/* 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 TC_HANDLE_T		ip6tc_handle_t#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_CHECK_PACKET		ip6tc_check_packet#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->in6_u.u6_addr32[(l) / 32]) >> (31 - ((l) & 31))) & 1)intipv6_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 intdump_entry(struct ip6t_entry *e, const ip6tc_handle_t 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) {		int pos = *(int *)t->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 intunconditional(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 voiddo_check(TC_HANDLE_T 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*/