diff options
Diffstat (limited to 'net/ipv6/ip6_offload.c')
| -rw-r--r-- | net/ipv6/ip6_offload.c | 488 |
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); |