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nuttx-apps/netutils/dhcpc/dhcpc.c
Xiang Xiao 857158451b Unify the void cast usage 
1.Remove void cast for function because many place ignore the returned value witout cast
2.Replace void cast for variable with UNUSED macro

Change-Id: Ie644129a563244a6397036789c4c3ea83c4e9b09
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
2020-01-02 23:21:01 +08:00

687 lines
21 KiB
C
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/****************************************************************************
* netutils/dhcpc/dhcpc.c
*
* Copyright (C) 2007, 2009, 2011-2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Based heavily on portions of uIP:
*
* Author: Adam Dunkels <adam@dunkels.com>
* Copyright (c) 2005, Swedish Institute of Computer Science
* 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. Neither the name of the Institute 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 INSTITUTE 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 INSTITUTE 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 <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <debug.h>
#include <arpa/inet.h>
#include <netinet/udp.h>
#include "netutils/dhcpc.h"
#include "netutils/netlib.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration */
/* DHCP Definitions */
#define STATE_INITIAL 0
#define STATE_HAVE_OFFER 1
#define STATE_HAVE_LEASE 2
#define BOOTP_BROADCAST 0x8000
#define DHCP_REQUEST 1
#define DHCP_REPLY 2
#define DHCP_HTYPE_ETHERNET 1
#define DHCP_HLEN_ETHERNET 6
#define DHCP_MSG_LEN 236
#define DHCPC_SERVER_PORT 67
#define DHCPC_CLIENT_PORT 68
#define DHCPDISCOVER 1
#define DHCPOFFER 2
#define DHCPREQUEST 3
#define DHCPDECLINE 4
#define DHCPACK 5
#define DHCPNAK 6
#define DHCPRELEASE 7
#define DHCP_OPTION_SUBNET_MASK 1
#define DHCP_OPTION_ROUTER 3
#define DHCP_OPTION_DNS_SERVER 6
#define DHCP_OPTION_HOST_NAME 12
#define DHCP_OPTION_REQ_IPADDR 50
#define DHCP_OPTION_LEASE_TIME 51
#define DHCP_OPTION_MSG_TYPE 53
#define DHCP_OPTION_SERVER_ID 54
#define DHCP_OPTION_REQ_LIST 55
#define DHCP_OPTION_END 255
#define BUFFER_SIZE 256
/****************************************************************************
* Private Types
****************************************************************************/
struct dhcp_msg
{
uint8_t op;
uint8_t htype;
uint8_t hlen;
uint8_t hops;
uint8_t xid[4];
uint16_t secs;
uint16_t flags;
uint8_t ciaddr[4];
uint8_t yiaddr[4];
uint8_t siaddr[4];
uint8_t giaddr[4];
uint8_t chaddr[16];
#ifndef CONFIG_NET_DHCP_LIGHT
uint8_t sname[64];
uint8_t file[128];
#endif
uint8_t options[312];
};
struct dhcpc_state_s
{
FAR const char *interface;
FAR const void *ds_macaddr;
int ds_maclen;
int sockfd;
struct in_addr ipaddr;
struct in_addr serverid;
struct dhcp_msg packet;
};
/****************************************************************************
* Private Data
****************************************************************************/
static const uint8_t xid[4] = {0xad, 0xde, 0x12, 0x23};
static const uint8_t magic_cookie[4] = {99, 130, 83, 99};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: dhcpc_add<option>
****************************************************************************/
static FAR uint8_t *dhcpc_addhostname(FAR const char *hostname,
FAR uint8_t *optptr)
{
int len = strlen(hostname);
*optptr++ = DHCP_OPTION_HOST_NAME;
*optptr++ = len;
memcpy(optptr, hostname, len);
return optptr + len;
}
static FAR uint8_t *dhcpc_addmsgtype(FAR uint8_t *optptr, uint8_t type)
{
*optptr++ = DHCP_OPTION_MSG_TYPE;
*optptr++ = 1;
*optptr++ = type;
return optptr;
}
static FAR uint8_t *dhcpc_addserverid(FAR struct in_addr *serverid,
FAR uint8_t *optptr)
{
*optptr++ = DHCP_OPTION_SERVER_ID;
*optptr++ = 4;
memcpy(optptr, &serverid->s_addr, 4);
return optptr + 4;
}
static FAR uint8_t *dhcpc_addreqipaddr(FAR struct in_addr *ipaddr,
FAR uint8_t *optptr)
{
*optptr++ = DHCP_OPTION_REQ_IPADDR;
*optptr++ = 4;
memcpy(optptr, &ipaddr->s_addr, 4);
return optptr + 4;
}
static FAR uint8_t *dhcpc_addreqoptions(FAR uint8_t *optptr)
{
*optptr++ = DHCP_OPTION_REQ_LIST;
*optptr++ = 3;
*optptr++ = DHCP_OPTION_SUBNET_MASK;
*optptr++ = DHCP_OPTION_ROUTER;
*optptr++ = DHCP_OPTION_DNS_SERVER;
return optptr;
}
static FAR uint8_t *dhcpc_addend(FAR uint8_t *optptr)
{
*optptr++ = DHCP_OPTION_END;
return optptr;
}
/****************************************************************************
* Name: dhcpc_sendmsg
****************************************************************************/
static int dhcpc_sendmsg(FAR struct dhcpc_state_s *pdhcpc,
FAR struct dhcpc_state *presult, int msgtype)
{
struct sockaddr_in addr;
FAR uint8_t *pend;
in_addr_t serverid = INADDR_BROADCAST;
int len;
/* Create the common message header settings */
memset(&pdhcpc->packet, 0, sizeof(struct dhcp_msg));
pdhcpc->packet.op = DHCP_REQUEST;
pdhcpc->packet.htype = DHCP_HTYPE_ETHERNET;
pdhcpc->packet.hlen = pdhcpc->ds_maclen;
memcpy(pdhcpc->packet.xid, xid, 4);
memcpy(pdhcpc->packet.chaddr, pdhcpc->ds_macaddr, pdhcpc->ds_maclen);
memset(&pdhcpc->packet.chaddr[pdhcpc->ds_maclen], 0, 16 - pdhcpc->ds_maclen);
memcpy(pdhcpc->packet.options, magic_cookie, sizeof(magic_cookie));
/* Add the common header options */
pend = &pdhcpc->packet.options[4];
pend = dhcpc_addmsgtype(pend, msgtype);
/* Handle the message specific settings */
switch (msgtype)
{
/* Broadcast DISCOVER message to all servers */
case DHCPDISCOVER:
/* REVISIT: We don't need the broadcast flag since we can receive
* unicast traffic before being fully configured.
*/
pdhcpc->packet.flags = HTONS(BOOTP_BROADCAST); /* Broadcast bit. */
pend = dhcpc_addhostname(CONFIG_NETUTILS_DHCPC_HOST_NAME, pend);
pend = dhcpc_addreqoptions(pend);
break;
/* Send REQUEST message to the server that sent the *first* OFFER */
case DHCPREQUEST:
/* REVISIT: We don't need the broadcast flag since we can receive
* unicast traffic before being fully configured.
*/
pdhcpc->packet.flags = HTONS(BOOTP_BROADCAST); /* Broadcast bit. */
pend = dhcpc_addhostname(CONFIG_NETUTILS_DHCPC_HOST_NAME, pend);
pend = dhcpc_addserverid(&pdhcpc->serverid, pend);
pend = dhcpc_addreqipaddr(&pdhcpc->ipaddr, pend);
break;
/* Send DECLINE message to the server that sent the *last* OFFER */
case DHCPDECLINE:
memcpy(pdhcpc->packet.ciaddr, &presult->ipaddr.s_addr, 4);
pend = dhcpc_addserverid(&presult->serverid, pend);
serverid = presult->serverid.s_addr;
break;
default:
return ERROR;
}
pend = dhcpc_addend(pend);
len = pend - (uint8_t*)&pdhcpc->packet;
/* Send the request */
addr.sin_family = AF_INET;
addr.sin_port = HTONS(DHCPC_SERVER_PORT);
addr.sin_addr.s_addr = serverid;
return sendto(pdhcpc->sockfd, &pdhcpc->packet, len, 0,
(struct sockaddr*)&addr, sizeof(struct sockaddr_in));
}
/****************************************************************************
* Name: dhcpc_parseoptions
****************************************************************************/
static uint8_t dhcpc_parseoptions(FAR struct dhcpc_state *presult,
FAR uint8_t *optptr, int len)
{
FAR uint8_t *end = optptr + len;
uint8_t type = 0;
while (optptr < end)
{
switch(*optptr)
{
case DHCP_OPTION_SUBNET_MASK:
/* Get subnet mask in network order */
memcpy(&presult->netmask.s_addr, optptr + 2, 4);
break;
case DHCP_OPTION_ROUTER:
/* Get the default router address in network order */
memcpy(&presult->default_router.s_addr, optptr + 2, 4);
break;
case DHCP_OPTION_DNS_SERVER:
/* Get the DNS server address in network order */
memcpy(&presult->dnsaddr.s_addr, optptr + 2, 4);
break;
case DHCP_OPTION_MSG_TYPE:
/* Get message type */
type = *(optptr + 2);
break;
case DHCP_OPTION_SERVER_ID:
/* Get server address in network order */
memcpy(&presult->serverid.s_addr, optptr + 2, 4);
break;
case DHCP_OPTION_LEASE_TIME:
{
/* Get lease time (in seconds) in host order */
uint16_t tmp[2];
memcpy(tmp, optptr + 2, 4);
presult->lease_time = ((uint32_t)ntohs(tmp[0])) << 16 |
(uint32_t)ntohs(tmp[1]);
}
break;
case DHCP_OPTION_END:
return type;
}
optptr += optptr[1] + 2;
}
return type;
}
/****************************************************************************
* Name: dhcpc_parsemsg
****************************************************************************/
static uint8_t dhcpc_parsemsg(FAR struct dhcpc_state_s *pdhcpc, int buflen,
FAR struct dhcpc_state *presult)
{
if (pdhcpc->packet.op == DHCP_REPLY &&
memcmp(pdhcpc->packet.xid, xid, sizeof(xid)) == 0 &&
memcmp(pdhcpc->packet.chaddr, pdhcpc->ds_macaddr, pdhcpc->ds_maclen) == 0)
{
memcpy(&presult->ipaddr.s_addr, pdhcpc->packet.yiaddr, 4);
return dhcpc_parseoptions(presult, &pdhcpc->packet.options[4], buflen);
}
return 0;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: dhcpc_open
****************************************************************************/
FAR void *dhcpc_open(FAR const char *interface, FAR const void *macaddr,
int maclen)
{
FAR struct dhcpc_state_s *pdhcpc;
struct sockaddr_in addr;
struct timeval tv;
int ret;
ninfo("MAC: %02x:%02x:%02x:%02x:%02x:%02x\n",
((uint8_t*)macaddr)[0], ((uint8_t*)macaddr)[1], ((uint8_t*)macaddr)[2],
((uint8_t*)macaddr)[3], ((uint8_t*)macaddr)[4], ((uint8_t*)macaddr)[5]);
/* Allocate an internal DHCP structure */
pdhcpc = (FAR struct dhcpc_state_s *)malloc(sizeof(struct dhcpc_state_s));
if (pdhcpc)
{
/* Initialize the allocated structure */
memset(pdhcpc, 0, sizeof(struct dhcpc_state_s));
pdhcpc->interface = interface;
pdhcpc->ds_macaddr = macaddr;
pdhcpc->ds_maclen = maclen;
/* Create a UDP socket */
pdhcpc->sockfd = socket(PF_INET, SOCK_DGRAM, 0);
if (pdhcpc->sockfd < 0)
{
ninfo("socket handle %d\n",ret);
free(pdhcpc);
return NULL;
}
/* Bind the socket */
addr.sin_family = AF_INET;
addr.sin_port = HTONS(DHCPC_CLIENT_PORT);
addr.sin_addr.s_addr = INADDR_ANY;
ret = bind(pdhcpc->sockfd, (struct sockaddr*)&addr,
sizeof(struct sockaddr_in));
if (ret < 0)
{
ninfo("bind status %d\n",ret);
close(pdhcpc->sockfd);
free(pdhcpc);
return NULL;
}
/* Configure for read timeouts */
tv.tv_sec = 10;
tv.tv_usec = 0;
ret = setsockopt(pdhcpc->sockfd, SOL_SOCKET, SO_RCVTIMEO, &tv,
sizeof(struct timeval));
if (ret < 0)
{
ninfo("setsockopt(RCVTIMEO) status %d\n",ret);
close(pdhcpc->sockfd);
free(pdhcpc);
return NULL;
}
#ifdef CONFIG_NET_UDP_BINDTODEVICE
/* Bind socket to interface, because UDP packets have to be sent to the
* broadcast address at a moment when it is not possible to decide the
* target network device using the local or remote address (which is,
* by definition and purpose of DHCP, undefined yet).
*/
ret = setsockopt(pdhcpc->sockfd, SOL_UDP, UDP_BINDTODEVICE,
pdhcpc->interface, strlen(pdhcpc->interface));
if (ret < 0)
{
ninfo("setsockopt(BINDTODEVICE) status %d\n",ret);
close(pdhcpc->sockfd);
free(pdhcpc);
return NULL;
}
#endif
}
return (FAR void *)pdhcpc;
}
/****************************************************************************
* Name: dhcpc_close
****************************************************************************/
void dhcpc_close(FAR void *handle)
{
struct dhcpc_state_s *pdhcpc = (struct dhcpc_state_s *)handle;
if (pdhcpc)
{
if (pdhcpc->sockfd)
{
close(pdhcpc->sockfd);
}
free(pdhcpc);
}
}
/****************************************************************************
* Name: dhcpc_request
****************************************************************************/
int dhcpc_request(FAR void *handle, FAR struct dhcpc_state *presult)
{
FAR struct dhcpc_state_s *pdhcpc = (FAR struct dhcpc_state_s *)handle;
struct in_addr oldaddr;
struct in_addr newaddr;
ssize_t result;
uint8_t msgtype;
int retries;
int state;
/* Save the currently assigned IP address (should be INADDR_ANY) */
oldaddr.s_addr = 0;
netlib_get_ipv4addr(pdhcpc->interface, &oldaddr);
/* Loop until we receive the lease (or an error occurs) */
do
{
/* Set the IP address to INADDR_ANY. */
newaddr.s_addr = INADDR_ANY;
netlib_set_ipv4addr(pdhcpc->interface, &newaddr);
/* Loop sending DISCOVER until we receive an OFFER from a DHCP
* server. We will lock on to the first OFFER and decline any
* subsequent offers (which will happen if there are more than one
* DHCP servers on the network.
*/
state = STATE_INITIAL;
do
{
/* Send the DISCOVER command */
ninfo("Broadcast DISCOVER\n");
if (dhcpc_sendmsg(pdhcpc, presult, DHCPDISCOVER) < 0)
{
return ERROR;
}
/* Get the DHCPOFFER response */
result = recv(pdhcpc->sockfd, &pdhcpc->packet,
sizeof(struct dhcp_msg), 0);
if (result >= 0)
{
msgtype = dhcpc_parsemsg(pdhcpc, result, presult);
if (msgtype == DHCPOFFER)
{
/* Save the servid from the presult so that it is not
* clobbered by a new OFFER.
*/
ninfo("Received OFFER from %08x\n",
ntohl(presult->serverid.s_addr));
pdhcpc->ipaddr.s_addr = presult->ipaddr.s_addr;
pdhcpc->serverid.s_addr = presult->serverid.s_addr;
/* Temporarily use the address offered by the server and break
* out of the loop.
*/
netlib_set_ipv4addr(pdhcpc->interface,
&presult->ipaddr);
state = STATE_HAVE_OFFER;
}
}
/* An error has occurred. If this was a timeout error (meaning that
* nothing was received on this socket for a long period of time).
* Then loop and send the DISCOVER command again.
*/
else if (errno != EAGAIN)
{
/* An error other than a timeout was received -- error out */
return ERROR;
}
}
while (state == STATE_INITIAL);
/* Loop sending the REQUEST up to three times (if there is no response) */
retries = 0;
do
{
/* Send the REQUEST message to obtain the lease that was offered to
* us.
*/
ninfo("Send REQUEST\n");
if (dhcpc_sendmsg(pdhcpc, presult, DHCPREQUEST) < 0)
{
return ERROR;
}
retries++;
/* Get the ACK/NAK response to the REQUEST (or timeout) */
result = recv(pdhcpc->sockfd, &pdhcpc->packet,
sizeof(struct dhcp_msg), 0);
if (result >= 0)
{
/* Parse the response */
msgtype = dhcpc_parsemsg(pdhcpc, result, presult);
/* The ACK response means that the server has accepted our request
* and we have the lease.
*/
if (msgtype == DHCPACK)
{
ninfo("Received ACK\n");
state = STATE_HAVE_LEASE;
}
/* NAK means the server has refused our request. Break out of
* this loop with state == STATE_HAVE_OFFER and send DISCOVER
* again
*/
else if (msgtype == DHCPNAK)
{
ninfo("Received NAK\n");
break;
}
/* If we get any OFFERs from other servers, then decline them now
* and continue waiting for the ACK from the server that we
* requested from.
*/
else if (msgtype == DHCPOFFER)
{
ninfo("Received another OFFER, send DECLINE\n");
dhcpc_sendmsg(pdhcpc, presult, DHCPDECLINE);
}
/* Otherwise, it is something that we do not recognize */
else
{
ninfo("Ignoring msgtype=%d\n", msgtype);
}
}
/* An error has occurred. If this was a timeout error (meaning
* that nothing was received on this socket for a long period of
* time). Then break out and send the DISCOVER command again (at most
* 3 times).
*/
else if (errno != EAGAIN)
{
/* An error other than a timeout was received */
netlib_set_ipv4addr(pdhcpc->interface, &oldaddr);
return ERROR;
}
}
while (state == STATE_HAVE_OFFER && retries < 3);
}
while (state != STATE_HAVE_LEASE);
ninfo("Got IP address %d.%d.%d.%d\n",
(presult->ipaddr.s_addr ) & 0xff,
(presult->ipaddr.s_addr >> 8 ) & 0xff,
(presult->ipaddr.s_addr >> 16 ) & 0xff,
(presult->ipaddr.s_addr >> 24 ) & 0xff);
ninfo("Got netmask %d.%d.%d.%d\n",
(presult->netmask.s_addr ) & 0xff,
(presult->netmask.s_addr >> 8 ) & 0xff,
(presult->netmask.s_addr >> 16 ) & 0xff,
(presult->netmask.s_addr >> 24 ) & 0xff);
ninfo("Got DNS server %d.%d.%d.%d\n",
(presult->dnsaddr.s_addr ) & 0xff,
(presult->dnsaddr.s_addr >> 8 ) & 0xff,
(presult->dnsaddr.s_addr >> 16 ) & 0xff,
(presult->dnsaddr.s_addr >> 24 ) & 0xff);
ninfo("Got default router %d.%d.%d.%d\n",
(presult->default_router.s_addr ) & 0xff,
(presult->default_router.s_addr >> 8 ) & 0xff,
(presult->default_router.s_addr >> 16 ) & 0xff,
(presult->default_router.s_addr >> 24 ) & 0xff);
ninfo("Lease expires in %d seconds\n", presult->lease_time);
return OK;
}
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