diff options
Diffstat (limited to 'net/netfilter/nf_conntrack_amanda.c')
| -rw-r--r-- | net/netfilter/nf_conntrack_amanda.c | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/net/netfilter/nf_conntrack_amanda.c b/net/netfilter/nf_conntrack_amanda.c new file mode 100644 index 00000000000..b8869eab765 --- /dev/null +++ b/net/netfilter/nf_conntrack_amanda.c @@ -0,0 +1,238 @@ +/* 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 + * + * 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 <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_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 **pskb, + enum ip_conntrack_info ctinfo, + 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 { + 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 **pskb, + unsigned int protoff, + struct nf_conn *ct, + enum ip_conntrack_info ctinfo) +{ + struct ts_state ts; + 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 family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num; + 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, *pskb, master_timeout * HZ); + + /* No data? */ + dataoff = protoff + sizeof(struct udphdr); + if (dataoff >= (*pskb)->len) { + if (net_ratelimit()) + printk("amanda_help: skblen = %u\n", (*pskb)->len); + return NF_ACCEPT; + } + + memset(&ts, 0, sizeof(ts)); + start = skb_find_text(*pskb, dataoff, (*pskb)->len, + search[SEARCH_CONNECT].ts, &ts); + if (start == UINT_MAX) + goto out; + start += dataoff + search[SEARCH_CONNECT].len; + + memset(&ts, 0, sizeof(ts)); + stop = skb_find_text(*pskb, start, (*pskb)->len, + search[SEARCH_NEWLINE].ts, &ts); + if (stop == UINT_MAX) + goto out; + stop += start; + + for (i = SEARCH_DATA; i <= SEARCH_INDEX; i++) { + memset(&ts, 0, sizeof(ts)); + off = skb_find_text(*pskb, start, stop, search[i].ts, &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(*pskb, 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_conntrack_expect_alloc(ct); + if (exp == NULL) { + ret = NF_DROP; + goto out; + } + tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple; + nf_conntrack_expect_init(exp, family, + &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(pskb, ctinfo, off - dataoff, + len, exp); + else if (nf_conntrack_expect_related(exp) != 0) + ret = NF_DROP; + nf_conntrack_expect_put(exp); + } + +out: + return ret; +} + +static struct nf_conntrack_helper amanda_helper[2] __read_mostly = { + { + .name = "amanda", + .max_expected = 3, + .timeout = 180, + .me = THIS_MODULE, + .help = amanda_help, + .tuple.src.l3num = AF_INET, + .tuple.src.u.udp.port = __constant_htons(10080), + .tuple.dst.protonum = IPPROTO_UDP, + .mask.src.l3num = 0xFFFF, + .mask.src.u.udp.port = __constant_htons(0xFFFF), + .mask.dst.protonum = 0xFF, + }, + { + .name = "amanda", + .max_expected = 3, + .timeout = 180, + .me = THIS_MODULE, + .help = amanda_help, + .tuple.src.l3num = AF_INET6, + .tuple.src.u.udp.port = __constant_htons(10080), + .tuple.dst.protonum = IPPROTO_UDP, + .mask.src.l3num = 0xFFFF, + .mask.src.u.udp.port = __constant_htons(0xFFFF), + .mask.dst.protonum = 0xFF, + }, +}; + +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); +} + +static int __init nf_conntrack_amanda_init(void) +{ + int ret, i; + + ret = -ENOMEM; + 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 (search[i].ts == NULL) + 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: + for (; i >= 0; i--) { + if (search[i].ts) + textsearch_destroy(search[i].ts); + } + return ret; +} + +module_init(nf_conntrack_amanda_init); +module_exit(nf_conntrack_amanda_fini); |