1 files changed, 185 insertions, 0 deletions
diff --git a/shared/nm-utils/nm-errno.h b/shared/nm-utils/nm-errno.h
new file mode 100644
index 00000000..d77735a7
--- /dev/null
+++ b/shared/nm-utils/nm-errno.h
@@ -0,0 +1,185 @@
+/* NetworkManager -- Network link manager
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ * Copyright 2018 Red Hat, Inc.
+ */
+
+#ifndef __NM_ERRNO_H__
+#define __NM_ERRNO_H__
+
+#include <errno.h>
+
+/*****************************************************************************/
+
+enum _NMErrno {
+	_NM_ERRNO_MININT         = G_MININT,
+	_NM_ERRNO_MAXINT         = G_MAXINT,
+	_NM_ERRNO_RESERVED_FIRST = 100000,
+
+
+	/* when we cannot represent a number as positive number, we resort to this
+	 * number. Basically, the values G_MININT, -NME_ERRNO_SUCCESS, NME_ERRNO_SUCCESS
+	 * and G_MAXINT all map to the same value. */
+	NME_ERRNO_OUT_OF_RANGE   = G_MAXINT,
+
+	/* Indicate that the original errno was zero. Zero denotes *no error*, but we know something
+	 * went wrong and we want to report some error. This is a placeholder to mean, something
+	 * was wrong, but errno was zero. */
+	NME_ERRNO_SUCCESS        = G_MAXINT - 1,
+
+
+	/* an unspecified error. */
+	NME_UNSPEC = _NM_ERRNO_RESERVED_FIRST,
+
+	/* A bug, for example when an assertion failed.
+	 * Should never happen. */
+	NME_BUG,
+
+	/* a native error number (from <errno.h>) cannot be mapped as
+	 * an nm-error, because it is in the range [_NM_ERRNO_RESERVED_FIRST,
+	 * _NM_ERRNO_RESERVED_LAST]. */
+	NME_NATIVE_ERRNO,
+
+	/* netlink errors. */
+	NME_NL_SEQ_MISMATCH,
+	NME_NL_MSG_TRUNC,
+	NME_NL_MSG_TOOSHORT,
+	NME_NL_DUMP_INTR,
+	NME_NL_ATTRSIZE,
+	NME_NL_BAD_SOCK,
+	NME_NL_NOADDR,
+	NME_NL_MSG_OVERFLOW,
+
+	/* platform errors. */
+	NME_PL_NOT_FOUND,
+	NME_PL_EXISTS,
+	NME_PL_WRONG_TYPE,
+	NME_PL_NOT_SLAVE,
+	NME_PL_NO_FIRMWARE,
+	NME_PL_OPNOTSUPP,
+	NME_PL_NETLINK,
+	NME_PL_CANT_SET_MTU,
+
+	_NM_ERRNO_RESERVED_LAST_PLUS_1,
+	_NM_ERRNO_RESERVED_LAST = _NM_ERRNO_RESERVED_LAST_PLUS_1 - 1,
+};
+
+/*****************************************************************************/
+
+/* When we receive an errno from a system function, we can safely assume
+ * that the error number is not negative. We rely on that, and possibly just
+ * "return -errsv;" to signal an error. We also rely on that, because libc
+ * is our trusted base: meaning, if it cannot even succeed at setting errno
+ * according to specification, all bets are off.
+ *
+ * This macro returns the input argument, and asserts that the error variable
+ * is positive.
+ *
+ * In a sense, the macro is related to nm_errno_native() function, but the difference
+ * is that this macro asserts that @errsv is positive, while nm_errno_native() coerces
+ * negative values to be non-negative. */
+#define NM_ERRNO_NATIVE(errsv) \
+	({ \
+		const int _errsv_x = (errsv); \
+		\
+		nm_assert (_errsv_x > 0); \
+		_errsv_x; \
+	})
+
+/* Normalize native errno.
+ *
+ * Our API may return native error codes (<errno.h>) as negative values. This function
+ * takes such an errno, and normalizes it to their positive value.
+ *
+ * The special values G_MININT and zero are coerced to NME_ERRNO_OUT_OF_RANGE and NME_ERRNO_SUCCESS
+ * respectively.
+ * Other values are coerced to their inverse.
+ * Other positive values are returned unchanged.
+ *
+ * Basically, this normalizes errsv to be positive (taking care of two pathological cases).
+ */
+static inline int
+nm_errno_native (int errsv)
+{
+	switch (errsv) {
+	case 0:                  return NME_ERRNO_SUCCESS;
+	case G_MININT:           return NME_ERRNO_OUT_OF_RANGE;
+	default:
+		return errsv >= 0 ? errsv : -errsv;
+	}
+}
+
+/* Normalizes an nm-error to be positive.
+ *
+ * Various API returns negative error codes, and this function converts the negative
+ * value to its positive.
+ *
+ * Note that @nmerr is on the domain of NetworkManager specific error numbers,
+ * which is not the same as the native error numbers (errsv from <errno.h>). But
+ * as far as normalizing goes, nm_errno() does exactly the same remapping as
+ * nm_errno_native(). */
+static inline int
+nm_errno (int nmerr)
+{
+	return nm_errno_native (nmerr);
+}
+
+/* this maps a native errno to a (always non-negative) nm-error number.
+ *
+ * Note that nm-error numbers are embedded into the range of regular
+ * errno. The only difference is, that nm-error numbers reserve a
+ * range (_NM_ERRNO_RESERVED_FIRST, _NM_ERRNO_RESERVED_LAST) for their
+ * own purpose.
+ *
+ * That means, converting an errno to nm-error number means in
+ * most cases just returning itself.
+ * Only pathological cases need special handling:
+ *
+ *  - 0 is mapped to NME_ERRNO_SUCCESS;
+ *  - G_MININT is mapped to NME_ERRNO_OUT_OF_RANGE;
+ *  - values in the range of (+/-) [_NM_ERRNO_RESERVED_FIRST, _NM_ERRNO_RESERVED_LAST]
+ *    are mapped to NME_NATIVE_ERRNO
+ *  - all other values are their (positive) absolute value.
+ */
+static inline int
+nm_errno_from_native (int errsv)
+{
+	switch (errsv) {
+	case 0:                  return NME_ERRNO_SUCCESS;
+	case G_MININT:           return NME_ERRNO_OUT_OF_RANGE;
+	default:
+		if (errsv < 0)
+			errsv = -errsv;
+		return   G_UNLIKELY (   errsv >= _NM_ERRNO_RESERVED_FIRST
+		                     && errsv <= _NM_ERRNO_RESERVED_LAST)
+		       ? NME_NATIVE_ERRNO
+		       : errsv;
+	}
+}
+
+const char *nm_strerror (int nmerr);
+
+/*****************************************************************************/
+
+#define NM_STRERROR_BUFSIZE 1024
+
+const char *nm_strerror_native_r (int errsv, char *buf, gsize buf_size);
+const char *nm_strerror_native (int errsv);
+
+/*****************************************************************************/
+
+#endif /* __NM_ERRNO_H__ */