Commit 37d41879 authored by Herbert Xu's avatar Herbert Xu Committed by David S. Miller
Browse files

[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: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7b995651
......@@ -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)
{
......
......@@ -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;
......
......@@ -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);
......
......@@ -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;
......
......@@ -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);
......
......@@ -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);
......
......@@ -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);
......
......@@ -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;
......
......@@ -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);
......
......@@ -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);
......
......@@ -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);
......
......@@ -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);
......
......@@ -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;
......
......@@ -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);
......
......@@ -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);
......
......@@ -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;
......
......@@ -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),
......
......@@ -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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