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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
fe1217c4 DB |
2 | /* |
3 | * net/core/netclassid_cgroup.c Classid Cgroupfs Handling | |
4 | * | |
fe1217c4 DB |
5 | * Authors: Thomas Graf <tgraf@suug.ch> |
6 | */ | |
7 | ||
fe1217c4 DB |
8 | #include <linux/slab.h> |
9 | #include <linux/cgroup.h> | |
10 | #include <linux/fdtable.h> | |
f719ff9b IM |
11 | #include <linux/sched/task.h> |
12 | ||
fe1217c4 DB |
13 | #include <net/cls_cgroup.h> |
14 | #include <net/sock.h> | |
15 | ||
16 | static inline struct cgroup_cls_state *css_cls_state(struct cgroup_subsys_state *css) | |
17 | { | |
18 | return css ? container_of(css, struct cgroup_cls_state, css) : NULL; | |
19 | } | |
20 | ||
21 | struct cgroup_cls_state *task_cls_state(struct task_struct *p) | |
22 | { | |
cc9f4daa KK |
23 | return css_cls_state(task_css_check(p, net_cls_cgrp_id, |
24 | rcu_read_lock_bh_held())); | |
fe1217c4 DB |
25 | } |
26 | EXPORT_SYMBOL_GPL(task_cls_state); | |
27 | ||
28 | static struct cgroup_subsys_state * | |
29 | cgrp_css_alloc(struct cgroup_subsys_state *parent_css) | |
30 | { | |
31 | struct cgroup_cls_state *cs; | |
32 | ||
33 | cs = kzalloc(sizeof(*cs), GFP_KERNEL); | |
34 | if (!cs) | |
35 | return ERR_PTR(-ENOMEM); | |
36 | ||
37 | return &cs->css; | |
38 | } | |
39 | ||
40 | static int cgrp_css_online(struct cgroup_subsys_state *css) | |
41 | { | |
42 | struct cgroup_cls_state *cs = css_cls_state(css); | |
5c9d535b | 43 | struct cgroup_cls_state *parent = css_cls_state(css->parent); |
fe1217c4 DB |
44 | |
45 | if (parent) | |
46 | cs->classid = parent->classid; | |
47 | ||
48 | return 0; | |
49 | } | |
50 | ||
51 | static void cgrp_css_free(struct cgroup_subsys_state *css) | |
52 | { | |
53 | kfree(css_cls_state(css)); | |
54 | } | |
55 | ||
018d26fc DY |
56 | /* |
57 | * To avoid freezing of sockets creation for tasks with big number of threads | |
58 | * and opened sockets lets release file_lock every 1000 iterated descriptors. | |
59 | * New sockets will already have been created with new classid. | |
60 | */ | |
61 | ||
62 | struct update_classid_context { | |
63 | u32 classid; | |
64 | unsigned int batch; | |
65 | }; | |
66 | ||
67 | #define UPDATE_CLASSID_BATCH 1000 | |
68 | ||
3b13758f | 69 | static int update_classid_sock(const void *v, struct file *file, unsigned n) |
fe1217c4 DB |
70 | { |
71 | int err; | |
018d26fc | 72 | struct update_classid_context *ctx = (void *)v; |
fe1217c4 DB |
73 | struct socket *sock = sock_from_file(file, &err); |
74 | ||
bd1060a1 TH |
75 | if (sock) { |
76 | spin_lock(&cgroup_sk_update_lock); | |
018d26fc | 77 | sock_cgroup_set_classid(&sock->sk->sk_cgrp_data, ctx->classid); |
bd1060a1 TH |
78 | spin_unlock(&cgroup_sk_update_lock); |
79 | } | |
018d26fc DY |
80 | if (--ctx->batch == 0) { |
81 | ctx->batch = UPDATE_CLASSID_BATCH; | |
82 | return n + 1; | |
83 | } | |
fe1217c4 DB |
84 | return 0; |
85 | } | |
86 | ||
018d26fc DY |
87 | static void update_classid_task(struct task_struct *p, u32 classid) |
88 | { | |
89 | struct update_classid_context ctx = { | |
90 | .classid = classid, | |
91 | .batch = UPDATE_CLASSID_BATCH | |
92 | }; | |
93 | unsigned int fd = 0; | |
94 | ||
95 | do { | |
96 | task_lock(p); | |
97 | fd = iterate_fd(p->files, fd, update_classid_sock, &ctx); | |
98 | task_unlock(p); | |
99 | cond_resched(); | |
100 | } while (fd); | |
101 | } | |
102 | ||
a05d4fd9 | 103 | static void cgrp_attach(struct cgroup_taskset *tset) |
fe1217c4 | 104 | { |
a05d4fd9 | 105 | struct cgroup_subsys_state *css; |
fe1217c4 DB |
106 | struct task_struct *p; |
107 | ||
a05d4fd9 | 108 | cgroup_taskset_for_each(p, css, tset) { |
018d26fc | 109 | update_classid_task(p, css_cls_state(css)->classid); |
fe1217c4 DB |
110 | } |
111 | } | |
112 | ||
113 | static u64 read_classid(struct cgroup_subsys_state *css, struct cftype *cft) | |
114 | { | |
115 | return css_cls_state(css)->classid; | |
116 | } | |
117 | ||
118 | static int write_classid(struct cgroup_subsys_state *css, struct cftype *cft, | |
119 | u64 value) | |
120 | { | |
3b13758f | 121 | struct cgroup_cls_state *cs = css_cls_state(css); |
a05d4fd9 TH |
122 | struct css_task_iter it; |
123 | struct task_struct *p; | |
3b13758f | 124 | |
bd1060a1 TH |
125 | cgroup_sk_alloc_disable(); |
126 | ||
3b13758f | 127 | cs->classid = (u32)value; |
fe1217c4 | 128 | |
bc2fb7ed | 129 | css_task_iter_start(css, 0, &it); |
a05d4fd9 | 130 | while ((p = css_task_iter_next(&it))) { |
018d26fc | 131 | update_classid_task(p, cs->classid); |
a90e90b7 | 132 | cond_resched(); |
a05d4fd9 TH |
133 | } |
134 | css_task_iter_end(&it); | |
135 | ||
fe1217c4 DB |
136 | return 0; |
137 | } | |
138 | ||
139 | static struct cftype ss_files[] = { | |
140 | { | |
141 | .name = "classid", | |
142 | .read_u64 = read_classid, | |
143 | .write_u64 = write_classid, | |
144 | }, | |
145 | { } /* terminate */ | |
146 | }; | |
147 | ||
073219e9 | 148 | struct cgroup_subsys net_cls_cgrp_subsys = { |
fe1217c4 DB |
149 | .css_alloc = cgrp_css_alloc, |
150 | .css_online = cgrp_css_online, | |
151 | .css_free = cgrp_css_free, | |
152 | .attach = cgrp_attach, | |
5577964e | 153 | .legacy_cftypes = ss_files, |
fe1217c4 | 154 | }; |