mptcp: unify ADD_ADDR and echo suboptions writing

There are two differences between ADD_ADDR suboption and ADD_ADDR echo
suboption: The length of the former is 8 octets longer than the length
of the latter. The former's echo-flag is 0, and latter's echo-flag is 1.

This patch added two local variables, len and echo, to unify ADD_ADDR
and ADD_ADDR echo suboptions writing.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 6b7b4b6..c0cf0f5 100644 (file)
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -1071,15 +1071,16 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,
 
 mp_capable_done:
        if (OPTION_MPTCP_ADD_ADDR & opts->suboptions) {
-               if (opts->ahmac)
-                       *ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR,
-                                             TCPOLEN_MPTCP_ADD_ADDR, 0,
-                                             opts->addr_id);
-               else
-                       *ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR,
-                                             TCPOLEN_MPTCP_ADD_ADDR_BASE,
-                                             MPTCP_ADDR_ECHO,
-                                             opts->addr_id);
+               u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
+               u8 echo = MPTCP_ADDR_ECHO;
+
+               if (opts->ahmac) {
+                       len += sizeof(opts->ahmac);
+                       echo = 0;
+               }
+
+               *ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR,
+                                     len, echo, opts->addr_id);
                memcpy((u8 *)ptr, (u8 *)&opts->addr.s_addr, 4);
                ptr += 1;
                if (opts->ahmac) {
@@ -1090,15 +1091,15 @@ mp_capable_done:
 
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
        if (OPTION_MPTCP_ADD_ADDR6 & opts->suboptions) {
-               if (opts->ahmac)
-                       *ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR,
-                                             TCPOLEN_MPTCP_ADD_ADDR6, 0,
-                                             opts->addr_id);
-               else
-                       *ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR,
-                                             TCPOLEN_MPTCP_ADD_ADDR6_BASE,
-                                             MPTCP_ADDR_ECHO,
-                                             opts->addr_id);
+               u8 len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
+               u8 echo = MPTCP_ADDR_ECHO;
+
+               if (opts->ahmac) {
+                       len += sizeof(opts->ahmac);
+                       echo = 0;
+               }
+               *ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR,
+                                     len, echo, opts->addr_id);
                memcpy((u8 *)ptr, opts->addr6.s6_addr, 16);
                ptr += 4;
                if (opts->ahmac) {