/xp/lnx/libip6tc.c
C | 442 lines | 344 code | 70 blank | 28 comment | 110 complexity | 501dab824332f2faf11af887c463b069 MD5 | raw file
Possible License(s): Apache-2.0
- /* 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
- /* BACON */
- /*#include "libiptc/libip6tc.h"*/
- #include "libip6tc.h"
- /* END BACON */
- #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_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)
- 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, 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 ", e->nfcache);
- if (e->nfcache & NFC_ALTERED) printf("ALTERED ");
- if (e->nfcache & NFC_UNKNOWN) printf("UNKNOWN ");
- printf("\n");
-
- 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->nfcache != b->nfcache
- || 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(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*/