| #include <stdio.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <errno.h> |
| #include <xtables.h> |
| #include <linux/netfilter_ipv6/ip6t_opts.h> |
| |
| enum { |
| O_HBH_LEN = 0, |
| O_HBH_OPTS, |
| }; |
| |
| static void hbh_help(void) |
| { |
| printf( |
| "hbh match options:\n" |
| "[!] --hbh-len length total length of this header\n" |
| " --hbh-opts TYPE[:LEN][,TYPE[:LEN]...] \n" |
| " Options and its length (list, max: %d)\n", |
| IP6T_OPTS_OPTSNR); |
| } |
| |
| static const struct xt_option_entry hbh_opts[] = { |
| {.name = "hbh-len", .id = O_HBH_LEN, .type = XTTYPE_UINT32, |
| .flags = XTOPT_INVERT | XTOPT_PUT, |
| XTOPT_POINTER(struct ip6t_opts, hdrlen)}, |
| {.name = "hbh-opts", .id = O_HBH_OPTS, .type = XTTYPE_STRING}, |
| XTOPT_TABLEEND, |
| }; |
| |
| static uint32_t |
| parse_opts_num(const char *idstr, const char *typestr) |
| { |
| unsigned long int id; |
| char* ep; |
| |
| id = strtoul(idstr,&ep,0) ; |
| |
| if ( idstr == ep ) { |
| xtables_error(PARAMETER_PROBLEM, |
| "hbh: no valid digits in %s `%s'", typestr, idstr); |
| } |
| if ( id == ULONG_MAX && errno == ERANGE ) { |
| xtables_error(PARAMETER_PROBLEM, |
| "%s `%s' specified too big: would overflow", |
| typestr, idstr); |
| } |
| if ( *idstr != '\0' && *ep != '\0' ) { |
| xtables_error(PARAMETER_PROBLEM, |
| "hbh: error parsing %s `%s'", typestr, idstr); |
| } |
| return id; |
| } |
| |
| static int |
| parse_options(const char *optsstr, uint16_t *opts) |
| { |
| char *buffer, *cp, *next, *range; |
| unsigned int i; |
| |
| buffer = strdup(optsstr); |
| if (!buffer) xtables_error(OTHER_PROBLEM, "strdup failed"); |
| |
| for (cp=buffer, i=0; cp && i<IP6T_OPTS_OPTSNR; cp=next,i++) |
| { |
| next=strchr(cp, ','); |
| if (next) *next++='\0'; |
| range = strchr(cp, ':'); |
| if (range) { |
| if (i == IP6T_OPTS_OPTSNR-1) |
| xtables_error(PARAMETER_PROBLEM, |
| "too many ports specified"); |
| *range++ = '\0'; |
| } |
| opts[i] = (parse_opts_num(cp, "opt") & 0xFF) << 8; |
| if (range) { |
| if (opts[i] == 0) |
| xtables_error(PARAMETER_PROBLEM, "PAD0 has not got length"); |
| opts[i] |= parse_opts_num(range, "length") & 0xFF; |
| } else { |
| opts[i] |= (0x00FF); |
| } |
| |
| #ifdef DEBUG |
| printf("opts str: %s %s\n", cp, range); |
| printf("opts opt: %04X\n", opts[i]); |
| #endif |
| } |
| if (cp) xtables_error(PARAMETER_PROBLEM, "too many addresses specified"); |
| |
| free(buffer); |
| |
| #ifdef DEBUG |
| printf("addr nr: %d\n", i); |
| #endif |
| |
| return i; |
| } |
| |
| static void hbh_parse(struct xt_option_call *cb) |
| { |
| struct ip6t_opts *optinfo = cb->data; |
| |
| xtables_option_parse(cb); |
| switch (cb->entry->id) { |
| case O_HBH_LEN: |
| if (cb->invert) |
| optinfo->invflags |= IP6T_OPTS_INV_LEN; |
| optinfo->flags |= IP6T_OPTS_LEN; |
| break; |
| case O_HBH_OPTS: |
| optinfo->optsnr = parse_options(cb->arg, optinfo->opts); |
| optinfo->flags |= IP6T_OPTS_OPTS; |
| break; |
| } |
| } |
| |
| static void |
| print_options(unsigned int optsnr, uint16_t *optsp) |
| { |
| unsigned int i; |
| |
| for(i=0; i<optsnr; i++){ |
| printf("%c", (i==0)?' ':','); |
| printf("%d", (optsp[i] & 0xFF00)>>8); |
| if ((optsp[i] & 0x00FF) != 0x00FF){ |
| printf(":%d", (optsp[i] & 0x00FF)); |
| } |
| } |
| } |
| |
| static void hbh_print(const void *ip, const struct xt_entry_match *match, |
| int numeric) |
| { |
| const struct ip6t_opts *optinfo = (struct ip6t_opts *)match->data; |
| |
| printf(" hbh"); |
| if (optinfo->flags & IP6T_OPTS_LEN) { |
| printf(" length"); |
| printf(":%s", optinfo->invflags & IP6T_OPTS_INV_LEN ? "!" : ""); |
| printf("%u", optinfo->hdrlen); |
| } |
| if (optinfo->flags & IP6T_OPTS_OPTS) printf(" opts"); |
| print_options(optinfo->optsnr, (uint16_t *)optinfo->opts); |
| if (optinfo->invflags & ~IP6T_OPTS_INV_MASK) |
| printf(" Unknown invflags: 0x%X", |
| optinfo->invflags & ~IP6T_OPTS_INV_MASK); |
| } |
| |
| static void hbh_save(const void *ip, const struct xt_entry_match *match) |
| { |
| const struct ip6t_opts *optinfo = (struct ip6t_opts *)match->data; |
| |
| if (optinfo->flags & IP6T_OPTS_LEN) { |
| printf("%s --hbh-len %u", |
| (optinfo->invflags & IP6T_OPTS_INV_LEN) ? " !" : "", |
| optinfo->hdrlen); |
| } |
| |
| if (optinfo->flags & IP6T_OPTS_OPTS) |
| printf(" --hbh-opts"); |
| print_options(optinfo->optsnr, (uint16_t *)optinfo->opts); |
| } |
| |
| static int hbh_xlate(struct xt_xlate *xl, |
| const struct xt_xlate_mt_params *params) |
| { |
| const struct ip6t_opts *optinfo = |
| (struct ip6t_opts *)params->match->data; |
| |
| if (!(optinfo->flags & IP6T_OPTS_LEN) || |
| (optinfo->flags & IP6T_OPTS_OPTS)) |
| return 0; |
| |
| xt_xlate_add(xl, "hbh hdrlength %s%u", |
| (optinfo->invflags & IP6T_OPTS_INV_LEN) ? "!= " : "", |
| optinfo->hdrlen); |
| |
| return 1; |
| } |
| |
| static struct xtables_match hbh_mt6_reg = { |
| .name = "hbh", |
| .version = XTABLES_VERSION, |
| .family = NFPROTO_IPV6, |
| .size = XT_ALIGN(sizeof(struct ip6t_opts)), |
| .userspacesize = XT_ALIGN(sizeof(struct ip6t_opts)), |
| .help = hbh_help, |
| .print = hbh_print, |
| .save = hbh_save, |
| .x6_parse = hbh_parse, |
| .x6_options = hbh_opts, |
| .xlate = hbh_xlate, |
| }; |
| |
| void |
| _init(void) |
| { |
| xtables_register_match(&hbh_mt6_reg); |
| } |