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815 lines
19 KiB
815 lines
19 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
/* |
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* kernel userspace event delivery |
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* |
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* Copyright (C) 2004 Red Hat, Inc. All rights reserved. |
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* Copyright (C) 2004 Novell, Inc. All rights reserved. |
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* Copyright (C) 2004 IBM, Inc. All rights reserved. |
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* |
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* Authors: |
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* Robert Love <[email protected]> |
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* Kay Sievers <[email protected]> |
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* Arjan van de Ven <[email protected]> |
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* Greg Kroah-Hartman <[email protected]> |
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*/ |
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|
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#include <linux/spinlock.h> |
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#include <linux/string.h> |
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#include <linux/kobject.h> |
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#include <linux/export.h> |
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#include <linux/kmod.h> |
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#include <linux/slab.h> |
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#include <linux/socket.h> |
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#include <linux/skbuff.h> |
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#include <linux/netlink.h> |
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#include <linux/uidgid.h> |
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#include <linux/uuid.h> |
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#include <linux/ctype.h> |
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#include <net/sock.h> |
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#include <net/netlink.h> |
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#include <net/net_namespace.h> |
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|
|
|
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u64 uevent_seqnum; |
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#ifdef CONFIG_UEVENT_HELPER |
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char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH; |
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#endif |
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|
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struct uevent_sock { |
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struct list_head list; |
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struct sock *sk; |
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}; |
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|
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#ifdef CONFIG_NET |
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static LIST_HEAD(uevent_sock_list); |
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#endif |
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|
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/* This lock protects uevent_seqnum and uevent_sock_list */ |
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static DEFINE_MUTEX(uevent_sock_mutex); |
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|
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/* the strings here must match the enum in include/linux/kobject.h */ |
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static const char *kobject_actions[] = { |
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[KOBJ_ADD] = "add", |
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[KOBJ_REMOVE] = "remove", |
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[KOBJ_CHANGE] = "change", |
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[KOBJ_MOVE] = "move", |
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[KOBJ_ONLINE] = "online", |
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[KOBJ_OFFLINE] = "offline", |
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[KOBJ_BIND] = "bind", |
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[KOBJ_UNBIND] = "unbind", |
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}; |
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|
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static int kobject_action_type(const char *buf, size_t count, |
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enum kobject_action *type, |
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const char **args) |
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{ |
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enum kobject_action action; |
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size_t count_first; |
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const char *args_start; |
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int ret = -EINVAL; |
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|
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if (count && (buf[count-1] == '\n' || buf[count-1] == '\0')) |
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count--; |
|
|
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if (!count) |
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goto out; |
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|
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args_start = strnchr(buf, count, ' '); |
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if (args_start) { |
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count_first = args_start - buf; |
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args_start = args_start + 1; |
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} else |
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count_first = count; |
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|
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for (action = 0; action < ARRAY_SIZE(kobject_actions); action++) { |
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if (strncmp(kobject_actions[action], buf, count_first) != 0) |
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continue; |
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if (kobject_actions[action][count_first] != '\0') |
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continue; |
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if (args) |
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*args = args_start; |
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*type = action; |
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ret = 0; |
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break; |
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} |
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out: |
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return ret; |
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} |
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|
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static const char *action_arg_word_end(const char *buf, const char *buf_end, |
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char delim) |
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{ |
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const char *next = buf; |
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|
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while (next <= buf_end && *next != delim) |
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if (!isalnum(*next++)) |
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return NULL; |
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|
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if (next == buf) |
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return NULL; |
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|
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return next; |
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} |
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|
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static int kobject_action_args(const char *buf, size_t count, |
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struct kobj_uevent_env **ret_env) |
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{ |
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struct kobj_uevent_env *env = NULL; |
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const char *next, *buf_end, *key; |
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int key_len; |
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int r = -EINVAL; |
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|
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if (count && (buf[count - 1] == '\n' || buf[count - 1] == '\0')) |
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count--; |
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|
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if (!count) |
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return -EINVAL; |
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|
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env = kzalloc(sizeof(*env), GFP_KERNEL); |
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if (!env) |
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return -ENOMEM; |
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|
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/* first arg is UUID */ |
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if (count < UUID_STRING_LEN || !uuid_is_valid(buf) || |
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add_uevent_var(env, "SYNTH_UUID=%.*s", UUID_STRING_LEN, buf)) |
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goto out; |
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|
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/* |
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* the rest are custom environment variables in KEY=VALUE |
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* format with ' ' delimiter between each KEY=VALUE pair |
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*/ |
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next = buf + UUID_STRING_LEN; |
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buf_end = buf + count - 1; |
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|
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while (next <= buf_end) { |
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if (*next != ' ') |
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goto out; |
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|
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/* skip the ' ', key must follow */ |
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key = ++next; |
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if (key > buf_end) |
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goto out; |
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|
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buf = next; |
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next = action_arg_word_end(buf, buf_end, '='); |
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if (!next || next > buf_end || *next != '=') |
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goto out; |
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key_len = next - buf; |
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|
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/* skip the '=', value must follow */ |
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if (++next > buf_end) |
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goto out; |
|
|
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buf = next; |
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next = action_arg_word_end(buf, buf_end, ' '); |
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if (!next) |
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goto out; |
|
|
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if (add_uevent_var(env, "SYNTH_ARG_%.*s=%.*s", |
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key_len, key, (int) (next - buf), buf)) |
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goto out; |
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} |
|
|
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r = 0; |
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out: |
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if (r) |
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kfree(env); |
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else |
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*ret_env = env; |
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return r; |
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} |
|
|
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/** |
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* kobject_synth_uevent - send synthetic uevent with arguments |
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* |
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* @kobj: struct kobject for which synthetic uevent is to be generated |
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* @buf: buffer containing action type and action args, newline is ignored |
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* @count: length of buffer |
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* |
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* Returns 0 if kobject_synthetic_uevent() is completed with success or the |
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* corresponding error when it fails. |
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*/ |
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int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count) |
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{ |
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char *no_uuid_envp[] = { "SYNTH_UUID=0", NULL }; |
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enum kobject_action action; |
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const char *action_args; |
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struct kobj_uevent_env *env; |
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const char *msg = NULL, *devpath; |
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int r; |
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|
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r = kobject_action_type(buf, count, &action, &action_args); |
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if (r) { |
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msg = "unknown uevent action string"; |
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goto out; |
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} |
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|
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if (!action_args) { |
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r = kobject_uevent_env(kobj, action, no_uuid_envp); |
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goto out; |
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} |
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|
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r = kobject_action_args(action_args, |
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count - (action_args - buf), &env); |
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if (r == -EINVAL) { |
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msg = "incorrect uevent action arguments"; |
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goto out; |
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} |
|
|
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if (r) |
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goto out; |
|
|
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r = kobject_uevent_env(kobj, action, env->envp); |
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kfree(env); |
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out: |
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if (r) { |
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devpath = kobject_get_path(kobj, GFP_KERNEL); |
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pr_warn("synth uevent: %s: %s\n", |
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devpath ?: "unknown device", |
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msg ?: "failed to send uevent"); |
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kfree(devpath); |
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} |
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return r; |
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} |
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|
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#ifdef CONFIG_UEVENT_HELPER |
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static int kobj_usermode_filter(struct kobject *kobj) |
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{ |
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const struct kobj_ns_type_operations *ops; |
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|
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ops = kobj_ns_ops(kobj); |
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if (ops) { |
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const void *init_ns, *ns; |
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|
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ns = kobj->ktype->namespace(kobj); |
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init_ns = ops->initial_ns(); |
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return ns != init_ns; |
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} |
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|
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return 0; |
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} |
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|
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static int init_uevent_argv(struct kobj_uevent_env *env, const char *subsystem) |
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{ |
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int buffer_size = sizeof(env->buf) - env->buflen; |
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int len; |
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|
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len = strlcpy(&env->buf[env->buflen], subsystem, buffer_size); |
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if (len >= buffer_size) { |
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pr_warn("init_uevent_argv: buffer size of %d too small, needed %d\n", |
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buffer_size, len); |
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return -ENOMEM; |
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} |
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env->argv[0] = uevent_helper; |
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env->argv[1] = &env->buf[env->buflen]; |
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env->argv[2] = NULL; |
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|
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env->buflen += len + 1; |
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return 0; |
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} |
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|
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static void cleanup_uevent_env(struct subprocess_info *info) |
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{ |
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kfree(info->data); |
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} |
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#endif |
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|
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#ifdef CONFIG_NET |
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static struct sk_buff *alloc_uevent_skb(struct kobj_uevent_env *env, |
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const char *action_string, |
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const char *devpath) |
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{ |
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struct netlink_skb_parms *parms; |
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struct sk_buff *skb = NULL; |
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char *scratch; |
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size_t len; |
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|
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/* allocate message with maximum possible size */ |
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len = strlen(action_string) + strlen(devpath) + 2; |
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skb = alloc_skb(len + env->buflen, GFP_KERNEL); |
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if (!skb) |
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return NULL; |
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|
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/* add header */ |
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scratch = skb_put(skb, len); |
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sprintf(scratch, "%s@%s", action_string, devpath); |
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|
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skb_put_data(skb, env->buf, env->buflen); |
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|
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parms = &NETLINK_CB(skb); |
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parms->creds.uid = GLOBAL_ROOT_UID; |
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parms->creds.gid = GLOBAL_ROOT_GID; |
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parms->dst_group = 1; |
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parms->portid = 0; |
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|
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return skb; |
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} |
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|
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static int uevent_net_broadcast_untagged(struct kobj_uevent_env *env, |
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const char *action_string, |
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const char *devpath) |
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{ |
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struct sk_buff *skb = NULL; |
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struct uevent_sock *ue_sk; |
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int retval = 0; |
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|
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/* send netlink message */ |
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list_for_each_entry(ue_sk, &uevent_sock_list, list) { |
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struct sock *uevent_sock = ue_sk->sk; |
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|
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if (!netlink_has_listeners(uevent_sock, 1)) |
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continue; |
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|
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if (!skb) { |
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retval = -ENOMEM; |
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skb = alloc_uevent_skb(env, action_string, devpath); |
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if (!skb) |
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continue; |
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} |
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|
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retval = netlink_broadcast(uevent_sock, skb_get(skb), 0, 1, |
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GFP_KERNEL); |
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/* ENOBUFS should be handled in userspace */ |
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if (retval == -ENOBUFS || retval == -ESRCH) |
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retval = 0; |
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} |
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consume_skb(skb); |
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|
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return retval; |
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} |
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|
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static int uevent_net_broadcast_tagged(struct sock *usk, |
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struct kobj_uevent_env *env, |
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const char *action_string, |
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const char *devpath) |
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{ |
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struct user_namespace *owning_user_ns = sock_net(usk)->user_ns; |
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struct sk_buff *skb = NULL; |
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int ret = 0; |
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|
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skb = alloc_uevent_skb(env, action_string, devpath); |
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if (!skb) |
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return -ENOMEM; |
|
|
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/* fix credentials */ |
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if (owning_user_ns != &init_user_ns) { |
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struct netlink_skb_parms *parms = &NETLINK_CB(skb); |
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kuid_t root_uid; |
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kgid_t root_gid; |
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|
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/* fix uid */ |
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root_uid = make_kuid(owning_user_ns, 0); |
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if (uid_valid(root_uid)) |
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parms->creds.uid = root_uid; |
|
|
|
/* fix gid */ |
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root_gid = make_kgid(owning_user_ns, 0); |
|
if (gid_valid(root_gid)) |
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parms->creds.gid = root_gid; |
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} |
|
|
|
ret = netlink_broadcast(usk, skb, 0, 1, GFP_KERNEL); |
|
/* ENOBUFS should be handled in userspace */ |
|
if (ret == -ENOBUFS || ret == -ESRCH) |
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ret = 0; |
|
|
|
return ret; |
|
} |
|
#endif |
|
|
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static int kobject_uevent_net_broadcast(struct kobject *kobj, |
|
struct kobj_uevent_env *env, |
|
const char *action_string, |
|
const char *devpath) |
|
{ |
|
int ret = 0; |
|
|
|
#ifdef CONFIG_NET |
|
const struct kobj_ns_type_operations *ops; |
|
const struct net *net = NULL; |
|
|
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ops = kobj_ns_ops(kobj); |
|
if (!ops && kobj->kset) { |
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struct kobject *ksobj = &kobj->kset->kobj; |
|
|
|
if (ksobj->parent != NULL) |
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ops = kobj_ns_ops(ksobj->parent); |
|
} |
|
|
|
/* kobjects currently only carry network namespace tags and they |
|
* are the only tag relevant here since we want to decide which |
|
* network namespaces to broadcast the uevent into. |
|
*/ |
|
if (ops && ops->netlink_ns && kobj->ktype->namespace) |
|
if (ops->type == KOBJ_NS_TYPE_NET) |
|
net = kobj->ktype->namespace(kobj); |
|
|
|
if (!net) |
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ret = uevent_net_broadcast_untagged(env, action_string, |
|
devpath); |
|
else |
|
ret = uevent_net_broadcast_tagged(net->uevent_sock->sk, env, |
|
action_string, devpath); |
|
#endif |
|
|
|
return ret; |
|
} |
|
|
|
static void zap_modalias_env(struct kobj_uevent_env *env) |
|
{ |
|
static const char modalias_prefix[] = "MODALIAS="; |
|
size_t len; |
|
int i, j; |
|
|
|
for (i = 0; i < env->envp_idx;) { |
|
if (strncmp(env->envp[i], modalias_prefix, |
|
sizeof(modalias_prefix) - 1)) { |
|
i++; |
|
continue; |
|
} |
|
|
|
len = strlen(env->envp[i]) + 1; |
|
|
|
if (i != env->envp_idx - 1) { |
|
memmove(env->envp[i], env->envp[i + 1], |
|
env->buflen - len); |
|
|
|
for (j = i; j < env->envp_idx - 1; j++) |
|
env->envp[j] = env->envp[j + 1] - len; |
|
} |
|
|
|
env->envp_idx--; |
|
env->buflen -= len; |
|
} |
|
} |
|
|
|
/** |
|
* kobject_uevent_env - send an uevent with environmental data |
|
* |
|
* @kobj: struct kobject that the action is happening to |
|
* @action: action that is happening |
|
* @envp_ext: pointer to environmental data |
|
* |
|
* Returns 0 if kobject_uevent_env() is completed with success or the |
|
* corresponding error when it fails. |
|
*/ |
|
int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, |
|
char *envp_ext[]) |
|
{ |
|
struct kobj_uevent_env *env; |
|
const char *action_string = kobject_actions[action]; |
|
const char *devpath = NULL; |
|
const char *subsystem; |
|
struct kobject *top_kobj; |
|
struct kset *kset; |
|
const struct kset_uevent_ops *uevent_ops; |
|
int i = 0; |
|
int retval = 0; |
|
|
|
/* |
|
* Mark "remove" event done regardless of result, for some subsystems |
|
* do not want to re-trigger "remove" event via automatic cleanup. |
|
*/ |
|
if (action == KOBJ_REMOVE) |
|
kobj->state_remove_uevent_sent = 1; |
|
|
|
pr_debug("kobject: '%s' (%p): %s\n", |
|
kobject_name(kobj), kobj, __func__); |
|
|
|
/* search the kset we belong to */ |
|
top_kobj = kobj; |
|
while (!top_kobj->kset && top_kobj->parent) |
|
top_kobj = top_kobj->parent; |
|
|
|
if (!top_kobj->kset) { |
|
pr_debug("kobject: '%s' (%p): %s: attempted to send uevent " |
|
"without kset!\n", kobject_name(kobj), kobj, |
|
__func__); |
|
return -EINVAL; |
|
} |
|
|
|
kset = top_kobj->kset; |
|
uevent_ops = kset->uevent_ops; |
|
|
|
/* skip the event, if uevent_suppress is set*/ |
|
if (kobj->uevent_suppress) { |
|
pr_debug("kobject: '%s' (%p): %s: uevent_suppress " |
|
"caused the event to drop!\n", |
|
kobject_name(kobj), kobj, __func__); |
|
return 0; |
|
} |
|
/* skip the event, if the filter returns zero. */ |
|
if (uevent_ops && uevent_ops->filter) |
|
if (!uevent_ops->filter(kset, kobj)) { |
|
pr_debug("kobject: '%s' (%p): %s: filter function " |
|
"caused the event to drop!\n", |
|
kobject_name(kobj), kobj, __func__); |
|
return 0; |
|
} |
|
|
|
/* originating subsystem */ |
|
if (uevent_ops && uevent_ops->name) |
|
subsystem = uevent_ops->name(kset, kobj); |
|
else |
|
subsystem = kobject_name(&kset->kobj); |
|
if (!subsystem) { |
|
pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the " |
|
"event to drop!\n", kobject_name(kobj), kobj, |
|
__func__); |
|
return 0; |
|
} |
|
|
|
/* environment buffer */ |
|
env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL); |
|
if (!env) |
|
return -ENOMEM; |
|
|
|
/* complete object path */ |
|
devpath = kobject_get_path(kobj, GFP_KERNEL); |
|
if (!devpath) { |
|
retval = -ENOENT; |
|
goto exit; |
|
} |
|
|
|
/* default keys */ |
|
retval = add_uevent_var(env, "ACTION=%s", action_string); |
|
if (retval) |
|
goto exit; |
|
retval = add_uevent_var(env, "DEVPATH=%s", devpath); |
|
if (retval) |
|
goto exit; |
|
retval = add_uevent_var(env, "SUBSYSTEM=%s", subsystem); |
|
if (retval) |
|
goto exit; |
|
|
|
/* keys passed in from the caller */ |
|
if (envp_ext) { |
|
for (i = 0; envp_ext[i]; i++) { |
|
retval = add_uevent_var(env, "%s", envp_ext[i]); |
|
if (retval) |
|
goto exit; |
|
} |
|
} |
|
|
|
/* let the kset specific function add its stuff */ |
|
if (uevent_ops && uevent_ops->uevent) { |
|
retval = uevent_ops->uevent(kset, kobj, env); |
|
if (retval) { |
|
pr_debug("kobject: '%s' (%p): %s: uevent() returned " |
|
"%d\n", kobject_name(kobj), kobj, |
|
__func__, retval); |
|
goto exit; |
|
} |
|
} |
|
|
|
switch (action) { |
|
case KOBJ_ADD: |
|
/* |
|
* Mark "add" event so we can make sure we deliver "remove" |
|
* event to userspace during automatic cleanup. If |
|
* the object did send an "add" event, "remove" will |
|
* automatically generated by the core, if not already done |
|
* by the caller. |
|
*/ |
|
kobj->state_add_uevent_sent = 1; |
|
break; |
|
|
|
case KOBJ_UNBIND: |
|
zap_modalias_env(env); |
|
break; |
|
|
|
default: |
|
break; |
|
} |
|
|
|
mutex_lock(&uevent_sock_mutex); |
|
/* we will send an event, so request a new sequence number */ |
|
retval = add_uevent_var(env, "SEQNUM=%llu", ++uevent_seqnum); |
|
if (retval) { |
|
mutex_unlock(&uevent_sock_mutex); |
|
goto exit; |
|
} |
|
retval = kobject_uevent_net_broadcast(kobj, env, action_string, |
|
devpath); |
|
mutex_unlock(&uevent_sock_mutex); |
|
|
|
#ifdef CONFIG_UEVENT_HELPER |
|
/* call uevent_helper, usually only enabled during early boot */ |
|
if (uevent_helper[0] && !kobj_usermode_filter(kobj)) { |
|
struct subprocess_info *info; |
|
|
|
retval = add_uevent_var(env, "HOME=/"); |
|
if (retval) |
|
goto exit; |
|
retval = add_uevent_var(env, |
|
"PATH=/sbin:/bin:/usr/sbin:/usr/bin"); |
|
if (retval) |
|
goto exit; |
|
retval = init_uevent_argv(env, subsystem); |
|
if (retval) |
|
goto exit; |
|
|
|
retval = -ENOMEM; |
|
info = call_usermodehelper_setup(env->argv[0], env->argv, |
|
env->envp, GFP_KERNEL, |
|
NULL, cleanup_uevent_env, env); |
|
if (info) { |
|
retval = call_usermodehelper_exec(info, UMH_NO_WAIT); |
|
env = NULL; /* freed by cleanup_uevent_env */ |
|
} |
|
} |
|
#endif |
|
|
|
exit: |
|
kfree(devpath); |
|
kfree(env); |
|
return retval; |
|
} |
|
EXPORT_SYMBOL_GPL(kobject_uevent_env); |
|
|
|
/** |
|
* kobject_uevent - notify userspace by sending an uevent |
|
* |
|
* @kobj: struct kobject that the action is happening to |
|
* @action: action that is happening |
|
* |
|
* Returns 0 if kobject_uevent() is completed with success or the |
|
* corresponding error when it fails. |
|
*/ |
|
int kobject_uevent(struct kobject *kobj, enum kobject_action action) |
|
{ |
|
return kobject_uevent_env(kobj, action, NULL); |
|
} |
|
EXPORT_SYMBOL_GPL(kobject_uevent); |
|
|
|
/** |
|
* add_uevent_var - add key value string to the environment buffer |
|
* @env: environment buffer structure |
|
* @format: printf format for the key=value pair |
|
* |
|
* Returns 0 if environment variable was added successfully or -ENOMEM |
|
* if no space was available. |
|
*/ |
|
int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...) |
|
{ |
|
va_list args; |
|
int len; |
|
|
|
if (env->envp_idx >= ARRAY_SIZE(env->envp)) { |
|
WARN(1, KERN_ERR "add_uevent_var: too many keys\n"); |
|
return -ENOMEM; |
|
} |
|
|
|
va_start(args, format); |
|
len = vsnprintf(&env->buf[env->buflen], |
|
sizeof(env->buf) - env->buflen, |
|
format, args); |
|
va_end(args); |
|
|
|
if (len >= (sizeof(env->buf) - env->buflen)) { |
|
WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n"); |
|
return -ENOMEM; |
|
} |
|
|
|
env->envp[env->envp_idx++] = &env->buf[env->buflen]; |
|
env->buflen += len + 1; |
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(add_uevent_var); |
|
|
|
#if defined(CONFIG_NET) |
|
static int uevent_net_broadcast(struct sock *usk, struct sk_buff *skb, |
|
struct netlink_ext_ack *extack) |
|
{ |
|
/* u64 to chars: 2^64 - 1 = 21 chars */ |
|
char buf[sizeof("SEQNUM=") + 21]; |
|
struct sk_buff *skbc; |
|
int ret; |
|
|
|
/* bump and prepare sequence number */ |
|
ret = snprintf(buf, sizeof(buf), "SEQNUM=%llu", ++uevent_seqnum); |
|
if (ret < 0 || (size_t)ret >= sizeof(buf)) |
|
return -ENOMEM; |
|
ret++; |
|
|
|
/* verify message does not overflow */ |
|
if ((skb->len + ret) > UEVENT_BUFFER_SIZE) { |
|
NL_SET_ERR_MSG(extack, "uevent message too big"); |
|
return -EINVAL; |
|
} |
|
|
|
/* copy skb and extend to accommodate sequence number */ |
|
skbc = skb_copy_expand(skb, 0, ret, GFP_KERNEL); |
|
if (!skbc) |
|
return -ENOMEM; |
|
|
|
/* append sequence number */ |
|
skb_put_data(skbc, buf, ret); |
|
|
|
/* remove msg header */ |
|
skb_pull(skbc, NLMSG_HDRLEN); |
|
|
|
/* set portid 0 to inform userspace message comes from kernel */ |
|
NETLINK_CB(skbc).portid = 0; |
|
NETLINK_CB(skbc).dst_group = 1; |
|
|
|
ret = netlink_broadcast(usk, skbc, 0, 1, GFP_KERNEL); |
|
/* ENOBUFS should be handled in userspace */ |
|
if (ret == -ENOBUFS || ret == -ESRCH) |
|
ret = 0; |
|
|
|
return ret; |
|
} |
|
|
|
static int uevent_net_rcv_skb(struct sk_buff *skb, struct nlmsghdr *nlh, |
|
struct netlink_ext_ack *extack) |
|
{ |
|
struct net *net; |
|
int ret; |
|
|
|
if (!nlmsg_data(nlh)) |
|
return -EINVAL; |
|
|
|
/* |
|
* Verify that we are allowed to send messages to the target |
|
* network namespace. The caller must have CAP_SYS_ADMIN in the |
|
* owning user namespace of the target network namespace. |
|
*/ |
|
net = sock_net(NETLINK_CB(skb).sk); |
|
if (!netlink_ns_capable(skb, net->user_ns, CAP_SYS_ADMIN)) { |
|
NL_SET_ERR_MSG(extack, "missing CAP_SYS_ADMIN capability"); |
|
return -EPERM; |
|
} |
|
|
|
mutex_lock(&uevent_sock_mutex); |
|
ret = uevent_net_broadcast(net->uevent_sock->sk, skb, extack); |
|
mutex_unlock(&uevent_sock_mutex); |
|
|
|
return ret; |
|
} |
|
|
|
static void uevent_net_rcv(struct sk_buff *skb) |
|
{ |
|
netlink_rcv_skb(skb, &uevent_net_rcv_skb); |
|
} |
|
|
|
static int uevent_net_init(struct net *net) |
|
{ |
|
struct uevent_sock *ue_sk; |
|
struct netlink_kernel_cfg cfg = { |
|
.groups = 1, |
|
.input = uevent_net_rcv, |
|
.flags = NL_CFG_F_NONROOT_RECV |
|
}; |
|
|
|
ue_sk = kzalloc(sizeof(*ue_sk), GFP_KERNEL); |
|
if (!ue_sk) |
|
return -ENOMEM; |
|
|
|
ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT, &cfg); |
|
if (!ue_sk->sk) { |
|
pr_err("kobject_uevent: unable to create netlink socket!\n"); |
|
kfree(ue_sk); |
|
return -ENODEV; |
|
} |
|
|
|
net->uevent_sock = ue_sk; |
|
|
|
/* Restrict uevents to initial user namespace. */ |
|
if (sock_net(ue_sk->sk)->user_ns == &init_user_ns) { |
|
mutex_lock(&uevent_sock_mutex); |
|
list_add_tail(&ue_sk->list, &uevent_sock_list); |
|
mutex_unlock(&uevent_sock_mutex); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static void uevent_net_exit(struct net *net) |
|
{ |
|
struct uevent_sock *ue_sk = net->uevent_sock; |
|
|
|
if (sock_net(ue_sk->sk)->user_ns == &init_user_ns) { |
|
mutex_lock(&uevent_sock_mutex); |
|
list_del(&ue_sk->list); |
|
mutex_unlock(&uevent_sock_mutex); |
|
} |
|
|
|
netlink_kernel_release(ue_sk->sk); |
|
kfree(ue_sk); |
|
} |
|
|
|
static struct pernet_operations uevent_net_ops = { |
|
.init = uevent_net_init, |
|
.exit = uevent_net_exit, |
|
}; |
|
|
|
static int __init kobject_uevent_init(void) |
|
{ |
|
return register_pernet_subsys(&uevent_net_ops); |
|
} |
|
|
|
|
|
postcore_initcall(kobject_uevent_init); |
|
#endif
|
|
|