slirp: add a fake NC-SI backend

NC-SI (Network Controller Sideband Interface) enables a BMC to manage
a set of NICs on a system. This model takes the simplest approach and
reverses the NC-SI packets to pretend a NIC is present and exercise
the Linux driver.

The NCSI header file <ncsi-pkt.h> comes from mainline Linux and was
untabified.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Acked-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>

1 files changed, 130 insertions, 0 deletions

diff --git a/slirp/ncsi.c b/slirp/ncsi.c
new file mode 100644
index 0000000..d12ba3e
--- /dev/null
+++ b/slirp/ncsi.c
@@ -0,0 +1,130 @@
+/*
+ * NC-SI (Network Controller Sideband Interface) "echo" model
+ *
+ * Copyright (C) 2016 IBM Corp.
+ *
+ * This code is licensed under the GPL version 2 or later. See the
+ * COPYING file in the top-level directory.
+ */
+#include "qemu/osdep.h"
+#include "slirp.h"
+
+#include "ncsi-pkt.h"
+
+/* Get Capabilities */
+static int ncsi_rsp_handler_gc(struct ncsi_rsp_pkt_hdr *rnh)
+{
+    struct ncsi_rsp_gc_pkt *rsp = (struct ncsi_rsp_gc_pkt *) rnh;
+
+    rsp->cap = htonl(~0);
+    rsp->bc_cap = htonl(~0);
+    rsp->mc_cap = htonl(~0);
+    rsp->buf_cap = htonl(~0);
+    rsp->aen_cap = htonl(~0);
+    rsp->vlan_mode = 0xff;
+    rsp->uc_cnt = 2;
+    return 0;
+}
+
+/* Get Link status */
+static int ncsi_rsp_handler_gls(struct ncsi_rsp_pkt_hdr *rnh)
+{
+    struct ncsi_rsp_gls_pkt *rsp = (struct ncsi_rsp_gls_pkt *) rnh;
+
+    rsp->status = htonl(0x1);
+    return 0;
+}
+
+static const struct ncsi_rsp_handler {
+        unsigned char   type;
+        int             payload;
+        int             (*handler)(struct ncsi_rsp_pkt_hdr *rnh);
+} ncsi_rsp_handlers[] = {
+        { NCSI_PKT_RSP_CIS,     4, NULL },
+        { NCSI_PKT_RSP_SP,      4, NULL },
+        { NCSI_PKT_RSP_DP,      4, NULL },
+        { NCSI_PKT_RSP_EC,      4, NULL },
+        { NCSI_PKT_RSP_DC,      4, NULL },
+        { NCSI_PKT_RSP_RC,      4, NULL },
+        { NCSI_PKT_RSP_ECNT,    4, NULL },
+        { NCSI_PKT_RSP_DCNT,    4, NULL },
+        { NCSI_PKT_RSP_AE,      4, NULL },
+        { NCSI_PKT_RSP_SL,      4, NULL },
+        { NCSI_PKT_RSP_GLS,    16, ncsi_rsp_handler_gls },
+        { NCSI_PKT_RSP_SVF,     4, NULL },
+        { NCSI_PKT_RSP_EV,      4, NULL },
+        { NCSI_PKT_RSP_DV,      4, NULL },
+        { NCSI_PKT_RSP_SMA,     4, NULL },
+        { NCSI_PKT_RSP_EBF,     4, NULL },
+        { NCSI_PKT_RSP_DBF,     4, NULL },
+        { NCSI_PKT_RSP_EGMF,    4, NULL },
+        { NCSI_PKT_RSP_DGMF,    4, NULL },
+        { NCSI_PKT_RSP_SNFC,    4, NULL },
+        { NCSI_PKT_RSP_GVI,    36, NULL },
+        { NCSI_PKT_RSP_GC,     32, ncsi_rsp_handler_gc },
+        { NCSI_PKT_RSP_GP,     -1, NULL },
+        { NCSI_PKT_RSP_GCPS,  172, NULL },
+        { NCSI_PKT_RSP_GNS,   172, NULL },
+        { NCSI_PKT_RSP_GNPTS, 172, NULL },
+        { NCSI_PKT_RSP_GPS,     8, NULL },
+        { NCSI_PKT_RSP_OEM,     0, NULL },
+        { NCSI_PKT_RSP_PLDM,    0, NULL },
+        { NCSI_PKT_RSP_GPUUID, 20, NULL }
+};
+
+/*
+ * packet format : ncsi header + payload + checksum
+ */
+#define NCSI_MAX_PAYLOAD 172
+#define NCSI_MAX_LEN     (sizeof(struct ncsi_pkt_hdr) + NCSI_MAX_PAYLOAD + 4)
+
+void ncsi_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
+{
+    struct ncsi_pkt_hdr *nh = (struct ncsi_pkt_hdr *)(pkt + ETH_HLEN);
+    uint8_t ncsi_reply[ETH_HLEN + NCSI_MAX_LEN];
+    struct ethhdr *reh = (struct ethhdr *)ncsi_reply;
+    struct ncsi_rsp_pkt_hdr *rnh = (struct ncsi_rsp_pkt_hdr *)
+        (ncsi_reply + ETH_HLEN);
+    const struct ncsi_rsp_handler *handler = NULL;
+    int i;
+
+    memset(ncsi_reply, 0, sizeof(ncsi_reply));
+
+    memset(reh->h_dest, 0xff, ETH_ALEN);
+    memset(reh->h_source, 0xff, ETH_ALEN);
+    reh->h_proto = htons(ETH_P_NCSI);
+
+    for (i = 0; i < ARRAY_SIZE(ncsi_rsp_handlers); i++) {
+        if (ncsi_rsp_handlers[i].type == nh->type + 0x80) {
+            handler = &ncsi_rsp_handlers[i];
+            break;
+        }
+    }
+
+    rnh->common.mc_id      = nh->mc_id;
+    rnh->common.revision   = NCSI_PKT_REVISION;
+    rnh->common.id         = nh->id;
+    rnh->common.type       = nh->type + 0x80;
+    rnh->common.channel    = nh->channel;
+
+    if (handler) {
+        rnh->common.length = htons(handler->payload);
+        rnh->code          = htons(NCSI_PKT_RSP_C_COMPLETED);
+        rnh->reason        = htons(NCSI_PKT_RSP_R_NO_ERROR);
+
+        if (handler->handler) {
+            /* TODO: handle errors */
+            handler->handler(rnh);
+        }
+    } else {
+        rnh->common.length = 0;
+        rnh->code          = htons(NCSI_PKT_RSP_C_UNAVAILABLE);
+        rnh->reason        = htons(NCSI_PKT_RSP_R_UNKNOWN);
+    }
+
+    /* TODO: add a checksum at the end of the frame but the specs
+     * allows it to be zero */
+
+    slirp_output(slirp->opaque, ncsi_reply, ETH_HLEN + sizeof(*nh) +
+                 (handler ? handler->payload : 0) + 4);
+}