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linux/net/openvswitch/conntrack.c
Hyunwoo Kim 5ea7b72d4f net: openvswitch: Fix Use-After-Free in ovs_ct_exit 
Since kfree_rcu, which is called in the hlist_for_each_entry_rcu traversal
of ovs_ct_limit_exit, is not part of the RCU read critical section, it
is possible that the RCU grace period will pass during the traversal and
the key will be free.

To prevent this, it should be changed to hlist_for_each_entry_safe.

Fixes: 11efd5cb04 ("openvswitch: Support conntrack zone limit")
Signed-off-by: Hyunwoo Kim <v4bel@theori.io>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Link: https://lore.kernel.org/r/ZiYvzQN/Ry5oeFQW@v4bel-B760M-AORUS-ELITE-AX
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-24 17:14:24 -07:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2015 Nicira, Inc.
*/
#include <linux/module.h>
#include <linux/openvswitch.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/sctp.h>
#include <linux/static_key.h>
#include <linux/string_helpers.h>
#include <net/ip.h>
#include <net/genetlink.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_count.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_labels.h>
#include <net/netfilter/nf_conntrack_seqadj.h>
#include <net/netfilter/nf_conntrack_timeout.h>
#include <net/netfilter/nf_conntrack_zones.h>
#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
#include <net/ipv6_frag.h>
#if IS_ENABLED(CONFIG_NF_NAT)
#include <net/netfilter/nf_nat.h>
#endif
#include <net/netfilter/nf_conntrack_act_ct.h>
#include "datapath.h"
#include "drop.h"
#include "conntrack.h"
#include "flow.h"
#include "flow_netlink.h"
struct ovs_ct_len_tbl {
int maxlen;
int minlen;
};
/* Metadata mark for masked write to conntrack mark */
struct md_mark {
u32 value;
u32 mask;
};
/* Metadata label for masked write to conntrack label. */
struct md_labels {
struct ovs_key_ct_labels value;
struct ovs_key_ct_labels mask;
};
enum ovs_ct_nat {
OVS_CT_NAT = 1 << 0, /* NAT for committed connections only. */
OVS_CT_SRC_NAT = 1 << 1, /* Source NAT for NEW connections. */
OVS_CT_DST_NAT = 1 << 2, /* Destination NAT for NEW connections. */
};
/* Conntrack action context for execution. */
struct ovs_conntrack_info {
struct nf_conntrack_helper *helper;
struct nf_conntrack_zone zone;
struct nf_conn *ct;
u8 commit : 1;
u8 nat : 3; /* enum ovs_ct_nat */
u8 force : 1;
u8 have_eventmask : 1;
u16 family;
u32 eventmask; /* Mask of 1 << IPCT_*. */
struct md_mark mark;
struct md_labels labels;
char timeout[CTNL_TIMEOUT_NAME_MAX];
struct nf_ct_timeout *nf_ct_timeout;
#if IS_ENABLED(CONFIG_NF_NAT)
struct nf_nat_range2 range; /* Only present for SRC NAT and DST NAT. */
#endif
};
#if IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
#define OVS_CT_LIMIT_UNLIMITED 0
#define OVS_CT_LIMIT_DEFAULT OVS_CT_LIMIT_UNLIMITED
#define CT_LIMIT_HASH_BUCKETS 512
static DEFINE_STATIC_KEY_FALSE(ovs_ct_limit_enabled);
struct ovs_ct_limit {
/* Elements in ovs_ct_limit_info->limits hash table */
struct hlist_node hlist_node;
struct rcu_head rcu;
u16 zone;
u32 limit;
};
struct ovs_ct_limit_info {
u32 default_limit;
struct hlist_head *limits;
struct nf_conncount_data *data;
};
static const struct nla_policy ct_limit_policy[OVS_CT_LIMIT_ATTR_MAX + 1] = {
[OVS_CT_LIMIT_ATTR_ZONE_LIMIT] = { .type = NLA_NESTED, },
};
#endif
static bool labels_nonzero(const struct ovs_key_ct_labels *labels);
static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info);
static u16 key_to_nfproto(const struct sw_flow_key *key)
{
switch (ntohs(key->eth.type)) {
case ETH_P_IP:
return NFPROTO_IPV4;
case ETH_P_IPV6:
return NFPROTO_IPV6;
default:
return NFPROTO_UNSPEC;
}
}
/* Map SKB connection state into the values used by flow definition. */
static u8 ovs_ct_get_state(enum ip_conntrack_info ctinfo)
{
u8 ct_state = OVS_CS_F_TRACKED;
switch (ctinfo) {
case IP_CT_ESTABLISHED_REPLY:
case IP_CT_RELATED_REPLY:
ct_state |= OVS_CS_F_REPLY_DIR;
break;
default:
break;
}
switch (ctinfo) {
case IP_CT_ESTABLISHED:
case IP_CT_ESTABLISHED_REPLY:
ct_state |= OVS_CS_F_ESTABLISHED;
break;
case IP_CT_RELATED:
case IP_CT_RELATED_REPLY:
ct_state |= OVS_CS_F_RELATED;
break;
case IP_CT_NEW:
ct_state |= OVS_CS_F_NEW;
break;
default:
break;
}
return ct_state;
}
static u32 ovs_ct_get_mark(const struct nf_conn *ct)
{
#if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
return ct ? READ_ONCE(ct->mark) : 0;
#else
return 0;
#endif
}
/* Guard against conntrack labels max size shrinking below 128 bits. */
#if NF_CT_LABELS_MAX_SIZE < 16
#error NF_CT_LABELS_MAX_SIZE must be at least 16 bytes
#endif
static void ovs_ct_get_labels(const struct nf_conn *ct,
struct ovs_key_ct_labels *labels)
{
struct nf_conn_labels *cl = ct ? nf_ct_labels_find(ct) : NULL;
if (cl)
memcpy(labels, cl->bits, OVS_CT_LABELS_LEN);
else
memset(labels, 0, OVS_CT_LABELS_LEN);
}
static void __ovs_ct_update_key_orig_tp(struct sw_flow_key *key,
const struct nf_conntrack_tuple *orig,
u8 icmp_proto)
{
key->ct_orig_proto = orig->dst.protonum;
if (orig->dst.protonum == icmp_proto) {
key->ct.orig_tp.src = htons(orig->dst.u.icmp.type);
key->ct.orig_tp.dst = htons(orig->dst.u.icmp.code);
} else {
key->ct.orig_tp.src = orig->src.u.all;
key->ct.orig_tp.dst = orig->dst.u.all;
}
}
static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state,
const struct nf_conntrack_zone *zone,
const struct nf_conn *ct)
{
key->ct_state = state;
key->ct_zone = zone->id;
key->ct.mark = ovs_ct_get_mark(ct);
ovs_ct_get_labels(ct, &key->ct.labels);
if (ct) {
const struct nf_conntrack_tuple *orig;
/* Use the master if we have one. */
if (ct->master)
ct = ct->master;
orig = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
/* IP version must match with the master connection. */
if (key->eth.type == htons(ETH_P_IP) &&
nf_ct_l3num(ct) == NFPROTO_IPV4) {
key->ipv4.ct_orig.src = orig->src.u3.ip;
key->ipv4.ct_orig.dst = orig->dst.u3.ip;
__ovs_ct_update_key_orig_tp(key, orig, IPPROTO_ICMP);
return;
} else if (key->eth.type == htons(ETH_P_IPV6) &&
!sw_flow_key_is_nd(key) &&
nf_ct_l3num(ct) == NFPROTO_IPV6) {
key->ipv6.ct_orig.src = orig->src.u3.in6;
key->ipv6.ct_orig.dst = orig->dst.u3.in6;
__ovs_ct_update_key_orig_tp(key, orig, NEXTHDR_ICMP);
return;
}
}
/* Clear 'ct_orig_proto' to mark the non-existence of conntrack
* original direction key fields.
*/
key->ct_orig_proto = 0;
}
/* Update 'key' based on skb->_nfct. If 'post_ct' is true, then OVS has
* previously sent the packet to conntrack via the ct action. If
* 'keep_nat_flags' is true, the existing NAT flags retained, else they are
* initialized from the connection status.
*/
static void ovs_ct_update_key(const struct sk_buff *skb,
const struct ovs_conntrack_info *info,
struct sw_flow_key *key, bool post_ct,
bool keep_nat_flags)
{
const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
enum ip_conntrack_info ctinfo;
struct nf_conn *ct;
u8 state = 0;
ct = nf_ct_get(skb, &ctinfo);
if (ct) {
state = ovs_ct_get_state(ctinfo);
/* All unconfirmed entries are NEW connections. */
if (!nf_ct_is_confirmed(ct))
state |= OVS_CS_F_NEW;
/* OVS persists the related flag for the duration of the
* connection.
*/
if (ct->master)
state |= OVS_CS_F_RELATED;
if (keep_nat_flags) {
state |= key->ct_state & OVS_CS_F_NAT_MASK;
} else {
if (ct->status & IPS_SRC_NAT)
state |= OVS_CS_F_SRC_NAT;
if (ct->status & IPS_DST_NAT)
state |= OVS_CS_F_DST_NAT;
}
zone = nf_ct_zone(ct);
} else if (post_ct) {
state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
if (info)
zone = &info->zone;
}
__ovs_ct_update_key(key, state, zone, ct);
}
/* This is called to initialize CT key fields possibly coming in from the local
* stack.
*/
void ovs_ct_fill_key(const struct sk_buff *skb,
struct sw_flow_key *key,
bool post_ct)
{
ovs_ct_update_key(skb, NULL, key, post_ct, false);
}
int ovs_ct_put_key(const struct sw_flow_key *swkey,
const struct sw_flow_key *output, struct sk_buff *skb)
{
if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, output->ct_state))
return -EMSGSIZE;
if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, output->ct_zone))
return -EMSGSIZE;
if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, output->ct.mark))
return -EMSGSIZE;
if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(output->ct.labels),
&output->ct.labels))
return -EMSGSIZE;
if (swkey->ct_orig_proto) {
if (swkey->eth.type == htons(ETH_P_IP)) {
struct ovs_key_ct_tuple_ipv4 orig;
memset(&orig, 0, sizeof(orig));
orig.ipv4_src = output->ipv4.ct_orig.src;
orig.ipv4_dst = output->ipv4.ct_orig.dst;
orig.src_port = output->ct.orig_tp.src;
orig.dst_port = output->ct.orig_tp.dst;
orig.ipv4_proto = output->ct_orig_proto;
if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4,
sizeof(orig), &orig))
return -EMSGSIZE;
} else if (swkey->eth.type == htons(ETH_P_IPV6)) {
struct ovs_key_ct_tuple_ipv6 orig;
memset(&orig, 0, sizeof(orig));
memcpy(orig.ipv6_src, output->ipv6.ct_orig.src.s6_addr32,
sizeof(orig.ipv6_src));
memcpy(orig.ipv6_dst, output->ipv6.ct_orig.dst.s6_addr32,
sizeof(orig.ipv6_dst));
orig.src_port = output->ct.orig_tp.src;
orig.dst_port = output->ct.orig_tp.dst;
orig.ipv6_proto = output->ct_orig_proto;
if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6,
sizeof(orig), &orig))
return -EMSGSIZE;
}
}
return 0;
}
static int ovs_ct_set_mark(struct nf_conn *ct, struct sw_flow_key *key,
u32 ct_mark, u32 mask)
{
#if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
u32 new_mark;
new_mark = ct_mark | (READ_ONCE(ct->mark) & ~(mask));
if (READ_ONCE(ct->mark) != new_mark) {
WRITE_ONCE(ct->mark, new_mark);
if (nf_ct_is_confirmed(ct))
nf_conntrack_event_cache(IPCT_MARK, ct);
key->ct.mark = new_mark;
}
return 0;
#else
return -ENOTSUPP;
#endif
}
static struct nf_conn_labels *ovs_ct_get_conn_labels(struct nf_conn *ct)
{
struct nf_conn_labels *cl;
cl = nf_ct_labels_find(ct);
if (!cl) {
nf_ct_labels_ext_add(ct);
cl = nf_ct_labels_find(ct);
}
return cl;
}
/* Initialize labels for a new, yet to be committed conntrack entry. Note that
* since the new connection is not yet confirmed, and thus no-one else has
* access to it's labels, we simply write them over.
*/
static int ovs_ct_init_labels(struct nf_conn *ct, struct sw_flow_key *key,
const struct ovs_key_ct_labels *labels,
const struct ovs_key_ct_labels *mask)
{
struct nf_conn_labels *cl, *master_cl;
bool have_mask = labels_nonzero(mask);
/* Inherit master's labels to the related connection? */
master_cl = ct->master ? nf_ct_labels_find(ct->master) : NULL;
if (!master_cl && !have_mask)
return 0; /* Nothing to do. */
cl = ovs_ct_get_conn_labels(ct);
if (!cl)
return -ENOSPC;
/* Inherit the master's labels, if any. */
if (master_cl)
*cl = *master_cl;
if (have_mask) {
u32 *dst = (u32 *)cl->bits;
int i;
for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
dst[i] = (dst[i] & ~mask->ct_labels_32[i]) |
(labels->ct_labels_32[i]
& mask->ct_labels_32[i]);
}
/* Labels are included in the IPCTNL_MSG_CT_NEW event only if the
* IPCT_LABEL bit is set in the event cache.
*/
nf_conntrack_event_cache(IPCT_LABEL, ct);
memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN);
return 0;
}
static int ovs_ct_set_labels(struct nf_conn *ct, struct sw_flow_key *key,
const struct ovs_key_ct_labels *labels,
const struct ovs_key_ct_labels *mask)
{
struct nf_conn_labels *cl;
int err;
cl = ovs_ct_get_conn_labels(ct);
if (!cl)
return -ENOSPC;
err = nf_connlabels_replace(ct, labels->ct_labels_32,
mask->ct_labels_32,
OVS_CT_LABELS_LEN_32);
if (err)
return err;
memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN);
return 0;
}
static int ovs_ct_handle_fragments(struct net *net, struct sw_flow_key *key,
u16 zone, int family, struct sk_buff *skb)
{
struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
int err;
err = nf_ct_handle_fragments(net, skb, zone, family, &key->ip.proto, &ovs_cb.mru);
if (err)
return err;
/* The key extracted from the fragment that completed this datagram
* likely didn't have an L4 header, so regenerate it.
*/
ovs_flow_key_update_l3l4(skb, key);
key->ip.frag = OVS_FRAG_TYPE_NONE;
*OVS_CB(skb) = ovs_cb;
return 0;
}
/* This replicates logic from nf_conntrack_core.c that is not exported. */
static enum ip_conntrack_info
ovs_ct_get_info(const struct nf_conntrack_tuple_hash *h)
{
const struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
return IP_CT_ESTABLISHED_REPLY;
/* Once we've had two way comms, always ESTABLISHED. */
if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status))
return IP_CT_ESTABLISHED;
if (test_bit(IPS_EXPECTED_BIT, &ct->status))
return IP_CT_RELATED;
return IP_CT_NEW;
}
/* Find an existing connection which this packet belongs to without
* re-attributing statistics or modifying the connection state. This allows an
* skb->_nfct lost due to an upcall to be recovered during actions execution.
*
* Must be called with rcu_read_lock.
*
* On success, populates skb->_nfct and returns the connection. Returns NULL
* if there is no existing entry.
*/
static struct nf_conn *
ovs_ct_find_existing(struct net *net, const struct nf_conntrack_zone *zone,
u8 l3num, struct sk_buff *skb, bool natted)
{
struct nf_conntrack_tuple tuple;
struct nf_conntrack_tuple_hash *h;
struct nf_conn *ct;
if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), l3num,
net, &tuple)) {
pr_debug("ovs_ct_find_existing: Can't get tuple\n");
return NULL;
}
/* Must invert the tuple if skb has been transformed by NAT. */
if (natted) {
struct nf_conntrack_tuple inverse;
if (!nf_ct_invert_tuple(&inverse, &tuple)) {
pr_debug("ovs_ct_find_existing: Inversion failed!\n");
return NULL;
}
tuple = inverse;
}
/* look for tuple match */
h = nf_conntrack_find_get(net, zone, &tuple);
if (!h)
return NULL; /* Not found. */
ct = nf_ct_tuplehash_to_ctrack(h);
/* Inverted packet tuple matches the reverse direction conntrack tuple,
* select the other tuplehash to get the right 'ctinfo' bits for this
* packet.
*/
if (natted)
h = &ct->tuplehash[!h->tuple.dst.dir];
nf_ct_set(skb, ct, ovs_ct_get_info(h));
return ct;
}
static
struct nf_conn *ovs_ct_executed(struct net *net,
const struct sw_flow_key *key,
const struct ovs_conntrack_info *info,
struct sk_buff *skb,
bool *ct_executed)
{
struct nf_conn *ct = NULL;
/* If no ct, check if we have evidence that an existing conntrack entry
* might be found for this skb. This happens when we lose a skb->_nfct
* due to an upcall, or if the direction is being forced. If the
* connection was not confirmed, it is not cached and needs to be run
* through conntrack again.
*/
*ct_executed = (key->ct_state & OVS_CS_F_TRACKED) &&
!(key->ct_state & OVS_CS_F_INVALID) &&
(key->ct_zone == info->zone.id);
if (*ct_executed || (!key->ct_state && info->force)) {
ct = ovs_ct_find_existing(net, &info->zone, info->family, skb,
!!(key->ct_state &
OVS_CS_F_NAT_MASK));
}
return ct;
}
/* Determine whether skb->_nfct is equal to the result of conntrack lookup. */
static bool skb_nfct_cached(struct net *net,
const struct sw_flow_key *key,
const struct ovs_conntrack_info *info,
struct sk_buff *skb)
{
enum ip_conntrack_info ctinfo;
struct nf_conn *ct;
bool ct_executed = true;
ct = nf_ct_get(skb, &ctinfo);
if (!ct)
ct = ovs_ct_executed(net, key, info, skb, &ct_executed);
if (ct)
nf_ct_get(skb, &ctinfo);
else
return false;
if (!net_eq(net, read_pnet(&ct->ct_net)))
return false;
if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
return false;
if (info->helper) {
struct nf_conn_help *help;
help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
if (help && rcu_access_pointer(help->helper) != info->helper)
return false;
}
if (info->nf_ct_timeout) {
struct nf_conn_timeout *timeout_ext;
timeout_ext = nf_ct_timeout_find(ct);
if (!timeout_ext || info->nf_ct_timeout !=
rcu_dereference(timeout_ext->timeout))
return false;
}
/* Force conntrack entry direction to the current packet? */
if (info->force && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) {
/* Delete the conntrack entry if confirmed, else just release
* the reference.
*/
if (nf_ct_is_confirmed(ct))
nf_ct_delete(ct, 0, 0);
nf_ct_put(ct);
nf_ct_set(skb, NULL, 0);
return false;
}
return ct_executed;
}
#if IS_ENABLED(CONFIG_NF_NAT)
static void ovs_nat_update_key(struct sw_flow_key *key,
const struct sk_buff *skb,
enum nf_nat_manip_type maniptype)
{
if (maniptype == NF_NAT_MANIP_SRC) {
__be16 src;
key->ct_state |= OVS_CS_F_SRC_NAT;
if (key->eth.type == htons(ETH_P_IP))
key->ipv4.addr.src = ip_hdr(skb)->saddr;
else if (key->eth.type == htons(ETH_P_IPV6))
memcpy(&key->ipv6.addr.src, &ipv6_hdr(skb)->saddr,
sizeof(key->ipv6.addr.src));
else
return;
if (key->ip.proto == IPPROTO_UDP)
src = udp_hdr(skb)->source;
else if (key->ip.proto == IPPROTO_TCP)
src = tcp_hdr(skb)->source;
else if (key->ip.proto == IPPROTO_SCTP)
src = sctp_hdr(skb)->source;
else
return;
key->tp.src = src;
} else {
__be16 dst;
key->ct_state |= OVS_CS_F_DST_NAT;
if (key->eth.type == htons(ETH_P_IP))
key->ipv4.addr.dst = ip_hdr(skb)->daddr;
else if (key->eth.type == htons(ETH_P_IPV6))
memcpy(&key->ipv6.addr.dst, &ipv6_hdr(skb)->daddr,
sizeof(key->ipv6.addr.dst));
else
return;
if (key->ip.proto == IPPROTO_UDP)
dst = udp_hdr(skb)->dest;
else if (key->ip.proto == IPPROTO_TCP)
dst = tcp_hdr(skb)->dest;
else if (key->ip.proto == IPPROTO_SCTP)
dst = sctp_hdr(skb)->dest;
else
return;
key->tp.dst = dst;
}
}
/* Returns NF_DROP if the packet should be dropped, NF_ACCEPT otherwise. */
static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
const struct ovs_conntrack_info *info,
struct sk_buff *skb, struct nf_conn *ct,
enum ip_conntrack_info ctinfo)
{
int err, action = 0;
if (!(info->nat & OVS_CT_NAT))
return NF_ACCEPT;
if (info->nat & OVS_CT_SRC_NAT)
action |= BIT(NF_NAT_MANIP_SRC);
if (info->nat & OVS_CT_DST_NAT)
action |= BIT(NF_NAT_MANIP_DST);
err = nf_ct_nat(skb, ct, ctinfo, &action, &info->range, info->commit);
if (action & BIT(NF_NAT_MANIP_SRC))
ovs_nat_update_key(key, skb, NF_NAT_MANIP_SRC);
if (action & BIT(NF_NAT_MANIP_DST))
ovs_nat_update_key(key, skb, NF_NAT_MANIP_DST);
return err;
}
#else /* !CONFIG_NF_NAT */
static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
const struct ovs_conntrack_info *info,
struct sk_buff *skb, struct nf_conn *ct,
enum ip_conntrack_info ctinfo)
{
return NF_ACCEPT;
}
#endif
/* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if
* not done already. Update key with new CT state after passing the packet
* through conntrack.
* Note that if the packet is deemed invalid by conntrack, skb->_nfct will be
* set to NULL and 0 will be returned.
*/
static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
const struct ovs_conntrack_info *info,
struct sk_buff *skb)
{
/* If we are recirculating packets to match on conntrack fields and
* committing with a separate conntrack action, then we don't need to
* actually run the packet through conntrack twice unless it's for a
* different zone.
*/
bool cached = skb_nfct_cached(net, key, info, skb);
enum ip_conntrack_info ctinfo;
struct nf_conn *ct;
if (!cached) {
struct nf_hook_state state = {
.hook = NF_INET_PRE_ROUTING,
.pf = info->family,
.net = net,
};
struct nf_conn *tmpl = info->ct;
int err;
/* Associate skb with specified zone. */
if (tmpl) {
ct = nf_ct_get(skb, &ctinfo);
nf_ct_put(ct);
nf_conntrack_get(&tmpl->ct_general);
nf_ct_set(skb, tmpl, IP_CT_NEW);
}
err = nf_conntrack_in(skb, &state);
if (err != NF_ACCEPT)
return -ENOENT;
/* Clear CT state NAT flags to mark that we have not yet done
* NAT after the nf_conntrack_in() call. We can actually clear
* the whole state, as it will be re-initialized below.
*/
key->ct_state = 0;
/* Update the key, but keep the NAT flags. */
ovs_ct_update_key(skb, info, key, true, true);
}
ct = nf_ct_get(skb, &ctinfo);
if (ct) {
bool add_helper = false;
/* Packets starting a new connection must be NATted before the
* helper, so that the helper knows about the NAT. We enforce
* this by delaying both NAT and helper calls for unconfirmed
* connections until the committing CT action. For later
* packets NAT and Helper may be called in either order.
*
* NAT will be done only if the CT action has NAT, and only
* once per packet (per zone), as guarded by the NAT bits in
* the key->ct_state.
*/
if (info->nat && !(key->ct_state & OVS_CS_F_NAT_MASK) &&
(nf_ct_is_confirmed(ct) || info->commit) &&
ovs_ct_nat(net, key, info, skb, ct, ctinfo) != NF_ACCEPT) {
return -EINVAL;
}
/* Userspace may decide to perform a ct lookup without a helper
* specified followed by a (recirculate and) commit with one,
* or attach a helper in a later commit. Therefore, for
* connections which we will commit, we may need to attach
* the helper here.
*/
if (!nf_ct_is_confirmed(ct) && info->commit &&
info->helper && !nfct_help(ct)) {
int err = __nf_ct_try_assign_helper(ct, info->ct,
GFP_ATOMIC);
if (err)
return err;
add_helper = true;
/* helper installed, add seqadj if NAT is required */
if (info->nat && !nfct_seqadj(ct)) {
if (!nfct_seqadj_ext_add(ct))
return -EINVAL;
}
}
/* Call the helper only if:
* - nf_conntrack_in() was executed above ("!cached") or a
* helper was just attached ("add_helper") for a confirmed
* connection, or
* - When committing an unconfirmed connection.
*/
if ((nf_ct_is_confirmed(ct) ? !cached || add_helper :
info->commit) &&
nf_ct_helper(skb, ct, ctinfo, info->family) != NF_ACCEPT) {
return -EINVAL;
}
if (nf_ct_protonum(ct) == IPPROTO_TCP &&
nf_ct_is_confirmed(ct) && nf_conntrack_tcp_established(ct)) {
/* Be liberal for tcp packets so that out-of-window
* packets are not marked invalid.
*/
nf_ct_set_tcp_be_liberal(ct);
}
nf_conn_act_ct_ext_fill(skb, ct, ctinfo);
}
return 0;
}
/* Lookup connection and read fields into key. */
static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
const struct ovs_conntrack_info *info,
struct sk_buff *skb)
{
struct nf_conn *ct;
int err;
err = __ovs_ct_lookup(net, key, info, skb);
if (err)
return err;
ct = (struct nf_conn *)skb_nfct(skb);
if (ct)
nf_ct_deliver_cached_events(ct);
return 0;
}
static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
{
size_t i;
for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
if (labels->ct_labels_32[i])
return true;
return false;
}
#if IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
static struct hlist_head *ct_limit_hash_bucket(
const struct ovs_ct_limit_info *info, u16 zone)
{
return &info->limits[zone & (CT_LIMIT_HASH_BUCKETS - 1)];
}
/* Call with ovs_mutex */
static void ct_limit_set(const struct ovs_ct_limit_info *info,
struct ovs_ct_limit *new_ct_limit)
{
struct ovs_ct_limit *ct_limit;
struct hlist_head *head;
head = ct_limit_hash_bucket(info, new_ct_limit->zone);
hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
if (ct_limit->zone == new_ct_limit->zone) {
hlist_replace_rcu(&ct_limit->hlist_node,
&new_ct_limit->hlist_node);
kfree_rcu(ct_limit, rcu);
return;
}
}
hlist_add_head_rcu(&new_ct_limit->hlist_node, head);
}
/* Call with ovs_mutex */
static void ct_limit_del(const struct ovs_ct_limit_info *info, u16 zone)
{
struct ovs_ct_limit *ct_limit;
struct hlist_head *head;
struct hlist_node *n;
head = ct_limit_hash_bucket(info, zone);
hlist_for_each_entry_safe(ct_limit, n, head, hlist_node) {
if (ct_limit->zone == zone) {
hlist_del_rcu(&ct_limit->hlist_node);
kfree_rcu(ct_limit, rcu);
return;
}
}
}
/* Call with RCU read lock */
static u32 ct_limit_get(const struct ovs_ct_limit_info *info, u16 zone)
{
struct ovs_ct_limit *ct_limit;
struct hlist_head *head;
head = ct_limit_hash_bucket(info, zone);
hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
if (ct_limit->zone == zone)
return ct_limit->limit;
}
return info->default_limit;
}
static int ovs_ct_check_limit(struct net *net,
const struct ovs_conntrack_info *info,
const struct nf_conntrack_tuple *tuple)
{
struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
const struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
u32 per_zone_limit, connections;
u32 conncount_key;
conncount_key = info->zone.id;
per_zone_limit = ct_limit_get(ct_limit_info, info->zone.id);
if (per_zone_limit == OVS_CT_LIMIT_UNLIMITED)
return 0;
connections = nf_conncount_count(net, ct_limit_info->data,
&conncount_key, tuple, &info->zone);
if (connections > per_zone_limit)
return -ENOMEM;
return 0;
}
#endif
/* Lookup connection and confirm if unconfirmed. */
static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
const struct ovs_conntrack_info *info,
struct sk_buff *skb)
{
enum ip_conntrack_info ctinfo;
struct nf_conn *ct;
int err;
err = __ovs_ct_lookup(net, key, info, skb);
if (err)
return err;
/* The connection could be invalid, in which case this is a no-op.*/
ct = nf_ct_get(skb, &ctinfo);
if (!ct)
return 0;
#if IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
if (static_branch_unlikely(&ovs_ct_limit_enabled)) {
if (!nf_ct_is_confirmed(ct)) {
err = ovs_ct_check_limit(net, info,
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
if (err) {
net_warn_ratelimited("openvswitch: zone: %u "
"exceeds conntrack limit\n",
info->zone.id);
return err;
}
}
}
#endif
/* Set the conntrack event mask if given. NEW and DELETE events have
* their own groups, but the NFNLGRP_CONNTRACK_UPDATE group listener
* typically would receive many kinds of updates. Setting the event
* mask allows those events to be filtered. The set event mask will
* remain in effect for the lifetime of the connection unless changed
* by a further CT action with both the commit flag and the eventmask
* option. */
if (info->have_eventmask) {
struct nf_conntrack_ecache *cache = nf_ct_ecache_find(ct);
if (cache)
cache->ctmask = info->eventmask;
}
/* Apply changes before confirming the connection so that the initial
* conntrack NEW netlink event carries the values given in the CT
* action.
*/
if (info->mark.mask) {
err = ovs_ct_set_mark(ct, key, info->mark.value,
info->mark.mask);
if (err)
return err;
}
if (!nf_ct_is_confirmed(ct)) {
err = ovs_ct_init_labels(ct, key, &info->labels.value,
&info->labels.mask);
if (err)
return err;
nf_conn_act_ct_ext_add(skb, ct, ctinfo);
} else if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
labels_nonzero(&info->labels.mask)) {
err = ovs_ct_set_labels(ct, key, &info->labels.value,
&info->labels.mask);
if (err)
return err;
}
/* This will take care of sending queued events even if the connection
* is already confirmed.
*/
if (nf_conntrack_confirm(skb) != NF_ACCEPT)
return -EINVAL;
return 0;
}
/* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
* value if 'skb' is freed.
*/
int ovs_ct_execute(struct net *net, struct sk_buff *skb,
struct sw_flow_key *key,
const struct ovs_conntrack_info *info)
{
int nh_ofs;
int err;
/* The conntrack module expects to be working at L3. */
nh_ofs = skb_network_offset(skb);
skb_pull_rcsum(skb, nh_ofs);
err = nf_ct_skb_network_trim(skb, info->family);
if (err) {
kfree_skb(skb);
return err;
}
if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
err = ovs_ct_handle_fragments(net, key, info->zone.id,
info->family, skb);
if (err)
return err;
}
if (info->commit)
err = ovs_ct_commit(net, key, info, skb);
else
err = ovs_ct_lookup(net, key, info, skb);
skb_push_rcsum(skb, nh_ofs);
if (err)
ovs_kfree_skb_reason(skb, OVS_DROP_CONNTRACK);
return err;
}
int ovs_ct_clear(struct sk_buff *skb, struct sw_flow_key *key)
{
enum ip_conntrack_info ctinfo;
struct nf_conn *ct;
ct = nf_ct_get(skb, &ctinfo);
nf_ct_put(ct);
nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
if (key)
ovs_ct_fill_key(skb, key, false);
return 0;
}
#if IS_ENABLED(CONFIG_NF_NAT)
static int parse_nat(const struct nlattr *attr,
struct ovs_conntrack_info *info, bool log)
{
struct nlattr *a;
int rem;
bool have_ip_max = false;
bool have_proto_max = false;
bool ip_vers = (info->family == NFPROTO_IPV6);
nla_for_each_nested(a, attr, rem) {
static const int ovs_nat_attr_lens[OVS_NAT_ATTR_MAX + 1][2] = {
[OVS_NAT_ATTR_SRC] = {0, 0},
[OVS_NAT_ATTR_DST] = {0, 0},
[OVS_NAT_ATTR_IP_MIN] = {sizeof(struct in_addr),
sizeof(struct in6_addr)},
[OVS_NAT_ATTR_IP_MAX] = {sizeof(struct in_addr),
sizeof(struct in6_addr)},
[OVS_NAT_ATTR_PROTO_MIN] = {sizeof(u16), sizeof(u16)},
[OVS_NAT_ATTR_PROTO_MAX] = {sizeof(u16), sizeof(u16)},
[OVS_NAT_ATTR_PERSISTENT] = {0, 0},
[OVS_NAT_ATTR_PROTO_HASH] = {0, 0},
[OVS_NAT_ATTR_PROTO_RANDOM] = {0, 0},
};
int type = nla_type(a);
if (type > OVS_NAT_ATTR_MAX) {
OVS_NLERR(log, "Unknown NAT attribute (type=%d, max=%d)",
type, OVS_NAT_ATTR_MAX);
return -EINVAL;
}
if (nla_len(a) != ovs_nat_attr_lens[type][ip_vers]) {
OVS_NLERR(log, "NAT attribute type %d has unexpected length (%d != %d)",
type, nla_len(a),
ovs_nat_attr_lens[type][ip_vers]);
return -EINVAL;
}
switch (type) {
case OVS_NAT_ATTR_SRC:
case OVS_NAT_ATTR_DST:
if (info->nat) {
OVS_NLERR(log, "Only one type of NAT may be specified");
return -ERANGE;
}
info->nat |= OVS_CT_NAT;
info->nat |= ((type == OVS_NAT_ATTR_SRC)
? OVS_CT_SRC_NAT : OVS_CT_DST_NAT);
break;
case OVS_NAT_ATTR_IP_MIN:
nla_memcpy(&info->range.min_addr, a,
sizeof(info->range.min_addr));
info->range.flags |= NF_NAT_RANGE_MAP_IPS;
break;
case OVS_NAT_ATTR_IP_MAX:
have_ip_max = true;
nla_memcpy(&info->range.max_addr, a,
sizeof(info->range.max_addr));
info->range.flags |= NF_NAT_RANGE_MAP_IPS;
break;
case OVS_NAT_ATTR_PROTO_MIN:
info->range.min_proto.all = htons(nla_get_u16(a));
info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
break;
case OVS_NAT_ATTR_PROTO_MAX:
have_proto_max = true;
info->range.max_proto.all = htons(nla_get_u16(a));
info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
break;
case OVS_NAT_ATTR_PERSISTENT:
info->range.flags |= NF_NAT_RANGE_PERSISTENT;
break;
case OVS_NAT_ATTR_PROTO_HASH:
info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM;
break;
case OVS_NAT_ATTR_PROTO_RANDOM:
info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM_FULLY;
break;
default:
OVS_NLERR(log, "Unknown nat attribute (%d)", type);
return -EINVAL;
}
}
if (rem > 0) {
OVS_NLERR(log, "NAT attribute has %d unknown bytes", rem);
return -EINVAL;
}
if (!info->nat) {
/* Do not allow flags if no type is given. */
if (info->range.flags) {
OVS_NLERR(log,
"NAT flags may be given only when NAT range (SRC or DST) is also specified."
);
return -EINVAL;
}
info->nat = OVS_CT_NAT; /* NAT existing connections. */
} else if (!info->commit) {
OVS_NLERR(log,
"NAT attributes may be specified only when CT COMMIT flag is also specified."
);
return -EINVAL;
}
/* Allow missing IP_MAX. */
if (info->range.flags & NF_NAT_RANGE_MAP_IPS && !have_ip_max) {
memcpy(&info->range.max_addr, &info->range.min_addr,
sizeof(info->range.max_addr));
}
/* Allow missing PROTO_MAX. */
if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
!have_proto_max) {
info->range.max_proto.all = info->range.min_proto.all;
}
return 0;
}
#endif
static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
[OVS_CT_ATTR_COMMIT] = { .minlen = 0, .maxlen = 0 },
[OVS_CT_ATTR_FORCE_COMMIT] = { .minlen = 0, .maxlen = 0 },
[OVS_CT_ATTR_ZONE] = { .minlen = sizeof(u16),
.maxlen = sizeof(u16) },
[OVS_CT_ATTR_MARK] = { .minlen = sizeof(struct md_mark),
.maxlen = sizeof(struct md_mark) },
[OVS_CT_ATTR_LABELS] = { .minlen = sizeof(struct md_labels),
.maxlen = sizeof(struct md_labels) },
[OVS_CT_ATTR_HELPER] = { .minlen = 1,
.maxlen = NF_CT_HELPER_NAME_LEN },
#if IS_ENABLED(CONFIG_NF_NAT)
/* NAT length is checked when parsing the nested attributes. */
[OVS_CT_ATTR_NAT] = { .minlen = 0, .maxlen = INT_MAX },
#endif
[OVS_CT_ATTR_EVENTMASK] = { .minlen = sizeof(u32),
.maxlen = sizeof(u32) },
[OVS_CT_ATTR_TIMEOUT] = { .minlen = 1,
.maxlen = CTNL_TIMEOUT_NAME_MAX },
};
static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
const char **helper, bool log)
{
struct nlattr *a;
int rem;
nla_for_each_nested(a, attr, rem) {
int type = nla_type(a);
int maxlen;
int minlen;
if (type > OVS_CT_ATTR_MAX) {
OVS_NLERR(log,
"Unknown conntrack attr (type=%d, max=%d)",
type, OVS_CT_ATTR_MAX);
return -EINVAL;
}
maxlen = ovs_ct_attr_lens[type].maxlen;
minlen = ovs_ct_attr_lens[type].minlen;
if (nla_len(a) < minlen || nla_len(a) > maxlen) {
OVS_NLERR(log,
"Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
type, nla_len(a), maxlen);
return -EINVAL;
}
switch (type) {
case OVS_CT_ATTR_FORCE_COMMIT:
info->force = true;
fallthrough;
case OVS_CT_ATTR_COMMIT:
info->commit = true;
break;
#ifdef CONFIG_NF_CONNTRACK_ZONES
case OVS_CT_ATTR_ZONE:
info->zone.id = nla_get_u16(a);
break;
#endif
#ifdef CONFIG_NF_CONNTRACK_MARK
case OVS_CT_ATTR_MARK: {
struct md_mark *mark = nla_data(a);
if (!mark->mask) {
OVS_NLERR(log, "ct_mark mask cannot be 0");
return -EINVAL;
}
info->mark = *mark;
break;
}
#endif
#ifdef CONFIG_NF_CONNTRACK_LABELS
case OVS_CT_ATTR_LABELS: {
struct md_labels *labels = nla_data(a);
if (!labels_nonzero(&labels->mask)) {
OVS_NLERR(log, "ct_labels mask cannot be 0");
return -EINVAL;
}
info->labels = *labels;
break;
}
#endif
case OVS_CT_ATTR_HELPER:
*helper = nla_data(a);
if (!string_is_terminated(*helper, nla_len(a))) {
OVS_NLERR(log, "Invalid conntrack helper");
return -EINVAL;
}
break;
#if IS_ENABLED(CONFIG_NF_NAT)
case OVS_CT_ATTR_NAT: {
int err = parse_nat(a, info, log);
if (err)
return err;
break;
}
#endif
case OVS_CT_ATTR_EVENTMASK:
info->have_eventmask = true;
info->eventmask = nla_get_u32(a);
break;
#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
case OVS_CT_ATTR_TIMEOUT:
memcpy(info->timeout, nla_data(a), nla_len(a));
if (!string_is_terminated(info->timeout, nla_len(a))) {
OVS_NLERR(log, "Invalid conntrack timeout");
return -EINVAL;
}
break;
#endif
default:
OVS_NLERR(log, "Unknown conntrack attr (%d)",
type);
return -EINVAL;
}
}
#ifdef CONFIG_NF_CONNTRACK_MARK
if (!info->commit && info->mark.mask) {
OVS_NLERR(log,
"Setting conntrack mark requires 'commit' flag.");
return -EINVAL;
}
#endif
#ifdef CONFIG_NF_CONNTRACK_LABELS
if (!info->commit && labels_nonzero(&info->labels.mask)) {
OVS_NLERR(log,
"Setting conntrack labels requires 'commit' flag.");
return -EINVAL;
}
#endif
if (rem > 0) {
OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
return -EINVAL;
}
return 0;
}
bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
{
if (attr == OVS_KEY_ATTR_CT_STATE)
return true;
if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
attr == OVS_KEY_ATTR_CT_ZONE)
return true;
if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
attr == OVS_KEY_ATTR_CT_MARK)
return true;
if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
attr == OVS_KEY_ATTR_CT_LABELS) {
struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
return ovs_net->xt_label;
}
return false;
}
int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
const struct sw_flow_key *key,
struct sw_flow_actions **sfa, bool log)
{
struct ovs_conntrack_info ct_info;
const char *helper = NULL;
u16 family;
int err;
family = key_to_nfproto(key);
if (family == NFPROTO_UNSPEC) {
OVS_NLERR(log, "ct family unspecified");
return -EINVAL;
}
memset(&ct_info, 0, sizeof(ct_info));
ct_info.family = family;
nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
NF_CT_DEFAULT_ZONE_DIR, 0);
err = parse_ct(attr, &ct_info, &helper, log);
if (err)
return err;
/* Set up template for tracking connections in specific zones. */
ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
if (!ct_info.ct) {
OVS_NLERR(log, "Failed to allocate conntrack template");
return -ENOMEM;
}
if (ct_info.timeout[0]) {
if (nf_ct_set_timeout(net, ct_info.ct, family, key->ip.proto,
ct_info.timeout))
OVS_NLERR(log,
"Failed to associated timeout policy '%s'",
ct_info.timeout);
else
ct_info.nf_ct_timeout = rcu_dereference(
nf_ct_timeout_find(ct_info.ct)->timeout);
}
if (helper) {
err = nf_ct_add_helper(ct_info.ct, helper, ct_info.family,
key->ip.proto, ct_info.nat, &ct_info.helper);
if (err) {
OVS_NLERR(log, "Failed to add %s helper %d", helper, err);
goto err_free_ct;
}
}
err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
sizeof(ct_info), log);
if (err)
goto err_free_ct;
if (ct_info.commit)
__set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
return 0;
err_free_ct:
__ovs_ct_free_action(&ct_info);
return err;
}
#if IS_ENABLED(CONFIG_NF_NAT)
static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
struct sk_buff *skb)
{
struct nlattr *start;
start = nla_nest_start_noflag(skb, OVS_CT_ATTR_NAT);
if (!start)
return false;
if (info->nat & OVS_CT_SRC_NAT) {
if (nla_put_flag(skb, OVS_NAT_ATTR_SRC))
return false;
} else if (info->nat & OVS_CT_DST_NAT) {
if (nla_put_flag(skb, OVS_NAT_ATTR_DST))
return false;
} else {
goto out;
}
if (info->range.flags & NF_NAT_RANGE_MAP_IPS) {
if (IS_ENABLED(CONFIG_NF_NAT) &&
info->family == NFPROTO_IPV4) {
if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN,
info->range.min_addr.ip) ||
(info->range.max_addr.ip
!= info->range.min_addr.ip &&
(nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX,
info->range.max_addr.ip))))
return false;
} else if (IS_ENABLED(CONFIG_IPV6) &&
info->family == NFPROTO_IPV6) {
if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN,
&info->range.min_addr.in6) ||
(memcmp(&info->range.max_addr.in6,
&info->range.min_addr.in6,
sizeof(info->range.max_addr.in6)) &&
(nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX,
&info->range.max_addr.in6))))
return false;
} else {
return false;
}
}
if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
(nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MIN,
ntohs(info->range.min_proto.all)) ||
(info->range.max_proto.all != info->range.min_proto.all &&
nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MAX,
ntohs(info->range.max_proto.all)))))
return false;
if (info->range.flags & NF_NAT_RANGE_PERSISTENT &&
nla_put_flag(skb, OVS_NAT_ATTR_PERSISTENT))
return false;
if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM &&
nla_put_flag(skb, OVS_NAT_ATTR_PROTO_HASH))
return false;
if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY &&
nla_put_flag(skb, OVS_NAT_ATTR_PROTO_RANDOM))
return false;
out:
nla_nest_end(skb, start);
return true;
}
#endif
int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
struct sk_buff *skb)
{
struct nlattr *start;
start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_CT);
if (!start)
return -EMSGSIZE;
if (ct_info->commit && nla_put_flag(skb, ct_info->force
? OVS_CT_ATTR_FORCE_COMMIT
: OVS_CT_ATTR_COMMIT))
return -EMSGSIZE;
if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
return -EMSGSIZE;
if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
&ct_info->mark))
return -EMSGSIZE;
if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
labels_nonzero(&ct_info->labels.mask) &&
nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
&ct_info->labels))
return -EMSGSIZE;
if (ct_info->helper) {
if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
ct_info->helper->name))
return -EMSGSIZE;
}
if (ct_info->have_eventmask &&
nla_put_u32(skb, OVS_CT_ATTR_EVENTMASK, ct_info->eventmask))
return -EMSGSIZE;
if (ct_info->timeout[0]) {
if (nla_put_string(skb, OVS_CT_ATTR_TIMEOUT, ct_info->timeout))
return -EMSGSIZE;
}
#if IS_ENABLED(CONFIG_NF_NAT)
if (ct_info->nat && !ovs_ct_nat_to_attr(ct_info, skb))
return -EMSGSIZE;
#endif
nla_nest_end(skb, start);
return 0;
}
void ovs_ct_free_action(const struct nlattr *a)
{
struct ovs_conntrack_info *ct_info = nla_data(a);
__ovs_ct_free_action(ct_info);
}
static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
{
if (ct_info->helper) {
#if IS_ENABLED(CONFIG_NF_NAT)
if (ct_info->nat)
nf_nat_helper_put(ct_info->helper);
#endif
nf_conntrack_helper_put(ct_info->helper);
}
if (ct_info->ct) {
if (ct_info->timeout[0])
nf_ct_destroy_timeout(ct_info->ct);
nf_ct_tmpl_free(ct_info->ct);
}
}
#if IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
static int ovs_ct_limit_init(struct net *net, struct ovs_net *ovs_net)
{
int i, err;
ovs_net->ct_limit_info = kmalloc(sizeof(*ovs_net->ct_limit_info),
GFP_KERNEL);
if (!ovs_net->ct_limit_info)
return -ENOMEM;
ovs_net->ct_limit_info->default_limit = OVS_CT_LIMIT_DEFAULT;
ovs_net->ct_limit_info->limits =
kmalloc_array(CT_LIMIT_HASH_BUCKETS, sizeof(struct hlist_head),
GFP_KERNEL);
if (!ovs_net->ct_limit_info->limits) {
kfree(ovs_net->ct_limit_info);
return -ENOMEM;
}
for (i = 0; i < CT_LIMIT_HASH_BUCKETS; i++)
INIT_HLIST_HEAD(&ovs_net->ct_limit_info->limits[i]);
ovs_net->ct_limit_info->data =
nf_conncount_init(net, NFPROTO_INET, sizeof(u32));
if (IS_ERR(ovs_net->ct_limit_info->data)) {
err = PTR_ERR(ovs_net->ct_limit_info->data);
kfree(ovs_net->ct_limit_info->limits);
kfree(ovs_net->ct_limit_info);
pr_err("openvswitch: failed to init nf_conncount %d\n", err);
return err;
}
return 0;
}
static void ovs_ct_limit_exit(struct net *net, struct ovs_net *ovs_net)
{
const struct ovs_ct_limit_info *info = ovs_net->ct_limit_info;
int i;
nf_conncount_destroy(net, NFPROTO_INET, info->data);
for (i = 0; i < CT_LIMIT_HASH_BUCKETS; ++i) {
struct hlist_head *head = &info->limits[i];
struct ovs_ct_limit *ct_limit;
struct hlist_node *next;
hlist_for_each_entry_safe(ct_limit, next, head, hlist_node)
kfree_rcu(ct_limit, rcu);
}
kfree(info->limits);
kfree(info);
}
static struct sk_buff *
ovs_ct_limit_cmd_reply_start(struct genl_info *info, u8 cmd,
struct ovs_header **ovs_reply_header)
{
struct ovs_header *ovs_header = genl_info_userhdr(info);
struct sk_buff *skb;
skb = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!skb)
return ERR_PTR(-ENOMEM);
*ovs_reply_header = genlmsg_put(skb, info->snd_portid,
info->snd_seq,
&dp_ct_limit_genl_family, 0, cmd);
if (!*ovs_reply_header) {
nlmsg_free(skb);
return ERR_PTR(-EMSGSIZE);
}
(*ovs_reply_header)->dp_ifindex = ovs_header->dp_ifindex;
return skb;
}
static bool check_zone_id(int zone_id, u16 *pzone)
{
if (zone_id >= 0 && zone_id <= 65535) {
*pzone = (u16)zone_id;
return true;
}
return false;
}
static int ovs_ct_limit_set_zone_limit(struct nlattr *nla_zone_limit,
struct ovs_ct_limit_info *info)
{
struct ovs_zone_limit *zone_limit;
int rem;
u16 zone;
rem = NLA_ALIGN(nla_len(nla_zone_limit));
zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
while (rem >= sizeof(*zone_limit)) {
if (unlikely(zone_limit->zone_id ==
OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
ovs_lock();
info->default_limit = zone_limit->limit;
ovs_unlock();
} else if (unlikely(!check_zone_id(
zone_limit->zone_id, &zone))) {
OVS_NLERR(true, "zone id is out of range");
} else {
struct ovs_ct_limit *ct_limit;
ct_limit = kmalloc(sizeof(*ct_limit),
GFP_KERNEL_ACCOUNT);
if (!ct_limit)
return -ENOMEM;
ct_limit->zone = zone;
ct_limit->limit = zone_limit->limit;
ovs_lock();
ct_limit_set(info, ct_limit);
ovs_unlock();
}
rem -= NLA_ALIGN(sizeof(*zone_limit));
zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
NLA_ALIGN(sizeof(*zone_limit)));
}
if (rem)
OVS_NLERR(true, "set zone limit has %d unknown bytes", rem);
return 0;
}
static int ovs_ct_limit_del_zone_limit(struct nlattr *nla_zone_limit,
struct ovs_ct_limit_info *info)
{
struct ovs_zone_limit *zone_limit;
int rem;
u16 zone;
rem = NLA_ALIGN(nla_len(nla_zone_limit));
zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
while (rem >= sizeof(*zone_limit)) {
if (unlikely(zone_limit->zone_id ==
OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
ovs_lock();
info->default_limit = OVS_CT_LIMIT_DEFAULT;
ovs_unlock();
} else if (unlikely(!check_zone_id(
zone_limit->zone_id, &zone))) {
OVS_NLERR(true, "zone id is out of range");
} else {
ovs_lock();
ct_limit_del(info, zone);
ovs_unlock();
}
rem -= NLA_ALIGN(sizeof(*zone_limit));
zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
NLA_ALIGN(sizeof(*zone_limit)));
}
if (rem)
OVS_NLERR(true, "del zone limit has %d unknown bytes", rem);
return 0;
}
static int ovs_ct_limit_get_default_limit(struct ovs_ct_limit_info *info,
struct sk_buff *reply)
{
struct ovs_zone_limit zone_limit = {
.zone_id = OVS_ZONE_LIMIT_DEFAULT_ZONE,
.limit = info->default_limit,
};
return nla_put_nohdr(reply, sizeof(zone_limit), &zone_limit);
}
static int __ovs_ct_limit_get_zone_limit(struct net *net,
struct nf_conncount_data *data,
u16 zone_id, u32 limit,
struct sk_buff *reply)
{
struct nf_conntrack_zone ct_zone;
struct ovs_zone_limit zone_limit;
u32 conncount_key = zone_id;
zone_limit.zone_id = zone_id;
zone_limit.limit = limit;
nf_ct_zone_init(&ct_zone, zone_id, NF_CT_DEFAULT_ZONE_DIR, 0);
zone_limit.count = nf_conncount_count(net, data, &conncount_key, NULL,
&ct_zone);
return nla_put_nohdr(reply, sizeof(zone_limit), &zone_limit);
}
static int ovs_ct_limit_get_zone_limit(struct net *net,
struct nlattr *nla_zone_limit,
struct ovs_ct_limit_info *info,
struct sk_buff *reply)
{
struct ovs_zone_limit *zone_limit;
int rem, err;
u32 limit;
u16 zone;
rem = NLA_ALIGN(nla_len(nla_zone_limit));
zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
while (rem >= sizeof(*zone_limit)) {
if (unlikely(zone_limit->zone_id ==
OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
err = ovs_ct_limit_get_default_limit(info, reply);
if (err)
return err;
} else if (unlikely(!check_zone_id(zone_limit->zone_id,
&zone))) {
OVS_NLERR(true, "zone id is out of range");
} else {
rcu_read_lock();
limit = ct_limit_get(info, zone);
rcu_read_unlock();
err = __ovs_ct_limit_get_zone_limit(
net, info->data, zone, limit, reply);
if (err)
return err;
}
rem -= NLA_ALIGN(sizeof(*zone_limit));
zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
NLA_ALIGN(sizeof(*zone_limit)));
}
if (rem)
OVS_NLERR(true, "get zone limit has %d unknown bytes", rem);
return 0;
}
static int ovs_ct_limit_get_all_zone_limit(struct net *net,
struct ovs_ct_limit_info *info,
struct sk_buff *reply)
{
struct ovs_ct_limit *ct_limit;
struct hlist_head *head;
int i, err = 0;
err = ovs_ct_limit_get_default_limit(info, reply);
if (err)
return err;
rcu_read_lock();
for (i = 0; i < CT_LIMIT_HASH_BUCKETS; ++i) {
head = &info->limits[i];
hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
err = __ovs_ct_limit_get_zone_limit(net, info->data,
ct_limit->zone, ct_limit->limit, reply);
if (err)
goto exit_err;
}
}
exit_err:
rcu_read_unlock();
return err;
}
static int ovs_ct_limit_cmd_set(struct sk_buff *skb, struct genl_info *info)
{
struct nlattr **a = info->attrs;
struct sk_buff *reply;
struct ovs_header *ovs_reply_header;
struct ovs_net *ovs_net = net_generic(sock_net(skb->sk), ovs_net_id);
struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
int err;
reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_SET,
&ovs_reply_header);
if (IS_ERR(reply))
return PTR_ERR(reply);
if (!a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
err = -EINVAL;
goto exit_err;
}
err = ovs_ct_limit_set_zone_limit(a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT],
ct_limit_info);
if (err)
goto exit_err;
static_branch_enable(&ovs_ct_limit_enabled);
genlmsg_end(reply, ovs_reply_header);
return genlmsg_reply(reply, info);
exit_err:
nlmsg_free(reply);
return err;
}
static int ovs_ct_limit_cmd_del(struct sk_buff *skb, struct genl_info *info)
{
struct nlattr **a = info->attrs;
struct sk_buff *reply;
struct ovs_header *ovs_reply_header;
struct ovs_net *ovs_net = net_generic(sock_net(skb->sk), ovs_net_id);
struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
int err;
reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_DEL,
&ovs_reply_header);
if (IS_ERR(reply))
return PTR_ERR(reply);
if (!a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
err = -EINVAL;
goto exit_err;
}
err = ovs_ct_limit_del_zone_limit(a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT],
ct_limit_info);
if (err)
goto exit_err;
genlmsg_end(reply, ovs_reply_header);
return genlmsg_reply(reply, info);
exit_err:
nlmsg_free(reply);
return err;
}
static int ovs_ct_limit_cmd_get(struct sk_buff *skb, struct genl_info *info)
{
struct nlattr **a = info->attrs;
struct nlattr *nla_reply;
struct sk_buff *reply;
struct ovs_header *ovs_reply_header;
struct net *net = sock_net(skb->sk);
struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
int err;
reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_GET,
&ovs_reply_header);
if (IS_ERR(reply))
return PTR_ERR(reply);
nla_reply = nla_nest_start_noflag(reply, OVS_CT_LIMIT_ATTR_ZONE_LIMIT);
if (!nla_reply) {
err = -EMSGSIZE;
goto exit_err;
}
if (a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
err = ovs_ct_limit_get_zone_limit(
net, a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT], ct_limit_info,
reply);
if (err)
goto exit_err;
} else {
err = ovs_ct_limit_get_all_zone_limit(net, ct_limit_info,
reply);
if (err)
goto exit_err;
}
nla_nest_end(reply, nla_reply);
genlmsg_end(reply, ovs_reply_header);
return genlmsg_reply(reply, info);
exit_err:
nlmsg_free(reply);
return err;
}
static const struct genl_small_ops ct_limit_genl_ops[] = {
{ .cmd = OVS_CT_LIMIT_CMD_SET,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.flags = GENL_UNS_ADMIN_PERM, /* Requires CAP_NET_ADMIN
* privilege.
*/
.doit = ovs_ct_limit_cmd_set,
},
{ .cmd = OVS_CT_LIMIT_CMD_DEL,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.flags = GENL_UNS_ADMIN_PERM, /* Requires CAP_NET_ADMIN
* privilege.
*/
.doit = ovs_ct_limit_cmd_del,
},
{ .cmd = OVS_CT_LIMIT_CMD_GET,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.flags = 0, /* OK for unprivileged users. */
.doit = ovs_ct_limit_cmd_get,
},
};
static const struct genl_multicast_group ovs_ct_limit_multicast_group = {
.name = OVS_CT_LIMIT_MCGROUP,
};
struct genl_family dp_ct_limit_genl_family __ro_after_init = {
.hdrsize = sizeof(struct ovs_header),
.name = OVS_CT_LIMIT_FAMILY,
.version = OVS_CT_LIMIT_VERSION,
.maxattr = OVS_CT_LIMIT_ATTR_MAX,
.policy = ct_limit_policy,
.netnsok = true,
.parallel_ops = true,
.small_ops = ct_limit_genl_ops,
.n_small_ops = ARRAY_SIZE(ct_limit_genl_ops),
.resv_start_op = OVS_CT_LIMIT_CMD_GET + 1,
.mcgrps = &ovs_ct_limit_multicast_group,
.n_mcgrps = 1,
.module = THIS_MODULE,
};
#endif
int ovs_ct_init(struct net *net)
{
unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
if (nf_connlabels_get(net, n_bits - 1)) {
ovs_net->xt_label = false;
OVS_NLERR(true, "Failed to set connlabel length");
} else {
ovs_net->xt_label = true;
}
#if IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
return ovs_ct_limit_init(net, ovs_net);
#else
return 0;
#endif
}
void ovs_ct_exit(struct net *net)
{
struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
#if IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
ovs_ct_limit_exit(net, ovs_net);
#endif
if (ovs_net->xt_label)
nf_connlabels_put(net);
}
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