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) + 10ULL;
Slirp uses rt_clock for expiry, let's stick with that clock.
+
diddit:
slirp-if_queued++;
@@ -153,6 +157,9 @@ diddit:
void
if_start(Slirp *slirp)
{
+int requeued = 0;
+uint64_t now;
+
struct mbuf *ifm, *ifqt;
DEBUG_CALL(if_start);
@@ -165,6 +172,8 @@ if_start(Slirp *slirp)
if (!slirp_can_output(slirp-opaque))
return;
+now = qemu_get_clock_ns(vm_clock);
+
/*
* See which queue to get next packet from
* If there's something in the fastq, select it immediately
@@ -199,11 +208,22 @@ if_start(Slirp *slirp)
ifm-ifq_so-so_nqueued = 0;
}
- /* Encapsulate the packet for sending */
-if_encap(slirp, (uint8_t *)ifm-m_data, ifm-m_len);
-
-m_free(ifm);
+if (ifm-expiration_date now) {
+/* Expired */
+m_free(ifm);
+} else {
+/* Encapsulate the packet for sending */
+if (if_encap(slirp, ifm)) {
+m_free(ifm);
+} else {
+/* re-queue */
+insque(ifm, ifqt);
+requeued++;
+}
+}
if (slirp-if_queued)
goto again;
+
+slirp-if_queued = requeued;
}
diff --git a/slirp/main.h b/slirp/main.h
index 0dd8d81..028df4b 100644
--- a/slirp/main.h
+++ b/slirp/main.h
@@ -42,5 +42,5 @@ extern int tcp_keepintvl;
#define PROTO_PPP 0x2
#endif
-void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len);
+int if_encap(Slirp *slirp, struct mbuf *ifm);
ssize_t slirp_send(struct socket *so, const void *buf, size_t len, int
flags);
diff --git a/slirp/mbuf.c b/slirp/mbuf.c
index ce2eb84..c699c75 100644
--- a/slirp/mbuf.c
+++ b/slirp/mbuf.c
@@ -70,6 +70,8 @@ m_get(Slirp *slirp)
m-m_len = 0;
m-m_nextpkt = NULL;
m-m_prevpkt = NULL;
+m-arp_requested = false;
+m-expiration_date = (uint64_t)-1;
end_error:
DEBUG_ARG(m = %lx, (long )m);
return m;
diff --git a/slirp/mbuf.h b/slirp/mbuf.h
index b74544b..55170e5 100644
--- a/slirp/mbuf.h
+++ b/slirp/mbuf.h
@@ -86,6 +86,8 @@ struct mbuf {
charm_dat_[1]; /* ANSI don't like 0 sized arrays */
char*m_ext_;
} M_dat;
+bool arp_requested;
+uint64_t expiration_date;
};
#define m_next m_hdr.mh_next
diff --git a/slirp/slirp.c b/slirp/slirp.c
index ba76757..b006620 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -237,6 +237,8 @@ Slirp *slirp_init(int restricted, struct in_addr vnetwork,
QTAILQ_INSERT_TAIL(slirp_instances, slirp, entry);
+slirp-delayed = NULL;
+
return slirp;
}
@@ -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: { }
if (!arp_table_search(slirp-arp_table, iph-ip_dst.s_addr, ethaddr)) {
uint8_t arp_req[ETH_HLEN + sizeof(struct arphdr)];
struct ethhdr *reh = (struct ethhdr *)arp_req;
struct arphdr *rah = (struct arphdr *)(arp_req + ETH_HLEN);
-/* If
