[PATCH 0/3 net-2.6.26] ip_options_compile cleanup

[PATCH 0/3 net-2.6.26] ip_options_compile cleanup

[Denis V. Lunev]

This set of patches has been originally sent to to netdev@ two weeks
ago.

The idea is the following: ip_options->is_data field is checked only
inside ip_options_compile when opt != NULL. This is possible only on the
following codepath:
    ip_options_get_finish
        opt->is_data = 1;
        ip_options_compile(opt, NULL)

ip_options->is_data is not a part of user<->kernel interface and can be
removed.

Regards,
	Den

[PATCH 1/3 net-2.6.26] Remove unnecessary check for opt->is_data in ip_options_compile.

[Denis V. Lunev]

There is the only way to reach ip_options compile with opt != NULL:

ip_options_get_finish
    opt->is_data = 1;
    ip_options_compile(opt, NULL)

So, checking for is_data inside opt != NULL branch is not needed.

Signed-off-by: Denis V. Lunev <den@openvz.org>
---
 net/ipv4/ip_options.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c
index df93a9c..7e94bf8 100644
--- a/net/ipv4/ip_options.c
+++ b/net/ipv4/ip_options.c
@@ -267,8 +267,7 @@ int ip_options_compile(struct ip_options * opt, struct sk_buff * skb)
 		optptr = iph + sizeof(struct iphdr);
 		opt->is_data = 0;
 	} else {
-		optptr = opt->is_data ? opt->__data :
-					(unsigned char *)&(ip_hdr(skb)[1]);
+		optptr = opt->__data;
 		iph = optptr - sizeof(struct iphdr);
 	}
 
-- 
1.5.3.rc5

[PATCH 2/3 nwt-2.6.26] Remove unused ip_options->is_data.

[Denis V. Lunev]

ip_options->is_data is assigned only and never checked. The structure is
not a part of kernel interface to the userspace. So, it is safe to remove
this field.

Signed-off-by: Denis V. Lunev <den@openvz.org>
---
 include/net/inet_sock.h |    3 +--
 net/ipv4/cipso_ipv4.c   |    1 -
 net/ipv4/ip_options.c   |    5 -----
 3 files changed, 1 insertions(+), 8 deletions(-)

diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index 8660cb0..b6db16d 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -43,8 +43,7 @@ struct ip_options {
 	unsigned char	srr;
 	unsigned char	rr;
 	unsigned char	ts;
-	unsigned char	is_data:1,
-			is_strictroute:1,
+	unsigned char	is_strictroute:1,
 			srr_is_hit:1,
 			is_changed:1,
 			rr_needaddr:1,
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 8cd357f..4637ded 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -1800,7 +1800,6 @@ int cipso_v4_sock_setattr(struct sock *sk,
 	}
 	memcpy(opt->__data, buf, buf_len);
 	opt->optlen = opt_len;
-	opt->is_data = 1;
 	opt->cipso = sizeof(struct iphdr);
 	kfree(buf);
 	buf = NULL;
diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c
index 7e94bf8..2fa4113 100644
--- a/net/ipv4/ip_options.c
+++ b/net/ipv4/ip_options.c
@@ -45,7 +45,6 @@ void ip_options_build(struct sk_buff * skb, struct ip_options * opt,
 	memcpy(&(IPCB(skb)->opt), opt, sizeof(struct ip_options));
 	memcpy(iph+sizeof(struct iphdr), opt->__data, opt->optlen);
 	opt = &(IPCB(skb)->opt);
-	opt->is_data = 0;
 
 	if (opt->srr)
 		memcpy(iph+opt->srr+iph[opt->srr+1]-4, &daddr, 4);
@@ -95,8 +94,6 @@ int ip_options_echo(struct ip_options * dopt, struct sk_buff * skb)
 
 	memset(dopt, 0, sizeof(struct ip_options));
 
-	dopt->is_data = 1;
-
 	sopt = &(IPCB(skb)->opt);
 
 	if (sopt->optlen == 0) {
@@ -265,7 +262,6 @@ int ip_options_compile(struct ip_options * opt, struct sk_buff * skb)
 		iph = skb_network_header(skb);
 		opt->optlen = ((struct iphdr *)iph)->ihl*4 - sizeof(struct iphdr);
 		optptr = iph + sizeof(struct iphdr);
-		opt->is_data = 0;
 	} else {
 		optptr = opt->__data;
 		iph = optptr - sizeof(struct iphdr);
@@ -519,7 +515,6 @@ static int ip_options_get_finish(struct ip_options **optp,
 	while (optlen & 3)
 		opt->__data[optlen++] = IPOPT_END;
 	opt->optlen = optlen;
-	opt->is_data = 1;
 	if (optlen && ip_options_compile(opt, NULL)) {
 		kfree(opt);
 		return -EINVAL;
-- 
1.5.3.rc5

[PATCH 3/3 net-2.6.26] [IPV4]: Always pass ip_options pointer into ip_options_compile.

[Denis V. Lunev]

This makes code a bit more uniform and straigthforward.

Signed-off-by: Denis V. Lunev <den@openvz.org>
---
 net/ipv4/ip_input.c   |    5 +++--
 net/ipv4/ip_options.c |   17 +++++++----------
 2 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index d36e310..e3a0c78 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -283,13 +283,14 @@ static inline int ip_rcv_options(struct sk_buff *skb)
 	}
 
 	iph = ip_hdr(skb);
+	opt = &(IPCB(skb)->opt);
+	opt->optlen = iph->ihl*4 - sizeof(struct iphdr);
 
-	if (ip_options_compile(NULL, skb)) {
+	if (ip_options_compile(opt, skb)) {
 		IP_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
 		goto drop;
 	}
 
-	opt = &(IPCB(skb)->opt);
 	if (unlikely(opt->srr)) {
 		struct in_device *in_dev = in_dev_get(dev);
 		if (in_dev) {
diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c
index 2fa4113..aeed4e5 100644
--- a/net/ipv4/ip_options.c
+++ b/net/ipv4/ip_options.c
@@ -255,17 +255,14 @@ int ip_options_compile(struct ip_options * opt, struct sk_buff * skb)
 	unsigned char * optptr;
 	int optlen;
 	unsigned char * pp_ptr = NULL;
-	struct rtable *rt = skb ? skb->rtable : NULL;
-
-	if (!opt) {
-		opt = &(IPCB(skb)->opt);
-		iph = skb_network_header(skb);
-		opt->optlen = ((struct iphdr *)iph)->ihl*4 - sizeof(struct iphdr);
-		optptr = iph + sizeof(struct iphdr);
-	} else {
+	struct rtable *rt = NULL;
+
+	if (skb != NULL) {
+		rt = skb->rtable;
+		optptr = (unsigned char *)&(ip_hdr(skb)[1]);
+	} else
 		optptr = opt->__data;
-		iph = optptr - sizeof(struct iphdr);
-	}
+	iph = optptr - sizeof(struct iphdr);
 
 	for (l = opt->optlen; l > 0; ) {
 		switch (*optptr) {
-- 
1.5.3.rc5

Re: [PATCH 0/3 net-2.6.26] ip_options_compile cleanup

[David Miller]

From: "Denis V. Lunev" <den@openvz.org>
Date: Wed, 19 Mar 2008 15:41:48 +0300

> This set of patches has been originally sent to to netdev@ two weeks
> ago.
> 
> The idea is the following: ip_options->is_data field is checked only
> inside ip_options_compile when opt != NULL. This is possible only on the
> following codepath:
>     ip_options_get_finish
>         opt->is_data = 1;
>         ip_options_compile(opt, NULL)
> 
> ip_options->is_data is not a part of user<->kernel interface and can be
> removed.

All applied and pushed to net-2.6.26, thanks.