From 3810013331414e53a0bde3a791b2ce3648c892d0 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Mon, 13 Nov 2006 19:38:44 +0000 Subject: Add ip6tables support for sctp match --- extensions/.sctp-test6 | 3 + extensions/libip6t_sctp.c | 550 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 553 insertions(+) create mode 100755 extensions/.sctp-test6 create mode 100644 extensions/libip6t_sctp.c diff --git a/extensions/.sctp-test6 b/extensions/.sctp-test6 new file mode 100755 index 00000000..3cfc7b84 --- /dev/null +++ b/extensions/.sctp-test6 @@ -0,0 +1,3 @@ +#!/bin/sh +[ -f $KERNEL_DIR/include/linux/netfilter/xt_sctp.h ] && echo sctp + diff --git a/extensions/libip6t_sctp.c b/extensions/libip6t_sctp.c new file mode 100644 index 00000000..aee70729 --- /dev/null +++ b/extensions/libip6t_sctp.c @@ -0,0 +1,550 @@ +/* Shared library add-on to iptables for SCTP matching + * + * (C) 2003 by Harald Welte + * + * This program is distributed under the terms of GNU GPL v2, 1991 + * + * libipt_ecn.c borrowed heavily from libipt_dscp.c + * + */ +#include +#include +#include +#include +#include +#include + +#include +#include + +#ifndef ARRAY_SIZE +#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) +#endif + +#include + +/* Some ZS!#@:$%*#$! has replaced the ELEMCOUNT macro in ipt_sctp.h with + * ARRAY_SIZE without noticing that this file is used from userserspace, + * and userspace doesn't have ARRAY_SIZE */ + +#ifndef ELEMCOUNT +#define ELEMCOUNT ARRAY_SIZE +#endif + +#if 0 +#define DEBUGP(format, first...) printf(format, ##first) +#define static +#else +#define DEBUGP(format, fist...) +#endif + +static void +print_chunk(u_int32_t chunknum, int numeric); + +/* Initialize the match. */ +static void +init(struct ip6t_entry_match *m, + unsigned int *nfcache) +{ + int i; + struct xt_sctp_info *einfo = (struct xt_sctp_info *)m->data; + + memset(einfo, 0, sizeof(struct xt_sctp_info)); + + for (i = 0; i < XT_NUM_SCTP_FLAGS; i++) { + einfo->flag_info[i].chunktype = -1; + } +} + +static void help(void) +{ + printf( +"SCTP match v%s options\n" +" --source-port [!] port[:port] match source port(s)\n" +" --sport ...\n" +" --destination-port [!] port[:port] match destination port(s)\n" +" --dport ...\n" +" --chunk-types [!] (all|any|none) (chunktype[:flags])+ match if all, any or none of\n" +" chunktypes are present\n" +"chunktypes - DATA INIT INIT_ACK SACK HEARTBEAT HEARTBEAT_ACK ABORT SHUTDOWN SHUTDOWN_ACK ERROR COOKIE_ECHO COOKIE_ACK ECN_ECNE ECN_CWR SHUTDOWN_COMPLETE ASCONF ASCONF_ACK ALL NONE\n", + IPTABLES_VERSION); +} + +static struct option opts[] = { + { .name = "source-port", .has_arg = 1, .flag = 0, .val = '1' }, + { .name = "sport", .has_arg = 1, .flag = 0, .val = '1' }, + { .name = "destination-port", .has_arg = 1, .flag = 0, .val = '2' }, + { .name = "dport", .has_arg = 1, .flag = 0, .val = '2' }, + { .name = "chunk-types", .has_arg = 1, .flag = 0, .val = '3' }, + { .name = 0 } +}; + +static void +parse_sctp_ports(const char *portstring, + u_int16_t *ports) +{ + char *buffer; + char *cp; + + buffer = strdup(portstring); + DEBUGP("%s\n", portstring); + if ((cp = strchr(buffer, ':')) == NULL) { + ports[0] = ports[1] = parse_port(buffer, "sctp"); + } + else { + *cp = '\0'; + cp++; + + ports[0] = buffer[0] ? parse_port(buffer, "sctp") : 0; + ports[1] = cp[0] ? parse_port(cp, "sctp") : 0xFFFF; + + if (ports[0] > ports[1]) + exit_error(PARAMETER_PROBLEM, + "invalid portrange (min > max)"); + } + free(buffer); +} + +struct sctp_chunk_names { + const char *name; + unsigned int chunk_type; + const char *valid_flags; +}; + +/*'ALL' and 'NONE' will be treated specially. */ +static struct sctp_chunk_names sctp_chunk_names[] += { { .name = "DATA", .chunk_type = 0, .valid_flags = "-----UBE"}, + { .name = "INIT", .chunk_type = 1, .valid_flags = "--------"}, + { .name = "INIT_ACK", .chunk_type = 2, .valid_flags = "--------"}, + { .name = "SACK", .chunk_type = 3, .valid_flags = "--------"}, + { .name = "HEARTBEAT", .chunk_type = 4, .valid_flags = "--------"}, + { .name = "HEARTBEAT_ACK", .chunk_type = 5, .valid_flags = "--------"}, + { .name = "ABORT", .chunk_type = 6, .valid_flags = "-------T"}, + { .name = "SHUTDOWN", .chunk_type = 7, .valid_flags = "--------"}, + { .name = "SHUTDOWN_ACK", .chunk_type = 8, .valid_flags = "--------"}, + { .name = "ERROR", .chunk_type = 9, .valid_flags = "--------"}, + { .name = "COOKIE_ECHO", .chunk_type = 10, .valid_flags = "--------"}, + { .name = "COOKIE_ACK", .chunk_type = 11, .valid_flags = "--------"}, + { .name = "ECN_ECNE", .chunk_type = 12, .valid_flags = "--------"}, + { .name = "ECN_CWR", .chunk_type = 13, .valid_flags = "--------"}, + { .name = "SHUTDOWN_COMPLETE", .chunk_type = 14, .valid_flags = "-------T"}, + { .name = "ASCONF", .chunk_type = 31, .valid_flags = "--------"}, + { .name = "ASCONF_ACK", .chunk_type = 30, .valid_flags = "--------"}, +}; + +static void +save_chunk_flag_info(struct xt_sctp_flag_info *flag_info, + int *flag_count, + int chunktype, + int bit, + int set) +{ + int i; + + for (i = 0; i < *flag_count; i++) { + if (flag_info[i].chunktype == chunktype) { + DEBUGP("Previous match found\n"); + flag_info[i].chunktype = chunktype; + flag_info[i].flag_mask |= (1 << bit); + if (set) { + flag_info[i].flag |= (1 << bit); + } + + return; + } + } + + if (*flag_count == XT_NUM_SCTP_FLAGS) { + exit_error (PARAMETER_PROBLEM, + "Number of chunk types with flags exceeds currently allowed limit." + "Increasing this limit involves changing XT_NUM_SCTP_FLAGS and" + "recompiling both the kernel space and user space modules\n"); + } + + flag_info[*flag_count].chunktype = chunktype; + flag_info[*flag_count].flag_mask |= (1 << bit); + if (set) { + flag_info[*flag_count].flag |= (1 << bit); + } + (*flag_count)++; +} + +static void +parse_sctp_chunk(struct xt_sctp_info *einfo, + const char *chunks) +{ + char *ptr; + char *buffer; + unsigned int i, j; + int found = 0; + char *chunk_flags; + + buffer = strdup(chunks); + DEBUGP("Buffer: %s\n", buffer); + + SCTP_CHUNKMAP_RESET(einfo->chunkmap); + + if (!strcasecmp(buffer, "ALL")) { + SCTP_CHUNKMAP_SET_ALL(einfo->chunkmap); + goto out; + } + + if (!strcasecmp(buffer, "NONE")) { + SCTP_CHUNKMAP_RESET(einfo->chunkmap); + goto out; + } + + for (ptr = strtok(buffer, ","); ptr; ptr = strtok(NULL, ",")) { + found = 0; + DEBUGP("Next Chunk type %s\n", ptr); + + if ((chunk_flags = strchr(ptr, ':')) != NULL) { + *chunk_flags++ = 0; + } + + for (i = 0; i < ELEMCOUNT(sctp_chunk_names); i++) { + if (strcasecmp(sctp_chunk_names[i].name, ptr) == 0) { + DEBUGP("Chunk num %d\n", sctp_chunk_names[i].chunk_type); + SCTP_CHUNKMAP_SET(einfo->chunkmap, + sctp_chunk_names[i].chunk_type); + found = 1; + break; + } + } + if (!found) + exit_error(PARAMETER_PROBLEM, + "Unknown sctp chunk `%s'", ptr); + + if (chunk_flags) { + DEBUGP("Chunk flags %s\n", chunk_flags); + for (j = 0; j < strlen(chunk_flags); j++) { + char *p; + int bit; + + if ((p = strchr(sctp_chunk_names[i].valid_flags, + toupper(chunk_flags[j]))) != NULL) { + bit = p - sctp_chunk_names[i].valid_flags; + bit = 7 - bit; + + save_chunk_flag_info(einfo->flag_info, + &(einfo->flag_count), i, bit, + isupper(chunk_flags[j])); + } else { + exit_error(PARAMETER_PROBLEM, + "Invalid flags for chunk type %d\n", i); + } + } + } + } +out: + free(buffer); +} + +static void +parse_sctp_chunks(struct xt_sctp_info *einfo, + const char *match_type, + const char *chunks) +{ + DEBUGP("Match type: %s Chunks: %s\n", match_type, chunks); + if (!strcasecmp(match_type, "ANY")) { + einfo->chunk_match_type = SCTP_CHUNK_MATCH_ANY; + } else if (!strcasecmp(match_type, "ALL")) { + einfo->chunk_match_type = SCTP_CHUNK_MATCH_ALL; + } else if (!strcasecmp(match_type, "ONLY")) { + einfo->chunk_match_type = SCTP_CHUNK_MATCH_ONLY; + } else { + exit_error (PARAMETER_PROBLEM, + "Match type has to be one of \"ALL\", \"ANY\" or \"ONLY\""); + } + + SCTP_CHUNKMAP_RESET(einfo->chunkmap); + parse_sctp_chunk(einfo, chunks); +} + +static int +parse(int c, char **argv, int invert, unsigned int *flags, + const struct ip6t_entry *entry, + unsigned int *nfcache, + struct ip6t_entry_match **match) +{ + struct xt_sctp_info *einfo + = (struct xt_sctp_info *)(*match)->data; + + switch (c) { + case '1': + if (*flags & XT_SCTP_SRC_PORTS) + exit_error(PARAMETER_PROBLEM, + "Only one `--source-port' allowed"); + einfo->flags |= XT_SCTP_SRC_PORTS; + check_inverse(optarg, &invert, &optind, 0); + parse_sctp_ports(argv[optind-1], einfo->spts); + if (invert) + einfo->invflags |= XT_SCTP_SRC_PORTS; + *flags |= XT_SCTP_SRC_PORTS; + break; + + case '2': + if (*flags & XT_SCTP_DEST_PORTS) + exit_error(PARAMETER_PROBLEM, + "Only one `--destination-port' allowed"); + einfo->flags |= XT_SCTP_DEST_PORTS; + check_inverse(optarg, &invert, &optind, 0); + parse_sctp_ports(argv[optind-1], einfo->dpts); + if (invert) + einfo->invflags |= XT_SCTP_DEST_PORTS; + *flags |= XT_SCTP_DEST_PORTS; + break; + + case '3': + if (*flags & XT_SCTP_CHUNK_TYPES) + exit_error(PARAMETER_PROBLEM, + "Only one `--chunk-types' allowed"); + check_inverse(optarg, &invert, &optind, 0); + + if (!argv[optind] + || argv[optind][0] == '-' || argv[optind][0] == '!') + exit_error(PARAMETER_PROBLEM, + "--chunk-types requires two args"); + + einfo->flags |= XT_SCTP_CHUNK_TYPES; + parse_sctp_chunks(einfo, argv[optind-1], argv[optind]); + if (invert) + einfo->invflags |= XT_SCTP_CHUNK_TYPES; + optind++; + *flags |= XT_SCTP_CHUNK_TYPES; + break; + + default: + return 0; + } + return 1; +} + +static void +final_check(unsigned int flags) +{ +} + +static char * +port_to_service(int port) +{ + struct servent *service; + + if ((service = getservbyport(htons(port), "sctp"))) + return service->s_name; + + return NULL; +} + +static void +print_port(u_int16_t port, int numeric) +{ + char *service; + + if (numeric || (service = port_to_service(port)) == NULL) + printf("%u", port); + else + printf("%s", service); +} + +static void +print_ports(const char *name, u_int16_t min, u_int16_t max, + int invert, int numeric) +{ + const char *inv = invert ? "!" : ""; + + if (min != 0 || max != 0xFFFF || invert) { + printf("%s", name); + if (min == max) { + printf(":%s", inv); + print_port(min, numeric); + } else { + printf("s:%s", inv); + print_port(min, numeric); + printf(":"); + print_port(max, numeric); + } + printf(" "); + } +} + +static void +print_chunk_flags(u_int32_t chunknum, u_int8_t chunk_flags, u_int8_t chunk_flags_mask) +{ + int i; + + DEBUGP("type: %d\tflags: %x\tflag mask: %x\n", chunknum, chunk_flags, + chunk_flags_mask); + + if (chunk_flags_mask) { + printf(":"); + } + + for (i = 7; i >= 0; i--) { + if (chunk_flags_mask & (1 << i)) { + if (chunk_flags & (1 << i)) { + printf("%c", sctp_chunk_names[chunknum].valid_flags[7-i]); + } else { + printf("%c", tolower(sctp_chunk_names[chunknum].valid_flags[7-i])); + } + } + } +} + +static void +print_chunk(u_int32_t chunknum, int numeric) +{ + if (numeric) { + printf("0x%04X", chunknum); + } + else { + int i; + + for (i = 0; i < ELEMCOUNT(sctp_chunk_names); i++) { + if (sctp_chunk_names[i].chunk_type == chunknum) + printf("%s", sctp_chunk_names[chunknum].name); + } + } +} + +static void +print_chunks(u_int32_t chunk_match_type, + const u_int32_t *chunkmap, + const struct xt_sctp_flag_info *flag_info, + int flag_count, + int numeric) +{ + int i, j; + int flag; + + switch (chunk_match_type) { + case SCTP_CHUNK_MATCH_ANY: printf("any "); break; + case SCTP_CHUNK_MATCH_ALL: printf("all "); break; + case SCTP_CHUNK_MATCH_ONLY: printf("only "); break; + default: printf("Never reach herer\n"); break; + } + + if (SCTP_CHUNKMAP_IS_CLEAR(chunkmap)) { + printf("NONE "); + goto out; + } + + if (SCTP_CHUNKMAP_IS_ALL_SET(chunkmap)) { + printf("ALL "); + goto out; + } + + flag = 0; + for (i = 0; i < 256; i++) { + if (SCTP_CHUNKMAP_IS_SET(chunkmap, i)) { + if (flag) + printf(","); + flag = 1; + print_chunk(i, numeric); + for (j = 0; j < flag_count; j++) { + if (flag_info[j].chunktype == i) { + print_chunk_flags(i, flag_info[j].flag, + flag_info[j].flag_mask); + } + } + } + } + + if (flag) + printf(" "); +out: + return; +} + +/* Prints out the matchinfo. */ +static void +print(const struct ip6t_ip6 *ip, + const struct ip6t_entry_match *match, + int numeric) +{ + const struct xt_sctp_info *einfo = + (const struct xt_sctp_info *)match->data; + + printf("sctp "); + + if (einfo->flags & XT_SCTP_SRC_PORTS) { + print_ports("spt", einfo->spts[0], einfo->spts[1], + einfo->invflags & XT_SCTP_SRC_PORTS, + numeric); + } + + if (einfo->flags & XT_SCTP_DEST_PORTS) { + print_ports("dpt", einfo->dpts[0], einfo->dpts[1], + einfo->invflags & XT_SCTP_DEST_PORTS, + numeric); + } + + if (einfo->flags & XT_SCTP_CHUNK_TYPES) { + /* FIXME: print_chunks() is used in save() where the printing of '!' + s taken care of, so we need to do that here as well */ + if (einfo->invflags & XT_SCTP_CHUNK_TYPES) { + printf("! "); + } + print_chunks(einfo->chunk_match_type, einfo->chunkmap, + einfo->flag_info, einfo->flag_count, numeric); + } +} + +/* Saves the union xt_matchinfo in parsable form to stdout. */ +static void +save(const struct ip6t_ip6 *ip, + const struct ip6t_entry_match *match) +{ + const struct xt_sctp_info *einfo = + (const struct xt_sctp_info *)match->data; + + if (einfo->flags & XT_SCTP_SRC_PORTS) { + if (einfo->invflags & XT_SCTP_SRC_PORTS) + printf("! "); + if (einfo->spts[0] != einfo->spts[1]) + printf("--sport %u:%u ", + einfo->spts[0], einfo->spts[1]); + else + printf("--sport %u ", einfo->spts[0]); + } + + if (einfo->flags & XT_SCTP_DEST_PORTS) { + if (einfo->invflags & XT_SCTP_DEST_PORTS) + printf("! "); + if (einfo->dpts[0] != einfo->dpts[1]) + printf("--dport %u:%u ", + einfo->dpts[0], einfo->dpts[1]); + else + printf("--dport %u ", einfo->dpts[0]); + } + + if (einfo->flags & XT_SCTP_CHUNK_TYPES) { + if (einfo->invflags & XT_SCTP_CHUNK_TYPES) + printf("! "); + printf("--chunk-types "); + + print_chunks(einfo->chunk_match_type, einfo->chunkmap, + einfo->flag_info, einfo->flag_count, 0); + } +} + +static +struct ip6tables_match sctp += { .name = "sctp", + .version = IPTABLES_VERSION, + .size = IP6T_ALIGN(sizeof(struct xt_sctp_info)), + .userspacesize = IP6T_ALIGN(sizeof(struct xt_sctp_info)), + .help = &help, + .init = &init, + .parse = &parse, + .final_check = &final_check, + .print = &print, + .save = &save, + .extra_opts = opts +}; + +void _init(void) +{ + register_match6(&sctp); +} + -- cgit v1.2.3