rxrpc: Split sendmsg from packet transmission code
authorDavid Howells <dhowells@redhat.com>
Fri, 2 Sep 2016 21:39:45 +0000 (22:39 +0100)
committerDavid Howells <dhowells@redhat.com>
Sun, 4 Sep 2016 20:41:39 +0000 (21:41 +0100)
Split the sendmsg code from the packet transmission code (mostly to be
found in output.c).

Signed-off-by: David Howells <dhowells@redhat.com>
net/rxrpc/Makefile
net/rxrpc/ar-internal.h
net/rxrpc/misc.c
net/rxrpc/output.c
net/rxrpc/sendmsg.c [new file with mode: 0644]

index 10f3f48..8fc6ea3 100644 (file)
@@ -22,6 +22,7 @@ af-rxrpc-y := \
        peer_object.o \
        recvmsg.o \
        security.o \
+       sendmsg.o \
        skbuff.o \
        utils.o
 
index 4e86d24..464dfda 100644 (file)
@@ -814,6 +814,7 @@ extern unsigned int rxrpc_idle_ack_delay;
 extern unsigned int rxrpc_rx_window_size;
 extern unsigned int rxrpc_rx_mtu;
 extern unsigned int rxrpc_rx_jumbo_max;
+extern unsigned int rxrpc_resend_timeout;
 
 extern const char *const rxrpc_pkts[];
 extern const s8 rxrpc_ack_priority[];
@@ -823,10 +824,7 @@ extern const char *rxrpc_acks(u8 reason);
 /*
  * output.c
  */
-extern unsigned int rxrpc_resend_timeout;
-
 int rxrpc_send_data_packet(struct rxrpc_connection *, struct sk_buff *);
-int rxrpc_do_sendmsg(struct rxrpc_sock *, struct msghdr *, size_t);
 
 /*
  * peer_event.c
@@ -888,6 +886,11 @@ int __init rxrpc_init_security(void);
 void rxrpc_exit_security(void);
 int rxrpc_init_client_conn_security(struct rxrpc_connection *);
 int rxrpc_init_server_conn_security(struct rxrpc_connection *);
+/*
+ * sendmsg.c
+ */
+int rxrpc_do_sendmsg(struct rxrpc_sock *, struct msghdr *, size_t);
 
 /*
  * skbuff.c
index bdc5e42..39e7cc3 100644 (file)
@@ -64,6 +64,11 @@ unsigned int rxrpc_rx_mtu = 5692;
  */
 unsigned int rxrpc_rx_jumbo_max = 4;
 
+/*
+ * Time till packet resend (in jiffies).
+ */
+unsigned int rxrpc_resend_timeout = 4 * HZ;
+
 const char *const rxrpc_pkts[] = {
        "?00",
        "DATA", "ACK", "BUSY", "ABORT", "ACKALL", "CHALL", "RESP", "DEBUG",
index 817ae80..5b5508f 100644 (file)
 #include <linux/net.h>
 #include <linux/gfp.h>
 #include <linux/skbuff.h>
-#include <linux/circ_buf.h>
 #include <linux/export.h>
 #include <net/sock.h>
 #include <net/af_rxrpc.h>
 #include "ar-internal.h"
 
 /*
- * Time till packet resend (in jiffies).
- */
-unsigned int rxrpc_resend_timeout = 4 * HZ;
-
-static int rxrpc_send_data(struct rxrpc_sock *rx,
-                          struct rxrpc_call *call,
-                          struct msghdr *msg, size_t len);
-
-/*
- * extract control messages from the sendmsg() control buffer
- */
-static int rxrpc_sendmsg_cmsg(struct msghdr *msg,
-                             unsigned long *user_call_ID,
-                             enum rxrpc_command *command,
-                             u32 *abort_code,
-                             bool *_exclusive)
-{
-       struct cmsghdr *cmsg;
-       bool got_user_ID = false;
-       int len;
-
-       *command = RXRPC_CMD_SEND_DATA;
-
-       if (msg->msg_controllen == 0)
-               return -EINVAL;
-
-       for_each_cmsghdr(cmsg, msg) {
-               if (!CMSG_OK(msg, cmsg))
-                       return -EINVAL;
-
-               len = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr));
-               _debug("CMSG %d, %d, %d",
-                      cmsg->cmsg_level, cmsg->cmsg_type, len);
-
-               if (cmsg->cmsg_level != SOL_RXRPC)
-                       continue;
-
-               switch (cmsg->cmsg_type) {
-               case RXRPC_USER_CALL_ID:
-                       if (msg->msg_flags & MSG_CMSG_COMPAT) {
-                               if (len != sizeof(u32))
-                                       return -EINVAL;
-                               *user_call_ID = *(u32 *) CMSG_DATA(cmsg);
-                       } else {
-                               if (len != sizeof(unsigned long))
-                                       return -EINVAL;
-                               *user_call_ID = *(unsigned long *)
-                                       CMSG_DATA(cmsg);
-                       }
-                       _debug("User Call ID %lx", *user_call_ID);
-                       got_user_ID = true;
-                       break;
-
-               case RXRPC_ABORT:
-                       if (*command != RXRPC_CMD_SEND_DATA)
-                               return -EINVAL;
-                       *command = RXRPC_CMD_SEND_ABORT;
-                       if (len != sizeof(*abort_code))
-                               return -EINVAL;
-                       *abort_code = *(unsigned int *) CMSG_DATA(cmsg);
-                       _debug("Abort %x", *abort_code);
-                       if (*abort_code == 0)
-                               return -EINVAL;
-                       break;
-
-               case RXRPC_ACCEPT:
-                       if (*command != RXRPC_CMD_SEND_DATA)
-                               return -EINVAL;
-                       *command = RXRPC_CMD_ACCEPT;
-                       if (len != 0)
-                               return -EINVAL;
-                       break;
-
-               case RXRPC_EXCLUSIVE_CALL:
-                       *_exclusive = true;
-                       if (len != 0)
-                               return -EINVAL;
-                       break;
-               default:
-                       return -EINVAL;
-               }
-       }
-
-       if (!got_user_ID)
-               return -EINVAL;
-       _leave(" = 0");
-       return 0;
-}
-
-/*
- * abort a call, sending an ABORT packet to the peer
- */
-static void rxrpc_send_abort(struct rxrpc_call *call, u32 abort_code)
-{
-       if (call->state >= RXRPC_CALL_COMPLETE)
-               return;
-
-       write_lock_bh(&call->state_lock);
-
-       if (__rxrpc_abort_call(call, abort_code, ECONNABORTED)) {
-               del_timer_sync(&call->resend_timer);
-               del_timer_sync(&call->ack_timer);
-               clear_bit(RXRPC_CALL_EV_RESEND_TIMER, &call->events);
-               clear_bit(RXRPC_CALL_EV_ACK, &call->events);
-               clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
-               rxrpc_queue_call(call);
-       }
-
-       write_unlock_bh(&call->state_lock);
-}
-
-/*
- * Create a new client call for sendmsg().
- */
-static struct rxrpc_call *
-rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
-                                 unsigned long user_call_ID, bool exclusive)
-{
-       struct rxrpc_conn_parameters cp;
-       struct rxrpc_call *call;
-       struct key *key;
-
-       DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
-
-       _enter("");
-
-       if (!msg->msg_name)
-               return ERR_PTR(-EDESTADDRREQ);
-
-       key = rx->key;
-       if (key && !rx->key->payload.data[0])
-               key = NULL;
-
-       memset(&cp, 0, sizeof(cp));
-       cp.local                = rx->local;
-       cp.key                  = rx->key;
-       cp.security_level       = rx->min_sec_level;
-       cp.exclusive            = rx->exclusive | exclusive;
-       cp.service_id           = srx->srx_service;
-       call = rxrpc_new_client_call(rx, &cp, srx, user_call_ID, GFP_KERNEL);
-
-       _leave(" = %p\n", call);
-       return call;
-}
-
-/*
- * send a message forming part of a client call through an RxRPC socket
- * - caller holds the socket locked
- * - the socket may be either a client socket or a server socket
- */
-int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
-{
-       enum rxrpc_command cmd;
-       struct rxrpc_call *call;
-       unsigned long user_call_ID = 0;
-       bool exclusive = false;
-       u32 abort_code = 0;
-       int ret;
-
-       _enter("");
-
-       ret = rxrpc_sendmsg_cmsg(msg, &user_call_ID, &cmd, &abort_code,
-                                &exclusive);
-       if (ret < 0)
-               return ret;
-
-       if (cmd == RXRPC_CMD_ACCEPT) {
-               if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
-                       return -EINVAL;
-               call = rxrpc_accept_call(rx, user_call_ID, NULL);
-               if (IS_ERR(call))
-                       return PTR_ERR(call);
-               rxrpc_put_call(call);
-               return 0;
-       }
-
-       call = rxrpc_find_call_by_user_ID(rx, user_call_ID);
-       if (!call) {
-               if (cmd != RXRPC_CMD_SEND_DATA)
-                       return -EBADSLT;
-               call = rxrpc_new_client_call_for_sendmsg(rx, msg, user_call_ID,
-                                                        exclusive);
-               if (IS_ERR(call))
-                       return PTR_ERR(call);
-       }
-
-       rxrpc_see_call(call);
-       _debug("CALL %d USR %lx ST %d on CONN %p",
-              call->debug_id, call->user_call_ID, call->state, call->conn);
-
-       if (call->state >= RXRPC_CALL_COMPLETE) {
-               /* it's too late for this call */
-               ret = -ESHUTDOWN;
-       } else if (cmd == RXRPC_CMD_SEND_ABORT) {
-               rxrpc_send_abort(call, abort_code);
-               ret = 0;
-       } else if (cmd != RXRPC_CMD_SEND_DATA) {
-               ret = -EINVAL;
-       } else if (rxrpc_is_client_call(call) &&
-                  call->state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
-               /* request phase complete for this client call */
-               ret = -EPROTO;
-       } else if (rxrpc_is_service_call(call) &&
-                  call->state != RXRPC_CALL_SERVER_ACK_REQUEST &&
-                  call->state != RXRPC_CALL_SERVER_SEND_REPLY) {
-               /* Reply phase not begun or not complete for service call. */
-               ret = -EPROTO;
-       } else {
-               ret = rxrpc_send_data(rx, call, msg, len);
-       }
-
-       rxrpc_put_call(call);
-       _leave(" = %d", ret);
-       return ret;
-}
-
-/**
- * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
- * @sock: The socket the call is on
- * @call: The call to send data through
- * @msg: The data to send
- * @len: The amount of data to send
- *
- * Allow a kernel service to send data on a call.  The call must be in an state
- * appropriate to sending data.  No control data should be supplied in @msg,
- * nor should an address be supplied.  MSG_MORE should be flagged if there's
- * more data to come, otherwise this data will end the transmission phase.
- */
-int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
-                          struct msghdr *msg, size_t len)
-{
-       int ret;
-
-       _enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
-
-       ASSERTCMP(msg->msg_name, ==, NULL);
-       ASSERTCMP(msg->msg_control, ==, NULL);
-
-       lock_sock(sock->sk);
-
-       _debug("CALL %d USR %lx ST %d on CONN %p",
-              call->debug_id, call->user_call_ID, call->state, call->conn);
-
-       if (call->state >= RXRPC_CALL_COMPLETE) {
-               ret = -ESHUTDOWN; /* it's too late for this call */
-       } else if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
-                  call->state != RXRPC_CALL_SERVER_ACK_REQUEST &&
-                  call->state != RXRPC_CALL_SERVER_SEND_REPLY) {
-               ret = -EPROTO; /* request phase complete for this client call */
-       } else {
-               ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len);
-       }
-
-       release_sock(sock->sk);
-       _leave(" = %d", ret);
-       return ret;
-}
-EXPORT_SYMBOL(rxrpc_kernel_send_data);
-
-/**
- * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
- * @sock: The socket the call is on
- * @call: The call to be aborted
- * @abort_code: The abort code to stick into the ABORT packet
- *
- * Allow a kernel service to abort a call, if it's still in an abortable state.
- */
-void rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
-                            u32 abort_code)
-{
-       _enter("{%d},%d", call->debug_id, abort_code);
-
-       lock_sock(sock->sk);
-
-       _debug("CALL %d USR %lx ST %d on CONN %p",
-              call->debug_id, call->user_call_ID, call->state, call->conn);
-
-       rxrpc_send_abort(call, abort_code);
-
-       release_sock(sock->sk);
-       _leave("");
-}
-
-EXPORT_SYMBOL(rxrpc_kernel_abort_call);
-
-/*
  * send a packet through the transport endpoint
  */
 int rxrpc_send_data_packet(struct rxrpc_connection *conn, struct sk_buff *skb)
@@ -375,346 +88,3 @@ send_fragmentable:
        _leave(" = %d [frag %u]", ret, conn->params.peer->maxdata);
        return ret;
 }
-
-/*
- * wait for space to appear in the transmit/ACK window
- * - caller holds the socket locked
- */
-static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
-                                   struct rxrpc_call *call,
-                                   long *timeo)
-{
-       DECLARE_WAITQUEUE(myself, current);
-       int ret;
-
-       _enter(",{%d},%ld",
-              CIRC_SPACE(call->acks_head, ACCESS_ONCE(call->acks_tail),
-                         call->acks_winsz),
-              *timeo);
-
-       add_wait_queue(&call->waitq, &myself);
-
-       for (;;) {
-               set_current_state(TASK_INTERRUPTIBLE);
-               ret = 0;
-               if (CIRC_SPACE(call->acks_head, ACCESS_ONCE(call->acks_tail),
-                              call->acks_winsz) > 0)
-                       break;
-               if (signal_pending(current)) {
-                       ret = sock_intr_errno(*timeo);
-                       break;
-               }
-
-               release_sock(&rx->sk);
-               *timeo = schedule_timeout(*timeo);
-               lock_sock(&rx->sk);
-       }
-
-       remove_wait_queue(&call->waitq, &myself);
-       set_current_state(TASK_RUNNING);
-       _leave(" = %d", ret);
-       return ret;
-}
-
-/*
- * attempt to schedule an instant Tx resend
- */
-static inline void rxrpc_instant_resend(struct rxrpc_call *call)
-{
-       read_lock_bh(&call->state_lock);
-       if (try_to_del_timer_sync(&call->resend_timer) >= 0) {
-               clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
-               if (call->state < RXRPC_CALL_COMPLETE &&
-                   !test_and_set_bit(RXRPC_CALL_EV_RESEND_TIMER, &call->events))
-                       rxrpc_queue_call(call);
-       }
-       read_unlock_bh(&call->state_lock);
-}
-
-/*
- * queue a packet for transmission, set the resend timer and attempt
- * to send the packet immediately
- */
-static void rxrpc_queue_packet(struct rxrpc_call *call, struct sk_buff *skb,
-                              bool last)
-{
-       struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
-       int ret;
-
-       _net("queue skb %p [%d]", skb, call->acks_head);
-
-       ASSERT(call->acks_window != NULL);
-       call->acks_window[call->acks_head] = (unsigned long) skb;
-       smp_wmb();
-       call->acks_head = (call->acks_head + 1) & (call->acks_winsz - 1);
-
-       if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
-               _debug("________awaiting reply/ACK__________");
-               write_lock_bh(&call->state_lock);
-               switch (call->state) {
-               case RXRPC_CALL_CLIENT_SEND_REQUEST:
-                       call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
-                       break;
-               case RXRPC_CALL_SERVER_ACK_REQUEST:
-                       call->state = RXRPC_CALL_SERVER_SEND_REPLY;
-                       if (!last)
-                               break;
-               case RXRPC_CALL_SERVER_SEND_REPLY:
-                       call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
-                       break;
-               default:
-                       break;
-               }
-               write_unlock_bh(&call->state_lock);
-       }
-
-       _proto("Tx DATA %%%u { #%u }", sp->hdr.serial, sp->hdr.seq);
-
-       sp->need_resend = false;
-       sp->resend_at = jiffies + rxrpc_resend_timeout;
-       if (!test_and_set_bit(RXRPC_CALL_RUN_RTIMER, &call->flags)) {
-               _debug("run timer");
-               call->resend_timer.expires = sp->resend_at;
-               add_timer(&call->resend_timer);
-       }
-
-       /* attempt to cancel the rx-ACK timer, deferring reply transmission if
-        * we're ACK'ing the request phase of an incoming call */
-       ret = -EAGAIN;
-       if (try_to_del_timer_sync(&call->ack_timer) >= 0) {
-               /* the packet may be freed by rxrpc_process_call() before this
-                * returns */
-               if (rxrpc_is_client_call(call))
-                       rxrpc_expose_client_call(call);
-               ret = rxrpc_send_data_packet(call->conn, skb);
-               _net("sent skb %p", skb);
-       } else {
-               _debug("failed to delete ACK timer");
-       }
-
-       if (ret < 0) {
-               _debug("need instant resend %d", ret);
-               sp->need_resend = true;
-               rxrpc_instant_resend(call);
-       }
-
-       _leave("");
-}
-
-/*
- * Convert a host-endian header into a network-endian header.
- */
-static void rxrpc_insert_header(struct sk_buff *skb)
-{
-       struct rxrpc_wire_header whdr;
-       struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
-
-       whdr.epoch      = htonl(sp->hdr.epoch);
-       whdr.cid        = htonl(sp->hdr.cid);
-       whdr.callNumber = htonl(sp->hdr.callNumber);
-       whdr.seq        = htonl(sp->hdr.seq);
-       whdr.serial     = htonl(sp->hdr.serial);
-       whdr.type       = sp->hdr.type;
-       whdr.flags      = sp->hdr.flags;
-       whdr.userStatus = sp->hdr.userStatus;
-       whdr.securityIndex = sp->hdr.securityIndex;
-       whdr._rsvd      = htons(sp->hdr._rsvd);
-       whdr.serviceId  = htons(sp->hdr.serviceId);
-
-       memcpy(skb->head, &whdr, sizeof(whdr));
-}
-
-/*
- * send data through a socket
- * - must be called in process context
- * - caller holds the socket locked
- */
-static int rxrpc_send_data(struct rxrpc_sock *rx,
-                          struct rxrpc_call *call,
-                          struct msghdr *msg, size_t len)
-{
-       struct rxrpc_skb_priv *sp;
-       struct sk_buff *skb;
-       struct sock *sk = &rx->sk;
-       long timeo;
-       bool more;
-       int ret, copied;
-
-       timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
-
-       /* this should be in poll */
-       sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
-
-       if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
-               return -EPIPE;
-
-       more = msg->msg_flags & MSG_MORE;
-
-       skb = call->tx_pending;
-       call->tx_pending = NULL;
-       rxrpc_see_skb(skb);
-
-       copied = 0;
-       do {
-               if (!skb) {
-                       size_t size, chunk, max, space;
-
-                       _debug("alloc");
-
-                       if (CIRC_SPACE(call->acks_head,
-                                      ACCESS_ONCE(call->acks_tail),
-                                      call->acks_winsz) <= 0) {
-                               ret = -EAGAIN;
-                               if (msg->msg_flags & MSG_DONTWAIT)
-                                       goto maybe_error;
-                               ret = rxrpc_wait_for_tx_window(rx, call,
-                                                              &timeo);
-                               if (ret < 0)
-                                       goto maybe_error;
-                       }
-
-                       max = call->conn->params.peer->maxdata;
-                       max -= call->conn->security_size;
-                       max &= ~(call->conn->size_align - 1UL);
-
-                       chunk = max;
-                       if (chunk > msg_data_left(msg) && !more)
-                               chunk = msg_data_left(msg);
-
-                       space = chunk + call->conn->size_align;
-                       space &= ~(call->conn->size_align - 1UL);
-
-                       size = space + call->conn->header_size;
-
-                       _debug("SIZE: %zu/%zu/%zu", chunk, space, size);
-
-                       /* create a buffer that we can retain until it's ACK'd */
-                       skb = sock_alloc_send_skb(
-                               sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
-                       if (!skb)
-                               goto maybe_error;
-
-                       rxrpc_new_skb(skb);
-
-                       _debug("ALLOC SEND %p", skb);
-
-                       ASSERTCMP(skb->mark, ==, 0);
-
-                       _debug("HS: %u", call->conn->header_size);
-                       skb_reserve(skb, call->conn->header_size);
-                       skb->len += call->conn->header_size;
-
-                       sp = rxrpc_skb(skb);
-                       sp->remain = chunk;
-                       if (sp->remain > skb_tailroom(skb))
-                               sp->remain = skb_tailroom(skb);
-
-                       _net("skb: hr %d, tr %d, hl %d, rm %d",
-                              skb_headroom(skb),
-                              skb_tailroom(skb),
-                              skb_headlen(skb),
-                              sp->remain);
-
-                       skb->ip_summed = CHECKSUM_UNNECESSARY;
-               }
-
-               _debug("append");
-               sp = rxrpc_skb(skb);
-
-               /* append next segment of data to the current buffer */
-               if (msg_data_left(msg) > 0) {
-                       int copy = skb_tailroom(skb);
-                       ASSERTCMP(copy, >, 0);
-                       if (copy > msg_data_left(msg))
-                               copy = msg_data_left(msg);
-                       if (copy > sp->remain)
-                               copy = sp->remain;
-
-                       _debug("add");
-                       ret = skb_add_data(skb, &msg->msg_iter, copy);
-                       _debug("added");
-                       if (ret < 0)
-                               goto efault;
-                       sp->remain -= copy;
-                       skb->mark += copy;
-                       copied += copy;
-               }
-
-               /* check for the far side aborting the call or a network error
-                * occurring */
-               if (call->state == RXRPC_CALL_COMPLETE)
-                       goto call_terminated;
-
-               /* add the packet to the send queue if it's now full */
-               if (sp->remain <= 0 ||
-                   (msg_data_left(msg) == 0 && !more)) {
-                       struct rxrpc_connection *conn = call->conn;
-                       uint32_t seq;
-                       size_t pad;
-
-                       /* pad out if we're using security */
-                       if (conn->security_ix) {
-                               pad = conn->security_size + skb->mark;
-                               pad = conn->size_align - pad;
-                               pad &= conn->size_align - 1;
-                               _debug("pad %zu", pad);
-                               if (pad)
-                                       memset(skb_put(skb, pad), 0, pad);
-                       }
-
-                       seq = atomic_inc_return(&call->sequence);
-
-                       sp->hdr.epoch   = conn->proto.epoch;
-                       sp->hdr.cid     = call->cid;
-                       sp->hdr.callNumber = call->call_id;
-                       sp->hdr.seq     = seq;
-                       sp->hdr.serial  = atomic_inc_return(&conn->serial);
-                       sp->hdr.type    = RXRPC_PACKET_TYPE_DATA;
-                       sp->hdr.userStatus = 0;
-                       sp->hdr.securityIndex = conn->security_ix;
-                       sp->hdr._rsvd   = 0;
-                       sp->hdr.serviceId = call->service_id;
-
-                       sp->hdr.flags = conn->out_clientflag;
-                       if (msg_data_left(msg) == 0 && !more)
-                               sp->hdr.flags |= RXRPC_LAST_PACKET;
-                       else if (CIRC_SPACE(call->acks_head,
-                                           ACCESS_ONCE(call->acks_tail),
-                                           call->acks_winsz) > 1)
-                               sp->hdr.flags |= RXRPC_MORE_PACKETS;
-                       if (more && seq & 1)
-                               sp->hdr.flags |= RXRPC_REQUEST_ACK;
-
-                       ret = conn->security->secure_packet(
-                               call, skb, skb->mark,
-                               skb->head + sizeof(struct rxrpc_wire_header));
-                       if (ret < 0)
-                               goto out;
-
-                       rxrpc_insert_header(skb);
-                       rxrpc_queue_packet(call, skb, !msg_data_left(msg) && !more);
-                       skb = NULL;
-               }
-       } while (msg_data_left(msg) > 0);
-
-success:
-       ret = copied;
-out:
-       call->tx_pending = skb;
-       _leave(" = %d", ret);
-       return ret;
-
-call_terminated:
-       rxrpc_free_skb(skb);
-       _leave(" = %d", -call->error);
-       return ret;
-
-maybe_error:
-       if (copied)
-               goto success;
-       goto out;
-
-efault:
-       ret = -EFAULT;
-       goto out;
-}
diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
new file mode 100644 (file)
index 0000000..ff3e28d
--- /dev/null
@@ -0,0 +1,645 @@
+/* AF_RXRPC sendmsg() implementation.
+ *
+ * Copyright (C) 2007, 2016 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 Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/net.h>
+#include <linux/gfp.h>
+#include <linux/skbuff.h>
+#include <linux/export.h>
+#include <linux/circ_buf.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+static int rxrpc_send_data(struct rxrpc_sock *rx,
+                          struct rxrpc_call *call,
+                          struct msghdr *msg, size_t len);
+
+/*
+ * extract control messages from the sendmsg() control buffer
+ */
+static int rxrpc_sendmsg_cmsg(struct msghdr *msg,
+                             unsigned long *user_call_ID,
+                             enum rxrpc_command *command,
+                             u32 *abort_code,
+                             bool *_exclusive)
+{
+       struct cmsghdr *cmsg;
+       bool got_user_ID = false;
+       int len;
+
+       *command = RXRPC_CMD_SEND_DATA;
+
+       if (msg->msg_controllen == 0)
+               return -EINVAL;
+
+       for_each_cmsghdr(cmsg, msg) {
+               if (!CMSG_OK(msg, cmsg))
+                       return -EINVAL;
+
+               len = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr));
+               _debug("CMSG %d, %d, %d",
+                      cmsg->cmsg_level, cmsg->cmsg_type, len);
+
+               if (cmsg->cmsg_level != SOL_RXRPC)
+                       continue;
+
+               switch (cmsg->cmsg_type) {
+               case RXRPC_USER_CALL_ID:
+                       if (msg->msg_flags & MSG_CMSG_COMPAT) {
+                               if (len != sizeof(u32))
+                                       return -EINVAL;
+                               *user_call_ID = *(u32 *) CMSG_DATA(cmsg);
+                       } else {
+                               if (len != sizeof(unsigned long))
+                                       return -EINVAL;
+                               *user_call_ID = *(unsigned long *)
+                                       CMSG_DATA(cmsg);
+                       }
+                       _debug("User Call ID %lx", *user_call_ID);
+                       got_user_ID = true;
+                       break;
+
+               case RXRPC_ABORT:
+                       if (*command != RXRPC_CMD_SEND_DATA)
+                               return -EINVAL;
+                       *command = RXRPC_CMD_SEND_ABORT;
+                       if (len != sizeof(*abort_code))
+                               return -EINVAL;
+                       *abort_code = *(unsigned int *) CMSG_DATA(cmsg);
+                       _debug("Abort %x", *abort_code);
+                       if (*abort_code == 0)
+                               return -EINVAL;
+                       break;
+
+               case RXRPC_ACCEPT:
+                       if (*command != RXRPC_CMD_SEND_DATA)
+                               return -EINVAL;
+                       *command = RXRPC_CMD_ACCEPT;
+                       if (len != 0)
+                               return -EINVAL;
+                       break;
+
+               case RXRPC_EXCLUSIVE_CALL:
+                       *_exclusive = true;
+                       if (len != 0)
+                               return -EINVAL;
+                       break;
+               default:
+                       return -EINVAL;
+               }
+       }
+
+       if (!got_user_ID)
+               return -EINVAL;
+       _leave(" = 0");
+       return 0;
+}
+
+/*
+ * abort a call, sending an ABORT packet to the peer
+ */
+static void rxrpc_send_abort(struct rxrpc_call *call, u32 abort_code)
+{
+       if (call->state >= RXRPC_CALL_COMPLETE)
+               return;
+
+       write_lock_bh(&call->state_lock);
+
+       if (__rxrpc_abort_call(call, abort_code, ECONNABORTED)) {
+               del_timer_sync(&call->resend_timer);
+               del_timer_sync(&call->ack_timer);
+               clear_bit(RXRPC_CALL_EV_RESEND_TIMER, &call->events);
+               clear_bit(RXRPC_CALL_EV_ACK, &call->events);
+               clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
+               rxrpc_queue_call(call);
+       }
+
+       write_unlock_bh(&call->state_lock);
+}
+
+/*
+ * Create a new client call for sendmsg().
+ */
+static struct rxrpc_call *
+rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
+                                 unsigned long user_call_ID, bool exclusive)
+{
+       struct rxrpc_conn_parameters cp;
+       struct rxrpc_call *call;
+       struct key *key;
+
+       DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
+
+       _enter("");
+
+       if (!msg->msg_name)
+               return ERR_PTR(-EDESTADDRREQ);
+
+       key = rx->key;
+       if (key && !rx->key->payload.data[0])
+               key = NULL;
+
+       memset(&cp, 0, sizeof(cp));
+       cp.local                = rx->local;
+       cp.key                  = rx->key;
+       cp.security_level       = rx->min_sec_level;
+       cp.exclusive            = rx->exclusive | exclusive;
+       cp.service_id           = srx->srx_service;
+       call = rxrpc_new_client_call(rx, &cp, srx, user_call_ID, GFP_KERNEL);
+
+       _leave(" = %p\n", call);
+       return call;
+}
+
+/*
+ * send a message forming part of a client call through an RxRPC socket
+ * - caller holds the socket locked
+ * - the socket may be either a client socket or a server socket
+ */
+int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
+{
+       enum rxrpc_command cmd;
+       struct rxrpc_call *call;
+       unsigned long user_call_ID = 0;
+       bool exclusive = false;
+       u32 abort_code = 0;
+       int ret;
+
+       _enter("");
+
+       ret = rxrpc_sendmsg_cmsg(msg, &user_call_ID, &cmd, &abort_code,
+                                &exclusive);
+       if (ret < 0)
+               return ret;
+
+       if (cmd == RXRPC_CMD_ACCEPT) {
+               if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
+                       return -EINVAL;
+               call = rxrpc_accept_call(rx, user_call_ID, NULL);
+               if (IS_ERR(call))
+                       return PTR_ERR(call);
+               rxrpc_put_call(call);
+               return 0;
+       }
+
+       call = rxrpc_find_call_by_user_ID(rx, user_call_ID);
+       if (!call) {
+               if (cmd != RXRPC_CMD_SEND_DATA)
+                       return -EBADSLT;
+               call = rxrpc_new_client_call_for_sendmsg(rx, msg, user_call_ID,
+                                                        exclusive);
+               if (IS_ERR(call))
+                       return PTR_ERR(call);
+       }
+
+       rxrpc_see_call(call);
+       _debug("CALL %d USR %lx ST %d on CONN %p",
+              call->debug_id, call->user_call_ID, call->state, call->conn);
+
+       if (call->state >= RXRPC_CALL_COMPLETE) {
+               /* it's too late for this call */
+               ret = -ESHUTDOWN;
+       } else if (cmd == RXRPC_CMD_SEND_ABORT) {
+               rxrpc_send_abort(call, abort_code);
+               ret = 0;
+       } else if (cmd != RXRPC_CMD_SEND_DATA) {
+               ret = -EINVAL;
+       } else if (rxrpc_is_client_call(call) &&
+                  call->state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
+               /* request phase complete for this client call */
+               ret = -EPROTO;
+       } else if (rxrpc_is_service_call(call) &&
+                  call->state != RXRPC_CALL_SERVER_ACK_REQUEST &&
+                  call->state != RXRPC_CALL_SERVER_SEND_REPLY) {
+               /* Reply phase not begun or not complete for service call. */
+               ret = -EPROTO;
+       } else {
+               ret = rxrpc_send_data(rx, call, msg, len);
+       }
+
+       rxrpc_put_call(call);
+       _leave(" = %d", ret);
+       return ret;
+}
+
+/**
+ * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
+ * @sock: The socket the call is on
+ * @call: The call to send data through
+ * @msg: The data to send
+ * @len: The amount of data to send
+ *
+ * Allow a kernel service to send data on a call.  The call must be in an state
+ * appropriate to sending data.  No control data should be supplied in @msg,
+ * nor should an address be supplied.  MSG_MORE should be flagged if there's
+ * more data to come, otherwise this data will end the transmission phase.
+ */
+int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
+                          struct msghdr *msg, size_t len)
+{
+       int ret;
+
+       _enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
+
+       ASSERTCMP(msg->msg_name, ==, NULL);
+       ASSERTCMP(msg->msg_control, ==, NULL);
+
+       lock_sock(sock->sk);
+
+       _debug("CALL %d USR %lx ST %d on CONN %p",
+              call->debug_id, call->user_call_ID, call->state, call->conn);
+
+       if (call->state >= RXRPC_CALL_COMPLETE) {
+               ret = -ESHUTDOWN; /* it's too late for this call */
+       } else if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
+                  call->state != RXRPC_CALL_SERVER_ACK_REQUEST &&
+                  call->state != RXRPC_CALL_SERVER_SEND_REPLY) {
+               ret = -EPROTO; /* request phase complete for this client call */
+       } else {
+               ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len);
+       }
+
+       release_sock(sock->sk);
+       _leave(" = %d", ret);
+       return ret;
+}
+EXPORT_SYMBOL(rxrpc_kernel_send_data);
+
+/**
+ * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
+ * @sock: The socket the call is on
+ * @call: The call to be aborted
+ * @abort_code: The abort code to stick into the ABORT packet
+ *
+ * Allow a kernel service to abort a call, if it's still in an abortable state.
+ */
+void rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
+                            u32 abort_code)
+{
+       _enter("{%d},%d", call->debug_id, abort_code);
+
+       lock_sock(sock->sk);
+
+       _debug("CALL %d USR %lx ST %d on CONN %p",
+              call->debug_id, call->user_call_ID, call->state, call->conn);
+
+       rxrpc_send_abort(call, abort_code);
+
+       release_sock(sock->sk);
+       _leave("");
+}
+
+EXPORT_SYMBOL(rxrpc_kernel_abort_call);
+
+/*
+ * wait for space to appear in the transmit/ACK window
+ * - caller holds the socket locked
+ */
+static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
+                                   struct rxrpc_call *call,
+                                   long *timeo)
+{
+       DECLARE_WAITQUEUE(myself, current);
+       int ret;
+
+       _enter(",{%d},%ld",
+              CIRC_SPACE(call->acks_head, ACCESS_ONCE(call->acks_tail),
+                         call->acks_winsz),
+              *timeo);
+
+       add_wait_queue(&call->waitq, &myself);
+
+       for (;;) {
+               set_current_state(TASK_INTERRUPTIBLE);
+               ret = 0;
+               if (CIRC_SPACE(call->acks_head, ACCESS_ONCE(call->acks_tail),
+                              call->acks_winsz) > 0)
+                       break;
+               if (signal_pending(current)) {
+                       ret = sock_intr_errno(*timeo);
+                       break;
+               }
+
+               release_sock(&rx->sk);
+               *timeo = schedule_timeout(*timeo);
+               lock_sock(&rx->sk);
+       }
+
+       remove_wait_queue(&call->waitq, &myself);
+       set_current_state(TASK_RUNNING);
+       _leave(" = %d", ret);
+       return ret;
+}
+
+/*
+ * attempt to schedule an instant Tx resend
+ */
+static inline void rxrpc_instant_resend(struct rxrpc_call *call)
+{
+       read_lock_bh(&call->state_lock);
+       if (try_to_del_timer_sync(&call->resend_timer) >= 0) {
+               clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
+               if (call->state < RXRPC_CALL_COMPLETE &&
+                   !test_and_set_bit(RXRPC_CALL_EV_RESEND_TIMER, &call->events))
+                       rxrpc_queue_call(call);
+       }
+       read_unlock_bh(&call->state_lock);
+}
+
+/*
+ * queue a packet for transmission, set the resend timer and attempt
+ * to send the packet immediately
+ */
+static void rxrpc_queue_packet(struct rxrpc_call *call, struct sk_buff *skb,
+                              bool last)
+{
+       struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+       int ret;
+
+       _net("queue skb %p [%d]", skb, call->acks_head);
+
+       ASSERT(call->acks_window != NULL);
+       call->acks_window[call->acks_head] = (unsigned long) skb;
+       smp_wmb();
+       call->acks_head = (call->acks_head + 1) & (call->acks_winsz - 1);
+
+       if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
+               _debug("________awaiting reply/ACK__________");
+               write_lock_bh(&call->state_lock);
+               switch (call->state) {
+               case RXRPC_CALL_CLIENT_SEND_REQUEST:
+                       call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
+                       break;
+               case RXRPC_CALL_SERVER_ACK_REQUEST:
+                       call->state = RXRPC_CALL_SERVER_SEND_REPLY;
+                       if (!last)
+                               break;
+               case RXRPC_CALL_SERVER_SEND_REPLY:
+                       call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
+                       break;
+               default:
+                       break;
+               }
+               write_unlock_bh(&call->state_lock);
+       }
+
+       _proto("Tx DATA %%%u { #%u }", sp->hdr.serial, sp->hdr.seq);
+
+       sp->need_resend = false;
+       sp->resend_at = jiffies + rxrpc_resend_timeout;
+       if (!test_and_set_bit(RXRPC_CALL_RUN_RTIMER, &call->flags)) {
+               _debug("run timer");
+               call->resend_timer.expires = sp->resend_at;
+               add_timer(&call->resend_timer);
+       }
+
+       /* attempt to cancel the rx-ACK timer, deferring reply transmission if
+        * we're ACK'ing the request phase of an incoming call */
+       ret = -EAGAIN;
+       if (try_to_del_timer_sync(&call->ack_timer) >= 0) {
+               /* the packet may be freed by rxrpc_process_call() before this
+                * returns */
+               if (rxrpc_is_client_call(call))
+                       rxrpc_expose_client_call(call);
+               ret = rxrpc_send_data_packet(call->conn, skb);
+               _net("sent skb %p", skb);
+       } else {
+               _debug("failed to delete ACK timer");
+       }
+
+       if (ret < 0) {
+               _debug("need instant resend %d", ret);
+               sp->need_resend = true;
+               rxrpc_instant_resend(call);
+       }
+
+       _leave("");
+}
+
+/*
+ * Convert a host-endian header into a network-endian header.
+ */
+static void rxrpc_insert_header(struct sk_buff *skb)
+{
+       struct rxrpc_wire_header whdr;
+       struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+       whdr.epoch      = htonl(sp->hdr.epoch);
+       whdr.cid        = htonl(sp->hdr.cid);
+       whdr.callNumber = htonl(sp->hdr.callNumber);
+       whdr.seq        = htonl(sp->hdr.seq);
+       whdr.serial     = htonl(sp->hdr.serial);
+       whdr.type       = sp->hdr.type;
+       whdr.flags      = sp->hdr.flags;
+       whdr.userStatus = sp->hdr.userStatus;
+       whdr.securityIndex = sp->hdr.securityIndex;
+       whdr._rsvd      = htons(sp->hdr._rsvd);
+       whdr.serviceId  = htons(sp->hdr.serviceId);
+
+       memcpy(skb->head, &whdr, sizeof(whdr));
+}
+
+/*
+ * send data through a socket
+ * - must be called in process context
+ * - caller holds the socket locked
+ */
+static int rxrpc_send_data(struct rxrpc_sock *rx,
+                          struct rxrpc_call *call,
+                          struct msghdr *msg, size_t len)
+{
+       struct rxrpc_skb_priv *sp;
+       struct sk_buff *skb;
+       struct sock *sk = &rx->sk;
+       long timeo;
+       bool more;
+       int ret, copied;
+
+       timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
+
+       /* this should be in poll */
+       sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
+
+       if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
+               return -EPIPE;
+
+       more = msg->msg_flags & MSG_MORE;
+
+       skb = call->tx_pending;
+       call->tx_pending = NULL;
+       rxrpc_see_skb(skb);
+
+       copied = 0;
+       do {
+               if (!skb) {
+                       size_t size, chunk, max, space;
+
+                       _debug("alloc");
+
+                       if (CIRC_SPACE(call->acks_head,
+                                      ACCESS_ONCE(call->acks_tail),
+                                      call->acks_winsz) <= 0) {
+                               ret = -EAGAIN;
+                               if (msg->msg_flags & MSG_DONTWAIT)
+                                       goto maybe_error;
+                               ret = rxrpc_wait_for_tx_window(rx, call,
+                                                              &timeo);
+                               if (ret < 0)
+                                       goto maybe_error;
+                       }
+
+                       max = call->conn->params.peer->maxdata;
+                       max -= call->conn->security_size;
+                       max &= ~(call->conn->size_align - 1UL);
+
+                       chunk = max;
+                       if (chunk > msg_data_left(msg) && !more)
+                               chunk = msg_data_left(msg);
+
+                       space = chunk + call->conn->size_align;
+                       space &= ~(call->conn->size_align - 1UL);
+
+                       size = space + call->conn->header_size;
+
+                       _debug("SIZE: %zu/%zu/%zu", chunk, space, size);
+
+                       /* create a buffer that we can retain until it's ACK'd */
+                       skb = sock_alloc_send_skb(
+                               sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
+                       if (!skb)
+                               goto maybe_error;
+
+                       rxrpc_new_skb(skb);
+
+                       _debug("ALLOC SEND %p", skb);
+
+                       ASSERTCMP(skb->mark, ==, 0);
+
+                       _debug("HS: %u", call->conn->header_size);
+                       skb_reserve(skb, call->conn->header_size);
+                       skb->len += call->conn->header_size;
+
+                       sp = rxrpc_skb(skb);
+                       sp->remain = chunk;
+                       if (sp->remain > skb_tailroom(skb))
+                               sp->remain = skb_tailroom(skb);
+
+                       _net("skb: hr %d, tr %d, hl %d, rm %d",
+                              skb_headroom(skb),
+                              skb_tailroom(skb),
+                              skb_headlen(skb),
+                              sp->remain);
+
+                       skb->ip_summed = CHECKSUM_UNNECESSARY;
+               }
+
+               _debug("append");
+               sp = rxrpc_skb(skb);
+
+               /* append next segment of data to the current buffer */
+               if (msg_data_left(msg) > 0) {
+                       int copy = skb_tailroom(skb);
+                       ASSERTCMP(copy, >, 0);
+                       if (copy > msg_data_left(msg))
+                               copy = msg_data_left(msg);
+                       if (copy > sp->remain)
+                               copy = sp->remain;
+
+                       _debug("add");
+                       ret = skb_add_data(skb, &msg->msg_iter, copy);
+                       _debug("added");
+                       if (ret < 0)
+                               goto efault;
+                       sp->remain -= copy;
+                       skb->mark += copy;
+                       copied += copy;
+               }
+
+               /* check for the far side aborting the call or a network error
+                * occurring */
+               if (call->state == RXRPC_CALL_COMPLETE)
+                       goto call_terminated;
+
+               /* add the packet to the send queue if it's now full */
+               if (sp->remain <= 0 ||
+                   (msg_data_left(msg) == 0 && !more)) {
+                       struct rxrpc_connection *conn = call->conn;
+                       uint32_t seq;
+                       size_t pad;
+
+                       /* pad out if we're using security */
+                       if (conn->security_ix) {
+                               pad = conn->security_size + skb->mark;
+                               pad = conn->size_align - pad;
+                               pad &= conn->size_align - 1;
+                               _debug("pad %zu", pad);
+                               if (pad)
+                                       memset(skb_put(skb, pad), 0, pad);
+                       }
+
+                       seq = atomic_inc_return(&call->sequence);
+
+                       sp->hdr.epoch   = conn->proto.epoch;
+                       sp->hdr.cid     = call->cid;
+                       sp->hdr.callNumber = call->call_id;
+                       sp->hdr.seq     = seq;
+                       sp->hdr.serial  = atomic_inc_return(&conn->serial);
+                       sp->hdr.type    = RXRPC_PACKET_TYPE_DATA;
+                       sp->hdr.userStatus = 0;
+                       sp->hdr.securityIndex = conn->security_ix;
+                       sp->hdr._rsvd   = 0;
+                       sp->hdr.serviceId = call->service_id;
+
+                       sp->hdr.flags = conn->out_clientflag;
+                       if (msg_data_left(msg) == 0 && !more)
+                               sp->hdr.flags |= RXRPC_LAST_PACKET;
+                       else if (CIRC_SPACE(call->acks_head,
+                                           ACCESS_ONCE(call->acks_tail),
+                                           call->acks_winsz) > 1)
+                               sp->hdr.flags |= RXRPC_MORE_PACKETS;
+                       if (more && seq & 1)
+                               sp->hdr.flags |= RXRPC_REQUEST_ACK;
+
+                       ret = conn->security->secure_packet(
+                               call, skb, skb->mark,
+                               skb->head + sizeof(struct rxrpc_wire_header));
+                       if (ret < 0)
+                               goto out;
+
+                       rxrpc_insert_header(skb);
+                       rxrpc_queue_packet(call, skb, !msg_data_left(msg) && !more);
+                       skb = NULL;
+               }
+       } while (msg_data_left(msg) > 0);
+
+success:
+       ret = copied;
+out:
+       call->tx_pending = skb;
+       _leave(" = %d", ret);
+       return ret;
+
+call_terminated:
+       rxrpc_free_skb(skb);
+       _leave(" = %d", -call->error);
+       return ret;
+
+maybe_error:
+       if (copied)
+               goto success;
+       goto out;
+
+efault:
+       ret = -EFAULT;
+       goto out;
+}