1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
//! For detailed description of the ptrace requests, consult `man ptrace`.

use cfg_if::cfg_if;
use std::{mem, ptr};
use crate::Result;
use crate::errno::Errno;
use libc::{self, c_void, c_long, siginfo_t};
use crate::unistd::Pid;
use crate::sys::signal::Signal;

pub type AddressType = *mut ::libc::c_void;

#[cfg(all(
    target_os = "linux",
    any(all(target_arch = "x86_64",
            any(target_env = "gnu", target_env = "musl")),
        all(target_arch = "x86", target_env = "gnu"))
))]
use libc::user_regs_struct;

cfg_if! {
    if #[cfg(any(all(target_os = "linux", target_arch = "s390x"),
                 all(target_os = "linux", target_env = "gnu")))] {
        #[doc(hidden)]
        pub type RequestType = ::libc::c_uint;
    } else {
        #[doc(hidden)]
        pub type RequestType = ::libc::c_int;
    }
}

libc_enum!{
    #[cfg_attr(not(any(target_env = "musl", target_os = "android")), repr(u32))]
    #[cfg_attr(any(target_env = "musl", target_os = "android"), repr(i32))]
    /// Ptrace Request enum defining the action to be taken.
    pub enum Request {
        PTRACE_TRACEME,
        PTRACE_PEEKTEXT,
        PTRACE_PEEKDATA,
        PTRACE_PEEKUSER,
        PTRACE_POKETEXT,
        PTRACE_POKEDATA,
        PTRACE_POKEUSER,
        PTRACE_CONT,
        PTRACE_KILL,
        PTRACE_SINGLESTEP,
        #[cfg(any(all(target_os = "android", target_pointer_width = "32"),
                  all(target_os = "linux", any(target_env = "musl",
                                               target_arch = "mips",
                                               target_arch = "mips64",
                                               target_arch = "x86_64",
                                               target_pointer_width = "32"))))]
        PTRACE_GETREGS,
        #[cfg(any(all(target_os = "android", target_pointer_width = "32"),
                  all(target_os = "linux", any(target_env = "musl",
                                               target_arch = "mips",
                                               target_arch = "mips64",
                                               target_arch = "x86_64",
                                               target_pointer_width = "32"))))]
        PTRACE_SETREGS,
        #[cfg(any(all(target_os = "android", target_pointer_width = "32"),
                  all(target_os = "linux", any(target_env = "musl",
                                               target_arch = "mips",
                                               target_arch = "mips64",
                                               target_arch = "x86_64",
                                               target_pointer_width = "32"))))]
        PTRACE_GETFPREGS,
        #[cfg(any(all(target_os = "android", target_pointer_width = "32"),
                  all(target_os = "linux", any(target_env = "musl",
                                               target_arch = "mips",
                                               target_arch = "mips64",
                                               target_arch = "x86_64",
                                               target_pointer_width = "32"))))]
        PTRACE_SETFPREGS,
        PTRACE_ATTACH,
        PTRACE_DETACH,
        #[cfg(all(target_os = "linux", any(target_env = "musl",
                                           target_arch = "mips",
                                           target_arch = "mips64",
                                           target_arch = "x86",
                                           target_arch = "x86_64")))]
        PTRACE_GETFPXREGS,
        #[cfg(all(target_os = "linux", any(target_env = "musl",
                                           target_arch = "mips",
                                           target_arch = "mips64",
                                           target_arch = "x86",
                                           target_arch = "x86_64")))]
        PTRACE_SETFPXREGS,
        PTRACE_SYSCALL,
        PTRACE_SETOPTIONS,
        PTRACE_GETEVENTMSG,
        PTRACE_GETSIGINFO,
        PTRACE_SETSIGINFO,
        #[cfg(all(target_os = "linux", not(any(target_arch = "mips",
                                               target_arch = "mips64"))))]
        PTRACE_GETREGSET,
        #[cfg(all(target_os = "linux", not(any(target_arch = "mips",
                                               target_arch = "mips64"))))]
        PTRACE_SETREGSET,
        #[cfg(all(target_os = "linux", not(any(target_arch = "mips",
                                               target_arch = "mips64"))))]
        PTRACE_SEIZE,
        #[cfg(all(target_os = "linux", not(any(target_arch = "mips",
                                               target_arch = "mips64"))))]
        PTRACE_INTERRUPT,
        #[cfg(all(target_os = "linux", not(any(target_arch = "mips",
                                               target_arch = "mips64"))))]
        PTRACE_LISTEN,
        #[cfg(all(target_os = "linux", not(any(target_arch = "mips",
                                               target_arch = "mips64"))))]
        PTRACE_PEEKSIGINFO,
        #[cfg(all(target_os = "linux", target_env = "gnu",
                  any(target_arch = "x86", target_arch = "x86_64")))]
        PTRACE_SYSEMU,
        #[cfg(all(target_os = "linux", target_env = "gnu",
                  any(target_arch = "x86", target_arch = "x86_64")))]
        PTRACE_SYSEMU_SINGLESTEP,
    }
}

libc_enum!{
    #[repr(i32)]
    /// Using the ptrace options the tracer can configure the tracee to stop
    /// at certain events. This enum is used to define those events as defined
    /// in `man ptrace`.
    pub enum Event {
        /// Event that stops before a return from fork or clone.
        PTRACE_EVENT_FORK,
        /// Event that stops before a return from vfork or clone.
        PTRACE_EVENT_VFORK,
        /// Event that stops before a return from clone.
        PTRACE_EVENT_CLONE,
        /// Event that stops before a return from execve.
        PTRACE_EVENT_EXEC,
        /// Event for a return from vfork.
        PTRACE_EVENT_VFORK_DONE,
        /// Event for a stop before an exit. Unlike the waitpid Exit status program.
        /// registers can still be examined
        PTRACE_EVENT_EXIT,
        /// STop triggered by a seccomp rule on a tracee.
        PTRACE_EVENT_SECCOMP,
        // PTRACE_EVENT_STOP not provided by libc because it's defined in glibc 2.26
    }
}

libc_bitflags! {
    /// Ptrace options used in conjunction with the PTRACE_SETOPTIONS request.
    /// See `man ptrace` for more details.
    pub struct Options: libc::c_int {
        /// When delivering system call traps set a bit to allow tracer to
        /// distinguish between normal stops or syscall stops. May not work on
        /// all systems.
        PTRACE_O_TRACESYSGOOD;
        /// Stop tracee at next fork and start tracing the forked process.
        PTRACE_O_TRACEFORK;
        /// Stop tracee at next vfork call and trace the vforked process.
        PTRACE_O_TRACEVFORK;
        /// Stop tracee at next clone call and trace the cloned process.
        PTRACE_O_TRACECLONE;
        /// Stop tracee at next execve call.
        PTRACE_O_TRACEEXEC;
        /// Stop tracee at vfork completion.
        PTRACE_O_TRACEVFORKDONE;
        /// Stop tracee at next exit call. Stops before exit commences allowing
        /// tracer to see location of exit and register states.
        PTRACE_O_TRACEEXIT;
        /// Stop tracee when a SECCOMP_RET_TRACE rule is triggered. See `man seccomp` for more
        /// details.
        PTRACE_O_TRACESECCOMP;
        /// Send a SIGKILL to the tracee if the tracer exits.  This is useful
        /// for ptrace jailers to prevent tracees from escaping their control.
        #[cfg(any(target_os = "android", target_os = "linux"))]
        PTRACE_O_EXITKILL;
    }
}

fn ptrace_peek(request: Request, pid: Pid, addr: AddressType, data: *mut c_void) -> Result<c_long> {
    let ret = unsafe {
        Errno::clear();
        libc::ptrace(request as RequestType, libc::pid_t::from(pid), addr, data)
    };
    match Errno::result(ret) {
        Ok(..) | Err(Errno::UnknownErrno) => Ok(ret),
        err @ Err(..) => err,
    }
}

/// Get user registers, as with `ptrace(PTRACE_GETREGS, ...)`
#[cfg(all(
    target_os = "linux",
    any(all(target_arch = "x86_64",
            any(target_env = "gnu", target_env = "musl")),
        all(target_arch = "x86", target_env = "gnu"))
))]
pub fn getregs(pid: Pid) -> Result<user_regs_struct> {
    ptrace_get_data::<user_regs_struct>(Request::PTRACE_GETREGS, pid)
}

/// Set user registers, as with `ptrace(PTRACE_SETREGS, ...)`
#[cfg(all(
    target_os = "linux",
    any(all(target_arch = "x86_64",
            any(target_env = "gnu", target_env = "musl")),
        all(target_arch = "x86", target_env = "gnu"))
))]
pub fn setregs(pid: Pid, regs: user_regs_struct) -> Result<()> {
    let res = unsafe {
        libc::ptrace(Request::PTRACE_SETREGS as RequestType,
                     libc::pid_t::from(pid),
                     ptr::null_mut::<c_void>(),
                     &regs as *const _ as *const c_void)
    };
    Errno::result(res).map(drop)
}

/// Function for ptrace requests that return values from the data field.
/// Some ptrace get requests populate structs or larger elements than `c_long`
/// and therefore use the data field to return values. This function handles these
/// requests.
fn ptrace_get_data<T>(request: Request, pid: Pid) -> Result<T> {
    let mut data = mem::MaybeUninit::uninit();
    let res = unsafe {
        libc::ptrace(request as RequestType,
                     libc::pid_t::from(pid),
                     ptr::null_mut::<T>(),
                     data.as_mut_ptr() as *const _ as *const c_void)
    };
    Errno::result(res)?;
    Ok(unsafe{ data.assume_init() })
}

unsafe fn ptrace_other(request: Request, pid: Pid, addr: AddressType, data: *mut c_void) -> Result<c_long> {
    Errno::result(libc::ptrace(request as RequestType, libc::pid_t::from(pid), addr, data)).map(|_| 0)
}

/// Set options, as with `ptrace(PTRACE_SETOPTIONS,...)`.
pub fn setoptions(pid: Pid, options: Options) -> Result<()> {
    let res = unsafe {
        libc::ptrace(Request::PTRACE_SETOPTIONS as RequestType,
                     libc::pid_t::from(pid),
                     ptr::null_mut::<c_void>(),
                     options.bits() as *mut c_void)
    };
    Errno::result(res).map(drop)
}

/// Gets a ptrace event as described by `ptrace(PTRACE_GETEVENTMSG,...)`
pub fn getevent(pid: Pid) -> Result<c_long> {
    ptrace_get_data::<c_long>(Request::PTRACE_GETEVENTMSG, pid)
}

/// Get siginfo as with `ptrace(PTRACE_GETSIGINFO,...)`
pub fn getsiginfo(pid: Pid) -> Result<siginfo_t> {
    ptrace_get_data::<siginfo_t>(Request::PTRACE_GETSIGINFO, pid)
}

/// Set siginfo as with `ptrace(PTRACE_SETSIGINFO,...)`
pub fn setsiginfo(pid: Pid, sig: &siginfo_t) -> Result<()> {
    let ret = unsafe{
        Errno::clear();
        libc::ptrace(Request::PTRACE_SETSIGINFO as RequestType,
                     libc::pid_t::from(pid),
                     ptr::null_mut::<c_void>(),
                     sig as *const _ as *const c_void)
    };
    match Errno::result(ret) {
        Ok(_) => Ok(()),
        Err(e) => Err(e),
    }
}

/// Sets the process as traceable, as with `ptrace(PTRACE_TRACEME, ...)`
///
/// Indicates that this process is to be traced by its parent.
/// This is the only ptrace request to be issued by the tracee.
pub fn traceme() -> Result<()> {
    unsafe {
        ptrace_other(
            Request::PTRACE_TRACEME,
            Pid::from_raw(0),
            ptr::null_mut(),
            ptr::null_mut(),
        ).map(drop) // ignore the useless return value
    }
}

/// Continue execution until the next syscall, as with `ptrace(PTRACE_SYSCALL, ...)`
///
/// Arranges for the tracee to be stopped at the next entry to or exit from a system call,
/// optionally delivering a signal specified by `sig`.
pub fn syscall<T: Into<Option<Signal>>>(pid: Pid, sig: T) -> Result<()> {
    let data = match sig.into() {
        Some(s) => s as i32 as *mut c_void,
        None => ptr::null_mut(),
    };
    unsafe {
        ptrace_other(
            Request::PTRACE_SYSCALL,
            pid,
            ptr::null_mut(),
            data,
        ).map(drop) // ignore the useless return value
    }
}

/// Continue execution until the next syscall, as with `ptrace(PTRACE_SYSEMU, ...)`
///
/// In contrast to the `syscall` function, the syscall stopped at will not be executed.
/// Thus the the tracee will only be stopped once per syscall,
/// optionally delivering a signal specified by `sig`.
#[cfg(all(target_os = "linux", target_env = "gnu", any(target_arch = "x86", target_arch = "x86_64")))]
pub fn sysemu<T: Into<Option<Signal>>>(pid: Pid, sig: T) -> Result<()> {
    let data = match sig.into() {
        Some(s) => s as i32 as *mut c_void,
        None => ptr::null_mut(),
    };
    unsafe {
        ptrace_other(Request::PTRACE_SYSEMU, pid, ptr::null_mut(), data).map(drop)
        // ignore the useless return value
    }
}

/// Attach to a running process, as with `ptrace(PTRACE_ATTACH, ...)`
///
/// Attaches to the process specified by `pid`, making it a tracee of the calling process.
pub fn attach(pid: Pid) -> Result<()> {
    unsafe {
        ptrace_other(
            Request::PTRACE_ATTACH,
            pid,
            ptr::null_mut(),
            ptr::null_mut(),
        ).map(drop) // ignore the useless return value
    }
}

/// Attach to a running process, as with `ptrace(PTRACE_SEIZE, ...)`
///
/// Attaches to the process specified in pid, making it a tracee of the calling process.
#[cfg(all(target_os = "linux", not(any(target_arch = "mips", target_arch = "mips64"))))]
pub fn seize(pid: Pid, options: Options) -> Result<()> {
    unsafe {
        ptrace_other(
            Request::PTRACE_SEIZE,
            pid,
            ptr::null_mut(),
            options.bits() as *mut c_void,
        ).map(drop) // ignore the useless return value
    }
}

/// Detaches the current running process, as with `ptrace(PTRACE_DETACH, ...)`
///
/// Detaches from the process specified by `pid` allowing it to run freely, optionally delivering a
/// signal specified by `sig`.
pub fn detach<T: Into<Option<Signal>>>(pid: Pid, sig: T) -> Result<()> {
    let data = match sig.into() {
        Some(s) => s as i32 as *mut c_void,
        None => ptr::null_mut(),
    };
    unsafe {
        ptrace_other(
            Request::PTRACE_DETACH,
            pid,
            ptr::null_mut(),
            data
        ).map(drop)
    }
}

/// Restart the stopped tracee process, as with `ptrace(PTRACE_CONT, ...)`
///
/// Continues the execution of the process with PID `pid`, optionally
/// delivering a signal specified by `sig`.
pub fn cont<T: Into<Option<Signal>>>(pid: Pid, sig: T) -> Result<()> {
    let data = match sig.into() {
        Some(s) => s as i32 as *mut c_void,
        None => ptr::null_mut(),
    };
    unsafe {
        ptrace_other(Request::PTRACE_CONT, pid, ptr::null_mut(), data).map(drop) // ignore the useless return value
    }
}

/// Issues a kill request as with `ptrace(PTRACE_KILL, ...)`
///
/// This request is equivalent to `ptrace(PTRACE_CONT, ..., SIGKILL);`
pub fn kill(pid: Pid) -> Result<()> {
    unsafe {
        ptrace_other(Request::PTRACE_KILL, pid, ptr::null_mut(), ptr::null_mut()).map(drop)
    }
}

/// Move the stopped tracee process forward by a single step as with 
/// `ptrace(PTRACE_SINGLESTEP, ...)`
///
/// Advances the execution of the process with PID `pid` by a single step optionally delivering a
/// signal specified by `sig`.
///
/// # Example
/// ```rust
/// use nix::sys::ptrace::step;
/// use nix::unistd::Pid;
/// use nix::sys::signal::Signal; 
/// use nix::sys::wait::*;
/// fn main() {
///     // If a process changes state to the stopped state because of a SIGUSR1 
///     // signal, this will step the process forward and forward the user 
///     // signal to the stopped process
///     match waitpid(Pid::from_raw(-1), None) {
///         Ok(WaitStatus::Stopped(pid, Signal::SIGUSR1)) => {
///             let _ = step(pid, Signal::SIGUSR1);
///         }
///         _ => {},
///     }
/// }
/// ```
pub fn step<T: Into<Option<Signal>>>(pid: Pid, sig: T) -> Result<()> {
    let data = match sig.into() {
        Some(s) => s as i32 as *mut c_void,
        None => ptr::null_mut(),
    };
    unsafe {
        ptrace_other(Request::PTRACE_SINGLESTEP, pid, ptr::null_mut(), data).map(drop)
    }
}

/// Move the stopped tracee process forward by a single step or stop at the next syscall
/// as with `ptrace(PTRACE_SYSEMU_SINGLESTEP, ...)`
///
/// Advances the execution by a single step or until the next syscall.
/// In case the tracee is stopped at a syscall, the syscall will not be executed.
/// Optionally, the signal specified by `sig` is delivered to the tracee upon continuation.
#[cfg(all(target_os = "linux", target_env = "gnu", any(target_arch = "x86", target_arch = "x86_64")))]
pub fn sysemu_step<T: Into<Option<Signal>>>(pid: Pid, sig: T) -> Result<()> {
    let data = match sig.into() {
        Some(s) => s as i32 as *mut c_void,
        None => ptr::null_mut(),
    };
    unsafe {
        ptrace_other(
            Request::PTRACE_SYSEMU_SINGLESTEP,
            pid,
            ptr::null_mut(),
            data,
        )
        .map(drop) // ignore the useless return value
    }
}

/// Reads a word from a processes memory at the given address
pub fn read(pid: Pid, addr: AddressType) -> Result<c_long> {
    ptrace_peek(Request::PTRACE_PEEKDATA, pid, addr, ptr::null_mut())
}

/// Writes a word into the processes memory at the given address
///
/// # Safety
///
/// The `data` argument is passed directly to `ptrace(2)`.  Read that man page
/// for guidance.
pub unsafe fn write(
    pid: Pid,
    addr: AddressType,
    data: *mut c_void) -> Result<()>
{
    ptrace_other(Request::PTRACE_POKEDATA, pid, addr, data).map(drop)
}