# HG changeset patch
# User Kai Engert <kaie@kuix.de>
# Date 1652465540 -7200
#      Fri May 13 20:12:20 2022 +0200
# Node ID 2be45a781ba18e5904c1eed4dc0e1d66248d303c
# Parent  005070e9849523de6c647dd15dd8a709db0f3b7d
Bug 1769293 - Add API PR_GetPrefLoopbackAddrInfo. r=rrelyea

Differential Revision: https://phabricator.services.mozilla.com/D146333

diff --git a/pr/include/prnetdb.h b/pr/include/prnetdb.h
--- a/pr/include/prnetdb.h
+++ b/pr/include/prnetdb.h
@@ -426,10 +426,13 @@ NSPR_API(void) PR_FreeAddrInfo(PRAddrInf
 **                      is ended if this value is NULL.
 ***********************************************************************/
 NSPR_API(void *) PR_EnumerateAddrInfo(
     void *enumPtr, const PRAddrInfo *addrInfo, PRUint16 port, PRNetAddr *result);
 
+NSPR_API(PRStatus) PR_GetPrefLoopbackAddrInfo(PRNetAddr *result,
+                                              PRUint16 port);
+
 /***********************************************************************
 ** FUNCTION:
 ** DESCRIPTION: PR_GetCanonNameFromAddrInfo()
 **  Extracts the canonical name of the hostname passed to
 **  PR_GetAddrInfoByName().
diff --git a/pr/src/misc/prnetdb.c b/pr/src/misc/prnetdb.c
--- a/pr/src/misc/prnetdb.c
+++ b/pr/src/misc/prnetdb.c
@@ -2176,10 +2176,77 @@ PR_IMPLEMENT(PRAddrInfo *) PR_GetAddrInf
     }
     return NULL;
 #endif
 }
 
+PR_IMPLEMENT(PRStatus)
+PR_GetPrefLoopbackAddrInfo(PRNetAddr *result,
+                           PRUint16 port)
+{
+    char          tmpBuf[ 40 ];
+    const int     tmpBufSize = sizeof( tmpBuf );
+
+    if (!result) {
+        PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
+        return PR_FAILURE;
+    }
+
+    if (!_pr_initialized) _PR_ImplicitInitialization();
+
+    PR_snprintf(tmpBuf, tmpBufSize, "%u", port );
+
+#if !defined(_PR_HAVE_GETADDRINFO) || !defined(AI_PASSIVE)
+    PR_SetError(PR_NOT_IMPLEMENTED_ERROR, 0);
+    return PR_FAILURE;
+#else
+
+    PRADDRINFO *res, hints;
+    PRStatus rv;
+
+    memset(&hints, 0, sizeof(hints));
+
+    rv = GETADDRINFO(NULL, tmpBuf, &hints, &res);
+    if (rv == 0) {
+        PRBool result_still_empty = PR_TRUE;
+        PRADDRINFO *ai = res;
+        do {
+            PRNetAddr aNetAddr;
+
+            while (ai && ai->ai_addrlen > sizeof(PRNetAddr))
+                ai = ai->ai_next;
+
+            if (ai) {
+                /* copy sockaddr to PRNetAddr */
+                memcpy(&aNetAddr, ai->ai_addr, ai->ai_addrlen);
+                aNetAddr.raw.family = ai->ai_addr->sa_family;
+#ifdef _PR_INET6
+                if (AF_INET6 == aNetAddr.raw.family)
+                    aNetAddr.raw.family = PR_AF_INET6;
+#endif
+                if (ai->ai_addrlen < sizeof(PRNetAddr))
+                    memset(((char*)result)+ai->ai_addrlen, 0,
+                           sizeof(PRNetAddr) - ai->ai_addrlen);
+            }
+
+            /* If we obtain more than one result, prefer IPv6. */
+            if (result_still_empty || aNetAddr.raw.family == PR_AF_INET6) {
+                memcpy(result, &aNetAddr, sizeof(PRNetAddr));
+            }
+            result_still_empty = PR_FALSE;
+            ai = ai->ai_next;
+        }
+        while (ai);
+
+        FREEADDRINFO(res);
+        return PR_SUCCESS;
+    }
+
+    PR_SetError(PR_DIRECTORY_LOOKUP_ERROR, rv);
+    return PR_FAILURE;
+#endif
+}
+
 PR_IMPLEMENT(void) PR_FreeAddrInfo(PRAddrInfo *ai)
 {
 #if defined(_PR_HAVE_GETADDRINFO)
 #if defined(_PR_INET6_PROBE)
     if (!_pr_ipv6_is_present()) {
diff --git a/pr/src/nspr.def b/pr/src/nspr.def
--- a/pr/src/nspr.def
+++ b/pr/src/nspr.def
@@ -460,5 +460,9 @@ EXPORTS ;-
 ;+NSPR_4.12 {
 ;+      global:
 		PR_DuplicateEnvironment;
 		PR_GetEnvSecure;
 ;+} NSPR_4.10.3;
+;+NSPR_4.34 {
+;+      global:
+    PR_GetPrefLoopbackAddrInfo;
+;+} NSPR_4.12;