Report TCP MD5 (RFC2385) signing keys, addresses and address prefixes to
processes with CAP_NET_ADMIN requesting INET_DIAG_INFO. Currently it is
not possible to retrieve these from the kernel once they have been
configured on sockets.
Signed-off-by: Ivan Delalande <col...@arista.com>
---
include/uapi/linux/inet_diag.h | 1 +
net/ipv4/inet_diag.c | 108 +++++++++++++++++++++++++++++++++++++++--
2 files changed, 105 insertions(+), 4 deletions(-)
diff --git a/include/uapi/linux/inet_diag.h b/include/uapi/linux/inet_diag.h
index 678496897a68..f52ff62bfabe 100644
--- a/include/uapi/linux/inet_diag.h
+++ b/include/uapi/linux/inet_diag.h
@@ -143,6 +143,7 @@ enum {
INET_DIAG_MARK,
INET_DIAG_BBRINFO,
INET_DIAG_CLASS_ID,
+ INET_DIAG_MD5SIG,
__INET_DIAG_MAX,
};
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 67325d5832d7..81bacf1d8da6 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -93,8 +93,27 @@ void inet_diag_msg_common_fill(struct inet_diag_msg *r,
struct sock *sk)
}
EXPORT_SYMBOL_GPL(inet_diag_msg_common_fill);
-static size_t inet_sk_attr_size(void)
+static size_t inet_sk_attr_size(struct sock *sp)
{
+#ifdef CONFIG_TCP_MD5SIG
+ const struct tcp_md5sig_info *md5sig;
+ const struct tcp_md5sig_key *key;
+ int md5sig_count = 0;
+
+ if (sp->sk_state == TCP_TIME_WAIT) {
+ if (tcp_twsk(sp)->tw_md5_key)
+ md5sig_count = 1;
+ } else {
+ rcu_read_lock();
+ md5sig = rcu_dereference(tcp_sk(sp)->md5sig_info);
+ if (md5sig) {
+ hlist_for_each_entry_rcu(key, &md5sig->head, node)
+ md5sig_count++;
+ }
+ rcu_read_unlock();
+ }
+#endif
+
return nla_total_size(sizeof(struct tcp_info))
+ nla_total_size(1) /* INET_DIAG_SHUTDOWN */
+ nla_total_size(1) /* INET_DIAG_TOS */
@@ -105,6 +124,9 @@ static size_t inet_sk_attr_size(void)
+ nla_total_size(SK_MEMINFO_VARS * sizeof(u32))
+ nla_total_size(TCP_CA_NAME_MAX)
+ nla_total_size(sizeof(struct tcpvegas_info))
+#ifdef CONFIG_TCP_MD5SIG
+ + nla_total_size(md5sig_count * sizeof(struct tcp_md5sig))
+#endif
+ 64;
}
@@ -150,6 +172,58 @@ int inet_diag_msg_attrs_fill(struct sock *sk, struct
sk_buff *skb,
}
EXPORT_SYMBOL_GPL(inet_diag_msg_attrs_fill);
+#ifdef CONFIG_TCP_MD5SIG
+static void inet_diag_md5sig_fill(struct tcp_md5sig *info,
+ const struct tcp_md5sig_key *key)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+ if (key->family == AF_INET6) {
+ struct sockaddr_in6 *sin6 =
+ (struct sockaddr_in6 *)&info->tcpm_addr;
+
+ memcpy(&sin6->sin6_addr, &key->addr.a6,
+ sizeof(struct in6_addr));
+ } else
+#endif
+ {
+ struct sockaddr_in *sin =
+ (struct sockaddr_in *)&info->tcpm_addr;
+
+ memcpy(&sin->sin_addr, &key->addr.a4, sizeof(struct in_addr));
+ }
+
+ info->tcpm_addr.ss_family = key->family;
+ info->tcpm_prefixlen = key->prefixlen;
+ info->tcpm_keylen = key->keylen;
+ memcpy(info->tcpm_key, key->key, key->keylen);
+}
+
+static int inet_diag_put_md5sig(struct sk_buff *skb,
+ const struct tcp_md5sig_info *md5sig)
+{
+ const struct tcp_md5sig_key *key;
+ struct nlattr *attr;
+ struct tcp_md5sig *info = NULL;
+ int md5sig_count = 0;
+
+ hlist_for_each_entry_rcu(key, &md5sig->head, node)
+ md5sig_count++;
+
+ attr = nla_reserve(skb, INET_DIAG_MD5SIG,
+ md5sig_count * sizeof(struct tcp_md5sig));
+ if (!attr)
+ return -EMSGSIZE;
+
+ info = nla_data(attr);
+ hlist_for_each_entry_rcu(key, &md5sig->head, node) {
+ inet_diag_md5sig_fill(info, key);
+ info++;
+ }
+
+ return 0;
+}
+#endif
+
int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
struct sk_buff *skb, const struct inet_diag_req_v2 *req,
struct user_namespace *user_ns,
@@ -260,6 +334,21 @@ int inet_sk_diag_fill(struct sock *sk, struct
inet_connection_sock *icsk,
handler->idiag_get_info(sk, r, info);
+#ifdef CONFIG_TCP_MD5SIG
+ if ((ext & (1 << (INET_DIAG_INFO - 1))) && net_admin) {
+ struct tcp_md5sig_info *md5sig;
+ int err = 0;
+
+ rcu_read_lock();
+ md5sig = rcu_dereference(tcp_sk(sk)->md5sig_info);
+ if (md5sig)
+ err = inet_diag_put_md5sig(skb, md5sig);
+ rcu_read_unlock();
+ if (err < 0)
+ goto errout;
+ }
+#endif
+
if (sk->sk_state < TCP_TIME_WAIT) {
union tcp_cc_info info;
size_t sz = 0;
@@ -310,7 +399,8 @@ static int inet_csk_diag_fill(struct sock *sk,
static int inet_twsk_diag_fill(struct sock *sk,
struct sk_buff *skb,
u32 portid, u32 seq, u16 nlmsg_flags,
- const struct nlmsghdr *unlh)
+ const struct nlmsghdr *unlh,
+ bool net_admin)
{
struct inet_timewait_sock *tw = inet_twsk(sk);
struct inet_diag_msg *r;
@@ -340,6 +430,16 @@ static int inet_twsk_diag_fill(struct sock *sk,
r->idiag_uid = 0;
r->idiag_inode = 0;
+#ifdef CONFIG_TCP_MD5SIG
+ if (net_admin && tcp_twsk(sk)->tw_md5_key) {
+ struct nlattr *attr = nla_reserve(skb, INET_DIAG_MD5SIG,
+ sizeof(struct tcp_md5sig));
+ if (!attr)
+ return -EMSGSIZE;
+ inet_diag_md5sig_fill(nla_data(attr), tcp_twsk(sk)->tw_md5_key);
+ }
+#endif
+
nlmsg_end(skb, nlh);
return 0;
}
@@ -390,7 +490,7 @@ static int sk_diag_fill(struct sock *sk, struct sk_buff
*skb,
{
if (sk->sk_state == TCP_TIME_WAIT)
return inet_twsk_diag_fill(sk, skb, portid, seq,
- nlmsg_flags, unlh);
+ nlmsg_flags, unlh, net_admin);
if (sk->sk_state == TCP_NEW_SYN_RECV)
return inet_req_diag_fill(sk, skb, portid, seq,
@@ -458,7 +558,7 @@ int inet_diag_dump_one_icsk(struct inet_hashinfo *hashinfo,
if (IS_ERR(sk))
return PTR_ERR(sk);
- rep = nlmsg_new(inet_sk_attr_size(), GFP_KERNEL);
+ rep = nlmsg_new(inet_sk_attr_size(sk), GFP_KERNEL);
if (!rep) {
err = -ENOMEM;
goto out;
--
2.14.1
