lib: Parse sense specific descriptor

Extend struct scsi_sense with sense specific descriptor information,
introduce the function scsi_parse_sense_data() and let that function
parse the sense specific descriptor.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>

include/scsi-lowlevel.h

@@ -254,6 +254,16 @@ struct scsi_sense {
 	unsigned char       error_type;
 	enum scsi_sense_key key;
 	int                 ascq;
+
+	/*
+	 * Sense specific descriptor. See also paragraph "Sense key specific
+	 * sense data descriptor" in SPC.
+	 */
+	unsigned            sense_specific:1;
+	unsigned            ill_param_in_cdb:1;
+	unsigned            bit_pointer_valid:1;
+	unsigned char       bit_pointer;
+	uint16_t            field_pointer;
 };
 
 struct scsi_data {
@@ -1051,6 +1061,8 @@ EXTERN int scsi_datain_getfullsize(struct scsi_task *task);
 EXTERN void *scsi_datain_unmarshall(struct scsi_task *task);
 EXTERN void *scsi_cdb_unmarshall(struct scsi_task *task, enum scsi_opcode opcode);
 
+EXTERN void scsi_parse_sense_data(struct scsi_sense *sense, const uint8_t *sb);
+
 EXTERN struct scsi_task *scsi_cdb_compareandwrite(uint64_t lba, uint32_t xferlen, int blocksize, int wrprotect, int dpo, int fua, int fua_nv, int group_number);
 EXTERN struct scsi_task *scsi_cdb_get_lba_status(uint64_t starting_lba, uint32_t alloc_len);
 EXTERN struct scsi_task *scsi_cdb_orwrite(uint64_t lba, uint32_t xferlen, int blocksize, int wrprotect, int dpo, int fua, int fua_nv, int group_number);

lib/iscsi-command.c

@@ -340,6 +340,62 @@ iscsi_scsi_command_async(struct iscsi_context *iscsi, int lun,
 	return 0;
 }
 
+/* Parse a sense key specific sense data descriptor */
+static void parse_sense_spec(struct scsi_sense *sense, const uint8_t inf[3])
+{
+	if (!(inf[0] & 0x80)) /* SKSV */
+		return;
+
+	sense->sense_specific = 1;
+	sense->ill_param_in_cdb = !!(inf[0] & 0x40); /* C/D flag */
+	if (inf[0] & 8) { /* BPV */
+		sense->bit_pointer_valid = 1;
+		sense->bit_pointer = inf[0] & 7;
+	}
+	sense->field_pointer = scsi_get_uint16(&inf[1]);
+}
+
+/* Parse descriptor format sense data */
+static void parse_sense_descriptors(struct scsi_sense *sense, const uint8_t *sb,
+				    unsigned sb_len)
+{
+	const unsigned char *p, *const end = sb + sb_len;
+
+	for (p = sb; p < end; p += p[1]) {
+		if (p[1] < 4) /* length */
+			break;
+		if (!(p[2] & 0x80)) /* VALID bit */
+			break;
+		switch (p[0]) {
+		case 2:
+			/* Sense key specific sense data descriptor */
+			parse_sense_spec(sense, p + 4);
+			break;
+		}
+	}
+}
+
+void scsi_parse_sense_data(struct scsi_sense *sense, const uint8_t *sb)
+{
+	sense->error_type = sb[0] & 0x7f;
+	switch (sense->error_type) {
+	case 0x70:
+	case 0x71:
+		/* Fixed format */
+		sense->key  = sb[2] & 0x0f;
+		sense->ascq = scsi_get_uint16(&sb[12]);
+		parse_sense_spec(sense, sb + 15);
+		break;
+	case 0x72:
+	case 0x73:
+		/* Descriptor format */
+		sense->key  = sb[1] & 0x0f;
+		sense->ascq = scsi_get_uint16(&sb[2]);
+		parse_sense_descriptors(sense, sb + 8, sb[7]);
+		break;
+	}
+}
+
 int
 iscsi_process_scsi_reply(struct iscsi_context *iscsi, struct iscsi_pdu *pdu,
 			 struct iscsi_in_pdu *in)
@@ -416,21 +472,7 @@ iscsi_process_scsi_reply(struct iscsi_context *iscsi, struct iscsi_pdu *pdu,
 		}
 		memcpy(task->datain.data, in->data, task->datain.size);
 
-		task->sense.error_type = task->datain.data[2] & 0x7f;
+		scsi_parse_sense_data(&task->sense, &task->datain.data[2]);
-		switch (task->sense.error_type) {
-		case 0x70:
-		case 0x71:
-		  task->sense.key        = task->datain.data[4] & 0x0f;
-		  task->sense.ascq       = scsi_get_uint16(
-						&(task->datain.data[14]));
-		  break;
-		case 0x72:
-		case 0x73:
-		  task->sense.key        = task->datain.data[3] & 0x0f;
-		  task->sense.ascq       = scsi_get_uint16(
-						&(task->datain.data[4]));
-		  break;
-		}
 		iscsi_set_error(iscsi, "SENSE KEY:%s(%d) ASCQ:%s(0x%04x)",
 				scsi_sense_key_str(task->sense.key),
 				task->sense.key,

lib/libiscsi.def

@@ -216,6 +216,7 @@ scsi_inquiry_pagecode_to_str
 scsi_malloc
 scsi_modesense_dataout_marshall
 scsi_modesense_get_page
+scsi_parse_sense_data
 scsi_protocol_identifier_to_str
 scsi_reportluns_cdb
 scsi_sense_ascq_str

lib/libiscsi.syms

@@ -214,6 +214,7 @@ scsi_inquiry_pagecode_to_str
 scsi_malloc
 scsi_modesense_dataout_marshall
 scsi_modesense_get_page
+scsi_parse_sense_data
 scsi_protocol_identifier_to_str
 scsi_reportluns_cdb
 scsi_sense_ascq_str

test-tool/iscsi-support.c

@@ -317,19 +317,7 @@ static struct scsi_task *send_scsi_command(struct scsi_device *sdev, struct scsi
 		/* now for the error processing */
 		if(io_hdr.sb_len_wr > 0){
 			task->status = SCSI_STATUS_CHECK_CONDITION;
-			task->sense.error_type = sense[0] & 0x7f;
+			scsi_parse_sense_data(&task->sense, sense);
-			switch (task->sense.error_type) {
-			case 0x70:
-			case 0x71:
-				task->sense.key = sense[2] & 0x0f;
-				task->sense.ascq  = scsi_get_uint16(&sense[12]);
-				break;
-			case 0x72:
-			case 0x73:
-				task->sense.key = sense[1] & 0x0f;
-				task->sense.ascq = scsi_get_uint16(&sense[2]);
-				break;
-			}
 			sense_len=io_hdr.sb_len_wr;
 			snprintf(buf, sizeof(buf), "SENSE KEY:%s(%d) ASCQ:%s(0x%04x)",
 				 scsi_sense_key_str(task->sense.key),