netdev-linux: Fix strict aliasing warnings.

[openvswitch] / lib / nx-match.c

diff --git a/lib/nx-match.c b/lib/nx-match.c
index c1d8fa84e1bd265a7d3cae9a60db69e82f7c64a1..f887cdb5796670a7ef2062b20e1b34af53301165 100644 (file)
--- a/lib/nx-match.c
+++ b/lib/nx-match.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010 Nicira Networks.
+ * Copyright (c) 2010, 2011 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -123,7 +123,7 @@ nxm_field_lookup(uint32_t header)
 
 /* Returns the width of the data for a field with the given 'header', in
  * bytes. */
-static int
+int
 nxm_field_bytes(uint32_t header)
 {
     unsigned int length = NXM_LENGTH(header);
@@ -132,7 +132,7 @@ nxm_field_bytes(uint32_t header)
 
 /* Returns the width of the data for a field with the given 'header', in
  * bits. */
-static int
+int
 nxm_field_bits(uint32_t header)
 {
     return nxm_field_bytes(header) * 8;
@@ -562,6 +562,16 @@ nxm_put_eth_dst(struct ofpbuf *b,
     }
 }
 
+/* Appends to 'b' the nx_match format that expresses 'cr' (except for
+ * 'cr->priority', because priority is not part of nx_match), plus enough
+ * zero bytes to pad the nx_match out to a multiple of 8.
+ *
+ * This function can cause 'b''s data to be reallocated.
+ *
+ * Returns the number of bytes appended to 'b', excluding padding.
+ *
+ * If 'cr' is a catch-all rule that matches every packet, then this function
+ * appends nothing to 'b' and returns 0. */
 int
 nx_put_match(struct ofpbuf *b, const struct cls_rule *cr)
 {
@@ -814,8 +824,8 @@ nx_match_from_string(const char *s, struct ofpbuf *b)
     return match_len;
 }
 \f
-static const char *
-parse_nxm_field_bits(const char *s, uint32_t *headerp, int *ofsp, int *n_bitsp)
+const char *
+nxm_parse_field_bits(const char *s, uint32_t *headerp, int *ofsp, int *n_bitsp)
 {
     const char *full_s = s;
     const char *name;
@@ -876,12 +886,12 @@ nxm_parse_reg_move(struct nx_action_reg_move *move, const char *s)
     int src_ofs, dst_ofs;
     int src_n_bits, dst_n_bits;
 
-    s = parse_nxm_field_bits(s, &src, &src_ofs, &src_n_bits);
+    s = nxm_parse_field_bits(s, &src, &src_ofs, &src_n_bits);
     if (strncmp(s, "->", 2)) {
         ovs_fatal(0, "%s: missing `->' following source", full_s);
     }
     s += 2;
-    s = parse_nxm_field_bits(s, &dst, &dst_ofs, &dst_n_bits);
+    s = nxm_parse_field_bits(s, &dst, &dst_ofs, &dst_n_bits);
     if (*s != '\0') {
         ovs_fatal(0, "%s: trailing garbage following destination", full_s);
     }
@@ -915,7 +925,7 @@ nxm_parse_reg_load(struct nx_action_reg_load *load, const char *s)
         ovs_fatal(0, "%s: missing `->' following value", full_s);
     }
     s += 2;
-    s = parse_nxm_field_bits(s, &dst, &ofs, &n_bits);
+    s = nxm_parse_field_bits(s, &dst, &ofs, &n_bits);
     if (*s != '\0') {
         ovs_fatal(0, "%s: trailing garbage following destination", full_s);
     }
@@ -929,21 +939,23 @@ nxm_parse_reg_load(struct nx_action_reg_load *load, const char *s)
     load->len = htons(sizeof *load);
     load->vendor = htonl(NX_VENDOR_ID);
     load->subtype = htons(NXAST_REG_LOAD);
-    load->ofs_nbits = htons((ofs << 6) | (n_bits - 1));
+    load->ofs_nbits = nxm_encode_ofs_nbits(ofs, n_bits);
     load->dst = htonl(dst);
     load->value = htonll(value);
 }
 \f
 /* nxm_format_reg_move(), nxm_format_reg_load(). */
 
-static void
-format_nxm_field_bits(struct ds *s, uint32_t header, int ofs, int n_bits)
+void
+nxm_format_field_bits(struct ds *s, uint32_t header, int ofs, int n_bits)
 {
     format_nxm_field_name(s, header);
-    if (n_bits != 1) {
-        ds_put_format(s, "[%d..%d]", ofs, ofs + n_bits - 1);
-    } else {
+    if (ofs == 0 && n_bits == nxm_field_bits(header)) {
+        ds_put_cstr(s, "[]");
+    } else if (n_bits == 1) {
         ds_put_format(s, "[%d]", ofs);
+    } else {
+        ds_put_format(s, "[%d..%d]", ofs, ofs + n_bits - 1);
     }
 }
 
@@ -957,22 +969,21 @@ nxm_format_reg_move(const struct nx_action_reg_move *move, struct ds *s)
     uint32_t dst = ntohl(move->dst);
 
     ds_put_format(s, "move:");
-    format_nxm_field_bits(s, src, src_ofs, n_bits);
+    nxm_format_field_bits(s, src, src_ofs, n_bits);
     ds_put_cstr(s, "->");
-    format_nxm_field_bits(s, dst, dst_ofs, n_bits);
+    nxm_format_field_bits(s, dst, dst_ofs, n_bits);
 }
 
 void
 nxm_format_reg_load(const struct nx_action_reg_load *load, struct ds *s)
 {
-    uint16_t ofs_nbits = ntohs(load->ofs_nbits);
-    int ofs = ofs_nbits >> 6;
-    int n_bits = (ofs_nbits & 0x3f) + 1;
+    int ofs = nxm_decode_ofs(load->ofs_nbits);
+    int n_bits = nxm_decode_n_bits(load->ofs_nbits);
     uint32_t dst = ntohl(load->dst);
     uint64_t value = ntohll(load->value);
 
-    ds_put_format(s, "load:%"PRIu64"->", value);
-    format_nxm_field_bits(s, dst, ofs, n_bits);
+    ds_put_format(s, "load:%#"PRIx64"->", value);
+    nxm_format_field_bits(s, dst, ofs, n_bits);
 }
 \f
 /* nxm_check_reg_move(), nxm_check_reg_load(). */
@@ -1021,8 +1032,8 @@ nxm_check_reg_load(const struct nx_action_reg_load *action,
     const struct nxm_field *dst;
     int ofs, n_bits;
 
-    ofs = ntohs(action->ofs_nbits) >> 6;
-    n_bits = (ntohs(action->ofs_nbits) & 0x3f) + 1;
+    ofs = nxm_decode_ofs(action->ofs_nbits);
+    n_bits = nxm_decode_n_bits(action->ofs_nbits);
     dst = nxm_field_lookup(ntohl(action->dst));
     if (!field_ok(dst, flow, ofs + n_bits)) {
         return BAD_ARGUMENT;
@@ -1165,7 +1176,7 @@ nxm_execute_reg_load(const struct nx_action_reg_load *action,
                      struct flow *flow)
 {
     /* Preparation. */
-    int n_bits = (ntohs(action->ofs_nbits) & 0x3f) + 1;
+    int n_bits = nxm_decode_n_bits(action->ofs_nbits);
     uint32_t mask = n_bits == 32 ? UINT32_MAX : (UINT32_C(1) << n_bits) - 1;
     uint32_t *reg = &flow->regs[NXM_NX_REG_IDX(ntohl(action->dst))];
 
@@ -1173,7 +1184,7 @@ nxm_execute_reg_load(const struct nx_action_reg_load *action,
     uint32_t src_data = ntohll(action->value);
 
     /* Get remaining bits of the destination field. */
-    int dst_ofs = ntohs(action->ofs_nbits) >> 6;
+    int dst_ofs = nxm_decode_ofs(action->ofs_nbits);
     uint32_t dst_data = *reg & ~(mask << dst_ofs);
 
     *reg = dst_data | (src_data << dst_ofs);