/*
- * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
+#include "byte-order.h"
#include "coverage.h"
+#include "openvswitch/types.h"
#include "vlog.h"
VLOG_DEFINE_THIS_MODULE(util);
program_name = slash ? slash + 1 : argv0;
free(program_version);
- program_version = xasprintf("%s (Open vSwitch) "VERSION BUILDNR"\n"
+ program_version = xasprintf("%s (Open vSwitch) "VERSION"\n"
"Compiled %s %s\n",
program_name, date, time);
}
return true;
}
+/* Copies 'n_bits' bits starting from bit 'src_ofs' in 'src' to the 'n_bits'
+ * starting from bit 'dst_ofs' in 'dst'. 'src' is 'src_len' bytes long and
+ * 'dst' is 'dst_len' bytes long.
+ *
+ * If you consider all of 'src' to be a single unsigned integer in network byte
+ * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
+ * with value 1 in src[src_len - 1], bit 1 is the bit with value 2, bit 2 is
+ * the bit with value 4, ..., bit 8 is the bit with value 1 in src[src_len -
+ * 2], and so on. Similarly for 'dst'.
+ *
+ * Required invariants:
+ * src_ofs + n_bits <= src_len * 8
+ * dst_ofs + n_bits <= dst_len * 8
+ * 'src' and 'dst' must not overlap.
+ */
+void
+bitwise_copy(const void *src_, unsigned int src_len, unsigned int src_ofs,
+ void *dst_, unsigned int dst_len, unsigned int dst_ofs,
+ unsigned int n_bits)
+{
+ const uint8_t *src = src_;
+ uint8_t *dst = dst_;
+
+ src += src_len - (src_ofs / 8 + 1);
+ src_ofs %= 8;
+
+ dst += dst_len - (dst_ofs / 8 + 1);
+ dst_ofs %= 8;
+
+ if (src_ofs == 0 && dst_ofs == 0) {
+ unsigned int n_bytes = n_bits / 8;
+ if (n_bytes) {
+ dst -= n_bytes - 1;
+ src -= n_bytes - 1;
+ memcpy(dst, src, n_bytes);
+
+ n_bits %= 8;
+ src--;
+ dst--;
+ }
+ if (n_bits) {
+ uint8_t mask = (1 << n_bits) - 1;
+ *dst = (*dst & ~mask) | (*src & mask);
+ }
+ } else {
+ while (n_bits > 0) {
+ unsigned int max_copy = 8 - MAX(src_ofs, dst_ofs);
+ unsigned int chunk = MIN(n_bits, max_copy);
+ uint8_t mask = ((1 << chunk) - 1) << dst_ofs;
+
+ *dst &= ~mask;
+ *dst |= ((*src >> src_ofs) << dst_ofs) & mask;
+
+ src_ofs += chunk;
+ if (src_ofs == 8) {
+ src--;
+ src_ofs = 0;
+ }
+ dst_ofs += chunk;
+ if (dst_ofs == 8) {
+ dst--;
+ dst_ofs = 0;
+ }
+ n_bits -= chunk;
+ }
+ }
+}
+
+/* Zeros the 'n_bits' bits starting from bit 'dst_ofs' in 'dst'. 'dst' is
+ * 'dst_len' bytes long.
+ *
+ * If you consider all of 'dst' to be a single unsigned integer in network byte
+ * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
+ * with value 1 in dst[dst_len - 1], bit 1 is the bit with value 2, bit 2 is
+ * the bit with value 4, ..., bit 8 is the bit with value 1 in dst[dst_len -
+ * 2], and so on.
+ *
+ * Required invariant:
+ * dst_ofs + n_bits <= dst_len * 8
+ */
+void
+bitwise_zero(void *dst_, unsigned int dst_len, unsigned dst_ofs,
+ unsigned int n_bits)
+{
+ uint8_t *dst = dst_;
+
+ if (!n_bits) {
+ return;
+ }
+
+ dst += dst_len - (dst_ofs / 8 + 1);
+ dst_ofs %= 8;
+
+ if (dst_ofs) {
+ unsigned int chunk = MIN(n_bits, 8 - dst_ofs);
+
+ *dst &= ~(((1 << chunk) - 1) << dst_ofs);
+
+ n_bits -= chunk;
+ if (!n_bits) {
+ return;
+ }
+
+ dst--;
+ }
+
+ while (n_bits >= 8) {
+ *dst-- = 0;
+ n_bits -= 8;
+ }
+
+ if (n_bits) {
+ *dst &= ~((1 << n_bits) - 1);
+ }
+}
+
+/* Copies the 'n_bits' low-order bits of 'value' into the 'n_bits' bits
+ * starting at bit 'dst_ofs' in 'dst', which is 'dst_len' bytes long.
+ *
+ * If you consider all of 'dst' to be a single unsigned integer in network byte
+ * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
+ * with value 1 in dst[dst_len - 1], bit 1 is the bit with value 2, bit 2 is
+ * the bit with value 4, ..., bit 8 is the bit with value 1 in dst[dst_len -
+ * 2], and so on.
+ *
+ * Required invariants:
+ * dst_ofs + n_bits <= dst_len * 8
+ * n_bits <= 64
+ */
+void
+bitwise_put(uint64_t value,
+ void *dst, unsigned int dst_len, unsigned int dst_ofs,
+ unsigned int n_bits)
+{
+ ovs_be64 n_value = htonll(value);
+ bitwise_copy(&n_value, sizeof n_value, 0,
+ dst, dst_len, dst_ofs,
+ n_bits);
+}
+
+/* Returns the value of the 'n_bits' bits starting at bit 'src_ofs' in 'src',
+ * which is 'src_len' bytes long.
+ *
+ * If you consider all of 'src' to be a single unsigned integer in network byte
+ * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
+ * with value 1 in src[src_len - 1], bit 1 is the bit with value 2, bit 2 is
+ * the bit with value 4, ..., bit 8 is the bit with value 1 in src[src_len -
+ * 2], and so on.
+ *
+ * Required invariants:
+ * src_ofs + n_bits <= src_len * 8
+ * n_bits <= 64
+ */
+uint64_t
+bitwise_get(const void *src, unsigned int src_len,
+ unsigned int src_ofs, unsigned int n_bits)
+{
+ ovs_be64 value = htonll(0);
+
+ bitwise_copy(src, src_len, src_ofs,
+ &value, sizeof value, 0,
+ n_bits);
+ return ntohll(value);
+}
git://git.onelab.eu / sliver-openvswitch.git / blobdiff