1 files changed, 23 insertions, 11 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 7404e5238e00..464bd8c5de69 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -518,17 +518,26 @@ static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp,
 
 	if (unlikely(OPTION_FAST_OPEN_COOKIE & options)) {
 		struct tcp_fastopen_cookie *foc = opts->fastopen_cookie;
+		u8 *p = (u8 *)ptr;
+		u32 len; /* Fast Open option length */
+
+		if (foc->exp) {
+			len = TCPOLEN_EXP_FASTOPEN_BASE + foc->len;
+			*ptr = htonl((TCPOPT_EXP << 24) | (len << 16) |
+				     TCPOPT_FASTOPEN_MAGIC);
+			p += TCPOLEN_EXP_FASTOPEN_BASE;
+		} else {
+			len = TCPOLEN_FASTOPEN_BASE + foc->len;
+			*p++ = TCPOPT_FASTOPEN;
+			*p++ = len;
+		}
 
-		*ptr++ = htonl((TCPOPT_EXP << 24) |
-			       ((TCPOLEN_EXP_FASTOPEN_BASE + foc->len) << 16) |
-			       TCPOPT_FASTOPEN_MAGIC);
-
-		memcpy(ptr, foc->val, foc->len);
-		if ((foc->len & 3) == 2) {
-			u8 *align = ((u8 *)ptr) + foc->len;
-			align[0] = align[1] = TCPOPT_NOP;
+		memcpy(p, foc->val, foc->len);
+		if ((len & 3) == 2) {
+			p[foc->len] = TCPOPT_NOP;
+			p[foc->len + 1] = TCPOPT_NOP;
 		}
-		ptr += (foc->len + 3) >> 2;
+		ptr += (len + 3) >> 2;
 	}
 }
 
@@ -641,8 +650,11 @@ static unsigned int tcp_synack_options(struct sock *sk,
 		if (unlikely(!ireq->tstamp_ok))
 			remaining -= TCPOLEN_SACKPERM_ALIGNED;
 	}
-	if (foc && foc->len >= 0) {
-		u32 need = TCPOLEN_EXP_FASTOPEN_BASE + foc->len;
+	if (foc != NULL && foc->len >= 0) {
+		u32 need = foc->len;
+
+		need += foc->exp ? TCPOLEN_EXP_FASTOPEN_BASE :
+				   TCPOLEN_FASTOPEN_BASE;
 		need = (need + 3) & ~3U;  /* Align to 32 bits */
 		if (remaining >= need) {
 			opts->options |= OPTION_FAST_OPEN_COOKIE;