| /* |
| * xfrm6_output.c - Common IPsec encapsulation code for IPv6. |
| * Copyright (C) 2002 USAGI/WIDE Project |
| * Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au> |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| #include <linux/compiler.h> |
| #include <linux/skbuff.h> |
| #include <linux/spinlock.h> |
| #include <linux/icmpv6.h> |
| #include <linux/netfilter_ipv6.h> |
| #include <net/ipv6.h> |
| #include <net/xfrm.h> |
| |
| static int xfrm6_tunnel_check_size(struct sk_buff *skb) |
| { |
| int mtu, ret = 0; |
| struct dst_entry *dst = skb->dst; |
| |
| mtu = dst_mtu(dst); |
| if (mtu < IPV6_MIN_MTU) |
| mtu = IPV6_MIN_MTU; |
| |
| if (skb->len > mtu) { |
| skb->dev = dst->dev; |
| icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev); |
| ret = -EMSGSIZE; |
| } |
| |
| return ret; |
| } |
| |
| static int xfrm6_output_one(struct sk_buff *skb) |
| { |
| struct dst_entry *dst = skb->dst; |
| struct xfrm_state *x = dst->xfrm; |
| int err; |
| |
| if (skb->ip_summed == CHECKSUM_HW) { |
| err = skb_checksum_help(skb, 0); |
| if (err) |
| goto error_nolock; |
| } |
| |
| if (x->props.mode) { |
| err = xfrm6_tunnel_check_size(skb); |
| if (err) |
| goto error_nolock; |
| } |
| |
| do { |
| spin_lock_bh(&x->lock); |
| err = xfrm_state_check(x, skb); |
| if (err) |
| goto error; |
| |
| err = x->mode->output(skb); |
| if (err) |
| goto error; |
| |
| err = x->type->output(x, skb); |
| if (err) |
| goto error; |
| |
| x->curlft.bytes += skb->len; |
| x->curlft.packets++; |
| |
| spin_unlock_bh(&x->lock); |
| |
| skb->nh.raw = skb->data; |
| |
| if (!(skb->dst = dst_pop(dst))) { |
| err = -EHOSTUNREACH; |
| goto error_nolock; |
| } |
| dst = skb->dst; |
| x = dst->xfrm; |
| } while (x && !x->props.mode); |
| |
| IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED; |
| err = 0; |
| |
| out_exit: |
| return err; |
| error: |
| spin_unlock_bh(&x->lock); |
| error_nolock: |
| kfree_skb(skb); |
| goto out_exit; |
| } |
| |
| static int xfrm6_output_finish2(struct sk_buff *skb) |
| { |
| int err; |
| |
| while (likely((err = xfrm6_output_one(skb)) == 0)) { |
| nf_reset(skb); |
| |
| err = nf_hook(PF_INET6, NF_IP6_LOCAL_OUT, &skb, NULL, |
| skb->dst->dev, dst_output); |
| if (unlikely(err != 1)) |
| break; |
| |
| if (!skb->dst->xfrm) |
| return dst_output(skb); |
| |
| err = nf_hook(PF_INET6, NF_IP6_POST_ROUTING, &skb, NULL, |
| skb->dst->dev, xfrm6_output_finish2); |
| if (unlikely(err != 1)) |
| break; |
| } |
| |
| return err; |
| } |
| |
| static int xfrm6_output_finish(struct sk_buff *skb) |
| { |
| struct sk_buff *segs; |
| |
| if (!skb_is_gso(skb)) |
| return xfrm6_output_finish2(skb); |
| |
| skb->protocol = htons(ETH_P_IP); |
| segs = skb_gso_segment(skb, 0); |
| kfree_skb(skb); |
| if (unlikely(IS_ERR(segs))) |
| return PTR_ERR(segs); |
| |
| do { |
| struct sk_buff *nskb = segs->next; |
| int err; |
| |
| segs->next = NULL; |
| err = xfrm6_output_finish2(segs); |
| |
| if (unlikely(err)) { |
| while ((segs = nskb)) { |
| nskb = segs->next; |
| segs->next = NULL; |
| kfree_skb(segs); |
| } |
| return err; |
| } |
| |
| segs = nskb; |
| } while (segs); |
| |
| return 0; |
| } |
| |
| int xfrm6_output(struct sk_buff *skb) |
| { |
| return NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, skb, NULL, skb->dst->dev, |
| xfrm6_output_finish); |
| } |