diff options
Diffstat (limited to 'net/sunrpc/auth_gss/svcauth_gss.c')
| -rw-r--r-- | net/sunrpc/auth_gss/svcauth_gss.c | 1080 |
1 files changed, 1080 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 000000000000..5c8fe3bfc494 --- /dev/null +++ b/net/sunrpc/auth_gss/svcauth_gss.c @@ -0,0 +1,1080 @@ +/* + * 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/types.h> +#include <linux/module.h> +#include <linux/pagemap.h> + +#include <linux/sunrpc/auth_gss.h> +#include <linux/sunrpc/svcauth.h> +#include <linux/sunrpc/gss_err.h> +#include <linux/sunrpc/svcauth.h> +#include <linux/sunrpc/svcauth_gss.h> +#include <linux/sunrpc/cache.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<<RSI_HASHBITS) +#define RSI_HASHMASK (RSI_HASHMAX-1) + +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; +}; + +static struct cache_head *rsi_table[RSI_HASHMAX]; +static struct cache_detail rsi_cache; +static struct rsi *rsi_lookup(struct rsi *item, int set); + +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_put(struct cache_head *item, struct cache_detail *cd) +{ + struct rsi *rsii = container_of(item, struct rsi, h); + if (cache_put(item, cd)) { + 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 inline int rsi_match(struct rsi *item, struct rsi *tmp) +{ + 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 ? kmalloc(len, GFP_KERNEL) : NULL); + if (dst->data) + memcpy(dst->data, src, len); + 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 inline void rsi_init(struct rsi *new, struct rsi *item) +{ + 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 inline void rsi_update(struct rsi *new, struct rsi *item) +{ + 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 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_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; + + 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; + if (len == 0) { + goto out; + } else { + 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_lookup(&rsii, 1); + status = 0; +out: + rsi_free(&rsii); + if (rsip) + rsi_put(&rsip->h, &rsi_cache); + return status; +} + +static struct cache_detail rsi_cache = { + .hash_size = RSI_HASHMAX, + .hash_table = rsi_table, + .name = "auth.rpcsec.init", + .cache_put = rsi_put, + .cache_request = rsi_request, + .cache_parse = rsi_parse, +}; + +static DefineSimpleCacheLookup(rsi, 0) + +/* + * 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 RSC_HASHMASK (RSC_HASHMAX-1) + +#define GSS_SEQ_WIN 128 + +struct gss_svc_seq_data { + /* highest seq number seen so far: */ + int 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; +}; + +static struct cache_head *rsc_table[RSC_HASHMAX]; +static struct cache_detail rsc_cache; +static struct rsc *rsc_lookup(struct rsc *item, int set); + +static void rsc_free(struct rsc *rsci) +{ + kfree(rsci->handle.data); + if (rsci->mechctx) + gss_delete_sec_context(&rsci->mechctx); + if (rsci->cred.cr_group_info) + put_group_info(rsci->cred.cr_group_info); +} + +static void rsc_put(struct cache_head *item, struct cache_detail *cd) +{ + struct rsc *rsci = container_of(item, struct rsc, h); + + if (cache_put(item, cd)) { + 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 inline int +rsc_match(struct rsc *new, struct rsc *tmp) +{ + return netobj_equal(&new->handle, &tmp->handle); +} + +static inline void +rsc_init(struct rsc *new, struct rsc *tmp) +{ + 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; +} + +static inline void +rsc_update(struct rsc *new, struct rsc *tmp) +{ + 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; +} + +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 len, rv; + struct rsc rsci, *rscp = NULL; + time_t expiry; + int status = -EINVAL; + + 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; + + /* 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; + struct gss_api_mech *gm; + + /* 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<N; i++) { + gid_t gid; + if (get_int(&mesg, &gid)) + goto out; + GROUP_AT(rsci.cred.cr_group_info, i) = gid; + } + + /* mech name */ + len = qword_get(&mesg, buf, mlen); + if (len < 0) + goto out; + gm = 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) { + gss_mech_put(gm); + goto out; + } + if (gss_import_sec_context(buf, len, gm, &rsci.mechctx)) { + gss_mech_put(gm); + goto out; + } + gss_mech_put(gm); + } + rsci.h.expiry_time = expiry; + rscp = rsc_lookup(&rsci, 1); + status = 0; +out: + rsc_free(&rsci); + if (rscp) + rsc_put(&rscp->h, &rsc_cache); + return status; +} + +static struct cache_detail rsc_cache = { + .hash_size = RSC_HASHMAX, + .hash_table = rsc_table, + .name = "auth.rpcsec.context", + .cache_put = rsc_put, + .cache_parse = rsc_parse, +}; + +static DefineSimpleCacheLookup(rsc, 0); + +static struct rsc * +gss_svc_searchbyctx(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(&rsci, 0); + rsc_free(&rsci); + if (!found) + return NULL; + if (cache_check(&rsc_cache, &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 = ntohl(svc_getu32(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) +{ + u32 *p; + + if (resv->iov_len + 4 > PAGE_SIZE) + return -1; + svc_putu32(resv, htonl(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((u8 *)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, + u32 *rpcstart, struct rpc_gss_wire_cred *gc, u32 *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 = ntohl(svc_getu32(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, NULL) + != 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_verf(struct svc_rqst *rqstp, struct gss_ctx *ctx_id, u32 seq) +{ + u32 xdr_seq; + u32 maj_stat; + struct xdr_buf verf_data; + struct xdr_netobj mic; + u32 *p; + struct kvec iov; + + svc_putu32(rqstp->rq_res.head, htonl(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, 0, &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); +} + +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; + cache_init(&new->h.h); + new->h.name = kmalloc(strlen(name) + 1, GFP_KERNEL); + if (!new->h.name) + goto out_free_dom; + strcpy(new->h.name, name); + new->h.flavour = RPC_AUTH_GSS; + new->pseudoflavor = pseudoflavor; + new->h.h.expiry_time = NEVER; + + test = auth_domain_lookup(&new->h, 1); + if (test == &new->h) { + BUG_ON(atomic_dec_and_test(&new->h.h.refcnt)); + } else { /* XXX Duplicate registration? */ + auth_domain_put(&new->h); + goto out; + } + return 0; + +out_free_dom: + kfree(new); +out: + return stat; +} + +EXPORT_SYMBOL(svcauth_gss_register_pseudoflavor); + +static inline int +read_u32_from_xdr_buf(struct xdr_buf *buf, int base, u32 *obj) +{ + u32 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 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; + + integ_len = ntohl(svc_getu32(&buf->head[0])); + if (integ_len & 3) + goto out; + if (integ_len > buf->len) + goto out; + 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) + goto out; + mic.data = kmalloc(mic.len, GFP_KERNEL); + if (!mic.data) + goto out; + 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, NULL); + if (maj_stat != GSS_S_COMPLETE) + goto out; + if (ntohl(svc_getu32(&buf->head[0])) != seq) + goto out; + stat = 0; +out: + return stat; +} + +struct gss_svc_data { + /* decoded gss client cred: */ + struct rpc_gss_wire_cred clcred; + /* pointer to the beginning of the procedure-specific results, + * which may be encrypted/checksummed in svcauth_gss_release: */ + u32 *body_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; + + rqstp->rq_client = find_gss_auth_domain(rsci->mechctx, gc->gc_svc); + if (rqstp->rq_client == NULL) + return SVC_DENIED; + return SVC_OK; +} + +/* + * 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, u32 *authp) +{ + struct kvec *argv = &rqstp->rq_arg.head[0]; + struct kvec *resv = &rqstp->rq_res.head[0]; + u32 crlen; + struct xdr_netobj tmpobj; + struct gss_svc_data *svcdata = rqstp->rq_auth_data; + struct rpc_gss_wire_cred *gc; + struct rsc *rsci = NULL; + struct rsi *rsip, rsikey; + u32 *rpcstart; + u32 *reject_stat = resv->iov_base + resv->iov_len; + int ret; + + 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->body_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 preceeded by length, so that makes 6. + */ + + if (argv->iov_len < 5 * 4) + goto auth_err; + crlen = ntohl(svc_getu32(argv)); + if (ntohl(svc_getu32(argv)) != RPC_GSS_VERSION) + goto auth_err; + gc->gc_proc = ntohl(svc_getu32(argv)); + gc->gc_seq = ntohl(svc_getu32(argv)); + gc->gc_svc = ntohl(svc_getu32(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; + + /* + * We've successfully parsed the credential. Let's check out the + * verifier. An AUTH_NULL verifier is allowed (and required) for + * INIT and CONTINUE_INIT requests. AUTH_RPCSEC_GSS is required for + * PROC_DATA and PROC_DESTROY. + * + * AUTH_NULL verifier is 0 (AUTH_NULL), 0 (length). + * AUTH_RPCSEC_GSS verifier is: + * 6 (AUTH_RPCSEC_GSS), length, checksum. + * checksum is calculated over rpcheader from xid up to here. + */ + *authp = rpc_autherr_badverf; + switch (gc->gc_proc) { + case RPC_GSS_PROC_INIT: + case RPC_GSS_PROC_CONTINUE_INIT: + if (argv->iov_len < 2 * 4) + goto auth_err; + if (ntohl(svc_getu32(argv)) != RPC_AUTH_NULL) + goto auth_err; + if (ntohl(svc_getu32(argv)) != 0) + goto auth_err; + break; + case RPC_GSS_PROC_DATA: + case RPC_GSS_PROC_DESTROY: + *authp = rpcsec_gsserr_credproblem; + rsci = gss_svc_searchbyctx(&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_INIT: + case RPC_GSS_PROC_CONTINUE_INIT: + *authp = rpc_autherr_badcred; + if (gc->gc_proc == RPC_GSS_PROC_INIT && gc->gc_ctx.len != 0) + goto auth_err; + memset(&rsikey, 0, sizeof(rsikey)); + if (dup_netobj(&rsikey.in_handle, &gc->gc_ctx)) + goto drop; + *authp = rpc_autherr_badverf; + if (svc_safe_getnetobj(argv, &tmpobj)) { + kfree(rsikey.in_handle.data); + goto auth_err; + } + if (dup_netobj(&rsikey.in_token, &tmpobj)) { + kfree(rsikey.in_handle.data); + goto drop; + } + + rsip = rsi_lookup(&rsikey, 0); + rsi_free(&rsikey); + if (!rsip) { + goto drop; + } + switch(cache_check(&rsi_cache, &rsip->h, &rqstp->rq_chandle)) { + case -EAGAIN: + goto drop; + case -ENOENT: + goto drop; + case 0: + rsci = gss_svc_searchbyctx(&rsip->out_handle); + if (!rsci) { + goto drop; + } + if (gss_write_verf(rqstp, rsci->mechctx, GSS_SEQ_WIN)) + goto drop; + if (resv->iov_len + 4 > PAGE_SIZE) + goto drop; + svc_putu32(resv, rpc_success); + if (svc_safe_putnetobj(resv, &rsip->out_handle)) + goto drop; + if (resv->iov_len + 3 * 4 > PAGE_SIZE) + goto drop; + svc_putu32(resv, htonl(rsip->major_status)); + svc_putu32(resv, htonl(rsip->minor_status)); + svc_putu32(resv, htonl(GSS_SEQ_WIN)); + if (svc_safe_putnetobj(resv, &rsip->out_token)) + goto drop; + rqstp->rq_client = NULL; + } + goto complete; + case RPC_GSS_PROC_DESTROY: + set_bit(CACHE_NEGATIVE, &rsci->h.flags); + if (resv->iov_len + 4 > PAGE_SIZE) + goto drop; + svc_putu32(resv, rpc_success); + goto complete; + case RPC_GSS_PROC_DATA: + *authp = rpcsec_gsserr_ctxproblem; + 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: + if (unwrap_integ_data(&rqstp->rq_arg, + gc->gc_seq, rsci->mechctx)) + goto auth_err; + /* placeholders for length and seq. number: */ + svcdata->body_start = resv->iov_base + resv->iov_len; + svc_putu32(resv, 0); + svc_putu32(resv, 0); + break; + case RPC_GSS_SVC_PRIVACY: + /* currently unsupported */ + default: + goto auth_err; + } + svcdata->rsci = rsci; + cache_get(&rsci->h); + ret = SVC_OK; + goto out; + } +auth_err: + /* Restore write pointer to 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) + rsc_put(&rsci->h, &rsc_cache); + return ret; +} + +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; + struct xdr_buf integ_buf; + struct xdr_netobj mic; + struct kvec *resv; + u32 *p; + int integ_offset, integ_len; + int stat = -EINVAL; + + if (gc->gc_proc != RPC_GSS_PROC_DATA) + goto out; + /* Release can be called twice, but we only wrap once. */ + if (gsd->body_start == NULL) + goto out; + /* normally not set till svc_send, but we need it here: */ + resbuf->len = resbuf->head[0].iov_len + + resbuf->page_len + resbuf->tail[0].iov_len; + switch (gc->gc_svc) { + case RPC_GSS_SVC_NONE: + break; + case RPC_GSS_SVC_INTEGRITY: + p = gsd->body_start; + gsd->body_start = NULL; + /* move accept_stat to right place: */ + memcpy(p, p + 2, 4); + /* don't wrap in failure case: */ + /* Note: counting on not getting here if call was not even + * accepted! */ + if (*p != rpc_success) { + resbuf->head[0].iov_len -= 2 * 4; + goto out; + } + p++; + 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->page_len == 0 + && resbuf->tail[0].iov_len + RPC_MAX_AUTH_SIZE + < PAGE_SIZE) { + BUG_ON(resbuf->tail[0].iov_len); + /* Use head for everything */ + resv = &resbuf->head[0]; + } else if (resbuf->tail[0].iov_base == NULL) { + /* copied from nfsd4_encode_read */ + svc_take_page(rqstp); + resbuf->tail[0].iov_base = page_address(rqstp + ->rq_respages[rqstp->rq_resused-1]); + rqstp->rq_restailpage = rqstp->rq_resused-1; + 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, 0, &integ_buf, &mic)) + goto out_err; + svc_putu32(resv, htonl(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); + break; + case RPC_GSS_SVC_PRIVACY: + default: + goto out_err; + } + +out: + stat = 0; +out_err: + if (rqstp->rq_client) + auth_domain_put(rqstp->rq_client); + rqstp->rq_client = 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) + rsc_put(&gsd->rsci->h, &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, +}; + +int +gss_svc_init(void) +{ + int rv = svc_auth_register(RPC_AUTH_GSS, &svcauthops_gss); + if (rv == 0) { + cache_register(&rsc_cache); + cache_register(&rsi_cache); + } + return rv; +} + +void +gss_svc_shutdown(void) +{ + cache_unregister(&rsc_cache); + cache_unregister(&rsi_cache); + svc_auth_unregister(RPC_AUTH_GSS); +} |
