* Copyright (C) 2002 David S. Miller (davem@redhat.com)
*
*/
-
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
arp = arp_hdr(skb);
do {
- if (arp_packet_match(arp, skb->dev, indev, outdev, &e->arp)) {
- struct arpt_entry_target *t;
- int hdr_len;
-
- hdr_len = sizeof(*arp) + (2 * sizeof(struct in_addr)) +
- (2 * skb->dev->addr_len);
+ struct arpt_entry_target *t;
+ int hdr_len;
- ADD_COUNTER(e->counters, hdr_len, 1);
+ if (!arp_packet_match(arp, skb->dev, indev, outdev, &e->arp)) {
+ e = arpt_next_entry(e);
+ continue;
+ }
- t = arpt_get_target(e);
+ hdr_len = sizeof(*arp) + (2 * sizeof(struct in_addr)) +
+ (2 * skb->dev->addr_len);
+ ADD_COUNTER(e->counters, hdr_len, 1);
- /* Standard target? */
- if (!t->u.kernel.target->target) {
- int v;
+ t = arpt_get_target(e);
- v = ((struct arpt_standard_target *)t)->verdict;
- if (v < 0) {
- /* Pop from stack? */
- if (v != ARPT_RETURN) {
- verdict = (unsigned)(-v) - 1;
- break;
- }
- e = back;
- back = get_entry(table_base,
- back->comefrom);
- continue;
- }
- if (table_base + v
- != arpt_next_entry(e)) {
- /* Save old back ptr in next entry */
- struct arpt_entry *next
- = arpt_next_entry(e);
- next->comefrom =
- (void *)back - table_base;
-
- /* set back pointer to next entry */
- back = next;
- }
+ /* Standard target? */
+ if (!t->u.kernel.target->target) {
+ int v;
- e = get_entry(table_base, v);
- } else {
- /* Targets which reenter must return
- * abs. verdicts
- */
- tgpar.target = t->u.kernel.target;
- tgpar.targinfo = t->data;
- verdict = t->u.kernel.target->target(skb,
- &tgpar);
-
- /* Target might have changed stuff. */
- arp = arp_hdr(skb);
-
- if (verdict == ARPT_CONTINUE)
- e = arpt_next_entry(e);
- else
- /* Verdict */
+ v = ((struct arpt_standard_target *)t)->verdict;
+ if (v < 0) {
+ /* Pop from stack? */
+ if (v != ARPT_RETURN) {
+ verdict = (unsigned)(-v) - 1;
break;
+ }
+ e = back;
+ back = get_entry(table_base, back->comefrom);
+ continue;
}
- } else {
- e = arpt_next_entry(e);
+ if (table_base + v
+ != arpt_next_entry(e)) {
+ /* Save old back ptr in next entry */
+ struct arpt_entry *next = arpt_next_entry(e);
+ next->comefrom = (void *)back - table_base;
+
+ /* set back pointer to next entry */
+ back = next;
+ }
+
+ e = get_entry(table_base, v);
+ continue;
}
+
+ /* Targets which reenter must return
+ * abs. verdicts
+ */
+ tgpar.target = t->u.kernel.target;
+ tgpar.targinfo = t->data;
+ verdict = t->u.kernel.target->target(skb, &tgpar);
+
+ /* Target might have changed stuff. */
+ arp = arp_hdr(skb);
+
+ if (verdict == ARPT_CONTINUE)
+ e = arpt_next_entry(e);
+ else
+ /* Verdict */
+ break;
} while (!hotdrop);
xt_info_rdunlock_bh();
}
/* All zeroes == unconditional rule. */
-static inline int unconditional(const struct arpt_arp *arp)
+static inline bool unconditional(const struct arpt_arp *arp)
{
- unsigned int i;
-
- for (i = 0; i < sizeof(*arp)/sizeof(__u32); i++)
- if (((__u32 *)arp)[i])
- return 0;
+ static const struct arpt_arp uncond;
- return 1;
+ return memcmp(arp, &uncond, sizeof(uncond)) == 0;
}
/* Figures out from what hook each rule can be called: returns 0 if
|= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
/* Unconditional return/END. */
- if ((e->target_offset == sizeof(struct arpt_entry)
- && (strcmp(t->target.u.user.name,
- ARPT_STANDARD_TARGET) == 0)
- && t->verdict < 0
- && unconditional(&e->arp)) || visited) {
+ if ((e->target_offset == sizeof(struct arpt_entry) &&
+ (strcmp(t->target.u.user.name,
+ ARPT_STANDARD_TARGET) == 0) &&
+ t->verdict < 0 && unconditional(&e->arp)) ||
+ visited) {
unsigned int oldpos, size;
if ((strcmp(t->target.u.user.name,
int newpos = t->verdict;
if (strcmp(t->target.u.user.name,
- ARPT_STANDARD_TARGET) == 0
- && newpos >= 0) {
+ ARPT_STANDARD_TARGET) == 0 &&
+ newpos >= 0) {
if (newpos > newinfo->size -
sizeof(struct arpt_entry)) {
duprintf("mark_source_chains: "
return ret;
}
+static bool check_underflow(struct arpt_entry *e)
+{
+ const struct arpt_entry_target *t;
+ unsigned int verdict;
+
+ if (!unconditional(&e->arp))
+ return false;
+ t = arpt_get_target(e);
+ if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
+ return false;
+ verdict = ((struct arpt_standard_target *)t)->verdict;
+ verdict = -verdict - 1;
+ return verdict == NF_DROP || verdict == NF_ACCEPT;
+}
+
static inline int check_entry_size_and_hooks(struct arpt_entry *e,
struct xt_table_info *newinfo,
unsigned char *base,
unsigned char *limit,
const unsigned int *hook_entries,
const unsigned int *underflows,
+ unsigned int valid_hooks,
unsigned int *i)
{
unsigned int h;
- if ((unsigned long)e % __alignof__(struct arpt_entry) != 0
- || (unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
+ if ((unsigned long)e % __alignof__(struct arpt_entry) != 0 ||
+ (unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
duprintf("Bad offset %p\n", e);
return -EINVAL;
}
/* Check hooks & underflows */
for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
+ if (!(valid_hooks & (1 << h)))
+ continue;
if ((unsigned char *)e - base == hook_entries[h])
newinfo->hook_entry[h] = hook_entries[h];
- if ((unsigned char *)e - base == underflows[h])
+ if ((unsigned char *)e - base == underflows[h]) {
+ if (!check_underflow(e)) {
+ pr_err("Underflows must be unconditional and "
+ "use the STANDARD target with "
+ "ACCEPT/DROP\n");
+ return -EINVAL;
+ }
newinfo->underflow[h] = underflows[h];
+ }
}
- /* FIXME: underflows must be unconditional, standard verdicts
- < 0 (not ARPT_RETURN). --RR */
-
/* Clear counters and comefrom */
e->counters = ((struct xt_counters) { 0, 0 });
e->comefrom = 0;
newinfo,
entry0,
entry0 + size,
- hook_entries, underflows, &i);
+ hook_entries, underflows, valid_hooks, &i);
duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
if (ret != 0)
return ret;
if (t && !IS_ERR(t)) {
struct arpt_getinfo info;
const struct xt_table_info *private = t->private;
-
#ifdef CONFIG_COMPAT
+ struct xt_table_info tmp;
+
if (compat) {
- struct xt_table_info tmp;
ret = compat_table_info(private, &tmp);
xt_compat_flush_offsets(NFPROTO_ARP);
private = &tmp;
int ret, off, h;
duprintf("check_compat_entry_size_and_hooks %p\n", e);
- if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0
- || (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit) {
+ if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0 ||
+ (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit) {
duprintf("Bad offset %p, limit = %p\n", e, limit);
return -EINVAL;
}
return ret;
}
-struct xt_table *arpt_register_table(struct net *net, struct xt_table *table,
+struct xt_table *arpt_register_table(struct net *net,
+ const struct xt_table *table,
const struct arpt_replace *repl)
{
int ret;
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff