// SPDX-License-Identifier: GPL-2.0 /* * Neil Brown * J. Bruce Fields * Andy Adamson * Dug Song * * 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 #include #include #include #include #include #include #include #include #include #include #include #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<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<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 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; igid[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 int 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 int 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 * * XXX: These return values do not match the return values documented * for the auth_ops ->release method in linux/sunrpc/svcauth.h. */ 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); }