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Diffstat (limited to 'net/netfilter/xt_tcpudp.c')
-rw-r--r--net/netfilter/xt_tcpudp.c148
1 files changed, 58 insertions, 90 deletions
diff --git a/net/netfilter/xt_tcpudp.c b/net/netfilter/xt_tcpudp.c
index 223f9bded67..c14d4645daa 100644
--- a/net/netfilter/xt_tcpudp.c
+++ b/net/netfilter/xt_tcpudp.c
@@ -1,3 +1,4 @@
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/types.h>
#include <linux/module.h>
#include <net/ip.h>
@@ -10,7 +11,7 @@
#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/netfilter_ipv6/ip6_tables.h>
-MODULE_DESCRIPTION("x_tables match for TCP and UDP(-Lite), supports IPv4 and IPv6");
+MODULE_DESCRIPTION("Xtables: TCP, UDP and UDP-Lite match");
MODULE_LICENSE("GPL");
MODULE_ALIAS("xt_tcp");
MODULE_ALIAS("xt_udp");
@@ -19,13 +20,6 @@ MODULE_ALIAS("ipt_tcp");
MODULE_ALIAS("ip6t_udp");
MODULE_ALIAS("ip6t_tcp");
-#ifdef DEBUG_IP_FIREWALL_USER
-#define duprintf(format, args...) printk(format , ## args)
-#else
-#define duprintf(format, args...)
-#endif
-
-
/* Returns 1 if the port is matched by the range, 0 otherwise */
static inline bool
port_match(u_int16_t min, u_int16_t max, u_int16_t port, bool invert)
@@ -42,10 +36,11 @@ tcp_find_option(u_int8_t option,
bool *hotdrop)
{
/* tcp.doff is only 4 bits, ie. max 15 * 4 bytes */
- u_int8_t _opt[60 - sizeof(struct tcphdr)], *op;
+ const u_int8_t *op;
+ u_int8_t _opt[60 - sizeof(struct tcphdr)];
unsigned int i;
- duprintf("tcp_match: finding option\n");
+ pr_debug("finding option\n");
if (!optlen)
return invert;
@@ -67,29 +62,22 @@ tcp_find_option(u_int8_t option,
return invert;
}
-static bool
-tcp_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,
- bool *hotdrop)
+static bool tcp_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
- struct tcphdr _tcph, *th;
- const struct xt_tcp *tcpinfo = matchinfo;
+ const struct tcphdr *th;
+ struct tcphdr _tcph;
+ const struct xt_tcp *tcpinfo = par->matchinfo;
- if (offset) {
+ if (par->fragoff != 0) {
/* To quote Alan:
Don't allow a fragment of TCP 8 bytes in. Nobody normal
causes this. Its a cracker trying to break in by doing a
flag overwrite to pass the direction checks.
*/
- if (offset == 1) {
- duprintf("Dropping evil TCP offset=1 frag.\n");
- *hotdrop = true;
+ if (par->fragoff == 1) {
+ pr_debug("Dropping evil TCP offset=1 frag.\n");
+ par->hotdrop = true;
}
/* Must not be a fragment. */
return false;
@@ -97,12 +85,12 @@ tcp_match(const struct sk_buff *skb,
#define FWINVTCP(bool, invflg) ((bool) ^ !!(tcpinfo->invflags & (invflg)))
- th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
+ th = skb_header_pointer(skb, par->thoff, sizeof(_tcph), &_tcph);
if (th == NULL) {
/* We've been asked to examine this packet, and we
can't. Hence, no choice but to drop. */
- duprintf("Dropping evil TCP offset=0 tinygram.\n");
- *hotdrop = true;
+ pr_debug("Dropping evil TCP offset=0 tinygram.\n");
+ par->hotdrop = true;
return false;
}
@@ -120,55 +108,42 @@ tcp_match(const struct sk_buff *skb,
return false;
if (tcpinfo->option) {
if (th->doff * 4 < sizeof(_tcph)) {
- *hotdrop = true;
+ par->hotdrop = true;
return false;
}
- if (!tcp_find_option(tcpinfo->option, skb, protoff,
+ if (!tcp_find_option(tcpinfo->option, skb, par->thoff,
th->doff*4 - sizeof(_tcph),
tcpinfo->invflags & XT_TCP_INV_OPTION,
- hotdrop))
+ &par->hotdrop))
return false;
}
return true;
}
-/* Called when user tries to insert an entry of this type. */
-static bool
-tcp_checkentry(const char *tablename,
- const void *info,
- const struct xt_match *match,
- void *matchinfo,
- unsigned int hook_mask)
+static int tcp_mt_check(const struct xt_mtchk_param *par)
{
- const struct xt_tcp *tcpinfo = matchinfo;
+ const struct xt_tcp *tcpinfo = par->matchinfo;
/* Must specify no unknown invflags */
- return !(tcpinfo->invflags & ~XT_TCP_INV_MASK);
+ return (tcpinfo->invflags & ~XT_TCP_INV_MASK) ? -EINVAL : 0;
}
-static bool
-udp_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,
- bool *hotdrop)
+static bool udp_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
- struct udphdr _udph, *uh;
- const struct xt_udp *udpinfo = matchinfo;
+ const struct udphdr *uh;
+ struct udphdr _udph;
+ const struct xt_udp *udpinfo = par->matchinfo;
/* Must not be a fragment. */
- if (offset)
+ if (par->fragoff != 0)
return false;
- uh = skb_header_pointer(skb, protoff, sizeof(_udph), &_udph);
+ uh = skb_header_pointer(skb, par->thoff, sizeof(_udph), &_udph);
if (uh == NULL) {
/* We've been asked to examine this packet, and we
can't. Hence, no choice but to drop. */
- duprintf("Dropping evil UDP tinygram.\n");
- *hotdrop = true;
+ pr_debug("Dropping evil UDP tinygram.\n");
+ par->hotdrop = true;
return false;
}
@@ -180,87 +155,80 @@ udp_match(const struct sk_buff *skb,
!!(udpinfo->invflags & XT_UDP_INV_DSTPT));
}
-/* Called when user tries to insert an entry of this type. */
-static bool
-udp_checkentry(const char *tablename,
- const void *info,
- const struct xt_match *match,
- void *matchinfo,
- unsigned int hook_mask)
+static int udp_mt_check(const struct xt_mtchk_param *par)
{
- const struct xt_udp *udpinfo = matchinfo;
+ const struct xt_udp *udpinfo = par->matchinfo;
/* Must specify no unknown invflags */
- return !(udpinfo->invflags & ~XT_UDP_INV_MASK);
+ return (udpinfo->invflags & ~XT_UDP_INV_MASK) ? -EINVAL : 0;
}
-static struct xt_match xt_tcpudp_match[] __read_mostly = {
+static struct xt_match tcpudp_mt_reg[] __read_mostly = {
{
.name = "tcp",
- .family = AF_INET,
- .checkentry = tcp_checkentry,
- .match = tcp_match,
+ .family = NFPROTO_IPV4,
+ .checkentry = tcp_mt_check,
+ .match = tcp_mt,
.matchsize = sizeof(struct xt_tcp),
.proto = IPPROTO_TCP,
.me = THIS_MODULE,
},
{
.name = "tcp",
- .family = AF_INET6,
- .checkentry = tcp_checkentry,
- .match = tcp_match,
+ .family = NFPROTO_IPV6,
+ .checkentry = tcp_mt_check,
+ .match = tcp_mt,
.matchsize = sizeof(struct xt_tcp),
.proto = IPPROTO_TCP,
.me = THIS_MODULE,
},
{
.name = "udp",
- .family = AF_INET,
- .checkentry = udp_checkentry,
- .match = udp_match,
+ .family = NFPROTO_IPV4,
+ .checkentry = udp_mt_check,
+ .match = udp_mt,
.matchsize = sizeof(struct xt_udp),
.proto = IPPROTO_UDP,
.me = THIS_MODULE,
},
{
.name = "udp",
- .family = AF_INET6,
- .checkentry = udp_checkentry,
- .match = udp_match,
+ .family = NFPROTO_IPV6,
+ .checkentry = udp_mt_check,
+ .match = udp_mt,
.matchsize = sizeof(struct xt_udp),
.proto = IPPROTO_UDP,
.me = THIS_MODULE,
},
{
.name = "udplite",
- .family = AF_INET,
- .checkentry = udp_checkentry,
- .match = udp_match,
+ .family = NFPROTO_IPV4,
+ .checkentry = udp_mt_check,
+ .match = udp_mt,
.matchsize = sizeof(struct xt_udp),
.proto = IPPROTO_UDPLITE,
.me = THIS_MODULE,
},
{
.name = "udplite",
- .family = AF_INET6,
- .checkentry = udp_checkentry,
- .match = udp_match,
+ .family = NFPROTO_IPV6,
+ .checkentry = udp_mt_check,
+ .match = udp_mt,
.matchsize = sizeof(struct xt_udp),
.proto = IPPROTO_UDPLITE,
.me = THIS_MODULE,
},
};
-static int __init xt_tcpudp_init(void)
+static int __init tcpudp_mt_init(void)
{
- return xt_register_matches(xt_tcpudp_match,
- ARRAY_SIZE(xt_tcpudp_match));
+ return xt_register_matches(tcpudp_mt_reg, ARRAY_SIZE(tcpudp_mt_reg));
}
-static void __exit xt_tcpudp_fini(void)
+static void __exit tcpudp_mt_exit(void)
{
- xt_unregister_matches(xt_tcpudp_match, ARRAY_SIZE(xt_tcpudp_match));
+ xt_unregister_matches(tcpudp_mt_reg, ARRAY_SIZE(tcpudp_mt_reg));
}
-module_init(xt_tcpudp_init);
-module_exit(xt_tcpudp_fini);
+module_init(tcpudp_mt_init);
+module_exit(tcpudp_mt_exit);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-12-06 14:16:37 +0000