linux-stable/net/ipv4/udplite.c
Kirill Tkhai f84c6821aa net: Convert pernet_subsys, registered from inet_init()
arp_net_ops just addr/removes /proc entry.

devinet_ops allocates and frees duplicate of init_net tables
and (un)registers sysctl entries.

fib_net_ops allocates and frees pernet tables, creates/destroys
netlink socket and (un)initializes /proc entries. Foreign
pernet_operations do not touch them.

ip_rt_proc_ops only modifies pernet /proc entries.

xfrm_net_ops creates/destroys /proc entries, allocates/frees
pernet statistics, hashes and tables, and (un)initializes
sysctl files. These are not touched by foreigh pernet_operations

xfrm4_net_ops allocates/frees private pernet memory, and
configures sysctls.

sysctl_route_ops creates/destroys sysctls.

rt_genid_ops only initializes fields of just allocated net.

ipv4_inetpeer_ops allocated/frees net private memory.

igmp_net_ops just creates/destroys /proc files and socket,
noone else interested in.

tcp_sk_ops seems to be safe, because tcp_sk_init() does not
depend on any other pernet_operations modifications. Iteration
over hash table in inet_twsk_purge() is made under RCU lock,
and it's safe to iterate the table this way. Removing from
the table happen from inet_twsk_deschedule_put(), but this
function is safe without any extern locks, as it's synchronized
inside itself. There are many examples, it's used in different
context. So, it's safe to leave tcp_sk_exit_batch() unlocked.

tcp_net_metrics_ops is synchronized on tcp_metrics_lock and safe.

udplite4_net_ops only creates/destroys pernet /proc file.

icmp_sk_ops creates percpu sockets, not touched by foreign
pernet_operations.

ipmr_net_ops creates/destroys pernet fib tables, (un)registers
fib rules and /proc files. This seem to be safe to execute
in parallel with foreign pernet_operations.

af_inet_ops just sets up default parameters of newly created net.

ipv4_mib_ops creates and destroys pernet percpu statistics.

raw_net_ops, tcp4_net_ops, udp4_net_ops, ping_v4_net_ops
and ip_proc_ops only create/destroy pernet /proc files.

ip4_frags_ops creates and destroys sysctl file.

So, it's safe to make the pernet_operations async.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-13 10:36:08 -05:00

140 lines
3.3 KiB
C

/*
* UDPLITE An implementation of the UDP-Lite protocol (RFC 3828).
*
* Authors: Gerrit Renker <gerrit@erg.abdn.ac.uk>
*
* Changes:
* Fixes:
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#define pr_fmt(fmt) "UDPLite: " fmt
#include <linux/export.h>
#include "udp_impl.h"
struct udp_table udplite_table __read_mostly;
EXPORT_SYMBOL(udplite_table);
static int udplite_rcv(struct sk_buff *skb)
{
return __udp4_lib_rcv(skb, &udplite_table, IPPROTO_UDPLITE);
}
static void udplite_err(struct sk_buff *skb, u32 info)
{
__udp4_lib_err(skb, info, &udplite_table);
}
static const struct net_protocol udplite_protocol = {
.handler = udplite_rcv,
.err_handler = udplite_err,
.no_policy = 1,
.netns_ok = 1,
};
struct proto udplite_prot = {
.name = "UDP-Lite",
.owner = THIS_MODULE,
.close = udp_lib_close,
.connect = ip4_datagram_connect,
.disconnect = udp_disconnect,
.ioctl = udp_ioctl,
.init = udplite_sk_init,
.destroy = udp_destroy_sock,
.setsockopt = udp_setsockopt,
.getsockopt = udp_getsockopt,
.sendmsg = udp_sendmsg,
.recvmsg = udp_recvmsg,
.sendpage = udp_sendpage,
.hash = udp_lib_hash,
.unhash = udp_lib_unhash,
.get_port = udp_v4_get_port,
.memory_allocated = &udp_memory_allocated,
.sysctl_mem = sysctl_udp_mem,
.obj_size = sizeof(struct udp_sock),
.h.udp_table = &udplite_table,
#ifdef CONFIG_COMPAT
.compat_setsockopt = compat_udp_setsockopt,
.compat_getsockopt = compat_udp_getsockopt,
#endif
};
EXPORT_SYMBOL(udplite_prot);
static struct inet_protosw udplite4_protosw = {
.type = SOCK_DGRAM,
.protocol = IPPROTO_UDPLITE,
.prot = &udplite_prot,
.ops = &inet_dgram_ops,
.flags = INET_PROTOSW_PERMANENT,
};
#ifdef CONFIG_PROC_FS
static const struct file_operations udplite_afinfo_seq_fops = {
.open = udp_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_net
};
static struct udp_seq_afinfo udplite4_seq_afinfo = {
.name = "udplite",
.family = AF_INET,
.udp_table = &udplite_table,
.seq_fops = &udplite_afinfo_seq_fops,
.seq_ops = {
.show = udp4_seq_show,
},
};
static int __net_init udplite4_proc_init_net(struct net *net)
{
return udp_proc_register(net, &udplite4_seq_afinfo);
}
static void __net_exit udplite4_proc_exit_net(struct net *net)
{
udp_proc_unregister(net, &udplite4_seq_afinfo);
}
static struct pernet_operations udplite4_net_ops = {
.init = udplite4_proc_init_net,
.exit = udplite4_proc_exit_net,
.async = true,
};
static __init int udplite4_proc_init(void)
{
return register_pernet_subsys(&udplite4_net_ops);
}
#else
static inline int udplite4_proc_init(void)
{
return 0;
}
#endif
void __init udplite4_register(void)
{
udp_table_init(&udplite_table, "UDP-Lite");
if (proto_register(&udplite_prot, 1))
goto out_register_err;
if (inet_add_protocol(&udplite_protocol, IPPROTO_UDPLITE) < 0)
goto out_unregister_proto;
inet_register_protosw(&udplite4_protosw);
if (udplite4_proc_init())
pr_err("%s: Cannot register /proc!\n", __func__);
return;
out_unregister_proto:
proto_unregister(&udplite_prot);
out_register_err:
pr_crit("%s: Cannot add UDP-Lite protocol\n", __func__);
}