[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both

Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve
answers to AFS clients.  KerberosIV security is fully supported.  The patches
and some example test programs can be found in:

	http://people.redhat.com/~dhowells/rxrpc/

This will eventually replace the old implementation of kernel-only RxRPC
currently resident in net/rxrpc/.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 387 insertions, 0 deletions

diff --git a/net/rxrpc/ar-connevent.c b/net/rxrpc/ar-connevent.c
new file mode 100644
index 000000000000..4b02815c1ded
--- /dev/null
+++ b/net/rxrpc/ar-connevent.c
@@ -0,0 +1,387 @@
+/* connection-level event handling
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/errqueue.h>
+#include <linux/udp.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/icmp.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <net/ip.h>
+#include "ar-internal.h"
+
+/*
+ * pass a connection-level abort onto all calls on that connection
+ */
+static void rxrpc_abort_calls(struct rxrpc_connection *conn, int state,
+                              u32 abort_code)
+{
+        struct rxrpc_call *call;
+        struct rb_node *p;
+
+        _enter("{%d},%x", conn->debug_id, abort_code);
+
+        read_lock_bh(&conn->lock);
+
+        for (p = rb_first(&conn->calls); p; p = rb_next(p)) {
+                call = rb_entry(p, struct rxrpc_call, conn_node);
+                write_lock(&call->state_lock);
+                if (call->state <= RXRPC_CALL_COMPLETE) {
+                        call->state = state;
+                        call->abort_code = abort_code;
+                        if (state == RXRPC_CALL_LOCALLY_ABORTED)
+                                set_bit(RXRPC_CALL_CONN_ABORT, &call->events);
+                        else
+                                set_bit(RXRPC_CALL_RCVD_ABORT, &call->events);
+                        schedule_work(&call->processor);
+                }
+                write_unlock(&call->state_lock);
+        }
+
+        read_unlock_bh(&conn->lock);
+        _leave("");
+}
+
+/*
+ * generate a connection-level abort
+ */
+static int rxrpc_abort_connection(struct rxrpc_connection *conn,
+                                  u32 error, u32 abort_code)
+{
+        struct rxrpc_header hdr;
+        struct msghdr msg;
+        struct kvec iov[2];
+        __be32 word;
+        size_t len;
+        int ret;
+
+        _enter("%d,,%u,%u", conn->debug_id, error, abort_code);
+
+        /* generate a connection-level abort */
+        spin_lock_bh(&conn->state_lock);
+        if (conn->state < RXRPC_CONN_REMOTELY_ABORTED) {
+                conn->state = RXRPC_CONN_LOCALLY_ABORTED;
+                conn->error = error;
+                spin_unlock_bh(&conn->state_lock);
+        } else {
+                spin_unlock_bh(&conn->state_lock);
+                _leave(" = 0 [already dead]");
+                return 0;
+        }
+
+        rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, abort_code);
+
+        msg.msg_name    = &conn->trans->peer->srx.transport.sin;
+        msg.msg_namelen = sizeof(conn->trans->peer->srx.transport.sin);
+        msg.msg_control = NULL;
+        msg.msg_controllen = 0;
+        msg.msg_flags   = 0;
+
+        hdr.epoch       = conn->epoch;
+        hdr.cid         = conn->cid;
+        hdr.callNumber  = 0;
+        hdr.seq         = 0;
+        hdr.type        = RXRPC_PACKET_TYPE_ABORT;
+        hdr.flags       = conn->out_clientflag;
+        hdr.userStatus  = 0;
+        hdr.securityIndex = conn->security_ix;
+        hdr._rsvd       = 0;
+        hdr.serviceId   = conn->service_id;
+
+        word = htonl(abort_code);
+
+        iov[0].iov_base = &hdr;
+        iov[0].iov_len  = sizeof(hdr);
+        iov[1].iov_base = &word;
+        iov[1].iov_len  = sizeof(word);
+
+        len = iov[0].iov_len + iov[1].iov_len;
+
+        hdr.serial = htonl(atomic_inc_return(&conn->serial));
+        _proto("Tx CONN ABORT %%%u { %d }", ntohl(hdr.serial), abort_code);
+
+        ret = kernel_sendmsg(conn->trans->local->socket, &msg, iov, 2, len);
+        if (ret < 0) {
+                _debug("sendmsg failed: %d", ret);
+                return -EAGAIN;
+        }
+
+        _leave(" = 0");
+        return 0;
+}
+
+/*
+ * mark a call as being on a now-secured channel
+ * - must be called with softirqs disabled
+ */
+void rxrpc_call_is_secure(struct rxrpc_call *call)
+{
+        _enter("%p", call);
+        if (call) {
+                read_lock(&call->state_lock);
+                if (call->state < RXRPC_CALL_COMPLETE &&
+                    !test_and_set_bit(RXRPC_CALL_SECURED, &call->events))
+                        schedule_work(&call->processor);
+                read_unlock(&call->state_lock);
+        }
+}
+
+/*
+ * connection-level Rx packet processor
+ */
+static int rxrpc_process_event(struct rxrpc_connection *conn,
+                               struct sk_buff *skb,
+                               u32 *_abort_code)
+{
+        struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+        __be32 tmp;
+        u32 serial;
+        int loop, ret;
+
+        if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED)
+                return -ECONNABORTED;
+
+        serial = ntohl(sp->hdr.serial);
+
+        switch (sp->hdr.type) {
+        case RXRPC_PACKET_TYPE_ABORT:
+                if (skb_copy_bits(skb, 0, &tmp, sizeof(tmp)) < 0)
+                        return -EPROTO;
+                _proto("Rx ABORT %%%u { ac=%d }", serial, ntohl(tmp));
+
+                conn->state = RXRPC_CONN_REMOTELY_ABORTED;
+                rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED,
+                                  ntohl(tmp));
+                return -ECONNABORTED;
+
+        case RXRPC_PACKET_TYPE_CHALLENGE:
+                if (conn->security)
+                        return conn->security->respond_to_challenge(
+                                conn, skb, _abort_code);
+                return -EPROTO;
+
+        case RXRPC_PACKET_TYPE_RESPONSE:
+                if (!conn->security)
+                        return -EPROTO;
+
+                ret = conn->security->verify_response(conn, skb, _abort_code);
+                if (ret < 0)
+                        return ret;
+
+                ret = conn->security->init_connection_security(conn);
+                if (ret < 0)
+                        return ret;
+
+                conn->security->prime_packet_security(conn);
+                read_lock_bh(&conn->lock);
+                spin_lock(&conn->state_lock);
+
+                if (conn->state == RXRPC_CONN_SERVER_CHALLENGING) {
+                        conn->state = RXRPC_CONN_SERVER;
+                        for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
+                                rxrpc_call_is_secure(conn->channels[loop]);
+                }
+
+                spin_unlock(&conn->state_lock);
+                read_unlock_bh(&conn->lock);
+                return 0;
+
+        default:
+                return -EPROTO;
+        }
+}
+
+/*
+ * set up security and issue a challenge
+ */
+static void rxrpc_secure_connection(struct rxrpc_connection *conn)
+{
+        u32 abort_code;
+        int ret;
+
+        _enter("{%d}", conn->debug_id);
+
+        ASSERT(conn->security_ix != 0);
+
+        if (!conn->key) {
+                _debug("set up security");
+                ret = rxrpc_init_server_conn_security(conn);
+                switch (ret) {
+                case 0:
+                        break;
+                case -ENOENT:
+                        abort_code = RX_CALL_DEAD;
+                        goto abort;
+                default:
+                        abort_code = RXKADNOAUTH;
+                        goto abort;
+                }
+        }
+
+        ASSERT(conn->security != NULL);
+
+        if (conn->security->issue_challenge(conn) < 0) {
+                abort_code = RX_CALL_DEAD;
+                ret = -ENOMEM;
+                goto abort;
+        }
+
+        _leave("");
+        return;
+
+abort:
+        _debug("abort %d, %d", ret, abort_code);
+        rxrpc_abort_connection(conn, -ret, abort_code);
+        _leave(" [aborted]");
+}
+
+/*
+ * connection-level event processor
+ */
+void rxrpc_process_connection(struct work_struct *work)
+{
+        struct rxrpc_connection *conn =
+                container_of(work, struct rxrpc_connection, processor);
+        struct rxrpc_skb_priv *sp;
+        struct sk_buff *skb;
+        u32 abort_code = RX_PROTOCOL_ERROR;
+        int ret;
+
+        _enter("{%d}", conn->debug_id);
+
+        atomic_inc(&conn->usage);
+
+        if (test_and_clear_bit(RXRPC_CONN_CHALLENGE, &conn->events)) {
+                rxrpc_secure_connection(conn);
+                rxrpc_put_connection(conn);
+        }
+
+        /* go through the conn-level event packets, releasing the ref on this
+         * connection that each one has when we've finished with it */
+        while ((skb = skb_dequeue(&conn->rx_queue))) {
+                sp = rxrpc_skb(skb);
+
+                ret = rxrpc_process_event(conn, skb, &abort_code);
+                switch (ret) {
+                case -EPROTO:
+                case -EKEYEXPIRED:
+                case -EKEYREJECTED:
+                        goto protocol_error;
+                case -EAGAIN:
+                        goto requeue_and_leave;
+                case -ECONNABORTED:
+                default:
+                        rxrpc_put_connection(conn);
+                        rxrpc_free_skb(skb);
+                        break;
+                }
+        }
+
+out:
+        rxrpc_put_connection(conn);
+        _leave("");
+        return;
+
+requeue_and_leave:
+        skb_queue_head(&conn->rx_queue, skb);
+        goto out;
+
+protocol_error:
+        if (rxrpc_abort_connection(conn, -ret, abort_code) < 0)
+                goto requeue_and_leave;
+        rxrpc_put_connection(conn);
+        rxrpc_free_skb(skb);
+        _leave(" [EPROTO]");
+        goto out;
+}
+
+/*
+ * reject packets through the local endpoint
+ */
+void rxrpc_reject_packets(struct work_struct *work)
+{
+        union {
+                struct sockaddr sa;
+                struct sockaddr_in sin;
+        } sa;
+        struct rxrpc_skb_priv *sp;
+        struct rxrpc_header hdr;
+        struct rxrpc_local *local;
+        struct sk_buff *skb;
+        struct msghdr msg;
+        struct kvec iov[2];
+        size_t size;
+        __be32 code;
+
+        local = container_of(work, struct rxrpc_local, rejecter);
+        rxrpc_get_local(local);
+
+        _enter("%d", local->debug_id);
+
+        iov[0].iov_base = &hdr;
+        iov[0].iov_len = sizeof(hdr);
+        iov[1].iov_base = &code;
+        iov[1].iov_len = sizeof(code);
+        size = sizeof(hdr) + sizeof(code);
+
+        msg.msg_name = &sa;
+        msg.msg_control = NULL;
+        msg.msg_controllen = 0;
+        msg.msg_flags = 0;
+
+        memset(&sa, 0, sizeof(sa));
+        sa.sa.sa_family = local->srx.transport.family;
+        switch (sa.sa.sa_family) {
+        case AF_INET:
+                msg.msg_namelen = sizeof(sa.sin);
+                break;
+        default:
+                msg.msg_namelen = 0;
+                break;
+        }
+
+        memset(&hdr, 0, sizeof(hdr));
+        hdr.type = RXRPC_PACKET_TYPE_ABORT;
+
+        while ((skb = skb_dequeue(&local->reject_queue))) {
+                sp = rxrpc_skb(skb);
+                switch (sa.sa.sa_family) {
+                case AF_INET:
+                        sa.sin.sin_port = udp_hdr(skb)->source;
+                        sa.sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
+                        code = htonl(skb->priority);
+
+                        hdr.epoch = sp->hdr.epoch;
+                        hdr.cid = sp->hdr.cid;
+                        hdr.callNumber = sp->hdr.callNumber;
+                        hdr.serviceId = sp->hdr.serviceId;
+                        hdr.flags = sp->hdr.flags;
+                        hdr.flags ^= RXRPC_CLIENT_INITIATED;
+                        hdr.flags &= RXRPC_CLIENT_INITIATED;
+
+                        kernel_sendmsg(local->socket, &msg, iov, 2, size);
+                        break;
+
+                default:
+                        break;
+                }
+
+                rxrpc_free_skb(skb);
+                rxrpc_put_local(local);
+        }
+
+        rxrpc_put_local(local);
+        _leave("");
+}