tcp: ulp: add functions to dump ulp-specific information

currently, only getsockopt(TCP_ULP) can be invoked to know if a ULP is on
top of a TCP socket. Extend idiag_get_aux() and idiag_get_aux_size(),
introduced by commit b37e88407c ("inet_diag: allow protocols to provide
additional data"), to report the ULP name and other information that can
be made available by the ULP through optional functions.

Users having CAP_NET_ADMIN privileges will then be able to retrieve this
information through inet_diag_handler, if they specify INET_DIAG_INFO in
the request.

Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Davide Caratti 2019-08-30 12:25:48 +02:00 committed by David S. Miller
parent 15a7dea750
commit 61723b3932
3 changed files with 62 additions and 1 deletions

View File

@ -2122,6 +2122,9 @@ struct tcp_ulp_ops {
void (*update)(struct sock *sk, struct proto *p);
/* cleanup ulp */
void (*release)(struct sock *sk);
/* diagnostic */
int (*get_info)(const struct sock *sk, struct sk_buff *skb);
size_t (*get_info_size)(const struct sock *sk);
char name[TCP_ULP_NAME_MAX];
struct module *owner;

View File

@ -153,11 +153,19 @@ enum {
INET_DIAG_BBRINFO, /* request as INET_DIAG_VEGASINFO */
INET_DIAG_CLASS_ID, /* request as INET_DIAG_TCLASS */
INET_DIAG_MD5SIG,
INET_DIAG_ULP_INFO,
__INET_DIAG_MAX,
};
#define INET_DIAG_MAX (__INET_DIAG_MAX - 1)
enum {
INET_ULP_INFO_UNSPEC,
INET_ULP_INFO_NAME,
__INET_ULP_INFO_MAX,
};
#define INET_ULP_INFO_MAX (__INET_ULP_INFO_MAX - 1)
/* INET_DIAG_MEM */
struct inet_diag_meminfo {

View File

@ -81,13 +81,42 @@ static int tcp_diag_put_md5sig(struct sk_buff *skb,
}
#endif
static int tcp_diag_put_ulp(struct sk_buff *skb, struct sock *sk,
const struct tcp_ulp_ops *ulp_ops)
{
struct nlattr *nest;
int err;
nest = nla_nest_start_noflag(skb, INET_DIAG_ULP_INFO);
if (!nest)
return -EMSGSIZE;
err = nla_put_string(skb, INET_ULP_INFO_NAME, ulp_ops->name);
if (err)
goto nla_failure;
if (ulp_ops->get_info)
err = ulp_ops->get_info(sk, skb);
if (err)
goto nla_failure;
nla_nest_end(skb, nest);
return 0;
nla_failure:
nla_nest_cancel(skb, nest);
return err;
}
static int tcp_diag_get_aux(struct sock *sk, bool net_admin,
struct sk_buff *skb)
{
struct inet_connection_sock *icsk = inet_csk(sk);
int err = 0;
#ifdef CONFIG_TCP_MD5SIG
if (net_admin) {
struct tcp_md5sig_info *md5sig;
int err = 0;
rcu_read_lock();
md5sig = rcu_dereference(tcp_sk(sk)->md5sig_info);
@ -99,11 +128,21 @@ static int tcp_diag_get_aux(struct sock *sk, bool net_admin,
}
#endif
if (net_admin) {
const struct tcp_ulp_ops *ulp_ops;
ulp_ops = icsk->icsk_ulp_ops;
if (ulp_ops)
err = tcp_diag_put_ulp(skb, sk, ulp_ops);
if (err)
return err;
}
return 0;
}
static size_t tcp_diag_get_aux_size(struct sock *sk, bool net_admin)
{
struct inet_connection_sock *icsk = inet_csk(sk);
size_t size = 0;
#ifdef CONFIG_TCP_MD5SIG
@ -124,6 +163,17 @@ static size_t tcp_diag_get_aux_size(struct sock *sk, bool net_admin)
}
#endif
if (net_admin) {
const struct tcp_ulp_ops *ulp_ops;
ulp_ops = icsk->icsk_ulp_ops;
if (ulp_ops) {
size += nla_total_size(0) +
nla_total_size(TCP_ULP_NAME_MAX);
if (ulp_ops->get_info_size)
size += ulp_ops->get_info_size(sk);
}
}
return size;
}