From 37d41879224108d6c24578ba6a3eeafce106ce84 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Sun, 14 Oct 2007 00:39:18 -0700 Subject: [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 Signed-off-by: David S. Miller --- 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 +- 17 files changed, 36 insertions(+), 46 deletions(-) (limited to 'net') diff --git a/net/ipv4/netfilter/ip_queue.c b/net/ipv4/netfilter/ip_queue.c index 23cbfc7c80f..62d8867ca7d 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 f1253bd3837..92744be1c55 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 25f5d0b3906..87b689ac09a 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 2b54e7b0cfe..3dd467611e1 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 7221aa20e6f..3b5eb7c1a13 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 93d8a0a8f03..6e81f7612b7 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 d562290b182..e7a2aafcce5 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 898d7377115..4087f4f42c3 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 5bbbb2acdc7..e544125dc03 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 a0af4fd9558..ebe9b42a8e9 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 6bfcd3a90f0..87011fe806c 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 0473145ac53..d7080dd475a 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 ad4d94310b8..f76197fc4dc 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 a523fa4136e..2c9e8e3652d 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 49f0480afe0..6ba98acdd7a 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 798ab731009..17066167438 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 d40f7e4b128..31b6f9d0982 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; -- cgit v1.2.3