summaryrefslogtreecommitdiff
path: root/src/sys/ptrace.rs
blob: 4bb7e06f60ae0b5777780bd77ab09bdc9bf82830 (plain)
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
//! For detailed description of the ptrace requests, consult `man ptrace`.

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


cfg_if! {
    if #[cfg(any(all(target_os = "linux", 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 = "s390x",
                                               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 = "s390x",
                                               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 = "s390x",
                                               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 = "s390x",
                                               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 = "arm",
                                           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 = "arm",
                                           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,
    }
}

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;
    }
}

/// Performs a ptrace request. If the request in question is provided by a specialised function
/// this function will return an unsupported operation error.
#[deprecated(
    since="0.10.0",
    note="usages of `ptrace()` should be replaced with the specialized helper functions instead"
)]
pub unsafe fn ptrace(request: Request, pid: Pid, addr: *mut c_void, data: *mut c_void) -> Result<c_long> {
    use self::Request::*;
    match request {
        PTRACE_PEEKTEXT | PTRACE_PEEKDATA | PTRACE_PEEKUSER => ptrace_peek(request, pid, addr, data),
        PTRACE_GETSIGINFO | PTRACE_GETEVENTMSG | PTRACE_SETSIGINFO | PTRACE_SETOPTIONS => Err(Error::UnsupportedOperation),
        _ => ptrace_other(request, pid, addr, data)
    }
}

fn ptrace_peek(request: Request, pid: Pid, addr: *mut c_void, 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(Error::Sys(Errno::UnknownErrno)) => Ok(ret),
        err @ Err(..) => err,
    }
}

/// 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> {
    // Creates an uninitialized pointer to store result in
    let data: T = unsafe { mem::uninitialized() };
    let res = unsafe {
        libc::ptrace(request as RequestType,
                     libc::pid_t::from(pid),
                     ptr::null_mut::<T>(),
                     &data as *const _ as *const c_void)
    };
    Errno::result(res)?;
    Ok(data)
}

unsafe fn ptrace_other(request: Request, pid: Pid, addr: *mut c_void, 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<()> {
    use std::ptr;

    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(|_| ())
}

/// 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(|_| ()) // ignore the useless return value
    }
}

/// Ask for 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.
pub fn syscall(pid: Pid) -> Result<()> {
    unsafe {
        ptrace_other(
            Request::PTRACE_SYSCALL,
            pid,
            ptr::null_mut(),
            ptr::null_mut(),
        ).map(|_| ()) // ignore the useless return value
    }
}

/// Attach to a running process, as with `ptrace(PTRACE_ATTACH, ...)`
///
/// Attaches to the process specified in 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(|_| ()) // ignore the useless return value
    }
}

/// Detaches the current running process, as with `ptrace(PTRACE_DETACH, ...)`
///
/// Detaches from the process specified in pid allowing it to run freely
pub fn detach(pid: Pid) -> Result<()> {
    unsafe {
        ptrace_other(
            Request::PTRACE_DETACH,
            pid,
            ptr::null_mut(),
            ptr::null_mut()
        ).map(|_| ())
    }
}

/// 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(|_| ()) // ignore the useless return value
    }
}

/// 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
/// extern crate nix;
/// 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(|_| ())
    }
}