From 848a4eb2e3972400b683bf525a84fdaff6f6dbcc Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Mon, 4 Jun 2018 10:53:29 -0400 Subject: NFSv4.0: Remove cl_ipaddr from non-UCS client ID It is possible for two distinct clients to have the same cl_ipaddr: - if the client admin disables callback with clientaddr=0.0.0.0 on more than one client - if two clients behind separate NATs use the same private subnet number - if the client admin specifies the same address via clientaddr= mount option (pointing the server at the same NAT box, for example) Because of the way the Linux NFSv4.0 client constructs its client ID string by default, such clients could interfere with each others' lease state when mounting the same server: scnprintf(str, len, "Linux NFSv4.0 %s/%s %s", clp->cl_ipaddr, rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR), rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_PROTO)); cl_ipaddr is set to the value of the clientaddr= mount option. Two clients whose addresses are 192.168.3.77 that mount the same server (whose public IP address is, say, 3.4.5.6) would both generate the same client ID string when sending a SETCLIENTID: Linux NFSv4.0 192.168.3.77/3.4.5.6 tcp and thus the server would not be able to distinguish the clients' leases. If both clients are using AUTH_SYS when sending SETCLIENTID then the server could possibly permit the two clients to interfere with or purge each others' leases. To better ensure that Linux's NFSv4.0 client ID strings are distinct in these cases, remove cl_ipaddr from the client ID string and replace it with something more likely to be unique. Note that the replacement looks a lot like the uniform client ID string. Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust --- fs/nfs/nfs4proc.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-) (limited to 'fs/nfs/nfs4proc.c') diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index e7998772bc51..fda45ff7a653 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -5618,13 +5618,16 @@ nfs4_init_nonuniform_client_string(struct nfs_client *clp) return 0; rcu_read_lock(); - len = 14 + strlen(clp->cl_ipaddr) + 1 + + len = 14 + + strlen(clp->cl_rpcclient->cl_nodename) + + 1 + strlen(rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR)) + 1 + strlen(rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_PROTO)) + 1; rcu_read_unlock(); - + if (nfs4_client_id_uniquifier[0] != '\0') + len += strlen(nfs4_client_id_uniquifier) + 1; if (len > NFS4_OPAQUE_LIMIT + 1) return -EINVAL; @@ -5638,10 +5641,21 @@ nfs4_init_nonuniform_client_string(struct nfs_client *clp) return -ENOMEM; rcu_read_lock(); - scnprintf(str, len, "Linux NFSv4.0 %s/%s %s", - clp->cl_ipaddr, - rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR), - rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_PROTO)); + if (nfs4_client_id_uniquifier[0] != '\0') + scnprintf(str, len, "Linux NFSv4.0 %s/%s/%s %s", + clp->cl_rpcclient->cl_nodename, + nfs4_client_id_uniquifier, + rpc_peeraddr2str(clp->cl_rpcclient, + RPC_DISPLAY_ADDR), + rpc_peeraddr2str(clp->cl_rpcclient, + RPC_DISPLAY_PROTO)); + else + scnprintf(str, len, "Linux NFSv4.0 %s/%s %s", + clp->cl_rpcclient->cl_nodename, + rpc_peeraddr2str(clp->cl_rpcclient, + RPC_DISPLAY_ADDR), + rpc_peeraddr2str(clp->cl_rpcclient, + RPC_DISPLAY_PROTO)); rcu_read_unlock(); clp->cl_owner_id = str; -- cgit v1.2.3