Mercurial > crates > nonstick
annotate src/module.rs @ 7:9380392b9a60
Changes type marker parameter type from Option<T> to PhantomData<T>
| author | Jesse Hallett <jesse@galois.com> |
|---|---|
| date | Fri, 03 Apr 2015 23:33:20 -0700 |
| parents | 2ec97116d72c |
| children | a83c56216e21 |
| rev | line source |
|---|---|
| 1 | 1 //! Functions for use in pam modules. |
| 2 | |
| 3 use libc::{c_char}; | |
| 4 use std::{mem, ptr}; | |
| 5 use std::ffi::{CStr, CString}; | |
|
7
9380392b9a60
Changes type marker parameter type from Option<T> to PhantomData<T>
Jesse Hallett <jesse@galois.com>
parents:
6
diff
changeset
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6 use std::marker::{PhantomData}; |
| 1 | 7 |
| 8 use constants; | |
| 9 use constants::*; | |
| 10 | |
| 11 /// Opaque type, used as a pointer when making pam API calls. | |
| 12 /// | |
| 13 /// A module is invoked via an external function such as `pam_sm_authenticate`. | |
| 14 /// Such a call provides a pam handle pointer. The same pointer should be given | |
| 15 /// as an argument when making API calls. | |
| 16 #[allow(missing_copy_implementations)] | |
| 17 pub enum PamHandleT {} | |
| 18 | |
| 19 #[allow(missing_copy_implementations)] | |
| 20 enum PamItemT {} | |
| 21 | |
| 22 #[allow(missing_copy_implementations)] | |
| 23 pub enum PamDataT {} | |
| 24 | |
| 25 #[link(name = "pam")] | |
| 26 extern { | |
| 27 fn pam_get_data(pamh: *const PamHandleT, | |
| 28 module_data_name: *const c_char, | |
|
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2ec97116d72c
Updates for rustc 1.0.0-beta
Jesse Hallett <jesse@galois.com>
parents:
1
diff
changeset
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29 data: &mut *const PamDataT, |
| 1 | 30 ) -> PamResultCode; |
| 31 | |
| 32 fn pam_set_data(pamh: *const PamHandleT, | |
| 33 module_data_name: *const c_char, | |
| 34 data: Box<PamDataT>, | |
| 35 cleanup: extern fn (pamh: *const PamHandleT, | |
| 36 data: Box<PamDataT>, | |
| 37 error_status: PamResultCode | |
| 38 ), | |
| 39 ) -> PamResultCode; | |
| 40 | |
| 41 fn pam_get_item(pamh: *const PamHandleT, | |
| 42 item_type: PamItemType, | |
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2ec97116d72c
Updates for rustc 1.0.0-beta
Jesse Hallett <jesse@galois.com>
parents:
1
diff
changeset
|
43 item: &mut *const PamItemT, |
| 1 | 44 ) -> PamResultCode; |
| 45 | |
| 46 fn pam_set_item(pamh: *mut PamHandleT, | |
| 47 item_type: PamItemType, | |
| 48 item: &PamItemT, | |
| 49 ) -> PamResultCode; | |
| 50 | |
| 51 fn pam_get_user(pamh: *const PamHandleT, | |
| 52 user: & *mut c_char, | |
| 53 prompt: *const c_char, | |
| 54 ) -> PamResultCode; | |
| 55 } | |
| 56 | |
| 57 pub type PamResult<T> = Result<T, PamResultCode>; | |
| 58 | |
| 59 /// Type-level mapping for safely retrieving values with `get_item`. | |
| 60 /// | |
| 61 /// See `pam_get_item` in | |
| 62 /// http://www.linux-pam.org/Linux-PAM-html/mwg-expected-by-module-item.html | |
| 63 pub trait PamItem { | |
| 64 /// Maps a Rust type to a pam constant. | |
| 65 /// | |
| 66 /// For example, the type PamConv maps to the constant PAM_CONV. The pam | |
| 67 /// API contract specifies that when the API function `pam_get_item` is | |
| 68 /// called with the constant PAM_CONV, it will return a value of type | |
| 69 /// `PamConv`. | |
|
7
9380392b9a60
Changes type marker parameter type from Option<T> to PhantomData<T>
Jesse Hallett <jesse@galois.com>
parents:
6
diff
changeset
|
70 fn item_type(_: PhantomData<Self>) -> PamItemType; |
| 1 | 71 } |
| 72 | |
| 73 /// Gets some value, identified by `key`, that has been set by the module | |
| 74 /// previously. | |
| 75 /// | |
| 76 /// See `pam_get_data` in | |
| 77 /// http://www.linux-pam.org/Linux-PAM-html/mwg-expected-by-module-item.html | |
| 78 pub unsafe fn get_data<'a, T>(pamh: &'a PamHandleT, key: &str) -> PamResult<&'a T> { | |
| 79 let c_key = CString::new(key).unwrap().as_ptr(); | |
|
6
2ec97116d72c
Updates for rustc 1.0.0-beta
Jesse Hallett <jesse@galois.com>
parents:
1
diff
changeset
|
80 let mut ptr: *const PamDataT = ptr::null(); |
| 1 | 81 let res = pam_get_data(pamh, c_key, &mut ptr); |
| 82 if constants::PAM_SUCCESS == res && !ptr.is_null() { | |
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6
2ec97116d72c
Updates for rustc 1.0.0-beta
Jesse Hallett <jesse@galois.com>
parents:
1
diff
changeset
|
83 let typed_ptr: *const T = mem::transmute(ptr); |
|
2ec97116d72c
Updates for rustc 1.0.0-beta
Jesse Hallett <jesse@galois.com>
parents:
1
diff
changeset
|
84 let data: &T = &*typed_ptr; |
| 1 | 85 Ok(data) |
| 86 } | |
| 87 else { | |
| 88 Err(res) | |
| 89 } | |
| 90 } | |
| 91 | |
| 92 /// Stores a value that can be retrieved later with `get_data`. The value lives | |
| 93 /// as long as the current pam cycle. | |
| 94 /// | |
| 95 /// See `pam_set_data` in | |
| 96 /// http://www.linux-pam.org/Linux-PAM-html/mwg-expected-by-module-item.html | |
| 97 pub fn set_data<T>(pamh: &PamHandleT, key: &str, data: Box<T>) -> PamResult<()> { | |
| 98 let c_key = CString::new(key).unwrap().as_ptr(); | |
| 99 let res = unsafe { | |
| 100 let c_data: Box<PamDataT> = mem::transmute(data); | |
| 101 pam_set_data(pamh, c_key, c_data, cleanup::<T>) | |
| 102 }; | |
| 103 if constants::PAM_SUCCESS == res { Ok(()) } else { Err(res) } | |
| 104 } | |
| 105 | |
| 106 #[no_mangle] | |
| 107 pub extern fn cleanup<T>(_: *const PamHandleT, c_data: Box<PamDataT>, _: PamResultCode) { | |
| 108 unsafe { | |
| 109 let data: Box<T> = mem::transmute(c_data); | |
| 110 mem::drop(data); | |
| 111 } | |
| 112 } | |
| 113 | |
| 114 /// Retrieves a value that has been set, possibly by the pam client. This is | |
| 115 /// particularly useful for getting a `PamConv` reference. | |
| 116 /// | |
| 117 /// See `pam_get_item` in | |
| 118 /// http://www.linux-pam.org/Linux-PAM-html/mwg-expected-by-module-item.html | |
| 119 pub fn get_item<'a, T: PamItem>(pamh: &'a PamHandleT) -> PamResult<&'a T> { | |
|
6
2ec97116d72c
Updates for rustc 1.0.0-beta
Jesse Hallett <jesse@galois.com>
parents:
1
diff
changeset
|
120 let mut ptr: *const PamItemT = ptr::null(); |
| 1 | 121 let (res, item) = unsafe { |
|
7
9380392b9a60
Changes type marker parameter type from Option<T> to PhantomData<T>
Jesse Hallett <jesse@galois.com>
parents:
6
diff
changeset
|
122 let r = pam_get_item(pamh, PamItem::item_type(PhantomData::<T>), &mut ptr); |
|
6
2ec97116d72c
Updates for rustc 1.0.0-beta
Jesse Hallett <jesse@galois.com>
parents:
1
diff
changeset
|
123 let typed_ptr: *const T = mem::transmute(ptr); |
|
2ec97116d72c
Updates for rustc 1.0.0-beta
Jesse Hallett <jesse@galois.com>
parents:
1
diff
changeset
|
124 let t: &T = &*typed_ptr; |
| 1 | 125 (r, t) |
| 126 }; | |
| 127 if constants::PAM_SUCCESS == res { Ok(item) } else { Err(res) } | |
| 128 } | |
| 129 | |
| 130 /// Retrieves the name of the user who is authenticating or logging in. | |
| 131 /// | |
| 132 /// This is really a specialization of `get_item`. | |
| 133 /// | |
| 134 /// See `pam_get_user` in | |
| 135 /// http://www.linux-pam.org/Linux-PAM-html/mwg-expected-by-module-item.html | |
| 136 pub fn get_user<'a>(pamh: &'a PamHandleT, prompt: Option<&str>) -> PamResult<String> { | |
| 137 let ptr: *mut c_char = ptr::null_mut(); | |
| 138 let c_prompt = match prompt { | |
| 139 Some(p) => CString::new(p).unwrap().as_ptr(), | |
| 140 None => ptr::null(), | |
| 141 }; | |
| 142 let res = unsafe { pam_get_user(pamh, &ptr, c_prompt) }; | |
| 143 if constants::PAM_SUCCESS == res && !ptr.is_null() { | |
| 144 let const_ptr = ptr as *const c_char; | |
| 145 let bytes = unsafe { CStr::from_ptr(const_ptr).to_bytes() }; | |
| 146 String::from_utf8(bytes.to_vec()) | |
| 147 .map_err(|_| PAM_CONV_ERR) | |
| 148 } | |
| 149 else { | |
| 150 Err(res) | |
| 151 } | |
| 152 } |