| /* Kernel module to match one of a list of TCP/UDP ports: ports are in |
| the same place so we can treat them as equal. */ |
| |
| /* (C) 1999-2001 Paul `Rusty' Russell |
| * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> |
| * |
| * 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/types.h> |
| #include <linux/udp.h> |
| #include <linux/skbuff.h> |
| #include <linux/in.h> |
| |
| #include <linux/netfilter_ipv6/ip6t_multiport.h> |
| #include <linux/netfilter_ipv6/ip6_tables.h> |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); |
| MODULE_DESCRIPTION("ip6tables match for multiple ports"); |
| |
| #if 0 |
| #define duprintf(format, args...) printk(format , ## args) |
| #else |
| #define duprintf(format, args...) |
| #endif |
| |
| /* Returns 1 if the port is matched by the test, 0 otherwise. */ |
| static inline int |
| ports_match(const u_int16_t *portlist, enum ip6t_multiport_flags flags, |
| u_int8_t count, u_int16_t src, u_int16_t dst) |
| { |
| unsigned int i; |
| for (i=0; i<count; i++) { |
| if (flags != IP6T_MULTIPORT_DESTINATION |
| && portlist[i] == src) |
| return 1; |
| |
| if (flags != IP6T_MULTIPORT_SOURCE |
| && portlist[i] == dst) |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| static int |
| match(const struct sk_buff *skb, |
| const struct net_device *in, |
| const struct net_device *out, |
| const void *matchinfo, |
| int offset, |
| unsigned int protoff, |
| int *hotdrop) |
| { |
| u16 _ports[2], *pptr; |
| const struct ip6t_multiport *multiinfo = matchinfo; |
| |
| /* Must not be a fragment. */ |
| if (offset) |
| return 0; |
| |
| /* Must be big enough to read ports (both UDP and TCP have |
| them at the start). */ |
| pptr = skb_header_pointer(skb, protoff, sizeof(_ports), &_ports[0]); |
| if (pptr == NULL) { |
| /* We've been asked to examine this packet, and we |
| * can't. Hence, no choice but to drop. |
| */ |
| duprintf("ip6t_multiport:" |
| " Dropping evil offset=0 tinygram.\n"); |
| *hotdrop = 1; |
| return 0; |
| } |
| |
| return ports_match(multiinfo->ports, |
| multiinfo->flags, multiinfo->count, |
| ntohs(pptr[0]), ntohs(pptr[1])); |
| } |
| |
| /* Called when user tries to insert an entry of this type. */ |
| static int |
| checkentry(const char *tablename, |
| const struct ip6t_ip6 *ip, |
| void *matchinfo, |
| unsigned int matchsize, |
| unsigned int hook_mask) |
| { |
| const struct ip6t_multiport *multiinfo = matchinfo; |
| |
| if (matchsize != IP6T_ALIGN(sizeof(struct ip6t_multiport))) |
| return 0; |
| |
| /* Must specify proto == TCP/UDP, no unknown flags or bad count */ |
| return (ip->proto == IPPROTO_TCP || ip->proto == IPPROTO_UDP) |
| && !(ip->invflags & IP6T_INV_PROTO) |
| && matchsize == IP6T_ALIGN(sizeof(struct ip6t_multiport)) |
| && (multiinfo->flags == IP6T_MULTIPORT_SOURCE |
| || multiinfo->flags == IP6T_MULTIPORT_DESTINATION |
| || multiinfo->flags == IP6T_MULTIPORT_EITHER) |
| && multiinfo->count <= IP6T_MULTI_PORTS; |
| } |
| |
| static struct ip6t_match multiport_match = { |
| .name = "multiport", |
| .match = &match, |
| .checkentry = &checkentry, |
| .me = THIS_MODULE, |
| }; |
| |
| static int __init init(void) |
| { |
| return ip6t_register_match(&multiport_match); |
| } |
| |
| static void __exit fini(void) |
| { |
| ip6t_unregister_match(&multiport_match); |
| } |
| |
| module_init(init); |
| module_exit(fini); |