@@ -545,36 +545,50 @@ local_rpcb(targaddr)
size_t tsize;
struct netbuf nbuf;
struct sockaddr_un sun;
+ int i;
/*
* Try connecting to the local rpcbind through a local socket
- * first. If this doesn't work, try all transports defined in
- * the netconfig file.
+ * first - trying both addresses. If this doesn't work, try all
+ * non-local transports defined in the netconfig file.
*/
- memset(&sun, 0, sizeof sun);
- sock = socket(AF_LOCAL, SOCK_STREAM, 0);
- if (sock < 0)
- goto try_nconf;
- sun.sun_family = AF_LOCAL;
- strcpy(sun.sun_path, _PATH_RPCBINDSOCK);
- nbuf.len = SUN_LEN(&sun);
- nbuf.maxlen = sizeof (struct sockaddr_un);
- nbuf.buf = &sun;
-
- tsize = __rpc_get_t_size(AF_LOCAL, 0, 0);
- client = clnt_vc_create(sock, &nbuf, (rpcprog_t)RPCBPROG,
- (rpcvers_t)RPCBVERS, tsize, tsize);
-
- if (client != NULL) {
- /* Mark the socket to be closed in destructor */
- (void) CLNT_CONTROL(client, CLSET_FD_CLOSE, NULL);
- if (targaddr)
- *targaddr = strdup(sun.sun_path);
- return client;
- }
+ for (i = 0; i < 2; i++) {
+ memset(&sun, 0, sizeof sun);
+ sock = socket(AF_LOCAL, SOCK_STREAM, 0);
+ if (sock < 0)
+ goto try_nconf;
+ sun.sun_family = AF_LOCAL;
+ switch (i) {
+ case 0:
+ memcpy(sun.sun_path, _PATH_RPCBINDSOCK_ABSTRACT,
+ sizeof(_PATH_RPCBINDSOCK_ABSTRACT));
+ break;
+ case 1:
+ strcpy(sun.sun_path, _PATH_RPCBINDSOCK);
+ break;
+ }
+ nbuf.len = SUN_LEN_A(&sun);
+ nbuf.maxlen = sizeof (struct sockaddr_un);
+ nbuf.buf = &sun;
+
+ tsize = __rpc_get_t_size(AF_LOCAL, 0, 0);
+ client = clnt_vc_create(sock, &nbuf, (rpcprog_t)RPCBPROG,
+ (rpcvers_t)RPCBVERS, tsize, tsize);
+
+ if (client != NULL) {
+ /* Mark the socket to be closed in destructor */
+ (void) CLNT_CONTROL(client, CLSET_FD_CLOSE, NULL);
+ if (targaddr) {
+ if (sun.sun_path[0] == 0)
+ sun.sun_path[0] = '@';
+ *targaddr = strdup(sun.sun_path);
+ }
+ return client;
+ }
- /* Nobody needs this socket anymore; free the descriptor. */
- close(sock);
+ /* Nobody needs this socket anymore; free the descriptor. */
+ close(sock);
+ }
try_nconf:
@@ -755,7 +769,7 @@ got_entry(relp, nconf)
/*
* Quick check to see if rpcbind is up. Tries to connect over
- * local transport.
+ * local transport - first abstract, then regular.
*/
bool_t
__rpcbind_is_up()
@@ -782,15 +796,22 @@ __rpcbind_is_up()
if (sock < 0)
return (FALSE);
sun.sun_family = AF_LOCAL;
- strncpy(sun.sun_path, _PATH_RPCBINDSOCK, sizeof(sun.sun_path));
- if (connect(sock, (struct sockaddr *)&sun, sizeof(sun)) < 0) {
+ memcpy(sun.sun_path, _PATH_RPCBINDSOCK_ABSTRACT,
+ sizeof(_PATH_RPCBINDSOCK_ABSTRACT));
+ if (connect(sock, (struct sockaddr *)&sun, SUN_LEN_A(&sun)) == 0) {
close(sock);
- return (FALSE);
+ return (TRUE);
+ }
+
+ strncpy(sun.sun_path, _PATH_RPCBINDSOCK, sizeof(sun.sun_path));
+ if (connect(sock, (struct sockaddr *)&sun, sizeof(sun)) == 0) {
+ close(sock);
+ return (TRUE);
}
close(sock);
- return (TRUE);
+ return (FALSE);
}
#endif
@@ -477,6 +477,7 @@ extern bool_t xdr_netbuf(XDR *, struct netbuf *);
#define RPCBVERS_4 RPCBVERS4
#define _PATH_RPCBINDSOCK "/var/run/rpcbind.sock"
+#define _PATH_RPCBINDSOCK_ABSTRACT "\0/run/rpcbind.sock"
#else /* ndef _KERNEL */
#ifdef __cplusplus
@@ -411,6 +411,7 @@ program RPCBPROG {
%#define RPCBVERS_4 RPCBVERS4
%
%#define _PATH_RPCBINDSOCK "/var/run/rpcbind.sock"
+%#define _PATH_RPCBINDSOCK_ABSTRACT "\0/run/rpcbind.sock"
%
%#else /* ndef _KERNEL */
%#ifdef __cplusplus
As RPC services are network services, it can make sense to localise them in a network namespace on Linux. Unfortunately the use of a path name - /var/run/rpcbind.sock - to contact rpcbind makes that difficult and requires a mount namespace to be created as well. Linux supports abstract addresses for AF_UNIX sockets. These start with a nul byte and (by convention) no other nul bytes with the length specified by the addrlen. Abstract addresses are matched by byte comparison without reference to the filesystem, and are local to the network namespace in which are used. Using an abstract address for contacting rpcbind removes the need for a mount namespace. Back comparability is assured by attempting to connect to the existing well known address (/var/run/rpcbind.sock) if the abstract address cannot be reached. Choosing the name needs some care as the same address will be configured for rpcbind, and needs to be built in to libtirpc for this enhancement to be fully successful. There is no formal standard for choosing abstract addresses. The defacto standard appears to be to use a path name similar to what would be used for a filesystem AF_UNIX address - but with a leading nul. In that case "\0/var/run/rpcbind.sock" seems like the best choice. However at this time /var/run is deprecated in favour of /run, so "\0/run/rpcbind.sock" might be better. Though as we are deliberately moving away from using the filesystem it might seem more sensible to explicitly break the connection and just have "\0rpcbind.socket" using the same name as the systemd unit file.. The linux kernel already attempts to connect to the second option, "\0/run/rpcbind.sock" since Linux v6.5 so this patch chooses that option. Signed-off-by: NeilBrown <neilb@suse.de> --- src/rpcb_clnt.c | 81 +++++++++++++++++++++++++++---------------- tirpc/rpc/rpcb_prot.h | 1 + tirpc/rpc/rpcb_prot.x | 1 + 3 files changed, 53 insertions(+), 30 deletions(-)