From 2ca7b0ac022aa0158599178fe1056b1ba9ec8b97 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Sun, 14 Oct 2007 00:39:55 -0700 Subject: [NETFILTER]: Avoid skb_copy/pskb_copy/skb_realloc_headroom This patch replaces unnecessary uses of skb_copy, pskb_copy and skb_realloc_headroom by functions such as skb_make_writable and pskb_expand_head. This allows us to remove the double pointers later. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/ipv4/netfilter.c | 31 +++++++++---------------------- net/ipv4/netfilter/arpt_mangle.c | 14 +++----------- net/ipv4/netfilter/ip_queue.c | 22 ++++++++-------------- net/ipv4/netfilter/nf_nat_helper.c | 10 +--------- 4 files changed, 21 insertions(+), 56 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c index b44192924f9..d1e3012d891 100644 --- a/net/ipv4/netfilter.c +++ b/net/ipv4/netfilter.c @@ -3,6 +3,7 @@ #include #include #include +#include #include #include #include @@ -66,17 +67,10 @@ int ip_route_me_harder(struct sk_buff **pskb, unsigned addr_type) /* Change in oif may mean change in hh_len. */ hh_len = (*pskb)->dst->dev->hard_header_len; - if (skb_headroom(*pskb) < hh_len) { - struct sk_buff *nskb; - - nskb = skb_realloc_headroom(*pskb, hh_len); - if (!nskb) - return -1; - if ((*pskb)->sk) - skb_set_owner_w(nskb, (*pskb)->sk); - kfree_skb(*pskb); - *pskb = nskb; - } + if (skb_headroom(*pskb) < hh_len && + pskb_expand_head(*pskb, hh_len - skb_headroom(*pskb), 0, + GFP_ATOMIC)) + return -1; return 0; } @@ -107,17 +101,10 @@ int ip_xfrm_me_harder(struct sk_buff **pskb) /* Change in oif may mean change in hh_len. */ hh_len = (*pskb)->dst->dev->hard_header_len; - if (skb_headroom(*pskb) < hh_len) { - struct sk_buff *nskb; - - nskb = skb_realloc_headroom(*pskb, hh_len); - if (!nskb) - return -1; - if ((*pskb)->sk) - skb_set_owner_w(nskb, (*pskb)->sk); - kfree_skb(*pskb); - *pskb = nskb; - } + if (skb_headroom(*pskb) < hh_len && + pskb_expand_head(*pskb, hh_len - skb_headroom(*pskb), 0, + GFP_ATOMIC)) + return -1; return 0; } EXPORT_SYMBOL(ip_xfrm_me_harder); diff --git a/net/ipv4/netfilter/arpt_mangle.c b/net/ipv4/netfilter/arpt_mangle.c index c4bdab47597..0181f919a79 100644 --- a/net/ipv4/netfilter/arpt_mangle.c +++ b/net/ipv4/netfilter/arpt_mangle.c @@ -1,5 +1,6 @@ /* module that allows mangling of the arp payload */ #include +#include #include #include @@ -18,17 +19,8 @@ target(struct sk_buff **pskb, unsigned char *arpptr; int pln, hln; - if (skb_shared(*pskb) || skb_cloned(*pskb)) { - struct sk_buff *nskb; - - nskb = skb_copy(*pskb, GFP_ATOMIC); - if (!nskb) - return NF_DROP; - if ((*pskb)->sk) - skb_set_owner_w(nskb, (*pskb)->sk); - kfree_skb(*pskb); - *pskb = nskb; - } + if (skb_make_writable(*pskb, (*pskb)->len)) + return NF_DROP; arp = arp_hdr(*pskb); arpptr = skb_network_header(*pskb) + sizeof(*arp); diff --git a/net/ipv4/netfilter/ip_queue.c b/net/ipv4/netfilter/ip_queue.c index 62d8867ca7d..10a2ce09fd8 100644 --- a/net/ipv4/netfilter/ip_queue.c +++ b/net/ipv4/netfilter/ip_queue.c @@ -335,6 +335,7 @@ static int ipq_mangle_ipv4(ipq_verdict_msg_t *v, struct ipq_queue_entry *e) { int diff; + int err; struct iphdr *user_iph = (struct iphdr *)v->payload; if (v->data_len < sizeof(*user_iph)) @@ -347,21 +348,14 @@ ipq_mangle_ipv4(ipq_verdict_msg_t *v, struct ipq_queue_entry *e) if (v->data_len > 0xFFFF) return -EINVAL; if (diff > skb_tailroom(e->skb)) { - struct sk_buff *newskb; - - newskb = skb_copy_expand(e->skb, - skb_headroom(e->skb), - diff, - GFP_ATOMIC); - if (newskb == NULL) { - printk(KERN_WARNING "ip_queue: OOM " - "in mangle, dropping packet\n"); - return -ENOMEM; + err = pskb_expand_head(e->skb, 0, + diff - skb_tailroom(e->skb), + GFP_ATOMIC); + if (err) { + printk(KERN_WARNING "ip_queue: error " + "in mangle, dropping packet: %d\n", -err); + return err; } - if (e->skb->sk) - skb_set_owner_w(newskb, e->skb->sk); - kfree_skb(e->skb); - e->skb = newskb; } skb_put(e->skb, diff); } diff --git a/net/ipv4/netfilter/nf_nat_helper.c b/net/ipv4/netfilter/nf_nat_helper.c index 6e81f7612b7..40b429e4540 100644 --- a/net/ipv4/netfilter/nf_nat_helper.c +++ b/net/ipv4/netfilter/nf_nat_helper.c @@ -113,20 +113,12 @@ static void mangle_contents(struct sk_buff *skb, /* Unusual, but possible case. */ static int enlarge_skb(struct sk_buff **pskb, unsigned int extra) { - struct sk_buff *nskb; - if ((*pskb)->len + extra > 65535) return 0; - nskb = skb_copy_expand(*pskb, skb_headroom(*pskb), extra, GFP_ATOMIC); - if (!nskb) + if (pskb_expand_head(*pskb, 0, extra - skb_tailroom(*pskb), GFP_ATOMIC)) return 0; - /* Transfer socket to new skb. */ - if ((*pskb)->sk) - skb_set_owner_w(nskb, (*pskb)->sk); - kfree_skb(*pskb); - *pskb = nskb; return 1; } -- cgit v1.2.3