Use a list of disconnected and connected sockets to talk to kpasswd

servers, so we automatically try TCP if we fail to change the password

UDP, or if the UDP-based server is just slow.

This patch looks big, but most of it's actually whitespace because

most of the logic is no longer called as part of a loop with UDP and

TCP being used in different iterations.  RT #5868.

Index: src/lib/krb5/os/changepw.c

===================================================================

--- src/lib/krb5/os/changepw.c	(revision 20199)

+++ src/lib/krb5/os/changepw.c	(working copy)

@@ -199,14 +199,14 @@

     krb5_address 		remote_kaddr;

     krb5_boolean		useTcp = 0;

     GETSOCKNAME_ARG3_TYPE 	addrlen;

-    krb5_error_code 		code = 0;

+    krb5_error_code 		code = 0, code2 = 0;

     char 			*code_string;

-    int				local_result_code;

+    int				local_result_code, i;

     struct sendto_callback_context  callback_ctx;

     struct sendto_callback_info	callback_info;

     struct sockaddr_storage	remote_addr;

-    struct addrlist 		al = ADDRLIST_INIT;

+    struct addrlist 		al = ADDRLIST_INIT, al2 = ADDRLIST_INIT;

     memset( &callback_ctx, 0, sizeof(struct sendto_callback_context));

     callback_ctx.context = context;

@@ -225,109 +225,104 @@

 				     &callback_ctx.ap_req)))

 	goto cleanup;

-    do {

-	if ((code = krb5_locate_kpasswd(callback_ctx.context,

-					krb5_princ_realm(callback_ctx.context,

-							 creds->server),

-					&al, useTcp)))

-	    break;

-

+    code = krb5_locate_kpasswd(callback_ctx.context,

+			       krb5_princ_realm(callback_ctx.context,

+						creds->server),

+			       &al, useTcp);

+    code2 = krb5_locate_kpasswd(callback_ctx.context,

+				krb5_princ_realm(callback_ctx.context,

+						 creds->server),

+				&al2, !useTcp);

+    if ((al.naddrs + al2.naddrs) == 0) {

+	if (!code)

+	    code = code2 ? code2 : KRB5_REALM_CANT_RESOLVE;

+	goto cleanup;

+    }

+

+    if (al2.naddrs > 0) {

+	if (krb5int_grow_addrlist(&al, al2.naddrs))

+	    goto cleanup;

+	for (i = 0; i < al2.naddrs; i++)

+	    al.addrs[al.naddrs++] = al2.addrs[i];

+	al2.naddrs = 0;

+    }

+

-	addrlen = sizeof(remote_addr);

-

-	callback_info.context = (void*) &callback_ctx;

-	callback_info.pfn_callback = kpasswd_sendto_msg_callback;

-	callback_info.pfn_cleanup = kpasswd_sendto_msg_cleanup;

-

-	if ((code = krb5int_sendto(callback_ctx.context, 

-				   NULL, 

-				   &al, 

-				   &callback_info,

-				   &chpw_rep,

-				   NULL,

-				   NULL,

-				   ss2sa(&remote_addr),

-                                   &addrlen,

-				   NULL,

-				   NULL,

-				   NULL

-		 ))) {

-

-	    /*

-	     * Here we may want to switch to TCP on some errors.

-	     * right?

-	     */

-	    break;

-	}

-

+    addrlen = sizeof(remote_addr);

+

+    callback_info.context = (void*) &callback_ctx;

+    callback_info.pfn_callback = kpasswd_sendto_msg_callback;

+    callback_info.pfn_cleanup = kpasswd_sendto_msg_cleanup;

+

+    if ((code = krb5int_sendto(callback_ctx.context, 

+			       NULL, 

+			       &al, 

+			       &callback_info,

+			       &chpw_rep,

+			       NULL,

+			       NULL,

+			       ss2sa(&remote_addr),

+			       &addrlen,

+			       NULL,

+			       NULL,

+			       NULL

+		 )))

+	goto cleanup;

+

-	remote_kaddr.addrtype = ADDRTYPE_INET;

-	remote_kaddr.length = sizeof(ss2sin(&remote_addr)->sin_addr);

-	remote_kaddr.contents = (krb5_octet *) &ss2sin(&remote_addr)->sin_addr;

-

-	if ((code = krb5_auth_con_setaddrs(callback_ctx.context,  

-					   callback_ctx.auth_context,  

-					   NULL, 

-					   &remote_kaddr)))

-	    break;

-

+    remote_kaddr.addrtype = ADDRTYPE_INET;

+    remote_kaddr.length = sizeof(ss2sin(&remote_addr)->sin_addr);

+    remote_kaddr.contents = (krb5_octet *) &ss2sin(&remote_addr)->sin_addr;

+

+    if ((code = krb5_auth_con_setaddrs(callback_ctx.context,  

+				       callback_ctx.auth_context,

+				       NULL,

+				       &remote_kaddr)))

+	goto cleanup;

+

-	if (set_password_for)

-	    code = krb5int_rd_setpw_rep(callback_ctx.context, 

-					callback_ctx.auth_context, 

-					&chpw_rep, 

-					&local_result_code, 

-					result_string);

-	else

-	    code = krb5int_rd_chpw_rep(callback_ctx.context, 

-				       callback_ctx.auth_context, 

-				       &chpw_rep, 

-				       &local_result_code, 

-				       result_string);

-

-	if (code) {

-	    if (code == KRB5KRB_ERR_RESPONSE_TOO_BIG && !useTcp ) {

-		krb5int_free_addrlist (&al);

-		useTcp = 1;

-		continue;

-	    }

-

-	    break;

-	}

-

-	if (result_code)

-	    *result_code = local_result_code;

-	

+    if (set_password_for)

+	code = krb5int_rd_setpw_rep(callback_ctx.context, 

+				    callback_ctx.auth_context, 

+				    &chpw_rep, 

+				    &local_result_code, 

+				    result_string);

+    else

+	code = krb5int_rd_chpw_rep(callback_ctx.context, 

+				   callback_ctx.auth_context, 

+				   &chpw_rep, 

+				   &local_result_code, 

+				   result_string);

+

+    if (code)

+	goto cleanup;

+

+    if (result_code)

+	*result_code = local_result_code;

+	

-	if (result_code_string) {

-	    if (set_password_for)

-		code = krb5int_setpw_result_code_string(callback_ctx.context, 

-							local_result_code, 

-							(const char **)&code_string);

-	    else

-		code = krb5_chpw_result_code_string(callback_ctx.context, 

-						    local_result_code, 

-						    &code_string);

-	    if(code)

-		goto cleanup;

-

-	    result_code_string->length = strlen(code_string);

-	    result_code_string->data = malloc(result_code_string->length);

-	    if (result_code_string->data == NULL) {

-		code = ENOMEM;

-		goto cleanup;

-	    }

-	    strncpy(result_code_string->data, code_string, result_code_string->length);

-	}

-

-	if (code == KRB5KRB_ERR_RESPONSE_TOO_BIG && !useTcp ) {

-	    krb5int_free_addrlist (&al);

-	    useTcp = 1;

-        } else {

-	    break;

-	} 

-    } while (TRUE);

+    if (result_code_string) {

+	if (set_password_for)

+	    code = krb5int_setpw_result_code_string(callback_ctx.context, 

+						    local_result_code, 

+						    (const char **) &code_string);

+	else

+	    code = krb5_chpw_result_code_string(callback_ctx.context, 

+						local_result_code, 

+						&code_string);

+	if (code)

+	    goto cleanup;

+

+	result_code_string->length = strlen(code_string);

+	result_code_string->data = malloc(result_code_string->length);

+	if (result_code_string->data == NULL) {

+	    code = ENOMEM;

+	    goto cleanup;

+	}

+	strncpy(result_code_string->data, code_string, result_code_string->length);

+    }

 cleanup:

     if (callback_ctx.auth_context != NULL)

 	krb5_auth_con_free(callback_ctx.context, callback_ctx.auth_context);

+    krb5int_free_addrlist (&al2;;

     krb5int_free_addrlist (&al);

     krb5_free_data_contents(callback_ctx.context, &callback_ctx.ap_req);