Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 1 | /* ipv6header match - matches IPv6 packets based |
| 2 | on whether they contain certain headers */ |
| 3 | |
| 4 | /* Original idea: Brad Chapman |
| 5 | * Rewritten by: Andras Kis-Szabo <kisza@sch.bme.hu> */ |
Jan Engelhardt | b26d08b | 2011-03-01 19:51:16 +0100 | [diff] [blame] | 6 | #include <stdint.h> |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 7 | #include <stdio.h> |
| 8 | #include <stdlib.h> |
| 9 | #include <string.h> |
| 10 | #include <netdb.h> |
Jan Engelhardt | b26d08b | 2011-03-01 19:51:16 +0100 | [diff] [blame] | 11 | #include <xtables.h> |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 12 | #include <linux/netfilter_ipv6/ip6t_ipv6header.h> |
| 13 | |
Jan Engelhardt | b26d08b | 2011-03-01 19:51:16 +0100 | [diff] [blame] | 14 | enum { |
| 15 | O_HEADER = 0, |
| 16 | O_SOFT, |
| 17 | }; |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 18 | |
| 19 | /* A few hardcoded protocols for 'all' and in case the user has no |
| 20 | * /etc/protocols */ |
| 21 | struct pprot { |
| 22 | char *name; |
Jan Engelhardt | 7ac4052 | 2011-01-07 12:34:04 +0100 | [diff] [blame] | 23 | uint8_t num; |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 24 | }; |
| 25 | |
| 26 | struct numflag { |
Jan Engelhardt | 7ac4052 | 2011-01-07 12:34:04 +0100 | [diff] [blame] | 27 | uint8_t proto; |
| 28 | uint8_t flag; |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 29 | }; |
| 30 | |
| 31 | static const struct pprot chain_protos[] = { |
| 32 | { "hop-by-hop", IPPROTO_HOPOPTS }, |
| 33 | { "protocol", IPPROTO_RAW }, |
| 34 | { "hop", IPPROTO_HOPOPTS }, |
| 35 | { "dst", IPPROTO_DSTOPTS }, |
| 36 | { "route", IPPROTO_ROUTING }, |
| 37 | { "frag", IPPROTO_FRAGMENT }, |
| 38 | { "auth", IPPROTO_AH }, |
| 39 | { "esp", IPPROTO_ESP }, |
| 40 | { "none", IPPROTO_NONE }, |
| 41 | { "prot", IPPROTO_RAW }, |
| 42 | { "0", IPPROTO_HOPOPTS }, |
| 43 | { "60", IPPROTO_DSTOPTS }, |
| 44 | { "43", IPPROTO_ROUTING }, |
| 45 | { "44", IPPROTO_FRAGMENT }, |
| 46 | { "51", IPPROTO_AH }, |
| 47 | { "50", IPPROTO_ESP }, |
| 48 | { "59", IPPROTO_NONE }, |
| 49 | { "255", IPPROTO_RAW }, |
| 50 | /* { "all", 0 }, */ |
| 51 | }; |
| 52 | |
| 53 | static const struct numflag chain_flags[] = { |
| 54 | { IPPROTO_HOPOPTS, MASK_HOPOPTS }, |
| 55 | { IPPROTO_DSTOPTS, MASK_DSTOPTS }, |
| 56 | { IPPROTO_ROUTING, MASK_ROUTING }, |
| 57 | { IPPROTO_FRAGMENT, MASK_FRAGMENT }, |
| 58 | { IPPROTO_AH, MASK_AH }, |
| 59 | { IPPROTO_ESP, MASK_ESP }, |
| 60 | { IPPROTO_NONE, MASK_NONE }, |
| 61 | { IPPROTO_RAW, MASK_PROTO }, |
| 62 | }; |
| 63 | |
Jan Engelhardt | dd6e4b9 | 2011-05-07 00:05:24 +0200 | [diff] [blame] | 64 | static const char * |
Jan Engelhardt | 7ac4052 | 2011-01-07 12:34:04 +0100 | [diff] [blame] | 65 | proto_to_name(uint8_t proto, int nolookup) |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 66 | { |
| 67 | unsigned int i; |
| 68 | |
| 69 | if (proto && !nolookup) { |
Jan Engelhardt | dd6e4b9 | 2011-05-07 00:05:24 +0200 | [diff] [blame] | 70 | const struct protoent *pent = getprotobynumber(proto); |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 71 | if (pent) |
| 72 | return pent->p_name; |
| 73 | } |
| 74 | |
Jan Engelhardt | 2c69b55 | 2009-04-30 19:32:02 +0200 | [diff] [blame] | 75 | for (i = 0; i < ARRAY_SIZE(chain_protos); ++i) |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 76 | if (chain_protos[i].num == proto) |
| 77 | return chain_protos[i].name; |
| 78 | |
| 79 | return NULL; |
| 80 | } |
| 81 | |
Jan Engelhardt | 7ac4052 | 2011-01-07 12:34:04 +0100 | [diff] [blame] | 82 | static uint16_t |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 83 | name_to_proto(const char *s) |
| 84 | { |
| 85 | unsigned int proto=0; |
Jan Engelhardt | dd6e4b9 | 2011-05-07 00:05:24 +0200 | [diff] [blame] | 86 | const struct protoent *pent; |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 87 | |
| 88 | if ((pent = getprotobyname(s))) |
| 89 | proto = pent->p_proto; |
| 90 | else { |
| 91 | unsigned int i; |
Jan Engelhardt | 2c69b55 | 2009-04-30 19:32:02 +0200 | [diff] [blame] | 92 | for (i = 0; i < ARRAY_SIZE(chain_protos); ++i) |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 93 | if (strcmp(s, chain_protos[i].name) == 0) { |
| 94 | proto = chain_protos[i].num; |
| 95 | break; |
| 96 | } |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 97 | |
Jan Engelhardt | 2c69b55 | 2009-04-30 19:32:02 +0200 | [diff] [blame] | 98 | if (i == ARRAY_SIZE(chain_protos)) |
Jan Engelhardt | 1829ed4 | 2009-02-21 03:29:44 +0100 | [diff] [blame] | 99 | xtables_error(PARAMETER_PROBLEM, |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 100 | "unknown header `%s' specified", |
| 101 | s); |
| 102 | } |
| 103 | |
Jan Engelhardt | 213e185 | 2009-01-27 17:24:34 +0100 | [diff] [blame] | 104 | return proto; |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 105 | } |
| 106 | |
| 107 | static unsigned int |
| 108 | add_proto_to_mask(int proto){ |
| 109 | unsigned int i=0, flag=0; |
| 110 | |
Jan Engelhardt | 2c69b55 | 2009-04-30 19:32:02 +0200 | [diff] [blame] | 111 | for (i = 0; i < ARRAY_SIZE(chain_flags); ++i) |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 112 | if (proto == chain_flags[i].proto){ |
| 113 | flag = chain_flags[i].flag; |
| 114 | break; |
| 115 | } |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 116 | |
Jan Engelhardt | 2c69b55 | 2009-04-30 19:32:02 +0200 | [diff] [blame] | 117 | if (i == ARRAY_SIZE(chain_flags)) |
Jan Engelhardt | 1829ed4 | 2009-02-21 03:29:44 +0100 | [diff] [blame] | 118 | xtables_error(PARAMETER_PROBLEM, |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 119 | "unknown header `%d' specified", |
| 120 | proto); |
| 121 | |
| 122 | return flag; |
| 123 | } |
| 124 | |
Jan Engelhardt | 997045f | 2007-10-04 16:29:21 +0000 | [diff] [blame] | 125 | static void ipv6header_help(void) |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 126 | { |
| 127 | printf( |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 128 | "ipv6header match options:\n" |
Jan Engelhardt | 9672792 | 2008-08-13 14:42:41 +0200 | [diff] [blame] | 129 | "[!] --header headers Type of header to match, by name\n" |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 130 | " names: hop,dst,route,frag,auth,esp,none,proto\n" |
| 131 | " long names: hop-by-hop,ipv6-opts,ipv6-route,\n" |
| 132 | " ipv6-frag,ah,esp,ipv6-nonxt,protocol\n" |
Harald Welte | 426d901 | 2001-12-25 09:27:03 +0000 | [diff] [blame] | 133 | " numbers: 0,60,43,44,51,50,59\n" |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 134 | "--soft The header CONTAINS the specified extensions\n"); |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 135 | } |
| 136 | |
Jan Engelhardt | b26d08b | 2011-03-01 19:51:16 +0100 | [diff] [blame] | 137 | static const struct xt_option_entry ipv6header_opts[] = { |
| 138 | {.name = "header", .id = O_HEADER, .type = XTTYPE_STRING, |
| 139 | .flags = XTOPT_MAND | XTOPT_INVERT}, |
| 140 | {.name = "soft", .id = O_SOFT, .type = XTTYPE_NONE}, |
| 141 | XTOPT_TABLEEND, |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 142 | }; |
| 143 | |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 144 | static unsigned int |
| 145 | parse_header(const char *flags) { |
| 146 | unsigned int ret = 0; |
| 147 | char *ptr; |
| 148 | char *buffer; |
| 149 | |
| 150 | buffer = strdup(flags); |
| 151 | |
| 152 | for (ptr = strtok(buffer, ","); ptr; ptr = strtok(NULL, ",")) |
| 153 | ret |= add_proto_to_mask(name_to_proto(ptr)); |
| 154 | |
| 155 | free(buffer); |
| 156 | return ret; |
| 157 | } |
| 158 | |
Jan Engelhardt | b26d08b | 2011-03-01 19:51:16 +0100 | [diff] [blame] | 159 | static void ipv6header_parse(struct xt_option_call *cb) |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 160 | { |
Jan Engelhardt | b26d08b | 2011-03-01 19:51:16 +0100 | [diff] [blame] | 161 | struct ip6t_ipv6header_info *info = cb->data; |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 162 | |
Jan Engelhardt | b26d08b | 2011-03-01 19:51:16 +0100 | [diff] [blame] | 163 | xtables_option_parse(cb); |
| 164 | switch (cb->entry->id) { |
| 165 | case O_HEADER: |
| 166 | if (!(info->matchflags = parse_header(cb->arg))) |
| 167 | xtables_error(PARAMETER_PROBLEM, "ip6t_ipv6header: cannot parse header names"); |
| 168 | if (cb->invert) |
| 169 | info->invflags |= 0xFF; |
| 170 | break; |
| 171 | case O_SOFT: |
| 172 | info->modeflag |= 0xFF; |
| 173 | break; |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 174 | } |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 175 | } |
| 176 | |
| 177 | static void |
Jan Engelhardt | 7ac4052 | 2011-01-07 12:34:04 +0100 | [diff] [blame] | 178 | print_header(uint8_t flags){ |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 179 | int have_flag = 0; |
| 180 | |
| 181 | while (flags) { |
| 182 | unsigned int i; |
| 183 | |
| 184 | for (i = 0; (flags & chain_flags[i].flag) == 0; i++); |
| 185 | |
| 186 | if (have_flag) |
| 187 | printf(","); |
| 188 | |
| 189 | printf("%s", proto_to_name(chain_flags[i].proto,0)); |
| 190 | have_flag = 1; |
| 191 | |
| 192 | flags &= ~chain_flags[i].flag; |
| 193 | } |
| 194 | |
| 195 | if (!have_flag) |
| 196 | printf("NONE"); |
| 197 | } |
| 198 | |
Jan Engelhardt | 997045f | 2007-10-04 16:29:21 +0000 | [diff] [blame] | 199 | static void ipv6header_print(const void *ip, |
| 200 | const struct xt_entry_match *match, int numeric) |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 201 | { |
| 202 | const struct ip6t_ipv6header_info *info = (const struct ip6t_ipv6header_info *)match->data; |
Jan Engelhardt | 7386635 | 2010-12-18 02:04:59 +0100 | [diff] [blame] | 203 | printf(" ipv6header"); |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 204 | |
| 205 | if (info->matchflags || info->invflags) { |
Jan Engelhardt | 7386635 | 2010-12-18 02:04:59 +0100 | [diff] [blame] | 206 | printf(" flags:%s", info->invflags ? "!" : ""); |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 207 | if (numeric) |
Jan Engelhardt | 7386635 | 2010-12-18 02:04:59 +0100 | [diff] [blame] | 208 | printf("0x%02X", info->matchflags); |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 209 | else { |
| 210 | print_header(info->matchflags); |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 211 | } |
| 212 | } |
| 213 | |
Harald Welte | 426d901 | 2001-12-25 09:27:03 +0000 | [diff] [blame] | 214 | if (info->modeflag) |
Jan Engelhardt | 7386635 | 2010-12-18 02:04:59 +0100 | [diff] [blame] | 215 | printf(" soft"); |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 216 | } |
| 217 | |
Jan Engelhardt | 997045f | 2007-10-04 16:29:21 +0000 | [diff] [blame] | 218 | static void ipv6header_save(const void *ip, const struct xt_entry_match *match) |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 219 | { |
| 220 | |
| 221 | const struct ip6t_ipv6header_info *info = (const struct ip6t_ipv6header_info *)match->data; |
| 222 | |
Jan Engelhardt | 7386635 | 2010-12-18 02:04:59 +0100 | [diff] [blame] | 223 | printf("%s --header ", info->invflags ? " !" : ""); |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 224 | print_header(info->matchflags); |
Harald Welte | 426d901 | 2001-12-25 09:27:03 +0000 | [diff] [blame] | 225 | if (info->modeflag) |
Jan Engelhardt | 7386635 | 2010-12-18 02:04:59 +0100 | [diff] [blame] | 226 | printf(" --soft"); |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 227 | } |
| 228 | |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 229 | static struct xtables_match ipv6header_mt6_reg = { |
Harald Welte | 02aa733 | 2005-02-01 15:38:20 +0000 | [diff] [blame] | 230 | .name = "ipv6header", |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 231 | .version = XTABLES_VERSION, |
Jan Engelhardt | 03d9948 | 2008-11-18 12:27:54 +0100 | [diff] [blame] | 232 | .family = NFPROTO_IPV6, |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 233 | .size = XT_ALIGN(sizeof(struct ip6t_ipv6header_info)), |
| 234 | .userspacesize = XT_ALIGN(sizeof(struct ip6t_ipv6header_info)), |
Jan Engelhardt | 997045f | 2007-10-04 16:29:21 +0000 | [diff] [blame] | 235 | .help = ipv6header_help, |
Jan Engelhardt | 997045f | 2007-10-04 16:29:21 +0000 | [diff] [blame] | 236 | .print = ipv6header_print, |
| 237 | .save = ipv6header_save, |
Jan Engelhardt | b26d08b | 2011-03-01 19:51:16 +0100 | [diff] [blame] | 238 | .x6_parse = ipv6header_parse, |
| 239 | .x6_options = ipv6header_opts, |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 240 | }; |
| 241 | |
| 242 | void _init(void) |
| 243 | { |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 244 | xtables_register_match(&ipv6header_mt6_reg); |
Harald Welte | 46281d4 | 2001-12-18 07:55:41 +0000 | [diff] [blame] | 245 | } |