| /* Shared library add-on to iptables for SCTP matching |
| * |
| * (C) 2003 by Harald Welte <laforge@gnumonks.org> |
| * |
| * This program is distributed under the terms of GNU GPL v2, 1991 |
| * |
| * libipt_ecn.c borrowed heavily from libipt_dscp.c |
| * |
| */ |
| #include <stdio.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <getopt.h> |
| #include <netdb.h> |
| #include <ctype.h> |
| |
| #include <iptables.h> |
| #include <linux/netfilter_ipv4/ip_tables.h> |
| #include <linux/netfilter_ipv4/ipt_sctp.h> |
| |
| #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 ipt_entry_match *m, |
| unsigned int *nfcache) |
| { |
| int i; |
| struct ipt_sctp_info *einfo = (struct ipt_sctp_info *)m->data; |
| |
| memset(einfo, 0, sizeof(struct ipt_sctp_info)); |
| |
| for (i = 0; i < IPT_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 int |
| service_to_port(const char *name) |
| { |
| struct servent *service; |
| |
| if ((service = getservbyname(name, "sctp")) != NULL) |
| return ntohs((unsigned short) service->s_port); |
| |
| return -1; |
| } |
| |
| static u_int16_t |
| parse_sctp_port(const char *port) |
| { |
| unsigned int portnum; |
| |
| DEBUGP("%s\n", port); |
| if (string_to_number(port, 0, 65535, &portnum) != -1 || |
| (portnum = service_to_port(port)) != -1) |
| return (u_int16_t)portnum; |
| |
| exit_error(PARAMETER_PROBLEM, |
| "invalid SCTP port/service `%s' specified", port); |
| } |
| |
| 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_sctp_port(buffer); |
| } |
| else { |
| *cp = '\0'; |
| cp++; |
| |
| ports[0] = buffer[0] ? parse_sctp_port(buffer) : 0; |
| ports[1] = cp[0] ? parse_sctp_port(cp) : 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 ipt_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 == IPT_NUM_SCTP_FLAGS) { |
| exit_error (PARAMETER_PROBLEM, |
| "Number of chunk types with flags exceeds currently allowed limit." |
| "Increasing this limit involves changing IPT_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 ipt_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 ipt_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 ipt_entry *entry, |
| unsigned int *nfcache, |
| struct ipt_entry_match **match) |
| { |
| struct ipt_sctp_info *einfo |
| = (struct ipt_sctp_info *)(*match)->data; |
| |
| switch (c) { |
| case '1': |
| if (*flags & IPT_SCTP_SRC_PORTS) |
| exit_error(PARAMETER_PROBLEM, |
| "Only one `--source-port' allowed"); |
| einfo->flags |= IPT_SCTP_SRC_PORTS; |
| check_inverse(optarg, &invert, &optind, 0); |
| parse_sctp_ports(argv[optind-1], einfo->spts); |
| if (invert) |
| einfo->invflags |= IPT_SCTP_SRC_PORTS; |
| *flags |= IPT_SCTP_SRC_PORTS; |
| *nfcache |= NFC_IP_SRC_PT; |
| break; |
| |
| case '2': |
| if (*flags & IPT_SCTP_DEST_PORTS) |
| exit_error(PARAMETER_PROBLEM, |
| "Only one `--destination-port' allowed"); |
| einfo->flags |= IPT_SCTP_DEST_PORTS; |
| check_inverse(optarg, &invert, &optind, 0); |
| parse_sctp_ports(argv[optind-1], einfo->dpts); |
| if (invert) |
| einfo->invflags |= IPT_SCTP_DEST_PORTS; |
| *flags |= IPT_SCTP_DEST_PORTS; |
| *nfcache |= NFC_IP_DST_PT; |
| break; |
| |
| case '3': |
| if (*flags & IPT_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 |= IPT_SCTP_CHUNK_TYPES; |
| parse_sctp_chunks(einfo, argv[optind-1], argv[optind]); |
| if (invert) |
| einfo->invflags |= IPT_SCTP_CHUNK_TYPES; |
| optind++; |
| *flags |= IPT_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 ipt_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)) { |
| 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); |
| } |
| } |
| } |
| } |
| |
| flag && printf(" "); |
| out: |
| return; |
| } |
| |
| /* Prints out the matchinfo. */ |
| static void |
| print(const struct ipt_ip *ip, |
| const struct ipt_entry_match *match, |
| int numeric) |
| { |
| const struct ipt_sctp_info *einfo = |
| (const struct ipt_sctp_info *)match->data; |
| |
| printf("sctp "); |
| |
| if (einfo->flags & IPT_SCTP_SRC_PORTS) { |
| print_ports("spt", einfo->spts[0], einfo->spts[1], |
| einfo->invflags & IPT_SCTP_SRC_PORTS, |
| numeric); |
| } |
| |
| if (einfo->flags & IPT_SCTP_DEST_PORTS) { |
| print_ports("dpt", einfo->dpts[0], einfo->dpts[1], |
| einfo->invflags & IPT_SCTP_DEST_PORTS, |
| numeric); |
| } |
| |
| if (einfo->flags & IPT_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 & IPT_SCTP_CHUNK_TYPES) { |
| printf("! "); |
| } |
| print_chunks(einfo->chunk_match_type, einfo->chunkmap, |
| einfo->flag_info, einfo->flag_count, numeric); |
| } |
| } |
| |
| /* Saves the union ipt_matchinfo in parsable form to stdout. */ |
| static void |
| save(const struct ipt_ip *ip, |
| const struct ipt_entry_match *match) |
| { |
| const struct ipt_sctp_info *einfo = |
| (const struct ipt_sctp_info *)match->data; |
| |
| if (einfo->flags & IPT_SCTP_SRC_PORTS) { |
| if (einfo->invflags & IPT_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 & IPT_SCTP_DEST_PORTS) { |
| if (einfo->invflags & IPT_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 & IPT_SCTP_CHUNK_TYPES) { |
| if (einfo->invflags & IPT_SCTP_CHUNK_TYPES) |
| printf("! "); |
| printf("--chunk-types "); |
| |
| print_chunks(einfo->chunk_match_type, einfo->chunkmap, |
| einfo->flag_info, einfo->flag_count, 0); |
| } |
| } |
| |
| static |
| struct iptables_match sctp |
| = { .name = "sctp", |
| .version = IPTABLES_VERSION, |
| .size = IPT_ALIGN(sizeof(struct ipt_sctp_info)), |
| .userspacesize = IPT_ALIGN(sizeof(struct ipt_sctp_info)), |
| .help = &help, |
| .init = &init, |
| .parse = &parse, |
| .final_check = &final_check, |
| .print = &print, |
| .save = &save, |
| .extra_opts = opts |
| }; |
| |
| void _init(void) |
| { |
| register_match(&sctp); |
| } |
| |