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|
/*
* Packet matching code.
*
* Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
* Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/capability.h>
#include <linux/in.h>
#include <linux/skbuff.h>
#include <linux/kmod.h>
#include <linux/vmalloc.h>
#include <linux/netdevice.h>
#include <linux/module.h>
#include <linux/poison.h>
#include <linux/icmpv6.h>
#include <net/ipv6.h>
#include <asm/uaccess.h>
#include <linux/mutex.h>
#include <linux/proc_fs.h>
#include <linux/cpumask.h>
#include <linux/netfilter_ipv6/ip6_tables.h>
#include <linux/netfilter/x_tables.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
MODULE_DESCRIPTION("IPv6 packet filter");
/*#define DEBUG_IP_FIREWALL*/
/*#define DEBUG_ALLOW_ALL*/ /* Useful for remote debugging */
/*#define DEBUG_IP_FIREWALL_USER*/
#ifdef DEBUG_IP_FIREWALL
#define dprintf(format, args...) printk(format , ## args)
#else
#define dprintf(format, args...)
#endif
#ifdef DEBUG_IP_FIREWALL_USER
#define duprintf(format, args...) printk(format , ## args)
#else
#define duprintf(format, args...)
#endif
#ifdef CONFIG_NETFILTER_DEBUG
#define IP_NF_ASSERT(x) \
do { \
if (!(x)) \
printk("IP_NF_ASSERT: %s:%s:%u\n", \
__FUNCTION__, __FILE__, __LINE__); \
} while(0)
#else
#define IP_NF_ASSERT(x)
#endif
#if 0
/* All the better to debug you with... */
#define static
#define inline
#endif
/*
We keep a set of rules for each CPU, so we can avoid write-locking
them in the softirq when updating the counters and therefore
only need to read-lock in the softirq; doing a write_lock_bh() in user
context stops packets coming through and allows user context to read
the counters or update the rules.
Hence the start of any table is given by get_table() below. */
/* Check for an extension */
int
ip6t_ext_hdr(u8 nexthdr)
{
return ( (nexthdr == IPPROTO_HOPOPTS) ||
(nexthdr == IPPROTO_ROUTING) ||
(nexthdr == IPPROTO_FRAGMENT) ||
(nexthdr == IPPROTO_ESP) ||
(nexthdr == IPPROTO_AH) ||
(nexthdr == IPPROTO_NONE) ||
(nexthdr == IPPROTO_DSTOPTS) );
}
/* Returns whether matches rule or not. */
static inline bool
ip6_packet_match(const struct sk_buff *skb,
const char *indev,
const char *outdev,
const struct ip6t_ip6 *ip6info,
unsigned int *protoff,
int *fragoff, bool *hotdrop)
{
size_t i;
unsigned long ret;
const struct ipv6hdr *ipv6 = ipv6_hdr(skb);
#define FWINV(bool,invflg) ((bool) ^ !!(ip6info->invflags & invflg))
if (FWINV(ipv6_masked_addr_cmp(&ipv6->saddr, &ip6info->smsk,
&ip6info->src), IP6T_INV_SRCIP)
|| FWINV(ipv6_masked_addr_cmp(&ipv6->daddr, &ip6info->dmsk,
&ip6info->dst), IP6T_INV_DSTIP)) {
dprintf("Source or dest mismatch.\n");
/*
dprintf("SRC: %u. Mask: %u. Target: %u.%s\n", ip->saddr,
ipinfo->smsk.s_addr, ipinfo->src.s_addr,
ipinfo->invflags & IP6T_INV_SRCIP ? " (INV)" : "");
dprintf("DST: %u. Mask: %u. Target: %u.%s\n", ip->daddr,
ipinfo->dmsk.s_addr, ipinfo->dst.s_addr,
ipinfo->invflags & IP6T_INV_DSTIP ? " (INV)" : "");*/
return false;
}
/* Look for ifname matches; this should unroll nicely. */
for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
ret |= (((const unsigned long *)indev)[i]
^ ((const unsigned long *)ip6info->iniface)[i])
& ((const unsigned long *)ip6info->iniface_mask)[i];
}
if (FWINV(ret != 0, IP6T_INV_VIA_IN)) {
dprintf("VIA in mismatch (%s vs %s).%s\n",
indev, ip6info->iniface,
ip6info->invflags&IP6T_INV_VIA_IN ?" (INV)":"");
return false;
}
for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
ret |= (((const unsigned long *)outdev)[i]
^ ((const unsigned long *)ip6info->outiface)[i])
& ((const unsigned long *)ip6info->outiface_mask)[i];
}
if (FWINV(ret != 0, IP6T_INV_VIA_OUT)) {
dprintf("VIA out mismatch (%s vs %s).%s\n",
outdev, ip6info->outiface,
ip6info->invflags&IP6T_INV_VIA_OUT ?" (INV)":"");
return false;
}
/* ... might want to do something with class and flowlabel here ... */
/* look for the desired protocol header */
if((ip6info->flags & IP6T_F_PROTO)) {
int protohdr;
unsigned short _frag_off;
protohdr = ipv6_find_hdr(skb, protoff, -1, &_frag_off);
if (protohdr < 0) {
if (_frag_off == 0)
*hotdrop = true;
return false;
}
*fragoff = _frag_off;
dprintf("Packet protocol %hi ?= %s%hi.\n",
protohdr,
ip6info->invflags & IP6T_INV_PROTO ? "!":"",
ip6info->proto);
if (ip6info->proto == protohdr) {
if(ip6info->invflags & IP6T_INV_PROTO) {
return false;
}
return true;
}
/* We need match for the '-p all', too! */
if ((ip6info->proto != 0) &&
!(ip6info->invflags & IP6T_INV_PROTO))
return false;
}
return true;
}
/* should be ip6 safe */
static inline bool
ip6_checkentry(const struct ip6t_ip6 *ipv6)
{
if (ipv6->flags & ~IP6T_F_MASK) {
duprintf("Unknown flag bits set: %08X\n",
ipv6->flags & ~IP6T_F_MASK);
return false;
}
if (ipv6->invflags & ~IP6T_INV_MASK) {
duprintf("Unknown invflag bits set: %08X\n",
ipv6->invflags & ~IP6T_INV_MASK);
return false;
}
return true;
}
static unsigned int
ip6t_error(struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
unsigned int hooknum,
const struct xt_target *target,
const void *targinfo)
{
if (net_ratelimit())
printk("ip6_tables: error: `%s'\n", (char *)targinfo);
return NF_DROP;
}
static inline
bool do_match(struct ip6t_entry_match *m,
const struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
int offset,
unsigned int protoff,
bool *hotdrop)
{
/* Stop iteration if it doesn't match */
if (!m->u.kernel.match->match(skb, in, out, m->u.kernel.match, m->data,
offset, protoff, hotdrop))
return true;
else
return false;
}
static inline struct ip6t_entry *
get_entry(void *base, unsigned int offset)
{
return (struct ip6t_entry *)(base + offset);
}
/* All zeroes == unconditional rule. */
static inline int
unconditional(const struct ip6t_ip6 *ipv6)
{
unsigned int i;
for (i = 0; i < sizeof(*ipv6); i++)
if (((char *)ipv6)[i])
break;
return (i == sizeof(*ipv6));
}
#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
/* This cries for unification! */
static const char *hooknames[] = {
[NF_INET_PRE_ROUTING] = "PREROUTING",
[NF_INET_LOCAL_IN] = "INPUT",
[NF_INET_FORWARD] = "FORWARD",
[NF_INET_LOCAL_OUT] = "OUTPUT",
[NF_INET_POST_ROUTING] = "POSTROUTING",
};
enum nf_ip_trace_comments {
NF_IP6_TRACE_COMMENT_RULE,
NF_IP6_TRACE_COMMENT_RETURN,
NF_IP6_TRACE_COMMENT_POLICY,
};
static const char *comments[] = {
[NF_IP6_TRACE_COMMENT_RULE] = "rule",
[NF_IP6_TRACE_COMMENT_RETURN] = "return",
[NF_IP6_TRACE_COMMENT_POLICY] = "policy",
};
static struct nf_loginfo trace_loginfo = {
.type = NF_LOG_TYPE_LOG,
.u = {
.log = {
.level = 4,
.logflags = NF_LOG_MASK,
},
},
};
static inline int
get_chainname_rulenum(struct ip6t_entry *s, struct ip6t_entry *e,
char *hookname, char **chainname,
char **comment, unsigned int *rulenum)
{
struct ip6t_standard_target *t = (void *)ip6t_get_target(s);
if (strcmp(t->target.u.kernel.target->name, IP6T_ERROR_TARGET) == 0) {
/* Head of user chain: ERROR target with chainname */
*chainname = t->target.data;
(*rulenum) = 0;
} else if (s == e) {
(*rulenum)++;
if (s->target_offset == sizeof(struct ip6t_entry)
&& strcmp(t->target.u.kernel.target->name,
IP6T_STANDARD_TARGET) == 0
&& t->verdict < 0
&& unconditional(&s->ipv6)) {
/* Tail of chains: STANDARD target (return/policy) */
*comment = *chainname == hookname
? (char *)comments[NF_IP6_TRACE_COMMENT_POLICY]
: (char *)comments[NF_IP6_TRACE_COMMENT_RETURN];
}
return 1;
} else
(*rulenum)++;
return 0;
}
static void trace_packet(struct sk_buff *skb,
unsigned int hook,
const struct net_device *in,
const struct net_device *out,
char *tablename,
struct xt_table_info *private,
struct ip6t_entry *e)
{
void *table_base;
struct ip6t_entry *root;
char *hookname, *chainname, *comment;
unsigned int rulenum = 0;
table_base = (void *)private->entries[smp_processor_id()];
root = get_entry(table_base, private->hook_entry[hook]);
hookname = chainname = (char *)hooknames[hook];
comment = (char *)comments[NF_IP6_TRACE_COMMENT_RULE];
IP6T_ENTRY_ITERATE(root,
private->size - private->hook_entry[hook],
get_chainname_rulenum,
e, hookname, &chainname, &comment, &rulenum);
nf_log_packet(AF_INET6, hook, skb, in, out, &trace_loginfo,
"TRACE: %s:%s:%s:%u ",
tablename, chainname, comment, rulenum);
}
#endif
/* Returns one of the generic firewall policies, like NF_ACCEPT. */
unsigned int
ip6t_do_table(struct sk_buff *skb,
unsigned int hook,
const struct net_device *in,
const struct net_device *out,
struct xt_table *table)
{
static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
int offset = 0;
unsigned int protoff = 0;
bool hotdrop = false;
/* Initializing verdict to NF_DROP keeps gcc happy. */
unsigned int verdict = NF_DROP;
const char *indev, *outdev;
void *table_base;
struct ip6t_entry *e, *back;
struct xt_table_info *private;
/* Initialization */
indev = in ? in->name : nulldevname;
outdev = out ? out->name : nulldevname;
/* We handle fragments by dealing with the first fragment as
* if it was a normal packet. All other fragments are treated
* normally, except that they will NEVER match rules that ask
* things we don't know, ie. tcp syn flag or ports). If the
* rule is also a fragment-specific rule, non-fragments won't
* match it. */
read_lock_bh(&table->lock);
private = table->private;
IP_NF_ASSERT(table->valid_hooks & (1 << hook));
table_base = (void *)private->entries[smp_processor_id()];
e = get_entry(table_base, private->hook_entry[hook]);
/* For return from builtin chain */
back = get_entry(table_base, private->underflow[hook]);
do {
IP_NF_ASSERT(e);
IP_NF_ASSERT(back);
if (ip6_packet_match(skb, indev, outdev, &e->ipv6,
&protoff, &offset, &hotdrop)) {
struct ip6t_entry_target *t;
if (IP6T_MATCH_ITERATE(e, do_match,
skb, in, out,
offset, protoff, &hotdrop) != 0)
goto no_match;
ADD_COUNTER(e->counters,
ntohs(ipv6_hdr(skb)->payload_len) +
sizeof(struct ipv6hdr), 1);
t = ip6t_get_target(e);
IP_NF_ASSERT(t->u.kernel.target);
#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
/* The packet is traced: log it */
if (unlikely(skb->nf_trace))
trace_packet(skb, hook, in, out,
table->name, private, e);
#endif
/* Standard target? */
if (!t->u.kernel.target->target) {
int v;
v = ((struct ip6t_standard_target *)t)->verdict;
if (v < 0) {
/* Pop from stack? */
if (v != IP6T_RETURN) {
verdict = (unsigned)(-v) - 1;
break;
}
e = back;
back = get_entry(table_base,
back->comefrom);
continue;
}
if (table_base + v != (void *)e + e->next_offset
&& !(e->ipv6.flags & IP6T_F_GOTO)) {
/* Save old back ptr in next entry */
struct ip6t_entry *next
= (void *)e + e->next_offset;
next->comefrom
= (void *)back - table_base;
/* set back pointer to next entry */
back = next;
}
e = get_entry(table_base, v);
} else {
/* Targets which reenter must return
abs. verdicts */
#ifdef CONFIG_NETFILTER_DEBUG
((struct ip6t_entry *)table_base)->comefrom
= 0xeeeeeeec;
#endif
verdict = t->u.kernel.target->target(skb,
in, out,
hook,
t->u.kernel.target,
t->data);
#ifdef CONFIG_NETFILTER_DEBUG
if (((struct ip6t_entry *)table_base)->comefrom
!= 0xeeeeeeec
&& verdict == IP6T_CONTINUE) {
printk("Target %s reentered!\n",
t->u.kernel.target->name);
verdict = NF_DROP;
}
((struct ip6t_entry *)table_base)->comefrom
= 0x57acc001;
#endif
if (verdict == IP6T_CONTINUE)
e = (void *)e + e->next_offset;
else
/* Verdict */
break;
}
} else {
no_match:
e = (void *)e + e->next_offset;
}
} while (!hotdrop);
#ifdef CONFIG_NETFILTER_DEBUG
((struct ip6t_entry *)table_base)->comefrom = NETFILTER_LINK_POISON;
#endif
read_unlock_bh(&table->lock);
#ifdef DEBUG_ALLOW_ALL
return NF_ACCEPT;
#else
if (hotdrop)
return NF_DROP;
else return verdict;
#endif
}
/* 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(struct xt_table_info *newinfo,
unsigned int valid_hooks, void *entry0)
{
unsigned int hook;
/* No recursion; use packet counter to save back ptrs (reset
to 0 as we leave), and comefrom to save source hook bitmask */
for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) {
unsigned int pos = newinfo->hook_entry[hook];
struct ip6t_entry *e
= (struct ip6t_entry *)(entry0 + pos);
int visited = e->comefrom & (1 << hook);
if (!(valid_hooks & (1 << hook)))
continue;
/* Set initial back pointer. */
e->counters.pcnt = pos;
for (;;) {
struct ip6t_standard_target *t
= (void *)ip6t_get_target(e);
if (e->comefrom & (1 << NF_INET_NUMHOOKS)) {
printk("iptables: loop hook %u pos %u %08X.\n",
hook, pos, e->comefrom);
return 0;
}
e->comefrom
|= ((1 << hook) | (1 << NF_INET_NUMHOOKS));
/* Unconditional return/END. */
if ((e->target_offset == sizeof(struct ip6t_entry)
&& (strcmp(t->target.u.user.name,
IP6T_STANDARD_TARGET) == 0)
&& t->verdict < 0
&& unconditional(&e->ipv6)) || visited) {
unsigned int oldpos, size;
if (t->verdict < -NF_MAX_VERDICT - 1) {
duprintf("mark_source_chains: bad "
"negative verdict (%i)\n",
t->verdict);
return 0;
}
/* Return: backtrack through the last
big jump. */
do {
e->comefrom ^= (1<<NF_INET_NUMHOOKS);
#ifdef DEBUG_IP_FIREWALL_USER
if (e->comefrom
& (1 << NF_INET_NUMHOOKS)) {
duprintf("Back unset "
"on hook %u "
"rule %u\n",
hook, pos);
}
#endif
oldpos = pos;
pos = e->counters.pcnt;
e->counters.pcnt = 0;
/* We're at the start. */
if (pos == oldpos)
goto next;
e = (struct ip6t_entry *)
(entry0 + pos);
} while (oldpos == pos + e->next_offset);
/* Move along one */
size = e->next_offset;
e = (struct ip6t_entry *)
(entry0 + pos + size);
e->counters.pcnt = pos;
pos += size;
} else {
int newpos = t->verdict;
if (strcmp(t->target.u.user.name,
IP6T_STANDARD_TARGET) == 0
&& newpos >= 0) {
if (newpos > newinfo->size -
sizeof(struct ip6t_entry)) {
duprintf("mark_source_chains: "
"bad verdict (%i)\n",
newpos);
return 0;
}
/* This a jump; chase it. */
duprintf("Jump rule %u -> %u\n",
pos, newpos);
} else {
/* ... this is a fallthru */
newpos = pos + e->next_offset;
}
e = (struct ip6t_entry *)
(entry0 + newpos);
e->counters.pcnt = pos;
pos = newpos;
}
}
next:
duprintf("Finished chain %u\n", hook);
}
return 1;
}
static inline int
cleanup_match(struct ip6t_entry_match *m, unsigned int *i)
{
if (i && (*i)-- == 0)
return 1;
if (m->u.kernel.match->destroy)
m->u.kernel.match->destroy(m->u.kernel.match, m->data);
module_put(m->u.kernel.match->me);
return 0;
}
static inline int
check_entry(struct ip6t_entry *e, const char *name)
{
struct ip6t_entry_target *t;
if (!ip6_checkentry(&e->ipv6)) {
duprintf("ip_tables: ip check failed %p %s.\n", e, name);
return -EINVAL;
}
if (e->target_offset + sizeof(struct ip6t_entry_target) >
e->next_offset)
return -EINVAL;
t = ip6t_get_target(e);
if (e->target_offset + t->u.target_size > e->next_offset)
return -EINVAL;
return 0;
}
static inline int check_match(struct ip6t_entry_match *m, const char *name,
const struct ip6t_ip6 *ipv6,
unsigned int hookmask, unsigned int *i)
{
struct xt_match *match;
int ret;
match = m->u.kernel.match;
ret = xt_check_match(match, AF_INET6, m->u.match_size - sizeof(*m),
name, hookmask, ipv6->proto,
ipv6->invflags & IP6T_INV_PROTO);
if (!ret && m->u.kernel.match->checkentry
&& !m->u.kernel.match->checkentry(name, ipv6, match, m->data,
hookmask)) {
duprintf("ip_tables: check failed for `%s'.\n",
m->u.kernel.match->name);
ret = -EINVAL;
}
if (!ret)
(*i)++;
return ret;
}
static inline int
find_check_match(struct ip6t_entry_match *m,
const char *name,
const struct ip6t_ip6 *ipv6,
unsigned int hookmask,
unsigned int *i)
{
struct xt_match *match;
int ret;
match = try_then_request_module(xt_find_match(AF_INET6, m->u.user.name,
m->u.user.revision),
"ip6t_%s", m->u.user.name);
if (IS_ERR(match) || !match) {
duprintf("find_check_match: `%s' not found\n", m->u.user.name);
return match ? PTR_ERR(match) : -ENOENT;
}
m->u.kernel.match = match;
ret = check_match(m, name, ipv6, hookmask, i);
if (ret)
goto err;
return 0;
err:
module_put(m->u.kernel.match->me);
return ret;
}
static inline int check_target(struct ip6t_entry *e, const char *name)
{
struct ip6t_entry_target *t;
struct xt_target *target;
int ret;
t = ip6t_get_target(e);
target = t->u.kernel.target;
ret = xt_check_target(target, AF_INET6, t->u.target_size - sizeof(*t),
name, e->comefrom, e->ipv6.proto,
e->ipv6.invflags & IP6T_INV_PROTO);
if (!ret && t->u.kernel.target->checkentry
&& !t->u.kernel.target->checkentry(name, e, target, t->data,
e->comefrom)) {
duprintf("ip_tables: check failed for `%s'.\n",
t->u.kernel.target->name);
ret = -EINVAL;
}
return ret;
}
static inline int
find_check_entry(struct ip6t_entry *e, const char *name, unsigned int size,
unsigned int *i)
{
struct ip6t_entry_target *t;
struct xt_target *target;
int ret;
unsigned int j;
ret = check_entry(e, name);
if (ret)
return ret;
j = 0;
ret = IP6T_MATCH_ITERATE(e, find_check_match, name, &e->ipv6,
e->comefrom, &j);
if (ret != 0)
goto cleanup_matches;
t = ip6t_get_target(e);
target = try_then_request_module(xt_find_target(AF_INET6,
t->u.user.name,
t->u.user.revision),
"ip6t_%s", t->u.user.name);
if (IS_ERR(target) || !target) {
duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
ret = target ? PTR_ERR(target) : -ENOENT;
goto cleanup_matches;
}
t->u.kernel.target = target;
ret = check_target(e, name);
if (ret)
goto err;
(*i)++;
return 0;
err:
module_put(t->u.kernel.target->me);
cleanup_matches:
IP6T_MATCH_ITERATE(e, cleanup_match, &j);
return ret;
}
static inline int
check_entry_size_and_hooks(struct ip6t_entry *e,
struct xt_table_info *newinfo,
unsigned char *base,
unsigned char *limit,
const unsigned int *hook_entries,
const unsigned int *underflows,
unsigned int *i)
{
unsigned int h;
if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0
|| (unsigned char *)e + sizeof(struct ip6t_entry) >= limit) {
duprintf("Bad offset %p\n", e);
return -EINVAL;
}
if (e->next_offset
< sizeof(struct ip6t_entry) + sizeof(struct ip6t_entry_target)) {
duprintf("checking: element %p size %u\n",
e, e->next_offset);
return -EINVAL;
}
/* Check hooks & underflows */
for (h = 0; h < NF_INET_NUMHOOKS; h++) {
if ((unsigned char *)e - base == hook_entries[h])
newinfo->hook_entry[h] = hook_entries[h];
if ((unsigned char *)e - base == underflows[h])
newinfo->underflow[h] = underflows[h];
}
/* FIXME: underflows must be unconditional, standard verdicts
< 0 (not IP6T_RETURN). --RR */
/* Clear counters and comefrom */
e->counters = ((struct xt_counters) { 0, 0 });
e->comefrom = 0;
(*i)++;
return 0;
}
static inline int
cleanup_entry(struct ip6t_entry *e, unsigned int *i)
{
struct ip6t_entry_target *t;
if (i && (*i)-- == 0)
return 1;
/* Cleanup all matches */
IP6T_MATCH_ITERATE(e, cleanup_match, NULL);
t = ip6t_get_target(e);
if (t->u.kernel.target->destroy)
t->u.kernel.target->destroy(t->u.kernel.target, t->data);
module_put(t->u.kernel.target->me);
return 0;
}
/* Checks and translates the user-supplied table segment (held in
newinfo) */
static int
translate_table(const char *name,
unsigned int valid_hooks,
struct xt_table_info *newinfo,
void *entry0,
unsigned int size,
unsigned int number,
const unsigned int *hook_entries,
const unsigned int *underflows)
{
unsigned int i;
int ret;
newinfo->size = size;
newinfo->number = number;
/* Init all hooks to impossible value. */
for (i = 0; i < NF_INET_NUMHOOKS; i++) {
newinfo->hook_entry[i] = 0xFFFFFFFF;
newinfo->underflow[i] = 0xFFFFFFFF;
}
duprintf("translate_table: size %u\n", newinfo->size);
i = 0;
/* Walk through entries, checking offsets. */
ret = IP6T_ENTRY_ITERATE(entry0, newinfo->size,
check_entry_size_and_hooks,
newinfo,
entry0,
entry0 + size,
hook_entries, underflows, &i);
if (ret != 0)
return ret;
if (i != number) {
duprintf("translate_table: %u not %u entries\n",
i, number);
return -EINVAL;
}
/* Check hooks all assigned */
for (i = 0; i < NF_INET_NUMHOOKS; i++) {
/* Only hooks which are valid */
if (!(valid_hooks & (1 << i)))
continue;
if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
duprintf("Invalid hook entry %u %u\n",
i, hook_entries[i]);
return -EINVAL;
}
if (newinfo->underflow[i] == 0xFFFFFFFF) {
duprintf("Invalid underflow %u %u\n",
i, underflows[i]);
return -EINVAL;
}
}
if (!mark_source_chains(newinfo, valid_hooks, entry0))
return -ELOOP;
/* Finally, each sanity check must pass */
i = 0;
ret = IP6T_ENTRY_ITERATE(entry0, newinfo->size,
find_check_entry, name, size, &i);
if (ret != 0) {
IP6T_ENTRY_ITERATE(entry0, newinfo->size,
cleanup_entry, &i);
return ret;
}
/* And one copy for every other CPU */
for_each_possible_cpu(i) {
if (newinfo->entries[i] && newinfo->entries[i] != entry0)
memcpy(newinfo->entries[i], entry0, newinfo->size);
}
return 0;
}
/* Gets counters. */
static inline int
add_entry_to_counter(const struct ip6t_entry *e,
struct xt_counters total[],
unsigned int *i)
{
ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
(*i)++;
return 0;
}
static inline int
set_entry_to_counter(const struct ip6t_entry *e,
struct ip6t_counters total[],
unsigned int *i)
{
SET_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
(*i)++;
return 0;
}
static void
get_counters(const struct xt_table_info *t,
struct xt_counters counters[])
{
unsigned int cpu;
unsigned int i;
unsigned int curcpu;
/* Instead of clearing (by a previous call to memset())
* the counters and using adds, we set the counters
* with data used by 'current' CPU
* We dont care about preemption here.
*/
curcpu = raw_smp_processor_id();
i = 0;
IP6T_ENTRY_ITERATE(t->entries[curcpu],
t->size,
set_entry_to_counter,
counters,
&i);
for_each_possible_cpu(cpu) {
if (cpu == curcpu)
continue;
i = 0;
IP6T_ENTRY_ITERATE(t->entries[cpu],
t->size,
add_entry_to_counter,
counters,
&i);
}
}
static int
copy_entries_to_user(unsigned int total_size,
struct xt_table *table,
void __user *userptr)
{
unsigned int off, num, countersize;
struct ip6t_entry *e;
struct xt_counters *counters;
struct xt_table_info *private = table->private;
int ret = 0;
void *loc_cpu_entry;
/* 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 = vmalloc_node(countersize, numa_node_id());
if (counters == NULL)
return -ENOMEM;
/* First, sum counters... */
write_lock_bh(&table->lock);
get_counters(private, counters);
write_unlock_bh(&table->lock);
/* choose the copy that is on ourc node/cpu */
loc_cpu_entry = private->entries[raw_smp_processor_id()];
if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
ret = -EFAULT;
goto free_counters;
}
/* FIXME: use iterator macros --RR */
/* ... then go back and fix counters and names */
for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
unsigned int i;
struct ip6t_entry_match *m;
struct ip6t_entry_target *t;
e = (struct ip6t_entry *)(loc_cpu_entry + off);
if (copy_to_user(userptr + off
+ offsetof(struct ip6t_entry, counters),
&counters[num],
sizeof(counters[num])) != 0) {
ret = -EFAULT;
goto free_counters;
}
for (i = sizeof(struct ip6t_entry);
i < e->target_offset;
i += m->u.match_size) {
m = (void *)e + i;
if (copy_to_user(userptr + off + i
+ offsetof(struct ip6t_entry_match,
u.user.name),
m->u.kernel.match->name,
strlen(m->u.kernel.match->name)+1)
!= 0) {
ret = -EFAULT;
goto free_counters;
}
}
t = ip6t_get_target(e);
if (copy_to_user(userptr + off + e->target_offset
+ offsetof(struct ip6t_entry_target,
u.user.name),
t->u.kernel.target->name,
strlen(t->u.kernel.target->name)+1) != 0) {
ret = -EFAULT;
goto free_counters;
}
}
free_counters:
vfree(counters);
return ret;
}
static int
get_entries(const struct ip6t_get_entries *entries,
struct ip6t_get_entries __user *uptr)
{
int ret;
struct xt_table *t;
t = xt_find_table_lock(AF_INET6, entries->name);
if (t && !IS_ERR(t)) {
struct xt_table_info *private = t->private;
duprintf("t->private->number = %u\n", private->number);
if (entries->size == private->size)
ret = copy_entries_to_user(private->size,
t, uptr->entrytable);
else {
duprintf("get_entries: I've got %u not %u!\n",
private->size, entries->size);
ret = -EINVAL;
}
module_put(t->me);
xt_table_unlock(t);
} else
ret = t ? PTR_ERR(t) : -ENOENT;
return ret;
}
static int
do_replace(void __user *user, unsigned int len)
{
int ret;
struct ip6t_replace tmp;
struct xt_table *t;
struct xt_table_info *newinfo, *oldinfo;
struct xt_counters *counters;
void *loc_cpu_entry, *loc_cpu_old_entry;
if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
return -EFAULT;
/* overflow check */
if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
return -ENOMEM;
newinfo = xt_alloc_table_info(tmp.size);
if (!newinfo)
return -ENOMEM;
/* choose the copy that is on our node/cpu */
loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
tmp.size) != 0) {
ret = -EFAULT;
goto free_newinfo;
}
counters = vmalloc_node(tmp.num_counters * sizeof(struct xt_counters),
numa_node_id());
if (!counters) {
ret = -ENOMEM;
goto free_newinfo;
}
ret = translate_table(tmp.name, tmp.valid_hooks,
newinfo, loc_cpu_entry, tmp.size, tmp.num_entries,
tmp.hook_entry, tmp.underflow);
if (ret != 0)
goto free_newinfo_counters;
duprintf("ip_tables: Translated table\n");
t = try_then_request_module(xt_find_table_lock(AF_INET6, tmp.name),
"ip6table_%s", tmp.name);
if (!t || IS_ERR(t)) {
ret = t ? PTR_ERR(t) : -ENOENT;
goto free_newinfo_counters_untrans;
}
/* You lied! */
if (tmp.valid_hooks != t->valid_hooks) {
duprintf("Valid hook crap: %08X vs %08X\n",
tmp.valid_hooks, t->valid_hooks);
ret = -EINVAL;
goto put_module;
}
oldinfo = xt_replace_table(t, tmp.num_counters, newinfo, &ret);
if (!oldinfo)
goto put_module;
/* Update module usage count based on number of rules */
duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
oldinfo->number, oldinfo->initial_entries, newinfo->number);
if ((oldinfo->number > oldinfo->initial_entries) ||
(newinfo->number <= oldinfo->initial_entries))
module_put(t->me);
if ((oldinfo->number > oldinfo->initial_entries) &&
(newinfo->number <= oldinfo->initial_entries))
module_put(t->me);
/* Get the old counters. */
get_counters(oldinfo, counters);
/* Decrease module usage counts and free resource */
loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
IP6T_ENTRY_ITERATE(loc_cpu_old_entry, oldinfo->size, cleanup_entry,NULL);
xt_free_table_info(oldinfo);
if (copy_to_user(tmp.counters, counters,
sizeof(struct xt_counters) * tmp.num_counters) != 0)
ret = -EFAULT;
vfree(counters);
xt_table_unlock(t);
return ret;
put_module:
module_put(t->me);
xt_table_unlock(t);
free_newinfo_counters_untrans:
IP6T_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry,NULL);
free_newinfo_counters:
vfree(counters);
free_newinfo:
xt_free_table_info(newinfo);
return ret;
}
/* We're lazy, and add to the first CPU; overflow works its fey magic
* and everything is OK. */
static inline int
add_counter_to_entry(struct ip6t_entry *e,
const struct xt_counters addme[],
unsigned int *i)
{
#if 0
duprintf("add_counter: Entry %u %lu/%lu + %lu/%lu\n",
*i,
(long unsigned int)e->counters.pcnt,
(long unsigned int)e->counters.bcnt,
(long unsigned int)addme[*i].pcnt,
(long unsigned int)addme[*i].bcnt);
#endif
ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt);
(*i)++;
return 0;
}
static int
do_add_counters(void __user *user, unsigned int len)
{
unsigned int i;
struct xt_counters_info tmp, *paddc;
struct xt_table_info *private;
struct xt_table *t;
int ret = 0;
void *loc_cpu_entry;
if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
return -EFAULT;
if (len != sizeof(tmp) + tmp.num_counters*sizeof(struct xt_counters))
return -EINVAL;
paddc = vmalloc_node(len, numa_node_id());
if (!paddc)
return -ENOMEM;
if (copy_from_user(paddc, user, len) != 0) {
ret = -EFAULT;
goto free;
}
t = xt_find_table_lock(AF_INET6, tmp.name);
if (!t || IS_ERR(t)) {
ret = t ? PTR_ERR(t) : -ENOENT;
goto free;
}
write_lock_bh(&t->lock);
private = t->private;
if (private->number != tmp.num_counters) {
ret = -EINVAL;
goto unlock_up_free;
}
i = 0;
/* Choose the copy that is on our node */
loc_cpu_entry = private->entries[smp_processor_id()];
IP6T_ENTRY_ITERATE(loc_cpu_entry,
private->size,
add_counter_to_entry,
paddc->counters,
&i);
unlock_up_free:
write_unlock_bh(&t->lock);
xt_table_unlock(t);
module_put(t->me);
free:
vfree(paddc);
return ret;
}
static int
do_ip6t_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
{
int ret;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
switch (cmd) {
case IP6T_SO_SET_REPLACE:
ret = do_replace(user, len);
break;
case IP6T_SO_SET_ADD_COUNTERS:
ret = do_add_counters(user, len);
break;
default:
duprintf("do_ip6t_set_ctl: unknown request %i\n", cmd);
ret = -EINVAL;
}
return ret;
}
static int
do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
{
int ret;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
switch (cmd) {
case IP6T_SO_GET_INFO: {
char name[IP6T_TABLE_MAXNAMELEN];
struct xt_table *t;
if (*len != sizeof(struct ip6t_getinfo)) {
duprintf("length %u != %u\n", *len,
sizeof(struct ip6t_getinfo));
ret = -EINVAL;
break;
}
if (copy_from_user(name, user, sizeof(name)) != 0) {
ret = -EFAULT;
break;
}
name[IP6T_TABLE_MAXNAMELEN-1] = '\0';
t = try_then_request_module(xt_find_table_lock(AF_INET6, name),
"ip6table_%s", name);
if (t && !IS_ERR(t)) {
struct ip6t_getinfo info;
struct xt_table_info *private = t->private;
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;
memcpy(info.name, name, sizeof(info.name));
if (copy_to_user(user, &info, *len) != 0)
ret = -EFAULT;
else
ret = 0;
xt_table_unlock(t);
module_put(t->me);
} else
ret = t ? PTR_ERR(t) : -ENOENT;
}
break;
case IP6T_SO_GET_ENTRIES: {
struct ip6t_get_entries get;
if (*len < sizeof(get)) {
duprintf("get_entries: %u < %u\n", *len, sizeof(get));
ret = -EINVAL;
} else if (copy_from_user(&get, user, sizeof(get)) != 0) {
ret = -EFAULT;
} else if (*len != sizeof(struct ip6t_get_entries) + get.size) {
duprintf("get_entries: %u != %u\n", *len,
sizeof(struct ip6t_get_entries) + get.size);
ret = -EINVAL;
} else
ret = get_entries(&get, user);
break;
}
case IP6T_SO_GET_REVISION_MATCH:
case IP6T_SO_GET_REVISION_TARGET: {
struct ip6t_get_revision rev;
int target;
if (*len != sizeof(rev)) {
ret = -EINVAL;
break;
}
if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
ret = -EFAULT;
break;
}
if (cmd == IP6T_SO_GET_REVISION_TARGET)
target = 1;
else
target = 0;
try_then_request_module(xt_find_revision(AF_INET6, rev.name,
rev.revision,
target, &ret),
"ip6t_%s", rev.name);
break;
}
default:
duprintf("do_ip6t_get_ctl: unknown request %i\n", cmd);
ret = -EINVAL;
}
return ret;
}
int ip6t_register_table(struct xt_table *table,
const struct ip6t_replace *repl)
{
int ret;
struct xt_table_info *newinfo;
struct xt_table_info bootstrap
= { 0, 0, 0, { 0 }, { 0 }, { } };
void *loc_cpu_entry;
newinfo = xt_alloc_table_info(repl->size);
if (!newinfo)
return -ENOMEM;
/* choose the copy on our node/cpu */
loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
memcpy(loc_cpu_entry, repl->entries, repl->size);
ret = translate_table(table->name, table->valid_hooks,
newinfo, loc_cpu_entry, repl->size,
repl->num_entries,
repl->hook_entry,
repl->underflow);
if (ret != 0) {
xt_free_table_info(newinfo);
return ret;
}
ret = xt_register_table(table, &bootstrap, newinfo);
if (ret != 0) {
xt_free_table_info(newinfo);
return ret;
}
return 0;
}
void ip6t_unregister_table(struct xt_table *table)
{
struct xt_table_info *private;
void *loc_cpu_entry;
private = xt_unregister_table(table);
/* Decrease module usage counts and free resources */
loc_cpu_entry = private->entries[raw_smp_processor_id()];
IP6T_ENTRY_ITERATE(loc_cpu_entry, private->size, cleanup_entry, NULL);
xt_free_table_info(private);
}
/* Returns 1 if the type and code is matched by the range, 0 otherwise */
static inline bool
icmp6_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code,
u_int8_t type, u_int8_t code,
bool invert)
{
return (type == test_type && code >= min_code && code <= max_code)
^ invert;
}
static bool
icmp6_match(const struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
const struct xt_match *match,
const void *matchinfo,
int offset,
unsigned int protoff,
bool *hotdrop)
{
struct icmp6hdr _icmp, *ic;
const struct ip6t_icmp *icmpinfo = matchinfo;
/* Must not be a fragment. */
if (offset)
return false;
ic = skb_header_pointer(skb, protoff, sizeof(_icmp), &_icmp);
if (ic == NULL) {
/* We've been asked to examine this packet, and we
can't. Hence, no choice but to drop. */
duprintf("Dropping evil ICMP tinygram.\n");
*hotdrop = true;
return false;
}
return icmp6_type_code_match(icmpinfo->type,
icmpinfo->code[0],
icmpinfo->code[1],
ic->icmp6_type, ic->icmp6_code,
!!(icmpinfo->invflags&IP6T_ICMP_INV));
}
/* Called when user tries to insert an entry of this type. */
static bool
icmp6_checkentry(const char *tablename,
const void *entry,
const struct xt_match *match,
void *matchinfo,
unsigned int hook_mask)
{
const struct ip6t_icmp *icmpinfo = matchinfo;
/* Must specify no unknown invflags */
return !(icmpinfo->invflags & ~IP6T_ICMP_INV);
}
/* The built-in targets: standard (NULL) and error. */
static struct xt_target ip6t_standard_target __read_mostly = {
.name = IP6T_STANDARD_TARGET,
.targetsize = sizeof(int),
.family = AF_INET6,
};
static struct xt_target ip6t_error_target __read_mostly = {
.name = IP6T_ERROR_TARGET,
.target = ip6t_error,
.targetsize = IP6T_FUNCTION_MAXNAMELEN,
.family = AF_INET6,
};
static struct nf_sockopt_ops ip6t_sockopts = {
.pf = PF_INET6,
.set_optmin = IP6T_BASE_CTL,
.set_optmax = IP6T_SO_SET_MAX+1,
.set = do_ip6t_set_ctl,
.get_optmin = IP6T_BASE_CTL,
.get_optmax = IP6T_SO_GET_MAX+1,
.get = do_ip6t_get_ctl,
.owner = THIS_MODULE,
};
static struct xt_match icmp6_matchstruct __read_mostly = {
.name = "icmp6",
.match = &icmp6_match,
.matchsize = sizeof(struct ip6t_icmp),
.checkentry = icmp6_checkentry,
.proto = IPPROTO_ICMPV6,
.family = AF_INET6,
};
static int __init ip6_tables_init(void)
{
int ret;
ret = xt_proto_init(AF_INET6);
if (ret < 0)
goto err1;
/* Noone else will be downing sem now, so we won't sleep */
ret = xt_register_target(&ip6t_standard_target);
if (ret < 0)
goto err2;
ret = xt_register_target(&ip6t_error_target);
if (ret < 0)
goto err3;
ret = xt_register_match(&icmp6_matchstruct);
if (ret < 0)
goto err4;
/* Register setsockopt */
ret = nf_register_sockopt(&ip6t_sockopts);
if (ret < 0)
goto err5;
printk(KERN_INFO "ip6_tables: (C) 2000-2006 Netfilter Core Team\n");
return 0;
err5:
xt_unregister_match(&icmp6_matchstruct);
err4:
xt_unregister_target(&ip6t_error_target);
err3:
xt_unregister_target(&ip6t_standard_target);
err2:
xt_proto_fini(AF_INET6);
err1:
return ret;
}
static void __exit ip6_tables_fini(void)
{
nf_unregister_sockopt(&ip6t_sockopts);
xt_unregister_match(&icmp6_matchstruct);
xt_unregister_target(&ip6t_error_target);
xt_unregister_target(&ip6t_standard_target);
xt_proto_fini(AF_INET6);
}
/*
* find the offset to specified header or the protocol number of last header
* if target < 0. "last header" is transport protocol header, ESP, or
* "No next header".
*
* If target header is found, its offset is set in *offset and return protocol
* number. Otherwise, return -1.
*
* If the first fragment doesn't contain the final protocol header or
* NEXTHDR_NONE it is considered invalid.
*
* Note that non-1st fragment is special case that "the protocol number
* of last header" is "next header" field in Fragment header. In this case,
* *offset is meaningless and fragment offset is stored in *fragoff if fragoff
* isn't NULL.
*
*/
int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
int target, unsigned short *fragoff)
{
unsigned int start = skb_network_offset(skb) + sizeof(struct ipv6hdr);
u8 nexthdr = ipv6_hdr(skb)->nexthdr;
unsigned int len = skb->len - start;
if (fragoff)
*fragoff = 0;
while (nexthdr != target) {
struct ipv6_opt_hdr _hdr, *hp;
unsigned int hdrlen;
if ((!ipv6_ext_hdr(nexthdr)) || nexthdr == NEXTHDR_NONE) {
if (target < 0)
break;
return -ENOENT;
}
hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr);
if (hp == NULL)
return -EBADMSG;
if (nexthdr == NEXTHDR_FRAGMENT) {
unsigned short _frag_off;
__be16 *fp;
fp = skb_header_pointer(skb,
start+offsetof(struct frag_hdr,
frag_off),
sizeof(_frag_off),
&_frag_off);
if (fp == NULL)
return -EBADMSG;
_frag_off = ntohs(*fp) & ~0x7;
if (_frag_off) {
if (target < 0 &&
((!ipv6_ext_hdr(hp->nexthdr)) ||
hp->nexthdr == NEXTHDR_NONE)) {
if (fragoff)
*fragoff = _frag_off;
return hp->nexthdr;
}
return -ENOENT;
}
hdrlen = 8;
} else if (nexthdr == NEXTHDR_AUTH)
hdrlen = (hp->hdrlen + 2) << 2;
else
hdrlen = ipv6_optlen(hp);
nexthdr = hp->nexthdr;
len -= hdrlen;
start += hdrlen;
}
*offset = start;
return nexthdr;
}
EXPORT_SYMBOL(ip6t_register_table);
EXPORT_SYMBOL(ip6t_unregister_table);
EXPORT_SYMBOL(ip6t_do_table);
EXPORT_SYMBOL(ip6t_ext_hdr);
EXPORT_SYMBOL(ipv6_find_hdr);
module_init(ip6_tables_init);
module_exit(ip6_tables_fini);
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