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1 #ifndef SG_PT_H
2 #define SG_PT_H
3 
4 /*
5  * Copyright (c) 2005-2018 Douglas Gilbert.
6  * All rights reserved.
7  * Use of this source code is governed by a BSD-style
8  * license that can be found in the BSD_LICENSE file.
9  */
10 
11 #include <stdint.h>
12 #include <stdbool.h>
13 
14 #ifdef __cplusplus
15 extern "C" {
16 #endif
17 
18 /* This declaration hides the fact that each implementation has its own
19  * structure "derived" (using a C++ term) from this one. It compiles
20  * because 'struct sg_pt_base' is only referenced (by pointer: 'objp')
21  * in this interface. An instance of this structure represents the
22  * context of one SCSI command. */
23 struct sg_pt_base;
24 
25 
26 /* The format of the version string is like this: "2.01 20090201".
27  * The leading digit will be incremented if this interface changes
28  * in a way that may impact backward compatibility. */
29 const char * scsi_pt_version();
30 
31 
32 /* Returns >= 0 if successful. If error in Unix returns negated errno. */
33 int scsi_pt_open_device(const char * device_name, bool read_only, int verbose);
34 
35 /* Similar to scsi_pt_open_device() but takes Unix style open flags OR-ed
36  * together. Returns valid file descriptor( >= 0 ) if successful, otherwise
37  * returns -1 or a negated errno.
38  * In Win32 O_EXCL translated to equivalent. */
39 int scsi_pt_open_flags(const char * device_name, int flags, int verbose);
40 
41 /* Returns 0 if successful. If error in Unix returns negated errno. */
42 int scsi_pt_close_device(int device_fd);
43 
44 /* Assumes dev_fd is an "open" file handle associated with device_name. If
45  * the implementation (possibly for one OS) cannot determine from dev_fd if
46  * a SCSI or NVMe pass-through is referenced, then it might guess based on
47  * device_name. Returns 1 if SCSI generic pass-though device, returns 2 if
48  * secondary SCSI pass-through device (in Linux a bsg device); returns 3 is
49  * char NVMe device (i.e. no NSID); returns 4 if block NVMe device (includes
50  * NSID), or 0 if something else (e.g. ATA block device) or dev_fd < 0.
51  * If error, returns negated errno (operating system) value. */
52 int check_pt_file_handle(int dev_fd, const char * device_name, int verbose);
53 
54 
55 /* Creates an object that can be used to issue one or more SCSI commands
56  * (or task management functions). Returns NULL if problem.
57  * Once this object has been created it should be destroyed with
58  * destruct_scsi_pt_obj() when it is no longer needed. */
59 struct sg_pt_base * construct_scsi_pt_obj(void);
60 
61 /* An alternate way to create an object that can be used to issue one or
62  * more SCSI commands (or task management functions). This variant
63  * associate a device file descriptor (handle) with the object and a
64  * verbose argument that causes error messages if errors occur. The
65  * reason for this is to optionally allow the detection of NVMe devices
66  * that will cause pt_device_is_nvme() to return true. Set dev_fd to
67  * -1 if no open device file descriptor is available. Caller should
68  *  additionally call get_scsi_pt_os_err() after this call. */
69 struct sg_pt_base *
70         construct_scsi_pt_obj_with_fd(int dev_fd, int verbose);
71 
72 /* Forget any previous dev_fd and install the one given. May attempt to
73  * find file type (e.g. if pass-though) from OS so there could be an error.
74  * Returns 0 for success or the same value as get_scsi_pt_os_err()
75  * will return. dev_fd should be >= 0 for a valid file handle or -1 . */
76 int set_pt_file_handle(struct sg_pt_base * objp, int dev_fd, int verbose);
77 
78 /* Valid file handles (which is the return value) are >= 0 . Returns -1
79  * if there is no valid file handle. */
80 int get_pt_file_handle(const struct sg_pt_base * objp);
81 
82 /* Clear state information held in *objp . This allows this object to be
83  * used to issue more than one SCSI command. The dev_fd is remembered.
84  * Use set_pt_file_handle() to change dev_fd. */
85 void clear_scsi_pt_obj(struct sg_pt_base * objp);
86 
87 /* Set the CDB (command descriptor block) */
88 void set_scsi_pt_cdb(struct sg_pt_base * objp, const unsigned char * cdb,
89                      int cdb_len);
90 /* Set the sense buffer and the maximum length that it can handle */
91 void set_scsi_pt_sense(struct sg_pt_base * objp, unsigned char * sense,
92                        int max_sense_len);
93 /* Set a pointer and length to be used for data transferred from device */
94 void set_scsi_pt_data_in(struct sg_pt_base * objp,   /* from device */
95                          unsigned char * dxferp, int dxfer_ilen);
96 /* Set a pointer and length to be used for data transferred to device */
97 void set_scsi_pt_data_out(struct sg_pt_base * objp,    /* to device */
98                           const unsigned char * dxferp, int dxfer_olen);
99 /* Set a pointer and length to be used for metadata transferred to
100  * (out_true=true) or from (out_true-false) device */
101 void set_pt_metadata_xfer(struct sg_pt_base * objp, unsigned char * mdxferp,
102                           uint32_t mdxfer_len, bool out_true);
103 /* The following "set_"s implementations may be dummies */
104 void set_scsi_pt_packet_id(struct sg_pt_base * objp, int pack_id);
105 void set_scsi_pt_tag(struct sg_pt_base * objp, uint64_t tag);
106 void set_scsi_pt_task_management(struct sg_pt_base * objp, int tmf_code);
107 void set_scsi_pt_task_attr(struct sg_pt_base * objp, int attribute,
108                            int priority);
109 
110 /* Following is a guard which is defined when set_scsi_pt_flags() is
111  * present. Older versions of this library may not have this function. */
112 #define SCSI_PT_FLAGS_FUNCTION 1
113 /* If neither QUEUE_AT_HEAD nor QUEUE_AT_TAIL are given, or both
114  * are given, use the pass-through default. */
115 #define SCSI_PT_FLAGS_QUEUE_AT_TAIL 0x10
116 #define SCSI_PT_FLAGS_QUEUE_AT_HEAD 0x20
117 /* Set (potentially OS dependent) flags for pass-through mechanism.
118  * Apart from contradictions, flags can be OR-ed together. */
119 void set_scsi_pt_flags(struct sg_pt_base * objp, int flags);
120 
121 #define SCSI_PT_DO_START_OK 0
122 #define SCSI_PT_DO_BAD_PARAMS 1
123 #define SCSI_PT_DO_TIMEOUT 2
124 #define SCSI_PT_DO_NVME_STATUS 48       /* == SG_LIB_NVME_STATUS */
125 /* If OS error prior to or during command submission then returns negated
126  * error value (e.g. Unix '-errno'). This includes interrupted system calls
127  * (e.g. by a signal) in which case -EINTR would be returned. Note that
128  * system call errors also can be fetched with get_scsi_pt_os_err().
129  * Return 0 if okay (i.e. at the very least: command sent). Positive
130  * return values are errors (see SCSI_PT_DO_* defines). If a file descriptor
131  * has already been provided by construct_scsi_pt_obj_with_fd() then the
132  * given 'fd' can be -1 or the same value as given to the constructor. */
133 int do_scsi_pt(struct sg_pt_base * objp, int fd, int timeout_secs,
134                int verbose);
135 
136 #define SCSI_PT_RESULT_GOOD 0
137 #define SCSI_PT_RESULT_STATUS 1 /* other than GOOD and CHECK CONDITION */
138 #define SCSI_PT_RESULT_SENSE 2
139 #define SCSI_PT_RESULT_TRANSPORT_ERR 3
140 #define SCSI_PT_RESULT_OS_ERR 4
141 /* highest numbered applicable category returned */
142 int get_scsi_pt_result_category(const struct sg_pt_base * objp);
143 
144 /* If not available return 0 which implies there is no residual
145  * value. If supported the number of bytes actually sent back by
146  * the device is 'dxfer_ilen - get_scsi_pt_len()' bytes.  */
147 int get_scsi_pt_resid(const struct sg_pt_base * objp);
148 
149 /* Returns SCSI status value (from device that received the command). If an
150  * NVMe command was issued directly (i.e. through do_scsi_pt() then return
151  * NVMe status (i.e. ((SCT << 8) | SC)) */
152 int get_scsi_pt_status_response(const struct sg_pt_base * objp);
153 
154 /* Returns SCSI status value or, if NVMe command given to do_scsi_pt(),
155  * then returns NVMe result (i.e. DWord(0) from completion queue). If
156  * 'objp' is NULL then returns 0xffffffff. */
157 uint32_t get_pt_result(const struct sg_pt_base * objp);
158 
159 /* Actual sense length returned. If sense data is present but
160    actual sense length is not known, return 'max_sense_len' */
161 int get_scsi_pt_sense_len(const struct sg_pt_base * objp);
162 
163 /* If not available return 0 (for success). */
164 int get_scsi_pt_os_err(const struct sg_pt_base * objp);
165 char * get_scsi_pt_os_err_str(const struct sg_pt_base * objp, int max_b_len,
166                               char * b);
167 
168 /* If not available return 0 (for success) */
169 int get_scsi_pt_transport_err(const struct sg_pt_base * objp);
170 void set_scsi_pt_transport_err(struct sg_pt_base * objp, int err);
171 char * get_scsi_pt_transport_err_str(const struct sg_pt_base * objp,
172                                      int max_b_len, char * b);
173 
174 /* If not available return -1 */
175 int get_scsi_pt_duration_ms(const struct sg_pt_base * objp);
176 
177 /* Return true if device associated with 'objp' uses NVMe command set. To
178  * be useful (in modifying the type of command sent (SCSI or NVMe) then
179  * construct_scsi_pt_obj_with_fd() should be used followed by an invocation
180  * of this function. */
181 bool pt_device_is_nvme(const struct sg_pt_base * objp);
182 
183 /* If a NVMe block device (which includes the NSID) handle is associated
184  * with 'objp', then its NSID is returned (values range from 0x1 to
185  * 0xffffffe). Otherwise 0 is returned. */
186 uint32_t get_pt_nvme_nsid(const struct sg_pt_base * objp);
187 
188 
189 /* Should be invoked once per objp after other processing is complete in
190  * order to clean up resources. For ever successful construct_scsi_pt_obj()
191  * call there should be one destruct_scsi_pt_obj(). If the
192  * construct_scsi_pt_obj_with_fd() function was used to create this object
193  * then the dev_fd provided to that constructor is not altered by this
194  * destructor. So the user should still close dev_fd (perhaps with
195  * scsi_pt_close_device() ).  */
196 void destruct_scsi_pt_obj(struct sg_pt_base * objp);
197 
198 #ifdef SG_LIB_WIN32
199 #define SG_LIB_WIN32_DIRECT 1
200 
201 /* Request SPT direct interface when state_direct is 1, state_direct set
202  * to 0 for the SPT indirect interface. Default setting selected by build
203  * (i.e. library compile time) and is usually indirect. */
204 void scsi_pt_win32_direct(int state_direct);
205 
206 /* Returns current SPT interface state, 1 for direct, 0 for indirect */
207 int scsi_pt_win32_spt_state(void);
208 
209 #endif
210 
211 #ifdef __cplusplus
212 }
213 #endif
214 
215 #endif
216