[TCP]: MD5 Signature Option (RFC2385) support.

Based on implementation by Rick Payne.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 32 insertions, 3 deletions

diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 2d36f6db3706..0aecfc955591 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -19,6 +19,7 @@
 
 #include <linux/types.h>
 #include <asm/byteorder.h>
+#include <linux/socket.h>
 
 struct tcphdr {
         __be16  source;
@@ -94,6 +95,7 @@ enum {
 #define TCP_INFO                11      /* Information about this connection. */
 #define TCP_QUICKACK            12      /* Block/reenable quick acks */
 #define TCP_CONGESTION          13      /* Congestion control algorithm */
+#define TCP_MD5SIG              14      /* TCP MD5 Signature (RFC2385) */
 
 #define TCPI_OPT_TIMESTAMPS     1
 #define TCPI_OPT_SACK           2
@@ -157,6 +159,17 @@ struct tcp_info
         __u32   tcpi_total_retrans;
 };
 
+/* for TCP_MD5SIG socket option */
+#define TCP_MD5SIG_MAXKEYLEN    80
+
+struct tcp_md5sig {
+        struct __kernel_sockaddr_storage tcpm_addr;     /* address associated */
+        __u16   __tcpm_pad1;                            /* zero */
+        __u16   tcpm_keylen;                            /* key length */
+        __u32   __tcpm_pad2;                            /* zero */
+        __u8    tcpm_key[TCP_MD5SIG_MAXKEYLEN];         /* key (binary) */
+};
+
 #ifdef __KERNEL__
 
 #include <linux/skbuff.h>
@@ -197,9 +210,13 @@ struct tcp_options_received {
 };
 
 struct tcp_request_sock {
-        struct inet_request_sock req;
-        __u32                    rcv_isn;
-        __u32                    snt_isn;
+        struct inet_request_sock        req;
+#ifdef CONFIG_TCP_MD5SIG
+        /* Only used by TCP MD5 Signature so far. */
+        struct tcp_request_sock_ops     *af_specific;
+#endif
+        __u32                           rcv_isn;
+        __u32                           snt_isn;
 };
 
 static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req)
@@ -363,6 +380,14 @@ struct tcp_sock {
                 __u32             probe_seq_start;
                 __u32             probe_seq_end;
         } mtu_probe;
+
+#ifdef CONFIG_TCP_MD5SIG
+/* TCP AF-Specific parts; only used by MD5 Signature support so far */
+        struct tcp_sock_af_ops  *af_specific;
+
+/* TCP MD5 Signagure Option information */
+        struct tcp_md5sig_info  *md5sig_info;
+#endif
 };
 
 static inline struct tcp_sock *tcp_sk(const struct sock *sk)
@@ -377,6 +402,10 @@ struct tcp_timewait_sock {
         __u32                     tw_rcv_wnd;
         __u32                     tw_ts_recent;
         long                      tw_ts_recent_stamp;
+#ifdef CONFIG_TCP_MD5SIG
+        __u16                     tw_md5_keylen;
+        __u8                      tw_md5_key[TCP_MD5SIG_MAXKEYLEN];
+#endif
 };
 
 static inline struct tcp_timewait_sock *tcp_twsk(const struct sock *sk)