new ip6 FRAG match by kisza
diff --git a/extensions/libip6t_frag.c b/extensions/libip6t_frag.c
new file mode 100644
index 0000000..aabb334
--- /dev/null
+++ b/extensions/libip6t_frag.c
@@ -0,0 +1,273 @@
+/* Shared library add-on to ip6tables to add Fragmentation header support. */
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <errno.h>
+#include <ip6tables.h>
+#include <linux/netfilter_ipv6/ip6t_frag.h>
+
+/* Function which prints out usage message. */
+static void
+help(void)
+{
+ printf(
+"FRAG v%s options:\n"
+" --fragid [!] id[:id] match the id (range)\n"
+" --fraglen [!] length total length of this header\n"
+" --fragres check the reserved filed, too\n"
+" --fragfirst matches on the frst fragment\n"
+" [--fragmore|--fraglast] there are more fragments or this\n"
+" is the last one\n",
+NETFILTER_VERSION);
+}
+
+static struct option opts[] = {
+ { "fragid", 1, 0, '1' },
+ { "fraglen", 1, 0, '2' },
+ { "fragres", 0, 0, '3' },
+ { "fragfirst", 0, 0, '4' },
+ { "fragmore", 0, 0, '5' },
+ { "fraglast", 0, 0, '6' },
+ {0}
+};
+
+static u_int32_t
+parse_frag_id(const char *idstr, const char *typestr)
+{
+ unsigned long int id;
+ char* ep;
+
+ id = strtoul(idstr,&ep,0) ;
+
+ if ( idstr == ep ) {
+ exit_error(PARAMETER_PROBLEM,
+ "FRAG 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,
+ "FRAG error parsing %s `%s'", typestr, idstr);
+ }
+ return (u_int32_t) id;
+}
+
+static void
+parse_frag_ids(const char *idstring, u_int32_t *ids)
+{
+ char *buffer;
+ char *cp;
+
+ buffer = strdup(idstring);
+ if ((cp = strchr(buffer, ':')) == NULL)
+ ids[0] = ids[1] = parse_frag_id(buffer,"id");
+ else {
+ *cp = '\0';
+ cp++;
+
+ ids[0] = buffer[0] ? parse_frag_id(buffer,"id") : 0;
+ ids[1] = cp[0] ? parse_frag_id(cp,"id") : 0xFFFFFFFF;
+ }
+ free(buffer);
+}
+
+/* Initialize the match. */
+static void
+init(struct ip6t_entry_match *m, unsigned int *nfcache)
+{
+ struct ip6t_frag *fraginfo = (struct ip6t_frag *)m->data;
+
+ fraginfo->ids[0] = 0x0L;
+ fraginfo->ids[1] = 0xFFFFFFFF;
+ fraginfo->hdrlen = 0;
+ fraginfo->flags = 0;
+ fraginfo->invflags = 0;
+}
+
+/* Function which parses command options; returns true if it
+ ate an option */
+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 ip6t_frag *fraginfo = (struct ip6t_frag *)(*match)->data;
+
+ switch (c) {
+ case '1':
+ if (*flags & IP6T_FRAG_IDS)
+ exit_error(PARAMETER_PROBLEM,
+ "Only one `--fragid' allowed");
+ check_inverse(optarg, &invert, &optind, 0);
+ parse_frag_ids(argv[optind-1], fraginfo->ids);
+ if (invert)
+ fraginfo->invflags |= IP6T_FRAG_INV_IDS;
+ fraginfo->flags |= IP6T_FRAG_IDS;
+ *flags |= IP6T_FRAG_IDS;
+ break;
+ case '2':
+ if (*flags & IP6T_FRAG_LEN)
+ exit_error(PARAMETER_PROBLEM,
+ "Only one `--fraglen' allowed");
+ check_inverse(optarg, &invert, &optind, 0);
+ fraginfo->hdrlen = parse_frag_id(argv[optind-1], "length");
+ if (invert)
+ fraginfo->invflags |= IP6T_FRAG_INV_LEN;
+ fraginfo->flags |= IP6T_FRAG_LEN;
+ *flags |= IP6T_FRAG_LEN;
+ break;
+ case '3':
+ if (*flags & IP6T_FRAG_RES)
+ exit_error(PARAMETER_PROBLEM,
+ "Only one `--fragres' allowed");
+ fraginfo->flags |= IP6T_FRAG_RES;
+ *flags |= IP6T_FRAG_RES;
+ break;
+ case '4':
+ if (*flags & IP6T_FRAG_FST)
+ exit_error(PARAMETER_PROBLEM,
+ "Only one `--fragfirst' allowed");
+ fraginfo->flags |= IP6T_FRAG_FST;
+ *flags |= IP6T_FRAG_FST;
+ break;
+ case '5':
+ if (*flags & (IP6T_FRAG_MF|IP6T_FRAG_NMF))
+ exit_error(PARAMETER_PROBLEM,
+ "Only one `--fragmore' or `--fraglast' allowed");
+ fraginfo->flags |= IP6T_FRAG_MF;
+ *flags |= IP6T_FRAG_MF;
+ break;
+ case '6':
+ if (*flags & (IP6T_FRAG_MF|IP6T_FRAG_NMF))
+ exit_error(PARAMETER_PROBLEM,
+ "Only one `--fragmore' or `--fraglast' allowed");
+ fraginfo->flags |= IP6T_FRAG_NMF;
+ *flags |= IP6T_FRAG_NMF;
+ break;
+ default:
+ return 0;
+ }
+
+ return 1;
+}
+
+/* Final check; we don't care. */
+static void
+final_check(unsigned int flags)
+{
+}
+
+static void
+print_ids(const char *name, u_int32_t min, u_int32_t max,
+ int invert)
+{
+ const char *inv = invert ? "!" : "";
+
+ if (min != 0 || max != 0xFFFFFFFF || invert) {
+ printf("%s", name);
+ if (min == max) {
+ printf(":%s", inv);
+ printf("%u", min);
+ } else {
+ printf("s:%s", inv);
+ printf("%u",min);
+ printf(":");
+ printf("%u",max);
+ }
+ printf(" ");
+ }
+}
+
+static void
+print_len(const char *name, u_int32_t len, int invert)
+{
+ const char *inv = invert ? "!" : "";
+
+ if (len != 0 || invert) {
+ printf("%s", name);
+ printf(":%s", inv);
+ printf("%u", len);
+ printf(" ");
+ }
+}
+
+/* Prints out the union ip6t_matchinfo. */
+static void
+print(const struct ip6t_ip6 *ip,
+ const struct ip6t_entry_match *match, int numeric)
+{
+ const struct ip6t_frag *frag = (struct ip6t_frag *)match->data;
+
+ printf("frag ");
+ print_ids("id", frag->ids[0], frag->ids[1],
+ frag->invflags & IP6T_FRAG_INV_IDS);
+ print_len("length", frag->hdrlen,
+ frag->invflags & IP6T_FRAG_INV_LEN);
+ if (frag->flags & IP6T_FRAG_RES) printf("reserved ");
+ if (frag->flags & IP6T_FRAG_FST) printf("first ");
+ if (frag->flags & IP6T_FRAG_MF) printf("more ");
+ if (frag->flags & IP6T_FRAG_NMF) printf("last ");
+ if (frag->invflags & ~IP6T_FRAG_INV_MASK)
+ printf("Unknown invflags: 0x%X ",
+ frag->invflags & ~IP6T_FRAG_INV_MASK);
+}
+
+/* Saves the union ip6t_matchinfo in parsable form to stdout. */
+static void save(const struct ip6t_ip6 *ip, const struct ip6t_entry_match *match)
+{
+ const struct ip6t_frag *fraginfo = (struct ip6t_frag *)match->data;
+
+ if (!(fraginfo->ids[0] == 0
+ && fraginfo->ids[1] == 0xFFFFFFFF)) {
+ printf("--fragid %s",
+ (fraginfo->invflags & IP6T_FRAG_INV_IDS) ? "! " : "");
+ if (fraginfo->ids[0]
+ != fraginfo->ids[1])
+ printf("%u:%u ",
+ fraginfo->ids[0],
+ fraginfo->ids[1]);
+ else
+ printf("%u ",
+ fraginfo->ids[0]);
+ }
+
+ if (fraginfo->hdrlen != 0 ) {
+ printf("--fraglen %s%u ",
+ (fraginfo->invflags & IP6T_FRAG_INV_LEN) ? "! " : "",
+ fraginfo->hdrlen);
+ }
+
+ if (fraginfo->flags & IP6T_FRAG_RES) printf("--fragres ");
+ if (fraginfo->flags & IP6T_FRAG_FST) printf("--fragfirst ");
+ if (fraginfo->flags & IP6T_FRAG_MF) printf("--fragmore ");
+ if (fraginfo->flags & IP6T_FRAG_NMF) printf("--fraglast ");
+
+}
+
+static
+struct ip6tables_match frag
+= { NULL,
+ "frag",
+ NETFILTER_VERSION,
+ IP6T_ALIGN(sizeof(struct ip6t_frag)),
+ IP6T_ALIGN(sizeof(struct ip6t_frag)),
+ &help,
+ &init,
+ &parse,
+ &final_check,
+ &print,
+ &save,
+ opts
+};
+
+void
+_init(void)
+{
+ register_match6(&frag);
+}