diff options
Diffstat (limited to 'net/netfilter/xt_TCPMSS.c')
-rw-r--r-- | net/netfilter/xt_TCPMSS.c | 58 |
1 files changed, 27 insertions, 31 deletions
diff --git a/net/netfilter/xt_TCPMSS.c b/net/netfilter/xt_TCPMSS.c index d40f7e4b128..07435a602b1 100644 --- a/net/netfilter/xt_TCPMSS.c +++ b/net/netfilter/xt_TCPMSS.c @@ -39,7 +39,7 @@ optlen(const u_int8_t *opt, unsigned int offset) } static int -tcpmss_mangle_packet(struct sk_buff **pskb, +tcpmss_mangle_packet(struct sk_buff *skb, const struct xt_tcpmss_info *info, unsigned int tcphoff, unsigned int minlen) @@ -50,11 +50,11 @@ tcpmss_mangle_packet(struct sk_buff **pskb, u16 newmss; u8 *opt; - if (!skb_make_writable(pskb, (*pskb)->len)) + if (!skb_make_writable(skb, skb->len)) return -1; - tcplen = (*pskb)->len - tcphoff; - tcph = (struct tcphdr *)(skb_network_header(*pskb) + tcphoff); + tcplen = skb->len - tcphoff; + tcph = (struct tcphdr *)(skb_network_header(skb) + tcphoff); /* Since it passed flags test in tcp match, we know it is is not a fragment, and has data >= tcp header length. SYN @@ -64,19 +64,19 @@ tcpmss_mangle_packet(struct sk_buff **pskb, if (tcplen != tcph->doff*4) { if (net_ratelimit()) printk(KERN_ERR "xt_TCPMSS: bad length (%u bytes)\n", - (*pskb)->len); + skb->len); return -1; } if (info->mss == XT_TCPMSS_CLAMP_PMTU) { - if (dst_mtu((*pskb)->dst) <= minlen) { + if (dst_mtu(skb->dst) <= minlen) { if (net_ratelimit()) printk(KERN_ERR "xt_TCPMSS: " "unknown or invalid path-MTU (%u)\n", - dst_mtu((*pskb)->dst)); + dst_mtu(skb->dst)); return -1; } - newmss = dst_mtu((*pskb)->dst) - minlen; + newmss = dst_mtu(skb->dst) - minlen; } else newmss = info->mss; @@ -95,7 +95,7 @@ tcpmss_mangle_packet(struct sk_buff **pskb, opt[i+2] = (newmss & 0xff00) >> 8; opt[i+3] = newmss & 0x00ff; - nf_proto_csum_replace2(&tcph->check, *pskb, + nf_proto_csum_replace2(&tcph->check, skb, htons(oldmss), htons(newmss), 0); return 0; } @@ -104,57 +104,53 @@ tcpmss_mangle_packet(struct sk_buff **pskb, /* * MSS Option not found ?! add it.. */ - if (skb_tailroom((*pskb)) < TCPOLEN_MSS) { - struct sk_buff *newskb; - - newskb = skb_copy_expand(*pskb, skb_headroom(*pskb), - TCPOLEN_MSS, GFP_ATOMIC); - if (!newskb) + if (skb_tailroom(skb) < TCPOLEN_MSS) { + if (pskb_expand_head(skb, 0, + TCPOLEN_MSS - skb_tailroom(skb), + GFP_ATOMIC)) return -1; - kfree_skb(*pskb); - *pskb = newskb; - tcph = (struct tcphdr *)(skb_network_header(*pskb) + tcphoff); + tcph = (struct tcphdr *)(skb_network_header(skb) + tcphoff); } - skb_put((*pskb), TCPOLEN_MSS); + skb_put(skb, TCPOLEN_MSS); opt = (u_int8_t *)tcph + sizeof(struct tcphdr); memmove(opt + TCPOLEN_MSS, opt, tcplen - sizeof(struct tcphdr)); - nf_proto_csum_replace2(&tcph->check, *pskb, + nf_proto_csum_replace2(&tcph->check, skb, htons(tcplen), htons(tcplen + TCPOLEN_MSS), 1); opt[0] = TCPOPT_MSS; opt[1] = TCPOLEN_MSS; opt[2] = (newmss & 0xff00) >> 8; opt[3] = newmss & 0x00ff; - nf_proto_csum_replace4(&tcph->check, *pskb, 0, *((__be32 *)opt), 0); + nf_proto_csum_replace4(&tcph->check, skb, 0, *((__be32 *)opt), 0); oldval = ((__be16 *)tcph)[6]; tcph->doff += TCPOLEN_MSS/4; - nf_proto_csum_replace2(&tcph->check, *pskb, + nf_proto_csum_replace2(&tcph->check, skb, oldval, ((__be16 *)tcph)[6], 0); return TCPOLEN_MSS; } static unsigned int -xt_tcpmss_target4(struct sk_buff **pskb, +xt_tcpmss_target4(struct sk_buff *skb, const struct net_device *in, const struct net_device *out, unsigned int hooknum, const struct xt_target *target, const void *targinfo) { - struct iphdr *iph = ip_hdr(*pskb); + struct iphdr *iph = ip_hdr(skb); __be16 newlen; int ret; - ret = tcpmss_mangle_packet(pskb, targinfo, iph->ihl * 4, + ret = tcpmss_mangle_packet(skb, targinfo, iph->ihl * 4, sizeof(*iph) + sizeof(struct tcphdr)); if (ret < 0) return NF_DROP; if (ret > 0) { - iph = ip_hdr(*pskb); + iph = ip_hdr(skb); newlen = htons(ntohs(iph->tot_len) + ret); nf_csum_replace2(&iph->check, iph->tot_len, newlen); iph->tot_len = newlen; @@ -164,30 +160,30 @@ xt_tcpmss_target4(struct sk_buff **pskb, #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) static unsigned int -xt_tcpmss_target6(struct sk_buff **pskb, +xt_tcpmss_target6(struct sk_buff *skb, const struct net_device *in, const struct net_device *out, unsigned int hooknum, const struct xt_target *target, const void *targinfo) { - struct ipv6hdr *ipv6h = ipv6_hdr(*pskb); + struct ipv6hdr *ipv6h = ipv6_hdr(skb); u8 nexthdr; int tcphoff; int ret; nexthdr = ipv6h->nexthdr; - tcphoff = ipv6_skip_exthdr(*pskb, sizeof(*ipv6h), &nexthdr); + tcphoff = ipv6_skip_exthdr(skb, sizeof(*ipv6h), &nexthdr); if (tcphoff < 0) { WARN_ON(1); return NF_DROP; } - ret = tcpmss_mangle_packet(pskb, targinfo, tcphoff, + ret = tcpmss_mangle_packet(skb, targinfo, tcphoff, sizeof(*ipv6h) + sizeof(struct tcphdr)); if (ret < 0) return NF_DROP; if (ret > 0) { - ipv6h = ipv6_hdr(*pskb); + ipv6h = ipv6_hdr(skb); ipv6h->payload_len = htons(ntohs(ipv6h->payload_len) + ret); } return XT_CONTINUE; |