/**************************************************************************** * net/net_send_buffered.c * * Copyright (C) 2007-2014 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * Jason Jiang * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #if defined(CONFIG_NET) && defined(CONFIG_NET_TCP) && \ defined(CONFIG_NET_TCP_WRITE_BUFFERS) #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_NET_ARP_IPIN # include #endif #include "net_internal.h" #include "uip/uip_internal.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ #define TCPBUF ((struct uip_tcpip_hdr *)&dev->d_buf[UIP_LLH_LEN]) /**************************************************************************** * Private Types ****************************************************************************/ /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Function: send_insert_seqment * * Description: * Insert a new segment in a write buffer queue, keep the segment queue in * ascending order of sequence number. * * Parameters: * segment The segment to be inserted * q The write buffer queue in which to insert the segment * * Returned Value: * None * * Assumptions: * Running at the interrupt level * ****************************************************************************/ static void send_insert_seqment(FAR struct uip_wrbuffer_s *segment, FAR sq_queue_t *q) { sq_entry_t *entry = (sq_entry_t*)segment; sq_entry_t *insert = NULL; sq_entry_t *itr; for (itr = sq_peek(q); itr; itr = sq_next(itr)) { FAR struct uip_wrbuffer_s *segment0 = (FAR struct uip_wrbuffer_s*)itr; if (segment0->wb_seqno < segment->wb_seqno) { insert = itr; } else { break; } } if (insert) { sq_addafter(insert, entry, q); } else { sq_addfirst(entry, q); } } /**************************************************************************** * Function: send_interrupt * * Description: * This function is called from the interrupt level to perform the actual * send operation when polled by the uIP layer. * * Parameters: * dev The structure of the network driver that caused the interrupt * conn The connection structure associated with the socket * flags Set of events describing why the callback was invoked * * Returned Value: * None * * Assumptions: * Running at the interrupt level * ****************************************************************************/ static uint16_t send_interrupt(FAR struct uip_driver_s *dev, FAR void *pvconn, FAR void *pvpriv, uint16_t flags) { FAR struct uip_conn *conn = (FAR struct uip_conn*)pvconn; FAR struct socket *psock = (FAR struct socket *)pvpriv; nllvdbg("flags: %04x\n", flags); /* If this packet contains an acknowledgement, then update the count of * acknowledged bytes. */ if ((flags & UIP_ACKDATA) != 0) { FAR sq_entry_t *entry, *next; FAR struct uip_wrbuffer_s *segment; uint32_t ackno; ackno = uip_tcpgetsequence(TCPBUF->ackno); for (entry = sq_peek(&conn->unacked_q); entry; entry = next) { next = sq_next(entry); segment = (FAR struct uip_wrbuffer_s*)entry; if (segment->wb_seqno < ackno) { nllvdbg("ACK: acked=%d buflen=%d ackno=%d\n", segment->wb_seqno, segment->wb_nbytes, ackno); /* Segment was ACKed. Remove from ACK waiting queue */ sq_rem(entry, &conn->unacked_q); /* Return the write buffer to the pool of free buffers */ uip_tcpwrbuffer_release(segment); } } } /* Check for a loss of connection */ else if ((flags & (UIP_CLOSE | UIP_ABORT | UIP_TIMEDOUT)) != 0) { /* Report not connected */ nllvdbg("Lost connection\n"); net_lostconnection(psock, flags); goto end_wait; } /* Check if we are being asked to retransmit data */ else if ((flags & UIP_REXMIT) != 0) { sq_entry_t *entry; /* Put all segments that have been sent but not ACKed to write queue * again note, the un-ACKed segment is put at the first of the write_q, * so it can be sent as soon as possible. */ while ((entry = sq_remlast(&conn->unacked_q))) { struct uip_wrbuffer_s *segment = (struct uip_wrbuffer_s*)entry; if (segment->wb_nrtx >= UIP_MAXRTX) { //conn->unacked -= segment->wb_nbytes; /* Return the write buffer */ uip_tcpwrbuffer_release(segment); /* NOTE expired is different from un-ACKed, it is designed to * represent the number of segments that have been sent, * retransmitted, and un-ACKed, if expired is not zero, the * connection will be closed. * * field expired can only be updated at UIP_ESTABLISHED state */ conn->expired++; continue; } send_insert_seqment(segment, &conn->write_q); } } /* Check if the outgoing packet is available (it may have been claimed * by a sendto interrupt serving a different thread). */ if (dev->d_sndlen > 0) { /* Another thread has beat us sending data, wait for the next poll */ return flags; } /* We get here if (1) not all of the data has been ACKed, (2) we have been * asked to retransmit data, (3) the connection is still healthy, and (4) * the outgoing packet is available for our use. In this case, we are * now free to send more data to receiver -- UNLESS the buffer contains * unprocesed incoming data. In that event, we will have to wait for the * next polling cycle. */ if ((conn->tcpstateflags & UIP_ESTABLISHED) && (flags & (UIP_POLL | UIP_REXMIT)) && !(sq_empty(&conn->write_q))) { /* Check if the destination IP address is in the ARP table. If not, * then the send won't actually make it out... it will be replaced with * an ARP request. * * NOTE 1: This could be an expensive check if there are a lot of * entries in the ARP table. * * NOTE 2: If we are actually harvesting IP addresses on incomming IP * packets, then this check should not be necessary; the MAC mapping * should already be in the ARP table. */ #if defined(CONFIG_NET_ETHERNET) && !defined(CONFIG_NET_ARP_IPIN) if (uip_arp_find(conn->ripaddr) != NULL) #endif { FAR struct uip_wrbuffer_s *segment; FAR void *sndbuf; size_t sndlen; /* Get the amount of data that we can send in the next packet */ segment = (FAR struct uip_wrbuffer_s *)sq_remfirst(&conn->write_q); if (segment) { sndbuf = segment->wb_buffer; sndlen = segment->wb_nbytes; DEBUGASSERT(sndlen <= uip_mss(conn)); /* REVISIT: There should be a check here to assure that we do * not excced the window (conn->winsize). */ /* Set the sequence number for this segment. NOTE: uIP * updates sndseq on receipt of ACK *before* this function * is called. In that case sndseq will point to the next * unacknowledged byte (which might have already been * sent). We will overwrite the value of sndseq here * before the packet is sent. */ if (segment->wb_nrtx == 0 && segment->wb_seqno == (unsigned)-1) { segment->wb_seqno = conn->isn + conn->sent; } uip_tcpsetsequence(conn->sndseq, segment->wb_seqno); /* Then set-up to send that amount of data. (this won't * actually happen until the polling cycle completes). */ uip_send(dev, sndbuf, sndlen); /* Remember how much data we send out now so that we know * when everything has been acknowledged. Just increment * the amount of data sent. This will be needed in * sequence* number calculations and we know that this is * not a re-transmission. Re-transmissions do not go through * this path. */ if (segment->wb_nrtx == 0) { conn->unacked += sndlen; conn->sent += sndlen; } /* Increment the retransmission counter before expiration. * NOTE we will not calculate the retransmission timer * (RTT) to save cpu cycles, each send_insert_seqment * segment will be retransmitted UIP_MAXRTX times in halt- * second interval before expiration. */ segment->wb_nrtx++; /* The segment is waiting for ACK again */ send_insert_seqment(segment, &conn->unacked_q); /* Only one data can be sent by low level driver at once, * tell the caller stop polling the other connection. */ flags &= ~UIP_POLL; } } } /* Continue waiting */ return flags; end_wait: /* Do not allow any further callbacks */ psock->s_sndcb->flags = 0; psock->s_sndcb->event = NULL; return flags; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Function: psock_send * * Description: * The send() call may be used only when the socket is in a connected state * (so that the intended recipient is known). The only difference between * send() and write() is the presence of flags. With zero flags parameter, * send() is equivalent to write(). Also, send(sockfd,buf,len,flags) is * equivalent to sendto(sockfd,buf,len,flags,NULL,0). * * Parameters: * psock An instance of the internal socket structure. * buf Data to send * len Length of data to send * flags Send flags * * Returned Value: * On success, returns the number of characters sent. On error, * -1 is returned, and errno is set appropriately: * * EAGAIN or EWOULDBLOCK * The socket is marked non-blocking and the requested operation * would block. * EBADF * An invalid descriptor was specified. * ECONNRESET * Connection reset by peer. * EDESTADDRREQ * The socket is not connection-mode, and no peer address is set. * EFAULT * An invalid user space address was specified for a parameter. * EINTR * A signal occurred before any data was transmitted. * EINVAL * Invalid argument passed. * EISCONN * The connection-mode socket was connected already but a recipient * was specified. (Now either this error is returned, or the recipient * specification is ignored.) * EMSGSIZE * The socket type requires that message be sent atomically, and the * size of the message to be sent made this impossible. * ENOBUFS * The output queue for a network interface was full. This generally * indicates that the interface has stopped sending, but may be * caused by transient congestion. * ENOMEM * No memory available. * ENOTCONN * The socket is not connected, and no target has been given. * ENOTSOCK * The argument s is not a socket. * EOPNOTSUPP * Some bit in the flags argument is inappropriate for the socket * type. * EPIPE * The local end has been shut down on a connection oriented socket. * In this case the process will also receive a SIGPIPE unless * MSG_NOSIGNAL is set. * * Assumptions: * ****************************************************************************/ ssize_t psock_send(FAR struct socket *psock, FAR const void *buf, size_t len, int flags) { uip_lock_t save; size_t completed = 0; int err; int ret = OK; if (!psock || psock->s_crefs <= 0) { err = EBADF; goto errout; } if (psock->s_type != SOCK_STREAM || !_SS_ISCONNECTED(psock->s_flags)) { err = ENOTCONN; goto errout; } /* Set the socket state to sending */ psock->s_flags = _SS_SETSTATE(psock->s_flags, _SF_SEND); save = uip_lock(); if (len > 0) { struct uip_conn *conn = (struct uip_conn*)psock->s_conn; if (!psock->s_sndcb) { psock->s_sndcb = uip_tcpcallbackalloc(conn); /* Set up the callback in the connection */ psock->s_sndcb->flags = (UIP_ACKDATA | UIP_REXMIT |UIP_POLL | \ UIP_CLOSE | UIP_ABORT | UIP_TIMEDOUT); psock->s_sndcb->priv = (void*)psock; psock->s_sndcb->event = send_interrupt; } /* Allocate resources to receive a callback */ while (completed < len) { FAR struct uip_wrbuffer_s *segment = uip_tcpwrbuffer_alloc(NULL); if (segment) { size_t cnt; segment->wb_seqno = (unsigned)-1; segment->wb_nrtx = 0; if (len - completed > CONFIG_NET_TCP_WRITE_BUFSIZE) { cnt = CONFIG_NET_TCP_WRITE_BUFSIZE; } else { cnt = len - completed; } segment->wb_nbytes = cnt; memcpy(segment->wb_buffer, (char*)buf + completed, cnt); completed += cnt; /* send_interrupt() will refer to all the write buffer by * conn->writebuff */ sq_addlast(&segment->wb_node, &conn->write_q); /* Notify the device driver of the availability of TX data */ netdev_txnotify(conn->ripaddr); } } } uip_unlock(save); /* Set the socket state to idle */ psock->s_flags = _SS_SETSTATE(psock->s_flags, _SF_IDLE); /* Check for a errors. Errors are signaled by negative errno values * for the send length */ if (completed < 0) { err = completed; goto errout; } /* If uip_lockedwait failed, then we were probably reawakened by a signal. * In this case, uip_lockedwait will have set errno appropriately. */ if (ret < 0) { err = -ret; goto errout; } /* Return the number of bytes actually sent */ return completed; errout: set_errno(err); return ERROR; } #endif /* CONFIG_NET && CONFIG_NET_TCP && CONFIG_NET_TCP_WRITE_BUFFERS */