* [Qemu-devel] [patch] slirp bootp, Request&Discover
@ 2004-05-12 15:30 Renzo Davoli
2004-05-12 20:09 ` Fabrice Bellard
0 siblings, 1 reply; 3+ messages in thread
From: Renzo Davoli @ 2004-05-12 15:30 UTC (permalink / raw)
To: qemu-devel
I have done some tests with Win98.
Sometimes it starts asking for an address with a DHCPdiscover
sometimes with a DHCPrequest.
In the latter case using the current cvs of bootp.c there is no answer
as there is no MAC address registered yet.
Maybe it is a workaround (although a working workaround ;-) but I
propose to manage a DHCPrequest with no registered MAC address as it
were a DHCPdiscover.
The patch is here enclosed.
ciao
renzo
-----------
--- bootp.cvs.c 2004-05-04 14:20:25.000000000 +0200
+++ bootp.c 2004-05-12 17:19:50.000000000 +0200
@@ -149,20 +149,18 @@
m->m_data += sizeof(struct udpiphdr);
memset(rbp, 0, sizeof(struct bootp_t));
- if (dhcp_msg_type == DHCPDISCOVER) {
+ bc=NULL;
+ if (dhcp_msg_type == DHCPREQUEST)
+ bc = find_addr(&daddr.sin_addr, bp->bp_hwaddr);
+ if (!bc) {
bc = get_new_addr(&daddr.sin_addr);
if (!bc) {
dprintf("no address left\n");
return;
}
memcpy(bc->macaddr, client_ethaddr, 6);
- } else {
- bc = find_addr(&daddr.sin_addr, bp->bp_hwaddr);
- if (!bc) {
- dprintf("no address assigned\n");
- return;
- }
}
+
dprintf("offered addr=%08x\n", ntohl(daddr.sin_addr.s_addr));
saddr.sin_addr.s_addr = htonl(ntohl(special_addr.s_addr) |
CTL_ALIAS);
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] [patch] slirp bootp, Request&Discover
2004-05-12 15:30 [Qemu-devel] [patch] slirp bootp, Request&Discover Renzo Davoli
@ 2004-05-12 20:09 ` Fabrice Bellard
2004-05-13 15:02 ` Renzo Davoli
0 siblings, 1 reply; 3+ messages in thread
From: Fabrice Bellard @ 2004-05-12 20:09 UTC (permalink / raw)
To: qemu-devel
Strange. If a real DHCP server accepts that, then I agree to merge it.
Otherwise, it may be bug in the NE2000 emulation.
Fabrice.
Renzo Davoli wrote:
> I have done some tests with Win98.
>
> Sometimes it starts asking for an address with a DHCPdiscover
> sometimes with a DHCPrequest.
> In the latter case using the current cvs of bootp.c there is no answer
> as there is no MAC address registered yet.
>
> Maybe it is a workaround (although a working workaround ;-) but I
> propose to manage a DHCPrequest with no registered MAC address as it
> were a DHCPdiscover.
>
> The patch is here enclosed.
>
> ciao
> renzo
>
> -----------
> --- bootp.cvs.c 2004-05-04 14:20:25.000000000 +0200
> +++ bootp.c 2004-05-12 17:19:50.000000000 +0200
> @@ -149,20 +149,18 @@
> m->m_data += sizeof(struct udpiphdr);
> memset(rbp, 0, sizeof(struct bootp_t));
>
> - if (dhcp_msg_type == DHCPDISCOVER) {
> + bc=NULL;
> + if (dhcp_msg_type == DHCPREQUEST)
> + bc = find_addr(&daddr.sin_addr, bp->bp_hwaddr);
> + if (!bc) {
> bc = get_new_addr(&daddr.sin_addr);
> if (!bc) {
> dprintf("no address left\n");
> return;
> }
> memcpy(bc->macaddr, client_ethaddr, 6);
> - } else {
> - bc = find_addr(&daddr.sin_addr, bp->bp_hwaddr);
> - if (!bc) {
> - dprintf("no address assigned\n");
> - return;
> - }
> }
> +
> dprintf("offered addr=%08x\n", ntohl(daddr.sin_addr.s_addr));
>
> saddr.sin_addr.s_addr = htonl(ntohl(special_addr.s_addr) |
> CTL_ALIAS);
>
>
>
> _______________________________________________
> Qemu-devel mailing list
> Qemu-devel@nongnu.org
> http://mail.nongnu.org/mailman/listinfo/qemu-devel
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] [patch] slirp bootp, Request&Discover
2004-05-12 20:09 ` Fabrice Bellard
@ 2004-05-13 15:02 ` Renzo Davoli
0 siblings, 0 replies; 3+ messages in thread
From: Renzo Davoli @ 2004-05-13 15:02 UTC (permalink / raw)
To: qemu-devel
[-- Attachment #1: Type: text/plain, Size: 1636 bytes --]
On Wed, May 12, 2004 at 10:09:44PM +0200, Fabrice Bellard wrote:
> Strange. If a real DHCP server accepts that, then I agree to merge it.
> Otherwise, it may be bug in the NE2000 emulation.
AFAIK it is not strange.
DHCP request is sent also for renewing a lease.
you use a very long lease time (1 day) but it seems that win 98 despite
of a boot remembers that it already had a lease and asks just for a renewal.
I have written a new patch that not only solves this problem but it
gives also a better approximation of the DHCP protocol by managing
a simplified version of the lease protocol.
It is useful for using qemu with user-net for a period of time longer than the
lease expire time (or to connect several interfaces-machines to the dhcp
server).
This patch:
- tries to reaasign the previous address to each MAC address.
- if there are no more available addresses re-assigns IP with expired
leases.
- If somebody tries to DISCOVER multiple times sends back the same
address (Win 98 ask several times when the address has changed)
- When REQUEST asks for an already assigned address returns DHCPNAK
(unfortunately Win 98 does not manage this correctly).
When 98 has a valid lease from a previous session it asks twice for
the previous address and regardless of the NAK coming from the server it tests
with a ping whether the address is available or not and *keeps it*!
IMHO this is plain against the RFC 2131.
Fabrice,
I am including this into slirpvde, maybe my previous fix is enough for
dhcp inside qemu (as it has a single guest machine) but if you like we
can keep the source code aligned.
ciao
renzo
[-- Attachment #2: bootp.diff --]
[-- Type: text/plain, Size: 4849 bytes --]
--- oldbootp.c 2004-05-03 14:11:44.000000000 +0200
+++ bootp.c 2004-05-13 16:57:08.000000000 +0200
@@ -29,10 +29,12 @@
#define START_ADDR 15
-#define LEASE_TIME (24 * 3600)
+#define LEASE_TIME (120)
typedef struct {
uint8_t allocated;
+ uint8_t macaddr[6];
+ int time;
} BOOTPClient;
BOOTPClient bootp_clients[NB_ADDR];
@@ -50,26 +52,69 @@
{
BOOTPClient *bc;
int i;
+ int now=time(NULL);
for(i = 0; i < NB_ADDR; i++) {
if (!bootp_clients[i].allocated)
goto found;
}
+ for(i = 0; i < NB_ADDR; i++) {
+ if (now-bootp_clients[i].time > 3*LEASE_TIME)
+ goto found;
+ }
return NULL;
found:
bc = &bootp_clients[i];
- bc->allocated = 1;
paddr->s_addr = htonl(ntohl(special_addr.s_addr) | (i + START_ADDR));
return bc;
}
+static BOOTPClient *find_addr(struct in_addr *paddr, const uint8_t *macaddr)
+{
+ BOOTPClient *bc;
+ int i;
+
+ for(i = 0; i < NB_ADDR; i++) {
+ if (!memcmp(macaddr, bootp_clients[i].macaddr, 6))
+ goto found;
+ }
+ return NULL;
+ found:
+ bc = &bootp_clients[i];
+ paddr->s_addr = htonl(ntohl(special_addr.s_addr) | (i + START_ADDR));
+ return bc;
+}
+
+static BOOTPClient *find_reqaddr(struct in_addr *paddr, struct in_addr *reqaddr, const uint8_t *macaddr)
+{
+ BOOTPClient *bc=NULL;
+ int i;
+ /*check the net prefix*/
+ if ((ntohl(reqaddr->s_addr) & 0xffffff00) ==
+ (ntohl(special_addr.s_addr) & 0xffffff00)) {
+ i=(ntohl(reqaddr->s_addr) & 0xff) - START_ADDR;
+ if (i>=0 && i< NB_ADDR) {
+ bc = &bootp_clients[i];
+ if (bc->allocated &&
+ (memcmp(macaddr, bootp_clients[i].macaddr, 6)==0)) {
+ paddr->s_addr = reqaddr->s_addr;
+ return bc;
+ }
+ else
+ bc=NULL;
+ }
+ }
+ return bc;
+}
+
static void dhcp_decode(const uint8_t *buf, int size,
- int *pmsg_type)
+ int *pmsg_type, struct sockaddr_in *preqaddr)
{
const uint8_t *p, *p_end;
int len, tag;
*pmsg_type = 0;
+ preqaddr->sin_addr.s_addr=htonl(0L);
p = buf;
p_end = buf + size;
@@ -96,6 +141,10 @@
if (len >= 1)
*pmsg_type = p[0];
break;
+ case RFC2132_REQ_ADDR:
+ if (len == 4) {
+ memcpy(&(preqaddr->sin_addr),p,4);
+ }
default:
break;
}
@@ -109,14 +158,14 @@
BOOTPClient *bc;
struct mbuf *m;
struct bootp_t *rbp;
- struct sockaddr_in saddr, daddr;
+ struct sockaddr_in saddr, daddr, reqaddr;
struct in_addr dns_addr;
int dhcp_msg_type, val;
- uint8_t *q;
+ uint8_t *q,replytype;
/* extract exact DHCP msg type */
- dhcp_decode(bp->bp_vend, DHCP_OPT_LEN, &dhcp_msg_type);
- dprintf("bootp packet op=%d msgtype=%d\n", bp->bp_op, dhcp_msg_type);
+ dhcp_decode(bp->bp_vend, DHCP_OPT_LEN, &dhcp_msg_type,&reqaddr);
+ dprintf("bootp packet op=%d msgtype=%d reqaddr=%x\n", bp->bp_op, dhcp_msg_type,ntohl(reqaddr.sin_addr.s_addr));
if (dhcp_msg_type != DHCPDISCOVER &&
dhcp_msg_type != DHCPREQUEST)
@@ -131,11 +180,20 @@
m->m_data += sizeof(struct udpiphdr);
memset(rbp, 0, sizeof(struct bootp_t));
+ bc=NULL;
+ daddr.sin_addr.s_addr=htonl(0L);
+ if (dhcp_msg_type == DHCPREQUEST) {
+ if (reqaddr.sin_addr.s_addr != htonl(0L))
+ bc = find_reqaddr(&daddr.sin_addr, &reqaddr.sin_addr, bp->bp_hwaddr);
+ else
+ bc = find_addr(&daddr.sin_addr, bp->bp_hwaddr);
+ }
+ else if (dhcp_msg_type == DHCPDISCOVER) {
+ bc = find_addr(&daddr.sin_addr, bp->bp_hwaddr);
+ if (!bc)
bc = get_new_addr(&daddr.sin_addr);
- if (!bc) {
- dprintf("no address left\n");
- return;
}
+
dprintf("offered addr=%08x\n", ntohl(daddr.sin_addr.s_addr));
saddr.sin_addr.s_addr = htonl(ntohl(special_addr.s_addr) | CTL_ALIAS);
@@ -155,18 +213,21 @@
memcpy(q, rfc1533_cookie, 4);
q += 4;
- if (dhcp_msg_type == DHCPDISCOVER) {
- *q++ = RFC2132_MSG_TYPE;
- *q++ = 1;
- *q++ = DHCPOFFER;
- } else if (dhcp_msg_type == DHCPREQUEST) {
+ if (bc != NULL) {
+ memcpy(bc->macaddr, client_ethaddr, 6);
+ bc->allocated = 1;
+ bc->time = time(NULL);
+ replytype=(dhcp_msg_type == DHCPDISCOVER)?DHCPOFFER:DHCPACK;
+ }
+ else
+ replytype=DHCPNACK;
+
*q++ = RFC2132_MSG_TYPE;
*q++ = 1;
- *q++ = DHCPACK;
- }
+ *q++ = replytype;
- if (dhcp_msg_type == DHCPDISCOVER ||
- dhcp_msg_type == DHCPREQUEST) {
+ if ((dhcp_msg_type == DHCPDISCOVER ||
+ dhcp_msg_type == DHCPREQUEST) && replytype!=DHCPNACK) {
*q++ = RFC2132_SRV_ID;
*q++ = 4;
memcpy(q, &saddr.sin_addr, 4);
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2004-05-13 15:11 UTC | newest]
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2004-05-12 15:30 [Qemu-devel] [patch] slirp bootp, Request&Discover Renzo Davoli
2004-05-12 20:09 ` Fabrice Bellard
2004-05-13 15:02 ` Renzo Davoli
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