Daniel Borkmann | fe1217c | 2013-12-29 18:27:10 +0100 | [diff] [blame] | 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 | |
| 19 | static 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 | |
| 24 | struct cgroup_cls_state *task_cls_state(struct task_struct *p) |
| 25 | { |
| 26 | return css_cls_state(task_css(p, net_cls_subsys_id)); |
| 27 | } |
| 28 | EXPORT_SYMBOL_GPL(task_cls_state); |
| 29 | |
| 30 | static struct cgroup_subsys_state * |
| 31 | cgrp_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 | |
| 42 | static 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 | |
| 53 | static void cgrp_css_free(struct cgroup_subsys_state *css) |
| 54 | { |
| 55 | kfree(css_cls_state(css)); |
| 56 | } |
| 57 | |
| 58 | static 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 | |
| 69 | static 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, css, tset) { |
| 77 | task_lock(p); |
| 78 | iterate_fd(p->files, 0, update_classid, v); |
| 79 | task_unlock(p); |
| 80 | } |
| 81 | } |
| 82 | |
| 83 | static u64 read_classid(struct cgroup_subsys_state *css, struct cftype *cft) |
| 84 | { |
| 85 | return css_cls_state(css)->classid; |
| 86 | } |
| 87 | |
| 88 | static 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 | |
| 96 | static struct cftype ss_files[] = { |
| 97 | { |
| 98 | .name = "classid", |
| 99 | .read_u64 = read_classid, |
| 100 | .write_u64 = write_classid, |
| 101 | }, |
| 102 | { } /* terminate */ |
| 103 | }; |
| 104 | |
| 105 | struct cgroup_subsys net_cls_subsys = { |
| 106 | .name = "net_cls", |
| 107 | .css_alloc = cgrp_css_alloc, |
| 108 | .css_online = cgrp_css_online, |
| 109 | .css_free = cgrp_css_free, |
| 110 | .attach = cgrp_attach, |
| 111 | .subsys_id = net_cls_subsys_id, |
| 112 | .base_cftypes = ss_files, |
| 113 | .module = THIS_MODULE, |
| 114 | }; |
| 115 | |
| 116 | static int __init init_netclassid_cgroup(void) |
| 117 | { |
| 118 | return cgroup_load_subsys(&net_cls_subsys); |
| 119 | } |
| 120 | __initcall(init_netclassid_cgroup); |