From 8e0eb02df52d15dd4317abeddec427cdbac4da3c Mon Sep 17 00:00:00 2001
From: huyan <hu.huyan@huawei.com>
Date: Mon, 8 Jul 2019 02:10:44 +0000
Subject: [PATCH] backport bugfix rpcbind GETADDR return client ip

---
 src/util.c | 45 +++++++++++++++++++++++++++++++++++++++------
 1 file changed, 39 insertions(+), 6 deletions(-)

diff --git a/src/util.c b/src/util.c
index 74b0284..d722d4f 100644
--- a/src/util.c
+++ b/src/util.c
@@ -103,7 +103,7 @@ char *
 addrmerge(struct netbuf *caller, char *serv_uaddr, char *clnt_uaddr,
 	  char *netid)
 {
-	struct ifaddrs *ifap, *ifp = NULL, *bestif;
+	struct ifaddrs *ifap, *ifp = NULL, *bestif, *exactif;
 	struct netbuf *serv_nbp = NULL, *hint_nbp = NULL, tbuf;
 	struct sockaddr *caller_sa, *hint_sa, *ifsa, *ifmasksa, *serv_sa;
 	struct sockaddr_storage ss;
@@ -157,7 +157,12 @@ addrmerge(struct netbuf *caller, char *serv_uaddr, char *clnt_uaddr,
 	 * network portion of its address is equal to that of the client.
 	 * If so, we have found the interface that we want to use.
 	 */
-	bestif = NULL;
+	bestif = NULL;  /* first interface UP with same network & family */
+	exactif = NULL; /* the interface requested by the client */
+	u_int8_t maskAllBits[16] = {  /* 16 bytes for IPv6 */
+				    0xff, 0xff, 0xff, 0xff,  0xff, 0xff, 0xff, 0xff,
+				    0xff, 0xff, 0xff, 0xff,  0xff, 0xff, 0xff, 0xff };
+
 	for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) {
 		ifsa = ifap->ifa_addr;
 		ifmasksa = ifap->ifa_netmask;
@@ -175,8 +180,21 @@ addrmerge(struct netbuf *caller, char *serv_uaddr, char *clnt_uaddr,
 			if (!bitmaskcmp(&SA2SINADDR(ifsa),
 			    &SA2SINADDR(hint_sa), &SA2SINADDR(ifmasksa),
 			    sizeof(struct in_addr))) {
-				bestif = ifap;
-				goto found;
+				if (getenv("RPCBIND_GETADDR_RETURN_CLIENT_IP") == NULL) {
+					bestif = ifap;
+					goto found;
+				}
+
+				if(!bestif) /* for compatibility with previous code */
+					bestif = ifap;
+				/* Is this an exact match? */
+				if (!bitmaskcmp(&SA2SINADDR(ifsa),
+				    &SA2SINADDR(hint_sa), maskAllBits,
+				    sizeof(struct in_addr))) {
+					exactif = ifap;
+					goto found;
+				}
+				/* else go-on looking for an exact match */
 			}
 			break;
 #ifdef INET6
@@ -197,8 +215,21 @@ addrmerge(struct netbuf *caller, char *serv_uaddr, char *clnt_uaddr,
 			} else if (!bitmaskcmp(&SA2SIN6ADDR(ifsa),
 			    &SA2SIN6ADDR(hint_sa), &SA2SIN6ADDR(ifmasksa),
 			    sizeof(struct in6_addr))) {
-				bestif = ifap;
-				goto found;
+				if (getenv("RPCBIND_GETADDR_RETURN_CLIENT_IP") == NULL) {
+					bestif = ifap;
+					goto found;
+				}
+
+				if(!bestif) /* for compatibility with previous code */
+					bestif = ifap;
+				/* Is this an exact match? */
+				if (!bitmaskcmp(&SA2SIN6ADDR(ifsa),
+				    &SA2SIN6ADDR(hint_sa), maskAllBits,
+				    sizeof(struct in6_addr))) {
+					exactif = ifap;
+					goto found;
+				}
+				/* else go-on looking for an exact match */
 			}
 			break;
 #endif
@@ -219,6 +250,8 @@ addrmerge(struct netbuf *caller, char *serv_uaddr, char *clnt_uaddr,
 		goto freeit;
 
 found:
+	if(exactif)
+		bestif = exactif;
 	/*
 	 * Construct the new address using the the address from
 	 * `bestif', and the port number from `serv_uaddr'.
-- 
1.7.12.4