[Qemu-devel] [PATCH 02/18] slirp: Generalizing and neutralizing code before adding IPv6 stuff

[Samuel Thibault <samuel.thibault@ens-lyon.org>]

Basically, this patch replaces "arp" by "resolution" every time "arp"
means "mac resolution" and not specifically ARP.

Some indentation problems are solved in functions that will be modified
in the next patches (ip_input…).

In if_encap, a switch is added to prepare for the IPv6 case. Some code
is factorized.

Signed-off-by: Guillaume Subiron <maethor@subiron.org>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
---
 slirp/mbuf.c  |  2 +-
 slirp/mbuf.h  |  2 +-
 slirp/slirp.c | 24 ++++++++++++++++++++----
 3 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/slirp/mbuf.c b/slirp/mbuf.c
index 4fefb04..92c429e 100644
--- a/slirp/mbuf.c
+++ b/slirp/mbuf.c
@@ -91,7 +91,7 @@ m_get(Slirp *slirp)
 	m->m_len = 0;
         m->m_nextpkt = NULL;
         m->m_prevpkt = NULL;
-        m->arp_requested = false;
+        m->resolution_requested = false;
         m->expiration_date = (uint64_t)-1;
 end_error:
 	DEBUG_ARG("m = %lx", (long )m);
diff --git a/slirp/mbuf.h b/slirp/mbuf.h
index b144f1c..38fedf4 100644
--- a/slirp/mbuf.h
+++ b/slirp/mbuf.h
@@ -79,7 +79,7 @@ struct mbuf {
 	int	m_len;			/* Amount of data in this mbuf */
 
 	Slirp *slirp;
-	bool	arp_requested;
+	bool	resolution_requested;
 	uint64_t expiration_date;
 	/* start of dynamic buffer area, must be last element */
 	union {
diff --git a/slirp/slirp.c b/slirp/slirp.c
index 35f819a..380ddc3 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -776,6 +776,8 @@ int if_encap(Slirp *slirp, struct mbuf *ifm)
         return 1;
     }
 
+    switch (iph->ip_v) {
+    case IPVERSION:
     if (iph->ip_dst.s_addr == 0) {
         /* 0.0.0.0 can not be a destination address, something went wrong,
          * avoid making it worse */
@@ -786,7 +788,7 @@ int if_encap(Slirp *slirp, struct mbuf *ifm)
         struct ethhdr *reh = (struct ethhdr *)arp_req;
         struct arphdr *rah = (struct arphdr *)(arp_req + ETH_HLEN);
 
-        if (!ifm->arp_requested) {
+        if (!ifm->resolution_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);
@@ -812,22 +814,36 @@ int if_encap(Slirp *slirp, struct mbuf *ifm)
             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;
+            ifm->resolution_requested = true;
 
             /* Expire request and drop outgoing packet after 1 second */
             ifm->expiration_date = qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + 1000000000ULL;
         }
         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);
+        break;
+    }
+
+    default:
+        /* Do not assert while we don't manage IP6VERSION */
+        /* assert(0); */
+        break;
+    }
+
+        memcpy(eh->h_dest, ethaddr, ETH_ALEN);
+        DEBUG_ARGS((dfd, " src = %02x:%02x:%02x:%02x:%02x:%02x\n",
+                    eh->h_source[0], eh->h_source[1], eh->h_source[2],
+                    eh->h_source[3], eh->h_source[4], eh->h_source[5]));
+        DEBUG_ARGS((dfd, " dst = %02x:%02x:%02x:%02x:%02x:%02x\n",
+                    eh->h_dest[0], eh->h_dest[1], eh->h_dest[2],
+                    eh->h_dest[3], eh->h_dest[4], eh->h_dest[5]));
         memcpy(buf + sizeof(struct ethhdr), ifm->m_data, ifm->m_len);
         slirp_output(slirp->opaque, buf, ifm->m_len + ETH_HLEN);
         return 1;
-    }
 }
 
 /* Drop host forwarding rule, return 0 if found. */
-- 
2.4.6