| /* Shared library add-on to ip6tables to add Hop-by-Hop and Dst headers support. */ |
| #include <stdio.h> |
| #include <netdb.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <getopt.h> |
| #include <errno.h> |
| #include <ip6tables.h> |
| /*#include <linux/in6.h>*/ |
| #include <linux/netfilter_ipv6/ip6t_opts.h> |
| #include <sys/types.h> |
| #include <sys/socket.h> |
| #include <arpa/inet.h> |
| |
| #define DEBUG 0 |
| |
| /* Function which prints out usage message. */ |
| static void hbh_help(void) |
| { |
| printf( |
| "hbh v%s 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", |
| IPTABLES_VERSION, IP6T_OPTS_OPTSNR); |
| } |
| |
| static const struct option hbh_opts[] = { |
| { "hbh-len", 1, NULL, '1' }, |
| { "hbh-opts", 1, NULL, '2' }, |
| { "hbh-not-strict", 1, NULL, '3' }, |
| { .name = NULL } |
| }; |
| |
| static u_int32_t |
| parse_opts_num(const char *idstr, const char *typestr) |
| { |
| unsigned long int id; |
| char* ep; |
| |
| id = strtoul(idstr,&ep,0) ; |
| |
| if ( idstr == ep ) { |
| exit_error(PARAMETER_PROBLEM, |
| "hbh: no valid digits in %s `%s'", typestr, idstr); |
| } |
| if ( id == ULONG_MAX && errno == ERANGE ) { |
| exit_error(PARAMETER_PROBLEM, |
| "%s `%s' specified too big: would overflow", |
| typestr, idstr); |
| } |
| if ( *idstr != '\0' && *ep != '\0' ) { |
| exit_error(PARAMETER_PROBLEM, |
| "hbh: error parsing %s `%s'", typestr, idstr); |
| } |
| return (u_int32_t) id; |
| } |
| |
| static int |
| parse_options(const char *optsstr, u_int16_t *opts) |
| { |
| char *buffer, *cp, *next, *range; |
| unsigned int i; |
| |
| buffer = strdup(optsstr); |
| if (!buffer) exit_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) |
| exit_error(PARAMETER_PROBLEM, |
| "too many ports specified"); |
| *range++ = '\0'; |
| } |
| opts[i] = (u_int16_t)((parse_opts_num(cp,"opt") & 0x000000FF)<<8); |
| if (range) { |
| if (opts[i] == 0) |
| exit_error(PARAMETER_PROBLEM, "PAD0 hasn't got length"); |
| opts[i] |= (u_int16_t)(parse_opts_num(range,"length") & |
| 0x000000FF); |
| } else { |
| opts[i] |= (0x00FF); |
| } |
| |
| #if DEBUG |
| printf("opts str: %s %s\n", cp, range); |
| printf("opts opt: %04X\n", opts[i]); |
| #endif |
| } |
| if (cp) exit_error(PARAMETER_PROBLEM, "too many addresses specified"); |
| |
| free(buffer); |
| |
| #if DEBUG |
| printf("addr nr: %d\n", i); |
| #endif |
| |
| return i; |
| } |
| |
| /* Initialize the match. */ |
| static void hbh_init(struct xt_entry_match *m) |
| { |
| struct ip6t_opts *optinfo = (struct ip6t_opts *)m->data; |
| |
| optinfo->hdrlen = 0; |
| optinfo->flags = 0; |
| optinfo->invflags = 0; |
| optinfo->optsnr = 0; |
| } |
| |
| /* Function which parses command options; returns true if it |
| ate an option */ |
| static int hbh_parse(int c, char **argv, int invert, unsigned int *flags, |
| const void *entry, struct xt_entry_match **match) |
| { |
| struct ip6t_opts *optinfo = (struct ip6t_opts *)(*match)->data; |
| |
| switch (c) { |
| case '1': |
| if (*flags & IP6T_OPTS_LEN) |
| exit_error(PARAMETER_PROBLEM, |
| "Only one `--hbh-len' allowed"); |
| check_inverse(optarg, &invert, &optind, 0); |
| optinfo->hdrlen = parse_opts_num(argv[optind-1], "length"); |
| if (invert) |
| optinfo->invflags |= IP6T_OPTS_INV_LEN; |
| optinfo->flags |= IP6T_OPTS_LEN; |
| *flags |= IP6T_OPTS_LEN; |
| break; |
| case '2': |
| if (*flags & IP6T_OPTS_OPTS) |
| exit_error(PARAMETER_PROBLEM, |
| "Only one `--hbh-opts' allowed"); |
| check_inverse(optarg, &invert, &optind, 0); |
| if (invert) |
| exit_error(PARAMETER_PROBLEM, |
| " '!' not allowed with `--hbh-opts'"); |
| optinfo->optsnr = parse_options(argv[optind-1], optinfo->opts); |
| optinfo->flags |= IP6T_OPTS_OPTS; |
| *flags |= IP6T_OPTS_OPTS; |
| break; |
| case '3': |
| if (*flags & IP6T_OPTS_NSTRICT) |
| exit_error(PARAMETER_PROBLEM, |
| "Only one `--hbh-not-strict' allowed"); |
| if ( !(*flags & IP6T_OPTS_OPTS) ) |
| exit_error(PARAMETER_PROBLEM, |
| "`--hbh-opts ...' required before `--hbh-not-strict'"); |
| optinfo->flags |= IP6T_OPTS_NSTRICT; |
| *flags |= IP6T_OPTS_NSTRICT; |
| break; |
| default: |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| static void |
| print_options(unsigned optsnr, u_int16_t *optsp) |
| { |
| unsigned int i; |
| |
| for(i=0; i<optsnr; i++){ |
| printf("%d", (optsp[i] & 0xFF00)>>8); |
| if ((optsp[i] & 0x00FF) != 0x00FF){ |
| printf(":%d", (optsp[i] & 0x00FF)); |
| } |
| printf("%c", (i!=optsnr-1)?',':' '); |
| } |
| } |
| |
| /* Prints out the union ip6t_matchinfo. */ |
| 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); |
| printf(" "); |
| } |
| if (optinfo->flags & IP6T_OPTS_OPTS) printf("opts "); |
| print_options(optinfo->optsnr, (u_int16_t *)optinfo->opts); |
| if (optinfo->flags & IP6T_OPTS_NSTRICT) printf("not-strict "); |
| if (optinfo->invflags & ~IP6T_OPTS_INV_MASK) |
| printf("Unknown invflags: 0x%X ", |
| optinfo->invflags & ~IP6T_OPTS_INV_MASK); |
| } |
| |
| /* Saves the union ip6t_matchinfo in parsable form to stdout. */ |
| 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("--hbh-len %s%u ", |
| (optinfo->invflags & IP6T_OPTS_INV_LEN) ? "! " : "", |
| optinfo->hdrlen); |
| } |
| |
| if (optinfo->flags & IP6T_OPTS_OPTS) |
| printf("--hbh-opts "); |
| print_options(optinfo->optsnr, (u_int16_t *)optinfo->opts); |
| if (optinfo->flags & IP6T_OPTS_NSTRICT) |
| printf("--hbh-not-strict "); |
| } |
| |
| static struct ip6tables_match hbh_match6 = { |
| .name = "hbh", |
| .version = IPTABLES_VERSION, |
| .size = IP6T_ALIGN(sizeof(struct ip6t_opts)), |
| .userspacesize = IP6T_ALIGN(sizeof(struct ip6t_opts)), |
| .help = hbh_help, |
| .init = hbh_init, |
| .parse = hbh_parse, |
| .print = hbh_print, |
| .save = hbh_save, |
| .extra_opts = hbh_opts, |
| }; |
| |
| void |
| _init(void) |
| { |
| register_match6(&hbh_match6); |
| } |