diff options
Diffstat (limited to 'net/xfrm/xfrm_output.c')
| -rw-r--r-- | net/xfrm/xfrm_output.c | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c new file mode 100644 index 000000000..fbcedbe33 --- /dev/null +++ b/net/xfrm/xfrm_output.c @@ -0,0 +1,236 @@ +/* + * xfrm_output.c - Common IPsec encapsulation code. + * + * Copyright (c) 2007 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/errno.h> +#include <linux/module.h> +#include <linux/netdevice.h> +#include <linux/netfilter.h> +#include <linux/skbuff.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <net/dst.h> +#include <net/xfrm.h> + +static int xfrm_output2(struct sock *sk, struct sk_buff *skb); + +static int xfrm_skb_check_space(struct sk_buff *skb) +{ + struct dst_entry *dst = skb_dst(skb); + int nhead = dst->header_len + LL_RESERVED_SPACE(dst->dev) + - skb_headroom(skb); + int ntail = dst->dev->needed_tailroom - skb_tailroom(skb); + + if (nhead <= 0) { + if (ntail <= 0) + return 0; + nhead = 0; + } else if (ntail < 0) + ntail = 0; + + return pskb_expand_head(skb, nhead, ntail, GFP_ATOMIC); +} + +static int xfrm_output_one(struct sk_buff *skb, int err) +{ + struct dst_entry *dst = skb_dst(skb); + struct xfrm_state *x = dst->xfrm; + struct net *net = xs_net(x); + + if (err <= 0) + goto resume; + + do { + err = xfrm_skb_check_space(skb); + if (err) { + XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR); + goto error_nolock; + } + + err = x->outer_mode->output(x, skb); + if (err) { + XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEMODEERROR); + goto error_nolock; + } + + spin_lock_bh(&x->lock); + + if (unlikely(x->km.state != XFRM_STATE_VALID)) { + XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEINVALID); + err = -EINVAL; + goto error; + } + + err = xfrm_state_check_expire(x); + if (err) { + XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEEXPIRED); + goto error; + } + + err = x->repl->overflow(x, skb); + if (err) { + XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATESEQERROR); + goto error; + } + + x->curlft.bytes += skb->len; + x->curlft.packets++; + + spin_unlock_bh(&x->lock); + + skb_dst_force(skb); + + err = x->type->output(x, skb); + if (err == -EINPROGRESS) + goto out; + +resume: + if (err) { + XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEPROTOERROR); + goto error_nolock; + } + + dst = skb_dst_pop(skb); + if (!dst) { + XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR); + err = -EHOSTUNREACH; + goto error_nolock; + } + skb_dst_set(skb, dst); + x = dst->xfrm; + } while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL)); + + return 0; + +error: + spin_unlock_bh(&x->lock); +error_nolock: + kfree_skb(skb); +out: + return err; +} + +int xfrm_output_resume(struct sk_buff *skb, int err) +{ + while (likely((err = xfrm_output_one(skb, err)) == 0)) { + nf_reset(skb); + + err = skb_dst(skb)->ops->local_out(skb); + if (unlikely(err != 1)) + goto out; + + if (!skb_dst(skb)->xfrm) + return dst_output(skb); + + err = nf_hook(skb_dst(skb)->ops->family, + NF_INET_POST_ROUTING, skb->sk, skb, + NULL, skb_dst(skb)->dev, xfrm_output2); + if (unlikely(err != 1)) + goto out; + } + + if (err == -EINPROGRESS) + err = 0; + +out: + return err; +} +EXPORT_SYMBOL_GPL(xfrm_output_resume); + +static int xfrm_output2(struct sock *sk, struct sk_buff *skb) +{ + return xfrm_output_resume(skb, 1); +} + +static int xfrm_output_gso(struct sock *sk, struct sk_buff *skb) +{ + struct sk_buff *segs; + + segs = skb_gso_segment(skb, 0); + kfree_skb(skb); + if (IS_ERR(segs)) + return PTR_ERR(segs); + if (segs == NULL) + return -EINVAL; + + do { + struct sk_buff *nskb = segs->next; + int err; + + segs->next = NULL; + err = xfrm_output2(sk, segs); + + if (unlikely(err)) { + kfree_skb_list(nskb); + return err; + } + + segs = nskb; + } while (segs); + + return 0; +} + +int xfrm_output(struct sock *sk, struct sk_buff *skb) +{ + struct net *net = dev_net(skb_dst(skb)->dev); + int err; + + if (skb_is_gso(skb)) + return xfrm_output_gso(sk, skb); + + if (skb->ip_summed == CHECKSUM_PARTIAL) { + err = skb_checksum_help(skb); + if (err) { + XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR); + kfree_skb(skb); + return err; + } + } + + return xfrm_output2(sk, skb); +} +EXPORT_SYMBOL_GPL(xfrm_output); + +int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb) +{ + struct xfrm_mode *inner_mode; + if (x->sel.family == AF_UNSPEC) + inner_mode = xfrm_ip2inner_mode(x, + xfrm_af2proto(skb_dst(skb)->ops->family)); + else + inner_mode = x->inner_mode; + + if (inner_mode == NULL) + return -EAFNOSUPPORT; + return inner_mode->afinfo->extract_output(x, skb); +} +EXPORT_SYMBOL_GPL(xfrm_inner_extract_output); + +void xfrm_local_error(struct sk_buff *skb, int mtu) +{ + unsigned int proto; + struct xfrm_state_afinfo *afinfo; + + if (skb->protocol == htons(ETH_P_IP)) + proto = AF_INET; + else if (skb->protocol == htons(ETH_P_IPV6)) + proto = AF_INET6; + else + return; + + afinfo = xfrm_state_get_afinfo(proto); + if (!afinfo) + return; + + afinfo->local_error(skb, mtu); + xfrm_state_put_afinfo(afinfo); +} +EXPORT_SYMBOL_GPL(xfrm_local_error); |