[nft] mnl: Remove dead code

Submitted by Phil Sutter on July 26, 2017, 4:16 p.m.

Details

Message ID 20170726161630.12919-1-phil@nwl.cc
State Changes Requested
Delegated to: Pablo Neira
Headers show

Commit Message

Phil Sutter July 26, 2017, 4:16 p.m.
Remove the functions mnl_nft_rule_add() and *_delete() since they are
not used throughout the code. Commit a72315d2bad47 ("src: add rule
batching support") changed their only caller to use the batch variant
introduced at the same time.

Signed-off-by: Phil Sutter <phil@nwl.cc>
---
 include/mnl.h |  4 ----
 src/mnl.c     | 28 ----------------------------
 2 files changed, 32 deletions(-)

Comments

Pablo Neira July 27, 2017, 8:46 a.m.
Cc'ing Pablo Bermudo.

On Wed, Jul 26, 2017 at 06:16:30PM +0200, Phil Sutter wrote:
> Remove the functions mnl_nft_rule_add() and *_delete() since they are
> not used throughout the code. Commit a72315d2bad47 ("src: add rule
> batching support") changed their only caller to use the batch variant
> introduced at the same time.

I think there are more useless functions. Pablo Bermudo mentioned this
to me a while ago. At least I remember some of them in netlink.c?

If not much asking, it would be good if we can kill them all in one go.
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Pablo M. Bermudo Garay Aug. 7, 2017, 4:54 p.m.
2017-07-27 10:46 GMT+02:00 Pablo Neira Ayuso <pablo@netfilter.org>:
> Cc'ing Pablo Bermudo.
>
> On Wed, Jul 26, 2017 at 06:16:30PM +0200, Phil Sutter wrote:
>> Remove the functions mnl_nft_rule_add() and *_delete() since they are
>> not used throughout the code. Commit a72315d2bad47 ("src: add rule
>> batching support") changed their only caller to use the batch variant
>> introduced at the same time.
>
> I think there are more useless functions. Pablo Bermudo mentioned this
> to me a while ago. At least I remember some of them in netlink.c?
>
> If not much asking, it would be good if we can kill them all in one go.

I am using a combination of compiler and linker options in order to obtain
a list of unused functions:

  $ make -j5 CFLAGS="-ffunction-sections -fdata-sections
-Wl,--gc-sections,--print-gc-sections"

You can find more information about --gc-sections and its pitfalls here [1].
The listing is printed on stderr by --print-gc-sections and it looks like this:

/usr/bin/ld: Removing unused section '.text.xt_stmt_xlate' in file 'statement.o'
/usr/bin/ld: Removing unused section '.text.xt_stmt_release' in file
'statement.o'
/usr/bin/ld: Removing unused section '.text.xt_stmt_print' in file 'statement.o'
...

There is also a small utility called callcatcher [2], written by LibreOffice
developer Caolán McNamara. But it seems not to be recursive, so unused
functions invoked from other unused functions are not shown until the callers
are deleted.

The complete list contains some functions that I think are not worth removing,
because are part of a "consolidated API" (e.g. those related to the
implementation of the red–black tree). A bunch of unused functions are
from the auto-generated file scanner.c.

The current list is attached.

--

[1] http://elinux.org/images/2/2d/ELC2010-gc-sections_Denys_Vlasenko.pdf
[2] http://www.skynet.ie/~caolan/Packages/callcatcher.html

Patch hide | download patch | download mbox

diff --git a/include/mnl.h b/include/mnl.h
index 9f5b34f60d023..3d2d7fef93ba2 100644
--- a/include/mnl.h
+++ b/include/mnl.h
@@ -33,10 +33,6 @@  int mnl_nft_rule_batch_del(struct nftnl_rule *nlr, struct nftnl_batch *batch,
 int mnl_nft_rule_batch_replace(struct nftnl_rule *nlr, struct nftnl_batch *batch,
 			       unsigned int flags, uint32_t seqnum);
 
-int mnl_nft_rule_add(struct mnl_socket *nf_sock, struct nftnl_rule *r,
-		     unsigned int flags);
-int mnl_nft_rule_delete(struct mnl_socket *nf_sock, struct nftnl_rule *r,
-			unsigned int flags);
 struct nftnl_rule_list *mnl_nft_rule_dump(struct mnl_socket *nf_sock,
 					int family);
 
diff --git a/src/mnl.c b/src/mnl.c
index 7639312381507..3db80de6da02d 100644
--- a/src/mnl.c
+++ b/src/mnl.c
@@ -339,34 +339,6 @@  int mnl_nft_rule_batch_del(struct nftnl_rule *nlr, struct nftnl_batch *batch,
 /*
  * Rule
  */
-int mnl_nft_rule_add(struct mnl_socket *nf_sock, struct nftnl_rule *nlr,
-		     unsigned int flags)
-{
-	char buf[MNL_SOCKET_BUFFER_SIZE];
-	struct nlmsghdr *nlh;
-
-	nlh = nftnl_nlmsg_build_hdr(buf, NFT_MSG_NEWRULE,
-				    nftnl_rule_get_u32(nlr, NFTNL_RULE_FAMILY),
-				    NLM_F_ACK | NLM_F_CREATE | flags, seq);
-	nftnl_rule_nlmsg_build_payload(nlh, nlr);
-
-	return nft_mnl_talk(nf_sock, nlh, nlh->nlmsg_len, NULL, NULL);
-}
-
-int mnl_nft_rule_delete(struct mnl_socket *nf_sock, struct nftnl_rule *nlr,
-			unsigned int flags)
-{
-	char buf[MNL_SOCKET_BUFFER_SIZE];
-	struct nlmsghdr *nlh;
-
-	nlh = nftnl_nlmsg_build_hdr(buf, NFT_MSG_DELRULE,
-				    nftnl_rule_get_u32(nlr, NFTNL_RULE_FAMILY),
-				    NLM_F_ACK, seq);
-	nftnl_rule_nlmsg_build_payload(nlh, nlr);
-
-	return nft_mnl_talk(nf_sock, nlh, nlh->nlmsg_len, NULL, NULL);
-}
-
 static int rule_cb(const struct nlmsghdr *nlh, void *data)
 {
 	struct nftnl_rule_list *nlr_list = data;