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Fix definition of NFNL_HEADER_LEN

PATCH Applied Pablo Neira 2 participants 2 messages Oct 29, 2005 – Oct 31, 2005 netfilter

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Pablo Neira

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#0 lore raw

PATCH 1/1 Fix definition of NFNL_HEADER_LEN

Hi Harald,

The current definition of NFNL_HEADER_LEN isn't OK. NLMSG_LENGTH already includes the size of the netlink header. We have to use NLMSG_ALIGN instead. NLMSG_LENGTH is a bit misleading, I didn't notice this at first sight either.

BTW, I think that we should add some kind of versioning of libnfnetlink as well, still missing.

cheers,
Pablo

libnfnetlink/libnfnetlink.h +5 -2
Index: include/libnfnetlink/libnfnetlink.h
===================================================================
@@ -1,6 +1,9 @@
 /* libnfnetlink.h: Header file for generic netfilter netlink interface
  *
  * (C) 2002 Harald Welte <[email protected]>
+ *
+ * 2005-10-29 Pablo Neira Ayuso <[email protected]>:
+ * 	Fix NFNL_HEADER_LEN
  */
 
 #ifndef __LIBNFNETLINK_H

@@ -18,8 +21,8 @@
 #define NLMSG_TAIL(nlh) \
 	(((void *) (nlh)) + NLMSG_ALIGN((nlh)->nlmsg_len))
 
-#define NFNL_HEADER_LEN	(NLMSG_LENGTH(sizeof(struct nlmsghdr))	\
-			 +NLMSG_LENGTH(sizeof(struct nfgenmsg)))
+#define NFNL_HEADER_LEN	(NLMSG_ALIGN(sizeof(struct nlmsghdr))	\
+			 +NLMSG_ALIGN(sizeof(struct nfgenmsg)))
 
 #define NFNL_BUFFSIZE		8192
Applied
#1 lore raw
Quoted 5 lines · Pablo Neira

Hi Harald,

The current definition of NFNL_HEADER_LEN isn't OK. NLMSG_LENGTH already includes the size of the netlink header. We have to use NLMSG_ALIGN instead. NLMSG_LENGTH is a bit misleading, I didn't notice this at first sight either.

thanks, applied.

Quoted 1 line

BTW, I think that we should add some kind of versioning of libnfnetlink as well, still missing.

yes, although I have to admit I don't [yet] know how symbol versioning actually works.

Signature · 5 lines
- Harald Welte <[email protected]>                 http://netfilter.org/
============================================================================
  "Fragmentation is like classful addressing -- an interesting early
   architectural error that shows how much experimentation was going
   on while IP was being designed."                    -- Paul Vixie