mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 19:29:37 +00:00
![Harshit Mogalapalli](/assets/img/avatar_default.png)
[ Upstream commit f123cffdd8
]
Adding a check on len parameter to avoid empty skb. This prevents a
division error in netem_enqueue function which is caused when skb->len=0
and skb->data_len=0 in the randomized corruption step as shown below.
skb->data[prandom_u32() % skb_headlen(skb)] ^= 1<<(prandom_u32() % 8);
Crash Report:
[ 343.170349] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family
0 port 6081 - 0
[ 343.216110] netem: version 1.3
[ 343.235841] divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI
[ 343.236680] CPU: 3 PID: 4288 Comm: reproducer Not tainted 5.16.0-rc1+
[ 343.237569] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 1.11.0-2.el7 04/01/2014
[ 343.238707] RIP: 0010:netem_enqueue+0x1590/0x33c0 [sch_netem]
[ 343.239499] Code: 89 85 58 ff ff ff e8 5f 5d e9 d3 48 8b b5 48 ff ff
ff 8b 8d 50 ff ff ff 8b 85 58 ff ff ff 48 8b bd 70 ff ff ff 31 d2 2b 4f
74 <f7> f1 48 b8 00 00 00 00 00 fc ff df 49 01 d5 4c 89 e9 48 c1 e9 03
[ 343.241883] RSP: 0018:ffff88800bcd7368 EFLAGS: 00010246
[ 343.242589] RAX: 00000000ba7c0a9c RBX: 0000000000000001 RCX:
0000000000000000
[ 343.243542] RDX: 0000000000000000 RSI: ffff88800f8edb10 RDI:
ffff88800f8eda40
[ 343.244474] RBP: ffff88800bcd7458 R08: 0000000000000000 R09:
ffffffff94fb8445
[ 343.245403] R10: ffffffff94fb8336 R11: ffffffff94fb8445 R12:
0000000000000000
[ 343.246355] R13: ffff88800a5a7000 R14: ffff88800a5b5800 R15:
0000000000000020
[ 343.247291] FS: 00007fdde2bd7700(0000) GS:ffff888109780000(0000)
knlGS:0000000000000000
[ 343.248350] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 343.249120] CR2: 00000000200000c0 CR3: 000000000ef4c000 CR4:
00000000000006e0
[ 343.250076] Call Trace:
[ 343.250423] <TASK>
[ 343.250713] ? memcpy+0x4d/0x60
[ 343.251162] ? netem_init+0xa0/0xa0 [sch_netem]
[ 343.251795] ? __sanitizer_cov_trace_pc+0x21/0x60
[ 343.252443] netem_enqueue+0xe28/0x33c0 [sch_netem]
[ 343.253102] ? stack_trace_save+0x87/0xb0
[ 343.253655] ? filter_irq_stacks+0xb0/0xb0
[ 343.254220] ? netem_init+0xa0/0xa0 [sch_netem]
[ 343.254837] ? __kasan_check_write+0x14/0x20
[ 343.255418] ? _raw_spin_lock+0x88/0xd6
[ 343.255953] dev_qdisc_enqueue+0x50/0x180
[ 343.256508] __dev_queue_xmit+0x1a7e/0x3090
[ 343.257083] ? netdev_core_pick_tx+0x300/0x300
[ 343.257690] ? check_kcov_mode+0x10/0x40
[ 343.258219] ? _raw_spin_unlock_irqrestore+0x29/0x40
[ 343.258899] ? __kasan_init_slab_obj+0x24/0x30
[ 343.259529] ? setup_object.isra.71+0x23/0x90
[ 343.260121] ? new_slab+0x26e/0x4b0
[ 343.260609] ? kasan_poison+0x3a/0x50
[ 343.261118] ? kasan_unpoison+0x28/0x50
[ 343.261637] ? __kasan_slab_alloc+0x71/0x90
[ 343.262214] ? memcpy+0x4d/0x60
[ 343.262674] ? write_comp_data+0x2f/0x90
[ 343.263209] ? __kasan_check_write+0x14/0x20
[ 343.263802] ? __skb_clone+0x5d6/0x840
[ 343.264329] ? __sanitizer_cov_trace_pc+0x21/0x60
[ 343.264958] dev_queue_xmit+0x1c/0x20
[ 343.265470] netlink_deliver_tap+0x652/0x9c0
[ 343.266067] netlink_unicast+0x5a0/0x7f0
[ 343.266608] ? netlink_attachskb+0x860/0x860
[ 343.267183] ? __sanitizer_cov_trace_pc+0x21/0x60
[ 343.267820] ? write_comp_data+0x2f/0x90
[ 343.268367] netlink_sendmsg+0x922/0xe80
[ 343.268899] ? netlink_unicast+0x7f0/0x7f0
[ 343.269472] ? __sanitizer_cov_trace_pc+0x21/0x60
[ 343.270099] ? write_comp_data+0x2f/0x90
[ 343.270644] ? netlink_unicast+0x7f0/0x7f0
[ 343.271210] sock_sendmsg+0x155/0x190
[ 343.271721] ____sys_sendmsg+0x75f/0x8f0
[ 343.272262] ? kernel_sendmsg+0x60/0x60
[ 343.272788] ? write_comp_data+0x2f/0x90
[ 343.273332] ? write_comp_data+0x2f/0x90
[ 343.273869] ___sys_sendmsg+0x10f/0x190
[ 343.274405] ? sendmsg_copy_msghdr+0x80/0x80
[ 343.274984] ? slab_post_alloc_hook+0x70/0x230
[ 343.275597] ? futex_wait_setup+0x240/0x240
[ 343.276175] ? security_file_alloc+0x3e/0x170
[ 343.276779] ? write_comp_data+0x2f/0x90
[ 343.277313] ? __sanitizer_cov_trace_pc+0x21/0x60
[ 343.277969] ? write_comp_data+0x2f/0x90
[ 343.278515] ? __fget_files+0x1ad/0x260
[ 343.279048] ? __sanitizer_cov_trace_pc+0x21/0x60
[ 343.279685] ? write_comp_data+0x2f/0x90
[ 343.280234] ? __sanitizer_cov_trace_pc+0x21/0x60
[ 343.280874] ? sockfd_lookup_light+0xd1/0x190
[ 343.281481] __sys_sendmsg+0x118/0x200
[ 343.281998] ? __sys_sendmsg_sock+0x40/0x40
[ 343.282578] ? alloc_fd+0x229/0x5e0
[ 343.283070] ? write_comp_data+0x2f/0x90
[ 343.283610] ? write_comp_data+0x2f/0x90
[ 343.284135] ? __sanitizer_cov_trace_pc+0x21/0x60
[ 343.284776] ? ktime_get_coarse_real_ts64+0xb8/0xf0
[ 343.285450] __x64_sys_sendmsg+0x7d/0xc0
[ 343.285981] ? syscall_enter_from_user_mode+0x4d/0x70
[ 343.286664] do_syscall_64+0x3a/0x80
[ 343.287158] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 343.287850] RIP: 0033:0x7fdde24cf289
[ 343.288344] Code: 01 00 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 00
48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f
05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d b7 db 2c 00 f7 d8 64 89 01 48
[ 343.290729] RSP: 002b:00007fdde2bd6d98 EFLAGS: 00000246 ORIG_RAX:
000000000000002e
[ 343.291730] RAX: ffffffffffffffda RBX: 0000000000000000 RCX:
00007fdde24cf289
[ 343.292673] RDX: 0000000000000000 RSI: 00000000200000c0 RDI:
0000000000000004
[ 343.293618] RBP: 00007fdde2bd6e20 R08: 0000000100000001 R09:
0000000000000000
[ 343.294557] R10: 0000000100000001 R11: 0000000000000246 R12:
0000000000000000
[ 343.295493] R13: 0000000000021000 R14: 0000000000000000 R15:
00007fdde2bd7700
[ 343.296432] </TASK>
[ 343.296735] Modules linked in: sch_netem ip6_vti ip_vti ip_gre ipip
sit ip_tunnel geneve macsec macvtap tap ipvlan macvlan 8021q garp mrp
hsr wireguard libchacha20poly1305 chacha_x86_64 poly1305_x86_64
ip6_udp_tunnel udp_tunnel libblake2s blake2s_x86_64 libblake2s_generic
curve25519_x86_64 libcurve25519_generic libchacha xfrm_interface
xfrm6_tunnel tunnel4 veth netdevsim psample batman_adv nlmon dummy team
bonding tls vcan ip6_gre ip6_tunnel tunnel6 gre tun ip6t_rpfilter
ipt_REJECT nf_reject_ipv4 ip6t_REJECT nf_reject_ipv6 xt_conntrack ip_set
ebtable_nat ebtable_broute ip6table_nat ip6table_mangle
ip6table_security ip6table_raw iptable_nat nf_nat nf_conntrack
nf_defrag_ipv6 nf_defrag_ipv4 iptable_mangle iptable_security
iptable_raw ebtable_filter ebtables rfkill ip6table_filter ip6_tables
iptable_filter ppdev bochs drm_vram_helper drm_ttm_helper ttm
drm_kms_helper cec parport_pc drm joydev floppy parport sg syscopyarea
sysfillrect sysimgblt i2c_piix4 qemu_fw_cfg fb_sys_fops pcspkr
[ 343.297459] ip_tables xfs virtio_net net_failover failover sd_mod
sr_mod cdrom t10_pi ata_generic pata_acpi ata_piix libata virtio_pci
virtio_pci_legacy_dev serio_raw virtio_pci_modern_dev dm_mirror
dm_region_hash dm_log dm_mod
[ 343.311074] Dumping ftrace buffer:
[ 343.311532] (ftrace buffer empty)
[ 343.312040] ---[ end trace a2e3db5a6ae05099 ]---
[ 343.312691] RIP: 0010:netem_enqueue+0x1590/0x33c0 [sch_netem]
[ 343.313481] Code: 89 85 58 ff ff ff e8 5f 5d e9 d3 48 8b b5 48 ff ff
ff 8b 8d 50 ff ff ff 8b 85 58 ff ff ff 48 8b bd 70 ff ff ff 31 d2 2b 4f
74 <f7> f1 48 b8 00 00 00 00 00 fc ff df 49 01 d5 4c 89 e9 48 c1 e9 03
[ 343.315893] RSP: 0018:ffff88800bcd7368 EFLAGS: 00010246
[ 343.316622] RAX: 00000000ba7c0a9c RBX: 0000000000000001 RCX:
0000000000000000
[ 343.317585] RDX: 0000000000000000 RSI: ffff88800f8edb10 RDI:
ffff88800f8eda40
[ 343.318549] RBP: ffff88800bcd7458 R08: 0000000000000000 R09:
ffffffff94fb8445
[ 343.319503] R10: ffffffff94fb8336 R11: ffffffff94fb8445 R12:
0000000000000000
[ 343.320455] R13: ffff88800a5a7000 R14: ffff88800a5b5800 R15:
0000000000000020
[ 343.321414] FS: 00007fdde2bd7700(0000) GS:ffff888109780000(0000)
knlGS:0000000000000000
[ 343.322489] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 343.323283] CR2: 00000000200000c0 CR3: 000000000ef4c000 CR4:
00000000000006e0
[ 343.324264] Kernel panic - not syncing: Fatal exception in interrupt
[ 343.333717] Dumping ftrace buffer:
[ 343.334175] (ftrace buffer empty)
[ 343.334653] Kernel Offset: 0x13600000 from 0xffffffff81000000
(relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[ 343.336027] Rebooting in 86400 seconds..
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Link: https://lore.kernel.org/r/20211129175328.55339-1-harshit.m.mogalapalli@oracle.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2803 lines
66 KiB
C
2803 lines
66 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* NETLINK Kernel-user communication protocol.
|
|
*
|
|
* Authors: Alan Cox <alan@lxorguk.ukuu.org.uk>
|
|
* Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
|
|
* Patrick McHardy <kaber@trash.net>
|
|
*
|
|
* Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith
|
|
* added netlink_proto_exit
|
|
* Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br>
|
|
* use nlk_sk, as sk->protinfo is on a diet 8)
|
|
* Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org>
|
|
* - inc module use count of module that owns
|
|
* the kernel socket in case userspace opens
|
|
* socket of same protocol
|
|
* - remove all module support, since netlink is
|
|
* mandatory if CONFIG_NET=y these days
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
|
|
#include <linux/capability.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/signal.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/string.h>
|
|
#include <linux/stat.h>
|
|
#include <linux/socket.h>
|
|
#include <linux/un.h>
|
|
#include <linux/fcntl.h>
|
|
#include <linux/termios.h>
|
|
#include <linux/sockios.h>
|
|
#include <linux/net.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/netdevice.h>
|
|
#include <linux/rtnetlink.h>
|
|
#include <linux/proc_fs.h>
|
|
#include <linux/seq_file.h>
|
|
#include <linux/notifier.h>
|
|
#include <linux/security.h>
|
|
#include <linux/jhash.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/random.h>
|
|
#include <linux/bitops.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/types.h>
|
|
#include <linux/audit.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/vmalloc.h>
|
|
#include <linux/if_arp.h>
|
|
#include <linux/rhashtable.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <linux/hash.h>
|
|
#include <linux/genetlink.h>
|
|
#include <linux/net_namespace.h>
|
|
#include <linux/nospec.h>
|
|
|
|
#include <net/net_namespace.h>
|
|
#include <net/netns/generic.h>
|
|
#include <net/sock.h>
|
|
#include <net/scm.h>
|
|
#include <net/netlink.h>
|
|
|
|
#include "af_netlink.h"
|
|
|
|
struct listeners {
|
|
struct rcu_head rcu;
|
|
unsigned long masks[0];
|
|
};
|
|
|
|
/* state bits */
|
|
#define NETLINK_S_CONGESTED 0x0
|
|
|
|
static inline int netlink_is_kernel(struct sock *sk)
|
|
{
|
|
return nlk_sk(sk)->flags & NETLINK_F_KERNEL_SOCKET;
|
|
}
|
|
|
|
struct netlink_table *nl_table __read_mostly;
|
|
EXPORT_SYMBOL_GPL(nl_table);
|
|
|
|
static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
|
|
|
|
static struct lock_class_key nlk_cb_mutex_keys[MAX_LINKS];
|
|
|
|
static const char *const nlk_cb_mutex_key_strings[MAX_LINKS + 1] = {
|
|
"nlk_cb_mutex-ROUTE",
|
|
"nlk_cb_mutex-1",
|
|
"nlk_cb_mutex-USERSOCK",
|
|
"nlk_cb_mutex-FIREWALL",
|
|
"nlk_cb_mutex-SOCK_DIAG",
|
|
"nlk_cb_mutex-NFLOG",
|
|
"nlk_cb_mutex-XFRM",
|
|
"nlk_cb_mutex-SELINUX",
|
|
"nlk_cb_mutex-ISCSI",
|
|
"nlk_cb_mutex-AUDIT",
|
|
"nlk_cb_mutex-FIB_LOOKUP",
|
|
"nlk_cb_mutex-CONNECTOR",
|
|
"nlk_cb_mutex-NETFILTER",
|
|
"nlk_cb_mutex-IP6_FW",
|
|
"nlk_cb_mutex-DNRTMSG",
|
|
"nlk_cb_mutex-KOBJECT_UEVENT",
|
|
"nlk_cb_mutex-GENERIC",
|
|
"nlk_cb_mutex-17",
|
|
"nlk_cb_mutex-SCSITRANSPORT",
|
|
"nlk_cb_mutex-ECRYPTFS",
|
|
"nlk_cb_mutex-RDMA",
|
|
"nlk_cb_mutex-CRYPTO",
|
|
"nlk_cb_mutex-SMC",
|
|
"nlk_cb_mutex-23",
|
|
"nlk_cb_mutex-24",
|
|
"nlk_cb_mutex-25",
|
|
"nlk_cb_mutex-26",
|
|
"nlk_cb_mutex-27",
|
|
"nlk_cb_mutex-28",
|
|
"nlk_cb_mutex-29",
|
|
"nlk_cb_mutex-30",
|
|
"nlk_cb_mutex-31",
|
|
"nlk_cb_mutex-MAX_LINKS"
|
|
};
|
|
|
|
static int netlink_dump(struct sock *sk);
|
|
|
|
/* nl_table locking explained:
|
|
* Lookup and traversal are protected with an RCU read-side lock. Insertion
|
|
* and removal are protected with per bucket lock while using RCU list
|
|
* modification primitives and may run in parallel to RCU protected lookups.
|
|
* Destruction of the Netlink socket may only occur *after* nl_table_lock has
|
|
* been acquired * either during or after the socket has been removed from
|
|
* the list and after an RCU grace period.
|
|
*/
|
|
DEFINE_RWLOCK(nl_table_lock);
|
|
EXPORT_SYMBOL_GPL(nl_table_lock);
|
|
static atomic_t nl_table_users = ATOMIC_INIT(0);
|
|
|
|
#define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock));
|
|
|
|
static BLOCKING_NOTIFIER_HEAD(netlink_chain);
|
|
|
|
|
|
static const struct rhashtable_params netlink_rhashtable_params;
|
|
|
|
static inline u32 netlink_group_mask(u32 group)
|
|
{
|
|
return group ? 1 << (group - 1) : 0;
|
|
}
|
|
|
|
static struct sk_buff *netlink_to_full_skb(const struct sk_buff *skb,
|
|
gfp_t gfp_mask)
|
|
{
|
|
unsigned int len = skb_end_offset(skb);
|
|
struct sk_buff *new;
|
|
|
|
new = alloc_skb(len, gfp_mask);
|
|
if (new == NULL)
|
|
return NULL;
|
|
|
|
NETLINK_CB(new).portid = NETLINK_CB(skb).portid;
|
|
NETLINK_CB(new).dst_group = NETLINK_CB(skb).dst_group;
|
|
NETLINK_CB(new).creds = NETLINK_CB(skb).creds;
|
|
|
|
skb_put_data(new, skb->data, len);
|
|
return new;
|
|
}
|
|
|
|
static unsigned int netlink_tap_net_id;
|
|
|
|
struct netlink_tap_net {
|
|
struct list_head netlink_tap_all;
|
|
struct mutex netlink_tap_lock;
|
|
};
|
|
|
|
int netlink_add_tap(struct netlink_tap *nt)
|
|
{
|
|
struct net *net = dev_net(nt->dev);
|
|
struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
|
|
|
|
if (unlikely(nt->dev->type != ARPHRD_NETLINK))
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&nn->netlink_tap_lock);
|
|
list_add_rcu(&nt->list, &nn->netlink_tap_all);
|
|
mutex_unlock(&nn->netlink_tap_lock);
|
|
|
|
__module_get(nt->module);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(netlink_add_tap);
|
|
|
|
static int __netlink_remove_tap(struct netlink_tap *nt)
|
|
{
|
|
struct net *net = dev_net(nt->dev);
|
|
struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
|
|
bool found = false;
|
|
struct netlink_tap *tmp;
|
|
|
|
mutex_lock(&nn->netlink_tap_lock);
|
|
|
|
list_for_each_entry(tmp, &nn->netlink_tap_all, list) {
|
|
if (nt == tmp) {
|
|
list_del_rcu(&nt->list);
|
|
found = true;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
pr_warn("__netlink_remove_tap: %p not found\n", nt);
|
|
out:
|
|
mutex_unlock(&nn->netlink_tap_lock);
|
|
|
|
if (found)
|
|
module_put(nt->module);
|
|
|
|
return found ? 0 : -ENODEV;
|
|
}
|
|
|
|
int netlink_remove_tap(struct netlink_tap *nt)
|
|
{
|
|
int ret;
|
|
|
|
ret = __netlink_remove_tap(nt);
|
|
synchronize_net();
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(netlink_remove_tap);
|
|
|
|
static __net_init int netlink_tap_init_net(struct net *net)
|
|
{
|
|
struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
|
|
|
|
INIT_LIST_HEAD(&nn->netlink_tap_all);
|
|
mutex_init(&nn->netlink_tap_lock);
|
|
return 0;
|
|
}
|
|
|
|
static struct pernet_operations netlink_tap_net_ops = {
|
|
.init = netlink_tap_init_net,
|
|
.id = &netlink_tap_net_id,
|
|
.size = sizeof(struct netlink_tap_net),
|
|
};
|
|
|
|
static bool netlink_filter_tap(const struct sk_buff *skb)
|
|
{
|
|
struct sock *sk = skb->sk;
|
|
|
|
/* We take the more conservative approach and
|
|
* whitelist socket protocols that may pass.
|
|
*/
|
|
switch (sk->sk_protocol) {
|
|
case NETLINK_ROUTE:
|
|
case NETLINK_USERSOCK:
|
|
case NETLINK_SOCK_DIAG:
|
|
case NETLINK_NFLOG:
|
|
case NETLINK_XFRM:
|
|
case NETLINK_FIB_LOOKUP:
|
|
case NETLINK_NETFILTER:
|
|
case NETLINK_GENERIC:
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static int __netlink_deliver_tap_skb(struct sk_buff *skb,
|
|
struct net_device *dev)
|
|
{
|
|
struct sk_buff *nskb;
|
|
struct sock *sk = skb->sk;
|
|
int ret = -ENOMEM;
|
|
|
|
if (!net_eq(dev_net(dev), sock_net(sk)))
|
|
return 0;
|
|
|
|
dev_hold(dev);
|
|
|
|
if (is_vmalloc_addr(skb->head))
|
|
nskb = netlink_to_full_skb(skb, GFP_ATOMIC);
|
|
else
|
|
nskb = skb_clone(skb, GFP_ATOMIC);
|
|
if (nskb) {
|
|
nskb->dev = dev;
|
|
nskb->protocol = htons((u16) sk->sk_protocol);
|
|
nskb->pkt_type = netlink_is_kernel(sk) ?
|
|
PACKET_KERNEL : PACKET_USER;
|
|
skb_reset_network_header(nskb);
|
|
ret = dev_queue_xmit(nskb);
|
|
if (unlikely(ret > 0))
|
|
ret = net_xmit_errno(ret);
|
|
}
|
|
|
|
dev_put(dev);
|
|
return ret;
|
|
}
|
|
|
|
static void __netlink_deliver_tap(struct sk_buff *skb, struct netlink_tap_net *nn)
|
|
{
|
|
int ret;
|
|
struct netlink_tap *tmp;
|
|
|
|
if (!netlink_filter_tap(skb))
|
|
return;
|
|
|
|
list_for_each_entry_rcu(tmp, &nn->netlink_tap_all, list) {
|
|
ret = __netlink_deliver_tap_skb(skb, tmp->dev);
|
|
if (unlikely(ret))
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void netlink_deliver_tap(struct net *net, struct sk_buff *skb)
|
|
{
|
|
struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
|
|
|
|
rcu_read_lock();
|
|
|
|
if (unlikely(!list_empty(&nn->netlink_tap_all)))
|
|
__netlink_deliver_tap(skb, nn);
|
|
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static void netlink_deliver_tap_kernel(struct sock *dst, struct sock *src,
|
|
struct sk_buff *skb)
|
|
{
|
|
if (!(netlink_is_kernel(dst) && netlink_is_kernel(src)))
|
|
netlink_deliver_tap(sock_net(dst), skb);
|
|
}
|
|
|
|
static void netlink_overrun(struct sock *sk)
|
|
{
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
|
|
if (!(nlk->flags & NETLINK_F_RECV_NO_ENOBUFS)) {
|
|
if (!test_and_set_bit(NETLINK_S_CONGESTED,
|
|
&nlk_sk(sk)->state)) {
|
|
sk->sk_err = ENOBUFS;
|
|
sk->sk_error_report(sk);
|
|
}
|
|
}
|
|
atomic_inc(&sk->sk_drops);
|
|
}
|
|
|
|
static void netlink_rcv_wake(struct sock *sk)
|
|
{
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
|
|
if (skb_queue_empty(&sk->sk_receive_queue))
|
|
clear_bit(NETLINK_S_CONGESTED, &nlk->state);
|
|
if (!test_bit(NETLINK_S_CONGESTED, &nlk->state))
|
|
wake_up_interruptible(&nlk->wait);
|
|
}
|
|
|
|
static void netlink_skb_destructor(struct sk_buff *skb)
|
|
{
|
|
if (is_vmalloc_addr(skb->head)) {
|
|
if (!skb->cloned ||
|
|
!atomic_dec_return(&(skb_shinfo(skb)->dataref)))
|
|
vfree(skb->head);
|
|
|
|
skb->head = NULL;
|
|
}
|
|
if (skb->sk != NULL)
|
|
sock_rfree(skb);
|
|
}
|
|
|
|
static void netlink_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
|
|
{
|
|
WARN_ON(skb->sk != NULL);
|
|
skb->sk = sk;
|
|
skb->destructor = netlink_skb_destructor;
|
|
atomic_add(skb->truesize, &sk->sk_rmem_alloc);
|
|
sk_mem_charge(sk, skb->truesize);
|
|
}
|
|
|
|
static void netlink_sock_destruct(struct sock *sk)
|
|
{
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
|
|
if (nlk->cb_running) {
|
|
if (nlk->cb.done)
|
|
nlk->cb.done(&nlk->cb);
|
|
module_put(nlk->cb.module);
|
|
kfree_skb(nlk->cb.skb);
|
|
}
|
|
|
|
skb_queue_purge(&sk->sk_receive_queue);
|
|
|
|
if (!sock_flag(sk, SOCK_DEAD)) {
|
|
printk(KERN_ERR "Freeing alive netlink socket %p\n", sk);
|
|
return;
|
|
}
|
|
|
|
WARN_ON(atomic_read(&sk->sk_rmem_alloc));
|
|
WARN_ON(refcount_read(&sk->sk_wmem_alloc));
|
|
WARN_ON(nlk_sk(sk)->groups);
|
|
}
|
|
|
|
static void netlink_sock_destruct_work(struct work_struct *work)
|
|
{
|
|
struct netlink_sock *nlk = container_of(work, struct netlink_sock,
|
|
work);
|
|
|
|
sk_free(&nlk->sk);
|
|
}
|
|
|
|
/* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on
|
|
* SMP. Look, when several writers sleep and reader wakes them up, all but one
|
|
* immediately hit write lock and grab all the cpus. Exclusive sleep solves
|
|
* this, _but_ remember, it adds useless work on UP machines.
|
|
*/
|
|
|
|
void netlink_table_grab(void)
|
|
__acquires(nl_table_lock)
|
|
{
|
|
might_sleep();
|
|
|
|
write_lock_irq(&nl_table_lock);
|
|
|
|
if (atomic_read(&nl_table_users)) {
|
|
DECLARE_WAITQUEUE(wait, current);
|
|
|
|
add_wait_queue_exclusive(&nl_table_wait, &wait);
|
|
for (;;) {
|
|
set_current_state(TASK_UNINTERRUPTIBLE);
|
|
if (atomic_read(&nl_table_users) == 0)
|
|
break;
|
|
write_unlock_irq(&nl_table_lock);
|
|
schedule();
|
|
write_lock_irq(&nl_table_lock);
|
|
}
|
|
|
|
__set_current_state(TASK_RUNNING);
|
|
remove_wait_queue(&nl_table_wait, &wait);
|
|
}
|
|
}
|
|
|
|
void netlink_table_ungrab(void)
|
|
__releases(nl_table_lock)
|
|
{
|
|
write_unlock_irq(&nl_table_lock);
|
|
wake_up(&nl_table_wait);
|
|
}
|
|
|
|
static inline void
|
|
netlink_lock_table(void)
|
|
{
|
|
unsigned long flags;
|
|
|
|
/* read_lock() synchronizes us to netlink_table_grab */
|
|
|
|
read_lock_irqsave(&nl_table_lock, flags);
|
|
atomic_inc(&nl_table_users);
|
|
read_unlock_irqrestore(&nl_table_lock, flags);
|
|
}
|
|
|
|
static inline void
|
|
netlink_unlock_table(void)
|
|
{
|
|
if (atomic_dec_and_test(&nl_table_users))
|
|
wake_up(&nl_table_wait);
|
|
}
|
|
|
|
struct netlink_compare_arg
|
|
{
|
|
possible_net_t pnet;
|
|
u32 portid;
|
|
};
|
|
|
|
/* Doing sizeof directly may yield 4 extra bytes on 64-bit. */
|
|
#define netlink_compare_arg_len \
|
|
(offsetof(struct netlink_compare_arg, portid) + sizeof(u32))
|
|
|
|
static inline int netlink_compare(struct rhashtable_compare_arg *arg,
|
|
const void *ptr)
|
|
{
|
|
const struct netlink_compare_arg *x = arg->key;
|
|
const struct netlink_sock *nlk = ptr;
|
|
|
|
return nlk->portid != x->portid ||
|
|
!net_eq(sock_net(&nlk->sk), read_pnet(&x->pnet));
|
|
}
|
|
|
|
static void netlink_compare_arg_init(struct netlink_compare_arg *arg,
|
|
struct net *net, u32 portid)
|
|
{
|
|
memset(arg, 0, sizeof(*arg));
|
|
write_pnet(&arg->pnet, net);
|
|
arg->portid = portid;
|
|
}
|
|
|
|
static struct sock *__netlink_lookup(struct netlink_table *table, u32 portid,
|
|
struct net *net)
|
|
{
|
|
struct netlink_compare_arg arg;
|
|
|
|
netlink_compare_arg_init(&arg, net, portid);
|
|
return rhashtable_lookup_fast(&table->hash, &arg,
|
|
netlink_rhashtable_params);
|
|
}
|
|
|
|
static int __netlink_insert(struct netlink_table *table, struct sock *sk)
|
|
{
|
|
struct netlink_compare_arg arg;
|
|
|
|
netlink_compare_arg_init(&arg, sock_net(sk), nlk_sk(sk)->portid);
|
|
return rhashtable_lookup_insert_key(&table->hash, &arg,
|
|
&nlk_sk(sk)->node,
|
|
netlink_rhashtable_params);
|
|
}
|
|
|
|
static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid)
|
|
{
|
|
struct netlink_table *table = &nl_table[protocol];
|
|
struct sock *sk;
|
|
|
|
rcu_read_lock();
|
|
sk = __netlink_lookup(table, portid, net);
|
|
if (sk)
|
|
sock_hold(sk);
|
|
rcu_read_unlock();
|
|
|
|
return sk;
|
|
}
|
|
|
|
static const struct proto_ops netlink_ops;
|
|
|
|
static void
|
|
netlink_update_listeners(struct sock *sk)
|
|
{
|
|
struct netlink_table *tbl = &nl_table[sk->sk_protocol];
|
|
unsigned long mask;
|
|
unsigned int i;
|
|
struct listeners *listeners;
|
|
|
|
listeners = nl_deref_protected(tbl->listeners);
|
|
if (!listeners)
|
|
return;
|
|
|
|
for (i = 0; i < NLGRPLONGS(tbl->groups); i++) {
|
|
mask = 0;
|
|
sk_for_each_bound(sk, &tbl->mc_list) {
|
|
if (i < NLGRPLONGS(nlk_sk(sk)->ngroups))
|
|
mask |= nlk_sk(sk)->groups[i];
|
|
}
|
|
listeners->masks[i] = mask;
|
|
}
|
|
/* this function is only called with the netlink table "grabbed", which
|
|
* makes sure updates are visible before bind or setsockopt return. */
|
|
}
|
|
|
|
static int netlink_insert(struct sock *sk, u32 portid)
|
|
{
|
|
struct netlink_table *table = &nl_table[sk->sk_protocol];
|
|
int err;
|
|
|
|
lock_sock(sk);
|
|
|
|
err = nlk_sk(sk)->portid == portid ? 0 : -EBUSY;
|
|
if (nlk_sk(sk)->bound)
|
|
goto err;
|
|
|
|
nlk_sk(sk)->portid = portid;
|
|
sock_hold(sk);
|
|
|
|
err = __netlink_insert(table, sk);
|
|
if (err) {
|
|
/* In case the hashtable backend returns with -EBUSY
|
|
* from here, it must not escape to the caller.
|
|
*/
|
|
if (unlikely(err == -EBUSY))
|
|
err = -EOVERFLOW;
|
|
if (err == -EEXIST)
|
|
err = -EADDRINUSE;
|
|
sock_put(sk);
|
|
goto err;
|
|
}
|
|
|
|
/* We need to ensure that the socket is hashed and visible. */
|
|
smp_wmb();
|
|
/* Paired with lockless reads from netlink_bind(),
|
|
* netlink_connect() and netlink_sendmsg().
|
|
*/
|
|
WRITE_ONCE(nlk_sk(sk)->bound, portid);
|
|
|
|
err:
|
|
release_sock(sk);
|
|
return err;
|
|
}
|
|
|
|
static void netlink_remove(struct sock *sk)
|
|
{
|
|
struct netlink_table *table;
|
|
|
|
table = &nl_table[sk->sk_protocol];
|
|
if (!rhashtable_remove_fast(&table->hash, &nlk_sk(sk)->node,
|
|
netlink_rhashtable_params)) {
|
|
WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
|
|
__sock_put(sk);
|
|
}
|
|
|
|
netlink_table_grab();
|
|
if (nlk_sk(sk)->subscriptions) {
|
|
__sk_del_bind_node(sk);
|
|
netlink_update_listeners(sk);
|
|
}
|
|
if (sk->sk_protocol == NETLINK_GENERIC)
|
|
atomic_inc(&genl_sk_destructing_cnt);
|
|
netlink_table_ungrab();
|
|
}
|
|
|
|
static struct proto netlink_proto = {
|
|
.name = "NETLINK",
|
|
.owner = THIS_MODULE,
|
|
.obj_size = sizeof(struct netlink_sock),
|
|
};
|
|
|
|
static int __netlink_create(struct net *net, struct socket *sock,
|
|
struct mutex *cb_mutex, int protocol,
|
|
int kern)
|
|
{
|
|
struct sock *sk;
|
|
struct netlink_sock *nlk;
|
|
|
|
sock->ops = &netlink_ops;
|
|
|
|
sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto, kern);
|
|
if (!sk)
|
|
return -ENOMEM;
|
|
|
|
sock_init_data(sock, sk);
|
|
|
|
nlk = nlk_sk(sk);
|
|
if (cb_mutex) {
|
|
nlk->cb_mutex = cb_mutex;
|
|
} else {
|
|
nlk->cb_mutex = &nlk->cb_def_mutex;
|
|
mutex_init(nlk->cb_mutex);
|
|
lockdep_set_class_and_name(nlk->cb_mutex,
|
|
nlk_cb_mutex_keys + protocol,
|
|
nlk_cb_mutex_key_strings[protocol]);
|
|
}
|
|
init_waitqueue_head(&nlk->wait);
|
|
|
|
sk->sk_destruct = netlink_sock_destruct;
|
|
sk->sk_protocol = protocol;
|
|
return 0;
|
|
}
|
|
|
|
static int netlink_create(struct net *net, struct socket *sock, int protocol,
|
|
int kern)
|
|
{
|
|
struct module *module = NULL;
|
|
struct mutex *cb_mutex;
|
|
struct netlink_sock *nlk;
|
|
int (*bind)(struct net *net, int group);
|
|
void (*unbind)(struct net *net, int group);
|
|
int err = 0;
|
|
|
|
sock->state = SS_UNCONNECTED;
|
|
|
|
if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
|
|
return -ESOCKTNOSUPPORT;
|
|
|
|
if (protocol < 0 || protocol >= MAX_LINKS)
|
|
return -EPROTONOSUPPORT;
|
|
protocol = array_index_nospec(protocol, MAX_LINKS);
|
|
|
|
netlink_lock_table();
|
|
#ifdef CONFIG_MODULES
|
|
if (!nl_table[protocol].registered) {
|
|
netlink_unlock_table();
|
|
request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
|
|
netlink_lock_table();
|
|
}
|
|
#endif
|
|
if (nl_table[protocol].registered &&
|
|
try_module_get(nl_table[protocol].module))
|
|
module = nl_table[protocol].module;
|
|
else
|
|
err = -EPROTONOSUPPORT;
|
|
cb_mutex = nl_table[protocol].cb_mutex;
|
|
bind = nl_table[protocol].bind;
|
|
unbind = nl_table[protocol].unbind;
|
|
netlink_unlock_table();
|
|
|
|
if (err < 0)
|
|
goto out;
|
|
|
|
err = __netlink_create(net, sock, cb_mutex, protocol, kern);
|
|
if (err < 0)
|
|
goto out_module;
|
|
|
|
local_bh_disable();
|
|
sock_prot_inuse_add(net, &netlink_proto, 1);
|
|
local_bh_enable();
|
|
|
|
nlk = nlk_sk(sock->sk);
|
|
nlk->module = module;
|
|
nlk->netlink_bind = bind;
|
|
nlk->netlink_unbind = unbind;
|
|
out:
|
|
return err;
|
|
|
|
out_module:
|
|
module_put(module);
|
|
goto out;
|
|
}
|
|
|
|
static void deferred_put_nlk_sk(struct rcu_head *head)
|
|
{
|
|
struct netlink_sock *nlk = container_of(head, struct netlink_sock, rcu);
|
|
struct sock *sk = &nlk->sk;
|
|
|
|
kfree(nlk->groups);
|
|
nlk->groups = NULL;
|
|
|
|
if (!refcount_dec_and_test(&sk->sk_refcnt))
|
|
return;
|
|
|
|
if (nlk->cb_running && nlk->cb.done) {
|
|
INIT_WORK(&nlk->work, netlink_sock_destruct_work);
|
|
schedule_work(&nlk->work);
|
|
return;
|
|
}
|
|
|
|
sk_free(sk);
|
|
}
|
|
|
|
static int netlink_release(struct socket *sock)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct netlink_sock *nlk;
|
|
|
|
if (!sk)
|
|
return 0;
|
|
|
|
netlink_remove(sk);
|
|
sock_orphan(sk);
|
|
nlk = nlk_sk(sk);
|
|
|
|
/*
|
|
* OK. Socket is unlinked, any packets that arrive now
|
|
* will be purged.
|
|
*/
|
|
|
|
/* must not acquire netlink_table_lock in any way again before unbind
|
|
* and notifying genetlink is done as otherwise it might deadlock
|
|
*/
|
|
if (nlk->netlink_unbind) {
|
|
int i;
|
|
|
|
for (i = 0; i < nlk->ngroups; i++)
|
|
if (test_bit(i, nlk->groups))
|
|
nlk->netlink_unbind(sock_net(sk), i + 1);
|
|
}
|
|
if (sk->sk_protocol == NETLINK_GENERIC &&
|
|
atomic_dec_return(&genl_sk_destructing_cnt) == 0)
|
|
wake_up(&genl_sk_destructing_waitq);
|
|
|
|
sock->sk = NULL;
|
|
wake_up_interruptible_all(&nlk->wait);
|
|
|
|
skb_queue_purge(&sk->sk_write_queue);
|
|
|
|
if (nlk->portid && nlk->bound) {
|
|
struct netlink_notify n = {
|
|
.net = sock_net(sk),
|
|
.protocol = sk->sk_protocol,
|
|
.portid = nlk->portid,
|
|
};
|
|
blocking_notifier_call_chain(&netlink_chain,
|
|
NETLINK_URELEASE, &n);
|
|
}
|
|
|
|
module_put(nlk->module);
|
|
|
|
if (netlink_is_kernel(sk)) {
|
|
netlink_table_grab();
|
|
BUG_ON(nl_table[sk->sk_protocol].registered == 0);
|
|
if (--nl_table[sk->sk_protocol].registered == 0) {
|
|
struct listeners *old;
|
|
|
|
old = nl_deref_protected(nl_table[sk->sk_protocol].listeners);
|
|
RCU_INIT_POINTER(nl_table[sk->sk_protocol].listeners, NULL);
|
|
kfree_rcu(old, rcu);
|
|
nl_table[sk->sk_protocol].module = NULL;
|
|
nl_table[sk->sk_protocol].bind = NULL;
|
|
nl_table[sk->sk_protocol].unbind = NULL;
|
|
nl_table[sk->sk_protocol].flags = 0;
|
|
nl_table[sk->sk_protocol].registered = 0;
|
|
}
|
|
netlink_table_ungrab();
|
|
}
|
|
|
|
local_bh_disable();
|
|
sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1);
|
|
local_bh_enable();
|
|
call_rcu(&nlk->rcu, deferred_put_nlk_sk);
|
|
return 0;
|
|
}
|
|
|
|
static int netlink_autobind(struct socket *sock)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct net *net = sock_net(sk);
|
|
struct netlink_table *table = &nl_table[sk->sk_protocol];
|
|
s32 portid = task_tgid_vnr(current);
|
|
int err;
|
|
s32 rover = -4096;
|
|
bool ok;
|
|
|
|
retry:
|
|
cond_resched();
|
|
rcu_read_lock();
|
|
ok = !__netlink_lookup(table, portid, net);
|
|
rcu_read_unlock();
|
|
if (!ok) {
|
|
/* Bind collision, search negative portid values. */
|
|
if (rover == -4096)
|
|
/* rover will be in range [S32_MIN, -4097] */
|
|
rover = S32_MIN + prandom_u32_max(-4096 - S32_MIN);
|
|
else if (rover >= -4096)
|
|
rover = -4097;
|
|
portid = rover--;
|
|
goto retry;
|
|
}
|
|
|
|
err = netlink_insert(sk, portid);
|
|
if (err == -EADDRINUSE)
|
|
goto retry;
|
|
|
|
/* If 2 threads race to autobind, that is fine. */
|
|
if (err == -EBUSY)
|
|
err = 0;
|
|
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* __netlink_ns_capable - General netlink message capability test
|
|
* @nsp: NETLINK_CB of the socket buffer holding a netlink command from userspace.
|
|
* @user_ns: The user namespace of the capability to use
|
|
* @cap: The capability to use
|
|
*
|
|
* Test to see if the opener of the socket we received the message
|
|
* from had when the netlink socket was created and the sender of the
|
|
* message has has the capability @cap in the user namespace @user_ns.
|
|
*/
|
|
bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
|
|
struct user_namespace *user_ns, int cap)
|
|
{
|
|
return ((nsp->flags & NETLINK_SKB_DST) ||
|
|
file_ns_capable(nsp->sk->sk_socket->file, user_ns, cap)) &&
|
|
ns_capable(user_ns, cap);
|
|
}
|
|
EXPORT_SYMBOL(__netlink_ns_capable);
|
|
|
|
/**
|
|
* netlink_ns_capable - General netlink message capability test
|
|
* @skb: socket buffer holding a netlink command from userspace
|
|
* @user_ns: The user namespace of the capability to use
|
|
* @cap: The capability to use
|
|
*
|
|
* Test to see if the opener of the socket we received the message
|
|
* from had when the netlink socket was created and the sender of the
|
|
* message has has the capability @cap in the user namespace @user_ns.
|
|
*/
|
|
bool netlink_ns_capable(const struct sk_buff *skb,
|
|
struct user_namespace *user_ns, int cap)
|
|
{
|
|
return __netlink_ns_capable(&NETLINK_CB(skb), user_ns, cap);
|
|
}
|
|
EXPORT_SYMBOL(netlink_ns_capable);
|
|
|
|
/**
|
|
* netlink_capable - Netlink global message capability test
|
|
* @skb: socket buffer holding a netlink command from userspace
|
|
* @cap: The capability to use
|
|
*
|
|
* Test to see if the opener of the socket we received the message
|
|
* from had when the netlink socket was created and the sender of the
|
|
* message has has the capability @cap in all user namespaces.
|
|
*/
|
|
bool netlink_capable(const struct sk_buff *skb, int cap)
|
|
{
|
|
return netlink_ns_capable(skb, &init_user_ns, cap);
|
|
}
|
|
EXPORT_SYMBOL(netlink_capable);
|
|
|
|
/**
|
|
* netlink_net_capable - Netlink network namespace message capability test
|
|
* @skb: socket buffer holding a netlink command from userspace
|
|
* @cap: The capability to use
|
|
*
|
|
* Test to see if the opener of the socket we received the message
|
|
* from had when the netlink socket was created and the sender of the
|
|
* message has has the capability @cap over the network namespace of
|
|
* the socket we received the message from.
|
|
*/
|
|
bool netlink_net_capable(const struct sk_buff *skb, int cap)
|
|
{
|
|
return netlink_ns_capable(skb, sock_net(skb->sk)->user_ns, cap);
|
|
}
|
|
EXPORT_SYMBOL(netlink_net_capable);
|
|
|
|
static inline int netlink_allowed(const struct socket *sock, unsigned int flag)
|
|
{
|
|
return (nl_table[sock->sk->sk_protocol].flags & flag) ||
|
|
ns_capable(sock_net(sock->sk)->user_ns, CAP_NET_ADMIN);
|
|
}
|
|
|
|
static void
|
|
netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions)
|
|
{
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
|
|
if (nlk->subscriptions && !subscriptions)
|
|
__sk_del_bind_node(sk);
|
|
else if (!nlk->subscriptions && subscriptions)
|
|
sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
|
|
nlk->subscriptions = subscriptions;
|
|
}
|
|
|
|
static int netlink_realloc_groups(struct sock *sk)
|
|
{
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
unsigned int groups;
|
|
unsigned long *new_groups;
|
|
int err = 0;
|
|
|
|
netlink_table_grab();
|
|
|
|
groups = nl_table[sk->sk_protocol].groups;
|
|
if (!nl_table[sk->sk_protocol].registered) {
|
|
err = -ENOENT;
|
|
goto out_unlock;
|
|
}
|
|
|
|
if (nlk->ngroups >= groups)
|
|
goto out_unlock;
|
|
|
|
new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC);
|
|
if (new_groups == NULL) {
|
|
err = -ENOMEM;
|
|
goto out_unlock;
|
|
}
|
|
memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0,
|
|
NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups));
|
|
|
|
nlk->groups = new_groups;
|
|
nlk->ngroups = groups;
|
|
out_unlock:
|
|
netlink_table_ungrab();
|
|
return err;
|
|
}
|
|
|
|
static void netlink_undo_bind(int group, long unsigned int groups,
|
|
struct sock *sk)
|
|
{
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
int undo;
|
|
|
|
if (!nlk->netlink_unbind)
|
|
return;
|
|
|
|
for (undo = 0; undo < group; undo++)
|
|
if (test_bit(undo, &groups))
|
|
nlk->netlink_unbind(sock_net(sk), undo + 1);
|
|
}
|
|
|
|
static int netlink_bind(struct socket *sock, struct sockaddr *addr,
|
|
int addr_len)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct net *net = sock_net(sk);
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
|
|
int err = 0;
|
|
unsigned long groups;
|
|
bool bound;
|
|
|
|
if (addr_len < sizeof(struct sockaddr_nl))
|
|
return -EINVAL;
|
|
|
|
if (nladdr->nl_family != AF_NETLINK)
|
|
return -EINVAL;
|
|
groups = nladdr->nl_groups;
|
|
|
|
/* Only superuser is allowed to listen multicasts */
|
|
if (groups) {
|
|
if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV))
|
|
return -EPERM;
|
|
err = netlink_realloc_groups(sk);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
if (nlk->ngroups < BITS_PER_LONG)
|
|
groups &= (1UL << nlk->ngroups) - 1;
|
|
|
|
/* Paired with WRITE_ONCE() in netlink_insert() */
|
|
bound = READ_ONCE(nlk->bound);
|
|
if (bound) {
|
|
/* Ensure nlk->portid is up-to-date. */
|
|
smp_rmb();
|
|
|
|
if (nladdr->nl_pid != nlk->portid)
|
|
return -EINVAL;
|
|
}
|
|
|
|
netlink_lock_table();
|
|
if (nlk->netlink_bind && groups) {
|
|
int group;
|
|
|
|
/* nl_groups is a u32, so cap the maximum groups we can bind */
|
|
for (group = 0; group < BITS_PER_TYPE(u32); group++) {
|
|
if (!test_bit(group, &groups))
|
|
continue;
|
|
err = nlk->netlink_bind(net, group + 1);
|
|
if (!err)
|
|
continue;
|
|
netlink_undo_bind(group, groups, sk);
|
|
goto unlock;
|
|
}
|
|
}
|
|
|
|
/* No need for barriers here as we return to user-space without
|
|
* using any of the bound attributes.
|
|
*/
|
|
if (!bound) {
|
|
err = nladdr->nl_pid ?
|
|
netlink_insert(sk, nladdr->nl_pid) :
|
|
netlink_autobind(sock);
|
|
if (err) {
|
|
netlink_undo_bind(BITS_PER_TYPE(u32), groups, sk);
|
|
goto unlock;
|
|
}
|
|
}
|
|
|
|
if (!groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
|
|
goto unlock;
|
|
netlink_unlock_table();
|
|
|
|
netlink_table_grab();
|
|
netlink_update_subscriptions(sk, nlk->subscriptions +
|
|
hweight32(groups) -
|
|
hweight32(nlk->groups[0]));
|
|
nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | groups;
|
|
netlink_update_listeners(sk);
|
|
netlink_table_ungrab();
|
|
|
|
return 0;
|
|
|
|
unlock:
|
|
netlink_unlock_table();
|
|
return err;
|
|
}
|
|
|
|
static int netlink_connect(struct socket *sock, struct sockaddr *addr,
|
|
int alen, int flags)
|
|
{
|
|
int err = 0;
|
|
struct sock *sk = sock->sk;
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
|
|
|
|
if (alen < sizeof(addr->sa_family))
|
|
return -EINVAL;
|
|
|
|
if (addr->sa_family == AF_UNSPEC) {
|
|
sk->sk_state = NETLINK_UNCONNECTED;
|
|
nlk->dst_portid = 0;
|
|
nlk->dst_group = 0;
|
|
return 0;
|
|
}
|
|
if (addr->sa_family != AF_NETLINK)
|
|
return -EINVAL;
|
|
|
|
if (alen < sizeof(struct sockaddr_nl))
|
|
return -EINVAL;
|
|
|
|
if ((nladdr->nl_groups || nladdr->nl_pid) &&
|
|
!netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
|
|
return -EPERM;
|
|
|
|
/* No need for barriers here as we return to user-space without
|
|
* using any of the bound attributes.
|
|
* Paired with WRITE_ONCE() in netlink_insert().
|
|
*/
|
|
if (!READ_ONCE(nlk->bound))
|
|
err = netlink_autobind(sock);
|
|
|
|
if (err == 0) {
|
|
sk->sk_state = NETLINK_CONNECTED;
|
|
nlk->dst_portid = nladdr->nl_pid;
|
|
nlk->dst_group = ffs(nladdr->nl_groups);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int netlink_getname(struct socket *sock, struct sockaddr *addr,
|
|
int peer)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr);
|
|
|
|
nladdr->nl_family = AF_NETLINK;
|
|
nladdr->nl_pad = 0;
|
|
|
|
if (peer) {
|
|
nladdr->nl_pid = nlk->dst_portid;
|
|
nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
|
|
} else {
|
|
nladdr->nl_pid = nlk->portid;
|
|
netlink_lock_table();
|
|
nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
|
|
netlink_unlock_table();
|
|
}
|
|
return sizeof(*nladdr);
|
|
}
|
|
|
|
static int netlink_ioctl(struct socket *sock, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
/* try to hand this ioctl down to the NIC drivers.
|
|
*/
|
|
return -ENOIOCTLCMD;
|
|
}
|
|
|
|
static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid)
|
|
{
|
|
struct sock *sock;
|
|
struct netlink_sock *nlk;
|
|
|
|
sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, portid);
|
|
if (!sock)
|
|
return ERR_PTR(-ECONNREFUSED);
|
|
|
|
/* Don't bother queuing skb if kernel socket has no input function */
|
|
nlk = nlk_sk(sock);
|
|
if (sock->sk_state == NETLINK_CONNECTED &&
|
|
nlk->dst_portid != nlk_sk(ssk)->portid) {
|
|
sock_put(sock);
|
|
return ERR_PTR(-ECONNREFUSED);
|
|
}
|
|
return sock;
|
|
}
|
|
|
|
struct sock *netlink_getsockbyfilp(struct file *filp)
|
|
{
|
|
struct inode *inode = file_inode(filp);
|
|
struct sock *sock;
|
|
|
|
if (!S_ISSOCK(inode->i_mode))
|
|
return ERR_PTR(-ENOTSOCK);
|
|
|
|
sock = SOCKET_I(inode)->sk;
|
|
if (sock->sk_family != AF_NETLINK)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
sock_hold(sock);
|
|
return sock;
|
|
}
|
|
|
|
static struct sk_buff *netlink_alloc_large_skb(unsigned int size,
|
|
int broadcast)
|
|
{
|
|
struct sk_buff *skb;
|
|
void *data;
|
|
|
|
if (size <= NLMSG_GOODSIZE || broadcast)
|
|
return alloc_skb(size, GFP_KERNEL);
|
|
|
|
size = SKB_DATA_ALIGN(size) +
|
|
SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
|
|
|
|
data = vmalloc(size);
|
|
if (data == NULL)
|
|
return NULL;
|
|
|
|
skb = __build_skb(data, size);
|
|
if (skb == NULL)
|
|
vfree(data);
|
|
else
|
|
skb->destructor = netlink_skb_destructor;
|
|
|
|
return skb;
|
|
}
|
|
|
|
/*
|
|
* Attach a skb to a netlink socket.
|
|
* The caller must hold a reference to the destination socket. On error, the
|
|
* reference is dropped. The skb is not send to the destination, just all
|
|
* all error checks are performed and memory in the queue is reserved.
|
|
* Return values:
|
|
* < 0: error. skb freed, reference to sock dropped.
|
|
* 0: continue
|
|
* 1: repeat lookup - reference dropped while waiting for socket memory.
|
|
*/
|
|
int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
|
|
long *timeo, struct sock *ssk)
|
|
{
|
|
struct netlink_sock *nlk;
|
|
|
|
nlk = nlk_sk(sk);
|
|
|
|
if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
|
|
test_bit(NETLINK_S_CONGESTED, &nlk->state))) {
|
|
DECLARE_WAITQUEUE(wait, current);
|
|
if (!*timeo) {
|
|
if (!ssk || netlink_is_kernel(ssk))
|
|
netlink_overrun(sk);
|
|
sock_put(sk);
|
|
kfree_skb(skb);
|
|
return -EAGAIN;
|
|
}
|
|
|
|
__set_current_state(TASK_INTERRUPTIBLE);
|
|
add_wait_queue(&nlk->wait, &wait);
|
|
|
|
if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
|
|
test_bit(NETLINK_S_CONGESTED, &nlk->state)) &&
|
|
!sock_flag(sk, SOCK_DEAD))
|
|
*timeo = schedule_timeout(*timeo);
|
|
|
|
__set_current_state(TASK_RUNNING);
|
|
remove_wait_queue(&nlk->wait, &wait);
|
|
sock_put(sk);
|
|
|
|
if (signal_pending(current)) {
|
|
kfree_skb(skb);
|
|
return sock_intr_errno(*timeo);
|
|
}
|
|
return 1;
|
|
}
|
|
netlink_skb_set_owner_r(skb, sk);
|
|
return 0;
|
|
}
|
|
|
|
static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
int len = skb->len;
|
|
|
|
netlink_deliver_tap(sock_net(sk), skb);
|
|
|
|
skb_queue_tail(&sk->sk_receive_queue, skb);
|
|
sk->sk_data_ready(sk);
|
|
return len;
|
|
}
|
|
|
|
int netlink_sendskb(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
int len = __netlink_sendskb(sk, skb);
|
|
|
|
sock_put(sk);
|
|
return len;
|
|
}
|
|
|
|
void netlink_detachskb(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
kfree_skb(skb);
|
|
sock_put(sk);
|
|
}
|
|
|
|
static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation)
|
|
{
|
|
int delta;
|
|
|
|
WARN_ON(skb->sk != NULL);
|
|
delta = skb->end - skb->tail;
|
|
if (is_vmalloc_addr(skb->head) || delta * 2 < skb->truesize)
|
|
return skb;
|
|
|
|
if (skb_shared(skb)) {
|
|
struct sk_buff *nskb = skb_clone(skb, allocation);
|
|
if (!nskb)
|
|
return skb;
|
|
consume_skb(skb);
|
|
skb = nskb;
|
|
}
|
|
|
|
pskb_expand_head(skb, 0, -delta,
|
|
(allocation & ~__GFP_DIRECT_RECLAIM) |
|
|
__GFP_NOWARN | __GFP_NORETRY);
|
|
return skb;
|
|
}
|
|
|
|
static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb,
|
|
struct sock *ssk)
|
|
{
|
|
int ret;
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
|
|
ret = -ECONNREFUSED;
|
|
if (nlk->netlink_rcv != NULL) {
|
|
ret = skb->len;
|
|
netlink_skb_set_owner_r(skb, sk);
|
|
NETLINK_CB(skb).sk = ssk;
|
|
netlink_deliver_tap_kernel(sk, ssk, skb);
|
|
nlk->netlink_rcv(skb);
|
|
consume_skb(skb);
|
|
} else {
|
|
kfree_skb(skb);
|
|
}
|
|
sock_put(sk);
|
|
return ret;
|
|
}
|
|
|
|
int netlink_unicast(struct sock *ssk, struct sk_buff *skb,
|
|
u32 portid, int nonblock)
|
|
{
|
|
struct sock *sk;
|
|
int err;
|
|
long timeo;
|
|
|
|
skb = netlink_trim(skb, gfp_any());
|
|
|
|
timeo = sock_sndtimeo(ssk, nonblock);
|
|
retry:
|
|
sk = netlink_getsockbyportid(ssk, portid);
|
|
if (IS_ERR(sk)) {
|
|
kfree_skb(skb);
|
|
return PTR_ERR(sk);
|
|
}
|
|
if (netlink_is_kernel(sk))
|
|
return netlink_unicast_kernel(sk, skb, ssk);
|
|
|
|
if (sk_filter(sk, skb)) {
|
|
err = skb->len;
|
|
kfree_skb(skb);
|
|
sock_put(sk);
|
|
return err;
|
|
}
|
|
|
|
err = netlink_attachskb(sk, skb, &timeo, ssk);
|
|
if (err == 1)
|
|
goto retry;
|
|
if (err)
|
|
return err;
|
|
|
|
return netlink_sendskb(sk, skb);
|
|
}
|
|
EXPORT_SYMBOL(netlink_unicast);
|
|
|
|
int netlink_has_listeners(struct sock *sk, unsigned int group)
|
|
{
|
|
int res = 0;
|
|
struct listeners *listeners;
|
|
|
|
BUG_ON(!netlink_is_kernel(sk));
|
|
|
|
rcu_read_lock();
|
|
listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners);
|
|
|
|
if (listeners && group - 1 < nl_table[sk->sk_protocol].groups)
|
|
res = test_bit(group - 1, listeners->masks);
|
|
|
|
rcu_read_unlock();
|
|
|
|
return res;
|
|
}
|
|
EXPORT_SYMBOL_GPL(netlink_has_listeners);
|
|
|
|
bool netlink_strict_get_check(struct sk_buff *skb)
|
|
{
|
|
const struct netlink_sock *nlk = nlk_sk(NETLINK_CB(skb).sk);
|
|
|
|
return nlk->flags & NETLINK_F_STRICT_CHK;
|
|
}
|
|
EXPORT_SYMBOL_GPL(netlink_strict_get_check);
|
|
|
|
static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
|
|
if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
|
|
!test_bit(NETLINK_S_CONGESTED, &nlk->state)) {
|
|
netlink_skb_set_owner_r(skb, sk);
|
|
__netlink_sendskb(sk, skb);
|
|
return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1);
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
struct netlink_broadcast_data {
|
|
struct sock *exclude_sk;
|
|
struct net *net;
|
|
u32 portid;
|
|
u32 group;
|
|
int failure;
|
|
int delivery_failure;
|
|
int congested;
|
|
int delivered;
|
|
gfp_t allocation;
|
|
struct sk_buff *skb, *skb2;
|
|
int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data);
|
|
void *tx_data;
|
|
};
|
|
|
|
static void do_one_broadcast(struct sock *sk,
|
|
struct netlink_broadcast_data *p)
|
|
{
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
int val;
|
|
|
|
if (p->exclude_sk == sk)
|
|
return;
|
|
|
|
if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups ||
|
|
!test_bit(p->group - 1, nlk->groups))
|
|
return;
|
|
|
|
if (!net_eq(sock_net(sk), p->net)) {
|
|
if (!(nlk->flags & NETLINK_F_LISTEN_ALL_NSID))
|
|
return;
|
|
|
|
if (!peernet_has_id(sock_net(sk), p->net))
|
|
return;
|
|
|
|
if (!file_ns_capable(sk->sk_socket->file, p->net->user_ns,
|
|
CAP_NET_BROADCAST))
|
|
return;
|
|
}
|
|
|
|
if (p->failure) {
|
|
netlink_overrun(sk);
|
|
return;
|
|
}
|
|
|
|
sock_hold(sk);
|
|
if (p->skb2 == NULL) {
|
|
if (skb_shared(p->skb)) {
|
|
p->skb2 = skb_clone(p->skb, p->allocation);
|
|
} else {
|
|
p->skb2 = skb_get(p->skb);
|
|
/*
|
|
* skb ownership may have been set when
|
|
* delivered to a previous socket.
|
|
*/
|
|
skb_orphan(p->skb2);
|
|
}
|
|
}
|
|
if (p->skb2 == NULL) {
|
|
netlink_overrun(sk);
|
|
/* Clone failed. Notify ALL listeners. */
|
|
p->failure = 1;
|
|
if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR)
|
|
p->delivery_failure = 1;
|
|
goto out;
|
|
}
|
|
if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) {
|
|
kfree_skb(p->skb2);
|
|
p->skb2 = NULL;
|
|
goto out;
|
|
}
|
|
if (sk_filter(sk, p->skb2)) {
|
|
kfree_skb(p->skb2);
|
|
p->skb2 = NULL;
|
|
goto out;
|
|
}
|
|
NETLINK_CB(p->skb2).nsid = peernet2id(sock_net(sk), p->net);
|
|
if (NETLINK_CB(p->skb2).nsid != NETNSA_NSID_NOT_ASSIGNED)
|
|
NETLINK_CB(p->skb2).nsid_is_set = true;
|
|
val = netlink_broadcast_deliver(sk, p->skb2);
|
|
if (val < 0) {
|
|
netlink_overrun(sk);
|
|
if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR)
|
|
p->delivery_failure = 1;
|
|
} else {
|
|
p->congested |= val;
|
|
p->delivered = 1;
|
|
p->skb2 = NULL;
|
|
}
|
|
out:
|
|
sock_put(sk);
|
|
}
|
|
|
|
int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 portid,
|
|
u32 group, gfp_t allocation,
|
|
int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
|
|
void *filter_data)
|
|
{
|
|
struct net *net = sock_net(ssk);
|
|
struct netlink_broadcast_data info;
|
|
struct sock *sk;
|
|
|
|
skb = netlink_trim(skb, allocation);
|
|
|
|
info.exclude_sk = ssk;
|
|
info.net = net;
|
|
info.portid = portid;
|
|
info.group = group;
|
|
info.failure = 0;
|
|
info.delivery_failure = 0;
|
|
info.congested = 0;
|
|
info.delivered = 0;
|
|
info.allocation = allocation;
|
|
info.skb = skb;
|
|
info.skb2 = NULL;
|
|
info.tx_filter = filter;
|
|
info.tx_data = filter_data;
|
|
|
|
/* While we sleep in clone, do not allow to change socket list */
|
|
|
|
netlink_lock_table();
|
|
|
|
sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list)
|
|
do_one_broadcast(sk, &info);
|
|
|
|
consume_skb(skb);
|
|
|
|
netlink_unlock_table();
|
|
|
|
if (info.delivery_failure) {
|
|
kfree_skb(info.skb2);
|
|
return -ENOBUFS;
|
|
}
|
|
consume_skb(info.skb2);
|
|
|
|
if (info.delivered) {
|
|
if (info.congested && gfpflags_allow_blocking(allocation))
|
|
yield();
|
|
return 0;
|
|
}
|
|
return -ESRCH;
|
|
}
|
|
EXPORT_SYMBOL(netlink_broadcast_filtered);
|
|
|
|
int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 portid,
|
|
u32 group, gfp_t allocation)
|
|
{
|
|
return netlink_broadcast_filtered(ssk, skb, portid, group, allocation,
|
|
NULL, NULL);
|
|
}
|
|
EXPORT_SYMBOL(netlink_broadcast);
|
|
|
|
struct netlink_set_err_data {
|
|
struct sock *exclude_sk;
|
|
u32 portid;
|
|
u32 group;
|
|
int code;
|
|
};
|
|
|
|
static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p)
|
|
{
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
int ret = 0;
|
|
|
|
if (sk == p->exclude_sk)
|
|
goto out;
|
|
|
|
if (!net_eq(sock_net(sk), sock_net(p->exclude_sk)))
|
|
goto out;
|
|
|
|
if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups ||
|
|
!test_bit(p->group - 1, nlk->groups))
|
|
goto out;
|
|
|
|
if (p->code == ENOBUFS && nlk->flags & NETLINK_F_RECV_NO_ENOBUFS) {
|
|
ret = 1;
|
|
goto out;
|
|
}
|
|
|
|
sk->sk_err = p->code;
|
|
sk->sk_error_report(sk);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* netlink_set_err - report error to broadcast listeners
|
|
* @ssk: the kernel netlink socket, as returned by netlink_kernel_create()
|
|
* @portid: the PORTID of a process that we want to skip (if any)
|
|
* @group: the broadcast group that will notice the error
|
|
* @code: error code, must be negative (as usual in kernelspace)
|
|
*
|
|
* This function returns the number of broadcast listeners that have set the
|
|
* NETLINK_NO_ENOBUFS socket option.
|
|
*/
|
|
int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code)
|
|
{
|
|
struct netlink_set_err_data info;
|
|
struct sock *sk;
|
|
int ret = 0;
|
|
|
|
info.exclude_sk = ssk;
|
|
info.portid = portid;
|
|
info.group = group;
|
|
/* sk->sk_err wants a positive error value */
|
|
info.code = -code;
|
|
|
|
read_lock(&nl_table_lock);
|
|
|
|
sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list)
|
|
ret += do_one_set_err(sk, &info);
|
|
|
|
read_unlock(&nl_table_lock);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(netlink_set_err);
|
|
|
|
/* must be called with netlink table grabbed */
|
|
static void netlink_update_socket_mc(struct netlink_sock *nlk,
|
|
unsigned int group,
|
|
int is_new)
|
|
{
|
|
int old, new = !!is_new, subscriptions;
|
|
|
|
old = test_bit(group - 1, nlk->groups);
|
|
subscriptions = nlk->subscriptions - old + new;
|
|
if (new)
|
|
__set_bit(group - 1, nlk->groups);
|
|
else
|
|
__clear_bit(group - 1, nlk->groups);
|
|
netlink_update_subscriptions(&nlk->sk, subscriptions);
|
|
netlink_update_listeners(&nlk->sk);
|
|
}
|
|
|
|
static int netlink_setsockopt(struct socket *sock, int level, int optname,
|
|
char __user *optval, unsigned int optlen)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
unsigned int val = 0;
|
|
int err;
|
|
|
|
if (level != SOL_NETLINK)
|
|
return -ENOPROTOOPT;
|
|
|
|
if (optlen >= sizeof(int) &&
|
|
get_user(val, (unsigned int __user *)optval))
|
|
return -EFAULT;
|
|
|
|
switch (optname) {
|
|
case NETLINK_PKTINFO:
|
|
if (val)
|
|
nlk->flags |= NETLINK_F_RECV_PKTINFO;
|
|
else
|
|
nlk->flags &= ~NETLINK_F_RECV_PKTINFO;
|
|
err = 0;
|
|
break;
|
|
case NETLINK_ADD_MEMBERSHIP:
|
|
case NETLINK_DROP_MEMBERSHIP: {
|
|
if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV))
|
|
return -EPERM;
|
|
err = netlink_realloc_groups(sk);
|
|
if (err)
|
|
return err;
|
|
if (!val || val - 1 >= nlk->ngroups)
|
|
return -EINVAL;
|
|
if (optname == NETLINK_ADD_MEMBERSHIP && nlk->netlink_bind) {
|
|
err = nlk->netlink_bind(sock_net(sk), val);
|
|
if (err)
|
|
return err;
|
|
}
|
|
netlink_table_grab();
|
|
netlink_update_socket_mc(nlk, val,
|
|
optname == NETLINK_ADD_MEMBERSHIP);
|
|
netlink_table_ungrab();
|
|
if (optname == NETLINK_DROP_MEMBERSHIP && nlk->netlink_unbind)
|
|
nlk->netlink_unbind(sock_net(sk), val);
|
|
|
|
err = 0;
|
|
break;
|
|
}
|
|
case NETLINK_BROADCAST_ERROR:
|
|
if (val)
|
|
nlk->flags |= NETLINK_F_BROADCAST_SEND_ERROR;
|
|
else
|
|
nlk->flags &= ~NETLINK_F_BROADCAST_SEND_ERROR;
|
|
err = 0;
|
|
break;
|
|
case NETLINK_NO_ENOBUFS:
|
|
if (val) {
|
|
nlk->flags |= NETLINK_F_RECV_NO_ENOBUFS;
|
|
clear_bit(NETLINK_S_CONGESTED, &nlk->state);
|
|
wake_up_interruptible(&nlk->wait);
|
|
} else {
|
|
nlk->flags &= ~NETLINK_F_RECV_NO_ENOBUFS;
|
|
}
|
|
err = 0;
|
|
break;
|
|
case NETLINK_LISTEN_ALL_NSID:
|
|
if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_BROADCAST))
|
|
return -EPERM;
|
|
|
|
if (val)
|
|
nlk->flags |= NETLINK_F_LISTEN_ALL_NSID;
|
|
else
|
|
nlk->flags &= ~NETLINK_F_LISTEN_ALL_NSID;
|
|
err = 0;
|
|
break;
|
|
case NETLINK_CAP_ACK:
|
|
if (val)
|
|
nlk->flags |= NETLINK_F_CAP_ACK;
|
|
else
|
|
nlk->flags &= ~NETLINK_F_CAP_ACK;
|
|
err = 0;
|
|
break;
|
|
case NETLINK_EXT_ACK:
|
|
if (val)
|
|
nlk->flags |= NETLINK_F_EXT_ACK;
|
|
else
|
|
nlk->flags &= ~NETLINK_F_EXT_ACK;
|
|
err = 0;
|
|
break;
|
|
case NETLINK_GET_STRICT_CHK:
|
|
if (val)
|
|
nlk->flags |= NETLINK_F_STRICT_CHK;
|
|
else
|
|
nlk->flags &= ~NETLINK_F_STRICT_CHK;
|
|
err = 0;
|
|
break;
|
|
default:
|
|
err = -ENOPROTOOPT;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int netlink_getsockopt(struct socket *sock, int level, int optname,
|
|
char __user *optval, int __user *optlen)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
int len, val, err;
|
|
|
|
if (level != SOL_NETLINK)
|
|
return -ENOPROTOOPT;
|
|
|
|
if (get_user(len, optlen))
|
|
return -EFAULT;
|
|
if (len < 0)
|
|
return -EINVAL;
|
|
|
|
switch (optname) {
|
|
case NETLINK_PKTINFO:
|
|
if (len < sizeof(int))
|
|
return -EINVAL;
|
|
len = sizeof(int);
|
|
val = nlk->flags & NETLINK_F_RECV_PKTINFO ? 1 : 0;
|
|
if (put_user(len, optlen) ||
|
|
put_user(val, optval))
|
|
return -EFAULT;
|
|
err = 0;
|
|
break;
|
|
case NETLINK_BROADCAST_ERROR:
|
|
if (len < sizeof(int))
|
|
return -EINVAL;
|
|
len = sizeof(int);
|
|
val = nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR ? 1 : 0;
|
|
if (put_user(len, optlen) ||
|
|
put_user(val, optval))
|
|
return -EFAULT;
|
|
err = 0;
|
|
break;
|
|
case NETLINK_NO_ENOBUFS:
|
|
if (len < sizeof(int))
|
|
return -EINVAL;
|
|
len = sizeof(int);
|
|
val = nlk->flags & NETLINK_F_RECV_NO_ENOBUFS ? 1 : 0;
|
|
if (put_user(len, optlen) ||
|
|
put_user(val, optval))
|
|
return -EFAULT;
|
|
err = 0;
|
|
break;
|
|
case NETLINK_LIST_MEMBERSHIPS: {
|
|
int pos, idx, shift;
|
|
|
|
err = 0;
|
|
netlink_lock_table();
|
|
for (pos = 0; pos * 8 < nlk->ngroups; pos += sizeof(u32)) {
|
|
if (len - pos < sizeof(u32))
|
|
break;
|
|
|
|
idx = pos / sizeof(unsigned long);
|
|
shift = (pos % sizeof(unsigned long)) * 8;
|
|
if (put_user((u32)(nlk->groups[idx] >> shift),
|
|
(u32 __user *)(optval + pos))) {
|
|
err = -EFAULT;
|
|
break;
|
|
}
|
|
}
|
|
if (put_user(ALIGN(nlk->ngroups / 8, sizeof(u32)), optlen))
|
|
err = -EFAULT;
|
|
netlink_unlock_table();
|
|
break;
|
|
}
|
|
case NETLINK_CAP_ACK:
|
|
if (len < sizeof(int))
|
|
return -EINVAL;
|
|
len = sizeof(int);
|
|
val = nlk->flags & NETLINK_F_CAP_ACK ? 1 : 0;
|
|
if (put_user(len, optlen) ||
|
|
put_user(val, optval))
|
|
return -EFAULT;
|
|
err = 0;
|
|
break;
|
|
case NETLINK_EXT_ACK:
|
|
if (len < sizeof(int))
|
|
return -EINVAL;
|
|
len = sizeof(int);
|
|
val = nlk->flags & NETLINK_F_EXT_ACK ? 1 : 0;
|
|
if (put_user(len, optlen) || put_user(val, optval))
|
|
return -EFAULT;
|
|
err = 0;
|
|
break;
|
|
case NETLINK_GET_STRICT_CHK:
|
|
if (len < sizeof(int))
|
|
return -EINVAL;
|
|
len = sizeof(int);
|
|
val = nlk->flags & NETLINK_F_STRICT_CHK ? 1 : 0;
|
|
if (put_user(len, optlen) || put_user(val, optval))
|
|
return -EFAULT;
|
|
err = 0;
|
|
break;
|
|
default:
|
|
err = -ENOPROTOOPT;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
|
|
{
|
|
struct nl_pktinfo info;
|
|
|
|
info.group = NETLINK_CB(skb).dst_group;
|
|
put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info);
|
|
}
|
|
|
|
static void netlink_cmsg_listen_all_nsid(struct sock *sk, struct msghdr *msg,
|
|
struct sk_buff *skb)
|
|
{
|
|
if (!NETLINK_CB(skb).nsid_is_set)
|
|
return;
|
|
|
|
put_cmsg(msg, SOL_NETLINK, NETLINK_LISTEN_ALL_NSID, sizeof(int),
|
|
&NETLINK_CB(skb).nsid);
|
|
}
|
|
|
|
static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name);
|
|
u32 dst_portid;
|
|
u32 dst_group;
|
|
struct sk_buff *skb;
|
|
int err;
|
|
struct scm_cookie scm;
|
|
u32 netlink_skb_flags = 0;
|
|
|
|
if (msg->msg_flags&MSG_OOB)
|
|
return -EOPNOTSUPP;
|
|
|
|
if (len == 0) {
|
|
pr_warn_once("Zero length message leads to an empty skb\n");
|
|
return -ENODATA;
|
|
}
|
|
|
|
err = scm_send(sock, msg, &scm, true);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
if (msg->msg_namelen) {
|
|
err = -EINVAL;
|
|
if (msg->msg_namelen < sizeof(struct sockaddr_nl))
|
|
goto out;
|
|
if (addr->nl_family != AF_NETLINK)
|
|
goto out;
|
|
dst_portid = addr->nl_pid;
|
|
dst_group = ffs(addr->nl_groups);
|
|
err = -EPERM;
|
|
if ((dst_group || dst_portid) &&
|
|
!netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
|
|
goto out;
|
|
netlink_skb_flags |= NETLINK_SKB_DST;
|
|
} else {
|
|
dst_portid = nlk->dst_portid;
|
|
dst_group = nlk->dst_group;
|
|
}
|
|
|
|
/* Paired with WRITE_ONCE() in netlink_insert() */
|
|
if (!READ_ONCE(nlk->bound)) {
|
|
err = netlink_autobind(sock);
|
|
if (err)
|
|
goto out;
|
|
} else {
|
|
/* Ensure nlk is hashed and visible. */
|
|
smp_rmb();
|
|
}
|
|
|
|
err = -EMSGSIZE;
|
|
if (len > sk->sk_sndbuf - 32)
|
|
goto out;
|
|
err = -ENOBUFS;
|
|
skb = netlink_alloc_large_skb(len, dst_group);
|
|
if (skb == NULL)
|
|
goto out;
|
|
|
|
NETLINK_CB(skb).portid = nlk->portid;
|
|
NETLINK_CB(skb).dst_group = dst_group;
|
|
NETLINK_CB(skb).creds = scm.creds;
|
|
NETLINK_CB(skb).flags = netlink_skb_flags;
|
|
|
|
err = -EFAULT;
|
|
if (memcpy_from_msg(skb_put(skb, len), msg, len)) {
|
|
kfree_skb(skb);
|
|
goto out;
|
|
}
|
|
|
|
err = security_netlink_send(sk, skb);
|
|
if (err) {
|
|
kfree_skb(skb);
|
|
goto out;
|
|
}
|
|
|
|
if (dst_group) {
|
|
refcount_inc(&skb->users);
|
|
netlink_broadcast(sk, skb, dst_portid, dst_group, GFP_KERNEL);
|
|
}
|
|
err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags&MSG_DONTWAIT);
|
|
|
|
out:
|
|
scm_destroy(&scm);
|
|
return err;
|
|
}
|
|
|
|
static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
|
|
int flags)
|
|
{
|
|
struct scm_cookie scm;
|
|
struct sock *sk = sock->sk;
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
int noblock = flags&MSG_DONTWAIT;
|
|
size_t copied;
|
|
struct sk_buff *skb, *data_skb;
|
|
int err, ret;
|
|
|
|
if (flags&MSG_OOB)
|
|
return -EOPNOTSUPP;
|
|
|
|
copied = 0;
|
|
|
|
skb = skb_recv_datagram(sk, flags, noblock, &err);
|
|
if (skb == NULL)
|
|
goto out;
|
|
|
|
data_skb = skb;
|
|
|
|
#ifdef CONFIG_COMPAT_NETLINK_MESSAGES
|
|
if (unlikely(skb_shinfo(skb)->frag_list)) {
|
|
/*
|
|
* If this skb has a frag_list, then here that means that we
|
|
* will have to use the frag_list skb's data for compat tasks
|
|
* and the regular skb's data for normal (non-compat) tasks.
|
|
*
|
|
* If we need to send the compat skb, assign it to the
|
|
* 'data_skb' variable so that it will be used below for data
|
|
* copying. We keep 'skb' for everything else, including
|
|
* freeing both later.
|
|
*/
|
|
if (flags & MSG_CMSG_COMPAT)
|
|
data_skb = skb_shinfo(skb)->frag_list;
|
|
}
|
|
#endif
|
|
|
|
/* Record the max length of recvmsg() calls for future allocations */
|
|
nlk->max_recvmsg_len = max(nlk->max_recvmsg_len, len);
|
|
nlk->max_recvmsg_len = min_t(size_t, nlk->max_recvmsg_len,
|
|
SKB_WITH_OVERHEAD(32768));
|
|
|
|
copied = data_skb->len;
|
|
if (len < copied) {
|
|
msg->msg_flags |= MSG_TRUNC;
|
|
copied = len;
|
|
}
|
|
|
|
skb_reset_transport_header(data_skb);
|
|
err = skb_copy_datagram_msg(data_skb, 0, msg, copied);
|
|
|
|
if (msg->msg_name) {
|
|
DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name);
|
|
addr->nl_family = AF_NETLINK;
|
|
addr->nl_pad = 0;
|
|
addr->nl_pid = NETLINK_CB(skb).portid;
|
|
addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group);
|
|
msg->msg_namelen = sizeof(*addr);
|
|
}
|
|
|
|
if (nlk->flags & NETLINK_F_RECV_PKTINFO)
|
|
netlink_cmsg_recv_pktinfo(msg, skb);
|
|
if (nlk->flags & NETLINK_F_LISTEN_ALL_NSID)
|
|
netlink_cmsg_listen_all_nsid(sk, msg, skb);
|
|
|
|
memset(&scm, 0, sizeof(scm));
|
|
scm.creds = *NETLINK_CREDS(skb);
|
|
if (flags & MSG_TRUNC)
|
|
copied = data_skb->len;
|
|
|
|
skb_free_datagram(sk, skb);
|
|
|
|
if (nlk->cb_running &&
|
|
atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) {
|
|
ret = netlink_dump(sk);
|
|
if (ret) {
|
|
sk->sk_err = -ret;
|
|
sk->sk_error_report(sk);
|
|
}
|
|
}
|
|
|
|
scm_recv(sock, msg, &scm, flags);
|
|
out:
|
|
netlink_rcv_wake(sk);
|
|
return err ? : copied;
|
|
}
|
|
|
|
static void netlink_data_ready(struct sock *sk)
|
|
{
|
|
BUG();
|
|
}
|
|
|
|
/*
|
|
* We export these functions to other modules. They provide a
|
|
* complete set of kernel non-blocking support for message
|
|
* queueing.
|
|
*/
|
|
|
|
struct sock *
|
|
__netlink_kernel_create(struct net *net, int unit, struct module *module,
|
|
struct netlink_kernel_cfg *cfg)
|
|
{
|
|
struct socket *sock;
|
|
struct sock *sk;
|
|
struct netlink_sock *nlk;
|
|
struct listeners *listeners = NULL;
|
|
struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL;
|
|
unsigned int groups;
|
|
|
|
BUG_ON(!nl_table);
|
|
|
|
if (unit < 0 || unit >= MAX_LINKS)
|
|
return NULL;
|
|
|
|
if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
|
|
return NULL;
|
|
|
|
if (__netlink_create(net, sock, cb_mutex, unit, 1) < 0)
|
|
goto out_sock_release_nosk;
|
|
|
|
sk = sock->sk;
|
|
|
|
if (!cfg || cfg->groups < 32)
|
|
groups = 32;
|
|
else
|
|
groups = cfg->groups;
|
|
|
|
listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
|
|
if (!listeners)
|
|
goto out_sock_release;
|
|
|
|
sk->sk_data_ready = netlink_data_ready;
|
|
if (cfg && cfg->input)
|
|
nlk_sk(sk)->netlink_rcv = cfg->input;
|
|
|
|
if (netlink_insert(sk, 0))
|
|
goto out_sock_release;
|
|
|
|
nlk = nlk_sk(sk);
|
|
nlk->flags |= NETLINK_F_KERNEL_SOCKET;
|
|
|
|
netlink_table_grab();
|
|
if (!nl_table[unit].registered) {
|
|
nl_table[unit].groups = groups;
|
|
rcu_assign_pointer(nl_table[unit].listeners, listeners);
|
|
nl_table[unit].cb_mutex = cb_mutex;
|
|
nl_table[unit].module = module;
|
|
if (cfg) {
|
|
nl_table[unit].bind = cfg->bind;
|
|
nl_table[unit].unbind = cfg->unbind;
|
|
nl_table[unit].flags = cfg->flags;
|
|
if (cfg->compare)
|
|
nl_table[unit].compare = cfg->compare;
|
|
}
|
|
nl_table[unit].registered = 1;
|
|
} else {
|
|
kfree(listeners);
|
|
nl_table[unit].registered++;
|
|
}
|
|
netlink_table_ungrab();
|
|
return sk;
|
|
|
|
out_sock_release:
|
|
kfree(listeners);
|
|
netlink_kernel_release(sk);
|
|
return NULL;
|
|
|
|
out_sock_release_nosk:
|
|
sock_release(sock);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(__netlink_kernel_create);
|
|
|
|
void
|
|
netlink_kernel_release(struct sock *sk)
|
|
{
|
|
if (sk == NULL || sk->sk_socket == NULL)
|
|
return;
|
|
|
|
sock_release(sk->sk_socket);
|
|
}
|
|
EXPORT_SYMBOL(netlink_kernel_release);
|
|
|
|
int __netlink_change_ngroups(struct sock *sk, unsigned int groups)
|
|
{
|
|
struct listeners *new, *old;
|
|
struct netlink_table *tbl = &nl_table[sk->sk_protocol];
|
|
|
|
if (groups < 32)
|
|
groups = 32;
|
|
|
|
if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) {
|
|
new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC);
|
|
if (!new)
|
|
return -ENOMEM;
|
|
old = nl_deref_protected(tbl->listeners);
|
|
memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups));
|
|
rcu_assign_pointer(tbl->listeners, new);
|
|
|
|
kfree_rcu(old, rcu);
|
|
}
|
|
tbl->groups = groups;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* netlink_change_ngroups - change number of multicast groups
|
|
*
|
|
* This changes the number of multicast groups that are available
|
|
* on a certain netlink family. Note that it is not possible to
|
|
* change the number of groups to below 32. Also note that it does
|
|
* not implicitly call netlink_clear_multicast_users() when the
|
|
* number of groups is reduced.
|
|
*
|
|
* @sk: The kernel netlink socket, as returned by netlink_kernel_create().
|
|
* @groups: The new number of groups.
|
|
*/
|
|
int netlink_change_ngroups(struct sock *sk, unsigned int groups)
|
|
{
|
|
int err;
|
|
|
|
netlink_table_grab();
|
|
err = __netlink_change_ngroups(sk, groups);
|
|
netlink_table_ungrab();
|
|
|
|
return err;
|
|
}
|
|
|
|
void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
|
|
{
|
|
struct sock *sk;
|
|
struct netlink_table *tbl = &nl_table[ksk->sk_protocol];
|
|
|
|
sk_for_each_bound(sk, &tbl->mc_list)
|
|
netlink_update_socket_mc(nlk_sk(sk), group, 0);
|
|
}
|
|
|
|
struct nlmsghdr *
|
|
__nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags)
|
|
{
|
|
struct nlmsghdr *nlh;
|
|
int size = nlmsg_msg_size(len);
|
|
|
|
nlh = skb_put(skb, NLMSG_ALIGN(size));
|
|
nlh->nlmsg_type = type;
|
|
nlh->nlmsg_len = size;
|
|
nlh->nlmsg_flags = flags;
|
|
nlh->nlmsg_pid = portid;
|
|
nlh->nlmsg_seq = seq;
|
|
if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0)
|
|
memset(nlmsg_data(nlh) + len, 0, NLMSG_ALIGN(size) - size);
|
|
return nlh;
|
|
}
|
|
EXPORT_SYMBOL(__nlmsg_put);
|
|
|
|
/*
|
|
* It looks a bit ugly.
|
|
* It would be better to create kernel thread.
|
|
*/
|
|
|
|
static int netlink_dump(struct sock *sk)
|
|
{
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
struct netlink_ext_ack extack = {};
|
|
struct netlink_callback *cb;
|
|
struct sk_buff *skb = NULL;
|
|
struct nlmsghdr *nlh;
|
|
struct module *module;
|
|
int err = -ENOBUFS;
|
|
int alloc_min_size;
|
|
int alloc_size;
|
|
|
|
mutex_lock(nlk->cb_mutex);
|
|
if (!nlk->cb_running) {
|
|
err = -EINVAL;
|
|
goto errout_skb;
|
|
}
|
|
|
|
if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
|
|
goto errout_skb;
|
|
|
|
/* NLMSG_GOODSIZE is small to avoid high order allocations being
|
|
* required, but it makes sense to _attempt_ a 16K bytes allocation
|
|
* to reduce number of system calls on dump operations, if user
|
|
* ever provided a big enough buffer.
|
|
*/
|
|
cb = &nlk->cb;
|
|
alloc_min_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE);
|
|
|
|
if (alloc_min_size < nlk->max_recvmsg_len) {
|
|
alloc_size = nlk->max_recvmsg_len;
|
|
skb = alloc_skb(alloc_size,
|
|
(GFP_KERNEL & ~__GFP_DIRECT_RECLAIM) |
|
|
__GFP_NOWARN | __GFP_NORETRY);
|
|
}
|
|
if (!skb) {
|
|
alloc_size = alloc_min_size;
|
|
skb = alloc_skb(alloc_size, GFP_KERNEL);
|
|
}
|
|
if (!skb)
|
|
goto errout_skb;
|
|
|
|
/* Trim skb to allocated size. User is expected to provide buffer as
|
|
* large as max(min_dump_alloc, 16KiB (mac_recvmsg_len capped at
|
|
* netlink_recvmsg())). dump will pack as many smaller messages as
|
|
* could fit within the allocated skb. skb is typically allocated
|
|
* with larger space than required (could be as much as near 2x the
|
|
* requested size with align to next power of 2 approach). Allowing
|
|
* dump to use the excess space makes it difficult for a user to have a
|
|
* reasonable static buffer based on the expected largest dump of a
|
|
* single netdev. The outcome is MSG_TRUNC error.
|
|
*/
|
|
skb_reserve(skb, skb_tailroom(skb) - alloc_size);
|
|
netlink_skb_set_owner_r(skb, sk);
|
|
|
|
if (nlk->dump_done_errno > 0) {
|
|
cb->extack = &extack;
|
|
nlk->dump_done_errno = cb->dump(skb, cb);
|
|
cb->extack = NULL;
|
|
}
|
|
|
|
if (nlk->dump_done_errno > 0 ||
|
|
skb_tailroom(skb) < nlmsg_total_size(sizeof(nlk->dump_done_errno))) {
|
|
mutex_unlock(nlk->cb_mutex);
|
|
|
|
if (sk_filter(sk, skb))
|
|
kfree_skb(skb);
|
|
else
|
|
__netlink_sendskb(sk, skb);
|
|
return 0;
|
|
}
|
|
|
|
nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE,
|
|
sizeof(nlk->dump_done_errno),
|
|
NLM_F_MULTI | cb->answer_flags);
|
|
if (WARN_ON(!nlh))
|
|
goto errout_skb;
|
|
|
|
nl_dump_check_consistent(cb, nlh);
|
|
|
|
memcpy(nlmsg_data(nlh), &nlk->dump_done_errno,
|
|
sizeof(nlk->dump_done_errno));
|
|
|
|
if (extack._msg && nlk->flags & NETLINK_F_EXT_ACK) {
|
|
nlh->nlmsg_flags |= NLM_F_ACK_TLVS;
|
|
if (!nla_put_string(skb, NLMSGERR_ATTR_MSG, extack._msg))
|
|
nlmsg_end(skb, nlh);
|
|
}
|
|
|
|
if (sk_filter(sk, skb))
|
|
kfree_skb(skb);
|
|
else
|
|
__netlink_sendskb(sk, skb);
|
|
|
|
if (cb->done)
|
|
cb->done(cb);
|
|
|
|
nlk->cb_running = false;
|
|
module = cb->module;
|
|
skb = cb->skb;
|
|
mutex_unlock(nlk->cb_mutex);
|
|
module_put(module);
|
|
consume_skb(skb);
|
|
return 0;
|
|
|
|
errout_skb:
|
|
mutex_unlock(nlk->cb_mutex);
|
|
kfree_skb(skb);
|
|
return err;
|
|
}
|
|
|
|
int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
|
|
const struct nlmsghdr *nlh,
|
|
struct netlink_dump_control *control)
|
|
{
|
|
struct netlink_sock *nlk, *nlk2;
|
|
struct netlink_callback *cb;
|
|
struct sock *sk;
|
|
int ret;
|
|
|
|
refcount_inc(&skb->users);
|
|
|
|
sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).portid);
|
|
if (sk == NULL) {
|
|
ret = -ECONNREFUSED;
|
|
goto error_free;
|
|
}
|
|
|
|
nlk = nlk_sk(sk);
|
|
mutex_lock(nlk->cb_mutex);
|
|
/* A dump is in progress... */
|
|
if (nlk->cb_running) {
|
|
ret = -EBUSY;
|
|
goto error_unlock;
|
|
}
|
|
/* add reference of module which cb->dump belongs to */
|
|
if (!try_module_get(control->module)) {
|
|
ret = -EPROTONOSUPPORT;
|
|
goto error_unlock;
|
|
}
|
|
|
|
cb = &nlk->cb;
|
|
memset(cb, 0, sizeof(*cb));
|
|
cb->dump = control->dump;
|
|
cb->done = control->done;
|
|
cb->nlh = nlh;
|
|
cb->data = control->data;
|
|
cb->module = control->module;
|
|
cb->min_dump_alloc = control->min_dump_alloc;
|
|
cb->skb = skb;
|
|
|
|
nlk2 = nlk_sk(NETLINK_CB(skb).sk);
|
|
cb->strict_check = !!(nlk2->flags & NETLINK_F_STRICT_CHK);
|
|
|
|
if (control->start) {
|
|
ret = control->start(cb);
|
|
if (ret)
|
|
goto error_put;
|
|
}
|
|
|
|
nlk->cb_running = true;
|
|
nlk->dump_done_errno = INT_MAX;
|
|
|
|
mutex_unlock(nlk->cb_mutex);
|
|
|
|
ret = netlink_dump(sk);
|
|
|
|
sock_put(sk);
|
|
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* We successfully started a dump, by returning -EINTR we
|
|
* signal not to send ACK even if it was requested.
|
|
*/
|
|
return -EINTR;
|
|
|
|
error_put:
|
|
module_put(control->module);
|
|
error_unlock:
|
|
sock_put(sk);
|
|
mutex_unlock(nlk->cb_mutex);
|
|
error_free:
|
|
kfree_skb(skb);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(__netlink_dump_start);
|
|
|
|
void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
|
|
const struct netlink_ext_ack *extack)
|
|
{
|
|
struct sk_buff *skb;
|
|
struct nlmsghdr *rep;
|
|
struct nlmsgerr *errmsg;
|
|
size_t payload = sizeof(*errmsg);
|
|
size_t tlvlen = 0;
|
|
struct netlink_sock *nlk = nlk_sk(NETLINK_CB(in_skb).sk);
|
|
unsigned int flags = 0;
|
|
bool nlk_has_extack = nlk->flags & NETLINK_F_EXT_ACK;
|
|
|
|
/* Error messages get the original request appened, unless the user
|
|
* requests to cap the error message, and get extra error data if
|
|
* requested.
|
|
*/
|
|
if (nlk_has_extack && extack && extack->_msg)
|
|
tlvlen += nla_total_size(strlen(extack->_msg) + 1);
|
|
|
|
if (err) {
|
|
if (!(nlk->flags & NETLINK_F_CAP_ACK))
|
|
payload += nlmsg_len(nlh);
|
|
else
|
|
flags |= NLM_F_CAPPED;
|
|
if (nlk_has_extack && extack && extack->bad_attr)
|
|
tlvlen += nla_total_size(sizeof(u32));
|
|
} else {
|
|
flags |= NLM_F_CAPPED;
|
|
|
|
if (nlk_has_extack && extack && extack->cookie_len)
|
|
tlvlen += nla_total_size(extack->cookie_len);
|
|
}
|
|
|
|
if (tlvlen)
|
|
flags |= NLM_F_ACK_TLVS;
|
|
|
|
skb = nlmsg_new(payload + tlvlen, GFP_KERNEL);
|
|
if (!skb) {
|
|
NETLINK_CB(in_skb).sk->sk_err = ENOBUFS;
|
|
NETLINK_CB(in_skb).sk->sk_error_report(NETLINK_CB(in_skb).sk);
|
|
return;
|
|
}
|
|
|
|
rep = __nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
|
|
NLMSG_ERROR, payload, flags);
|
|
errmsg = nlmsg_data(rep);
|
|
errmsg->error = err;
|
|
memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh));
|
|
|
|
if (nlk_has_extack && extack) {
|
|
if (extack->_msg) {
|
|
WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG,
|
|
extack->_msg));
|
|
}
|
|
if (err) {
|
|
if (extack->bad_attr &&
|
|
!WARN_ON((u8 *)extack->bad_attr < in_skb->data ||
|
|
(u8 *)extack->bad_attr >= in_skb->data +
|
|
in_skb->len))
|
|
WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS,
|
|
(u8 *)extack->bad_attr -
|
|
(u8 *)nlh));
|
|
} else {
|
|
if (extack->cookie_len)
|
|
WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE,
|
|
extack->cookie_len,
|
|
extack->cookie));
|
|
}
|
|
}
|
|
|
|
nlmsg_end(skb, rep);
|
|
|
|
netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid, MSG_DONTWAIT);
|
|
}
|
|
EXPORT_SYMBOL(netlink_ack);
|
|
|
|
int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
|
|
struct nlmsghdr *,
|
|
struct netlink_ext_ack *))
|
|
{
|
|
struct netlink_ext_ack extack;
|
|
struct nlmsghdr *nlh;
|
|
int err;
|
|
|
|
while (skb->len >= nlmsg_total_size(0)) {
|
|
int msglen;
|
|
|
|
memset(&extack, 0, sizeof(extack));
|
|
nlh = nlmsg_hdr(skb);
|
|
err = 0;
|
|
|
|
if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
|
|
return 0;
|
|
|
|
/* Only requests are handled by the kernel */
|
|
if (!(nlh->nlmsg_flags & NLM_F_REQUEST))
|
|
goto ack;
|
|
|
|
/* Skip control messages */
|
|
if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
|
|
goto ack;
|
|
|
|
err = cb(skb, nlh, &extack);
|
|
if (err == -EINTR)
|
|
goto skip;
|
|
|
|
ack:
|
|
if (nlh->nlmsg_flags & NLM_F_ACK || err)
|
|
netlink_ack(skb, nlh, err, &extack);
|
|
|
|
skip:
|
|
msglen = NLMSG_ALIGN(nlh->nlmsg_len);
|
|
if (msglen > skb->len)
|
|
msglen = skb->len;
|
|
skb_pull(skb, msglen);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(netlink_rcv_skb);
|
|
|
|
/**
|
|
* nlmsg_notify - send a notification netlink message
|
|
* @sk: netlink socket to use
|
|
* @skb: notification message
|
|
* @portid: destination netlink portid for reports or 0
|
|
* @group: destination multicast group or 0
|
|
* @report: 1 to report back, 0 to disable
|
|
* @flags: allocation flags
|
|
*/
|
|
int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
|
|
unsigned int group, int report, gfp_t flags)
|
|
{
|
|
int err = 0;
|
|
|
|
if (group) {
|
|
int exclude_portid = 0;
|
|
|
|
if (report) {
|
|
refcount_inc(&skb->users);
|
|
exclude_portid = portid;
|
|
}
|
|
|
|
/* errors reported via destination sk->sk_err, but propagate
|
|
* delivery errors if NETLINK_BROADCAST_ERROR flag is set */
|
|
err = nlmsg_multicast(sk, skb, exclude_portid, group, flags);
|
|
if (err == -ESRCH)
|
|
err = 0;
|
|
}
|
|
|
|
if (report) {
|
|
int err2;
|
|
|
|
err2 = nlmsg_unicast(sk, skb, portid);
|
|
if (!err)
|
|
err = err2;
|
|
}
|
|
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(nlmsg_notify);
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
struct nl_seq_iter {
|
|
struct seq_net_private p;
|
|
struct rhashtable_iter hti;
|
|
int link;
|
|
};
|
|
|
|
static void netlink_walk_start(struct nl_seq_iter *iter)
|
|
{
|
|
rhashtable_walk_enter(&nl_table[iter->link].hash, &iter->hti);
|
|
rhashtable_walk_start(&iter->hti);
|
|
}
|
|
|
|
static void netlink_walk_stop(struct nl_seq_iter *iter)
|
|
{
|
|
rhashtable_walk_stop(&iter->hti);
|
|
rhashtable_walk_exit(&iter->hti);
|
|
}
|
|
|
|
static void *__netlink_seq_next(struct seq_file *seq)
|
|
{
|
|
struct nl_seq_iter *iter = seq->private;
|
|
struct netlink_sock *nlk;
|
|
|
|
do {
|
|
for (;;) {
|
|
nlk = rhashtable_walk_next(&iter->hti);
|
|
|
|
if (IS_ERR(nlk)) {
|
|
if (PTR_ERR(nlk) == -EAGAIN)
|
|
continue;
|
|
|
|
return nlk;
|
|
}
|
|
|
|
if (nlk)
|
|
break;
|
|
|
|
netlink_walk_stop(iter);
|
|
if (++iter->link >= MAX_LINKS)
|
|
return NULL;
|
|
|
|
netlink_walk_start(iter);
|
|
}
|
|
} while (sock_net(&nlk->sk) != seq_file_net(seq));
|
|
|
|
return nlk;
|
|
}
|
|
|
|
static void *netlink_seq_start(struct seq_file *seq, loff_t *posp)
|
|
{
|
|
struct nl_seq_iter *iter = seq->private;
|
|
void *obj = SEQ_START_TOKEN;
|
|
loff_t pos;
|
|
|
|
iter->link = 0;
|
|
|
|
netlink_walk_start(iter);
|
|
|
|
for (pos = *posp; pos && obj && !IS_ERR(obj); pos--)
|
|
obj = __netlink_seq_next(seq);
|
|
|
|
return obj;
|
|
}
|
|
|
|
static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
|
|
{
|
|
++*pos;
|
|
return __netlink_seq_next(seq);
|
|
}
|
|
|
|
static void netlink_seq_stop(struct seq_file *seq, void *v)
|
|
{
|
|
struct nl_seq_iter *iter = seq->private;
|
|
|
|
if (iter->link >= MAX_LINKS)
|
|
return;
|
|
|
|
netlink_walk_stop(iter);
|
|
}
|
|
|
|
|
|
static int netlink_seq_show(struct seq_file *seq, void *v)
|
|
{
|
|
if (v == SEQ_START_TOKEN) {
|
|
seq_puts(seq,
|
|
"sk Eth Pid Groups "
|
|
"Rmem Wmem Dump Locks Drops Inode\n");
|
|
} else {
|
|
struct sock *s = v;
|
|
struct netlink_sock *nlk = nlk_sk(s);
|
|
|
|
seq_printf(seq, "%pK %-3d %-10u %08x %-8d %-8d %-5d %-8d %-8u %-8lu\n",
|
|
s,
|
|
s->sk_protocol,
|
|
nlk->portid,
|
|
nlk->groups ? (u32)nlk->groups[0] : 0,
|
|
sk_rmem_alloc_get(s),
|
|
sk_wmem_alloc_get(s),
|
|
nlk->cb_running,
|
|
refcount_read(&s->sk_refcnt),
|
|
atomic_read(&s->sk_drops),
|
|
sock_i_ino(s)
|
|
);
|
|
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations netlink_seq_ops = {
|
|
.start = netlink_seq_start,
|
|
.next = netlink_seq_next,
|
|
.stop = netlink_seq_stop,
|
|
.show = netlink_seq_show,
|
|
};
|
|
#endif
|
|
|
|
int netlink_register_notifier(struct notifier_block *nb)
|
|
{
|
|
return blocking_notifier_chain_register(&netlink_chain, nb);
|
|
}
|
|
EXPORT_SYMBOL(netlink_register_notifier);
|
|
|
|
int netlink_unregister_notifier(struct notifier_block *nb)
|
|
{
|
|
return blocking_notifier_chain_unregister(&netlink_chain, nb);
|
|
}
|
|
EXPORT_SYMBOL(netlink_unregister_notifier);
|
|
|
|
static const struct proto_ops netlink_ops = {
|
|
.family = PF_NETLINK,
|
|
.owner = THIS_MODULE,
|
|
.release = netlink_release,
|
|
.bind = netlink_bind,
|
|
.connect = netlink_connect,
|
|
.socketpair = sock_no_socketpair,
|
|
.accept = sock_no_accept,
|
|
.getname = netlink_getname,
|
|
.poll = datagram_poll,
|
|
.ioctl = netlink_ioctl,
|
|
.listen = sock_no_listen,
|
|
.shutdown = sock_no_shutdown,
|
|
.setsockopt = netlink_setsockopt,
|
|
.getsockopt = netlink_getsockopt,
|
|
.sendmsg = netlink_sendmsg,
|
|
.recvmsg = netlink_recvmsg,
|
|
.mmap = sock_no_mmap,
|
|
.sendpage = sock_no_sendpage,
|
|
};
|
|
|
|
static const struct net_proto_family netlink_family_ops = {
|
|
.family = PF_NETLINK,
|
|
.create = netlink_create,
|
|
.owner = THIS_MODULE, /* for consistency 8) */
|
|
};
|
|
|
|
static int __net_init netlink_net_init(struct net *net)
|
|
{
|
|
#ifdef CONFIG_PROC_FS
|
|
if (!proc_create_net("netlink", 0, net->proc_net, &netlink_seq_ops,
|
|
sizeof(struct nl_seq_iter)))
|
|
return -ENOMEM;
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
static void __net_exit netlink_net_exit(struct net *net)
|
|
{
|
|
#ifdef CONFIG_PROC_FS
|
|
remove_proc_entry("netlink", net->proc_net);
|
|
#endif
|
|
}
|
|
|
|
static void __init netlink_add_usersock_entry(void)
|
|
{
|
|
struct listeners *listeners;
|
|
int groups = 32;
|
|
|
|
listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
|
|
if (!listeners)
|
|
panic("netlink_add_usersock_entry: Cannot allocate listeners\n");
|
|
|
|
netlink_table_grab();
|
|
|
|
nl_table[NETLINK_USERSOCK].groups = groups;
|
|
rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners);
|
|
nl_table[NETLINK_USERSOCK].module = THIS_MODULE;
|
|
nl_table[NETLINK_USERSOCK].registered = 1;
|
|
nl_table[NETLINK_USERSOCK].flags = NL_CFG_F_NONROOT_SEND;
|
|
|
|
netlink_table_ungrab();
|
|
}
|
|
|
|
static struct pernet_operations __net_initdata netlink_net_ops = {
|
|
.init = netlink_net_init,
|
|
.exit = netlink_net_exit,
|
|
};
|
|
|
|
static inline u32 netlink_hash(const void *data, u32 len, u32 seed)
|
|
{
|
|
const struct netlink_sock *nlk = data;
|
|
struct netlink_compare_arg arg;
|
|
|
|
netlink_compare_arg_init(&arg, sock_net(&nlk->sk), nlk->portid);
|
|
return jhash2((u32 *)&arg, netlink_compare_arg_len / sizeof(u32), seed);
|
|
}
|
|
|
|
static const struct rhashtable_params netlink_rhashtable_params = {
|
|
.head_offset = offsetof(struct netlink_sock, node),
|
|
.key_len = netlink_compare_arg_len,
|
|
.obj_hashfn = netlink_hash,
|
|
.obj_cmpfn = netlink_compare,
|
|
.automatic_shrinking = true,
|
|
};
|
|
|
|
static int __init netlink_proto_init(void)
|
|
{
|
|
int i;
|
|
int err = proto_register(&netlink_proto, 0);
|
|
|
|
if (err != 0)
|
|
goto out;
|
|
|
|
BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > FIELD_SIZEOF(struct sk_buff, cb));
|
|
|
|
nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL);
|
|
if (!nl_table)
|
|
goto panic;
|
|
|
|
for (i = 0; i < MAX_LINKS; i++) {
|
|
if (rhashtable_init(&nl_table[i].hash,
|
|
&netlink_rhashtable_params) < 0) {
|
|
while (--i > 0)
|
|
rhashtable_destroy(&nl_table[i].hash);
|
|
kfree(nl_table);
|
|
goto panic;
|
|
}
|
|
}
|
|
|
|
netlink_add_usersock_entry();
|
|
|
|
sock_register(&netlink_family_ops);
|
|
register_pernet_subsys(&netlink_net_ops);
|
|
register_pernet_subsys(&netlink_tap_net_ops);
|
|
/* The netlink device handler may be needed early. */
|
|
rtnetlink_init();
|
|
out:
|
|
return err;
|
|
panic:
|
|
panic("netlink_init: Cannot allocate nl_table\n");
|
|
}
|
|
|
|
core_initcall(netlink_proto_init);
|