src/tools/sgutils2.rs

   1 //! Bindings for libsgutils2
   2 //!
   3 //! Incomplete, but we currently do not need more.
   4 //!
   5 //! See: `/usr/include/scsi/sg_pt.h`
   6
   7 use std::os::unix::io::AsRawFd;
   8
   9 use anyhow::{bail, Error};
  10 use libc::{c_char, c_int};
  11
  12 // Opaque wrapper for sg_pt_base
  13 #[repr(C)]
  14 struct SgPtBase { _private: [u8; 0] }
  15
  16 impl Drop for SgPtBase  {
  17     fn drop(&mut self) {
  18         unsafe { destruct_scsi_pt_obj(self as *mut SgPtBase) };
  19     }
  20 }
  21
  22 pub const SCSI_PT_RESULT_GOOD:c_int = 0;
  23 pub const SCSI_PT_RESULT_STATUS:c_int = 1;
  24 pub const SCSI_PT_RESULT_SENSE:c_int = 2;
  25 pub const SCSI_PT_RESULT_TRANSPORT_ERR:c_int = 3;
  26 pub const SCSI_PT_RESULT_OS_ERR:c_int = 4;
  27
  28 #[link(name = "sgutils2")]
  29 extern {
  30
  31     #[allow(dead_code)]
  32     fn scsi_pt_open_device(
  33         device_name: * const c_char,
  34         read_only: bool,
  35         verbose: c_int,
  36     ) -> c_int;
  37
  38     fn sg_is_scsi_cdb(
  39         cdbp: *const u8,
  40         clen: c_int,
  41     ) -> bool;
  42
  43     fn construct_scsi_pt_obj() -> *mut SgPtBase;
  44     fn destruct_scsi_pt_obj(objp: *mut SgPtBase);
  45
  46     fn set_scsi_pt_data_in(
  47         objp: *mut SgPtBase,
  48         dxferp: *const u8,
  49         dxfer_ilen: c_int,
  50     );
  51
  52     fn set_scsi_pt_data_out(
  53         objp: *mut SgPtBase,
  54         dxferp: *const u8,
  55         dxfer_olen: c_int,
  56     );
  57
  58     fn set_scsi_pt_cdb(
  59         objp: *mut SgPtBase,
  60         cdb: *const u8,
  61         cdb_len: c_int,
  62     );
  63
  64     fn set_scsi_pt_sense(
  65         objp: *mut SgPtBase,
  66         sense: *const u8,
  67         max_sense_len: c_int,
  68     );
  69
  70     fn do_scsi_pt(
  71         objp: *mut SgPtBase,
  72         fd: c_int,
  73         timeout_secs: c_int,
  74         verbose: c_int,
  75     ) -> c_int;
  76
  77     fn get_scsi_pt_resid(objp: *const SgPtBase) -> c_int;
  78
  79     fn get_scsi_pt_sense_len(objp: *const SgPtBase) -> c_int;
  80
  81     fn get_scsi_pt_status_response(objp: *const SgPtBase) -> c_int;
  82
  83     #[allow(dead_code)]
  84     fn get_scsi_pt_result_category(objp: *const SgPtBase) -> c_int;
  85 }
  86
  87 /// Creates a `Box<SgPtBase>`
  88 ///
  89 /// Which get automatically dropped, so you do not need to call
  90 /// destruct_scsi_pt_obj yourself.
  91 fn boxed_scsi_pt_obj() -> Result<Box<SgPtBase>, Error> {
  92     let objp = unsafe {
  93         construct_scsi_pt_obj()
  94     };
  95     if objp.is_null() {
  96         bail!("construct_scsi_pt_ob failed");
  97     }
  98
  99     Ok(unsafe { std::mem::transmute(objp)})
 100 }
 101
 102 /// Safe interface to run RAW SCSI commands
 103 pub struct SgRaw<'a, F> {
 104     file: &'a mut F,
 105     buffer: Box<[u8]>,
 106     sense_buffer: [u8; 32],
 107 }
 108
 109 /// Allocate a page aligned buffer
 110 ///
 111 /// SG RAWIO commands needs page aligned transfer buffers.
 112 pub fn alloc_page_aligned_buffer(buffer_size: usize) -> Result<Box<[u8]> , Error> {
 113     let page_size = unsafe { libc::sysconf(libc::_SC_PAGESIZE) } as usize;
 114     let layout = std::alloc::Layout::from_size_align(buffer_size, page_size)?;
 115     let dinp = unsafe { std::alloc::alloc_zeroed(layout) };
 116     if dinp.is_null() {
 117         bail!("alloc SCSI output buffer failed");
 118     }
 119
 120     let buffer_slice = unsafe { std::slice::from_raw_parts_mut(dinp, buffer_size)};
 121     Ok(unsafe { Box::from_raw(buffer_slice) })
 122 }
 123
 124 impl <'a, F: AsRawFd> SgRaw<'a, F> {
 125
 126     /// Create a new instance to run commands
 127     ///
 128     /// The file must be a handle to a SCSI device.
 129     pub fn new(file: &'a mut F, buffer_size: usize) -> Result<Self, Error> {
 130
 131         let buffer;
 132
 133         if buffer_size > 0 {
 134             buffer = alloc_page_aligned_buffer(buffer_size)?;
 135         } else {
 136             buffer =  Box::new([]);
 137         }
 138
 139         let sense_buffer = [0u8; 32];
 140
 141         Ok(Self { file, buffer, sense_buffer })
 142     }
 143
 144     // create new object with initialized data_in and sense buffer
 145     fn create_boxed_scsi_pt_obj(&mut self) -> Result<Box<SgPtBase>, Error> {
 146
 147         let mut ptvp = boxed_scsi_pt_obj()?;
 148
 149         if self.buffer.len() > 0 {
 150             unsafe {
 151                 set_scsi_pt_data_in(
 152                     &mut *ptvp,
 153                     self.buffer.as_ptr(),
 154                     self.buffer.len() as c_int,
 155                 )
 156             };
 157         }
 158
 159         unsafe {
 160             set_scsi_pt_sense(
 161                 &mut *ptvp,
 162                 self.sense_buffer.as_ptr(),
 163                 self.sense_buffer.len() as c_int,
 164             )
 165         };
 166
 167         Ok(ptvp)
 168     }
 169
 170     /// Run the specified RAW SCSI command
 171     pub fn do_command(&mut self, cmd: &[u8]) -> Result<&[u8], Error> {
 172
 173         if !unsafe { sg_is_scsi_cdb(cmd.as_ptr(), cmd.len() as c_int) } {
 174             bail!("no valid SCSI command");
 175         }
 176
 177         if self.buffer.len() < 16 {
 178             bail!("output buffer too small");
 179         }
 180
 181         let mut ptvp = self.create_boxed_scsi_pt_obj()?;
 182
 183         unsafe {
 184             set_scsi_pt_cdb(
 185                 &mut *ptvp,
 186                 cmd.as_ptr(),
 187                 cmd.len() as c_int,
 188             )
 189         };
 190
 191         let res = unsafe { do_scsi_pt(&mut *ptvp, self.file.as_raw_fd(), 0, 0) };
 192         if res < 0 {
 193             let err = nix::Error::last();
 194             bail!("do_scsi_pt failed  - {}", err);
 195         }
 196         if res != 0 {
 197             bail!("do_scsi_pt failed {}", res);
 198         }
 199
 200         // todo: what about sense data?
 201         let _sense_len = unsafe { get_scsi_pt_sense_len(&*ptvp) };
 202
 203         let status = unsafe { get_scsi_pt_status_response(&*ptvp) };
 204         if status != 0 {
 205             // toto: improve error reporting
 206             bail!("unknown scsi error - status response {}", status);
 207         }
 208
 209         let data_len = self.buffer.len() -
 210             (unsafe { get_scsi_pt_resid(&*ptvp) } as usize);
 211         if data_len == 0 {
 212             bail!("do_scsi_pt failed - no data received");
 213         }
 214
 215         Ok(&self.buffer[..data_len])
 216     }
 217
 218     /// Run dataout command
 219     ///
 220     /// Note: use alloc_page_aligned_buffer to alloc data transfer buffer
 221     pub fn do_out_command(&mut self, cmd: &[u8], data: &[u8]) -> Result<(), Error> {
 222
 223         if !unsafe { sg_is_scsi_cdb(cmd.as_ptr(), cmd.len() as c_int) } {
 224             bail!("no valid SCSI command");
 225         }
 226
 227         let page_size = unsafe { libc::sysconf(libc::_SC_PAGESIZE) } as usize;
 228         if ((data.as_ptr() as usize) & (page_size -1)) != 0 {
 229             bail!("wrong transfer buffer alignment");
 230         }
 231
 232         let mut ptvp = self.create_boxed_scsi_pt_obj()?;
 233
 234         unsafe {
 235             set_scsi_pt_data_out(
 236                 &mut *ptvp,
 237                 data.as_ptr(),
 238                 data.len() as c_int,
 239             );
 240
 241             set_scsi_pt_cdb(
 242                 &mut *ptvp,
 243                 cmd.as_ptr(),
 244                 cmd.len() as c_int,
 245             );
 246          };
 247
 248         let res = unsafe { do_scsi_pt(&mut *ptvp, self.file.as_raw_fd(), 0, 0) };
 249         if res < 0 {
 250             let err = nix::Error::last();
 251             bail!("do_scsi_pt failed  - {}", err);
 252         }
 253         if res != 0 {
 254             bail!("do_scsi_pt failed {}", res);
 255         }
 256
 257         // todo: what about sense data?
 258         let _sense_len = unsafe { get_scsi_pt_sense_len(&*ptvp) };
 259
 260         let status = unsafe { get_scsi_pt_status_response(&*ptvp) };
 261         if status != 0 {
 262             // toto: improve error reporting
 263             bail!("unknown scsi error - status response {}", status);
 264         }
 265
 266         Ok(())
 267     }
 268 }