android_kernel_xiaomi_sm8350/net/rxrpc/ar-connevent.c

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/* 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);
[AF_RXRPC]: Add an interface to the AF_RXRPC module for the AFS filesystem to use Add an interface to the AF_RXRPC module so that the AFS filesystem module can more easily make use of the services available. AFS still opens a socket but then uses the action functions in lieu of sendmsg() and registers an intercept functions to grab messages before they're queued on the socket Rx queue. This permits AFS (or whatever) to: (1) Avoid the overhead of using the recvmsg() call. (2) Use different keys directly on individual client calls on one socket rather than having to open a whole slew of sockets, one for each key it might want to use. (3) Avoid calling request_key() at the point of issue of a call or opening of a socket. This is done instead by AFS at the point of open(), unlink() or other VFS operation and the key handed through. (4) Request the use of something other than GFP_KERNEL to allocate memory. Furthermore: (*) The socket buffer markings used by RxRPC are made available for AFS so that it can interpret the cooked RxRPC messages itself. (*) rxgen (un)marshalling abort codes are made available. The following documentation for the kernel interface is added to Documentation/networking/rxrpc.txt: ========================= AF_RXRPC KERNEL INTERFACE ========================= The AF_RXRPC module also provides an interface for use by in-kernel utilities such as the AFS filesystem. This permits such a utility to: (1) Use different keys directly on individual client calls on one socket rather than having to open a whole slew of sockets, one for each key it might want to use. (2) Avoid having RxRPC call request_key() at the point of issue of a call or opening of a socket. Instead the utility is responsible for requesting a key at the appropriate point. AFS, for instance, would do this during VFS operations such as open() or unlink(). The key is then handed through when the call is initiated. (3) Request the use of something other than GFP_KERNEL to allocate memory. (4) Avoid the overhead of using the recvmsg() call. RxRPC messages can be intercepted before they get put into the socket Rx queue and the socket buffers manipulated directly. To use the RxRPC facility, a kernel utility must still open an AF_RXRPC socket, bind an addess as appropriate and listen if it's to be a server socket, but then it passes this to the kernel interface functions. The kernel interface functions are as follows: (*) Begin a new client call. struct rxrpc_call * rxrpc_kernel_begin_call(struct socket *sock, struct sockaddr_rxrpc *srx, struct key *key, unsigned long user_call_ID, gfp_t gfp); This allocates the infrastructure to make a new RxRPC call and assigns call and connection numbers. The call will be made on the UDP port that the socket is bound to. The call will go to the destination address of a connected client socket unless an alternative is supplied (srx is non-NULL). If a key is supplied then this will be used to secure the call instead of the key bound to the socket with the RXRPC_SECURITY_KEY sockopt. Calls secured in this way will still share connections if at all possible. The user_call_ID is equivalent to that supplied to sendmsg() in the control data buffer. It is entirely feasible to use this to point to a kernel data structure. If this function is successful, an opaque reference to the RxRPC call is returned. The caller now holds a reference on this and it must be properly ended. (*) End a client call. void rxrpc_kernel_end_call(struct rxrpc_call *call); This is used to end a previously begun call. The user_call_ID is expunged from AF_RXRPC's knowledge and will not be seen again in association with the specified call. (*) Send data through a call. int rxrpc_kernel_send_data(struct rxrpc_call *call, struct msghdr *msg, size_t len); This is used to supply either the request part of a client call or the reply part of a server call. msg.msg_iovlen and msg.msg_iov specify the data buffers to be used. msg_iov may not be NULL and must point exclusively to in-kernel virtual addresses. msg.msg_flags may be given MSG_MORE if there will be subsequent data sends for this call. The msg must not specify a destination address, control data or any flags other than MSG_MORE. len is the total amount of data to transmit. (*) Abort a call. void rxrpc_kernel_abort_call(struct rxrpc_call *call, u32 abort_code); This is used to abort a call if it's still in an abortable state. The abort code specified will be placed in the ABORT message sent. (*) Intercept received RxRPC messages. typedef void (*rxrpc_interceptor_t)(struct sock *sk, unsigned long user_call_ID, struct sk_buff *skb); void rxrpc_kernel_intercept_rx_messages(struct socket *sock, rxrpc_interceptor_t interceptor); This installs an interceptor function on the specified AF_RXRPC socket. All messages that would otherwise wind up in the socket's Rx queue are then diverted to this function. Note that care must be taken to process the messages in the right order to maintain DATA message sequentiality. The interceptor function itself is provided with the address of the socket and handling the incoming message, the ID assigned by the kernel utility to the call and the socket buffer containing the message. The skb->mark field indicates the type of message: MARK MEANING =============================== ======================================= RXRPC_SKB_MARK_DATA Data message RXRPC_SKB_MARK_FINAL_ACK Final ACK received for an incoming call RXRPC_SKB_MARK_BUSY Client call rejected as server busy RXRPC_SKB_MARK_REMOTE_ABORT Call aborted by peer RXRPC_SKB_MARK_NET_ERROR Network error detected RXRPC_SKB_MARK_LOCAL_ERROR Local error encountered RXRPC_SKB_MARK_NEW_CALL New incoming call awaiting acceptance The remote abort message can be probed with rxrpc_kernel_get_abort_code(). The two error messages can be probed with rxrpc_kernel_get_error_number(). A new call can be accepted with rxrpc_kernel_accept_call(). Data messages can have their contents extracted with the usual bunch of socket buffer manipulation functions. A data message can be determined to be the last one in a sequence with rxrpc_kernel_is_data_last(). When a data message has been used up, rxrpc_kernel_data_delivered() should be called on it.. Non-data messages should be handled to rxrpc_kernel_free_skb() to dispose of. It is possible to get extra refs on all types of message for later freeing, but this may pin the state of a call until the message is finally freed. (*) Accept an incoming call. struct rxrpc_call * rxrpc_kernel_accept_call(struct socket *sock, unsigned long user_call_ID); This is used to accept an incoming call and to assign it a call ID. This function is similar to rxrpc_kernel_begin_call() and calls accepted must be ended in the same way. If this function is successful, an opaque reference to the RxRPC call is returned. The caller now holds a reference on this and it must be properly ended. (*) Reject an incoming call. int rxrpc_kernel_reject_call(struct socket *sock); This is used to reject the first incoming call on the socket's queue with a BUSY message. -ENODATA is returned if there were no incoming calls. Other errors may be returned if the call had been aborted (-ECONNABORTED) or had timed out (-ETIME). (*) Record the delivery of a data message and free it. void rxrpc_kernel_data_delivered(struct sk_buff *skb); This is used to record a data message as having been delivered and to update the ACK state for the call. The socket buffer will be freed. (*) Free a message. void rxrpc_kernel_free_skb(struct sk_buff *skb); This is used to free a non-DATA socket buffer intercepted from an AF_RXRPC socket. (*) Determine if a data message is the last one on a call. bool rxrpc_kernel_is_data_last(struct sk_buff *skb); This is used to determine if a socket buffer holds the last data message to be received for a call (true will be returned if it does, false if not). The data message will be part of the reply on a client call and the request on an incoming call. In the latter case there will be more messages, but in the former case there will not. (*) Get the abort code from an abort message. u32 rxrpc_kernel_get_abort_code(struct sk_buff *skb); This is used to extract the abort code from a remote abort message. (*) Get the error number from a local or network error message. int rxrpc_kernel_get_error_number(struct sk_buff *skb); This is used to extract the error number from a message indicating either a local error occurred or a network error occurred. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 18:50:17 -04:00
rxrpc_queue_call(call);
}
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))
[AF_RXRPC]: Add an interface to the AF_RXRPC module for the AFS filesystem to use Add an interface to the AF_RXRPC module so that the AFS filesystem module can more easily make use of the services available. AFS still opens a socket but then uses the action functions in lieu of sendmsg() and registers an intercept functions to grab messages before they're queued on the socket Rx queue. This permits AFS (or whatever) to: (1) Avoid the overhead of using the recvmsg() call. (2) Use different keys directly on individual client calls on one socket rather than having to open a whole slew of sockets, one for each key it might want to use. (3) Avoid calling request_key() at the point of issue of a call or opening of a socket. This is done instead by AFS at the point of open(), unlink() or other VFS operation and the key handed through. (4) Request the use of something other than GFP_KERNEL to allocate memory. Furthermore: (*) The socket buffer markings used by RxRPC are made available for AFS so that it can interpret the cooked RxRPC messages itself. (*) rxgen (un)marshalling abort codes are made available. The following documentation for the kernel interface is added to Documentation/networking/rxrpc.txt: ========================= AF_RXRPC KERNEL INTERFACE ========================= The AF_RXRPC module also provides an interface for use by in-kernel utilities such as the AFS filesystem. This permits such a utility to: (1) Use different keys directly on individual client calls on one socket rather than having to open a whole slew of sockets, one for each key it might want to use. (2) Avoid having RxRPC call request_key() at the point of issue of a call or opening of a socket. Instead the utility is responsible for requesting a key at the appropriate point. AFS, for instance, would do this during VFS operations such as open() or unlink(). The key is then handed through when the call is initiated. (3) Request the use of something other than GFP_KERNEL to allocate memory. (4) Avoid the overhead of using the recvmsg() call. RxRPC messages can be intercepted before they get put into the socket Rx queue and the socket buffers manipulated directly. To use the RxRPC facility, a kernel utility must still open an AF_RXRPC socket, bind an addess as appropriate and listen if it's to be a server socket, but then it passes this to the kernel interface functions. The kernel interface functions are as follows: (*) Begin a new client call. struct rxrpc_call * rxrpc_kernel_begin_call(struct socket *sock, struct sockaddr_rxrpc *srx, struct key *key, unsigned long user_call_ID, gfp_t gfp); This allocates the infrastructure to make a new RxRPC call and assigns call and connection numbers. The call will be made on the UDP port that the socket is bound to. The call will go to the destination address of a connected client socket unless an alternative is supplied (srx is non-NULL). If a key is supplied then this will be used to secure the call instead of the key bound to the socket with the RXRPC_SECURITY_KEY sockopt. Calls secured in this way will still share connections if at all possible. The user_call_ID is equivalent to that supplied to sendmsg() in the control data buffer. It is entirely feasible to use this to point to a kernel data structure. If this function is successful, an opaque reference to the RxRPC call is returned. The caller now holds a reference on this and it must be properly ended. (*) End a client call. void rxrpc_kernel_end_call(struct rxrpc_call *call); This is used to end a previously begun call. The user_call_ID is expunged from AF_RXRPC's knowledge and will not be seen again in association with the specified call. (*) Send data through a call. int rxrpc_kernel_send_data(struct rxrpc_call *call, struct msghdr *msg, size_t len); This is used to supply either the request part of a client call or the reply part of a server call. msg.msg_iovlen and msg.msg_iov specify the data buffers to be used. msg_iov may not be NULL and must point exclusively to in-kernel virtual addresses. msg.msg_flags may be given MSG_MORE if there will be subsequent data sends for this call. The msg must not specify a destination address, control data or any flags other than MSG_MORE. len is the total amount of data to transmit. (*) Abort a call. void rxrpc_kernel_abort_call(struct rxrpc_call *call, u32 abort_code); This is used to abort a call if it's still in an abortable state. The abort code specified will be placed in the ABORT message sent. (*) Intercept received RxRPC messages. typedef void (*rxrpc_interceptor_t)(struct sock *sk, unsigned long user_call_ID, struct sk_buff *skb); void rxrpc_kernel_intercept_rx_messages(struct socket *sock, rxrpc_interceptor_t interceptor); This installs an interceptor function on the specified AF_RXRPC socket. All messages that would otherwise wind up in the socket's Rx queue are then diverted to this function. Note that care must be taken to process the messages in the right order to maintain DATA message sequentiality. The interceptor function itself is provided with the address of the socket and handling the incoming message, the ID assigned by the kernel utility to the call and the socket buffer containing the message. The skb->mark field indicates the type of message: MARK MEANING =============================== ======================================= RXRPC_SKB_MARK_DATA Data message RXRPC_SKB_MARK_FINAL_ACK Final ACK received for an incoming call RXRPC_SKB_MARK_BUSY Client call rejected as server busy RXRPC_SKB_MARK_REMOTE_ABORT Call aborted by peer RXRPC_SKB_MARK_NET_ERROR Network error detected RXRPC_SKB_MARK_LOCAL_ERROR Local error encountered RXRPC_SKB_MARK_NEW_CALL New incoming call awaiting acceptance The remote abort message can be probed with rxrpc_kernel_get_abort_code(). The two error messages can be probed with rxrpc_kernel_get_error_number(). A new call can be accepted with rxrpc_kernel_accept_call(). Data messages can have their contents extracted with the usual bunch of socket buffer manipulation functions. A data message can be determined to be the last one in a sequence with rxrpc_kernel_is_data_last(). When a data message has been used up, rxrpc_kernel_data_delivered() should be called on it.. Non-data messages should be handled to rxrpc_kernel_free_skb() to dispose of. It is possible to get extra refs on all types of message for later freeing, but this may pin the state of a call until the message is finally freed. (*) Accept an incoming call. struct rxrpc_call * rxrpc_kernel_accept_call(struct socket *sock, unsigned long user_call_ID); This is used to accept an incoming call and to assign it a call ID. This function is similar to rxrpc_kernel_begin_call() and calls accepted must be ended in the same way. If this function is successful, an opaque reference to the RxRPC call is returned. The caller now holds a reference on this and it must be properly ended. (*) Reject an incoming call. int rxrpc_kernel_reject_call(struct socket *sock); This is used to reject the first incoming call on the socket's queue with a BUSY message. -ENODATA is returned if there were no incoming calls. Other errors may be returned if the call had been aborted (-ECONNABORTED) or had timed out (-ETIME). (*) Record the delivery of a data message and free it. void rxrpc_kernel_data_delivered(struct sk_buff *skb); This is used to record a data message as having been delivered and to update the ACK state for the call. The socket buffer will be freed. (*) Free a message. void rxrpc_kernel_free_skb(struct sk_buff *skb); This is used to free a non-DATA socket buffer intercepted from an AF_RXRPC socket. (*) Determine if a data message is the last one on a call. bool rxrpc_kernel_is_data_last(struct sk_buff *skb); This is used to determine if a socket buffer holds the last data message to be received for a call (true will be returned if it does, false if not). The data message will be part of the reply on a client call and the request on an incoming call. In the latter case there will be more messages, but in the former case there will not. (*) Get the abort code from an abort message. u32 rxrpc_kernel_get_abort_code(struct sk_buff *skb); This is used to extract the abort code from a remote abort message. (*) Get the error number from a local or network error message. int rxrpc_kernel_get_error_number(struct sk_buff *skb); This is used to extract the error number from a message indicating either a local error occurred or a network error occurred. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 18:50:17 -04:00
rxrpc_queue_call(call);
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;
}
[AF_RXRPC]: Add an interface to the AF_RXRPC module for the AFS filesystem to use Add an interface to the AF_RXRPC module so that the AFS filesystem module can more easily make use of the services available. AFS still opens a socket but then uses the action functions in lieu of sendmsg() and registers an intercept functions to grab messages before they're queued on the socket Rx queue. This permits AFS (or whatever) to: (1) Avoid the overhead of using the recvmsg() call. (2) Use different keys directly on individual client calls on one socket rather than having to open a whole slew of sockets, one for each key it might want to use. (3) Avoid calling request_key() at the point of issue of a call or opening of a socket. This is done instead by AFS at the point of open(), unlink() or other VFS operation and the key handed through. (4) Request the use of something other than GFP_KERNEL to allocate memory. Furthermore: (*) The socket buffer markings used by RxRPC are made available for AFS so that it can interpret the cooked RxRPC messages itself. (*) rxgen (un)marshalling abort codes are made available. The following documentation for the kernel interface is added to Documentation/networking/rxrpc.txt: ========================= AF_RXRPC KERNEL INTERFACE ========================= The AF_RXRPC module also provides an interface for use by in-kernel utilities such as the AFS filesystem. This permits such a utility to: (1) Use different keys directly on individual client calls on one socket rather than having to open a whole slew of sockets, one for each key it might want to use. (2) Avoid having RxRPC call request_key() at the point of issue of a call or opening of a socket. Instead the utility is responsible for requesting a key at the appropriate point. AFS, for instance, would do this during VFS operations such as open() or unlink(). The key is then handed through when the call is initiated. (3) Request the use of something other than GFP_KERNEL to allocate memory. (4) Avoid the overhead of using the recvmsg() call. RxRPC messages can be intercepted before they get put into the socket Rx queue and the socket buffers manipulated directly. To use the RxRPC facility, a kernel utility must still open an AF_RXRPC socket, bind an addess as appropriate and listen if it's to be a server socket, but then it passes this to the kernel interface functions. The kernel interface functions are as follows: (*) Begin a new client call. struct rxrpc_call * rxrpc_kernel_begin_call(struct socket *sock, struct sockaddr_rxrpc *srx, struct key *key, unsigned long user_call_ID, gfp_t gfp); This allocates the infrastructure to make a new RxRPC call and assigns call and connection numbers. The call will be made on the UDP port that the socket is bound to. The call will go to the destination address of a connected client socket unless an alternative is supplied (srx is non-NULL). If a key is supplied then this will be used to secure the call instead of the key bound to the socket with the RXRPC_SECURITY_KEY sockopt. Calls secured in this way will still share connections if at all possible. The user_call_ID is equivalent to that supplied to sendmsg() in the control data buffer. It is entirely feasible to use this to point to a kernel data structure. If this function is successful, an opaque reference to the RxRPC call is returned. The caller now holds a reference on this and it must be properly ended. (*) End a client call. void rxrpc_kernel_end_call(struct rxrpc_call *call); This is used to end a previously begun call. The user_call_ID is expunged from AF_RXRPC's knowledge and will not be seen again in association with the specified call. (*) Send data through a call. int rxrpc_kernel_send_data(struct rxrpc_call *call, struct msghdr *msg, size_t len); This is used to supply either the request part of a client call or the reply part of a server call. msg.msg_iovlen and msg.msg_iov specify the data buffers to be used. msg_iov may not be NULL and must point exclusively to in-kernel virtual addresses. msg.msg_flags may be given MSG_MORE if there will be subsequent data sends for this call. The msg must not specify a destination address, control data or any flags other than MSG_MORE. len is the total amount of data to transmit. (*) Abort a call. void rxrpc_kernel_abort_call(struct rxrpc_call *call, u32 abort_code); This is used to abort a call if it's still in an abortable state. The abort code specified will be placed in the ABORT message sent. (*) Intercept received RxRPC messages. typedef void (*rxrpc_interceptor_t)(struct sock *sk, unsigned long user_call_ID, struct sk_buff *skb); void rxrpc_kernel_intercept_rx_messages(struct socket *sock, rxrpc_interceptor_t interceptor); This installs an interceptor function on the specified AF_RXRPC socket. All messages that would otherwise wind up in the socket's Rx queue are then diverted to this function. Note that care must be taken to process the messages in the right order to maintain DATA message sequentiality. The interceptor function itself is provided with the address of the socket and handling the incoming message, the ID assigned by the kernel utility to the call and the socket buffer containing the message. The skb->mark field indicates the type of message: MARK MEANING =============================== ======================================= RXRPC_SKB_MARK_DATA Data message RXRPC_SKB_MARK_FINAL_ACK Final ACK received for an incoming call RXRPC_SKB_MARK_BUSY Client call rejected as server busy RXRPC_SKB_MARK_REMOTE_ABORT Call aborted by peer RXRPC_SKB_MARK_NET_ERROR Network error detected RXRPC_SKB_MARK_LOCAL_ERROR Local error encountered RXRPC_SKB_MARK_NEW_CALL New incoming call awaiting acceptance The remote abort message can be probed with rxrpc_kernel_get_abort_code(). The two error messages can be probed with rxrpc_kernel_get_error_number(). A new call can be accepted with rxrpc_kernel_accept_call(). Data messages can have their contents extracted with the usual bunch of socket buffer manipulation functions. A data message can be determined to be the last one in a sequence with rxrpc_kernel_is_data_last(). When a data message has been used up, rxrpc_kernel_data_delivered() should be called on it.. Non-data messages should be handled to rxrpc_kernel_free_skb() to dispose of. It is possible to get extra refs on all types of message for later freeing, but this may pin the state of a call until the message is finally freed. (*) Accept an incoming call. struct rxrpc_call * rxrpc_kernel_accept_call(struct socket *sock, unsigned long user_call_ID); This is used to accept an incoming call and to assign it a call ID. This function is similar to rxrpc_kernel_begin_call() and calls accepted must be ended in the same way. If this function is successful, an opaque reference to the RxRPC call is returned. The caller now holds a reference on this and it must be properly ended. (*) Reject an incoming call. int rxrpc_kernel_reject_call(struct socket *sock); This is used to reject the first incoming call on the socket's queue with a BUSY message. -ENODATA is returned if there were no incoming calls. Other errors may be returned if the call had been aborted (-ECONNABORTED) or had timed out (-ETIME). (*) Record the delivery of a data message and free it. void rxrpc_kernel_data_delivered(struct sk_buff *skb); This is used to record a data message as having been delivered and to update the ACK state for the call. The socket buffer will be freed. (*) Free a message. void rxrpc_kernel_free_skb(struct sk_buff *skb); This is used to free a non-DATA socket buffer intercepted from an AF_RXRPC socket. (*) Determine if a data message is the last one on a call. bool rxrpc_kernel_is_data_last(struct sk_buff *skb); This is used to determine if a socket buffer holds the last data message to be received for a call (true will be returned if it does, false if not). The data message will be part of the reply on a client call and the request on an incoming call. In the latter case there will be more messages, but in the former case there will not. (*) Get the abort code from an abort message. u32 rxrpc_kernel_get_abort_code(struct sk_buff *skb); This is used to extract the abort code from a remote abort message. (*) Get the error number from a local or network error message. int rxrpc_kernel_get_error_number(struct sk_buff *skb); This is used to extract the error number from a message indicating either a local error occurred or a network error occurred. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 18:50:17 -04:00
/*
* put a packet up for transport-level abort
*/
void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
{
CHECK_SLAB_OKAY(&local->usage);
if (!atomic_inc_not_zero(&local->usage)) {
printk("resurrected on reject\n");
BUG();
}
skb_queue_tail(&local->reject_queue, skb);
rxrpc_queue_work(&local->rejecter);
}
/*
* 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("");
}