Detect the case where we sent an rpcbind v4 UNSET but user space
doesn't support rpcbind protocol version 4.
We down-shift to version 2 and print a warning once in this case.
Olaf says a v2 UNSET should properly clear all entries in the rpcbind
database.
As svc_unregister() is usually done first to clear old portmapper
entries before trying to set up new ones, a v4 UNSET call will almost
always be the first to detect an rpcbind protocol version mismatch
problem.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
net/sunrpc/svc.c | 51 ++++++++++++++++++++++++++++++++++++++++++++-------
1 files changed, 44 insertions(+), 7 deletions(-)
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index a278a82..e93bc55 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -721,6 +721,21 @@ EXPORT_SYMBOL_GPL(svc_exit_thread);
#ifdef CONFIG_SUNRPC_REGISTER_V4
+static u32 __svc_register_version = 4;
+
+static void __svc_rpcb_prog_mismatch_error(void)
+{
+ if (__svc_register_version == 4) {
+ printk(KERN_WARNING
+ "svc: The kernel tried an rpcbind version 4 request, "
+ "but your portmapper\n"
+ "svc: does not support rpcbind version 4. "
+ "Switching to rpcbind version 2.\n");
+
+ __svc_register_version = 2;
+ }
+}
+
/*
* Register an "inet" protocol family netid with the local
* rpcbind daemon via an rpcbind v4 SET request.
@@ -896,10 +911,20 @@ int svc_register(const struct svc_serv *serv, const unsigned short proto,
return error;
}
+static void __svc_v2_unregister(const u32 program, const u32 version,
+ const char *progname)
+{
+ int error;
+
+ error = rpcb_register(program, version, 0, 0);
+ dprintk("svc: %s(%sv%u), error %d\n",
+ __func__, progname, version, error);
+}
+
#ifdef CONFIG_SUNRPC_REGISTER_V4
-static void __svc_unregister(const u32 program, const u32 version,
- const char *progname)
+static int __svc_v4_unregister(const u32 program, const u32 version,
+ const char *progname)
{
struct sockaddr_in6 sin6 = {
.sin6_family = AF_INET6,
@@ -912,6 +937,22 @@ static void __svc_unregister(const u32 program, const u32 version,
(struct sockaddr *)&sin6, "");
dprintk("svc: %s(%sv%u), error %d\n",
__func__, progname, version, error);
+ return error;
+}
+
+static void __svc_unregister(const u32 program, const u32 version,
+ const char *progname)
+{
+ if (__svc_register_version == 4) {
+ int error = __svc_v4_unregister(program, version, progname);
+ if (error != -EPROTONOSUPPORT)
+ return;
+ }
+
+ __svc_rpcb_prog_mismatch_error();
+
+ /* Olaf says a v2 UNSET _should_ wipe everything */
+ __svc_v2_unregister(program, version, progname);
}
#else /* CONFIG_SUNRPC_REGISTER_V4 */
@@ -919,11 +960,7 @@ static void __svc_unregister(const u32 program, const u32 version,
static void __svc_unregister(const u32 program, const u32 version,
const char *progname)
{
- int error;
-
- error = rpcb_register(program, version, 0, 0);
- dprintk("svc: %s(%sv%u), error %d\n",
- __func__, progname, version, error);
+ __svc_v2_unregister(program, version, progname);
}
#endif /* CONFIG_SUNRPC_REGISTER_V4 */
--
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