Merge pull request #8564 from rameshabhinay/bgp_tcp_mss

bgpd: Support tcp-mss for bgp neighbors

2 files changed, 56 insertions, 0 deletions

diff --git a/lib/sockopt.c b/lib/sockopt.c
index b624fe2230..98bfda5079 100644
--- a/lib/sockopt.c
+++ b/lib/sockopt.c
@@ -667,3 +667,39 @@ int sockopt_tcp_signature(int sock, union sockunion *su, const char *password)
 {
 	return sockopt_tcp_signature_ext(sock, su, 0, password);
 }
+
+/* set TCP mss value to socket */
+int sockopt_tcp_mss_set(int sock, int tcp_maxseg)
+{
+	int ret = 0;
+	socklen_t tcp_maxseg_len = sizeof(tcp_maxseg);
+
+	ret = setsockopt(sock, IPPROTO_TCP, TCP_MAXSEG, &tcp_maxseg,
+			 tcp_maxseg_len);
+	if (ret != 0) {
+		flog_err_sys(EC_LIB_SYSTEM_CALL,
+			     "%s failed: setsockopt(%d): %s", __func__, sock,
+			     safe_strerror(errno));
+	}
+
+	return ret;
+}
+
+/* get TCP mss value synced by socket */
+int sockopt_tcp_mss_get(int sock)
+{
+	int ret = 0;
+	int tcp_maxseg = 0;
+	socklen_t tcp_maxseg_len = sizeof(tcp_maxseg);
+
+	ret = getsockopt(sock, IPPROTO_TCP, TCP_MAXSEG, &tcp_maxseg,
+			 &tcp_maxseg_len);
+	if (ret != 0) {
+		flog_err_sys(EC_LIB_SYSTEM_CALL,
+			     "%s failed: getsockopt(%d): %s", __func__, sock,
+			     safe_strerror(errno));
+		return 0;
+	}
+
+	return tcp_maxseg;
+}
diff --git a/lib/sockopt.h b/lib/sockopt.h
index 545abe631f..6c80841e3c 100644
--- a/lib/sockopt.h
+++ b/lib/sockopt.h
@@ -133,6 +133,26 @@ extern int sockopt_tcp_signature(int sock, union sockunion *su,
 extern int sockopt_tcp_signature_ext(int sock, union sockunion *su,
 				     uint16_t prefixlen, const char *password);
 
+/*
+ * set TCP max segment size. This option allows user to configure
+ * max segment size for TCP session
+ *
+ * sock
+ *    Socket to enable option on.
+ *
+ * tcp_maxseg
+ *    value used for TCP segment size negotiation during SYN
+ */
+extern int sockopt_tcp_mss_set(int sock, int tcp_maxseg);
+
+/*
+ * get TCP max segment size. This option allows user to get
+ * the segment size for TCP session
+ *
+ * sock
+ *    Socket to get max segement size.
+ */
+extern int sockopt_tcp_mss_get(int sock);
 #ifdef __cplusplus
 }
 #endif