRIu64 ".%u > %" PRIu64 ".%u %s, length %u",
                hdr_src_cid, hdr_src_port,
                hdr_dst_cid, hdr_dst_port,
                tok2str(vsock_op, " invalid op (%u)", hdr_op),
                caplen);

       if (ret < 0)
               goto trunc;

       /* If debug level is more than 1 print payload contents */
       /* This size had better fit in a u_int */
       total_hdr_size = (u_int)sizeof(struct af_vsockmon_hdr) +
                        vsock_transport_hdr_size(hdr_transport);
       if (ndo->ndo_vflag > 1 && hdr_op == AF_VSOCK_OP_PAYLOAD) {
               if (caplen > total_hdr_size) {
                       const u_char *payload = p + total_hdr_size;

                       ND_PRINT("\n");
                       print_unknown_data(ndo, payload, "\t",
                                          caplen - total_hdr_size);
               } else
                       goto trunc;
       }
       return;

trunc:
       nd_print_trunc(ndo);
}

void
vsock_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h,
              const u_char *cp)
{
       u_int caplen = h->caplen;

       ndo->ndo_protocol = "vsock";

       if (caplen < sizeof(struct af_vsockmon_hdr)) {
               nd_print_trunc(ndo);
               ndo->ndo_ll_hdr_len += caplen;
               return;
       }
       ndo->ndo_ll_hdr_len += sizeof(struct af_vsockmon_hdr);
       vsock_hdr_print(ndo, cp, caplen);
}

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