diff options
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/netfilter/ipt_ECN.c | 141 | ||||
| -rw-r--r-- | net/ipv4/tcp.c | 3 |
2 files changed, 141 insertions, 3 deletions
diff --git a/net/ipv4/netfilter/ipt_ECN.c b/net/ipv4/netfilter/ipt_ECN.c new file mode 100644 index 00000000000..f7e2fa0974d --- /dev/null +++ b/net/ipv4/netfilter/ipt_ECN.c @@ -0,0 +1,141 @@ +/* iptables module for the IPv4 and TCP ECN bits, Version 1.5 + * + * (C) 2002 by Harald Welte <laforge@netfilter.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. +*/ + +#include <linux/in.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/ip.h> +#include <net/ip.h> +#include <linux/tcp.h> +#include <net/checksum.h> + +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_ipv4/ip_tables.h> +#include <linux/netfilter_ipv4/ipt_ECN.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); +MODULE_DESCRIPTION("Xtables: Explicit Congestion Notification (ECN) flag modification"); + +/* set ECT codepoint from IP header. + * return false if there was an error. */ +static inline bool +set_ect_ip(struct sk_buff *skb, const struct ipt_ECN_info *einfo) +{ + struct iphdr *iph = ip_hdr(skb); + + if ((iph->tos & IPT_ECN_IP_MASK) != (einfo->ip_ect & IPT_ECN_IP_MASK)) { + __u8 oldtos; + if (!skb_make_writable(skb, sizeof(struct iphdr))) + return false; + iph = ip_hdr(skb); + oldtos = iph->tos; + iph->tos &= ~IPT_ECN_IP_MASK; + iph->tos |= (einfo->ip_ect & IPT_ECN_IP_MASK); + csum_replace2(&iph->check, htons(oldtos), htons(iph->tos)); + } + return true; +} + +/* Return false if there was an error. */ +static inline bool +set_ect_tcp(struct sk_buff *skb, const struct ipt_ECN_info *einfo) +{ + struct tcphdr _tcph, *tcph; + __be16 oldval; + + /* Not enought header? */ + tcph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph); + if (!tcph) + return false; + + if ((!(einfo->operation & IPT_ECN_OP_SET_ECE) || + tcph->ece == einfo->proto.tcp.ece) && + (!(einfo->operation & IPT_ECN_OP_SET_CWR) || + tcph->cwr == einfo->proto.tcp.cwr)) + return true; + + if (!skb_make_writable(skb, ip_hdrlen(skb) + sizeof(*tcph))) + return false; + tcph = (void *)ip_hdr(skb) + ip_hdrlen(skb); + + oldval = ((__be16 *)tcph)[6]; + if (einfo->operation & IPT_ECN_OP_SET_ECE) + tcph->ece = einfo->proto.tcp.ece; + if (einfo->operation & IPT_ECN_OP_SET_CWR) + tcph->cwr = einfo->proto.tcp.cwr; + + inet_proto_csum_replace2(&tcph->check, skb, + oldval, ((__be16 *)tcph)[6], 0); + return true; +} + +static unsigned int +ecn_tg(struct sk_buff *skb, const struct xt_target_param *par) +{ + const struct ipt_ECN_info *einfo = par->targinfo; + + if (einfo->operation & IPT_ECN_OP_SET_IP) + if (!set_ect_ip(skb, einfo)) + return NF_DROP; + + if (einfo->operation & (IPT_ECN_OP_SET_ECE | IPT_ECN_OP_SET_CWR) + && ip_hdr(skb)->protocol == IPPROTO_TCP) + if (!set_ect_tcp(skb, einfo)) + return NF_DROP; + + return XT_CONTINUE; +} + +static bool ecn_tg_check(const struct xt_tgchk_param *par) +{ + const struct ipt_ECN_info *einfo = par->targinfo; + const struct ipt_entry *e = par->entryinfo; + + if (einfo->operation & IPT_ECN_OP_MASK) { + printk(KERN_WARNING "ECN: unsupported ECN operation %x\n", + einfo->operation); + return false; + } + if (einfo->ip_ect & ~IPT_ECN_IP_MASK) { + printk(KERN_WARNING "ECN: new ECT codepoint %x out of mask\n", + einfo->ip_ect); + return false; + } + if ((einfo->operation & (IPT_ECN_OP_SET_ECE|IPT_ECN_OP_SET_CWR)) + && (e->ip.proto != IPPROTO_TCP || (e->ip.invflags & XT_INV_PROTO))) { + printk(KERN_WARNING "ECN: cannot use TCP operations on a " + "non-tcp rule\n"); + return false; + } + return true; +} + +static struct xt_target ecn_tg_reg __read_mostly = { + .name = "ECN", + .family = NFPROTO_IPV4, + .target = ecn_tg, + .targetsize = sizeof(struct ipt_ECN_info), + .table = "mangle", + .checkentry = ecn_tg_check, + .me = THIS_MODULE, +}; + +static int __init ecn_tg_init(void) +{ + return xt_register_target(&ecn_tg_reg); +} + +static void __exit ecn_tg_exit(void) +{ + xt_unregister_target(&ecn_tg_reg); +} + +module_init(ecn_tg_init); +module_exit(ecn_tg_exit); diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index b66a1d32de4..72fa141d17d 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -658,13 +658,10 @@ ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos, } if (sk->sk_shutdown & RCV_SHUTDOWN) { - -/* SH - 04/15/11 - removed print, these were filling up logs in some environments printk(KERN_ERR "%s:%s:%d\n" "breaking %d\n", __FUNCTION__, __FILE__, __LINE__, ret); -*/ break; } if (sk->sk_state == TCP_CLOSE) { |