diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/net/ipv6/netfilter/nf_reject_ipv6.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/net/ipv6/netfilter/nf_reject_ipv6.c')
-rw-r--r-- | kernel/net/ipv6/netfilter/nf_reject_ipv6.c | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/kernel/net/ipv6/netfilter/nf_reject_ipv6.c b/kernel/net/ipv6/netfilter/nf_reject_ipv6.c new file mode 100644 index 000000000..94b4c6dfb --- /dev/null +++ b/kernel/net/ipv6/netfilter/nf_reject_ipv6.c @@ -0,0 +1,248 @@ +/* (C) 1999-2001 Paul `Rusty' Russell + * (C) 2002-2004 Netfilter Core Team <coreteam@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/module.h> +#include <net/ipv6.h> +#include <net/ip6_route.h> +#include <net/ip6_fib.h> +#include <net/ip6_checksum.h> +#include <net/netfilter/ipv6/nf_reject.h> +#include <linux/netfilter_ipv6.h> +#include <linux/netfilter_bridge.h> +#include <net/netfilter/ipv6/nf_reject.h> + +const struct tcphdr *nf_reject_ip6_tcphdr_get(struct sk_buff *oldskb, + struct tcphdr *otcph, + unsigned int *otcplen, int hook) +{ + const struct ipv6hdr *oip6h = ipv6_hdr(oldskb); + u8 proto; + __be16 frag_off; + int tcphoff; + + proto = oip6h->nexthdr; + tcphoff = ipv6_skip_exthdr(oldskb, ((u8*)(oip6h+1) - oldskb->data), + &proto, &frag_off); + + if ((tcphoff < 0) || (tcphoff > oldskb->len)) { + pr_debug("Cannot get TCP header.\n"); + return NULL; + } + + *otcplen = oldskb->len - tcphoff; + + /* IP header checks: fragment, too short. */ + if (proto != IPPROTO_TCP || *otcplen < sizeof(struct tcphdr)) { + pr_debug("proto(%d) != IPPROTO_TCP or too short (len = %d)\n", + proto, *otcplen); + return NULL; + } + + otcph = skb_header_pointer(oldskb, tcphoff, sizeof(struct tcphdr), + otcph); + if (otcph == NULL) + return NULL; + + /* No RST for RST. */ + if (otcph->rst) { + pr_debug("RST is set\n"); + return NULL; + } + + /* Check checksum. */ + if (nf_ip6_checksum(oldskb, hook, tcphoff, IPPROTO_TCP)) { + pr_debug("TCP checksum is invalid\n"); + return NULL; + } + + return otcph; +} +EXPORT_SYMBOL_GPL(nf_reject_ip6_tcphdr_get); + +struct ipv6hdr *nf_reject_ip6hdr_put(struct sk_buff *nskb, + const struct sk_buff *oldskb, + __u8 protocol, int hoplimit) +{ + struct ipv6hdr *ip6h; + const struct ipv6hdr *oip6h = ipv6_hdr(oldskb); +#define DEFAULT_TOS_VALUE 0x0U + const __u8 tclass = DEFAULT_TOS_VALUE; + + skb_put(nskb, sizeof(struct ipv6hdr)); + skb_reset_network_header(nskb); + ip6h = ipv6_hdr(nskb); + ip6_flow_hdr(ip6h, tclass, 0); + ip6h->hop_limit = hoplimit; + ip6h->nexthdr = protocol; + ip6h->saddr = oip6h->daddr; + ip6h->daddr = oip6h->saddr; + + nskb->protocol = htons(ETH_P_IPV6); + + return ip6h; +} +EXPORT_SYMBOL_GPL(nf_reject_ip6hdr_put); + +void nf_reject_ip6_tcphdr_put(struct sk_buff *nskb, + const struct sk_buff *oldskb, + const struct tcphdr *oth, unsigned int otcplen) +{ + struct tcphdr *tcph; + int needs_ack; + + skb_reset_transport_header(nskb); + tcph = (struct tcphdr *)skb_put(nskb, sizeof(struct tcphdr)); + /* Truncate to length (no data) */ + tcph->doff = sizeof(struct tcphdr)/4; + tcph->source = oth->dest; + tcph->dest = oth->source; + + if (oth->ack) { + needs_ack = 0; + tcph->seq = oth->ack_seq; + tcph->ack_seq = 0; + } else { + needs_ack = 1; + tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin + + otcplen - (oth->doff<<2)); + tcph->seq = 0; + } + + /* Reset flags */ + ((u_int8_t *)tcph)[13] = 0; + tcph->rst = 1; + tcph->ack = needs_ack; + tcph->window = 0; + tcph->urg_ptr = 0; + tcph->check = 0; + + /* Adjust TCP checksum */ + tcph->check = csum_ipv6_magic(&ipv6_hdr(nskb)->saddr, + &ipv6_hdr(nskb)->daddr, + sizeof(struct tcphdr), IPPROTO_TCP, + csum_partial(tcph, + sizeof(struct tcphdr), 0)); +} +EXPORT_SYMBOL_GPL(nf_reject_ip6_tcphdr_put); + +void nf_send_reset6(struct net *net, struct sk_buff *oldskb, int hook) +{ + struct sk_buff *nskb; + struct tcphdr _otcph; + const struct tcphdr *otcph; + unsigned int otcplen, hh_len; + const struct ipv6hdr *oip6h = ipv6_hdr(oldskb); + struct ipv6hdr *ip6h; + struct dst_entry *dst = NULL; + struct flowi6 fl6; + + if ((!(ipv6_addr_type(&oip6h->saddr) & IPV6_ADDR_UNICAST)) || + (!(ipv6_addr_type(&oip6h->daddr) & IPV6_ADDR_UNICAST))) { + pr_debug("addr is not unicast.\n"); + return; + } + + otcph = nf_reject_ip6_tcphdr_get(oldskb, &_otcph, &otcplen, hook); + if (!otcph) + return; + + memset(&fl6, 0, sizeof(fl6)); + fl6.flowi6_proto = IPPROTO_TCP; + fl6.saddr = oip6h->daddr; + fl6.daddr = oip6h->saddr; + fl6.fl6_sport = otcph->dest; + fl6.fl6_dport = otcph->source; + security_skb_classify_flow(oldskb, flowi6_to_flowi(&fl6)); + dst = ip6_route_output(net, NULL, &fl6); + if (dst == NULL || dst->error) { + dst_release(dst); + return; + } + dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); + if (IS_ERR(dst)) + return; + + hh_len = (dst->dev->hard_header_len + 15)&~15; + nskb = alloc_skb(hh_len + 15 + dst->header_len + sizeof(struct ipv6hdr) + + sizeof(struct tcphdr) + dst->trailer_len, + GFP_ATOMIC); + + if (!nskb) { + net_dbg_ratelimited("cannot alloc skb\n"); + dst_release(dst); + return; + } + + skb_dst_set(nskb, dst); + + skb_reserve(nskb, hh_len + dst->header_len); + ip6h = nf_reject_ip6hdr_put(nskb, oldskb, IPPROTO_TCP, + ip6_dst_hoplimit(dst)); + nf_reject_ip6_tcphdr_put(nskb, oldskb, otcph, otcplen); + + nf_ct_attach(nskb, oldskb); + +#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) + /* If we use ip6_local_out for bridged traffic, the MAC source on + * the RST will be ours, instead of the destination's. This confuses + * some routers/firewalls, and they drop the packet. So we need to + * build the eth header using the original destination's MAC as the + * source, and send the RST packet directly. + */ + if (oldskb->nf_bridge) { + struct ethhdr *oeth = eth_hdr(oldskb); + + nskb->dev = nf_bridge_get_physindev(oldskb); + nskb->protocol = htons(ETH_P_IPV6); + ip6h->payload_len = htons(sizeof(struct tcphdr)); + if (dev_hard_header(nskb, nskb->dev, ntohs(nskb->protocol), + oeth->h_source, oeth->h_dest, nskb->len) < 0) + return; + dev_queue_xmit(nskb); + } else +#endif + ip6_local_out(nskb); +} +EXPORT_SYMBOL_GPL(nf_send_reset6); + +static bool reject6_csum_ok(struct sk_buff *skb, int hook) +{ + const struct ipv6hdr *ip6h = ipv6_hdr(skb); + int thoff; + __be16 fo; + u8 proto; + + if (skb->csum_bad) + return false; + + if (skb_csum_unnecessary(skb)) + return true; + + proto = ip6h->nexthdr; + thoff = ipv6_skip_exthdr(skb, ((u8*)(ip6h+1) - skb->data), &proto, &fo); + + if (thoff < 0 || thoff >= skb->len || (fo & htons(~0x7)) != 0) + return false; + + return nf_ip6_checksum(skb, hook, thoff, proto) == 0; +} + +void nf_send_unreach6(struct net *net, struct sk_buff *skb_in, + unsigned char code, unsigned int hooknum) +{ + if (!reject6_csum_ok(skb_in, hooknum)) + return; + + if (hooknum == NF_INET_LOCAL_OUT && skb_in->dev == NULL) + skb_in->dev = net->loopback_dev; + + icmpv6_send(skb_in, ICMPV6_DEST_UNREACH, code, 0); +} +EXPORT_SYMBOL_GPL(nf_send_unreach6); + +MODULE_LICENSE("GPL"); |