From 8d35301d7db4165f2430c428865f7b0add47615d Mon Sep 17 00:00:00 2001 From: Andy Adamson Date: Wed, 1 Apr 2009 09:22:32 -0400 Subject: [PATCH] nfs41: verify session channel attribues Invalidate the session if the server returns invalid fore or back channel attributes. Use a KERN_WARNING to report the fatal session estabishment error. Signed-off-by: Andy Adamson [refactor nfs4_verify_channel_attrs] Signed-off-by: Benny Halevy Signed-off-by: Trond Myklebust --- fs/nfs/nfs4proc.c | 50 +++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 48 insertions(+), 2 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 7d81d6e57533..4d7a8b9e1291 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -4409,6 +4409,51 @@ static void nfs4_init_channel_attrs(struct nfs41_create_session_args *args) args->bc_attrs.max_reqs); } +static int _verify_channel_attr(char *chan, char *attr_name, u32 sent, u32 rcvd) +{ + if (rcvd <= sent) + return 0; + printk(KERN_WARNING "%s: Session INVALID: %s channel %s increased. " + "sent=%u rcvd=%u\n", __func__, chan, attr_name, sent, rcvd); + return -EINVAL; +} + +#define _verify_fore_channel_attr(_name_) \ + _verify_channel_attr("fore", #_name_, \ + args->fc_attrs._name_, \ + session->fc_attrs._name_) + +#define _verify_back_channel_attr(_name_) \ + _verify_channel_attr("back", #_name_, \ + args->bc_attrs._name_, \ + session->bc_attrs._name_) + +/* + * The server is not allowed to increase the fore channel header pad size, + * maximum response size, or maximum number of operations. + * + * The back channel attributes are only negotiatied down: We send what the + * (back channel) server insists upon. + */ +static int nfs4_verify_channel_attrs(struct nfs41_create_session_args *args, + struct nfs4_session *session) +{ + int ret = 0; + + ret |= _verify_fore_channel_attr(headerpadsz); + ret |= _verify_fore_channel_attr(max_resp_sz); + ret |= _verify_fore_channel_attr(max_ops); + + ret |= _verify_back_channel_attr(headerpadsz); + ret |= _verify_back_channel_attr(max_rqst_sz); + ret |= _verify_back_channel_attr(max_resp_sz); + ret |= _verify_back_channel_attr(max_resp_sz_cached); + ret |= _verify_back_channel_attr(max_ops); + ret |= _verify_back_channel_attr(max_reqs); + + return ret; +} + static int _nfs4_proc_create_session(struct nfs_client *clp) { struct nfs4_session *session = clp->cl_session; @@ -4431,8 +4476,9 @@ static int _nfs4_proc_create_session(struct nfs_client *clp) status = rpc_call_sync(session->clp->cl_rpcclient, &msg, 0); - /* Set the negotiated values in the session's channel_attrs struct */ - + if (!status) + /* Verify the session's negotiated channel_attrs values */ + status = nfs4_verify_channel_attrs(&args, session); if (!status) { /* Increment the clientid slot sequence id */ clp->cl_seqid++;