rxrpc: Rename files matching ar-*.c to git rid of the "ar-" prefix

Rename files matching net/rxrpc/ar-*.c to get rid of the "ar-" prefix.
This will aid splitting those files by making easier to come up with new
names.

Note that the not all files are simply renamed from ar-X.c to X.c.  The
following exceptions are made:

 (*) ar-call.c -> call_object.c
     ar-ack.c -> call_event.c

     call_object.c is going to contain the core of the call object
     handling.  Call event handling is all going to be in call_event.c.

 (*) ar-accept.c -> call_accept.c

     Incoming call handling is going to be here.

 (*) ar-connection.c -> conn_object.c
     ar-connevent.c -> conn_event.c

     The former file is going to have the basic connection object handling,
     but there will likely be some differentiation between client
     connections and service connections in additional files later.  The
     latter file will have all the connection-level event handling.

 (*) ar-local.c -> local_object.c

     This will have the local endpoint object handling code.  The local
     endpoint event handling code will later be split out into
     local_event.c.

 (*) ar-peer.c -> peer_object.c

     This will have the peer endpoint object handling code.  Peer event
     handling code will be placed in peer_event.c (for the moment, there is
     none).

 (*) ar-error.c -> peer_event.c

     This will become the peer event handling code, though for the moment
     it's actually driven from the local endpoint's perspective.

Note that I haven't renamed ar-transport.c to transport_object.c as the
intention is to delete it when the rxrpc_transport struct is excised.

The only file that actually has its contents changed is net/rxrpc/Makefile.

net/rxrpc/ar-internal.h will need its section marker comments updating, but
I'll do that in a separate patch to make it easier for git to follow the
history across the rename.  I may also want to rename ar-internal.h at some
point - but that would mean updating all the #includes and I'd rather do
that in a separate step.

Signed-off-by: David Howells <dhowells@redhat.com.

1 files changed, 1237 insertions, 0 deletions

diff --git a/net/rxrpc/key.c b/net/rxrpc/key.c
new file mode 100644
index 000000000000..4ad56fafe3a7
--- /dev/null
+++ b/net/rxrpc/key.c
@@ -0,0 +1,1237 @@
+/* RxRPC key management
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * RxRPC keys should have a description of describing their purpose:
+ *      "afs@CAMBRIDGE.REDHAT.COM>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <crypto/skcipher.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/key-type.h>
+#include <linux/ctype.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <keys/rxrpc-type.h>
+#include <keys/user-type.h>
+#include "ar-internal.h"
+
+static int rxrpc_vet_description_s(const char *);
+static int rxrpc_preparse(struct key_preparsed_payload *);
+static int rxrpc_preparse_s(struct key_preparsed_payload *);
+static void rxrpc_free_preparse(struct key_preparsed_payload *);
+static void rxrpc_free_preparse_s(struct key_preparsed_payload *);
+static void rxrpc_destroy(struct key *);
+static void rxrpc_destroy_s(struct key *);
+static void rxrpc_describe(const struct key *, struct seq_file *);
+static long rxrpc_read(const struct key *, char __user *, size_t);
+
+/*
+ * rxrpc defined keys take an arbitrary string as the description and an
+ * arbitrary blob of data as the payload
+ */
+struct key_type key_type_rxrpc = {
+        .name           = "rxrpc",
+        .preparse       = rxrpc_preparse,
+        .free_preparse  = rxrpc_free_preparse,
+        .instantiate    = generic_key_instantiate,
+        .destroy        = rxrpc_destroy,
+        .describe       = rxrpc_describe,
+        .read           = rxrpc_read,
+};
+EXPORT_SYMBOL(key_type_rxrpc);
+
+/*
+ * rxrpc server defined keys take "<serviceId>:<securityIndex>" as the
+ * description and an 8-byte decryption key as the payload
+ */
+struct key_type key_type_rxrpc_s = {
+        .name           = "rxrpc_s",
+        .vet_description = rxrpc_vet_description_s,
+        .preparse       = rxrpc_preparse_s,
+        .free_preparse  = rxrpc_free_preparse_s,
+        .instantiate    = generic_key_instantiate,
+        .destroy        = rxrpc_destroy_s,
+        .describe       = rxrpc_describe,
+};
+
+/*
+ * Vet the description for an RxRPC server key
+ */
+static int rxrpc_vet_description_s(const char *desc)
+{
+        unsigned long num;
+        char *p;
+
+        num = simple_strtoul(desc, &p, 10);
+        if (*p != ':' || num > 65535)
+                return -EINVAL;
+        num = simple_strtoul(p + 1, &p, 10);
+        if (*p || num < 1 || num > 255)
+                return -EINVAL;
+        return 0;
+}
+
+/*
+ * parse an RxKAD type XDR format token
+ * - the caller guarantees we have at least 4 words
+ */
+static int rxrpc_preparse_xdr_rxkad(struct key_preparsed_payload *prep,
+                                    size_t datalen,
+                                    const __be32 *xdr, unsigned int toklen)
+{
+        struct rxrpc_key_token *token, **pptoken;
+        size_t plen;
+        u32 tktlen;
+
+        _enter(",{%x,%x,%x,%x},%u",
+               ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
+               toklen);
+
+        if (toklen <= 8 * 4)
+                return -EKEYREJECTED;
+        tktlen = ntohl(xdr[7]);
+        _debug("tktlen: %x", tktlen);
+        if (tktlen > AFSTOKEN_RK_TIX_MAX)
+                return -EKEYREJECTED;
+        if (toklen < 8 * 4 + tktlen)
+                return -EKEYREJECTED;
+
+        plen = sizeof(*token) + sizeof(*token->kad) + tktlen;
+        prep->quotalen = datalen + plen;
+
+        plen -= sizeof(*token);
+        token = kzalloc(sizeof(*token), GFP_KERNEL);
+        if (!token)
+                return -ENOMEM;
+
+        token->kad = kzalloc(plen, GFP_KERNEL);
+        if (!token->kad) {
+                kfree(token);
+                return -ENOMEM;
+        }
+
+        token->security_index   = RXRPC_SECURITY_RXKAD;
+        token->kad->ticket_len  = tktlen;
+        token->kad->vice_id     = ntohl(xdr[0]);
+        token->kad->kvno        = ntohl(xdr[1]);
+        token->kad->start       = ntohl(xdr[4]);
+        token->kad->expiry      = ntohl(xdr[5]);
+        token->kad->primary_flag = ntohl(xdr[6]);
+        memcpy(&token->kad->session_key, &xdr[2], 8);
+        memcpy(&token->kad->ticket, &xdr[8], tktlen);
+
+        _debug("SCIX: %u", token->security_index);
+        _debug("TLEN: %u", token->kad->ticket_len);
+        _debug("EXPY: %x", token->kad->expiry);
+        _debug("KVNO: %u", token->kad->kvno);
+        _debug("PRIM: %u", token->kad->primary_flag);
+        _debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
+               token->kad->session_key[0], token->kad->session_key[1],
+               token->kad->session_key[2], token->kad->session_key[3],
+               token->kad->session_key[4], token->kad->session_key[5],
+               token->kad->session_key[6], token->kad->session_key[7]);
+        if (token->kad->ticket_len >= 8)
+                _debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
+                       token->kad->ticket[0], token->kad->ticket[1],
+                       token->kad->ticket[2], token->kad->ticket[3],
+                       token->kad->ticket[4], token->kad->ticket[5],
+                       token->kad->ticket[6], token->kad->ticket[7]);
+
+        /* count the number of tokens attached */
+        prep->payload.data[1] = (void *)((unsigned long)prep->payload.data[1] + 1);
+
+        /* attach the data */
+        for (pptoken = (struct rxrpc_key_token **)&prep->payload.data[0];
+             *pptoken;
+             pptoken = &(*pptoken)->next)
+                continue;
+        *pptoken = token;
+        if (token->kad->expiry < prep->expiry)
+                prep->expiry = token->kad->expiry;
+
+        _leave(" = 0");
+        return 0;
+}
+
+static void rxrpc_free_krb5_principal(struct krb5_principal *princ)
+{
+        int loop;
+
+        if (princ->name_parts) {
+                for (loop = princ->n_name_parts - 1; loop >= 0; loop--)
+                        kfree(princ->name_parts[loop]);
+                kfree(princ->name_parts);
+        }
+        kfree(princ->realm);
+}
+
+static void rxrpc_free_krb5_tagged(struct krb5_tagged_data *td)
+{
+        kfree(td->data);
+}
+
+/*
+ * free up an RxK5 token
+ */
+static void rxrpc_rxk5_free(struct rxk5_key *rxk5)
+{
+        int loop;
+
+        rxrpc_free_krb5_principal(&rxk5->client);
+        rxrpc_free_krb5_principal(&rxk5->server);
+        rxrpc_free_krb5_tagged(&rxk5->session);
+
+        if (rxk5->addresses) {
+                for (loop = rxk5->n_addresses - 1; loop >= 0; loop--)
+                        rxrpc_free_krb5_tagged(&rxk5->addresses[loop]);
+                kfree(rxk5->addresses);
+        }
+        if (rxk5->authdata) {
+                for (loop = rxk5->n_authdata - 1; loop >= 0; loop--)
+                        rxrpc_free_krb5_tagged(&rxk5->authdata[loop]);
+                kfree(rxk5->authdata);
+        }
+
+        kfree(rxk5->ticket);
+        kfree(rxk5->ticket2);
+        kfree(rxk5);
+}
+
+/*
+ * extract a krb5 principal
+ */
+static int rxrpc_krb5_decode_principal(struct krb5_principal *princ,
+                                       const __be32 **_xdr,
+                                       unsigned int *_toklen)
+{
+        const __be32 *xdr = *_xdr;
+        unsigned int toklen = *_toklen, n_parts, loop, tmp;
+
+        /* there must be at least one name, and at least #names+1 length
+         * words */
+        if (toklen <= 12)
+                return -EINVAL;
+
+        _enter(",{%x,%x,%x},%u",
+               ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), toklen);
+
+        n_parts = ntohl(*xdr++);
+        toklen -= 4;
+        if (n_parts <= 0 || n_parts > AFSTOKEN_K5_COMPONENTS_MAX)
+                return -EINVAL;
+        princ->n_name_parts = n_parts;
+
+        if (toklen <= (n_parts + 1) * 4)
+                return -EINVAL;
+
+        princ->name_parts = kcalloc(n_parts, sizeof(char *), GFP_KERNEL);
+        if (!princ->name_parts)
+                return -ENOMEM;
+
+        for (loop = 0; loop < n_parts; loop++) {
+                if (toklen < 4)
+                        return -EINVAL;
+                tmp = ntohl(*xdr++);
+                toklen -= 4;
+                if (tmp <= 0 || tmp > AFSTOKEN_STRING_MAX)
+                        return -EINVAL;
+                if (tmp > toklen)
+                        return -EINVAL;
+                princ->name_parts[loop] = kmalloc(tmp + 1, GFP_KERNEL);
+                if (!princ->name_parts[loop])
+                        return -ENOMEM;
+                memcpy(princ->name_parts[loop], xdr, tmp);
+                princ->name_parts[loop][tmp] = 0;
+                tmp = (tmp + 3) & ~3;
+                toklen -= tmp;
+                xdr += tmp >> 2;
+        }
+
+        if (toklen < 4)
+                return -EINVAL;
+        tmp = ntohl(*xdr++);
+        toklen -= 4;
+        if (tmp <= 0 || tmp > AFSTOKEN_K5_REALM_MAX)
+                return -EINVAL;
+        if (tmp > toklen)
+                return -EINVAL;
+        princ->realm = kmalloc(tmp + 1, GFP_KERNEL);
+        if (!princ->realm)
+                return -ENOMEM;
+        memcpy(princ->realm, xdr, tmp);
+        princ->realm[tmp] = 0;
+        tmp = (tmp + 3) & ~3;
+        toklen -= tmp;
+        xdr += tmp >> 2;
+
+        _debug("%s/...@%s", princ->name_parts[0], princ->realm);
+
+        *_xdr = xdr;
+        *_toklen = toklen;
+        _leave(" = 0 [toklen=%u]", toklen);
+        return 0;
+}
+
+/*
+ * extract a piece of krb5 tagged data
+ */
+static int rxrpc_krb5_decode_tagged_data(struct krb5_tagged_data *td,
+                                         size_t max_data_size,
+                                         const __be32 **_xdr,
+                                         unsigned int *_toklen)
+{
+        const __be32 *xdr = *_xdr;
+        unsigned int toklen = *_toklen, len;
+
+        /* there must be at least one tag and one length word */
+        if (toklen <= 8)
+                return -EINVAL;
+
+        _enter(",%zu,{%x,%x},%u",
+               max_data_size, ntohl(xdr[0]), ntohl(xdr[1]), toklen);
+
+        td->tag = ntohl(*xdr++);
+        len = ntohl(*xdr++);
+        toklen -= 8;
+        if (len > max_data_size)
+                return -EINVAL;
+        td->data_len = len;
+
+        if (len > 0) {
+                td->data = kmemdup(xdr, len, GFP_KERNEL);
+                if (!td->data)
+                        return -ENOMEM;
+                len = (len + 3) & ~3;
+                toklen -= len;
+                xdr += len >> 2;
+        }
+
+        _debug("tag %x len %x", td->tag, td->data_len);
+
+        *_xdr = xdr;
+        *_toklen = toklen;
+        _leave(" = 0 [toklen=%u]", toklen);
+        return 0;
+}
+
+/*
+ * extract an array of tagged data
+ */
+static int rxrpc_krb5_decode_tagged_array(struct krb5_tagged_data **_td,
+                                          u8 *_n_elem,
+                                          u8 max_n_elem,
+                                          size_t max_elem_size,
+                                          const __be32 **_xdr,
+                                          unsigned int *_toklen)
+{
+        struct krb5_tagged_data *td;
+        const __be32 *xdr = *_xdr;
+        unsigned int toklen = *_toklen, n_elem, loop;
+        int ret;
+
+        /* there must be at least one count */
+        if (toklen < 4)
+                return -EINVAL;
+
+        _enter(",,%u,%zu,{%x},%u",
+               max_n_elem, max_elem_size, ntohl(xdr[0]), toklen);
+
+        n_elem = ntohl(*xdr++);
+        toklen -= 4;
+        if (n_elem > max_n_elem)
+                return -EINVAL;
+        *_n_elem = n_elem;
+        if (n_elem > 0) {
+                if (toklen <= (n_elem + 1) * 4)
+                        return -EINVAL;
+
+                _debug("n_elem %d", n_elem);
+
+                td = kcalloc(n_elem, sizeof(struct krb5_tagged_data),
+                             GFP_KERNEL);
+                if (!td)
+                        return -ENOMEM;
+                *_td = td;
+
+                for (loop = 0; loop < n_elem; loop++) {
+                        ret = rxrpc_krb5_decode_tagged_data(&td[loop],
+                                                            max_elem_size,
+                                                            &xdr, &toklen);
+                        if (ret < 0)
+                                return ret;
+                }
+        }
+
+        *_xdr = xdr;
+        *_toklen = toklen;
+        _leave(" = 0 [toklen=%u]", toklen);
+        return 0;
+}
+
+/*
+ * extract a krb5 ticket
+ */
+static int rxrpc_krb5_decode_ticket(u8 **_ticket, u16 *_tktlen,
+                                    const __be32 **_xdr, unsigned int *_toklen)
+{
+        const __be32 *xdr = *_xdr;
+        unsigned int toklen = *_toklen, len;
+
+        /* there must be at least one length word */
+        if (toklen <= 4)
+                return -EINVAL;
+
+        _enter(",{%x},%u", ntohl(xdr[0]), toklen);
+
+        len = ntohl(*xdr++);
+        toklen -= 4;
+        if (len > AFSTOKEN_K5_TIX_MAX)
+                return -EINVAL;
+        *_tktlen = len;
+
+        _debug("ticket len %u", len);
+
+        if (len > 0) {
+                *_ticket = kmemdup(xdr, len, GFP_KERNEL);
+                if (!*_ticket)
+                        return -ENOMEM;
+                len = (len + 3) & ~3;
+                toklen -= len;
+                xdr += len >> 2;
+        }
+
+        *_xdr = xdr;
+        *_toklen = toklen;
+        _leave(" = 0 [toklen=%u]", toklen);
+        return 0;
+}
+
+/*
+ * parse an RxK5 type XDR format token
+ * - the caller guarantees we have at least 4 words
+ */
+static int rxrpc_preparse_xdr_rxk5(struct key_preparsed_payload *prep,
+                                   size_t datalen,
+                                   const __be32 *xdr, unsigned int toklen)
+{
+        struct rxrpc_key_token *token, **pptoken;
+        struct rxk5_key *rxk5;
+        const __be32 *end_xdr = xdr + (toklen >> 2);
+        int ret;
+
+        _enter(",{%x,%x,%x,%x},%u",
+               ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
+               toklen);
+
+        /* reserve some payload space for this subkey - the length of the token
+         * is a reasonable approximation */
+        prep->quotalen = datalen + toklen;
+
+        token = kzalloc(sizeof(*token), GFP_KERNEL);
+        if (!token)
+                return -ENOMEM;
+
+        rxk5 = kzalloc(sizeof(*rxk5), GFP_KERNEL);
+        if (!rxk5) {
+                kfree(token);
+                return -ENOMEM;
+        }
+
+        token->security_index = RXRPC_SECURITY_RXK5;
+        token->k5 = rxk5;
+
+        /* extract the principals */
+        ret = rxrpc_krb5_decode_principal(&rxk5->client, &xdr, &toklen);
+        if (ret < 0)
+                goto error;
+        ret = rxrpc_krb5_decode_principal(&rxk5->server, &xdr, &toklen);
+        if (ret < 0)
+                goto error;
+
+        /* extract the session key and the encoding type (the tag field ->
+         * ENCTYPE_xxx) */
+        ret = rxrpc_krb5_decode_tagged_data(&rxk5->session, AFSTOKEN_DATA_MAX,
+                                            &xdr, &toklen);
+        if (ret < 0)
+                goto error;
+
+        if (toklen < 4 * 8 + 2 * 4)
+                goto inval;
+        rxk5->authtime  = be64_to_cpup((const __be64 *) xdr);
+        xdr += 2;
+        rxk5->starttime = be64_to_cpup((const __be64 *) xdr);
+        xdr += 2;
+        rxk5->endtime   = be64_to_cpup((const __be64 *) xdr);
+        xdr += 2;
+        rxk5->renew_till = be64_to_cpup((const __be64 *) xdr);
+        xdr += 2;
+        rxk5->is_skey = ntohl(*xdr++);
+        rxk5->flags = ntohl(*xdr++);
+        toklen -= 4 * 8 + 2 * 4;
+
+        _debug("times: a=%llx s=%llx e=%llx rt=%llx",
+               rxk5->authtime, rxk5->starttime, rxk5->endtime,
+               rxk5->renew_till);
+        _debug("is_skey=%x flags=%x", rxk5->is_skey, rxk5->flags);
+
+        /* extract the permitted client addresses */
+        ret = rxrpc_krb5_decode_tagged_array(&rxk5->addresses,
+                                             &rxk5->n_addresses,
+                                             AFSTOKEN_K5_ADDRESSES_MAX,
+                                             AFSTOKEN_DATA_MAX,
+                                             &xdr, &toklen);
+        if (ret < 0)
+                goto error;
+
+        ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
+
+        /* extract the tickets */
+        ret = rxrpc_krb5_decode_ticket(&rxk5->ticket, &rxk5->ticket_len,
+                                       &xdr, &toklen);
+        if (ret < 0)
+                goto error;
+        ret = rxrpc_krb5_decode_ticket(&rxk5->ticket2, &rxk5->ticket2_len,
+                                       &xdr, &toklen);
+        if (ret < 0)
+                goto error;
+
+        ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
+
+        /* extract the typed auth data */
+        ret = rxrpc_krb5_decode_tagged_array(&rxk5->authdata,
+                                             &rxk5->n_authdata,
+                                             AFSTOKEN_K5_AUTHDATA_MAX,
+                                             AFSTOKEN_BDATALN_MAX,
+                                             &xdr, &toklen);
+        if (ret < 0)
+                goto error;
+
+        ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
+
+        if (toklen != 0)
+                goto inval;
+
+        /* attach the payload */
+        for (pptoken = (struct rxrpc_key_token **)&prep->payload.data[0];
+             *pptoken;
+             pptoken = &(*pptoken)->next)
+                continue;
+        *pptoken = token;
+        if (token->kad->expiry < prep->expiry)
+                prep->expiry = token->kad->expiry;
+
+        _leave(" = 0");
+        return 0;
+
+inval:
+        ret = -EINVAL;
+error:
+        rxrpc_rxk5_free(rxk5);
+        kfree(token);
+        _leave(" = %d", ret);
+        return ret;
+}
+
+/*
+ * attempt to parse the data as the XDR format
+ * - the caller guarantees we have more than 7 words
+ */
+static int rxrpc_preparse_xdr(struct key_preparsed_payload *prep)
+{
+        const __be32 *xdr = prep->data, *token;
+        const char *cp;
+        unsigned int len, tmp, loop, ntoken, toklen, sec_ix;
+        size_t datalen = prep->datalen;
+        int ret;
+
+        _enter(",{%x,%x,%x,%x},%zu",
+               ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
+               prep->datalen);
+
+        if (datalen > AFSTOKEN_LENGTH_MAX)
+                goto not_xdr;
+
+        /* XDR is an array of __be32's */
+        if (datalen & 3)
+                goto not_xdr;
+
+        /* the flags should be 0 (the setpag bit must be handled by
+         * userspace) */
+        if (ntohl(*xdr++) != 0)
+                goto not_xdr;
+        datalen -= 4;
+
+        /* check the cell name */
+        len = ntohl(*xdr++);
+        if (len < 1 || len > AFSTOKEN_CELL_MAX)
+                goto not_xdr;
+        datalen -= 4;
+        tmp = (len + 3) & ~3;
+        if (tmp > datalen)
+                goto not_xdr;
+
+        cp = (const char *) xdr;
+        for (loop = 0; loop < len; loop++)
+                if (!isprint(cp[loop]))
+                        goto not_xdr;
+        if (len < tmp)
+                for (; loop < tmp; loop++)
+                        if (cp[loop])
+                                goto not_xdr;
+        _debug("cellname: [%u/%u] '%*.*s'",
+               len, tmp, len, len, (const char *) xdr);
+        datalen -= tmp;
+        xdr += tmp >> 2;
+
+        /* get the token count */
+        if (datalen < 12)
+                goto not_xdr;
+        ntoken = ntohl(*xdr++);
+        datalen -= 4;
+        _debug("ntoken: %x", ntoken);
+        if (ntoken < 1 || ntoken > AFSTOKEN_MAX)
+                goto not_xdr;
+
+        /* check each token wrapper */
+        token = xdr;
+        loop = ntoken;
+        do {
+                if (datalen < 8)
+                        goto not_xdr;
+                toklen = ntohl(*xdr++);
+                sec_ix = ntohl(*xdr);
+                datalen -= 4;
+                _debug("token: [%x/%zx] %x", toklen, datalen, sec_ix);
+                if (toklen < 20 || toklen > datalen)
+                        goto not_xdr;
+                datalen -= (toklen + 3) & ~3;
+                xdr += (toklen + 3) >> 2;
+
+        } while (--loop > 0);
+
+        _debug("remainder: %zu", datalen);
+        if (datalen != 0)
+                goto not_xdr;
+
+        /* okay: we're going to assume it's valid XDR format
+         * - we ignore the cellname, relying on the key to be correctly named
+         */
+        do {
+                xdr = token;
+                toklen = ntohl(*xdr++);
+                token = xdr + ((toklen + 3) >> 2);
+                sec_ix = ntohl(*xdr++);
+                toklen -= 4;
+
+                _debug("TOKEN type=%u [%p-%p]", sec_ix, xdr, token);
+
+                switch (sec_ix) {
+                case RXRPC_SECURITY_RXKAD:
+                        ret = rxrpc_preparse_xdr_rxkad(prep, datalen, xdr, toklen);
+                        if (ret != 0)
+                                goto error;
+                        break;
+
+                case RXRPC_SECURITY_RXK5:
+                        ret = rxrpc_preparse_xdr_rxk5(prep, datalen, xdr, toklen);
+                        if (ret != 0)
+                                goto error;
+                        break;
+
+                default:
+                        ret = -EPROTONOSUPPORT;
+                        goto error;
+                }
+
+        } while (--ntoken > 0);
+
+        _leave(" = 0");
+        return 0;
+
+not_xdr:
+        _leave(" = -EPROTO");
+        return -EPROTO;
+error:
+        _leave(" = %d", ret);
+        return ret;
+}
+
+/*
+ * Preparse an rxrpc defined key.
+ *
+ * Data should be of the form:
+ *      OFFSET  LEN     CONTENT
+ *      0       4       key interface version number
+ *      4       2       security index (type)
+ *      6       2       ticket length
+ *      8       4       key expiry time (time_t)
+ *      12      4       kvno
+ *      16      8       session key
+ *      24      [len]   ticket
+ *
+ * if no data is provided, then a no-security key is made
+ */
+static int rxrpc_preparse(struct key_preparsed_payload *prep)
+{
+        const struct rxrpc_key_data_v1 *v1;
+        struct rxrpc_key_token *token, **pp;
+        size_t plen;
+        u32 kver;
+        int ret;
+
+        _enter("%zu", prep->datalen);
+
+        /* handle a no-security key */
+        if (!prep->data && prep->datalen == 0)
+                return 0;
+
+        /* determine if the XDR payload format is being used */
+        if (prep->datalen > 7 * 4) {
+                ret = rxrpc_preparse_xdr(prep);
+                if (ret != -EPROTO)
+                        return ret;
+        }
+
+        /* get the key interface version number */
+        ret = -EINVAL;
+        if (prep->datalen <= 4 || !prep->data)
+                goto error;
+        memcpy(&kver, prep->data, sizeof(kver));
+        prep->data += sizeof(kver);
+        prep->datalen -= sizeof(kver);
+
+        _debug("KEY I/F VERSION: %u", kver);
+
+        ret = -EKEYREJECTED;
+        if (kver != 1)
+                goto error;
+
+        /* deal with a version 1 key */
+        ret = -EINVAL;
+        if (prep->datalen < sizeof(*v1))
+                goto error;
+
+        v1 = prep->data;
+        if (prep->datalen != sizeof(*v1) + v1->ticket_length)
+                goto error;
+
+        _debug("SCIX: %u", v1->security_index);
+        _debug("TLEN: %u", v1->ticket_length);
+        _debug("EXPY: %x", v1->expiry);
+        _debug("KVNO: %u", v1->kvno);
+        _debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
+               v1->session_key[0], v1->session_key[1],
+               v1->session_key[2], v1->session_key[3],
+               v1->session_key[4], v1->session_key[5],
+               v1->session_key[6], v1->session_key[7]);
+        if (v1->ticket_length >= 8)
+                _debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
+                       v1->ticket[0], v1->ticket[1],
+                       v1->ticket[2], v1->ticket[3],
+                       v1->ticket[4], v1->ticket[5],
+                       v1->ticket[6], v1->ticket[7]);
+
+        ret = -EPROTONOSUPPORT;
+        if (v1->security_index != RXRPC_SECURITY_RXKAD)
+                goto error;
+
+        plen = sizeof(*token->kad) + v1->ticket_length;
+        prep->quotalen = plen + sizeof(*token);
+
+        ret = -ENOMEM;
+        token = kzalloc(sizeof(*token), GFP_KERNEL);
+        if (!token)
+                goto error;
+        token->kad = kzalloc(plen, GFP_KERNEL);
+        if (!token->kad)
+                goto error_free;
+
+        token->security_index           = RXRPC_SECURITY_RXKAD;
+        token->kad->ticket_len          = v1->ticket_length;
+        token->kad->expiry              = v1->expiry;
+        token->kad->kvno                = v1->kvno;
+        memcpy(&token->kad->session_key, &v1->session_key, 8);
+        memcpy(&token->kad->ticket, v1->ticket, v1->ticket_length);
+
+        /* count the number of tokens attached */
+        prep->payload.data[1] = (void *)((unsigned long)prep->payload.data[1] + 1);
+
+        /* attach the data */
+        pp = (struct rxrpc_key_token **)&prep->payload.data[0];
+        while (*pp)
+                pp = &(*pp)->next;
+        *pp = token;
+        if (token->kad->expiry < prep->expiry)
+                prep->expiry = token->kad->expiry;
+        token = NULL;
+        ret = 0;
+
+error_free:
+        kfree(token);
+error:
+        return ret;
+}
+
+/*
+ * Free token list.
+ */
+static void rxrpc_free_token_list(struct rxrpc_key_token *token)
+{
+        struct rxrpc_key_token *next;
+
+        for (; token; token = next) {
+                next = token->next;
+                switch (token->security_index) {
+                case RXRPC_SECURITY_RXKAD:
+                        kfree(token->kad);
+                        break;
+                case RXRPC_SECURITY_RXK5:
+                        if (token->k5)
+                                rxrpc_rxk5_free(token->k5);
+                        break;
+                default:
+                        pr_err("Unknown token type %x on rxrpc key\n",
+                               token->security_index);
+                        BUG();
+                }
+
+                kfree(token);
+        }
+}
+
+/*
+ * Clean up preparse data.
+ */
+static void rxrpc_free_preparse(struct key_preparsed_payload *prep)
+{
+        rxrpc_free_token_list(prep->payload.data[0]);
+}
+
+/*
+ * Preparse a server secret key.
+ *
+ * The data should be the 8-byte secret key.
+ */
+static int rxrpc_preparse_s(struct key_preparsed_payload *prep)
+{
+        struct crypto_skcipher *ci;
+
+        _enter("%zu", prep->datalen);
+
+        if (prep->datalen != 8)
+                return -EINVAL;
+
+        memcpy(&prep->payload.data[2], prep->data, 8);
+
+        ci = crypto_alloc_skcipher("pcbc(des)", 0, CRYPTO_ALG_ASYNC);
+        if (IS_ERR(ci)) {
+                _leave(" = %ld", PTR_ERR(ci));
+                return PTR_ERR(ci);
+        }
+
+        if (crypto_skcipher_setkey(ci, prep->data, 8) < 0)
+                BUG();
+
+        prep->payload.data[0] = ci;
+        _leave(" = 0");
+        return 0;
+}
+
+/*
+ * Clean up preparse data.
+ */
+static void rxrpc_free_preparse_s(struct key_preparsed_payload *prep)
+{
+        if (prep->payload.data[0])
+                crypto_free_skcipher(prep->payload.data[0]);
+}
+
+/*
+ * dispose of the data dangling from the corpse of a rxrpc key
+ */
+static void rxrpc_destroy(struct key *key)
+{
+        rxrpc_free_token_list(key->payload.data[0]);
+}
+
+/*
+ * dispose of the data dangling from the corpse of a rxrpc key
+ */
+static void rxrpc_destroy_s(struct key *key)
+{
+        if (key->payload.data[0]) {
+                crypto_free_skcipher(key->payload.data[0]);
+                key->payload.data[0] = NULL;
+        }
+}
+
+/*
+ * describe the rxrpc key
+ */
+static void rxrpc_describe(const struct key *key, struct seq_file *m)
+{
+        seq_puts(m, key->description);
+}
+
+/*
+ * grab the security key for a socket
+ */
+int rxrpc_request_key(struct rxrpc_sock *rx, char __user *optval, int optlen)
+{
+        struct key *key;
+        char *description;
+
+        _enter("");
+
+        if (optlen <= 0 || optlen > PAGE_SIZE - 1)
+                return -EINVAL;
+
+        description = memdup_user_nul(optval, optlen);
+        if (IS_ERR(description))
+                return PTR_ERR(description);
+
+        key = request_key(&key_type_rxrpc, description, NULL);
+        if (IS_ERR(key)) {
+                kfree(description);
+                _leave(" = %ld", PTR_ERR(key));
+                return PTR_ERR(key);
+        }
+
+        rx->key = key;
+        kfree(description);
+        _leave(" = 0 [key %x]", key->serial);
+        return 0;
+}
+
+/*
+ * grab the security keyring for a server socket
+ */
+int rxrpc_server_keyring(struct rxrpc_sock *rx, char __user *optval,
+                         int optlen)
+{
+        struct key *key;
+        char *description;
+
+        _enter("");
+
+        if (optlen <= 0 || optlen > PAGE_SIZE - 1)
+                return -EINVAL;
+
+        description = memdup_user_nul(optval, optlen);
+        if (IS_ERR(description))
+                return PTR_ERR(description);
+
+        key = request_key(&key_type_keyring, description, NULL);
+        if (IS_ERR(key)) {
+                kfree(description);
+                _leave(" = %ld", PTR_ERR(key));
+                return PTR_ERR(key);
+        }
+
+        rx->securities = key;
+        kfree(description);
+        _leave(" = 0 [key %x]", key->serial);
+        return 0;
+}
+
+/*
+ * generate a server data key
+ */
+int rxrpc_get_server_data_key(struct rxrpc_connection *conn,
+                              const void *session_key,
+                              time_t expiry,
+                              u32 kvno)
+{
+        const struct cred *cred = current_cred();
+        struct key *key;
+        int ret;
+
+        struct {
+                u32 kver;
+                struct rxrpc_key_data_v1 v1;
+        } data;
+
+        _enter("");
+
+        key = key_alloc(&key_type_rxrpc, "x",
+                        GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred, 0,
+                        KEY_ALLOC_NOT_IN_QUOTA, NULL);
+        if (IS_ERR(key)) {
+                _leave(" = -ENOMEM [alloc %ld]", PTR_ERR(key));
+                return -ENOMEM;
+        }
+
+        _debug("key %d", key_serial(key));
+
+        data.kver = 1;
+        data.v1.security_index = RXRPC_SECURITY_RXKAD;
+        data.v1.ticket_length = 0;
+        data.v1.expiry = expiry;
+        data.v1.kvno = 0;
+
+        memcpy(&data.v1.session_key, session_key, sizeof(data.v1.session_key));
+
+        ret = key_instantiate_and_link(key, &data, sizeof(data), NULL, NULL);
+        if (ret < 0)
+                goto error;
+
+        conn->key = key;
+        _leave(" = 0 [%d]", key_serial(key));
+        return 0;
+
+error:
+        key_revoke(key);
+        key_put(key);
+        _leave(" = -ENOMEM [ins %d]", ret);
+        return -ENOMEM;
+}
+EXPORT_SYMBOL(rxrpc_get_server_data_key);
+
+/**
+ * rxrpc_get_null_key - Generate a null RxRPC key
+ * @keyname: The name to give the key.
+ *
+ * Generate a null RxRPC key that can be used to indicate anonymous security is
+ * required for a particular domain.
+ */
+struct key *rxrpc_get_null_key(const char *keyname)
+{
+        const struct cred *cred = current_cred();
+        struct key *key;
+        int ret;
+
+        key = key_alloc(&key_type_rxrpc, keyname,
+                        GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
+                        KEY_POS_SEARCH, KEY_ALLOC_NOT_IN_QUOTA, NULL);
+        if (IS_ERR(key))
+                return key;
+
+        ret = key_instantiate_and_link(key, NULL, 0, NULL, NULL);
+        if (ret < 0) {
+                key_revoke(key);
+                key_put(key);
+                return ERR_PTR(ret);
+        }
+
+        return key;
+}
+EXPORT_SYMBOL(rxrpc_get_null_key);
+
+/*
+ * read the contents of an rxrpc key
+ * - this returns the result in XDR form
+ */
+static long rxrpc_read(const struct key *key,
+                       char __user *buffer, size_t buflen)
+{
+        const struct rxrpc_key_token *token;
+        const struct krb5_principal *princ;
+        size_t size;
+        __be32 __user *xdr, *oldxdr;
+        u32 cnlen, toksize, ntoks, tok, zero;
+        u16 toksizes[AFSTOKEN_MAX];
+        int loop;
+
+        _enter("");
+
+        /* we don't know what form we should return non-AFS keys in */
+        if (memcmp(key->description, "afs@", 4) != 0)
+                return -EOPNOTSUPP;
+        cnlen = strlen(key->description + 4);
+
+#define RND(X) (((X) + 3) & ~3)
+
+        /* AFS keys we return in XDR form, so we need to work out the size of
+         * the XDR */
+        size = 2 * 4;   /* flags, cellname len */
+        size += RND(cnlen);     /* cellname */
+        size += 1 * 4;  /* token count */
+
+        ntoks = 0;
+        for (token = key->payload.data[0]; token; token = token->next) {
+                toksize = 4;    /* sec index */
+
+                switch (token->security_index) {
+                case RXRPC_SECURITY_RXKAD:
+                        toksize += 8 * 4;       /* viceid, kvno, key*2, begin,
+                                                 * end, primary, tktlen */
+                        toksize += RND(token->kad->ticket_len);
+                        break;
+
+                case RXRPC_SECURITY_RXK5:
+                        princ = &token->k5->client;
+                        toksize += 4 + princ->n_name_parts * 4;
+                        for (loop = 0; loop < princ->n_name_parts; loop++)
+                                toksize += RND(strlen(princ->name_parts[loop]));
+                        toksize += 4 + RND(strlen(princ->realm));
+
+                        princ = &token->k5->server;
+                        toksize += 4 + princ->n_name_parts * 4;
+                        for (loop = 0; loop < princ->n_name_parts; loop++)
+                                toksize += RND(strlen(princ->name_parts[loop]));
+                        toksize += 4 + RND(strlen(princ->realm));
+
+                        toksize += 8 + RND(token->k5->session.data_len);
+
+                        toksize += 4 * 8 + 2 * 4;
+
+                        toksize += 4 + token->k5->n_addresses * 8;
+                        for (loop = 0; loop < token->k5->n_addresses; loop++)
+                                toksize += RND(token->k5->addresses[loop].data_len);
+
+                        toksize += 4 + RND(token->k5->ticket_len);
+                        toksize += 4 + RND(token->k5->ticket2_len);
+
+                        toksize += 4 + token->k5->n_authdata * 8;
+                        for (loop = 0; loop < token->k5->n_authdata; loop++)
+                                toksize += RND(token->k5->authdata[loop].data_len);
+                        break;
+
+                default: /* we have a ticket we can't encode */
+                        BUG();
+                        continue;
+                }
+
+                _debug("token[%u]: toksize=%u", ntoks, toksize);
+                ASSERTCMP(toksize, <=, AFSTOKEN_LENGTH_MAX);
+
+                toksizes[ntoks++] = toksize;
+                size += toksize + 4; /* each token has a length word */
+        }
+
+#undef RND
+
+        if (!buffer || buflen < size)
+                return size;
+
+        xdr = (__be32 __user *) buffer;
+        zero = 0;
+#define ENCODE(x)                               \
+        do {                                    \
+                __be32 y = htonl(x);            \
+                if (put_user(y, xdr++) < 0)     \
+                        goto fault;             \
+        } while(0)
+#define ENCODE_DATA(l, s)                                               \
+        do {                                                            \
+                u32 _l = (l);                                           \
+                ENCODE(l);                                              \
+                if (copy_to_user(xdr, (s), _l) != 0)                    \
+                        goto fault;                                     \
+                if (_l & 3 &&                                           \
+                    copy_to_user((u8 __user *)xdr + _l, &zero, 4 - (_l & 3)) != 0) \
+                        goto fault;                                     \
+                xdr += (_l + 3) >> 2;                                   \
+        } while(0)
+#define ENCODE64(x)                                     \
+        do {                                            \
+                __be64 y = cpu_to_be64(x);              \
+                if (copy_to_user(xdr, &y, 8) != 0)      \
+                        goto fault;                     \
+                xdr += 8 >> 2;                          \
+        } while(0)
+#define ENCODE_STR(s)                           \
+        do {                                    \
+                const char *_s = (s);           \
+                ENCODE_DATA(strlen(_s), _s);    \
+        } while(0)
+
+        ENCODE(0);                                      /* flags */
+        ENCODE_DATA(cnlen, key->description + 4);       /* cellname */
+        ENCODE(ntoks);
+
+        tok = 0;
+        for (token = key->payload.data[0]; token; token = token->next) {
+                toksize = toksizes[tok++];
+                ENCODE(toksize);
+                oldxdr = xdr;
+                ENCODE(token->security_index);
+
+                switch (token->security_index) {
+                case RXRPC_SECURITY_RXKAD:
+                        ENCODE(token->kad->vice_id);
+                        ENCODE(token->kad->kvno);
+                        ENCODE_DATA(8, token->kad->session_key);
+                        ENCODE(token->kad->start);
+                        ENCODE(token->kad->expiry);
+                        ENCODE(token->kad->primary_flag);
+                        ENCODE_DATA(token->kad->ticket_len, token->kad->ticket);
+                        break;
+
+                case RXRPC_SECURITY_RXK5:
+                        princ = &token->k5->client;
+                        ENCODE(princ->n_name_parts);
+                        for (loop = 0; loop < princ->n_name_parts; loop++)
+                                ENCODE_STR(princ->name_parts[loop]);
+                        ENCODE_STR(princ->realm);
+
+                        princ = &token->k5->server;
+                        ENCODE(princ->n_name_parts);
+                        for (loop = 0; loop < princ->n_name_parts; loop++)
+                                ENCODE_STR(princ->name_parts[loop]);
+                        ENCODE_STR(princ->realm);
+
+                        ENCODE(token->k5->session.tag);
+                        ENCODE_DATA(token->k5->session.data_len,
+                                    token->k5->session.data);
+
+                        ENCODE64(token->k5->authtime);
+                        ENCODE64(token->k5->starttime);
+                        ENCODE64(token->k5->endtime);
+                        ENCODE64(token->k5->renew_till);
+                        ENCODE(token->k5->is_skey);
+                        ENCODE(token->k5->flags);
+
+                        ENCODE(token->k5->n_addresses);
+                        for (loop = 0; loop < token->k5->n_addresses; loop++) {
+                                ENCODE(token->k5->addresses[loop].tag);
+                                ENCODE_DATA(token->k5->addresses[loop].data_len,
+                                            token->k5->addresses[loop].data);
+                        }
+
+                        ENCODE_DATA(token->k5->ticket_len, token->k5->ticket);
+                        ENCODE_DATA(token->k5->ticket2_len, token->k5->ticket2);
+
+                        ENCODE(token->k5->n_authdata);
+                        for (loop = 0; loop < token->k5->n_authdata; loop++) {
+                                ENCODE(token->k5->authdata[loop].tag);
+                                ENCODE_DATA(token->k5->authdata[loop].data_len,
+                                            token->k5->authdata[loop].data);
+                        }
+                        break;
+
+                default:
+                        BUG();
+                        break;
+                }
+
+                ASSERTCMP((unsigned long)xdr - (unsigned long)oldxdr, ==,
+                          toksize);
+        }
+
+#undef ENCODE_STR
+#undef ENCODE_DATA
+#undef ENCODE64
+#undef ENCODE
+
+        ASSERTCMP(tok, ==, ntoks);
+        ASSERTCMP((char __user *) xdr - buffer, ==, size);
+        _leave(" = %zu", size);
+        return size;
+
+fault:
+        _leave(" = -EFAULT");
+        return -EFAULT;
+}