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Release 4.11 net/netfilter/nf_conntrack_amanda.c

Directory: net/netfilter
/* Amanda extension for IP connection tracking
 *
 * (C) 2002 by Brian J. Murrell <netfilter@interlinx.bc.ca>
 * based on HW's ip_conntrack_irc.c as well as other modules
 * (C) 2006 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
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/textsearch.h>
#include <linux/skbuff.h>
#include <linux/in.h>
#include <linux/udp.h>
#include <linux/netfilter.h>
#include <linux/gfp.h>

#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_expect.h>
#include <net/netfilter/nf_conntrack_ecache.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <linux/netfilter/nf_conntrack_amanda.h>


static unsigned int master_timeout __read_mostly = 300;

static char *ts_algo = "kmp";

MODULE_AUTHOR("Brian J. Murrell <netfilter@interlinx.bc.ca>");
MODULE_DESCRIPTION("Amanda connection tracking module");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ip_conntrack_amanda");
MODULE_ALIAS_NFCT_HELPER("amanda");

module_param(master_timeout, uint, 0600);
MODULE_PARM_DESC(master_timeout, "timeout for the master connection");
module_param(ts_algo, charp, 0400);
MODULE_PARM_DESC(ts_algo, "textsearch algorithm to use (default kmp)");

unsigned int (*nf_nat_amanda_hook)(struct sk_buff *skb,
				   enum ip_conntrack_info ctinfo,
				   unsigned int protoff,
				   unsigned int matchoff,
				   unsigned int matchlen,
				   struct nf_conntrack_expect *exp)
				   __read_mostly;

EXPORT_SYMBOL_GPL(nf_nat_amanda_hook);


enum amanda_strings {
	
SEARCH_CONNECT,
	
SEARCH_NEWLINE,
	
SEARCH_DATA,
	
SEARCH_MESG,
	
SEARCH_INDEX,
};

static struct {
	
const char		*string;
	
size_t			len;
	
struct ts_config	*ts;
} 
search[] __read_mostly = {
	[SEARCH_CONNECT] = {
		.string	= "CONNECT ",
		.len	= 8,
        },
	[SEARCH_NEWLINE] = {
		.string	= "\n",
		.len	= 1,
        },
	[SEARCH_DATA] = {
		.string	= "DATA ",
		.len	= 5,
        },
	[SEARCH_MESG] = {
		.string	= "MESG ",
		.len	= 5,
        },
	[SEARCH_INDEX] = {
		.string = "INDEX ",
		.len	= 6,
        },
};


static int amanda_help(struct sk_buff *skb, unsigned int protoff, struct nf_conn *ct, enum ip_conntrack_info ctinfo) { struct nf_conntrack_expect *exp; struct nf_conntrack_tuple *tuple; unsigned int dataoff, start, stop, off, i; char pbuf[sizeof("65535")], *tmp; u_int16_t len; __be16 port; int ret = NF_ACCEPT; typeof(nf_nat_amanda_hook) nf_nat_amanda; /* Only look at packets from the Amanda server */ if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) return NF_ACCEPT; /* increase the UDP timeout of the master connection as replies from * Amanda clients to the server can be quite delayed */ nf_ct_refresh(ct, skb, master_timeout * HZ); /* No data? */ dataoff = protoff + sizeof(struct udphdr); if (dataoff >= skb->len) { net_err_ratelimited("amanda_help: skblen = %u\n", skb->len); return NF_ACCEPT; } start = skb_find_text(skb, dataoff, skb->len, search[SEARCH_CONNECT].ts); if (start == UINT_MAX) goto out; start += dataoff + search[SEARCH_CONNECT].len; stop = skb_find_text(skb, start, skb->len, search[SEARCH_NEWLINE].ts); if (stop == UINT_MAX) goto out; stop += start; for (i = SEARCH_DATA; i <= SEARCH_INDEX; i++) { off = skb_find_text(skb, start, stop, search[i].ts); if (off == UINT_MAX) continue; off += start + search[i].len; len = min_t(unsigned int, sizeof(pbuf) - 1, stop - off); if (skb_copy_bits(skb, off, pbuf, len)) break; pbuf[len] = '\0'; port = htons(simple_strtoul(pbuf, &tmp, 10)); len = tmp - pbuf; if (port == 0 || len > 5) break; exp = nf_ct_expect_alloc(ct); if (exp == NULL) { nf_ct_helper_log(skb, ct, "cannot alloc expectation"); ret = NF_DROP; goto out; } tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple; nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), &tuple->src.u3, &tuple->dst.u3, IPPROTO_TCP, NULL, &port); nf_nat_amanda = rcu_dereference(nf_nat_amanda_hook); if (nf_nat_amanda && ct->status & IPS_NAT_MASK) ret = nf_nat_amanda(skb, ctinfo, protoff, off - dataoff, len, exp); else if (nf_ct_expect_related(exp) != 0) { nf_ct_helper_log(skb, ct, "cannot add expectation"); ret = NF_DROP; } nf_ct_expect_put(exp); } out: return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Patrick McHardy43793.18%562.50%
Pablo Neira Ayuso204.26%112.50%
Herbert Xu112.35%112.50%
Joe Perches10.21%112.50%
Total469100.00%8100.00%

static const struct nf_conntrack_expect_policy amanda_exp_policy = { .max_expected = 3, .timeout = 180, }; static struct nf_conntrack_helper amanda_helper[2] __read_mostly = { { .name = "amanda", .me = THIS_MODULE, .help = amanda_help, .tuple.src.l3num = AF_INET, .tuple.src.u.udp.port = cpu_to_be16(10080), .tuple.dst.protonum = IPPROTO_UDP, .expect_policy = &amanda_exp_policy, }, { .name = "amanda", .me = THIS_MODULE, .help = amanda_help, .tuple.src.l3num = AF_INET6, .tuple.src.u.udp.port = cpu_to_be16(10080), .tuple.dst.protonum = IPPROTO_UDP, .expect_policy = &amanda_exp_policy, }, };
static void __exit nf_conntrack_amanda_fini(void) { int i; nf_conntrack_helper_unregister(&amanda_helper[0]); nf_conntrack_helper_unregister(&amanda_helper[1]); for (i = 0; i < ARRAY_SIZE(search); i++) textsearch_destroy(search[i].ts); }

Contributors

PersonTokensPropCommitsCommitProp
Patrick McHardy56100.00%1100.00%
Total56100.00%1100.00%


static int __init nf_conntrack_amanda_init(void) { int ret, i; for (i = 0; i < ARRAY_SIZE(search); i++) { search[i].ts = textsearch_prepare(ts_algo, search[i].string, search[i].len, GFP_KERNEL, TS_AUTOLOAD); if (IS_ERR(search[i].ts)) { ret = PTR_ERR(search[i].ts); goto err1; } } ret = nf_conntrack_helper_register(&amanda_helper[0]); if (ret < 0) goto err1; ret = nf_conntrack_helper_register(&amanda_helper[1]); if (ret < 0) goto err2; return 0; err2: nf_conntrack_helper_unregister(&amanda_helper[0]); err1: while (--i >= 0) textsearch_destroy(search[i].ts); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Patrick McHardy14788.02%150.00%
Akinobu Mita2011.98%150.00%
Total167100.00%2100.00%

module_init(nf_conntrack_amanda_init); module_exit(nf_conntrack_amanda_fini);

Overall Contributors

PersonTokensPropCommitsCommitProp
Patrick McHardy105094.00%640.00%
Pablo Neira Ayuso252.24%213.33%
Akinobu Mita201.79%16.67%
Herbert Xu121.07%16.67%
Tejun Heo30.27%16.67%
Yasuyuki Kozakai30.27%16.67%
Harvey Harrison20.18%16.67%
Joe Perches10.09%16.67%
Jan Engelhardt10.09%16.67%
Total1117100.00%15100.00%
Directory: net/netfilter
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