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-rw-r--r--net/xfrm/xfrm_output.c909
1 files changed, 909 insertions, 0 deletions
diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
new file mode 100644
index 000000000..9a5e79a38
--- /dev/null
+++ b/net/xfrm/xfrm_output.c
@@ -0,0 +1,909 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * xfrm_output.c - Common IPsec encapsulation code.
+ *
+ * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+
+#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/icmp.h>
+#include <net/inet_ecn.h>
+#include <net/xfrm.h>
+
+#if IS_ENABLED(CONFIG_IPV6)
+#include <net/ip6_route.h>
+#include <net/ipv6_stubs.h>
+#endif
+
+#include "xfrm_inout.h"
+
+static int xfrm_output2(struct net *net, struct sock *sk, struct sk_buff *skb);
+static int xfrm_inner_extract_output(struct xfrm_state *x, 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);
+}
+
+/* Children define the path of the packet through the
+ * Linux networking. Thus, destinations are stackable.
+ */
+
+static struct dst_entry *skb_dst_pop(struct sk_buff *skb)
+{
+ struct dst_entry *child = dst_clone(xfrm_dst_child(skb_dst(skb)));
+
+ skb_dst_drop(skb);
+ return child;
+}
+
+/* Add encapsulation header.
+ *
+ * The IP header will be moved forward to make space for the encapsulation
+ * header.
+ */
+static int xfrm4_transport_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+ struct iphdr *iph = ip_hdr(skb);
+ int ihl = iph->ihl * 4;
+
+ skb_set_inner_transport_header(skb, skb_transport_offset(skb));
+
+ skb_set_network_header(skb, -x->props.header_len);
+ skb->mac_header = skb->network_header +
+ offsetof(struct iphdr, protocol);
+ skb->transport_header = skb->network_header + ihl;
+ __skb_pull(skb, ihl);
+ memmove(skb_network_header(skb), iph, ihl);
+ return 0;
+}
+
+#if IS_ENABLED(CONFIG_IPV6_MIP6)
+static int mip6_rthdr_offset(struct sk_buff *skb, u8 **nexthdr, int type)
+{
+ const unsigned char *nh = skb_network_header(skb);
+ unsigned int offset = sizeof(struct ipv6hdr);
+ unsigned int packet_len;
+ int found_rhdr = 0;
+
+ packet_len = skb_tail_pointer(skb) - nh;
+ *nexthdr = &ipv6_hdr(skb)->nexthdr;
+
+ while (offset <= packet_len) {
+ struct ipv6_opt_hdr *exthdr;
+
+ switch (**nexthdr) {
+ case NEXTHDR_HOP:
+ break;
+ case NEXTHDR_ROUTING:
+ if (type == IPPROTO_ROUTING && offset + 3 <= packet_len) {
+ struct ipv6_rt_hdr *rt;
+
+ rt = (struct ipv6_rt_hdr *)(nh + offset);
+ if (rt->type != 0)
+ return offset;
+ }
+ found_rhdr = 1;
+ break;
+ case NEXTHDR_DEST:
+ /* HAO MUST NOT appear more than once.
+ * XXX: It is better to try to find by the end of
+ * XXX: packet if HAO exists.
+ */
+ if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) {
+ net_dbg_ratelimited("mip6: hao exists already, override\n");
+ return offset;
+ }
+
+ if (found_rhdr)
+ return offset;
+
+ break;
+ default:
+ return offset;
+ }
+
+ if (offset + sizeof(struct ipv6_opt_hdr) > packet_len)
+ return -EINVAL;
+
+ exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
+ offset);
+ offset += ipv6_optlen(exthdr);
+ if (offset > IPV6_MAXPLEN)
+ return -EINVAL;
+ *nexthdr = &exthdr->nexthdr;
+ }
+
+ return -EINVAL;
+}
+#endif
+
+#if IS_ENABLED(CONFIG_IPV6)
+static int xfrm6_hdr_offset(struct xfrm_state *x, struct sk_buff *skb, u8 **prevhdr)
+{
+ switch (x->type->proto) {
+#if IS_ENABLED(CONFIG_IPV6_MIP6)
+ case IPPROTO_DSTOPTS:
+ case IPPROTO_ROUTING:
+ return mip6_rthdr_offset(skb, prevhdr, x->type->proto);
+#endif
+ default:
+ break;
+ }
+
+ return ip6_find_1stfragopt(skb, prevhdr);
+}
+#endif
+
+/* Add encapsulation header.
+ *
+ * The IP header and mutable extension headers will be moved forward to make
+ * space for the encapsulation header.
+ */
+static int xfrm6_transport_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+ struct ipv6hdr *iph;
+ u8 *prevhdr;
+ int hdr_len;
+
+ iph = ipv6_hdr(skb);
+ skb_set_inner_transport_header(skb, skb_transport_offset(skb));
+
+ hdr_len = xfrm6_hdr_offset(x, skb, &prevhdr);
+ if (hdr_len < 0)
+ return hdr_len;
+ skb_set_mac_header(skb,
+ (prevhdr - x->props.header_len) - skb->data);
+ skb_set_network_header(skb, -x->props.header_len);
+ skb->transport_header = skb->network_header + hdr_len;
+ __skb_pull(skb, hdr_len);
+ memmove(ipv6_hdr(skb), iph, hdr_len);
+ return 0;
+#else
+ WARN_ON_ONCE(1);
+ return -EAFNOSUPPORT;
+#endif
+}
+
+/* Add route optimization header space.
+ *
+ * The IP header and mutable extension headers will be moved forward to make
+ * space for the route optimization header.
+ */
+static int xfrm6_ro_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+ struct ipv6hdr *iph;
+ u8 *prevhdr;
+ int hdr_len;
+
+ iph = ipv6_hdr(skb);
+
+ hdr_len = xfrm6_hdr_offset(x, skb, &prevhdr);
+ if (hdr_len < 0)
+ return hdr_len;
+ skb_set_mac_header(skb,
+ (prevhdr - x->props.header_len) - skb->data);
+ skb_set_network_header(skb, -x->props.header_len);
+ skb->transport_header = skb->network_header + hdr_len;
+ __skb_pull(skb, hdr_len);
+ memmove(ipv6_hdr(skb), iph, hdr_len);
+
+ x->lastused = ktime_get_real_seconds();
+
+ return 0;
+#else
+ WARN_ON_ONCE(1);
+ return -EAFNOSUPPORT;
+#endif
+}
+
+/* Add encapsulation header.
+ *
+ * The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt.
+ */
+static int xfrm4_beet_encap_add(struct xfrm_state *x, struct sk_buff *skb)
+{
+ struct ip_beet_phdr *ph;
+ struct iphdr *top_iph;
+ int hdrlen, optlen;
+
+ hdrlen = 0;
+ optlen = XFRM_MODE_SKB_CB(skb)->optlen;
+ if (unlikely(optlen))
+ hdrlen += IPV4_BEET_PHMAXLEN - (optlen & 4);
+
+ skb_set_network_header(skb, -x->props.header_len - hdrlen +
+ (XFRM_MODE_SKB_CB(skb)->ihl - sizeof(*top_iph)));
+ if (x->sel.family != AF_INET6)
+ skb->network_header += IPV4_BEET_PHMAXLEN;
+ skb->mac_header = skb->network_header +
+ offsetof(struct iphdr, protocol);
+ skb->transport_header = skb->network_header + sizeof(*top_iph);
+
+ xfrm4_beet_make_header(skb);
+
+ ph = __skb_pull(skb, XFRM_MODE_SKB_CB(skb)->ihl - hdrlen);
+
+ top_iph = ip_hdr(skb);
+
+ if (unlikely(optlen)) {
+ if (WARN_ON(optlen < 0))
+ return -EINVAL;
+
+ ph->padlen = 4 - (optlen & 4);
+ ph->hdrlen = optlen / 8;
+ ph->nexthdr = top_iph->protocol;
+ if (ph->padlen)
+ memset(ph + 1, IPOPT_NOP, ph->padlen);
+
+ top_iph->protocol = IPPROTO_BEETPH;
+ top_iph->ihl = sizeof(struct iphdr) / 4;
+ }
+
+ top_iph->saddr = x->props.saddr.a4;
+ top_iph->daddr = x->id.daddr.a4;
+
+ return 0;
+}
+
+/* Add encapsulation header.
+ *
+ * The top IP header will be constructed per RFC 2401.
+ */
+static int xfrm4_tunnel_encap_add(struct xfrm_state *x, struct sk_buff *skb)
+{
+ bool small_ipv6 = (skb->protocol == htons(ETH_P_IPV6)) && (skb->len <= IPV6_MIN_MTU);
+ struct dst_entry *dst = skb_dst(skb);
+ struct iphdr *top_iph;
+ int flags;
+
+ skb_set_inner_network_header(skb, skb_network_offset(skb));
+ skb_set_inner_transport_header(skb, skb_transport_offset(skb));
+
+ skb_set_network_header(skb, -x->props.header_len);
+ skb->mac_header = skb->network_header +
+ offsetof(struct iphdr, protocol);
+ skb->transport_header = skb->network_header + sizeof(*top_iph);
+ top_iph = ip_hdr(skb);
+
+ top_iph->ihl = 5;
+ top_iph->version = 4;
+
+ top_iph->protocol = xfrm_af2proto(skb_dst(skb)->ops->family);
+
+ /* DS disclosing depends on XFRM_SA_XFLAG_DONT_ENCAP_DSCP */
+ if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP)
+ top_iph->tos = 0;
+ else
+ top_iph->tos = XFRM_MODE_SKB_CB(skb)->tos;
+ top_iph->tos = INET_ECN_encapsulate(top_iph->tos,
+ XFRM_MODE_SKB_CB(skb)->tos);
+
+ flags = x->props.flags;
+ if (flags & XFRM_STATE_NOECN)
+ IP_ECN_clear(top_iph);
+
+ top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) || small_ipv6 ?
+ 0 : (XFRM_MODE_SKB_CB(skb)->frag_off & htons(IP_DF));
+
+ top_iph->ttl = ip4_dst_hoplimit(xfrm_dst_child(dst));
+
+ top_iph->saddr = x->props.saddr.a4;
+ top_iph->daddr = x->id.daddr.a4;
+ ip_select_ident(dev_net(dst->dev), skb, NULL);
+
+ return 0;
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static int xfrm6_tunnel_encap_add(struct xfrm_state *x, struct sk_buff *skb)
+{
+ struct dst_entry *dst = skb_dst(skb);
+ struct ipv6hdr *top_iph;
+ int dsfield;
+
+ skb_set_inner_network_header(skb, skb_network_offset(skb));
+ skb_set_inner_transport_header(skb, skb_transport_offset(skb));
+
+ skb_set_network_header(skb, -x->props.header_len);
+ skb->mac_header = skb->network_header +
+ offsetof(struct ipv6hdr, nexthdr);
+ skb->transport_header = skb->network_header + sizeof(*top_iph);
+ top_iph = ipv6_hdr(skb);
+
+ top_iph->version = 6;
+
+ memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
+ sizeof(top_iph->flow_lbl));
+ top_iph->nexthdr = xfrm_af2proto(skb_dst(skb)->ops->family);
+
+ if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP)
+ dsfield = 0;
+ else
+ dsfield = XFRM_MODE_SKB_CB(skb)->tos;
+ dsfield = INET_ECN_encapsulate(dsfield, XFRM_MODE_SKB_CB(skb)->tos);
+ if (x->props.flags & XFRM_STATE_NOECN)
+ dsfield &= ~INET_ECN_MASK;
+ ipv6_change_dsfield(top_iph, 0, dsfield);
+ top_iph->hop_limit = ip6_dst_hoplimit(xfrm_dst_child(dst));
+ top_iph->saddr = *(struct in6_addr *)&x->props.saddr;
+ top_iph->daddr = *(struct in6_addr *)&x->id.daddr;
+ return 0;
+}
+
+static int xfrm6_beet_encap_add(struct xfrm_state *x, struct sk_buff *skb)
+{
+ struct ipv6hdr *top_iph;
+ struct ip_beet_phdr *ph;
+ int optlen, hdr_len;
+
+ hdr_len = 0;
+ optlen = XFRM_MODE_SKB_CB(skb)->optlen;
+ if (unlikely(optlen))
+ hdr_len += IPV4_BEET_PHMAXLEN - (optlen & 4);
+
+ skb_set_network_header(skb, -x->props.header_len - hdr_len);
+ if (x->sel.family != AF_INET6)
+ skb->network_header += IPV4_BEET_PHMAXLEN;
+ skb->mac_header = skb->network_header +
+ offsetof(struct ipv6hdr, nexthdr);
+ skb->transport_header = skb->network_header + sizeof(*top_iph);
+ ph = __skb_pull(skb, XFRM_MODE_SKB_CB(skb)->ihl - hdr_len);
+
+ xfrm6_beet_make_header(skb);
+
+ top_iph = ipv6_hdr(skb);
+ if (unlikely(optlen)) {
+ if (WARN_ON(optlen < 0))
+ return -EINVAL;
+
+ ph->padlen = 4 - (optlen & 4);
+ ph->hdrlen = optlen / 8;
+ ph->nexthdr = top_iph->nexthdr;
+ if (ph->padlen)
+ memset(ph + 1, IPOPT_NOP, ph->padlen);
+
+ top_iph->nexthdr = IPPROTO_BEETPH;
+ }
+
+ top_iph->saddr = *(struct in6_addr *)&x->props.saddr;
+ top_iph->daddr = *(struct in6_addr *)&x->id.daddr;
+ return 0;
+}
+#endif
+
+/* Add encapsulation header.
+ *
+ * On exit, the transport header will be set to the start of the
+ * encapsulation header to be filled in by x->type->output and the mac
+ * header will be set to the nextheader (protocol for IPv4) field of the
+ * extension header directly preceding the encapsulation header, or in
+ * its absence, that of the top IP header.
+ * The value of the network header will always point to the top IP header
+ * while skb->data will point to the payload.
+ */
+static int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+ int err;
+
+ err = xfrm_inner_extract_output(x, skb);
+ if (err)
+ return err;
+
+ IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
+ skb->protocol = htons(ETH_P_IP);
+
+ switch (x->outer_mode.encap) {
+ case XFRM_MODE_BEET:
+ return xfrm4_beet_encap_add(x, skb);
+ case XFRM_MODE_TUNNEL:
+ return xfrm4_tunnel_encap_add(x, skb);
+ }
+
+ WARN_ON_ONCE(1);
+ return -EOPNOTSUPP;
+}
+
+static int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+ int err;
+
+ err = xfrm_inner_extract_output(x, skb);
+ if (err)
+ return err;
+
+ skb->ignore_df = 1;
+ skb->protocol = htons(ETH_P_IPV6);
+
+ switch (x->outer_mode.encap) {
+ case XFRM_MODE_BEET:
+ return xfrm6_beet_encap_add(x, skb);
+ case XFRM_MODE_TUNNEL:
+ return xfrm6_tunnel_encap_add(x, skb);
+ default:
+ WARN_ON_ONCE(1);
+ return -EOPNOTSUPP;
+ }
+#endif
+ WARN_ON_ONCE(1);
+ return -EAFNOSUPPORT;
+}
+
+static int xfrm_outer_mode_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+ switch (x->outer_mode.encap) {
+ case XFRM_MODE_BEET:
+ case XFRM_MODE_TUNNEL:
+ if (x->outer_mode.family == AF_INET)
+ return xfrm4_prepare_output(x, skb);
+ if (x->outer_mode.family == AF_INET6)
+ return xfrm6_prepare_output(x, skb);
+ break;
+ case XFRM_MODE_TRANSPORT:
+ if (x->outer_mode.family == AF_INET)
+ return xfrm4_transport_output(x, skb);
+ if (x->outer_mode.family == AF_INET6)
+ return xfrm6_transport_output(x, skb);
+ break;
+ case XFRM_MODE_ROUTEOPTIMIZATION:
+ if (x->outer_mode.family == AF_INET6)
+ return xfrm6_ro_output(x, skb);
+ WARN_ON_ONCE(1);
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ break;
+ }
+
+ return -EOPNOTSUPP;
+}
+
+#if IS_ENABLED(CONFIG_NET_PKTGEN)
+int pktgen_xfrm_outer_mode_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+ return xfrm_outer_mode_output(x, skb);
+}
+EXPORT_SYMBOL_GPL(pktgen_xfrm_outer_mode_output);
+#endif
+
+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;
+ }
+
+ skb->mark = xfrm_smark_get(skb->mark, x);
+
+ err = xfrm_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 = xfrm_replay_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);
+ if (!skb_dst(skb)) {
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
+ err = -EHOSTUNREACH;
+ goto error_nolock;
+ }
+
+ if (xfrm_offload(skb)) {
+ x->type_offload->encap(x, skb);
+ } else {
+ /* Inner headers are invalid now. */
+ skb->encapsulation = 0;
+
+ 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 sock *sk, struct sk_buff *skb, int err)
+{
+ struct net *net = xs_net(skb_dst(skb)->xfrm);
+
+ while (likely((err = xfrm_output_one(skb, err)) == 0)) {
+ nf_reset_ct(skb);
+
+ err = skb_dst(skb)->ops->local_out(net, sk, skb);
+ if (unlikely(err != 1))
+ goto out;
+
+ if (!skb_dst(skb)->xfrm)
+ return dst_output(net, sk, skb);
+
+ err = nf_hook(skb_dst(skb)->ops->family,
+ NF_INET_POST_ROUTING, net, 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 net *net, struct sock *sk, struct sk_buff *skb)
+{
+ return xfrm_output_resume(sk, skb, 1);
+}
+
+static int xfrm_output_gso(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+ struct sk_buff *segs, *nskb;
+
+ BUILD_BUG_ON(sizeof(*IPCB(skb)) > SKB_GSO_CB_OFFSET);
+ BUILD_BUG_ON(sizeof(*IP6CB(skb)) > SKB_GSO_CB_OFFSET);
+ segs = skb_gso_segment(skb, 0);
+ kfree_skb(skb);
+ if (IS_ERR(segs))
+ return PTR_ERR(segs);
+ if (segs == NULL)
+ return -EINVAL;
+
+ skb_list_walk_safe(segs, segs, nskb) {
+ int err;
+
+ skb_mark_not_on_list(segs);
+ err = xfrm_output2(net, sk, segs);
+
+ if (unlikely(err)) {
+ kfree_skb_list(nskb);
+ return err;
+ }
+ }
+
+ return 0;
+}
+
+/* For partial checksum offload, the outer header checksum is calculated
+ * by software and the inner header checksum is calculated by hardware.
+ * This requires hardware to know the inner packet type to calculate
+ * the inner header checksum. Save inner ip protocol here to avoid
+ * traversing the packet in the vendor's xmit code.
+ * For IPsec tunnel mode save the ip protocol from the IP header of the
+ * plain text packet. Otherwise If the encap type is IPIP, just save
+ * skb->inner_ipproto in any other case get the ip protocol from the IP
+ * header.
+ */
+static void xfrm_get_inner_ipproto(struct sk_buff *skb, struct xfrm_state *x)
+{
+ struct xfrm_offload *xo = xfrm_offload(skb);
+ const struct ethhdr *eth;
+
+ if (!xo)
+ return;
+
+ if (x->outer_mode.encap == XFRM_MODE_TUNNEL) {
+ switch (x->outer_mode.family) {
+ case AF_INET:
+ xo->inner_ipproto = ip_hdr(skb)->protocol;
+ break;
+ case AF_INET6:
+ xo->inner_ipproto = ipv6_hdr(skb)->nexthdr;
+ break;
+ default:
+ break;
+ }
+
+ return;
+ }
+
+ /* non-Tunnel Mode */
+ if (!skb->encapsulation)
+ return;
+
+ if (skb->inner_protocol_type == ENCAP_TYPE_IPPROTO) {
+ xo->inner_ipproto = skb->inner_ipproto;
+ return;
+ }
+
+ if (skb->inner_protocol_type != ENCAP_TYPE_ETHER)
+ return;
+
+ eth = (struct ethhdr *)skb_inner_mac_header(skb);
+
+ switch (ntohs(eth->h_proto)) {
+ case ETH_P_IPV6:
+ xo->inner_ipproto = inner_ipv6_hdr(skb)->nexthdr;
+ break;
+ case ETH_P_IP:
+ xo->inner_ipproto = inner_ip_hdr(skb)->protocol;
+ break;
+ }
+}
+
+int xfrm_output(struct sock *sk, struct sk_buff *skb)
+{
+ struct net *net = dev_net(skb_dst(skb)->dev);
+ struct xfrm_state *x = skb_dst(skb)->xfrm;
+ int err;
+
+ switch (x->outer_mode.family) {
+ case AF_INET:
+ memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
+ IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
+ break;
+ case AF_INET6:
+ memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
+
+ IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
+ break;
+ }
+
+ secpath_reset(skb);
+
+ if (xfrm_dev_offload_ok(skb, x)) {
+ struct sec_path *sp;
+
+ sp = secpath_set(skb);
+ if (!sp) {
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
+ kfree_skb(skb);
+ return -ENOMEM;
+ }
+
+ sp->olen++;
+ sp->xvec[sp->len++] = x;
+ xfrm_state_hold(x);
+
+ xfrm_get_inner_ipproto(skb, x);
+ skb->encapsulation = 1;
+
+ if (skb_is_gso(skb)) {
+ if (skb->inner_protocol)
+ return xfrm_output_gso(net, sk, skb);
+
+ skb_shinfo(skb)->gso_type |= SKB_GSO_ESP;
+ goto out;
+ }
+
+ if (x->xso.dev && x->xso.dev->features & NETIF_F_HW_ESP_TX_CSUM)
+ goto out;
+ } else {
+ if (skb_is_gso(skb))
+ return xfrm_output_gso(net, 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;
+ }
+ }
+
+out:
+ return xfrm_output2(net, sk, skb);
+}
+EXPORT_SYMBOL_GPL(xfrm_output);
+
+static int xfrm4_tunnel_check_size(struct sk_buff *skb)
+{
+ int mtu, ret = 0;
+
+ if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE)
+ goto out;
+
+ if (!(ip_hdr(skb)->frag_off & htons(IP_DF)) || skb->ignore_df)
+ goto out;
+
+ mtu = dst_mtu(skb_dst(skb));
+ if ((!skb_is_gso(skb) && skb->len > mtu) ||
+ (skb_is_gso(skb) &&
+ !skb_gso_validate_network_len(skb, ip_skb_dst_mtu(skb->sk, skb)))) {
+ skb->protocol = htons(ETH_P_IP);
+
+ if (skb->sk)
+ xfrm_local_error(skb, mtu);
+ else
+ icmp_send(skb, ICMP_DEST_UNREACH,
+ ICMP_FRAG_NEEDED, htonl(mtu));
+ ret = -EMSGSIZE;
+ }
+out:
+ return ret;
+}
+
+static int xfrm4_extract_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+ int err;
+
+ if (x->outer_mode.encap == XFRM_MODE_BEET &&
+ ip_is_fragment(ip_hdr(skb))) {
+ net_warn_ratelimited("BEET mode doesn't support inner IPv4 fragments\n");
+ return -EAFNOSUPPORT;
+ }
+
+ err = xfrm4_tunnel_check_size(skb);
+ if (err)
+ return err;
+
+ XFRM_MODE_SKB_CB(skb)->protocol = ip_hdr(skb)->protocol;
+
+ xfrm4_extract_header(skb);
+ return 0;
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static int xfrm6_tunnel_check_size(struct sk_buff *skb)
+{
+ int mtu, ret = 0;
+ struct dst_entry *dst = skb_dst(skb);
+
+ if (skb->ignore_df)
+ goto out;
+
+ mtu = dst_mtu(dst);
+ if (mtu < IPV6_MIN_MTU)
+ mtu = IPV6_MIN_MTU;
+
+ if ((!skb_is_gso(skb) && skb->len > mtu) ||
+ (skb_is_gso(skb) &&
+ !skb_gso_validate_network_len(skb, ip6_skb_dst_mtu(skb)))) {
+ skb->dev = dst->dev;
+ skb->protocol = htons(ETH_P_IPV6);
+
+ if (xfrm6_local_dontfrag(skb->sk))
+ ipv6_stub->xfrm6_local_rxpmtu(skb, mtu);
+ else if (skb->sk)
+ xfrm_local_error(skb, mtu);
+ else
+ icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+ ret = -EMSGSIZE;
+ }
+out:
+ return ret;
+}
+#endif
+
+static int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+ int err;
+
+ err = xfrm6_tunnel_check_size(skb);
+ if (err)
+ return err;
+
+ XFRM_MODE_SKB_CB(skb)->protocol = ipv6_hdr(skb)->nexthdr;
+
+ xfrm6_extract_header(skb);
+ return 0;
+#else
+ WARN_ON_ONCE(1);
+ return -EAFNOSUPPORT;
+#endif
+}
+
+static int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+ const 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;
+
+ switch (inner_mode->family) {
+ case AF_INET:
+ return xfrm4_extract_output(x, skb);
+ case AF_INET6:
+ return xfrm6_extract_output(x, skb);
+ }
+
+ return -EAFNOSUPPORT;
+}
+
+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) &&
+ skb->sk->sk_family == AF_INET6)
+ proto = AF_INET6;
+ else
+ return;
+
+ afinfo = xfrm_state_get_afinfo(proto);
+ if (afinfo) {
+ afinfo->local_error(skb, mtu);
+ rcu_read_unlock();
+ }
+}
+EXPORT_SYMBOL_GPL(xfrm_local_error);