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Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
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Pablo Neira Ayuso says:

====================
Netfilter fixes for net-next

This batch contains two fixes for what you have in your net-next,
they are:

1) Remove nf_send_reset6() from header file. This function now resides
   in the nf_reject_ipv6 module. Reported by Eric Dumazet.

2) Fix wrong NFT_REJECT_ICMPX_MAX definition and adjust code to fix
   errors reported by Dan Carpenter's static analysis tools.
====================

Signed-off-by: David S. Miller <[email protected]>
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@davem330
davem330 committed Oct 10, 2014
2 parents 4511a4a + f0d1f04 commit 7b6fa1e
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Showing 3 changed files with 7 additions and 162 deletions.
157 changes: 2 additions & 155 deletions include/net/netfilter/ipv6/nf_reject.h
View file
Original file line number Diff line number Diff line change
@@ -1,11 +1,7 @@
#ifndef _IPV6_NF_REJECT_H
#define _IPV6_NF_REJECT_H

#include <net/ipv6.h>
#include <net/ip6_route.h>
#include <net/ip6_fib.h>
#include <net/ip6_checksum.h>
#include <linux/netfilter_ipv6.h>
#include <linux/icmpv6.h>

static inline void
nf_send_unreach6(struct net *net, struct sk_buff *skb_in, unsigned char code,
Expand All @@ -17,155 +13,6 @@ nf_send_unreach6(struct net *net, struct sk_buff *skb_in, unsigned char code,
icmpv6_send(skb_in, ICMPV6_DEST_UNREACH, code, 0);
}

/* Send RST reply */
static void nf_send_reset6(struct net *net, struct sk_buff *oldskb, int hook)
{
struct sk_buff *nskb;
struct tcphdr otcph, *tcph;
unsigned int otcplen, hh_len;
int tcphoff, needs_ack;
const struct ipv6hdr *oip6h = ipv6_hdr(oldskb);
struct ipv6hdr *ip6h;
#define DEFAULT_TOS_VALUE 0x0U
const __u8 tclass = DEFAULT_TOS_VALUE;
struct dst_entry *dst = NULL;
u8 proto;
__be16 frag_off;
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;
}

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;
}

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. otcplen = %d\n",
proto, otcplen);
return;
}

if (skb_copy_bits(oldskb, tcphoff, &otcph, sizeof(struct tcphdr)))
BUG();

/* No RST for RST. */
if (otcph.rst) {
pr_debug("RST is set\n");
return;
}

/* Check checksum. */
if (nf_ip6_checksum(oldskb, hook, tcphoff, IPPROTO_TCP)) {
pr_debug("TCP checksum is invalid\n");
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);

skb_put(nskb, sizeof(struct ipv6hdr));
skb_reset_network_header(nskb);
ip6h = ipv6_hdr(nskb);
ip6_flow_hdr(ip6h, tclass, 0);
ip6h->hop_limit = ip6_dst_hoplimit(dst);
ip6h->nexthdr = IPPROTO_TCP;
ip6h->saddr = oip6h->daddr;
ip6h->daddr = oip6h->saddr;

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 = otcph.dest;
tcph->dest = otcph.source;

if (otcph.ack) {
needs_ack = 0;
tcph->seq = otcph.ack_seq;
tcph->ack_seq = 0;
} else {
needs_ack = 1;
tcph->ack_seq = htonl(ntohl(otcph.seq) + otcph.syn + otcph.fin
+ otcplen - (otcph.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));

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 = oldskb->nf_bridge->physindev;
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);
}
void nf_send_reset6(struct net *net, struct sk_buff *oldskb, int hook);

#endif /* _IPV6_NF_REJECT_H */
2 changes: 1 addition & 1 deletion include/uapi/linux/netfilter/nf_tables.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -774,7 +774,7 @@ enum nft_reject_inet_code {
NFT_REJECT_ICMPX_ADMIN_PROHIBITED,
__NFT_REJECT_ICMPX_MAX
};
#define NFT_REJECT_ICMPX_MAX (__NFT_REJECT_ICMPX_MAX + 1)
#define NFT_REJECT_ICMPX_MAX (__NFT_REJECT_ICMPX_MAX - 1)

/**
* enum nft_reject_attributes - nf_tables reject expression netlink attributes
Expand Down
10 changes: 4 additions & 6 deletions net/netfilter/nft_reject.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -72,7 +72,7 @@ int nft_reject_dump(struct sk_buff *skb, const struct nft_expr *expr)
}
EXPORT_SYMBOL_GPL(nft_reject_dump);

static u8 icmp_code_v4[NFT_REJECT_ICMPX_MAX] = {
static u8 icmp_code_v4[NFT_REJECT_ICMPX_MAX + 1] = {
[NFT_REJECT_ICMPX_NO_ROUTE] = ICMP_NET_UNREACH,
[NFT_REJECT_ICMPX_PORT_UNREACH] = ICMP_PORT_UNREACH,
[NFT_REJECT_ICMPX_HOST_UNREACH] = ICMP_HOST_UNREACH,
Expand All @@ -81,16 +81,15 @@ static u8 icmp_code_v4[NFT_REJECT_ICMPX_MAX] = {

int nft_reject_icmp_code(u8 code)
{
if (code > NFT_REJECT_ICMPX_MAX)
return -EINVAL;
BUG_ON(code > NFT_REJECT_ICMPX_MAX);

return icmp_code_v4[code];
}

EXPORT_SYMBOL_GPL(nft_reject_icmp_code);


static u8 icmp_code_v6[NFT_REJECT_ICMPX_MAX] = {
static u8 icmp_code_v6[NFT_REJECT_ICMPX_MAX + 1] = {
[NFT_REJECT_ICMPX_NO_ROUTE] = ICMPV6_NOROUTE,
[NFT_REJECT_ICMPX_PORT_UNREACH] = ICMPV6_PORT_UNREACH,
[NFT_REJECT_ICMPX_HOST_UNREACH] = ICMPV6_ADDR_UNREACH,
Expand All @@ -99,8 +98,7 @@ static u8 icmp_code_v6[NFT_REJECT_ICMPX_MAX] = {

int nft_reject_icmpv6_code(u8 code)
{
if (code > NFT_REJECT_ICMPX_MAX)
return -EINVAL;
BUG_ON(code > NFT_REJECT_ICMPX_MAX);

return icmp_code_v6[code];
}
Expand Down

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