xref: /DragonOS/kernel/src/namespaces/ucount.rs (revision 7b0ef10895108a0de5ff5ef3d2f93f40cf2e33a5)
1 #![allow(dead_code, unused_variables, unused_imports)]
2 use alloc::vec::Vec;
3 use core::{hash::Hash, sync::atomic::AtomicU32};
4 use system_error::SystemError;
5 
6 use alloc::sync::Arc;
7 use hashbrown::HashMap;
8 use log::warn;
9 
10 use super::user_namespace::UserNamespace;
11 use crate::libs::mutex::Mutex;
12 
13 #[derive(Clone, Copy)]
14 pub enum Ucount {
15     UserNamespaces = 1,
16     PidNamespaces = 2,
17     UtsNamespaces = 3,
18     IpcNamespaces = 4,
19     NetNamespaces = 5,
20     MntNamespaces = 6,
21     CgroupNamespaces = 7,
22     TimeNamespaces = 8,
23     Counts = 9,
24 }
25 
26 pub enum UcountRlimit {
27     Nproc = 1,
28     Msgqueue = 2,
29     Sigpending = 3,
30     Memlock = 4,
31     Counts = 5,
32 }
33 
34 lazy_static! {
35     static ref COUNT_MANAGER: Arc<CountManager> = Arc::new(CountManager::new());
36 }
37 
38 #[derive(Debug)]
39 pub struct UCounts {
40     /// 对应的user_namespace
41     ns: Arc<UserNamespace>,
42     /// 用户标识符
43     uid: usize,
44     count: AtomicU32,
45     ucount: Vec<AtomicU32>, //[AtomicU32; UCOUNT_COUNTS as usize],
46     rlimit: Vec<AtomicU32>, //[AtomicU32; UCOUNT_RLIMIT_COUNTS as usize],
47 }
48 
49 impl Default for UCounts {
50     fn default() -> Self {
51         Self::new()
52     }
53 }
54 impl UCounts {
55     pub fn new() -> Self {
56         Self {
57             ns: Arc::new(UserNamespace::new()),
58             uid: 0,
59             count: AtomicU32::new(1),
60             ucount: (0..Ucount::Counts as usize)
61                 .map(|_| AtomicU32::new(0))
62                 .collect(),
63             rlimit: (0..UcountRlimit::Counts as usize)
64                 .map(|_| AtomicU32::new(0))
65                 .collect(),
66         }
67     }
68 
69     fn alloc_ucounts(&self, ns: Arc<UserNamespace>, uid: usize) -> Arc<Self> {
70         let mut counts = COUNT_MANAGER.counts.lock();
71         let key = UKey {
72             user_ns: ns.clone(),
73             uid,
74         };
75         let uc = if let Some(uc) = counts.get(&key) {
76             self.count
77                 .fetch_add(1, core::sync::atomic::Ordering::SeqCst);
78             uc.clone()
79         } else {
80             Arc::new(Self {
81                 ns,
82                 uid,
83                 count: AtomicU32::new(1),
84                 ucount: (0..Ucount::Counts as usize)
85                     .map(|_| AtomicU32::new(0))
86                     .collect(),
87                 rlimit: (0..UcountRlimit::Counts as usize)
88                     .map(|_| AtomicU32::new(0))
89                     .collect(),
90             })
91         };
92         counts.insert(key, uc.clone());
93         uc
94     }
95 
96     pub fn inc_ucounts(
97         &self,
98         user_ns: Arc<UserNamespace>,
99         uid: usize,
100         ucount_type: Ucount,
101     ) -> Option<Arc<UCounts>> {
102         let uc_type = ucount_type as usize;
103         let uc = self.alloc_ucounts(user_ns, uid);
104         let mut uc_iter = Some(uc.clone());
105         let mut ucounts_add = vec![];
106         while let Some(iter) = uc_iter {
107             let num = iter.ucount[uc_type].fetch_add(1, core::sync::atomic::Ordering::SeqCst);
108             ucounts_add.push(iter.clone());
109             // 分配失败回滚
110             if num > iter.ns.ucount_max[uc_type] {
111                 for add_iter in &ucounts_add {
112                     add_iter.ucount[uc_type].fetch_sub(1, core::sync::atomic::Ordering::SeqCst);
113                 }
114                 return None;
115             }
116             uc_iter = iter.ns.ucounts.clone();
117         }
118         return Some(uc);
119     }
120 
121     fn find_ucounts(user_ns: Arc<UserNamespace>, uid: usize) -> Option<Arc<UCounts>> {
122         let counts = COUNT_MANAGER.counts.lock();
123         let key = UKey { user_ns, uid };
124         counts.get(&key).cloned()
125     }
126 
127     fn get_ucounts(uc: Arc<UCounts>) {
128         let mut counts = COUNT_MANAGER.counts.lock();
129         let ukey = UKey {
130             user_ns: uc.ns.clone(),
131             uid: uc.uid,
132         };
133         counts.insert(ukey, uc);
134     }
135 
136     pub fn dec_ucount(uc: Arc<UCounts>, ucount_type: Ucount) {
137         let mut uc_iter = Some(uc.clone());
138         let uc_type = ucount_type as usize;
139         while let Some(iter) = uc_iter {
140             let num = iter.ucount[uc_type].fetch_sub(1, core::sync::atomic::Ordering::SeqCst);
141             if num == 0 {
142                 warn!("count has reached zero");
143             }
144             uc_iter = iter.ns.ucounts.clone();
145         }
146         Self::put_ucounts(uc);
147     }
148 
149     fn put_ucounts(uc: Arc<UCounts>) {
150         let mut counts = COUNT_MANAGER.counts.lock();
151         let key = UKey {
152             user_ns: uc.ns.clone(),
153             uid: uc.uid,
154         };
155         counts.remove(&key);
156     }
157 }
158 struct UKey {
159     user_ns: Arc<UserNamespace>,
160     uid: usize,
161 }
162 
163 impl Hash for UKey {
164     fn hash<H: core::hash::Hasher>(&self, state: &mut H) {
165         let user_ns_ptr = Arc::as_ptr(&self.user_ns);
166         user_ns_ptr.hash(state);
167         self.uid.hash(state)
168     }
169 }
170 impl Eq for UKey {}
171 impl PartialEq for UKey {
172     fn eq(&self, other: &Self) -> bool {
173         Arc::ptr_eq(&self.user_ns, &other.user_ns) && self.uid == other.uid
174     }
175 }
176 
177 struct CountManager {
178     counts: Mutex<HashMap<UKey, Arc<UCounts>>>,
179 }
180 
181 impl CountManager {
182     fn new() -> Self {
183         Self {
184             counts: Mutex::new(HashMap::new()),
185         }
186     }
187 }
188