leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity
master
linux/include/scsi/iscsi_proto.h
Zhen Lei 40d6b939e4 scsi: Fix spelling mistakes in header files 
Fix some spelling mistakes in comments:

  pathes ==> paths
  Resouce ==> Resource
  retreived ==> retrieved
  recevied ==> received
  interruped ==> interrupted

[mkp: kept 'keep-alives' and 'busses']

Link: https://lore.kernel.org/r/20210517095945.7363-1-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-05-21 17:22:45 -04:00

658 lines
16 KiB
C
Raw Permalink Blame History

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* RFC 3720 (iSCSI) protocol data types
*
* Copyright (C) 2005 Dmitry Yusupov
* Copyright (C) 2005 Alex Aizman
* maintained by open-iscsi@googlegroups.com
*/
#ifndef ISCSI_PROTO_H
#define ISCSI_PROTO_H
#include <linux/types.h>
#include <scsi/scsi.h>
#define ISCSI_DRAFT20_VERSION 0x00
/* default iSCSI listen port for incoming connections */
#define ISCSI_LISTEN_PORT 3260
/* iSCSI header length */
#define ISCSI_HDR_LEN 48
/* iSCSI CRC32C length */
#define ISCSI_CRC_LEN 4
/* Padding word length */
#define ISCSI_PAD_LEN 4
/*
* Serial Number Arithmetic, 32 bits, RFC1982
*/
static inline int iscsi_sna_lt(u32 n1, u32 n2)
{
return (s32)(n1 - n2) < 0;
}
static inline int iscsi_sna_lte(u32 n1, u32 n2)
{
return (s32)(n1 - n2) <= 0;
}
static inline int iscsi_sna_gt(u32 n1, u32 n2)
{
return (s32)(n1 - n2) > 0;
}
static inline int iscsi_sna_gte(u32 n1, u32 n2)
{
return (s32)(n1 - n2) >= 0;
}
/*
* useful common(control and data paths) macro
*/
#define ntoh24(p) (((p)[0] << 16) | ((p)[1] << 8) | ((p)[2]))
#define hton24(p, v) { \
p[0] = (((v) >> 16) & 0xFF); \
p[1] = (((v) >> 8) & 0xFF); \
p[2] = ((v) & 0xFF); \
}
#define zero_data(p) {p[0]=0;p[1]=0;p[2]=0;}
/* initiator tags; opaque for target */
typedef uint32_t __bitwise itt_t;
/* below makes sense only for initiator that created this tag */
#define build_itt(itt, age) ((__force itt_t)\
((itt) | ((age) << ISCSI_AGE_SHIFT)))
#define get_itt(itt) ((__force uint32_t)(itt_t)(itt) & ISCSI_ITT_MASK)
#define RESERVED_ITT ((__force itt_t)0xffffffff)
/*
* iSCSI Template Message Header
*/
struct iscsi_hdr {
uint8_t opcode;
uint8_t flags; /* Final bit */
uint8_t rsvd2[2];
uint8_t hlength; /* AHSs total length */
uint8_t dlength[3]; /* Data length */
struct scsi_lun lun;
itt_t itt; /* Initiator Task Tag, opaque for target */
__be32 ttt; /* Target Task Tag */
__be32 statsn;
__be32 exp_statsn;
__be32 max_statsn;
uint8_t other[12];
};
/************************* RFC 3720 Begin *****************************/
#define ISCSI_RESERVED_TAG 0xffffffff
/* Opcode encoding bits */
#define ISCSI_OP_RETRY 0x80
#define ISCSI_OP_IMMEDIATE 0x40
#define ISCSI_OPCODE_MASK 0x3F
/* Initiator Opcode values */
#define ISCSI_OP_NOOP_OUT 0x00
#define ISCSI_OP_SCSI_CMD 0x01
#define ISCSI_OP_SCSI_TMFUNC 0x02
#define ISCSI_OP_LOGIN 0x03
#define ISCSI_OP_TEXT 0x04
#define ISCSI_OP_SCSI_DATA_OUT 0x05
#define ISCSI_OP_LOGOUT 0x06
#define ISCSI_OP_SNACK 0x10
#define ISCSI_OP_VENDOR1_CMD 0x1c
#define ISCSI_OP_VENDOR2_CMD 0x1d
#define ISCSI_OP_VENDOR3_CMD 0x1e
#define ISCSI_OP_VENDOR4_CMD 0x1f
/* Target Opcode values */
#define ISCSI_OP_NOOP_IN 0x20
#define ISCSI_OP_SCSI_CMD_RSP 0x21
#define ISCSI_OP_SCSI_TMFUNC_RSP 0x22
#define ISCSI_OP_LOGIN_RSP 0x23
#define ISCSI_OP_TEXT_RSP 0x24
#define ISCSI_OP_SCSI_DATA_IN 0x25
#define ISCSI_OP_LOGOUT_RSP 0x26
#define ISCSI_OP_R2T 0x31
#define ISCSI_OP_ASYNC_EVENT 0x32
#define ISCSI_OP_REJECT 0x3f
struct iscsi_ahs_hdr {
__be16 ahslength;
uint8_t ahstype;
uint8_t ahspec[5];
};
#define ISCSI_AHSTYPE_CDB 1
#define ISCSI_AHSTYPE_RLENGTH 2
#define ISCSI_CDB_SIZE 16
/* iSCSI PDU Header */
struct iscsi_scsi_req {
uint8_t opcode;
uint8_t flags;
__be16 rsvd2;
uint8_t hlength;
uint8_t dlength[3];
struct scsi_lun lun;
itt_t itt; /* Initiator Task Tag */
__be32 data_length;
__be32 cmdsn;
__be32 exp_statsn;
uint8_t cdb[ISCSI_CDB_SIZE]; /* SCSI Command Block */
/* Additional Data (Command Dependent) */
};
/* Command PDU flags */
#define ISCSI_FLAG_CMD_FINAL 0x80
#define ISCSI_FLAG_CMD_READ 0x40
#define ISCSI_FLAG_CMD_WRITE 0x20
#define ISCSI_FLAG_CMD_ATTR_MASK 0x07 /* 3 bits */
/* SCSI Command Attribute values */
#define ISCSI_ATTR_UNTAGGED 0
#define ISCSI_ATTR_SIMPLE 1
#define ISCSI_ATTR_ORDERED 2
#define ISCSI_ATTR_HEAD_OF_QUEUE 3
#define ISCSI_ATTR_ACA 4
struct iscsi_rlength_ahdr {
__be16 ahslength;
uint8_t ahstype;
uint8_t reserved;
__be32 read_length;
};
/* Extended CDB AHS */
struct iscsi_ecdb_ahdr {
__be16 ahslength; /* CDB length - 15, including reserved byte */
uint8_t ahstype;
uint8_t reserved;
/* 4-byte aligned extended CDB spillover */
uint8_t ecdb[SCSI_MAX_VARLEN_CDB_SIZE - ISCSI_CDB_SIZE];
};
/* SCSI Response Header */
struct iscsi_scsi_rsp {
uint8_t opcode;
uint8_t flags;
uint8_t response;
uint8_t cmd_status;
uint8_t hlength;
uint8_t dlength[3];
uint8_t rsvd[8];
itt_t itt; /* Initiator Task Tag */
__be32 rsvd1;
__be32 statsn;
__be32 exp_cmdsn;
__be32 max_cmdsn;
__be32 exp_datasn;
__be32 bi_residual_count;
__be32 residual_count;
/* Response or Sense Data (optional) */
};
/* Command Response PDU flags */
#define ISCSI_FLAG_CMD_BIDI_OVERFLOW 0x10
#define ISCSI_FLAG_CMD_BIDI_UNDERFLOW 0x08
#define ISCSI_FLAG_CMD_OVERFLOW 0x04
#define ISCSI_FLAG_CMD_UNDERFLOW 0x02
/* iSCSI Status values. Valid if Rsp Selector bit is not set */
#define ISCSI_STATUS_CMD_COMPLETED 0
#define ISCSI_STATUS_TARGET_FAILURE 1
#define ISCSI_STATUS_SUBSYS_FAILURE 2
/* Asynchronous Event Header */
struct iscsi_async {
uint8_t opcode;
uint8_t flags;
uint8_t rsvd2[2];
uint8_t rsvd3;
uint8_t dlength[3];
struct scsi_lun lun;
uint8_t rsvd4[8];
__be32 statsn;
__be32 exp_cmdsn;
__be32 max_cmdsn;
uint8_t async_event;
uint8_t async_vcode;
__be16 param1;
__be16 param2;
__be16 param3;
uint8_t rsvd5[4];
};
/* iSCSI Event Codes */
#define ISCSI_ASYNC_MSG_SCSI_EVENT 0
#define ISCSI_ASYNC_MSG_REQUEST_LOGOUT 1
#define ISCSI_ASYNC_MSG_DROPPING_CONNECTION 2
#define ISCSI_ASYNC_MSG_DROPPING_ALL_CONNECTIONS 3
#define ISCSI_ASYNC_MSG_PARAM_NEGOTIATION 4
#define ISCSI_ASYNC_MSG_VENDOR_SPECIFIC 255
/* NOP-Out Message */
struct iscsi_nopout {
uint8_t opcode;
uint8_t flags;
__be16 rsvd2;
uint8_t rsvd3;
uint8_t dlength[3];
struct scsi_lun lun;
itt_t itt; /* Initiator Task Tag */
__be32 ttt; /* Target Transfer Tag */
__be32 cmdsn;
__be32 exp_statsn;
uint8_t rsvd4[16];
};
/* NOP-In Message */
struct iscsi_nopin {
uint8_t opcode;
uint8_t flags;
__be16 rsvd2;
uint8_t rsvd3;
uint8_t dlength[3];
struct scsi_lun lun;
itt_t itt; /* Initiator Task Tag */
__be32 ttt; /* Target Transfer Tag */
__be32 statsn;
__be32 exp_cmdsn;
__be32 max_cmdsn;
uint8_t rsvd4[12];
};
/* SCSI Task Management Message Header */
struct iscsi_tm {
uint8_t opcode;
uint8_t flags;
uint8_t rsvd1[2];
uint8_t hlength;
uint8_t dlength[3];
struct scsi_lun lun;
itt_t itt; /* Initiator Task Tag */
itt_t rtt; /* Reference Task Tag */
__be32 cmdsn;
__be32 exp_statsn;
__be32 refcmdsn;
__be32 exp_datasn;
uint8_t rsvd2[8];
};
#define ISCSI_FLAG_TM_FUNC_MASK 0x7F
/* Function values */
#define ISCSI_TM_FUNC_ABORT_TASK 1
#define ISCSI_TM_FUNC_ABORT_TASK_SET 2
#define ISCSI_TM_FUNC_CLEAR_ACA 3
#define ISCSI_TM_FUNC_CLEAR_TASK_SET 4
#define ISCSI_TM_FUNC_LOGICAL_UNIT_RESET 5
#define ISCSI_TM_FUNC_TARGET_WARM_RESET 6
#define ISCSI_TM_FUNC_TARGET_COLD_RESET 7
#define ISCSI_TM_FUNC_TASK_REASSIGN 8
#define ISCSI_TM_FUNC_VALUE(hdr) ((hdr)->flags & ISCSI_FLAG_TM_FUNC_MASK)
/* SCSI Task Management Response Header */
struct iscsi_tm_rsp {
uint8_t opcode;
uint8_t flags;
uint8_t response; /* see Response values below */
uint8_t qualifier;
uint8_t hlength;
uint8_t dlength[3];
uint8_t rsvd2[8];
itt_t itt; /* Initiator Task Tag */
itt_t rtt; /* Reference Task Tag */
__be32 statsn;
__be32 exp_cmdsn;
__be32 max_cmdsn;
uint8_t rsvd3[12];
};
/* Response values */
#define ISCSI_TMF_RSP_COMPLETE 0x00
#define ISCSI_TMF_RSP_NO_TASK 0x01
#define ISCSI_TMF_RSP_NO_LUN 0x02
#define ISCSI_TMF_RSP_TASK_ALLEGIANT 0x03
#define ISCSI_TMF_RSP_NO_FAILOVER 0x04
#define ISCSI_TMF_RSP_NOT_SUPPORTED 0x05
#define ISCSI_TMF_RSP_AUTH_FAILED 0x06
#define ISCSI_TMF_RSP_REJECTED 0xff
/* Ready To Transfer Header */
struct iscsi_r2t_rsp {
uint8_t opcode;
uint8_t flags;
uint8_t rsvd2[2];
uint8_t hlength;
uint8_t dlength[3];
struct scsi_lun lun;
itt_t itt; /* Initiator Task Tag */
__be32 ttt; /* Target Transfer Tag */
__be32 statsn;
__be32 exp_cmdsn;
__be32 max_cmdsn;
__be32 r2tsn;
__be32 data_offset;
__be32 data_length;
};
/* SCSI Data Hdr */
struct iscsi_data {
uint8_t opcode;
uint8_t flags;
uint8_t rsvd2[2];
uint8_t rsvd3;
uint8_t dlength[3];
struct scsi_lun lun;
itt_t itt;
__be32 ttt;
__be32 rsvd4;
__be32 exp_statsn;
__be32 rsvd5;
__be32 datasn;
__be32 offset;
__be32 rsvd6;
/* Payload */
};
/* SCSI Data Response Hdr */
struct iscsi_data_rsp {
uint8_t opcode;
uint8_t flags;
uint8_t rsvd2;
uint8_t cmd_status;
uint8_t hlength;
uint8_t dlength[3];
struct scsi_lun lun;
itt_t itt;
__be32 ttt;
__be32 statsn;
__be32 exp_cmdsn;
__be32 max_cmdsn;
__be32 datasn;
__be32 offset;
__be32 residual_count;
};
/* Data Response PDU flags */
#define ISCSI_FLAG_DATA_ACK 0x40
#define ISCSI_FLAG_DATA_OVERFLOW 0x04
#define ISCSI_FLAG_DATA_UNDERFLOW 0x02
#define ISCSI_FLAG_DATA_STATUS 0x01
/* Text Header */
struct iscsi_text {
uint8_t opcode;
uint8_t flags;
uint8_t rsvd2[2];
uint8_t hlength;
uint8_t dlength[3];
uint8_t rsvd4[8];
itt_t itt;
__be32 ttt;
__be32 cmdsn;
__be32 exp_statsn;
uint8_t rsvd5[16];
/* Text - key=value pairs */
};
#define ISCSI_FLAG_TEXT_CONTINUE 0x40
/* Text Response Header */
struct iscsi_text_rsp {
uint8_t opcode;
uint8_t flags;
uint8_t rsvd2[2];
uint8_t hlength;
uint8_t dlength[3];
uint8_t rsvd4[8];
itt_t itt;
__be32 ttt;
__be32 statsn;
__be32 exp_cmdsn;
__be32 max_cmdsn;
uint8_t rsvd5[12];
/* Text Response - key:value pairs */
};
/* Login Header */
struct iscsi_login_req {
uint8_t opcode;
uint8_t flags;
uint8_t max_version; /* Max. version supported */
uint8_t min_version; /* Min. version supported */
uint8_t hlength;
uint8_t dlength[3];
uint8_t isid[6]; /* Initiator Session ID */
__be16 tsih; /* Target Session Handle */
itt_t itt; /* Initiator Task Tag */
__be16 cid;
__be16 rsvd3;
__be32 cmdsn;
__be32 exp_statsn;
uint8_t rsvd5[16];
};
/* Login PDU flags */
#define ISCSI_FLAG_LOGIN_TRANSIT 0x80
#define ISCSI_FLAG_LOGIN_CONTINUE 0x40
#define ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK 0x0C /* 2 bits */
#define ISCSI_FLAG_LOGIN_CURRENT_STAGE1 0x04
#define ISCSI_FLAG_LOGIN_CURRENT_STAGE2 0x08
#define ISCSI_FLAG_LOGIN_CURRENT_STAGE3 0x0C
#define ISCSI_FLAG_LOGIN_NEXT_STAGE_MASK 0x03 /* 2 bits */
#define ISCSI_FLAG_LOGIN_NEXT_STAGE1 0x01
#define ISCSI_FLAG_LOGIN_NEXT_STAGE2 0x02
#define ISCSI_FLAG_LOGIN_NEXT_STAGE3 0x03
#define ISCSI_LOGIN_CURRENT_STAGE(flags) \
((flags & ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK) >> 2)
#define ISCSI_LOGIN_NEXT_STAGE(flags) \
(flags & ISCSI_FLAG_LOGIN_NEXT_STAGE_MASK)
/* Login Response Header */
struct iscsi_login_rsp {
uint8_t opcode;
uint8_t flags;
uint8_t max_version; /* Max. version supported */
uint8_t active_version; /* Active version */
uint8_t hlength;
uint8_t dlength[3];
uint8_t isid[6]; /* Initiator Session ID */
__be16 tsih; /* Target Session Handle */
itt_t itt; /* Initiator Task Tag */
__be32 rsvd3;
__be32 statsn;
__be32 exp_cmdsn;
__be32 max_cmdsn;
uint8_t status_class; /* see Login RSP ststus classes below */
uint8_t status_detail; /* see Login RSP Status details below */
uint8_t rsvd4[10];
};
/* Login stage (phase) codes for CSG, NSG */
#define ISCSI_INITIAL_LOGIN_STAGE -1
#define ISCSI_SECURITY_NEGOTIATION_STAGE 0
#define ISCSI_OP_PARMS_NEGOTIATION_STAGE 1
#define ISCSI_FULL_FEATURE_PHASE 3
/* Login Status response classes */
#define ISCSI_STATUS_CLS_SUCCESS 0x00
#define ISCSI_STATUS_CLS_REDIRECT 0x01
#define ISCSI_STATUS_CLS_INITIATOR_ERR 0x02
#define ISCSI_STATUS_CLS_TARGET_ERR 0x03
/* Login Status response detail codes */
/* Class-0 (Success) */
#define ISCSI_LOGIN_STATUS_ACCEPT 0x00
/* Class-1 (Redirection) */
#define ISCSI_LOGIN_STATUS_TGT_MOVED_TEMP 0x01
#define ISCSI_LOGIN_STATUS_TGT_MOVED_PERM 0x02
/* Class-2 (Initiator Error) */
#define ISCSI_LOGIN_STATUS_INIT_ERR 0x00
#define ISCSI_LOGIN_STATUS_AUTH_FAILED 0x01
#define ISCSI_LOGIN_STATUS_TGT_FORBIDDEN 0x02
#define ISCSI_LOGIN_STATUS_TGT_NOT_FOUND 0x03
#define ISCSI_LOGIN_STATUS_TGT_REMOVED 0x04
#define ISCSI_LOGIN_STATUS_NO_VERSION 0x05
#define ISCSI_LOGIN_STATUS_ISID_ERROR 0x06
#define ISCSI_LOGIN_STATUS_MISSING_FIELDS 0x07
#define ISCSI_LOGIN_STATUS_CONN_ADD_FAILED 0x08
#define ISCSI_LOGIN_STATUS_NO_SESSION_TYPE 0x09
#define ISCSI_LOGIN_STATUS_NO_SESSION 0x0a
#define ISCSI_LOGIN_STATUS_INVALID_REQUEST 0x0b
/* Class-3 (Target Error) */
#define ISCSI_LOGIN_STATUS_TARGET_ERROR 0x00
#define ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE 0x01
#define ISCSI_LOGIN_STATUS_NO_RESOURCES 0x02
/* Logout Header */
struct iscsi_logout {
uint8_t opcode;
uint8_t flags;
uint8_t rsvd1[2];
uint8_t hlength;
uint8_t dlength[3];
uint8_t rsvd2[8];
itt_t itt; /* Initiator Task Tag */
__be16 cid;
uint8_t rsvd3[2];
__be32 cmdsn;
__be32 exp_statsn;
uint8_t rsvd4[16];
};
/* Logout PDU flags */
#define ISCSI_FLAG_LOGOUT_REASON_MASK 0x7F
/* logout reason_code values */
#define ISCSI_LOGOUT_REASON_CLOSE_SESSION 0
#define ISCSI_LOGOUT_REASON_CLOSE_CONNECTION 1
#define ISCSI_LOGOUT_REASON_RECOVERY 2
#define ISCSI_LOGOUT_REASON_AEN_REQUEST 3
/* Logout Response Header */
struct iscsi_logout_rsp {
uint8_t opcode;
uint8_t flags;
uint8_t response; /* see Logout response values below */
uint8_t rsvd2;
uint8_t hlength;
uint8_t dlength[3];
uint8_t rsvd3[8];
itt_t itt; /* Initiator Task Tag */
__be32 rsvd4;
__be32 statsn;
__be32 exp_cmdsn;
__be32 max_cmdsn;
__be32 rsvd5;
__be16 t2wait;
__be16 t2retain;
__be32 rsvd6;
};
/* logout response status values */
#define ISCSI_LOGOUT_SUCCESS 0
#define ISCSI_LOGOUT_CID_NOT_FOUND 1
#define ISCSI_LOGOUT_RECOVERY_UNSUPPORTED 2
#define ISCSI_LOGOUT_CLEANUP_FAILED 3
/* SNACK Header */
struct iscsi_snack {
uint8_t opcode;
uint8_t flags;
uint8_t rsvd2[2];
uint8_t hlength;
uint8_t dlength[3];
uint8_t lun[8];
itt_t itt;
__be32 ttt;
uint8_t rsvd3[4];
__be32 exp_statsn;
uint8_t rsvd4[8];
__be32 begrun;
__be32 runlength;
};
/* SNACK PDU flags */
#define ISCSI_FLAG_SNACK_TYPE_DATA 0
#define ISCSI_FLAG_SNACK_TYPE_R2T 0
#define ISCSI_FLAG_SNACK_TYPE_STATUS 1
#define ISCSI_FLAG_SNACK_TYPE_DATA_ACK 2
#define ISCSI_FLAG_SNACK_TYPE_RDATA 3
#define ISCSI_FLAG_SNACK_TYPE_MASK 0x0F /* 4 bits */
/* Reject Message Header */
struct iscsi_reject {
uint8_t opcode;
uint8_t flags;
uint8_t reason;
uint8_t rsvd2;
uint8_t hlength;
uint8_t dlength[3];
uint8_t rsvd3[8];
__be32 ffffffff;
uint8_t rsvd4[4];
__be32 statsn;
__be32 exp_cmdsn;
__be32 max_cmdsn;
__be32 datasn;
uint8_t rsvd5[8];
/* Text - Rejected hdr */
};
/* Reason for Reject */
#define ISCSI_REASON_CMD_BEFORE_LOGIN 1
#define ISCSI_REASON_DATA_DIGEST_ERROR 2
#define ISCSI_REASON_DATA_SNACK_REJECT 3
#define ISCSI_REASON_PROTOCOL_ERROR 4
#define ISCSI_REASON_CMD_NOT_SUPPORTED 5
#define ISCSI_REASON_IMM_CMD_REJECT 6
#define ISCSI_REASON_TASK_IN_PROGRESS 7
#define ISCSI_REASON_INVALID_SNACK 8
#define ISCSI_REASON_BOOKMARK_INVALID 9
#define ISCSI_REASON_BOOKMARK_NO_RESOURCES 10
#define ISCSI_REASON_NEGOTIATION_RESET 11
/* Max. number of Key=Value pairs in a text message */
#define MAX_KEY_VALUE_PAIRS 8192
/* maximum length for text keys/values */
#define KEY_MAXLEN 64
#define VALUE_MAXLEN 255
#define TARGET_NAME_MAXLEN VALUE_MAXLEN
#define ISCSI_DEF_MAX_RECV_SEG_LEN 8192
#define ISCSI_MIN_MAX_RECV_SEG_LEN 512
#define ISCSI_MAX_MAX_RECV_SEG_LEN 16777215
#define ISCSI_DEF_FIRST_BURST_LEN 65536
#define ISCSI_MIN_FIRST_BURST_LEN 512
#define ISCSI_MAX_FIRST_BURST_LEN 16777215
#define ISCSI_DEF_MAX_BURST_LEN 262144
#define ISCSI_MIN_MAX_BURST_LEN 512
#define ISCSI_MAX_MAX_BURST_LEN 16777215
#define ISCSI_DEF_TIME2WAIT 2
#define ISCSI_NAME_LEN 224
/************************* RFC 3720 End *****************************/
#endif /* ISCSI_PROTO_H */
Reference in New Issue View Git Blame Copy Permalink