diff options
author | Dmitry Torokhov <dtor_core@ameritech.net> | 2006-04-29 01:11:23 -0400 |
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committer | Dmitry Torokhov <dtor_core@ameritech.net> | 2006-04-29 01:11:23 -0400 |
commit | 7b7e394185014e0f3bd8989cac937003f20ef9ce (patch) | |
tree | 3beda5f979bba0aa9822534e239cf1b45f3be69c /net/netfilter/xt_multiport.c | |
parent | ddc5d3414593e4d7ad7fbd33e7f7517fcc234544 (diff) | |
parent | 693f7d362055261882659475d2ef022e32edbff1 (diff) |
Merge rsync://rsync.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'net/netfilter/xt_multiport.c')
-rw-r--r-- | net/netfilter/xt_multiport.c | 314 |
1 files changed, 314 insertions, 0 deletions
diff --git a/net/netfilter/xt_multiport.c b/net/netfilter/xt_multiport.c new file mode 100644 index 00000000000..b56cd2baaac --- /dev/null +++ b/net/netfilter/xt_multiport.c @@ -0,0 +1,314 @@ +/* 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/xt_multiport.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_ipv4/ip_tables.h> +#include <linux/netfilter_ipv6/ip6_tables.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); +MODULE_DESCRIPTION("x_tables multiple port match module"); +MODULE_ALIAS("ipt_multiport"); +MODULE_ALIAS("ip6t_multiport"); + +#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 xt_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 != XT_MULTIPORT_DESTINATION && portlist[i] == src) + return 1; + + if (flags != XT_MULTIPORT_SOURCE && portlist[i] == dst) + return 1; + } + + return 0; +} + +/* Returns 1 if the port is matched by the test, 0 otherwise. */ +static inline int +ports_match_v1(const struct xt_multiport_v1 *minfo, + u_int16_t src, u_int16_t dst) +{ + unsigned int i; + u_int16_t s, e; + + for (i = 0; i < minfo->count; i++) { + s = minfo->ports[i]; + + if (minfo->pflags[i]) { + /* range port matching */ + e = minfo->ports[++i]; + duprintf("src or dst matches with %d-%d?\n", s, e); + + if (minfo->flags == XT_MULTIPORT_SOURCE + && src >= s && src <= e) + return 1 ^ minfo->invert; + if (minfo->flags == XT_MULTIPORT_DESTINATION + && dst >= s && dst <= e) + return 1 ^ minfo->invert; + if (minfo->flags == XT_MULTIPORT_EITHER + && ((dst >= s && dst <= e) + || (src >= s && src <= e))) + return 1 ^ minfo->invert; + } else { + /* exact port matching */ + duprintf("src or dst matches with %d?\n", s); + + if (minfo->flags == XT_MULTIPORT_SOURCE + && src == s) + return 1 ^ minfo->invert; + if (minfo->flags == XT_MULTIPORT_DESTINATION + && dst == s) + return 1 ^ minfo->invert; + if (minfo->flags == XT_MULTIPORT_EITHER + && (src == s || dst == s)) + return 1 ^ minfo->invert; + } + } + + return minfo->invert; +} + +static int +match(const struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + const struct xt_match *match, + const void *matchinfo, + int offset, + unsigned int protoff, + int *hotdrop) +{ + u16 _ports[2], *pptr; + const struct xt_multiport *multiinfo = matchinfo; + + if (offset) + return 0; + + pptr = skb_header_pointer(skb, protoff, sizeof(_ports), _ports); + if (pptr == NULL) { + /* We've been asked to examine this packet, and we + * can't. Hence, no choice but to drop. + */ + duprintf("xt_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])); +} + +static int +match_v1(const struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + const struct xt_match *match, + const void *matchinfo, + int offset, + unsigned int protoff, + int *hotdrop) +{ + u16 _ports[2], *pptr; + const struct xt_multiport_v1 *multiinfo = matchinfo; + + if (offset) + return 0; + + pptr = skb_header_pointer(skb, protoff, sizeof(_ports), _ports); + if (pptr == NULL) { + /* We've been asked to examine this packet, and we + * can't. Hence, no choice but to drop. + */ + duprintf("xt_multiport: Dropping evil offset=0 tinygram.\n"); + *hotdrop = 1; + return 0; + } + + return ports_match_v1(multiinfo, ntohs(pptr[0]), ntohs(pptr[1])); +} + +static inline int +check(u_int16_t proto, + u_int8_t ip_invflags, + u_int8_t match_flags, + u_int8_t count) +{ + /* Must specify proto == TCP/UDP, no unknown flags or bad count */ + return (proto == IPPROTO_TCP || proto == IPPROTO_UDP) + && !(ip_invflags & XT_INV_PROTO) + && (match_flags == XT_MULTIPORT_SOURCE + || match_flags == XT_MULTIPORT_DESTINATION + || match_flags == XT_MULTIPORT_EITHER) + && count <= XT_MULTI_PORTS; +} + +/* Called when user tries to insert an entry of this type. */ +static int +checkentry(const char *tablename, + const void *info, + const struct xt_match *match, + void *matchinfo, + unsigned int matchsize, + unsigned int hook_mask) +{ + const struct ipt_ip *ip = info; + const struct xt_multiport *multiinfo = matchinfo; + + return check(ip->proto, ip->invflags, multiinfo->flags, + multiinfo->count); +} + +static int +checkentry_v1(const char *tablename, + const void *info, + const struct xt_match *match, + void *matchinfo, + unsigned int matchsize, + unsigned int hook_mask) +{ + const struct ipt_ip *ip = info; + const struct xt_multiport_v1 *multiinfo = matchinfo; + + return check(ip->proto, ip->invflags, multiinfo->flags, + multiinfo->count); +} + +static int +checkentry6(const char *tablename, + const void *info, + const struct xt_match *match, + void *matchinfo, + unsigned int matchsize, + unsigned int hook_mask) +{ + const struct ip6t_ip6 *ip = info; + const struct xt_multiport *multiinfo = matchinfo; + + return check(ip->proto, ip->invflags, multiinfo->flags, + multiinfo->count); +} + +static int +checkentry6_v1(const char *tablename, + const void *info, + const struct xt_match *match, + void *matchinfo, + unsigned int matchsize, + unsigned int hook_mask) +{ + const struct ip6t_ip6 *ip = info; + const struct xt_multiport_v1 *multiinfo = matchinfo; + + return check(ip->proto, ip->invflags, multiinfo->flags, + multiinfo->count); +} + +static struct xt_match multiport_match = { + .name = "multiport", + .revision = 0, + .matchsize = sizeof(struct xt_multiport), + .match = &match, + .checkentry = &checkentry, + .family = AF_INET, + .me = THIS_MODULE, +}; + +static struct xt_match multiport_match_v1 = { + .name = "multiport", + .revision = 1, + .matchsize = sizeof(struct xt_multiport_v1), + .match = &match_v1, + .checkentry = &checkentry_v1, + .family = AF_INET, + .me = THIS_MODULE, +}; + +static struct xt_match multiport6_match = { + .name = "multiport", + .revision = 0, + .matchsize = sizeof(struct xt_multiport), + .match = &match, + .checkentry = &checkentry6, + .family = AF_INET6, + .me = THIS_MODULE, +}; + +static struct xt_match multiport6_match_v1 = { + .name = "multiport", + .revision = 1, + .matchsize = sizeof(struct xt_multiport_v1), + .match = &match_v1, + .checkentry = &checkentry6_v1, + .family = AF_INET6, + .me = THIS_MODULE, +}; + +static int __init xt_multiport_init(void) +{ + int ret; + + ret = xt_register_match(&multiport_match); + if (ret) + goto out; + + ret = xt_register_match(&multiport_match_v1); + if (ret) + goto out_unreg_multi_v0; + + ret = xt_register_match(&multiport6_match); + if (ret) + goto out_unreg_multi_v1; + + ret = xt_register_match(&multiport6_match_v1); + if (ret) + goto out_unreg_multi6_v0; + + return ret; + +out_unreg_multi6_v0: + xt_unregister_match(&multiport6_match); +out_unreg_multi_v1: + xt_unregister_match(&multiport_match_v1); +out_unreg_multi_v0: + xt_unregister_match(&multiport_match); +out: + return ret; +} + +static void __exit xt_multiport_fini(void) +{ + xt_unregister_match(&multiport_match); + xt_unregister_match(&multiport_match_v1); + xt_unregister_match(&multiport6_match); + xt_unregister_match(&multiport6_match_v1); +} + +module_init(xt_multiport_init); +module_exit(xt_multiport_fini); |