Home | History | Annotate | Download | only in extensions
      1 /*
      2  * Shared library add-on to iptables to add TOS target support
      3  *
      4  * Copyright  CC Computer Consultants GmbH, 2007
      5  * Contact: Jan Engelhardt <jengelh (at) medozas.de>
      6  */
      7 #include <getopt.h>
      8 #include <stdbool.h>
      9 #include <stdio.h>
     10 #include <stdlib.h>
     11 #include <string.h>
     12 #include <netinet/in.h>
     13 
     14 #include <xtables.h>
     15 #include <linux/netfilter/xt_DSCP.h>
     16 #include "tos_values.c"
     17 
     18 struct ipt_tos_target_info {
     19 	uint8_t tos;
     20 };
     21 
     22 enum {
     23 	O_SET_TOS = 0,
     24 	O_AND_TOS,
     25 	O_OR_TOS,
     26 	O_XOR_TOS,
     27 	F_SET_TOS = 1 << O_SET_TOS,
     28 	F_AND_TOS = 1 << O_AND_TOS,
     29 	F_OR_TOS  = 1 << O_OR_TOS,
     30 	F_XOR_TOS = 1 << O_XOR_TOS,
     31 	F_ANY     = F_SET_TOS | F_AND_TOS | F_OR_TOS | F_XOR_TOS,
     32 };
     33 
     34 static const struct xt_option_entry tos_tg_opts_v0[] = {
     35 	{.name = "set-tos", .id = O_SET_TOS, .type = XTTYPE_TOSMASK,
     36 	 .excl = F_ANY, .max = 0xFF},
     37 	XTOPT_TABLEEND,
     38 };
     39 
     40 static const struct xt_option_entry tos_tg_opts[] = {
     41 	{.name = "set-tos", .id = O_SET_TOS, .type = XTTYPE_TOSMASK,
     42 	 .excl = F_ANY, .max = 0x3F},
     43 	{.name = "and-tos", .id = O_AND_TOS, .type = XTTYPE_UINT8,
     44 	 .excl = F_ANY},
     45 	{.name = "or-tos", .id = O_OR_TOS, .type = XTTYPE_UINT8,
     46 	 .excl = F_ANY},
     47 	{.name = "xor-tos", .id = O_XOR_TOS, .type = XTTYPE_UINT8,
     48 	 .excl = F_ANY},
     49 	XTOPT_TABLEEND,
     50 };
     51 
     52 static void tos_tg_help_v0(void)
     53 {
     54 	const struct tos_symbol_info *symbol;
     55 
     56 	printf(
     57 "TOS target options:\n"
     58 "  --set-tos value     Set Type of Service/Priority field to value\n"
     59 "  --set-tos symbol    Set TOS field (IPv4 only) by symbol\n"
     60 "                      Accepted symbolic names for value are:\n");
     61 
     62 	for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
     63 		printf("                        (0x%02x) %2u %s\n",
     64 		       symbol->value, symbol->value, symbol->name);
     65 
     66 	printf("\n");
     67 }
     68 
     69 static void tos_tg_help(void)
     70 {
     71 	const struct tos_symbol_info *symbol;
     72 
     73 	printf(
     74 "TOS target v%s options:\n"
     75 "  --set-tos value[/mask]  Set Type of Service/Priority field to value\n"
     76 "                          (Zero out bits in mask and XOR value into TOS)\n"
     77 "  --set-tos symbol        Set TOS field (IPv4 only) by symbol\n"
     78 "                          (this zeroes the 4-bit Precedence part!)\n"
     79 "                          Accepted symbolic names for value are:\n",
     80 XTABLES_VERSION);
     81 
     82 	for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
     83 		printf("                            (0x%02x) %2u %s\n",
     84 		       symbol->value, symbol->value, symbol->name);
     85 
     86 	printf(
     87 "\n"
     88 "  --and-tos bits          Binary AND the TOS value with bits\n"
     89 "  --or-tos  bits          Binary OR the TOS value with bits\n"
     90 "  --xor-tos bits          Binary XOR the TOS value with bits\n"
     91 );
     92 }
     93 
     94 static void tos_tg_parse_v0(struct xt_option_call *cb)
     95 {
     96 	struct ipt_tos_target_info *info = cb->data;
     97 
     98 	xtables_option_parse(cb);
     99 	if (cb->val.tos_mask != 0xFF)
    100 		xtables_error(PARAMETER_PROBLEM, "tos match: Your kernel "
    101 		           "is too old to support anything besides "
    102 			   "/0xFF as a mask.");
    103 	info->tos = cb->val.tos_value;
    104 }
    105 
    106 static void tos_tg_parse(struct xt_option_call *cb)
    107 {
    108 	struct xt_tos_target_info *info = cb->data;
    109 
    110 	xtables_option_parse(cb);
    111 	switch (cb->entry->id) {
    112 	case O_SET_TOS:
    113 		info->tos_value = cb->val.tos_value;
    114 		info->tos_mask  = cb->val.tos_mask;
    115 		break;
    116 	case O_AND_TOS:
    117 		info->tos_value = 0;
    118 		info->tos_mask  = ~cb->val.u8;
    119 		break;
    120 	case O_OR_TOS:
    121 		info->tos_value = cb->val.u8;
    122 		info->tos_mask  = cb->val.u8;
    123 		break;
    124 	case O_XOR_TOS:
    125 		info->tos_value = cb->val.u8;
    126 		info->tos_mask  = 0;
    127 		break;
    128 	}
    129 }
    130 
    131 static void tos_tg_check(struct xt_fcheck_call *cb)
    132 {
    133 	if (!(cb->xflags & F_ANY))
    134 		xtables_error(PARAMETER_PROBLEM,
    135 		           "TOS: An action is required");
    136 }
    137 
    138 static void tos_tg_print_v0(const void *ip,
    139                             const struct xt_entry_target *target, int numeric)
    140 {
    141 	const struct ipt_tos_target_info *info = (const void *)target->data;
    142 
    143 	printf(" TOS set ");
    144 	if (numeric || !tos_try_print_symbolic("", info->tos, 0xFF))
    145 		printf("0x%02x", info->tos);
    146 }
    147 
    148 static void tos_tg_print(const void *ip, const struct xt_entry_target *target,
    149                          int numeric)
    150 {
    151 	const struct xt_tos_target_info *info = (const void *)target->data;
    152 
    153 	if (numeric)
    154 		printf(" TOS set 0x%02x/0x%02x",
    155 		       info->tos_value, info->tos_mask);
    156 	else if (tos_try_print_symbolic(" TOS set",
    157 	    info->tos_value, info->tos_mask))
    158 		/* already printed by call */
    159 		return;
    160 	else if (info->tos_value == 0)
    161 		printf(" TOS and 0x%02x",
    162 		       (unsigned int)(uint8_t)~info->tos_mask);
    163 	else if (info->tos_value == info->tos_mask)
    164 		printf(" TOS or 0x%02x", info->tos_value);
    165 	else if (info->tos_mask == 0)
    166 		printf(" TOS xor 0x%02x", info->tos_value);
    167 	else
    168 		printf(" TOS set 0x%02x/0x%02x",
    169 		       info->tos_value, info->tos_mask);
    170 }
    171 
    172 static void tos_tg_save_v0(const void *ip, const struct xt_entry_target *target)
    173 {
    174 	const struct ipt_tos_target_info *info = (const void *)target->data;
    175 
    176 	printf(" --set-tos 0x%02x", info->tos);
    177 }
    178 
    179 static void tos_tg_save(const void *ip, const struct xt_entry_target *target)
    180 {
    181 	const struct xt_tos_target_info *info = (const void *)target->data;
    182 
    183 	printf(" --set-tos 0x%02x/0x%02x", info->tos_value, info->tos_mask);
    184 }
    185 
    186 static struct xtables_target tos_tg_reg[] = {
    187 	{
    188 		.version       = XTABLES_VERSION,
    189 		.name          = "TOS",
    190 		.revision      = 0,
    191 		.family        = NFPROTO_IPV4,
    192 		.size          = XT_ALIGN(sizeof(struct xt_tos_target_info)),
    193 		.userspacesize = XT_ALIGN(sizeof(struct xt_tos_target_info)),
    194 		.help          = tos_tg_help_v0,
    195 		.print         = tos_tg_print_v0,
    196 		.save          = tos_tg_save_v0,
    197 		.x6_parse      = tos_tg_parse_v0,
    198 		.x6_fcheck     = tos_tg_check,
    199 		.x6_options    = tos_tg_opts_v0,
    200 	},
    201 	{
    202 		.version       = XTABLES_VERSION,
    203 		.name          = "TOS",
    204 		.revision      = 1,
    205 		.family        = NFPROTO_UNSPEC,
    206 		.size          = XT_ALIGN(sizeof(struct xt_tos_target_info)),
    207 		.userspacesize = XT_ALIGN(sizeof(struct xt_tos_target_info)),
    208 		.help          = tos_tg_help,
    209 		.print         = tos_tg_print,
    210 		.save          = tos_tg_save,
    211 		.x6_parse      = tos_tg_parse,
    212 		.x6_fcheck     = tos_tg_check,
    213 		.x6_options    = tos_tg_opts,
    214 	},
    215 };
    216 
    217 void _init(void)
    218 {
    219 	xtables_register_targets(tos_tg_reg, ARRAY_SIZE(tos_tg_reg));
    220 }
    221