Loading...
1/*
2 * net/core/netclassid_cgroup.c Classid Cgroupfs Handling
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 *
9 * Authors: Thomas Graf <tgraf@suug.ch>
10 */
11
12#include <linux/module.h>
13#include <linux/slab.h>
14#include <linux/cgroup.h>
15#include <linux/fdtable.h>
16#include <net/cls_cgroup.h>
17#include <net/sock.h>
18
19static inline struct cgroup_cls_state *css_cls_state(struct cgroup_subsys_state *css)
20{
21 return css ? container_of(css, struct cgroup_cls_state, css) : NULL;
22}
23
24struct cgroup_cls_state *task_cls_state(struct task_struct *p)
25{
26 return css_cls_state(task_css(p, net_cls_cgrp_id));
27}
28EXPORT_SYMBOL_GPL(task_cls_state);
29
30static struct cgroup_subsys_state *
31cgrp_css_alloc(struct cgroup_subsys_state *parent_css)
32{
33 struct cgroup_cls_state *cs;
34
35 cs = kzalloc(sizeof(*cs), GFP_KERNEL);
36 if (!cs)
37 return ERR_PTR(-ENOMEM);
38
39 return &cs->css;
40}
41
42static int cgrp_css_online(struct cgroup_subsys_state *css)
43{
44 struct cgroup_cls_state *cs = css_cls_state(css);
45 struct cgroup_cls_state *parent = css_cls_state(css_parent(css));
46
47 if (parent)
48 cs->classid = parent->classid;
49
50 return 0;
51}
52
53static void cgrp_css_free(struct cgroup_subsys_state *css)
54{
55 kfree(css_cls_state(css));
56}
57
58static int update_classid(const void *v, struct file *file, unsigned n)
59{
60 int err;
61 struct socket *sock = sock_from_file(file, &err);
62
63 if (sock)
64 sock->sk->sk_classid = (u32)(unsigned long)v;
65
66 return 0;
67}
68
69static void cgrp_attach(struct cgroup_subsys_state *css,
70 struct cgroup_taskset *tset)
71{
72 struct cgroup_cls_state *cs = css_cls_state(css);
73 void *v = (void *)(unsigned long)cs->classid;
74 struct task_struct *p;
75
76 cgroup_taskset_for_each(p, tset) {
77 task_lock(p);
78 iterate_fd(p->files, 0, update_classid, v);
79 task_unlock(p);
80 }
81}
82
83static u64 read_classid(struct cgroup_subsys_state *css, struct cftype *cft)
84{
85 return css_cls_state(css)->classid;
86}
87
88static int write_classid(struct cgroup_subsys_state *css, struct cftype *cft,
89 u64 value)
90{
91 css_cls_state(css)->classid = (u32) value;
92
93 return 0;
94}
95
96static struct cftype ss_files[] = {
97 {
98 .name = "classid",
99 .read_u64 = read_classid,
100 .write_u64 = write_classid,
101 },
102 { } /* terminate */
103};
104
105struct cgroup_subsys net_cls_cgrp_subsys = {
106 .css_alloc = cgrp_css_alloc,
107 .css_online = cgrp_css_online,
108 .css_free = cgrp_css_free,
109 .attach = cgrp_attach,
110 .base_cftypes = ss_files,
111};
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * net/core/netclassid_cgroup.c Classid Cgroupfs Handling
4 *
5 * Authors: Thomas Graf <tgraf@suug.ch>
6 */
7
8#include <linux/slab.h>
9#include <linux/cgroup.h>
10#include <linux/fdtable.h>
11#include <linux/sched/task.h>
12
13#include <net/cls_cgroup.h>
14#include <net/sock.h>
15
16static 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
21struct cgroup_cls_state *task_cls_state(struct task_struct *p)
22{
23 return css_cls_state(task_css_check(p, net_cls_cgrp_id,
24 rcu_read_lock_bh_held()));
25}
26EXPORT_SYMBOL_GPL(task_cls_state);
27
28static struct cgroup_subsys_state *
29cgrp_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
40static int cgrp_css_online(struct cgroup_subsys_state *css)
41{
42 struct cgroup_cls_state *cs = css_cls_state(css);
43 struct cgroup_cls_state *parent = css_cls_state(css->parent);
44
45 if (parent)
46 cs->classid = parent->classid;
47
48 return 0;
49}
50
51static void cgrp_css_free(struct cgroup_subsys_state *css)
52{
53 kfree(css_cls_state(css));
54}
55
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
62struct update_classid_context {
63 u32 classid;
64 unsigned int batch;
65};
66
67#define UPDATE_CLASSID_BATCH 1000
68
69static int update_classid_sock(const void *v, struct file *file, unsigned n)
70{
71 int err;
72 struct update_classid_context *ctx = (void *)v;
73 struct socket *sock = sock_from_file(file, &err);
74
75 if (sock) {
76 spin_lock(&cgroup_sk_update_lock);
77 sock_cgroup_set_classid(&sock->sk->sk_cgrp_data, ctx->classid);
78 spin_unlock(&cgroup_sk_update_lock);
79 }
80 if (--ctx->batch == 0) {
81 ctx->batch = UPDATE_CLASSID_BATCH;
82 return n + 1;
83 }
84 return 0;
85}
86
87static 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
103static void cgrp_attach(struct cgroup_taskset *tset)
104{
105 struct cgroup_subsys_state *css;
106 struct task_struct *p;
107
108 cgroup_taskset_for_each(p, css, tset) {
109 update_classid_task(p, css_cls_state(css)->classid);
110 }
111}
112
113static u64 read_classid(struct cgroup_subsys_state *css, struct cftype *cft)
114{
115 return css_cls_state(css)->classid;
116}
117
118static int write_classid(struct cgroup_subsys_state *css, struct cftype *cft,
119 u64 value)
120{
121 struct cgroup_cls_state *cs = css_cls_state(css);
122 struct css_task_iter it;
123 struct task_struct *p;
124
125 cgroup_sk_alloc_disable();
126
127 cs->classid = (u32)value;
128
129 css_task_iter_start(css, 0, &it);
130 while ((p = css_task_iter_next(&it)))
131 update_classid_task(p, cs->classid);
132 css_task_iter_end(&it);
133
134 return 0;
135}
136
137static struct cftype ss_files[] = {
138 {
139 .name = "classid",
140 .read_u64 = read_classid,
141 .write_u64 = write_classid,
142 },
143 { } /* terminate */
144};
145
146struct cgroup_subsys net_cls_cgrp_subsys = {
147 .css_alloc = cgrp_css_alloc,
148 .css_online = cgrp_css_online,
149 .css_free = cgrp_css_free,
150 .attach = cgrp_attach,
151 .legacy_cftypes = ss_files,
152};