Rationalize CMSG_SPACE usage:
in lib/zebra.h, ensure that RFC3542-required CMSG_SPACE and CMSG_LEN
are defined. Warn if alignment assumptions are made, since they are
i386-centric.
in lib/sockopt.h, declare that sockopt sizes are without
CMSG_SPACE-required padding - just simple sizeof.
in ospfd/ospf_packet.c, simply use CMSG_SPACE
This should remove all instances of CMSG_ALIGN from the source code.
This is a nonstandard, though rational, construct; quagga should use
only those defines in RFC3542.
diff --git a/lib/zebra.h b/lib/zebra.h
index 6980529..f2c396d 100644
--- a/lib/zebra.h
+++ b/lib/zebra.h
@@ -210,7 +210,13 @@
#endif /* BSDI_NRL */
/*
- * RFC 2553-bis defines not available on some systems.
+ * RFC 3542 defines several macros for using struct cmsghdr.
+ * Here, we define those that are not present
+ */
+
+/*
+ * Internal defines, for use only in this file.
+ * These are likely wrong on other than ILP32 machines, so warn.
*/
#ifndef _CMSG_DATA_ALIGN
#define _CMSG_DATA_ALIGN(n) (((n) + 3) & ~3)
@@ -220,16 +226,24 @@
#define _CMSG_HDR_ALIGN(n) (((n) + 3) & ~3)
#endif /* _CMSG_HDR_ALIGN */
+/*
+ * CMSG_SPACE and CMSG_LEN are required in RFC3542, but were new in that
+ * version.
+ */
#ifndef CMSG_SPACE
#define CMSG_SPACE(l) (_CMSG_DATA_ALIGN(sizeof(struct cmsghdr)) + \
_CMSG_HDR_ALIGN(l))
+#warning "assuming 4-byte alignment for CMSG_SPACE"
#endif /* CMSG_SPACE */
#ifndef CMSG_LEN
#define CMSG_LEN(l) (_CMSG_DATA_ALIGN(sizeof(struct cmsghdr)) + (l))
+#warning "assuming 4-byte alignment for CMSG_LEN"
#endif /* CMSG_LEN */
+
+
#if !(defined(__GNUC__) || defined(VTYSH_EXTRACT_PL))
#define __attribute__(x)
#endif /* !__GNUC__ */