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https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-15 00:04:15 +08:00
5024c33ac3
Add functions and basic definitions for processing standard flags, private flags, and control messages. This includes definitions to compute length of optional fields corresponding to a set of flags. Flag validation is in validate_gue_flags function. This checks for unknown flags, and that length of optional fields is <= length in guehdr hlen. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
637 lines
13 KiB
C
637 lines
13 KiB
C
#include <linux/module.h>
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#include <linux/errno.h>
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#include <linux/socket.h>
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#include <linux/skbuff.h>
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#include <linux/ip.h>
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#include <linux/udp.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <net/genetlink.h>
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#include <net/gue.h>
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#include <net/ip.h>
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#include <net/protocol.h>
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#include <net/udp.h>
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#include <net/udp_tunnel.h>
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#include <net/xfrm.h>
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#include <uapi/linux/fou.h>
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#include <uapi/linux/genetlink.h>
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static DEFINE_SPINLOCK(fou_lock);
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static LIST_HEAD(fou_list);
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struct fou {
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struct socket *sock;
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u8 protocol;
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u16 port;
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struct udp_offload udp_offloads;
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struct list_head list;
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};
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struct fou_cfg {
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u16 type;
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u8 protocol;
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struct udp_port_cfg udp_config;
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};
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static inline struct fou *fou_from_sock(struct sock *sk)
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{
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return sk->sk_user_data;
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}
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static void fou_recv_pull(struct sk_buff *skb, size_t len)
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{
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struct iphdr *iph = ip_hdr(skb);
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/* Remove 'len' bytes from the packet (UDP header and
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* FOU header if present).
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*/
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iph->tot_len = htons(ntohs(iph->tot_len) - len);
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__skb_pull(skb, len);
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skb_postpull_rcsum(skb, udp_hdr(skb), len);
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skb_reset_transport_header(skb);
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}
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static int fou_udp_recv(struct sock *sk, struct sk_buff *skb)
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{
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struct fou *fou = fou_from_sock(sk);
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if (!fou)
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return 1;
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fou_recv_pull(skb, sizeof(struct udphdr));
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return -fou->protocol;
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}
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static int gue_control_message(struct sk_buff *skb, struct guehdr *guehdr)
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{
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/* No support yet */
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kfree_skb(skb);
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return 0;
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}
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static int gue_udp_recv(struct sock *sk, struct sk_buff *skb)
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{
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struct fou *fou = fou_from_sock(sk);
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size_t len, optlen, hdrlen;
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struct guehdr *guehdr;
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void *data;
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if (!fou)
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return 1;
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len = sizeof(struct udphdr) + sizeof(struct guehdr);
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if (!pskb_may_pull(skb, len))
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goto drop;
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guehdr = (struct guehdr *)&udp_hdr(skb)[1];
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optlen = guehdr->hlen << 2;
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len += optlen;
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if (!pskb_may_pull(skb, len))
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goto drop;
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/* guehdr may change after pull */
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guehdr = (struct guehdr *)&udp_hdr(skb)[1];
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hdrlen = sizeof(struct guehdr) + optlen;
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if (guehdr->version != 0 || validate_gue_flags(guehdr, optlen))
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goto drop;
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/* Pull UDP and GUE headers */
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fou_recv_pull(skb, len);
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data = &guehdr[1];
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if (guehdr->flags & GUE_FLAG_PRIV) {
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data += GUE_LEN_PRIV;
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/* Process private flags */
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}
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if (unlikely(guehdr->control))
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return gue_control_message(skb, guehdr);
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return -guehdr->proto_ctype;
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drop:
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kfree_skb(skb);
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return 0;
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}
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static struct sk_buff **fou_gro_receive(struct sk_buff **head,
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struct sk_buff *skb)
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{
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const struct net_offload *ops;
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struct sk_buff **pp = NULL;
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u8 proto = NAPI_GRO_CB(skb)->proto;
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const struct net_offload **offloads;
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rcu_read_lock();
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offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
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ops = rcu_dereference(offloads[proto]);
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if (!ops || !ops->callbacks.gro_receive)
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goto out_unlock;
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pp = ops->callbacks.gro_receive(head, skb);
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out_unlock:
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rcu_read_unlock();
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return pp;
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}
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static int fou_gro_complete(struct sk_buff *skb, int nhoff)
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{
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const struct net_offload *ops;
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u8 proto = NAPI_GRO_CB(skb)->proto;
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int err = -ENOSYS;
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const struct net_offload **offloads;
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rcu_read_lock();
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offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
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ops = rcu_dereference(offloads[proto]);
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if (WARN_ON(!ops || !ops->callbacks.gro_complete))
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goto out_unlock;
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err = ops->callbacks.gro_complete(skb, nhoff);
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out_unlock:
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rcu_read_unlock();
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return err;
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}
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static struct sk_buff **gue_gro_receive(struct sk_buff **head,
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struct sk_buff *skb)
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{
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const struct net_offload **offloads;
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const struct net_offload *ops;
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struct sk_buff **pp = NULL;
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struct sk_buff *p;
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struct guehdr *guehdr;
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size_t len, optlen, hdrlen, off;
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void *data;
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int flush = 1;
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off = skb_gro_offset(skb);
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len = off + sizeof(*guehdr);
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guehdr = skb_gro_header_fast(skb, off);
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if (skb_gro_header_hard(skb, len)) {
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guehdr = skb_gro_header_slow(skb, len, off);
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if (unlikely(!guehdr))
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goto out;
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}
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optlen = guehdr->hlen << 2;
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len += optlen;
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if (skb_gro_header_hard(skb, len)) {
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guehdr = skb_gro_header_slow(skb, len, off);
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if (unlikely(!guehdr))
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goto out;
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}
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if (unlikely(guehdr->control) || guehdr->version != 0 ||
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validate_gue_flags(guehdr, optlen))
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goto out;
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hdrlen = sizeof(*guehdr) + optlen;
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skb_gro_pull(skb, hdrlen);
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/* Adjusted NAPI_GRO_CB(skb)->csum after skb_gro_pull()*/
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skb_gro_postpull_rcsum(skb, guehdr, hdrlen);
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data = &guehdr[1];
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if (guehdr->flags & GUE_FLAG_PRIV) {
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data += GUE_LEN_PRIV;
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/* Process private flags */
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}
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flush = 0;
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for (p = *head; p; p = p->next) {
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const struct guehdr *guehdr2;
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if (!NAPI_GRO_CB(p)->same_flow)
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continue;
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guehdr2 = (struct guehdr *)(p->data + off);
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/* Compare base GUE header to be equal (covers
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* hlen, version, proto_ctype, and flags.
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*/
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if (guehdr->word != guehdr2->word) {
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NAPI_GRO_CB(p)->same_flow = 0;
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continue;
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}
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/* Compare optional fields are the same. */
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if (guehdr->hlen && memcmp(&guehdr[1], &guehdr2[1],
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guehdr->hlen << 2)) {
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NAPI_GRO_CB(p)->same_flow = 0;
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continue;
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}
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}
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rcu_read_lock();
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offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
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ops = rcu_dereference(offloads[guehdr->proto_ctype]);
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if (WARN_ON(!ops || !ops->callbacks.gro_receive))
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goto out_unlock;
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pp = ops->callbacks.gro_receive(head, skb);
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out_unlock:
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rcu_read_unlock();
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out:
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NAPI_GRO_CB(skb)->flush |= flush;
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return pp;
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}
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static int gue_gro_complete(struct sk_buff *skb, int nhoff)
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{
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const struct net_offload **offloads;
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struct guehdr *guehdr = (struct guehdr *)(skb->data + nhoff);
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const struct net_offload *ops;
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unsigned int guehlen;
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u8 proto;
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int err = -ENOENT;
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proto = guehdr->proto_ctype;
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guehlen = sizeof(*guehdr) + (guehdr->hlen << 2);
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rcu_read_lock();
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offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
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ops = rcu_dereference(offloads[proto]);
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if (WARN_ON(!ops || !ops->callbacks.gro_complete))
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goto out_unlock;
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err = ops->callbacks.gro_complete(skb, nhoff + guehlen);
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out_unlock:
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rcu_read_unlock();
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return err;
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}
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static int fou_add_to_port_list(struct fou *fou)
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{
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struct fou *fout;
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spin_lock(&fou_lock);
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list_for_each_entry(fout, &fou_list, list) {
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if (fou->port == fout->port) {
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spin_unlock(&fou_lock);
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return -EALREADY;
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}
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}
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list_add(&fou->list, &fou_list);
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spin_unlock(&fou_lock);
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return 0;
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}
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static void fou_release(struct fou *fou)
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{
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struct socket *sock = fou->sock;
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struct sock *sk = sock->sk;
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udp_del_offload(&fou->udp_offloads);
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list_del(&fou->list);
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/* Remove hooks into tunnel socket */
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sk->sk_user_data = NULL;
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sock_release(sock);
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kfree(fou);
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}
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static int fou_encap_init(struct sock *sk, struct fou *fou, struct fou_cfg *cfg)
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{
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udp_sk(sk)->encap_rcv = fou_udp_recv;
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fou->protocol = cfg->protocol;
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fou->udp_offloads.callbacks.gro_receive = fou_gro_receive;
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fou->udp_offloads.callbacks.gro_complete = fou_gro_complete;
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fou->udp_offloads.port = cfg->udp_config.local_udp_port;
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fou->udp_offloads.ipproto = cfg->protocol;
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return 0;
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}
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static int gue_encap_init(struct sock *sk, struct fou *fou, struct fou_cfg *cfg)
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{
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udp_sk(sk)->encap_rcv = gue_udp_recv;
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fou->udp_offloads.callbacks.gro_receive = gue_gro_receive;
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fou->udp_offloads.callbacks.gro_complete = gue_gro_complete;
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fou->udp_offloads.port = cfg->udp_config.local_udp_port;
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return 0;
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}
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static int fou_create(struct net *net, struct fou_cfg *cfg,
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struct socket **sockp)
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{
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struct fou *fou = NULL;
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int err;
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struct socket *sock = NULL;
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struct sock *sk;
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/* Open UDP socket */
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err = udp_sock_create(net, &cfg->udp_config, &sock);
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if (err < 0)
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goto error;
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/* Allocate FOU port structure */
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fou = kzalloc(sizeof(*fou), GFP_KERNEL);
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if (!fou) {
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err = -ENOMEM;
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goto error;
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}
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sk = sock->sk;
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fou->port = cfg->udp_config.local_udp_port;
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/* Initial for fou type */
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switch (cfg->type) {
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case FOU_ENCAP_DIRECT:
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err = fou_encap_init(sk, fou, cfg);
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if (err)
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goto error;
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break;
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case FOU_ENCAP_GUE:
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err = gue_encap_init(sk, fou, cfg);
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if (err)
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goto error;
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break;
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default:
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err = -EINVAL;
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goto error;
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}
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udp_sk(sk)->encap_type = 1;
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udp_encap_enable();
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sk->sk_user_data = fou;
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fou->sock = sock;
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udp_set_convert_csum(sk, true);
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sk->sk_allocation = GFP_ATOMIC;
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if (cfg->udp_config.family == AF_INET) {
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err = udp_add_offload(&fou->udp_offloads);
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if (err)
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goto error;
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}
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err = fou_add_to_port_list(fou);
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if (err)
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goto error;
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if (sockp)
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*sockp = sock;
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return 0;
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error:
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kfree(fou);
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if (sock)
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sock_release(sock);
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return err;
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}
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static int fou_destroy(struct net *net, struct fou_cfg *cfg)
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{
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struct fou *fou;
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u16 port = cfg->udp_config.local_udp_port;
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int err = -EINVAL;
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spin_lock(&fou_lock);
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list_for_each_entry(fou, &fou_list, list) {
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if (fou->port == port) {
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udp_del_offload(&fou->udp_offloads);
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fou_release(fou);
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err = 0;
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break;
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}
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}
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spin_unlock(&fou_lock);
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return err;
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}
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static struct genl_family fou_nl_family = {
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.id = GENL_ID_GENERATE,
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.hdrsize = 0,
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.name = FOU_GENL_NAME,
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.version = FOU_GENL_VERSION,
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.maxattr = FOU_ATTR_MAX,
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.netnsok = true,
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};
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static struct nla_policy fou_nl_policy[FOU_ATTR_MAX + 1] = {
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[FOU_ATTR_PORT] = { .type = NLA_U16, },
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[FOU_ATTR_AF] = { .type = NLA_U8, },
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[FOU_ATTR_IPPROTO] = { .type = NLA_U8, },
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[FOU_ATTR_TYPE] = { .type = NLA_U8, },
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};
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static int parse_nl_config(struct genl_info *info,
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struct fou_cfg *cfg)
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{
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memset(cfg, 0, sizeof(*cfg));
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cfg->udp_config.family = AF_INET;
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if (info->attrs[FOU_ATTR_AF]) {
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u8 family = nla_get_u8(info->attrs[FOU_ATTR_AF]);
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if (family != AF_INET && family != AF_INET6)
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return -EINVAL;
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cfg->udp_config.family = family;
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}
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if (info->attrs[FOU_ATTR_PORT]) {
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u16 port = nla_get_u16(info->attrs[FOU_ATTR_PORT]);
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cfg->udp_config.local_udp_port = port;
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}
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if (info->attrs[FOU_ATTR_IPPROTO])
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cfg->protocol = nla_get_u8(info->attrs[FOU_ATTR_IPPROTO]);
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if (info->attrs[FOU_ATTR_TYPE])
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cfg->type = nla_get_u8(info->attrs[FOU_ATTR_TYPE]);
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return 0;
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}
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static int fou_nl_cmd_add_port(struct sk_buff *skb, struct genl_info *info)
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{
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struct fou_cfg cfg;
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int err;
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err = parse_nl_config(info, &cfg);
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if (err)
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return err;
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return fou_create(&init_net, &cfg, NULL);
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}
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static int fou_nl_cmd_rm_port(struct sk_buff *skb, struct genl_info *info)
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{
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struct fou_cfg cfg;
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parse_nl_config(info, &cfg);
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return fou_destroy(&init_net, &cfg);
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}
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static const struct genl_ops fou_nl_ops[] = {
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{
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.cmd = FOU_CMD_ADD,
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.doit = fou_nl_cmd_add_port,
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.policy = fou_nl_policy,
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.flags = GENL_ADMIN_PERM,
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},
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{
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.cmd = FOU_CMD_DEL,
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.doit = fou_nl_cmd_rm_port,
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.policy = fou_nl_policy,
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.flags = GENL_ADMIN_PERM,
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},
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};
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static void fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
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struct flowi4 *fl4, u8 *protocol, __be16 sport)
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{
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struct udphdr *uh;
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skb_push(skb, sizeof(struct udphdr));
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skb_reset_transport_header(skb);
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uh = udp_hdr(skb);
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uh->dest = e->dport;
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uh->source = sport;
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uh->len = htons(skb->len);
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uh->check = 0;
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udp_set_csum(!(e->flags & TUNNEL_ENCAP_FLAG_CSUM), skb,
|
|
fl4->saddr, fl4->daddr, skb->len);
|
|
|
|
*protocol = IPPROTO_UDP;
|
|
}
|
|
|
|
int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
|
|
u8 *protocol, struct flowi4 *fl4)
|
|
{
|
|
bool csum = !!(e->flags & TUNNEL_ENCAP_FLAG_CSUM);
|
|
int type = csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
|
|
__be16 sport;
|
|
|
|
skb = iptunnel_handle_offloads(skb, csum, type);
|
|
|
|
if (IS_ERR(skb))
|
|
return PTR_ERR(skb);
|
|
|
|
sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
|
|
skb, 0, 0, false);
|
|
fou_build_udp(skb, e, fl4, protocol, sport);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(fou_build_header);
|
|
|
|
int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
|
|
u8 *protocol, struct flowi4 *fl4)
|
|
{
|
|
bool csum = !!(e->flags & TUNNEL_ENCAP_FLAG_CSUM);
|
|
int type = csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
|
|
struct guehdr *guehdr;
|
|
size_t optlen = 0;
|
|
__be16 sport;
|
|
void *data;
|
|
bool need_priv = false;
|
|
|
|
optlen += need_priv ? GUE_LEN_PRIV : 0;
|
|
|
|
skb = iptunnel_handle_offloads(skb, csum, type);
|
|
|
|
if (IS_ERR(skb))
|
|
return PTR_ERR(skb);
|
|
|
|
/* Get source port (based on flow hash) before skb_push */
|
|
sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
|
|
skb, 0, 0, false);
|
|
|
|
skb_push(skb, sizeof(struct guehdr) + optlen);
|
|
|
|
guehdr = (struct guehdr *)skb->data;
|
|
|
|
guehdr->control = 0;
|
|
guehdr->version = 0;
|
|
guehdr->hlen = optlen >> 2;
|
|
guehdr->flags = 0;
|
|
guehdr->proto_ctype = *protocol;
|
|
|
|
data = &guehdr[1];
|
|
|
|
if (need_priv) {
|
|
__be32 *flags = data;
|
|
|
|
guehdr->flags |= GUE_FLAG_PRIV;
|
|
*flags = 0;
|
|
data += GUE_LEN_PRIV;
|
|
|
|
/* Add private flags */
|
|
}
|
|
|
|
fou_build_udp(skb, e, fl4, protocol, sport);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(gue_build_header);
|
|
|
|
static int __init fou_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = genl_register_family_with_ops(&fou_nl_family,
|
|
fou_nl_ops);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void __exit fou_fini(void)
|
|
{
|
|
struct fou *fou, *next;
|
|
|
|
genl_unregister_family(&fou_nl_family);
|
|
|
|
/* Close all the FOU sockets */
|
|
|
|
spin_lock(&fou_lock);
|
|
list_for_each_entry_safe(fou, next, &fou_list, list)
|
|
fou_release(fou);
|
|
spin_unlock(&fou_lock);
|
|
}
|
|
|
|
module_init(fou_init);
|
|
module_exit(fou_fini);
|
|
MODULE_AUTHOR("Tom Herbert <therbert@google.com>");
|
|
MODULE_LICENSE("GPL");
|