diff options
Diffstat (limited to 'net/sunrpc/auth_gss/svcauth_gss.c')
| -rw-r--r-- | net/sunrpc/auth_gss/svcauth_gss.c | 2134 |
1 files changed, 2134 insertions, 0 deletions
diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c new file mode 100644 index 000000000..18734e70c --- /dev/null +++ b/net/sunrpc/auth_gss/svcauth_gss.c @@ -0,0 +1,2134 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Neil Brown <neilb@cse.unsw.edu.au> + * J. Bruce Fields <bfields@umich.edu> + * Andy Adamson <andros@umich.edu> + * Dug Song <dugsong@monkey.org> + * + * RPCSEC_GSS server authentication. + * This implements RPCSEC_GSS as defined in rfc2203 (rpcsec_gss) and rfc2078 + * (gssapi) + * + * The RPCSEC_GSS involves three stages: + * 1/ context creation + * 2/ data exchange + * 3/ context destruction + * + * Context creation is handled largely by upcalls to user-space. + * In particular, GSS_Accept_sec_context is handled by an upcall + * Data exchange is handled entirely within the kernel + * In particular, GSS_GetMIC, GSS_VerifyMIC, GSS_Seal, GSS_Unseal are in-kernel. + * Context destruction is handled in-kernel + * GSS_Delete_sec_context is in-kernel + * + * Context creation is initiated by a RPCSEC_GSS_INIT request arriving. + * The context handle and gss_token are used as a key into the rpcsec_init cache. + * The content of this cache includes some of the outputs of GSS_Accept_sec_context, + * being major_status, minor_status, context_handle, reply_token. + * These are sent back to the client. + * Sequence window management is handled by the kernel. The window size if currently + * a compile time constant. + * + * When user-space is happy that a context is established, it places an entry + * in the rpcsec_context cache. The key for this cache is the context_handle. + * The content includes: + * uid/gidlist - for determining access rights + * mechanism type + * mechanism specific information, such as a key + * + */ + +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/module.h> +#include <linux/pagemap.h> +#include <linux/user_namespace.h> + +#include <linux/sunrpc/auth_gss.h> +#include <linux/sunrpc/gss_err.h> +#include <linux/sunrpc/svcauth.h> +#include <linux/sunrpc/svcauth_gss.h> +#include <linux/sunrpc/cache.h> +#include <linux/sunrpc/gss_krb5.h> + +#include <trace/events/rpcgss.h> + +#include "gss_rpc_upcall.h" + +/* + * Unfortunately there isn't a maximum checksum size exported via the + * GSS API. Manufacture one based on GSS mechanisms supported by this + * implementation. + */ +#define GSS_MAX_CKSUMSIZE (GSS_KRB5_TOK_HDR_LEN + GSS_KRB5_MAX_CKSUM_LEN) + +/* + * This value may be increased in the future to accommodate other + * usage of the scratch buffer. + */ +#define GSS_SCRATCH_SIZE GSS_MAX_CKSUMSIZE + +struct gss_svc_data { + /* decoded gss client cred: */ + struct rpc_gss_wire_cred clcred; + u32 gsd_databody_offset; + struct rsc *rsci; + + /* for temporary results */ + __be32 gsd_seq_num; + u8 gsd_scratch[GSS_SCRATCH_SIZE]; +}; + +/* The rpcsec_init cache is used for mapping RPCSEC_GSS_{,CONT_}INIT requests + * into replies. + * + * Key is context handle (\x if empty) and gss_token. + * Content is major_status minor_status (integers) context_handle, reply_token. + * + */ + +static int netobj_equal(struct xdr_netobj *a, struct xdr_netobj *b) +{ + return a->len == b->len && 0 == memcmp(a->data, b->data, a->len); +} + +#define RSI_HASHBITS 6 +#define RSI_HASHMAX (1<<RSI_HASHBITS) + +struct rsi { + struct cache_head h; + struct xdr_netobj in_handle, in_token; + struct xdr_netobj out_handle, out_token; + int major_status, minor_status; + struct rcu_head rcu_head; +}; + +static struct rsi *rsi_update(struct cache_detail *cd, struct rsi *new, struct rsi *old); +static struct rsi *rsi_lookup(struct cache_detail *cd, struct rsi *item); + +static void rsi_free(struct rsi *rsii) +{ + kfree(rsii->in_handle.data); + kfree(rsii->in_token.data); + kfree(rsii->out_handle.data); + kfree(rsii->out_token.data); +} + +static void rsi_free_rcu(struct rcu_head *head) +{ + struct rsi *rsii = container_of(head, struct rsi, rcu_head); + + rsi_free(rsii); + kfree(rsii); +} + +static void rsi_put(struct kref *ref) +{ + struct rsi *rsii = container_of(ref, struct rsi, h.ref); + + call_rcu(&rsii->rcu_head, rsi_free_rcu); +} + +static inline int rsi_hash(struct rsi *item) +{ + return hash_mem(item->in_handle.data, item->in_handle.len, RSI_HASHBITS) + ^ hash_mem(item->in_token.data, item->in_token.len, RSI_HASHBITS); +} + +static int rsi_match(struct cache_head *a, struct cache_head *b) +{ + struct rsi *item = container_of(a, struct rsi, h); + struct rsi *tmp = container_of(b, struct rsi, h); + return netobj_equal(&item->in_handle, &tmp->in_handle) && + netobj_equal(&item->in_token, &tmp->in_token); +} + +static int dup_to_netobj(struct xdr_netobj *dst, char *src, int len) +{ + dst->len = len; + dst->data = (len ? kmemdup(src, len, GFP_KERNEL) : NULL); + if (len && !dst->data) + return -ENOMEM; + return 0; +} + +static inline int dup_netobj(struct xdr_netobj *dst, struct xdr_netobj *src) +{ + return dup_to_netobj(dst, src->data, src->len); +} + +static void rsi_init(struct cache_head *cnew, struct cache_head *citem) +{ + struct rsi *new = container_of(cnew, struct rsi, h); + struct rsi *item = container_of(citem, struct rsi, h); + + new->out_handle.data = NULL; + new->out_handle.len = 0; + new->out_token.data = NULL; + new->out_token.len = 0; + new->in_handle.len = item->in_handle.len; + item->in_handle.len = 0; + new->in_token.len = item->in_token.len; + item->in_token.len = 0; + new->in_handle.data = item->in_handle.data; + item->in_handle.data = NULL; + new->in_token.data = item->in_token.data; + item->in_token.data = NULL; +} + +static void update_rsi(struct cache_head *cnew, struct cache_head *citem) +{ + struct rsi *new = container_of(cnew, struct rsi, h); + struct rsi *item = container_of(citem, struct rsi, h); + + BUG_ON(new->out_handle.data || new->out_token.data); + new->out_handle.len = item->out_handle.len; + item->out_handle.len = 0; + new->out_token.len = item->out_token.len; + item->out_token.len = 0; + new->out_handle.data = item->out_handle.data; + item->out_handle.data = NULL; + new->out_token.data = item->out_token.data; + item->out_token.data = NULL; + + new->major_status = item->major_status; + new->minor_status = item->minor_status; +} + +static struct cache_head *rsi_alloc(void) +{ + struct rsi *rsii = kmalloc(sizeof(*rsii), GFP_KERNEL); + if (rsii) + return &rsii->h; + else + return NULL; +} + +static int rsi_upcall(struct cache_detail *cd, struct cache_head *h) +{ + return sunrpc_cache_pipe_upcall_timeout(cd, h); +} + +static void rsi_request(struct cache_detail *cd, + struct cache_head *h, + char **bpp, int *blen) +{ + struct rsi *rsii = container_of(h, struct rsi, h); + + qword_addhex(bpp, blen, rsii->in_handle.data, rsii->in_handle.len); + qword_addhex(bpp, blen, rsii->in_token.data, rsii->in_token.len); + (*bpp)[-1] = '\n'; + WARN_ONCE(*blen < 0, + "RPCSEC/GSS credential too large - please use gssproxy\n"); +} + +static int rsi_parse(struct cache_detail *cd, + char *mesg, int mlen) +{ + /* context token expiry major minor context token */ + char *buf = mesg; + char *ep; + int len; + struct rsi rsii, *rsip = NULL; + time64_t expiry; + int status = -EINVAL; + + memset(&rsii, 0, sizeof(rsii)); + /* handle */ + len = qword_get(&mesg, buf, mlen); + if (len < 0) + goto out; + status = -ENOMEM; + if (dup_to_netobj(&rsii.in_handle, buf, len)) + goto out; + + /* token */ + len = qword_get(&mesg, buf, mlen); + status = -EINVAL; + if (len < 0) + goto out; + status = -ENOMEM; + if (dup_to_netobj(&rsii.in_token, buf, len)) + goto out; + + rsip = rsi_lookup(cd, &rsii); + if (!rsip) + goto out; + + rsii.h.flags = 0; + /* expiry */ + status = get_expiry(&mesg, &expiry); + if (status) + goto out; + + status = -EINVAL; + /* major/minor */ + len = qword_get(&mesg, buf, mlen); + if (len <= 0) + goto out; + rsii.major_status = simple_strtoul(buf, &ep, 10); + if (*ep) + goto out; + len = qword_get(&mesg, buf, mlen); + if (len <= 0) + goto out; + rsii.minor_status = simple_strtoul(buf, &ep, 10); + if (*ep) + goto out; + + /* out_handle */ + len = qword_get(&mesg, buf, mlen); + if (len < 0) + goto out; + status = -ENOMEM; + if (dup_to_netobj(&rsii.out_handle, buf, len)) + goto out; + + /* out_token */ + len = qword_get(&mesg, buf, mlen); + status = -EINVAL; + if (len < 0) + goto out; + status = -ENOMEM; + if (dup_to_netobj(&rsii.out_token, buf, len)) + goto out; + rsii.h.expiry_time = expiry; + rsip = rsi_update(cd, &rsii, rsip); + status = 0; +out: + rsi_free(&rsii); + if (rsip) + cache_put(&rsip->h, cd); + else + status = -ENOMEM; + return status; +} + +static const struct cache_detail rsi_cache_template = { + .owner = THIS_MODULE, + .hash_size = RSI_HASHMAX, + .name = "auth.rpcsec.init", + .cache_put = rsi_put, + .cache_upcall = rsi_upcall, + .cache_request = rsi_request, + .cache_parse = rsi_parse, + .match = rsi_match, + .init = rsi_init, + .update = update_rsi, + .alloc = rsi_alloc, +}; + +static struct rsi *rsi_lookup(struct cache_detail *cd, struct rsi *item) +{ + struct cache_head *ch; + int hash = rsi_hash(item); + + ch = sunrpc_cache_lookup_rcu(cd, &item->h, hash); + if (ch) + return container_of(ch, struct rsi, h); + else + return NULL; +} + +static struct rsi *rsi_update(struct cache_detail *cd, struct rsi *new, struct rsi *old) +{ + struct cache_head *ch; + int hash = rsi_hash(new); + + ch = sunrpc_cache_update(cd, &new->h, + &old->h, hash); + if (ch) + return container_of(ch, struct rsi, h); + else + return NULL; +} + + +/* + * The rpcsec_context cache is used to store a context that is + * used in data exchange. + * The key is a context handle. The content is: + * uid, gidlist, mechanism, service-set, mech-specific-data + */ + +#define RSC_HASHBITS 10 +#define RSC_HASHMAX (1<<RSC_HASHBITS) + +#define GSS_SEQ_WIN 128 + +struct gss_svc_seq_data { + /* highest seq number seen so far: */ + u32 sd_max; + /* for i such that sd_max-GSS_SEQ_WIN < i <= sd_max, the i-th bit of + * sd_win is nonzero iff sequence number i has been seen already: */ + unsigned long sd_win[GSS_SEQ_WIN/BITS_PER_LONG]; + spinlock_t sd_lock; +}; + +struct rsc { + struct cache_head h; + struct xdr_netobj handle; + struct svc_cred cred; + struct gss_svc_seq_data seqdata; + struct gss_ctx *mechctx; + struct rcu_head rcu_head; +}; + +static struct rsc *rsc_update(struct cache_detail *cd, struct rsc *new, struct rsc *old); +static struct rsc *rsc_lookup(struct cache_detail *cd, struct rsc *item); + +static void rsc_free(struct rsc *rsci) +{ + kfree(rsci->handle.data); + if (rsci->mechctx) + gss_delete_sec_context(&rsci->mechctx); + free_svc_cred(&rsci->cred); +} + +static void rsc_free_rcu(struct rcu_head *head) +{ + struct rsc *rsci = container_of(head, struct rsc, rcu_head); + + kfree(rsci->handle.data); + kfree(rsci); +} + +static void rsc_put(struct kref *ref) +{ + struct rsc *rsci = container_of(ref, struct rsc, h.ref); + + if (rsci->mechctx) + gss_delete_sec_context(&rsci->mechctx); + free_svc_cred(&rsci->cred); + call_rcu(&rsci->rcu_head, rsc_free_rcu); +} + +static inline int +rsc_hash(struct rsc *rsci) +{ + return hash_mem(rsci->handle.data, rsci->handle.len, RSC_HASHBITS); +} + +static int +rsc_match(struct cache_head *a, struct cache_head *b) +{ + struct rsc *new = container_of(a, struct rsc, h); + struct rsc *tmp = container_of(b, struct rsc, h); + + return netobj_equal(&new->handle, &tmp->handle); +} + +static void +rsc_init(struct cache_head *cnew, struct cache_head *ctmp) +{ + struct rsc *new = container_of(cnew, struct rsc, h); + struct rsc *tmp = container_of(ctmp, struct rsc, h); + + new->handle.len = tmp->handle.len; + tmp->handle.len = 0; + new->handle.data = tmp->handle.data; + tmp->handle.data = NULL; + new->mechctx = NULL; + init_svc_cred(&new->cred); +} + +static void +update_rsc(struct cache_head *cnew, struct cache_head *ctmp) +{ + struct rsc *new = container_of(cnew, struct rsc, h); + struct rsc *tmp = container_of(ctmp, struct rsc, h); + + new->mechctx = tmp->mechctx; + tmp->mechctx = NULL; + memset(&new->seqdata, 0, sizeof(new->seqdata)); + spin_lock_init(&new->seqdata.sd_lock); + new->cred = tmp->cred; + init_svc_cred(&tmp->cred); +} + +static struct cache_head * +rsc_alloc(void) +{ + struct rsc *rsci = kmalloc(sizeof(*rsci), GFP_KERNEL); + if (rsci) + return &rsci->h; + else + return NULL; +} + +static int rsc_upcall(struct cache_detail *cd, struct cache_head *h) +{ + return -EINVAL; +} + +static int rsc_parse(struct cache_detail *cd, + char *mesg, int mlen) +{ + /* contexthandle expiry [ uid gid N <n gids> mechname ...mechdata... ] */ + char *buf = mesg; + int id; + int len, rv; + struct rsc rsci, *rscp = NULL; + time64_t expiry; + int status = -EINVAL; + struct gss_api_mech *gm = NULL; + + memset(&rsci, 0, sizeof(rsci)); + /* context handle */ + len = qword_get(&mesg, buf, mlen); + if (len < 0) goto out; + status = -ENOMEM; + if (dup_to_netobj(&rsci.handle, buf, len)) + goto out; + + rsci.h.flags = 0; + /* expiry */ + status = get_expiry(&mesg, &expiry); + if (status) + goto out; + + status = -EINVAL; + rscp = rsc_lookup(cd, &rsci); + if (!rscp) + goto out; + + /* uid, or NEGATIVE */ + rv = get_int(&mesg, &id); + if (rv == -EINVAL) + goto out; + if (rv == -ENOENT) + set_bit(CACHE_NEGATIVE, &rsci.h.flags); + else { + int N, i; + + /* + * NOTE: we skip uid_valid()/gid_valid() checks here: + * instead, * -1 id's are later mapped to the + * (export-specific) anonymous id by nfsd_setuser. + * + * (But supplementary gid's get no such special + * treatment so are checked for validity here.) + */ + /* uid */ + rsci.cred.cr_uid = make_kuid(current_user_ns(), id); + + /* gid */ + if (get_int(&mesg, &id)) + goto out; + rsci.cred.cr_gid = make_kgid(current_user_ns(), id); + + /* number of additional gid's */ + if (get_int(&mesg, &N)) + goto out; + if (N < 0 || N > NGROUPS_MAX) + goto out; + status = -ENOMEM; + rsci.cred.cr_group_info = groups_alloc(N); + if (rsci.cred.cr_group_info == NULL) + goto out; + + /* gid's */ + status = -EINVAL; + for (i=0; i<N; i++) { + kgid_t kgid; + if (get_int(&mesg, &id)) + goto out; + kgid = make_kgid(current_user_ns(), id); + if (!gid_valid(kgid)) + goto out; + rsci.cred.cr_group_info->gid[i] = kgid; + } + groups_sort(rsci.cred.cr_group_info); + + /* mech name */ + len = qword_get(&mesg, buf, mlen); + if (len < 0) + goto out; + gm = rsci.cred.cr_gss_mech = gss_mech_get_by_name(buf); + status = -EOPNOTSUPP; + if (!gm) + goto out; + + status = -EINVAL; + /* mech-specific data: */ + len = qword_get(&mesg, buf, mlen); + if (len < 0) + goto out; + status = gss_import_sec_context(buf, len, gm, &rsci.mechctx, + NULL, GFP_KERNEL); + if (status) + goto out; + + /* get client name */ + len = qword_get(&mesg, buf, mlen); + if (len > 0) { + rsci.cred.cr_principal = kstrdup(buf, GFP_KERNEL); + if (!rsci.cred.cr_principal) { + status = -ENOMEM; + goto out; + } + } + + } + rsci.h.expiry_time = expiry; + rscp = rsc_update(cd, &rsci, rscp); + status = 0; +out: + rsc_free(&rsci); + if (rscp) + cache_put(&rscp->h, cd); + else + status = -ENOMEM; + return status; +} + +static const struct cache_detail rsc_cache_template = { + .owner = THIS_MODULE, + .hash_size = RSC_HASHMAX, + .name = "auth.rpcsec.context", + .cache_put = rsc_put, + .cache_upcall = rsc_upcall, + .cache_parse = rsc_parse, + .match = rsc_match, + .init = rsc_init, + .update = update_rsc, + .alloc = rsc_alloc, +}; + +static struct rsc *rsc_lookup(struct cache_detail *cd, struct rsc *item) +{ + struct cache_head *ch; + int hash = rsc_hash(item); + + ch = sunrpc_cache_lookup_rcu(cd, &item->h, hash); + if (ch) + return container_of(ch, struct rsc, h); + else + return NULL; +} + +static struct rsc *rsc_update(struct cache_detail *cd, struct rsc *new, struct rsc *old) +{ + struct cache_head *ch; + int hash = rsc_hash(new); + + ch = sunrpc_cache_update(cd, &new->h, + &old->h, hash); + if (ch) + return container_of(ch, struct rsc, h); + else + return NULL; +} + + +static struct rsc * +gss_svc_searchbyctx(struct cache_detail *cd, struct xdr_netobj *handle) +{ + struct rsc rsci; + struct rsc *found; + + memset(&rsci, 0, sizeof(rsci)); + if (dup_to_netobj(&rsci.handle, handle->data, handle->len)) + return NULL; + found = rsc_lookup(cd, &rsci); + rsc_free(&rsci); + if (!found) + return NULL; + if (cache_check(cd, &found->h, NULL)) + return NULL; + return found; +} + +/** + * gss_check_seq_num - GSS sequence number window check + * @rqstp: RPC Call to use when reporting errors + * @rsci: cached GSS context state (updated on return) + * @seq_num: sequence number to check + * + * Implements sequence number algorithm as specified in + * RFC 2203, Section 5.3.3.1. "Context Management". + * + * Return values: + * %true: @rqstp's GSS sequence number is inside the window + * %false: @rqstp's GSS sequence number is outside the window + */ +static bool gss_check_seq_num(const struct svc_rqst *rqstp, struct rsc *rsci, + u32 seq_num) +{ + struct gss_svc_seq_data *sd = &rsci->seqdata; + bool result = false; + + spin_lock(&sd->sd_lock); + if (seq_num > sd->sd_max) { + if (seq_num >= sd->sd_max + GSS_SEQ_WIN) { + memset(sd->sd_win, 0, sizeof(sd->sd_win)); + sd->sd_max = seq_num; + } else while (sd->sd_max < seq_num) { + sd->sd_max++; + __clear_bit(sd->sd_max % GSS_SEQ_WIN, sd->sd_win); + } + __set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win); + goto ok; + } else if (seq_num + GSS_SEQ_WIN <= sd->sd_max) { + goto toolow; + } + if (__test_and_set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win)) + goto alreadyseen; + +ok: + result = true; +out: + spin_unlock(&sd->sd_lock); + return result; + +toolow: + trace_rpcgss_svc_seqno_low(rqstp, seq_num, + sd->sd_max - GSS_SEQ_WIN, + sd->sd_max); + goto out; +alreadyseen: + trace_rpcgss_svc_seqno_seen(rqstp, seq_num); + goto out; +} + +/* + * Decode and verify a Call's verifier field. For RPC_AUTH_GSS Calls, + * the body of this field contains a variable length checksum. + * + * GSS-specific auth_stat values are mandated by RFC 2203 Section + * 5.3.3.3. + */ +static int +svcauth_gss_verify_header(struct svc_rqst *rqstp, struct rsc *rsci, + __be32 *rpcstart, struct rpc_gss_wire_cred *gc) +{ + struct xdr_stream *xdr = &rqstp->rq_arg_stream; + struct gss_ctx *ctx_id = rsci->mechctx; + u32 flavor, maj_stat; + struct xdr_buf rpchdr; + struct xdr_netobj checksum; + struct kvec iov; + + /* + * Compute the checksum of the incoming Call from the + * XID field to credential field: + */ + iov.iov_base = rpcstart; + iov.iov_len = (u8 *)xdr->p - (u8 *)rpcstart; + xdr_buf_from_iov(&iov, &rpchdr); + + /* Call's verf field: */ + if (xdr_stream_decode_opaque_auth(xdr, &flavor, + (void **)&checksum.data, + &checksum.len) < 0) { + rqstp->rq_auth_stat = rpc_autherr_badverf; + return SVC_DENIED; + } + if (flavor != RPC_AUTH_GSS) { + rqstp->rq_auth_stat = rpc_autherr_badverf; + return SVC_DENIED; + } + + if (rqstp->rq_deferred) + return SVC_OK; + maj_stat = gss_verify_mic(ctx_id, &rpchdr, &checksum); + if (maj_stat != GSS_S_COMPLETE) { + trace_rpcgss_svc_mic(rqstp, maj_stat); + rqstp->rq_auth_stat = rpcsec_gsserr_credproblem; + return SVC_DENIED; + } + + if (gc->gc_seq > MAXSEQ) { + trace_rpcgss_svc_seqno_large(rqstp, gc->gc_seq); + rqstp->rq_auth_stat = rpcsec_gsserr_ctxproblem; + return SVC_DENIED; + } + if (!gss_check_seq_num(rqstp, rsci, gc->gc_seq)) + return SVC_DROP; + return SVC_OK; +} + +/* + * Construct and encode a Reply's verifier field. The verifier's body + * field contains a variable-length checksum of the GSS sequence + * number. + */ +static bool +svcauth_gss_encode_verf(struct svc_rqst *rqstp, struct gss_ctx *ctx_id, u32 seq) +{ + struct gss_svc_data *gsd = rqstp->rq_auth_data; + u32 maj_stat; + struct xdr_buf verf_data; + struct xdr_netobj checksum; + struct kvec iov; + + gsd->gsd_seq_num = cpu_to_be32(seq); + iov.iov_base = &gsd->gsd_seq_num; + iov.iov_len = XDR_UNIT; + xdr_buf_from_iov(&iov, &verf_data); + + checksum.data = gsd->gsd_scratch; + maj_stat = gss_get_mic(ctx_id, &verf_data, &checksum); + if (maj_stat != GSS_S_COMPLETE) + goto bad_mic; + + return xdr_stream_encode_opaque_auth(&rqstp->rq_res_stream, RPC_AUTH_GSS, + checksum.data, checksum.len) > 0; + +bad_mic: + trace_rpcgss_svc_get_mic(rqstp, maj_stat); + return false; +} + +struct gss_domain { + struct auth_domain h; + u32 pseudoflavor; +}; + +static struct auth_domain * +find_gss_auth_domain(struct gss_ctx *ctx, u32 svc) +{ + char *name; + + name = gss_service_to_auth_domain_name(ctx->mech_type, svc); + if (!name) + return NULL; + return auth_domain_find(name); +} + +static struct auth_ops svcauthops_gss; + +u32 svcauth_gss_flavor(struct auth_domain *dom) +{ + struct gss_domain *gd = container_of(dom, struct gss_domain, h); + + return gd->pseudoflavor; +} + +EXPORT_SYMBOL_GPL(svcauth_gss_flavor); + +struct auth_domain * +svcauth_gss_register_pseudoflavor(u32 pseudoflavor, char * name) +{ + struct gss_domain *new; + struct auth_domain *test; + int stat = -ENOMEM; + + new = kmalloc(sizeof(*new), GFP_KERNEL); + if (!new) + goto out; + kref_init(&new->h.ref); + new->h.name = kstrdup(name, GFP_KERNEL); + if (!new->h.name) + goto out_free_dom; + new->h.flavour = &svcauthops_gss; + new->pseudoflavor = pseudoflavor; + + test = auth_domain_lookup(name, &new->h); + if (test != &new->h) { + pr_warn("svc: duplicate registration of gss pseudo flavour %s.\n", + name); + stat = -EADDRINUSE; + auth_domain_put(test); + goto out_free_name; + } + return test; + +out_free_name: + kfree(new->h.name); +out_free_dom: + kfree(new); +out: + return ERR_PTR(stat); +} +EXPORT_SYMBOL_GPL(svcauth_gss_register_pseudoflavor); + +/* + * RFC 2203, Section 5.3.2.2 + * + * struct rpc_gss_integ_data { + * opaque databody_integ<>; + * opaque checksum<>; + * }; + * + * struct rpc_gss_data_t { + * unsigned int seq_num; + * proc_req_arg_t arg; + * }; + */ +static noinline_for_stack int +svcauth_gss_unwrap_integ(struct svc_rqst *rqstp, u32 seq, struct gss_ctx *ctx) +{ + struct gss_svc_data *gsd = rqstp->rq_auth_data; + struct xdr_stream *xdr = &rqstp->rq_arg_stream; + u32 len, offset, seq_num, maj_stat; + struct xdr_buf *buf = xdr->buf; + struct xdr_buf databody_integ; + struct xdr_netobj checksum; + + /* NFS READ normally uses splice to send data in-place. However + * the data in cache can change after the reply's MIC is computed + * but before the RPC reply is sent. To prevent the client from + * rejecting the server-computed MIC in this somewhat rare case, + * do not use splice with the GSS integrity service. + */ + clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags); + + /* Did we already verify the signature on the original pass through? */ + if (rqstp->rq_deferred) + return 0; + + if (xdr_stream_decode_u32(xdr, &len) < 0) + goto unwrap_failed; + if (len & 3) + goto unwrap_failed; + offset = xdr_stream_pos(xdr); + if (xdr_buf_subsegment(buf, &databody_integ, offset, len)) + goto unwrap_failed; + + /* + * The xdr_stream now points to the @seq_num field. The next + * XDR data item is the @arg field, which contains the clear + * text RPC program payload. The checksum, which follows the + * @arg field, is located and decoded without updating the + * xdr_stream. + */ + + offset += len; + if (xdr_decode_word(buf, offset, &checksum.len)) + goto unwrap_failed; + if (checksum.len > sizeof(gsd->gsd_scratch)) + goto unwrap_failed; + checksum.data = gsd->gsd_scratch; + if (read_bytes_from_xdr_buf(buf, offset + XDR_UNIT, checksum.data, + checksum.len)) + goto unwrap_failed; + + maj_stat = gss_verify_mic(ctx, &databody_integ, &checksum); + if (maj_stat != GSS_S_COMPLETE) + goto bad_mic; + + /* The received seqno is protected by the checksum. */ + if (xdr_stream_decode_u32(xdr, &seq_num) < 0) + goto unwrap_failed; + if (seq_num != seq) + goto bad_seqno; + + xdr_truncate_decode(xdr, XDR_UNIT + checksum.len); + return 0; + +unwrap_failed: + trace_rpcgss_svc_unwrap_failed(rqstp); + return -EINVAL; +bad_seqno: + trace_rpcgss_svc_seqno_bad(rqstp, seq, seq_num); + return -EINVAL; +bad_mic: + trace_rpcgss_svc_mic(rqstp, maj_stat); + return -EINVAL; +} + +/* + * RFC 2203, Section 5.3.2.3 + * + * struct rpc_gss_priv_data { + * opaque databody_priv<> + * }; + * + * struct rpc_gss_data_t { + * unsigned int seq_num; + * proc_req_arg_t arg; + * }; + */ +static noinline_for_stack int +svcauth_gss_unwrap_priv(struct svc_rqst *rqstp, u32 seq, struct gss_ctx *ctx) +{ + struct xdr_stream *xdr = &rqstp->rq_arg_stream; + u32 len, maj_stat, seq_num, offset; + struct xdr_buf *buf = xdr->buf; + unsigned int saved_len; + + clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags); + + if (xdr_stream_decode_u32(xdr, &len) < 0) + goto unwrap_failed; + if (rqstp->rq_deferred) { + /* Already decrypted last time through! The sequence number + * check at out_seq is unnecessary but harmless: */ + goto out_seq; + } + if (len > xdr_stream_remaining(xdr)) + goto unwrap_failed; + offset = xdr_stream_pos(xdr); + + saved_len = buf->len; + maj_stat = gss_unwrap(ctx, offset, offset + len, buf); + if (maj_stat != GSS_S_COMPLETE) + goto bad_unwrap; + xdr->nwords -= XDR_QUADLEN(saved_len - buf->len); + +out_seq: + /* gss_unwrap() decrypted the sequence number. */ + if (xdr_stream_decode_u32(xdr, &seq_num) < 0) + goto unwrap_failed; + if (seq_num != seq) + goto bad_seqno; + return 0; + +unwrap_failed: + trace_rpcgss_svc_unwrap_failed(rqstp); + return -EINVAL; +bad_seqno: + trace_rpcgss_svc_seqno_bad(rqstp, seq, seq_num); + return -EINVAL; +bad_unwrap: + trace_rpcgss_svc_unwrap(rqstp, maj_stat); + return -EINVAL; +} + +static enum svc_auth_status +svcauth_gss_set_client(struct svc_rqst *rqstp) +{ + struct gss_svc_data *svcdata = rqstp->rq_auth_data; + struct rsc *rsci = svcdata->rsci; + struct rpc_gss_wire_cred *gc = &svcdata->clcred; + int stat; + + rqstp->rq_auth_stat = rpc_autherr_badcred; + + /* + * A gss export can be specified either by: + * export *(sec=krb5,rw) + * or by + * export gss/krb5(rw) + * The latter is deprecated; but for backwards compatibility reasons + * the nfsd code will still fall back on trying it if the former + * doesn't work; so we try to make both available to nfsd, below. + */ + rqstp->rq_gssclient = find_gss_auth_domain(rsci->mechctx, gc->gc_svc); + if (rqstp->rq_gssclient == NULL) + return SVC_DENIED; + stat = svcauth_unix_set_client(rqstp); + if (stat == SVC_DROP || stat == SVC_CLOSE) + return stat; + + rqstp->rq_auth_stat = rpc_auth_ok; + return SVC_OK; +} + +static bool +svcauth_gss_proc_init_verf(struct cache_detail *cd, struct svc_rqst *rqstp, + struct xdr_netobj *out_handle, int *major_status, + u32 seq_num) +{ + struct xdr_stream *xdr = &rqstp->rq_res_stream; + struct rsc *rsci; + bool rc; + + if (*major_status != GSS_S_COMPLETE) + goto null_verifier; + rsci = gss_svc_searchbyctx(cd, out_handle); + if (rsci == NULL) { + *major_status = GSS_S_NO_CONTEXT; + goto null_verifier; + } + + rc = svcauth_gss_encode_verf(rqstp, rsci->mechctx, seq_num); + cache_put(&rsci->h, cd); + return rc; + +null_verifier: + return xdr_stream_encode_opaque_auth(xdr, RPC_AUTH_NULL, NULL, 0) > 0; +} + +static void gss_free_in_token_pages(struct gssp_in_token *in_token) +{ + u32 inlen; + int i; + + i = 0; + inlen = in_token->page_len; + while (inlen) { + if (in_token->pages[i]) + put_page(in_token->pages[i]); + inlen -= inlen > PAGE_SIZE ? PAGE_SIZE : inlen; + } + + kfree(in_token->pages); + in_token->pages = NULL; +} + +static int gss_read_proxy_verf(struct svc_rqst *rqstp, + struct rpc_gss_wire_cred *gc, + struct xdr_netobj *in_handle, + struct gssp_in_token *in_token) +{ + struct xdr_stream *xdr = &rqstp->rq_arg_stream; + unsigned int length, pgto_offs, pgfrom_offs; + int pages, i, pgto, pgfrom; + size_t to_offs, from_offs; + u32 inlen; + + if (dup_netobj(in_handle, &gc->gc_ctx)) + return SVC_CLOSE; + + /* + * RFC 2203 Section 5.2.2 + * + * struct rpc_gss_init_arg { + * opaque gss_token<>; + * }; + */ + if (xdr_stream_decode_u32(xdr, &inlen) < 0) + goto out_denied_free; + if (inlen > xdr_stream_remaining(xdr)) + goto out_denied_free; + + pages = DIV_ROUND_UP(inlen, PAGE_SIZE); + in_token->pages = kcalloc(pages, sizeof(struct page *), GFP_KERNEL); + if (!in_token->pages) + goto out_denied_free; + in_token->page_base = 0; + in_token->page_len = inlen; + for (i = 0; i < pages; i++) { + in_token->pages[i] = alloc_page(GFP_KERNEL); + if (!in_token->pages[i]) { + gss_free_in_token_pages(in_token); + goto out_denied_free; + } + } + + length = min_t(unsigned int, inlen, (char *)xdr->end - (char *)xdr->p); + memcpy(page_address(in_token->pages[0]), xdr->p, length); + inlen -= length; + + to_offs = length; + from_offs = rqstp->rq_arg.page_base; + while (inlen) { + pgto = to_offs >> PAGE_SHIFT; + pgfrom = from_offs >> PAGE_SHIFT; + pgto_offs = to_offs & ~PAGE_MASK; + pgfrom_offs = from_offs & ~PAGE_MASK; + + length = min_t(unsigned int, inlen, + min_t(unsigned int, PAGE_SIZE - pgto_offs, + PAGE_SIZE - pgfrom_offs)); + memcpy(page_address(in_token->pages[pgto]) + pgto_offs, + page_address(rqstp->rq_arg.pages[pgfrom]) + pgfrom_offs, + length); + + to_offs += length; + from_offs += length; + inlen -= length; + } + return 0; + +out_denied_free: + kfree(in_handle->data); + return SVC_DENIED; +} + +/* + * RFC 2203, Section 5.2.3.1. + * + * struct rpc_gss_init_res { + * opaque handle<>; + * unsigned int gss_major; + * unsigned int gss_minor; + * unsigned int seq_window; + * opaque gss_token<>; + * }; + */ +static bool +svcxdr_encode_gss_init_res(struct xdr_stream *xdr, + struct xdr_netobj *handle, + struct xdr_netobj *gss_token, + unsigned int major_status, + unsigned int minor_status, u32 seq_num) +{ + if (xdr_stream_encode_opaque(xdr, handle->data, handle->len) < 0) + return false; + if (xdr_stream_encode_u32(xdr, major_status) < 0) + return false; + if (xdr_stream_encode_u32(xdr, minor_status) < 0) + return false; + if (xdr_stream_encode_u32(xdr, seq_num) < 0) + return false; + if (xdr_stream_encode_opaque(xdr, gss_token->data, gss_token->len) < 0) + return false; + return true; +} + +/* + * Having read the cred already and found we're in the context + * initiation case, read the verifier and initiate (or check the results + * of) upcalls to userspace for help with context initiation. If + * the upcall results are available, write the verifier and result. + * Otherwise, drop the request pending an answer to the upcall. + */ +static int +svcauth_gss_legacy_init(struct svc_rqst *rqstp, + struct rpc_gss_wire_cred *gc) +{ + struct xdr_stream *xdr = &rqstp->rq_arg_stream; + struct rsi *rsip, rsikey; + __be32 *p; + u32 len; + int ret; + struct sunrpc_net *sn = net_generic(SVC_NET(rqstp), sunrpc_net_id); + + memset(&rsikey, 0, sizeof(rsikey)); + if (dup_netobj(&rsikey.in_handle, &gc->gc_ctx)) + return SVC_CLOSE; + + /* + * RFC 2203 Section 5.2.2 + * + * struct rpc_gss_init_arg { + * opaque gss_token<>; + * }; + */ + if (xdr_stream_decode_u32(xdr, &len) < 0) { + kfree(rsikey.in_handle.data); + return SVC_DENIED; + } + p = xdr_inline_decode(xdr, len); + if (!p) { + kfree(rsikey.in_handle.data); + return SVC_DENIED; + } + rsikey.in_token.data = kmalloc(len, GFP_KERNEL); + if (ZERO_OR_NULL_PTR(rsikey.in_token.data)) { + kfree(rsikey.in_handle.data); + return SVC_CLOSE; + } + memcpy(rsikey.in_token.data, p, len); + rsikey.in_token.len = len; + + /* Perform upcall, or find upcall result: */ + rsip = rsi_lookup(sn->rsi_cache, &rsikey); + rsi_free(&rsikey); + if (!rsip) + return SVC_CLOSE; + if (cache_check(sn->rsi_cache, &rsip->h, &rqstp->rq_chandle) < 0) + /* No upcall result: */ + return SVC_CLOSE; + + ret = SVC_CLOSE; + if (!svcauth_gss_proc_init_verf(sn->rsc_cache, rqstp, &rsip->out_handle, + &rsip->major_status, GSS_SEQ_WIN)) + goto out; + if (!svcxdr_set_accept_stat(rqstp)) + goto out; + if (!svcxdr_encode_gss_init_res(&rqstp->rq_res_stream, &rsip->out_handle, + &rsip->out_token, rsip->major_status, + rsip->minor_status, GSS_SEQ_WIN)) + goto out; + + ret = SVC_COMPLETE; +out: + cache_put(&rsip->h, sn->rsi_cache); + return ret; +} + +static int gss_proxy_save_rsc(struct cache_detail *cd, + struct gssp_upcall_data *ud, + uint64_t *handle) +{ + struct rsc rsci, *rscp = NULL; + static atomic64_t ctxhctr; + long long ctxh; + struct gss_api_mech *gm = NULL; + time64_t expiry; + int status; + + memset(&rsci, 0, sizeof(rsci)); + /* context handle */ + status = -ENOMEM; + /* the handle needs to be just a unique id, + * use a static counter */ + ctxh = atomic64_inc_return(&ctxhctr); + + /* make a copy for the caller */ + *handle = ctxh; + + /* make a copy for the rsc cache */ + if (dup_to_netobj(&rsci.handle, (char *)handle, sizeof(uint64_t))) + goto out; + rscp = rsc_lookup(cd, &rsci); + if (!rscp) + goto out; + + /* creds */ + if (!ud->found_creds) { + /* userspace seem buggy, we should always get at least a + * mapping to nobody */ + goto out; + } else { + struct timespec64 boot; + + /* steal creds */ + rsci.cred = ud->creds; + memset(&ud->creds, 0, sizeof(struct svc_cred)); + + status = -EOPNOTSUPP; + /* get mech handle from OID */ + gm = gss_mech_get_by_OID(&ud->mech_oid); + if (!gm) + goto out; + rsci.cred.cr_gss_mech = gm; + + status = -EINVAL; + /* mech-specific data: */ + status = gss_import_sec_context(ud->out_handle.data, + ud->out_handle.len, + gm, &rsci.mechctx, + &expiry, GFP_KERNEL); + if (status) + goto out; + + getboottime64(&boot); + expiry -= boot.tv_sec; + } + + rsci.h.expiry_time = expiry; + rscp = rsc_update(cd, &rsci, rscp); + status = 0; +out: + rsc_free(&rsci); + if (rscp) + cache_put(&rscp->h, cd); + else + status = -ENOMEM; + return status; +} + +static int svcauth_gss_proxy_init(struct svc_rqst *rqstp, + struct rpc_gss_wire_cred *gc) +{ + struct xdr_netobj cli_handle; + struct gssp_upcall_data ud; + uint64_t handle; + int status; + int ret; + struct net *net = SVC_NET(rqstp); + struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); + + memset(&ud, 0, sizeof(ud)); + ret = gss_read_proxy_verf(rqstp, gc, &ud.in_handle, &ud.in_token); + if (ret) + return ret; + + ret = SVC_CLOSE; + + /* Perform synchronous upcall to gss-proxy */ + status = gssp_accept_sec_context_upcall(net, &ud); + if (status) + goto out; + + trace_rpcgss_svc_accept_upcall(rqstp, ud.major_status, ud.minor_status); + + switch (ud.major_status) { + case GSS_S_CONTINUE_NEEDED: + cli_handle = ud.out_handle; + break; + case GSS_S_COMPLETE: + status = gss_proxy_save_rsc(sn->rsc_cache, &ud, &handle); + if (status) + goto out; + cli_handle.data = (u8 *)&handle; + cli_handle.len = sizeof(handle); + break; + default: + goto out; + } + + if (!svcauth_gss_proc_init_verf(sn->rsc_cache, rqstp, &cli_handle, + &ud.major_status, GSS_SEQ_WIN)) + goto out; + if (!svcxdr_set_accept_stat(rqstp)) + goto out; + if (!svcxdr_encode_gss_init_res(&rqstp->rq_res_stream, &cli_handle, + &ud.out_token, ud.major_status, + ud.minor_status, GSS_SEQ_WIN)) + goto out; + + ret = SVC_COMPLETE; +out: + gss_free_in_token_pages(&ud.in_token); + gssp_free_upcall_data(&ud); + return ret; +} + +/* + * Try to set the sn->use_gss_proxy variable to a new value. We only allow + * it to be changed if it's currently undefined (-1). If it's any other value + * then return -EBUSY unless the type wouldn't have changed anyway. + */ +static int set_gss_proxy(struct net *net, int type) +{ + struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); + int ret; + + WARN_ON_ONCE(type != 0 && type != 1); + ret = cmpxchg(&sn->use_gss_proxy, -1, type); + if (ret != -1 && ret != type) + return -EBUSY; + return 0; +} + +static bool use_gss_proxy(struct net *net) +{ + struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); + + /* If use_gss_proxy is still undefined, then try to disable it */ + if (sn->use_gss_proxy == -1) + set_gss_proxy(net, 0); + return sn->use_gss_proxy; +} + +static noinline_for_stack int +svcauth_gss_proc_init(struct svc_rqst *rqstp, struct rpc_gss_wire_cred *gc) +{ + struct xdr_stream *xdr = &rqstp->rq_arg_stream; + u32 flavor, len; + void *body; + + /* Call's verf field: */ + if (xdr_stream_decode_opaque_auth(xdr, &flavor, &body, &len) < 0) + return SVC_GARBAGE; + if (flavor != RPC_AUTH_NULL || len != 0) { + rqstp->rq_auth_stat = rpc_autherr_badverf; + return SVC_DENIED; + } + + if (gc->gc_proc == RPC_GSS_PROC_INIT && gc->gc_ctx.len != 0) { + rqstp->rq_auth_stat = rpc_autherr_badcred; + return SVC_DENIED; + } + + if (!use_gss_proxy(SVC_NET(rqstp))) + return svcauth_gss_legacy_init(rqstp, gc); + return svcauth_gss_proxy_init(rqstp, gc); +} + +#ifdef CONFIG_PROC_FS + +static ssize_t write_gssp(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct net *net = pde_data(file_inode(file)); + char tbuf[20]; + unsigned long i; + int res; + + if (*ppos || count > sizeof(tbuf)-1) + return -EINVAL; + if (copy_from_user(tbuf, buf, count)) + return -EFAULT; + + tbuf[count] = 0; + res = kstrtoul(tbuf, 0, &i); + if (res) + return res; + if (i != 1) + return -EINVAL; + res = set_gssp_clnt(net); + if (res) + return res; + res = set_gss_proxy(net, 1); + if (res) + return res; + return count; +} + +static ssize_t read_gssp(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct net *net = pde_data(file_inode(file)); + struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); + unsigned long p = *ppos; + char tbuf[10]; + size_t len; + + snprintf(tbuf, sizeof(tbuf), "%d\n", sn->use_gss_proxy); + len = strlen(tbuf); + if (p >= len) + return 0; + len -= p; + if (len > count) + len = count; + if (copy_to_user(buf, (void *)(tbuf+p), len)) + return -EFAULT; + *ppos += len; + return len; +} + +static const struct proc_ops use_gss_proxy_proc_ops = { + .proc_open = nonseekable_open, + .proc_write = write_gssp, + .proc_read = read_gssp, +}; + +static int create_use_gss_proxy_proc_entry(struct net *net) +{ + struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); + struct proc_dir_entry **p = &sn->use_gssp_proc; + + sn->use_gss_proxy = -1; + *p = proc_create_data("use-gss-proxy", S_IFREG | 0600, + sn->proc_net_rpc, + &use_gss_proxy_proc_ops, net); + if (!*p) + return -ENOMEM; + init_gssp_clnt(sn); + return 0; +} + +static void destroy_use_gss_proxy_proc_entry(struct net *net) +{ + struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); + + if (sn->use_gssp_proc) { + remove_proc_entry("use-gss-proxy", sn->proc_net_rpc); + clear_gssp_clnt(sn); + } +} + +static ssize_t read_gss_krb5_enctypes(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct rpcsec_gss_oid oid = { + .len = 9, + .data = "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02", + }; + struct gss_api_mech *mech; + ssize_t ret; + + mech = gss_mech_get_by_OID(&oid); + if (!mech) + return 0; + if (!mech->gm_upcall_enctypes) { + gss_mech_put(mech); + return 0; + } + + ret = simple_read_from_buffer(buf, count, ppos, + mech->gm_upcall_enctypes, + strlen(mech->gm_upcall_enctypes)); + gss_mech_put(mech); + return ret; +} + +static const struct proc_ops gss_krb5_enctypes_proc_ops = { + .proc_open = nonseekable_open, + .proc_read = read_gss_krb5_enctypes, +}; + +static int create_krb5_enctypes_proc_entry(struct net *net) +{ + struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); + + sn->gss_krb5_enctypes = + proc_create_data("gss_krb5_enctypes", S_IFREG | 0444, + sn->proc_net_rpc, &gss_krb5_enctypes_proc_ops, + net); + return sn->gss_krb5_enctypes ? 0 : -ENOMEM; +} + +static void destroy_krb5_enctypes_proc_entry(struct net *net) +{ + struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); + + if (sn->gss_krb5_enctypes) + remove_proc_entry("gss_krb5_enctypes", sn->proc_net_rpc); +} + +#else /* CONFIG_PROC_FS */ + +static int create_use_gss_proxy_proc_entry(struct net *net) +{ + return 0; +} + +static void destroy_use_gss_proxy_proc_entry(struct net *net) {} + +static int create_krb5_enctypes_proc_entry(struct net *net) +{ + return 0; +} + +static void destroy_krb5_enctypes_proc_entry(struct net *net) {} + +#endif /* CONFIG_PROC_FS */ + +/* + * The Call's credential body should contain a struct rpc_gss_cred_t. + * + * RFC 2203 Section 5 + * + * struct rpc_gss_cred_t { + * union switch (unsigned int version) { + * case RPCSEC_GSS_VERS_1: + * struct { + * rpc_gss_proc_t gss_proc; + * unsigned int seq_num; + * rpc_gss_service_t service; + * opaque handle<>; + * } rpc_gss_cred_vers_1_t; + * } + * }; + */ +static bool +svcauth_gss_decode_credbody(struct xdr_stream *xdr, + struct rpc_gss_wire_cred *gc, + __be32 **rpcstart) +{ + ssize_t handle_len; + u32 body_len; + __be32 *p; + + p = xdr_inline_decode(xdr, XDR_UNIT); + if (!p) + return false; + /* + * start of rpc packet is 7 u32's back from here: + * xid direction rpcversion prog vers proc flavour + */ + *rpcstart = p - 7; + body_len = be32_to_cpup(p); + if (body_len > RPC_MAX_AUTH_SIZE) + return false; + + /* struct rpc_gss_cred_t */ + if (xdr_stream_decode_u32(xdr, &gc->gc_v) < 0) + return false; + if (xdr_stream_decode_u32(xdr, &gc->gc_proc) < 0) + return false; + if (xdr_stream_decode_u32(xdr, &gc->gc_seq) < 0) + return false; + if (xdr_stream_decode_u32(xdr, &gc->gc_svc) < 0) + return false; + handle_len = xdr_stream_decode_opaque_inline(xdr, + (void **)&gc->gc_ctx.data, + body_len); + if (handle_len < 0) + return false; + if (body_len != XDR_UNIT * 5 + xdr_align_size(handle_len)) + return false; + + gc->gc_ctx.len = handle_len; + return true; +} + +/** + * svcauth_gss_accept - Decode and validate incoming RPC_AUTH_GSS credential + * @rqstp: RPC transaction + * + * Return values: + * %SVC_OK: Success + * %SVC_COMPLETE: GSS context lifetime event + * %SVC_DENIED: Credential or verifier is not valid + * %SVC_GARBAGE: Failed to decode credential or verifier + * %SVC_CLOSE: Temporary failure + * + * The rqstp->rq_auth_stat field is also set (see RFCs 2203 and 5531). + */ +static enum svc_auth_status +svcauth_gss_accept(struct svc_rqst *rqstp) +{ + struct gss_svc_data *svcdata = rqstp->rq_auth_data; + __be32 *rpcstart; + struct rpc_gss_wire_cred *gc; + struct rsc *rsci = NULL; + int ret; + struct sunrpc_net *sn = net_generic(SVC_NET(rqstp), sunrpc_net_id); + + rqstp->rq_auth_stat = rpc_autherr_badcred; + if (!svcdata) + svcdata = kmalloc(sizeof(*svcdata), GFP_KERNEL); + if (!svcdata) + goto auth_err; + rqstp->rq_auth_data = svcdata; + svcdata->gsd_databody_offset = 0; + svcdata->rsci = NULL; + gc = &svcdata->clcred; + + if (!svcauth_gss_decode_credbody(&rqstp->rq_arg_stream, gc, &rpcstart)) + goto auth_err; + if (gc->gc_v != RPC_GSS_VERSION) + goto auth_err; + + switch (gc->gc_proc) { + case RPC_GSS_PROC_INIT: + case RPC_GSS_PROC_CONTINUE_INIT: + if (rqstp->rq_proc != 0) + goto auth_err; + return svcauth_gss_proc_init(rqstp, gc); + case RPC_GSS_PROC_DESTROY: + if (rqstp->rq_proc != 0) + goto auth_err; + fallthrough; + case RPC_GSS_PROC_DATA: + rqstp->rq_auth_stat = rpcsec_gsserr_credproblem; + rsci = gss_svc_searchbyctx(sn->rsc_cache, &gc->gc_ctx); + if (!rsci) + goto auth_err; + switch (svcauth_gss_verify_header(rqstp, rsci, rpcstart, gc)) { + case SVC_OK: + break; + case SVC_DENIED: + goto auth_err; + case SVC_DROP: + goto drop; + } + break; + default: + if (rqstp->rq_proc != 0) + goto auth_err; + rqstp->rq_auth_stat = rpc_autherr_rejectedcred; + goto auth_err; + } + + /* now act upon the command: */ + switch (gc->gc_proc) { + case RPC_GSS_PROC_DESTROY: + if (!svcauth_gss_encode_verf(rqstp, rsci->mechctx, gc->gc_seq)) + goto auth_err; + if (!svcxdr_set_accept_stat(rqstp)) + goto auth_err; + /* Delete the entry from the cache_list and call cache_put */ + sunrpc_cache_unhash(sn->rsc_cache, &rsci->h); + goto complete; + case RPC_GSS_PROC_DATA: + rqstp->rq_auth_stat = rpcsec_gsserr_ctxproblem; + if (!svcauth_gss_encode_verf(rqstp, rsci->mechctx, gc->gc_seq)) + goto auth_err; + if (!svcxdr_set_accept_stat(rqstp)) + goto auth_err; + svcdata->gsd_databody_offset = xdr_stream_pos(&rqstp->rq_res_stream); + rqstp->rq_cred = rsci->cred; + get_group_info(rsci->cred.cr_group_info); + rqstp->rq_auth_stat = rpc_autherr_badcred; + switch (gc->gc_svc) { + case RPC_GSS_SVC_NONE: + break; + case RPC_GSS_SVC_INTEGRITY: + /* placeholders for body length and seq. number: */ + xdr_reserve_space(&rqstp->rq_res_stream, XDR_UNIT * 2); + if (svcauth_gss_unwrap_integ(rqstp, gc->gc_seq, + rsci->mechctx)) + goto garbage_args; + svcxdr_set_auth_slack(rqstp, RPC_MAX_AUTH_SIZE); + break; + case RPC_GSS_SVC_PRIVACY: + /* placeholders for body length and seq. number: */ + xdr_reserve_space(&rqstp->rq_res_stream, XDR_UNIT * 2); + if (svcauth_gss_unwrap_priv(rqstp, gc->gc_seq, + rsci->mechctx)) + goto garbage_args; + svcxdr_set_auth_slack(rqstp, RPC_MAX_AUTH_SIZE * 2); + break; + default: + goto auth_err; + } + svcdata->rsci = rsci; + cache_get(&rsci->h); + rqstp->rq_cred.cr_flavor = gss_svc_to_pseudoflavor( + rsci->mechctx->mech_type, + GSS_C_QOP_DEFAULT, + gc->gc_svc); + ret = SVC_OK; + trace_rpcgss_svc_authenticate(rqstp, gc); + goto out; + } +garbage_args: + ret = SVC_GARBAGE; + goto out; +auth_err: + xdr_truncate_encode(&rqstp->rq_res_stream, XDR_UNIT * 2); + ret = SVC_DENIED; + goto out; +complete: + ret = SVC_COMPLETE; + goto out; +drop: + ret = SVC_CLOSE; +out: + if (rsci) + cache_put(&rsci->h, sn->rsc_cache); + return ret; +} + +static u32 +svcauth_gss_prepare_to_wrap(struct svc_rqst *rqstp, struct gss_svc_data *gsd) +{ + u32 offset; + + /* Release can be called twice, but we only wrap once. */ + offset = gsd->gsd_databody_offset; + gsd->gsd_databody_offset = 0; + + /* AUTH_ERROR replies are not wrapped. */ + if (rqstp->rq_auth_stat != rpc_auth_ok) + return 0; + + /* Also don't wrap if the accept_stat is nonzero: */ + if (*rqstp->rq_accept_statp != rpc_success) + return 0; + + return offset; +} + +/* + * RFC 2203, Section 5.3.2.2 + * + * struct rpc_gss_integ_data { + * opaque databody_integ<>; + * opaque checksum<>; + * }; + * + * struct rpc_gss_data_t { + * unsigned int seq_num; + * proc_req_arg_t arg; + * }; + * + * The RPC Reply message has already been XDR-encoded. rq_res_stream + * is now positioned so that the checksum can be written just past + * the RPC Reply message. + */ +static int svcauth_gss_wrap_integ(struct svc_rqst *rqstp) +{ + struct gss_svc_data *gsd = rqstp->rq_auth_data; + struct xdr_stream *xdr = &rqstp->rq_res_stream; + struct rpc_gss_wire_cred *gc = &gsd->clcred; + struct xdr_buf *buf = xdr->buf; + struct xdr_buf databody_integ; + struct xdr_netobj checksum; + u32 offset, maj_stat; + + offset = svcauth_gss_prepare_to_wrap(rqstp, gsd); + if (!offset) + goto out; + + if (xdr_buf_subsegment(buf, &databody_integ, offset + XDR_UNIT, + buf->len - offset - XDR_UNIT)) + goto wrap_failed; + /* Buffer space for these has already been reserved in + * svcauth_gss_accept(). */ + if (xdr_encode_word(buf, offset, databody_integ.len)) + goto wrap_failed; + if (xdr_encode_word(buf, offset + XDR_UNIT, gc->gc_seq)) + goto wrap_failed; + + checksum.data = gsd->gsd_scratch; + maj_stat = gss_get_mic(gsd->rsci->mechctx, &databody_integ, &checksum); + if (maj_stat != GSS_S_COMPLETE) + goto bad_mic; + + if (xdr_stream_encode_opaque(xdr, checksum.data, checksum.len) < 0) + goto wrap_failed; + xdr_commit_encode(xdr); + +out: + return 0; + +bad_mic: + trace_rpcgss_svc_get_mic(rqstp, maj_stat); + return -EINVAL; +wrap_failed: + trace_rpcgss_svc_wrap_failed(rqstp); + return -EINVAL; +} + +/* + * RFC 2203, Section 5.3.2.3 + * + * struct rpc_gss_priv_data { + * opaque databody_priv<> + * }; + * + * struct rpc_gss_data_t { + * unsigned int seq_num; + * proc_req_arg_t arg; + * }; + * + * gss_wrap() expands the size of the RPC message payload in the + * response buffer. The main purpose of svcauth_gss_wrap_priv() + * is to ensure there is adequate space in the response buffer to + * avoid overflow during the wrap. + */ +static int svcauth_gss_wrap_priv(struct svc_rqst *rqstp) +{ + struct gss_svc_data *gsd = rqstp->rq_auth_data; + struct rpc_gss_wire_cred *gc = &gsd->clcred; + struct xdr_buf *buf = &rqstp->rq_res; + struct kvec *head = buf->head; + struct kvec *tail = buf->tail; + u32 offset, pad, maj_stat; + __be32 *p; + + offset = svcauth_gss_prepare_to_wrap(rqstp, gsd); + if (!offset) + return 0; + + /* + * Buffer space for this field has already been reserved + * in svcauth_gss_accept(). Note that the GSS sequence + * number is encrypted along with the RPC reply payload. + */ + if (xdr_encode_word(buf, offset + XDR_UNIT, gc->gc_seq)) + goto wrap_failed; + + /* + * If there is currently tail data, make sure there is + * room for the head, tail, and 2 * RPC_MAX_AUTH_SIZE in + * the page, and move the current tail data such that + * there is RPC_MAX_AUTH_SIZE slack space available in + * both the head and tail. + */ + if (tail->iov_base) { + if (tail->iov_base >= head->iov_base + PAGE_SIZE) + goto wrap_failed; + if (tail->iov_base < head->iov_base) + goto wrap_failed; + if (tail->iov_len + head->iov_len + + 2 * RPC_MAX_AUTH_SIZE > PAGE_SIZE) + goto wrap_failed; + memmove(tail->iov_base + RPC_MAX_AUTH_SIZE, tail->iov_base, + tail->iov_len); + tail->iov_base += RPC_MAX_AUTH_SIZE; + } + /* + * If there is no current tail data, make sure there is + * room for the head data, and 2 * RPC_MAX_AUTH_SIZE in the + * allotted page, and set up tail information such that there + * is RPC_MAX_AUTH_SIZE slack space available in both the + * head and tail. + */ + if (!tail->iov_base) { + if (head->iov_len + 2 * RPC_MAX_AUTH_SIZE > PAGE_SIZE) + goto wrap_failed; + tail->iov_base = head->iov_base + + head->iov_len + RPC_MAX_AUTH_SIZE; + tail->iov_len = 0; + } + + maj_stat = gss_wrap(gsd->rsci->mechctx, offset + XDR_UNIT, buf, + buf->pages); + if (maj_stat != GSS_S_COMPLETE) + goto bad_wrap; + + /* Wrapping can change the size of databody_priv. */ + if (xdr_encode_word(buf, offset, buf->len - offset - XDR_UNIT)) + goto wrap_failed; + pad = xdr_pad_size(buf->len - offset - XDR_UNIT); + p = (__be32 *)(tail->iov_base + tail->iov_len); + memset(p, 0, pad); + tail->iov_len += pad; + buf->len += pad; + + return 0; +wrap_failed: + trace_rpcgss_svc_wrap_failed(rqstp); + return -EINVAL; +bad_wrap: + trace_rpcgss_svc_wrap(rqstp, maj_stat); + return -ENOMEM; +} + +/** + * svcauth_gss_release - Wrap payload and release resources + * @rqstp: RPC transaction context + * + * Return values: + * %0: the Reply is ready to be sent + * %-ENOMEM: failed to allocate memory + * %-EINVAL: encoding error + */ +static int +svcauth_gss_release(struct svc_rqst *rqstp) +{ + struct sunrpc_net *sn = net_generic(SVC_NET(rqstp), sunrpc_net_id); + struct gss_svc_data *gsd = rqstp->rq_auth_data; + struct rpc_gss_wire_cred *gc; + int stat; + + if (!gsd) + goto out; + gc = &gsd->clcred; + if (gc->gc_proc != RPC_GSS_PROC_DATA) + goto out; + + switch (gc->gc_svc) { + case RPC_GSS_SVC_NONE: + break; + case RPC_GSS_SVC_INTEGRITY: + stat = svcauth_gss_wrap_integ(rqstp); + if (stat) + goto out_err; + break; + case RPC_GSS_SVC_PRIVACY: + stat = svcauth_gss_wrap_priv(rqstp); + if (stat) + goto out_err; + break; + /* + * For any other gc_svc value, svcauth_gss_accept() already set + * the auth_error appropriately; just fall through: + */ + } + +out: + stat = 0; +out_err: + if (rqstp->rq_client) + auth_domain_put(rqstp->rq_client); + rqstp->rq_client = NULL; + if (rqstp->rq_gssclient) + auth_domain_put(rqstp->rq_gssclient); + rqstp->rq_gssclient = NULL; + if (rqstp->rq_cred.cr_group_info) + put_group_info(rqstp->rq_cred.cr_group_info); + rqstp->rq_cred.cr_group_info = NULL; + if (gsd && gsd->rsci) { + cache_put(&gsd->rsci->h, sn->rsc_cache); + gsd->rsci = NULL; + } + return stat; +} + +static void +svcauth_gss_domain_release_rcu(struct rcu_head *head) +{ + struct auth_domain *dom = container_of(head, struct auth_domain, rcu_head); + struct gss_domain *gd = container_of(dom, struct gss_domain, h); + + kfree(dom->name); + kfree(gd); +} + +static void +svcauth_gss_domain_release(struct auth_domain *dom) +{ + call_rcu(&dom->rcu_head, svcauth_gss_domain_release_rcu); +} + +static struct auth_ops svcauthops_gss = { + .name = "rpcsec_gss", + .owner = THIS_MODULE, + .flavour = RPC_AUTH_GSS, + .accept = svcauth_gss_accept, + .release = svcauth_gss_release, + .domain_release = svcauth_gss_domain_release, + .set_client = svcauth_gss_set_client, +}; + +static int rsi_cache_create_net(struct net *net) +{ + struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); + struct cache_detail *cd; + int err; + + cd = cache_create_net(&rsi_cache_template, net); + if (IS_ERR(cd)) + return PTR_ERR(cd); + err = cache_register_net(cd, net); + if (err) { + cache_destroy_net(cd, net); + return err; + } + sn->rsi_cache = cd; + return 0; +} + +static void rsi_cache_destroy_net(struct net *net) +{ + struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); + struct cache_detail *cd = sn->rsi_cache; + + sn->rsi_cache = NULL; + cache_purge(cd); + cache_unregister_net(cd, net); + cache_destroy_net(cd, net); +} + +static int rsc_cache_create_net(struct net *net) +{ + struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); + struct cache_detail *cd; + int err; + + cd = cache_create_net(&rsc_cache_template, net); + if (IS_ERR(cd)) + return PTR_ERR(cd); + err = cache_register_net(cd, net); + if (err) { + cache_destroy_net(cd, net); + return err; + } + sn->rsc_cache = cd; + return 0; +} + +static void rsc_cache_destroy_net(struct net *net) +{ + struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); + struct cache_detail *cd = sn->rsc_cache; + + sn->rsc_cache = NULL; + cache_purge(cd); + cache_unregister_net(cd, net); + cache_destroy_net(cd, net); +} + +int +gss_svc_init_net(struct net *net) +{ + int rv; + + rv = rsc_cache_create_net(net); + if (rv) + return rv; + rv = rsi_cache_create_net(net); + if (rv) + goto out1; + rv = create_use_gss_proxy_proc_entry(net); + if (rv) + goto out2; + + rv = create_krb5_enctypes_proc_entry(net); + if (rv) + goto out3; + + return 0; + +out3: + destroy_use_gss_proxy_proc_entry(net); +out2: + rsi_cache_destroy_net(net); +out1: + rsc_cache_destroy_net(net); + return rv; +} + +void +gss_svc_shutdown_net(struct net *net) +{ + destroy_krb5_enctypes_proc_entry(net); + destroy_use_gss_proxy_proc_entry(net); + rsi_cache_destroy_net(net); + rsc_cache_destroy_net(net); +} + +int +gss_svc_init(void) +{ + return svc_auth_register(RPC_AUTH_GSS, &svcauthops_gss); +} + +void +gss_svc_shutdown(void) +{ + svc_auth_unregister(RPC_AUTH_GSS); +} |