scsi: target: core: Generate correct identifiers for PR OUT transport IDs

JIRA: https://issues.redhat.com/browse/RHEL-111938

Fix target_parse_pr_out_transport_id() to return a string representing
the transport ID in a human-readable format (e.g., naa.xxxxxxxx...)  for
various SCSI protocol types (SAS, FCP, SRP, SBP).

Previously, the function returned a pointer to the raw binary buffer,
which was incorrectly compared against human-readable strings, causing
comparisons to fail.  Now, the function writes a properly formatted
string into a buffer provided by the caller.  The output format depends
on the transport protocol:

* SAS: 64-bit identifier, "naa." prefix.
* FCP: 64-bit identifier, colon separated values.
* SBP: 64-bit identifier, no prefix.
* SRP: 128-bit identifier, "0x" prefix.
* iSCSI: IQN string.

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Link: https://lore.kernel.org/r/20250714133738.11054-1-mlombard@redhat.com
Reviewed-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit 6e0f6aa)
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>

Author: maurizio-lombardi

drivers/target/target_core_fabric_lib.c

@@ -257,11 +257,41 @@ static int iscsi_get_pr_transport_id_len(
 	return len;
 }
 
-static char *iscsi_parse_pr_out_transport_id(
+static void sas_parse_pr_out_transport_id(char *buf, char *i_str)
+{
+	char hex[17] = {};
+
+	bin2hex(hex, buf + 4, 8);
+	snprintf(i_str, TRANSPORT_IQN_LEN, "naa.%s", hex);
+}
+
+static void srp_parse_pr_out_transport_id(char *buf, char *i_str)
+{
+	char hex[33] = {};
+
+	bin2hex(hex, buf + 8, 16);
+	snprintf(i_str, TRANSPORT_IQN_LEN, "0x%s", hex);
+}
+
+static void fcp_parse_pr_out_transport_id(char *buf, char *i_str)
+{
+	snprintf(i_str, TRANSPORT_IQN_LEN, "%8phC", buf + 8);
+}
+
+static void sbp_parse_pr_out_transport_id(char *buf, char *i_str)
+{
+	char hex[17] = {};
+
+	bin2hex(hex, buf + 8, 8);
+	snprintf(i_str, TRANSPORT_IQN_LEN, "%s", hex);
+}
+
+static bool iscsi_parse_pr_out_transport_id(
 	struct se_portal_group *se_tpg,
 	char *buf,
 	u32 *out_tid_len,
-	char **port_nexus_ptr)
+	char **port_nexus_ptr,
+	char *i_str)
 {
 	char *p;
 	int i;
@@ -282,7 +312,7 @@ static char *iscsi_parse_pr_out_transport_id(
 	if ((format_code != 0x00) && (format_code != 0x40)) {
 		pr_err("Illegal format code: 0x%02x for iSCSI"
 			" Initiator Transport ID\n", format_code);
-		return NULL;
+		return false;
 	}
 	/*
 	 * If the caller wants the TransportID Length, we set that value for the
@@ -306,7 +336,7 @@ static char *iscsi_parse_pr_out_transport_id(
 			pr_err("Unable to locate \",i,0x\" separator"
 				" for Initiator port identifier: %s\n",
 				&buf[4]);
-			return NULL;
+			return false;
 		}
 		*p = '\0'; /* Terminate iSCSI Name */
 		p += 5; /* Skip over ",i,0x" separator */
@@ -339,7 +369,8 @@ static char *iscsi_parse_pr_out_transport_id(
 	} else
 		*port_nexus_ptr = NULL;
 
-	return &buf[4];
+	strscpy(i_str, &buf[4], TRANSPORT_IQN_LEN);
+	return true;
 }
 
 int target_get_pr_transport_id_len(struct se_node_acl *nacl,
@@ -387,33 +418,35 @@ int target_get_pr_transport_id(struct se_node_acl *nacl,
 	}
 }
 
-const char *target_parse_pr_out_transport_id(struct se_portal_group *tpg,
-		char *buf, u32 *out_tid_len, char **port_nexus_ptr)
+bool target_parse_pr_out_transport_id(struct se_portal_group *tpg,
+		char *buf, u32 *out_tid_len, char **port_nexus_ptr, char *i_str)
 {
-	u32 offset;
-
 	switch (tpg->proto_id) {
 	case SCSI_PROTOCOL_SAS:
 		/*
 		 * Assume the FORMAT CODE 00b from spc4r17, 7.5.4.7 TransportID
 		 * for initiator ports using SCSI over SAS Serial SCSI Protocol.
 		 */
-		offset = 4;
+		sas_parse_pr_out_transport_id(buf, i_str);
 		break;
-	case SCSI_PROTOCOL_SBP:
 	case SCSI_PROTOCOL_SRP:
+		srp_parse_pr_out_transport_id(buf, i_str);
+		break;
 	case SCSI_PROTOCOL_FCP:
-		offset = 8;
+		fcp_parse_pr_out_transport_id(buf, i_str);
+		break;
+	case SCSI_PROTOCOL_SBP:
+		sbp_parse_pr_out_transport_id(buf, i_str);
 		break;
 	case SCSI_PROTOCOL_ISCSI:
 		return iscsi_parse_pr_out_transport_id(tpg, buf, out_tid_len,
-					port_nexus_ptr);
+					port_nexus_ptr, i_str);
 	default:
 		pr_err("Unknown proto_id: 0x%02x\n", tpg->proto_id);
-		return NULL;
+		return false;
 	}
 
 	*port_nexus_ptr = NULL;
 	*out_tid_len = 24;
-	return buf + offset;
+	return true;
 }

drivers/target/target_core_internal.h

@@ -103,8 +103,8 @@ int	target_get_pr_transport_id_len(struct se_node_acl *nacl,
 int	target_get_pr_transport_id(struct se_node_acl *nacl,
 		struct t10_pr_registration *pr_reg, int *format_code,
 		unsigned char *buf);
-const char *target_parse_pr_out_transport_id(struct se_portal_group *tpg,
-		char *buf, u32 *out_tid_len, char **port_nexus_ptr);
+bool target_parse_pr_out_transport_id(struct se_portal_group *tpg,
+		char *buf, u32 *out_tid_len, char **port_nexus_ptr, char *i_str);
 
 /* target_core_hba.c */
 struct se_hba *core_alloc_hba(const char *, u32, u32);

drivers/target/target_core_pr.c

@@ -1478,11 +1478,12 @@ core_scsi3_decode_spec_i_port(
 	LIST_HEAD(tid_dest_list);
 	struct pr_transport_id_holder *tidh_new, *tidh, *tidh_tmp;
 	unsigned char *buf, *ptr, proto_ident;
-	const unsigned char *i_str = NULL;
+	unsigned char i_str[TRANSPORT_IQN_LEN];
 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
 	sense_reason_t ret;
 	u32 tpdl, tid_len = 0;
 	u32 dest_rtpi = 0;
+	bool tid_found;
 
 	/*
 	 * Allocate a struct pr_transport_id_holder and setup the
@@ -1571,9 +1572,9 @@ core_scsi3_decode_spec_i_port(
 			dest_rtpi = tmp_lun->lun_tpg->tpg_rtpi;
 
 			iport_ptr = NULL;
-			i_str = target_parse_pr_out_transport_id(tmp_tpg,
-					ptr, &tid_len, &iport_ptr);
-			if (!i_str)
+			tid_found = target_parse_pr_out_transport_id(tmp_tpg,
+					ptr, &tid_len, &iport_ptr, i_str);
+			if (!tid_found)
 				continue;
 			/*
 			 * Determine if this SCSI device server requires that
@@ -3153,13 +3154,14 @@ core_scsi3_emulate_pro_register_and_move(struct se_cmd *cmd, u64 res_key,
 	struct t10_pr_registration *pr_reg, *pr_res_holder, *dest_pr_reg;
 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
 	unsigned char *buf;
-	const unsigned char *initiator_str;
+	unsigned char initiator_str[TRANSPORT_IQN_LEN];
 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN] = { };
 	u32 tid_len, tmp_tid_len;
 	int new_reg = 0, type, scope, matching_iname;
 	sense_reason_t ret;
 	unsigned short rtpi;
 	unsigned char proto_ident;
+	bool tid_found;
 
 	if (!se_sess || !se_lun) {
 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
@@ -3278,9 +3280,9 @@ core_scsi3_emulate_pro_register_and_move(struct se_cmd *cmd, u64 res_key,
 		ret = TCM_INVALID_PARAMETER_LIST;
 		goto out;
 	}
-	initiator_str = target_parse_pr_out_transport_id(dest_se_tpg,
-			&buf[24], &tmp_tid_len, &iport_ptr);
-	if (!initiator_str) {
+	tid_found = target_parse_pr_out_transport_id(dest_se_tpg,
+			&buf[24], &tmp_tid_len, &iport_ptr, initiator_str);
+	if (!tid_found) {
 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
 			" initiator_str from Transport ID\n");
 		ret = TCM_INVALID_PARAMETER_LIST;