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112 lines
3.4 KiB
Diff
112 lines
3.4 KiB
Diff
--- a/net/ipv4/netfilter/ip_tables.c
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+++ b/net/ipv4/netfilter/ip_tables.c
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@@ -308,6 +308,33 @@ struct ipt_entry *ipt_next_entry(const s
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return (void *)entry + entry->next_offset;
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}
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+static bool
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+ipt_handle_default_rule(struct ipt_entry *e, unsigned int *verdict)
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+{
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+ struct xt_entry_target *t;
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+ struct xt_standard_target *st;
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+
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+ if (e->target_offset != sizeof(struct ipt_entry))
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+ return false;
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+
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+ if (!(e->ip.flags & IPT_F_NO_DEF_MATCH))
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+ return false;
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+
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+ t = ipt_get_target(e);
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+ if (t->u.kernel.target->target)
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+ return false;
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+
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+ st = (struct xt_standard_target *) t;
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+ if (st->verdict == XT_RETURN)
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+ return false;
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+
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+ if (st->verdict >= 0)
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+ return false;
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+
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+ *verdict = (unsigned)(-st->verdict) - 1;
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+ return true;
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+}
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+
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/* Returns one of the generic firewall policies, like NF_ACCEPT. */
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unsigned int
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ipt_do_table(struct sk_buff *skb,
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@@ -328,28 +355,8 @@ ipt_do_table(struct sk_buff *skb,
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unsigned int addend;
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/* Initialization */
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- stackidx = 0;
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- ip = ip_hdr(skb);
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- indev = state->in ? state->in->name : nulldevname;
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- outdev = state->out ? state->out->name : nulldevname;
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- /* We handle fragments by dealing with the first fragment as
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- * if it was a normal packet. All other fragments are treated
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- * normally, except that they will NEVER match rules that ask
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- * things we don't know, ie. tcp syn flag or ports). If the
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- * rule is also a fragment-specific rule, non-fragments won't
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- * match it. */
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- acpar.fragoff = ntohs(ip->frag_off) & IP_OFFSET;
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- acpar.thoff = ip_hdrlen(skb);
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- acpar.hotdrop = false;
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- acpar.net = state->net;
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- acpar.in = state->in;
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- acpar.out = state->out;
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- acpar.family = NFPROTO_IPV4;
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- acpar.hooknum = hook;
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-
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IP_NF_ASSERT(table->valid_hooks & (1 << hook));
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local_bh_disable();
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- addend = xt_write_recseq_begin();
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private = table->private;
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cpu = smp_processor_id();
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/*
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@@ -358,6 +365,23 @@ ipt_do_table(struct sk_buff *skb,
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*/
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smp_read_barrier_depends();
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table_base = private->entries;
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+
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+ e = get_entry(table_base, private->hook_entry[hook]);
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+ if (ipt_handle_default_rule(e, &verdict)) {
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+ struct xt_counters *counter;
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+
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+ counter = xt_get_this_cpu_counter(&e->counters);
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+ ADD_COUNTER(*counter, skb->len, 1);
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+ local_bh_enable();
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+ return verdict;
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+ }
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+
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+ stackidx = 0;
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+ ip = ip_hdr(skb);
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+ indev = state->in ? state->in->name : nulldevname;
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+ outdev = state->out ? state->out->name : nulldevname;
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+
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+ addend = xt_write_recseq_begin();
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jumpstack = (struct ipt_entry **)private->jumpstack[cpu];
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/* Switch to alternate jumpstack if we're being invoked via TEE.
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@@ -370,7 +394,20 @@ ipt_do_table(struct sk_buff *skb,
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if (static_key_false(&xt_tee_enabled))
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jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated);
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- e = get_entry(table_base, private->hook_entry[hook]);
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+ /* We handle fragments by dealing with the first fragment as
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+ * if it was a normal packet. All other fragments are treated
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+ * normally, except that they will NEVER match rules that ask
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+ * things we don't know, ie. tcp syn flag or ports). If the
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+ * rule is also a fragment-specific rule, non-fragments won't
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+ * match it. */
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+ acpar.fragoff = ntohs(ip->frag_off) & IP_OFFSET;
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+ acpar.thoff = ip_hdrlen(skb);
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+ acpar.hotdrop = false;
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+ acpar.net = state->net;
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+ acpar.in = state->in;
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+ acpar.out = state->out;
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+ acpar.family = NFPROTO_IPV4;
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+ acpar.hooknum = hook;
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pr_debug("Entering %s(hook %u), UF %p\n",
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table->name, hook,
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