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linux-next/net/sched/em_meta.c
Johannes Berg 8cb081746c netlink: make validation more configurable for future strictness 
We currently have two levels of strict validation:

 1) liberal (default)
     - undefined (type >= max) & NLA_UNSPEC attributes accepted
     - attribute length >= expected accepted
     - garbage at end of message accepted
 2) strict (opt-in)
     - NLA_UNSPEC attributes accepted
     - attribute length >= expected accepted

Split out parsing strictness into four different options:
 * TRAILING     - check that there's no trailing data after parsing
                  attributes (in message or nested)
 * MAXTYPE      - reject attrs > max known type
 * UNSPEC       - reject attributes with NLA_UNSPEC policy entries
 * STRICT_ATTRS - strictly validate attribute size

The default for future things should be *everything*.
The current *_strict() is a combination of TRAILING and MAXTYPE,
and is renamed to _deprecated_strict().
The current regular parsing has none of this, and is renamed to
*_parse_deprecated().

Additionally it allows us to selectively set one of the new flags
even on old policies. Notably, the UNSPEC flag could be useful in
this case, since it can be arranged (by filling in the policy) to
not be an incompatible userspace ABI change, but would then going
forward prevent forgetting attribute entries. Similar can apply
to the POLICY flag.

We end up with the following renames:
 * nla_parse           -> nla_parse_deprecated
 * nla_parse_strict    -> nla_parse_deprecated_strict
 * nlmsg_parse         -> nlmsg_parse_deprecated
 * nlmsg_parse_strict  -> nlmsg_parse_deprecated_strict
 * nla_parse_nested    -> nla_parse_nested_deprecated
 * nla_validate_nested -> nla_validate_nested_deprecated

Using spatch, of course:
    @@
    expression TB, MAX, HEAD, LEN, POL, EXT;
    @@
    -nla_parse(TB, MAX, HEAD, LEN, POL, EXT)
    +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT)

    @@
    expression NLH, HDRLEN, TB, MAX, POL, EXT;
    @@
    -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT)
    +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT)

    @@
    expression NLH, HDRLEN, TB, MAX, POL, EXT;
    @@
    -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
    +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT)

    @@
    expression TB, MAX, NLA, POL, EXT;
    @@
    -nla_parse_nested(TB, MAX, NLA, POL, EXT)
    +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT)

    @@
    expression START, MAX, POL, EXT;
    @@
    -nla_validate_nested(START, MAX, POL, EXT)
    +nla_validate_nested_deprecated(START, MAX, POL, EXT)

    @@
    expression NLH, HDRLEN, MAX, POL, EXT;
    @@
    -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT)
    +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT)

For this patch, don't actually add the strict, non-renamed versions
yet so that it breaks compile if I get it wrong.

Also, while at it, make nla_validate and nla_parse go down to a
common __nla_validate_parse() function to avoid code duplication.

Ultimately, this allows us to have very strict validation for every
new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the
next patch, while existing things will continue to work as is.

In effect then, this adds fully strict validation for any new command.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-27 17:07:21 -04:00

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/*
* net/sched/em_meta.c Metadata ematch
*
* 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.
*
* Authors: Thomas Graf <tgraf@suug.ch>
*
* ==========================================================================
*
* The metadata ematch compares two meta objects where each object
* represents either a meta value stored in the kernel or a static
* value provided by userspace. The objects are not provided by
* userspace itself but rather a definition providing the information
* to build them. Every object is of a certain type which must be
* equal to the object it is being compared to.
*
* The definition of a objects conists of the type (meta type), a
* identifier (meta id) and additional type specific information.
* The meta id is either TCF_META_TYPE_VALUE for values provided by
* userspace or a index to the meta operations table consisting of
* function pointers to type specific meta data collectors returning
* the value of the requested meta value.
*
* lvalue rvalue
* +-----------+ +-----------+
* | type: INT | | type: INT |
* def | id: DEV | | id: VALUE |
* | data: | | data: 3 |
* +-----------+ +-----------+
* | |
* ---> meta_ops[INT][DEV](...) |
* | |
* ----------- |
* V V
* +-----------+ +-----------+
* | type: INT | | type: INT |
* obj | id: DEV | | id: VALUE |
* | data: 2 |<--data got filled out | data: 3 |
* +-----------+ +-----------+
* | |
* --------------> 2 equals 3 <--------------
*
* This is a simplified schema, the complexity varies depending
* on the meta type. Obviously, the length of the data must also
* be provided for non-numeric types.
*
* Additionally, type dependent modifiers such as shift operators
* or mask may be applied to extend the functionaliy. As of now,
* the variable length type supports shifting the byte string to
* the right, eating up any number of octets and thus supporting
* wildcard interface name comparisons such as "ppp%" matching
* ppp0..9.
*
* NOTE: Certain meta values depend on other subsystems and are
* only available if that subsystem is enabled in the kernel.
*/
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/sched/loadavg.h>
#include <linux/string.h>
#include <linux/skbuff.h>
#include <linux/random.h>
#include <linux/if_vlan.h>
#include <linux/tc_ematch/tc_em_meta.h>
#include <net/dst.h>
#include <net/route.h>
#include <net/pkt_cls.h>
#include <net/sock.h>
struct meta_obj {
unsigned long value;
unsigned int len;
};
struct meta_value {
struct tcf_meta_val hdr;
unsigned long val;
unsigned int len;
};
struct meta_match {
struct meta_value lvalue;
struct meta_value rvalue;
};
static inline int meta_id(struct meta_value *v)
{
return TCF_META_ID(v->hdr.kind);
}
static inline int meta_type(struct meta_value *v)
{
return TCF_META_TYPE(v->hdr.kind);
}
#define META_COLLECTOR(FUNC) static void meta_##FUNC(struct sk_buff *skb, \
struct tcf_pkt_info *info, struct meta_value *v, \
struct meta_obj *dst, int *err)
/**************************************************************************
* System status & misc
**************************************************************************/
META_COLLECTOR(int_random)
{
get_random_bytes(&dst->value, sizeof(dst->value));
}
static inline unsigned long fixed_loadavg(int load)
{
int rnd_load = load + (FIXED_1/200);
int rnd_frac = ((rnd_load & (FIXED_1-1)) * 100) >> FSHIFT;
return ((rnd_load >> FSHIFT) * 100) + rnd_frac;
}
META_COLLECTOR(int_loadavg_0)
{
dst->value = fixed_loadavg(avenrun[0]);
}
META_COLLECTOR(int_loadavg_1)
{
dst->value = fixed_loadavg(avenrun[1]);
}
META_COLLECTOR(int_loadavg_2)
{
dst->value = fixed_loadavg(avenrun[2]);
}
/**************************************************************************
* Device names & indices
**************************************************************************/
static inline int int_dev(struct net_device *dev, struct meta_obj *dst)
{
if (unlikely(dev == NULL))
return -1;
dst->value = dev->ifindex;
return 0;
}
static inline int var_dev(struct net_device *dev, struct meta_obj *dst)
{
if (unlikely(dev == NULL))
return -1;
dst->value = (unsigned long) dev->name;
dst->len = strlen(dev->name);
return 0;
}
META_COLLECTOR(int_dev)
{
*err = int_dev(skb->dev, dst);
}
META_COLLECTOR(var_dev)
{
*err = var_dev(skb->dev, dst);
}
/**************************************************************************
* vlan tag
**************************************************************************/
META_COLLECTOR(int_vlan_tag)
{
unsigned short tag;
if (skb_vlan_tag_present(skb))
dst->value = skb_vlan_tag_get(skb);
else if (!__vlan_get_tag(skb, &tag))
dst->value = tag;
else
*err = -1;
}
/**************************************************************************
* skb attributes
**************************************************************************/
META_COLLECTOR(int_priority)
{
dst->value = skb->priority;
}
META_COLLECTOR(int_protocol)
{
/* Let userspace take care of the byte ordering */
dst->value = tc_skb_protocol(skb);
}
META_COLLECTOR(int_pkttype)
{
dst->value = skb->pkt_type;
}
META_COLLECTOR(int_pktlen)
{
dst->value = skb->len;
}
META_COLLECTOR(int_datalen)
{
dst->value = skb->data_len;
}
META_COLLECTOR(int_maclen)
{
dst->value = skb->mac_len;
}
META_COLLECTOR(int_rxhash)
{
dst->value = skb_get_hash(skb);
}
/**************************************************************************
* Netfilter
**************************************************************************/
META_COLLECTOR(int_mark)
{
dst->value = skb->mark;
}
/**************************************************************************
* Traffic Control
**************************************************************************/
META_COLLECTOR(int_tcindex)
{
dst->value = skb->tc_index;
}
/**************************************************************************
* Routing
**************************************************************************/
META_COLLECTOR(int_rtclassid)
{
if (unlikely(skb_dst(skb) == NULL))
*err = -1;
else
#ifdef CONFIG_IP_ROUTE_CLASSID
dst->value = skb_dst(skb)->tclassid;
#else
dst->value = 0;
#endif
}
META_COLLECTOR(int_rtiif)
{
if (unlikely(skb_rtable(skb) == NULL))
*err = -1;
else
dst->value = inet_iif(skb);
}
/**************************************************************************
* Socket Attributes
**************************************************************************/
#define skip_nonlocal(skb) \
(unlikely(skb->sk == NULL))
META_COLLECTOR(int_sk_family)
{
if (skip_nonlocal(skb)) {
*err = -1;
return;
}
dst->value = skb->sk->sk_family;
}
META_COLLECTOR(int_sk_state)
{
if (skip_nonlocal(skb)) {
*err = -1;
return;
}
dst->value = skb->sk->sk_state;
}
META_COLLECTOR(int_sk_reuse)
{
if (skip_nonlocal(skb)) {
*err = -1;
return;
}
dst->value = skb->sk->sk_reuse;
}
META_COLLECTOR(int_sk_bound_if)
{
if (skip_nonlocal(skb)) {
*err = -1;
return;
}
/* No error if bound_dev_if is 0, legal userspace check */
dst->value = skb->sk->sk_bound_dev_if;
}
META_COLLECTOR(var_sk_bound_if)
{
if (skip_nonlocal(skb)) {
*err = -1;
return;
}
if (skb->sk->sk_bound_dev_if == 0) {
dst->value = (unsigned long) "any";
dst->len = 3;
} else {
struct net_device *dev;
rcu_read_lock();
dev = dev_get_by_index_rcu(sock_net(skb->sk),
skb->sk->sk_bound_dev_if);
*err = var_dev(dev, dst);
rcu_read_unlock();
}
}
META_COLLECTOR(int_sk_refcnt)
{
if (skip_nonlocal(skb)) {
*err = -1;
return;
}
dst->value = refcount_read(&skb->sk->sk_refcnt);
}
META_COLLECTOR(int_sk_rcvbuf)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk->sk_rcvbuf;
}
META_COLLECTOR(int_sk_shutdown)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk->sk_shutdown;
}
META_COLLECTOR(int_sk_proto)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk->sk_protocol;
}
META_COLLECTOR(int_sk_type)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk->sk_type;
}
META_COLLECTOR(int_sk_rmem_alloc)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk_rmem_alloc_get(sk);
}
META_COLLECTOR(int_sk_wmem_alloc)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk_wmem_alloc_get(sk);
}
META_COLLECTOR(int_sk_omem_alloc)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = atomic_read(&sk->sk_omem_alloc);
}
META_COLLECTOR(int_sk_rcv_qlen)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk->sk_receive_queue.qlen;
}
META_COLLECTOR(int_sk_snd_qlen)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk->sk_write_queue.qlen;
}
META_COLLECTOR(int_sk_wmem_queued)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk->sk_wmem_queued;
}
META_COLLECTOR(int_sk_fwd_alloc)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk->sk_forward_alloc;
}
META_COLLECTOR(int_sk_sndbuf)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk->sk_sndbuf;
}
META_COLLECTOR(int_sk_alloc)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = (__force int) sk->sk_allocation;
}
META_COLLECTOR(int_sk_hash)
{
if (skip_nonlocal(skb)) {
*err = -1;
return;
}
dst->value = skb->sk->sk_hash;
}
META_COLLECTOR(int_sk_lingertime)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk->sk_lingertime / HZ;
}
META_COLLECTOR(int_sk_err_qlen)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk->sk_error_queue.qlen;
}
META_COLLECTOR(int_sk_ack_bl)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk->sk_ack_backlog;
}
META_COLLECTOR(int_sk_max_ack_bl)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk->sk_max_ack_backlog;
}
META_COLLECTOR(int_sk_prio)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk->sk_priority;
}
META_COLLECTOR(int_sk_rcvlowat)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk->sk_rcvlowat;
}
META_COLLECTOR(int_sk_rcvtimeo)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk->sk_rcvtimeo / HZ;
}
META_COLLECTOR(int_sk_sndtimeo)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk->sk_sndtimeo / HZ;
}
META_COLLECTOR(int_sk_sendmsg_off)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk->sk_frag.offset;
}
META_COLLECTOR(int_sk_write_pend)
{
const struct sock *sk = skb_to_full_sk(skb);
if (!sk) {
*err = -1;
return;
}
dst->value = sk->sk_write_pending;
}
/**************************************************************************
* Meta value collectors assignment table
**************************************************************************/
struct meta_ops {
void (*get)(struct sk_buff *, struct tcf_pkt_info *,
struct meta_value *, struct meta_obj *, int *);
};
#define META_ID(name) TCF_META_ID_##name
#define META_FUNC(name) { .get = meta_##name }
/* Meta value operations table listing all meta value collectors and
* assigns them to a type and meta id. */
static struct meta_ops __meta_ops[TCF_META_TYPE_MAX + 1][TCF_META_ID_MAX + 1] = {
[TCF_META_TYPE_VAR] = {
[META_ID(DEV)] = META_FUNC(var_dev),
[META_ID(SK_BOUND_IF)] = META_FUNC(var_sk_bound_if),
},
[TCF_META_TYPE_INT] = {
[META_ID(RANDOM)] = META_FUNC(int_random),
[META_ID(LOADAVG_0)] = META_FUNC(int_loadavg_0),
[META_ID(LOADAVG_1)] = META_FUNC(int_loadavg_1),
[META_ID(LOADAVG_2)] = META_FUNC(int_loadavg_2),
[META_ID(DEV)] = META_FUNC(int_dev),
[META_ID(PRIORITY)] = META_FUNC(int_priority),
[META_ID(PROTOCOL)] = META_FUNC(int_protocol),
[META_ID(PKTTYPE)] = META_FUNC(int_pkttype),
[META_ID(PKTLEN)] = META_FUNC(int_pktlen),
[META_ID(DATALEN)] = META_FUNC(int_datalen),
[META_ID(MACLEN)] = META_FUNC(int_maclen),
[META_ID(NFMARK)] = META_FUNC(int_mark),
[META_ID(TCINDEX)] = META_FUNC(int_tcindex),
[META_ID(RTCLASSID)] = META_FUNC(int_rtclassid),
[META_ID(RTIIF)] = META_FUNC(int_rtiif),
[META_ID(SK_FAMILY)] = META_FUNC(int_sk_family),
[META_ID(SK_STATE)] = META_FUNC(int_sk_state),
[META_ID(SK_REUSE)] = META_FUNC(int_sk_reuse),
[META_ID(SK_BOUND_IF)] = META_FUNC(int_sk_bound_if),
[META_ID(SK_REFCNT)] = META_FUNC(int_sk_refcnt),
[META_ID(SK_RCVBUF)] = META_FUNC(int_sk_rcvbuf),
[META_ID(SK_SNDBUF)] = META_FUNC(int_sk_sndbuf),
[META_ID(SK_SHUTDOWN)] = META_FUNC(int_sk_shutdown),
[META_ID(SK_PROTO)] = META_FUNC(int_sk_proto),
[META_ID(SK_TYPE)] = META_FUNC(int_sk_type),
[META_ID(SK_RMEM_ALLOC)] = META_FUNC(int_sk_rmem_alloc),
[META_ID(SK_WMEM_ALLOC)] = META_FUNC(int_sk_wmem_alloc),
[META_ID(SK_OMEM_ALLOC)] = META_FUNC(int_sk_omem_alloc),
[META_ID(SK_WMEM_QUEUED)] = META_FUNC(int_sk_wmem_queued),
[META_ID(SK_RCV_QLEN)] = META_FUNC(int_sk_rcv_qlen),
[META_ID(SK_SND_QLEN)] = META_FUNC(int_sk_snd_qlen),
[META_ID(SK_ERR_QLEN)] = META_FUNC(int_sk_err_qlen),
[META_ID(SK_FORWARD_ALLOCS)] = META_FUNC(int_sk_fwd_alloc),
[META_ID(SK_ALLOCS)] = META_FUNC(int_sk_alloc),
[META_ID(SK_HASH)] = META_FUNC(int_sk_hash),
[META_ID(SK_LINGERTIME)] = META_FUNC(int_sk_lingertime),
[META_ID(SK_ACK_BACKLOG)] = META_FUNC(int_sk_ack_bl),
[META_ID(SK_MAX_ACK_BACKLOG)] = META_FUNC(int_sk_max_ack_bl),
[META_ID(SK_PRIO)] = META_FUNC(int_sk_prio),
[META_ID(SK_RCVLOWAT)] = META_FUNC(int_sk_rcvlowat),
[META_ID(SK_RCVTIMEO)] = META_FUNC(int_sk_rcvtimeo),
[META_ID(SK_SNDTIMEO)] = META_FUNC(int_sk_sndtimeo),
[META_ID(SK_SENDMSG_OFF)] = META_FUNC(int_sk_sendmsg_off),
[META_ID(SK_WRITE_PENDING)] = META_FUNC(int_sk_write_pend),
[META_ID(VLAN_TAG)] = META_FUNC(int_vlan_tag),
[META_ID(RXHASH)] = META_FUNC(int_rxhash),
}
};
static inline struct meta_ops *meta_ops(struct meta_value *val)
{
return &__meta_ops[meta_type(val)][meta_id(val)];
}
/**************************************************************************
* Type specific operations for TCF_META_TYPE_VAR
**************************************************************************/
static int meta_var_compare(struct meta_obj *a, struct meta_obj *b)
{
int r = a->len - b->len;
if (r == 0)
r = memcmp((void *) a->value, (void *) b->value, a->len);
return r;
}
static int meta_var_change(struct meta_value *dst, struct nlattr *nla)
{
int len = nla_len(nla);
dst->val = (unsigned long)kmemdup(nla_data(nla), len, GFP_KERNEL);
if (dst->val == 0UL)
return -ENOMEM;
dst->len = len;
return 0;
}
static void meta_var_destroy(struct meta_value *v)
{
kfree((void *) v->val);
}
static void meta_var_apply_extras(struct meta_value *v,
struct meta_obj *dst)
{
int shift = v->hdr.shift;
if (shift && shift < dst->len)
dst->len -= shift;
}
static int meta_var_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
{
if (v->val && v->len &&
nla_put(skb, tlv, v->len, (void *) v->val))
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
/**************************************************************************
* Type specific operations for TCF_META_TYPE_INT
**************************************************************************/
static int meta_int_compare(struct meta_obj *a, struct meta_obj *b)
{
/* Let gcc optimize it, the unlikely is not really based on
* some numbers but jump free code for mismatches seems
* more logical. */
if (unlikely(a->value == b->value))
return 0;
else if (a->value < b->value)
return -1;
else
return 1;
}
static int meta_int_change(struct meta_value *dst, struct nlattr *nla)
{
if (nla_len(nla) >= sizeof(unsigned long)) {
dst->val = *(unsigned long *) nla_data(nla);
dst->len = sizeof(unsigned long);
} else if (nla_len(nla) == sizeof(u32)) {
dst->val = nla_get_u32(nla);
dst->len = sizeof(u32);
} else
return -EINVAL;
return 0;
}
static void meta_int_apply_extras(struct meta_value *v,
struct meta_obj *dst)
{
if (v->hdr.shift)
dst->value >>= v->hdr.shift;
if (v->val)
dst->value &= v->val;
}
static int meta_int_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
{
if (v->len == sizeof(unsigned long)) {
if (nla_put(skb, tlv, sizeof(unsigned long), &v->val))
goto nla_put_failure;
} else if (v->len == sizeof(u32)) {
if (nla_put_u32(skb, tlv, v->val))
goto nla_put_failure;
}
return 0;
nla_put_failure:
return -1;
}
/**************************************************************************
* Type specific operations table
**************************************************************************/
struct meta_type_ops {
void (*destroy)(struct meta_value *);
int (*compare)(struct meta_obj *, struct meta_obj *);
int (*change)(struct meta_value *, struct nlattr *);
void (*apply_extras)(struct meta_value *, struct meta_obj *);
int (*dump)(struct sk_buff *, struct meta_value *, int);
};
static const struct meta_type_ops __meta_type_ops[TCF_META_TYPE_MAX + 1] = {
[TCF_META_TYPE_VAR] = {
.destroy = meta_var_destroy,
.compare = meta_var_compare,
.change = meta_var_change,
.apply_extras = meta_var_apply_extras,
.dump = meta_var_dump
},
[TCF_META_TYPE_INT] = {
.compare = meta_int_compare,
.change = meta_int_change,
.apply_extras = meta_int_apply_extras,
.dump = meta_int_dump
}
};
static inline const struct meta_type_ops *meta_type_ops(struct meta_value *v)
{
return &__meta_type_ops[meta_type(v)];
}
/**************************************************************************
* Core
**************************************************************************/
static int meta_get(struct sk_buff *skb, struct tcf_pkt_info *info,
struct meta_value *v, struct meta_obj *dst)
{
int err = 0;
if (meta_id(v) == TCF_META_ID_VALUE) {
dst->value = v->val;
dst->len = v->len;
return 0;
}
meta_ops(v)->get(skb, info, v, dst, &err);
if (err < 0)
return err;
if (meta_type_ops(v)->apply_extras)
meta_type_ops(v)->apply_extras(v, dst);
return 0;
}
static int em_meta_match(struct sk_buff *skb, struct tcf_ematch *m,
struct tcf_pkt_info *info)
{
int r;
struct meta_match *meta = (struct meta_match *) m->data;
struct meta_obj l_value, r_value;
if (meta_get(skb, info, &meta->lvalue, &l_value) < 0 ||
meta_get(skb, info, &meta->rvalue, &r_value) < 0)
return 0;
r = meta_type_ops(&meta->lvalue)->compare(&l_value, &r_value);
switch (meta->lvalue.hdr.op) {
case TCF_EM_OPND_EQ:
return !r;
case TCF_EM_OPND_LT:
return r < 0;
case TCF_EM_OPND_GT:
return r > 0;
}
return 0;
}
static void meta_delete(struct meta_match *meta)
{
if (meta) {
const struct meta_type_ops *ops = meta_type_ops(&meta->lvalue);
if (ops && ops->destroy) {
ops->destroy(&meta->lvalue);
ops->destroy(&meta->rvalue);
}
}
kfree(meta);
}
static inline int meta_change_data(struct meta_value *dst, struct nlattr *nla)
{
if (nla) {
if (nla_len(nla) == 0)
return -EINVAL;
return meta_type_ops(dst)->change(dst, nla);
}
return 0;
}
static inline int meta_is_supported(struct meta_value *val)
{
return !meta_id(val) || meta_ops(val)->get;
}
static const struct nla_policy meta_policy[TCA_EM_META_MAX + 1] = {
[TCA_EM_META_HDR] = { .len = sizeof(struct tcf_meta_hdr) },
};
static int em_meta_change(struct net *net, void *data, int len,
struct tcf_ematch *m)
{
int err;
struct nlattr *tb[TCA_EM_META_MAX + 1];
struct tcf_meta_hdr *hdr;
struct meta_match *meta = NULL;
err = nla_parse_deprecated(tb, TCA_EM_META_MAX, data, len,
meta_policy, NULL);
if (err < 0)
goto errout;
err = -EINVAL;
if (tb[TCA_EM_META_HDR] == NULL)
goto errout;
hdr = nla_data(tb[TCA_EM_META_HDR]);
if (TCF_META_TYPE(hdr->left.kind) != TCF_META_TYPE(hdr->right.kind) ||
TCF_META_TYPE(hdr->left.kind) > TCF_META_TYPE_MAX ||
TCF_META_ID(hdr->left.kind) > TCF_META_ID_MAX ||
TCF_META_ID(hdr->right.kind) > TCF_META_ID_MAX)
goto errout;
meta = kzalloc(sizeof(*meta), GFP_KERNEL);
if (meta == NULL) {
err = -ENOMEM;
goto errout;
}
memcpy(&meta->lvalue.hdr, &hdr->left, sizeof(hdr->left));
memcpy(&meta->rvalue.hdr, &hdr->right, sizeof(hdr->right));
if (!meta_is_supported(&meta->lvalue) ||
!meta_is_supported(&meta->rvalue)) {
err = -EOPNOTSUPP;
goto errout;
}
if (meta_change_data(&meta->lvalue, tb[TCA_EM_META_LVALUE]) < 0 ||
meta_change_data(&meta->rvalue, tb[TCA_EM_META_RVALUE]) < 0)
goto errout;
m->datalen = sizeof(*meta);
m->data = (unsigned long) meta;
err = 0;
errout:
if (err && meta)
meta_delete(meta);
return err;
}
static void em_meta_destroy(struct tcf_ematch *m)
{
if (m)
meta_delete((struct meta_match *) m->data);
}
static int em_meta_dump(struct sk_buff *skb, struct tcf_ematch *em)
{
struct meta_match *meta = (struct meta_match *) em->data;
struct tcf_meta_hdr hdr;
const struct meta_type_ops *ops;
memset(&hdr, 0, sizeof(hdr));
memcpy(&hdr.left, &meta->lvalue.hdr, sizeof(hdr.left));
memcpy(&hdr.right, &meta->rvalue.hdr, sizeof(hdr.right));
if (nla_put(skb, TCA_EM_META_HDR, sizeof(hdr), &hdr))
goto nla_put_failure;
ops = meta_type_ops(&meta->lvalue);
if (ops->dump(skb, &meta->lvalue, TCA_EM_META_LVALUE) < 0 ||
ops->dump(skb, &meta->rvalue, TCA_EM_META_RVALUE) < 0)
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
static struct tcf_ematch_ops em_meta_ops = {
.kind = TCF_EM_META,
.change = em_meta_change,
.match = em_meta_match,
.destroy = em_meta_destroy,
.dump = em_meta_dump,
.owner = THIS_MODULE,
.link = LIST_HEAD_INIT(em_meta_ops.link)
};
static int __init init_em_meta(void)
{
return tcf_em_register(&em_meta_ops);
}
static void __exit exit_em_meta(void)
{
tcf_em_unregister(&em_meta_ops);
}
MODULE_LICENSE("GPL");
module_init(init_em_meta);
module_exit(exit_em_meta);
MODULE_ALIAS_TCF_EMATCH(TCF_EM_META);
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