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apache / nuttx / d889b7362ddcf7184bd23b3d664924eae9792fb0 / . / net / tcp / tcp_conn.c
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/****************************************************************************
* net/tcp/tcp_conn.c
*
* Copyright (C) 2007-2011, 2013-2015, 2018 Gregory Nutt. All rights
* reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Large parts of this file were leveraged from uIP logic:
*
* Copyright (c) 2001-2003, Adam Dunkels.
* All rights reserved.
*
* 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. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 <nuttx/config.h>
#if defined(CONFIG_NET) && defined(CONFIG_NET_TCP)
#include <stdint.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <sys/random.h>
#include <netinet/in.h>
#include <arch/irq.h>
#include <nuttx/clock.h>
#include <nuttx/kmalloc.h>
#include <nuttx/net/netconfig.h>
#include <nuttx/net/net.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/ip.h>
#include <nuttx/net/tcp.h>
#include "devif/devif.h"
#include "inet/inet.h"
#include "tcp/tcp.h"
#include "arp/arp.h"
#include "icmpv6/icmpv6.h"
#include "nat/nat.h"
#include "netdev/netdev.h"
/****************************************************************************
* Private Data
****************************************************************************/
/* The array containing all TCP connections. */
#if CONFIG_NET_TCP_PREALLOC_CONNS > 0
static struct tcp_conn_s g_tcp_connections[CONFIG_NET_TCP_PREALLOC_CONNS];
#endif
/* A list of all free TCP connections */
static dq_queue_t g_free_tcp_connections;
/* A list of all connected TCP connections */
static dq_queue_t g_active_tcp_connections;
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: tcp_listener
*
* Description:
* Given a local port number (in network byte order), find the TCP
* connection that listens on this port.
*
* Primary uses: (1) to determine if a port number is available, (2) to
* To identify the socket that will accept new connections on a local port.
*
****************************************************************************/
static FAR struct tcp_conn_s *
tcp_listener(uint8_t domain, FAR const union ip_addr_u *ipaddr,
uint16_t portno)
{
FAR struct tcp_conn_s *conn = NULL;
/* Check if this port number is in use by any active UIP TCP connection */
while ((conn = tcp_nextconn(conn)) != NULL)
{
/* Check if this connection is open and the local port assignment
* matches the requested port number.
*/
if (conn->tcpstateflags != TCP_CLOSED && conn->lport == portno
#if defined(CONFIG_NET_IPv4) && defined(CONFIG_NET_IPv6)
&& domain == conn->domain
#endif
)
{
/* If there are multiple interface devices, then the local IP
* address of the connection must also match. INADDR_ANY is a
* special case: There can only be instance of a port number
* with INADDR_ANY.
*/
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
if (domain == PF_INET)
#endif /* CONFIG_NET_IPv6 */
{
if (net_ipv4addr_cmp(conn->u.ipv4.laddr, ipaddr->ipv4) ||
net_ipv4addr_cmp(conn->u.ipv4.laddr, INADDR_ANY))
{
/* The port number is in use, return the connection */
return conn;
}
}
#endif /* CONFIG_NET_IPv4 */
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
else
#endif /* CONFIG_NET_IPv4 */
{
if (net_ipv6addr_cmp(conn->u.ipv6.laddr, ipaddr->ipv6) ||
net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_unspecaddr))
{
/* The port number is in use, return the connection */
return conn;
}
}
#endif /* CONFIG_NET_IPv6 */
}
}
return NULL;
}
/****************************************************************************
* Name: tcp_ipv4_active
*
* Description:
* Find a connection structure that is the appropriate
* connection to be used with the provided TCP/IP header
*
* Assumptions:
* This function is called from network logic with the network locked.
*
****************************************************************************/
#ifdef CONFIG_NET_IPv4
static inline FAR struct tcp_conn_s *
tcp_ipv4_active(FAR struct net_driver_s *dev, FAR struct tcp_hdr_s *tcp)
{
FAR struct ipv4_hdr_s *ip = IPv4BUF;
FAR struct tcp_conn_s *conn;
in_addr_t srcipaddr;
in_addr_t destipaddr;
conn = (FAR struct tcp_conn_s *)g_active_tcp_connections.head;
srcipaddr = net_ip4addr_conv32(ip->srcipaddr);
destipaddr = net_ip4addr_conv32(ip->destipaddr);
while (conn)
{
/* Find an open connection matching the TCP input. The following
* checks are performed:
*
* - The local port number is checked against the destination port
* number in the received packet.
* - The remote port number is checked if the connection is bound
* to a remote port.
* - Insist that the destination IP matches the bound address. If
* a socket is bound to INADDRY_ANY, then it should receive all
* packets directed to the port.
* - Finally, if the connection is bound to a remote IP address,
* the source IP address of the packet is checked.
*
* If all of the above are true then the newly received TCP packet
* is destined for this TCP connection.
*/
if (conn->tcpstateflags != TCP_CLOSED &&
tcp->destport == conn->lport &&
tcp->srcport == conn->rport &&
(net_ipv4addr_cmp(conn->u.ipv4.laddr, INADDR_ANY) ||
net_ipv4addr_cmp(destipaddr, conn->u.ipv4.laddr)) &&
net_ipv4addr_cmp(srcipaddr, conn->u.ipv4.raddr))
{
/* Matching connection found.. break out of the loop and return a
* reference to it.
*/
break;
}
/* Look at the next active connection */
conn = (FAR struct tcp_conn_s *)conn->sconn.node.flink;
}
return conn;
}
#endif /* CONFIG_NET_IPv4 */
/****************************************************************************
* Name: tcp_ipv6_active
*
* Description:
* Find a connection structure that is the appropriate
* connection to be used with the provided TCP/IP header
*
* Assumptions:
* This function is called from network logic with the network locked.
*
****************************************************************************/
#ifdef CONFIG_NET_IPv6
static inline FAR struct tcp_conn_s *
tcp_ipv6_active(FAR struct net_driver_s *dev, FAR struct tcp_hdr_s *tcp)
{
FAR struct ipv6_hdr_s *ip = IPv6BUF;
FAR struct tcp_conn_s *conn;
net_ipv6addr_t *srcipaddr;
net_ipv6addr_t *destipaddr;
conn = (FAR struct tcp_conn_s *)g_active_tcp_connections.head;
srcipaddr = (net_ipv6addr_t *)ip->srcipaddr;
destipaddr = (net_ipv6addr_t *)ip->destipaddr;
while (conn)
{
/* Find an open connection matching the TCP input. The following
* checks are performed:
*
* - The local port number is checked against the destination port
* number in the received packet.
* - The remote port number is checked if the connection is bound
* to a remote port.
* - Insist that the destination IP matches the bound address. If
* a socket is bound to the IPv6 unspecified address, then it
* should receive all packets directed to the port.
* - Finally, if the connection is bound to a remote IP address,
* the source IP address of the packet is checked.
*
* If all of the above are true then the newly received TCP packet
* is destined for this TCP connection.
*/
if (conn->tcpstateflags != TCP_CLOSED &&
tcp->destport == conn->lport &&
tcp->srcport == conn->rport &&
(net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_unspecaddr) ||
net_ipv6addr_cmp(*destipaddr, conn->u.ipv6.laddr)) &&
net_ipv6addr_cmp(*srcipaddr, conn->u.ipv6.raddr))
{
/* Matching connection found.. break out of the loop and return a
* reference to it.
*/
break;
}
/* Look at the next active connection */
conn = (FAR struct tcp_conn_s *)conn->sconn.node.flink;
}
return conn;
}
#endif /* CONFIG_NET_IPv6 */
/****************************************************************************
* Name: tcp_ipv4_bind
*
* Description:
* This function implements the lower level parts of the standard TCP
* bind() operation.
*
* Returned Value:
* 0 on success or -EADDRINUSE on failure
*
* Assumptions:
* This function is called from normal user level code.
*
****************************************************************************/
#ifdef CONFIG_NET_IPv4
static inline int tcp_ipv4_bind(FAR struct tcp_conn_s *conn,
FAR const struct sockaddr_in *addr)
{
int port;
int ret;
FAR struct net_driver_s *dev;
/* Verify or select a local port and address */
net_lock();
if (conn->lport != 0)
{
net_unlock();
return -EINVAL;
}
if (!net_ipv4addr_cmp(addr->sin_addr.s_addr, INADDR_ANY) &&
!net_ipv4addr_cmp(addr->sin_addr.s_addr, HTONL(INADDR_LOOPBACK)) &&
!net_ipv4addr_cmp(addr->sin_addr.s_addr, INADDR_BROADCAST) &&
!IN_MULTICAST(NTOHL(addr->sin_addr.s_addr)))
{
ret = -EADDRNOTAVAIL;
for (dev = g_netdevices; dev; dev = dev->flink)
{
if (net_ipv4addr_cmp(addr->sin_addr.s_addr, dev->d_ipaddr))
{
ret = 0;
break;
}
}
if (ret == -EADDRNOTAVAIL)
{
net_unlock();
return ret;
}
}
/* Verify or select a local port (network byte order) */
port = tcp_selectport(PF_INET,
(FAR const union ip_addr_u *)&addr->sin_addr.s_addr,
addr->sin_port);
if (port < 0)
{
nerr("ERROR: tcp_selectport failed: %d\n", port);
net_unlock();
return port;
}
/* Save the local address in the connection structure (network order). */
conn->lport = port;
net_ipv4addr_copy(conn->u.ipv4.laddr, addr->sin_addr.s_addr);
/* Find the device that can receive packets on the network associated with
* this local address.
*/
ret = tcp_local_ipv4_device(conn);
if (ret < 0)
{
/* If no device is found, then the address is not reachable */
nerr("ERROR: tcp_local_ipv4_device failed: %d\n", ret);
/* Back out the local address setting */
conn->lport = 0;
net_ipv4addr_copy(conn->u.ipv4.laddr, INADDR_ANY);
}
net_unlock();
return ret;
}
#endif /* CONFIG_NET_IPv4 */
/****************************************************************************
* Name: tcp_ipv6_bind
*
* Description:
* This function implements the lower level parts of the standard TCP
* bind() operation.
*
* Returned Value:
* 0 on success or -EADDRINUSE on failure
*
* Assumptions:
* This function is called from normal user level code.
*
****************************************************************************/
#ifdef CONFIG_NET_IPv6
static inline int tcp_ipv6_bind(FAR struct tcp_conn_s *conn,
FAR const struct sockaddr_in6 *addr)
{
int port;
int ret;
FAR struct net_driver_s *dev;
/* Verify or select a local port and address */
net_lock();
if (conn->lport != 0)
{
net_unlock();
return -EINVAL;
}
if (!net_ipv6addr_cmp(addr->sin6_addr.in6_u.u6_addr16,
g_ipv6_unspecaddr) &&
!net_ipv6addr_cmp(addr->sin6_addr.in6_u.u6_addr16,
g_ipv6_loopback) &&
!net_ipv6addr_cmp(addr->sin6_addr.in6_u.u6_addr16,
g_ipv6_allnodes) &&
!net_ipv6addr_cmp(addr->sin6_addr.in6_u.u6_addr16, g_ipv6_allnodes))
{
ret = -EADDRNOTAVAIL;
for (dev = g_netdevices; dev; dev = dev->flink)
{
if (net_ipv6addr_cmp(addr->sin6_addr.in6_u.u6_addr16,
dev->d_ipv6addr))
{
ret = 0;
break;
}
}
if (ret == -EADDRNOTAVAIL)
{
net_unlock();
return ret;
}
}
/* Verify or select a local port (network byte order) */
/* The port number must be unique for this address binding */
port = tcp_selectport(PF_INET6,
(FAR const union ip_addr_u *)addr->sin6_addr.in6_u.u6_addr16,
addr->sin6_port);
if (port < 0)
{
nerr("ERROR: tcp_selectport failed: %d\n", port);
net_unlock();
return port;
}
/* Save the local address in the connection structure (network order). */
conn->lport = port;
net_ipv6addr_copy(conn->u.ipv6.laddr, addr->sin6_addr.in6_u.u6_addr16);
/* Find the device that can receive packets on the network
* associated with this local address.
*/
ret = tcp_local_ipv6_device(conn);
if (ret < 0)
{
/* If no device is found, then the address is not reachable */
nerr("ERROR: tcp_local_ipv6_device failed: %d\n", ret);
/* Back out the local address setting */
conn->lport = 0;
net_ipv6addr_copy(conn->u.ipv6.laddr, g_ipv6_unspecaddr);
}
net_unlock();
return ret;
}
#endif /* CONFIG_NET_IPv6 */
/****************************************************************************
* Name: tcp_alloc_conn
*
* Description:
* Find or allocate a free TCP/IP connection structure for use.
*
****************************************************************************/
#if CONFIG_NET_TCP_ALLOC_CONNS > 0
static FAR struct tcp_conn_s *tcp_alloc_conn(void)
{
FAR struct tcp_conn_s *conn;
int i;
/* Return the entry from the head of the free list */
if (dq_peek(&g_free_tcp_connections) == NULL)
{
#if CONFIG_NET_TCP_MAX_CONNS > 0
if (dq_count(&g_active_tcp_connections) + CONFIG_NET_TCP_ALLOC_CONNS
>= CONFIG_NET_TCP_MAX_CONNS)
{
return NULL;
}
#endif
conn = kmm_zalloc(sizeof(struct tcp_conn_s) *
CONFIG_NET_TCP_ALLOC_CONNS);
if (conn == NULL)
{
return conn;
}
/* Now initialize each connection structure */
for (i = 0; i < CONFIG_NET_TCP_ALLOC_CONNS; i++)
{
/* Mark the connection closed and move it to the free list */
conn[i].tcpstateflags = TCP_CLOSED;
dq_addlast(&conn[i].sconn.node, &g_free_tcp_connections);
}
}
return (FAR struct tcp_conn_s *)dq_remfirst(&g_free_tcp_connections);
}
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: tcp_selectport
*
* Description:
* If the port number is zero; select an unused port for the connection.
* If the port number is non-zero, verify that no other connection has
* been created with this port number.
*
* Input Parameters:
* portno -- the selected port number in network order. Zero means no port
* selected.
*
* Returned Value:
* Selected or verified port number in network order on success, a negated
* errno on failure:
*
* EADDRINUSE
* The given address is already in use.
* EADDRNOTAVAIL
* Cannot assign requested address (unlikely)
*
* Assumptions:
* Interrupts are disabled
*
****************************************************************************/
int tcp_selectport(uint8_t domain,
FAR const union ip_addr_u *ipaddr,
uint16_t portno)
{
static uint16_t g_last_tcp_port;
ssize_t ret;
/* Generate port base dynamically */
if (g_last_tcp_port == 0)
{
ret = getrandom(&g_last_tcp_port, sizeof(uint16_t), 0);
if (ret < 0)
{
ret = getrandom(&g_last_tcp_port, sizeof(uint16_t), GRND_RANDOM);
}
if (ret != sizeof(uint16_t))
{
g_last_tcp_port = clock_systime_ticks() % 32000;
}
else
{
g_last_tcp_port = g_last_tcp_port % 32000;
}
if (g_last_tcp_port < 4096)
{
g_last_tcp_port += 4096;
}
}
if (portno == 0)
{
/* No local port assigned. Loop until we find a valid listen port
* number that is not being used by any other connection. NOTE the
* following loop is assumed to terminate but could not if all
* 32000-4096+1 ports are in used (unlikely).
*/
do
{
/* Guess that the next available port number will be the one after
* the last port number assigned. Make sure that the port number
* is within range.
*/
if (++g_last_tcp_port >= 32000)
{
g_last_tcp_port = 4096;
}
portno = HTONS(g_last_tcp_port);
}
while (tcp_listener(domain, ipaddr, portno)
#if defined(CONFIG_NET_NAT) && defined(CONFIG_NET_IPv4)
|| (domain == PF_INET &&
ipv4_nat_port_inuse(IP_PROTO_TCP, ipaddr->ipv4, portno))
#endif
);
}
else
{
/* A port number has been supplied. Verify that no other TCP/IP
* connection is using this local port.
*/
if (tcp_listener(domain, ipaddr, portno)
#if defined(CONFIG_NET_NAT) && defined(CONFIG_NET_IPv4)
|| (domain == PF_INET &&
ipv4_nat_port_inuse(IP_PROTO_TCP, ipaddr->ipv4, portno))
#endif
)
{
/* It is in use... return EADDRINUSE */
return -EADDRINUSE;
}
}
/* Return the selected or verified port number (host byte order) */
return portno;
}
/****************************************************************************
* Name: tcp_initialize
*
* Description:
* Initialize the TCP/IP connection structures. Called only once and only
* from the network layer at start-up.
*
****************************************************************************/
void tcp_initialize(void)
{
#if CONFIG_NET_TCP_PREALLOC_CONNS > 0
int i;
for (i = 0; i < CONFIG_NET_TCP_PREALLOC_CONNS; i++)
{
/* Mark the connection closed and move it to the free list */
g_tcp_connections[i].tcpstateflags = TCP_CLOSED;
dq_addlast(&g_tcp_connections[i].sconn.node, &g_free_tcp_connections);
}
#endif
}
/****************************************************************************
* Name: tcp_alloc
*
* Description:
* Find a free TCP/IP connection structure and allocate it
* for use. This is normally something done by the implementation of the
* socket() API but is also called from the event processing logic when a
* TCP packet is received while "listening"
*
****************************************************************************/
FAR struct tcp_conn_s *tcp_alloc(uint8_t domain)
{
FAR struct tcp_conn_s *conn;
/* Because this routine is called from both event processing (with the
* network locked) and and from user level. Make sure that the network
* locked in any cased while accessing g_free_tcp_connections[];
*/
net_lock();
/* Return the entry from the head of the free list */
conn = (FAR struct tcp_conn_s *)dq_remfirst(&g_free_tcp_connections);
#ifndef CONFIG_NET_SOLINGER
/* Is the free list empty? */
if (!conn)
{
/* As a fall-back, check for connection structures which can be
* stalled.
* Search the active connection list for the oldest connection
* that is about to be closed anyway.
*/
FAR struct tcp_conn_s *tmp =
(FAR struct tcp_conn_s *)g_active_tcp_connections.head;
while (tmp)
{
ninfo("conn: %p state: %02x\n", tmp, tmp->tcpstateflags);
/* Is this connection in a state we can sacrifice. */
if ((tmp->crefs == 0) &&
(tmp->tcpstateflags == TCP_CLOSED ||
tmp->tcpstateflags == TCP_CLOSING ||
tmp->tcpstateflags == TCP_FIN_WAIT_1 ||
tmp->tcpstateflags == TCP_FIN_WAIT_2 ||
tmp->tcpstateflags == TCP_TIME_WAIT ||
tmp->tcpstateflags == TCP_LAST_ACK))
{
/* Yes.. Is it the oldest one we have seen so far? */
if (!conn || tmp->timer < conn->timer)
{
/* Yes.. remember it */
conn = tmp;
}
}
/* Look at the next active connection */
tmp = (FAR struct tcp_conn_s *)tmp->sconn.node.flink;
}
/* Did we find a connection that we can re-use? */
if (conn != NULL)
{
nwarn("WARNING: Closing unestablished connection: %p\n", conn);
/* Yes... free it. This will remove the connection from the list
* of active connections and release all resources held by the
* connection.
*
* REVISIT: Could there be any higher level, socket interface
* that needs to be informed that we did this to them?
*
* Actually yes. When CONFIG_NET_SOLINGER is enabled there is a
* pending callback in netclose_disconnect waiting for getting
* woken up. Otherwise there's the callback too, but no one is
* waiting for it.
*/
tcp_free(conn);
/* Now there should be one free connection. If dynamic connections
* allocation is disabled, it is guaranteed so. In case that
* dynamic connections are used, it may be already in the free
* list, or at least there should be enough space in the heap for
* a new connection.
*/
conn = (FAR struct tcp_conn_s *)
dq_remfirst(&g_free_tcp_connections);
}
}
#endif
/* Allocate the connect entry from heap */
#if CONFIG_NET_TCP_ALLOC_CONNS > 0
if (conn == NULL)
{
conn = tcp_alloc_conn();
}
#endif
net_unlock();
/* Mark the connection allocated */
if (conn)
{
memset(conn, 0, sizeof(struct tcp_conn_s));
conn->sconn.ttl = IP_TTL_DEFAULT;
conn->tcpstateflags = TCP_ALLOCATED;
#if defined(CONFIG_NET_IPv4) && defined(CONFIG_NET_IPv6)
conn->domain = domain;
#endif
#ifdef CONFIG_NET_TCP_KEEPALIVE
conn->keepidle = 2 * DSEC_PER_HOUR;
conn->keepintvl = 2 * DSEC_PER_SEC;
conn->keepcnt = 3;
#endif
#if CONFIG_NET_RECV_BUFSIZE > 0
conn->rcv_bufs = CONFIG_NET_RECV_BUFSIZE;
#endif
#if CONFIG_NET_SEND_BUFSIZE > 0
conn->snd_bufs = CONFIG_NET_SEND_BUFSIZE;
nxsem_init(&conn->snd_sem, 0, 0);
#endif
/* Set the default value of mss to max, this field will changed when
* receive SYN.
*/
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
if (domain == PF_INET)
#endif
{
conn->mss = MIN_IPv4_TCP_INITIAL_MSS;
}
#endif /* CONFIG_NET_IPv4 */
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
else
#endif
{
conn->mss = MIN_IPv6_TCP_INITIAL_MSS;
}
#endif /* CONFIG_NET_IPv6 */
}
return conn;
}
/****************************************************************************
* Name: tcp_free_rx_buffers
*
* Description:
* Free rx buffer of a connection
*
****************************************************************************/
void tcp_free_rx_buffers(FAR struct tcp_conn_s *conn)
{
/* Release any read-ahead buffers attached to the connection */
iob_free_chain(conn->readahead);
conn->readahead = NULL;
#ifdef CONFIG_NET_TCP_OUT_OF_ORDER
/* Release any out-of-order buffers */
if (conn->nofosegs > 0)
{
int i;
for (i = 0; i < conn->nofosegs; i++)
{
iob_free_chain(conn->ofosegs[i].data);
}
conn->nofosegs = 0;
}
#endif /* CONFIG_NET_TCP_OUT_OF_ORDER */
}
/****************************************************************************
* Name: tcp_free
*
* Description:
* Free a connection structure that is no longer in use. This should be
* done by the implementation of close()
*
****************************************************************************/
void tcp_free(FAR struct tcp_conn_s *conn)
{
FAR struct devif_callback_s *cb;
FAR struct devif_callback_s *next;
#ifdef CONFIG_NET_TCP_WRITE_BUFFERS
FAR struct tcp_wrbuffer_s *wrbuffer;
#endif
/* Because g_free_tcp_connections is accessed from user level and event
* processing logic, it is necessary to keep the network locked during this
* operation.
*/
net_lock();
DEBUGASSERT(conn->crefs == 0);
/* Cancel close work */
if ((conn->flags & TCP_CLOSE_ARRANGED) &&
work_cancel(LPWORK, &conn->clswork) != OK)
{
/* Close work is already running, tcp_free will be called again. */
net_unlock();
return;
}
/* Cancel tcp timer */
tcp_stop_timer(conn);
/* Make sure monitor is stopped. */
tcp_stop_monitor(conn, TCP_CLOSE);
/* Free remaining callbacks, actually there should be only the send
* callback for CONFIG_NET_TCP_WRITE_BUFFERS is left.
*/
for (cb = conn->sconn.list; cb; cb = next)
{
next = cb->nxtconn;
tcp_callback_free(conn, cb);
}
/* TCP_ALLOCATED means that that the connection is not in the active list
* yet.
*/
if (conn->tcpstateflags != TCP_ALLOCATED)
{
/* Remove the connection from the active list */
dq_rem(&conn->sconn.node, &g_active_tcp_connections);
}
tcp_free_rx_buffers(conn);
#ifdef CONFIG_NET_TCP_WRITE_BUFFERS
/* Release any write buffers attached to the connection */
while ((wrbuffer = (struct tcp_wrbuffer_s *)
sq_remfirst(&conn->write_q)) != NULL)
{
tcp_wrbuffer_release(wrbuffer);
}
while ((wrbuffer = (struct tcp_wrbuffer_s *)
sq_remfirst(&conn->unacked_q)) != NULL)
{
tcp_wrbuffer_release(wrbuffer);
}
#if CONFIG_NET_SEND_BUFSIZE > 0
/* Notify the send buffer available */
tcp_sendbuffer_notify(conn);
#endif /* CONFIG_NET_SEND_BUFSIZE */
#endif
#ifdef CONFIG_NET_TCPBACKLOG
/* Remove any backlog attached to this connection */
if (conn->backlog)
{
tcp_backlogdestroy(conn);
}
/* If this connection is, itself, backlogged, then remove it from the
* parent connection's backlog list.
*/
if (conn->blparent)
{
tcp_backlogdelete(conn->blparent, conn);
}
#endif
/* Mark the connection available. */
conn->tcpstateflags = TCP_CLOSED;
/* If this is a preallocated or a batch allocated connection store it in
* the free connections list. Else free it.
*/
#if CONFIG_NET_TCP_ALLOC_CONNS == 1
if (conn < g_tcp_connections || conn >= (g_tcp_connections +
CONFIG_NET_TCP_PREALLOC_CONNS))
{
kmm_free(conn);
}
else
#endif
{
dq_addlast(&conn->sconn.node, &g_free_tcp_connections);
}
net_unlock();
}
/****************************************************************************
* Name: tcp_active
*
* Description:
* Find a connection structure that is the appropriate
* connection to be used with the provided TCP/IP header
*
* Assumptions:
* This function is called from network logic with the network locked.
*
****************************************************************************/
FAR struct tcp_conn_s *tcp_active(FAR struct net_driver_s *dev,
FAR struct tcp_hdr_s *tcp)
{
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
if (IFF_IS_IPv6(dev->d_flags))
#endif
{
return tcp_ipv6_active(dev, tcp);
}
#endif /* CONFIG_NET_IPv6 */
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
else
#endif
{
return tcp_ipv4_active(dev, tcp);
}
#endif /* CONFIG_NET_IPv4 */
}
/****************************************************************************
* Name: tcp_nextconn
*
* Description:
* Traverse the list of active TCP connections
*
* Assumptions:
* This function is called from network logic with the network locked.
*
****************************************************************************/
FAR struct tcp_conn_s *tcp_nextconn(FAR struct tcp_conn_s *conn)
{
if (!conn)
{
return (FAR struct tcp_conn_s *)g_active_tcp_connections.head;
}
else
{
return (FAR struct tcp_conn_s *)conn->sconn.node.flink;
}
}
/****************************************************************************
* Name: tcp_alloc_accept
*
* Description:
* Called when driver event processing matches the incoming packet
* with a connection in LISTEN. In that case, this function will create
* a new connection and initialize it to send a SYNACK in return.
*
* Assumptions:
* This function is called from network logic with the network locked.
*
****************************************************************************/
FAR struct tcp_conn_s *tcp_alloc_accept(FAR struct net_driver_s *dev,
FAR struct tcp_hdr_s *tcp,
FAR struct tcp_conn_s *listener)
{
FAR struct tcp_conn_s *conn;
uint8_t domain;
int ret;
/* Get the appropriate IP domain */
#if defined(CONFIG_NET_IPv4) && defined(CONFIG_NET_IPv6)
bool ipv6 = IFF_IS_IPv6(dev->d_flags);
domain = ipv6 ? PF_INET6 : PF_INET;
#elif defined(CONFIG_NET_IPv4)
domain = PF_INET;
#else /* defined(CONFIG_NET_IPv6) */
domain = PF_INET6;
#endif
/* Allocate the connection structure */
conn = tcp_alloc(domain);
if (conn)
{
/* Set up the local address (laddr) and the remote address (raddr)
* that describes the TCP connection.
*/
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
if (ipv6)
#endif
{
FAR struct ipv6_hdr_s *ip = IPv6BUF;
net_ipv6addr_copy(conn->u.ipv6.raddr, ip->srcipaddr);
net_ipv6addr_copy(conn->u.ipv6.laddr, ip->destipaddr);
/* We now have to filter all outgoing transfers so that they use
* only the MSS of this device.
*/
DEBUGASSERT(conn->dev == NULL || conn->dev == dev);
conn->dev = dev;
/* Find the device that can receive packets on the network
* associated with this local address.
*/
ret = tcp_remote_ipv6_device(conn);
}
#endif /* CONFIG_NET_IPv6 */
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
else
#endif
{
FAR struct ipv4_hdr_s *ip = IPv4BUF;
net_ipv4addr_copy(conn->u.ipv4.raddr,
net_ip4addr_conv32(ip->srcipaddr));
/* Set the local address as well */
net_ipv4addr_copy(conn->u.ipv4.laddr,
net_ip4addr_conv32(ip->destipaddr));
/* We now have to filter all outgoing transfers so that they use
* only the MSS of this device.
*/
DEBUGASSERT(conn->dev == NULL || conn->dev == dev);
conn->dev = dev;
/* Find the device that can receive packets on the network
* associated with this local address.
*/
ret = tcp_remote_ipv4_device(conn);
}
#endif /* CONFIG_NET_IPv4 */
/* Verify that a network device that can provide packets to this
* local address was found.
*/
if (ret < 0)
{
/* If no device is found, then the address is not reachable.
* That should be impossible in this context and we should
* probably really just assert here.
*/
nerr("ERROR: Failed to find network device: %d\n", ret);
tcp_free(conn);
return NULL;
}
/* Inherits the necessary fields from listener conn for
* the new connection.
*/
#ifdef CONFIG_NET_SOCKOPTS
conn->sconn.s_rcvtimeo = listener->sconn.s_rcvtimeo;
conn->sconn.s_sndtimeo = listener->sconn.s_sndtimeo;
# ifdef CONFIG_NET_BINDTODEVICE
conn->sconn.s_boundto = listener->sconn.s_boundto;
# endif
#endif
conn->sconn.s_tos = listener->sconn.s_tos;
conn->sconn.ttl = listener->sconn.ttl;
#if CONFIG_NET_RECV_BUFSIZE > 0
conn->rcv_bufs = listener->rcv_bufs;
#endif
#if CONFIG_NET_SEND_BUFSIZE > 0
conn->snd_bufs = listener->snd_bufs;
#endif
conn->mss = listener->mss;
/* Fill in the necessary fields for the new connection. */
conn->rto = TCP_RTO;
conn->sa = 0;
conn->sv = 4;
conn->nrtx = 0;
conn->lport = tcp->destport;
conn->rport = tcp->srcport;
conn->tcpstateflags = TCP_SYN_RCVD;
tcp_initsequence(conn->sndseq);
#if !defined(CONFIG_NET_TCP_WRITE_BUFFERS)
conn->rexmit_seq = tcp_getsequence(conn->sndseq);
#endif
conn->tx_unacked = 1;
#ifdef CONFIG_NET_TCP_WRITE_BUFFERS
conn->expired = 0;
conn->isn = 0;
conn->sent = 0;
conn->sndseq_max = 0;
#endif
#ifdef CONFIG_NET_TCP_CC_NEWRENO
/* Initialize the variables of congestion control */
tcp_cc_init(conn);
#endif
/* rcvseq should be the seqno from the incoming packet + 1. */
memcpy(conn->rcvseq, tcp->seqno, 4);
conn->rcv_adv = tcp_getsequence(conn->rcvseq);
/* Initialize the list of TCP read-ahead buffers */
conn->readahead = NULL;
#ifdef CONFIG_NET_TCP_WRITE_BUFFERS
/* Initialize the write buffer lists */
sq_init(&conn->write_q);
sq_init(&conn->unacked_q);
#endif
/* And, finally, put the connection structure into the active list.
* Interrupts should already be disabled in this context.
*/
dq_addlast(&conn->sconn.node, &g_active_tcp_connections);
tcp_update_retrantimer(conn, TCP_RTO);
}
return conn;
}
/****************************************************************************
* Name: tcp_bind
*
* Description:
* This function implements the lower level parts of the standard TCP
* bind() operation.
*
* Returned Value:
* 0 on success or -EADDRINUSE on failure
*
* Assumptions:
* This function is called from normal user level code.
*
****************************************************************************/
int tcp_bind(FAR struct tcp_conn_s *conn, FAR const struct sockaddr *addr)
{
#if defined(CONFIG_NET_IPv4) && defined(CONFIG_NET_IPv6)
if (conn->domain != addr->sa_family)
{
nerr("ERROR: Invalid address type: %d != %d\n", conn->domain,
addr->sa_family);
return -EINVAL;
}
#endif
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
if (conn->domain == PF_INET)
#endif
{
FAR const struct sockaddr_in *inaddr =
(FAR const struct sockaddr_in *)addr;
return tcp_ipv4_bind(conn, inaddr);
}
#endif /* CONFIG_NET_IPv4 */
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
else
#endif
{
FAR const struct sockaddr_in6 *inaddr =
(FAR const struct sockaddr_in6 *)addr;
return tcp_ipv6_bind(conn, inaddr);
}
#endif /* CONFIG_NET_IPv6 */
}
/****************************************************************************
* Name: tcp_connect
*
* Description:
* This function implements the lower level parts of the standard
* TCP connect() operation: It connects to a remote host using TCP.
*
* This function is used to start a new connection to the specified
* port on the specified host. It uses the connection structure that was
* allocated by a preceding socket() call. It sets the connection to
* the SYN_SENT state and sets the retransmission timer to 0. This will
* cause a TCP SYN segment to be sent out the next time this connection
* is periodically processed, which usually is done within 0.5 seconds
* after the call to tcp_connect().
*
* Assumptions:
* This function is called from normal user level code.
*
****************************************************************************/
int tcp_connect(FAR struct tcp_conn_s *conn, FAR const struct sockaddr *addr)
{
int port;
int ret;
/* The connection is expected to be in the TCP_ALLOCATED state.. i.e.,
* allocated via up_tcpalloc(), but not yet put into the active connections
* list.
*/
if (!conn || conn->tcpstateflags != TCP_ALLOCATED)
{
return -EISCONN;
}
/* If the TCP port has not already been bound to a local port, then select
* one now. We assume that the IP address has been bound to a local device,
* but the port may still be INPORT_ANY.
*/
net_lock();
/* Check if the local port has been bind() */
port = conn->lport;
if (port == 0)
{
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
if (conn->domain == PF_INET)
#endif
{
/* Select a port that is unique for this IPv4 local address
* (network order).
*/
port = tcp_selectport(PF_INET,
(FAR const union ip_addr_u *)
&conn->u.ipv4.laddr, 0);
}
#endif /* CONFIG_NET_IPv4 */
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
else
#endif
{
/* Select a port that is unique for this IPv6 local address
* (network order).
*/
port = tcp_selectport(PF_INET6,
(FAR const union ip_addr_u *)
conn->u.ipv6.laddr, 0);
}
#endif /* CONFIG_NET_IPv6 */
/* Did we have a port assignment? */
if (port < 0)
{
ret = port;
goto errout_with_lock;
}
}
/* Set up the local address (laddr) and the remote address (raddr) that
* describes the TCP connection.
*/
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
if (conn->domain == PF_INET)
#endif
{
FAR const struct sockaddr_in *inaddr =
(FAR const struct sockaddr_in *)addr;
conn->rport = inaddr->sin_port;
/* The sockaddr address is 32-bits in network order.
* Note: 0.0.0.0 is mapped to 127.0.0.1 by convention.
*/
if (inaddr->sin_addr.s_addr == INADDR_ANY)
{
net_ipv4addr_copy(conn->u.ipv4.raddr, HTONL(INADDR_LOOPBACK));
}
else
{
net_ipv4addr_copy(conn->u.ipv4.raddr, inaddr->sin_addr.s_addr);
}
/* Find the device that can receive packets on the network associated
* with this remote address.
*/
ret = tcp_remote_ipv4_device(conn);
}
#endif /* CONFIG_NET_IPv4 */
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
else
#endif
{
FAR const struct sockaddr_in6 *inaddr =
(FAR const struct sockaddr_in6 *)addr;
conn->rport = inaddr->sin6_port;
/* The sockaddr address is 128-bits in network order.
* Note: ::0 is mapped to ::1 by convention.
*/
if (net_ipv6addr_cmp(addr, g_ipv6_unspecaddr))
{
struct in6_addr loopback_sin6_addr = IN6ADDR_LOOPBACK_INIT;
net_ipv6addr_copy(conn->u.ipv6.raddr,
loopback_sin6_addr.s6_addr16);
}
else
{
net_ipv6addr_copy(conn->u.ipv6.raddr, inaddr->sin6_addr.s6_addr16);
}
/* Find the device that can receive packets on the network associated
* with this local address.
*/
ret = tcp_remote_ipv6_device(conn);
}
#endif /* CONFIG_NET_IPv6 */
/* Verify that a network device that can provide packets to this local
* address was found.
*/
if (ret < 0)
{
/* If no device is found, then the address is not reachable. That
* should be impossible in this context and we should probably really
* just assert here.
*/
nerr("ERROR: Failed to find network device: %d\n", ret);
goto errout_with_lock;
}
#if defined(CONFIG_NET_ARP_SEND) || defined(CONFIG_NET_ICMPv6_NEIGHBOR)
#ifdef CONFIG_NET_ARP_SEND
#ifdef CONFIG_NET_ICMPv6_NEIGHBOR
if (conn->domain == PF_INET)
#endif
{
/* Make sure that the IP address mapping is in the ARP table */
ret = arp_send(conn->u.ipv4.raddr);
}
#endif /* CONFIG_NET_ARP_SEND */
#ifdef CONFIG_NET_ICMPv6_NEIGHBOR
#ifdef CONFIG_NET_ARP_SEND
else
#endif
{
/* Make sure that the IP address mapping is in the Neighbor Table */
ret = icmpv6_neighbor(NULL, conn->u.ipv6.raddr);
}
#endif /* CONFIG_NET_ICMPv6_NEIGHBOR */
/* Did we successfully get the address mapping? */
if (ret < 0)
{
ret = -ENETUNREACH;
goto errout_with_lock;
}
#endif /* CONFIG_NET_ARP_SEND || CONFIG_NET_ICMPv6_NEIGHBOR */
/* Initialize and return the connection structure, bind it to the port
* number. At this point, we do not know the size of the initial MSS We
* know the total size of the packet buffer, but we don't yet know the
* size of link layer header.
*/
conn->tcpstateflags = TCP_SYN_SENT;
tcp_initsequence(conn->sndseq);
/* Save initial sndseq to rexmit_seq, otherwise it will be zero */
#if !defined(CONFIG_NET_TCP_WRITE_BUFFERS)
conn->rexmit_seq = tcp_getsequence(conn->sndseq);
#endif
conn->tx_unacked = 1; /* TCP length of the SYN is one. */
conn->nrtx = 0;
conn->timeout = true; /* Send the SYN immediately. */
conn->rto = TCP_RTO;
conn->sa = 0;
conn->sv = 16; /* Initial value of the RTT variance. */
conn->lport = (uint16_t)port;
#ifdef CONFIG_NET_TCP_WRITE_BUFFERS
conn->expired = 0;
conn->isn = 0;
conn->sent = 0;
conn->sndseq_max = 0;
#endif
#ifdef CONFIG_NET_TCP_CC_NEWRENO
/* Initialize the variables of congestion control. */
tcp_cc_init(conn);
#endif
/* Initialize the list of TCP read-ahead buffers */
conn->readahead = NULL;
#ifdef CONFIG_NET_TCP_WRITE_BUFFERS
/* Initialize the TCP write buffer lists */
sq_init(&conn->write_q);
sq_init(&conn->unacked_q);
#endif
/* And, finally, put the connection structure into the active list. */
dq_addlast(&conn->sconn.node, &g_active_tcp_connections);
ret = OK;
errout_with_lock:
net_unlock();
return ret;
}
#endif /* CONFIG_NET && CONFIG_NET_TCP */