* Packet matching code.
*
* Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
- * Copyright (C) 2000-2002 Netfilter core team <coreteam@netfilter.org>
+ * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/icmpv6.h>
-#include <net/ip.h>
#include <net/ipv6.h>
#include <asm/uaccess.h>
#include <asm/semaphore.h>
#define inline
#endif
-/* Locking is simple: we assume at worst case there will be one packet
- in user context and one from bottom halves (or soft irq if Alexey's
- softnet patch was applied).
-
+/*
We keep a set of rules for each CPU, so we can avoid write-locking
- them; doing a readlock_bh() stops packets coming through if we're
- in user context.
+ them in the softirq when updating the counters and therefore
+ only need to read-lock in the softirq; doing a write_lock_bh() in user
+ context stops packets coming through and allows user context to read
+ the counters or update the rules.
To be cache friendly on SMP, we arrange them like so:
[ n-entries ]
struct ip6t_table *table,
void *userdata)
{
- static const char nulldevname[IFNAMSIZ];
+ static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
int offset = 0;
unsigned int protoff = 0;
int hotdrop = 0;
/* Initialization */
indev = in ? in->name : nulldevname;
outdev = out ? out->name : nulldevname;
-
/* We handle fragments by dealing with the first fragment as
* if it was a normal packet. All other fragments are treated
* normally, except that they will NEVER match rules that ask
#endif
}
-/* If it succeeds, returns element and locks mutex */
-static inline void *
-find_inlist_lock_noload(struct list_head *head,
- const char *name,
- int *error,
- struct semaphore *mutex)
+/*
+ * These are weird, but module loading must not be done with mutex
+ * held (since they will register), and we have to have a single
+ * function to use try_then_request_module().
+ */
+
+/* Find table by name, grabs mutex & ref. Returns ERR_PTR() on error. */
+static inline struct ip6t_table *find_table_lock(const char *name)
{
- void *ret;
+ struct ip6t_table *t;
-#if 1
- duprintf("find_inlist: searching for `%s' in %s.\n",
- name, head == &ip6t_target ? "ip6t_target"
- : head == &ip6t_match ? "ip6t_match"
- : head == &ip6t_tables ? "ip6t_tables" : "UNKNOWN");
-#endif
+ if (down_interruptible(&ip6t_mutex) != 0)
+ return ERR_PTR(-EINTR);
- *error = down_interruptible(mutex);
- if (*error != 0)
- return NULL;
+ list_for_each_entry(t, &ip6t_tables, list)
+ if (strcmp(t->name, name) == 0 && try_module_get(t->me))
+ return t;
+ up(&ip6t_mutex);
+ return NULL;
+}
+
+/* Find match, grabs ref. Returns ERR_PTR() on error. */
+static inline struct ip6t_match *find_match(const char *name, u8 revision)
+{
+ struct ip6t_match *m;
+ int err = 0;
- ret = list_named_find(head, name);
- if (!ret) {
- *error = -ENOENT;
- up(mutex);
+ if (down_interruptible(&ip6t_mutex) != 0)
+ return ERR_PTR(-EINTR);
+
+ list_for_each_entry(m, &ip6t_match, list) {
+ if (strcmp(m->name, name) == 0) {
+ if (m->revision == revision) {
+ if (try_module_get(m->me)) {
+ up(&ip6t_mutex);
+ return m;
+ }
+ } else
+ err = -EPROTOTYPE; /* Found something. */
+ }
}
- return ret;
+ up(&ip6t_mutex);
+ return ERR_PTR(err);
}
-#ifndef CONFIG_KMOD
-#define find_inlist_lock(h,n,p,e,m) find_inlist_lock_noload((h),(n),(e),(m))
-#else
-static void *
-find_inlist_lock(struct list_head *head,
- const char *name,
- const char *prefix,
- int *error,
- struct semaphore *mutex)
+/* Find target, grabs ref. Returns ERR_PTR() on error. */
+static inline struct ip6t_target *find_target(const char *name, u8 revision)
{
- void *ret;
+ struct ip6t_target *t;
+ int err = 0;
- ret = find_inlist_lock_noload(head, name, error, mutex);
- if (!ret) {
- duprintf("find_inlist: loading `%s%s'.\n", prefix, name);
- request_module("%s%s", prefix, name);
- ret = find_inlist_lock_noload(head, name, error, mutex);
+ if (down_interruptible(&ip6t_mutex) != 0)
+ return ERR_PTR(-EINTR);
+
+ list_for_each_entry(t, &ip6t_target, list) {
+ if (strcmp(t->name, name) == 0) {
+ if (t->revision == revision) {
+ if (try_module_get(t->me)) {
+ up(&ip6t_mutex);
+ return t;
+ }
+ } else
+ err = -EPROTOTYPE; /* Found something. */
+ }
}
+ up(&ip6t_mutex);
+ return ERR_PTR(err);
+}
- return ret;
+struct ip6t_target *ip6t_find_target(const char *name, u8 revision)
+{
+ struct ip6t_target *target;
+
+ target = try_then_request_module(find_target(name, revision),
+ "ip6t_%s", name);
+ if (IS_ERR(target) || !target)
+ return NULL;
+ return target;
}
-#endif
-static inline struct ip6t_table *
-ip6t_find_table_lock(const char *name, int *error, struct semaphore *mutex)
+static int match_revfn(const char *name, u8 revision, int *bestp)
{
- return find_inlist_lock(&ip6t_tables, name, "ip6table_", error, mutex);
+ struct ip6t_match *m;
+ int have_rev = 0;
+
+ list_for_each_entry(m, &ip6t_match, list) {
+ if (strcmp(m->name, name) == 0) {
+ if (m->revision > *bestp)
+ *bestp = m->revision;
+ if (m->revision == revision)
+ have_rev = 1;
+ }
+ }
+ return have_rev;
}
-static inline struct ip6t_match *
-find_match_lock(const char *name, int *error, struct semaphore *mutex)
+static int target_revfn(const char *name, u8 revision, int *bestp)
{
- return find_inlist_lock(&ip6t_match, name, "ip6t_", error, mutex);
+ struct ip6t_target *t;
+ int have_rev = 0;
+
+ list_for_each_entry(t, &ip6t_target, list) {
+ if (strcmp(t->name, name) == 0) {
+ if (t->revision > *bestp)
+ *bestp = t->revision;
+ if (t->revision == revision)
+ have_rev = 1;
+ }
+ }
+ return have_rev;
}
-static struct ip6t_target *
-ip6t_find_target_lock(const char *name, int *error, struct semaphore *mutex)
+/* Returns true or fals (if no such extension at all) */
+static inline int find_revision(const char *name, u8 revision,
+ int (*revfn)(const char *, u8, int *),
+ int *err)
{
- return find_inlist_lock(&ip6t_target, name, "ip6t_", error, mutex);
+ int have_rev, best = -1;
+
+ if (down_interruptible(&ip6t_mutex) != 0) {
+ *err = -EINTR;
+ return 1;
+ }
+ have_rev = revfn(name, revision, &best);
+ up(&ip6t_mutex);
+
+ /* Nothing at all? Return 0 to try loading module. */
+ if (best == -1) {
+ *err = -ENOENT;
+ return 0;
+ }
+
+ *err = best;
+ if (!have_rev)
+ *err = -EPROTONOSUPPORT;
+ return 1;
}
+
/* All zeroes == unconditional rule. */
static inline int
unconditional(const struct ip6t_ip6 *ipv6)
unsigned int hookmask,
unsigned int *i)
{
- int ret;
struct ip6t_match *match;
- match = find_match_lock(m->u.user.name, &ret, &ip6t_mutex);
- if (!match) {
- // duprintf("check_match: `%s' not found\n", m->u.name);
- return ret;
- }
- if (!try_module_get(match->me)) {
- up(&ip6t_mutex);
- return -ENOENT;
+ match = try_then_request_module(find_match(m->u.user.name,
+ m->u.user.revision),
+ "ip6t_%s", m->u.user.name);
+ if (IS_ERR(match) || !match) {
+ duprintf("check_match: `%s' not found\n", m->u.user.name);
+ return match ? PTR_ERR(match) : -ENOENT;
}
m->u.kernel.match = match;
- up(&ip6t_mutex);
if (m->u.kernel.match->checkentry
&& !m->u.kernel.match->checkentry(name, ipv6, m->data,
goto cleanup_matches;
t = ip6t_get_target(e);
- target = ip6t_find_target_lock(t->u.user.name, &ret, &ip6t_mutex);
- if (!target) {
+ target = try_then_request_module(find_target(t->u.user.name,
+ t->u.user.revision),
+ "ip6t_%s", t->u.user.name);
+ if (IS_ERR(target) || !target) {
duprintf("check_entry: `%s' not found\n", t->u.user.name);
- goto cleanup_matches;
- }
- if (!try_module_get(target->me)) {
- up(&ip6t_mutex);
- ret = -ENOENT;
+ ret = target ? PTR_ERR(target) : -ENOENT;
goto cleanup_matches;
}
t->u.kernel.target = target;
- up(&ip6t_mutex);
- if (!t->u.kernel.target) {
- ret = -EBUSY;
- goto cleanup_matches;
- }
+
if (t->u.kernel.target == &ip6t_standard_target) {
if (!standard_check(t, size)) {
ret = -EINVAL;
int ret;
struct ip6t_table *t;
- t = ip6t_find_table_lock(entries->name, &ret, &ip6t_mutex);
- if (t) {
+ t = find_table_lock(entries->name);
+ if (t && !IS_ERR(t)) {
duprintf("t->private->number = %u\n",
t->private->number);
if (entries->size == t->private->size)
entries->size);
ret = -EINVAL;
}
+ module_put(t->me);
up(&ip6t_mutex);
} else
- duprintf("get_entries: Can't find %s!\n",
- entries->name);
+ ret = t ? PTR_ERR(t) : -ENOENT;
return ret;
}
duprintf("ip_tables: Translated table\n");
- t = ip6t_find_table_lock(tmp.name, &ret, &ip6t_mutex);
- if (!t)
+ t = try_then_request_module(find_table_lock(tmp.name),
+ "ip6table_%s", tmp.name);
+ if (!t || IS_ERR(t)) {
+ ret = t ? PTR_ERR(t) : -ENOENT;
goto free_newinfo_counters_untrans;
+ }
/* You lied! */
if (tmp.valid_hooks != t->valid_hooks) {
duprintf("Valid hook crap: %08X vs %08X\n",
tmp.valid_hooks, t->valid_hooks);
ret = -EINVAL;
- goto free_newinfo_counters_untrans_unlock;
- }
-
- /* Get a reference in advance, we're not allowed fail later */
- if (!try_module_get(t->me)) {
- ret = -EBUSY;
- goto free_newinfo_counters_untrans_unlock;
+ goto put_module;
}
oldinfo = replace_table(t, tmp.num_counters, newinfo, &ret);
/* Decrease module usage counts and free resource */
IP6T_ENTRY_ITERATE(oldinfo->entries, oldinfo->size, cleanup_entry,NULL);
vfree(oldinfo);
- /* Silent error: too late now. */
if (copy_to_user(tmp.counters, counters,
sizeof(struct ip6t_counters) * tmp.num_counters) != 0)
ret = -EFAULT;
put_module:
module_put(t->me);
- free_newinfo_counters_untrans_unlock:
up(&ip6t_mutex);
free_newinfo_counters_untrans:
IP6T_ENTRY_ITERATE(newinfo->entries, newinfo->size, cleanup_entry,NULL);
unsigned int i;
struct ip6t_counters_info tmp, *paddc;
struct ip6t_table *t;
- int ret;
+ int ret = 0;
if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
return -EFAULT;
goto free;
}
- t = ip6t_find_table_lock(tmp.name, &ret, &ip6t_mutex);
- if (!t)
+ t = find_table_lock(tmp.name);
+ if (!t || IS_ERR(t)) {
+ ret = t ? PTR_ERR(t) : -ENOENT;
goto free;
+ }
write_lock_bh(&t->lock);
if (t->private->number != paddc->num_counters) {
unlock_up_free:
write_unlock_bh(&t->lock);
up(&ip6t_mutex);
+ module_put(t->me);
free:
vfree(paddc);
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;
ret = -EFAULT;
else
ret = 0;
-
up(&ip6t_mutex);
- }
+ module_put(t->me);
+ } else
+ ret = t ? PTR_ERR(t) : -ENOENT;
}
break;
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;
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;
}
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;
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