inet_diag: support for wider protocol numbers

After commit bf9765145b ("sock: Make sk_protocol a 16-bit value")
the current size of 'sdiag_protocol' is not sufficient to represent
the possible protocol values.

This change introduces a new inet diag request attribute to let
user space specify the relevant protocol number using u32 values.

The attribute is parsed by inet diag core on get/dump command
and the extended protocol value, if available, is preferred to
'sdiag_protocol' to lookup the diag handler.

The parse attributed are exposed to all the diag handlers via
the cb->data.

Note that inet_diag_dump_one_icsk() is left unmodified, as it
will not be used by protocol using the extended attribute.

Suggested-by: David S. Miller <davem@davemloft.net>
Co-developed-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Acked-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Paolo Abeni 2020-07-09 15:12:39 +02:00 committed by David S. Miller
parent 5ca670e58d
commit 3f935c75eb
3 changed files with 50 additions and 17 deletions

View File

@ -65,6 +65,7 @@ enum {
INET_DIAG_REQ_NONE,
INET_DIAG_REQ_BYTECODE,
INET_DIAG_REQ_SK_BPF_STORAGES,
INET_DIAG_REQ_PROTOCOL,
__INET_DIAG_REQ_MAX,
};

View File

@ -3566,6 +3566,7 @@ int sock_load_diag_module(int family, int protocol)
#ifdef CONFIG_INET
if (family == AF_INET &&
protocol != IPPROTO_RAW &&
protocol < MAX_INET_PROTOS &&
!rcu_access_pointer(inet_protos[protocol]))
return -ENOENT;
#endif

View File

@ -52,6 +52,11 @@ static DEFINE_MUTEX(inet_diag_table_mutex);
static const struct inet_diag_handler *inet_diag_lock_handler(int proto)
{
if (proto < 0 || proto >= IPPROTO_MAX) {
mutex_lock(&inet_diag_table_mutex);
return ERR_PTR(-ENOENT);
}
if (!inet_diag_table[proto])
sock_load_diag_module(AF_INET, proto);
@ -181,6 +186,28 @@ errout:
}
EXPORT_SYMBOL_GPL(inet_diag_msg_attrs_fill);
static void inet_diag_parse_attrs(const struct nlmsghdr *nlh, int hdrlen,
struct nlattr **req_nlas)
{
struct nlattr *nla;
int remaining;
nlmsg_for_each_attr(nla, nlh, hdrlen, remaining) {
int type = nla_type(nla);
if (type < __INET_DIAG_REQ_MAX)
req_nlas[type] = nla;
}
}
static int inet_diag_get_protocol(const struct inet_diag_req_v2 *req,
const struct inet_diag_dump_data *data)
{
if (data->req_nlas[INET_DIAG_REQ_PROTOCOL])
return nla_get_u32(data->req_nlas[INET_DIAG_REQ_PROTOCOL]);
return req->sdiag_protocol;
}
#define MAX_DUMP_ALLOC_SIZE (KMALLOC_MAX_SIZE - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
@ -198,7 +225,7 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
void *info = NULL;
cb_data = cb->data;
handler = inet_diag_table[req->sdiag_protocol];
handler = inet_diag_table[inet_diag_get_protocol(req, cb_data)];
BUG_ON(!handler);
nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
@ -539,20 +566,25 @@ EXPORT_SYMBOL_GPL(inet_diag_dump_one_icsk);
static int inet_diag_cmd_exact(int cmd, struct sk_buff *in_skb,
const struct nlmsghdr *nlh,
int hdrlen,
const struct inet_diag_req_v2 *req)
{
const struct inet_diag_handler *handler;
int err;
struct inet_diag_dump_data dump_data;
int err, protocol;
handler = inet_diag_lock_handler(req->sdiag_protocol);
memset(&dump_data, 0, sizeof(dump_data));
inet_diag_parse_attrs(nlh, hdrlen, dump_data.req_nlas);
protocol = inet_diag_get_protocol(req, &dump_data);
handler = inet_diag_lock_handler(protocol);
if (IS_ERR(handler)) {
err = PTR_ERR(handler);
} else if (cmd == SOCK_DIAG_BY_FAMILY) {
struct inet_diag_dump_data empty_dump_data = {};
struct netlink_callback cb = {
.nlh = nlh,
.skb = in_skb,
.data = &empty_dump_data,
.data = &dump_data,
};
err = handler->dump_one(&cb, req);
} else if (cmd == SOCK_DESTROY && handler->destroy) {
@ -1103,13 +1135,16 @@ EXPORT_SYMBOL_GPL(inet_diag_dump_icsk);
static int __inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
const struct inet_diag_req_v2 *r)
{
struct inet_diag_dump_data *cb_data = cb->data;
const struct inet_diag_handler *handler;
u32 prev_min_dump_alloc;
int err = 0;
int protocol, err = 0;
protocol = inet_diag_get_protocol(r, cb_data);
again:
prev_min_dump_alloc = cb->min_dump_alloc;
handler = inet_diag_lock_handler(r->sdiag_protocol);
handler = inet_diag_lock_handler(protocol);
if (!IS_ERR(handler))
handler->dump(skb, cb, r);
else
@ -1139,19 +1174,13 @@ static int __inet_diag_dump_start(struct netlink_callback *cb, int hdrlen)
struct inet_diag_dump_data *cb_data;
struct sk_buff *skb = cb->skb;
struct nlattr *nla;
int rem, err;
int err;
cb_data = kzalloc(sizeof(*cb_data), GFP_KERNEL);
if (!cb_data)
return -ENOMEM;
nla_for_each_attr(nla, nlmsg_attrdata(nlh, hdrlen),
nlmsg_attrlen(nlh, hdrlen), rem) {
int type = nla_type(nla);
if (type < __INET_DIAG_REQ_MAX)
cb_data->req_nlas[type] = nla;
}
inet_diag_parse_attrs(nlh, hdrlen, cb_data->req_nlas);
nla = cb_data->inet_diag_nla_bc;
if (nla) {
@ -1237,7 +1266,8 @@ static int inet_diag_get_exact_compat(struct sk_buff *in_skb,
req.idiag_states = rc->idiag_states;
req.id = rc->id;
return inet_diag_cmd_exact(SOCK_DIAG_BY_FAMILY, in_skb, nlh, &req);
return inet_diag_cmd_exact(SOCK_DIAG_BY_FAMILY, in_skb, nlh,
sizeof(struct inet_diag_req), &req);
}
static int inet_diag_rcv_msg_compat(struct sk_buff *skb, struct nlmsghdr *nlh)
@ -1279,7 +1309,8 @@ static int inet_diag_handler_cmd(struct sk_buff *skb, struct nlmsghdr *h)
return netlink_dump_start(net->diag_nlsk, skb, h, &c);
}
return inet_diag_cmd_exact(h->nlmsg_type, skb, h, nlmsg_data(h));
return inet_diag_cmd_exact(h->nlmsg_type, skb, h, hdrlen,
nlmsg_data(h));
}
static