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[NETFILTER]: Do not copy skb in skb_make_writable

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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@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Herbert Xu 2007-10-14 00:39:18 -07:00 committed by David S. Miller
parent 7b995651e3
commit 37d4187922
18 changed files with 35 additions and 45 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/linux/netfilter.h
View File

@ -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)
{

2
net/ipv4/netfilter/ip_queue.c
View File

@ -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;

4
net/ipv4/netfilter/ipt_ECN.c
View File

@ -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);

2
net/ipv4/netfilter/ipt_TOS.c
View File

@ -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;

2
net/ipv4/netfilter/ipt_TTL.c
View File

@ -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);

4
net/ipv4/netfilter/nf_nat_core.c
View File

@ -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);

8
net/ipv4/netfilter/nf_nat_helper.c
View File

@ -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);

2
net/ipv4/netfilter/nf_nat_proto_gre.c
View File

@ -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;

2
net/ipv4/netfilter/nf_nat_proto_icmp.c
View File

@ -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);

2
net/ipv4/netfilter/nf_nat_proto_tcp.c
View File

@ -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);

2
net/ipv4/netfilter/nf_nat_proto_udp.c
View File

@ -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);

2
net/ipv4/netfilter/nf_nat_snmp_basic.c
View File

@ -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);

2
net/ipv6/netfilter/ip6_queue.c
View File

@ -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;

2
net/ipv6/netfilter/ip6t_HL.c
View File

@ -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);

34
net/netfilter/core.c
View File

@ -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;
if (!skb_cloned(skb)) {
if (writable_len <= skb_headlen(skb))
return 1;
} else if (skb_clone_writable(skb, writable_len))
return 1;
return pskb_may_pull(*pskb, writable_len);
if (writable_len <= skb_headlen(skb))
writable_len = 0;
else
writable_len -= skb_headlen(skb);
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;
return !!__pskb_pull_tail(skb, writable_len);
}
EXPORT_SYMBOL(skb_make_writable);

2
net/netfilter/nfnetlink_queue.c
View File

@ -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;

4
net/netfilter/xt_DSCP.c
View File

@ -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),

2
net/netfilter/xt_TCPMSS.c
View File

@ -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;