[ovs-dev] [patch v8 2/9] flow: Enhance parse_ipv6_ext_hdrs.

Darrell Ball dlu998 at gmail.com
Tue Jul 17 02:39:44 UTC 2018


Enhance the api parse_ipv6_ext_hdrs to return the
fragmentation header to be used in later patches.

Signed-off-by: Darrell Ball <dlu998 at gmail.com>
Acked-by: Justin Pettit <jpettit at ovn.org>
---
 lib/conntrack.c |  4 ++--
 lib/flow.c      | 31 +++++++++++++++++++++----------
 lib/flow.h      |  3 ++-
 3 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/lib/conntrack.c b/lib/conntrack.c
index 974f985..682feb9 100644
--- a/lib/conntrack.c
+++ b/lib/conntrack.c
@@ -1310,7 +1310,6 @@ conntrack_execute(struct conntrack *ct, struct dp_packet_batch *pkt_batch,
                   const struct nat_action_info_t *nat_action_info,
                   long long now)
 {
-
     struct dp_packet *packet;
     struct conn_lookup_ctx ctx;
 
@@ -1558,7 +1557,8 @@ extract_l3_ipv6(struct conn_key *key, const void *data, size_t size,
     uint8_t nw_proto = ip6->ip6_nxt;
     uint8_t nw_frag = 0;
 
-    if (!parse_ipv6_ext_hdrs(&data, &size, &nw_proto, &nw_frag)) {
+    const struct ovs_16aligned_ip6_frag *frag_hdr;
+    if (!parse_ipv6_ext_hdrs(&data, &size, &nw_proto, &nw_frag, &frag_hdr)) {
         return false;
     }
 
diff --git a/lib/flow.c b/lib/flow.c
index 76a8b9a..e84a40d 100644
--- a/lib/flow.c
+++ b/lib/flow.c
@@ -453,9 +453,14 @@ invalid:
     return true;
 }
 
+/* datap points to the first extension header and advances as parsing
+ * occurs; sizep is the remaining size and is decreased accordingly.
+ * nw_proto starts as the first extension header to process and is
+ * updated as the extension headers are parsed. */
 static inline bool
 parse_ipv6_ext_hdrs__(const void **datap, size_t *sizep, uint8_t *nw_proto,
-                      uint8_t *nw_frag)
+                      uint8_t *nw_frag,
+                      const struct ovs_16aligned_ip6_frag **frag_hdr)
 {
     while (1) {
         if (OVS_LIKELY((*nw_proto != IPPROTO_HOPOPTS)
@@ -502,17 +507,17 @@ parse_ipv6_ext_hdrs__(const void **datap, size_t *sizep, uint8_t *nw_proto,
                 return false;
             }
         } else if (*nw_proto == IPPROTO_FRAGMENT) {
-            const struct ovs_16aligned_ip6_frag *frag_hdr = *datap;
+            *frag_hdr = *datap;
 
-            *nw_proto = frag_hdr->ip6f_nxt;
-            if (!data_try_pull(datap, sizep, sizeof *frag_hdr)) {
+            *nw_proto = (*frag_hdr)->ip6f_nxt;
+            if (!data_try_pull(datap, sizep, sizeof **frag_hdr)) {
                 return false;
             }
 
             /* We only process the first fragment. */
-            if (frag_hdr->ip6f_offlg != htons(0)) {
+            if ((*frag_hdr)->ip6f_offlg != htons(0)) {
                 *nw_frag = FLOW_NW_FRAG_ANY;
-                if ((frag_hdr->ip6f_offlg & IP6F_OFF_MASK) != htons(0)) {
+                if (((*frag_hdr)->ip6f_offlg & IP6F_OFF_MASK) != htons(0)) {
                     *nw_frag |= FLOW_NW_FRAG_LATER;
                     *nw_proto = IPPROTO_FRAGMENT;
                     return true;
@@ -524,9 +529,11 @@ parse_ipv6_ext_hdrs__(const void **datap, size_t *sizep, uint8_t *nw_proto,
 
 bool
 parse_ipv6_ext_hdrs(const void **datap, size_t *sizep, uint8_t *nw_proto,
-                    uint8_t *nw_frag)
+                    uint8_t *nw_frag,
+                    const struct ovs_16aligned_ip6_frag **frag_hdr)
 {
-    return parse_ipv6_ext_hdrs__(datap, sizep, nw_proto, nw_frag);
+    return parse_ipv6_ext_hdrs__(datap, sizep, nw_proto, nw_frag,
+                                 frag_hdr);
 }
 
 bool
@@ -877,7 +884,9 @@ miniflow_extract(struct dp_packet *packet, struct miniflow *dst)
         nw_ttl = nh->ip6_hlim;
         nw_proto = nh->ip6_nxt;
 
-        if (!parse_ipv6_ext_hdrs__(&data, &size, &nw_proto, &nw_frag)) {
+        const struct ovs_16aligned_ip6_frag *frag_hdr;
+        if (!parse_ipv6_ext_hdrs__(&data, &size, &nw_proto, &nw_frag,
+                                   &frag_hdr)) {
             goto out;
         }
     } else {
@@ -1067,7 +1076,9 @@ parse_tcp_flags(struct dp_packet *packet)
         plen = ntohs(nh->ip6_plen); /* Never pull padding. */
         dp_packet_set_l2_pad_size(packet, size - plen);
         size = plen;
-        if (!parse_ipv6_ext_hdrs__(&data, &size, &nw_proto, &nw_frag)) {
+        const struct ovs_16aligned_ip6_frag *frag_hdr;
+        if (!parse_ipv6_ext_hdrs__(&data, &size, &nw_proto, &nw_frag,
+            &frag_hdr)) {
             return 0;
         }
         nw_proto = nh->ip6_nxt;
diff --git a/lib/flow.h b/lib/flow.h
index af7b5e9..e3e30f1 100644
--- a/lib/flow.h
+++ b/lib/flow.h
@@ -130,7 +130,8 @@ void flow_compose(struct dp_packet *, const struct flow *,
 void packet_expand(struct dp_packet *, const struct flow *, size_t size);
 
 bool parse_ipv6_ext_hdrs(const void **datap, size_t *sizep, uint8_t *nw_proto,
-                         uint8_t *nw_frag);
+                         uint8_t *nw_frag,
+                         const struct ovs_16aligned_ip6_frag **frag_hdr);
 ovs_be16 parse_dl_type(const struct eth_header *data_, size_t size);
 bool parse_nsh(const void **datap, size_t *sizep, struct ovs_key_nsh *key);
 uint16_t parse_tcp_flags(struct dp_packet *packet);
-- 
1.9.1



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