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@@ -2,7 +2,7 @@
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* Packet matching code.
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*
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* Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
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- * Copyright (C) 2000-2002 Netfilter core team <coreteam@netfilter.org>
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+ * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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@@ -23,7 +23,6 @@
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#include <linux/tcp.h>
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#include <linux/udp.h>
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#include <linux/icmpv6.h>
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-#include <net/ip.h>
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#include <net/ipv6.h>
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#include <asm/uaccess.h>
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#include <asm/semaphore.h>
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@@ -80,13 +79,12 @@ static DECLARE_MUTEX(ip6t_mutex);
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#define inline
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#endif
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-/* Locking is simple: we assume at worst case there will be one packet
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- in user context and one from bottom halves (or soft irq if Alexey's
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- softnet patch was applied).
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-
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+/*
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We keep a set of rules for each CPU, so we can avoid write-locking
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- them; doing a readlock_bh() stops packets coming through if we're
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- in user context.
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+ them in the softirq when updating the counters and therefore
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+ only need to read-lock in the softirq; doing a write_lock_bh() in user
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+ context stops packets coming through and allows user context to read
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+ the counters or update the rules.
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To be cache friendly on SMP, we arrange them like so:
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[ n-entries ]
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@@ -356,7 +354,7 @@ ip6t_do_table(struct sk_buff **pskb,
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struct ip6t_table *table,
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void *userdata)
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{
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- static const char nulldevname[IFNAMSIZ];
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+ static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
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int offset = 0;
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unsigned int protoff = 0;
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int hotdrop = 0;
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@@ -369,7 +367,6 @@ ip6t_do_table(struct sk_buff **pskb,
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/* Initialization */
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indev = in ? in->name : nulldevname;
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outdev = out ? out->name : nulldevname;
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-
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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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@@ -497,75 +494,145 @@ ip6t_do_table(struct sk_buff **pskb,
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#endif
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}
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-/* If it succeeds, returns element and locks mutex */
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-static inline void *
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-find_inlist_lock_noload(struct list_head *head,
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- const char *name,
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- int *error,
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- struct semaphore *mutex)
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+/*
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+ * These are weird, but module loading must not be done with mutex
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+ * held (since they will register), and we have to have a single
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+ * function to use try_then_request_module().
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+ */
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+
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+/* Find table by name, grabs mutex & ref. Returns ERR_PTR() on error. */
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+static inline struct ip6t_table *find_table_lock(const char *name)
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{
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- void *ret;
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+ struct ip6t_table *t;
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-#if 1
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- duprintf("find_inlist: searching for `%s' in %s.\n",
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- name, head == &ip6t_target ? "ip6t_target"
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- : head == &ip6t_match ? "ip6t_match"
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- : head == &ip6t_tables ? "ip6t_tables" : "UNKNOWN");
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-#endif
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+ if (down_interruptible(&ip6t_mutex) != 0)
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+ return ERR_PTR(-EINTR);
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- *error = down_interruptible(mutex);
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- if (*error != 0)
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- return NULL;
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+ list_for_each_entry(t, &ip6t_tables, list)
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+ if (strcmp(t->name, name) == 0 && try_module_get(t->me))
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+ return t;
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+ up(&ip6t_mutex);
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+ return NULL;
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+}
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+
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+/* Find match, grabs ref. Returns ERR_PTR() on error. */
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+static inline struct ip6t_match *find_match(const char *name, u8 revision)
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+{
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+ struct ip6t_match *m;
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+ int err = 0;
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- ret = list_named_find(head, name);
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- if (!ret) {
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- *error = -ENOENT;
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- up(mutex);
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+ if (down_interruptible(&ip6t_mutex) != 0)
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+ return ERR_PTR(-EINTR);
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+
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+ list_for_each_entry(m, &ip6t_match, list) {
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+ if (strcmp(m->name, name) == 0) {
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+ if (m->revision == revision) {
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+ if (try_module_get(m->me)) {
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+ up(&ip6t_mutex);
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+ return m;
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+ }
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+ } else
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+ err = -EPROTOTYPE; /* Found something. */
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+ }
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}
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- return ret;
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+ up(&ip6t_mutex);
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+ return ERR_PTR(err);
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}
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-#ifndef CONFIG_KMOD
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-#define find_inlist_lock(h,n,p,e,m) find_inlist_lock_noload((h),(n),(e),(m))
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-#else
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-static void *
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-find_inlist_lock(struct list_head *head,
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- const char *name,
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- const char *prefix,
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- int *error,
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- struct semaphore *mutex)
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+/* Find target, grabs ref. Returns ERR_PTR() on error. */
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+static inline struct ip6t_target *find_target(const char *name, u8 revision)
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{
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- void *ret;
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+ struct ip6t_target *t;
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+ int err = 0;
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- ret = find_inlist_lock_noload(head, name, error, mutex);
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- if (!ret) {
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- duprintf("find_inlist: loading `%s%s'.\n", prefix, name);
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- request_module("%s%s", prefix, name);
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- ret = find_inlist_lock_noload(head, name, error, mutex);
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+ if (down_interruptible(&ip6t_mutex) != 0)
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+ return ERR_PTR(-EINTR);
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+
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+ list_for_each_entry(t, &ip6t_target, list) {
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+ if (strcmp(t->name, name) == 0) {
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+ if (t->revision == revision) {
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+ if (try_module_get(t->me)) {
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+ up(&ip6t_mutex);
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+ return t;
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+ }
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+ } else
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+ err = -EPROTOTYPE; /* Found something. */
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+ }
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}
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+ up(&ip6t_mutex);
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+ return ERR_PTR(err);
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+}
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- return ret;
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+struct ip6t_target *ip6t_find_target(const char *name, u8 revision)
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+{
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+ struct ip6t_target *target;
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+
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+ target = try_then_request_module(find_target(name, revision),
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+ "ip6t_%s", name);
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+ if (IS_ERR(target) || !target)
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+ return NULL;
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+ return target;
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}
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-#endif
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-static inline struct ip6t_table *
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-ip6t_find_table_lock(const char *name, int *error, struct semaphore *mutex)
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+static int match_revfn(const char *name, u8 revision, int *bestp)
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{
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- return find_inlist_lock(&ip6t_tables, name, "ip6table_", error, mutex);
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+ struct ip6t_match *m;
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+ int have_rev = 0;
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+
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+ list_for_each_entry(m, &ip6t_match, list) {
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+ if (strcmp(m->name, name) == 0) {
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+ if (m->revision > *bestp)
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+ *bestp = m->revision;
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+ if (m->revision == revision)
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+ have_rev = 1;
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+ }
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+ }
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+ return have_rev;
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}
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-static inline struct ip6t_match *
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-find_match_lock(const char *name, int *error, struct semaphore *mutex)
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+static int target_revfn(const char *name, u8 revision, int *bestp)
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{
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- return find_inlist_lock(&ip6t_match, name, "ip6t_", error, mutex);
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+ struct ip6t_target *t;
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+ int have_rev = 0;
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+
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+ list_for_each_entry(t, &ip6t_target, list) {
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+ if (strcmp(t->name, name) == 0) {
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+ if (t->revision > *bestp)
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+ *bestp = t->revision;
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+ if (t->revision == revision)
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+ have_rev = 1;
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+ }
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+ }
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+ return have_rev;
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}
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-static struct ip6t_target *
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-ip6t_find_target_lock(const char *name, int *error, struct semaphore *mutex)
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+/* Returns true or fals (if no such extension at all) */
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+static inline int find_revision(const char *name, u8 revision,
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+ int (*revfn)(const char *, u8, int *),
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+ int *err)
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{
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- return find_inlist_lock(&ip6t_target, name, "ip6t_", error, mutex);
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+ int have_rev, best = -1;
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+
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+ if (down_interruptible(&ip6t_mutex) != 0) {
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+ *err = -EINTR;
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+ return 1;
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+ }
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+ have_rev = revfn(name, revision, &best);
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+ up(&ip6t_mutex);
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+
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+ /* Nothing at all? Return 0 to try loading module. */
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+ if (best == -1) {
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+ *err = -ENOENT;
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+ return 0;
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+ }
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+
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+ *err = best;
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+ if (!have_rev)
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+ *err = -EPROTONOSUPPORT;
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+ return 1;
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}
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+
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/* All zeroes == unconditional rule. */
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static inline int
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unconditional(const struct ip6t_ip6 *ipv6)
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@@ -725,20 +792,16 @@ check_match(struct ip6t_entry_match *m,
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unsigned int hookmask,
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unsigned int *i)
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{
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- int ret;
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struct ip6t_match *match;
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- match = find_match_lock(m->u.user.name, &ret, &ip6t_mutex);
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- if (!match) {
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- // duprintf("check_match: `%s' not found\n", m->u.name);
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- return ret;
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- }
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- if (!try_module_get(match->me)) {
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- up(&ip6t_mutex);
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- return -ENOENT;
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+ match = try_then_request_module(find_match(m->u.user.name,
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+ m->u.user.revision),
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+ "ip6t_%s", m->u.user.name);
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+ if (IS_ERR(match) || !match) {
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+ duprintf("check_match: `%s' not found\n", m->u.user.name);
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+ return match ? PTR_ERR(match) : -ENOENT;
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}
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m->u.kernel.match = match;
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- up(&ip6t_mutex);
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if (m->u.kernel.match->checkentry
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&& !m->u.kernel.match->checkentry(name, ipv6, m->data,
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@@ -776,22 +839,16 @@ check_entry(struct ip6t_entry *e, const char *name, unsigned int size,
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goto cleanup_matches;
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t = ip6t_get_target(e);
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- target = ip6t_find_target_lock(t->u.user.name, &ret, &ip6t_mutex);
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- if (!target) {
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+ target = try_then_request_module(find_target(t->u.user.name,
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+ t->u.user.revision),
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+ "ip6t_%s", t->u.user.name);
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+ if (IS_ERR(target) || !target) {
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duprintf("check_entry: `%s' not found\n", t->u.user.name);
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- goto cleanup_matches;
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- }
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- if (!try_module_get(target->me)) {
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- up(&ip6t_mutex);
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- ret = -ENOENT;
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+ ret = target ? PTR_ERR(target) : -ENOENT;
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goto cleanup_matches;
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}
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t->u.kernel.target = target;
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- up(&ip6t_mutex);
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- if (!t->u.kernel.target) {
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- ret = -EBUSY;
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- goto cleanup_matches;
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- }
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+
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if (t->u.kernel.target == &ip6t_standard_target) {
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if (!standard_check(t, size)) {
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ret = -EINVAL;
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@@ -1118,8 +1175,8 @@ get_entries(const struct ip6t_get_entries *entries,
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int ret;
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struct ip6t_table *t;
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- t = ip6t_find_table_lock(entries->name, &ret, &ip6t_mutex);
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- if (t) {
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+ t = find_table_lock(entries->name);
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+ if (t && !IS_ERR(t)) {
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duprintf("t->private->number = %u\n",
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t->private->number);
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if (entries->size == t->private->size)
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@@ -1131,10 +1188,10 @@ get_entries(const struct ip6t_get_entries *entries,
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entries->size);
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ret = -EINVAL;
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}
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+ module_put(t->me);
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up(&ip6t_mutex);
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} else
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- duprintf("get_entries: Can't find %s!\n",
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- entries->name);
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+ ret = t ? PTR_ERR(t) : -ENOENT;
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return ret;
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}
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@@ -1182,22 +1239,19 @@ do_replace(void __user *user, unsigned int len)
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duprintf("ip_tables: Translated table\n");
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- t = ip6t_find_table_lock(tmp.name, &ret, &ip6t_mutex);
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- if (!t)
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+ t = try_then_request_module(find_table_lock(tmp.name),
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+ "ip6table_%s", tmp.name);
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+ if (!t || IS_ERR(t)) {
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+ ret = t ? PTR_ERR(t) : -ENOENT;
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goto free_newinfo_counters_untrans;
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+ }
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/* You lied! */
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if (tmp.valid_hooks != t->valid_hooks) {
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duprintf("Valid hook crap: %08X vs %08X\n",
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tmp.valid_hooks, t->valid_hooks);
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ret = -EINVAL;
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- goto free_newinfo_counters_untrans_unlock;
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- }
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-
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- /* Get a reference in advance, we're not allowed fail later */
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- if (!try_module_get(t->me)) {
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- ret = -EBUSY;
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- goto free_newinfo_counters_untrans_unlock;
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+ goto put_module;
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}
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oldinfo = replace_table(t, tmp.num_counters, newinfo, &ret);
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@@ -1219,7 +1273,6 @@ do_replace(void __user *user, unsigned int len)
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/* Decrease module usage counts and free resource */
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IP6T_ENTRY_ITERATE(oldinfo->entries, oldinfo->size, cleanup_entry,NULL);
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vfree(oldinfo);
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- /* Silent error: too late now. */
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if (copy_to_user(tmp.counters, counters,
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sizeof(struct ip6t_counters) * tmp.num_counters) != 0)
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ret = -EFAULT;
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@@ -1229,7 +1282,6 @@ do_replace(void __user *user, unsigned int len)
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put_module:
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module_put(t->me);
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- free_newinfo_counters_untrans_unlock:
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up(&ip6t_mutex);
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free_newinfo_counters_untrans:
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IP6T_ENTRY_ITERATE(newinfo->entries, newinfo->size, cleanup_entry,NULL);
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@@ -1268,7 +1320,7 @@ do_add_counters(void __user *user, unsigned int len)
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unsigned int i;
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struct ip6t_counters_info tmp, *paddc;
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struct ip6t_table *t;
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- int ret;
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+ int ret = 0;
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if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
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return -EFAULT;
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@@ -1285,9 +1337,11 @@ do_add_counters(void __user *user, unsigned int len)
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goto free;
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}
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- t = ip6t_find_table_lock(tmp.name, &ret, &ip6t_mutex);
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- if (!t)
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+ t = find_table_lock(tmp.name);
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+ if (!t || IS_ERR(t)) {
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+ ret = t ? PTR_ERR(t) : -ENOENT;
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goto free;
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+ }
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|
|
|
|
write_lock_bh(&t->lock);
|
|
|
if (t->private->number != paddc->num_counters) {
|
|
|
@@ -1304,6 +1358,7 @@ do_add_counters(void __user *user, unsigned int len)
|
|
|
unlock_up_free:
|
|
|
write_unlock_bh(&t->lock);
|
|
|
up(&ip6t_mutex);
|
|
|
+ module_put(t->me);
|
|
|
free:
|
|
|
vfree(paddc);
|
|
|
|
|
|
@@ -1360,8 +1415,10 @@ do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
|
|
|
break;
|
|
|
}
|
|
|
name[IP6T_TABLE_MAXNAMELEN-1] = '\0';
|
|
|
- t = ip6t_find_table_lock(name, &ret, &ip6t_mutex);
|
|
|
- if (t) {
|
|
|
+
|
|
|
+ t = try_then_request_module(find_table_lock(name),
|
|
|
+ "ip6table_%s", name);
|
|
|
+ if (t && !IS_ERR(t)) {
|
|
|
struct ip6t_getinfo info;
|
|
|
|
|
|
info.valid_hooks = t->valid_hooks;
|
|
|
@@ -1377,9 +1434,10 @@ do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
|
|
|
ret = -EFAULT;
|
|
|
else
|
|
|
ret = 0;
|
|
|
-
|
|
|
up(&ip6t_mutex);
|
|
|
- }
|
|
|
+ module_put(t->me);
|
|
|
+ } else
|
|
|
+ ret = t ? PTR_ERR(t) : -ENOENT;
|
|
|
}
|
|
|
break;
|
|
|
|
|
|
@@ -1400,6 +1458,31 @@ do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
|
|
|
break;
|
|
|
}
|
|
|
|
|
|
+ case IP6T_SO_GET_REVISION_MATCH:
|
|
|
+ case IP6T_SO_GET_REVISION_TARGET: {
|
|
|
+ struct ip6t_get_revision rev;
|
|
|
+ int (*revfn)(const char *, u8, int *);
|
|
|
+
|
|
|
+ if (*len != sizeof(rev)) {
|
|
|
+ ret = -EINVAL;
|
|
|
+ break;
|
|
|
+ }
|
|
|
+ if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
|
|
|
+ ret = -EFAULT;
|
|
|
+ break;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (cmd == IP6T_SO_GET_REVISION_TARGET)
|
|
|
+ revfn = target_revfn;
|
|
|
+ else
|
|
|
+ revfn = match_revfn;
|
|
|
+
|
|
|
+ try_then_request_module(find_revision(rev.name, rev.revision,
|
|
|
+ revfn, &ret),
|
|
|
+ "ip6t_%s", rev.name);
|
|
|
+ break;
|
|
|
+ }
|
|
|
+
|
|
|
default:
|
|
|
duprintf("do_ip6t_get_ctl: unknown request %i\n", cmd);
|
|
|
ret = -EINVAL;
|
|
|
@@ -1417,12 +1500,7 @@ ip6t_register_target(struct ip6t_target *target)
|
|
|
ret = down_interruptible(&ip6t_mutex);
|
|
|
if (ret != 0)
|
|
|
return ret;
|
|
|
-
|
|
|
- if (!list_named_insert(&ip6t_target, target)) {
|
|
|
- duprintf("ip6t_register_target: `%s' already in list!\n",
|
|
|
- target->name);
|
|
|
- ret = -EINVAL;
|
|
|
- }
|
|
|
+ list_add(&target->list, &ip6t_target);
|
|
|
up(&ip6t_mutex);
|
|
|
return ret;
|
|
|
}
|
|
|
@@ -1444,11 +1522,7 @@ ip6t_register_match(struct ip6t_match *match)
|
|
|
if (ret != 0)
|
|
|
return ret;
|
|
|
|
|
|
- if (!list_named_insert(&ip6t_match, match)) {
|
|
|
- duprintf("ip6t_register_match: `%s' already in list!\n",
|
|
|
- match->name);
|
|
|
- ret = -EINVAL;
|
|
|
- }
|
|
|
+ list_add(&match->list, &ip6t_match);
|
|
|
up(&ip6t_mutex);
|
|
|
|
|
|
return ret;
|
Linus Torvalds