linux/net/sunrpc/auth_null.c, branch v4.9

sunrpc: move NO_CRKEY_TIMEOUT to the auth->au_flags

2016-07-19T20:23:24Z

A generic_cred can be used to look up a unx_cred or a gss_cred, so it's not really safe to use the the generic_cred->acred->ac_flags to store the NO_CRKEY_TIMEOUT flag. A lookup for a unx_cred triggered while the KEY_EXPIRE_SOON flag is already set will cause both NO_CRKEY_TIMEOUT and KEY_EXPIRE_SOON to be set in the ac_flags, leaving the user associated with the auth_cred to be in a state where they're perpetually doing 4K NFS_FILE_SYNC writes. This can be reproduced as follows: 1. Mount two NFS filesystems, one with sec=krb5 and one with sec=sys. They do not need to be the same export, nor do they even need to be from the same NFS server. Also, v3 is fine. $ sudo mount -o v3,sec=krb5 server1:/export /mnt/krb5 $ sudo mount -o v3,sec=sys server2:/export /mnt/sys 2. As the normal user, before accessing the kerberized mount, kinit with a short lifetime (but not so short that renewing the ticket would leave you within the 4-minute window again by the time the original ticket expires), e.g. $ kinit -l 10m -r 60m 3. Do some I/O to the kerberized mount and verify that the writes are wsize, UNSTABLE: $ dd if=/dev/zero of=/mnt/krb5/file bs=1M count=1 4. Wait until you're within 4 minutes of key expiry, then do some more I/O to the kerberized mount to ensure that RPC_CRED_KEY_EXPIRE_SOON gets set. Verify that the writes are 4K, FILE_SYNC: $ dd if=/dev/zero of=/mnt/krb5/file bs=1M count=1 5. Now do some I/O to the sec=sys mount. This will cause RPC_CRED_NO_CRKEY_TIMEOUT to be set: $ dd if=/dev/zero of=/mnt/sys/file bs=1M count=1 6. Writes for that user will now be permanently 4K, FILE_SYNC for that user, regardless of which mount is being written to, until you reboot the client. Renewing the kerberos ticket (assuming it hasn't already expired) will have no effect. Grabbing a new kerberos ticket at this point will have no effect either. Move the flag to the auth->au_flags field (which is currently unused) and rename it slightly to reflect that it's no longer associated with the auth_cred->ac_flags. Add the rpc_auth to the arg list of rpcauth_cred_key_to_expire and check the au_flags there too. Finally, add the inode to the arg list of nfs_ctx_key_to_expire so we can determine the rpc_auth to pass to rpcauth_cred_key_to_expire. Signed-off-by: Scott Mayhew Signed-off-by: Trond Myklebust

nfsd: Lower NFSv4.1 callback message size limit

2016-03-01T21:06:35Z

The maximum size of a backchannel message on RPC-over-RDMA depends on the connection's inline threshold. Today that threshold is typically 1024 bytes, making the maximum message size 996 bytes. The Linux server's CREATE_SESSION operation checks that the size of callback Calls can be as large as 1044 bytes, to accommodate RPCSEC_GSS. Thus CREATE_SESSION fails if a client advertises the true message size maximum of 996 bytes. But the server's backchannel currently does not support RPCSEC_GSS. The actual maximum size it needs is much smaller. It is safe to reduce the limit to enable NFSv4.1 on RDMA backchannel operation. Signed-off-by: Chuck Lever Signed-off-by: J. Bruce Fields

sunrpc: eliminate RPC_DEBUG

2014-11-24T22:31:46Z

It's always set to whatever CONFIG_SUNRPC_DEBUG is, so just use that. Signed-off-by: Jeff Layton Signed-off-by: Trond Myklebust

sunrpc/auth: allow lockless (rcu) lookup of credential cache.

2014-08-03T21:14:12Z

The new flag RPCAUTH_LOOKUP_RCU to credential lookup avoids locking, does not take a reference on the returned credential, and returns -ECHILD if a simple lookup was not possible. The returned value can only be used within an rcu_read_lock protected region. The main user of this is the new rpc_lookup_cred_nonblock() which returns a pointer to the current credential which is only rcu-safe (no ref-count held), and might return -ECHILD if allocation was required. Signed-off-by: NeilBrown Signed-off-by: Trond Myklebust

SUNRPC refactor rpcauth_checkverf error returns

2013-09-03T19:25:09Z

Most of the time an error from the credops crvalidate function means the server has sent us a garbage verifier. The gss_validate function is the exception where there is an -EACCES case if the user GSS_context on the client has expired. Signed-off-by: Andy Adamson Signed-off-by: Trond Myklebust

SUNRPC: Replace clnt->cl_principal

2013-08-30T13:19:36Z

The clnt->cl_principal is being used exclusively to store the service target name for RPCSEC_GSS/krb5 callbacks. Replace it with something that is stored only in the RPCSEC_GSS-specific code. Signed-off-by: Trond Myklebust

SUNRPC: Move the bound cred to struct rpc_rqst

2010-08-04T12:54:09Z

This will allow us to save the original generic cred in rpc_message, so that if we migrate from one server to another, we can generate a new bound cred without having to punt back to the NFS layer. Signed-off-by: Trond Myklebust

headers: utsname.h redux

2009-09-24T01:13:10Z

* remove asm/atomic.h inclusion from linux/utsname.h -- not needed after kref conversion * remove linux/utsname.h inclusion from files which do not need it NOTE: it looks like fs/binfmt_elf.c do not need utsname.h, however due to some personality stuff it _is_ needed -- cowardly leave ELF-related headers and files alone. Signed-off-by: Alexey Dobriyan Signed-off-by: Linus Torvalds

NFSv4: Don't use cred->cr_ops->cr_name in nfs4_proc_setclientid()

2008-04-19T20:54:53Z

With the recent change to generic creds, we can no longer use cred->cr_ops->cr_name to distinguish between RPCSEC_GSS principals and AUTH_SYS/AUTH_NULL identities. Replace it with the rpc_authops->au_name instead... Signed-off-by: Trond Myklebust

SUNRPC: Add an rpc_credop callback for binding a credential to an rpc_task

2008-03-14T17:42:41Z

We need the ability to treat 'generic' creds specially, since they want to bind instances of the auth cred instead of binding themselves. Signed-off-by: Trond Myklebust