1 files changed, 437 insertions, 0 deletions

diff --git a/libiptc/libip6tc.c b/libiptc/libip6tc.c
new file mode 100644
index 0000000..27fe4c4
--- /dev/null
+++ b/libiptc/libip6tc.c
@@ -0,0 +1,437 @@
+/* Library which manipulates firewall rules.  Version 0.1. */
+
+/* Architecture of firewall rules is as follows:
+ *
+ * Chains go INPUT, FORWARD, OUTPUT then user chains.
+ * Each user chain starts with an ERROR node.
+ * Every chain ends with an unconditional jump: a RETURN for user chains,
+ * and a POLICY for built-ins.
+ */
+
+/* (C)1999 Paul ``Rusty'' Russell - Placed under the GNU GPL (See
+   COPYING for details). */
+
+#include <assert.h>
+#include <string.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+
+#ifdef DEBUG_CONNTRACK
+#define inline
+#endif
+
+#if !defined(__GLIBC__) || (__GLIBC__ < 2)
+typedef unsigned int socklen_t;
+#endif
+
+#include "libiptc/libip6tc.h"
+
+#define HOOK_PRE_ROUTING	NF_IP6_PRE_ROUTING
+#define HOOK_LOCAL_IN		NF_IP6_LOCAL_IN
+#define HOOK_FORWARD		NF_IP6_FORWARD
+#define HOOK_LOCAL_OUT		NF_IP6_LOCAL_OUT
+#define HOOK_POST_ROUTING	NF_IP6_POST_ROUTING
+
+#define STRUCT_ENTRY_TARGET	struct ip6t_entry_target
+#define STRUCT_ENTRY		struct ip6t_entry
+#define STRUCT_ENTRY_MATCH	struct ip6t_entry_match
+#define STRUCT_GETINFO		struct ip6t_getinfo
+#define STRUCT_GET_ENTRIES	struct ip6t_get_entries
+#define STRUCT_COUNTERS		struct ip6t_counters
+#define STRUCT_COUNTERS_INFO	struct ip6t_counters_info
+#define STRUCT_STANDARD_TARGET	struct ip6t_standard_target
+#define STRUCT_REPLACE		struct ip6t_replace
+
+#define STRUCT_TC_HANDLE	struct ip6tc_handle
+#define xtc_handle		ip6tc_handle
+
+#define ENTRY_ITERATE		IP6T_ENTRY_ITERATE
+#define TABLE_MAXNAMELEN	IP6T_TABLE_MAXNAMELEN
+#define FUNCTION_MAXNAMELEN	IP6T_FUNCTION_MAXNAMELEN
+
+#define GET_TARGET		ip6t_get_target
+
+#define ERROR_TARGET		IP6T_ERROR_TARGET
+#define NUMHOOKS		NF_IP6_NUMHOOKS
+
+#define IPT_CHAINLABEL		ip6t_chainlabel
+
+#define TC_DUMP_ENTRIES		dump_entries6
+#define TC_IS_CHAIN		ip6tc_is_chain
+#define TC_FIRST_CHAIN		ip6tc_first_chain
+#define TC_NEXT_CHAIN		ip6tc_next_chain
+#define TC_FIRST_RULE		ip6tc_first_rule
+#define TC_NEXT_RULE		ip6tc_next_rule
+#define TC_GET_TARGET		ip6tc_get_target
+#define TC_BUILTIN		ip6tc_builtin
+#define TC_GET_POLICY		ip6tc_get_policy
+#define TC_INSERT_ENTRY		ip6tc_insert_entry
+#define TC_REPLACE_ENTRY	ip6tc_replace_entry
+#define TC_APPEND_ENTRY		ip6tc_append_entry
+#define TC_DELETE_ENTRY		ip6tc_delete_entry
+#define TC_DELETE_NUM_ENTRY	ip6tc_delete_num_entry
+#define TC_FLUSH_ENTRIES	ip6tc_flush_entries
+#define TC_ZERO_ENTRIES		ip6tc_zero_entries
+#define TC_ZERO_COUNTER		ip6tc_zero_counter
+#define TC_READ_COUNTER		ip6tc_read_counter
+#define TC_SET_COUNTER		ip6tc_set_counter
+#define TC_CREATE_CHAIN		ip6tc_create_chain
+#define TC_GET_REFERENCES	ip6tc_get_references
+#define TC_DELETE_CHAIN		ip6tc_delete_chain
+#define TC_RENAME_CHAIN		ip6tc_rename_chain
+#define TC_SET_POLICY		ip6tc_set_policy
+#define TC_GET_RAW_SOCKET	ip6tc_get_raw_socket
+#define TC_INIT			ip6tc_init
+#define TC_FREE			ip6tc_free
+#define TC_COMMIT		ip6tc_commit
+#define TC_STRERROR		ip6tc_strerror
+#define TC_NUM_RULES		ip6tc_num_rules
+#define TC_GET_RULE		ip6tc_get_rule
+
+#define TC_AF			AF_INET6
+#define TC_IPPROTO		IPPROTO_IPV6
+
+#define SO_SET_REPLACE		IP6T_SO_SET_REPLACE
+#define SO_SET_ADD_COUNTERS	IP6T_SO_SET_ADD_COUNTERS
+#define SO_GET_INFO		IP6T_SO_GET_INFO
+#define SO_GET_ENTRIES		IP6T_SO_GET_ENTRIES
+#define SO_GET_VERSION		IP6T_SO_GET_VERSION
+
+#define STANDARD_TARGET		IP6T_STANDARD_TARGET
+#define LABEL_RETURN		IP6TC_LABEL_RETURN
+#define LABEL_ACCEPT		IP6TC_LABEL_ACCEPT
+#define LABEL_DROP		IP6TC_LABEL_DROP
+#define LABEL_QUEUE		IP6TC_LABEL_QUEUE
+
+#define ALIGN			IP6T_ALIGN
+#define RETURN			IP6T_RETURN
+
+#include "libiptc.c"
+
+#define BIT6(a, l) \
+ ((ntohl(a->s6_addr32[(l) / 32]) >> (31 - ((l) & 31))) & 1)
+
+int
+ipv6_prefix_length(const struct in6_addr *a)
+{
+	int l, i;
+	for (l = 0; l < 128; l++) {
+		if (BIT6(a, l) == 0)
+			break;
+	}
+	for (i = l + 1; i < 128; i++) {
+		if (BIT6(a, i) == 1)
+			return -1;
+	}
+	return l;
+}
+
+static int
+dump_entry(struct ip6t_entry *e, struct ip6tc_handle *const handle)
+{
+	size_t i;
+	char buf[40];
+	int len;
+	struct ip6t_entry_target *t;
+	
+	printf("Entry %u (%lu):\n", iptcb_entry2index(handle, e),
+	       iptcb_entry2offset(handle, e));
+	puts("SRC IP: ");
+	inet_ntop(AF_INET6, &e->ipv6.src, buf, sizeof buf);
+	puts(buf);
+	putchar('/');
+	len = ipv6_prefix_length(&e->ipv6.smsk);
+	if (len != -1)
+		printf("%d", len);
+	else {
+		inet_ntop(AF_INET6, &e->ipv6.smsk, buf, sizeof buf);
+		puts(buf);
+	}
+	putchar('\n');
+	
+	puts("DST IP: ");
+	inet_ntop(AF_INET6, &e->ipv6.dst, buf, sizeof buf);
+	puts(buf);
+	putchar('/');
+	len = ipv6_prefix_length(&e->ipv6.dmsk);
+	if (len != -1)
+		printf("%d", len);
+	else {
+		inet_ntop(AF_INET6, &e->ipv6.dmsk, buf, sizeof buf);
+		puts(buf);
+	}
+	putchar('\n');
+	
+	printf("Interface: `%s'/", e->ipv6.iniface);
+	for (i = 0; i < IFNAMSIZ; i++)
+		printf("%c", e->ipv6.iniface_mask[i] ? 'X' : '.');
+	printf("to `%s'/", e->ipv6.outiface);
+	for (i = 0; i < IFNAMSIZ; i++)
+		printf("%c", e->ipv6.outiface_mask[i] ? 'X' : '.');
+	printf("\nProtocol: %u\n", e->ipv6.proto);
+	if (e->ipv6.flags & IP6T_F_TOS)
+		printf("TOS: %u\n", e->ipv6.tos);
+	printf("Flags: %02X\n", e->ipv6.flags);
+	printf("Invflags: %02X\n", e->ipv6.invflags);
+	printf("Counters: %llu packets, %llu bytes\n",
+	       (unsigned long long)e->counters.pcnt, (unsigned long long)e->counters.bcnt);
+	printf("Cache: %08X\n", e->nfcache);
+	
+	IP6T_MATCH_ITERATE(e, print_match);
+
+	t = ip6t_get_target(e);
+	printf("Target name: `%s' [%u]\n", t->u.user.name, t->u.target_size);
+	if (strcmp(t->u.user.name, IP6T_STANDARD_TARGET) == 0) {
+		const unsigned char *data = t->data;
+		int pos = *(const int *)data;
+		if (pos < 0)
+			printf("verdict=%s\n",
+			       pos == -NF_ACCEPT-1 ? "NF_ACCEPT"
+			       : pos == -NF_DROP-1 ? "NF_DROP"
+			       : pos == IP6T_RETURN ? "RETURN"
+			       : "UNKNOWN");
+		else
+			printf("verdict=%u\n", pos);
+	} else if (strcmp(t->u.user.name, IP6T_ERROR_TARGET) == 0)
+		printf("error=`%s'\n", t->data);
+
+	printf("\n");
+	return 0;
+}
+
+static unsigned char *
+is_same(const STRUCT_ENTRY *a, const STRUCT_ENTRY *b,
+	unsigned char *matchmask)
+{
+	unsigned int i;
+	unsigned char *mptr;
+
+	/* Always compare head structures: ignore mask here. */
+	if (memcmp(&a->ipv6.src, &b->ipv6.src, sizeof(struct in6_addr))
+	    || memcmp(&a->ipv6.dst, &b->ipv6.dst, sizeof(struct in6_addr))
+	    || memcmp(&a->ipv6.smsk, &b->ipv6.smsk, sizeof(struct in6_addr))
+	    || memcmp(&a->ipv6.dmsk, &b->ipv6.dmsk, sizeof(struct in6_addr))
+	    || a->ipv6.proto != b->ipv6.proto
+	    || a->ipv6.tos != b->ipv6.tos
+	    || a->ipv6.flags != b->ipv6.flags
+	    || a->ipv6.invflags != b->ipv6.invflags)
+		return NULL;
+
+	for (i = 0; i < IFNAMSIZ; i++) {
+		if (a->ipv6.iniface_mask[i] != b->ipv6.iniface_mask[i])
+			return NULL;
+		if ((a->ipv6.iniface[i] & a->ipv6.iniface_mask[i])
+		    != (b->ipv6.iniface[i] & b->ipv6.iniface_mask[i]))
+			return NULL;
+		if (a->ipv6.outiface_mask[i] != b->ipv6.outiface_mask[i])
+			return NULL;
+		if ((a->ipv6.outiface[i] & a->ipv6.outiface_mask[i])
+		    != (b->ipv6.outiface[i] & b->ipv6.outiface_mask[i]))
+			return NULL;
+	}
+
+	if (a->target_offset != b->target_offset
+	    || a->next_offset != b->next_offset)
+		return NULL;
+
+	mptr = matchmask + sizeof(STRUCT_ENTRY);
+	if (IP6T_MATCH_ITERATE(a, match_different, a->elems, b->elems, &mptr))
+		return NULL;
+	mptr += IP6T_ALIGN(sizeof(struct ip6t_entry_target));
+
+	return mptr;
+}
+
+/* All zeroes == unconditional rule. */
+static inline int
+unconditional(const struct ip6t_ip6 *ipv6)
+{
+	unsigned int i;
+
+	for (i = 0; i < sizeof(*ipv6); i++)
+		if (((char *)ipv6)[i])
+			break;
+
+	return (i == sizeof(*ipv6));
+}
+
+#ifdef IPTC_DEBUG
+/* Do every conceivable sanity check on the handle */
+static void
+do_check(struct xtc_handle *h, unsigned int line)
+{
+	unsigned int i, n;
+	unsigned int user_offset; /* Offset of first user chain */
+	int was_return;
+
+	assert(h->changed == 0 || h->changed == 1);
+	if (strcmp(h->info.name, "filter") == 0) {
+		assert(h->info.valid_hooks
+		       == (1 << NF_IP6_LOCAL_IN
+			   | 1 << NF_IP6_FORWARD
+			   | 1 << NF_IP6_LOCAL_OUT));
+
+		/* Hooks should be first three */
+		assert(h->info.hook_entry[NF_IP6_LOCAL_IN] == 0);
+
+		n = get_chain_end(h, 0);
+		n += get_entry(h, n)->next_offset;
+		assert(h->info.hook_entry[NF_IP6_FORWARD] == n);
+
+		n = get_chain_end(h, n);
+		n += get_entry(h, n)->next_offset;
+		assert(h->info.hook_entry[NF_IP6_LOCAL_OUT] == n);
+
+		user_offset = h->info.hook_entry[NF_IP6_LOCAL_OUT];
+	} else if (strcmp(h->info.name, "nat") == 0) {
+		assert((h->info.valid_hooks
+			== (1 << NF_IP6_PRE_ROUTING
+			    | 1 << NF_IP6_LOCAL_OUT
+			    | 1 << NF_IP6_POST_ROUTING)) ||
+		       (h->info.valid_hooks
+			== (1 << NF_IP6_PRE_ROUTING
+			    | 1 << NF_IP6_LOCAL_IN
+			    | 1 << NF_IP6_LOCAL_OUT
+			    | 1 << NF_IP6_POST_ROUTING)));
+
+		assert(h->info.hook_entry[NF_IP6_PRE_ROUTING] == 0);
+
+		n = get_chain_end(h, 0);
+
+		n += get_entry(h, n)->next_offset;
+		assert(h->info.hook_entry[NF_IP6_POST_ROUTING] == n);
+		n = get_chain_end(h, n);
+
+		n += get_entry(h, n)->next_offset;
+		assert(h->info.hook_entry[NF_IP6_LOCAL_OUT] == n);
+		user_offset = h->info.hook_entry[NF_IP6_LOCAL_OUT];
+
+		if (h->info.valid_hooks & (1 << NF_IP6_LOCAL_IN)) {
+			n = get_chain_end(h, n);
+			n += get_entry(h, n)->next_offset;
+			assert(h->info.hook_entry[NF_IP6_LOCAL_IN] == n);
+			user_offset = h->info.hook_entry[NF_IP6_LOCAL_IN];
+		}
+
+	} else if (strcmp(h->info.name, "mangle") == 0) {
+		/* This code is getting ugly because linux < 2.4.18-pre6 had
+		 * two mangle hooks, linux >= 2.4.18-pre6 has five mangle hooks
+		 * */
+		assert((h->info.valid_hooks
+			== (1 << NF_IP6_PRE_ROUTING
+			    | 1 << NF_IP6_LOCAL_OUT)) ||
+		       (h->info.valid_hooks
+			== (1 << NF_IP6_PRE_ROUTING
+			    | 1 << NF_IP6_LOCAL_IN
+			    | 1 << NF_IP6_FORWARD
+			    | 1 << NF_IP6_LOCAL_OUT
+			    | 1 << NF_IP6_POST_ROUTING)));
+
+		/* Hooks should be first five */
+		assert(h->info.hook_entry[NF_IP6_PRE_ROUTING] == 0);
+
+		n = get_chain_end(h, 0);
+
+		if (h->info.valid_hooks & (1 << NF_IP6_LOCAL_IN)) {
+			n += get_entry(h, n)->next_offset;
+			assert(h->info.hook_entry[NF_IP6_LOCAL_IN] == n);
+			n = get_chain_end(h, n);
+		}
+
+		if (h->info.valid_hooks & (1 << NF_IP6_FORWARD)) {
+			n += get_entry(h, n)->next_offset;
+			assert(h->info.hook_entry[NF_IP6_FORWARD] == n);
+			n = get_chain_end(h, n);
+		}
+
+		n += get_entry(h, n)->next_offset;
+		assert(h->info.hook_entry[NF_IP6_LOCAL_OUT] == n);
+		user_offset = h->info.hook_entry[NF_IP6_LOCAL_OUT];
+
+		if (h->info.valid_hooks & (1 << NF_IP6_POST_ROUTING)) {
+			n = get_chain_end(h, n);
+			n += get_entry(h, n)->next_offset;
+			assert(h->info.hook_entry[NF_IP6_POST_ROUTING] == n);
+			user_offset = h->info.hook_entry[NF_IP6_POST_ROUTING];
+		}
+	} else if (strcmp(h->info.name, "raw") == 0) {
+		assert(h->info.valid_hooks
+		       == (1 << NF_IP6_PRE_ROUTING
+			   | 1 << NF_IP6_LOCAL_OUT));
+
+		/* Hooks should be first three */
+		assert(h->info.hook_entry[NF_IP6_PRE_ROUTING] == 0);
+
+		n = get_chain_end(h, n);
+		n += get_entry(h, n)->next_offset;
+		assert(h->info.hook_entry[NF_IP6_LOCAL_OUT] == n);
+
+		user_offset = h->info.hook_entry[NF_IP6_LOCAL_OUT];
+	} else {
+                fprintf(stderr, "Unknown table `%s'\n", h->info.name);
+		abort();
+	}
+
+	/* User chain == end of last builtin + policy entry */
+	user_offset = get_chain_end(h, user_offset);
+	user_offset += get_entry(h, user_offset)->next_offset;
+
+	/* Overflows should be end of entry chains, and unconditional
+           policy nodes. */
+	for (i = 0; i < NUMHOOKS; i++) {
+		STRUCT_ENTRY *e;
+		STRUCT_STANDARD_TARGET *t;
+
+		if (!(h->info.valid_hooks & (1 << i)))
+			continue;
+		assert(h->info.underflow[i]
+		       == get_chain_end(h, h->info.hook_entry[i]));
+
+		e = get_entry(h, get_chain_end(h, h->info.hook_entry[i]));
+		assert(unconditional(&e->ipv6));
+		assert(e->target_offset == sizeof(*e));
+		t = (STRUCT_STANDARD_TARGET *)GET_TARGET(e);
+		printf("target_size=%u, align=%u\n",
+			t->target.u.target_size, ALIGN(sizeof(*t)));
+		assert(t->target.u.target_size == ALIGN(sizeof(*t)));
+		assert(e->next_offset == sizeof(*e) + ALIGN(sizeof(*t)));
+
+		assert(strcmp(t->target.u.user.name, STANDARD_TARGET)==0);
+		assert(t->verdict == -NF_DROP-1 || t->verdict == -NF_ACCEPT-1);
+
+		/* Hooks and underflows must be valid entries */
+		iptcb_entry2index(h, get_entry(h, h->info.hook_entry[i]));
+		iptcb_entry2index(h, get_entry(h, h->info.underflow[i]));
+	}
+
+	assert(h->info.size
+	       >= h->info.num_entries * (sizeof(STRUCT_ENTRY)
+					 +sizeof(STRUCT_STANDARD_TARGET)));
+
+	assert(h->entries.size
+	       >= (h->new_number
+		   * (sizeof(STRUCT_ENTRY)
+		      + sizeof(STRUCT_STANDARD_TARGET))));
+	assert(strcmp(h->info.name, h->entries.name) == 0);
+
+	i = 0; n = 0;
+	was_return = 0;
+
+#if 0
+	/* Check all the entries. */
+	ENTRY_ITERATE(h->entries.entrytable, h->entries.size,
+		      check_entry, &i, &n, user_offset, &was_return, h);
+
+	assert(i == h->new_number);
+	assert(n == h->entries.size);
+
+	/* Final entry must be error node */
+	assert(strcmp(GET_TARGET(index2entry(h, h->new_number-1))
+		      ->u.user.name,
+		      ERROR_TARGET) == 0);
+#endif
+}
+#endif /*IPTC_DEBUG*/