From 6ee95d1c899186c0798cafd25998d436bcdb9618 Mon Sep 17 00:00:00 2001 From: Scott Mayhew Date: Mon, 9 Sep 2019 16:10:31 -0400 Subject: [PATCH] nfsd: add support for upcall version 2 Version 2 upcalls will allow the nfsd to include a hash of the kerberos principal string in the Cld_Create upcall. If a principal is present in the svc_cred, then the hash will be included in the Cld_Create upcall. We attempt to use the svc_cred.cr_raw_principal (which is returned by gssproxy) first, and then fall back to using the svc_cred.cr_principal (which is returned by both gssproxy and rpc.svcgssd). Upon a subsequent restart, the hash will be returned in the Cld_Gracestart downcall and stored in the reclaim_str_hashtbl so it can be used when handling reclaim opens. Signed-off-by: Scott Mayhew Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4recover.c | 223 +++++++++++++++++++++++++++++++--- fs/nfsd/nfs4state.c | 6 +- fs/nfsd/state.h | 3 +- include/uapi/linux/nfsd/cld.h | 30 ++++- 4 files changed, 245 insertions(+), 17 deletions(-) diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c index 58a61339d40c..cdc75ad4438b 100644 --- a/fs/nfsd/nfs4recover.c +++ b/fs/nfsd/nfs4recover.c @@ -64,6 +64,7 @@ struct nfsd4_client_tracking_ops { }; static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops; +static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v2; /* Globals */ static char user_recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery"; @@ -177,6 +178,7 @@ __nfsd4_create_reclaim_record_grace(struct nfs4_client *clp, const char *dname, int len, struct nfsd_net *nn) { struct xdr_netobj name; + struct xdr_netobj princhash = { .len = 0, .data = NULL }; struct nfs4_client_reclaim *crp; name.data = kmemdup(dname, len, GFP_KERNEL); @@ -186,7 +188,7 @@ __nfsd4_create_reclaim_record_grace(struct nfs4_client *clp, return; } name.len = len; - crp = nfs4_client_to_reclaim(name, nn); + crp = nfs4_client_to_reclaim(name, princhash, nn); if (!crp) { kfree(name.data); return; @@ -486,6 +488,7 @@ static int load_recdir(struct dentry *parent, struct dentry *child, struct nfsd_net *nn) { struct xdr_netobj name; + struct xdr_netobj princhash = { .len = 0, .data = NULL }; if (child->d_name.len != HEXDIR_LEN - 1) { printk("%s: illegal name %pd in recovery directory\n", @@ -500,7 +503,7 @@ load_recdir(struct dentry *parent, struct dentry *child, struct nfsd_net *nn) goto out; } name.len = HEXDIR_LEN; - if (!nfs4_client_to_reclaim(name, nn)) + if (!nfs4_client_to_reclaim(name, princhash, nn)) kfree(name.data); out: return 0; @@ -737,6 +740,7 @@ struct cld_net { struct list_head cn_list; unsigned int cn_xid; bool cn_has_legacy; + struct crypto_shash *cn_tfm; }; struct cld_upcall { @@ -746,6 +750,7 @@ struct cld_upcall { union { struct cld_msg_hdr cu_hdr; struct cld_msg cu_msg; + struct cld_msg_v2 cu_msg_v2; } cu_u; }; @@ -792,11 +797,11 @@ cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg) } static ssize_t -__cld_pipe_inprogress_downcall(const struct cld_msg __user *cmsg, +__cld_pipe_inprogress_downcall(const struct cld_msg_v2 __user *cmsg, struct nfsd_net *nn) { - uint8_t cmd; - struct xdr_netobj name; + uint8_t cmd, princhashlen; + struct xdr_netobj name, princhash = { .len = 0, .data = NULL }; uint16_t namelen; struct cld_net *cn = nn->cld_net; @@ -805,19 +810,45 @@ __cld_pipe_inprogress_downcall(const struct cld_msg __user *cmsg, return -EFAULT; } if (cmd == Cld_GraceStart) { - if (get_user(namelen, &cmsg->cm_u.cm_name.cn_len)) - return -EFAULT; - name.data = memdup_user(&cmsg->cm_u.cm_name.cn_id, namelen); - if (IS_ERR_OR_NULL(name.data)) - return -EFAULT; - name.len = namelen; + if (nn->client_tracking_ops->version >= 2) { + const struct cld_clntinfo __user *ci; + + ci = &cmsg->cm_u.cm_clntinfo; + if (get_user(namelen, &ci->cc_name.cn_len)) + return -EFAULT; + name.data = memdup_user(&ci->cc_name.cn_id, namelen); + if (IS_ERR_OR_NULL(name.data)) + return -EFAULT; + name.len = namelen; + get_user(princhashlen, &ci->cc_princhash.cp_len); + if (princhashlen > 0) { + princhash.data = memdup_user( + &ci->cc_princhash.cp_data, + princhashlen); + if (IS_ERR_OR_NULL(princhash.data)) + return -EFAULT; + princhash.len = princhashlen; + } else + princhash.len = 0; + } else { + const struct cld_name __user *cnm; + + cnm = &cmsg->cm_u.cm_name; + if (get_user(namelen, &cnm->cn_len)) + return -EFAULT; + name.data = memdup_user(&cnm->cn_id, namelen); + if (IS_ERR_OR_NULL(name.data)) + return -EFAULT; + name.len = namelen; + } if (name.len > 5 && memcmp(name.data, "hash:", 5) == 0) { name.len = name.len - 5; memmove(name.data, name.data + 5, name.len); cn->cn_has_legacy = true; } - if (!nfs4_client_to_reclaim(name, nn)) { + if (!nfs4_client_to_reclaim(name, princhash, nn)) { kfree(name.data); + kfree(princhash.data); return -EFAULT; } return nn->client_tracking_ops->msglen; @@ -830,7 +861,7 @@ cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen) { struct cld_upcall *tmp, *cup; struct cld_msg_hdr __user *hdr = (struct cld_msg_hdr __user *)src; - struct cld_msg __user *cmsg = (struct cld_msg __user *)src; + struct cld_msg_v2 __user *cmsg = (struct cld_msg_v2 __user *)src; uint32_t xid; struct nfsd_net *nn = net_generic(file_inode(filp)->i_sb->s_fs_info, nfsd_net_id); @@ -881,7 +912,7 @@ cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen) if (status == -EINPROGRESS) return __cld_pipe_inprogress_downcall(cmsg, nn); - if (copy_from_user(&cup->cu_u.cu_msg, src, mlen) != 0) + if (copy_from_user(&cup->cu_u.cu_msg_v2, src, mlen) != 0) return -EFAULT; complete(&cup->cu_done); @@ -1019,6 +1050,8 @@ nfsd4_remove_cld_pipe(struct net *net) nfsd4_cld_unregister_net(net, cn->cn_pipe); rpc_destroy_pipe_data(cn->cn_pipe); + if (cn->cn_tfm) + crypto_free_shash(cn->cn_tfm); kfree(nn->cld_net); nn->cld_net = NULL; } @@ -1103,6 +1136,75 @@ nfsd4_cld_create(struct nfs4_client *clp) "record on stable storage: %d\n", ret); } +/* Ask daemon to create a new record */ +static void +nfsd4_cld_create_v2(struct nfs4_client *clp) +{ + int ret; + struct cld_upcall *cup; + struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id); + struct cld_net *cn = nn->cld_net; + struct cld_msg_v2 *cmsg; + struct crypto_shash *tfm = cn->cn_tfm; + struct xdr_netobj cksum; + char *principal = NULL; + SHASH_DESC_ON_STACK(desc, tfm); + + /* Don't upcall if it's already stored */ + if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) + return; + + cup = alloc_cld_upcall(nn); + if (!cup) { + ret = -ENOMEM; + goto out_err; + } + + cmsg = &cup->cu_u.cu_msg_v2; + cmsg->cm_cmd = Cld_Create; + cmsg->cm_u.cm_clntinfo.cc_name.cn_len = clp->cl_name.len; + memcpy(cmsg->cm_u.cm_clntinfo.cc_name.cn_id, clp->cl_name.data, + clp->cl_name.len); + if (clp->cl_cred.cr_raw_principal) + principal = clp->cl_cred.cr_raw_principal; + else if (clp->cl_cred.cr_principal) + principal = clp->cl_cred.cr_principal; + if (principal) { + desc->tfm = tfm; + cksum.len = crypto_shash_digestsize(tfm); + cksum.data = kmalloc(cksum.len, GFP_KERNEL); + if (cksum.data == NULL) { + ret = -ENOMEM; + goto out; + } + ret = crypto_shash_digest(desc, principal, strlen(principal), + cksum.data); + shash_desc_zero(desc); + if (ret) { + kfree(cksum.data); + goto out; + } + cmsg->cm_u.cm_clntinfo.cc_princhash.cp_len = cksum.len; + memcpy(cmsg->cm_u.cm_clntinfo.cc_princhash.cp_data, + cksum.data, cksum.len); + kfree(cksum.data); + } else + cmsg->cm_u.cm_clntinfo.cc_princhash.cp_len = 0; + + ret = cld_pipe_upcall(cn->cn_pipe, cmsg); + if (!ret) { + ret = cmsg->cm_status; + set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags); + } + +out: + free_cld_upcall(cup); +out_err: + if (ret) + pr_err("NFSD: Unable to create client record on stable storage: %d\n", + ret); +} + /* Ask daemon to create a new record */ static void nfsd4_cld_remove(struct nfs4_client *clp) @@ -1229,6 +1331,79 @@ nfsd4_cld_check(struct nfs4_client *clp) return 0; } +static int +nfsd4_cld_check_v2(struct nfs4_client *clp) +{ + struct nfs4_client_reclaim *crp; + struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id); + struct cld_net *cn = nn->cld_net; + int status; + char dname[HEXDIR_LEN]; + struct xdr_netobj name; + struct crypto_shash *tfm = cn->cn_tfm; + struct xdr_netobj cksum; + char *principal = NULL; + SHASH_DESC_ON_STACK(desc, tfm); + + /* did we already find that this client is stable? */ + if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) + return 0; + + /* look for it in the reclaim hashtable otherwise */ + crp = nfsd4_find_reclaim_client(clp->cl_name, nn); + if (crp) + goto found; + + if (cn->cn_has_legacy) { + status = nfs4_make_rec_clidname(dname, &clp->cl_name); + if (status) + return -ENOENT; + + name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL); + if (!name.data) { + dprintk("%s: failed to allocate memory for name.data\n", + __func__); + return -ENOENT; + } + name.len = HEXDIR_LEN; + crp = nfsd4_find_reclaim_client(name, nn); + kfree(name.data); + if (crp) + goto found; + + } + return -ENOENT; +found: + if (crp->cr_princhash.len) { + if (clp->cl_cred.cr_raw_principal) + principal = clp->cl_cred.cr_raw_principal; + else if (clp->cl_cred.cr_principal) + principal = clp->cl_cred.cr_principal; + if (principal == NULL) + return -ENOENT; + desc->tfm = tfm; + cksum.len = crypto_shash_digestsize(tfm); + cksum.data = kmalloc(cksum.len, GFP_KERNEL); + if (cksum.data == NULL) + return -ENOENT; + status = crypto_shash_digest(desc, principal, strlen(principal), + cksum.data); + shash_desc_zero(desc); + if (status) { + kfree(cksum.data); + return -ENOENT; + } + if (memcmp(crp->cr_princhash.data, cksum.data, + crp->cr_princhash.len)) { + kfree(cksum.data); + return -ENOENT; + } + kfree(cksum.data); + } + crp->cr_clp = clp; + return 0; +} + static int nfsd4_cld_grace_start(struct nfsd_net *nn) { @@ -1380,6 +1555,9 @@ nfsd4_cld_get_version(struct nfsd_net *nn) case 1: nn->client_tracking_ops = &nfsd4_cld_tracking_ops; break; + case 2: + nn->client_tracking_ops = &nfsd4_cld_tracking_ops_v2; + break; default: break; } @@ -1408,6 +1586,11 @@ nfsd4_cld_tracking_init(struct net *net) status = __nfsd4_init_cld_pipe(net); if (status) goto err_shutdown; + nn->cld_net->cn_tfm = crypto_alloc_shash("sha256", 0, 0); + if (IS_ERR(nn->cld_net->cn_tfm)) { + status = PTR_ERR(nn->cld_net->cn_tfm); + goto err_remove; + } /* * rpc pipe upcalls take 30 seconds to time out, so we don't want to @@ -1480,6 +1663,18 @@ static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops = { .msglen = sizeof(struct cld_msg), }; +/* v2 create/check ops include the principal, if available */ +static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v2 = { + .init = nfsd4_cld_tracking_init, + .exit = nfsd4_cld_tracking_exit, + .create = nfsd4_cld_create_v2, + .remove = nfsd4_cld_remove, + .check = nfsd4_cld_check_v2, + .grace_done = nfsd4_cld_grace_done, + .version = 2, + .msglen = sizeof(struct cld_msg_v2), +}; + /* upcall via usermodehelper */ static char cltrack_prog[PATH_MAX] = "/sbin/nfsdcltrack"; module_param_string(cltrack_prog, cltrack_prog, sizeof(cltrack_prog), diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 906e214dcce8..da1093dd5016 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -6887,7 +6887,8 @@ nfs4_has_reclaimed_state(struct xdr_netobj name, struct nfsd_net *nn) * will be freed in nfs4_remove_reclaim_record in the normal case). */ struct nfs4_client_reclaim * -nfs4_client_to_reclaim(struct xdr_netobj name, struct nfsd_net *nn) +nfs4_client_to_reclaim(struct xdr_netobj name, struct xdr_netobj princhash, + struct nfsd_net *nn) { unsigned int strhashval; struct nfs4_client_reclaim *crp; @@ -6900,6 +6901,8 @@ nfs4_client_to_reclaim(struct xdr_netobj name, struct nfsd_net *nn) list_add(&crp->cr_strhash, &nn->reclaim_str_hashtbl[strhashval]); crp->cr_name.data = name.data; crp->cr_name.len = name.len; + crp->cr_princhash.data = princhash.data; + crp->cr_princhash.len = princhash.len; crp->cr_clp = NULL; nn->reclaim_str_hashtbl_size++; } @@ -6911,6 +6914,7 @@ nfs4_remove_reclaim_record(struct nfs4_client_reclaim *crp, struct nfsd_net *nn) { list_del(&crp->cr_strhash); kfree(crp->cr_name.data); + kfree(crp->cr_princhash.data); kfree(crp); nn->reclaim_str_hashtbl_size--; } diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index d00c86d05beb..46f56afb6cb8 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -378,6 +378,7 @@ struct nfs4_client_reclaim { struct list_head cr_strhash; /* hash by cr_name */ struct nfs4_client *cr_clp; /* pointer to associated clp */ struct xdr_netobj cr_name; /* recovery dir name */ + struct xdr_netobj cr_princhash; }; /* A reasonable value for REPLAY_ISIZE was estimated as follows: @@ -645,7 +646,7 @@ extern void nfsd4_shutdown_callback(struct nfs4_client *); extern void nfsd4_shutdown_copy(struct nfs4_client *clp); extern void nfsd4_prepare_cb_recall(struct nfs4_delegation *dp); extern struct nfs4_client_reclaim *nfs4_client_to_reclaim(struct xdr_netobj name, - struct nfsd_net *nn); + struct xdr_netobj princhash, struct nfsd_net *nn); extern bool nfs4_has_reclaimed_state(struct xdr_netobj name, struct nfsd_net *nn); struct nfs4_file *find_file(struct knfsd_fh *fh); diff --git a/include/uapi/linux/nfsd/cld.h b/include/uapi/linux/nfsd/cld.h index c5aad16d10c0..a519313af953 100644 --- a/include/uapi/linux/nfsd/cld.h +++ b/include/uapi/linux/nfsd/cld.h @@ -26,11 +26,15 @@ #include /* latest upcall version available */ -#define CLD_UPCALL_VERSION 1 +#define CLD_UPCALL_VERSION 2 /* defined by RFC3530 */ #define NFS4_OPAQUE_LIMIT 1024 +#ifndef SHA256_DIGEST_SIZE +#define SHA256_DIGEST_SIZE 32 +#endif + enum cld_command { Cld_Create, /* create a record for this cm_id */ Cld_Remove, /* remove record of this cm_id */ @@ -46,6 +50,17 @@ struct cld_name { unsigned char cn_id[NFS4_OPAQUE_LIMIT]; /* client-provided */ } __attribute__((packed)); +/* sha256 hash of the kerberos principal */ +struct cld_princhash { + __u8 cp_len; /* length of cp_data */ + unsigned char cp_data[SHA256_DIGEST_SIZE]; /* hash of principal */ +} __attribute__((packed)); + +struct cld_clntinfo { + struct cld_name cc_name; + struct cld_princhash cc_princhash; +} __attribute__((packed)); + /* message struct for communication with userspace */ struct cld_msg { __u8 cm_vers; /* upcall version */ @@ -59,6 +74,19 @@ struct cld_msg { } __attribute__((packed)) cm_u; } __attribute__((packed)); +/* version 2 message can include hash of kerberos principal */ +struct cld_msg_v2 { + __u8 cm_vers; /* upcall version */ + __u8 cm_cmd; /* upcall command */ + __s16 cm_status; /* return code */ + __u32 cm_xid; /* transaction id */ + union { + struct cld_name cm_name; + __u8 cm_version; /* for getting max version */ + struct cld_clntinfo cm_clntinfo; /* name & princ hash */ + } __attribute__((packed)) cm_u; +} __attribute__((packed)); + struct cld_msg_hdr { __u8 cm_vers; /* upcall version */ __u8 cm_cmd; /* upcall command */