Commit 32a4f5ec authored by Jiri Pirko's avatar Jiri Pirko Committed by David S. Miller

net: sched: introduce chain object to uapi

Allow user to create, destroy, get and dump chain objects. Do that by
extending rtnl commands by the chain-specific ones. User will now be
able to explicitly create or destroy chains (so far this was done only
automatically according the filter/act needs and refcounting). Also, the
user will receive notification about any chain creation or destuction.
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f71e0ca4
......@@ -304,6 +304,7 @@ struct tcf_chain {
struct tcf_block *block;
u32 index; /* chain index */
unsigned int refcnt;
bool explicitly_created;
};
struct tcf_block {
......
......@@ -150,6 +150,13 @@ enum {
RTM_NEWCACHEREPORT = 96,
#define RTM_NEWCACHEREPORT RTM_NEWCACHEREPORT
RTM_NEWCHAIN = 100,
#define RTM_NEWCHAIN RTM_NEWCHAIN
RTM_DELCHAIN,
#define RTM_DELCHAIN RTM_DELCHAIN
RTM_GETCHAIN,
#define RTM_GETCHAIN RTM_GETCHAIN
__RTM_MAX,
#define RTM_MAX (((__RTM_MAX + 3) & ~3) - 1)
};
......
......@@ -262,29 +262,57 @@ static void tcf_chain_hold(struct tcf_chain *chain)
++chain->refcnt;
}
struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
bool create)
static struct tcf_chain *tcf_chain_lookup(struct tcf_block *block,
u32 chain_index)
{
struct tcf_chain *chain;
list_for_each_entry(chain, &block->chain_list, list) {
if (chain->index == chain_index) {
tcf_chain_hold(chain);
if (chain->index == chain_index)
return chain;
}
return NULL;
}
static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
u32 seq, u16 flags, int event, bool unicast);
struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
bool create)
{
struct tcf_chain *chain = tcf_chain_lookup(block, chain_index);
if (chain) {
tcf_chain_hold(chain);
return chain;
}
return create ? tcf_chain_create(block, chain_index) : NULL;
if (!create)
return NULL;
chain = tcf_chain_create(block, chain_index);
if (!chain)
return NULL;
tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
RTM_NEWCHAIN, false);
return chain;
}
EXPORT_SYMBOL(tcf_chain_get);
void tcf_chain_put(struct tcf_chain *chain)
{
if (--chain->refcnt == 0)
if (--chain->refcnt == 0) {
tc_chain_notify(chain, NULL, 0, 0, RTM_DELCHAIN, false);
tcf_chain_destroy(chain);
}
}
EXPORT_SYMBOL(tcf_chain_put);
static void tcf_chain_put_explicitly_created(struct tcf_chain *chain)
{
if (chain->explicitly_created)
tcf_chain_put(chain);
}
static bool tcf_block_offload_in_use(struct tcf_block *block)
{
return block->offloadcnt;
......@@ -694,8 +722,10 @@ void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
if (block->refcnt == 1) {
/* At this point, all the chains should have refcnt >= 1. */
list_for_each_entry_safe(chain, tmp, &block->chain_list, list)
list_for_each_entry_safe(chain, tmp, &block->chain_list, list) {
tcf_chain_put_explicitly_created(chain);
tcf_chain_put(chain);
}
block->refcnt--;
if (list_empty(&block->chain_list))
......@@ -1609,6 +1639,264 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
return skb->len;
}
static int tc_chain_fill_node(struct tcf_chain *chain, struct net *net,
struct sk_buff *skb, struct tcf_block *block,
u32 portid, u32 seq, u16 flags, int event)
{
unsigned char *b = skb_tail_pointer(skb);
struct nlmsghdr *nlh;
struct tcmsg *tcm;
nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
if (!nlh)
goto out_nlmsg_trim;
tcm = nlmsg_data(nlh);
tcm->tcm_family = AF_UNSPEC;
tcm->tcm__pad1 = 0;
tcm->tcm__pad2 = 0;
tcm->tcm_handle = 0;
if (block->q) {
tcm->tcm_ifindex = qdisc_dev(block->q)->ifindex;
tcm->tcm_parent = block->q->handle;
} else {
tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
tcm->tcm_block_index = block->index;
}
if (nla_put_u32(skb, TCA_CHAIN, chain->index))
goto nla_put_failure;
nlh->nlmsg_len = skb_tail_pointer(skb) - b;
return skb->len;
out_nlmsg_trim:
nla_put_failure:
nlmsg_trim(skb, b);
return -EMSGSIZE;
}
static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
u32 seq, u16 flags, int event, bool unicast)
{
u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
struct tcf_block *block = chain->block;
struct net *net = block->net;
struct sk_buff *skb;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
return -ENOBUFS;
if (tc_chain_fill_node(chain, net, skb, block, portid,
seq, flags, event) <= 0) {
kfree_skb(skb);
return -EINVAL;
}
if (unicast)
return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
return rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
}
/* Add/delete/get a chain */
static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
struct nlattr *tca[TCA_MAX + 1];
struct tcmsg *t;
u32 parent;
u32 chain_index;
struct Qdisc *q = NULL;
struct tcf_chain *chain = NULL;
struct tcf_block *block;
unsigned long cl;
int err;
if (n->nlmsg_type != RTM_GETCHAIN &&
!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
return -EPERM;
replay:
err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL, extack);
if (err < 0)
return err;
t = nlmsg_data(n);
parent = t->tcm_parent;
cl = 0;
block = tcf_block_find(net, &q, &parent, &cl,
t->tcm_ifindex, t->tcm_block_index, extack);
if (IS_ERR(block))
return PTR_ERR(block);
chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
if (chain_index > TC_ACT_EXT_VAL_MASK) {
NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
return -EINVAL;
}
chain = tcf_chain_lookup(block, chain_index);
if (n->nlmsg_type == RTM_NEWCHAIN) {
if (chain) {
NL_SET_ERR_MSG(extack, "Filter chain already exists");
return -EEXIST;
}
if (!(n->nlmsg_flags & NLM_F_CREATE)) {
NL_SET_ERR_MSG(extack, "Need both RTM_NEWCHAIN and NLM_F_CREATE to create a new chain");
return -ENOENT;
}
chain = tcf_chain_create(block, chain_index);
if (!chain) {
NL_SET_ERR_MSG(extack, "Failed to create filter chain");
return -ENOMEM;
}
} else {
if (!chain) {
NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
return -EINVAL;
}
tcf_chain_hold(chain);
}
switch (n->nlmsg_type) {
case RTM_NEWCHAIN:
/* In case the chain was successfully added, take a reference
* to the chain. This ensures that an empty chain
* does not disappear at the end of this function.
*/
tcf_chain_hold(chain);
chain->explicitly_created = true;
tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
RTM_NEWCHAIN, false);
break;
case RTM_DELCHAIN:
/* Flush the chain first as the user requested chain removal. */
tcf_chain_flush(chain);
/* In case the chain was successfully deleted, put a reference
* to the chain previously taken during addition.
*/
tcf_chain_put_explicitly_created(chain);
break;
case RTM_GETCHAIN:
break;
err = tc_chain_notify(chain, skb, n->nlmsg_seq,
n->nlmsg_seq, n->nlmsg_type, true);
if (err < 0)
NL_SET_ERR_MSG(extack, "Failed to send chain notify message");
break;
default:
err = -EOPNOTSUPP;
NL_SET_ERR_MSG(extack, "Unsupported message type");
goto errout;
}
errout:
tcf_chain_put(chain);
if (err == -EAGAIN)
/* Replay the request. */
goto replay;
return err;
}
/* called with RTNL */
static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
{
struct net *net = sock_net(skb->sk);
struct nlattr *tca[TCA_MAX + 1];
struct Qdisc *q = NULL;
struct tcf_block *block;
struct tcf_chain *chain;
struct tcmsg *tcm = nlmsg_data(cb->nlh);
long index_start;
long index;
u32 parent;
int err;
if (nlmsg_len(cb->nlh) < sizeof(*tcm))
return skb->len;
err = nlmsg_parse(cb->nlh, sizeof(*tcm), tca, TCA_MAX, NULL, NULL);
if (err)
return err;
if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
block = tcf_block_lookup(net, tcm->tcm_block_index);
if (!block)
goto out;
/* If we work with block index, q is NULL and parent value
* will never be used in the following code. The check
* in tcf_fill_node prevents it. However, compiler does not
* see that far, so set parent to zero to silence the warning
* about parent being uninitialized.
*/
parent = 0;
} else {
const struct Qdisc_class_ops *cops;
struct net_device *dev;
unsigned long cl = 0;
dev = __dev_get_by_index(net, tcm->tcm_ifindex);
if (!dev)
return skb->len;
parent = tcm->tcm_parent;
if (!parent) {
q = dev->qdisc;
parent = q->handle;
} else {
q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
}
if (!q)
goto out;
cops = q->ops->cl_ops;
if (!cops)
goto out;
if (!cops->tcf_block)
goto out;
if (TC_H_MIN(tcm->tcm_parent)) {
cl = cops->find(q, tcm->tcm_parent);
if (cl == 0)
goto out;
}
block = cops->tcf_block(q, cl, NULL);
if (!block)
goto out;
if (tcf_block_shared(block))
q = NULL;
}
index_start = cb->args[0];
index = 0;
list_for_each_entry(chain, &block->chain_list, list) {
if ((tca[TCA_CHAIN] &&
nla_get_u32(tca[TCA_CHAIN]) != chain->index))
continue;
if (index < index_start) {
index++;
continue;
}
err = tc_chain_fill_node(chain, net, skb, block,
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI,
RTM_NEWCHAIN);
if (err <= 0)
break;
index++;
}
cb->args[0] = index;
out:
/* If we did no progress, the error (EMSGSIZE) is real */
if (skb->len == 0 && err)
return err;
return skb->len;
}
void tcf_exts_destroy(struct tcf_exts *exts)
{
#ifdef CONFIG_NET_CLS_ACT
......@@ -1825,6 +2113,10 @@ static int __init tc_filter_init(void)
rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL, 0);
rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_get_tfilter,
tc_dump_tfilter, 0);
rtnl_register(PF_UNSPEC, RTM_NEWCHAIN, tc_ctl_chain, NULL, 0);
rtnl_register(PF_UNSPEC, RTM_DELCHAIN, tc_ctl_chain, NULL, 0);
rtnl_register(PF_UNSPEC, RTM_GETCHAIN, tc_ctl_chain,
tc_dump_chain, 0);
return 0;
......
......@@ -159,7 +159,7 @@ int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm)
switch (sclass) {
case SECCLASS_NETLINK_ROUTE_SOCKET:
/* RTM_MAX always point to RTM_SETxxxx, ie RTM_NEWxxx + 3 */
BUILD_BUG_ON(RTM_MAX != (RTM_NEWCACHEREPORT + 3));
BUILD_BUG_ON(RTM_MAX != (RTM_NEWCHAIN + 3));
err = nlmsg_perm(nlmsg_type, perm, nlmsg_route_perms,
sizeof(nlmsg_route_perms));
break;
......
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