/* * 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(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_state_check_space(x, 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); err = xfrm_state_check_expire(x); if (err) { XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEEXPIRED); goto error; } if (x->type->flags & XFRM_TYPE_REPLAY_PROT) { XFRM_SKB_CB(skb)->seq.output = ++x->replay.oseq; if (unlikely(x->replay.oseq == 0)) { XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATESEQERROR); x->replay.oseq--; xfrm_audit_state_replay_overflow(x, skb); err = -EOVERFLOW; goto error; } if (xfrm_aevent_is_on(net)) 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(net, LINUX_MIB_XFRMOUTSTATEPROTOERROR); goto error_nolock; } dst = dst_pop(dst); 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)); 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)) { 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, 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 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 (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) { struct net *net = dev_net(skb_dst(skb)->dev); 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(net, LINUX_MIB_XFRMOUTERROR); kfree_skb(skb); return err; } } return xfrm_output2(skb); } 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_output); EXPORT_SYMBOL_GPL(xfrm_inner_extract_output);