[NETFILTER]: ipt_REJECT: remove largely duplicate route_reverse function

Use ip_route_me_harder instead, which now allows to specify how we wish
the packet to be routed.

Based on patch by Simon Horman <horms@verge.net.au>.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy 2006-10-02 16:12:20 -07:00 committed by David S. Miller
parent 901eaf6c8f
commit 9d02002d2d

View File

@ -38,76 +38,16 @@ MODULE_DESCRIPTION("iptables REJECT target module");
#define DEBUGP(format, args...)
#endif
static inline struct rtable *route_reverse(struct sk_buff *skb,
struct tcphdr *tcph, int hook)
{
struct iphdr *iph = skb->nh.iph;
struct dst_entry *odst;
struct flowi fl = {};
struct rtable *rt;
/* We don't require ip forwarding to be enabled to be able to
* send a RST reply for bridged traffic. */
if (hook != NF_IP_FORWARD
#ifdef CONFIG_BRIDGE_NETFILTER
|| (skb->nf_bridge && skb->nf_bridge->mask & BRNF_BRIDGED)
#endif
) {
fl.nl_u.ip4_u.daddr = iph->saddr;
if (hook == NF_IP_LOCAL_IN)
fl.nl_u.ip4_u.saddr = iph->daddr;
fl.nl_u.ip4_u.tos = RT_TOS(iph->tos);
if (ip_route_output_key(&rt, &fl) != 0)
return NULL;
} else {
/* non-local src, find valid iif to satisfy
* rp-filter when calling ip_route_input. */
fl.nl_u.ip4_u.daddr = iph->daddr;
if (ip_route_output_key(&rt, &fl) != 0)
return NULL;
odst = skb->dst;
if (ip_route_input(skb, iph->saddr, iph->daddr,
RT_TOS(iph->tos), rt->u.dst.dev) != 0) {
dst_release(&rt->u.dst);
return NULL;
}
dst_release(&rt->u.dst);
rt = (struct rtable *)skb->dst;
skb->dst = odst;
fl.nl_u.ip4_u.daddr = iph->saddr;
fl.nl_u.ip4_u.saddr = iph->daddr;
fl.nl_u.ip4_u.tos = RT_TOS(iph->tos);
}
if (rt->u.dst.error) {
dst_release(&rt->u.dst);
return NULL;
}
fl.proto = IPPROTO_TCP;
fl.fl_ip_sport = tcph->dest;
fl.fl_ip_dport = tcph->source;
security_skb_classify_flow(skb, &fl);
xfrm_lookup((struct dst_entry **)&rt, &fl, NULL, 0);
return rt;
}
/* Send RST reply */
static void send_reset(struct sk_buff *oldskb, int hook)
{
struct sk_buff *nskb;
struct iphdr *iph = oldskb->nh.iph;
struct tcphdr _otcph, *oth, *tcph;
struct rtable *rt;
__be16 tmp_port;
__be32 tmp_addr;
int needs_ack;
int hh_len;
unsigned int addr_type;
/* IP header checks: fragment. */
if (oldskb->nh.iph->frag_off & htons(IP_OFFSET))
@ -126,23 +66,13 @@ static void send_reset(struct sk_buff *oldskb, int hook)
if (nf_ip_checksum(oldskb, hook, iph->ihl * 4, IPPROTO_TCP))
return;
if ((rt = route_reverse(oldskb, oth, hook)) == NULL)
return;
hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
/* We need a linear, writeable skb. We also need to expand
headroom in case hh_len of incoming interface < hh_len of
outgoing interface */
nskb = skb_copy_expand(oldskb, hh_len, skb_tailroom(oldskb),
nskb = skb_copy_expand(oldskb, LL_MAX_HEADER, skb_tailroom(oldskb),
GFP_ATOMIC);
if (!nskb) {
dst_release(&rt->u.dst);
if (!nskb)
return;
}
dst_release(nskb->dst);
nskb->dst = &rt->u.dst;
/* This packet will not be the same as the other: clear nf fields */
nf_reset(nskb);
@ -184,6 +114,21 @@ static void send_reset(struct sk_buff *oldskb, int hook)
tcph->window = 0;
tcph->urg_ptr = 0;
/* Set DF, id = 0 */
nskb->nh.iph->frag_off = htons(IP_DF);
nskb->nh.iph->id = 0;
addr_type = RTN_UNSPEC;
if (hook != NF_IP_FORWARD
#ifdef CONFIG_BRIDGE_NETFILTER
|| (nskb->nf_bridge && nskb->nf_bridge->mask & BRNF_BRIDGED)
#endif
)
addr_type = RTN_LOCAL;
if (ip_route_me_harder(&nskb, addr_type))
goto free_nskb;
/* Adjust TCP checksum */
nskb->ip_summed = CHECKSUM_NONE;
tcph->check = 0;
@ -192,12 +137,8 @@ static void send_reset(struct sk_buff *oldskb, int hook)
nskb->nh.iph->daddr,
csum_partial((char *)tcph,
sizeof(struct tcphdr), 0));
/* Adjust IP TTL, DF */
/* Adjust IP TTL */
nskb->nh.iph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT);
/* Set DF, id = 0 */
nskb->nh.iph->frag_off = htons(IP_DF);
nskb->nh.iph->id = 0;
/* Adjust IP checksum */
nskb->nh.iph->check = 0;