[PATCH 4/4] slirp: Add oob-eth-addr to -netdev options

[Peter Delevoryas]

With this change, you can now request the out-of-band MAC address from
slirp in fby35-bmc:

    wget 
https://github.com/facebook/openbmc/releases/download/openbmc-e2294ff5d31d/fby35.mtd
    qemu-system-arm -machine fby35-bmc \
        -drive file=fby35.mtd,format=raw,if=mtd \
        -nographic \
        -netdev 
user,id=nic,mfr-id=0x8119,oob-eth-addr=de:ad:be:ef:ca:fe,hostfwd=::2222-:22 \
        -net nic,model=ftgmac100,netdev=nic

    ...
    username: root
    password: 0penBmc
    ...

    root@bmc-oob:~# ncsi-util -n eth0 -c 0 0x50 0 0 0x81 0x19 0 0 0x1b 0
    NC-SI Command Response:
    cmd: NCSI_OEM_CMD(0x50)
    Response: COMMAND_COMPLETED(0x0000)  Reason: NO_ERROR(0x0000)
    Payload length = 24

    20: 0x00 0x00 0x81 0x19
    24: 0x01 0x00 0x1b 0x00
    28: 0x00 0x00 0x00 0x00
    32: 0xde 0xad 0xbe 0xef
    36: 0xca 0xfe 0x00 0x00

    root@bmc-oob:~# ifconfig
    eth0      Link encap:Ethernet  HWaddr DE:AD:BE:EF:CA:FE
              inet addr:10.0.2.15  Bcast:10.0.2.255  Mask:255.255.255.0
              inet6 addr: fec0::dcad:beff:feef:cafe/64 Scope:Site
              inet6 addr: fe80::dcad:beff:feef:cafe/64 Scope:Link
              UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
              RX packets:253 errors:0 dropped:0 overruns:0 frame:0
              TX packets:271 errors:0 dropped:0 overruns:0 carrier:0
              collisions:0 txqueuelen:1000
              RX bytes:24638 (24.0 KiB)  TX bytes:18876 (18.4 KiB)
              Interrupt:32

    lo        Link encap:Local Loopback
              inet addr:127.0.0.1  Mask:255.0.0.0
              inet6 addr: ::1/128 Scope:Host
              UP LOOPBACK RUNNING  MTU:65536  Metric:1
              RX packets:2 errors:0 dropped:0 overruns:0 frame:0
              TX packets:2 errors:0 dropped:0 overruns:0 carrier:0
              collisions:0 txqueuelen:1000
              RX bytes:120 (120.0 B)  TX bytes:120 (120.0 B)

Signed-off-by: Peter Delevoryas <pdel@fb.com>
---
 net/slirp.c   | 13 +++++++++++--
 qapi/net.json |  5 ++++-
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/net/slirp.c b/net/slirp.c
index 231068c1e2..858d3da859 100644
--- a/net/slirp.c
+++ b/net/slirp.c
@@ -414,7 +414,7 @@ static int net_slirp_init(NetClientState *peer, const char 
*model,
                           const char *smb_export, const char *vsmbserver,
                           const char **dnssearch, const char *vdomainname,
                           const char *tftp_server_name, uint32_t mfr_id,
-                          Error **errp)
+                          uint8_t oob_eth_addr[ETH_ALEN], Error **errp)
 {
     /* default settings according to historic slirp */
     struct in_addr net  = { .s_addr = htonl(0x0a000200) }; /* 10.0.2.0 */
@@ -637,6 +637,7 @@ static int net_slirp_init(NetClientState *peer, const char 
*model,
     cfg.vdnssearch = dnssearch;
     cfg.vdomainname = vdomainname;
     cfg.mfr_id = mfr_id;
+    memcpy(cfg.oob_eth_addr, oob_eth_addr, ETH_ALEN);
     s->slirp = slirp_new(&cfg, &slirp_cb, s);
     QTAILQ_INSERT_TAIL(&slirp_stacks, s, entry);
 
@@ -1142,6 +1143,7 @@ int net_init_slirp(const Netdev *netdev, const char *name,
     const NetdevUserOptions *user;
     const char **dnssearch;
     bool ipv4 = true, ipv6 = true;
+    MACAddr oob_eth_addr = {};
 
     assert(netdev->type == NET_CLIENT_DRIVER_USER);
     user = &netdev->u.user;
@@ -1166,6 +1168,12 @@ int net_init_slirp(const Netdev *netdev, const char 
*name,
     net_init_slirp_configs(user->hostfwd, SLIRP_CFG_HOSTFWD);
     net_init_slirp_configs(user->guestfwd, 0);
 
+    if (user->has_oob_eth_addr &&
+        net_parse_macaddr(oob_eth_addr.a, user->oob_eth_addr) < 0) {
+        error_setg(errp, "invalid syntax for OOB ethernet address");
+        return -1;
+    }
+
     ret = net_slirp_init(peer, "user", name, user->q_restrict,
                          ipv4, vnet, user->host,
                          ipv6, user->ipv6_prefix, user->ipv6_prefixlen,
@@ -1173,7 +1181,8 @@ int net_init_slirp(const Netdev *netdev, const char *name,
                          user->bootfile, user->dhcpstart,
                          user->dns, user->ipv6_dns, user->smb,
                          user->smbserver, dnssearch, user->domainname,
-                         user->tftp_server_name, user->mfr_id, errp);
+                         user->tftp_server_name, user->mfr_id, oob_eth_addr.a,
+                         errp);
 
     while (slirp_configs) {
         config = slirp_configs;
diff --git a/qapi/net.json b/qapi/net.json
index efc5cb3fb6..7b2c3c205c 100644
--- a/qapi/net.json
+++ b/qapi/net.json
@@ -169,6 +169,8 @@
 #
 # @mfr-id: Manufacturer ID (Private Enterprise Number: IANA)
 #
+# @oob-eth-addr: Out-of-band ethernet address for BMC
+#
 # Since: 1.2
 ##
 { 'struct': 'NetdevUserOptions',
@@ -195,7 +197,8 @@
     '*hostfwd':   ['String'],
     '*guestfwd':  ['String'],
     '*tftp-server-name': 'str',
-    '*mfr-id': 'uint32' } }
+    '*mfr-id': 'uint32',
+    '*oob-eth-addr': 'str' } }
 
 ##
 # @NetdevTapOptions:
-- 
2.30.2