--- /dev/null
+/*
+ * Packet matching code for ARP packets.
+ *
+ * Based heavily, if not almost entirely, upon ip_tables.c framework.
+ *
+ * Some ARP specific bits are:
+ *
+ * Copyright (C) 2002 David S. Miller (davem@redhat.com)
+ * Copyright (C) 2006-2009 Patrick McHardy <kaber@trash.net>
+ *
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/capability.h>
+#include <linux/if_arp.h>
+#include <linux/kmod.h>
+#include <linux/vmalloc.h>
+#include <linux/proc_fs.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/err.h>
+#include <net/compat.h>
+#include <net/sock.h>
+#include <asm/uaccess.h>
+
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_arp/arp_tables.h>
+#include "../../netfilter/xt_repldata.h"
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
+MODULE_DESCRIPTION("arptables core");
+
+/*#define DEBUG_ARP_TABLES*/
+/*#define DEBUG_ARP_TABLES_USER*/
+
+#ifdef DEBUG_ARP_TABLES
+#define dprintf(format, args...) printk(format , ## args)
+#else
+#define dprintf(format, args...)
+#endif
+
+#ifdef DEBUG_ARP_TABLES_USER
+#define duprintf(format, args...) printk(format , ## args)
+#else
+#define duprintf(format, args...)
+#endif
+
+#ifdef CONFIG_NETFILTER_DEBUG
+#define ARP_NF_ASSERT(x) WARN_ON(!(x))
+#else
+#define ARP_NF_ASSERT(x)
+#endif
+
+void *arpt_alloc_initial_table(const struct xt_table *info)
+{
+ return xt_alloc_initial_table(arpt, ARPT);
+}
+EXPORT_SYMBOL_GPL(arpt_alloc_initial_table);
+
+static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap,
+ const char *hdr_addr, int len)
+{
+ int i, ret;
+
+ if (len > ARPT_DEV_ADDR_LEN_MAX)
+ len = ARPT_DEV_ADDR_LEN_MAX;
+
+ ret = 0;
+ for (i = 0; i < len; i++)
+ ret |= (hdr_addr[i] ^ ap->addr[i]) & ap->mask[i];
+
+ return ret != 0;
+}
+
+/*
+ * Unfortunately, _b and _mask are not aligned to an int (or long int)
+ * Some arches dont care, unrolling the loop is a win on them.
+ * For other arches, we only have a 16bit alignement.
+ */
+static unsigned long ifname_compare(const char *_a, const char *_b, const char *_mask)
+{
+#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+ unsigned long ret = ifname_compare_aligned(_a, _b, _mask);
+#else
+ unsigned long ret = 0;
+ const u16 *a = (const u16 *)_a;
+ const u16 *b = (const u16 *)_b;
+ const u16 *mask = (const u16 *)_mask;
+ int i;
+
+ for (i = 0; i < IFNAMSIZ/sizeof(u16); i++)
+ ret |= (a[i] ^ b[i]) & mask[i];
+#endif
+ return ret;
+}
+
+/* Returns whether packet matches rule or not. */
+static inline int arp_packet_match(const struct arphdr *arphdr,
+ struct net_device *dev,
+ const char *indev,
+ const char *outdev,
+ const struct arpt_arp *arpinfo)
+{
+ const char *arpptr = (char *)(arphdr + 1);
+ const char *src_devaddr, *tgt_devaddr;
+ __be32 src_ipaddr, tgt_ipaddr;
+ long ret;
+
+#define FWINV(bool, invflg) ((bool) ^ !!(arpinfo->invflags & (invflg)))
+
+ if (FWINV((arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop,
+ ARPT_INV_ARPOP)) {
+ dprintf("ARP operation field mismatch.\n");
+ dprintf("ar_op: %04x info->arpop: %04x info->arpop_mask: %04x\n",
+ arphdr->ar_op, arpinfo->arpop, arpinfo->arpop_mask);
+ return 0;
+ }
+
+ if (FWINV((arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd,
+ ARPT_INV_ARPHRD)) {
+ dprintf("ARP hardware address format mismatch.\n");
+ dprintf("ar_hrd: %04x info->arhrd: %04x info->arhrd_mask: %04x\n",
+ arphdr->ar_hrd, arpinfo->arhrd, arpinfo->arhrd_mask);
+ return 0;
+ }
+
+ if (FWINV((arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro,
+ ARPT_INV_ARPPRO)) {
+ dprintf("ARP protocol address format mismatch.\n");
+ dprintf("ar_pro: %04x info->arpro: %04x info->arpro_mask: %04x\n",
+ arphdr->ar_pro, arpinfo->arpro, arpinfo->arpro_mask);
+ return 0;
+ }
+
+ if (FWINV((arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln,
+ ARPT_INV_ARPHLN)) {
+ dprintf("ARP hardware address length mismatch.\n");
+ dprintf("ar_hln: %02x info->arhln: %02x info->arhln_mask: %02x\n",
+ arphdr->ar_hln, arpinfo->arhln, arpinfo->arhln_mask);
+ return 0;
+ }
+
+ src_devaddr = arpptr;
+ arpptr += dev->addr_len;
+ memcpy(&src_ipaddr, arpptr, sizeof(u32));
+ arpptr += sizeof(u32);
+ tgt_devaddr = arpptr;
+ arpptr += dev->addr_len;
+ memcpy(&tgt_ipaddr, arpptr, sizeof(u32));
+
+ if (FWINV(arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr, dev->addr_len),
+ ARPT_INV_SRCDEVADDR) ||
+ FWINV(arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr, dev->addr_len),
+ ARPT_INV_TGTDEVADDR)) {
+ dprintf("Source or target device address mismatch.\n");
+
+ return 0;
+ }
+
+ if (FWINV((src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr,
+ ARPT_INV_SRCIP) ||
+ FWINV(((tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr),
+ ARPT_INV_TGTIP)) {
+ dprintf("Source or target IP address mismatch.\n");
+
+ dprintf("SRC: %pI4. Mask: %pI4. Target: %pI4.%s\n",
+ &src_ipaddr,
+ &arpinfo->smsk.s_addr,
+ &arpinfo->src.s_addr,
+ arpinfo->invflags & ARPT_INV_SRCIP ? " (INV)" : "");
+ dprintf("TGT: %pI4 Mask: %pI4 Target: %pI4.%s\n",
+ &tgt_ipaddr,
+ &arpinfo->tmsk.s_addr,
+ &arpinfo->tgt.s_addr,
+ arpinfo->invflags & ARPT_INV_TGTIP ? " (INV)" : "");
+ return 0;
+ }
+
+ /* Look for ifname matches. */
+ ret = ifname_compare(indev, arpinfo->iniface, arpinfo->iniface_mask);
+
+ if (FWINV(ret != 0, ARPT_INV_VIA_IN)) {
+ dprintf("VIA in mismatch (%s vs %s).%s\n",
+ indev, arpinfo->iniface,
+ arpinfo->invflags&ARPT_INV_VIA_IN ?" (INV)":"");
+ return 0;
+ }
+
+ ret = ifname_compare(outdev, arpinfo->outiface, arpinfo->outiface_mask);
+
+ if (FWINV(ret != 0, ARPT_INV_VIA_OUT)) {
+ dprintf("VIA out mismatch (%s vs %s).%s\n",
+ outdev, arpinfo->outiface,
+ arpinfo->invflags&ARPT_INV_VIA_OUT ?" (INV)":"");
+ return 0;
+ }
+
+ return 1;
+#undef FWINV
+}
+
+static inline int arp_checkentry(const struct arpt_arp *arp)
+{
+ if (arp->flags & ~ARPT_F_MASK) {
+ duprintf("Unknown flag bits set: %08X\n",
+ arp->flags & ~ARPT_F_MASK);
+ return 0;
+ }
+ if (arp->invflags & ~ARPT_INV_MASK) {
+ duprintf("Unknown invflag bits set: %08X\n",
+ arp->invflags & ~ARPT_INV_MASK);
+ return 0;
+ }
+
+ return 1;
+}
+
+static unsigned int
+arpt_error(struct sk_buff *skb, const struct xt_action_param *par)
+{
+ net_err_ratelimited("arp_tables: error: '%s'\n",
+ (const char *)par->targinfo);
+
+ return NF_DROP;
+}
+
+static inline const struct xt_entry_target *
+arpt_get_target_c(const struct arpt_entry *e)
+{
+ return arpt_get_target((struct arpt_entry *)e);
+}
+
+static inline struct arpt_entry *
+get_entry(const void *base, unsigned int offset)
+{
+ return (struct arpt_entry *)(base + offset);
+}
+
+static inline __pure
+struct arpt_entry *arpt_next_entry(const struct arpt_entry *entry)
+{
+ return (void *)entry + entry->next_offset;
+}
+
+unsigned int arpt_do_table(struct sk_buff *skb,
+ unsigned int hook,
+ const struct nf_hook_state *state,
+ struct xt_table *table)
+{
+ static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
+ unsigned int verdict = NF_DROP;
+ const struct arphdr *arp;
+ struct arpt_entry *e, *back;
+ const char *indev, *outdev;
+ void *table_base;
+ const struct xt_table_info *private;
+ struct xt_action_param acpar;
+ unsigned int addend;
+
+ if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
+ return NF_DROP;
+
+ indev = state->in ? state->in->name : nulldevname;
+ outdev = state->out ? state->out->name : nulldevname;
+
+ local_bh_disable();
+ addend = xt_write_recseq_begin();
+ private = table->private;
+ /*
+ * Ensure we load private-> members after we've fetched the base
+ * pointer.
+ */
+ smp_read_barrier_depends();
+ table_base = private->entries[smp_processor_id()];
+
+ e = get_entry(table_base, private->hook_entry[hook]);
+ back = get_entry(table_base, private->underflow[hook]);
+
+ acpar.in = state->in;
+ acpar.out = state->out;
+ acpar.hooknum = hook;
+ acpar.family = NFPROTO_ARP;
+ acpar.hotdrop = false;
+
+ arp = arp_hdr(skb);
+ do {
+ const struct xt_entry_target *t;
+
+ if (!arp_packet_match(arp, skb->dev, indev, outdev, &e->arp)) {
+ e = arpt_next_entry(e);
+ continue;
+ }
+
+ ADD_COUNTER(e->counters, arp_hdr_len(skb->dev), 1);
+
+ t = arpt_get_target_c(e);
+
+ /* Standard target? */
+ if (!t->u.kernel.target->target) {
+ int v;
+
+ v = ((struct xt_standard_target *)t)->verdict;
+ if (v < 0) {
+ /* Pop from stack? */
+ if (v != XT_RETURN) {
+ verdict = (unsigned int)(-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;
+ }
+
+ e = get_entry(table_base, v);
+ continue;
+ }
+
+ /* Targets which reenter must return
+ * abs. verdicts
+ */
+ acpar.target = t->u.kernel.target;
+ acpar.targinfo = t->data;
+ verdict = t->u.kernel.target->target(skb, &acpar);
+
+ /* Target might have changed stuff. */
+ arp = arp_hdr(skb);
+
+ if (verdict == XT_CONTINUE)
+ e = arpt_next_entry(e);
+ else
+ /* Verdict */
+ break;
+ } while (!acpar.hotdrop);
+ xt_write_recseq_end(addend);
+ local_bh_enable();
+
+ if (acpar.hotdrop)
+ return NF_DROP;
+ else
+ return verdict;
+}
+
+/* All zeroes == unconditional rule. */
+static inline bool unconditional(const struct arpt_arp *arp)
+{
+ static const struct arpt_arp uncond;
+
+ return memcmp(arp, &uncond, sizeof(uncond)) == 0;
+}
+
+/* Figures out from what hook each rule can be called: returns 0 if
+ * there are loops. Puts hook bitmask in comefrom.
+ */
+static int mark_source_chains(const struct xt_table_info *newinfo,
+ unsigned int valid_hooks, void *entry0)
+{
+ unsigned int hook;
+
+ /* No recursion; use packet counter to save back ptrs (reset
+ * to 0 as we leave), and comefrom to save source hook bitmask.
+ */
+ for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) {
+ unsigned int pos = newinfo->hook_entry[hook];
+ struct arpt_entry *e
+ = (struct arpt_entry *)(entry0 + pos);
+
+ if (!(valid_hooks & (1 << hook)))
+ continue;
+
+ /* Set initial back pointer. */
+ e->counters.pcnt = pos;
+
+ for (;;) {
+ const struct xt_standard_target *t
+ = (void *)arpt_get_target_c(e);
+ int visited = e->comefrom & (1 << hook);
+
+ if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
+ pr_notice("arptables: loop hook %u pos %u %08X.\n",
+ hook, pos, e->comefrom);
+ return 0;
+ }
+ e->comefrom
+ |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
+
+ /* Unconditional return/END. */
+ if ((e->target_offset == sizeof(struct arpt_entry) &&
+ (strcmp(t->target.u.user.name,
+ XT_STANDARD_TARGET) == 0) &&
+ t->verdict < 0 && unconditional(&e->arp)) ||
+ visited) {
+ unsigned int oldpos, size;
+
+ if ((strcmp(t->target.u.user.name,
+ XT_STANDARD_TARGET) == 0) &&
+ t->verdict < -NF_MAX_VERDICT - 1) {
+ duprintf("mark_source_chains: bad "
+ "negative verdict (%i)\n",
+ t->verdict);
+ return 0;
+ }
+
+ /* Return: backtrack through the last
+ * big jump.
+ */
+ do {
+ e->comefrom ^= (1<<NF_ARP_NUMHOOKS);
+ oldpos = pos;
+ pos = e->counters.pcnt;
+ e->counters.pcnt = 0;
+
+ /* We're at the start. */
+ if (pos == oldpos)
+ goto next;
+
+ e = (struct arpt_entry *)
+ (entry0 + pos);
+ } while (oldpos == pos + e->next_offset);
+
+ /* Move along one */
+ size = e->next_offset;
+ e = (struct arpt_entry *)
+ (entry0 + pos + size);
+ e->counters.pcnt = pos;
+ pos += size;
+ } else {
+ int newpos = t->verdict;
+
+ if (strcmp(t->target.u.user.name,
+ XT_STANDARD_TARGET) == 0 &&
+ newpos >= 0) {
+ if (newpos > newinfo->size -
+ sizeof(struct arpt_entry)) {
+ duprintf("mark_source_chains: "
+ "bad verdict (%i)\n",
+ newpos);
+ return 0;
+ }
+
+ /* This a jump; chase it. */
+ duprintf("Jump rule %u -> %u\n",
+ pos, newpos);
+ } else {
+ /* ... this is a fallthru */
+ newpos = pos + e->next_offset;
+ }
+ e = (struct arpt_entry *)
+ (entry0 + newpos);
+ e->counters.pcnt = pos;
+ pos = newpos;
+ }
+ }
+ next:
+ duprintf("Finished chain %u\n", hook);
+ }
+ return 1;
+}
+
+static inline int check_entry(const struct arpt_entry *e, const char *name)
+{
+ const struct xt_entry_target *t;
+
+ if (!arp_checkentry(&e->arp)) {
+ duprintf("arp_tables: arp check failed %p %s.\n", e, name);
+ return -EINVAL;
+ }
+
+ if (e->target_offset + sizeof(struct xt_entry_target) > e->next_offset)
+ return -EINVAL;
+
+ t = arpt_get_target_c(e);
+ if (e->target_offset + t->u.target_size > e->next_offset)
+ return -EINVAL;
+
+ return 0;
+}
+
+static inline int check_target(struct arpt_entry *e, const char *name)
+{
+ struct xt_entry_target *t = arpt_get_target(e);
+ int ret;
+ struct xt_tgchk_param par = {
+ .table = name,
+ .entryinfo = e,
+ .target = t->u.kernel.target,
+ .targinfo = t->data,
+ .hook_mask = e->comefrom,
+ .family = NFPROTO_ARP,
+ };
+
+ ret = xt_check_target(&par, t->u.target_size - sizeof(*t), 0, false);
+ if (ret < 0) {
+ duprintf("arp_tables: check failed for `%s'.\n",
+ t->u.kernel.target->name);
+ return ret;
+ }
+ return 0;
+}
+
+static inline int
+find_check_entry(struct arpt_entry *e, const char *name, unsigned int size)
+{
+ struct xt_entry_target *t;
+ struct xt_target *target;
+ int ret;
+
+ ret = check_entry(e, name);
+ if (ret)
+ return ret;
+
+ t = arpt_get_target(e);
+ target = xt_request_find_target(NFPROTO_ARP, t->u.user.name,
+ t->u.user.revision);
+ if (IS_ERR(target)) {
+ duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
+ ret = PTR_ERR(target);
+ goto out;
+ }
+ t->u.kernel.target = target;
+
+ ret = check_target(e, name);
+ if (ret)
+ goto err;
+ return 0;
+err:
+ module_put(t->u.kernel.target->me);
+out:
+ return ret;
+}
+
+static bool check_underflow(const struct arpt_entry *e)
+{
+ const struct xt_entry_target *t;
+ unsigned int verdict;
+
+ if (!unconditional(&e->arp))
+ return false;
+ t = arpt_get_target_c(e);
+ if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
+ return false;
+ verdict = ((struct xt_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,
+ const unsigned char *base,
+ const unsigned char *limit,
+ const unsigned int *hook_entries,
+ const unsigned int *underflows,
+ unsigned int valid_hooks)
+{
+ unsigned int h;
+
+ 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;
+ }
+
+ if (e->next_offset
+ < sizeof(struct arpt_entry) + sizeof(struct xt_entry_target)) {
+ duprintf("checking: element %p size %u\n",
+ e, e->next_offset);
+ 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 (!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];
+ }
+ }
+
+ /* Clear counters and comefrom */
+ e->counters = ((struct xt_counters) { 0, 0 });
+ e->comefrom = 0;
+ return 0;
+}
+
+static inline void cleanup_entry(struct arpt_entry *e)
+{
+ struct xt_tgdtor_param par;
+ struct xt_entry_target *t;
+
+ t = arpt_get_target(e);
+ par.target = t->u.kernel.target;
+ par.targinfo = t->data;
+ par.family = NFPROTO_ARP;
+ if (par.target->destroy != NULL)
+ par.target->destroy(&par);
+ module_put(par.target->me);
+}
+
+/* Checks and translates the user-supplied table segment (held in
+ * newinfo).
+ */
+static int translate_table(struct xt_table_info *newinfo, void *entry0,
+ const struct arpt_replace *repl)
+{
+ struct arpt_entry *iter;
+ unsigned int i;
+ int ret = 0;
+
+ newinfo->size = repl->size;
+ newinfo->number = repl->num_entries;
+
+ /* Init all hooks to impossible value. */
+ for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
+ newinfo->hook_entry[i] = 0xFFFFFFFF;
+ newinfo->underflow[i] = 0xFFFFFFFF;
+ }
+
+ duprintf("translate_table: size %u\n", newinfo->size);
+ i = 0;
+
+ /* Walk through entries, checking offsets. */
+ xt_entry_foreach(iter, entry0, newinfo->size) {
+ ret = check_entry_size_and_hooks(iter, newinfo, entry0,
+ entry0 + repl->size,
+ repl->hook_entry,
+ repl->underflow,
+ repl->valid_hooks);
+ if (ret != 0)
+ break;
+ ++i;
+ if (strcmp(arpt_get_target(iter)->u.user.name,
+ XT_ERROR_TARGET) == 0)
+ ++newinfo->stacksize;
+ }
+ duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
+ if (ret != 0)
+ return ret;
+
+ if (i != repl->num_entries) {
+ duprintf("translate_table: %u not %u entries\n",
+ i, repl->num_entries);
+ return -EINVAL;
+ }
+
+ /* Check hooks all assigned */
+ for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
+ /* Only hooks which are valid */
+ if (!(repl->valid_hooks & (1 << i)))
+ continue;
+ if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
+ duprintf("Invalid hook entry %u %u\n",
+ i, repl->hook_entry[i]);
+ return -EINVAL;
+ }
+ if (newinfo->underflow[i] == 0xFFFFFFFF) {
+ duprintf("Invalid underflow %u %u\n",
+ i, repl->underflow[i]);
+ return -EINVAL;
+ }
+ }
+
+ if (!mark_source_chains(newinfo, repl->valid_hooks, entry0)) {
+ duprintf("Looping hook\n");
+ return -ELOOP;
+ }
+
+ /* Finally, each sanity check must pass */
+ i = 0;
+ xt_entry_foreach(iter, entry0, newinfo->size) {
+ ret = find_check_entry(iter, repl->name, repl->size);
+ if (ret != 0)
+ break;
+ ++i;
+ }
+
+ if (ret != 0) {
+ xt_entry_foreach(iter, entry0, newinfo->size) {
+ if (i-- == 0)
+ break;
+ cleanup_entry(iter);
+ }
+ return ret;
+ }
+
+ /* And one copy for every other CPU */
+ for_each_possible_cpu(i) {
+ if (newinfo->entries[i] && newinfo->entries[i] != entry0)
+ memcpy(newinfo->entries[i], entry0, newinfo->size);
+ }
+
+ return ret;
+}
+
+static void get_counters(const struct xt_table_info *t,
+ struct xt_counters counters[])
+{
+ struct arpt_entry *iter;
+ unsigned int cpu;
+ unsigned int i;
+
+ for_each_possible_cpu(cpu) {
+ seqcount_t *s = &per_cpu(xt_recseq, cpu);
+
+ i = 0;
+ xt_entry_foreach(iter, t->entries[cpu], t->size) {
+ u64 bcnt, pcnt;
+ unsigned int start;
+
+ do {
+ start = read_seqcount_begin(s);
+ bcnt = iter->counters.bcnt;
+ pcnt = iter->counters.pcnt;
+ } while (read_seqcount_retry(s, start));
+
+ ADD_COUNTER(counters[i], bcnt, pcnt);
+ ++i;
+ }
+ }
+}
+
+static struct xt_counters *alloc_counters(const struct xt_table *table)
+{
+ unsigned int countersize;
+ struct xt_counters *counters;
+ const struct xt_table_info *private = table->private;
+
+ /* We need atomic snapshot of counters: rest doesn't change
+ * (other than comefrom, which userspace doesn't care
+ * about).
+ */
+ countersize = sizeof(struct xt_counters) * private->number;
+ counters = vzalloc(countersize);
+
+ if (counters == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ get_counters(private, counters);
+
+ return counters;
+}
+
+static int copy_entries_to_user(unsigned int total_size,
+ const struct xt_table *table,
+ void __user *userptr)
+{
+ unsigned int off, num;
+ const struct arpt_entry *e;
+ struct xt_counters *counters;
+ struct xt_table_info *private = table->private;
+ int ret = 0;
+ void *loc_cpu_entry;
+
+ counters = alloc_counters(table);
+ if (IS_ERR(counters))
+ return PTR_ERR(counters);
+
+ loc_cpu_entry = private->entries[raw_smp_processor_id()];
+ /* ... then copy entire thing ... */
+ if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
+ ret = -EFAULT;
+ goto free_counters;
+ }
+
+ /* FIXME: use iterator macros --RR */
+ /* ... then go back and fix counters and names */
+ for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
+ const struct xt_entry_target *t;
+
+ e = (struct arpt_entry *)(loc_cpu_entry + off);
+ if (copy_to_user(userptr + off
+ + offsetof(struct arpt_entry, counters),
+ &counters[num],
+ sizeof(counters[num])) != 0) {
+ ret = -EFAULT;
+ goto free_counters;
+ }
+
+ t = arpt_get_target_c(e);
+ if (copy_to_user(userptr + off + e->target_offset
+ + offsetof(struct xt_entry_target,
+ u.user.name),
+ t->u.kernel.target->name,
+ strlen(t->u.kernel.target->name)+1) != 0) {
+ ret = -EFAULT;
+ goto free_counters;
+ }
+ }
+
+ free_counters:
+ vfree(counters);
+ return ret;
+}
+
+#ifdef CONFIG_COMPAT
+static void compat_standard_from_user(void *dst, const void *src)
+{
+ int v = *(compat_int_t *)src;
+
+ if (v > 0)
+ v += xt_compat_calc_jump(NFPROTO_ARP, v);
+ memcpy(dst, &v, sizeof(v));
+}
+
+static int compat_standard_to_user(void __user *dst, const void *src)
+{
+ compat_int_t cv = *(int *)src;
+
+ if (cv > 0)
+ cv -= xt_compat_calc_jump(NFPROTO_ARP, cv);
+ return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
+}
+
+static int compat_calc_entry(const struct arpt_entry *e,
+ const struct xt_table_info *info,
+ const void *base, struct xt_table_info *newinfo)
+{
+ const struct xt_entry_target *t;
+ unsigned int entry_offset;
+ int off, i, ret;
+
+ off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
+ entry_offset = (void *)e - base;
+
+ t = arpt_get_target_c(e);
+ off += xt_compat_target_offset(t->u.kernel.target);
+ newinfo->size -= off;
+ ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
+ if (info->hook_entry[i] &&
+ (e < (struct arpt_entry *)(base + info->hook_entry[i])))
+ newinfo->hook_entry[i] -= off;
+ if (info->underflow[i] &&
+ (e < (struct arpt_entry *)(base + info->underflow[i])))
+ newinfo->underflow[i] -= off;
+ }
+ return 0;
+}
+
+static int compat_table_info(const struct xt_table_info *info,
+ struct xt_table_info *newinfo)
+{
+ struct arpt_entry *iter;
+ void *loc_cpu_entry;
+ int ret;
+
+ if (!newinfo || !info)
+ return -EINVAL;
+
+ /* we dont care about newinfo->entries[] */
+ memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
+ newinfo->initial_entries = 0;
+ loc_cpu_entry = info->entries[raw_smp_processor_id()];
+ xt_compat_init_offsets(NFPROTO_ARP, info->number);
+ xt_entry_foreach(iter, loc_cpu_entry, info->size) {
+ ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
+ if (ret != 0)
+ return ret;
+ }
+ return 0;
+}
+#endif
+
+static int get_info(struct net *net, void __user *user,
+ const int *len, int compat)
+{
+ char name[XT_TABLE_MAXNAMELEN];
+ struct xt_table *t;
+ int ret;
+
+ if (*len != sizeof(struct arpt_getinfo)) {
+ duprintf("length %u != %Zu\n", *len,
+ sizeof(struct arpt_getinfo));
+ return -EINVAL;
+ }
+
+ if (copy_from_user(name, user, sizeof(name)) != 0)
+ return -EFAULT;
+
+ name[XT_TABLE_MAXNAMELEN-1] = '\0';
+#ifdef CONFIG_COMPAT
+ if (compat)
+ xt_compat_lock(NFPROTO_ARP);
+#endif
+ t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
+ "arptable_%s", name);
+ if (!IS_ERR_OR_NULL(t)) {
+ struct arpt_getinfo info;
+ const struct xt_table_info *private = t->private;
+#ifdef CONFIG_COMPAT
+ struct xt_table_info tmp;
+
+ if (compat) {
+ ret = compat_table_info(private, &tmp);
+ xt_compat_flush_offsets(NFPROTO_ARP);
+ private = &tmp;
+ }
+#endif
+ memset(&info, 0, sizeof(info));
+ info.valid_hooks = t->valid_hooks;
+ memcpy(info.hook_entry, private->hook_entry,
+ sizeof(info.hook_entry));
+ memcpy(info.underflow, private->underflow,
+ sizeof(info.underflow));
+ info.num_entries = private->number;
+ info.size = private->size;
+ strcpy(info.name, name);
+
+ if (copy_to_user(user, &info, *len) != 0)
+ ret = -EFAULT;
+ else
+ ret = 0;
+ xt_table_unlock(t);
+ module_put(t->me);
+ } else
+ ret = t ? PTR_ERR(t) : -ENOENT;
+#ifdef CONFIG_COMPAT
+ if (compat)
+ xt_compat_unlock(NFPROTO_ARP);
+#endif
+ return ret;
+}
+
+static int get_entries(struct net *net, struct arpt_get_entries __user *uptr,
+ const int *len)
+{
+ int ret;
+ struct arpt_get_entries get;
+ struct xt_table *t;
+
+ if (*len < sizeof(get)) {
+ duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
+ return -EINVAL;
+ }
+ if (copy_from_user(&get, uptr, sizeof(get)) != 0)
+ return -EFAULT;
+ if (*len != sizeof(struct arpt_get_entries) + get.size) {
+ duprintf("get_entries: %u != %Zu\n", *len,
+ sizeof(struct arpt_get_entries) + get.size);
+ return -EINVAL;
+ }
+
+ t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
+ if (!IS_ERR_OR_NULL(t)) {
+ const struct xt_table_info *private = t->private;
+
+ duprintf("t->private->number = %u\n",
+ private->number);
+ if (get.size == private->size)
+ ret = copy_entries_to_user(private->size,
+ t, uptr->entrytable);
+ else {
+ duprintf("get_entries: I've got %u not %u!\n",
+ private->size, get.size);
+ ret = -EAGAIN;
+ }
+ module_put(t->me);
+ xt_table_unlock(t);
+ } else
+ ret = t ? PTR_ERR(t) : -ENOENT;
+
+ return ret;
+}
+
+static int __do_replace(struct net *net, const char *name,
+ unsigned int valid_hooks,
+ struct xt_table_info *newinfo,
+ unsigned int num_counters,
+ void __user *counters_ptr)
+{
+ int ret;
+ struct xt_table *t;
+ struct xt_table_info *oldinfo;
+ struct xt_counters *counters;
+ void *loc_cpu_old_entry;
+ struct arpt_entry *iter;
+
+ ret = 0;
+ counters = vzalloc(num_counters * sizeof(struct xt_counters));
+ if (!counters) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
+ "arptable_%s", name);
+ if (IS_ERR_OR_NULL(t)) {
+ ret = t ? PTR_ERR(t) : -ENOENT;
+ goto free_newinfo_counters_untrans;
+ }
+
+ /* You lied! */
+ if (valid_hooks != t->valid_hooks) {
+ duprintf("Valid hook crap: %08X vs %08X\n",
+ valid_hooks, t->valid_hooks);
+ ret = -EINVAL;
+ goto put_module;
+ }
+
+ oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
+ if (!oldinfo)
+ goto put_module;
+
+ /* Update module usage count based on number of rules */
+ duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
+ oldinfo->number, oldinfo->initial_entries, newinfo->number);
+ if ((oldinfo->number > oldinfo->initial_entries) ||
+ (newinfo->number <= oldinfo->initial_entries))
+ module_put(t->me);
+ if ((oldinfo->number > oldinfo->initial_entries) &&
+ (newinfo->number <= oldinfo->initial_entries))
+ module_put(t->me);
+
+ /* Get the old counters, and synchronize with replace */
+ get_counters(oldinfo, counters);
+
+ /* Decrease module usage counts and free resource */
+ loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
+ xt_entry_foreach(iter, loc_cpu_old_entry, oldinfo->size)
+ cleanup_entry(iter);
+
+ xt_free_table_info(oldinfo);
+ if (copy_to_user(counters_ptr, counters,
+ sizeof(struct xt_counters) * num_counters) != 0) {
+ /* Silent error, can't fail, new table is already in place */
+ net_warn_ratelimited("arptables: counters copy to user failed while replacing table\n");
+ }
+ vfree(counters);
+ xt_table_unlock(t);
+ return ret;
+
+ put_module:
+ module_put(t->me);
+ xt_table_unlock(t);
+ free_newinfo_counters_untrans:
+ vfree(counters);
+ out:
+ return ret;
+}
+
+static int do_replace(struct net *net, const void __user *user,
+ unsigned int len)
+{
+ int ret;
+ struct arpt_replace tmp;
+ struct xt_table_info *newinfo;
+ void *loc_cpu_entry;
+ struct arpt_entry *iter;
+
+ if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
+ return -EFAULT;
+
+ /* overflow check */
+ if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
+ return -ENOMEM;
+ if (tmp.num_counters == 0)
+ return -EINVAL;
+
+ tmp.name[sizeof(tmp.name)-1] = 0;
+
+ newinfo = xt_alloc_table_info(tmp.size);
+ if (!newinfo)
+ return -ENOMEM;
+
+ /* choose the copy that is on our node/cpu */
+ loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
+ if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
+ tmp.size) != 0) {
+ ret = -EFAULT;
+ goto free_newinfo;
+ }
+
+ ret = translate_table(newinfo, loc_cpu_entry, &tmp);
+ if (ret != 0)
+ goto free_newinfo;
+
+ duprintf("arp_tables: Translated table\n");
+
+ ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
+ tmp.num_counters, tmp.counters);
+ if (ret)
+ goto free_newinfo_untrans;
+ return 0;
+
+ free_newinfo_untrans:
+ xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
+ cleanup_entry(iter);
+ free_newinfo:
+ xt_free_table_info(newinfo);
+ return ret;
+}
+
+static int do_add_counters(struct net *net, const void __user *user,
+ unsigned int len, int compat)
+{
+ unsigned int i, curcpu;
+ struct xt_counters_info tmp;
+ struct xt_counters *paddc;
+ unsigned int num_counters;
+ const char *name;
+ int size;
+ void *ptmp;
+ struct xt_table *t;
+ const struct xt_table_info *private;
+ int ret = 0;
+ void *loc_cpu_entry;
+ struct arpt_entry *iter;
+ unsigned int addend;
+#ifdef CONFIG_COMPAT
+ struct compat_xt_counters_info compat_tmp;
+
+ if (compat) {
+ ptmp = &compat_tmp;
+ size = sizeof(struct compat_xt_counters_info);
+ } else
+#endif
+ {
+ ptmp = &tmp;
+ size = sizeof(struct xt_counters_info);
+ }
+
+ if (copy_from_user(ptmp, user, size) != 0)
+ return -EFAULT;
+
+#ifdef CONFIG_COMPAT
+ if (compat) {
+ num_counters = compat_tmp.num_counters;
+ name = compat_tmp.name;
+ } else
+#endif
+ {
+ num_counters = tmp.num_counters;
+ name = tmp.name;
+ }
+
+ if (len != size + num_counters * sizeof(struct xt_counters))
+ return -EINVAL;
+
+ paddc = vmalloc(len - size);
+ if (!paddc)
+ return -ENOMEM;
+
+ if (copy_from_user(paddc, user + size, len - size) != 0) {
+ ret = -EFAULT;
+ goto free;
+ }
+
+ t = xt_find_table_lock(net, NFPROTO_ARP, name);
+ if (IS_ERR_OR_NULL(t)) {
+ ret = t ? PTR_ERR(t) : -ENOENT;
+ goto free;
+ }
+
+ local_bh_disable();
+ private = t->private;
+ if (private->number != num_counters) {
+ ret = -EINVAL;
+ goto unlock_up_free;
+ }
+
+ i = 0;
+ /* Choose the copy that is on our node */
+ curcpu = smp_processor_id();
+ loc_cpu_entry = private->entries[curcpu];
+ addend = xt_write_recseq_begin();
+ xt_entry_foreach(iter, loc_cpu_entry, private->size) {
+ ADD_COUNTER(iter->counters, paddc[i].bcnt, paddc[i].pcnt);
+ ++i;
+ }
+ xt_write_recseq_end(addend);
+ unlock_up_free:
+ local_bh_enable();
+ xt_table_unlock(t);
+ module_put(t->me);
+ free:
+ vfree(paddc);
+
+ return ret;
+}
+
+#ifdef CONFIG_COMPAT
+static inline void compat_release_entry(struct compat_arpt_entry *e)
+{
+ struct xt_entry_target *t;
+
+ t = compat_arpt_get_target(e);
+ module_put(t->u.kernel.target->me);
+}
+
+static inline int
+check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
+ struct xt_table_info *newinfo,
+ unsigned int *size,
+ const unsigned char *base,
+ const unsigned char *limit,
+ const unsigned int *hook_entries,
+ const unsigned int *underflows,
+ const char *name)
+{
+ struct xt_entry_target *t;
+ struct xt_target *target;
+ unsigned int entry_offset;
+ 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) {
+ duprintf("Bad offset %p, limit = %p\n", e, limit);
+ return -EINVAL;
+ }
+
+ if (e->next_offset < sizeof(struct compat_arpt_entry) +
+ sizeof(struct compat_xt_entry_target)) {
+ duprintf("checking: element %p size %u\n",
+ e, e->next_offset);
+ return -EINVAL;
+ }
+
+ /* For purposes of check_entry casting the compat entry is fine */
+ ret = check_entry((struct arpt_entry *)e, name);
+ if (ret)
+ return ret;
+
+ off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
+ entry_offset = (void *)e - (void *)base;
+
+ t = compat_arpt_get_target(e);
+ target = xt_request_find_target(NFPROTO_ARP, t->u.user.name,
+ t->u.user.revision);
+ if (IS_ERR(target)) {
+ duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
+ t->u.user.name);
+ ret = PTR_ERR(target);
+ goto out;
+ }
+ t->u.kernel.target = target;
+
+ off += xt_compat_target_offset(target);
+ *size += off;
+ ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
+ if (ret)
+ goto release_target;
+
+ /* Check hooks & underflows */
+ for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
+ if ((unsigned char *)e - base == hook_entries[h])
+ newinfo->hook_entry[h] = hook_entries[h];
+ if ((unsigned char *)e - base == underflows[h])
+ newinfo->underflow[h] = underflows[h];
+ }
+
+ /* Clear counters and comefrom */
+ memset(&e->counters, 0, sizeof(e->counters));
+ e->comefrom = 0;
+ return 0;
+
+release_target:
+ module_put(t->u.kernel.target->me);
+out:
+ return ret;
+}
+
+static int
+compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr,
+ unsigned int *size, const char *name,
+ struct xt_table_info *newinfo, unsigned char *base)
+{
+ struct xt_entry_target *t;
+ struct xt_target *target;
+ struct arpt_entry *de;
+ unsigned int origsize;
+ int ret, h;
+
+ ret = 0;
+ origsize = *size;
+ de = (struct arpt_entry *)*dstptr;
+ memcpy(de, e, sizeof(struct arpt_entry));
+ memcpy(&de->counters, &e->counters, sizeof(e->counters));
+
+ *dstptr += sizeof(struct arpt_entry);
+ *size += sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
+
+ de->target_offset = e->target_offset - (origsize - *size);
+ t = compat_arpt_get_target(e);
+ target = t->u.kernel.target;
+ xt_compat_target_from_user(t, dstptr, size);
+
+ de->next_offset = e->next_offset - (origsize - *size);
+ for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
+ if ((unsigned char *)de - base < newinfo->hook_entry[h])
+ newinfo->hook_entry[h] -= origsize - *size;
+ if ((unsigned char *)de - base < newinfo->underflow[h])
+ newinfo->underflow[h] -= origsize - *size;
+ }
+ return ret;
+}
+
+static int translate_compat_table(const char *name,
+ unsigned int valid_hooks,
+ struct xt_table_info **pinfo,
+ void **pentry0,
+ unsigned int total_size,
+ unsigned int number,
+ unsigned int *hook_entries,
+ unsigned int *underflows)
+{
+ unsigned int i, j;
+ struct xt_table_info *newinfo, *info;
+ void *pos, *entry0, *entry1;
+ struct compat_arpt_entry *iter0;
+ struct arpt_entry *iter1;
+ unsigned int size;
+ int ret = 0;
+
+ info = *pinfo;
+ entry0 = *pentry0;
+ size = total_size;
+ info->number = number;
+
+ /* Init all hooks to impossible value. */
+ for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
+ info->hook_entry[i] = 0xFFFFFFFF;
+ info->underflow[i] = 0xFFFFFFFF;
+ }
+
+ duprintf("translate_compat_table: size %u\n", info->size);
+ j = 0;
+ xt_compat_lock(NFPROTO_ARP);
+ xt_compat_init_offsets(NFPROTO_ARP, number);
+ /* Walk through entries, checking offsets. */
+ xt_entry_foreach(iter0, entry0, total_size) {
+ ret = check_compat_entry_size_and_hooks(iter0, info, &size,
+ entry0,
+ entry0 + total_size,
+ hook_entries,
+ underflows,
+ name);
+ if (ret != 0)
+ goto out_unlock;
+ ++j;
+ }
+
+ ret = -EINVAL;
+ if (j != number) {
+ duprintf("translate_compat_table: %u not %u entries\n",
+ j, number);
+ goto out_unlock;
+ }
+
+ /* Check hooks all assigned */
+ for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
+ /* Only hooks which are valid */
+ if (!(valid_hooks & (1 << i)))
+ continue;
+ if (info->hook_entry[i] == 0xFFFFFFFF) {
+ duprintf("Invalid hook entry %u %u\n",
+ i, hook_entries[i]);
+ goto out_unlock;
+ }
+ if (info->underflow[i] == 0xFFFFFFFF) {
+ duprintf("Invalid underflow %u %u\n",
+ i, underflows[i]);
+ goto out_unlock;
+ }
+ }
+
+ ret = -ENOMEM;
+ newinfo = xt_alloc_table_info(size);
+ if (!newinfo)
+ goto out_unlock;
+
+ newinfo->number = number;
+ for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
+ newinfo->hook_entry[i] = info->hook_entry[i];
+ newinfo->underflow[i] = info->underflow[i];
+ }
+ entry1 = newinfo->entries[raw_smp_processor_id()];
+ pos = entry1;
+ size = total_size;
+ xt_entry_foreach(iter0, entry0, total_size) {
+ ret = compat_copy_entry_from_user(iter0, &pos, &size,
+ name, newinfo, entry1);
+ if (ret != 0)
+ break;
+ }
+ xt_compat_flush_offsets(NFPROTO_ARP);
+ xt_compat_unlock(NFPROTO_ARP);
+ if (ret)
+ goto free_newinfo;
+
+ ret = -ELOOP;
+ if (!mark_source_chains(newinfo, valid_hooks, entry1))
+ goto free_newinfo;
+
+ i = 0;
+ xt_entry_foreach(iter1, entry1, newinfo->size) {
+ ret = check_target(iter1, name);
+ if (ret != 0)
+ break;
+ ++i;
+ if (strcmp(arpt_get_target(iter1)->u.user.name,
+ XT_ERROR_TARGET) == 0)
+ ++newinfo->stacksize;
+ }
+ if (ret) {
+ /*
+ * The first i matches need cleanup_entry (calls ->destroy)
+ * because they had called ->check already. The other j-i
+ * entries need only release.
+ */
+ int skip = i;
+ j -= i;
+ xt_entry_foreach(iter0, entry0, newinfo->size) {
+ if (skip-- > 0)
+ continue;
+ if (j-- == 0)
+ break;
+ compat_release_entry(iter0);
+ }
+ xt_entry_foreach(iter1, entry1, newinfo->size) {
+ if (i-- == 0)
+ break;
+ cleanup_entry(iter1);
+ }
+ xt_free_table_info(newinfo);
+ return ret;
+ }
+
+ /* And one copy for every other CPU */
+ for_each_possible_cpu(i)
+ if (newinfo->entries[i] && newinfo->entries[i] != entry1)
+ memcpy(newinfo->entries[i], entry1, newinfo->size);
+
+ *pinfo = newinfo;
+ *pentry0 = entry1;
+ xt_free_table_info(info);
+ return 0;
+
+free_newinfo:
+ xt_free_table_info(newinfo);
+out:
+ xt_entry_foreach(iter0, entry0, total_size) {
+ if (j-- == 0)
+ break;
+ compat_release_entry(iter0);
+ }
+ return ret;
+out_unlock:
+ xt_compat_flush_offsets(NFPROTO_ARP);
+ xt_compat_unlock(NFPROTO_ARP);
+ goto out;
+}
+
+struct compat_arpt_replace {
+ char name[XT_TABLE_MAXNAMELEN];
+ u32 valid_hooks;
+ u32 num_entries;
+ u32 size;
+ u32 hook_entry[NF_ARP_NUMHOOKS];
+ u32 underflow[NF_ARP_NUMHOOKS];
+ u32 num_counters;
+ compat_uptr_t counters;
+ struct compat_arpt_entry entries[0];
+};
+
+static int compat_do_replace(struct net *net, void __user *user,
+ unsigned int len)
+{
+ int ret;
+ struct compat_arpt_replace tmp;
+ struct xt_table_info *newinfo;
+ void *loc_cpu_entry;
+ struct arpt_entry *iter;
+
+ if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
+ return -EFAULT;
+
+ /* overflow check */
+ if (tmp.size >= INT_MAX / num_possible_cpus())
+ return -ENOMEM;
+ if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
+ return -ENOMEM;
+ if (tmp.num_counters == 0)
+ return -EINVAL;
+
+ tmp.name[sizeof(tmp.name)-1] = 0;
+
+ newinfo = xt_alloc_table_info(tmp.size);
+ if (!newinfo)
+ return -ENOMEM;
+
+ /* choose the copy that is on our node/cpu */
+ loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
+ if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), tmp.size) != 0) {
+ ret = -EFAULT;
+ goto free_newinfo;
+ }
+
+ ret = translate_compat_table(tmp.name, tmp.valid_hooks,
+ &newinfo, &loc_cpu_entry, tmp.size,
+ tmp.num_entries, tmp.hook_entry,
+ tmp.underflow);
+ if (ret != 0)
+ goto free_newinfo;
+
+ duprintf("compat_do_replace: Translated table\n");
+
+ ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
+ tmp.num_counters, compat_ptr(tmp.counters));
+ if (ret)
+ goto free_newinfo_untrans;
+ return 0;
+
+ free_newinfo_untrans:
+ xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
+ cleanup_entry(iter);
+ free_newinfo:
+ xt_free_table_info(newinfo);
+ return ret;
+}
+
+static int compat_do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user,
+ unsigned int len)
+{
+ int ret;
+
+ if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
+ return -EPERM;
+
+ switch (cmd) {
+ case ARPT_SO_SET_REPLACE:
+ ret = compat_do_replace(sock_net(sk), user, len);
+ break;
+
+ case ARPT_SO_SET_ADD_COUNTERS:
+ ret = do_add_counters(sock_net(sk), user, len, 1);
+ break;
+
+ default:
+ duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
+static int compat_copy_entry_to_user(struct arpt_entry *e, void __user **dstptr,
+ compat_uint_t *size,
+ struct xt_counters *counters,
+ unsigned int i)
+{
+ struct xt_entry_target *t;
+ struct compat_arpt_entry __user *ce;
+ u_int16_t target_offset, next_offset;
+ compat_uint_t origsize;
+ int ret;
+
+ origsize = *size;
+ ce = (struct compat_arpt_entry __user *)*dstptr;
+ if (copy_to_user(ce, e, sizeof(struct arpt_entry)) != 0 ||
+ copy_to_user(&ce->counters, &counters[i],
+ sizeof(counters[i])) != 0)
+ return -EFAULT;
+
+ *dstptr += sizeof(struct compat_arpt_entry);
+ *size -= sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
+
+ target_offset = e->target_offset - (origsize - *size);
+
+ t = arpt_get_target(e);
+ ret = xt_compat_target_to_user(t, dstptr, size);
+ if (ret)
+ return ret;
+ next_offset = e->next_offset - (origsize - *size);
+ if (put_user(target_offset, &ce->target_offset) != 0 ||
+ put_user(next_offset, &ce->next_offset) != 0)
+ return -EFAULT;
+ return 0;
+}
+
+static int compat_copy_entries_to_user(unsigned int total_size,
+ struct xt_table *table,
+ void __user *userptr)
+{
+ struct xt_counters *counters;
+ const struct xt_table_info *private = table->private;
+ void __user *pos;
+ unsigned int size;
+ int ret = 0;
+ void *loc_cpu_entry;
+ unsigned int i = 0;
+ struct arpt_entry *iter;
+
+ counters = alloc_counters(table);
+ if (IS_ERR(counters))
+ return PTR_ERR(counters);
+
+ /* choose the copy on our node/cpu */
+ loc_cpu_entry = private->entries[raw_smp_processor_id()];
+ pos = userptr;
+ size = total_size;
+ xt_entry_foreach(iter, loc_cpu_entry, total_size) {
+ ret = compat_copy_entry_to_user(iter, &pos,
+ &size, counters, i++);
+ if (ret != 0)
+ break;
+ }
+ vfree(counters);
+ return ret;
+}
+
+struct compat_arpt_get_entries {
+ char name[XT_TABLE_MAXNAMELEN];
+ compat_uint_t size;
+ struct compat_arpt_entry entrytable[0];
+};
+
+static int compat_get_entries(struct net *net,
+ struct compat_arpt_get_entries __user *uptr,
+ int *len)
+{
+ int ret;
+ struct compat_arpt_get_entries get;
+ struct xt_table *t;
+
+ if (*len < sizeof(get)) {
+ duprintf("compat_get_entries: %u < %zu\n", *len, sizeof(get));
+ return -EINVAL;
+ }
+ if (copy_from_user(&get, uptr, sizeof(get)) != 0)
+ return -EFAULT;
+ if (*len != sizeof(struct compat_arpt_get_entries) + get.size) {
+ duprintf("compat_get_entries: %u != %zu\n",
+ *len, sizeof(get) + get.size);
+ return -EINVAL;
+ }
+
+ xt_compat_lock(NFPROTO_ARP);
+ t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
+ if (!IS_ERR_OR_NULL(t)) {
+ const struct xt_table_info *private = t->private;
+ struct xt_table_info info;
+
+ duprintf("t->private->number = %u\n", private->number);
+ ret = compat_table_info(private, &info);
+ if (!ret && get.size == info.size) {
+ ret = compat_copy_entries_to_user(private->size,
+ t, uptr->entrytable);
+ } else if (!ret) {
+ duprintf("compat_get_entries: I've got %u not %u!\n",
+ private->size, get.size);
+ ret = -EAGAIN;
+ }
+ xt_compat_flush_offsets(NFPROTO_ARP);
+ module_put(t->me);
+ xt_table_unlock(t);
+ } else
+ ret = t ? PTR_ERR(t) : -ENOENT;
+
+ xt_compat_unlock(NFPROTO_ARP);
+ return ret;
+}
+
+static int do_arpt_get_ctl(struct sock *, int, void __user *, int *);
+
+static int compat_do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user,
+ int *len)
+{
+ int ret;
+
+ if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
+ return -EPERM;
+
+ switch (cmd) {
+ case ARPT_SO_GET_INFO:
+ ret = get_info(sock_net(sk), user, len, 1);
+ break;
+ case ARPT_SO_GET_ENTRIES:
+ ret = compat_get_entries(sock_net(sk), user, len);
+ break;
+ default:
+ ret = do_arpt_get_ctl(sk, cmd, user, len);
+ }
+ return ret;
+}
+#endif
+
+static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
+{
+ int ret;
+
+ if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
+ return -EPERM;
+
+ switch (cmd) {
+ case ARPT_SO_SET_REPLACE:
+ ret = do_replace(sock_net(sk), user, len);
+ break;
+
+ case ARPT_SO_SET_ADD_COUNTERS:
+ ret = do_add_counters(sock_net(sk), user, len, 0);
+ break;
+
+ default:
+ duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
+static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
+{
+ int ret;
+
+ if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
+ return -EPERM;
+
+ switch (cmd) {
+ case ARPT_SO_GET_INFO:
+ ret = get_info(sock_net(sk), user, len, 0);
+ break;
+
+ case ARPT_SO_GET_ENTRIES:
+ ret = get_entries(sock_net(sk), user, len);
+ break;
+
+ case ARPT_SO_GET_REVISION_TARGET: {
+ struct xt_get_revision rev;
+
+ if (*len != sizeof(rev)) {
+ ret = -EINVAL;
+ break;
+ }
+ if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
+ ret = -EFAULT;
+ break;
+ }
+ rev.name[sizeof(rev.name)-1] = 0;
+
+ try_then_request_module(xt_find_revision(NFPROTO_ARP, rev.name,
+ rev.revision, 1, &ret),
+ "arpt_%s", rev.name);
+ break;
+ }
+
+ default:
+ duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
+struct xt_table *arpt_register_table(struct net *net,
+ const struct xt_table *table,
+ const struct arpt_replace *repl)
+{
+ int ret;
+ struct xt_table_info *newinfo;
+ struct xt_table_info bootstrap = {0};
+ void *loc_cpu_entry;
+ struct xt_table *new_table;
+
+ newinfo = xt_alloc_table_info(repl->size);
+ if (!newinfo) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ /* choose the copy on our node/cpu */
+ loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
+ memcpy(loc_cpu_entry, repl->entries, repl->size);
+
+ ret = translate_table(newinfo, loc_cpu_entry, repl);
+ duprintf("arpt_register_table: translate table gives %d\n", ret);
+ if (ret != 0)
+ goto out_free;
+
+ new_table = xt_register_table(net, table, &bootstrap, newinfo);
+ if (IS_ERR(new_table)) {
+ ret = PTR_ERR(new_table);
+ goto out_free;
+ }
+ return new_table;
+
+out_free:
+ xt_free_table_info(newinfo);
+out:
+ return ERR_PTR(ret);
+}
+
+void arpt_unregister_table(struct xt_table *table)
+{
+ struct xt_table_info *private;
+ void *loc_cpu_entry;
+ struct module *table_owner = table->me;
+ struct arpt_entry *iter;
+
+ private = xt_unregister_table(table);
+
+ /* Decrease module usage counts and free resources */
+ loc_cpu_entry = private->entries[raw_smp_processor_id()];
+ xt_entry_foreach(iter, loc_cpu_entry, private->size)
+ cleanup_entry(iter);
+ if (private->number > private->initial_entries)
+ module_put(table_owner);
+ xt_free_table_info(private);
+}
+
+/* The built-in targets: standard (NULL) and error. */
+static struct xt_target arpt_builtin_tg[] __read_mostly = {
+ {
+ .name = XT_STANDARD_TARGET,
+ .targetsize = sizeof(int),
+ .family = NFPROTO_ARP,
+#ifdef CONFIG_COMPAT
+ .compatsize = sizeof(compat_int_t),
+ .compat_from_user = compat_standard_from_user,
+ .compat_to_user = compat_standard_to_user,
+#endif
+ },
+ {
+ .name = XT_ERROR_TARGET,
+ .target = arpt_error,
+ .targetsize = XT_FUNCTION_MAXNAMELEN,
+ .family = NFPROTO_ARP,
+ },
+};
+
+static struct nf_sockopt_ops arpt_sockopts = {
+ .pf = PF_INET,
+ .set_optmin = ARPT_BASE_CTL,
+ .set_optmax = ARPT_SO_SET_MAX+1,
+ .set = do_arpt_set_ctl,
+#ifdef CONFIG_COMPAT
+ .compat_set = compat_do_arpt_set_ctl,
+#endif
+ .get_optmin = ARPT_BASE_CTL,
+ .get_optmax = ARPT_SO_GET_MAX+1,
+ .get = do_arpt_get_ctl,
+#ifdef CONFIG_COMPAT
+ .compat_get = compat_do_arpt_get_ctl,
+#endif
+ .owner = THIS_MODULE,
+};
+
+static int __net_init arp_tables_net_init(struct net *net)
+{
+ return xt_proto_init(net, NFPROTO_ARP);
+}
+
+static void __net_exit arp_tables_net_exit(struct net *net)
+{
+ xt_proto_fini(net, NFPROTO_ARP);
+}
+
+static struct pernet_operations arp_tables_net_ops = {
+ .init = arp_tables_net_init,
+ .exit = arp_tables_net_exit,
+};
+
+static int __init arp_tables_init(void)
+{
+ int ret;
+
+ ret = register_pernet_subsys(&arp_tables_net_ops);
+ if (ret < 0)
+ goto err1;
+
+ /* No one else will be downing sem now, so we won't sleep */
+ ret = xt_register_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
+ if (ret < 0)
+ goto err2;
+
+ /* Register setsockopt */
+ ret = nf_register_sockopt(&arpt_sockopts);
+ if (ret < 0)
+ goto err4;
+
+ printk(KERN_INFO "arp_tables: (C) 2002 David S. Miller\n");
+ return 0;
+
+err4:
+ xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
+err2:
+ unregister_pernet_subsys(&arp_tables_net_ops);
+err1:
+ return ret;
+}
+
+static void __exit arp_tables_fini(void)
+{
+ nf_unregister_sockopt(&arpt_sockopts);
+ xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
+ unregister_pernet_subsys(&arp_tables_net_ops);
+}
+
+EXPORT_SYMBOL(arpt_register_table);
+EXPORT_SYMBOL(arpt_unregister_table);
+EXPORT_SYMBOL(arpt_do_table);
+
+module_init(arp_tables_init);
+module_exit(arp_tables_fini);
Code Review / kvmfornfv.git / blobdiff