DHCPC logic changes - should now handle case with multiple DHCP servers

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@446 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo 2007-12-11 22:07:18 +00:00
parent 0800757e00
commit 8027ff2a0e
3 changed files with 195 additions and 82 deletions

View File

@ -55,7 +55,7 @@
struct dhcpc_state struct dhcpc_state
{ {
uint16 lease_time[2]; uint16 lease_time[2];
uint8 serverid[4]; struct in_addr serverid;
struct in_addr ipaddr; struct in_addr ipaddr;
struct in_addr netmask; struct in_addr netmask;
struct in_addr dnsaddr; struct in_addr dnsaddr;

View File

@ -61,9 +61,8 @@
****************************************************************************/ ****************************************************************************/
#define STATE_INITIAL 0 #define STATE_INITIAL 0
#define STATE_SENDING 1 #define STATE_HAVE_OFFER 1
#define STATE_OFFER_RECEIVED 2 #define STATE_HAVE_LEASE 2
#define STATE_CONFIG_RECEIVED 3
#define BOOTP_BROADCAST 0x8000 #define BOOTP_BROADCAST 0x8000
@ -127,6 +126,7 @@ struct dhcpc_state_s
const void *ds_macaddr; const void *ds_macaddr;
int ds_maclen; int ds_maclen;
int sockfd; int sockfd;
struct in_addr serverid;
struct dhcp_msg packet; struct dhcp_msg packet;
}; };
@ -141,7 +141,11 @@ static const uint8 magic_cookie[4] = {99, 130, 83, 99};
* Private Functions * Private Functions
****************************************************************************/ ****************************************************************************/
static uint8 *add_msg_type(uint8 *optptr, uint8 type) /****************************************************************************
* Name: dhcpc_add<option>
****************************************************************************/
static uint8 *dhcpc_addmsgtype(uint8 *optptr, uint8 type)
{ {
*optptr++ = DHCP_OPTION_MSG_TYPE; *optptr++ = DHCP_OPTION_MSG_TYPE;
*optptr++ = 1; *optptr++ = 1;
@ -149,15 +153,15 @@ static uint8 *add_msg_type(uint8 *optptr, uint8 type)
return optptr; return optptr;
} }
static uint8 *add_server_id(struct dhcpc_state *presult, uint8 *optptr) static uint8 *dhcpc_addserverid(struct in_addr *serverid, uint8 *optptr)
{ {
*optptr++ = DHCP_OPTION_SERVER_ID; *optptr++ = DHCP_OPTION_SERVER_ID;
*optptr++ = 4; *optptr++ = 4;
memcpy(optptr, presult->serverid, 4); memcpy(optptr, &serverid->s_addr, 4);
return optptr + 4; return optptr + 4;
} }
static uint8 *add_req_ipaddr(struct dhcpc_state *presult, uint8 *optptr) static uint8 *dhcpc_addreqipaddr(struct dhcpc_state *presult, uint8 *optptr)
{ {
*optptr++ = DHCP_OPTION_REQ_IPADDR; *optptr++ = DHCP_OPTION_REQ_IPADDR;
*optptr++ = 4; *optptr++ = 4;
@ -165,7 +169,7 @@ static uint8 *add_req_ipaddr(struct dhcpc_state *presult, uint8 *optptr)
return optptr + 4; return optptr + 4;
} }
static uint8 *add_req_options(uint8 *optptr) static uint8 *dhcpc_addreqoptions(uint8 *optptr)
{ {
*optptr++ = DHCP_OPTION_REQ_LIST; *optptr++ = DHCP_OPTION_REQ_LIST;
*optptr++ = 3; *optptr++ = 3;
@ -175,83 +179,90 @@ static uint8 *add_req_options(uint8 *optptr)
return optptr; return optptr;
} }
static uint8 *add_end(uint8 *optptr) static uint8 *dhcpc_addend(uint8 *optptr)
{ {
*optptr++ = DHCP_OPTION_END; *optptr++ = DHCP_OPTION_END;
return optptr; return optptr;
} }
static void create_msg(struct dhcpc_state_s *pdhcpc) /****************************************************************************
* Name: dhcpc_sendmsg
****************************************************************************/
static int dhcpc_sendmsg(struct dhcpc_state_s *pdhcpc,
struct dhcpc_state *presult, int msgtype)
{ {
struct sockaddr_in addr;
uint8 *pend;
in_addr_t serverid = INADDR_BROADCAST;
int len;
/* Create the common message header settings */
memset(&pdhcpc->packet, 0, sizeof(struct dhcp_msg)); memset(&pdhcpc->packet, 0, sizeof(struct dhcp_msg));
pdhcpc->packet.op = DHCP_REQUEST; pdhcpc->packet.op = DHCP_REQUEST;
pdhcpc->packet.htype = DHCP_HTYPE_ETHERNET; pdhcpc->packet.htype = DHCP_HTYPE_ETHERNET;
pdhcpc->packet.hlen = pdhcpc->ds_maclen; pdhcpc->packet.hlen = pdhcpc->ds_maclen;
memcpy(pdhcpc->packet.xid, xid, 4); memcpy(pdhcpc->packet.xid, xid, 4);
pdhcpc->packet.flags = HTONS(BOOTP_BROADCAST); /* Broadcast bit. */
memcpy(pdhcpc->packet.chaddr, pdhcpc->ds_macaddr, pdhcpc->ds_maclen); memcpy(pdhcpc->packet.chaddr, pdhcpc->ds_macaddr, pdhcpc->ds_maclen);
memset(&pdhcpc->packet.chaddr[pdhcpc->ds_maclen], 0, 16 - pdhcpc->ds_maclen); memset(&pdhcpc->packet.chaddr[pdhcpc->ds_maclen], 0, 16 - pdhcpc->ds_maclen);
memcpy(pdhcpc->packet.options, magic_cookie, sizeof(magic_cookie)); memcpy(pdhcpc->packet.options, magic_cookie, sizeof(magic_cookie));
}
static int send_discover(struct dhcpc_state_s *pdhcpc) /* Add the common header options */
{
struct sockaddr_in addr;
uint8 *pend;
int len;
/* Create the basic message header */
create_msg(pdhcpc);
/* Add the options */
pend = &pdhcpc->packet.options[4]; pend = &pdhcpc->packet.options[4];
pend = add_msg_type(pend, DHCPDISCOVER); pend = dhcpc_addmsgtype(pend, msgtype);
pend = add_req_options(pend);
pend = add_end(pend); /* Handle the message specific settings */
switch (msgtype)
{
/* Broadcast DISCOVER message to all servers */
case DHCPDISCOVER:
pdhcpc->packet.flags = HTONS(BOOTP_BROADCAST); /* Broadcast bit. */
pend = dhcpc_addreqoptions(pend);
break;
/* Send REQUEST message to the server that send the OFFER */
case DHCPREQUEST:
pdhcpc->packet.flags = HTONS(BOOTP_BROADCAST); /* Broadcast bit. */
memcpy(pdhcpc->packet.ciaddr, &presult->ipaddr.s_addr, 4);
pend = dhcpc_addserverid(&pdhcpc->serverid, pend);
pend = dhcpc_addreqipaddr(presult, pend);
break;
/* Send DECLINE message to the server that sent the 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*)&pdhcpc->packet; len = pend - (uint8*)&pdhcpc->packet;
/* Send the request */ /* Send the request */
addr.sin_family = AF_INET; addr.sin_family = AF_INET;
addr.sin_port = HTONS(DHCPC_SERVER_PORT); addr.sin_port = HTONS(DHCPC_SERVER_PORT);
addr.sin_addr.s_addr = INADDR_BROADCAST; addr.sin_addr.s_addr = serverid;
return sendto(pdhcpc->sockfd, &pdhcpc->packet, len, 0,
(struct sockaddr*)&addr, sizeof(struct sockaddr_in));
}
static int send_request(struct dhcpc_state_s *pdhcpc, struct dhcpc_state *presult)
{
struct sockaddr_in addr;
uint8 *pend;
int len;
/* Create the basic message header */
create_msg(pdhcpc);
memcpy(pdhcpc->packet.ciaddr, &presult->ipaddr.s_addr, 4);
/* Add the options */
pend = &pdhcpc->packet.options[4];
pend = add_msg_type(pend, DHCPREQUEST);
pend = add_server_id(presult, pend);
pend = add_req_ipaddr(presult, pend);
pend = add_end(pend);
len = pend - (uint8*)&pdhcpc->packet;
/* Send the request */
addr.sin_family = AF_INET;
addr.sin_port = HTONS(DHCPC_SERVER_PORT);
addr.sin_addr.s_addr = INADDR_BROADCAST;
return sendto(pdhcpc->sockfd, &pdhcpc->packet, len, 0, return sendto(pdhcpc->sockfd, &pdhcpc->packet, len, 0,
(struct sockaddr*)&addr, sizeof(struct sockaddr_in)); (struct sockaddr*)&addr, sizeof(struct sockaddr_in));
} }
static uint8 parse_options(struct dhcpc_state *presult, uint8 *optptr, int len) /****************************************************************************
* Name: dhcpc_parseoptions
****************************************************************************/
static uint8 dhcpc_parseoptions(struct dhcpc_state *presult, uint8 *optptr, int len)
{ {
uint8 *end = optptr + len; uint8 *end = optptr + len;
uint8 type = 0; uint8 type = 0;
@ -273,7 +284,7 @@ static uint8 parse_options(struct dhcpc_state *presult, uint8 *optptr, int len)
type = *(optptr + 2); type = *(optptr + 2);
break; break;
case DHCP_OPTION_SERVER_ID: case DHCP_OPTION_SERVER_ID:
memcpy(presult->serverid, optptr + 2, 4); memcpy(&presult->serverid.s_addr, optptr + 2, 4);
break; break;
case DHCP_OPTION_LEASE_TIME: case DHCP_OPTION_LEASE_TIME:
memcpy(presult->lease_time, optptr + 2, 4); memcpy(presult->lease_time, optptr + 2, 4);
@ -287,15 +298,19 @@ static uint8 parse_options(struct dhcpc_state *presult, uint8 *optptr, int len)
return type; return type;
} }
static uint8 parse_msg(struct dhcpc_state_s *pdhcpc, int buflen, /****************************************************************************
struct dhcpc_state *presult) * Name: dhcpc_parsemsg
****************************************************************************/
static uint8 dhcpc_parsemsg(struct dhcpc_state_s *pdhcpc, int buflen,
struct dhcpc_state *presult)
{ {
if (pdhcpc->packet.op == DHCP_REPLY && if (pdhcpc->packet.op == DHCP_REPLY &&
memcmp(pdhcpc->packet.xid, xid, sizeof(xid)) == 0 && memcmp(pdhcpc->packet.xid, xid, sizeof(xid)) == 0 &&
memcmp(pdhcpc->packet.chaddr, pdhcpc->ds_macaddr, pdhcpc->ds_maclen) == 0) memcmp(pdhcpc->packet.chaddr, pdhcpc->ds_macaddr, pdhcpc->ds_maclen) == 0)
{ {
memcpy(&presult->ipaddr.s_addr, pdhcpc->packet.yiaddr, 4); memcpy(&presult->ipaddr.s_addr, pdhcpc->packet.yiaddr, 4);
return parse_options(presult, &pdhcpc->packet.options[4], buflen); return dhcpc_parseoptions(presult, &pdhcpc->packet.options[4], buflen);
} }
return 0; return 0;
} }
@ -304,12 +319,20 @@ static uint8 parse_msg(struct dhcpc_state_s *pdhcpc, int buflen,
* Global Functions * Global Functions
****************************************************************************/ ****************************************************************************/
/****************************************************************************
* Name: dhcpc_open
****************************************************************************/
void *dhcpc_open(const void *macaddr, int maclen) void *dhcpc_open(const void *macaddr, int maclen)
{ {
struct dhcpc_state_s *pdhcpc; struct dhcpc_state_s *pdhcpc;
struct sockaddr_in addr; struct sockaddr_in addr;
struct timeval tv; struct timeval tv;
dbg("MAC: %02x:%02x:%02x:%02x:%02x:%02x\n",
((uint8*)macaddr)[0], ((uint8*)macaddr)[1], ((uint8*)macaddr)[2],
((uint8*)macaddr)[3], ((uint8*)macaddr)[4], ((uint8*)macaddr)[5]);
/* Allocate an internal DHCP structure */ /* Allocate an internal DHCP structure */
pdhcpc = (struct dhcpc_state_s *)malloc(sizeof(struct dhcpc_state_s)); pdhcpc = (struct dhcpc_state_s *)malloc(sizeof(struct dhcpc_state_s));
@ -358,6 +381,10 @@ void *dhcpc_open(const void *macaddr, int maclen)
return (void*)pdhcpc; return (void*)pdhcpc;
} }
/****************************************************************************
* Name: dhcpc_close
****************************************************************************/
void dhcpc_close(void *handle) void dhcpc_close(void *handle)
{ {
struct dchcpc_state_internal *pdhcpc = (struct dchcpc_state_internal *)handle; struct dchcpc_state_internal *pdhcpc = (struct dchcpc_state_internal *)handle;
@ -367,72 +394,158 @@ void dhcpc_close(void *handle)
} }
} }
/****************************************************************************
* Name: dhcpc_request
****************************************************************************/
int dhcpc_request(void *handle, struct dhcpc_state *presult) int dhcpc_request(void *handle, struct dhcpc_state *presult)
{ {
struct dhcpc_state_s *pdhcpc = (struct dhcpc_state_s *)handle; struct dhcpc_state_s *pdhcpc = (struct dhcpc_state_s *)handle;
struct in_addr oldaddr; struct in_addr oldaddr;
struct in_addr newaddr;
ssize_t result; ssize_t result;
int state; uint8 msgtype;
int retries;
int state;
/* Save the currently assigned IP address (should be zero) */ /* Save the currently assigned IP address (should be INADDR_ANY) */
oldaddr.s_addr = 0; oldaddr.s_addr = 0;
uip_gethostaddr("eth0", &oldaddr); uip_gethostaddr("eth0", &oldaddr);
/* Loop until we receive the offer */ /* Loop until we receive the lease (or an error occurs) */
do do
{ {
state = STATE_SENDING; /* Set the IP address to INADDR_ANY. */
newaddr.s_addr = INADDR_ANY;
(void)uip_sethostaddr("eth0", &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 do
{ {
/* Send the command */ /* Send the DISCOVER command */
if (send_discover(pdhcpc) < 0) dbg("Broadcast DISCOVER\n");
if (dhcpc_sendmsg(pdhcpc, presult, DHCPDISCOVER) < 0)
{ {
return ERROR; return ERROR;
} }
/* Get the response */ /* Get the DHCPOFFER response */
result = recv(pdhcpc->sockfd, &pdhcpc->packet, sizeof(struct dhcp_msg), 0); result = recv(pdhcpc->sockfd, &pdhcpc->packet, sizeof(struct dhcp_msg), 0);
if (result >= 0) if (result >= 0)
{ {
if (parse_msg(pdhcpc, result, presult) == DHCPOFFER) 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.
*/
dbg("Received OFFER from %08x\n", ntohl(presult->serverid.s_addr));
pdhcpc->serverid.s_addr = presult->serverid.s_addr;
/* Temporarily use the address offered by the server and break
* out of the loop.
*/
(void)uip_sethostaddr("eth0", &presult->ipaddr); (void)uip_sethostaddr("eth0", &presult->ipaddr);
state = STATE_OFFER_RECEIVED; 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 (*get_errno_ptr() != EAGAIN) else if (*get_errno_ptr() != EAGAIN)
{ {
/* An error other than a timeout was received */ /* An error other than a timeout was received -- error out */
return ERROR; return ERROR;
} }
} }
while (state != STATE_OFFER_RECEIVED); while (state == STATE_INITIAL);
/* Loop sending the REQUEST up to three times (if there is no response) */
retries = 0;
do do
{ {
/* Send the request */ /* Send the REQUEST message to obtain the lease that was offered to us. */
if (send_request(pdhcpc, presult) < 0) dbg("Send REQUEST\n");
if (dhcpc_sendmsg(pdhcpc, presult, DHCPREQUEST) < 0)
{ {
return ERROR; return ERROR;
} }
retries++;
/* Get the response */ /* Get the ACK/NAK response to the REQUEST (or timeout) */
result = recv(pdhcpc->sockfd, &pdhcpc->packet, sizeof(struct dhcp_msg), 0); result = recv(pdhcpc->sockfd, &pdhcpc->packet, sizeof(struct dhcp_msg), 0);
if (result >= 0) if (result >= 0)
{ {
if (parse_msg(pdhcpc, result, presult) == DHCPACK) /* 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)
{ {
state = STATE_CONFIG_RECEIVED; dbg("Received ACK\n");
state = STATE_HAVE_LEASE;
}
/* NAK means the the server has refused our request. Break out of
* this loop with state == STATE_HAVE_OFFER and send DISCOVER again
*/
else if (msgtype == DHCPNAK)
{
dbg("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)
{
dbg("Received another OFFER, send DECLINE\n");
(void)dhcpc_sendmsg(pdhcpc, presult, DHCPDECLINE);
}
/* Otherwise, it is something that we do not recognize */
else
{
dbg("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 (*get_errno_ptr() != EAGAIN) else if (*get_errno_ptr() != EAGAIN)
{ {
/* An error other than a timeout was received */ /* An error other than a timeout was received */
@ -441,9 +554,9 @@ int dhcpc_request(void *handle, struct dhcpc_state *presult)
return ERROR; return ERROR;
} }
} }
while (state != STATE_CONFIG_RECEIVED); while (state == STATE_HAVE_OFFER && retries < 3);
} }
while(state != STATE_CONFIG_RECEIVED); while (state != STATE_HAVE_LEASE);
dbg("Got IP address %d.%d.%d.%d\n", dbg("Got IP address %d.%d.%d.%d\n",
(presult->ipaddr.s_addr >> 24 ) & 0xff, (presult->ipaddr.s_addr >> 24 ) & 0xff,

View File

@ -1283,7 +1283,7 @@ int dhcpd_run(void)
#ifdef CONFIG_NETUTILS_DHCPD_HOST #ifdef CONFIG_NETUTILS_DHCPD_HOST
/* Get the poor little uC a change to get its recvfrom in place */ /* Get the poor little uC a change to get its recvfrom in place */
sleep(2); usleep(500*1000);
#endif #endif
/* Now process the incoming DHCP message by its message type */ /* Now process the incoming DHCP message by its message type */
@ -1298,7 +1298,7 @@ int dhcpd_run(void)
case DHCPREQUEST: case DHCPREQUEST:
vdbg("DHCPREQUEST\n"); vdbg("DHCPREQUEST\n");
dhcpd_request(); dhcpd_request();
break; break;
case DHCPDECLINE: case DHCPDECLINE:
vdbg("DHCPDECLINE\n"); vdbg("DHCPDECLINE\n");