András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 1 | /* Shared library add-on to ip6tables to add Fragmentation header support. */ |
| 2 | #include <stdio.h> |
| 3 | #include <netdb.h> |
| 4 | #include <string.h> |
| 5 | #include <stdlib.h> |
| 6 | #include <getopt.h> |
| 7 | #include <errno.h> |
Jan Engelhardt | 5d9678a | 2008-11-20 10:15:35 +0100 | [diff] [blame] | 8 | #include <xtables.h> |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 9 | #include <linux/netfilter_ipv6/ip6t_frag.h> |
Jan Engelhardt | ddac6c5 | 2008-09-01 14:22:19 +0200 | [diff] [blame] | 10 | |
Jan Engelhardt | 997045f | 2007-10-04 16:29:21 +0000 | [diff] [blame] | 11 | static void frag_help(void) |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 12 | { |
| 13 | printf( |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 14 | "frag match options:\n" |
Jan Engelhardt | 9672792 | 2008-08-13 14:42:41 +0200 | [diff] [blame] | 15 | "[!] --fragid id[:id] match the id (range)\n" |
| 16 | "[!] --fraglen length total length of this header\n" |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 17 | " --fragres check the reserved filed, too\n" |
András Kis-Szabó | d8a12a8 | 2002-04-24 09:36:30 +0000 | [diff] [blame] | 18 | " --fragfirst matches on the first fragment\n" |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 19 | " [--fragmore|--fraglast] there are more fragments or this\n" |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 20 | " is the last one\n"); |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 21 | } |
| 22 | |
Jan Engelhardt | 997045f | 2007-10-04 16:29:21 +0000 | [diff] [blame] | 23 | static const struct option frag_opts[] = { |
Patrick McHardy | 500f483 | 2007-09-08 15:59:04 +0000 | [diff] [blame] | 24 | { .name = "fragid", .has_arg = 1, .val = '1' }, |
| 25 | { .name = "fraglen", .has_arg = 1, .val = '2' }, |
| 26 | { .name = "fragres", .has_arg = 0, .val = '3' }, |
| 27 | { .name = "fragfirst", .has_arg = 0, .val = '4' }, |
| 28 | { .name = "fragmore", .has_arg = 0, .val = '5' }, |
| 29 | { .name = "fraglast", .has_arg = 0, .val = '6' }, |
Max Kellermann | 9ee386a | 2008-01-29 13:48:05 +0000 | [diff] [blame] | 30 | { .name = NULL } |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 31 | }; |
| 32 | |
| 33 | static u_int32_t |
| 34 | parse_frag_id(const char *idstr, const char *typestr) |
| 35 | { |
| 36 | unsigned long int id; |
| 37 | char* ep; |
| 38 | |
Harald Welte | 46a73cf | 2003-09-05 12:53:44 +0000 | [diff] [blame] | 39 | id = strtoul(idstr, &ep, 0); |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 40 | |
| 41 | if ( idstr == ep ) { |
| 42 | exit_error(PARAMETER_PROBLEM, |
| 43 | "FRAG no valid digits in %s `%s'", typestr, idstr); |
| 44 | } |
| 45 | if ( id == ULONG_MAX && errno == ERANGE ) { |
| 46 | exit_error(PARAMETER_PROBLEM, |
| 47 | "%s `%s' specified too big: would overflow", |
| 48 | typestr, idstr); |
| 49 | } |
| 50 | if ( *idstr != '\0' && *ep != '\0' ) { |
| 51 | exit_error(PARAMETER_PROBLEM, |
| 52 | "FRAG error parsing %s `%s'", typestr, idstr); |
| 53 | } |
Jan Engelhardt | 213e185 | 2009-01-27 17:24:34 +0100 | [diff] [blame] | 54 | return id; |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 55 | } |
| 56 | |
| 57 | static void |
| 58 | parse_frag_ids(const char *idstring, u_int32_t *ids) |
| 59 | { |
| 60 | char *buffer; |
| 61 | char *cp; |
| 62 | |
| 63 | buffer = strdup(idstring); |
| 64 | if ((cp = strchr(buffer, ':')) == NULL) |
| 65 | ids[0] = ids[1] = parse_frag_id(buffer,"id"); |
| 66 | else { |
| 67 | *cp = '\0'; |
| 68 | cp++; |
| 69 | |
| 70 | ids[0] = buffer[0] ? parse_frag_id(buffer,"id") : 0; |
| 71 | ids[1] = cp[0] ? parse_frag_id(cp,"id") : 0xFFFFFFFF; |
| 72 | } |
| 73 | free(buffer); |
| 74 | } |
| 75 | |
Jan Engelhardt | 997045f | 2007-10-04 16:29:21 +0000 | [diff] [blame] | 76 | static void frag_init(struct xt_entry_match *m) |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 77 | { |
| 78 | struct ip6t_frag *fraginfo = (struct ip6t_frag *)m->data; |
| 79 | |
| 80 | fraginfo->ids[0] = 0x0L; |
| 81 | fraginfo->ids[1] = 0xFFFFFFFF; |
| 82 | fraginfo->hdrlen = 0; |
| 83 | fraginfo->flags = 0; |
| 84 | fraginfo->invflags = 0; |
| 85 | } |
| 86 | |
Jan Engelhardt | 997045f | 2007-10-04 16:29:21 +0000 | [diff] [blame] | 87 | static int frag_parse(int c, char **argv, int invert, unsigned int *flags, |
| 88 | const void *entry, struct xt_entry_match **match) |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 89 | { |
| 90 | struct ip6t_frag *fraginfo = (struct ip6t_frag *)(*match)->data; |
| 91 | |
| 92 | switch (c) { |
| 93 | case '1': |
| 94 | if (*flags & IP6T_FRAG_IDS) |
| 95 | exit_error(PARAMETER_PROBLEM, |
| 96 | "Only one `--fragid' allowed"); |
| 97 | check_inverse(optarg, &invert, &optind, 0); |
| 98 | parse_frag_ids(argv[optind-1], fraginfo->ids); |
| 99 | if (invert) |
| 100 | fraginfo->invflags |= IP6T_FRAG_INV_IDS; |
| 101 | fraginfo->flags |= IP6T_FRAG_IDS; |
| 102 | *flags |= IP6T_FRAG_IDS; |
| 103 | break; |
| 104 | case '2': |
| 105 | if (*flags & IP6T_FRAG_LEN) |
| 106 | exit_error(PARAMETER_PROBLEM, |
| 107 | "Only one `--fraglen' allowed"); |
| 108 | check_inverse(optarg, &invert, &optind, 0); |
| 109 | fraginfo->hdrlen = parse_frag_id(argv[optind-1], "length"); |
| 110 | if (invert) |
| 111 | fraginfo->invflags |= IP6T_FRAG_INV_LEN; |
| 112 | fraginfo->flags |= IP6T_FRAG_LEN; |
| 113 | *flags |= IP6T_FRAG_LEN; |
| 114 | break; |
| 115 | case '3': |
| 116 | if (*flags & IP6T_FRAG_RES) |
| 117 | exit_error(PARAMETER_PROBLEM, |
| 118 | "Only one `--fragres' allowed"); |
| 119 | fraginfo->flags |= IP6T_FRAG_RES; |
| 120 | *flags |= IP6T_FRAG_RES; |
| 121 | break; |
| 122 | case '4': |
| 123 | if (*flags & IP6T_FRAG_FST) |
| 124 | exit_error(PARAMETER_PROBLEM, |
| 125 | "Only one `--fragfirst' allowed"); |
| 126 | fraginfo->flags |= IP6T_FRAG_FST; |
| 127 | *flags |= IP6T_FRAG_FST; |
| 128 | break; |
| 129 | case '5': |
| 130 | if (*flags & (IP6T_FRAG_MF|IP6T_FRAG_NMF)) |
| 131 | exit_error(PARAMETER_PROBLEM, |
| 132 | "Only one `--fragmore' or `--fraglast' allowed"); |
| 133 | fraginfo->flags |= IP6T_FRAG_MF; |
| 134 | *flags |= IP6T_FRAG_MF; |
| 135 | break; |
| 136 | case '6': |
| 137 | if (*flags & (IP6T_FRAG_MF|IP6T_FRAG_NMF)) |
| 138 | exit_error(PARAMETER_PROBLEM, |
| 139 | "Only one `--fragmore' or `--fraglast' allowed"); |
| 140 | fraginfo->flags |= IP6T_FRAG_NMF; |
| 141 | *flags |= IP6T_FRAG_NMF; |
| 142 | break; |
| 143 | default: |
| 144 | return 0; |
| 145 | } |
| 146 | |
| 147 | return 1; |
| 148 | } |
| 149 | |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 150 | static void |
| 151 | print_ids(const char *name, u_int32_t min, u_int32_t max, |
| 152 | int invert) |
| 153 | { |
| 154 | const char *inv = invert ? "!" : ""; |
| 155 | |
| 156 | if (min != 0 || max != 0xFFFFFFFF || invert) { |
| 157 | printf("%s", name); |
Harald Welte | 46a73cf | 2003-09-05 12:53:44 +0000 | [diff] [blame] | 158 | if (min == max) |
| 159 | printf(":%s%u ", inv, min); |
| 160 | else |
| 161 | printf("s:%s%u:%u ", inv, min, max); |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 162 | } |
| 163 | } |
| 164 | |
Jan Engelhardt | 997045f | 2007-10-04 16:29:21 +0000 | [diff] [blame] | 165 | static void frag_print(const void *ip, const struct xt_entry_match *match, |
| 166 | int numeric) |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 167 | { |
| 168 | const struct ip6t_frag *frag = (struct ip6t_frag *)match->data; |
| 169 | |
| 170 | printf("frag "); |
| 171 | print_ids("id", frag->ids[0], frag->ids[1], |
| 172 | frag->invflags & IP6T_FRAG_INV_IDS); |
Harald Welte | 46a73cf | 2003-09-05 12:53:44 +0000 | [diff] [blame] | 173 | |
András Kis-Szabó | d8a12a8 | 2002-04-24 09:36:30 +0000 | [diff] [blame] | 174 | if (frag->flags & IP6T_FRAG_LEN) { |
Harald Welte | 46a73cf | 2003-09-05 12:53:44 +0000 | [diff] [blame] | 175 | printf("length:%s%u ", |
| 176 | frag->invflags & IP6T_FRAG_INV_LEN ? "!" : "", |
| 177 | frag->hdrlen); |
András Kis-Szabó | d8a12a8 | 2002-04-24 09:36:30 +0000 | [diff] [blame] | 178 | } |
Harald Welte | 46a73cf | 2003-09-05 12:53:44 +0000 | [diff] [blame] | 179 | |
| 180 | if (frag->flags & IP6T_FRAG_RES) |
| 181 | printf("reserved "); |
| 182 | |
| 183 | if (frag->flags & IP6T_FRAG_FST) |
| 184 | printf("first "); |
| 185 | |
| 186 | if (frag->flags & IP6T_FRAG_MF) |
| 187 | printf("more "); |
| 188 | |
| 189 | if (frag->flags & IP6T_FRAG_NMF) |
| 190 | printf("last "); |
| 191 | |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 192 | if (frag->invflags & ~IP6T_FRAG_INV_MASK) |
| 193 | printf("Unknown invflags: 0x%X ", |
| 194 | frag->invflags & ~IP6T_FRAG_INV_MASK); |
| 195 | } |
| 196 | |
Jan Engelhardt | 997045f | 2007-10-04 16:29:21 +0000 | [diff] [blame] | 197 | static void frag_save(const void *ip, const struct xt_entry_match *match) |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 198 | { |
| 199 | const struct ip6t_frag *fraginfo = (struct ip6t_frag *)match->data; |
| 200 | |
| 201 | if (!(fraginfo->ids[0] == 0 |
| 202 | && fraginfo->ids[1] == 0xFFFFFFFF)) { |
Jan Engelhardt | cea9f71 | 2008-12-09 15:06:20 +0100 | [diff] [blame] | 203 | printf("%s--fragid ", |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 204 | (fraginfo->invflags & IP6T_FRAG_INV_IDS) ? "! " : ""); |
| 205 | if (fraginfo->ids[0] |
| 206 | != fraginfo->ids[1]) |
| 207 | printf("%u:%u ", |
| 208 | fraginfo->ids[0], |
| 209 | fraginfo->ids[1]); |
| 210 | else |
| 211 | printf("%u ", |
| 212 | fraginfo->ids[0]); |
| 213 | } |
| 214 | |
András Kis-Szabó | d8a12a8 | 2002-04-24 09:36:30 +0000 | [diff] [blame] | 215 | if (fraginfo->flags & IP6T_FRAG_LEN) { |
Jan Engelhardt | cea9f71 | 2008-12-09 15:06:20 +0100 | [diff] [blame] | 216 | printf("%s--fraglen %u ", |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 217 | (fraginfo->invflags & IP6T_FRAG_INV_LEN) ? "! " : "", |
| 218 | fraginfo->hdrlen); |
| 219 | } |
| 220 | |
Harald Welte | 46a73cf | 2003-09-05 12:53:44 +0000 | [diff] [blame] | 221 | if (fraginfo->flags & IP6T_FRAG_RES) |
| 222 | printf("--fragres "); |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 223 | |
Harald Welte | 46a73cf | 2003-09-05 12:53:44 +0000 | [diff] [blame] | 224 | if (fraginfo->flags & IP6T_FRAG_FST) |
| 225 | printf("--fragfirst "); |
| 226 | |
| 227 | if (fraginfo->flags & IP6T_FRAG_MF) |
| 228 | printf("--fragmore "); |
| 229 | |
| 230 | if (fraginfo->flags & IP6T_FRAG_NMF) |
| 231 | printf("--fraglast "); |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 232 | } |
| 233 | |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 234 | static struct xtables_match frag_mt6_reg = { |
Harald Welte | 46a73cf | 2003-09-05 12:53:44 +0000 | [diff] [blame] | 235 | .name = "frag", |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 236 | .version = XTABLES_VERSION, |
Jan Engelhardt | 03d9948 | 2008-11-18 12:27:54 +0100 | [diff] [blame] | 237 | .family = NFPROTO_IPV6, |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 238 | .size = XT_ALIGN(sizeof(struct ip6t_frag)), |
| 239 | .userspacesize = XT_ALIGN(sizeof(struct ip6t_frag)), |
Jan Engelhardt | 997045f | 2007-10-04 16:29:21 +0000 | [diff] [blame] | 240 | .help = frag_help, |
| 241 | .init = frag_init, |
| 242 | .parse = frag_parse, |
| 243 | .print = frag_print, |
| 244 | .save = frag_save, |
| 245 | .extra_opts = frag_opts, |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 246 | }; |
| 247 | |
| 248 | void |
| 249 | _init(void) |
| 250 | { |
Jan Engelhardt | 8b7c64d | 2008-04-15 11:48:25 +0200 | [diff] [blame] | 251 | xtables_register_match(&frag_mt6_reg); |
András Kis-Szabó | f1f447b | 2002-03-26 12:45:19 +0000 | [diff] [blame] | 252 | } |