1 /* Shared library add-on to iptables for ECN, $Version$
2 *
3 * (C) 2002 by Harald Welte <laforge@gnumonks.org>
4 *
5 * This program is distributed under the terms of GNU GPL v2, 1991
6 *
7 * libipt_ECN.c borrowed heavily from libipt_DSCP.c
8 */
9 #include <stdio.h>
10 #include <xtables.h>
11 #include <linux/netfilter_ipv4/ipt_ECN.h>
12
13 enum {
14 O_ECN_TCP_REMOVE = 0,
15 O_ECN_TCP_CWR,
16 O_ECN_TCP_ECE,
17 O_ECN_IP_ECT,
18 F_ECN_TCP_REMOVE = 1 << O_ECN_TCP_REMOVE,
19 F_ECN_TCP_CWR = 1 << O_ECN_TCP_CWR,
20 F_ECN_TCP_ECE = 1 << O_ECN_TCP_ECE,
21 };
22
ECN_help(void)23 static void ECN_help(void)
24 {
25 printf(
26 "ECN target options\n"
27 " --ecn-tcp-remove Remove all ECN bits from TCP header\n");
28 }
29
30 #if 0
31 "ECN target v%s EXPERIMENTAL options (use with extreme care!)\n"
32 " --ecn-ip-ect Set the IPv4 ECT codepoint (0 to 3)\n"
33 " --ecn-tcp-cwr Set the IPv4 CWR bit (0 or 1)\n"
34 " --ecn-tcp-ece Set the IPv4 ECE bit (0 or 1)\n",
35 #endif
36
37 static const struct xt_option_entry ECN_opts[] = {
38 {.name = "ecn-tcp-remove", .id = O_ECN_TCP_REMOVE, .type = XTTYPE_NONE,
39 .excl = F_ECN_TCP_CWR | F_ECN_TCP_ECE},
40 {.name = "ecn-tcp-cwr", .id = O_ECN_TCP_CWR, .type = XTTYPE_UINT8,
41 .min = 0, .max = 1, .excl = F_ECN_TCP_REMOVE},
42 {.name = "ecn-tcp-ece", .id = O_ECN_TCP_ECE, .type = XTTYPE_UINT8,
43 .min = 0, .max = 1, .excl = F_ECN_TCP_REMOVE},
44 {.name = "ecn-ip-ect", .id = O_ECN_IP_ECT, .type = XTTYPE_UINT8,
45 .min = 0, .max = 3},
46 XTOPT_TABLEEND,
47 };
48
ECN_parse(struct xt_option_call * cb)49 static void ECN_parse(struct xt_option_call *cb)
50 {
51 struct ipt_ECN_info *einfo = cb->data;
52
53 xtables_option_parse(cb);
54 switch (cb->entry->id) {
55 case O_ECN_TCP_REMOVE:
56 einfo->operation = IPT_ECN_OP_SET_ECE | IPT_ECN_OP_SET_CWR;
57 einfo->proto.tcp.ece = 0;
58 einfo->proto.tcp.cwr = 0;
59 break;
60 case O_ECN_TCP_CWR:
61 einfo->operation |= IPT_ECN_OP_SET_CWR;
62 einfo->proto.tcp.cwr = cb->val.u8;
63 break;
64 case O_ECN_TCP_ECE:
65 einfo->operation |= IPT_ECN_OP_SET_ECE;
66 einfo->proto.tcp.ece = cb->val.u8;
67 break;
68 case O_ECN_IP_ECT:
69 einfo->operation |= IPT_ECN_OP_SET_IP;
70 einfo->ip_ect = cb->val.u8;
71 break;
72 }
73 }
74
ECN_check(struct xt_fcheck_call * cb)75 static void ECN_check(struct xt_fcheck_call *cb)
76 {
77 if (cb->xflags == 0)
78 xtables_error(PARAMETER_PROBLEM,
79 "ECN target: An operation is required");
80 }
81
ECN_print(const void * ip,const struct xt_entry_target * target,int numeric)82 static void ECN_print(const void *ip, const struct xt_entry_target *target,
83 int numeric)
84 {
85 const struct ipt_ECN_info *einfo =
86 (const struct ipt_ECN_info *)target->data;
87
88 printf(" ECN");
89
90 if (einfo->operation == (IPT_ECN_OP_SET_ECE|IPT_ECN_OP_SET_CWR)
91 && einfo->proto.tcp.ece == 0
92 && einfo->proto.tcp.cwr == 0)
93 printf(" TCP remove");
94 else {
95 if (einfo->operation & IPT_ECN_OP_SET_ECE)
96 printf(" ECE=%u", einfo->proto.tcp.ece);
97
98 if (einfo->operation & IPT_ECN_OP_SET_CWR)
99 printf(" CWR=%u", einfo->proto.tcp.cwr);
100
101 if (einfo->operation & IPT_ECN_OP_SET_IP)
102 printf(" ECT codepoint=%u", einfo->ip_ect);
103 }
104 }
105
ECN_save(const void * ip,const struct xt_entry_target * target)106 static void ECN_save(const void *ip, const struct xt_entry_target *target)
107 {
108 const struct ipt_ECN_info *einfo =
109 (const struct ipt_ECN_info *)target->data;
110
111 if (einfo->operation == (IPT_ECN_OP_SET_ECE|IPT_ECN_OP_SET_CWR)
112 && einfo->proto.tcp.ece == 0
113 && einfo->proto.tcp.cwr == 0)
114 printf(" --ecn-tcp-remove");
115 else {
116
117 if (einfo->operation & IPT_ECN_OP_SET_ECE)
118 printf(" --ecn-tcp-ece %d", einfo->proto.tcp.ece);
119
120 if (einfo->operation & IPT_ECN_OP_SET_CWR)
121 printf(" --ecn-tcp-cwr %d", einfo->proto.tcp.cwr);
122
123 if (einfo->operation & IPT_ECN_OP_SET_IP)
124 printf(" --ecn-ip-ect %d", einfo->ip_ect);
125 }
126 }
127
128 static struct xtables_target ecn_tg_reg = {
129 .name = "ECN",
130 .version = XTABLES_VERSION,
131 .family = NFPROTO_IPV4,
132 .size = XT_ALIGN(sizeof(struct ipt_ECN_info)),
133 .userspacesize = XT_ALIGN(sizeof(struct ipt_ECN_info)),
134 .help = ECN_help,
135 .print = ECN_print,
136 .save = ECN_save,
137 .x6_parse = ECN_parse,
138 .x6_fcheck = ECN_check,
139 .x6_options = ECN_opts,
140 };
141
_init(void)142 void _init(void)
143 {
144 xtables_register_target(&ecn_tg_reg);
145 }
146