On 29/07/2011 19:35, Jan Kiszka wrote:
> On 2011-07-29 18:25, Fabien Chouteau wrote:
>> In the current implementation, if Slirp tries to send an IP packet to a
>> client
>> with an unknown hardware address, the packet is simply dropped and an ARP
>> request is sent (if_encap in slirp/slirp.c).
>>
>> With this patch, Slirp will send the ARP request, re-queue the packet and try
>> to send it later. The packet is dropped after one second if the ARP reply is
>> not received.
>>
>> Signed-off-by: Fabien Chouteau <chout...@adacore.com>
>> ---
>> slirp/if.c | 28 ++++++++++++++++++++---
>> slirp/main.h | 2 +-
>> slirp/mbuf.c | 2 +
>> slirp/mbuf.h | 2 +
>> slirp/slirp.c | 67
>> ++++++++++++++++++++++++++++++--------------------------
>> slirp/slirp.h | 15 ++++++++++++
>> 6 files changed, 80 insertions(+), 36 deletions(-)
>>
>> diff --git a/slirp/if.c b/slirp/if.c
>> index 0f04e13..80a5c4e 100644
>> --- a/slirp/if.c
>> +++ b/slirp/if.c
>> @@ -6,6 +6,7 @@
>> */
>>
>> #include <slirp.h>
>> +#include "qemu-timer.h"
>>
>> #define ifs_init(ifm) ((ifm)->ifs_next = (ifm)->ifs_prev = (ifm))
>>
>> @@ -105,6 +106,9 @@ if_output(struct socket *so, struct mbuf *ifm)
>> ifs_init(ifm);
>> insque(ifm, ifq);
>>
>> + /* Expiration date = Now + 1 second */
>> + ifm->expiration_date = qemu_get_clock_ns(vm_clock) + 1000000000ULL;
>
> Slirp uses rt_clock for expiry, let's stick with that clock.
OK, fixed.
>> @@ -693,54 +695,57 @@ void slirp_input(Slirp *slirp, const uint8_t *pkt, int
>> pkt_len)
>> }
>>
>> /* output the IP packet to the ethernet device */
>> -void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len)
>> +int if_encap(Slirp *slirp, struct mbuf *ifm)
>> {
>> uint8_t buf[1600];
>> struct ethhdr *eh = (struct ethhdr *)buf;
>> uint8_t ethaddr[ETH_ALEN];
>> - const struct ip *iph = (const struct ip *)ip_data;
>> + const struct ip *iph = (const struct ip *)ifm->m_data;
>>
>> - if (ip_data_len + ETH_HLEN > sizeof(buf))
>> - return;
>> + if (ifm->m_len + ETH_HLEN > sizeof(buf))
>> + return 1;
>
> Even if the old cold lacked them as well: { }
I forgot to use checkpatch.pl...
>> + memset(rah->ar_tha, 0, ETH_ALEN);
>> + /* target IP */
>> + rah->ar_tip = iph->ip_dst.s_addr;
>> + slirp->client_ipaddr = iph->ip_dst;
>> + slirp_output(slirp->opaque, arp_req, sizeof(arp_req));
>> + ifm->arp_requested = true;
>> + }
>> + return 0;
>> } else {
>> + ifm->arp_requested = false;
>
> Why? If that is required, you would have to make expiry checks depend on
> arp_requested as well - or reset the expiry date here.
>
That's right, the packet is sent so there's no need to reset this value.
Thanks for your review.
--
Fabien Chouteau
