[Qemu-devel] [RFC Patch 09/10] IPv6 support.

[wexu]

1. Callback for IPv6
2. Filter & Sanity Check.

Signed-off-by: Wei Xu <address@hidden>
---
 hw/net/virtio-net.c | 104 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 102 insertions(+), 2 deletions(-)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 55e8e99..362f304 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -46,12 +46,19 @@
 #define TCP4_OFFSET (IP_OFFSET + sizeof(struct ip_header)) /* tcp4 header */
 #define TCP4_PORT_OFFSET TCP4_OFFSET        /* tcp4 port offset */
 #define IP4_ADDR_SIZE   8                   /* ipv4 saddr + daddr */
+
+#define IP6_ADDR_OFFSET (IP_OFFSET + 8)     /* ipv6 address start */
+#define TCP6_OFFSET (IP_OFFSET + sizeof(struct ip6_header)) /* tcp6 header */
+#define TCP6_PORT_OFFSET TCP6_OFFSET        /* tcp6 port offset */
+#define IP6_ADDR_SIZE   32                  /* ipv6 saddr + daddr */
 #define TCP_PORT_SIZE   4                   /* sport + dport */
 #define TCP_WINDOW      65535
 
 /* ip4 max payload, 16 bits in the header */
 #define MAX_IP4_PAYLOAD  (65535 - sizeof(struct ip_header))
 
+/* ip6 max payload, payload in ipv6 don't include the  header */
+#define MAX_IP6_PAYLOAD  65535
 #define MAX_VIRTIO_IP_PAYLOAD  (65535 + IP_OFFSET)
 
 /* Purge coalesced packets timer interval */
@@ -1856,6 +1863,42 @@ static int32_t virtio_net_rsc_try_coalesce4(NetRscChain 
*chain,
                                     o_data, &o_ip->ip_len, MAX_IP4_PAYLOAD);
 }
 
+static int32_t virtio_net_rsc_try_coalesce6(NetRscChain *chain,
+                        NetRscSeg *seg, const uint8_t *buf, size_t size)
+{
+    uint16_t o_ip_len, n_ip_len;    /* len in ip header field */
+    uint16_t n_tcp_len, o_tcp_len;  /* tcp header len */
+    uint16_t o_data, n_data;        /* payload without virtio/eth/ip/tcp */
+    struct ip6_header *n_ip, *o_ip;
+    struct tcp_header *n_tcp, *o_tcp;
+
+    n_ip = (struct ip6_header *)(buf + IP_OFFSET);
+    n_ip_len = htons(n_ip->ip6_ctlun.ip6_un1.ip6_un1_plen);
+    n_tcp = (struct tcp_header *)(((uint8_t *)n_ip)\
+                                    + sizeof(struct ip6_header));
+    n_tcp_len = (htons(n_tcp->th_offset_flags) & 0xF000) >> 10;
+    n_data = n_ip_len - n_tcp_len;
+
+    o_ip = (struct ip6_header *)(seg->buf + IP_OFFSET);
+    o_ip_len = htons(o_ip->ip6_ctlun.ip6_un1.ip6_un1_plen);
+    o_tcp = (struct tcp_header *)(((uint8_t *)o_ip)\
+                                    + sizeof(struct ip6_header));
+    o_tcp_len = (htons(o_tcp->th_offset_flags) & 0xF000) >> 10;
+    o_data = o_ip_len - o_tcp_len;
+
+    if (memcmp(&n_ip->ip6_src, &o_ip->ip6_src, sizeof(struct in6_address))
+        || memcmp(&n_ip->ip6_dst, &o_ip->ip6_dst, sizeof(struct in6_address))
+        || (n_tcp->th_sport ^ o_tcp->th_sport)
+        || (n_tcp->th_dport ^ o_tcp->th_dport)) {
+            return RSC_NO_MATCH;
+    }
+
+    /* There is a difference between payload lenght in ipv4 and v6,
+       ip header is excluded in ipv6 */
+    return virtio_net_rsc_coalesce_tcp(chain, seg, buf,
+                       n_tcp, n_tcp_len, n_data, o_tcp, o_tcp_len, o_data,
+                       &o_ip->ip6_ctlun.ip6_un1.ip6_un1_plen, MAX_IP6_PAYLOAD);
+}
 
 /* Pakcets with 'SYN' should bypass, other flag should be sent after drain
  * to prevent out of order */
@@ -2015,6 +2058,59 @@ static size_t virtio_net_rsc_receive4(void *opq, 
NetClientState* nc,
                                    virtio_net_rsc_try_coalesce4);
 }
 
+static int32_t virtio_net_rsc_filter6(NetRscChain *chain, struct ip6_header 
*ip,
+                                      const uint8_t *buf, size_t size)
+{
+    uint16_t ip_len;
+
+    if (size < (TCP6_OFFSET + sizeof(tcp_header))) {
+        return RSC_BYPASS;
+    }
+
+    if (0x6 != (0xF & ip->ip6_ctlun.ip6_un1.ip6_un1_flow)) {
+        return RSC_BYPASS;
+    }
+
+    /* Both option and protocol is checked in this */
+    if (ip->ip6_ctlun.ip6_un1.ip6_un1_nxt != IPPROTO_TCP) {
+        return RSC_BYPASS;
+    }
+
+    /* Sanity check */
+    ip_len = htons(ip->ip6_ctlun.ip6_un1.ip6_un1_plen);
+    if (ip_len < sizeof(struct tcp_header)
+        || ip_len > (size - TCP6_OFFSET)) {
+        return RSC_BYPASS;
+    }
+
+    return 0;
+}
+
+static size_t virtio_net_rsc_receive6(void *opq, NetClientState* nc,
+                                      const uint8_t *buf, size_t size)
+{
+    int32_t ret;
+    NetRscChain *chain;
+    struct ip6_header *ip;
+
+    chain = (NetRscChain *)opq;
+    ip = (struct ip6_header *)(buf + IP_OFFSET);
+    if (RSC_WANT != virtio_net_rsc_filter6(chain, ip, buf, size)) {
+        return virtio_net_do_receive(nc, buf, size);
+    }
+
+    ret = virtio_net_rsc_parse_tcp_ctrl((uint8_t *)ip, sizeof(*ip));
+    if (RSC_BYPASS == ret) {
+        return virtio_net_do_receive(nc, buf, size);
+    } else if (RSC_FINAL == ret) {
+        return virtio_net_rsc_drain_one(chain, nc, buf, size, IP6_ADDR_OFFSET,
+                        IP6_ADDR_SIZE, TCP6_PORT_OFFSET, TCP_PORT_SIZE);
+    }
+
+    return virtio_net_rsc_callback(chain, nc, buf, size,
+                                   virtio_net_rsc_try_coalesce6);
+}
+
 static NetRscChain *virtio_net_rsc_lookup_chain(NetClientState *nc,
                                                 uint16_t proto)
 {
@@ -2023,7 +2119,7 @@ static NetRscChain 
*virtio_net_rsc_lookup_chain(NetClientState *nc,
     NICState *nic;
 
     /* Only handle IPv4/6 */
-    if (proto != (uint16_t)ETH_P_IP) {
+    if ((proto != (uint16_t)ETH_P_IP) && (proto != (uint16_t)ETH_P_IPV6)) {
         return NULL;
     }
 
@@ -2044,7 +2140,11 @@ static NetRscChain 
*virtio_net_rsc_lookup_chain(NetClientState *nc,
     chain->proto = proto;
     chain->drain_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
                                       virtio_net_rsc_purge, chain);
-    chain->do_receive = virtio_net_rsc_receive4;
+    if (ETH_P_IP == proto) {
+        chain->do_receive = virtio_net_rsc_receive4;
+    } else {
+        chain->do_receive = virtio_net_rsc_receive6;
+    }
 
     QTAILQ_INIT(&chain->buffers);
     QTAILQ_INSERT_TAIL(&n->rsc_chains, chain, next);
-- 
2.4.0