X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fnx-match.c;h=2654dde07fc325d019e82c77172a4036291d6326;hb=df2c07f4338faac04f4969f243fe4e8083b309ac;hp=cccf6fe671c6c644f8994b9da4d40376e237d216;hpb=01ba0d769dc78a05ed61a6267ca99a4a84361962;p=openvswitch

diff --git a/lib/nx-match.c b/lib/nx-match.c
index cccf6fe6..2654dde0 100644
--- a/lib/nx-match.c
+++ b/lib/nx-match.c
@@ -1191,49 +1191,54 @@ int
 nxm_check_reg_move(const struct nx_action_reg_move *action,
                    const struct flow *flow)
 {
-    const struct nxm_field *src;
-    const struct nxm_field *dst;
+    int src_ofs, dst_ofs, n_bits;
+    int error;
 
-    if (action->n_bits == htons(0)) {
-        return BAD_ARGUMENT;
-    }
+    n_bits = ntohs(action->n_bits);
+    src_ofs = ntohs(action->src_ofs);
+    dst_ofs = ntohs(action->dst_ofs);
 
-    src = nxm_field_lookup(ntohl(action->src));
-    if (!field_ok(src, flow, ntohs(action->src_ofs) + ntohs(action->n_bits))) {
-        return BAD_ARGUMENT;
+    error = nxm_src_check(action->src, src_ofs, n_bits, flow);
+    if (error) {
+        return error;
     }
 
-    dst = nxm_field_lookup(ntohl(action->dst));
-    if (!field_ok(dst, flow, ntohs(action->dst_ofs) + ntohs(action->n_bits))) {
-        return BAD_ARGUMENT;
-    }
+    return nxm_dst_check(action->dst, dst_ofs, n_bits, flow);
+}
 
-    if (!dst->writable) {
-        return BAD_ARGUMENT;
+/* Given a flow, checks that the source field represented by 'src_header'
+ * in the range ['ofs', 'ofs' + 'n_bits') is valid. */
+int
+nxm_src_check(ovs_be32 src_header, unsigned int ofs, unsigned int n_bits,
+              const struct flow *flow)
+{
+    const struct nxm_field *src = nxm_field_lookup(ntohl(src_header));
+
+    if (!n_bits) {
+        VLOG_WARN_RL(&rl, "zero bit source field");
+    } else if (!field_ok(src, flow, ofs + n_bits)) {
+        VLOG_WARN_RL(&rl, "invalid source field");
+    } else {
+        return 0;
     }
 
-    return 0;
+    return BAD_ARGUMENT;
 }
 
 /* Given a flow, checks that the destination field represented by 'dst_header'
- * and 'ofs_nbits' is valid and large enough for 'min_n_bits' bits of data. */
+ * in the range ['ofs', 'ofs' + 'n_bits') is valid. */
 int
-nxm_dst_check(ovs_be32 dst_header, ovs_be16 ofs_nbits, size_t min_n_bits,
+nxm_dst_check(ovs_be32 dst_header, unsigned int ofs, unsigned int n_bits,
               const struct flow *flow)
 {
-    const struct nxm_field *dst;
-    int ofs, n_bits;
-
-    ofs = nxm_decode_ofs(ofs_nbits);
-    n_bits = nxm_decode_n_bits(ofs_nbits);
-    dst = nxm_field_lookup(ntohl(dst_header));
+    const struct nxm_field *dst = nxm_field_lookup(ntohl(dst_header));
 
-    if (!field_ok(dst, flow, ofs + n_bits)) {
+    if (!n_bits) {
+        VLOG_WARN_RL(&rl, "zero bit destination field");
+    } else if (!field_ok(dst, flow, ofs + n_bits)) {
         VLOG_WARN_RL(&rl, "invalid destination field");
     } else if (!dst->writable) {
         VLOG_WARN_RL(&rl, "destination field is not writable");
-    } else if (n_bits < min_n_bits) {
-        VLOG_WARN_RL(&rl, "insufficient bits in destination");
     } else {
         return 0;
     }
@@ -1245,17 +1250,17 @@ int
 nxm_check_reg_load(const struct nx_action_reg_load *action,
                    const struct flow *flow)
 {
-    int n_bits;
+    unsigned int ofs = nxm_decode_ofs(action->ofs_nbits);
+    unsigned int n_bits = nxm_decode_n_bits(action->ofs_nbits);
     int error;
 
-    error = nxm_dst_check(action->dst, action->ofs_nbits, 0, flow);
+    error = nxm_dst_check(action->dst, ofs, n_bits, flow);
     if (error) {
         return error;
     }
 
     /* Reject 'action' if a bit numbered 'n_bits' or higher is set to 1 in
      * action->value. */
-    n_bits = nxm_decode_n_bits(action->ofs_nbits);
     if (n_bits < 64 && ntohll(action->value) >> n_bits) {
         return BAD_ARGUMENT;
     }
@@ -1365,6 +1370,23 @@ nxm_read_field(const struct nxm_field *src, const struct flow *flow)
     NOT_REACHED();
 }
 
+/* Returns the value of the NXM field corresponding to 'header' at 'ofs_nbits'
+ * in 'flow'. */
+uint64_t
+nxm_read_field_bits(ovs_be32 header, ovs_be16 ofs_nbits,
+                    const struct flow *flow)
+{
+    int n_bits = nxm_decode_n_bits(ofs_nbits);
+    int ofs = nxm_decode_ofs(ofs_nbits);
+    uint64_t mask, data;
+
+    mask = n_bits == 64 ? UINT64_MAX : (UINT64_C(1) << n_bits) - 1;
+    data = nxm_read_field(nxm_field_lookup(ntohl(header)), flow);
+    data = (data >> ofs) & mask;
+
+    return data;
+}
+
 static void
 nxm_write_field(const struct nxm_field *dst, struct flow *flow,
                 uint64_t new_value)
@@ -1464,18 +1486,16 @@ void
 nxm_execute_reg_move(const struct nx_action_reg_move *action,
                      struct flow *flow)
 {
-    /* Preparation. */
-    int n_bits = ntohs(action->n_bits);
-    uint64_t mask = n_bits == 64 ? UINT64_MAX : (UINT64_C(1) << n_bits) - 1;
+    ovs_be16 src_ofs_nbits, dst_ofs_nbits;
+    uint64_t src_data;
+    int n_bits;
 
-    /* Get the interesting bits of the source field. */
-    const struct nxm_field *src = nxm_field_lookup(ntohl(action->src));
-    int src_ofs = ntohs(action->src_ofs);
-    uint64_t src_data = (nxm_read_field(src, flow) >> src_ofs) & mask;
+    n_bits = ntohs(action->n_bits);
+    src_ofs_nbits = nxm_encode_ofs_nbits(ntohs(action->src_ofs), n_bits);
+    dst_ofs_nbits = nxm_encode_ofs_nbits(ntohs(action->dst_ofs), n_bits);
 
-    nxm_reg_load(action->dst,
-                 nxm_encode_ofs_nbits(ntohs(action->dst_ofs), n_bits),
-                 src_data, flow);
+    src_data = nxm_read_field_bits(action->src, src_ofs_nbits, flow);
+    nxm_reg_load(action->dst, dst_ofs_nbits, src_data, flow);
 }
 
 void