tap_ip_send() doesn't take a destination address, because it's specifically
for inbound packets, and the IP addresses of the guest/namespace are
already known to us. Rather than open-coding this destination address
logic, make helper functions for it which will enable some later cleanups.
Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au>
---
tap.c | 29 ++++++++++++++++++++++++-----
tap.h | 3 +++
2 files changed, 27 insertions(+), 5 deletions(-)
diff --git a/tap.c b/tap.c
index de02c56..41e8ff2 100644
--- a/tap.c
+++ b/tap.c
@@ -96,6 +96,28 @@ int tap_send(const struct ctx *c, const void *data, size_t len, int
vnet_pre)
return write(c->fd_tap, (char *)data + (vnet_pre ? 4 : 0), len);
}
+/**
+ * tap_ip4_daddr() - Normal IPv4 destination address for inbound packets
+ * @c: Execution context
+ */
+in_addr_t tap_ip4_daddr(const struct ctx *c)
+{
+ return c->ip4.addr_seen;
+}
+
+/**
+ * tap_ip6_daddr() - Normal IPv4 destination address for inbound packets
+ * @c: Execution context
+ * @src: Source address
+ */
+const struct in6_addr *tap_ip6_daddr(const struct ctx *c,
+ const struct in6_addr *src)
+{
+ if (IN6_IS_ADDR_LINKLOCAL(src))
+ return &c->ip6.addr_ll_seen;
+ return &c->ip6.addr_seen;
+}
+
/**
* tap_ip_send() - Send IP packet, with L2 headers, calculating L3/L4 checksums
* @c: Execution context
@@ -132,7 +154,7 @@ void tap_ip_send(const struct ctx *c, const struct in6_addr *src,
uint8_t proto,
iph->frag_off = 0;
iph->ttl = 255;
iph->protocol = proto;
- iph->daddr = c->ip4.addr_seen;
+ iph->daddr = tap_ip4_daddr(c);
memcpy(&iph->saddr, &src->s6_addr[12], 4);
csum_ip4_header(iph);
@@ -163,10 +185,7 @@ void tap_ip_send(const struct ctx *c, const struct in6_addr *src,
uint8_t proto,
ip6h->priority = 0;
ip6h->saddr = *src;
- if (IN6_IS_ADDR_LINKLOCAL(src))
- ip6h->daddr = c->ip6.addr_ll_seen;
- else
- ip6h->daddr = c->ip6.addr_seen;
+ ip6h->daddr = *tap_ip6_daddr(c, src);
memcpy(data, in, len);
diff --git a/tap.h b/tap.h
index df3aec0..a6764b4 100644
--- a/tap.h
+++ b/tap.h
@@ -6,6 +6,9 @@
#ifndef TAP_H
#define TAP_H
+in_addr_t tap_ip4_daddr(const struct ctx *c);
+const struct in6_addr *tap_ip6_daddr(const struct ctx *c,
+ const struct in6_addr *src);
void tap_ip_send(const struct ctx *c, const struct in6_addr *src, uint8_t proto,
const char *in, size_t len, uint32_t flow);
int tap_send(const struct ctx *c, const void *data, size_t len, int vnet_pre);
--
2.37.3