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Date: Sun, 14 Oct 2007 12:27:45 +0800
From: Herbert Xu <herbert@...dor.apana.org.au>
To: Patrick McHardy <kaber@...sh.net>,
David Miller <davem@...emloft.net>, hadi@...erus.ca,
netdev@...r.kernel.org, kuznet@....inr.ac.ru,
Herbert Xu <herbert@...dor.apana.org.au>
Subject: [PATCH 7/10] [NETFILTER]: Do not copy skb in skb_make_writable
[NETFILTER]: Do not copy skb in skb_make_writable
Now that all callers of netfilter can guarantee that the skb is not shared,
we no longer have to copy the skb in skb_make_writable.
Signed-off-by: Herbert Xu <herbert@...dor.apana.org.au>
---
include/linux/netfilter.h | 2 -
net/ipv4/netfilter/ip_queue.c | 2 -
net/ipv4/netfilter/ipt_ECN.c | 4 +--
net/ipv4/netfilter/ipt_TOS.c | 2 -
net/ipv4/netfilter/ipt_TTL.c | 2 -
net/ipv4/netfilter/nf_nat_core.c | 4 +--
net/ipv4/netfilter/nf_nat_helper.c | 8 +++---
net/ipv4/netfilter/nf_nat_proto_gre.c | 2 -
net/ipv4/netfilter/nf_nat_proto_icmp.c | 2 -
net/ipv4/netfilter/nf_nat_proto_tcp.c | 2 -
net/ipv4/netfilter/nf_nat_proto_udp.c | 2 -
net/ipv4/netfilter/nf_nat_snmp_basic.c | 2 -
net/ipv6/netfilter/ip6_queue.c | 2 -
net/ipv6/netfilter/ip6t_HL.c | 2 -
net/netfilter/core.c | 38 ++++++++++++---------------------
net/netfilter/nfnetlink_queue.c | 2 -
net/netfilter/xt_DSCP.c | 4 +--
net/netfilter/xt_TCPMSS.c | 2 -
18 files changed, 37 insertions(+), 47 deletions(-)
diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index 1dd075e..2505348 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -287,7 +287,7 @@ extern void nf_invalidate_cache(int pf);
/* Call this before modifying an existing packet: ensures it is
modifiable and linear to the point you care about (writable_len).
Returns true or false. */
-extern int skb_make_writable(struct sk_buff **pskb, unsigned int writable_len);
+extern int skb_make_writable(struct sk_buff *skb, unsigned int writable_len);
static inline void nf_csum_replace4(__sum16 *sum, __be32 from, __be32 to)
{
diff --git a/net/ipv4/netfilter/ip_queue.c b/net/ipv4/netfilter/ip_queue.c
index 23cbfc7..62d8867 100644
--- a/net/ipv4/netfilter/ip_queue.c
+++ b/net/ipv4/netfilter/ip_queue.c
@@ -365,7 +365,7 @@ ipq_mangle_ipv4(ipq_verdict_msg_t *v, struct ipq_queue_entry *e)
}
skb_put(e->skb, diff);
}
- if (!skb_make_writable(&e->skb, v->data_len))
+ if (!skb_make_writable(e->skb, v->data_len))
return -ENOMEM;
skb_copy_to_linear_data(e->skb, v->payload, v->data_len);
e->skb->ip_summed = CHECKSUM_NONE;
diff --git a/net/ipv4/netfilter/ipt_ECN.c b/net/ipv4/netfilter/ipt_ECN.c
index f1253bd..92744be 100644
--- a/net/ipv4/netfilter/ipt_ECN.c
+++ b/net/ipv4/netfilter/ipt_ECN.c
@@ -32,7 +32,7 @@ set_ect_ip(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
if ((iph->tos & IPT_ECN_IP_MASK) != (einfo->ip_ect & IPT_ECN_IP_MASK)) {
__u8 oldtos;
- if (!skb_make_writable(pskb, sizeof(struct iphdr)))
+ if (!skb_make_writable(*pskb, sizeof(struct iphdr)))
return false;
iph = ip_hdr(*pskb);
oldtos = iph->tos;
@@ -62,7 +62,7 @@ set_ect_tcp(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
tcph->cwr == einfo->proto.tcp.cwr))
return true;
- if (!skb_make_writable(pskb, ip_hdrlen(*pskb) + sizeof(*tcph)))
+ if (!skb_make_writable(*pskb, ip_hdrlen(*pskb) + sizeof(*tcph)))
return false;
tcph = (void *)ip_hdr(*pskb) + ip_hdrlen(*pskb);
diff --git a/net/ipv4/netfilter/ipt_TOS.c b/net/ipv4/netfilter/ipt_TOS.c
index 25f5d0b..87b689a 100644
--- a/net/ipv4/netfilter/ipt_TOS.c
+++ b/net/ipv4/netfilter/ipt_TOS.c
@@ -33,7 +33,7 @@ target(struct sk_buff **pskb,
if ((iph->tos & IPTOS_TOS_MASK) != tosinfo->tos) {
__u8 oldtos;
- if (!skb_make_writable(pskb, sizeof(struct iphdr)))
+ if (!skb_make_writable(*pskb, sizeof(struct iphdr)))
return NF_DROP;
iph = ip_hdr(*pskb);
oldtos = iph->tos;
diff --git a/net/ipv4/netfilter/ipt_TTL.c b/net/ipv4/netfilter/ipt_TTL.c
index 2b54e7b..3dd4676 100644
--- a/net/ipv4/netfilter/ipt_TTL.c
+++ b/net/ipv4/netfilter/ipt_TTL.c
@@ -29,7 +29,7 @@ ipt_ttl_target(struct sk_buff **pskb,
const struct ipt_TTL_info *info = targinfo;
int new_ttl;
- if (!skb_make_writable(pskb, (*pskb)->len))
+ if (!skb_make_writable(*pskb, (*pskb)->len))
return NF_DROP;
iph = ip_hdr(*pskb);
diff --git a/net/ipv4/netfilter/nf_nat_core.c b/net/ipv4/netfilter/nf_nat_core.c
index 7221aa2..3b5eb7c 100644
--- a/net/ipv4/netfilter/nf_nat_core.c
+++ b/net/ipv4/netfilter/nf_nat_core.c
@@ -357,7 +357,7 @@ manip_pkt(u_int16_t proto,
struct iphdr *iph;
struct nf_nat_protocol *p;
- if (!skb_make_writable(pskb, iphdroff + sizeof(*iph)))
+ if (!skb_make_writable(*pskb, iphdroff + sizeof(*iph)))
return 0;
iph = (void *)(*pskb)->data + iphdroff;
@@ -431,7 +431,7 @@ int nf_nat_icmp_reply_translation(struct nf_conn *ct,
unsigned long statusbit;
enum nf_nat_manip_type manip = HOOK2MANIP(hooknum);
- if (!skb_make_writable(pskb, hdrlen + sizeof(*inside)))
+ if (!skb_make_writable(*pskb, hdrlen + sizeof(*inside)))
return 0;
inside = (void *)(*pskb)->data + ip_hdrlen(*pskb);
diff --git a/net/ipv4/netfilter/nf_nat_helper.c b/net/ipv4/netfilter/nf_nat_helper.c
index 93d8a0a..6e81f76 100644
--- a/net/ipv4/netfilter/nf_nat_helper.c
+++ b/net/ipv4/netfilter/nf_nat_helper.c
@@ -152,7 +152,7 @@ nf_nat_mangle_tcp_packet(struct sk_buff **pskb,
struct tcphdr *tcph;
int oldlen, datalen;
- if (!skb_make_writable(pskb, (*pskb)->len))
+ if (!skb_make_writable(*pskb, (*pskb)->len))
return 0;
if (rep_len > match_len &&
@@ -234,7 +234,7 @@ nf_nat_mangle_udp_packet(struct sk_buff **pskb,
match_offset + match_len)
return 0;
- if (!skb_make_writable(pskb, (*pskb)->len))
+ if (!skb_make_writable(*pskb, (*pskb)->len))
return 0;
if (rep_len > match_len &&
@@ -341,7 +341,7 @@ nf_nat_sack_adjust(struct sk_buff **pskb,
optoff = ip_hdrlen(*pskb) + sizeof(struct tcphdr);
optend = ip_hdrlen(*pskb) + tcph->doff * 4;
- if (!skb_make_writable(pskb, optend))
+ if (!skb_make_writable(*pskb, optend))
return 0;
dir = CTINFO2DIR(ctinfo);
@@ -390,7 +390,7 @@ nf_nat_seq_adjust(struct sk_buff **pskb,
this_way = &nat->seq[dir];
other_way = &nat->seq[!dir];
- if (!skb_make_writable(pskb, ip_hdrlen(*pskb) + sizeof(*tcph)))
+ if (!skb_make_writable(*pskb, ip_hdrlen(*pskb) + sizeof(*tcph)))
return 0;
tcph = (void *)(*pskb)->data + ip_hdrlen(*pskb);
diff --git a/net/ipv4/netfilter/nf_nat_proto_gre.c b/net/ipv4/netfilter/nf_nat_proto_gre.c
index d562290..e7a2aaf 100644
--- a/net/ipv4/netfilter/nf_nat_proto_gre.c
+++ b/net/ipv4/netfilter/nf_nat_proto_gre.c
@@ -109,7 +109,7 @@ gre_manip_pkt(struct sk_buff **pskb, unsigned int iphdroff,
/* pgreh includes two optional 32bit fields which are not required
* to be there. That's where the magic '8' comes from */
- if (!skb_make_writable(pskb, hdroff + sizeof(*pgreh) - 8))
+ if (!skb_make_writable(*pskb, hdroff + sizeof(*pgreh) - 8))
return 0;
greh = (void *)(*pskb)->data + hdroff;
diff --git a/net/ipv4/netfilter/nf_nat_proto_icmp.c b/net/ipv4/netfilter/nf_nat_proto_icmp.c
index 898d737..4087f4f 100644
--- a/net/ipv4/netfilter/nf_nat_proto_icmp.c
+++ b/net/ipv4/netfilter/nf_nat_proto_icmp.c
@@ -61,7 +61,7 @@ icmp_manip_pkt(struct sk_buff **pskb,
struct icmphdr *hdr;
unsigned int hdroff = iphdroff + iph->ihl*4;
- if (!skb_make_writable(pskb, hdroff + sizeof(*hdr)))
+ if (!skb_make_writable(*pskb, hdroff + sizeof(*hdr)))
return 0;
hdr = (struct icmphdr *)((*pskb)->data + hdroff);
diff --git a/net/ipv4/netfilter/nf_nat_proto_tcp.c b/net/ipv4/netfilter/nf_nat_proto_tcp.c
index 5bbbb2a..e544125 100644
--- a/net/ipv4/netfilter/nf_nat_proto_tcp.c
+++ b/net/ipv4/netfilter/nf_nat_proto_tcp.c
@@ -106,7 +106,7 @@ tcp_manip_pkt(struct sk_buff **pskb,
if ((*pskb)->len >= hdroff + sizeof(struct tcphdr))
hdrsize = sizeof(struct tcphdr);
- if (!skb_make_writable(pskb, hdroff + hdrsize))
+ if (!skb_make_writable(*pskb, hdroff + hdrsize))
return 0;
iph = (struct iphdr *)((*pskb)->data + iphdroff);
diff --git a/net/ipv4/netfilter/nf_nat_proto_udp.c b/net/ipv4/netfilter/nf_nat_proto_udp.c
index a0af4fd..ebe9b42 100644
--- a/net/ipv4/netfilter/nf_nat_proto_udp.c
+++ b/net/ipv4/netfilter/nf_nat_proto_udp.c
@@ -97,7 +97,7 @@ udp_manip_pkt(struct sk_buff **pskb,
__be32 oldip, newip;
__be16 *portptr, newport;
- if (!skb_make_writable(pskb, hdroff + sizeof(*hdr)))
+ if (!skb_make_writable(*pskb, hdroff + sizeof(*hdr)))
return 0;
iph = (struct iphdr *)((*pskb)->data + iphdroff);
diff --git a/net/ipv4/netfilter/nf_nat_snmp_basic.c b/net/ipv4/netfilter/nf_nat_snmp_basic.c
index 6bfcd3a..87011fe 100644
--- a/net/ipv4/netfilter/nf_nat_snmp_basic.c
+++ b/net/ipv4/netfilter/nf_nat_snmp_basic.c
@@ -1258,7 +1258,7 @@ static int help(struct sk_buff **pskb, unsigned int protoff,
return NF_DROP;
}
- if (!skb_make_writable(pskb, (*pskb)->len))
+ if (!skb_make_writable(*pskb, (*pskb)->len))
return NF_DROP;
spin_lock_bh(&snmp_lock);
diff --git a/net/ipv6/netfilter/ip6_queue.c b/net/ipv6/netfilter/ip6_queue.c
index 0473145..d7080dd 100644
--- a/net/ipv6/netfilter/ip6_queue.c
+++ b/net/ipv6/netfilter/ip6_queue.c
@@ -362,7 +362,7 @@ ipq_mangle_ipv6(ipq_verdict_msg_t *v, struct ipq_queue_entry *e)
}
skb_put(e->skb, diff);
}
- if (!skb_make_writable(&e->skb, v->data_len))
+ if (!skb_make_writable(e->skb, v->data_len))
return -ENOMEM;
skb_copy_to_linear_data(e->skb, v->payload, v->data_len);
e->skb->ip_summed = CHECKSUM_NONE;
diff --git a/net/ipv6/netfilter/ip6t_HL.c b/net/ipv6/netfilter/ip6t_HL.c
index ad4d943..f76197f 100644
--- a/net/ipv6/netfilter/ip6t_HL.c
+++ b/net/ipv6/netfilter/ip6t_HL.c
@@ -29,7 +29,7 @@ static unsigned int ip6t_hl_target(struct sk_buff **pskb,
const struct ip6t_HL_info *info = targinfo;
int new_hl;
- if (!skb_make_writable(pskb, (*pskb)->len))
+ if (!skb_make_writable(*pskb, (*pskb)->len))
return NF_DROP;
ip6h = ipv6_hdr(*pskb);
diff --git a/net/netfilter/core.c b/net/netfilter/core.c
index a523fa4..2c9e8e3 100644
--- a/net/netfilter/core.c
+++ b/net/netfilter/core.c
@@ -196,34 +196,24 @@ unlock:
EXPORT_SYMBOL(nf_hook_slow);
-int skb_make_writable(struct sk_buff **pskb, unsigned int writable_len)
+int skb_make_writable(struct sk_buff *skb, unsigned int writable_len)
{
- struct sk_buff *nskb;
-
- if (writable_len > (*pskb)->len)
+ if (writable_len > skb->len)
return 0;
/* Not exclusive use of packet? Must copy. */
- if (skb_cloned(*pskb) && !skb_clone_writable(*pskb, writable_len))
- goto copy_skb;
- if (skb_shared(*pskb))
- goto copy_skb;
-
- return pskb_may_pull(*pskb, writable_len);
-
-copy_skb:
- nskb = skb_copy(*pskb, GFP_ATOMIC);
- if (!nskb)
- return 0;
- BUG_ON(skb_is_nonlinear(nskb));
-
- /* Rest of kernel will get very unhappy if we pass it a
- suddenly-orphaned skbuff */
- if ((*pskb)->sk)
- skb_set_owner_w(nskb, (*pskb)->sk);
- kfree_skb(*pskb);
- *pskb = nskb;
- return 1;
+ if (!skb_cloned(skb)) {
+ if (writable_len <= skb_headlen(skb))
+ return 1;
+ } else if (skb_clone_writable(skb, writable_len))
+ return 1;
+
+ if (writable_len <= skb_headlen(skb))
+ writable_len = 0;
+ else
+ writable_len -= skb_headlen(skb);
+
+ return !!__pskb_pull_tail(skb, writable_len);
}
EXPORT_SYMBOL(skb_make_writable);
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index 49f0480..6ba98ac 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -644,7 +644,7 @@ nfqnl_mangle(void *data, int data_len, struct nfqnl_queue_entry *e)
}
skb_put(e->skb, diff);
}
- if (!skb_make_writable(&e->skb, data_len))
+ if (!skb_make_writable(e->skb, data_len))
return -ENOMEM;
skb_copy_to_linear_data(e->skb, data, data_len);
e->skb->ip_summed = CHECKSUM_NONE;
diff --git a/net/netfilter/xt_DSCP.c b/net/netfilter/xt_DSCP.c
index 798ab73..1706616 100644
--- a/net/netfilter/xt_DSCP.c
+++ b/net/netfilter/xt_DSCP.c
@@ -36,7 +36,7 @@ static unsigned int target(struct sk_buff **pskb,
u_int8_t dscp = ipv4_get_dsfield(ip_hdr(*pskb)) >> XT_DSCP_SHIFT;
if (dscp != dinfo->dscp) {
- if (!skb_make_writable(pskb, sizeof(struct iphdr)))
+ if (!skb_make_writable(*pskb, sizeof(struct iphdr)))
return NF_DROP;
ipv4_change_dsfield(ip_hdr(*pskb), (__u8)(~XT_DSCP_MASK),
@@ -57,7 +57,7 @@ static unsigned int target6(struct sk_buff **pskb,
u_int8_t dscp = ipv6_get_dsfield(ipv6_hdr(*pskb)) >> XT_DSCP_SHIFT;
if (dscp != dinfo->dscp) {
- if (!skb_make_writable(pskb, sizeof(struct ipv6hdr)))
+ if (!skb_make_writable(*pskb, sizeof(struct ipv6hdr)))
return NF_DROP;
ipv6_change_dsfield(ipv6_hdr(*pskb), (__u8)(~XT_DSCP_MASK),
diff --git a/net/netfilter/xt_TCPMSS.c b/net/netfilter/xt_TCPMSS.c
index d40f7e4..31b6f9d 100644
--- a/net/netfilter/xt_TCPMSS.c
+++ b/net/netfilter/xt_TCPMSS.c
@@ -50,7 +50,7 @@ tcpmss_mangle_packet(struct sk_buff **pskb,
u16 newmss;
u8 *opt;
- if (!skb_make_writable(pskb, (*pskb)->len))
+ if (!skb_make_writable(*pskb, (*pskb)->len))
return -1;
tcplen = (*pskb)->len - tcphoff;
-
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