mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 10:49:33 +00:00
![Christoph Hellwig](/assets/img/avatar_default.png)
Variants of proc_create{,_data} that directly take a struct seq_operations and deal with network namespaces in ->open and ->release. All callers of proc_create + seq_open_net converted over, and seq_{open,release}_net are removed entirely. Signed-off-by: Christoph Hellwig <hch@lst.de>
420 lines
9.7 KiB
C
420 lines
9.7 KiB
C
/*
|
|
* Copyright (c) 2013 Patrick McHardy <kaber@trash.net>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/skbuff.h>
|
|
#include <asm/unaligned.h>
|
|
#include <net/tcp.h>
|
|
#include <net/netns/generic.h>
|
|
#include <linux/proc_fs.h>
|
|
|
|
#include <linux/netfilter_ipv4/ip_tables.h>
|
|
#include <linux/netfilter/x_tables.h>
|
|
#include <linux/netfilter/xt_tcpudp.h>
|
|
#include <linux/netfilter/xt_SYNPROXY.h>
|
|
|
|
#include <net/netfilter/nf_conntrack.h>
|
|
#include <net/netfilter/nf_conntrack_extend.h>
|
|
#include <net/netfilter/nf_conntrack_seqadj.h>
|
|
#include <net/netfilter/nf_conntrack_synproxy.h>
|
|
#include <net/netfilter/nf_conntrack_zones.h>
|
|
|
|
unsigned int synproxy_net_id;
|
|
EXPORT_SYMBOL_GPL(synproxy_net_id);
|
|
|
|
bool
|
|
synproxy_parse_options(const struct sk_buff *skb, unsigned int doff,
|
|
const struct tcphdr *th, struct synproxy_options *opts)
|
|
{
|
|
int length = (th->doff * 4) - sizeof(*th);
|
|
u8 buf[40], *ptr;
|
|
|
|
ptr = skb_header_pointer(skb, doff + sizeof(*th), length, buf);
|
|
if (ptr == NULL)
|
|
return false;
|
|
|
|
opts->options = 0;
|
|
while (length > 0) {
|
|
int opcode = *ptr++;
|
|
int opsize;
|
|
|
|
switch (opcode) {
|
|
case TCPOPT_EOL:
|
|
return true;
|
|
case TCPOPT_NOP:
|
|
length--;
|
|
continue;
|
|
default:
|
|
opsize = *ptr++;
|
|
if (opsize < 2)
|
|
return true;
|
|
if (opsize > length)
|
|
return true;
|
|
|
|
switch (opcode) {
|
|
case TCPOPT_MSS:
|
|
if (opsize == TCPOLEN_MSS) {
|
|
opts->mss = get_unaligned_be16(ptr);
|
|
opts->options |= XT_SYNPROXY_OPT_MSS;
|
|
}
|
|
break;
|
|
case TCPOPT_WINDOW:
|
|
if (opsize == TCPOLEN_WINDOW) {
|
|
opts->wscale = *ptr;
|
|
if (opts->wscale > TCP_MAX_WSCALE)
|
|
opts->wscale = TCP_MAX_WSCALE;
|
|
opts->options |= XT_SYNPROXY_OPT_WSCALE;
|
|
}
|
|
break;
|
|
case TCPOPT_TIMESTAMP:
|
|
if (opsize == TCPOLEN_TIMESTAMP) {
|
|
opts->tsval = get_unaligned_be32(ptr);
|
|
opts->tsecr = get_unaligned_be32(ptr + 4);
|
|
opts->options |= XT_SYNPROXY_OPT_TIMESTAMP;
|
|
}
|
|
break;
|
|
case TCPOPT_SACK_PERM:
|
|
if (opsize == TCPOLEN_SACK_PERM)
|
|
opts->options |= XT_SYNPROXY_OPT_SACK_PERM;
|
|
break;
|
|
}
|
|
|
|
ptr += opsize - 2;
|
|
length -= opsize;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL_GPL(synproxy_parse_options);
|
|
|
|
unsigned int synproxy_options_size(const struct synproxy_options *opts)
|
|
{
|
|
unsigned int size = 0;
|
|
|
|
if (opts->options & XT_SYNPROXY_OPT_MSS)
|
|
size += TCPOLEN_MSS_ALIGNED;
|
|
if (opts->options & XT_SYNPROXY_OPT_TIMESTAMP)
|
|
size += TCPOLEN_TSTAMP_ALIGNED;
|
|
else if (opts->options & XT_SYNPROXY_OPT_SACK_PERM)
|
|
size += TCPOLEN_SACKPERM_ALIGNED;
|
|
if (opts->options & XT_SYNPROXY_OPT_WSCALE)
|
|
size += TCPOLEN_WSCALE_ALIGNED;
|
|
|
|
return size;
|
|
}
|
|
EXPORT_SYMBOL_GPL(synproxy_options_size);
|
|
|
|
void
|
|
synproxy_build_options(struct tcphdr *th, const struct synproxy_options *opts)
|
|
{
|
|
__be32 *ptr = (__be32 *)(th + 1);
|
|
u8 options = opts->options;
|
|
|
|
if (options & XT_SYNPROXY_OPT_MSS)
|
|
*ptr++ = htonl((TCPOPT_MSS << 24) |
|
|
(TCPOLEN_MSS << 16) |
|
|
opts->mss);
|
|
|
|
if (options & XT_SYNPROXY_OPT_TIMESTAMP) {
|
|
if (options & XT_SYNPROXY_OPT_SACK_PERM)
|
|
*ptr++ = htonl((TCPOPT_SACK_PERM << 24) |
|
|
(TCPOLEN_SACK_PERM << 16) |
|
|
(TCPOPT_TIMESTAMP << 8) |
|
|
TCPOLEN_TIMESTAMP);
|
|
else
|
|
*ptr++ = htonl((TCPOPT_NOP << 24) |
|
|
(TCPOPT_NOP << 16) |
|
|
(TCPOPT_TIMESTAMP << 8) |
|
|
TCPOLEN_TIMESTAMP);
|
|
|
|
*ptr++ = htonl(opts->tsval);
|
|
*ptr++ = htonl(opts->tsecr);
|
|
} else if (options & XT_SYNPROXY_OPT_SACK_PERM)
|
|
*ptr++ = htonl((TCPOPT_NOP << 24) |
|
|
(TCPOPT_NOP << 16) |
|
|
(TCPOPT_SACK_PERM << 8) |
|
|
TCPOLEN_SACK_PERM);
|
|
|
|
if (options & XT_SYNPROXY_OPT_WSCALE)
|
|
*ptr++ = htonl((TCPOPT_NOP << 24) |
|
|
(TCPOPT_WINDOW << 16) |
|
|
(TCPOLEN_WINDOW << 8) |
|
|
opts->wscale);
|
|
}
|
|
EXPORT_SYMBOL_GPL(synproxy_build_options);
|
|
|
|
void synproxy_init_timestamp_cookie(const struct xt_synproxy_info *info,
|
|
struct synproxy_options *opts)
|
|
{
|
|
opts->tsecr = opts->tsval;
|
|
opts->tsval = tcp_time_stamp_raw() & ~0x3f;
|
|
|
|
if (opts->options & XT_SYNPROXY_OPT_WSCALE) {
|
|
opts->tsval |= opts->wscale;
|
|
opts->wscale = info->wscale;
|
|
} else
|
|
opts->tsval |= 0xf;
|
|
|
|
if (opts->options & XT_SYNPROXY_OPT_SACK_PERM)
|
|
opts->tsval |= 1 << 4;
|
|
|
|
if (opts->options & XT_SYNPROXY_OPT_ECN)
|
|
opts->tsval |= 1 << 5;
|
|
}
|
|
EXPORT_SYMBOL_GPL(synproxy_init_timestamp_cookie);
|
|
|
|
void synproxy_check_timestamp_cookie(struct synproxy_options *opts)
|
|
{
|
|
opts->wscale = opts->tsecr & 0xf;
|
|
if (opts->wscale != 0xf)
|
|
opts->options |= XT_SYNPROXY_OPT_WSCALE;
|
|
|
|
opts->options |= opts->tsecr & (1 << 4) ? XT_SYNPROXY_OPT_SACK_PERM : 0;
|
|
|
|
opts->options |= opts->tsecr & (1 << 5) ? XT_SYNPROXY_OPT_ECN : 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(synproxy_check_timestamp_cookie);
|
|
|
|
unsigned int synproxy_tstamp_adjust(struct sk_buff *skb,
|
|
unsigned int protoff,
|
|
struct tcphdr *th,
|
|
struct nf_conn *ct,
|
|
enum ip_conntrack_info ctinfo,
|
|
const struct nf_conn_synproxy *synproxy)
|
|
{
|
|
unsigned int optoff, optend;
|
|
__be32 *ptr, old;
|
|
|
|
if (synproxy->tsoff == 0)
|
|
return 1;
|
|
|
|
optoff = protoff + sizeof(struct tcphdr);
|
|
optend = protoff + th->doff * 4;
|
|
|
|
if (!skb_make_writable(skb, optend))
|
|
return 0;
|
|
|
|
while (optoff < optend) {
|
|
unsigned char *op = skb->data + optoff;
|
|
|
|
switch (op[0]) {
|
|
case TCPOPT_EOL:
|
|
return 1;
|
|
case TCPOPT_NOP:
|
|
optoff++;
|
|
continue;
|
|
default:
|
|
if (optoff + 1 == optend ||
|
|
optoff + op[1] > optend ||
|
|
op[1] < 2)
|
|
return 0;
|
|
if (op[0] == TCPOPT_TIMESTAMP &&
|
|
op[1] == TCPOLEN_TIMESTAMP) {
|
|
if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY) {
|
|
ptr = (__be32 *)&op[2];
|
|
old = *ptr;
|
|
*ptr = htonl(ntohl(*ptr) -
|
|
synproxy->tsoff);
|
|
} else {
|
|
ptr = (__be32 *)&op[6];
|
|
old = *ptr;
|
|
*ptr = htonl(ntohl(*ptr) +
|
|
synproxy->tsoff);
|
|
}
|
|
inet_proto_csum_replace4(&th->check, skb,
|
|
old, *ptr, false);
|
|
return 1;
|
|
}
|
|
optoff += op[1];
|
|
}
|
|
}
|
|
return 1;
|
|
}
|
|
EXPORT_SYMBOL_GPL(synproxy_tstamp_adjust);
|
|
|
|
static struct nf_ct_ext_type nf_ct_synproxy_extend __read_mostly = {
|
|
.len = sizeof(struct nf_conn_synproxy),
|
|
.align = __alignof__(struct nf_conn_synproxy),
|
|
.id = NF_CT_EXT_SYNPROXY,
|
|
};
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
static void *synproxy_cpu_seq_start(struct seq_file *seq, loff_t *pos)
|
|
{
|
|
struct synproxy_net *snet = synproxy_pernet(seq_file_net(seq));
|
|
int cpu;
|
|
|
|
if (*pos == 0)
|
|
return SEQ_START_TOKEN;
|
|
|
|
for (cpu = *pos - 1; cpu < nr_cpu_ids; cpu++) {
|
|
if (!cpu_possible(cpu))
|
|
continue;
|
|
*pos = cpu + 1;
|
|
return per_cpu_ptr(snet->stats, cpu);
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void *synproxy_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
|
|
{
|
|
struct synproxy_net *snet = synproxy_pernet(seq_file_net(seq));
|
|
int cpu;
|
|
|
|
for (cpu = *pos; cpu < nr_cpu_ids; cpu++) {
|
|
if (!cpu_possible(cpu))
|
|
continue;
|
|
*pos = cpu + 1;
|
|
return per_cpu_ptr(snet->stats, cpu);
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void synproxy_cpu_seq_stop(struct seq_file *seq, void *v)
|
|
{
|
|
return;
|
|
}
|
|
|
|
static int synproxy_cpu_seq_show(struct seq_file *seq, void *v)
|
|
{
|
|
struct synproxy_stats *stats = v;
|
|
|
|
if (v == SEQ_START_TOKEN) {
|
|
seq_puts(seq, "entries\t\tsyn_received\t"
|
|
"cookie_invalid\tcookie_valid\t"
|
|
"cookie_retrans\tconn_reopened\n");
|
|
return 0;
|
|
}
|
|
|
|
seq_printf(seq, "%08x\t%08x\t%08x\t%08x\t%08x\t%08x\n", 0,
|
|
stats->syn_received,
|
|
stats->cookie_invalid,
|
|
stats->cookie_valid,
|
|
stats->cookie_retrans,
|
|
stats->conn_reopened);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations synproxy_cpu_seq_ops = {
|
|
.start = synproxy_cpu_seq_start,
|
|
.next = synproxy_cpu_seq_next,
|
|
.stop = synproxy_cpu_seq_stop,
|
|
.show = synproxy_cpu_seq_show,
|
|
};
|
|
|
|
static int __net_init synproxy_proc_init(struct net *net)
|
|
{
|
|
if (!proc_create_net("synproxy", 0444, net->proc_net_stat,
|
|
&synproxy_cpu_seq_ops, sizeof(struct seq_net_private)))
|
|
return -ENOMEM;
|
|
return 0;
|
|
}
|
|
|
|
static void __net_exit synproxy_proc_exit(struct net *net)
|
|
{
|
|
remove_proc_entry("synproxy", net->proc_net_stat);
|
|
}
|
|
#else
|
|
static int __net_init synproxy_proc_init(struct net *net)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void __net_exit synproxy_proc_exit(struct net *net)
|
|
{
|
|
return;
|
|
}
|
|
#endif /* CONFIG_PROC_FS */
|
|
|
|
static int __net_init synproxy_net_init(struct net *net)
|
|
{
|
|
struct synproxy_net *snet = synproxy_pernet(net);
|
|
struct nf_conn *ct;
|
|
int err = -ENOMEM;
|
|
|
|
ct = nf_ct_tmpl_alloc(net, &nf_ct_zone_dflt, GFP_KERNEL);
|
|
if (!ct)
|
|
goto err1;
|
|
|
|
if (!nfct_seqadj_ext_add(ct))
|
|
goto err2;
|
|
if (!nfct_synproxy_ext_add(ct))
|
|
goto err2;
|
|
|
|
__set_bit(IPS_CONFIRMED_BIT, &ct->status);
|
|
nf_conntrack_get(&ct->ct_general);
|
|
snet->tmpl = ct;
|
|
|
|
snet->stats = alloc_percpu(struct synproxy_stats);
|
|
if (snet->stats == NULL)
|
|
goto err2;
|
|
|
|
err = synproxy_proc_init(net);
|
|
if (err < 0)
|
|
goto err3;
|
|
|
|
return 0;
|
|
|
|
err3:
|
|
free_percpu(snet->stats);
|
|
err2:
|
|
nf_ct_tmpl_free(ct);
|
|
err1:
|
|
return err;
|
|
}
|
|
|
|
static void __net_exit synproxy_net_exit(struct net *net)
|
|
{
|
|
struct synproxy_net *snet = synproxy_pernet(net);
|
|
|
|
nf_ct_put(snet->tmpl);
|
|
synproxy_proc_exit(net);
|
|
free_percpu(snet->stats);
|
|
}
|
|
|
|
static struct pernet_operations synproxy_net_ops = {
|
|
.init = synproxy_net_init,
|
|
.exit = synproxy_net_exit,
|
|
.id = &synproxy_net_id,
|
|
.size = sizeof(struct synproxy_net),
|
|
};
|
|
|
|
static int __init synproxy_core_init(void)
|
|
{
|
|
int err;
|
|
|
|
err = nf_ct_extend_register(&nf_ct_synproxy_extend);
|
|
if (err < 0)
|
|
goto err1;
|
|
|
|
err = register_pernet_subsys(&synproxy_net_ops);
|
|
if (err < 0)
|
|
goto err2;
|
|
|
|
return 0;
|
|
|
|
err2:
|
|
nf_ct_extend_unregister(&nf_ct_synproxy_extend);
|
|
err1:
|
|
return err;
|
|
}
|
|
|
|
static void __exit synproxy_core_exit(void)
|
|
{
|
|
unregister_pernet_subsys(&synproxy_net_ops);
|
|
nf_ct_extend_unregister(&nf_ct_synproxy_extend);
|
|
}
|
|
|
|
module_init(synproxy_core_init);
|
|
module_exit(synproxy_core_exit);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
|