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![Eric Dumazet](/assets/img/avatar_default.png)
All gro_receive() handlers are called from dev_gro_receive() while rcu_read_lock() has been called. There is no point stacking more rcu_read_lock() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
206 lines
5.4 KiB
C
206 lines
5.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* IPV6 GSO/GRO offload support
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* Linux INET6 implementation
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*
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* UDPv6 GSO support
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*/
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#include <linux/skbuff.h>
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#include <linux/netdevice.h>
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#include <linux/indirect_call_wrapper.h>
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#include <net/protocol.h>
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#include <net/ipv6.h>
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#include <net/udp.h>
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#include <net/ip6_checksum.h>
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#include "ip6_offload.h"
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#include <net/gro.h>
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static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
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netdev_features_t features)
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{
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struct sk_buff *segs = ERR_PTR(-EINVAL);
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unsigned int mss;
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unsigned int unfrag_ip6hlen, unfrag_len;
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struct frag_hdr *fptr;
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u8 *packet_start, *prevhdr;
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u8 nexthdr;
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u8 frag_hdr_sz = sizeof(struct frag_hdr);
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__wsum csum;
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int tnl_hlen;
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int err;
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if (skb->encapsulation && skb_shinfo(skb)->gso_type &
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(SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))
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segs = skb_udp_tunnel_segment(skb, features, true);
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else {
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const struct ipv6hdr *ipv6h;
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struct udphdr *uh;
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if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_UDP | SKB_GSO_UDP_L4)))
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goto out;
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if (!pskb_may_pull(skb, sizeof(struct udphdr)))
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goto out;
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if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
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return __udp_gso_segment(skb, features, true);
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mss = skb_shinfo(skb)->gso_size;
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if (unlikely(skb->len <= mss))
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goto out;
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/* Do software UFO. Complete and fill in the UDP checksum as HW cannot
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* do checksum of UDP packets sent as multiple IP fragments.
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*/
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uh = udp_hdr(skb);
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ipv6h = ipv6_hdr(skb);
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uh->check = 0;
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csum = skb_checksum(skb, 0, skb->len, 0);
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uh->check = udp_v6_check(skb->len, &ipv6h->saddr,
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&ipv6h->daddr, csum);
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if (uh->check == 0)
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uh->check = CSUM_MANGLED_0;
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skb->ip_summed = CHECKSUM_UNNECESSARY;
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/* If there is no outer header we can fake a checksum offload
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* due to the fact that we have already done the checksum in
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* software prior to segmenting the frame.
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*/
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if (!skb->encap_hdr_csum)
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features |= NETIF_F_HW_CSUM;
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/* Check if there is enough headroom to insert fragment header. */
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tnl_hlen = skb_tnl_header_len(skb);
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if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) {
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if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz))
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goto out;
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}
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/* Find the unfragmentable header and shift it left by frag_hdr_sz
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* bytes to insert fragment header.
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*/
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err = ip6_find_1stfragopt(skb, &prevhdr);
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if (err < 0)
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return ERR_PTR(err);
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unfrag_ip6hlen = err;
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nexthdr = *prevhdr;
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*prevhdr = NEXTHDR_FRAGMENT;
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unfrag_len = (skb_network_header(skb) - skb_mac_header(skb)) +
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unfrag_ip6hlen + tnl_hlen;
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packet_start = (u8 *) skb->head + SKB_GSO_CB(skb)->mac_offset;
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memmove(packet_start-frag_hdr_sz, packet_start, unfrag_len);
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SKB_GSO_CB(skb)->mac_offset -= frag_hdr_sz;
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skb->mac_header -= frag_hdr_sz;
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skb->network_header -= frag_hdr_sz;
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fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen);
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fptr->nexthdr = nexthdr;
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fptr->reserved = 0;
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fptr->identification = ipv6_proxy_select_ident(dev_net(skb->dev), skb);
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/* Fragment the skb. ipv6 header and the remaining fields of the
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* fragment header are updated in ipv6_gso_segment()
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*/
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segs = skb_segment(skb, features);
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}
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out:
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return segs;
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}
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static struct sock *udp6_gro_lookup_skb(struct sk_buff *skb, __be16 sport,
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__be16 dport)
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{
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const struct ipv6hdr *iph = skb_gro_network_header(skb);
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return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
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&iph->daddr, dport, inet6_iif(skb),
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inet6_sdif(skb), &udp_table, NULL);
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}
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INDIRECT_CALLABLE_SCOPE
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struct sk_buff *udp6_gro_receive(struct list_head *head, struct sk_buff *skb)
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{
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struct udphdr *uh = udp_gro_udphdr(skb);
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struct sock *sk = NULL;
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struct sk_buff *pp;
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if (unlikely(!uh))
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goto flush;
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/* Don't bother verifying checksum if we're going to flush anyway. */
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if (NAPI_GRO_CB(skb)->flush)
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goto skip;
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if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check,
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ip6_gro_compute_pseudo))
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goto flush;
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else if (uh->check)
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skb_gro_checksum_try_convert(skb, IPPROTO_UDP,
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ip6_gro_compute_pseudo);
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skip:
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NAPI_GRO_CB(skb)->is_ipv6 = 1;
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if (static_branch_unlikely(&udpv6_encap_needed_key))
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sk = udp6_gro_lookup_skb(skb, uh->source, uh->dest);
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pp = udp_gro_receive(head, skb, uh, sk);
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return pp;
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flush:
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NAPI_GRO_CB(skb)->flush = 1;
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return NULL;
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}
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INDIRECT_CALLABLE_SCOPE int udp6_gro_complete(struct sk_buff *skb, int nhoff)
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{
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const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
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struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
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/* do fraglist only if there is no outer UDP encap (or we already processed it) */
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if (NAPI_GRO_CB(skb)->is_flist && !NAPI_GRO_CB(skb)->encap_mark) {
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uh->len = htons(skb->len - nhoff);
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skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4);
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skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
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if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
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if (skb->csum_level < SKB_MAX_CSUM_LEVEL)
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skb->csum_level++;
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} else {
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skb->ip_summed = CHECKSUM_UNNECESSARY;
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skb->csum_level = 0;
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}
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return 0;
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}
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if (uh->check)
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uh->check = ~udp_v6_check(skb->len - nhoff, &ipv6h->saddr,
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&ipv6h->daddr, 0);
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return udp_gro_complete(skb, nhoff, udp6_lib_lookup_skb);
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}
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static const struct net_offload udpv6_offload = {
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.callbacks = {
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.gso_segment = udp6_ufo_fragment,
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.gro_receive = udp6_gro_receive,
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.gro_complete = udp6_gro_complete,
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},
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};
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int udpv6_offload_init(void)
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{
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return inet6_add_offload(&udpv6_offload, IPPROTO_UDP);
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}
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int udpv6_offload_exit(void)
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{
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return inet6_del_offload(&udpv6_offload, IPPROTO_UDP);
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}
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