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Diffstat (limited to 'include/sg_pt.h')
| -rw-r--r-- | include/sg_pt.h | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/include/sg_pt.h b/include/sg_pt.h new file mode 100644 index 00000000..a1017f50 --- /dev/null +++ b/include/sg_pt.h @@ -0,0 +1,292 @@ +#ifndef SG_PT_H +#define SG_PT_H + +/* + * Copyright (c) 2005-2021 Douglas Gilbert. + * All rights reserved. + * Use of this source code is governed by a BSD-style + * license that can be found in the BSD_LICENSE file. + * + * SPDX-License-Identifier: BSD-2-Clause + */ + +#include <stdint.h> +#include <stdbool.h> + +#ifdef __cplusplus +extern "C" { +#endif + +/* This declaration hides the fact that each implementation has its own + * structure "derived" (using a C++ term) from this one. It compiles + * because 'struct sg_pt_base' is only referenced (by pointer: 'objp') + * in this interface. An instance of this structure represents the + * context of one synchronous SCSI (or NVME) command and the context + * can be re-used. If an instance of sg_pt_base is shared across several + * threads then it is up to the application to take care of multi-threaded + * issues with that instance. */ +struct sg_pt_base; + + +/* The format of the version string is like this: "3.04 20180213". + * The leading digit will be incremented if this interface changes + * in a way that may impact backward compatibility. */ +const char * scsi_pt_version(); +const char * sg_pt_version(); /* both functions give same result */ + + +/* Returns file descriptor or file handle and is >= 0 if successful. + * If error in Unix returns negated errno. */ +int scsi_pt_open_device(const char * device_name, bool read_only, + int verbose); + +/* Similar to scsi_pt_open_device() but takes Unix style open flags OR-ed + * together. Returns valid file descriptor or handle ( >= 0 ) if successful, + * otherwise returns -1 or a negated errno. + * In Win32 O_EXCL translated to equivalent. */ +int scsi_pt_open_flags(const char * device_name, int flags, int verbose); + +/* Returns 0 if successful. 'device_fd' should be a value that was previously + * returned by scsi_pt_open_device() or scsi_pt_open_flags() that has not + * already been closed. If error in Unix returns negated errno. */ +int scsi_pt_close_device(int device_fd); + +/* Assumes dev_fd is an "open" file handle associated with device_name. If + * the implementation (possibly for one OS) cannot determine from dev_fd if + * a SCSI or NVMe pass-through is referenced, then it might guess based on + * device_name. Returns 1 if SCSI generic pass-though device, returns 2 if + * secondary SCSI pass-through device (in Linux a bsg device); returns 3 is + * char NVMe device (i.e. no NSID); returns 4 if block NVMe device (includes + * NSID), 5 is also a NVMe device (FreeBSD CAM NVMe (e.g. /dev/nda0)) or 0 + * if something else (e.g. ATA block device) or dev_fd < 0. + * The return value differs somewhat by OS. + * If error, returns negated errno (operating system) value. */ +int check_pt_file_handle(int dev_fd, const char * device_name, int verbose); + + +/* Creates an object that can be used to issue one or more SCSI commands + * (or task management functions). Returns NULL if problem. + * Once this object has been created it should be destroyed with + * destruct_scsi_pt_obj() when it is no longer needed. */ +struct sg_pt_base * construct_scsi_pt_obj(void); + +/* An alternate and preferred way to create an object that can be used to + * issue one or more SCSI (or NVMe) commands (or task management functions). + * This variant associates a device file descriptor (handle) with the object + * and a verbose argument that causes messages to be written to stderr if + * errors occur. The reason for this is to optionally allow the detection of + * NVMe devices that will cause pt_device_is_nvme() to return true. Set + * dev_fd to -1 if no open device file descriptor is available. Caller + * should additionally call get_scsi_pt_os_err() after this call to check + * for errors. The dev_fd argument may be -1 to indicate no device file + * descriptor. */ +struct sg_pt_base * + construct_scsi_pt_obj_with_fd(int dev_fd, int verbose); + +/* Forget any previous dev_fd and install the one given. May attempt to + * find file type (e.g. if pass-though) from OS so there could be an error. + * Returns 0 for success or the same value as get_scsi_pt_os_err() + * will return. dev_fd should be >= 0 for a valid file handle or -1 . */ +int set_pt_file_handle(struct sg_pt_base * objp, int dev_fd, int verbose); + +/* Valid file handles (which is the return value) are >= 0 . Returns -1 + * if there is no valid file handle. */ +int get_pt_file_handle(const struct sg_pt_base * objp); + +/* Clear state information held in *objp . This allows this object to be + * used to issue more than one SCSI command. The dev_fd is remembered. + * Use set_pt_file_handle() to change dev_fd. */ +void clear_scsi_pt_obj(struct sg_pt_base * objp); + +/* Partially clear state information held in *objp . Any error settings and + * the data-in and data-out settings are cleared. So dev_fd, cdb and sense + * settings are kept. */ +void partial_clear_scsi_pt_obj(struct sg_pt_base * objp); + +/* Set the CDB (command descriptor block). May also be a NVMe Admin command + * which will be 64 bytes long. + * + * Note that the sg_cmds_is_nvme() function found in sg_cmds_basic.h can be + * called after this function to "guess" which command set the given command + * belongs to. It is valid to supply a cdb value of NULL. */ +void set_scsi_pt_cdb(struct sg_pt_base * objp, const uint8_t * cdb, + int cdb_len); + +/* Set the sense buffer and the maximum length of that buffer. For NVMe + * commands this "sense" buffer will receive the 4 DWORDs of from the + * completion queue. It is valid to supply a sense value of NULL. */ +void set_scsi_pt_sense(struct sg_pt_base * objp, uint8_t * sense, + int max_sense_len); + +/* Set a pointer and length to be used for data transferred from device */ +void set_scsi_pt_data_in(struct sg_pt_base * objp, /* from device */ + uint8_t * dxferp, int dxfer_ilen); + +/* Set a pointer and length to be used for data transferred to device */ +void set_scsi_pt_data_out(struct sg_pt_base * objp, /* to device */ + const uint8_t * dxferp, int dxfer_olen); + +/* Set a pointer and length to be used for metadata transferred to + * (out_true=true) or from (out_true=false) device (NVMe only) */ +void set_pt_metadata_xfer(struct sg_pt_base * objp, uint8_t * mdxferp, + uint32_t mdxfer_len, bool out_true); + +/* The following "set_"s implementations may be dummies */ +void set_scsi_pt_packet_id(struct sg_pt_base * objp, int pack_id); +void set_scsi_pt_tag(struct sg_pt_base * objp, uint64_t tag); +void set_scsi_pt_task_management(struct sg_pt_base * objp, int tmf_code); +void set_scsi_pt_task_attr(struct sg_pt_base * objp, int attribute, + int priority); + +/* Following is a guard which is defined when set_scsi_pt_flags() is + * present. Older versions of this library may not have this function. */ +#define SCSI_PT_FLAGS_FUNCTION 1 +/* If neither QUEUE_AT_HEAD nor QUEUE_AT_TAIL are given, or both + * are given, use the pass-through default. */ +#define SCSI_PT_FLAGS_QUEUE_AT_TAIL 0x10 +#define SCSI_PT_FLAGS_QUEUE_AT_HEAD 0x20 +/* Set (potentially OS dependent) flags for pass-through mechanism. + * Apart from contradictions, flags can be OR-ed together. */ +void set_scsi_pt_flags(struct sg_pt_base * objp, int flags); + +#define SCSI_PT_DO_START_OK 0 +#define SCSI_PT_DO_BAD_PARAMS 1 +#define SCSI_PT_DO_TIMEOUT 2 +#define SCSI_PT_DO_NOT_SUPPORTED 4 +#define SCSI_PT_DO_NVME_STATUS 48 /* == SG_LIB_NVME_STATUS */ +/* If OS error prior to or during command submission then returns negated + * error value (e.g. Unix '-errno'). This includes interrupted system calls + * (e.g. by a signal) in which case -EINTR would be returned. Note that + * system call errors also can be fetched with get_scsi_pt_os_err(). + * Return 0 if okay (i.e. at the very least: command sent). Positive + * return values are errors (see SCSI_PT_DO_* defines). If a file descriptor + * has already been provided by construct_scsi_pt_obj_with_fd() then the + * given 'fd' can be -1 or the same value as given to the constructor. */ +int do_scsi_pt(struct sg_pt_base * objp, int fd, int timeout_secs, + int verbose); + +/* NVMe Admin commands can be sent directly to do_scsi_pt(). Unfortunately + * NVMe has at least one other command set: "NVM" to access user data and + * the opcodes in the NVM command set overlap with the Admin command set. + * So NVMe Admin commands should be sent do_scsi_pt() while NVMe "NVM" + * commands should be sent to this function. No SCSI commands should be + * sent to this function. Currently submq is not implemented and all + * submitted NVM commands are sent on queue 0, the same queue use for + * Admin commands. The return values follow the same pattern as do_scsi_pt(), + * with 0 returned being good. The NVMe device file descriptor must either + * be given to the obj constructor, or a prior set_pt_file_handle() call. */ +int do_nvm_pt(struct sg_pt_base * objp, int submq, int timeout_secs, + int verbose); + +#define SCSI_PT_RESULT_GOOD 0 +#define SCSI_PT_RESULT_STATUS 1 /* other than GOOD and CHECK CONDITION */ +#define SCSI_PT_RESULT_SENSE 2 +#define SCSI_PT_RESULT_TRANSPORT_ERR 3 +#define SCSI_PT_RESULT_OS_ERR 4 +/* This function, called soon after do_scsi_pt(), returns one of the above + * result categories. The highest numbered applicable category is returned. + * + * Note that the sg_cmds_process_resp() function found in sg_cmds_basic.h + * is useful for processing SCSI command responses. + * And the sg_cmds_is_nvme() function found in sg_cmds_basic.h can be called + * after set_scsi_pt_cdb() to "guess" which command set the given command + * belongs to. */ +int get_scsi_pt_result_category(const struct sg_pt_base * objp); + +/* If not available return 0 which implies there is no residual value. If + * supported it is the number of bytes requested to transfer less the + * number actually transferred. This it typically important for data-in + * transfers. For data-out (only) transfers, the 'dout_req_len - + * dout_act_len' is returned. For bidi transfer the data-in residual is + * returned. */ +int get_scsi_pt_resid(const struct sg_pt_base * objp); + +/* Returns SCSI status value (from device that received the command). If an + * NVMe command was issued directly (i.e. through do_scsi_pt() then return + * NVMe status (i.e. ((SCT << 8) | SC)). If problem returns -1. */ +int get_scsi_pt_status_response(const struct sg_pt_base * objp); + +/* Returns SCSI status value or, if NVMe command given to do_scsi_pt(), + * then returns NVMe result (i.e. DWord(0) from completion queue). If + * 'objp' is NULL then returns 0xffffffff. */ +uint32_t get_pt_result(const struct sg_pt_base * objp); + +/* These two get functions should just echo what has been given to + * set_scsi_pt_cdb(). If it has not been called or clear_scsi_pt_obj() + * has been called then they return 0 and NULL respectively. */ +int get_scsi_pt_cdb_len(const struct sg_pt_base * objp); +uint8_t * get_scsi_pt_cdb_buf(const struct sg_pt_base * objp); + +/* Actual sense length returned. If sense data is present but + actual sense length is not known, return 'max_sense_len' */ +int get_scsi_pt_sense_len(const struct sg_pt_base * objp); +uint8_t * get_scsi_pt_sense_buf(const struct sg_pt_base * objp); + +/* If not available return 0 (for success). */ +int get_scsi_pt_os_err(const struct sg_pt_base * objp); +char * get_scsi_pt_os_err_str(const struct sg_pt_base * objp, int max_b_len, + char * b); + +/* If not available return 0 (for success) */ +int get_scsi_pt_transport_err(const struct sg_pt_base * objp); +void set_scsi_pt_transport_err(struct sg_pt_base * objp, int err); +char * get_scsi_pt_transport_err_str(const struct sg_pt_base * objp, + int max_b_len, char * b); + +/* If not available return -1 otherwise return number of milliseconds + * that the lower layers (and hardware) took to execute the previous + * command. */ +int get_scsi_pt_duration_ms(const struct sg_pt_base * objp); + +/* If not available return 0 otherwise return number of nanoseconds that the + * lower layers (and hardware) took to execute the command just completed. */ +uint64_t get_pt_duration_ns(const struct sg_pt_base * objp); + +/* The two functions yield requested and actual data transfer lengths in + * bytes. The second argument is a pointer to the data-in length; the third + * argument is a pointer to the data-out length. The pointers may be NULL. + * The _actual_ values are related to resid (residual count from DMA) */ +void get_pt_req_lengths(const struct sg_pt_base * objp, int * req_dinp, + int * req_doutp); +void get_pt_actual_lengths(const struct sg_pt_base * objp, int * act_dinp, + int * act_doutp); + +/* Return true if device associated with 'objp' uses NVMe command set. To + * be useful (in modifying the type of command sent (SCSI or NVMe) then + * construct_scsi_pt_obj_with_fd() should be used followed by an invocation + * of this function. */ +bool pt_device_is_nvme(const struct sg_pt_base * objp); + +/* If a NVMe block device (which includes the NSID) handle is associated + * with 'objp', then its NSID is returned (values range from 0x1 to + * 0xffffffe). Otherwise 0 is returned. */ +uint32_t get_pt_nvme_nsid(const struct sg_pt_base * objp); + + +/* Should be invoked once per objp after other processing is complete in + * order to clean up resources. For ever successful construct_scsi_pt_obj() + * call there should be one destruct_scsi_pt_obj(). If the + * construct_scsi_pt_obj_with_fd() function was used to create this object + * then the dev_fd provided to that constructor is not altered by this + * destructor. So the user should still close dev_fd (perhaps with + * scsi_pt_close_device() ). */ +void destruct_scsi_pt_obj(struct sg_pt_base * objp); + +#ifdef SG_LIB_WIN32 +#define SG_LIB_WIN32_DIRECT 1 + +/* Request SPT direct interface when state_direct is 1, state_direct set + * to 0 for the SPT indirect interface. Default setting selected by build + * (i.e. library compile time) and is usually indirect. */ +void scsi_pt_win32_direct(int state_direct); + +/* Returns current SPT interface state, 1 for direct, 0 for indirect */ +int scsi_pt_win32_spt_state(void); + +#endif + +#ifdef __cplusplus +} +#endif + +#endif /* SG_PT_H */ |