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nuttx/net/udp/udp_recvfrom.c
Michael Jung 61f3bd10a5 Fix udp recvfrom to correctly return addrlen 
According to POSIX the length of the source address of the received
message shall be stored in the object pointed to by the address_len
argument.

This patch fixes two places where this did not happen correctly.

Signed-off-by: Michael Jung <michael.jung@secore.ly>
2022-04-28 20:25:38 +08:00

702 lines
20 KiB
C
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/****************************************************************************
* net/udp/udp_recvfrom.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#if defined(CONFIG_NET) && defined(CONFIG_NET_UDP)
#include <string.h>
#include <errno.h>
#include <debug.h>
#include <assert.h>
#include <nuttx/semaphore.h>
#include <nuttx/net/net.h>
#include <nuttx/mm/iob.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/ip.h>
#include <nuttx/net/udp.h>
#include "netdev/netdev.h"
#include "devif/devif.h"
#include "udp/udp.h"
#include "socket/socket.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define IPv4BUF ((FAR struct ipv4_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)])
#define IPv6BUF ((FAR struct ipv6_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)])
#define UDPIPv4BUF ((FAR struct udp_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev) + IPv4_HDRLEN])
#define UDPIPv6BUF ((FAR struct udp_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev) + IPv6_HDRLEN])
/****************************************************************************
* Private Types
****************************************************************************/
struct udp_recvfrom_s
{
FAR struct udp_conn_s *ir_conn; /* Connection associated with the socket */
FAR struct devif_callback_s *ir_cb; /* Reference to callback instance */
sem_t ir_sem; /* Semaphore signals recv completion */
size_t ir_buflen; /* Length of receive buffer */
uint8_t *ir_buffer; /* Pointer to receive buffer */
FAR struct sockaddr *ir_from; /* Address of sender */
FAR socklen_t *ir_fromlen; /* Number of bytes allocated for address of sender */
ssize_t ir_recvlen; /* The received length */
int ir_result; /* Success:OK, failure:negated errno */
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: udp_update_recvlen
*
* Description:
* Update information about space available for new data and update size
* of data in buffer, This logic accounts for the case where
* udp_readahead() sets state.ir_recvlen == -1 .
*
* Input Parameters:
* pstate recvfrom state structure
* recvlen size of new data appended to buffer
*
* Returned Value:
* None
*
****************************************************************************/
static inline void udp_update_recvlen(FAR struct udp_recvfrom_s *pstate,
size_t recvlen)
{
if (pstate->ir_recvlen < 0)
{
pstate->ir_recvlen = 0;
}
pstate->ir_recvlen += recvlen;
pstate->ir_buffer += recvlen;
pstate->ir_buflen -= recvlen;
}
/****************************************************************************
* Name: udp_recvfrom_newdata
*
* Description:
* Copy the read data from the packet
*
* Input Parameters:
* dev The structure of the network driver that generated the event.
* pstate recvfrom state structure
*
* Returned Value:
* The number of bytes taken from the packet.
*
* Assumptions:
* The network is locked.
*
****************************************************************************/
static size_t udp_recvfrom_newdata(FAR struct net_driver_s *dev,
FAR struct udp_recvfrom_s *pstate)
{
size_t recvlen;
/* Get the length of the data to return */
if (dev->d_len > pstate->ir_buflen)
{
recvlen = pstate->ir_buflen;
}
else
{
recvlen = dev->d_len;
}
/* Copy the new appdata into the user buffer */
memcpy(pstate->ir_buffer, dev->d_appdata, recvlen);
ninfo("Received %d bytes (of %d)\n", (int)recvlen, (int)dev->d_len);
/* Update the accumulated size of the data read */
udp_update_recvlen(pstate, recvlen);
return recvlen;
}
/****************************************************************************
* Name: udp_newdata
*
* Description:
* Copy the read data from the packet
*
* Input Parameters:
* dev The structure of the network driver that generated the event
* pstate recvfrom state structure
*
* Returned Value:
* None.
*
* Assumptions:
* The network is locked.
*
****************************************************************************/
static inline void udp_newdata(FAR struct net_driver_s *dev,
FAR struct udp_recvfrom_s *pstate)
{
/* Take as much data from the packet as we can */
udp_recvfrom_newdata(dev, pstate);
/* Indicate no data in the buffer */
dev->d_len = 0;
}
static inline void udp_readahead(struct udp_recvfrom_s *pstate)
{
FAR struct udp_conn_s *conn = pstate->ir_conn;
FAR struct iob_s *iob;
int recvlen;
/* Check there is any UDP datagram already buffered in a read-ahead
* buffer.
*/
pstate->ir_recvlen = -1;
if ((iob = iob_peek_queue(&conn->readahead)) != NULL)
{
FAR struct iob_s *tmp;
uint8_t src_addr_size;
DEBUGASSERT(iob->io_pktlen > 0);
/* Transfer that buffered data from the I/O buffer chain into
* the user buffer.
*/
recvlen = iob_copyout(&src_addr_size, iob, sizeof(uint8_t), 0);
if (recvlen != sizeof(uint8_t))
{
goto out;
}
if (0
#ifdef CONFIG_NET_IPv6
|| src_addr_size == sizeof(struct sockaddr_in6)
#endif
#ifdef CONFIG_NET_IPv4
|| src_addr_size == sizeof(struct sockaddr_in)
#endif
)
{
if (pstate->ir_from)
{
socklen_t len = *pstate->ir_fromlen;
len = (socklen_t)
src_addr_size > len ? len : (socklen_t)src_addr_size;
recvlen = iob_copyout((FAR uint8_t *)pstate->ir_from, iob,
len, sizeof(uint8_t));
if (recvlen != len)
{
goto out;
}
}
}
if (pstate->ir_buflen > 0)
{
recvlen = iob_copyout(pstate->ir_buffer, iob, pstate->ir_buflen,
src_addr_size + sizeof(uint8_t));
ninfo("Received %d bytes (of %d)\n", recvlen, iob->io_pktlen);
/* Update the accumulated size of the data read */
pstate->ir_recvlen = recvlen;
pstate->ir_buffer += recvlen;
pstate->ir_buflen -= recvlen;
*pstate->ir_fromlen = src_addr_size;
}
else
{
pstate->ir_recvlen = 0;
}
out:
/* Remove the I/O buffer chain from the head of the read-ahead
* buffer queue.
*/
tmp = iob_remove_queue(&conn->readahead);
DEBUGASSERT(tmp == iob);
UNUSED(tmp);
/* And free the I/O buffer chain */
iob_free_chain(iob, IOBUSER_NET_UDP_READAHEAD);
}
}
/****************************************************************************
* Name: udp_sender
*
* Description:
* Getting the sender's address from the UDP packet
*
* Input Parameters:
* dev - The device driver data structure
* pstate - the recvfrom state structure
*
* Returned Value:
* None
*
* Assumptions:
* The network is locked.
*
****************************************************************************/
static inline void udp_sender(FAR struct net_driver_s *dev,
FAR struct udp_recvfrom_s *pstate)
{
/* Get the family from the packet type, IP address from the IP header, and
* the port number from the UDP header.
*/
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
if (IFF_IS_IPv6(dev->d_flags))
#endif
{
FAR struct sockaddr_in6 *infrom =
(FAR struct sockaddr_in6 *)pstate->ir_from;
FAR socklen_t *fromlen = pstate->ir_fromlen;
if (infrom)
{
FAR struct udp_hdr_s *udp = UDPIPv6BUF;
FAR struct ipv6_hdr_s *ipv6 = IPv6BUF;
infrom->sin6_family = AF_INET6;
infrom->sin6_port = udp->srcport;
*fromlen = sizeof(struct sockaddr_in6);
net_ipv6addr_copy(infrom->sin6_addr.s6_addr, ipv6->srcipaddr);
}
}
#endif /* CONFIG_NET_IPv6 */
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
else
#endif
{
FAR struct sockaddr_in *infrom =
(FAR struct sockaddr_in *)pstate->ir_from;
FAR socklen_t *fromlen = pstate->ir_fromlen;
if (infrom)
{
#ifdef CONFIG_NET_IPv6
FAR struct udp_conn_s *conn = pstate->ir_conn;
/* Hybrid dual-stack IPv6/IPv4 implementations recognize a special
* class of addresses, the IPv4-mapped IPv6 addresses.
*/
if (conn->domain == PF_INET6)
{
FAR struct sockaddr_in6 *infrom6 =
(FAR struct sockaddr_in6 *)infrom;
FAR struct udp_hdr_s *udp = UDPIPv6BUF;
FAR struct ipv6_hdr_s *ipv6 = IPv6BUF;
in_addr_t ipv4addr;
/* Encode the IPv4 address as an IPv4-mapped IPv6 address */
infrom6->sin6_family = AF_INET6;
infrom6->sin6_port = udp->srcport;
*fromlen = sizeof(struct sockaddr_in6);
ipv4addr = net_ip4addr_conv32(ipv6->srcipaddr);
ip6_map_ipv4addr(ipv4addr, infrom6->sin6_addr.s6_addr16);
}
else
#endif
{
FAR struct udp_hdr_s *udp = UDPIPv4BUF;
FAR struct ipv4_hdr_s *ipv4 = IPv4BUF;
infrom->sin_family = AF_INET;
infrom->sin_port = udp->srcport;
*fromlen = sizeof(struct sockaddr_in);
net_ipv4addr_copy(infrom->sin_addr.s_addr,
net_ip4addr_conv32(ipv4->srcipaddr));
memset(infrom->sin_zero, 0, sizeof(infrom->sin_zero));
}
}
}
#endif /* CONFIG_NET_IPv4 */
}
/****************************************************************************
* Name: udp_terminate
*
* Description:
* Terminate the UDP transfer.
*
* Input Parameters:
* pstate - The recvfrom state structure
* result - The result of the operation
*
* Returned Value:
* None
*
****************************************************************************/
static void udp_terminate(FAR struct udp_recvfrom_s *pstate, int result)
{
/* Don't allow any further UDP call backs. */
pstate->ir_cb->flags = 0;
pstate->ir_cb->priv = NULL;
pstate->ir_cb->event = NULL;
/* Save the result of the transfer */
pstate->ir_result = result;
/* Wake up the waiting thread, returning the number of bytes
* actually read.
*/
nxsem_post(&pstate->ir_sem);
}
/****************************************************************************
* Name: udp_eventhandler
*
* Description:
* This function is called with the network locked to perform the actual
* UDP receive operation via by the lower, device interfacing layer.
*
* Input Parameters:
* dev The structure of the network driver that generated the event.
* pvconn The connection structure associated with the socket
* flags Set of events describing why the callback was invoked
*
* Returned Value:
* None
*
* Assumptions:
* The network is locked.
*
****************************************************************************/
static uint16_t udp_eventhandler(FAR struct net_driver_s *dev,
FAR void *pvconn, FAR void *pvpriv,
uint16_t flags)
{
FAR struct udp_recvfrom_s *pstate = (FAR struct udp_recvfrom_s *)pvpriv;
ninfo("flags: %04x\n", flags);
/* 'priv' might be null in some race conditions (?) */
if (pstate)
{
/* If the network device has gone down, then we will have terminate
* the wait now with an error.
*/
if ((flags & NETDEV_DOWN) != 0)
{
/* Terminate the transfer with an error. */
nerr("ERROR: Network is down\n");
udp_terminate(pstate, -ENETUNREACH);
}
/* If new data is available, then complete the read action. */
else if ((flags & UDP_NEWDATA) != 0)
{
/* Copy the data from the packet */
udp_newdata(dev, pstate);
/* We are finished. */
ninfo("UDP done\n");
/* Save the sender's address in the caller's 'from' location */
udp_sender(dev, pstate);
/* Don't allow any further UDP call backs. */
udp_terminate(pstate, OK);
/* Indicate that the data has been consumed */
flags &= ~UDP_NEWDATA;
}
}
return flags;
}
/****************************************************************************
* Name: udp_recvfrom_initialize
*
* Description:
* Initialize the state structure
*
* Input Parameters:
* conn The UDP connection of interest
* buf Buffer to receive data
* len Length of buffer
* pstate A pointer to the state structure to be initialized
*
* Returned Value:
* None
*
* Assumptions:
*
****************************************************************************/
static void udp_recvfrom_initialize(FAR struct udp_conn_s *conn,
FAR void *buf, size_t len,
FAR struct sockaddr *infrom,
FAR socklen_t *fromlen,
FAR struct udp_recvfrom_s *pstate)
{
/* Initialize the state structure. */
memset(pstate, 0, sizeof(struct udp_recvfrom_s));
/* This semaphore is used for signaling and, hence, should not have
* priority inheritance enabled.
*/
nxsem_init(&pstate->ir_sem, 0, 0); /* Doesn't really fail */
nxsem_set_protocol(&pstate->ir_sem, SEM_PRIO_NONE);
pstate->ir_buflen = len;
pstate->ir_buffer = buf;
pstate->ir_from = infrom;
pstate->ir_fromlen = fromlen;
/* Set up the start time for the timeout */
pstate->ir_conn = conn;
}
/* The only un-initialization that has to be performed is destroying the
* semaphore.
*/
#define udp_recvfrom_uninitialize(s) nxsem_destroy(&(s)->ir_sem)
/****************************************************************************
* Name: udp_recvfrom_result
*
* Description:
* Evaluate the result of the recv operations
*
* Input Parameters:
* result The result of the net_timedwait operation (may indicate EINTR)
* pstate A pointer to the state structure to be initialized
*
* Returned Value:
* The result of the recv operation with errno set appropriately
*
* Assumptions:
*
****************************************************************************/
static ssize_t udp_recvfrom_result(int result, struct udp_recvfrom_s *pstate)
{
/* Check for a error/timeout detected by the event handler. Errors are
* signaled by negative errno values for the rcv length
*/
if (pstate->ir_result < 0)
{
/* This might return EAGAIN on a timeout or ENOTCONN on loss of
* connection (TCP only)
*/
return pstate->ir_result;
}
/* If net_timedwait failed, then we were probably reawakened by a signal.
* In this case, net_timedwait will have returned negated errno
* appropriately.
*/
if (result < 0)
{
return result;
}
return pstate->ir_recvlen;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: psock_udp_recvfrom
*
* Description:
* Perform the recvfrom operation for a UDP SOCK_DGRAM
*
* Input Parameters:
* psock Pointer to the socket structure for the SOCK_DRAM socket
* buf Buffer to receive data
* len Length of buffer
* from INET address of source (may be NULL)
*
* Returned Value:
* On success, returns the number of characters received. On error,
* -errno is returned (see recvfrom for list of errnos).
*
* Assumptions:
*
****************************************************************************/
ssize_t psock_udp_recvfrom(FAR struct socket *psock, FAR void *buf,
size_t len, int flags, FAR struct sockaddr *from,
FAR socklen_t *fromlen)
{
FAR struct udp_conn_s *conn = (FAR struct udp_conn_s *)psock->s_conn;
FAR struct net_driver_s *dev;
struct udp_recvfrom_s state;
int ret;
/* Perform the UDP recvfrom() operation */
/* Initialize the state structure. This is done with the network locked
* because we don't want anything to happen until we are ready.
*/
net_lock();
udp_recvfrom_initialize(conn, buf, len, from, fromlen, &state);
/* Copy the read-ahead data from the packet */
udp_readahead(&state);
/* The default return value is the number of bytes that we just copied
* into the user buffer. We will return this if the socket has become
* disconnected or if the user request was completely satisfied with
* data from the readahead buffers.
*/
ret = state.ir_recvlen;
/* Handle non-blocking UDP sockets */
if (_SS_ISNONBLOCK(conn->sconn.s_flags) || (flags & MSG_DONTWAIT) != 0)
{
/* Return the number of bytes read from the read-ahead buffer if
* something was received (already in 'ret'); EAGAIN if not.
*/
if (ret < 0)
{
/* Nothing was received */
ret = -EAGAIN;
}
}
/* It is okay to block if we need to. If there is space to receive
* anything more, then we will wait to receive the data. Otherwise
* return the number of bytes read from the read-ahead buffer
* (already in 'ret').
*
* NOTE: that udp_readahead() may set state.ir_recvlen == -1.
*/
else if (state.ir_recvlen <= 0)
{
/* Get the device that will handle the packet transfers. This may be
* NULL if the UDP socket is bound to INADDR_ANY. In that case, no
* NETDEV_DOWN notifications will be received.
*/
dev = udp_find_laddr_device(conn);
/* Set up the callback in the connection */
state.ir_cb = udp_callback_alloc(dev, conn);
if (state.ir_cb)
{
/* Set up the callback in the connection */
state.ir_cb->flags = (UDP_NEWDATA | NETDEV_DOWN);
state.ir_cb->priv = (FAR void *)&state;
state.ir_cb->event = udp_eventhandler;
/* Wait for either the receive to complete or for an error/timeout
* to occur. net_timedwait will also terminate if a signal is
* received.
*/
ret = net_timedwait(&state.ir_sem,
_SO_TIMEOUT(conn->sconn.s_rcvtimeo));
if (ret == -ETIMEDOUT)
{
ret = -EAGAIN;
}
/* Make sure that no further events are processed */
udp_callback_free(dev, conn, state.ir_cb);
ret = udp_recvfrom_result(ret, &state);
}
else
{
ret = -EBUSY;
}
}
net_unlock();
udp_recvfrom_uninitialize(&state);
return ret;
}
#endif /* CONFIG_NET && CONFIG_NET_UDP */
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