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-rw-r--r--net/ipv6/ip6_offload.c488
1 files changed, 488 insertions, 0 deletions
diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
new file mode 100644
index 000000000..3ee345672
--- /dev/null
+++ b/net/ipv6/ip6_offload.c
@@ -0,0 +1,488 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * IPV6 GSO/GRO offload support
+ * Linux INET6 implementation
+ */
+
+#include <linux/kernel.h>
+#include <linux/socket.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/printk.h>
+
+#include <net/protocol.h>
+#include <net/ipv6.h>
+#include <net/inet_common.h>
+#include <net/tcp.h>
+#include <net/udp.h>
+#include <net/gro.h>
+
+#include "ip6_offload.h"
+
+/* All GRO functions are always builtin, except UDP over ipv6, which lays in
+ * ipv6 module, as it depends on UDPv6 lookup function, so we need special care
+ * when ipv6 is built as a module
+ */
+#if IS_BUILTIN(CONFIG_IPV6)
+#define INDIRECT_CALL_L4(f, f2, f1, ...) INDIRECT_CALL_2(f, f2, f1, __VA_ARGS__)
+#else
+#define INDIRECT_CALL_L4(f, f2, f1, ...) INDIRECT_CALL_1(f, f2, __VA_ARGS__)
+#endif
+
+#define indirect_call_gro_receive_l4(f2, f1, cb, head, skb) \
+({ \
+ unlikely(gro_recursion_inc_test(skb)) ? \
+ NAPI_GRO_CB(skb)->flush |= 1, NULL : \
+ INDIRECT_CALL_L4(cb, f2, f1, head, skb); \
+})
+
+static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto)
+{
+ const struct net_offload *ops = NULL;
+
+ for (;;) {
+ struct ipv6_opt_hdr *opth;
+ int len;
+
+ if (proto != NEXTHDR_HOP) {
+ ops = rcu_dereference(inet6_offloads[proto]);
+
+ if (unlikely(!ops))
+ break;
+
+ if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
+ break;
+ }
+
+ if (unlikely(!pskb_may_pull(skb, 8)))
+ break;
+
+ opth = (void *)skb->data;
+ len = ipv6_optlen(opth);
+
+ if (unlikely(!pskb_may_pull(skb, len)))
+ break;
+
+ opth = (void *)skb->data;
+ proto = opth->nexthdr;
+ __skb_pull(skb, len);
+ }
+
+ return proto;
+}
+
+static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
+ netdev_features_t features)
+{
+ struct sk_buff *segs = ERR_PTR(-EINVAL);
+ struct ipv6hdr *ipv6h;
+ const struct net_offload *ops;
+ int proto, nexthdr;
+ struct frag_hdr *fptr;
+ unsigned int payload_len;
+ u8 *prevhdr;
+ int offset = 0;
+ bool encap, udpfrag;
+ int nhoff;
+ bool gso_partial;
+
+ skb_reset_network_header(skb);
+ nexthdr = ipv6_has_hopopt_jumbo(skb);
+ if (nexthdr) {
+ const int hophdr_len = sizeof(struct hop_jumbo_hdr);
+ int err;
+
+ err = skb_cow_head(skb, 0);
+ if (err < 0)
+ return ERR_PTR(err);
+
+ /* remove the HBH header.
+ * Layout: [Ethernet header][IPv6 header][HBH][TCP header]
+ */
+ memmove(skb_mac_header(skb) + hophdr_len,
+ skb_mac_header(skb),
+ ETH_HLEN + sizeof(struct ipv6hdr));
+ skb->data += hophdr_len;
+ skb->len -= hophdr_len;
+ skb->network_header += hophdr_len;
+ skb->mac_header += hophdr_len;
+ ipv6h = (struct ipv6hdr *)skb->data;
+ ipv6h->nexthdr = nexthdr;
+ }
+ nhoff = skb_network_header(skb) - skb_mac_header(skb);
+ if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
+ goto out;
+
+ encap = SKB_GSO_CB(skb)->encap_level > 0;
+ if (encap)
+ features &= skb->dev->hw_enc_features;
+ SKB_GSO_CB(skb)->encap_level += sizeof(*ipv6h);
+
+ ipv6h = ipv6_hdr(skb);
+ __skb_pull(skb, sizeof(*ipv6h));
+ segs = ERR_PTR(-EPROTONOSUPPORT);
+
+ proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr);
+
+ if (skb->encapsulation &&
+ skb_shinfo(skb)->gso_type & (SKB_GSO_IPXIP4 | SKB_GSO_IPXIP6))
+ udpfrag = proto == IPPROTO_UDP && encap &&
+ (skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
+ else
+ udpfrag = proto == IPPROTO_UDP && !skb->encapsulation &&
+ (skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
+
+ ops = rcu_dereference(inet6_offloads[proto]);
+ if (likely(ops && ops->callbacks.gso_segment)) {
+ skb_reset_transport_header(skb);
+ segs = ops->callbacks.gso_segment(skb, features);
+ if (!segs)
+ skb->network_header = skb_mac_header(skb) + nhoff - skb->head;
+ }
+
+ if (IS_ERR_OR_NULL(segs))
+ goto out;
+
+ gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
+
+ for (skb = segs; skb; skb = skb->next) {
+ ipv6h = (struct ipv6hdr *)(skb_mac_header(skb) + nhoff);
+ if (gso_partial && skb_is_gso(skb))
+ payload_len = skb_shinfo(skb)->gso_size +
+ SKB_GSO_CB(skb)->data_offset +
+ skb->head - (unsigned char *)(ipv6h + 1);
+ else
+ payload_len = skb->len - nhoff - sizeof(*ipv6h);
+ ipv6h->payload_len = htons(payload_len);
+ skb->network_header = (u8 *)ipv6h - skb->head;
+ skb_reset_mac_len(skb);
+
+ if (udpfrag) {
+ int err = ip6_find_1stfragopt(skb, &prevhdr);
+ if (err < 0) {
+ kfree_skb_list(segs);
+ return ERR_PTR(err);
+ }
+ fptr = (struct frag_hdr *)((u8 *)ipv6h + err);
+ fptr->frag_off = htons(offset);
+ if (skb->next)
+ fptr->frag_off |= htons(IP6_MF);
+ offset += (ntohs(ipv6h->payload_len) -
+ sizeof(struct frag_hdr));
+ }
+ if (encap)
+ skb_reset_inner_headers(skb);
+ }
+
+out:
+ return segs;
+}
+
+/* Return the total length of all the extension hdrs, following the same
+ * logic in ipv6_gso_pull_exthdrs() when parsing ext-hdrs.
+ */
+static int ipv6_exthdrs_len(struct ipv6hdr *iph,
+ const struct net_offload **opps)
+{
+ struct ipv6_opt_hdr *opth = (void *)iph;
+ int len = 0, proto, optlen = sizeof(*iph);
+
+ proto = iph->nexthdr;
+ for (;;) {
+ if (proto != NEXTHDR_HOP) {
+ *opps = rcu_dereference(inet6_offloads[proto]);
+ if (unlikely(!(*opps)))
+ break;
+ if (!((*opps)->flags & INET6_PROTO_GSO_EXTHDR))
+ break;
+ }
+ opth = (void *)opth + optlen;
+ optlen = ipv6_optlen(opth);
+ len += optlen;
+ proto = opth->nexthdr;
+ }
+ return len;
+}
+
+INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receive(struct list_head *head,
+ struct sk_buff *skb)
+{
+ const struct net_offload *ops;
+ struct sk_buff *pp = NULL;
+ struct sk_buff *p;
+ struct ipv6hdr *iph;
+ unsigned int nlen;
+ unsigned int hlen;
+ unsigned int off;
+ u16 flush = 1;
+ int proto;
+
+ off = skb_gro_offset(skb);
+ hlen = off + sizeof(*iph);
+ iph = skb_gro_header(skb, hlen, off);
+ if (unlikely(!iph))
+ goto out;
+
+ skb_set_network_header(skb, off);
+ skb_gro_pull(skb, sizeof(*iph));
+ skb_set_transport_header(skb, skb_gro_offset(skb));
+
+ flush += ntohs(iph->payload_len) != skb_gro_len(skb);
+
+ proto = iph->nexthdr;
+ ops = rcu_dereference(inet6_offloads[proto]);
+ if (!ops || !ops->callbacks.gro_receive) {
+ pskb_pull(skb, skb_gro_offset(skb));
+ skb_gro_frag0_invalidate(skb);
+ proto = ipv6_gso_pull_exthdrs(skb, proto);
+ skb_gro_pull(skb, -skb_transport_offset(skb));
+ skb_reset_transport_header(skb);
+ __skb_push(skb, skb_gro_offset(skb));
+
+ ops = rcu_dereference(inet6_offloads[proto]);
+ if (!ops || !ops->callbacks.gro_receive)
+ goto out;
+
+ iph = ipv6_hdr(skb);
+ }
+
+ NAPI_GRO_CB(skb)->proto = proto;
+
+ flush--;
+ nlen = skb_network_header_len(skb);
+
+ list_for_each_entry(p, head, list) {
+ const struct ipv6hdr *iph2;
+ __be32 first_word; /* <Version:4><Traffic_Class:8><Flow_Label:20> */
+
+ if (!NAPI_GRO_CB(p)->same_flow)
+ continue;
+
+ iph2 = (struct ipv6hdr *)(p->data + off);
+ first_word = *(__be32 *)iph ^ *(__be32 *)iph2;
+
+ /* All fields must match except length and Traffic Class.
+ * XXX skbs on the gro_list have all been parsed and pulled
+ * already so we don't need to compare nlen
+ * (nlen != (sizeof(*iph2) + ipv6_exthdrs_len(iph2, &ops)))
+ * memcmp() alone below is sufficient, right?
+ */
+ if ((first_word & htonl(0xF00FFFFF)) ||
+ !ipv6_addr_equal(&iph->saddr, &iph2->saddr) ||
+ !ipv6_addr_equal(&iph->daddr, &iph2->daddr) ||
+ iph->nexthdr != iph2->nexthdr) {
+not_same_flow:
+ NAPI_GRO_CB(p)->same_flow = 0;
+ continue;
+ }
+ if (unlikely(nlen > sizeof(struct ipv6hdr))) {
+ if (memcmp(iph + 1, iph2 + 1,
+ nlen - sizeof(struct ipv6hdr)))
+ goto not_same_flow;
+ }
+ /* flush if Traffic Class fields are different */
+ NAPI_GRO_CB(p)->flush |= !!((first_word & htonl(0x0FF00000)) |
+ (__force __be32)(iph->hop_limit ^ iph2->hop_limit));
+ NAPI_GRO_CB(p)->flush |= flush;
+
+ /* If the previous IP ID value was based on an atomic
+ * datagram we can overwrite the value and ignore it.
+ */
+ if (NAPI_GRO_CB(skb)->is_atomic)
+ NAPI_GRO_CB(p)->flush_id = 0;
+ }
+
+ NAPI_GRO_CB(skb)->is_atomic = true;
+ NAPI_GRO_CB(skb)->flush |= flush;
+
+ skb_gro_postpull_rcsum(skb, iph, nlen);
+
+ pp = indirect_call_gro_receive_l4(tcp6_gro_receive, udp6_gro_receive,
+ ops->callbacks.gro_receive, head, skb);
+
+out:
+ skb_gro_flush_final(skb, pp, flush);
+
+ return pp;
+}
+
+static struct sk_buff *sit_ip6ip6_gro_receive(struct list_head *head,
+ struct sk_buff *skb)
+{
+ /* Common GRO receive for SIT and IP6IP6 */
+
+ if (NAPI_GRO_CB(skb)->encap_mark) {
+ NAPI_GRO_CB(skb)->flush = 1;
+ return NULL;
+ }
+
+ NAPI_GRO_CB(skb)->encap_mark = 1;
+
+ return ipv6_gro_receive(head, skb);
+}
+
+static struct sk_buff *ip4ip6_gro_receive(struct list_head *head,
+ struct sk_buff *skb)
+{
+ /* Common GRO receive for SIT and IP6IP6 */
+
+ if (NAPI_GRO_CB(skb)->encap_mark) {
+ NAPI_GRO_CB(skb)->flush = 1;
+ return NULL;
+ }
+
+ NAPI_GRO_CB(skb)->encap_mark = 1;
+
+ return inet_gro_receive(head, skb);
+}
+
+INDIRECT_CALLABLE_SCOPE int ipv6_gro_complete(struct sk_buff *skb, int nhoff)
+{
+ const struct net_offload *ops;
+ struct ipv6hdr *iph;
+ int err = -ENOSYS;
+ u32 payload_len;
+
+ if (skb->encapsulation) {
+ skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IPV6));
+ skb_set_inner_network_header(skb, nhoff);
+ }
+
+ payload_len = skb->len - nhoff - sizeof(*iph);
+ if (unlikely(payload_len > IPV6_MAXPLEN)) {
+ struct hop_jumbo_hdr *hop_jumbo;
+ int hoplen = sizeof(*hop_jumbo);
+
+ /* Move network header left */
+ memmove(skb_mac_header(skb) - hoplen, skb_mac_header(skb),
+ skb->transport_header - skb->mac_header);
+ skb->data -= hoplen;
+ skb->len += hoplen;
+ skb->mac_header -= hoplen;
+ skb->network_header -= hoplen;
+ iph = (struct ipv6hdr *)(skb->data + nhoff);
+ hop_jumbo = (struct hop_jumbo_hdr *)(iph + 1);
+
+ /* Build hop-by-hop options */
+ hop_jumbo->nexthdr = iph->nexthdr;
+ hop_jumbo->hdrlen = 0;
+ hop_jumbo->tlv_type = IPV6_TLV_JUMBO;
+ hop_jumbo->tlv_len = 4;
+ hop_jumbo->jumbo_payload_len = htonl(payload_len + hoplen);
+
+ iph->nexthdr = NEXTHDR_HOP;
+ iph->payload_len = 0;
+ } else {
+ iph = (struct ipv6hdr *)(skb->data + nhoff);
+ iph->payload_len = htons(payload_len);
+ }
+
+ nhoff += sizeof(*iph) + ipv6_exthdrs_len(iph, &ops);
+ if (WARN_ON(!ops || !ops->callbacks.gro_complete))
+ goto out;
+
+ err = INDIRECT_CALL_L4(ops->callbacks.gro_complete, tcp6_gro_complete,
+ udp6_gro_complete, skb, nhoff);
+
+out:
+ return err;
+}
+
+static int sit_gro_complete(struct sk_buff *skb, int nhoff)
+{
+ skb->encapsulation = 1;
+ skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
+ return ipv6_gro_complete(skb, nhoff);
+}
+
+static int ip6ip6_gro_complete(struct sk_buff *skb, int nhoff)
+{
+ skb->encapsulation = 1;
+ skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
+ return ipv6_gro_complete(skb, nhoff);
+}
+
+static int ip4ip6_gro_complete(struct sk_buff *skb, int nhoff)
+{
+ skb->encapsulation = 1;
+ skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
+ return inet_gro_complete(skb, nhoff);
+}
+
+static struct packet_offload ipv6_packet_offload __read_mostly = {
+ .type = cpu_to_be16(ETH_P_IPV6),
+ .callbacks = {
+ .gso_segment = ipv6_gso_segment,
+ .gro_receive = ipv6_gro_receive,
+ .gro_complete = ipv6_gro_complete,
+ },
+};
+
+static struct sk_buff *sit_gso_segment(struct sk_buff *skb,
+ netdev_features_t features)
+{
+ if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
+ return ERR_PTR(-EINVAL);
+
+ return ipv6_gso_segment(skb, features);
+}
+
+static struct sk_buff *ip4ip6_gso_segment(struct sk_buff *skb,
+ netdev_features_t features)
+{
+ if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP6))
+ return ERR_PTR(-EINVAL);
+
+ return inet_gso_segment(skb, features);
+}
+
+static struct sk_buff *ip6ip6_gso_segment(struct sk_buff *skb,
+ netdev_features_t features)
+{
+ if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP6))
+ return ERR_PTR(-EINVAL);
+
+ return ipv6_gso_segment(skb, features);
+}
+
+static const struct net_offload sit_offload = {
+ .callbacks = {
+ .gso_segment = sit_gso_segment,
+ .gro_receive = sit_ip6ip6_gro_receive,
+ .gro_complete = sit_gro_complete,
+ },
+};
+
+static const struct net_offload ip4ip6_offload = {
+ .callbacks = {
+ .gso_segment = ip4ip6_gso_segment,
+ .gro_receive = ip4ip6_gro_receive,
+ .gro_complete = ip4ip6_gro_complete,
+ },
+};
+
+static const struct net_offload ip6ip6_offload = {
+ .callbacks = {
+ .gso_segment = ip6ip6_gso_segment,
+ .gro_receive = sit_ip6ip6_gro_receive,
+ .gro_complete = ip6ip6_gro_complete,
+ },
+};
+static int __init ipv6_offload_init(void)
+{
+
+ if (tcpv6_offload_init() < 0)
+ pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
+ if (ipv6_exthdrs_offload_init() < 0)
+ pr_crit("%s: Cannot add EXTHDRS protocol offload\n", __func__);
+
+ dev_add_offload(&ipv6_packet_offload);
+
+ inet_add_offload(&sit_offload, IPPROTO_IPV6);
+ inet6_add_offload(&ip6ip6_offload, IPPROTO_IPV6);
+ inet6_add_offload(&ip4ip6_offload, IPPROTO_IPIP);
+
+ return 0;
+}
+
+fs_initcall(ipv6_offload_init);