| 1 | --- a/include/linux/netfilter_ipv4/ipt_multiport.h |
| 2 | +++ b/include/linux/netfilter_ipv4/ipt_multiport.h |
| 3 | @@ -11,11 +11,12 @@ enum ipt_multiport_flags |
| 4 | |
| 5 | #define IPT_MULTI_PORTS 15 |
| 6 | |
| 7 | -/* Must fit inside union ipt_matchinfo: 16 bytes */ |
| 8 | -struct ipt_multiport |
| 9 | +struct ipt_multiport_v1 |
| 10 | { |
| 11 | u_int8_t flags; /* Type of comparison */ |
| 12 | u_int8_t count; /* Number of ports */ |
| 13 | u_int16_t ports[IPT_MULTI_PORTS]; /* Ports */ |
| 14 | + u_int8_t pflags[IPT_MULTI_PORTS]; /* Port flags */ |
| 15 | + u_int8_t invert; /* Invert flag */ |
| 16 | }; |
| 17 | #endif /*_IPT_MULTIPORT_H*/ |
| 18 | --- a/net/ipv4/netfilter/ipt_multiport.c |
| 19 | +++ b/net/ipv4/netfilter/ipt_multiport.c |
| 20 | @@ -1,5 +1,14 @@ |
| 21 | /* Kernel module to match one of a list of TCP/UDP ports: ports are in |
| 22 | the same place so we can treat them as equal. */ |
| 23 | + |
| 24 | +/* (C) 1999-2001 Paul `Rusty' Russell |
| 25 | + * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> |
| 26 | + * |
| 27 | + * This program is free software; you can redistribute it and/or modify |
| 28 | + * it under the terms of the GNU General Public License version 2 as |
| 29 | + * published by the Free Software Foundation. |
| 30 | + */ |
| 31 | + |
| 32 | #include <linux/module.h> |
| 33 | #include <linux/types.h> |
| 34 | #include <linux/udp.h> |
| 35 | @@ -8,97 +17,136 @@ |
| 36 | #include <linux/netfilter_ipv4/ipt_multiport.h> |
| 37 | #include <linux/netfilter_ipv4/ip_tables.h> |
| 38 | |
| 39 | +MODULE_LICENSE("GPL"); |
| 40 | +MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); |
| 41 | +MODULE_DESCRIPTION("iptables multiple port match module"); |
| 42 | + |
| 43 | #if 0 |
| 44 | #define duprintf(format, args...) printk(format , ## args) |
| 45 | #else |
| 46 | #define duprintf(format, args...) |
| 47 | #endif |
| 48 | |
| 49 | +/* from linux 2.6 skbuff.h */ |
| 50 | +static inline void *skb_header_pointer(const struct sk_buff *skb, int offset, |
| 51 | + int len, void *buffer) |
| 52 | +{ |
| 53 | + int hlen = skb_headlen(skb); |
| 54 | + |
| 55 | + if (hlen - offset >= len) |
| 56 | + return skb->data + offset; |
| 57 | + |
| 58 | + if (skb_copy_bits(skb, offset, buffer, len) < 0) |
| 59 | + return NULL; |
| 60 | + |
| 61 | + return buffer; |
| 62 | +} |
| 63 | + |
| 64 | + |
| 65 | /* Returns 1 if the port is matched by the test, 0 otherwise. */ |
| 66 | static inline int |
| 67 | -ports_match(const u_int16_t *portlist, enum ipt_multiport_flags flags, |
| 68 | - u_int8_t count, u_int16_t src, u_int16_t dst) |
| 69 | +ports_match_v1(const struct ipt_multiport_v1 *minfo, |
| 70 | + u_int16_t src, u_int16_t dst) |
| 71 | { |
| 72 | unsigned int i; |
| 73 | - for (i=0; i<count; i++) { |
| 74 | - if (flags != IPT_MULTIPORT_DESTINATION |
| 75 | - && portlist[i] == src) |
| 76 | - return 1; |
| 77 | - |
| 78 | - if (flags != IPT_MULTIPORT_SOURCE |
| 79 | - && portlist[i] == dst) |
| 80 | - return 1; |
| 81 | - } |
| 82 | + u_int16_t s, e; |
| 83 | |
| 84 | - return 0; |
| 85 | + for (i=0; i < minfo->count; i++) { |
| 86 | + s = minfo->ports[i]; |
| 87 | + |
| 88 | + if (minfo->pflags[i]) { |
| 89 | + /* range port matching */ |
| 90 | + e = minfo->ports[++i]; |
| 91 | + duprintf("src or dst matches with %d-%d?\n", s, e); |
| 92 | + |
| 93 | + if (minfo->flags == IPT_MULTIPORT_SOURCE |
| 94 | + && src >= s && src <= e) |
| 95 | + return 1 ^ minfo->invert; |
| 96 | + if (minfo->flags == IPT_MULTIPORT_DESTINATION |
| 97 | + && dst >= s && dst <= e) |
| 98 | + return 1 ^ minfo->invert; |
| 99 | + if (minfo->flags == IPT_MULTIPORT_EITHER |
| 100 | + && ((dst >= s && dst <= e) |
| 101 | + || (src >= s && src <= e))) |
| 102 | + return 1 ^ minfo->invert; |
| 103 | + } else { |
| 104 | + /* exact port matching */ |
| 105 | + duprintf("src or dst matches with %d?\n", s); |
| 106 | + |
| 107 | + if (minfo->flags == IPT_MULTIPORT_SOURCE |
| 108 | + && src == s) |
| 109 | + return 1 ^ minfo->invert; |
| 110 | + if (minfo->flags == IPT_MULTIPORT_DESTINATION |
| 111 | + && dst == s) |
| 112 | + return 1 ^ minfo->invert; |
| 113 | + if (minfo->flags == IPT_MULTIPORT_EITHER |
| 114 | + && (src == s || dst == s)) |
| 115 | + return 1 ^ minfo->invert; |
| 116 | + } |
| 117 | + } |
| 118 | + |
| 119 | + return minfo->invert; |
| 120 | } |
| 121 | |
| 122 | static int |
| 123 | -match(const struct sk_buff *skb, |
| 124 | - const struct net_device *in, |
| 125 | - const struct net_device *out, |
| 126 | - const void *matchinfo, |
| 127 | - int offset, |
| 128 | - const void *hdr, |
| 129 | - u_int16_t datalen, |
| 130 | - int *hotdrop) |
| 131 | +match_v1(const struct sk_buff *skb, |
| 132 | + const struct net_device *in, |
| 133 | + const struct net_device *out, |
| 134 | + const void *matchinfo, |
| 135 | + int offset, |
| 136 | + int *hotdrop) |
| 137 | { |
| 138 | - const struct udphdr *udp = hdr; |
| 139 | - const struct ipt_multiport *multiinfo = matchinfo; |
| 140 | + u16 _ports[2], *pptr; |
| 141 | + const struct ipt_multiport_v1 *multiinfo = matchinfo; |
| 142 | + |
| 143 | + if (offset) |
| 144 | + return 0; |
| 145 | |
| 146 | - /* Must be big enough to read ports. */ |
| 147 | - if (offset == 0 && datalen < sizeof(struct udphdr)) { |
| 148 | + pptr = skb_header_pointer(skb, skb->nh.iph->ihl * 4, |
| 149 | + sizeof(_ports), _ports); |
| 150 | + if (pptr == NULL) { |
| 151 | /* We've been asked to examine this packet, and we |
| 152 | - can't. Hence, no choice but to drop. */ |
| 153 | - duprintf("ipt_multiport:" |
| 154 | - " Dropping evil offset=0 tinygram.\n"); |
| 155 | - *hotdrop = 1; |
| 156 | - return 0; |
| 157 | + * can't. Hence, no choice but to drop. |
| 158 | + */ |
| 159 | + duprintf("ipt_multiport:" |
| 160 | + " Dropping evil offset=0 tinygram.\n"); |
| 161 | + *hotdrop = 1; |
| 162 | + return 0; |
| 163 | } |
| 164 | |
| 165 | - /* Must not be a fragment. */ |
| 166 | - return !offset |
| 167 | - && ports_match(multiinfo->ports, |
| 168 | - multiinfo->flags, multiinfo->count, |
| 169 | - ntohs(udp->source), ntohs(udp->dest)); |
| 170 | + return ports_match_v1(multiinfo, ntohs(pptr[0]), ntohs(pptr[1])); |
| 171 | } |
| 172 | |
| 173 | -/* Called when user tries to insert an entry of this type. */ |
| 174 | static int |
| 175 | -checkentry(const char *tablename, |
| 176 | - const struct ipt_ip *ip, |
| 177 | - void *matchinfo, |
| 178 | - unsigned int matchsize, |
| 179 | - unsigned int hook_mask) |
| 180 | +checkentry_v1(const char *tablename, |
| 181 | + const struct ipt_ip *ip, |
| 182 | + void *matchinfo, |
| 183 | + unsigned int matchsize, |
| 184 | + unsigned int hook_mask) |
| 185 | { |
| 186 | - const struct ipt_multiport *multiinfo = matchinfo; |
| 187 | - |
| 188 | - if (matchsize != IPT_ALIGN(sizeof(struct ipt_multiport))) |
| 189 | - return 0; |
| 190 | - |
| 191 | - /* Must specify proto == TCP/UDP, no unknown flags or bad count */ |
| 192 | - return (ip->proto == IPPROTO_TCP || ip->proto == IPPROTO_UDP) |
| 193 | - && !(ip->invflags & IPT_INV_PROTO) |
| 194 | - && matchsize == IPT_ALIGN(sizeof(struct ipt_multiport)) |
| 195 | - && (multiinfo->flags == IPT_MULTIPORT_SOURCE |
| 196 | - || multiinfo->flags == IPT_MULTIPORT_DESTINATION |
| 197 | - || multiinfo->flags == IPT_MULTIPORT_EITHER) |
| 198 | - && multiinfo->count <= IPT_MULTI_PORTS; |
| 199 | + return (matchsize == IPT_ALIGN(sizeof(struct ipt_multiport_v1))); |
| 200 | } |
| 201 | |
| 202 | -static struct ipt_match multiport_match |
| 203 | -= { { NULL, NULL }, "multiport", &match, &checkentry, NULL, THIS_MODULE }; |
| 204 | +static struct ipt_match multiport_match_v1 = { |
| 205 | + .name = "multiport", |
| 206 | + .match = &match_v1, |
| 207 | + .checkentry = &checkentry_v1, |
| 208 | + .me = THIS_MODULE, |
| 209 | +}; |
| 210 | |
| 211 | static int __init init(void) |
| 212 | { |
| 213 | - return ipt_register_match(&multiport_match); |
| 214 | + int err; |
| 215 | + |
| 216 | + err = ipt_register_match(&multiport_match_v1); |
| 217 | + |
| 218 | + return err; |
| 219 | } |
| 220 | |
| 221 | static void __exit fini(void) |
| 222 | { |
| 223 | - ipt_unregister_match(&multiport_match); |
| 224 | + ipt_unregister_match(&multiport_match_v1); |
| 225 | } |
| 226 | |
| 227 | module_init(init); |
| 228 | module_exit(fini); |
| 229 | -MODULE_LICENSE("GPL"); |
| 230 | |
