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 b37e88407c1d ("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 <dcara...@redhat.com>
---
include/net/tcp.h | 3 +++
include/uapi/linux/inet_diag.h | 8 ++++++++
net/ipv4/tcp_diag.c | 34 ++++++++++++++++++++++++++++++++--
3 files changed, 43 insertions(+), 2 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 0083a14fb64f..94431562c4b4 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2108,6 +2108,9 @@ struct tcp_ulp_ops {
int (*init)(struct sock *sk);
/* cleanup ulp */
void (*release)(struct sock *sk);
+ /* diagnostic */
+ int (*get_info)(struct sock *sk, struct sk_buff *skb);
+ size_t (*get_info_size)(struct sock *sk);
char name[TCP_ULP_NAME_MAX];
struct module *owner;
diff --git a/include/uapi/linux/inet_diag.h b/include/uapi/linux/inet_diag.h
index e8baca85bac6..844133de3212 100644
--- a/include/uapi/linux/inet_diag.h
+++ b/include/uapi/linux/inet_diag.h
@@ -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 {
+ ULP_INFO_NAME,
+ __ULP_INFO_MAX,
+};
+
+#define ULP_INFO_MAX (__ULP_INFO_MAX - 1)
+
/* INET_DIAG_MEM */
struct inet_diag_meminfo {
diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c
index 81148f7a2323..de2e9e75b8e0 100644
--- a/net/ipv4/tcp_diag.c
+++ b/net/ipv4/tcp_diag.c
@@ -88,10 +88,12 @@ static int tcp_diag_put_md5sig(struct sk_buff *skb,
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);
@@ -103,11 +105,33 @@ static int tcp_diag_get_aux(struct sock *sk, bool
net_admin,
}
#endif
- return 0;
+ if (net_admin && icsk->icsk_ulp_ops) {
+ struct nlattr *nest;
+
+ nest = nla_nest_start_noflag(skb, INET_DIAG_ULP_INFO);
+ if (!nest) {
+ err = -EMSGSIZE;
+ goto nla_failure;
+ }
+ err = nla_put_string(skb, ULP_INFO_NAME,
+ icsk->icsk_ulp_ops->name);
+ if (err < 0)
+ goto nla_failure;
+ if (icsk->icsk_ulp_ops->get_info)
+ err = icsk->icsk_ulp_ops->get_info(sk, skb);
+ if (err < 0) {
+nla_failure:
+ nla_nest_cancel(skb, nest);
+ return err;
+ }
+ nla_nest_end(skb, nest);
+ }
+ return err;
}
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
@@ -128,6 +152,12 @@ static size_t tcp_diag_get_aux_size(struct sock *sk, bool
net_admin)
}
#endif
+ if (net_admin && icsk->icsk_ulp_ops) {
+ size += nla_total_size(0) /* INET_DIAG_ULP_INFO */
+ + nla_total_size(TCP_ULP_NAME_MAX); /* ULP_INFO_NAME */
+ if (icsk->icsk_ulp_ops->get_info_size)
+ size += icsk->icsk_ulp_ops->get_info_size(sk);
+ }
return size;
}
--
2.20.1
