aboutsummaryrefslogtreecommitdiff
path: root/slirp
diff options
context:
space:
mode:
authorFabien Chouteau <chouteau@adacore.com>2011-08-01 18:18:37 +0200
committerJan Kiszka <jan.kiszka@siemens.com>2011-08-03 12:57:11 +0200
commit1ab74cea060d776b19857c3babc64d729bbdba5c (patch)
tree024f3b1df329cc1cbf5cd0069df0e585e5ffe957 /slirp
parent1a0ca1e1f6011a8623ec0653a1b35bbfc3f576c9 (diff)
downloadqemu-1ab74cea060d776b19857c3babc64d729bbdba5c.zip
qemu-1ab74cea060d776b19857c3babc64d729bbdba5c.tar.gz
qemu-1ab74cea060d776b19857c3babc64d729bbdba5c.tar.bz2
Delayed IP packets
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 <chouteau@adacore.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Diffstat (limited to 'slirp')
-rw-r--r--slirp/if.c28
-rw-r--r--slirp/main.h2
-rw-r--r--slirp/mbuf.c2
-rw-r--r--slirp/mbuf.h2
-rw-r--r--slirp/slirp.c72
5 files changed, 69 insertions, 37 deletions
diff --git a/slirp/if.c b/slirp/if.c
index 0f04e13..2d79e45 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(rt_clock) + 1000000000ULL;
+
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(rt_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 {
char m_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 4a9a4d5..a86cc6e 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -692,55 +692,63 @@ 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)
+/* Output the IP packet to the ethernet device. Returns 0 if the packet must be
+ * re-queued.
+ */
+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;
+ }
if (!arp_table_search(slirp, 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 the client addr is not known, there is no point in
- sending the packet to it. Normally the sender should have
- done an ARP request to get its MAC address. Here we do it
- in place of sending the packet and we hope that the sender
- will retry sending its packet. */
- memset(reh->h_dest, 0xff, ETH_ALEN);
- memcpy(reh->h_source, special_ethaddr, ETH_ALEN - 4);
- memcpy(&reh->h_source[2], &slirp->vhost_addr, 4);
- reh->h_proto = htons(ETH_P_ARP);
- rah->ar_hrd = htons(1);
- rah->ar_pro = htons(ETH_P_IP);
- rah->ar_hln = ETH_ALEN;
- rah->ar_pln = 4;
- rah->ar_op = htons(ARPOP_REQUEST);
- /* source hw addr */
- memcpy(rah->ar_sha, special_ethaddr, ETH_ALEN - 4);
- memcpy(&rah->ar_sha[2], &slirp->vhost_addr, 4);
- /* source IP */
- rah->ar_sip = slirp->vhost_addr.s_addr;
- /* target hw addr (none) */
- 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));
+ if (!ifm->arp_requested) {
+ /* If the client addr is not known, send an ARP request */
+ memset(reh->h_dest, 0xff, ETH_ALEN);
+ memcpy(reh->h_source, special_ethaddr, ETH_ALEN - 4);
+ memcpy(&reh->h_source[2], &slirp->vhost_addr, 4);
+ reh->h_proto = htons(ETH_P_ARP);
+ rah->ar_hrd = htons(1);
+ rah->ar_pro = htons(ETH_P_IP);
+ rah->ar_hln = ETH_ALEN;
+ rah->ar_pln = 4;
+ rah->ar_op = htons(ARPOP_REQUEST);
+
+ /* source hw addr */
+ memcpy(rah->ar_sha, special_ethaddr, ETH_ALEN - 4);
+ memcpy(&rah->ar_sha[2], &slirp->vhost_addr, 4);
+
+ /* source IP */
+ rah->ar_sip = slirp->vhost_addr.s_addr;
+
+ /* target hw addr (none) */
+ 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 {
memcpy(eh->h_dest, ethaddr, ETH_ALEN);
memcpy(eh->h_source, special_ethaddr, ETH_ALEN - 4);
/* XXX: not correct */
memcpy(&eh->h_source[2], &slirp->vhost_addr, 4);
eh->h_proto = htons(ETH_P_IP);
- memcpy(buf + sizeof(struct ethhdr), ip_data, ip_data_len);
- slirp_output(slirp->opaque, buf, ip_data_len + ETH_HLEN);
+ memcpy(buf + sizeof(struct ethhdr), ifm->m_data, ifm->m_len);
+ slirp_output(slirp->opaque, buf, ifm->m_len + ETH_HLEN);
+ return 1;
}
}