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-rw-r--r--extensions/libxt_sctp.c565
1 files changed, 565 insertions, 0 deletions
diff --git a/extensions/libxt_sctp.c b/extensions/libxt_sctp.c
new file mode 100644
index 00000000..5d23f091
--- /dev/null
+++ b/extensions/libxt_sctp.c
@@ -0,0 +1,565 @@
+/* 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 <xtables.h>
+
+#ifndef ARRAY_SIZE
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+#endif
+
+#include <linux/netfilter/xt_sctp.h>
+
+/* 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 xt_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 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 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 void *entry,
+ unsigned int *nfcache,
+ struct xt_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 void *ip,
+ const struct xt_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 ipt_matchinfo in parsable form to stdout. */
+static void
+save(const void *ip,
+ const struct xt_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 xtables_match sctp = {
+ .name = "sctp",
+ .family = AF_INET,
+ .version = IPTABLES_VERSION,
+ .size = XT_ALIGN(sizeof(struct xt_sctp_info)),
+ .userspacesize = XT_ALIGN(sizeof(struct xt_sctp_info)),
+ .help = &help,
+ .init = &init,
+ .parse = &parse,
+ .final_check = &final_check,
+ .print = &print,
+ .save = &save,
+ .extra_opts = opts
+};
+
+static struct xtables_match sctp6 = {
+ .name = "sctp",
+ .family = AF_INET6,
+ .version = IPTABLES_VERSION,
+ .size = XT_ALIGN(sizeof(struct xt_sctp_info)),
+ .userspacesize = XT_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)
+{
+ xtables_register_match(&sctp);
+ xtables_register_match(&sctp6);
+}
+
generated by cgit v1.2.3 (git 2.25.0) at 2024-11-16 15:22:40 +0000