d4156e8cd9
Since conntrack currently allows to use masks for every bit of both helper and expectation tuples, we can't hash them and have to keep them on two global lists that are searched for every new connection. This patch removes the never used ability to use masks for the destination part of the expectation tuple and completely removes masks from helpers since the only reasonable choice is a full match on l3num, protonum and src.u.all. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
156 lines
4.2 KiB
C
156 lines
4.2 KiB
C
/* (C) 2001-2002 Magnus Boden <mb@ozaba.mine.nu>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/in.h>
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#include <linux/udp.h>
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#include <linux/netfilter.h>
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_conntrack_tuple.h>
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#include <net/netfilter/nf_conntrack_expect.h>
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#include <net/netfilter/nf_conntrack_ecache.h>
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#include <net/netfilter/nf_conntrack_helper.h>
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#include <linux/netfilter/nf_conntrack_tftp.h>
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MODULE_AUTHOR("Magnus Boden <mb@ozaba.mine.nu>");
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MODULE_DESCRIPTION("TFTP connection tracking helper");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("ip_conntrack_tftp");
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#define MAX_PORTS 8
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static unsigned short ports[MAX_PORTS];
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static int ports_c;
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module_param_array(ports, ushort, &ports_c, 0400);
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MODULE_PARM_DESC(ports, "Port numbers of TFTP servers");
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#if 0
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#define DEBUGP(format, args...) printk("%s:%s:" format, \
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__FILE__, __FUNCTION__ , ## args)
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#else
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#define DEBUGP(format, args...)
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#endif
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unsigned int (*nf_nat_tftp_hook)(struct sk_buff **pskb,
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enum ip_conntrack_info ctinfo,
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struct nf_conntrack_expect *exp) __read_mostly;
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EXPORT_SYMBOL_GPL(nf_nat_tftp_hook);
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static int tftp_help(struct sk_buff **pskb,
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unsigned int protoff,
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struct nf_conn *ct,
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enum ip_conntrack_info ctinfo)
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{
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struct tftphdr _tftph, *tfh;
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struct nf_conntrack_expect *exp;
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struct nf_conntrack_tuple *tuple;
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unsigned int ret = NF_ACCEPT;
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int family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
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typeof(nf_nat_tftp_hook) nf_nat_tftp;
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tfh = skb_header_pointer(*pskb, protoff + sizeof(struct udphdr),
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sizeof(_tftph), &_tftph);
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if (tfh == NULL)
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return NF_ACCEPT;
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switch (ntohs(tfh->opcode)) {
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case TFTP_OPCODE_READ:
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case TFTP_OPCODE_WRITE:
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/* RRQ and WRQ works the same way */
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DEBUGP("");
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NF_CT_DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
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NF_CT_DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
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exp = nf_ct_expect_alloc(ct);
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if (exp == NULL)
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return NF_DROP;
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tuple = &ct->tuplehash[IP_CT_DIR_REPLY].tuple;
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nf_ct_expect_init(exp, family, &tuple->src.u3, &tuple->dst.u3,
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IPPROTO_UDP, NULL, &tuple->dst.u.udp.port);
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DEBUGP("expect: ");
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NF_CT_DUMP_TUPLE(&exp->tuple);
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NF_CT_DUMP_TUPLE(&exp->mask);
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nf_nat_tftp = rcu_dereference(nf_nat_tftp_hook);
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if (nf_nat_tftp && ct->status & IPS_NAT_MASK)
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ret = nf_nat_tftp(pskb, ctinfo, exp);
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else if (nf_ct_expect_related(exp) != 0)
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ret = NF_DROP;
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nf_ct_expect_put(exp);
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break;
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case TFTP_OPCODE_DATA:
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case TFTP_OPCODE_ACK:
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DEBUGP("Data/ACK opcode\n");
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break;
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case TFTP_OPCODE_ERROR:
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DEBUGP("Error opcode\n");
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break;
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default:
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DEBUGP("Unknown opcode\n");
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}
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return ret;
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}
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static struct nf_conntrack_helper tftp[MAX_PORTS][2] __read_mostly;
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static char tftp_names[MAX_PORTS][2][sizeof("tftp-65535")] __read_mostly;
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static void nf_conntrack_tftp_fini(void)
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{
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int i, j;
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for (i = 0; i < ports_c; i++) {
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for (j = 0; j < 2; j++)
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nf_conntrack_helper_unregister(&tftp[i][j]);
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}
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}
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static int __init nf_conntrack_tftp_init(void)
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{
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int i, j, ret;
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char *tmpname;
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if (ports_c == 0)
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ports[ports_c++] = TFTP_PORT;
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for (i = 0; i < ports_c; i++) {
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memset(&tftp[i], 0, sizeof(tftp[i]));
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tftp[i][0].tuple.src.l3num = AF_INET;
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tftp[i][1].tuple.src.l3num = AF_INET6;
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for (j = 0; j < 2; j++) {
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tftp[i][j].tuple.dst.protonum = IPPROTO_UDP;
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tftp[i][j].tuple.src.u.udp.port = htons(ports[i]);
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tftp[i][j].max_expected = 1;
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tftp[i][j].timeout = 5 * 60; /* 5 minutes */
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tftp[i][j].me = THIS_MODULE;
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tftp[i][j].help = tftp_help;
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tmpname = &tftp_names[i][j][0];
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if (ports[i] == TFTP_PORT)
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sprintf(tmpname, "tftp");
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else
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sprintf(tmpname, "tftp-%u", i);
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tftp[i][j].name = tmpname;
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ret = nf_conntrack_helper_register(&tftp[i][j]);
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if (ret) {
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printk("nf_ct_tftp: failed to register helper "
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"for pf: %u port: %u\n",
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tftp[i][j].tuple.src.l3num, ports[i]);
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nf_conntrack_tftp_fini();
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return ret;
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}
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}
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}
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return 0;
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}
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module_init(nf_conntrack_tftp_init);
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module_exit(nf_conntrack_tftp_fini);
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