| /* |
| * ebtables |
| * |
| * Author: |
| * Bart De Schuymer <bdschuym@pandora.be> |
| * |
| * ebtables.c,v 2.0, July, 2002 |
| * |
| * This code is strongly inspired by the iptables code which is |
| * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| #include <linux/kmod.h> |
| #include <linux/module.h> |
| #include <linux/vmalloc.h> |
| #include <linux/netfilter/x_tables.h> |
| #include <linux/netfilter_bridge/ebtables.h> |
| #include <linux/spinlock.h> |
| #include <linux/mutex.h> |
| #include <linux/slab.h> |
| #include <asm/uaccess.h> |
| #include <linux/smp.h> |
| #include <linux/cpumask.h> |
| #include <linux/audit.h> |
| #include <net/sock.h> |
| /* needed for logical [in,out]-dev filtering */ |
| #include "../br_private.h" |
| |
| #define BUGPRINT(format, args...) printk("kernel msg: ebtables bug: please "\ |
| "report to author: "format, ## args) |
| /* #define BUGPRINT(format, args...) */ |
| |
| /* |
| * Each cpu has its own set of counters, so there is no need for write_lock in |
| * the softirq |
| * For reading or updating the counters, the user context needs to |
| * get a write_lock |
| */ |
| |
| /* The size of each set of counters is altered to get cache alignment */ |
| #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1)) |
| #define COUNTER_OFFSET(n) (SMP_ALIGN(n * sizeof(struct ebt_counter))) |
| #define COUNTER_BASE(c, n, cpu) ((struct ebt_counter *)(((char *)c) + \ |
| COUNTER_OFFSET(n) * cpu)) |
| |
| |
| |
| static DEFINE_MUTEX(ebt_mutex); |
| |
| #ifdef CONFIG_COMPAT |
| static void ebt_standard_compat_from_user(void *dst, const void *src) |
| { |
| int v = *(compat_int_t *)src; |
| |
| if (v >= 0) |
| v += xt_compat_calc_jump(NFPROTO_BRIDGE, v); |
| memcpy(dst, &v, sizeof(v)); |
| } |
| |
| static int ebt_standard_compat_to_user(void __user *dst, const void *src) |
| { |
| compat_int_t cv = *(int *)src; |
| |
| if (cv >= 0) |
| cv -= xt_compat_calc_jump(NFPROTO_BRIDGE, cv); |
| return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0; |
| } |
| #endif |
| |
| |
| static struct xt_target ebt_standard_target = { |
| .name = "standard", |
| .revision = 0, |
| .family = NFPROTO_BRIDGE, |
| .targetsize = sizeof(int), |
| #ifdef CONFIG_COMPAT |
| .compatsize = sizeof(compat_int_t), |
| .compat_from_user = ebt_standard_compat_from_user, |
| .compat_to_user = ebt_standard_compat_to_user, |
| #endif |
| }; |
| |
| static inline int |
| ebt_do_watcher(const struct ebt_entry_watcher *w, struct sk_buff *skb, |
| struct xt_action_param *par) |
| { |
| par->target = w->u.watcher; |
| par->targinfo = w->data; |
| w->u.watcher->target(skb, par); |
| /* watchers don't give a verdict */ |
| return 0; |
| } |
| |
| static inline int |
| ebt_do_match(struct ebt_entry_match *m, const struct sk_buff *skb, |
| struct xt_action_param *par) |
| { |
| par->match = m->u.match; |
| par->matchinfo = m->data; |
| return m->u.match->match(skb, par) ? EBT_MATCH : EBT_NOMATCH; |
| } |
| |
| static inline int |
| ebt_dev_check(const char *entry, const struct net_device *device) |
| { |
| int i = 0; |
| const char *devname; |
| |
| if (*entry == '\0') |
| return 0; |
| if (!device) |
| return 1; |
| devname = device->name; |
| /* 1 is the wildcard token */ |
| while (entry[i] != '\0' && entry[i] != 1 && entry[i] == devname[i]) |
| i++; |
| return devname[i] != entry[i] && entry[i] != 1; |
| } |
| |
| #define FWINV2(bool, invflg) ((bool) ^ !!(e->invflags & invflg)) |
| /* process standard matches */ |
| static inline int |
| ebt_basic_match(const struct ebt_entry *e, const struct sk_buff *skb, |
| const struct net_device *in, const struct net_device *out) |
| { |
| const struct ethhdr *h = eth_hdr(skb); |
| const struct net_bridge_port *p; |
| __be16 ethproto; |
| int verdict, i; |
| |
| if (skb_vlan_tag_present(skb)) |
| ethproto = htons(ETH_P_8021Q); |
| else |
| ethproto = h->h_proto; |
| |
| if (e->bitmask & EBT_802_3) { |
| if (FWINV2(eth_proto_is_802_3(ethproto), EBT_IPROTO)) |
| return 1; |
| } else if (!(e->bitmask & EBT_NOPROTO) && |
| FWINV2(e->ethproto != ethproto, EBT_IPROTO)) |
| return 1; |
| |
| if (FWINV2(ebt_dev_check(e->in, in), EBT_IIN)) |
| return 1; |
| if (FWINV2(ebt_dev_check(e->out, out), EBT_IOUT)) |
| return 1; |
| /* rcu_read_lock()ed by nf_hook_slow */ |
| if (in && (p = br_port_get_rcu(in)) != NULL && |
| FWINV2(ebt_dev_check(e->logical_in, p->br->dev), EBT_ILOGICALIN)) |
| return 1; |
| if (out && (p = br_port_get_rcu(out)) != NULL && |
| FWINV2(ebt_dev_check(e->logical_out, p->br->dev), EBT_ILOGICALOUT)) |
| return 1; |
| |
| if (e->bitmask & EBT_SOURCEMAC) { |
| verdict = 0; |
| for (i = 0; i < 6; i++) |
| verdict |= (h->h_source[i] ^ e->sourcemac[i]) & |
| e->sourcemsk[i]; |
| if (FWINV2(verdict != 0, EBT_ISOURCE) ) |
| return 1; |
| } |
| if (e->bitmask & EBT_DESTMAC) { |
| verdict = 0; |
| for (i = 0; i < 6; i++) |
| verdict |= (h->h_dest[i] ^ e->destmac[i]) & |
| e->destmsk[i]; |
| if (FWINV2(verdict != 0, EBT_IDEST) ) |
| return 1; |
| } |
| return 0; |
| } |
| |
| static inline |
| struct ebt_entry *ebt_next_entry(const struct ebt_entry *entry) |
| { |
| return (void *)entry + entry->next_offset; |
| } |
| |
| /* Do some firewalling */ |
| unsigned int ebt_do_table(struct sk_buff *skb, |
| const struct nf_hook_state *state, |
| struct ebt_table *table) |
| { |
| unsigned int hook = state->hook; |
| int i, nentries; |
| struct ebt_entry *point; |
| struct ebt_counter *counter_base, *cb_base; |
| const struct ebt_entry_target *t; |
| int verdict, sp = 0; |
| struct ebt_chainstack *cs; |
| struct ebt_entries *chaininfo; |
| const char *base; |
| const struct ebt_table_info *private; |
| struct xt_action_param acpar; |
| |
| acpar.family = NFPROTO_BRIDGE; |
| acpar.net = state->net; |
| acpar.in = state->in; |
| acpar.out = state->out; |
| acpar.hotdrop = false; |
| acpar.hooknum = hook; |
| |
| read_lock_bh(&table->lock); |
| private = table->private; |
| cb_base = COUNTER_BASE(private->counters, private->nentries, |
| smp_processor_id()); |
| if (private->chainstack) |
| cs = private->chainstack[smp_processor_id()]; |
| else |
| cs = NULL; |
| chaininfo = private->hook_entry[hook]; |
| nentries = private->hook_entry[hook]->nentries; |
| point = (struct ebt_entry *)(private->hook_entry[hook]->data); |
| counter_base = cb_base + private->hook_entry[hook]->counter_offset; |
| /* base for chain jumps */ |
| base = private->entries; |
| i = 0; |
| while (i < nentries) { |
| if (ebt_basic_match(point, skb, state->in, state->out)) |
| goto letscontinue; |
| |
| if (EBT_MATCH_ITERATE(point, ebt_do_match, skb, &acpar) != 0) |
| goto letscontinue; |
| if (acpar.hotdrop) { |
| read_unlock_bh(&table->lock); |
| return NF_DROP; |
| } |
| |
| /* increase counter */ |
| (*(counter_base + i)).pcnt++; |
| (*(counter_base + i)).bcnt += skb->len; |
| |
| /* these should only watch: not modify, nor tell us |
| what to do with the packet */ |
| EBT_WATCHER_ITERATE(point, ebt_do_watcher, skb, &acpar); |
| |
| t = (struct ebt_entry_target *) |
| (((char *)point) + point->target_offset); |
| /* standard target */ |
| if (!t->u.target->target) |
| verdict = ((struct ebt_standard_target *)t)->verdict; |
| else { |
| acpar.target = t->u.target; |
| acpar.targinfo = t->data; |
| verdict = t->u.target->target(skb, &acpar); |
| } |
| if (verdict == EBT_ACCEPT) { |
| read_unlock_bh(&table->lock); |
| return NF_ACCEPT; |
| } |
| if (verdict == EBT_DROP) { |
| read_unlock_bh(&table->lock); |
| return NF_DROP; |
| } |
| if (verdict == EBT_RETURN) { |
| letsreturn: |
| #ifdef CONFIG_NETFILTER_DEBUG |
| if (sp == 0) { |
| BUGPRINT("RETURN on base chain"); |
| /* act like this is EBT_CONTINUE */ |
| goto letscontinue; |
| } |
| #endif |
| sp--; |
| /* put all the local variables right */ |
| i = cs[sp].n; |
| chaininfo = cs[sp].chaininfo; |
| nentries = chaininfo->nentries; |
| point = cs[sp].e; |
| counter_base = cb_base + |
| chaininfo->counter_offset; |
| continue; |
| } |
| if (verdict == EBT_CONTINUE) |
| goto letscontinue; |
| #ifdef CONFIG_NETFILTER_DEBUG |
| if (verdict < 0) { |
| BUGPRINT("bogus standard verdict\n"); |
| read_unlock_bh(&table->lock); |
| return NF_DROP; |
| } |
| #endif |
| /* jump to a udc */ |
| cs[sp].n = i + 1; |
| cs[sp].chaininfo = chaininfo; |
| cs[sp].e = ebt_next_entry(point); |
| i = 0; |
| chaininfo = (struct ebt_entries *) (base + verdict); |
| #ifdef CONFIG_NETFILTER_DEBUG |
| if (chaininfo->distinguisher) { |
| BUGPRINT("jump to non-chain\n"); |
| read_unlock_bh(&table->lock); |
| return NF_DROP; |
| } |
| #endif |
| nentries = chaininfo->nentries; |
| point = (struct ebt_entry *)chaininfo->data; |
| counter_base = cb_base + chaininfo->counter_offset; |
| sp++; |
| continue; |
| letscontinue: |
| point = ebt_next_entry(point); |
| i++; |
| } |
| |
| /* I actually like this :) */ |
| if (chaininfo->policy == EBT_RETURN) |
| goto letsreturn; |
| if (chaininfo->policy == EBT_ACCEPT) { |
| read_unlock_bh(&table->lock); |
| return NF_ACCEPT; |
| } |
| read_unlock_bh(&table->lock); |
| return NF_DROP; |
| } |
| |
| /* If it succeeds, returns element and locks mutex */ |
| static inline void * |
| find_inlist_lock_noload(struct list_head *head, const char *name, int *error, |
| struct mutex *mutex) |
| { |
| struct { |
| struct list_head list; |
| char name[EBT_FUNCTION_MAXNAMELEN]; |
| } *e; |
| |
| mutex_lock(mutex); |
| list_for_each_entry(e, head, list) { |
| if (strcmp(e->name, name) == 0) |
| return e; |
| } |
| *error = -ENOENT; |
| mutex_unlock(mutex); |
| return NULL; |
| } |
| |
| static void * |
| find_inlist_lock(struct list_head *head, const char *name, const char *prefix, |
| int *error, struct mutex *mutex) |
| { |
| return try_then_request_module( |
| find_inlist_lock_noload(head, name, error, mutex), |
| "%s%s", prefix, name); |
| } |
| |
| static inline struct ebt_table * |
| find_table_lock(struct net *net, const char *name, int *error, |
| struct mutex *mutex) |
| { |
| return find_inlist_lock(&net->xt.tables[NFPROTO_BRIDGE], name, |
| "ebtable_", error, mutex); |
| } |
| |
| static inline int |
| ebt_check_match(struct ebt_entry_match *m, struct xt_mtchk_param *par, |
| unsigned int *cnt) |
| { |
| const struct ebt_entry *e = par->entryinfo; |
| struct xt_match *match; |
| size_t left = ((char *)e + e->watchers_offset) - (char *)m; |
| int ret; |
| |
| if (left < sizeof(struct ebt_entry_match) || |
| left - sizeof(struct ebt_entry_match) < m->match_size) |
| return -EINVAL; |
| |
| match = xt_request_find_match(NFPROTO_BRIDGE, m->u.name, 0); |
| if (IS_ERR(match)) |
| return PTR_ERR(match); |
| m->u.match = match; |
| |
| par->match = match; |
| par->matchinfo = m->data; |
| ret = xt_check_match(par, m->match_size, |
| e->ethproto, e->invflags & EBT_IPROTO); |
| if (ret < 0) { |
| module_put(match->me); |
| return ret; |
| } |
| |
| (*cnt)++; |
| return 0; |
| } |
| |
| static inline int |
| ebt_check_watcher(struct ebt_entry_watcher *w, struct xt_tgchk_param *par, |
| unsigned int *cnt) |
| { |
| const struct ebt_entry *e = par->entryinfo; |
| struct xt_target *watcher; |
| size_t left = ((char *)e + e->target_offset) - (char *)w; |
| int ret; |
| |
| if (left < sizeof(struct ebt_entry_watcher) || |
| left - sizeof(struct ebt_entry_watcher) < w->watcher_size) |
| return -EINVAL; |
| |
| watcher = xt_request_find_target(NFPROTO_BRIDGE, w->u.name, 0); |
| if (IS_ERR(watcher)) |
| return PTR_ERR(watcher); |
| w->u.watcher = watcher; |
| |
| par->target = watcher; |
| par->targinfo = w->data; |
| ret = xt_check_target(par, w->watcher_size, |
| e->ethproto, e->invflags & EBT_IPROTO); |
| if (ret < 0) { |
| module_put(watcher->me); |
| return ret; |
| } |
| |
| (*cnt)++; |
| return 0; |
| } |
| |
| static int ebt_verify_pointers(const struct ebt_replace *repl, |
| struct ebt_table_info *newinfo) |
| { |
| unsigned int limit = repl->entries_size; |
| unsigned int valid_hooks = repl->valid_hooks; |
| unsigned int offset = 0; |
| int i; |
| |
| for (i = 0; i < NF_BR_NUMHOOKS; i++) |
| newinfo->hook_entry[i] = NULL; |
| |
| newinfo->entries_size = repl->entries_size; |
| newinfo->nentries = repl->nentries; |
| |
| while (offset < limit) { |
| size_t left = limit - offset; |
| struct ebt_entry *e = (void *)newinfo->entries + offset; |
| |
| if (left < sizeof(unsigned int)) |
| break; |
| |
| for (i = 0; i < NF_BR_NUMHOOKS; i++) { |
| if ((valid_hooks & (1 << i)) == 0) |
| continue; |
| if ((char __user *)repl->hook_entry[i] == |
| repl->entries + offset) |
| break; |
| } |
| |
| if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) { |
| if (e->bitmask != 0) { |
| /* we make userspace set this right, |
| so there is no misunderstanding */ |
| BUGPRINT("EBT_ENTRY_OR_ENTRIES shouldn't be set " |
| "in distinguisher\n"); |
| return -EINVAL; |
| } |
| if (i != NF_BR_NUMHOOKS) |
| newinfo->hook_entry[i] = (struct ebt_entries *)e; |
| if (left < sizeof(struct ebt_entries)) |
| break; |
| offset += sizeof(struct ebt_entries); |
| } else { |
| if (left < sizeof(struct ebt_entry)) |
| break; |
| if (left < e->next_offset) |
| break; |
| if (e->next_offset < sizeof(struct ebt_entry)) |
| return -EINVAL; |
| offset += e->next_offset; |
| } |
| } |
| if (offset != limit) { |
| BUGPRINT("entries_size too small\n"); |
| return -EINVAL; |
| } |
| |
| /* check if all valid hooks have a chain */ |
| for (i = 0; i < NF_BR_NUMHOOKS; i++) { |
| if (!newinfo->hook_entry[i] && |
| (valid_hooks & (1 << i))) { |
| BUGPRINT("Valid hook without chain\n"); |
| return -EINVAL; |
| } |
| } |
| return 0; |
| } |
| |
| /* |
| * this one is very careful, as it is the first function |
| * to parse the userspace data |
| */ |
| static inline int |
| ebt_check_entry_size_and_hooks(const struct ebt_entry *e, |
| const struct ebt_table_info *newinfo, |
| unsigned int *n, unsigned int *cnt, |
| unsigned int *totalcnt, unsigned int *udc_cnt) |
| { |
| int i; |
| |
| for (i = 0; i < NF_BR_NUMHOOKS; i++) { |
| if ((void *)e == (void *)newinfo->hook_entry[i]) |
| break; |
| } |
| /* beginning of a new chain |
| if i == NF_BR_NUMHOOKS it must be a user defined chain */ |
| if (i != NF_BR_NUMHOOKS || !e->bitmask) { |
| /* this checks if the previous chain has as many entries |
| as it said it has */ |
| if (*n != *cnt) { |
| BUGPRINT("nentries does not equal the nr of entries " |
| "in the chain\n"); |
| return -EINVAL; |
| } |
| if (((struct ebt_entries *)e)->policy != EBT_DROP && |
| ((struct ebt_entries *)e)->policy != EBT_ACCEPT) { |
| /* only RETURN from udc */ |
| if (i != NF_BR_NUMHOOKS || |
| ((struct ebt_entries *)e)->policy != EBT_RETURN) { |
| BUGPRINT("bad policy\n"); |
| return -EINVAL; |
| } |
| } |
| if (i == NF_BR_NUMHOOKS) /* it's a user defined chain */ |
| (*udc_cnt)++; |
| if (((struct ebt_entries *)e)->counter_offset != *totalcnt) { |
| BUGPRINT("counter_offset != totalcnt"); |
| return -EINVAL; |
| } |
| *n = ((struct ebt_entries *)e)->nentries; |
| *cnt = 0; |
| return 0; |
| } |
| /* a plain old entry, heh */ |
| if (sizeof(struct ebt_entry) > e->watchers_offset || |
| e->watchers_offset > e->target_offset || |
| e->target_offset >= e->next_offset) { |
| BUGPRINT("entry offsets not in right order\n"); |
| return -EINVAL; |
| } |
| /* this is not checked anywhere else */ |
| if (e->next_offset - e->target_offset < sizeof(struct ebt_entry_target)) { |
| BUGPRINT("target size too small\n"); |
| return -EINVAL; |
| } |
| (*cnt)++; |
| (*totalcnt)++; |
| return 0; |
| } |
| |
| struct ebt_cl_stack |
| { |
| struct ebt_chainstack cs; |
| int from; |
| unsigned int hookmask; |
| }; |
| |
| /* |
| * we need these positions to check that the jumps to a different part of the |
| * entries is a jump to the beginning of a new chain. |
| */ |
| static inline int |
| ebt_get_udc_positions(struct ebt_entry *e, struct ebt_table_info *newinfo, |
| unsigned int *n, struct ebt_cl_stack *udc) |
| { |
| int i; |
| |
| /* we're only interested in chain starts */ |
| if (e->bitmask) |
| return 0; |
| for (i = 0; i < NF_BR_NUMHOOKS; i++) { |
| if (newinfo->hook_entry[i] == (struct ebt_entries *)e) |
| break; |
| } |
| /* only care about udc */ |
| if (i != NF_BR_NUMHOOKS) |
| return 0; |
| |
| udc[*n].cs.chaininfo = (struct ebt_entries *)e; |
| /* these initialisations are depended on later in check_chainloops() */ |
| udc[*n].cs.n = 0; |
| udc[*n].hookmask = 0; |
| |
| (*n)++; |
| return 0; |
| } |
| |
| static inline int |
| ebt_cleanup_match(struct ebt_entry_match *m, struct net *net, unsigned int *i) |
| { |
| struct xt_mtdtor_param par; |
| |
| if (i && (*i)-- == 0) |
| return 1; |
| |
| par.net = net; |
| par.match = m->u.match; |
| par.matchinfo = m->data; |
| par.family = NFPROTO_BRIDGE; |
| if (par.match->destroy != NULL) |
| par.match->destroy(&par); |
| module_put(par.match->me); |
| return 0; |
| } |
| |
| static inline int |
| ebt_cleanup_watcher(struct ebt_entry_watcher *w, struct net *net, unsigned int *i) |
| { |
| struct xt_tgdtor_param par; |
| |
| if (i && (*i)-- == 0) |
| return 1; |
| |
| par.net = net; |
| par.target = w->u.watcher; |
| par.targinfo = w->data; |
| par.family = NFPROTO_BRIDGE; |
| if (par.target->destroy != NULL) |
| par.target->destroy(&par); |
| module_put(par.target->me); |
| return 0; |
| } |
| |
| static inline int |
| ebt_cleanup_entry(struct ebt_entry *e, struct net *net, unsigned int *cnt) |
| { |
| struct xt_tgdtor_param par; |
| struct ebt_entry_target *t; |
| |
| if (e->bitmask == 0) |
| return 0; |
| /* we're done */ |
| if (cnt && (*cnt)-- == 0) |
| return 1; |
| EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, NULL); |
| EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, NULL); |
| t = (struct ebt_entry_target *)(((char *)e) + e->target_offset); |
| |
| par.net = net; |
| par.target = t->u.target; |
| par.targinfo = t->data; |
| par.family = NFPROTO_BRIDGE; |
| if (par.target->destroy != NULL) |
| par.target->destroy(&par); |
| module_put(par.target->me); |
| return 0; |
| } |
| |
| static inline int |
| ebt_check_entry(struct ebt_entry *e, struct net *net, |
| const struct ebt_table_info *newinfo, |
| const char *name, unsigned int *cnt, |
| struct ebt_cl_stack *cl_s, unsigned int udc_cnt) |
| { |
| struct ebt_entry_target *t; |
| struct xt_target *target; |
| unsigned int i, j, hook = 0, hookmask = 0; |
| size_t gap; |
| int ret; |
| struct xt_mtchk_param mtpar; |
| struct xt_tgchk_param tgpar; |
| |
| /* don't mess with the struct ebt_entries */ |
| if (e->bitmask == 0) |
| return 0; |
| |
| if (e->bitmask & ~EBT_F_MASK) { |
| BUGPRINT("Unknown flag for bitmask\n"); |
| return -EINVAL; |
| } |
| if (e->invflags & ~EBT_INV_MASK) { |
| BUGPRINT("Unknown flag for inv bitmask\n"); |
| return -EINVAL; |
| } |
| if ( (e->bitmask & EBT_NOPROTO) && (e->bitmask & EBT_802_3) ) { |
| BUGPRINT("NOPROTO & 802_3 not allowed\n"); |
| return -EINVAL; |
| } |
| /* what hook do we belong to? */ |
| for (i = 0; i < NF_BR_NUMHOOKS; i++) { |
| if (!newinfo->hook_entry[i]) |
| continue; |
| if ((char *)newinfo->hook_entry[i] < (char *)e) |
| hook = i; |
| else |
| break; |
| } |
| /* (1 << NF_BR_NUMHOOKS) tells the check functions the rule is on |
| a base chain */ |
| if (i < NF_BR_NUMHOOKS) |
| hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS); |
| else { |
| for (i = 0; i < udc_cnt; i++) |
| if ((char *)(cl_s[i].cs.chaininfo) > (char *)e) |
| break; |
| if (i == 0) |
| hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS); |
| else |
| hookmask = cl_s[i - 1].hookmask; |
| } |
| i = 0; |
| |
| mtpar.net = tgpar.net = net; |
| mtpar.table = tgpar.table = name; |
| mtpar.entryinfo = tgpar.entryinfo = e; |
| mtpar.hook_mask = tgpar.hook_mask = hookmask; |
| mtpar.family = tgpar.family = NFPROTO_BRIDGE; |
| ret = EBT_MATCH_ITERATE(e, ebt_check_match, &mtpar, &i); |
| if (ret != 0) |
| goto cleanup_matches; |
| j = 0; |
| ret = EBT_WATCHER_ITERATE(e, ebt_check_watcher, &tgpar, &j); |
| if (ret != 0) |
| goto cleanup_watchers; |
| t = (struct ebt_entry_target *)(((char *)e) + e->target_offset); |
| gap = e->next_offset - e->target_offset; |
| |
| target = xt_request_find_target(NFPROTO_BRIDGE, t->u.name, 0); |
| if (IS_ERR(target)) { |
| ret = PTR_ERR(target); |
| goto cleanup_watchers; |
| } |
| |
| t->u.target = target; |
| if (t->u.target == &ebt_standard_target) { |
| if (gap < sizeof(struct ebt_standard_target)) { |
| BUGPRINT("Standard target size too big\n"); |
| ret = -EFAULT; |
| goto cleanup_watchers; |
| } |
| if (((struct ebt_standard_target *)t)->verdict < |
| -NUM_STANDARD_TARGETS) { |
| BUGPRINT("Invalid standard target\n"); |
| ret = -EFAULT; |
| goto cleanup_watchers; |
| } |
| } else if (t->target_size > gap - sizeof(struct ebt_entry_target)) { |
| module_put(t->u.target->me); |
| ret = -EFAULT; |
| goto cleanup_watchers; |
| } |
| |
| tgpar.target = target; |
| tgpar.targinfo = t->data; |
| ret = xt_check_target(&tgpar, t->target_size, |
| e->ethproto, e->invflags & EBT_IPROTO); |
| if (ret < 0) { |
| module_put(target->me); |
| goto cleanup_watchers; |
| } |
| (*cnt)++; |
| return 0; |
| cleanup_watchers: |
| EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, &j); |
| cleanup_matches: |
| EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, &i); |
| return ret; |
| } |
| |
| /* |
| * checks for loops and sets the hook mask for udc |
| * the hook mask for udc tells us from which base chains the udc can be |
| * accessed. This mask is a parameter to the check() functions of the extensions |
| */ |
| static int check_chainloops(const struct ebt_entries *chain, struct ebt_cl_stack *cl_s, |
| unsigned int udc_cnt, unsigned int hooknr, char *base) |
| { |
| int i, chain_nr = -1, pos = 0, nentries = chain->nentries, verdict; |
| const struct ebt_entry *e = (struct ebt_entry *)chain->data; |
| const struct ebt_entry_target *t; |
| |
| while (pos < nentries || chain_nr != -1) { |
| /* end of udc, go back one 'recursion' step */ |
| if (pos == nentries) { |
| /* put back values of the time when this chain was called */ |
| e = cl_s[chain_nr].cs.e; |
| if (cl_s[chain_nr].from != -1) |
| nentries = |
| cl_s[cl_s[chain_nr].from].cs.chaininfo->nentries; |
| else |
| nentries = chain->nentries; |
| pos = cl_s[chain_nr].cs.n; |
| /* make sure we won't see a loop that isn't one */ |
| cl_s[chain_nr].cs.n = 0; |
| chain_nr = cl_s[chain_nr].from; |
| if (pos == nentries) |
| continue; |
| } |
| t = (struct ebt_entry_target *) |
| (((char *)e) + e->target_offset); |
| if (strcmp(t->u.name, EBT_STANDARD_TARGET)) |
| goto letscontinue; |
| if (e->target_offset + sizeof(struct ebt_standard_target) > |
| e->next_offset) { |
| BUGPRINT("Standard target size too big\n"); |
| return -1; |
| } |
| verdict = ((struct ebt_standard_target *)t)->verdict; |
| if (verdict >= 0) { /* jump to another chain */ |
| struct ebt_entries *hlp2 = |
| (struct ebt_entries *)(base + verdict); |
| for (i = 0; i < udc_cnt; i++) |
| if (hlp2 == cl_s[i].cs.chaininfo) |
| break; |
| /* bad destination or loop */ |
| if (i == udc_cnt) { |
| BUGPRINT("bad destination\n"); |
| return -1; |
| } |
| if (cl_s[i].cs.n) { |
| BUGPRINT("loop\n"); |
| return -1; |
| } |
| if (cl_s[i].hookmask & (1 << hooknr)) |
| goto letscontinue; |
| /* this can't be 0, so the loop test is correct */ |
| cl_s[i].cs.n = pos + 1; |
| pos = 0; |
| cl_s[i].cs.e = ebt_next_entry(e); |
| e = (struct ebt_entry *)(hlp2->data); |
| nentries = hlp2->nentries; |
| cl_s[i].from = chain_nr; |
| chain_nr = i; |
| /* this udc is accessible from the base chain for hooknr */ |
| cl_s[i].hookmask |= (1 << hooknr); |
| continue; |
| } |
| letscontinue: |
| e = ebt_next_entry(e); |
| pos++; |
| } |
| return 0; |
| } |
| |
| /* do the parsing of the table/chains/entries/matches/watchers/targets, heh */ |
| static int translate_table(struct net *net, const char *name, |
| struct ebt_table_info *newinfo) |
| { |
| unsigned int i, j, k, udc_cnt; |
| int ret; |
| struct ebt_cl_stack *cl_s = NULL; /* used in the checking for chain loops */ |
| |
| i = 0; |
| while (i < NF_BR_NUMHOOKS && !newinfo->hook_entry[i]) |
| i++; |
| if (i == NF_BR_NUMHOOKS) { |
| BUGPRINT("No valid hooks specified\n"); |
| return -EINVAL; |
| } |
| if (newinfo->hook_entry[i] != (struct ebt_entries *)newinfo->entries) { |
| BUGPRINT("Chains don't start at beginning\n"); |
| return -EINVAL; |
| } |
| /* make sure chains are ordered after each other in same order |
| as their corresponding hooks */ |
| for (j = i + 1; j < NF_BR_NUMHOOKS; j++) { |
| if (!newinfo->hook_entry[j]) |
| continue; |
| if (newinfo->hook_entry[j] <= newinfo->hook_entry[i]) { |
| BUGPRINT("Hook order must be followed\n"); |
| return -EINVAL; |
| } |
| i = j; |
| } |
| |
| /* do some early checkings and initialize some things */ |
| i = 0; /* holds the expected nr. of entries for the chain */ |
| j = 0; /* holds the up to now counted entries for the chain */ |
| k = 0; /* holds the total nr. of entries, should equal |
| newinfo->nentries afterwards */ |
| udc_cnt = 0; /* will hold the nr. of user defined chains (udc) */ |
| ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, |
| ebt_check_entry_size_and_hooks, newinfo, |
| &i, &j, &k, &udc_cnt); |
| |
| if (ret != 0) |
| return ret; |
| |
| if (i != j) { |
| BUGPRINT("nentries does not equal the nr of entries in the " |
| "(last) chain\n"); |
| return -EINVAL; |
| } |
| if (k != newinfo->nentries) { |
| BUGPRINT("Total nentries is wrong\n"); |
| return -EINVAL; |
| } |
| |
| /* get the location of the udc, put them in an array |
| while we're at it, allocate the chainstack */ |
| if (udc_cnt) { |
| /* this will get free'd in do_replace()/ebt_register_table() |
| if an error occurs */ |
| newinfo->chainstack = |
| vmalloc(nr_cpu_ids * sizeof(*(newinfo->chainstack))); |
| if (!newinfo->chainstack) |
| return -ENOMEM; |
| for_each_possible_cpu(i) { |
| newinfo->chainstack[i] = |
| vmalloc(udc_cnt * sizeof(*(newinfo->chainstack[0]))); |
| if (!newinfo->chainstack[i]) { |
| while (i) |
| vfree(newinfo->chainstack[--i]); |
| vfree(newinfo->chainstack); |
| newinfo->chainstack = NULL; |
| return -ENOMEM; |
| } |
| } |
| |
| cl_s = vmalloc(udc_cnt * sizeof(*cl_s)); |
| if (!cl_s) |
| return -ENOMEM; |
| i = 0; /* the i'th udc */ |
| EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, |
| ebt_get_udc_positions, newinfo, &i, cl_s); |
| /* sanity check */ |
| if (i != udc_cnt) { |
| BUGPRINT("i != udc_cnt\n"); |
| vfree(cl_s); |
| return -EFAULT; |
| } |
| } |
| |
| /* Check for loops */ |
| for (i = 0; i < NF_BR_NUMHOOKS; i++) |
| if (newinfo->hook_entry[i]) |
| if (check_chainloops(newinfo->hook_entry[i], |
| cl_s, udc_cnt, i, newinfo->entries)) { |
| vfree(cl_s); |
| return -EINVAL; |
| } |
| |
| /* we now know the following (along with E=mc²): |
| - the nr of entries in each chain is right |
| - the size of the allocated space is right |
| - all valid hooks have a corresponding chain |
| - there are no loops |
| - wrong data can still be on the level of a single entry |
| - could be there are jumps to places that are not the |
| beginning of a chain. This can only occur in chains that |
| are not accessible from any base chains, so we don't care. */ |
| |
| /* used to know what we need to clean up if something goes wrong */ |
| i = 0; |
| ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, |
| ebt_check_entry, net, newinfo, name, &i, cl_s, udc_cnt); |
| if (ret != 0) { |
| EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, |
| ebt_cleanup_entry, net, &i); |
| } |
| vfree(cl_s); |
| return ret; |
| } |
| |
| /* called under write_lock */ |
| static void get_counters(const struct ebt_counter *oldcounters, |
| struct ebt_counter *counters, unsigned int nentries) |
| { |
| int i, cpu; |
| struct ebt_counter *counter_base; |
| |
| /* counters of cpu 0 */ |
| memcpy(counters, oldcounters, |
| sizeof(struct ebt_counter) * nentries); |
| |
| /* add other counters to those of cpu 0 */ |
| for_each_possible_cpu(cpu) { |
| if (cpu == 0) |
| continue; |
| counter_base = COUNTER_BASE(oldcounters, nentries, cpu); |
| for (i = 0; i < nentries; i++) { |
| counters[i].pcnt += counter_base[i].pcnt; |
| counters[i].bcnt += counter_base[i].bcnt; |
| } |
| } |
| } |
| |
| static int do_replace_finish(struct net *net, struct ebt_replace *repl, |
| struct ebt_table_info *newinfo) |
| { |
| int ret, i; |
| struct ebt_counter *counterstmp = NULL; |
| /* used to be able to unlock earlier */ |
| struct ebt_table_info *table; |
| struct ebt_table *t; |
| |
| /* the user wants counters back |
| the check on the size is done later, when we have the lock */ |
| if (repl->num_counters) { |
| unsigned long size = repl->num_counters * sizeof(*counterstmp); |
| counterstmp = vmalloc(size); |
| if (!counterstmp) |
| return -ENOMEM; |
| } |
| |
| newinfo->chainstack = NULL; |
| ret = ebt_verify_pointers(repl, newinfo); |
| if (ret != 0) |
| goto free_counterstmp; |
| |
| ret = translate_table(net, repl->name, newinfo); |
| |
| if (ret != 0) |
| goto free_counterstmp; |
| |
| t = find_table_lock(net, repl->name, &ret, &ebt_mutex); |
| if (!t) { |
| ret = -ENOENT; |
| goto free_iterate; |
| } |
| |
| /* the table doesn't like it */ |
| if (t->check && (ret = t->check(newinfo, repl->valid_hooks))) |
| goto free_unlock; |
| |
| if (repl->num_counters && repl->num_counters != t->private->nentries) { |
| BUGPRINT("Wrong nr. of counters requested\n"); |
| ret = -EINVAL; |
| goto free_unlock; |
| } |
| |
| /* we have the mutex lock, so no danger in reading this pointer */ |
| table = t->private; |
| /* make sure the table can only be rmmod'ed if it contains no rules */ |
| if (!table->nentries && newinfo->nentries && !try_module_get(t->me)) { |
| ret = -ENOENT; |
| goto free_unlock; |
| } else if (table->nentries && !newinfo->nentries) |
| module_put(t->me); |
| /* we need an atomic snapshot of the counters */ |
| write_lock_bh(&t->lock); |
| if (repl->num_counters) |
| get_counters(t->private->counters, counterstmp, |
| t->private->nentries); |
| |
| t->private = newinfo; |
| write_unlock_bh(&t->lock); |
| mutex_unlock(&ebt_mutex); |
| /* so, a user can change the chains while having messed up her counter |
| allocation. Only reason why this is done is because this way the lock |
| is held only once, while this doesn't bring the kernel into a |
| dangerous state. */ |
| if (repl->num_counters && |
| copy_to_user(repl->counters, counterstmp, |
| repl->num_counters * sizeof(struct ebt_counter))) { |
| /* Silent error, can't fail, new table is already in place */ |
| net_warn_ratelimited("ebtables: counters copy to user failed while replacing table\n"); |
| } |
| |
| /* decrease module count and free resources */ |
| EBT_ENTRY_ITERATE(table->entries, table->entries_size, |
| ebt_cleanup_entry, net, NULL); |
| |
| vfree(table->entries); |
| if (table->chainstack) { |
| for_each_possible_cpu(i) |
| vfree(table->chainstack[i]); |
| vfree(table->chainstack); |
| } |
| vfree(table); |
| |
| vfree(counterstmp); |
| |
| #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", |
| repl->name, AF_BRIDGE, repl->nentries); |
| audit_log_end(ab); |
| } |
| } |
| #endif |
| return ret; |
| |
| free_unlock: |
| mutex_unlock(&ebt_mutex); |
| free_iterate: |
| EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, |
| ebt_cleanup_entry, net, NULL); |
| free_counterstmp: |
| vfree(counterstmp); |
| /* can be initialized in translate_table() */ |
| if (newinfo->chainstack) { |
| for_each_possible_cpu(i) |
| vfree(newinfo->chainstack[i]); |
| vfree(newinfo->chainstack); |
| } |
| return ret; |
| } |
| |
| /* replace the table */ |
| static int do_replace(struct net *net, const void __user *user, |
| unsigned int len) |
| { |
| int ret, countersize; |
| struct ebt_table_info *newinfo; |
| struct ebt_replace tmp; |
| |
| if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) |
| return -EFAULT; |
| |
| if (len != sizeof(tmp) + tmp.entries_size) { |
| BUGPRINT("Wrong len argument\n"); |
| return -EINVAL; |
| } |
| |
| if (tmp.entries_size == 0) { |
| BUGPRINT("Entries_size never zero\n"); |
| return -EINVAL; |
| } |
| /* overflow check */ |
| if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) / |
| NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter)) |
| return -ENOMEM; |
| if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter)) |
| return -ENOMEM; |
| |
| tmp.name[sizeof(tmp.name) - 1] = 0; |
| |
| countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids; |
| newinfo = vmalloc(sizeof(*newinfo) + countersize); |
| if (!newinfo) |
| return -ENOMEM; |
| |
| if (countersize) |
| memset(newinfo->counters, 0, countersize); |
| |
| newinfo->entries = vmalloc(tmp.entries_size); |
| if (!newinfo->entries) { |
| ret = -ENOMEM; |
| goto free_newinfo; |
| } |
| if (copy_from_user( |
| newinfo->entries, tmp.entries, tmp.entries_size) != 0) { |
| BUGPRINT("Couldn't copy entries from userspace\n"); |
| ret = -EFAULT; |
| goto free_entries; |
| } |
| |
| ret = do_replace_finish(net, &tmp, newinfo); |
| if (ret == 0) |
| return ret; |
| free_entries: |
| vfree(newinfo->entries); |
| free_newinfo: |
| vfree(newinfo); |
| return ret; |
| } |
| |
| struct ebt_table * |
| ebt_register_table(struct net *net, const struct ebt_table *input_table) |
| { |
| struct ebt_table_info *newinfo; |
| struct ebt_table *t, *table; |
| struct ebt_replace_kernel *repl; |
| int ret, i, countersize; |
| void *p; |
| |
| if (input_table == NULL || (repl = input_table->table) == NULL || |
| repl->entries == NULL || repl->entries_size == 0 || |
| repl->counters != NULL || input_table->private != NULL) { |
| BUGPRINT("Bad table data for ebt_register_table!!!\n"); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| /* Don't add one table to multiple lists. */ |
| table = kmemdup(input_table, sizeof(struct ebt_table), GFP_KERNEL); |
| if (!table) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids; |
| newinfo = vmalloc(sizeof(*newinfo) + countersize); |
| ret = -ENOMEM; |
| if (!newinfo) |
| goto free_table; |
| |
| p = vmalloc(repl->entries_size); |
| if (!p) |
| goto free_newinfo; |
| |
| memcpy(p, repl->entries, repl->entries_size); |
| newinfo->entries = p; |
| |
| newinfo->entries_size = repl->entries_size; |
| newinfo->nentries = repl->nentries; |
| |
| if (countersize) |
| memset(newinfo->counters, 0, countersize); |
| |
| /* fill in newinfo and parse the entries */ |
| newinfo->chainstack = NULL; |
| for (i = 0; i < NF_BR_NUMHOOKS; i++) { |
| if ((repl->valid_hooks & (1 << i)) == 0) |
| newinfo->hook_entry[i] = NULL; |
| else |
| newinfo->hook_entry[i] = p + |
| ((char *)repl->hook_entry[i] - repl->entries); |
| } |
| ret = translate_table(net, repl->name, newinfo); |
| if (ret != 0) { |
| BUGPRINT("Translate_table failed\n"); |
| goto free_chainstack; |
| } |
| |
| if (table->check && table->check(newinfo, table->valid_hooks)) { |
| BUGPRINT("The table doesn't like its own initial data, lol\n"); |
| ret = -EINVAL; |
| goto free_chainstack; |
| } |
| |
| table->private = newinfo; |
| rwlock_init(&table->lock); |
| mutex_lock(&ebt_mutex); |
| list_for_each_entry(t, &net->xt.tables[NFPROTO_BRIDGE], list) { |
| if (strcmp(t->name, table->name) == 0) { |
| ret = -EEXIST; |
| BUGPRINT("Table name already exists\n"); |
| goto free_unlock; |
| } |
| } |
| |
| /* Hold a reference count if the chains aren't empty */ |
| if (newinfo->nentries && !try_module_get(table->me)) { |
| ret = -ENOENT; |
| goto free_unlock; |
| } |
| list_add(&table->list, &net->xt.tables[NFPROTO_BRIDGE]); |
| mutex_unlock(&ebt_mutex); |
| return table; |
| free_unlock: |
| mutex_unlock(&ebt_mutex); |
| free_chainstack: |
| if (newinfo->chainstack) { |
| for_each_possible_cpu(i) |
| vfree(newinfo->chainstack[i]); |
| vfree(newinfo->chainstack); |
| } |
| vfree(newinfo->entries); |
| free_newinfo: |
| vfree(newinfo); |
| free_table: |
| kfree(table); |
| out: |
| return ERR_PTR(ret); |
| } |
| |
| void ebt_unregister_table(struct net *net, struct ebt_table *table) |
| { |
| int i; |
| |
| if (!table) { |
| BUGPRINT("Request to unregister NULL table!!!\n"); |
| return; |
| } |
| mutex_lock(&ebt_mutex); |
| list_del(&table->list); |
| mutex_unlock(&ebt_mutex); |
| EBT_ENTRY_ITERATE(table->private->entries, table->private->entries_size, |
| ebt_cleanup_entry, net, NULL); |
| if (table->private->nentries) |
| module_put(table->me); |
| vfree(table->private->entries); |
| if (table->private->chainstack) { |
| for_each_possible_cpu(i) |
| vfree(table->private->chainstack[i]); |
| vfree(table->private->chainstack); |
| } |
| vfree(table->private); |
| kfree(table); |
| } |
| |
| /* userspace just supplied us with counters */ |
| static int do_update_counters(struct net *net, const char *name, |
| struct ebt_counter __user *counters, |
| unsigned int num_counters, |
| const void __user *user, unsigned int len) |
| { |
| int i, ret; |
| struct ebt_counter *tmp; |
| struct ebt_table *t; |
| |
| if (num_counters == 0) |
| return -EINVAL; |
| |
| tmp = vmalloc(num_counters * sizeof(*tmp)); |
| if (!tmp) |
| return -ENOMEM; |
| |
| t = find_table_lock(net, name, &ret, &ebt_mutex); |
| if (!t) |
| goto free_tmp; |
| |
| if (num_counters != t->private->nentries) { |
| BUGPRINT("Wrong nr of counters\n"); |
| ret = -EINVAL; |
| goto unlock_mutex; |
| } |
| |
| if (copy_from_user(tmp, counters, num_counters * sizeof(*counters))) { |
| ret = -EFAULT; |
| goto unlock_mutex; |
| } |
| |
| /* we want an atomic add of the counters */ |
| write_lock_bh(&t->lock); |
| |
| /* we add to the counters of the first cpu */ |
| for (i = 0; i < num_counters; i++) { |
| t->private->counters[i].pcnt += tmp[i].pcnt; |
| t->private->counters[i].bcnt += tmp[i].bcnt; |
| } |
| |
| write_unlock_bh(&t->lock); |
| ret = 0; |
| unlock_mutex: |
| mutex_unlock(&ebt_mutex); |
| free_tmp: |
| vfree(tmp); |
| return ret; |
| } |
| |
| static int update_counters(struct net *net, const void __user *user, |
| unsigned int len) |
| { |
| struct ebt_replace hlp; |
| |
| if (copy_from_user(&hlp, user, sizeof(hlp))) |
| return -EFAULT; |
| |
| if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter)) |
| return -EINVAL; |
| |
| return do_update_counters(net, hlp.name, hlp.counters, |
| hlp.num_counters, user, len); |
| } |
| |
| static inline int ebt_make_matchname(const struct ebt_entry_match *m, |
| const char *base, char __user *ubase) |
| { |
| char __user *hlp = ubase + ((char *)m - base); |
| char name[EBT_FUNCTION_MAXNAMELEN] = {}; |
| |
| /* ebtables expects 32 bytes long names but xt_match names are 29 bytes |
| long. Copy 29 bytes and fill remaining bytes with zeroes. */ |
| strlcpy(name, m->u.match->name, sizeof(name)); |
| if (copy_to_user(hlp, name, EBT_FUNCTION_MAXNAMELEN)) |
| return -EFAULT; |
| return 0; |
| } |
| |
| static inline int ebt_make_watchername(const struct ebt_entry_watcher *w, |
| const char *base, char __user *ubase) |
| { |
| char __user *hlp = ubase + ((char *)w - base); |
| char name[EBT_FUNCTION_MAXNAMELEN] = {}; |
| |
| strlcpy(name, w->u.watcher->name, sizeof(name)); |
| if (copy_to_user(hlp , name, EBT_FUNCTION_MAXNAMELEN)) |
| return -EFAULT; |
| return 0; |
| } |
| |
| static inline int |
| ebt_make_names(struct ebt_entry *e, const char *base, char __user *ubase) |
| { |
| int ret; |
| char __user *hlp; |
| const struct ebt_entry_target *t; |
| char name[EBT_FUNCTION_MAXNAMELEN] = {}; |
| |
| if (e->bitmask == 0) |
| return 0; |
| |
| hlp = ubase + (((char *)e + e->target_offset) - base); |
| t = (struct ebt_entry_target *)(((char *)e) + e->target_offset); |
| |
| ret = EBT_MATCH_ITERATE(e, ebt_make_matchname, base, ubase); |
| if (ret != 0) |
| return ret; |
| ret = EBT_WATCHER_ITERATE(e, ebt_make_watchername, base, ubase); |
| if (ret != 0) |
| return ret; |
| strlcpy(name, t->u.target->name, sizeof(name)); |
| if (copy_to_user(hlp, name, EBT_FUNCTION_MAXNAMELEN)) |
| return -EFAULT; |
| return 0; |
| } |
| |
| static int copy_counters_to_user(struct ebt_table *t, |
| const struct ebt_counter *oldcounters, |
| void __user *user, unsigned int num_counters, |
| unsigned int nentries) |
| { |
| struct ebt_counter *counterstmp; |
| int ret = 0; |
| |
| /* userspace might not need the counters */ |
| if (num_counters == 0) |
| return 0; |
| |
| if (num_counters != nentries) { |
| BUGPRINT("Num_counters wrong\n"); |
| return -EINVAL; |
| } |
| |
| counterstmp = vmalloc(nentries * sizeof(*counterstmp)); |
| if (!counterstmp) |
| return -ENOMEM; |
| |
| write_lock_bh(&t->lock); |
| get_counters(oldcounters, counterstmp, nentries); |
| write_unlock_bh(&t->lock); |
| |
| if (copy_to_user(user, counterstmp, |
| nentries * sizeof(struct ebt_counter))) |
| ret = -EFAULT; |
| vfree(counterstmp); |
| return ret; |
| } |
| |
| /* called with ebt_mutex locked */ |
| static int copy_everything_to_user(struct ebt_table *t, void __user *user, |
| const int *len, int cmd) |
| { |
| struct ebt_replace tmp; |
| const struct ebt_counter *oldcounters; |
| unsigned int entries_size, nentries; |
| int ret; |
| char *entries; |
| |
| if (cmd == EBT_SO_GET_ENTRIES) { |
| entries_size = t->private->entries_size; |
| nentries = t->private->nentries; |
| entries = t->private->entries; |
| oldcounters = t->private->counters; |
| } else { |
| entries_size = t->table->entries_size; |
| nentries = t->table->nentries; |
| entries = t->table->entries; |
| oldcounters = t->table->counters; |
| } |
| |
| if (copy_from_user(&tmp, user, sizeof(tmp))) |
| return -EFAULT; |
| |
| if (*len != sizeof(struct ebt_replace) + entries_size + |
| (tmp.num_counters ? nentries * sizeof(struct ebt_counter) : 0)) |
| return -EINVAL; |
| |
| if (tmp.nentries != nentries) { |
| BUGPRINT("Nentries wrong\n"); |
| return -EINVAL; |
| } |
| |
| if (tmp.entries_size != entries_size) { |
| BUGPRINT("Wrong size\n"); |
| return -EINVAL; |
| } |
| |
| ret = copy_counters_to_user(t, oldcounters, tmp.counters, |
| tmp.num_counters, nentries); |
| if (ret) |
| return ret; |
| |
| if (copy_to_user(tmp.entries, entries, entries_size)) { |
| BUGPRINT("Couldn't copy entries to userspace\n"); |
| return -EFAULT; |
| } |
| /* set the match/watcher/target names right */ |
| return EBT_ENTRY_ITERATE(entries, entries_size, |
| ebt_make_names, entries, tmp.entries); |
| } |
| |
| static int do_ebt_set_ctl(struct sock *sk, |
| int cmd, void __user *user, unsigned int len) |
| { |
| int ret; |
| struct net *net = sock_net(sk); |
| |
| if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) |
| return -EPERM; |
| |
| switch (cmd) { |
| case EBT_SO_SET_ENTRIES: |
| ret = do_replace(net, user, len); |
| break; |
| case EBT_SO_SET_COUNTERS: |
| ret = update_counters(net, user, len); |
| break; |
| default: |
| ret = -EINVAL; |
| } |
| return ret; |
| } |
| |
| static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) |
| { |
| int ret; |
| struct ebt_replace tmp; |
| struct ebt_table *t; |
| struct net *net = sock_net(sk); |
| |
| if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) |
| return -EPERM; |
| |
| if (copy_from_user(&tmp, user, sizeof(tmp))) |
| return -EFAULT; |
| |
| t = find_table_lock(net, tmp.name, &ret, &ebt_mutex); |
| if (!t) |
| return ret; |
| |
| switch (cmd) { |
| case EBT_SO_GET_INFO: |
| case EBT_SO_GET_INIT_INFO: |
| if (*len != sizeof(struct ebt_replace)) { |
| ret = -EINVAL; |
| mutex_unlock(&ebt_mutex); |
| break; |
| } |
| if (cmd == EBT_SO_GET_INFO) { |
| tmp.nentries = t->private->nentries; |
| tmp.entries_size = t->private->entries_size; |
| tmp.valid_hooks = t->valid_hooks; |
| } else { |
| tmp.nentries = t->table->nentries; |
| tmp.entries_size = t->table->entries_size; |
| tmp.valid_hooks = t->table->valid_hooks; |
| } |
| mutex_unlock(&ebt_mutex); |
| if (copy_to_user(user, &tmp, *len) != 0) { |
| BUGPRINT("c2u Didn't work\n"); |
| ret = -EFAULT; |
| break; |
| } |
| ret = 0; |
| break; |
| |
| case EBT_SO_GET_ENTRIES: |
| case EBT_SO_GET_INIT_ENTRIES: |
| ret = copy_everything_to_user(t, user, len, cmd); |
| mutex_unlock(&ebt_mutex); |
| break; |
| |
| default: |
| mutex_unlock(&ebt_mutex); |
| ret = -EINVAL; |
| } |
| |
| return ret; |
| } |
| |
| #ifdef CONFIG_COMPAT |
| /* 32 bit-userspace compatibility definitions. */ |
| struct compat_ebt_replace { |
| char name[EBT_TABLE_MAXNAMELEN]; |
| compat_uint_t valid_hooks; |
| compat_uint_t nentries; |
| compat_uint_t entries_size; |
| /* start of the chains */ |
| compat_uptr_t hook_entry[NF_BR_NUMHOOKS]; |
| /* nr of counters userspace expects back */ |
| compat_uint_t num_counters; |
| /* where the kernel will put the old counters. */ |
| compat_uptr_t counters; |
| compat_uptr_t entries; |
| }; |
| |
| /* struct ebt_entry_match, _target and _watcher have same layout */ |
| struct compat_ebt_entry_mwt { |
| union { |
| char name[EBT_FUNCTION_MAXNAMELEN]; |
| compat_uptr_t ptr; |
| } u; |
| compat_uint_t match_size; |
| compat_uint_t data[0]; |
| }; |
| |
| /* account for possible padding between match_size and ->data */ |
| static int ebt_compat_entry_padsize(void) |
| { |
| BUILD_BUG_ON(XT_ALIGN(sizeof(struct ebt_entry_match)) < |
| COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt))); |
| return (int) XT_ALIGN(sizeof(struct ebt_entry_match)) - |
| COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt)); |
| } |
| |
| static int ebt_compat_match_offset(const struct xt_match *match, |
| unsigned int userlen) |
| { |
| /* |
| * ebt_among needs special handling. The kernel .matchsize is |
| * set to -1 at registration time; at runtime an EBT_ALIGN()ed |
| * value is expected. |
| * Example: userspace sends 4500, ebt_among.c wants 4504. |
| */ |
| if (unlikely(match->matchsize == -1)) |
| return XT_ALIGN(userlen) - COMPAT_XT_ALIGN(userlen); |
| return xt_compat_match_offset(match); |
| } |
| |
| static int compat_match_to_user(struct ebt_entry_match *m, void __user **dstptr, |
| unsigned int *size) |
| { |
| const struct xt_match *match = m->u.match; |
| struct compat_ebt_entry_mwt __user *cm = *dstptr; |
| int off = ebt_compat_match_offset(match, m->match_size); |
| compat_uint_t msize = m->match_size - off; |
| |
| BUG_ON(off >= m->match_size); |
| |
| if (copy_to_user(cm->u.name, match->name, |
| strlen(match->name) + 1) || put_user(msize, &cm->match_size)) |
| return -EFAULT; |
| |
| if (match->compat_to_user) { |
| if (match->compat_to_user(cm->data, m->data)) |
| return -EFAULT; |
| } else if (copy_to_user(cm->data, m->data, msize)) |
| return -EFAULT; |
| |
| *size -= ebt_compat_entry_padsize() + off; |
| *dstptr = cm->data; |
| *dstptr += msize; |
| return 0; |
| } |
| |
| static int compat_target_to_user(struct ebt_entry_target *t, |
| void __user **dstptr, |
| unsigned int *size) |
| { |
| const struct xt_target *target = t->u.target; |
| struct compat_ebt_entry_mwt __user *cm = *dstptr; |
| int off = xt_compat_target_offset(target); |
| compat_uint_t tsize = t->target_size - off; |
| |
| BUG_ON(off >= t->target_size); |
| |
| if (copy_to_user(cm->u.name, target->name, |
| strlen(target->name) + 1) || put_user(tsize, &cm->match_size)) |
| return -EFAULT; |
| |
| if (target->compat_to_user) { |
| if (target->compat_to_user(cm->data, t->data)) |
| return -EFAULT; |
| } else if (copy_to_user(cm->data, t->data, tsize)) |
| return -EFAULT; |
| |
| *size -= ebt_compat_entry_padsize() + off; |
| *dstptr = cm->data; |
| *dstptr += tsize; |
| return 0; |
| } |
| |
| static int compat_watcher_to_user(struct ebt_entry_watcher *w, |
| void __user **dstptr, |
| unsigned int *size) |
| { |
| return compat_target_to_user((struct ebt_entry_target *)w, |
| dstptr, size); |
| } |
| |
| static int compat_copy_entry_to_user(struct ebt_entry *e, void __user **dstptr, |
| unsigned int *size) |
| { |
| struct ebt_entry_target *t; |
| struct ebt_entry __user *ce; |
| u32 watchers_offset, target_offset, next_offset; |
| compat_uint_t origsize; |
| int ret; |
| |
| if (e->bitmask == 0) { |
| if (*size < sizeof(struct ebt_entries)) |
| return -EINVAL; |
| if (copy_to_user(*dstptr, e, sizeof(struct ebt_entries))) |
| return -EFAULT; |
| |
| *dstptr += sizeof(struct ebt_entries); |
| *size -= sizeof(struct ebt_entries); |
| return 0; |
| } |
| |
| if (*size < sizeof(*ce)) |
| return -EINVAL; |
| |
| ce = (struct ebt_entry __user *)*dstptr; |
| if (copy_to_user(ce, e, sizeof(*ce))) |
| return -EFAULT; |
| |
| origsize = *size; |
| *dstptr += sizeof(*ce); |
| |
| ret = EBT_MATCH_ITERATE(e, compat_match_to_user, dstptr, size); |
| if (ret) |
| return ret; |
| watchers_offset = e->watchers_offset - (origsize - *size); |
| |
| ret = EBT_WATCHER_ITERATE(e, compat_watcher_to_user, dstptr, size); |
| if (ret) |
| return ret; |
| target_offset = e->target_offset - (origsize - *size); |
| |
| t = (struct ebt_entry_target *) ((char *) e + e->target_offset); |
| |
| ret = compat_target_to_user(t, dstptr, size); |
| if (ret) |
| return ret; |
| next_offset = e->next_offset - (origsize - *size); |
| |
| if (put_user(watchers_offset, &ce->watchers_offset) || |
| put_user(target_offset, &ce->target_offset) || |
| put_user(next_offset, &ce->next_offset)) |
| return -EFAULT; |
| |
| *size -= sizeof(*ce); |
| return 0; |
| } |
| |
| static int compat_calc_match(struct ebt_entry_match *m, int *off) |
| { |
| *off += ebt_compat_match_offset(m->u.match, m->match_size); |
| *off += ebt_compat_entry_padsize(); |
| return 0; |
| } |
| |
| static int compat_calc_watcher(struct ebt_entry_watcher *w, int *off) |
| { |
| *off += xt_compat_target_offset(w->u.watcher); |
| *off += ebt_compat_entry_padsize(); |
| return 0; |
| } |
| |
| static int compat_calc_entry(const struct ebt_entry *e, |
| const struct ebt_table_info *info, |
| const void *base, |
| struct compat_ebt_replace *newinfo) |
| { |
| const struct ebt_entry_target *t; |
| unsigned int entry_offset; |
| int off, ret, i; |
| |
| if (e->bitmask == 0) |
| return 0; |
| |
| off = 0; |
| entry_offset = (void *)e - base; |
| |
| EBT_MATCH_ITERATE(e, compat_calc_match, &off); |
| EBT_WATCHER_ITERATE(e, compat_calc_watcher, &off); |
| |
| t = (const struct ebt_entry_target *) ((char *) e + e->target_offset); |
| |
| off += xt_compat_target_offset(t->u.target); |
| off += ebt_compat_entry_padsize(); |
| |
| newinfo->entries_size -= off; |
| |
| ret = xt_compat_add_offset(NFPROTO_BRIDGE, entry_offset, off); |
| if (ret) |
| return ret; |
| |
| for (i = 0; i < NF_BR_NUMHOOKS; i++) { |
| const void *hookptr = info->hook_entry[i]; |
| if (info->hook_entry[i] && |
| (e < (struct ebt_entry *)(base - hookptr))) { |
| newinfo->hook_entry[i] -= off; |
| pr_debug("0x%08X -> 0x%08X\n", |
| newinfo->hook_entry[i] + off, |
| newinfo->hook_entry[i]); |
| } |
| } |
| |
| return 0; |
| } |
| |
| |
| static int compat_table_info(const struct ebt_table_info *info, |
| struct compat_ebt_replace *newinfo) |
| { |
| unsigned int size = info->entries_size; |
| const void *entries = info->entries; |
| |
| newinfo->entries_size = size; |
| |
| xt_compat_init_offsets(NFPROTO_BRIDGE, info->nentries); |
| return EBT_ENTRY_ITERATE(entries, size, compat_calc_entry, info, |
| entries, newinfo); |
| } |
| |
| static int compat_copy_everything_to_user(struct ebt_table *t, |
| void __user *user, int *len, int cmd) |
| { |
| struct compat_ebt_replace repl, tmp; |
| struct ebt_counter *oldcounters; |
| struct ebt_table_info tinfo; |
| int ret; |
| void __user *pos; |
| |
| memset(&tinfo, 0, sizeof(tinfo)); |
| |
| if (cmd == EBT_SO_GET_ENTRIES) { |
| tinfo.entries_size = t->private->entries_size; |
| tinfo.nentries = t->private->nentries; |
| tinfo.entries = t->private->entries; |
| oldcounters = t->private->counters; |
| } else { |
| tinfo.entries_size = t->table->entries_size; |
| tinfo.nentries = t->table->nentries; |
| tinfo.entries = t->table->entries; |
| oldcounters = t->table->counters; |
| } |
| |
| if (copy_from_user(&tmp, user, sizeof(tmp))) |
| return -EFAULT; |
| |
| if (tmp.nentries != tinfo.nentries || |
| (tmp.num_counters && tmp.num_counters != tinfo.nentries)) |
| return -EINVAL; |
| |
| memcpy(&repl, &tmp, sizeof(repl)); |
| if (cmd == EBT_SO_GET_ENTRIES) |
| ret = compat_table_info(t->private, &repl); |
| else |
| ret = compat_table_info(&tinfo, &repl); |
| if (ret) |
| return ret; |
| |
| if (*len != sizeof(tmp) + repl.entries_size + |
| (tmp.num_counters? tinfo.nentries * sizeof(struct ebt_counter): 0)) { |
| pr_err("wrong size: *len %d, entries_size %u, replsz %d\n", |
| *len, tinfo.entries_size, repl.entries_size); |
| return -EINVAL; |
| } |
| |
| /* userspace might not need the counters */ |
| ret = copy_counters_to_user(t, oldcounters, compat_ptr(tmp.counters), |
| tmp.num_counters, tinfo.nentries); |
| if (ret) |
| return ret; |
| |
| pos = compat_ptr(tmp.entries); |
| return EBT_ENTRY_ITERATE(tinfo.entries, tinfo.entries_size, |
| compat_copy_entry_to_user, &pos, &tmp.entries_size); |
| } |
| |
| struct ebt_entries_buf_state { |
| char *buf_kern_start; /* kernel buffer to copy (translated) data to */ |
| u32 buf_kern_len; /* total size of kernel buffer */ |
| u32 buf_kern_offset; /* amount of data copied so far */ |
| u32 buf_user_offset; /* read position in userspace buffer */ |
| }; |
| |
| static int ebt_buf_count(struct ebt_entries_buf_state *state, unsigned int sz) |
| { |
| state->buf_kern_offset += sz; |
| return state->buf_kern_offset >= sz ? 0 : -EINVAL; |
| } |
| |
| static int ebt_buf_add(struct ebt_entries_buf_state *state, |
| void *data, unsigned int sz) |
| { |
| if (state->buf_kern_start == NULL) |
| goto count_only; |
| |
| BUG_ON(state->buf_kern_offset + sz > state->buf_kern_len); |
| |
| memcpy(state->buf_kern_start + state->buf_kern_offset, data, sz); |
| |
| count_only: |
| state->buf_user_offset += sz; |
| return ebt_buf_count(state, sz); |
| } |
| |
| static int ebt_buf_add_pad(struct ebt_entries_buf_state *state, unsigned int sz) |
| { |
| char *b = state->buf_kern_start; |
| |
| BUG_ON(b && state->buf_kern_offset > state->buf_kern_len); |
| |
| if (b != NULL && sz > 0) |
| memset(b + state->buf_kern_offset, 0, sz); |
| /* do not adjust ->buf_user_offset here, we added kernel-side padding */ |
| return ebt_buf_count(state, sz); |
| } |
| |
| enum compat_mwt { |
| EBT_COMPAT_MATCH, |
| EBT_COMPAT_WATCHER, |
| EBT_COMPAT_TARGET, |
| }; |
| |
| static int compat_mtw_from_user(struct compat_ebt_entry_mwt *mwt, |
| enum compat_mwt compat_mwt, |
| struct ebt_entries_buf_state *state, |
| const unsigned char *base) |
| { |
| char name[EBT_FUNCTION_MAXNAMELEN]; |
| struct xt_match *match; |
| struct xt_target *wt; |
| void *dst = NULL; |
| int off, pad = 0; |
| unsigned int size_kern, match_size = mwt->match_size; |
| |
| strlcpy(name, mwt->u.name, sizeof(name)); |
| |
| if (state->buf_kern_start) |
| dst = state->buf_kern_start + state->buf_kern_offset; |
| |
| switch (compat_mwt) { |
| case EBT_COMPAT_MATCH: |
| match = xt_request_find_match(NFPROTO_BRIDGE, name, 0); |
| if (IS_ERR(match)) |
| return PTR_ERR(match); |
| |
| off = ebt_compat_match_offset(match, match_size); |
| if (dst) { |
| if (match->compat_from_user) |
| match->compat_from_user(dst, mwt->data); |
| else |
| memcpy(dst, mwt->data, match_size); |
| } |
| |
| size_kern = match->matchsize; |
| if (unlikely(size_kern == -1)) |
| size_kern = match_size; |
| module_put(match->me); |
| break; |
| case EBT_COMPAT_WATCHER: /* fallthrough */ |
| case EBT_COMPAT_TARGET: |
| wt = xt_request_find_target(NFPROTO_BRIDGE, name, 0); |
| if (IS_ERR(wt)) |
| return PTR_ERR(wt); |
| off = xt_compat_target_offset(wt); |
| |
| if (dst) { |
| if (wt->compat_from_user) |
| wt->compat_from_user(dst, mwt->data); |
| else |
| memcpy(dst, mwt->data, match_size); |
| } |
| |
| size_kern = wt->targetsize; |
| module_put(wt->me); |
| break; |
| |
| default: |
| return -EINVAL; |
| } |
| |
| state->buf_kern_offset += match_size + off; |
| state->buf_user_offset += match_size; |
| pad = XT_ALIGN(size_kern) - size_kern; |
| |
| if (pad > 0 && dst) { |
| BUG_ON(state->buf_kern_len <= pad); |
| BUG_ON(state->buf_kern_offset - (match_size + off) + size_kern > state->buf_kern_len - pad); |
| memset(dst + size_kern, 0, pad); |
| } |
| return off + match_size; |
| } |
| |
| /* |
| * return size of all matches, watchers or target, including necessary |
| * alignment and padding. |
| */ |
| static int ebt_size_mwt(struct compat_ebt_entry_mwt *match32, |
| unsigned int size_left, enum compat_mwt type, |
| struct ebt_entries_buf_state *state, const void *base) |
| { |
| int growth = 0; |
| char *buf; |
| |
| if (size_left == 0) |
| return 0; |
| |
| buf = (char *) match32; |
| |
| while (size_left >= sizeof(*match32)) { |
| struct ebt_entry_match *match_kern; |
| int ret; |
| |
| match_kern = (struct ebt_entry_match *) state->buf_kern_start; |
| if (match_kern) { |
| char *tmp; |
| tmp = state->buf_kern_start + state->buf_kern_offset; |
| match_kern = (struct ebt_entry_match *) tmp; |
| } |
| ret = ebt_buf_add(state, buf, sizeof(*match32)); |
| if (ret < 0) |
| return ret; |
| size_left -= sizeof(*match32); |
| |
| /* add padding before match->data (if any) */ |
| ret = ebt_buf_add_pad(state, ebt_compat_entry_padsize()); |
| if (ret < 0) |
| return ret; |
| |
| if (match32->match_size > size_left) |
| return -EINVAL; |
| |
| size_left -= match32->match_size; |
| |
| ret = compat_mtw_from_user(match32, type, state, base); |
| if (ret < 0) |
| return ret; |
| |
| BUG_ON(ret < match32->match_size); |
| growth += ret - match32->match_size; |
| growth += ebt_compat_entry_padsize(); |
| |
| buf += sizeof(*match32); |
| buf += match32->match_size; |
| |
| if (match_kern) |
| match_kern->match_size = ret; |
| |
| WARN_ON(type == EBT_COMPAT_TARGET && size_left); |
| match32 = (struct compat_ebt_entry_mwt *) buf; |
| } |
| |
| return growth; |
| } |
| |
| /* called for all ebt_entry structures. */ |
| static int size_entry_mwt(struct ebt_entry *entry, const unsigned char *base, |
| unsigned int *total, |
| struct ebt_entries_buf_state *state) |
| { |
| unsigned int i, j, startoff, new_offset = 0; |
| /* stores match/watchers/targets & offset of next struct ebt_entry: */ |
| unsigned int offsets[4]; |
| unsigned int *offsets_update = NULL; |
| int ret; |
| char *buf_start; |
| |
| if (*total < sizeof(struct ebt_entries)) |
| return -EINVAL; |
| |
| if (!entry->bitmask) { |
| *total -= sizeof(struct ebt_entries); |
| return ebt_buf_add(state, entry, sizeof(struct ebt_entries)); |
| } |
| if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry)) |
| return -EINVAL; |
| |
| startoff = state->buf_user_offset; |
| /* pull in most part of ebt_entry, it does not need to be changed. */ |
| ret = ebt_buf_add(state, entry, |
| offsetof(struct ebt_entry, watchers_offset)); |
| if (ret < 0) |
| return ret; |
| |
| offsets[0] = sizeof(struct ebt_entry); /* matches come first */ |
| memcpy(&offsets[1], &entry->watchers_offset, |
| sizeof(offsets) - sizeof(offsets[0])); |
| |
| if (state->buf_kern_start) { |
| buf_start = state->buf_kern_start + state->buf_kern_offset; |
| offsets_update = (unsigned int *) buf_start; |
| } |
| ret = ebt_buf_add(state, &offsets[1], |
| sizeof(offsets) - sizeof(offsets[0])); |
| if (ret < 0) |
| return ret; |
| buf_start = (char *) entry; |
| /* |
| * 0: matches offset, always follows ebt_entry. |
| * 1: watchers offset, from ebt_entry structure |
| * 2: target offset, from ebt_entry structure |
| * 3: next ebt_entry offset, from ebt_entry structure |
| * |
| * offsets are relative to beginning of struct ebt_entry (i.e., 0). |
| */ |
| for (i = 0, j = 1 ; j < 4 ; j++, i++) { |
| struct compat_ebt_entry_mwt *match32; |
| unsigned int size; |
| char *buf = buf_start; |
| |
| buf = buf_start + offsets[i]; |
| if (offsets[i] > offsets[j]) |
| return -EINVAL; |
| |
| match32 = (struct compat_ebt_entry_mwt *) buf; |
| size = offsets[j] - offsets[i]; |
| ret = ebt_size_mwt(match32, size, i, state, base); |
| if (ret < 0) |
| return ret; |
| new_offset += ret; |
| if (offsets_update && new_offset) { |
| pr_debug("change offset %d to %d\n", |
| offsets_update[i], offsets[j] + new_offset); |
| offsets_update[i] = offsets[j] + new_offset; |
| } |
| } |
| |
| if (state->buf_kern_start == NULL) { |
| unsigned int offset = buf_start - (char *) base; |
| |
| ret = xt_compat_add_offset(NFPROTO_BRIDGE, offset, new_offset); |
| if (ret < 0) |
| return ret; |
| } |
| |
| startoff = state->buf_user_offset - startoff; |
| |
| BUG_ON(*total < startoff); |
| *total -= startoff; |
| return 0; |
| } |
| |
| /* |
| * repl->entries_size is the size of the ebt_entry blob in userspace. |
| * It might need more memory when copied to a 64 bit kernel in case |
| * userspace is 32-bit. So, first task: find out how much memory is needed. |
| * |
| * Called before validation is performed. |
| */ |
| static int compat_copy_entries(unsigned char *data, unsigned int size_user, |
| struct ebt_entries_buf_state *state) |
| { |
| unsigned int size_remaining = size_user; |
| int ret; |
| |
| ret = EBT_ENTRY_ITERATE(data, size_user, size_entry_mwt, data, |
| &size_remaining, state); |
| if (ret < 0) |
| return ret; |
| |
| WARN_ON(size_remaining); |
| return state->buf_kern_offset; |
| } |
| |
| |
| static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl, |
| void __user *user, unsigned int len) |
| { |
| struct compat_ebt_replace tmp; |
| int i; |
| |
| if (len < sizeof(tmp)) |
| return -EINVAL; |
| |
| if (copy_from_user(&tmp, user, sizeof(tmp))) |
| return -EFAULT; |
| |
| if (len != sizeof(tmp) + tmp.entries_size) |
| return -EINVAL; |
| |
| if (tmp.entries_size == 0) |
| return -EINVAL; |
| |
| if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) / |
| NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter)) |
| return -ENOMEM; |
| if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter)) |
| return -ENOMEM; |
| |
| memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry)); |
| |
| /* starting with hook_entry, 32 vs. 64 bit structures are different */ |
| for (i = 0; i < NF_BR_NUMHOOKS; i++) |
| repl->hook_entry[i] = compat_ptr(tmp.hook_entry[i]); |
| |
| repl->num_counters = tmp.num_counters; |
| repl->counters = compat_ptr(tmp.counters); |
| repl->entries = compat_ptr(tmp.entries); |
| return 0; |
| } |
| |
| static int compat_do_replace(struct net *net, void __user *user, |
| unsigned int len) |
| { |
| int ret, i, countersize, size64; |
| struct ebt_table_info *newinfo; |
| struct ebt_replace tmp; |
| struct ebt_entries_buf_state state; |
| void *entries_tmp; |
| |
| ret = compat_copy_ebt_replace_from_user(&tmp, user, len); |
| if (ret) { |
| /* try real handler in case userland supplied needed padding */ |
| if (ret == -EINVAL && do_replace(net, user, len) == 0) |
| ret = 0; |
| return ret; |
| } |
| |
| countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids; |
| newinfo = vmalloc(sizeof(*newinfo) + countersize); |
| if (!newinfo) |
| return -ENOMEM; |
| |
| if (countersize) |
| memset(newinfo->counters, 0, countersize); |
| |
| memset(&state, 0, sizeof(state)); |
| |
| newinfo->entries = vmalloc(tmp.entries_size); |
| if (!newinfo->entries) { |
| ret = -ENOMEM; |
| goto free_newinfo; |
| } |
| if (copy_from_user( |
| newinfo->entries, tmp.entries, tmp.entries_size) != 0) { |
| ret = -EFAULT; |
| goto free_entries; |
| } |
| |
| entries_tmp = newinfo->entries; |
| |
| xt_compat_lock(NFPROTO_BRIDGE); |
| |
| xt_compat_init_offsets(NFPROTO_BRIDGE, tmp.nentries); |
| ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state); |
| if (ret < 0) |
| goto out_unlock; |
| |
| pr_debug("tmp.entries_size %d, kern off %d, user off %d delta %d\n", |
| tmp.entries_size, state.buf_kern_offset, state.buf_user_offset, |
| xt_compat_calc_jump(NFPROTO_BRIDGE, tmp.entries_size)); |
| |
| size64 = ret; |
| newinfo->entries = vmalloc(size64); |
| if (!newinfo->entries) { |
| vfree(entries_tmp); |
| ret = -ENOMEM; |
| goto out_unlock; |
| } |
| |
| memset(&state, 0, sizeof(state)); |
| state.buf_kern_start = newinfo->entries; |
| state.buf_kern_len = size64; |
| |
| ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state); |
| BUG_ON(ret < 0); /* parses same data again */ |
| |
| vfree(entries_tmp); |
| tmp.entries_size = size64; |
| |
| for (i = 0; i < NF_BR_NUMHOOKS; i++) { |
| char __user *usrptr; |
| if (tmp.hook_entry[i]) { |
| unsigned int delta; |
| usrptr = (char __user *) tmp.hook_entry[i]; |
| delta = usrptr - tmp.entries; |
| usrptr += xt_compat_calc_jump(NFPROTO_BRIDGE, delta); |
| tmp.hook_entry[i] = (struct ebt_entries __user *)usrptr; |
| } |
| } |
| |
| xt_compat_flush_offsets(NFPROTO_BRIDGE); |
| xt_compat_unlock(NFPROTO_BRIDGE); |
| |
| ret = do_replace_finish(net, &tmp, newinfo); |
| if (ret == 0) |
| return ret; |
| free_entries: |
| vfree(newinfo->entries); |
| free_newinfo: |
| vfree(newinfo); |
| return ret; |
| out_unlock: |
| xt_compat_flush_offsets(NFPROTO_BRIDGE); |
| xt_compat_unlock(NFPROTO_BRIDGE); |
| goto free_entries; |
| } |
| |
| static int compat_update_counters(struct net *net, void __user *user, |
| unsigned int len) |
| { |
| struct compat_ebt_replace hlp; |
| |
| if (copy_from_user(&hlp, user, sizeof(hlp))) |
| return -EFAULT; |
| |
| /* try real handler in case userland supplied needed padding */ |
| if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter)) |
| return update_counters(net, user, len); |
| |
| return do_update_counters(net, hlp.name, compat_ptr(hlp.counters), |
| hlp.num_counters, user, len); |
| } |
| |
| static int compat_do_ebt_set_ctl(struct sock *sk, |
| int cmd, void __user *user, unsigned int len) |
| { |
| int ret; |
| struct net *net = sock_net(sk); |
| |
| if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) |
| return -EPERM; |
| |
| switch (cmd) { |
| case EBT_SO_SET_ENTRIES: |
| ret = compat_do_replace(net, user, len); |
| break; |
| case EBT_SO_SET_COUNTERS: |
| ret = compat_update_counters(net, user, len); |
| break; |
| default: |
| ret = -EINVAL; |
| } |
| return ret; |
| } |
| |
| static int compat_do_ebt_get_ctl(struct sock *sk, int cmd, |
| void __user *user, int *len) |
| { |
| int ret; |
| struct compat_ebt_replace tmp; |
| struct ebt_table *t; |
| struct net *net = sock_net(sk); |
| |
| if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) |
| return -EPERM; |
| |
| /* try real handler in case userland supplied needed padding */ |
| if ((cmd == EBT_SO_GET_INFO || |
| cmd == EBT_SO_GET_INIT_INFO) && *len != sizeof(tmp)) |
| return do_ebt_get_ctl(sk, cmd, user, len); |
| |
| if (copy_from_user(&tmp, user, sizeof(tmp))) |
| return -EFAULT; |
| |
| t = find_table_lock(net, tmp.name, &ret, &ebt_mutex); |
| if (!t) |
| return ret; |
| |
| xt_compat_lock(NFPROTO_BRIDGE); |
| switch (cmd) { |
| case EBT_SO_GET_INFO: |
| tmp.nentries = t->private->nentries; |
| ret = compat_table_info(t->private, &tmp); |
| if (ret) |
| goto out; |
| tmp.valid_hooks = t->valid_hooks; |
| |
| if (copy_to_user(user, &tmp, *len) != 0) { |
| ret = -EFAULT; |
| break; |
| } |
| ret = 0; |
| break; |
| case EBT_SO_GET_INIT_INFO: |
| tmp.nentries = t->table->nentries; |
| tmp.entries_size = t->table->entries_size; |
| tmp.valid_hooks = t->table->valid_hooks; |
| |
| if (copy_to_user(user, &tmp, *len) != 0) { |
| ret = -EFAULT; |
| break; |
| } |
| ret = 0; |
| break; |
| case EBT_SO_GET_ENTRIES: |
| case EBT_SO_GET_INIT_ENTRIES: |
| /* |
| * try real handler first in case of userland-side padding. |
| * in case we are dealing with an 'ordinary' 32 bit binary |
| * without 64bit compatibility padding, this will fail right |
| * after copy_from_user when the *len argument is validated. |
| * |
| * the compat_ variant needs to do one pass over the kernel |
| * data set to adjust for size differences before it the check. |
| */ |
| if (copy_everything_to_user(t, user, len, cmd) == 0) |
| ret = 0; |
| else |
| ret = compat_copy_everything_to_user(t, user, len, cmd); |
| break; |
| default: |
| ret = -EINVAL; |
| } |
| out: |
| xt_compat_flush_offsets(NFPROTO_BRIDGE); |
| xt_compat_unlock(NFPROTO_BRIDGE); |
| mutex_unlock(&ebt_mutex); |
| return ret; |
| } |
| #endif |
| |
| static struct nf_sockopt_ops ebt_sockopts = { |
| .pf = PF_INET, |
| .set_optmin = EBT_BASE_CTL, |
| .set_optmax = EBT_SO_SET_MAX + 1, |
| .set = do_ebt_set_ctl, |
| #ifdef CONFIG_COMPAT |
| .compat_set = compat_do_ebt_set_ctl, |
| #endif |
| .get_optmin = EBT_BASE_CTL, |
| .get_optmax = EBT_SO_GET_MAX + 1, |
| .get = do_ebt_get_ctl, |
| #ifdef CONFIG_COMPAT |
| .compat_get = compat_do_ebt_get_ctl, |
| #endif |
| .owner = THIS_MODULE, |
| }; |
| |
| static int __init ebtables_init(void) |
| { |
| int ret; |
| |
| ret = xt_register_target(&ebt_standard_target); |
| if (ret < 0) |
| return ret; |
| ret = nf_register_sockopt(&ebt_sockopts); |
| if (ret < 0) { |
| xt_unregister_target(&ebt_standard_target); |
| return ret; |
| } |
| |
| printk(KERN_INFO "Ebtables v2.0 registered\n"); |
| return 0; |
| } |
| |
| static void __exit ebtables_fini(void) |
| { |
| nf_unregister_sockopt(&ebt_sockopts); |
| xt_unregister_target(&ebt_standard_target); |
| printk(KERN_INFO "Ebtables v2.0 unregistered\n"); |
| } |
| |
| EXPORT_SYMBOL(ebt_register_table); |
| EXPORT_SYMBOL(ebt_unregister_table); |
| EXPORT_SYMBOL(ebt_do_table); |
| module_init(ebtables_init); |
| module_exit(ebtables_fini); |
| MODULE_LICENSE("GPL"); |