/* * 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/spinlock.h> #include <net/dst.h> #include <net/xfrm.h> static int xfrm_output2(struct sk_buff *skb); static int xfrm_state_check_space(struct xfrm_state *x, struct sk_buff *skb) { struct dst_entry *dst = skb->dst; int nhead = dst->header_len + LL_RESERVED_SPACE(dst->dev) - skb_headroom(skb); if (nhead > 0) return pskb_expand_head(skb, nhead, 0, GFP_ATOMIC); /* Check tail too... */ return 0; } static int xfrm_output_one(struct sk_buff *skb, int err) { struct dst_entry *dst = skb->dst; struct xfrm_state *x = dst->xfrm; if (err <= 0) goto resume; do { err = xfrm_state_check_space(x, skb); if (err) { XFRM_INC_STATS(LINUX_MIB_XFRMOUTERROR); goto error_nolock; } err = x->outer_mode->output(x, skb); if (err) { XFRM_INC_STATS(LINUX_MIB_XFRMOUTSTATEMODEERROR); goto error_nolock; } spin_lock_bh(&x->lock); err = xfrm_state_check_expire(x); if (err) { XFRM_INC_STATS(LINUX_MIB_XFRMOUTSTATEEXPIRED); goto error; } if (x->type->flags & XFRM_TYPE_REPLAY_PROT) { XFRM_SKB_CB(skb)->seq = ++x->replay.oseq; if (unlikely(x->replay.oseq == 0)) { XFRM_INC_STATS(LINUX_MIB_XFRMOUTSTATESEQERROR); x->replay.oseq--; xfrm_audit_state_replay_overflow(x, skb); err = -EOVERFLOW; goto error; } if (xfrm_aevent_is_on()) xfrm_replay_notify(x, XFRM_REPLAY_UPDATE); } x->curlft.bytes += skb->len; x->curlft.packets++; spin_unlock_bh(&x->lock); err = x->type->output(x, skb); if (err == -EINPROGRESS) goto out_exit; resume: if (err) { XFRM_INC_STATS(LINUX_MIB_XFRMOUTSTATEPROTOERROR); goto error_nolock; } if (!(skb->dst = dst_pop(dst))) { XFRM_INC_STATS(LINUX_MIB_XFRMOUTERROR); err = -EHOSTUNREACH; goto error_nolock; } dst = skb->dst; x = dst->xfrm; } while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL)); err = 0; out_exit: return err; error: spin_unlock_bh(&x->lock); error_nolock: kfree_skb(skb); goto out_exit; } int xfrm_output_resume(struct sk_buff *skb, int err) { while (likely((err = xfrm_output_one(skb, err)) == 0)) { struct xfrm_state *x; nf_reset(skb); err = skb->dst->ops->local_out(skb); if (unlikely(err != 1)) goto out; x = skb->dst->xfrm; if (!x) return dst_output(skb); err = nf_hook(x->inner_mode->afinfo->family, NF_INET_POST_ROUTING, skb, NULL, skb->dst->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 sk_buff *skb) { return xfrm_output_resume(skb, 1); } static int xfrm_output_gso(struct sk_buff *skb) { struct sk_buff *segs; 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 = xfrm_output2(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 xfrm_output(struct sk_buff *skb) { int err; if (skb_is_gso(skb)) return xfrm_output_gso(skb); if (skb->ip_summed == CHECKSUM_PARTIAL) { err = skb_checksum_help(skb); if (err) { XFRM_INC_STATS(LINUX_MIB_XFRMOUTERROR); kfree_skb(skb); return err; } } return xfrm_output2(skb); } EXPORT_SYMBOL_GPL(xfrm_output);