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-rw-r--r--path_priority/pp_alua/rtpg.c280
1 files changed, 280 insertions, 0 deletions
diff --git a/path_priority/pp_alua/rtpg.c b/path_priority/pp_alua/rtpg.c
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+++ b/path_priority/pp_alua/rtpg.c
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+/*
+ * (C) Copyright IBM Corp. 2004, 2005 All Rights Reserved.
+ *
+ * rtpg.c
+ *
+ * Tool to make use of a SCSI-feature called Asymmetric Logical Unit Access.
+ * It determines the ALUA state of a device and prints a priority value to
+ * stdout.
+ *
+ * Author(s): Jan Kunigk
+ * S. Bader <shbader@de.ibm.com>
+ *
+ * This file is released under the GPL.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <errno.h>
+
+#define __user
+#include <scsi/sg.h>
+
+#include "rtpg.h"
+
+#define SENSE_BUFF_LEN 32
+#define DEF_TIMEOUT 60000
+
+/*
+ * Macro used to print debug messaged.
+ */
+#if DEBUG > 0
+#define PRINT_DEBUG(f, a...) \
+ fprintf(stderr, "DEBUG: " f, ##a)
+#else
+#define PRINT_DEBUG(f, a...)
+#endif
+
+/*
+ * Optionally print the commands sent and the data received a hex dump.
+ */
+#if DEBUG > 0
+#if DEBUG_DUMPHEX > 0
+#define PRINT_HEX(p, l) print_hex(p, l)
+void
+print_hex(unsigned char *p, unsigned long len)
+{
+ int i;
+
+ for(i = 0; i < len; i++) {
+ if (i % 16 == 0)
+ printf("%04x: ", i);
+ printf("%02x%s", p[i], (((i + 1) % 16) == 0) ? "\n" : " ");
+ }
+ printf("\n");
+}
+#else
+#define PRINT_HEX(p, l)
+#endif
+#else
+#define PRINT_HEX(p, l)
+#endif
+
+/*
+ * Returns 0 if the SCSI command either was successful or if the an error was
+ * recovered, otherwise 1. (definitions taken from sg_err.h)
+ */
+#define SCSI_CHECK_CONDITION 0x2
+#define SCSI_COMMAND_TERMINATED 0x22
+#define SG_ERR_DRIVER_SENSE 0x08
+#define RECOVERED_ERROR 0x01
+
+static int
+scsi_error(struct sg_io_hdr *hdr)
+{
+ /* Treat SG_ERR here to get rid of sg_err.[ch] */
+ hdr->status &= 0x7e;
+
+ if (
+ (hdr->status == 0) &&
+ (hdr->host_status == 0) &&
+ (hdr->driver_status == 0)
+ ) {
+ return 0;
+ }
+
+ if (
+ (hdr->status == SCSI_CHECK_CONDITION) ||
+ (hdr->status == SCSI_COMMAND_TERMINATED) ||
+ ((hdr->driver_status & 0xf) == SG_ERR_DRIVER_SENSE)
+ ) {
+ if (hdr->sbp && (hdr->sb_len_wr > 2)) {
+ int sense_key;
+ unsigned char * sense_buffer = hdr->sbp;
+
+ if (sense_buffer[0] & 0x2)
+ sense_key = sense_buffer[1] & 0xf;
+ else
+ sense_key = sense_buffer[2] & 0xf;
+
+ if (sense_key == RECOVERED_ERROR)
+ return 0;
+ }
+ }
+
+ return 1;
+}
+
+/*
+ * Helper function to setup and run a SCSI inquiry command.
+ */
+int
+do_inquiry(int fd, int evpd, unsigned int codepage, void *resp, int resplen)
+{
+ struct inquiry_command cmd;
+ struct sg_io_hdr hdr;
+ unsigned char sense[SENSE_BUFF_LEN];
+
+ memset(&cmd, 0, sizeof(cmd));
+ cmd.op = OPERATION_CODE_INQUIRY;
+ if (evpd) {
+ cmd.evpd = 1;
+ cmd.page = codepage;
+ }
+ set_uint16(cmd.length, resplen);
+ PRINT_HEX((unsigned char *) &cmd, sizeof(cmd));
+
+ memset(&hdr, 0, sizeof(hdr));
+ hdr.interface_id = 'S';
+ hdr.cmdp = (unsigned char *) &cmd;
+ hdr.cmd_len = sizeof(cmd);
+ hdr.dxfer_direction = SG_DXFER_FROM_DEV;
+ hdr.dxferp = resp;
+ hdr.dxfer_len = resplen;
+ hdr.sbp = sense;
+ hdr.mx_sb_len = sizeof(sense);
+ hdr.timeout = DEF_TIMEOUT;
+
+ if (ioctl(fd, SG_IO, &hdr) < 0) {
+ PRINT_DEBUG("do_inquiry: IOCTL failed!\n");
+ return -RTPG_INQUIRY_FAILED;
+ }
+
+ if (scsi_error(&hdr)) {
+ PRINT_DEBUG("do_inquiry: SCSI error!\n");
+ return -RTPG_INQUIRY_FAILED;
+ }
+ PRINT_HEX((unsigned char *) resp, resplen);
+
+ return 0;
+}
+
+/*
+ * This function returns the support for target port groups by evaluating the
+ * data returned by the standard inquiry command.
+ */
+int
+get_target_port_group_support(int fd)
+{
+ struct inquiry_data inq;
+ int rc;
+
+ rc = do_inquiry(fd, 0, 0x00, &inq, sizeof(inq));
+ if (!rc) {
+ rc = inq.tpgs;
+ }
+
+ return rc;
+}
+
+int
+get_target_port_group(int fd)
+{
+ unsigned char buf[128];
+ struct vpd83_data * vpd83;
+ struct vpd83_dscr * dscr;
+ int rc;
+
+ rc = do_inquiry(fd, 1, 0x83, buf, sizeof(buf));
+ if (!rc) {
+ vpd83 = (struct vpd83_data *) buf;
+
+ rc = -RTPG_NO_TPG_IDENTIFIER;
+ FOR_EACH_VPD83_DSCR(vpd83, dscr) {
+ if ((((char *) dscr) - ((char *) vpd83)) > sizeof(buf))
+ break;
+
+ if (dscr->id_type == IDTYPE_TARGET_PORT_GROUP) {
+ struct vpd83_tpg_dscr * p;
+
+ if (rc != -RTPG_NO_TPG_IDENTIFIER) {
+ PRINT_DEBUG("get_target_port_group: "
+ "more than one TPG identifier "
+ "found!\n");
+ continue;
+ }
+
+ p = (struct vpd83_tpg_dscr *) dscr->data;
+ rc = get_uint16(p->tpg);
+ }
+ }
+ if (rc == -RTPG_NO_TPG_IDENTIFIER) {
+ PRINT_DEBUG("get_target_port_group: "
+ "no TPG identifier found!\n");
+ }
+ }
+
+ return rc;
+}
+
+int
+do_rtpg(int fd, void* resp, long resplen)
+{
+ struct rtpg_command cmd;
+ struct sg_io_hdr hdr;
+ unsigned char sense[SENSE_BUFF_LEN];
+
+ memset(&cmd, 0, sizeof(cmd));
+ cmd.op = OPERATION_CODE_RTPG;
+ cmd.service_action = SERVICE_ACTION_RTPG;
+ set_uint32(cmd.length, resplen);
+ PRINT_HEX((unsigned char *) &cmd, sizeof(cmd));
+
+ memset(&hdr, 0, sizeof(hdr));
+ hdr.interface_id = 'S';
+ hdr.cmdp = (unsigned char *) &cmd;
+ hdr.cmd_len = sizeof(cmd);
+ hdr.dxfer_direction = SG_DXFER_FROM_DEV;
+ hdr.dxferp = resp;
+ hdr.dxfer_len = resplen;
+ hdr.mx_sb_len = sizeof(sense);
+ hdr.sbp = sense;
+ hdr.timeout = DEF_TIMEOUT;
+
+ if (ioctl(fd, SG_IO, &hdr) < 0)
+ return -RTPG_RTPG_FAILED;
+
+ if (scsi_error(&hdr)) {
+ PRINT_DEBUG("do_rtpg: SCSI error!\n");
+ return -RTPG_RTPG_FAILED;
+ }
+ PRINT_HEX(resp, resplen);
+
+ return 0;
+}
+
+int
+get_asymmetric_access_state(int fd, unsigned int tpg)
+{
+ unsigned char buf[128];
+ struct rtpg_data * tpgd;
+ struct rtpg_tpg_dscr * dscr;
+ int rc;
+
+ rc = do_rtpg(fd, buf, sizeof(buf));
+ if (rc < 0)
+ return rc;
+
+ tpgd = (struct rtpg_data *) buf;
+ rc = -RTPG_TPG_NOT_FOUND;
+ RTPG_FOR_EACH_PORT_GROUP(tpgd, dscr) {
+ if (get_uint16(dscr->tpg) == tpg) {
+ if (rc != -RTPG_TPG_NOT_FOUND) {
+ PRINT_DEBUG("get_asymmetric_access_state: "
+ "more than one entry with same port "
+ "group.\n");
+ } else {
+ PRINT_DEBUG("pref=%i\n", dscr->pref);
+ rc = dscr->aas;
+ }
+ }
+ }
+
+ return rc;
+}
+
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