![Linus Torvalds](/assets/img/avatar_default.png)
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
213 lines
5 KiB
C
213 lines
5 KiB
C
/* Kernel module to match one of a list of TCP/UDP ports: ports are in
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the same place so we can treat them as equal. */
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/* (C) 1999-2001 Paul `Rusty' Russell
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* (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
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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/types.h>
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#include <linux/udp.h>
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#include <linux/skbuff.h>
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#include <linux/netfilter_ipv4/ipt_multiport.h>
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#include <linux/netfilter_ipv4/ip_tables.h>
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
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MODULE_DESCRIPTION("iptables multiple port match module");
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#if 0
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#define duprintf(format, args...) printk(format , ## args)
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#else
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#define duprintf(format, args...)
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#endif
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/* Returns 1 if the port is matched by the test, 0 otherwise. */
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static inline int
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ports_match(const u_int16_t *portlist, enum ipt_multiport_flags flags,
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u_int8_t count, u_int16_t src, u_int16_t dst)
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{
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unsigned int i;
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for (i=0; i<count; i++) {
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if (flags != IPT_MULTIPORT_DESTINATION
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&& portlist[i] == src)
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return 1;
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if (flags != IPT_MULTIPORT_SOURCE
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&& portlist[i] == dst)
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return 1;
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}
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return 0;
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}
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/* Returns 1 if the port is matched by the test, 0 otherwise. */
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static inline int
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ports_match_v1(const struct ipt_multiport_v1 *minfo,
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u_int16_t src, u_int16_t dst)
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{
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unsigned int i;
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u_int16_t s, e;
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for (i=0; i < minfo->count; i++) {
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s = minfo->ports[i];
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if (minfo->pflags[i]) {
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/* range port matching */
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e = minfo->ports[++i];
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duprintf("src or dst matches with %d-%d?\n", s, e);
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if (minfo->flags == IPT_MULTIPORT_SOURCE
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&& src >= s && src <= e)
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return 1 ^ minfo->invert;
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if (minfo->flags == IPT_MULTIPORT_DESTINATION
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&& dst >= s && dst <= e)
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return 1 ^ minfo->invert;
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if (minfo->flags == IPT_MULTIPORT_EITHER
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&& ((dst >= s && dst <= e)
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|| (src >= s && src <= e)))
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return 1 ^ minfo->invert;
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} else {
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/* exact port matching */
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duprintf("src or dst matches with %d?\n", s);
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if (minfo->flags == IPT_MULTIPORT_SOURCE
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&& src == s)
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return 1 ^ minfo->invert;
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if (minfo->flags == IPT_MULTIPORT_DESTINATION
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&& dst == s)
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return 1 ^ minfo->invert;
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if (minfo->flags == IPT_MULTIPORT_EITHER
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&& (src == s || dst == s))
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return 1 ^ minfo->invert;
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}
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}
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return minfo->invert;
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}
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static int
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match(const struct sk_buff *skb,
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const struct net_device *in,
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const struct net_device *out,
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const void *matchinfo,
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int offset,
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int *hotdrop)
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{
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u16 _ports[2], *pptr;
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const struct ipt_multiport *multiinfo = matchinfo;
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if (offset)
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return 0;
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pptr = skb_header_pointer(skb, skb->nh.iph->ihl * 4,
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sizeof(_ports), _ports);
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if (pptr == NULL) {
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/* We've been asked to examine this packet, and we
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* can't. Hence, no choice but to drop.
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*/
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duprintf("ipt_multiport:"
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" Dropping evil offset=0 tinygram.\n");
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*hotdrop = 1;
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return 0;
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}
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return ports_match(multiinfo->ports,
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multiinfo->flags, multiinfo->count,
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ntohs(pptr[0]), ntohs(pptr[1]));
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}
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static int
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match_v1(const struct sk_buff *skb,
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const struct net_device *in,
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const struct net_device *out,
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const void *matchinfo,
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int offset,
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int *hotdrop)
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{
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u16 _ports[2], *pptr;
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const struct ipt_multiport_v1 *multiinfo = matchinfo;
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if (offset)
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return 0;
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pptr = skb_header_pointer(skb, skb->nh.iph->ihl * 4,
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sizeof(_ports), _ports);
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if (pptr == NULL) {
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/* We've been asked to examine this packet, and we
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* can't. Hence, no choice but to drop.
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*/
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duprintf("ipt_multiport:"
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" Dropping evil offset=0 tinygram.\n");
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*hotdrop = 1;
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return 0;
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}
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return ports_match_v1(multiinfo, ntohs(pptr[0]), ntohs(pptr[1]));
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}
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/* Called when user tries to insert an entry of this type. */
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static int
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checkentry(const char *tablename,
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const struct ipt_ip *ip,
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void *matchinfo,
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unsigned int matchsize,
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unsigned int hook_mask)
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{
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return (matchsize == IPT_ALIGN(sizeof(struct ipt_multiport)));
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}
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static int
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checkentry_v1(const char *tablename,
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const struct ipt_ip *ip,
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void *matchinfo,
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unsigned int matchsize,
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unsigned int hook_mask)
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{
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return (matchsize == IPT_ALIGN(sizeof(struct ipt_multiport_v1)));
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}
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static struct ipt_match multiport_match = {
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.name = "multiport",
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.revision = 0,
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.match = &match,
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.checkentry = &checkentry,
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.me = THIS_MODULE,
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};
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static struct ipt_match multiport_match_v1 = {
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.name = "multiport",
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.revision = 1,
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.match = &match_v1,
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.checkentry = &checkentry_v1,
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.me = THIS_MODULE,
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};
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static int __init init(void)
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{
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int err;
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err = ipt_register_match(&multiport_match);
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if (!err) {
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err = ipt_register_match(&multiport_match_v1);
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if (err)
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ipt_unregister_match(&multiport_match);
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}
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return err;
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}
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static void __exit fini(void)
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{
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ipt_unregister_match(&multiport_match);
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ipt_unregister_match(&multiport_match_v1);
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}
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module_init(init);
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module_exit(fini);
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