[PATCH 2/2] tcp: md5: export all configured signature keys in /proc/net
From: Ivan Delalande
Date: Thu Jun 22 2017 - 21:42:12 EST
Add files "tcpmd5" and "tcp6md5" in /proc/net containing all the TCP
MD5 keys configured for sockets using this signature option (RFC2385).
These files contain a line for each key configured on each socket, with
the index number of the socket (as found in /proc/net/tcp{,6}), its
inode number, the address, prefix length and the key itself.
Note that IPv4-mapped IPv6 addresses will be printed as a regular IPv4
address in the tcp6md5 file.
Signed-off-by: Ani Sinha <ani@xxxxxxxxxx>
Signed-off-by: Ken Kofman <kkofman@xxxxxxxxxx>
Signed-off-by: Ivan Delalande <colona@xxxxxxxxxx>
---
Documentation/filesystems/proc.txt | 2 ++
include/net/tcp.h | 1 +
net/ipv4/tcp.c | 55 ++++++++++++++++++++++++++++++++++++++
net/ipv4/tcp_ipv4.c | 29 +++++++++++++++++++-
net/ipv6/tcp_ipv6.c | 29 +++++++++++++++++++-
5 files changed, 114 insertions(+), 2 deletions(-)
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index 4cddbce85ac9..d52a03b2e534 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -1105,6 +1105,7 @@ Table 1-8: IPv6 info in /proc/net
File Content
udp6 UDP sockets (IPv6)
tcp6 TCP sockets (IPv6)
+ tcp6md5 MD5 signature keys configured on IPv6 TCP sockets
raw6 Raw device statistics (IPv6)
igmp6 IP multicast addresses, which this host joined (IPv6)
if_inet6 List of IPv6 interface addresses
@@ -1136,6 +1137,7 @@ Table 1-9: Network info in /proc/net
snmp SNMP data
sockstat Socket statistics
tcp TCP sockets
+ tcpmd5 MD5 signature keys configured on IPv4 TCP sockets
udp UDP sockets
unix UNIX domain sockets
wireless Wireless interface data (Wavelan etc)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 5d78f9af309e..95c9dc47e0c5 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1450,6 +1450,7 @@ struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk,
struct tcp_md5sig_key *tcp_md5_do_lookup(const struct sock *sk,
const union tcp_md5_addr *addr,
int family);
+int tcp_md5_seq_show(struct seq_file *seq, void *v);
#define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key)
#else
static inline struct tcp_md5sig_key *tcp_md5_do_lookup(const struct sock *sk,
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 2a68221d2e55..47bcaeed3605 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3279,6 +3279,61 @@ int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *ke
}
EXPORT_SYMBOL(tcp_md5_hash_key);
+static void do_md5_seq_print_key(struct seq_file *seq,
+ const struct tcp_iter_state *st,
+ const struct tcp_md5sig_key *key,
+ unsigned long ino)
+{
+ if (key->keylen == 0)
+ return;
+
+ seq_printf(seq, "%4d: %6lu ", st->num, ino);
+ if (key->family == AF_INET)
+ seq_printf(seq, "%39pI4/%-3u ", &key->addr.a4, key->prefixlen);
+ else
+ seq_printf(seq, "%39pI6c/%-3u ", &key->addr.a6, key->prefixlen);
+ seq_printf(seq, "%*pE\n", key->keylen, key->key);
+}
+
+int tcp_md5_seq_show(struct seq_file *seq, void *v)
+{
+ struct sock *sp = v;
+ const struct tcp_sock *tp = tcp_sk(sp);
+ const struct tcp_iter_state *st = seq->private;
+ const struct tcp_md5sig_info *md5sig;
+ const struct tcp_md5sig_key *key;
+ unsigned long ino;
+
+ if (v == SEQ_START_TOKEN) {
+ seq_puts(seq, " sl inode addr key\n");
+ goto out;
+ }
+
+ if (sp->sk_state == TCP_TIME_WAIT) {
+ const struct tcp_timewait_sock *tcptw = tcp_twsk(sp);
+
+ key = tcptw->tw_md5_key;
+ if (key)
+ do_md5_seq_print_key(seq, st, key, 0);
+ goto out;
+ }
+
+ ino = sock_i_ino(sp);
+ rcu_read_lock();
+ md5sig = rcu_dereference(tp->md5sig_info);
+ if (!md5sig)
+ goto out_unlock;
+
+ hlist_for_each_entry_rcu(key, &md5sig->head, node) {
+ do_md5_seq_print_key(seq, st, key, ino);
+ }
+
+out_unlock:
+ rcu_read_unlock();
+out:
+ return 0;
+}
+EXPORT_SYMBOL(tcp_md5_seq_show);
#endif
void tcp_done(struct sock *sk)
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 0ae3d7cd59a3..d15a6e3cbdb2 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2395,13 +2395,40 @@ static struct tcp_seq_afinfo tcp4_seq_afinfo = {
},
};
+#ifdef CONFIG_TCP_MD5SIG
+static struct tcp_seq_afinfo tcp4_md5_seq_afinfo = {
+ .name = "tcpmd5",
+ .family = AF_INET,
+ .seq_fops = &tcp_afinfo_seq_fops,
+ .seq_ops = {
+ .show = tcp_md5_seq_show,
+ }
+};
+#endif
+
static int __net_init tcp4_proc_init_net(struct net *net)
{
- return tcp_proc_register(net, &tcp4_seq_afinfo, S_IRUGO);
+ if (tcp_proc_register(net, &tcp4_seq_afinfo, S_IRUGO))
+ goto out_tcp;
+#ifdef CONFIG_TCP_MD5SIG
+ if (tcp_proc_register(net, &tcp4_md5_seq_afinfo, S_IRUSR))
+ goto out_tcpmd5;
+#endif
+ return 0;
+
+#ifdef CONFIG_TCP_MD5SIG
+out_tcpmd5:
+ tcp_proc_unregister(net, &tcp4_seq_afinfo);
+#endif
+out_tcp:
+ return -ENOMEM;
}
static void __net_exit tcp4_proc_exit_net(struct net *net)
{
+#ifdef CONFIG_TCP_MD5SIG
+ tcp_proc_unregister(net, &tcp4_md5_seq_afinfo);
+#endif
tcp_proc_unregister(net, &tcp4_seq_afinfo);
}
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index d97d6627666f..006f5bfae50d 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1886,13 +1886,40 @@ static struct tcp_seq_afinfo tcp6_seq_afinfo = {
},
};
+#ifdef CONFIG_TCP_MD5SIG
+static struct tcp_seq_afinfo tcp6_md5_seq_afinfo = {
+ .name = "tcp6md5",
+ .family = AF_INET6,
+ .seq_fops = &tcp6_afinfo_seq_fops,
+ .seq_ops = {
+ .show = tcp_md5_seq_show,
+ }
+};
+#endif
+
int __net_init tcp6_proc_init(struct net *net)
{
- return tcp_proc_register(net, &tcp6_seq_afinfo, S_IRUGO);
+ if (tcp_proc_register(net, &tcp6_seq_afinfo, S_IRUGO))
+ goto out_tcp6;
+#ifdef CONFIG_TCP_MD5SIG
+ if (tcp_proc_register(net, &tcp6_md5_seq_afinfo, S_IRUSR))
+ goto out_tcp6md5;
+#endif
+ return 0;
+
+#ifdef CONFIG_TCP_MD5SIG
+out_tcp6md5:
+ tcp_proc_unregister(net, &tcp6_seq_afinfo);
+#endif
+out_tcp6:
+ return -ENOMEM;
}
void tcp6_proc_exit(struct net *net)
{
+#ifdef CONFIG_TCP_MD5SIG
+ tcp_proc_unregister(net, &tcp6_md5_seq_afinfo);
+#endif
tcp_proc_unregister(net, &tcp6_seq_afinfo);
}
#endif
--
2.13.1