--- /dev/null
+/*
+ * x_tables core - Backend for {ip,ip6,arp}_tables
+ *
+ * Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org>
+ * Copyright (C) 2006-2012 Patrick McHardy <kaber@trash.net>
+ *
+ * Based on existing ip_tables code which is
+ * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
+ * 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
+ * published by the Free Software Foundation.
+ *
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/socket.h>
+#include <linux/net.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/string.h>
+#include <linux/vmalloc.h>
+#include <linux/mutex.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/audit.h>
+#include <net/net_namespace.h>
+
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_arp.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv6/ip6_tables.h>
+#include <linux/netfilter_arp/arp_tables.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
+MODULE_DESCRIPTION("{ip,ip6,arp,eb}_tables backend module");
+
+#define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
+
+struct compat_delta {
+ unsigned int offset; /* offset in kernel */
+ int delta; /* delta in 32bit user land */
+};
+
+struct xt_af {
+ struct mutex mutex;
+ struct list_head match;
+ struct list_head target;
+#ifdef CONFIG_COMPAT
+ struct mutex compat_mutex;
+ struct compat_delta *compat_tab;
+ unsigned int number; /* number of slots in compat_tab[] */
+ unsigned int cur; /* number of used slots in compat_tab[] */
+#endif
+};
+
+static struct xt_af *xt;
+
+static const char *const xt_prefix[NFPROTO_NUMPROTO] = {
+ [NFPROTO_UNSPEC] = "x",
+ [NFPROTO_IPV4] = "ip",
+ [NFPROTO_ARP] = "arp",
+ [NFPROTO_BRIDGE] = "eb",
+ [NFPROTO_IPV6] = "ip6",
+};
+
+/* Allow this many total (re)entries. */
+static const unsigned int xt_jumpstack_multiplier = 2;
+
+/* Registration hooks for targets. */
+int xt_register_target(struct xt_target *target)
+{
+ u_int8_t af = target->family;
+
+ mutex_lock(&xt[af].mutex);
+ list_add(&target->list, &xt[af].target);
+ mutex_unlock(&xt[af].mutex);
+ return 0;
+}
+EXPORT_SYMBOL(xt_register_target);
+
+void
+xt_unregister_target(struct xt_target *target)
+{
+ u_int8_t af = target->family;
+
+ mutex_lock(&xt[af].mutex);
+ list_del(&target->list);
+ mutex_unlock(&xt[af].mutex);
+}
+EXPORT_SYMBOL(xt_unregister_target);
+
+int
+xt_register_targets(struct xt_target *target, unsigned int n)
+{
+ unsigned int i;
+ int err = 0;
+
+ for (i = 0; i < n; i++) {
+ err = xt_register_target(&target[i]);
+ if (err)
+ goto err;
+ }
+ return err;
+
+err:
+ if (i > 0)
+ xt_unregister_targets(target, i);
+ return err;
+}
+EXPORT_SYMBOL(xt_register_targets);
+
+void
+xt_unregister_targets(struct xt_target *target, unsigned int n)
+{
+ while (n-- > 0)
+ xt_unregister_target(&target[n]);
+}
+EXPORT_SYMBOL(xt_unregister_targets);
+
+int xt_register_match(struct xt_match *match)
+{
+ u_int8_t af = match->family;
+
+ mutex_lock(&xt[af].mutex);
+ list_add(&match->list, &xt[af].match);
+ mutex_unlock(&xt[af].mutex);
+ return 0;
+}
+EXPORT_SYMBOL(xt_register_match);
+
+void
+xt_unregister_match(struct xt_match *match)
+{
+ u_int8_t af = match->family;
+
+ mutex_lock(&xt[af].mutex);
+ list_del(&match->list);
+ mutex_unlock(&xt[af].mutex);
+}
+EXPORT_SYMBOL(xt_unregister_match);
+
+int
+xt_register_matches(struct xt_match *match, unsigned int n)
+{
+ unsigned int i;
+ int err = 0;
+
+ for (i = 0; i < n; i++) {
+ err = xt_register_match(&match[i]);
+ if (err)
+ goto err;
+ }
+ return err;
+
+err:
+ if (i > 0)
+ xt_unregister_matches(match, i);
+ return err;
+}
+EXPORT_SYMBOL(xt_register_matches);
+
+void
+xt_unregister_matches(struct xt_match *match, unsigned int n)
+{
+ while (n-- > 0)
+ xt_unregister_match(&match[n]);
+}
+EXPORT_SYMBOL(xt_unregister_matches);
+
+
+/*
+ * 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.
+ */
+
+/* Find match, grabs ref. Returns ERR_PTR() on error. */
+struct xt_match *xt_find_match(u8 af, const char *name, u8 revision)
+{
+ struct xt_match *m;
+ int err = -ENOENT;
+
+ mutex_lock(&xt[af].mutex);
+ list_for_each_entry(m, &xt[af].match, list) {
+ if (strcmp(m->name, name) == 0) {
+ if (m->revision == revision) {
+ if (try_module_get(m->me)) {
+ mutex_unlock(&xt[af].mutex);
+ return m;
+ }
+ } else
+ err = -EPROTOTYPE; /* Found something. */
+ }
+ }
+ mutex_unlock(&xt[af].mutex);
+
+ if (af != NFPROTO_UNSPEC)
+ /* Try searching again in the family-independent list */
+ return xt_find_match(NFPROTO_UNSPEC, name, revision);
+
+ return ERR_PTR(err);
+}
+EXPORT_SYMBOL(xt_find_match);
+
+struct xt_match *
+xt_request_find_match(uint8_t nfproto, const char *name, uint8_t revision)
+{
+ struct xt_match *match;
+
+ match = xt_find_match(nfproto, name, revision);
+ if (IS_ERR(match)) {
+ request_module("%st_%s", xt_prefix[nfproto], name);
+ match = xt_find_match(nfproto, name, revision);
+ }
+
+ return match;
+}
+EXPORT_SYMBOL_GPL(xt_request_find_match);
+
+/* Find target, grabs ref. Returns ERR_PTR() on error. */
+struct xt_target *xt_find_target(u8 af, const char *name, u8 revision)
+{
+ struct xt_target *t;
+ int err = -ENOENT;
+
+ mutex_lock(&xt[af].mutex);
+ list_for_each_entry(t, &xt[af].target, list) {
+ if (strcmp(t->name, name) == 0) {
+ if (t->revision == revision) {
+ if (try_module_get(t->me)) {
+ mutex_unlock(&xt[af].mutex);
+ return t;
+ }
+ } else
+ err = -EPROTOTYPE; /* Found something. */
+ }
+ }
+ mutex_unlock(&xt[af].mutex);
+
+ if (af != NFPROTO_UNSPEC)
+ /* Try searching again in the family-independent list */
+ return xt_find_target(NFPROTO_UNSPEC, name, revision);
+
+ return ERR_PTR(err);
+}
+EXPORT_SYMBOL(xt_find_target);
+
+struct xt_target *xt_request_find_target(u8 af, const char *name, u8 revision)
+{
+ struct xt_target *target;
+
+ target = xt_find_target(af, name, revision);
+ if (IS_ERR(target)) {
+ request_module("%st_%s", xt_prefix[af], name);
+ target = xt_find_target(af, name, revision);
+ }
+
+ return target;
+}
+EXPORT_SYMBOL_GPL(xt_request_find_target);
+
+static int match_revfn(u8 af, const char *name, u8 revision, int *bestp)
+{
+ const struct xt_match *m;
+ int have_rev = 0;
+
+ list_for_each_entry(m, &xt[af].match, list) {
+ if (strcmp(m->name, name) == 0) {
+ if (m->revision > *bestp)
+ *bestp = m->revision;
+ if (m->revision == revision)
+ have_rev = 1;
+ }
+ }
+
+ if (af != NFPROTO_UNSPEC && !have_rev)
+ return match_revfn(NFPROTO_UNSPEC, name, revision, bestp);
+
+ return have_rev;
+}
+
+static int target_revfn(u8 af, const char *name, u8 revision, int *bestp)
+{
+ const struct xt_target *t;
+ int have_rev = 0;
+
+ list_for_each_entry(t, &xt[af].target, list) {
+ if (strcmp(t->name, name) == 0) {
+ if (t->revision > *bestp)
+ *bestp = t->revision;
+ if (t->revision == revision)
+ have_rev = 1;
+ }
+ }
+
+ if (af != NFPROTO_UNSPEC && !have_rev)
+ return target_revfn(NFPROTO_UNSPEC, name, revision, bestp);
+
+ return have_rev;
+}
+
+/* Returns true or false (if no such extension at all) */
+int xt_find_revision(u8 af, const char *name, u8 revision, int target,
+ int *err)
+{
+ int have_rev, best = -1;
+
+ mutex_lock(&xt[af].mutex);
+ if (target == 1)
+ have_rev = target_revfn(af, name, revision, &best);
+ else
+ have_rev = match_revfn(af, name, revision, &best);
+ mutex_unlock(&xt[af].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;
+}
+EXPORT_SYMBOL_GPL(xt_find_revision);
+
+static char *
+textify_hooks(char *buf, size_t size, unsigned int mask, uint8_t nfproto)
+{
+ static const char *const inetbr_names[] = {
+ "PREROUTING", "INPUT", "FORWARD",
+ "OUTPUT", "POSTROUTING", "BROUTING",
+ };
+ static const char *const arp_names[] = {
+ "INPUT", "FORWARD", "OUTPUT",
+ };
+ const char *const *names;
+ unsigned int i, max;
+ char *p = buf;
+ bool np = false;
+ int res;
+
+ names = (nfproto == NFPROTO_ARP) ? arp_names : inetbr_names;
+ max = (nfproto == NFPROTO_ARP) ? ARRAY_SIZE(arp_names) :
+ ARRAY_SIZE(inetbr_names);
+ *p = '\0';
+ for (i = 0; i < max; ++i) {
+ if (!(mask & (1 << i)))
+ continue;
+ res = snprintf(p, size, "%s%s", np ? "/" : "", names[i]);
+ if (res > 0) {
+ size -= res;
+ p += res;
+ }
+ np = true;
+ }
+
+ return buf;
+}
+
+int xt_check_match(struct xt_mtchk_param *par,
+ unsigned int size, u_int8_t proto, bool inv_proto)
+{
+ int ret;
+
+ if (XT_ALIGN(par->match->matchsize) != size &&
+ par->match->matchsize != -1) {
+ /*
+ * ebt_among is exempt from centralized matchsize checking
+ * because it uses a dynamic-size data set.
+ */
+ pr_err("%s_tables: %s.%u match: invalid size "
+ "%u (kernel) != (user) %u\n",
+ xt_prefix[par->family], par->match->name,
+ par->match->revision,
+ XT_ALIGN(par->match->matchsize), size);
+ return -EINVAL;
+ }
+ if (par->match->table != NULL &&
+ strcmp(par->match->table, par->table) != 0) {
+ pr_err("%s_tables: %s match: only valid in %s table, not %s\n",
+ xt_prefix[par->family], par->match->name,
+ par->match->table, par->table);
+ return -EINVAL;
+ }
+ if (par->match->hooks && (par->hook_mask & ~par->match->hooks) != 0) {
+ char used[64], allow[64];
+
+ pr_err("%s_tables: %s match: used from hooks %s, but only "
+ "valid from %s\n",
+ xt_prefix[par->family], par->match->name,
+ textify_hooks(used, sizeof(used), par->hook_mask,
+ par->family),
+ textify_hooks(allow, sizeof(allow), par->match->hooks,
+ par->family));
+ return -EINVAL;
+ }
+ if (par->match->proto && (par->match->proto != proto || inv_proto)) {
+ pr_err("%s_tables: %s match: only valid for protocol %u\n",
+ xt_prefix[par->family], par->match->name,
+ par->match->proto);
+ return -EINVAL;
+ }
+ if (par->match->checkentry != NULL) {
+ ret = par->match->checkentry(par);
+ if (ret < 0)
+ return ret;
+ else if (ret > 0)
+ /* Flag up potential errors. */
+ return -EIO;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(xt_check_match);
+
+#ifdef CONFIG_COMPAT
+int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta)
+{
+ struct xt_af *xp = &xt[af];
+
+ if (!xp->compat_tab) {
+ if (!xp->number)
+ return -EINVAL;
+ xp->compat_tab = vmalloc(sizeof(struct compat_delta) * xp->number);
+ if (!xp->compat_tab)
+ return -ENOMEM;
+ xp->cur = 0;
+ }
+
+ if (xp->cur >= xp->number)
+ return -EINVAL;
+
+ if (xp->cur)
+ delta += xp->compat_tab[xp->cur - 1].delta;
+ xp->compat_tab[xp->cur].offset = offset;
+ xp->compat_tab[xp->cur].delta = delta;
+ xp->cur++;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(xt_compat_add_offset);
+
+void xt_compat_flush_offsets(u_int8_t af)
+{
+ if (xt[af].compat_tab) {
+ vfree(xt[af].compat_tab);
+ xt[af].compat_tab = NULL;
+ xt[af].number = 0;
+ xt[af].cur = 0;
+ }
+}
+EXPORT_SYMBOL_GPL(xt_compat_flush_offsets);
+
+int xt_compat_calc_jump(u_int8_t af, unsigned int offset)
+{
+ struct compat_delta *tmp = xt[af].compat_tab;
+ int mid, left = 0, right = xt[af].cur - 1;
+
+ while (left <= right) {
+ mid = (left + right) >> 1;
+ if (offset > tmp[mid].offset)
+ left = mid + 1;
+ else if (offset < tmp[mid].offset)
+ right = mid - 1;
+ else
+ return mid ? tmp[mid - 1].delta : 0;
+ }
+ return left ? tmp[left - 1].delta : 0;
+}
+EXPORT_SYMBOL_GPL(xt_compat_calc_jump);
+
+void xt_compat_init_offsets(u_int8_t af, unsigned int number)
+{
+ xt[af].number = number;
+ xt[af].cur = 0;
+}
+EXPORT_SYMBOL(xt_compat_init_offsets);
+
+int xt_compat_match_offset(const struct xt_match *match)
+{
+ u_int16_t csize = match->compatsize ? : match->matchsize;
+ return XT_ALIGN(match->matchsize) - COMPAT_XT_ALIGN(csize);
+}
+EXPORT_SYMBOL_GPL(xt_compat_match_offset);
+
+int xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
+ unsigned int *size)
+{
+ const struct xt_match *match = m->u.kernel.match;
+ struct compat_xt_entry_match *cm = (struct compat_xt_entry_match *)m;
+ int pad, off = xt_compat_match_offset(match);
+ u_int16_t msize = cm->u.user.match_size;
+
+ m = *dstptr;
+ memcpy(m, cm, sizeof(*cm));
+ if (match->compat_from_user)
+ match->compat_from_user(m->data, cm->data);
+ else
+ memcpy(m->data, cm->data, msize - sizeof(*cm));
+ pad = XT_ALIGN(match->matchsize) - match->matchsize;
+ if (pad > 0)
+ memset(m->data + match->matchsize, 0, pad);
+
+ msize += off;
+ m->u.user.match_size = msize;
+
+ *size += off;
+ *dstptr += msize;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(xt_compat_match_from_user);
+
+int xt_compat_match_to_user(const struct xt_entry_match *m,
+ void __user **dstptr, unsigned int *size)
+{
+ const struct xt_match *match = m->u.kernel.match;
+ struct compat_xt_entry_match __user *cm = *dstptr;
+ int off = xt_compat_match_offset(match);
+ u_int16_t msize = m->u.user.match_size - off;
+
+ if (copy_to_user(cm, m, sizeof(*cm)) ||
+ put_user(msize, &cm->u.user.match_size) ||
+ copy_to_user(cm->u.user.name, m->u.kernel.match->name,
+ strlen(m->u.kernel.match->name) + 1))
+ return -EFAULT;
+
+ if (match->compat_to_user) {
+ if (match->compat_to_user((void __user *)cm->data, m->data))
+ return -EFAULT;
+ } else {
+ if (copy_to_user(cm->data, m->data, msize - sizeof(*cm)))
+ return -EFAULT;
+ }
+
+ *size -= off;
+ *dstptr += msize;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(xt_compat_match_to_user);
+#endif /* CONFIG_COMPAT */
+
+int xt_check_target(struct xt_tgchk_param *par,
+ unsigned int size, u_int8_t proto, bool inv_proto)
+{
+ int ret;
+
+ if (XT_ALIGN(par->target->targetsize) != size) {
+ pr_err("%s_tables: %s.%u target: invalid size "
+ "%u (kernel) != (user) %u\n",
+ xt_prefix[par->family], par->target->name,
+ par->target->revision,
+ XT_ALIGN(par->target->targetsize), size);
+ return -EINVAL;
+ }
+ if (par->target->table != NULL &&
+ strcmp(par->target->table, par->table) != 0) {
+ pr_err("%s_tables: %s target: only valid in %s table, not %s\n",
+ xt_prefix[par->family], par->target->name,
+ par->target->table, par->table);
+ return -EINVAL;
+ }
+ if (par->target->hooks && (par->hook_mask & ~par->target->hooks) != 0) {
+ char used[64], allow[64];
+
+ pr_err("%s_tables: %s target: used from hooks %s, but only "
+ "usable from %s\n",
+ xt_prefix[par->family], par->target->name,
+ textify_hooks(used, sizeof(used), par->hook_mask,
+ par->family),
+ textify_hooks(allow, sizeof(allow), par->target->hooks,
+ par->family));
+ return -EINVAL;
+ }
+ if (par->target->proto && (par->target->proto != proto || inv_proto)) {
+ pr_err("%s_tables: %s target: only valid for protocol %u\n",
+ xt_prefix[par->family], par->target->name,
+ par->target->proto);
+ return -EINVAL;
+ }
+ if (par->target->checkentry != NULL) {
+ ret = par->target->checkentry(par);
+ if (ret < 0)
+ return ret;
+ else if (ret > 0)
+ /* Flag up potential errors. */
+ return -EIO;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(xt_check_target);
+
+#ifdef CONFIG_COMPAT
+int xt_compat_target_offset(const struct xt_target *target)
+{
+ u_int16_t csize = target->compatsize ? : target->targetsize;
+ return XT_ALIGN(target->targetsize) - COMPAT_XT_ALIGN(csize);
+}
+EXPORT_SYMBOL_GPL(xt_compat_target_offset);
+
+void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
+ unsigned int *size)
+{
+ const struct xt_target *target = t->u.kernel.target;
+ struct compat_xt_entry_target *ct = (struct compat_xt_entry_target *)t;
+ int pad, off = xt_compat_target_offset(target);
+ u_int16_t tsize = ct->u.user.target_size;
+
+ t = *dstptr;
+ memcpy(t, ct, sizeof(*ct));
+ if (target->compat_from_user)
+ target->compat_from_user(t->data, ct->data);
+ else
+ memcpy(t->data, ct->data, tsize - sizeof(*ct));
+ pad = XT_ALIGN(target->targetsize) - target->targetsize;
+ if (pad > 0)
+ memset(t->data + target->targetsize, 0, pad);
+
+ tsize += off;
+ t->u.user.target_size = tsize;
+
+ *size += off;
+ *dstptr += tsize;
+}
+EXPORT_SYMBOL_GPL(xt_compat_target_from_user);
+
+int xt_compat_target_to_user(const struct xt_entry_target *t,
+ void __user **dstptr, unsigned int *size)
+{
+ const struct xt_target *target = t->u.kernel.target;
+ struct compat_xt_entry_target __user *ct = *dstptr;
+ int off = xt_compat_target_offset(target);
+ u_int16_t tsize = t->u.user.target_size - off;
+
+ if (copy_to_user(ct, t, sizeof(*ct)) ||
+ put_user(tsize, &ct->u.user.target_size) ||
+ copy_to_user(ct->u.user.name, t->u.kernel.target->name,
+ strlen(t->u.kernel.target->name) + 1))
+ return -EFAULT;
+
+ if (target->compat_to_user) {
+ if (target->compat_to_user((void __user *)ct->data, t->data))
+ return -EFAULT;
+ } else {
+ if (copy_to_user(ct->data, t->data, tsize - sizeof(*ct)))
+ return -EFAULT;
+ }
+
+ *size -= off;
+ *dstptr += tsize;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(xt_compat_target_to_user);
+#endif
+
+struct xt_table_info *xt_alloc_table_info(unsigned int size)
+{
+ struct xt_table_info *newinfo;
+ int cpu;
+
+ /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
+ if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > totalram_pages)
+ return NULL;
+
+ newinfo = kzalloc(XT_TABLE_INFO_SZ, GFP_KERNEL);
+ if (!newinfo)
+ return NULL;
+
+ newinfo->size = size;
+
+ for_each_possible_cpu(cpu) {
+ if (size <= PAGE_SIZE)
+ newinfo->entries[cpu] = kmalloc_node(size,
+ GFP_KERNEL,
+ cpu_to_node(cpu));
+ else
+ newinfo->entries[cpu] = vmalloc_node(size,
+ cpu_to_node(cpu));
+
+ if (newinfo->entries[cpu] == NULL) {
+ xt_free_table_info(newinfo);
+ return NULL;
+ }
+ }
+
+ return newinfo;
+}
+EXPORT_SYMBOL(xt_alloc_table_info);
+
+void xt_free_table_info(struct xt_table_info *info)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ kvfree(info->entries[cpu]);
+
+ if (info->jumpstack != NULL) {
+ for_each_possible_cpu(cpu)
+ kvfree(info->jumpstack[cpu]);
+ kvfree(info->jumpstack);
+ }
+
+ free_percpu(info->stackptr);
+
+ kfree(info);
+}
+EXPORT_SYMBOL(xt_free_table_info);
+
+/* Find table by name, grabs mutex & ref. Returns ERR_PTR() on error. */
+struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
+ const char *name)
+{
+ struct xt_table *t;
+
+ mutex_lock(&xt[af].mutex);
+ list_for_each_entry(t, &net->xt.tables[af], list)
+ if (strcmp(t->name, name) == 0 && try_module_get(t->me))
+ return t;
+ mutex_unlock(&xt[af].mutex);
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(xt_find_table_lock);
+
+void xt_table_unlock(struct xt_table *table)
+{
+ mutex_unlock(&xt[table->af].mutex);
+}
+EXPORT_SYMBOL_GPL(xt_table_unlock);
+
+#ifdef CONFIG_COMPAT
+void xt_compat_lock(u_int8_t af)
+{
+ mutex_lock(&xt[af].compat_mutex);
+}
+EXPORT_SYMBOL_GPL(xt_compat_lock);
+
+void xt_compat_unlock(u_int8_t af)
+{
+ mutex_unlock(&xt[af].compat_mutex);
+}
+EXPORT_SYMBOL_GPL(xt_compat_unlock);
+#endif
+
+DEFINE_PER_CPU(seqcount_t, xt_recseq);
+EXPORT_PER_CPU_SYMBOL_GPL(xt_recseq);
+
+static int xt_jumpstack_alloc(struct xt_table_info *i)
+{
+ unsigned int size;
+ int cpu;
+
+ i->stackptr = alloc_percpu(unsigned int);
+ if (i->stackptr == NULL)
+ return -ENOMEM;
+
+ size = sizeof(void **) * nr_cpu_ids;
+ if (size > PAGE_SIZE)
+ i->jumpstack = vzalloc(size);
+ else
+ i->jumpstack = kzalloc(size, GFP_KERNEL);
+ if (i->jumpstack == NULL)
+ return -ENOMEM;
+
+ i->stacksize *= xt_jumpstack_multiplier;
+ size = sizeof(void *) * i->stacksize;
+ for_each_possible_cpu(cpu) {
+ if (size > PAGE_SIZE)
+ i->jumpstack[cpu] = vmalloc_node(size,
+ cpu_to_node(cpu));
+ else
+ i->jumpstack[cpu] = kmalloc_node(size,
+ GFP_KERNEL, cpu_to_node(cpu));
+ if (i->jumpstack[cpu] == NULL)
+ /*
+ * Freeing will be done later on by the callers. The
+ * chain is: xt_replace_table -> __do_replace ->
+ * do_replace -> xt_free_table_info.
+ */
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+struct xt_table_info *
+xt_replace_table(struct xt_table *table,
+ unsigned int num_counters,
+ struct xt_table_info *newinfo,
+ int *error)
+{
+ struct xt_table_info *private;
+ int ret;
+
+ ret = xt_jumpstack_alloc(newinfo);
+ if (ret < 0) {
+ *error = ret;
+ return NULL;
+ }
+
+ /* Do the substitution. */
+ local_bh_disable();
+ private = table->private;
+
+ /* Check inside lock: is the old number correct? */
+ if (num_counters != private->number) {
+ pr_debug("num_counters != table->private->number (%u/%u)\n",
+ num_counters, private->number);
+ local_bh_enable();
+ *error = -EAGAIN;
+ return NULL;
+ }
+
+ newinfo->initial_entries = private->initial_entries;
+ /*
+ * Ensure contents of newinfo are visible before assigning to
+ * private.
+ */
+ smp_wmb();
+ table->private = newinfo;
+
+ /*
+ * Even though table entries have now been swapped, other CPU's
+ * may still be using the old entries. This is okay, because
+ * resynchronization happens because of the locking done
+ * during the get_counters() routine.
+ */
+ local_bh_enable();
+
+#ifdef CONFIG_AUDIT
+ if (audit_enabled) {
+ struct audit_buffer *ab;
+
+ ab = audit_log_start(current->audit_context, GFP_KERNEL,
+ AUDIT_NETFILTER_CFG);
+ if (ab) {
+ audit_log_format(ab, "table=%s family=%u entries=%u",
+ table->name, table->af,
+ private->number);
+ audit_log_end(ab);
+ }
+ }
+#endif
+
+ return private;
+}
+EXPORT_SYMBOL_GPL(xt_replace_table);
+
+struct xt_table *xt_register_table(struct net *net,
+ const struct xt_table *input_table,
+ struct xt_table_info *bootstrap,
+ struct xt_table_info *newinfo)
+{
+ int ret;
+ struct xt_table_info *private;
+ struct xt_table *t, *table;
+
+ /* Don't add one object to multiple lists. */
+ table = kmemdup(input_table, sizeof(struct xt_table), GFP_KERNEL);
+ if (!table) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ mutex_lock(&xt[table->af].mutex);
+ /* Don't autoload: we'd eat our tail... */
+ list_for_each_entry(t, &net->xt.tables[table->af], list) {
+ if (strcmp(t->name, table->name) == 0) {
+ ret = -EEXIST;
+ goto unlock;
+ }
+ }
+
+ /* Simplifies replace_table code. */
+ table->private = bootstrap;
+
+ if (!xt_replace_table(table, 0, newinfo, &ret))
+ goto unlock;
+
+ private = table->private;
+ pr_debug("table->private->number = %u\n", private->number);
+
+ /* save number of initial entries */
+ private->initial_entries = private->number;
+
+ list_add(&table->list, &net->xt.tables[table->af]);
+ mutex_unlock(&xt[table->af].mutex);
+ return table;
+
+unlock:
+ mutex_unlock(&xt[table->af].mutex);
+ kfree(table);
+out:
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(xt_register_table);
+
+void *xt_unregister_table(struct xt_table *table)
+{
+ struct xt_table_info *private;
+
+ mutex_lock(&xt[table->af].mutex);
+ private = table->private;
+ list_del(&table->list);
+ mutex_unlock(&xt[table->af].mutex);
+ kfree(table);
+
+ return private;
+}
+EXPORT_SYMBOL_GPL(xt_unregister_table);
+
+#ifdef CONFIG_PROC_FS
+struct xt_names_priv {
+ struct seq_net_private p;
+ u_int8_t af;
+};
+static void *xt_table_seq_start(struct seq_file *seq, loff_t *pos)
+{
+ struct xt_names_priv *priv = seq->private;
+ struct net *net = seq_file_net(seq);
+ u_int8_t af = priv->af;
+
+ mutex_lock(&xt[af].mutex);
+ return seq_list_start(&net->xt.tables[af], *pos);
+}
+
+static void *xt_table_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ struct xt_names_priv *priv = seq->private;
+ struct net *net = seq_file_net(seq);
+ u_int8_t af = priv->af;
+
+ return seq_list_next(v, &net->xt.tables[af], pos);
+}
+
+static void xt_table_seq_stop(struct seq_file *seq, void *v)
+{
+ struct xt_names_priv *priv = seq->private;
+ u_int8_t af = priv->af;
+
+ mutex_unlock(&xt[af].mutex);
+}
+
+static int xt_table_seq_show(struct seq_file *seq, void *v)
+{
+ struct xt_table *table = list_entry(v, struct xt_table, list);
+
+ if (strlen(table->name)) {
+ seq_printf(seq, "%s\n", table->name);
+ return seq_has_overflowed(seq);
+ } else
+ return 0;
+}
+
+static const struct seq_operations xt_table_seq_ops = {
+ .start = xt_table_seq_start,
+ .next = xt_table_seq_next,
+ .stop = xt_table_seq_stop,
+ .show = xt_table_seq_show,
+};
+
+static int xt_table_open(struct inode *inode, struct file *file)
+{
+ int ret;
+ struct xt_names_priv *priv;
+
+ ret = seq_open_net(inode, file, &xt_table_seq_ops,
+ sizeof(struct xt_names_priv));
+ if (!ret) {
+ priv = ((struct seq_file *)file->private_data)->private;
+ priv->af = (unsigned long)PDE_DATA(inode);
+ }
+ return ret;
+}
+
+static const struct file_operations xt_table_ops = {
+ .owner = THIS_MODULE,
+ .open = xt_table_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_net,
+};
+
+/*
+ * Traverse state for ip{,6}_{tables,matches} for helping crossing
+ * the multi-AF mutexes.
+ */
+struct nf_mttg_trav {
+ struct list_head *head, *curr;
+ uint8_t class, nfproto;
+};
+
+enum {
+ MTTG_TRAV_INIT,
+ MTTG_TRAV_NFP_UNSPEC,
+ MTTG_TRAV_NFP_SPEC,
+ MTTG_TRAV_DONE,
+};
+
+static void *xt_mttg_seq_next(struct seq_file *seq, void *v, loff_t *ppos,
+ bool is_target)
+{
+ static const uint8_t next_class[] = {
+ [MTTG_TRAV_NFP_UNSPEC] = MTTG_TRAV_NFP_SPEC,
+ [MTTG_TRAV_NFP_SPEC] = MTTG_TRAV_DONE,
+ };
+ struct nf_mttg_trav *trav = seq->private;
+
+ switch (trav->class) {
+ case MTTG_TRAV_INIT:
+ trav->class = MTTG_TRAV_NFP_UNSPEC;
+ mutex_lock(&xt[NFPROTO_UNSPEC].mutex);
+ trav->head = trav->curr = is_target ?
+ &xt[NFPROTO_UNSPEC].target : &xt[NFPROTO_UNSPEC].match;
+ break;
+ case MTTG_TRAV_NFP_UNSPEC:
+ trav->curr = trav->curr->next;
+ if (trav->curr != trav->head)
+ break;
+ mutex_unlock(&xt[NFPROTO_UNSPEC].mutex);
+ mutex_lock(&xt[trav->nfproto].mutex);
+ trav->head = trav->curr = is_target ?
+ &xt[trav->nfproto].target : &xt[trav->nfproto].match;
+ trav->class = next_class[trav->class];
+ break;
+ case MTTG_TRAV_NFP_SPEC:
+ trav->curr = trav->curr->next;
+ if (trav->curr != trav->head)
+ break;
+ /* fallthru, _stop will unlock */
+ default:
+ return NULL;
+ }
+
+ if (ppos != NULL)
+ ++*ppos;
+ return trav;
+}
+
+static void *xt_mttg_seq_start(struct seq_file *seq, loff_t *pos,
+ bool is_target)
+{
+ struct nf_mttg_trav *trav = seq->private;
+ unsigned int j;
+
+ trav->class = MTTG_TRAV_INIT;
+ for (j = 0; j < *pos; ++j)
+ if (xt_mttg_seq_next(seq, NULL, NULL, is_target) == NULL)
+ return NULL;
+ return trav;
+}
+
+static void xt_mttg_seq_stop(struct seq_file *seq, void *v)
+{
+ struct nf_mttg_trav *trav = seq->private;
+
+ switch (trav->class) {
+ case MTTG_TRAV_NFP_UNSPEC:
+ mutex_unlock(&xt[NFPROTO_UNSPEC].mutex);
+ break;
+ case MTTG_TRAV_NFP_SPEC:
+ mutex_unlock(&xt[trav->nfproto].mutex);
+ break;
+ }
+}
+
+static void *xt_match_seq_start(struct seq_file *seq, loff_t *pos)
+{
+ return xt_mttg_seq_start(seq, pos, false);
+}
+
+static void *xt_match_seq_next(struct seq_file *seq, void *v, loff_t *ppos)
+{
+ return xt_mttg_seq_next(seq, v, ppos, false);
+}
+
+static int xt_match_seq_show(struct seq_file *seq, void *v)
+{
+ const struct nf_mttg_trav *trav = seq->private;
+ const struct xt_match *match;
+
+ switch (trav->class) {
+ case MTTG_TRAV_NFP_UNSPEC:
+ case MTTG_TRAV_NFP_SPEC:
+ if (trav->curr == trav->head)
+ return 0;
+ match = list_entry(trav->curr, struct xt_match, list);
+ if (*match->name == '\0')
+ return 0;
+ seq_printf(seq, "%s\n", match->name);
+ return seq_has_overflowed(seq);
+ }
+ return 0;
+}
+
+static const struct seq_operations xt_match_seq_ops = {
+ .start = xt_match_seq_start,
+ .next = xt_match_seq_next,
+ .stop = xt_mttg_seq_stop,
+ .show = xt_match_seq_show,
+};
+
+static int xt_match_open(struct inode *inode, struct file *file)
+{
+ struct nf_mttg_trav *trav;
+ trav = __seq_open_private(file, &xt_match_seq_ops, sizeof(*trav));
+ if (!trav)
+ return -ENOMEM;
+
+ trav->nfproto = (unsigned long)PDE_DATA(inode);
+ return 0;
+}
+
+static const struct file_operations xt_match_ops = {
+ .owner = THIS_MODULE,
+ .open = xt_match_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_private,
+};
+
+static void *xt_target_seq_start(struct seq_file *seq, loff_t *pos)
+{
+ return xt_mttg_seq_start(seq, pos, true);
+}
+
+static void *xt_target_seq_next(struct seq_file *seq, void *v, loff_t *ppos)
+{
+ return xt_mttg_seq_next(seq, v, ppos, true);
+}
+
+static int xt_target_seq_show(struct seq_file *seq, void *v)
+{
+ const struct nf_mttg_trav *trav = seq->private;
+ const struct xt_target *target;
+
+ switch (trav->class) {
+ case MTTG_TRAV_NFP_UNSPEC:
+ case MTTG_TRAV_NFP_SPEC:
+ if (trav->curr == trav->head)
+ return 0;
+ target = list_entry(trav->curr, struct xt_target, list);
+ if (*target->name == '\0')
+ return 0;
+ seq_printf(seq, "%s\n", target->name);
+ return seq_has_overflowed(seq);
+ }
+ return 0;
+}
+
+static const struct seq_operations xt_target_seq_ops = {
+ .start = xt_target_seq_start,
+ .next = xt_target_seq_next,
+ .stop = xt_mttg_seq_stop,
+ .show = xt_target_seq_show,
+};
+
+static int xt_target_open(struct inode *inode, struct file *file)
+{
+ struct nf_mttg_trav *trav;
+ trav = __seq_open_private(file, &xt_target_seq_ops, sizeof(*trav));
+ if (!trav)
+ return -ENOMEM;
+
+ trav->nfproto = (unsigned long)PDE_DATA(inode);
+ return 0;
+}
+
+static const struct file_operations xt_target_ops = {
+ .owner = THIS_MODULE,
+ .open = xt_target_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_private,
+};
+
+#define FORMAT_TABLES "_tables_names"
+#define FORMAT_MATCHES "_tables_matches"
+#define FORMAT_TARGETS "_tables_targets"
+
+#endif /* CONFIG_PROC_FS */
+
+/**
+ * xt_hook_link - set up hooks for a new table
+ * @table: table with metadata needed to set up hooks
+ * @fn: Hook function
+ *
+ * This function will take care of creating and registering the necessary
+ * Netfilter hooks for XT tables.
+ */
+struct nf_hook_ops *xt_hook_link(const struct xt_table *table, nf_hookfn *fn)
+{
+ unsigned int hook_mask = table->valid_hooks;
+ uint8_t i, num_hooks = hweight32(hook_mask);
+ uint8_t hooknum;
+ struct nf_hook_ops *ops;
+ int ret;
+
+ ops = kmalloc(sizeof(*ops) * num_hooks, GFP_KERNEL);
+ if (ops == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ for (i = 0, hooknum = 0; i < num_hooks && hook_mask != 0;
+ hook_mask >>= 1, ++hooknum) {
+ if (!(hook_mask & 1))
+ continue;
+ ops[i].hook = fn;
+ ops[i].owner = table->me;
+ ops[i].pf = table->af;
+ ops[i].hooknum = hooknum;
+ ops[i].priority = table->priority;
+ ++i;
+ }
+
+ ret = nf_register_hooks(ops, num_hooks);
+ if (ret < 0) {
+ kfree(ops);
+ return ERR_PTR(ret);
+ }
+
+ return ops;
+}
+EXPORT_SYMBOL_GPL(xt_hook_link);
+
+/**
+ * xt_hook_unlink - remove hooks for a table
+ * @ops: nf_hook_ops array as returned by nf_hook_link
+ * @hook_mask: the very same mask that was passed to nf_hook_link
+ */
+void xt_hook_unlink(const struct xt_table *table, struct nf_hook_ops *ops)
+{
+ nf_unregister_hooks(ops, hweight32(table->valid_hooks));
+ kfree(ops);
+}
+EXPORT_SYMBOL_GPL(xt_hook_unlink);
+
+int xt_proto_init(struct net *net, u_int8_t af)
+{
+#ifdef CONFIG_PROC_FS
+ char buf[XT_FUNCTION_MAXNAMELEN];
+ struct proc_dir_entry *proc;
+#endif
+
+ if (af >= ARRAY_SIZE(xt_prefix))
+ return -EINVAL;
+
+
+#ifdef CONFIG_PROC_FS
+ strlcpy(buf, xt_prefix[af], sizeof(buf));
+ strlcat(buf, FORMAT_TABLES, sizeof(buf));
+ proc = proc_create_data(buf, 0440, net->proc_net, &xt_table_ops,
+ (void *)(unsigned long)af);
+ if (!proc)
+ goto out;
+
+ strlcpy(buf, xt_prefix[af], sizeof(buf));
+ strlcat(buf, FORMAT_MATCHES, sizeof(buf));
+ proc = proc_create_data(buf, 0440, net->proc_net, &xt_match_ops,
+ (void *)(unsigned long)af);
+ if (!proc)
+ goto out_remove_tables;
+
+ strlcpy(buf, xt_prefix[af], sizeof(buf));
+ strlcat(buf, FORMAT_TARGETS, sizeof(buf));
+ proc = proc_create_data(buf, 0440, net->proc_net, &xt_target_ops,
+ (void *)(unsigned long)af);
+ if (!proc)
+ goto out_remove_matches;
+#endif
+
+ return 0;
+
+#ifdef CONFIG_PROC_FS
+out_remove_matches:
+ strlcpy(buf, xt_prefix[af], sizeof(buf));
+ strlcat(buf, FORMAT_MATCHES, sizeof(buf));
+ remove_proc_entry(buf, net->proc_net);
+
+out_remove_tables:
+ strlcpy(buf, xt_prefix[af], sizeof(buf));
+ strlcat(buf, FORMAT_TABLES, sizeof(buf));
+ remove_proc_entry(buf, net->proc_net);
+out:
+ return -1;
+#endif
+}
+EXPORT_SYMBOL_GPL(xt_proto_init);
+
+void xt_proto_fini(struct net *net, u_int8_t af)
+{
+#ifdef CONFIG_PROC_FS
+ char buf[XT_FUNCTION_MAXNAMELEN];
+
+ strlcpy(buf, xt_prefix[af], sizeof(buf));
+ strlcat(buf, FORMAT_TABLES, sizeof(buf));
+ remove_proc_entry(buf, net->proc_net);
+
+ strlcpy(buf, xt_prefix[af], sizeof(buf));
+ strlcat(buf, FORMAT_TARGETS, sizeof(buf));
+ remove_proc_entry(buf, net->proc_net);
+
+ strlcpy(buf, xt_prefix[af], sizeof(buf));
+ strlcat(buf, FORMAT_MATCHES, sizeof(buf));
+ remove_proc_entry(buf, net->proc_net);
+#endif /*CONFIG_PROC_FS*/
+}
+EXPORT_SYMBOL_GPL(xt_proto_fini);
+
+static int __net_init xt_net_init(struct net *net)
+{
+ int i;
+
+ for (i = 0; i < NFPROTO_NUMPROTO; i++)
+ INIT_LIST_HEAD(&net->xt.tables[i]);
+ return 0;
+}
+
+static struct pernet_operations xt_net_ops = {
+ .init = xt_net_init,
+};
+
+static int __init xt_init(void)
+{
+ unsigned int i;
+ int rv;
+
+ for_each_possible_cpu(i) {
+ seqcount_init(&per_cpu(xt_recseq, i));
+ }
+
+ xt = kmalloc(sizeof(struct xt_af) * NFPROTO_NUMPROTO, GFP_KERNEL);
+ if (!xt)
+ return -ENOMEM;
+
+ for (i = 0; i < NFPROTO_NUMPROTO; i++) {
+ mutex_init(&xt[i].mutex);
+#ifdef CONFIG_COMPAT
+ mutex_init(&xt[i].compat_mutex);
+ xt[i].compat_tab = NULL;
+#endif
+ INIT_LIST_HEAD(&xt[i].target);
+ INIT_LIST_HEAD(&xt[i].match);
+ }
+ rv = register_pernet_subsys(&xt_net_ops);
+ if (rv < 0)
+ kfree(xt);
+ return rv;
+}
+
+static void __exit xt_fini(void)
+{
+ unregister_pernet_subsys(&xt_net_ops);
+ kfree(xt);
+}
+
+module_init(xt_init);
+module_exit(xt_fini);
+
Code Review / kvmfornfv.git / blobdiff