| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * 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 <linux/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"); |
| |
| 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; |
| |
| if (NF_INVF(arpinfo, ARPT_INV_ARPOP, |
| (arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop)) |
| return 0; |
| |
| if (NF_INVF(arpinfo, ARPT_INV_ARPHRD, |
| (arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd)) |
| return 0; |
| |
| if (NF_INVF(arpinfo, ARPT_INV_ARPPRO, |
| (arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro)) |
| return 0; |
| |
| if (NF_INVF(arpinfo, ARPT_INV_ARPHLN, |
| (arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln)) |
| 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 (NF_INVF(arpinfo, ARPT_INV_SRCDEVADDR, |
| arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr, |
| dev->addr_len)) || |
| NF_INVF(arpinfo, ARPT_INV_TGTDEVADDR, |
| arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr, |
| dev->addr_len))) |
| return 0; |
| |
| if (NF_INVF(arpinfo, ARPT_INV_SRCIP, |
| (src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr) || |
| NF_INVF(arpinfo, ARPT_INV_TGTIP, |
| (tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr)) |
| return 0; |
| |
| /* Look for ifname matches. */ |
| ret = ifname_compare(indev, arpinfo->iniface, arpinfo->iniface_mask); |
| |
| if (NF_INVF(arpinfo, ARPT_INV_VIA_IN, ret != 0)) |
| return 0; |
| |
| ret = ifname_compare(outdev, arpinfo->outiface, arpinfo->outiface_mask); |
| |
| if (NF_INVF(arpinfo, ARPT_INV_VIA_OUT, ret != 0)) |
| return 0; |
| |
| return 1; |
| } |
| |
| static inline int arp_checkentry(const struct arpt_arp *arp) |
| { |
| if (arp->flags & ~ARPT_F_MASK) |
| return 0; |
| if (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 |
| 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, |
| const struct nf_hook_state *state, |
| struct xt_table *table) |
| { |
| unsigned int hook = state->hook; |
| static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long)))); |
| unsigned int verdict = NF_DROP; |
| const struct arphdr *arp; |
| struct arpt_entry *e, **jumpstack; |
| const char *indev, *outdev; |
| const void *table_base; |
| unsigned int cpu, stackidx = 0; |
| 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 = READ_ONCE(table->private); /* Address dependency. */ |
| cpu = smp_processor_id(); |
| table_base = private->entries; |
| jumpstack = (struct arpt_entry **)private->jumpstack[cpu]; |
| |
| /* No TEE support for arptables, so no need to switch to alternate |
| * stack. All targets that reenter must return absolute verdicts. |
| */ |
| e = get_entry(table_base, private->hook_entry[hook]); |
| |
| acpar.state = state; |
| acpar.hotdrop = false; |
| |
| arp = arp_hdr(skb); |
| do { |
| const struct xt_entry_target *t; |
| struct xt_counters *counter; |
| |
| if (!arp_packet_match(arp, skb->dev, indev, outdev, &e->arp)) { |
| e = arpt_next_entry(e); |
| continue; |
| } |
| |
| counter = xt_get_this_cpu_counter(&e->counters); |
| ADD_COUNTER(*counter, 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; |
| } |
| if (stackidx == 0) { |
| e = get_entry(table_base, |
| private->underflow[hook]); |
| } else { |
| e = jumpstack[--stackidx]; |
| e = arpt_next_entry(e); |
| } |
| continue; |
| } |
| if (table_base + v |
| != arpt_next_entry(e)) { |
| if (unlikely(stackidx >= private->stacksize)) { |
| verdict = NF_DROP; |
| break; |
| } |
| jumpstack[stackidx++] = e; |
| } |
| |
| e = get_entry(table_base, v); |
| continue; |
| } |
| |
| acpar.target = t->u.kernel.target; |
| acpar.targinfo = t->data; |
| verdict = t->u.kernel.target->target(skb, &acpar); |
| |
| if (verdict == XT_CONTINUE) { |
| /* Target might have changed stuff. */ |
| arp = arp_hdr(skb); |
| 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_entry *e) |
| { |
| static const struct arpt_arp uncond; |
| |
| return e->target_offset == sizeof(struct arpt_entry) && |
| memcmp(&e->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 *offsets) |
| { |
| 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 = 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)) |
| return 0; |
| |
| e->comefrom |
| |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS)); |
| |
| /* Unconditional return/END. */ |
| if ((unconditional(e) && |
| (strcmp(t->target.u.user.name, |
| XT_STANDARD_TARGET) == 0) && |
| t->verdict < 0) || visited) { |
| unsigned int oldpos, size; |
| |
| /* 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 = entry0 + pos; |
| } while (oldpos == pos + e->next_offset); |
| |
| /* Move along one */ |
| size = e->next_offset; |
| e = entry0 + pos + size; |
| if (pos + size >= newinfo->size) |
| return 0; |
| e->counters.pcnt = pos; |
| pos += size; |
| } else { |
| int newpos = t->verdict; |
| |
| if (strcmp(t->target.u.user.name, |
| XT_STANDARD_TARGET) == 0 && |
| newpos >= 0) { |
| /* This a jump; chase it. */ |
| if (!xt_find_jump_offset(offsets, newpos, |
| newinfo->number)) |
| return 0; |
| } else { |
| /* ... this is a fallthru */ |
| newpos = pos + e->next_offset; |
| if (newpos >= newinfo->size) |
| return 0; |
| } |
| e = entry0 + newpos; |
| e->counters.pcnt = pos; |
| pos = newpos; |
| } |
| } |
| next: ; |
| } |
| return 1; |
| } |
| |
| static int check_target(struct arpt_entry *e, struct net *net, const char *name) |
| { |
| struct xt_entry_target *t = arpt_get_target(e); |
| struct xt_tgchk_param par = { |
| .net = net, |
| .table = name, |
| .entryinfo = e, |
| .target = t->u.kernel.target, |
| .targinfo = t->data, |
| .hook_mask = e->comefrom, |
| .family = NFPROTO_ARP, |
| }; |
| |
| return xt_check_target(&par, t->u.target_size - sizeof(*t), 0, false); |
| } |
| |
| static int |
| find_check_entry(struct arpt_entry *e, struct net *net, const char *name, |
| unsigned int size, |
| struct xt_percpu_counter_alloc_state *alloc_state) |
| { |
| struct xt_entry_target *t; |
| struct xt_target *target; |
| int ret; |
| |
| if (!xt_percpu_counter_alloc(alloc_state, &e->counters)) |
| return -ENOMEM; |
| |
| t = arpt_get_target(e); |
| target = xt_request_find_target(NFPROTO_ARP, t->u.user.name, |
| t->u.user.revision); |
| if (IS_ERR(target)) { |
| ret = PTR_ERR(target); |
| goto out; |
| } |
| t->u.kernel.target = target; |
| |
| ret = check_target(e, net, name); |
| if (ret) |
| goto err; |
| return 0; |
| err: |
| module_put(t->u.kernel.target->me); |
| out: |
| xt_percpu_counter_free(&e->counters); |
| |
| return ret; |
| } |
| |
| static bool check_underflow(const struct arpt_entry *e) |
| { |
| const struct xt_entry_target *t; |
| unsigned int verdict; |
| |
| if (!unconditional(e)) |
| 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; |
| int err; |
| |
| if ((unsigned long)e % __alignof__(struct arpt_entry) != 0 || |
| (unsigned char *)e + sizeof(struct arpt_entry) >= limit || |
| (unsigned char *)e + e->next_offset > limit) |
| return -EINVAL; |
| |
| if (e->next_offset |
| < sizeof(struct arpt_entry) + sizeof(struct xt_entry_target)) |
| return -EINVAL; |
| |
| if (!arp_checkentry(&e->arp)) |
| return -EINVAL; |
| |
| err = xt_check_entry_offsets(e, e->elems, e->target_offset, |
| e->next_offset); |
| if (err) |
| return err; |
| |
| /* 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)) |
| return -EINVAL; |
| |
| newinfo->underflow[h] = underflows[h]; |
| } |
| } |
| |
| /* Clear counters and comefrom */ |
| e->counters = ((struct xt_counters) { 0, 0 }); |
| e->comefrom = 0; |
| return 0; |
| } |
| |
| static void cleanup_entry(struct arpt_entry *e, struct net *net) |
| { |
| struct xt_tgdtor_param par; |
| struct xt_entry_target *t; |
| |
| t = arpt_get_target(e); |
| par.net = net; |
| 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); |
| xt_percpu_counter_free(&e->counters); |
| } |
| |
| /* Checks and translates the user-supplied table segment (held in |
| * newinfo). |
| */ |
| static int translate_table(struct net *net, |
| struct xt_table_info *newinfo, |
| void *entry0, |
| const struct arpt_replace *repl) |
| { |
| struct xt_percpu_counter_alloc_state alloc_state = { 0 }; |
| struct arpt_entry *iter; |
| unsigned int *offsets; |
| 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; |
| } |
| |
| offsets = xt_alloc_entry_offsets(newinfo->number); |
| if (!offsets) |
| return -ENOMEM; |
| 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) |
| goto out_free; |
| if (i < repl->num_entries) |
| offsets[i] = (void *)iter - entry0; |
| ++i; |
| if (strcmp(arpt_get_target(iter)->u.user.name, |
| XT_ERROR_TARGET) == 0) |
| ++newinfo->stacksize; |
| } |
| |
| ret = -EINVAL; |
| if (i != repl->num_entries) |
| goto out_free; |
| |
| ret = xt_check_table_hooks(newinfo, repl->valid_hooks); |
| if (ret) |
| goto out_free; |
| |
| if (!mark_source_chains(newinfo, repl->valid_hooks, entry0, offsets)) { |
| ret = -ELOOP; |
| goto out_free; |
| } |
| kvfree(offsets); |
| |
| /* Finally, each sanity check must pass */ |
| i = 0; |
| xt_entry_foreach(iter, entry0, newinfo->size) { |
| ret = find_check_entry(iter, net, repl->name, repl->size, |
| &alloc_state); |
| if (ret != 0) |
| break; |
| ++i; |
| } |
| |
| if (ret != 0) { |
| xt_entry_foreach(iter, entry0, newinfo->size) { |
| if (i-- == 0) |
| break; |
| cleanup_entry(iter, net); |
| } |
| return ret; |
| } |
| |
| return ret; |
| out_free: |
| kvfree(offsets); |
| 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, t->size) { |
| struct xt_counters *tmp; |
| u64 bcnt, pcnt; |
| unsigned int start; |
| |
| tmp = xt_get_per_cpu_counter(&iter->counters, cpu); |
| do { |
| start = read_seqcount_begin(s); |
| bcnt = tmp->bcnt; |
| pcnt = tmp->pcnt; |
| } while (read_seqcount_retry(s, start)); |
| |
| ADD_COUNTER(counters[i], bcnt, pcnt); |
| ++i; |
| cond_resched(); |
| } |
| } |
| } |
| |
| static void get_old_counters(const struct xt_table_info *t, |
| struct xt_counters counters[]) |
| { |
| struct arpt_entry *iter; |
| unsigned int cpu, i; |
| |
| for_each_possible_cpu(cpu) { |
| i = 0; |
| xt_entry_foreach(iter, t->entries, t->size) { |
| struct xt_counters *tmp; |
| |
| tmp = xt_get_per_cpu_counter(&iter->counters, cpu); |
| ADD_COUNTER(counters[i], tmp->bcnt, tmp->pcnt); |
| ++i; |
| } |
| cond_resched(); |
| } |
| } |
| |
| 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; |
| |
| /* 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 = loc_cpu_entry + off; |
| if (copy_to_user(userptr + off, e, sizeof(*e))) { |
| ret = -EFAULT; |
| goto free_counters; |
| } |
| 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 (xt_target_to_user(t, userptr + off + e->target_offset)) { |
| ret = -EFAULT; |
| goto free_counters; |
| } |
| } |
| |
| free_counters: |
| vfree(counters); |
| return ret; |
| } |
| |
| #ifdef CONFIG_NETFILTER_XTABLES_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; |
| const 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; |
| ret = xt_compat_init_offsets(NFPROTO_ARP, info->number); |
| if (ret) |
| return ret; |
| 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) |
| { |
| char name[XT_TABLE_MAXNAMELEN]; |
| struct xt_table *t; |
| int ret; |
| |
| if (*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_NETFILTER_XTABLES_COMPAT |
| if (in_compat_syscall()) |
| xt_compat_lock(NFPROTO_ARP); |
| #endif |
| t = xt_request_find_table_lock(net, NFPROTO_ARP, name); |
| if (!IS_ERR(t)) { |
| struct arpt_getinfo info; |
| const struct xt_table_info *private = t->private; |
| #ifdef CONFIG_NETFILTER_XTABLES_COMPAT |
| struct xt_table_info tmp; |
| |
| if (in_compat_syscall()) { |
| 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 = PTR_ERR(t); |
| #ifdef CONFIG_NETFILTER_XTABLES_COMPAT |
| if (in_compat_syscall()) |
| 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)) |
| return -EINVAL; |
| if (copy_from_user(&get, uptr, sizeof(get)) != 0) |
| return -EFAULT; |
| if (*len != sizeof(struct arpt_get_entries) + get.size) |
| return -EINVAL; |
| |
| get.name[sizeof(get.name) - 1] = '\0'; |
| |
| t = xt_find_table_lock(net, NFPROTO_ARP, get.name); |
| if (!IS_ERR(t)) { |
| const struct xt_table_info *private = t->private; |
| |
| if (get.size == private->size) |
| ret = copy_entries_to_user(private->size, |
| t, uptr->entrytable); |
| else |
| ret = -EAGAIN; |
| |
| module_put(t->me); |
| xt_table_unlock(t); |
| } else |
| ret = PTR_ERR(t); |
| |
| 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 = xt_counters_alloc(num_counters); |
| if (!counters) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| t = xt_request_find_table_lock(net, NFPROTO_ARP, name); |
| if (IS_ERR(t)) { |
| ret = PTR_ERR(t); |
| goto free_newinfo_counters_untrans; |
| } |
| |
| /* You lied! */ |
| if (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 */ |
| 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); |
| |
| xt_table_unlock(t); |
| |
| get_old_counters(oldinfo, counters); |
| |
| /* Decrease module usage counts and free resource */ |
| loc_cpu_old_entry = oldinfo->entries; |
| xt_entry_foreach(iter, loc_cpu_old_entry, oldinfo->size) |
| cleanup_entry(iter, net); |
| |
| 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); |
| 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, sockptr_t arg, 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_sockptr(&tmp, arg, 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; |
| |
| loc_cpu_entry = newinfo->entries; |
| if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp), |
| tmp.size) != 0) { |
| ret = -EFAULT; |
| goto free_newinfo; |
| } |
| |
| ret = translate_table(net, newinfo, loc_cpu_entry, &tmp); |
| if (ret != 0) |
| goto free_newinfo; |
| |
| 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, net); |
| free_newinfo: |
| xt_free_table_info(newinfo); |
| return ret; |
| } |
| |
| static int do_add_counters(struct net *net, sockptr_t arg, unsigned int len) |
| { |
| unsigned int i; |
| struct xt_counters_info tmp; |
| struct xt_counters *paddc; |
| struct xt_table *t; |
| const struct xt_table_info *private; |
| int ret = 0; |
| struct arpt_entry *iter; |
| unsigned int addend; |
| |
| paddc = xt_copy_counters(arg, len, &tmp); |
| if (IS_ERR(paddc)) |
| return PTR_ERR(paddc); |
| |
| t = xt_find_table_lock(net, NFPROTO_ARP, tmp.name); |
| if (IS_ERR(t)) { |
| ret = PTR_ERR(t); |
| goto free; |
| } |
| |
| local_bh_disable(); |
| private = t->private; |
| if (private->number != tmp.num_counters) { |
| ret = -EINVAL; |
| goto unlock_up_free; |
| } |
| |
| i = 0; |
| |
| addend = xt_write_recseq_begin(); |
| xt_entry_foreach(iter, private->entries, private->size) { |
| struct xt_counters *tmp; |
| |
| tmp = xt_get_this_cpu_counter(&iter->counters); |
| ADD_COUNTER(*tmp, 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_NETFILTER_XTABLES_COMPAT |
| 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[]; |
| }; |
| |
| 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 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) |
| { |
| struct xt_entry_target *t; |
| struct xt_target *target; |
| unsigned int entry_offset; |
| int ret, off; |
| |
| if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0 || |
| (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit || |
| (unsigned char *)e + e->next_offset > limit) |
| return -EINVAL; |
| |
| if (e->next_offset < sizeof(struct compat_arpt_entry) + |
| sizeof(struct compat_xt_entry_target)) |
| return -EINVAL; |
| |
| if (!arp_checkentry(&e->arp)) |
| return -EINVAL; |
| |
| ret = xt_compat_check_entry_offsets(e, e->elems, e->target_offset, |
| e->next_offset); |
| 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)) { |
| 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; |
| |
| return 0; |
| |
| release_target: |
| module_put(t->u.kernel.target->me); |
| out: |
| return ret; |
| } |
| |
| static void |
| compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr, |
| unsigned int *size, |
| struct xt_table_info *newinfo, unsigned char *base) |
| { |
| struct xt_entry_target *t; |
| struct arpt_entry *de; |
| unsigned int origsize; |
| int h; |
| |
| origsize = *size; |
| de = *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); |
| 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; |
| } |
| } |
| |
| static int translate_compat_table(struct net *net, |
| struct xt_table_info **pinfo, |
| void **pentry0, |
| const struct compat_arpt_replace *compatr) |
| { |
| unsigned int i, j; |
| struct xt_table_info *newinfo, *info; |
| void *pos, *entry0, *entry1; |
| struct compat_arpt_entry *iter0; |
| struct arpt_replace repl; |
| unsigned int size; |
| int ret; |
| |
| info = *pinfo; |
| entry0 = *pentry0; |
| size = compatr->size; |
| info->number = compatr->num_entries; |
| |
| j = 0; |
| xt_compat_lock(NFPROTO_ARP); |
| ret = xt_compat_init_offsets(NFPROTO_ARP, compatr->num_entries); |
| if (ret) |
| goto out_unlock; |
| /* Walk through entries, checking offsets. */ |
| xt_entry_foreach(iter0, entry0, compatr->size) { |
| ret = check_compat_entry_size_and_hooks(iter0, info, &size, |
| entry0, |
| entry0 + compatr->size); |
| if (ret != 0) |
| goto out_unlock; |
| ++j; |
| } |
| |
| ret = -EINVAL; |
| if (j != compatr->num_entries) |
| goto out_unlock; |
| |
| ret = -ENOMEM; |
| newinfo = xt_alloc_table_info(size); |
| if (!newinfo) |
| goto out_unlock; |
| |
| memset(newinfo->entries, 0, size); |
| |
| newinfo->number = compatr->num_entries; |
| for (i = 0; i < NF_ARP_NUMHOOKS; i++) { |
| newinfo->hook_entry[i] = compatr->hook_entry[i]; |
| newinfo->underflow[i] = compatr->underflow[i]; |
| } |
| entry1 = newinfo->entries; |
| pos = entry1; |
| size = compatr->size; |
| xt_entry_foreach(iter0, entry0, compatr->size) |
| compat_copy_entry_from_user(iter0, &pos, &size, |
| newinfo, entry1); |
| |
| /* all module references in entry0 are now gone */ |
| |
| xt_compat_flush_offsets(NFPROTO_ARP); |
| xt_compat_unlock(NFPROTO_ARP); |
| |
| memcpy(&repl, compatr, sizeof(*compatr)); |
| |
| for (i = 0; i < NF_ARP_NUMHOOKS; i++) { |
| repl.hook_entry[i] = newinfo->hook_entry[i]; |
| repl.underflow[i] = newinfo->underflow[i]; |
| } |
| |
| repl.num_counters = 0; |
| repl.counters = NULL; |
| repl.size = newinfo->size; |
| ret = translate_table(net, newinfo, entry1, &repl); |
| if (ret) |
| goto free_newinfo; |
| |
| *pinfo = newinfo; |
| *pentry0 = entry1; |
| xt_free_table_info(info); |
| return 0; |
| |
| free_newinfo: |
| xt_free_table_info(newinfo); |
| return ret; |
| out_unlock: |
| xt_compat_flush_offsets(NFPROTO_ARP); |
| xt_compat_unlock(NFPROTO_ARP); |
| xt_entry_foreach(iter0, entry0, compatr->size) { |
| if (j-- == 0) |
| break; |
| compat_release_entry(iter0); |
| } |
| return ret; |
| } |
| |
| static int compat_do_replace(struct net *net, sockptr_t arg, 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_sockptr(&tmp, arg, 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; |
| |
| loc_cpu_entry = newinfo->entries; |
| if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp), |
| tmp.size) != 0) { |
| ret = -EFAULT; |
| goto free_newinfo; |
| } |
| |
| ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp); |
| if (ret != 0) |
| goto free_newinfo; |
| |
| 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, net); |
| free_newinfo: |
| xt_free_table_info(newinfo); |
| 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 = *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; |
| unsigned int i = 0; |
| struct arpt_entry *iter; |
| |
| counters = alloc_counters(table); |
| if (IS_ERR(counters)) |
| return PTR_ERR(counters); |
| |
| pos = userptr; |
| size = total_size; |
| xt_entry_foreach(iter, private->entries, 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[]; |
| }; |
| |
| 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)) |
| return -EINVAL; |
| if (copy_from_user(&get, uptr, sizeof(get)) != 0) |
| return -EFAULT; |
| if (*len != sizeof(struct compat_arpt_get_entries) + get.size) |
| return -EINVAL; |
| |
| get.name[sizeof(get.name) - 1] = '\0'; |
| |
| xt_compat_lock(NFPROTO_ARP); |
| t = xt_find_table_lock(net, NFPROTO_ARP, get.name); |
| if (!IS_ERR(t)) { |
| const struct xt_table_info *private = t->private; |
| struct xt_table_info info; |
| |
| 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) |
| ret = -EAGAIN; |
| |
| xt_compat_flush_offsets(NFPROTO_ARP); |
| module_put(t->me); |
| xt_table_unlock(t); |
| } else |
| ret = PTR_ERR(t); |
| |
| xt_compat_unlock(NFPROTO_ARP); |
| return ret; |
| } |
| #endif |
| |
| static int do_arpt_set_ctl(struct sock *sk, int cmd, sockptr_t arg, |
| 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: |
| #ifdef CONFIG_NETFILTER_XTABLES_COMPAT |
| if (in_compat_syscall()) |
| ret = compat_do_replace(sock_net(sk), arg, len); |
| else |
| #endif |
| ret = do_replace(sock_net(sk), arg, len); |
| break; |
| |
| case ARPT_SO_SET_ADD_COUNTERS: |
| ret = do_add_counters(sock_net(sk), arg, len); |
| break; |
| |
| default: |
| 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); |
| break; |
| |
| case ARPT_SO_GET_ENTRIES: |
| #ifdef CONFIG_NETFILTER_XTABLES_COMPAT |
| if (in_compat_syscall()) |
| ret = compat_get_entries(sock_net(sk), user, len); |
| else |
| #endif |
| 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: |
| ret = -EINVAL; |
| } |
| |
| return ret; |
| } |
| |
| static void __arpt_unregister_table(struct net *net, 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; |
| xt_entry_foreach(iter, loc_cpu_entry, private->size) |
| cleanup_entry(iter, net); |
| if (private->number > private->initial_entries) |
| module_put(table_owner); |
| xt_free_table_info(private); |
| } |
| |
| int arpt_register_table(struct net *net, |
| const struct xt_table *table, |
| const struct arpt_replace *repl, |
| const struct nf_hook_ops *template_ops) |
| { |
| struct nf_hook_ops *ops; |
| unsigned int num_ops; |
| int ret, i; |
| 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) |
| return -ENOMEM; |
| |
| loc_cpu_entry = newinfo->entries; |
| memcpy(loc_cpu_entry, repl->entries, repl->size); |
| |
| ret = translate_table(net, newinfo, loc_cpu_entry, repl); |
| if (ret != 0) { |
| xt_free_table_info(newinfo); |
| return ret; |
| } |
| |
| new_table = xt_register_table(net, table, &bootstrap, newinfo); |
| if (IS_ERR(new_table)) { |
| xt_free_table_info(newinfo); |
| return PTR_ERR(new_table); |
| } |
| |
| num_ops = hweight32(table->valid_hooks); |
| if (num_ops == 0) { |
| ret = -EINVAL; |
| goto out_free; |
| } |
| |
| ops = kmemdup(template_ops, sizeof(*ops) * num_ops, GFP_KERNEL); |
| if (!ops) { |
| ret = -ENOMEM; |
| goto out_free; |
| } |
| |
| for (i = 0; i < num_ops; i++) |
| ops[i].priv = new_table; |
| |
| new_table->ops = ops; |
| |
| ret = nf_register_net_hooks(net, ops, num_ops); |
| if (ret != 0) |
| goto out_free; |
| |
| return ret; |
| |
| out_free: |
| __arpt_unregister_table(net, new_table); |
| return ret; |
| } |
| |
| void arpt_unregister_table_pre_exit(struct net *net, const char *name) |
| { |
| struct xt_table *table = xt_find_table(net, NFPROTO_ARP, name); |
| |
| if (table) |
| nf_unregister_net_hooks(net, table->ops, hweight32(table->valid_hooks)); |
| } |
| EXPORT_SYMBOL(arpt_unregister_table_pre_exit); |
| |
| void arpt_unregister_table(struct net *net, const char *name) |
| { |
| struct xt_table *table = xt_find_table(net, NFPROTO_ARP, name); |
| |
| if (table) |
| __arpt_unregister_table(net, table); |
| } |
| |
| /* 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_NETFILTER_XTABLES_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, |
| .get_optmin = ARPT_BASE_CTL, |
| .get_optmax = ARPT_SO_GET_MAX+1, |
| .get = do_arpt_get_ctl, |
| .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; |
| |
| 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); |