Lines Matching defs:*
2 * Shared library add-on to iptables to add TCPOPTSTRIP target support.
3 * Copyright (c) 2007 Sven Schnelle <svens@bitebene.org>
4 * Copyright �� CC Computer Consultants GmbH, 2007
5 * Jan Engelhardt <jengelh@computergmbh.de>
7 #include <stdio.h>
8 #include <string.h>
9 #include <xtables.h>
10 #include <netinet/tcp.h>
11 #include <linux/netfilter/xt_TCPOPTSTRIP.h>
12 #ifndef TCPOPT_MD5SIG
13 # define TCPOPT_MD5SIG 19
14 #endif
16 enum {
17 O_STRIP_OPTION = 0,
20 struct tcp_optionmap {
21 const char *name, *desc;
22 const unsigned int option;
25 static const struct xt_option_entry tcpoptstrip_tg_opts[] = {
26 {.name = "strip-options", .id = O_STRIP_OPTION, .type = XTTYPE_STRING},
27 XTOPT_TABLEEND,
30 static const struct tcp_optionmap tcp_optionmap[] = {
31 {"wscale", "Window scale", TCPOPT_WINDOW},
32 {"mss", "Maximum Segment Size", TCPOPT_MAXSEG},
33 {"sack-permitted", "SACK permitted", TCPOPT_SACK_PERMITTED},
34 {"sack", "Selective ACK", TCPOPT_SACK},
35 {"timestamp", "Timestamp", TCPOPT_TIMESTAMP},
36 {"md5", "MD5 signature", TCPOPT_MD5SIG},
37 {NULL},
40 static void tcpoptstrip_tg_help(void)
42 const struct tcp_optionmap *w;
44 printf(
45 "TCPOPTSTRIP target options:\n"
46 " --strip-options value strip specified TCP options denoted by value\n"
47 " (separated by comma) from TCP header\n"
48 " Instead of the numeric value, you can also use the following names:\n"
51 for (w = tcp_optionmap; w->name != NULL; ++w)
52 printf(" %-14s strip \"%s\" option\n", w->name, w->desc);
55 static void
56 parse_list(struct xt_tcpoptstrip_target_info *info, const char *arg)
58 unsigned int option;
59 char *p;
60 int i;
62 while (true) {
63 p = strchr(arg, ',');
64 if (p != NULL)
65 *p = '\0';
67 option = 0;
68 for (i = 0; tcp_optionmap[i].name != NULL; ++i)
69 if (strcmp(tcp_optionmap[i].name, arg) == 0) {
70 option = tcp_optionmap[i].option;
71 break;
74 if (option == 0 &&
75 !xtables_strtoui(arg, NULL, &option, 0, UINT8_MAX))
76 xtables_error(PARAMETER_PROBLEM,
77 "Bad TCP option value \"%s\"", arg);
79 if (option < 2)
80 xtables_error(PARAMETER_PROBLEM,
81 "Option value may not be 0 or 1");
83 if (tcpoptstrip_test_bit(info->strip_bmap, option))
84 xtables_error(PARAMETER_PROBLEM,
85 "Option \"%s\" already specified", arg);
87 tcpoptstrip_set_bit(info->strip_bmap, option);
88 if (p == NULL)
89 break;
90 arg = p + 1;
94 static void tcpoptstrip_tg_parse(struct xt_option_call *cb)
96 struct xt_tcpoptstrip_target_info *info = cb->data;
98 xtables_option_parse(cb);
99 parse_list(info, cb->arg);
102 static void
103 tcpoptstrip_print_list(const struct xt_tcpoptstrip_target_info *info,
104 bool numeric)
106 unsigned int i, j;
107 const char *name;
108 bool first = true;
110 for (i = 0; i < 256; ++i) {
111 if (!tcpoptstrip_test_bit(info->strip_bmap, i))
112 continue;
113 if (!first)
114 printf(",");
116 first = false;
117 name = NULL;
118 if (!numeric)
119 for (j = 0; tcp_optionmap[j].name != NULL; ++j)
120 if (tcp_optionmap[j].option == i)
121 name = tcp_optionmap[j].name;
123 if (name != NULL)
124 printf("%s", name);
125 else
126 printf("%u", i);
130 static void
131 tcpoptstrip_tg_print(const void *ip, const struct xt_entry_target *target,
132 int numeric)
134 const struct xt_tcpoptstrip_target_info *info =
135 (const void *)target->data;
137 printf(" TCPOPTSTRIP options ");
138 tcpoptstrip_print_list(info, numeric);
141 static void
142 tcpoptstrip_tg_save(const void *ip, const struct xt_entry_target *target)
144 const struct xt_tcpoptstrip_target_info *info =
145 (const void *)target->data;
147 printf(" --strip-options ");
148 tcpoptstrip_print_list(info, true);
151 static struct xtables_target tcpoptstrip_tg_reg = {
152 .version = XTABLES_VERSION,
153 .name = "TCPOPTSTRIP",
154 .family = NFPROTO_UNSPEC,
155 .size = XT_ALIGN(sizeof(struct xt_tcpoptstrip_target_info)),
156 .userspacesize = XT_ALIGN(sizeof(struct xt_tcpoptstrip_target_info)),
157 .help = tcpoptstrip_tg_help,
158 .print = tcpoptstrip_tg_print,
159 .save = tcpoptstrip_tg_save,
160 .x6_parse = tcpoptstrip_tg_parse,
161 .x6_options = tcpoptstrip_tg_opts,
164 void _init(void)
166 xtables_register_target(&tcpoptstrip_tg_reg);