ipmi: add oem message handling

Enable userspace to receive messages that a BMC transmits using an OEM
medium.  This is used by the HP iLO2.

Based on code originally written by Patrick Schoeller.

Signed-off-by: dann frazier <dannf@hp.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 137 insertions, 5 deletions

diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index 83c7477ba801..aa83a0865ec1 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -3284,6 +3284,114 @@ static int handle_lan_get_msg_cmd(ipmi_smi_t          intf,
         return rv;
 }
 
+/*
+ * This routine will handle "Get Message" command responses with
+ * channels that use an OEM Medium. The message format belongs to
+ * the OEM.  See IPMI 2.0 specification, Chapter 6 and
+ * Chapter 22, sections 22.6 and 22.24 for more details.
+ */
+static int handle_oem_get_msg_cmd(ipmi_smi_t          intf,
+                                  struct ipmi_smi_msg *msg)
+{
+        struct cmd_rcvr       *rcvr;
+        int                   rv = 0;
+        unsigned char         netfn;
+        unsigned char         cmd;
+        unsigned char         chan;
+        ipmi_user_t           user = NULL;
+        struct ipmi_system_interface_addr *smi_addr;
+        struct ipmi_recv_msg  *recv_msg;
+
+        /*
+         * We expect the OEM SW to perform error checking
+         * so we just do some basic sanity checks
+         */
+        if (msg->rsp_size < 4) {
+                /* Message not big enough, just ignore it. */
+                ipmi_inc_stat(intf, invalid_commands);
+                return 0;
+        }
+
+        if (msg->rsp[2] != 0) {
+                /* An error getting the response, just ignore it. */
+                return 0;
+        }
+
+        /*
+         * This is an OEM Message so the OEM needs to know how
+         * handle the message. We do no interpretation.
+         */
+        netfn = msg->rsp[0] >> 2;
+        cmd = msg->rsp[1];
+        chan = msg->rsp[3] & 0xf;
+
+        rcu_read_lock();
+        rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
+        if (rcvr) {
+                user = rcvr->user;
+                kref_get(&user->refcount);
+        } else
+                user = NULL;
+        rcu_read_unlock();
+
+        if (user == NULL) {
+                /* We didn't find a user, just give up. */
+                ipmi_inc_stat(intf, unhandled_commands);
+
+                /*
+                 * Don't do anything with these messages, just allow
+                 * them to be freed.
+                 */
+
+                rv = 0;
+        } else {
+                /* Deliver the message to the user. */
+                ipmi_inc_stat(intf, handled_commands);
+
+                recv_msg = ipmi_alloc_recv_msg();
+                if (!recv_msg) {
+                        /*
+                         * We couldn't allocate memory for the
+                         * message, so requeue it for handling
+                         * later.
+                         */
+                        rv = 1;
+                        kref_put(&user->refcount, free_user);
+                } else {
+                        /*
+                         * OEM Messages are expected to be delivered via
+                         * the system interface to SMS software.  We might
+                         * need to visit this again depending on OEM
+                         * requirements
+                         */
+                        smi_addr = ((struct ipmi_system_interface_addr *)
+                                    &(recv_msg->addr));
+                        smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
+                        smi_addr->channel = IPMI_BMC_CHANNEL;
+                        smi_addr->lun = msg->rsp[0] & 3;
+
+                        recv_msg->user = user;
+                        recv_msg->user_msg_data = NULL;
+                        recv_msg->recv_type = IPMI_OEM_RECV_TYPE;
+                        recv_msg->msg.netfn = msg->rsp[0] >> 2;
+                        recv_msg->msg.cmd = msg->rsp[1];
+                        recv_msg->msg.data = recv_msg->msg_data;
+
+                        /*
+                         * The message starts at byte 4 which follows the
+                         * the Channel Byte in the "GET MESSAGE" command
+                         */
+                        recv_msg->msg.data_len = msg->rsp_size - 4;
+                        memcpy(recv_msg->msg_data,
+                               &(msg->rsp[4]),
+                               msg->rsp_size - 4);
+                        deliver_response(recv_msg);
+                }
+        }
+
+        return rv;
+}
+
 static void copy_event_into_recv_msg(struct ipmi_recv_msg *recv_msg,
                                      struct ipmi_smi_msg  *msg)
 {
@@ -3539,6 +3647,17 @@ static int handle_new_recv_msg(ipmi_smi_t          intf,
                         goto out;
                 }
 
+                /*
+                ** We need to make sure the channels have been initialized.
+                ** The channel_handler routine will set the "curr_channel"
+                ** equal to or greater than IPMI_MAX_CHANNELS when all the
+                ** channels for this interface have been initialized.
+                */
+                if (intf->curr_channel < IPMI_MAX_CHANNELS) {
+                        requeue = 1;     /* Just put the message back for now */
+                        goto out;
+                }
+
                 switch (intf->channels[chan].medium) {
                 case IPMI_CHANNEL_MEDIUM_IPMB:
                         if (msg->rsp[4] & 0x04) {
@@ -3574,11 +3693,20 @@ static int handle_new_recv_msg(ipmi_smi_t          intf,
                         break;
 
                 default:
-                        /*
-                         * We don't handle the channel type, so just
-                         * free the message.
-                         */
-                        requeue = 0;
+                        /* Check for OEM Channels.  Clients had better
+                           register for these commands. */
+                        if ((intf->channels[chan].medium
+                             >= IPMI_CHANNEL_MEDIUM_OEM_MIN)
+                            && (intf->channels[chan].medium
+                                <= IPMI_CHANNEL_MEDIUM_OEM_MAX)) {
+                                requeue = handle_oem_get_msg_cmd(intf, msg);
+                        } else {
+                                /*
+                                 * We don't handle the channel type, so just
+                                 * free the message.
+                                 */
+                                requeue = 0;
+                        }
                 }
 
         } else if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
diff --git a/include/linux/ipmi.h b/include/linux/ipmi.h
index 7ebdb4fb4e54..65aae34759de 100644
--- a/include/linux/ipmi.h
+++ b/include/linux/ipmi.h
@@ -198,6 +198,8 @@ struct kernel_ipmi_msg {
                                               response.  When you send a
                                               response message, this will
                                               be returned. */
+#define IPMI_OEM_RECV_TYPE              5 /* The response for OEM Channels */
+
 /* Note that async events and received commands do not have a completion
    code as the first byte of the incoming data, unlike a response. */
 
diff --git a/include/linux/ipmi_msgdefs.h b/include/linux/ipmi_msgdefs.h
index a079f586e907..df97e6e31e87 100644
--- a/include/linux/ipmi_msgdefs.h
+++ b/include/linux/ipmi_msgdefs.h
@@ -115,5 +115,7 @@
 #define IPMI_CHANNEL_MEDIUM_USB1        10
 #define IPMI_CHANNEL_MEDIUM_USB2        11
 #define IPMI_CHANNEL_MEDIUM_SYSINTF     12
+#define IPMI_CHANNEL_MEDIUM_OEM_MIN     0x60
+#define IPMI_CHANNEL_MEDIUM_OEM_MAX     0x7f
 
 #endif /* __LINUX_IPMI_MSGDEFS_H */