/* * 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 "../netns.h" #ifdef RPC_DEBUG # define RPCDBG_FACILITY RPCDBG_AUTH #endif /* 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_put(struct kref *ref) { struct rsi *rsii = container_of(ref, struct rsi, h.ref); rsi_free(rsii); kfree(rsii); } 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 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'; } static int rsi_upcall(struct cache_detail *cd, struct cache_head *h) { return sunrpc_cache_pipe_upcall(cd, h, cd->cache_request); } 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; time_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 */ expiry = get_expiry(&mesg); status = -EINVAL; if (expiry == 0) goto out; /* 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 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(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_put(struct kref *ref) { struct rsc *rsci = container_of(ref, struct rsc, h.ref); rsc_free(rsci); kfree(rsci); } 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; new->cred.cr_group_info = NULL; new->cred.cr_principal = NULL; } 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; tmp->cred.cr_group_info = NULL; new->cred.cr_principal = tmp->cred.cr_principal; tmp->cred.cr_principal = NULL; } 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_parse(struct cache_detail *cd, char *mesg, int mlen) { /* contexthandle expiry [ uid gid N mechname ...mechdata... ] */ char *buf = mesg; int len, rv; struct rsc rsci, *rscp = NULL; time_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 */ expiry = get_expiry(&mesg); status = -EINVAL; if (expiry == 0) goto out; rscp = rsc_lookup(cd, &rsci); if (!rscp) goto out; /* uid, or NEGATIVE */ rv = get_int(&mesg, &rsci.cred.cr_uid); if (rv == -EINVAL) goto out; if (rv == -ENOENT) set_bit(CACHE_NEGATIVE, &rsci.h.flags); else { int N, i; /* gid */ if (get_int(&mesg, &rsci.cred.cr_gid)) goto out; /* number of additional gid's */ if (get_int(&mesg, &N)) 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 0) { rsci.cred.cr_principal = kstrdup(buf, GFP_KERNEL); if (!rsci.cred.cr_principal) goto out; } } rsci.h.expiry_time = expiry; rscp = rsc_update(cd, &rsci, rscp); status = 0; out: gss_mech_put(gm); rsc_free(&rsci); if (rscp) cache_put(&rscp->h, cd); else status = -ENOMEM; return status; } static struct cache_detail rsc_cache_template = { .owner = THIS_MODULE, .hash_size = RSC_HASHMAX, .name = "auth.rpcsec.context", .cache_put = rsc_put, .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(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; } /* Implements sequence number algorithm as specified in RFC 2203. */ static int gss_check_seq_num(struct rsc *rsci, int seq_num) { struct gss_svc_seq_data *sd = &rsci->seqdata; 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 <= sd->sd_max - GSS_SEQ_WIN) { goto drop; } /* sd_max - GSS_SEQ_WIN < seq_num <= sd_max */ if (__test_and_set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win)) goto drop; ok: spin_unlock(&sd->sd_lock); return 1; drop: spin_unlock(&sd->sd_lock); return 0; } static inline u32 round_up_to_quad(u32 i) { return (i + 3 ) & ~3; } static inline int svc_safe_getnetobj(struct kvec *argv, struct xdr_netobj *o) { int l; if (argv->iov_len < 4) return -1; o->len = svc_getnl(argv); l = round_up_to_quad(o->len); if (argv->iov_len < l) return -1; o->data = argv->iov_base; argv->iov_base += l; argv->iov_len -= l; return 0; } static inline int svc_safe_putnetobj(struct kvec *resv, struct xdr_netobj *o) { u8 *p; if (resv->iov_len + 4 > PAGE_SIZE) return -1; svc_putnl(resv, o->len); p = resv->iov_base + resv->iov_len; resv->iov_len += round_up_to_quad(o->len); if (resv->iov_len > PAGE_SIZE) return -1; memcpy(p, o->data, o->len); memset(p + o->len, 0, round_up_to_quad(o->len) - o->len); return 0; } /* * Verify the checksum on the header and return SVC_OK on success. * Otherwise, return SVC_DROP (in the case of a bad sequence number) * or return SVC_DENIED and indicate error in authp. */ static int gss_verify_header(struct svc_rqst *rqstp, struct rsc *rsci, __be32 *rpcstart, struct rpc_gss_wire_cred *gc, __be32 *authp) { struct gss_ctx *ctx_id = rsci->mechctx; struct xdr_buf rpchdr; struct xdr_netobj checksum; u32 flavor = 0; struct kvec *argv = &rqstp->rq_arg.head[0]; struct kvec iov; /* data to compute the checksum over: */ iov.iov_base = rpcstart; iov.iov_len = (u8 *)argv->iov_base - (u8 *)rpcstart; xdr_buf_from_iov(&iov, &rpchdr); *authp = rpc_autherr_badverf; if (argv->iov_len < 4) return SVC_DENIED; flavor = svc_getnl(argv); if (flavor != RPC_AUTH_GSS) return SVC_DENIED; if (svc_safe_getnetobj(argv, &checksum)) return SVC_DENIED; if (rqstp->rq_deferred) /* skip verification of revisited request */ return SVC_OK; if (gss_verify_mic(ctx_id, &rpchdr, &checksum) != GSS_S_COMPLETE) { *authp = rpcsec_gsserr_credproblem; return SVC_DENIED; } if (gc->gc_seq > MAXSEQ) { dprintk("RPC: svcauth_gss: discarding request with " "large sequence number %d\n", gc->gc_seq); *authp = rpcsec_gsserr_ctxproblem; return SVC_DENIED; } if (!gss_check_seq_num(rsci, gc->gc_seq)) { dprintk("RPC: svcauth_gss: discarding request with " "old sequence number %d\n", gc->gc_seq); return SVC_DROP; } return SVC_OK; } static int gss_write_null_verf(struct svc_rqst *rqstp) { __be32 *p; svc_putnl(rqstp->rq_res.head, RPC_AUTH_NULL); p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len; /* don't really need to check if head->iov_len > PAGE_SIZE ... */ *p++ = 0; if (!xdr_ressize_check(rqstp, p)) return -1; return 0; } static int gss_write_verf(struct svc_rqst *rqstp, struct gss_ctx *ctx_id, u32 seq) { __be32 xdr_seq; u32 maj_stat; struct xdr_buf verf_data; struct xdr_netobj mic; __be32 *p; struct kvec iov; svc_putnl(rqstp->rq_res.head, RPC_AUTH_GSS); xdr_seq = htonl(seq); iov.iov_base = &xdr_seq; iov.iov_len = sizeof(xdr_seq); xdr_buf_from_iov(&iov, &verf_data); p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len; mic.data = (u8 *)(p + 1); maj_stat = gss_get_mic(ctx_id, &verf_data, &mic); if (maj_stat != GSS_S_COMPLETE) return -1; *p++ = htonl(mic.len); memset((u8 *)p + mic.len, 0, round_up_to_quad(mic.len) - mic.len); p += XDR_QUADLEN(mic.len); if (!xdr_ressize_check(rqstp, p)) return -1; return 0; } 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); int 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; stat = 0; test = auth_domain_lookup(name, &new->h); if (test != &new->h) { /* Duplicate registration */ auth_domain_put(test); kfree(new->h.name); goto out_free_dom; } return 0; out_free_dom: kfree(new); out: return stat; } EXPORT_SYMBOL_GPL(svcauth_gss_register_pseudoflavor); static inline int read_u32_from_xdr_buf(struct xdr_buf *buf, int base, u32 *obj) { __be32 raw; int status; status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj)); if (status) return status; *obj = ntohl(raw); return 0; } /* It would be nice if this bit of code could be shared with the client. * Obstacles: * The client shouldn't malloc(), would have to pass in own memory. * The server uses base of head iovec as read pointer, while the * client uses separate pointer. */ static int unwrap_integ_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx) { int stat = -EINVAL; u32 integ_len, maj_stat; struct xdr_netobj mic; struct xdr_buf integ_buf; /* Did we already verify the signature on the original pass through? */ if (rqstp->rq_deferred) return 0; integ_len = svc_getnl(&buf->head[0]); if (integ_len & 3) return stat; if (integ_len > buf->len) return stat; if (xdr_buf_subsegment(buf, &integ_buf, 0, integ_len)) BUG(); /* copy out mic... */ if (read_u32_from_xdr_buf(buf, integ_len, &mic.len)) BUG(); if (mic.len > RPC_MAX_AUTH_SIZE) return stat; mic.data = kmalloc(mic.len, GFP_KERNEL); if (!mic.data) return stat; if (read_bytes_from_xdr_buf(buf, integ_len + 4, mic.data, mic.len)) goto out; maj_stat = gss_verify_mic(ctx, &integ_buf, &mic); if (maj_stat != GSS_S_COMPLETE) goto out; if (svc_getnl(&buf->head[0]) != seq) goto out; /* trim off the mic at the end before returning */ xdr_buf_trim(buf, mic.len + 4); stat = 0; out: kfree(mic.data); return stat; } static inline int total_buf_len(struct xdr_buf *buf) { return buf->head[0].iov_len + buf->page_len + buf->tail[0].iov_len; } static void fix_priv_head(struct xdr_buf *buf, int pad) { if (buf->page_len == 0) { /* We need to adjust head and buf->len in tandem in this * case to make svc_defer() work--it finds the original * buffer start using buf->len - buf->head[0].iov_len. */ buf->head[0].iov_len -= pad; } } static int unwrap_priv_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx) { u32 priv_len, maj_stat; int pad, saved_len, remaining_len, offset; rqstp->rq_splice_ok = 0; priv_len = svc_getnl(&buf->head[0]); if (rqstp->rq_deferred) { /* Already decrypted last time through! The sequence number * check at out_seq is unnecessary but harmless: */ goto out_seq; } /* buf->len is the number of bytes from the original start of the * request to the end, where head[0].iov_len is just the bytes * not yet read from the head, so these two values are different: */ remaining_len = total_buf_len(buf); if (priv_len > remaining_len) return -EINVAL; pad = remaining_len - priv_len; buf->len -= pad; fix_priv_head(buf, pad); /* Maybe it would be better to give gss_unwrap a length parameter: */ saved_len = buf->len; buf->len = priv_len; maj_stat = gss_unwrap(ctx, 0, buf); pad = priv_len - buf->len; buf->len = saved_len; buf->len -= pad; /* The upper layers assume the buffer is aligned on 4-byte boundaries. * In the krb5p case, at least, the data ends up offset, so we need to * move it around. */ /* XXX: This is very inefficient. It would be better to either do * this while we encrypt, or maybe in the receive code, if we can peak * ahead and work out the service and mechanism there. */ offset = buf->head[0].iov_len % 4; if (offset) { buf->buflen = RPCSVC_MAXPAYLOAD; xdr_shift_buf(buf, offset); fix_priv_head(buf, pad); } if (maj_stat != GSS_S_COMPLETE) return -EINVAL; out_seq: if (svc_getnl(&buf->head[0]) != seq) return -EINVAL; return 0; } struct gss_svc_data { /* decoded gss client cred: */ struct rpc_gss_wire_cred clcred; /* save a pointer to the beginning of the encoded verifier, * for use in encryption/checksumming in svcauth_gss_release: */ __be32 *verf_start; struct rsc *rsci; }; 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; /* * 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; return SVC_OK; } static inline int gss_write_init_verf(struct cache_detail *cd, struct svc_rqst *rqstp, struct xdr_netobj *out_handle, int *major_status) { struct rsc *rsci; int rc; if (*major_status != GSS_S_COMPLETE) return gss_write_null_verf(rqstp); rsci = gss_svc_searchbyctx(cd, out_handle); if (rsci == NULL) { *major_status = GSS_S_NO_CONTEXT; return gss_write_null_verf(rqstp); } rc = gss_write_verf(rqstp, rsci->mechctx, GSS_SEQ_WIN); cache_put(&rsci->h, cd); return rc; } static inline int gss_read_verf(struct rpc_gss_wire_cred *gc, struct kvec *argv, __be32 *authp, struct xdr_netobj *in_handle, struct xdr_netobj *in_token) { struct xdr_netobj tmpobj; /* Read the verifier; should be NULL: */ *authp = rpc_autherr_badverf; if (argv->iov_len < 2 * 4) return SVC_DENIED; if (svc_getnl(argv) != RPC_AUTH_NULL) return SVC_DENIED; if (svc_getnl(argv) != 0) return SVC_DENIED; /* Martial context handle and token for upcall: */ *authp = rpc_autherr_badcred; if (gc->gc_proc == RPC_GSS_PROC_INIT && gc->gc_ctx.len != 0) return SVC_DENIED; if (dup_netobj(in_handle, &gc->gc_ctx)) return SVC_CLOSE; *authp = rpc_autherr_badverf; if (svc_safe_getnetobj(argv, &tmpobj)) { kfree(in_handle->data); return SVC_DENIED; } if (dup_netobj(in_token, &tmpobj)) { kfree(in_handle->data); return SVC_CLOSE; } return 0; } static inline int gss_write_resv(struct kvec *resv, size_t size_limit, struct xdr_netobj *out_handle, struct xdr_netobj *out_token, int major_status, int minor_status) { if (resv->iov_len + 4 > size_limit) return -1; svc_putnl(resv, RPC_SUCCESS); if (svc_safe_putnetobj(resv, out_handle)) return -1; if (resv->iov_len + 3 * 4 > size_limit) return -1; svc_putnl(resv, major_status); svc_putnl(resv, minor_status); svc_putnl(resv, GSS_SEQ_WIN); if (svc_safe_putnetobj(resv, out_token)) return -1; return 0; } /* * 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_handle_init(struct svc_rqst *rqstp, struct rpc_gss_wire_cred *gc, __be32 *authp) { struct kvec *argv = &rqstp->rq_arg.head[0]; struct kvec *resv = &rqstp->rq_res.head[0]; struct rsi *rsip, rsikey; int ret; struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id); memset(&rsikey, 0, sizeof(rsikey)); ret = gss_read_verf(gc, argv, authp, &rsikey.in_handle, &rsikey.in_token); if (ret) return ret; /* 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; /* Got an answer to the upcall; use it: */ if (gss_write_init_verf(sn->rsc_cache, rqstp, &rsip->out_handle, &rsip->major_status)) goto out; if (gss_write_resv(resv, PAGE_SIZE, &rsip->out_handle, &rsip->out_token, rsip->major_status, rsip->minor_status)) goto out; ret = SVC_COMPLETE; out: cache_put(&rsip->h, sn->rsi_cache); return ret; } /* * Accept an rpcsec packet. * If context establishment, punt to user space * If data exchange, verify/decrypt * If context destruction, handle here * In the context establishment and destruction case we encode * response here and return SVC_COMPLETE. */ static int svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp) { struct kvec *argv = &rqstp->rq_arg.head[0]; struct kvec *resv = &rqstp->rq_res.head[0]; u32 crlen; struct gss_svc_data *svcdata = rqstp->rq_auth_data; struct rpc_gss_wire_cred *gc; struct rsc *rsci = NULL; __be32 *rpcstart; __be32 *reject_stat = resv->iov_base + resv->iov_len; int ret; struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id); dprintk("RPC: svcauth_gss: argv->iov_len = %zd\n", argv->iov_len); *authp = rpc_autherr_badcred; if (!svcdata) svcdata = kmalloc(sizeof(*svcdata), GFP_KERNEL); if (!svcdata) goto auth_err; rqstp->rq_auth_data = svcdata; svcdata->verf_start = NULL; svcdata->rsci = NULL; gc = &svcdata->clcred; /* start of rpc packet is 7 u32's back from here: * xid direction rpcversion prog vers proc flavour */ rpcstart = argv->iov_base; rpcstart -= 7; /* credential is: * version(==1), proc(0,1,2,3), seq, service (1,2,3), handle * at least 5 u32s, and is preceded by length, so that makes 6. */ if (argv->iov_len < 5 * 4) goto auth_err; crlen = svc_getnl(argv); if (svc_getnl(argv) != RPC_GSS_VERSION) goto auth_err; gc->gc_proc = svc_getnl(argv); gc->gc_seq = svc_getnl(argv); gc->gc_svc = svc_getnl(argv); if (svc_safe_getnetobj(argv, &gc->gc_ctx)) goto auth_err; if (crlen != round_up_to_quad(gc->gc_ctx.len) + 5 * 4) goto auth_err; if ((gc->gc_proc != RPC_GSS_PROC_DATA) && (rqstp->rq_proc != 0)) goto auth_err; *authp = rpc_autherr_badverf; switch (gc->gc_proc) { case RPC_GSS_PROC_INIT: case RPC_GSS_PROC_CONTINUE_INIT: return svcauth_gss_handle_init(rqstp, gc, authp); case RPC_GSS_PROC_DATA: case RPC_GSS_PROC_DESTROY: /* Look up the context, and check the verifier: */ *authp = rpcsec_gsserr_credproblem; rsci = gss_svc_searchbyctx(sn->rsc_cache, &gc->gc_ctx); if (!rsci) goto auth_err; switch (gss_verify_header(rqstp, rsci, rpcstart, gc, authp)) { case SVC_OK: break; case SVC_DENIED: goto auth_err; case SVC_DROP: goto drop; } break; default: *authp = rpc_autherr_rejectedcred; goto auth_err; } /* now act upon the command: */ switch (gc->gc_proc) { case RPC_GSS_PROC_DESTROY: if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq)) goto auth_err; rsci->h.expiry_time = get_seconds(); set_bit(CACHE_NEGATIVE, &rsci->h.flags); if (resv->iov_len + 4 > PAGE_SIZE) goto drop; svc_putnl(resv, RPC_SUCCESS); goto complete; case RPC_GSS_PROC_DATA: *authp = rpcsec_gsserr_ctxproblem; svcdata->verf_start = resv->iov_base + resv->iov_len; if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq)) goto auth_err; rqstp->rq_cred = rsci->cred; get_group_info(rsci->cred.cr_group_info); *authp = rpc_autherr_badcred; switch (gc->gc_svc) { case RPC_GSS_SVC_NONE: break; case RPC_GSS_SVC_INTEGRITY: /* placeholders for length and seq. number: */ svc_putnl(resv, 0); svc_putnl(resv, 0); if (unwrap_integ_data(rqstp, &rqstp->rq_arg, gc->gc_seq, rsci->mechctx)) goto garbage_args; break; case RPC_GSS_SVC_PRIVACY: /* placeholders for length and seq. number: */ svc_putnl(resv, 0); svc_putnl(resv, 0); if (unwrap_priv_data(rqstp, &rqstp->rq_arg, gc->gc_seq, rsci->mechctx)) goto garbage_args; 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, gc->gc_svc); ret = SVC_OK; goto out; } garbage_args: ret = SVC_GARBAGE; goto out; auth_err: /* Restore write pointer to its original value: */ xdr_ressize_check(rqstp, reject_stat); ret = SVC_DENIED; goto out; complete: ret = SVC_COMPLETE; goto out; drop: ret = SVC_DROP; out: if (rsci) cache_put(&rsci->h, sn->rsc_cache); return ret; } static __be32 * svcauth_gss_prepare_to_wrap(struct xdr_buf *resbuf, struct gss_svc_data *gsd) { __be32 *p; u32 verf_len; p = gsd->verf_start; gsd->verf_start = NULL; /* If the reply stat is nonzero, don't wrap: */ if (*(p-1) != rpc_success) return NULL; /* Skip the verifier: */ p += 1; verf_len = ntohl(*p++); p += XDR_QUADLEN(verf_len); /* move accept_stat to right place: */ memcpy(p, p + 2, 4); /* Also don't wrap if the accept stat is nonzero: */ if (*p != rpc_success) { resbuf->head[0].iov_len -= 2 * 4; return NULL; } p++; return p; } static inline int svcauth_gss_wrap_resp_integ(struct svc_rqst *rqstp) { struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data; struct rpc_gss_wire_cred *gc = &gsd->clcred; struct xdr_buf *resbuf = &rqstp->rq_res; struct xdr_buf integ_buf; struct xdr_netobj mic; struct kvec *resv; __be32 *p; int integ_offset, integ_len; int stat = -EINVAL; p = svcauth_gss_prepare_to_wrap(resbuf, gsd); if (p == NULL) goto out; integ_offset = (u8 *)(p + 1) - (u8 *)resbuf->head[0].iov_base; integ_len = resbuf->len - integ_offset; BUG_ON(integ_len % 4); *p++ = htonl(integ_len); *p++ = htonl(gc->gc_seq); if (xdr_buf_subsegment(resbuf, &integ_buf, integ_offset, integ_len)) BUG(); if (resbuf->tail[0].iov_base == NULL) { if (resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE > PAGE_SIZE) goto out_err; resbuf->tail[0].iov_base = resbuf->head[0].iov_base + resbuf->head[0].iov_len; resbuf->tail[0].iov_len = 0; resv = &resbuf->tail[0]; } else { resv = &resbuf->tail[0]; } mic.data = (u8 *)resv->iov_base + resv->iov_len + 4; if (gss_get_mic(gsd->rsci->mechctx, &integ_buf, &mic)) goto out_err; svc_putnl(resv, mic.len); memset(mic.data + mic.len, 0, round_up_to_quad(mic.len) - mic.len); resv->iov_len += XDR_QUADLEN(mic.len) << 2; /* not strictly required: */ resbuf->len += XDR_QUADLEN(mic.len) << 2; BUG_ON(resv->iov_len > PAGE_SIZE); out: stat = 0; out_err: return stat; } static inline int svcauth_gss_wrap_resp_priv(struct svc_rqst *rqstp) { struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data; struct rpc_gss_wire_cred *gc = &gsd->clcred; struct xdr_buf *resbuf = &rqstp->rq_res; struct page **inpages = NULL; __be32 *p, *len; int offset; int pad; p = svcauth_gss_prepare_to_wrap(resbuf, gsd); if (p == NULL) return 0; len = p++; offset = (u8 *)p - (u8 *)resbuf->head[0].iov_base; *p++ = htonl(gc->gc_seq); inpages = resbuf->pages; /* XXX: Would be better to write some xdr helper functions for * nfs{2,3,4}xdr.c that place the data right, instead of copying: */ /* * 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 (resbuf->tail[0].iov_base) { BUG_ON(resbuf->tail[0].iov_base >= resbuf->head[0].iov_base + PAGE_SIZE); BUG_ON(resbuf->tail[0].iov_base < resbuf->head[0].iov_base); if (resbuf->tail[0].iov_len + resbuf->head[0].iov_len + 2 * RPC_MAX_AUTH_SIZE > PAGE_SIZE) return -ENOMEM; memmove(resbuf->tail[0].iov_base + RPC_MAX_AUTH_SIZE, resbuf->tail[0].iov_base, resbuf->tail[0].iov_len); resbuf->tail[0].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 (resbuf->tail[0].iov_base == NULL) { if (resbuf->head[0].iov_len + 2*RPC_MAX_AUTH_SIZE > PAGE_SIZE) return -ENOMEM; resbuf->tail[0].iov_base = resbuf->head[0].iov_base + resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE; resbuf->tail[0].iov_len = 0; } if (gss_wrap(gsd->rsci->mechctx, offset, resbuf, inpages)) return -ENOMEM; *len = htonl(resbuf->len - offset); pad = 3 - ((resbuf->len - offset - 1)&3); p = (__be32 *)(resbuf->tail[0].iov_base + resbuf->tail[0].iov_len); memset(p, 0, pad); resbuf->tail[0].iov_len += pad; resbuf->len += pad; return 0; } static int svcauth_gss_release(struct svc_rqst *rqstp) { struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data; struct rpc_gss_wire_cred *gc = &gsd->clcred; struct xdr_buf *resbuf = &rqstp->rq_res; int stat = -EINVAL; struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id); if (gc->gc_proc != RPC_GSS_PROC_DATA) goto out; /* Release can be called twice, but we only wrap once. */ if (gsd->verf_start == NULL) goto out; /* normally not set till svc_send, but we need it here: */ /* XXX: what for? Do we mess it up the moment we call svc_putu32 * or whatever? */ resbuf->len = total_buf_len(resbuf); switch (gc->gc_svc) { case RPC_GSS_SVC_NONE: break; case RPC_GSS_SVC_INTEGRITY: stat = svcauth_gss_wrap_resp_integ(rqstp); if (stat) goto out_err; break; case RPC_GSS_SVC_PRIVACY: stat = svcauth_gss_wrap_resp_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->rsci) cache_put(&gsd->rsci->h, sn->rsc_cache); gsd->rsci = NULL; return stat; } static void svcauth_gss_domain_release(struct auth_domain *dom) { struct gss_domain *gd = container_of(dom, struct gss_domain, h); kfree(dom->name); kfree(gd); } 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; return 0; out1: rsc_cache_destroy_net(net); return rv; } void gss_svc_shutdown_net(struct net *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); }