slirp/ncsi.c

   1 /*
   2  * NC-SI (Network Controller Sideband Interface) "echo" model
   3  *
   4  * Copyright (C) 2016-2018 IBM Corp.
   5  *
   6  * This code is licensed under the GPL version 2 or later. See the
   7  * COPYING file in the top-level directory.
   8  */
   9 #include "qemu/osdep.h"
  10 #include "slirp.h"
  11
  12 #include "ncsi-pkt.h"
  13
  14 static uint32_t ncsi_calculate_checksum(uint16_t *data, int len)
  15 {
  16     uint32_t checksum = 0;
  17     int i;
  18
  19     /*
  20      * 32-bit unsigned sum of the NC-SI packet header and NC-SI packet
  21      * payload interpreted as a series of 16-bit unsigned integer values.
  22      */
  23     for (i = 0; i < len; i++) {
  24         checksum += htons(data[i]);
  25     }
  26
  27     checksum = (~checksum + 1);
  28     return checksum;
  29 }
  30
  31 /* Get Capabilities */
  32 static int ncsi_rsp_handler_gc(struct ncsi_rsp_pkt_hdr *rnh)
  33 {
  34     struct ncsi_rsp_gc_pkt *rsp = (struct ncsi_rsp_gc_pkt *) rnh;
  35
  36     rsp->cap = htonl(~0);
  37     rsp->bc_cap = htonl(~0);
  38     rsp->mc_cap = htonl(~0);
  39     rsp->buf_cap = htonl(~0);
  40     rsp->aen_cap = htonl(~0);
  41     rsp->vlan_mode = 0xff;
  42     rsp->uc_cnt = 2;
  43     return 0;
  44 }
  45
  46 /* Get Link status */
  47 static int ncsi_rsp_handler_gls(struct ncsi_rsp_pkt_hdr *rnh)
  48 {
  49     struct ncsi_rsp_gls_pkt *rsp = (struct ncsi_rsp_gls_pkt *) rnh;
  50
  51     rsp->status = htonl(0x1);
  52     return 0;
  53 }
  54
  55 /* Get Parameters */
  56 static int ncsi_rsp_handler_gp(struct ncsi_rsp_pkt_hdr *rnh)
  57 {
  58     struct ncsi_rsp_gp_pkt *rsp = (struct ncsi_rsp_gp_pkt *) rnh;
  59
  60     /* no MAC address filters or VLAN filters on the channel */
  61     rsp->mac_cnt = 0;
  62     rsp->mac_enable = 0;
  63     rsp->vlan_cnt = 0;
  64     rsp->vlan_enable = 0;
  65
  66     return 0;
  67 }
  68
  69 static const struct ncsi_rsp_handler {
  70         unsigned char   type;
  71         int             payload;
  72         int             (*handler)(struct ncsi_rsp_pkt_hdr *rnh);
  73 } ncsi_rsp_handlers[] = {
  74         { NCSI_PKT_RSP_CIS,     4, NULL },
  75         { NCSI_PKT_RSP_SP,      4, NULL },
  76         { NCSI_PKT_RSP_DP,      4, NULL },
  77         { NCSI_PKT_RSP_EC,      4, NULL },
  78         { NCSI_PKT_RSP_DC,      4, NULL },
  79         { NCSI_PKT_RSP_RC,      4, NULL },
  80         { NCSI_PKT_RSP_ECNT,    4, NULL },
  81         { NCSI_PKT_RSP_DCNT,    4, NULL },
  82         { NCSI_PKT_RSP_AE,      4, NULL },
  83         { NCSI_PKT_RSP_SL,      4, NULL },
  84         { NCSI_PKT_RSP_GLS,    16, ncsi_rsp_handler_gls },
  85         { NCSI_PKT_RSP_SVF,     4, NULL },
  86         { NCSI_PKT_RSP_EV,      4, NULL },
  87         { NCSI_PKT_RSP_DV,      4, NULL },
  88         { NCSI_PKT_RSP_SMA,     4, NULL },
  89         { NCSI_PKT_RSP_EBF,     4, NULL },
  90         { NCSI_PKT_RSP_DBF,     4, NULL },
  91         { NCSI_PKT_RSP_EGMF,    4, NULL },
  92         { NCSI_PKT_RSP_DGMF,    4, NULL },
  93         { NCSI_PKT_RSP_SNFC,    4, NULL },
  94         { NCSI_PKT_RSP_GVI,    40, NULL },
  95         { NCSI_PKT_RSP_GC,     32, ncsi_rsp_handler_gc },
  96         { NCSI_PKT_RSP_GP,     40, ncsi_rsp_handler_gp },
  97         { NCSI_PKT_RSP_GCPS,  172, NULL },
  98         { NCSI_PKT_RSP_GNS,   172, NULL },
  99         { NCSI_PKT_RSP_GNPTS, 172, NULL },
 100         { NCSI_PKT_RSP_GPS,     8, NULL },
 101         { NCSI_PKT_RSP_OEM,     0, NULL },
 102         { NCSI_PKT_RSP_PLDM,    0, NULL },
 103         { NCSI_PKT_RSP_GPUUID, 20, NULL }
 104 };
 105
 106 /*
 107  * packet format : ncsi header + payload + checksum
 108  */
 109 #define NCSI_MAX_PAYLOAD 172
 110 #define NCSI_MAX_LEN     (sizeof(struct ncsi_pkt_hdr) + NCSI_MAX_PAYLOAD + 4)
 111
 112 void ncsi_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
 113 {
 114     struct ncsi_pkt_hdr *nh = (struct ncsi_pkt_hdr *)(pkt + ETH_HLEN);
 115     uint8_t ncsi_reply[ETH_HLEN + NCSI_MAX_LEN];
 116     struct ethhdr *reh = (struct ethhdr *)ncsi_reply;
 117     struct ncsi_rsp_pkt_hdr *rnh = (struct ncsi_rsp_pkt_hdr *)
 118         (ncsi_reply + ETH_HLEN);
 119     const struct ncsi_rsp_handler *handler = NULL;
 120     int i;
 121     int ncsi_rsp_len = sizeof(*nh);
 122     uint32_t checksum;
 123     uint32_t *pchecksum;
 124
 125     memset(ncsi_reply, 0, sizeof(ncsi_reply));
 126
 127     memset(reh->h_dest, 0xff, ETH_ALEN);
 128     memset(reh->h_source, 0xff, ETH_ALEN);
 129     reh->h_proto = htons(ETH_P_NCSI);
 130
 131     for (i = 0; i < ARRAY_SIZE(ncsi_rsp_handlers); i++) {
 132         if (ncsi_rsp_handlers[i].type == nh->type + 0x80) {
 133             handler = &ncsi_rsp_handlers[i];
 134             break;
 135         }
 136     }
 137
 138     rnh->common.mc_id      = nh->mc_id;
 139     rnh->common.revision   = NCSI_PKT_REVISION;
 140     rnh->common.id         = nh->id;
 141     rnh->common.type       = nh->type + 0x80;
 142     rnh->common.channel    = nh->channel;
 143
 144     if (handler) {
 145         rnh->common.length = htons(handler->payload);
 146         rnh->code          = htons(NCSI_PKT_RSP_C_COMPLETED);
 147         rnh->reason        = htons(NCSI_PKT_RSP_R_NO_ERROR);
 148
 149         if (handler->handler) {
 150             /* TODO: handle errors */
 151             handler->handler(rnh);
 152         }
 153         ncsi_rsp_len += handler->payload;
 154     } else {
 155         rnh->common.length = 0;
 156         rnh->code          = htons(NCSI_PKT_RSP_C_UNAVAILABLE);
 157         rnh->reason        = htons(NCSI_PKT_RSP_R_UNKNOWN);
 158     }
 159
 160     /* Add the optional checksum at the end of the frame. */
 161     checksum = ncsi_calculate_checksum((uint16_t *) rnh, ncsi_rsp_len);
 162     pchecksum = (uint32_t *)((void *) rnh + ncsi_rsp_len);
 163     *pchecksum = htonl(checksum);
 164     ncsi_rsp_len += 4;
 165
 166     slirp_output(slirp->opaque, ncsi_reply, ETH_HLEN + ncsi_rsp_len);
 167 }