event: Fix event submission via SSIF

IPMI 2.0 specification is quite inconsistent about system interfaces.

They have section 1.7.16 "System Interfaces" that clearly states that
there are FOUR system interfaces (KCS, SMIC, BT and SSIF), but then they
have section 1.7.31 saying that "It is mandatory to implement a system
interface that is compatible with one of the **three** specified system
interfaces" without specifying which three of the four interfaces are
meant. Then in section 6 "IPMI Messaging interfaces" they again say that
"As mentioned earlier, there are three System Interface implementations
specified for the BMC: SMIC, KCS, and BT". Is all looks like during
update from 1.5 to 2.0 they have updated section 1.7.16, but forgot to
update Table 6-3, section 1.7.31 and section 6. Yet again, there is 'Get
System Interface Capabilities' command that has a parameter 'System
Interface Type' that can specify that SI is of SSIF type.

All that have lead to a situation where some BMC manufacturers treated
the specification as if it prohibited specifying media type 0xC
(which is "System Interface") for system interfaces using SSIF
(SMBus Sustem Interface), and so they specified an SMBUS media type
for their system interface channels.

As a result, ipmitool failed to properly send event data via such
system interfaces as it treated them as non-system and didn't add
the required Generator ID.

To mitigate the inconsistency of IPMI specification and yet not
ask BMC manufacturers to alter their code, thus increasing compatibility
with legacy BMCs, this commit adds checking of current interface number.
The system interface, according to Table 6-1 of IPMI Specification is
required to have channel number 15 (0Fh). So with this commit the
generator ID is added for any interfaces that are either marked
as media type 0Ch 'System Interface' or have channel number 0Fh.

Resolves ipmitool/ipmitool#111

Signed-off-by: Alexander Amelkin <alexander@amelkin.msk.ru>

3 files changed, 84 insertions, 19 deletions

diff --git a/include/ipmitool/ipmi_channel.h b/include/ipmitool/ipmi_channel.h
index 7ff723c..85d158f 100644
--- a/include/ipmitool/ipmi_channel.h
+++ b/include/ipmitool/ipmi_channel.h
@@ -57,6 +57,28 @@
 #define IPMI_CHANNEL_SESSION_MULTI 0x80
 #define IPMI_CHANNEL_SESSION_BASED 0xC0
 
+/* Fixed channel numbers as per Table 6-1 */
+typedef enum {
+	CH_PRIMARY_IPMB,
+	CH_IMP_SPECIFIC_1,
+	CH_IMP_SPECIFIC_2,
+	CH_IMP_SPECIFIC_3,
+	CH_IMP_SPECIFIC_4,
+	CH_IMP_SPECIFIC_5,
+	CH_IMP_SPECIFIC_6,
+	CH_IMP_SPECIFIC_7,
+	CH_IMP_SPECIFIC_8,
+	CH_IMP_SPECIFIC_9,
+	CH_IMP_SPECIFIC_A,
+	CH_IMP_SPECIFIC_B,
+	CH_RSVD1,
+	CH_RSVD2,
+	CH_CURRENT,
+	CH_SYSTEM,
+	CH_TOTAL,
+	CH_UNKNOWN = UINT8_MAX
+} ipmi_channel_num_t;
+
 /* (22.24) Get Channel Info */
 struct channel_info_t {
 	uint8_t channel;
@@ -189,7 +211,8 @@ int _ipmi_set_channel_access(struct ipmi_intf *intf,
                              uint8_t privilege_option);
 
 uint8_t ipmi_get_channel_medium(struct ipmi_intf * intf, uint8_t channel);
-uint8_t ipmi_current_channel_medium(struct ipmi_intf * intf);
+void ipmi_current_channel_info(struct ipmi_intf *intf,
+                               struct channel_info_t *chinfo);
 int ipmi_channel_main(struct ipmi_intf * intf, int argc, char ** argv);
 int ipmi_get_channel_auth_cap(struct ipmi_intf * intf,
                               uint8_t channel, uint8_t priv);
diff --git a/lib/ipmi_channel.c b/lib/ipmi_channel.c
index 65da32a..a6a6a42 100644
--- a/lib/ipmi_channel.c
+++ b/lib/ipmi_channel.c
@@ -244,10 +244,28 @@ ipmi_1_5_authtypes(uint8_t n)
 	return supportedTypes;
 }
 
-uint8_t
-ipmi_current_channel_medium(struct ipmi_intf *intf)
+void
+ipmi_current_channel_info(struct ipmi_intf *intf,
+                          struct channel_info_t *chinfo)
 {
-	return ipmi_get_channel_medium(intf, 0xE);
+	int ccode = 0;
+
+	chinfo->channel = CH_CURRENT;
+	ccode = _ipmi_get_channel_info(intf, chinfo);
+	if (ccode) {
+		if (ccode != IPMI_CC_INV_DATA_FIELD_IN_REQ) {
+			if (ccode > 0) {
+				lprintf(LOG_ERR, "Get Channel Info command failed: %s",
+				        val2str(ccode, completion_code_vals));
+			}
+			else {
+				eval_ccode(ccode);
+			}
+		}
+		chinfo->channel = CH_UNKNOWN;
+		chinfo->medium = IPMI_CHANNEL_MEDIUM_RESERVED;
+	}
+	return;
 }
 
 /**
@@ -684,13 +702,16 @@ ipmi_get_channel_medium(struct ipmi_intf *intf, uint8_t channel)
 
 	channel_info.channel = channel;
 	ccode = _ipmi_get_channel_info(intf, &channel_info);
-	if (ccode == 0xCC) {
-		return IPMI_CHANNEL_MEDIUM_RESERVED;
-	} else if (ccode < 0 && eval_ccode(ccode) != 0) {
-		return 0;
-	} else if (ccode) {
-		lprintf(LOG_ERR, "Get Channel Info command failed: %s",
-				val2str(ccode, completion_code_vals));
+	if (ccode) {
+		if (ccode != IPMI_CC_INV_DATA_FIELD_IN_REQ) {
+			if (ccode > 0) {
+				lprintf(LOG_ERR, "Get Channel Info command failed: %s",
+				        val2str(ccode, completion_code_vals));
+			}
+			else {
+				eval_ccode(ccode);
+			}
+		}
 		return IPMI_CHANNEL_MEDIUM_RESERVED;
 	}
 	lprintf(LOG_DEBUG, "Channel type: %s",
diff --git a/lib/ipmi_event.c b/lib/ipmi_event.c
index 0088032..d9a5e4e 100644
--- a/lib/ipmi_event.c
+++ b/lib/ipmi_event.c
@@ -52,6 +52,14 @@
 #include <ipmitool/ipmi_event.h>
 #include <ipmitool/ipmi_sdr.h>
 
+static
+inline
+bool
+is_system(const struct channel_info_t *chinfo)
+{
+	return (IPMI_CHANNEL_MEDIUM_SYSTEM == chinfo.medium
+	        || CH_SYSTEM == chinfo.channel);
+}
 
 static void
 ipmi_event_msg_print(struct ipmi_intf * intf, struct platform_event_msg * pmsg)
@@ -84,7 +92,7 @@ ipmi_send_platform_event(struct ipmi_intf * intf, struct platform_event_msg * em
 	struct ipmi_rs * rsp;
 	struct ipmi_rq req;
 	uint8_t rqdata[8];
-	uint8_t chmed;
+	struct channel_info_t chinfo;
 
 	memset(&req, 0, sizeof(req));
 	memset(rqdata, 0, 8);
@@ -93,8 +101,14 @@ ipmi_send_platform_event(struct ipmi_intf * intf, struct platform_event_msg * em
 	req.msg.cmd = 0x02;
 	req.msg.data = rqdata;
 
-	chmed = ipmi_current_channel_medium(intf);
-	if (chmed == IPMI_CHANNEL_MEDIUM_SYSTEM) {
+	ipmi_current_channel_info(intf, &chinfo);
+	if (chinfo.channel == CH_UNKNOWN) {
+	    lprintf(LOG_ERR, "Failed to send the platform event "
+	                     "via an unknown channel");
+	    return -3;
+	}
+
+	if (is_system(&chinfo)) {
 		/* system interface, need extra generator ID */
 		req.msg.data_len = 8;
 		rqdata[0] = 0x41;   // As per Fig. 29-2 and Table 5-4
@@ -491,7 +505,7 @@ ipmi_event_fromfile(struct ipmi_intf * intf, char * file)
 	char buf[1024];
 	char * ptr, * tok;
 	int i, j;
-	uint8_t chmed;
+	struct channel_info_t chinfo;
 	int rc = 0;
 
 	if (!file)
@@ -506,8 +520,14 @@ ipmi_event_fromfile(struct ipmi_intf * intf, char * file)
 	req.msg.data = rqdata;
 	req.msg.data_len = 7;
 
-	chmed = ipmi_current_channel_medium(intf);
-	if (chmed == IPMI_CHANNEL_MEDIUM_SYSTEM) {
+	ipmi_current_channel_info(intf, &chinfo);
+	if (chinfo.channel == CH_UNKNOWN) {
+	    lprintf(LOG_ERR, "Failed to send the event from file "
+	                     "via an unknown channel");
+	    return -3;
+	}
+
+	if (is_system(&chinfo)) {
 		/* system interface, need extra generator ID */
 		rqdata[0] = 0x41;   // As per Fig. 29-2 and Table 5-4
 		req.msg.data_len = 8;
@@ -546,8 +566,9 @@ ipmi_event_fromfile(struct ipmi_intf * intf, char * file)
 			if (i == 7)
 				break;
 			j = i++;
-			if (chmed == IPMI_CHANNEL_MEDIUM_SYSTEM)
+			if (is_system(&chinfo)) {
 				j++;
+			}
 			rqdata[j] = (uint8_t)strtol(tok, NULL, 0);
 			tok = strtok(NULL, " ");
 		}
@@ -561,7 +582,7 @@ ipmi_event_fromfile(struct ipmi_intf * intf, char * file)
 		sel_event.record_id = 0;
 		sel_event.sel_type.standard_type.gen_id = 2;
 
-		j = (chmed == IPMI_CHANNEL_MEDIUM_SYSTEM) ? 1 : 0;
+		j = (int)is_system(&chinfo);
 		sel_event.sel_type.standard_type.evm_rev = rqdata[j++];
 		sel_event.sel_type.standard_type.sensor_type = rqdata[j++];
 		sel_event.sel_type.standard_type.sensor_num = rqdata[j++];