diff options
Diffstat (limited to 'net/ipv4/fou.c')
| -rw-r--r-- | net/ipv4/fou.c | 1294 |
1 files changed, 1294 insertions, 0 deletions
diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c new file mode 100644 index 000000000..0c3c6d0ce --- /dev/null +++ b/net/ipv4/fou.c @@ -0,0 +1,1294 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/module.h> +#include <linux/errno.h> +#include <linux/socket.h> +#include <linux/skbuff.h> +#include <linux/ip.h> +#include <linux/icmp.h> +#include <linux/udp.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <net/genetlink.h> +#include <net/gro.h> +#include <net/gue.h> +#include <net/fou.h> +#include <net/ip.h> +#include <net/protocol.h> +#include <net/udp.h> +#include <net/udp_tunnel.h> +#include <uapi/linux/fou.h> +#include <uapi/linux/genetlink.h> + +struct fou { + struct socket *sock; + u8 protocol; + u8 flags; + __be16 port; + u8 family; + u16 type; + struct list_head list; + struct rcu_head rcu; +}; + +#define FOU_F_REMCSUM_NOPARTIAL BIT(0) + +struct fou_cfg { + u16 type; + u8 protocol; + u8 flags; + struct udp_port_cfg udp_config; +}; + +static unsigned int fou_net_id; + +struct fou_net { + struct list_head fou_list; + struct mutex fou_lock; +}; + +static inline struct fou *fou_from_sock(struct sock *sk) +{ + return sk->sk_user_data; +} + +static int fou_recv_pull(struct sk_buff *skb, struct fou *fou, size_t len) +{ + /* Remove 'len' bytes from the packet (UDP header and + * FOU header if present). + */ + if (fou->family == AF_INET) + ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(skb)->tot_len) - len); + else + ipv6_hdr(skb)->payload_len = + htons(ntohs(ipv6_hdr(skb)->payload_len) - len); + + __skb_pull(skb, len); + skb_postpull_rcsum(skb, udp_hdr(skb), len); + skb_reset_transport_header(skb); + return iptunnel_pull_offloads(skb); +} + +static int fou_udp_recv(struct sock *sk, struct sk_buff *skb) +{ + struct fou *fou = fou_from_sock(sk); + + if (!fou) + return 1; + + if (fou_recv_pull(skb, fou, sizeof(struct udphdr))) + goto drop; + + return -fou->protocol; + +drop: + kfree_skb(skb); + return 0; +} + +static struct guehdr *gue_remcsum(struct sk_buff *skb, struct guehdr *guehdr, + void *data, size_t hdrlen, u8 ipproto, + bool nopartial) +{ + __be16 *pd = data; + size_t start = ntohs(pd[0]); + size_t offset = ntohs(pd[1]); + size_t plen = sizeof(struct udphdr) + hdrlen + + max_t(size_t, offset + sizeof(u16), start); + + if (skb->remcsum_offload) + return guehdr; + + if (!pskb_may_pull(skb, plen)) + return NULL; + guehdr = (struct guehdr *)&udp_hdr(skb)[1]; + + skb_remcsum_process(skb, (void *)guehdr + hdrlen, + start, offset, nopartial); + + return guehdr; +} + +static int gue_control_message(struct sk_buff *skb, struct guehdr *guehdr) +{ + /* No support yet */ + kfree_skb(skb); + return 0; +} + +static int gue_udp_recv(struct sock *sk, struct sk_buff *skb) +{ + struct fou *fou = fou_from_sock(sk); + size_t len, optlen, hdrlen; + struct guehdr *guehdr; + void *data; + u16 doffset = 0; + u8 proto_ctype; + + if (!fou) + return 1; + + len = sizeof(struct udphdr) + sizeof(struct guehdr); + if (!pskb_may_pull(skb, len)) + goto drop; + + guehdr = (struct guehdr *)&udp_hdr(skb)[1]; + + switch (guehdr->version) { + case 0: /* Full GUE header present */ + break; + + case 1: { + /* Direct encapsulation of IPv4 or IPv6 */ + + int prot; + + switch (((struct iphdr *)guehdr)->version) { + case 4: + prot = IPPROTO_IPIP; + break; + case 6: + prot = IPPROTO_IPV6; + break; + default: + goto drop; + } + + if (fou_recv_pull(skb, fou, sizeof(struct udphdr))) + goto drop; + + return -prot; + } + + default: /* Undefined version */ + goto drop; + } + + optlen = guehdr->hlen << 2; + len += optlen; + + if (!pskb_may_pull(skb, len)) + goto drop; + + /* guehdr may change after pull */ + guehdr = (struct guehdr *)&udp_hdr(skb)[1]; + + if (validate_gue_flags(guehdr, optlen)) + goto drop; + + hdrlen = sizeof(struct guehdr) + optlen; + + if (fou->family == AF_INET) + ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(skb)->tot_len) - len); + else + ipv6_hdr(skb)->payload_len = + htons(ntohs(ipv6_hdr(skb)->payload_len) - len); + + /* Pull csum through the guehdr now . This can be used if + * there is a remote checksum offload. + */ + skb_postpull_rcsum(skb, udp_hdr(skb), len); + + data = &guehdr[1]; + + if (guehdr->flags & GUE_FLAG_PRIV) { + __be32 flags = *(__be32 *)(data + doffset); + + doffset += GUE_LEN_PRIV; + + if (flags & GUE_PFLAG_REMCSUM) { + guehdr = gue_remcsum(skb, guehdr, data + doffset, + hdrlen, guehdr->proto_ctype, + !!(fou->flags & + FOU_F_REMCSUM_NOPARTIAL)); + if (!guehdr) + goto drop; + + data = &guehdr[1]; + + doffset += GUE_PLEN_REMCSUM; + } + } + + if (unlikely(guehdr->control)) + return gue_control_message(skb, guehdr); + + proto_ctype = guehdr->proto_ctype; + __skb_pull(skb, sizeof(struct udphdr) + hdrlen); + skb_reset_transport_header(skb); + + if (iptunnel_pull_offloads(skb)) + goto drop; + + return -proto_ctype; + +drop: + kfree_skb(skb); + return 0; +} + +static struct sk_buff *fou_gro_receive(struct sock *sk, + struct list_head *head, + struct sk_buff *skb) +{ + const struct net_offload __rcu **offloads; + u8 proto = fou_from_sock(sk)->protocol; + const struct net_offload *ops; + struct sk_buff *pp = NULL; + + /* We can clear the encap_mark for FOU as we are essentially doing + * one of two possible things. We are either adding an L4 tunnel + * header to the outer L3 tunnel header, or we are simply + * treating the GRE tunnel header as though it is a UDP protocol + * specific header such as VXLAN or GENEVE. + */ + NAPI_GRO_CB(skb)->encap_mark = 0; + + /* Flag this frame as already having an outer encap header */ + NAPI_GRO_CB(skb)->is_fou = 1; + + offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads; + ops = rcu_dereference(offloads[proto]); + if (!ops || !ops->callbacks.gro_receive) + goto out; + + pp = call_gro_receive(ops->callbacks.gro_receive, head, skb); + +out: + return pp; +} + +static int fou_gro_complete(struct sock *sk, struct sk_buff *skb, + int nhoff) +{ + const struct net_offload __rcu **offloads; + u8 proto = fou_from_sock(sk)->protocol; + const struct net_offload *ops; + int err = -ENOSYS; + + offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads; + ops = rcu_dereference(offloads[proto]); + if (WARN_ON(!ops || !ops->callbacks.gro_complete)) + goto out; + + err = ops->callbacks.gro_complete(skb, nhoff); + + skb_set_inner_mac_header(skb, nhoff); + +out: + return err; +} + +static struct guehdr *gue_gro_remcsum(struct sk_buff *skb, unsigned int off, + struct guehdr *guehdr, void *data, + size_t hdrlen, struct gro_remcsum *grc, + bool nopartial) +{ + __be16 *pd = data; + size_t start = ntohs(pd[0]); + size_t offset = ntohs(pd[1]); + + if (skb->remcsum_offload) + return guehdr; + + if (!NAPI_GRO_CB(skb)->csum_valid) + return NULL; + + guehdr = skb_gro_remcsum_process(skb, (void *)guehdr, off, hdrlen, + start, offset, grc, nopartial); + + skb->remcsum_offload = 1; + + return guehdr; +} + +static struct sk_buff *gue_gro_receive(struct sock *sk, + struct list_head *head, + struct sk_buff *skb) +{ + const struct net_offload __rcu **offloads; + const struct net_offload *ops; + struct sk_buff *pp = NULL; + struct sk_buff *p; + struct guehdr *guehdr; + size_t len, optlen, hdrlen, off; + void *data; + u16 doffset = 0; + int flush = 1; + struct fou *fou = fou_from_sock(sk); + struct gro_remcsum grc; + u8 proto; + + skb_gro_remcsum_init(&grc); + + off = skb_gro_offset(skb); + len = off + sizeof(*guehdr); + + guehdr = skb_gro_header(skb, len, off); + if (unlikely(!guehdr)) + goto out; + + switch (guehdr->version) { + case 0: + break; + case 1: + switch (((struct iphdr *)guehdr)->version) { + case 4: + proto = IPPROTO_IPIP; + break; + case 6: + proto = IPPROTO_IPV6; + break; + default: + goto out; + } + goto next_proto; + default: + goto out; + } + + optlen = guehdr->hlen << 2; + len += optlen; + + if (skb_gro_header_hard(skb, len)) { + guehdr = skb_gro_header_slow(skb, len, off); + if (unlikely(!guehdr)) + goto out; + } + + if (unlikely(guehdr->control) || guehdr->version != 0 || + validate_gue_flags(guehdr, optlen)) + goto out; + + hdrlen = sizeof(*guehdr) + optlen; + + /* Adjust NAPI_GRO_CB(skb)->csum to account for guehdr, + * this is needed if there is a remote checkcsum offload. + */ + skb_gro_postpull_rcsum(skb, guehdr, hdrlen); + + data = &guehdr[1]; + + if (guehdr->flags & GUE_FLAG_PRIV) { + __be32 flags = *(__be32 *)(data + doffset); + + doffset += GUE_LEN_PRIV; + + if (flags & GUE_PFLAG_REMCSUM) { + guehdr = gue_gro_remcsum(skb, off, guehdr, + data + doffset, hdrlen, &grc, + !!(fou->flags & + FOU_F_REMCSUM_NOPARTIAL)); + + if (!guehdr) + goto out; + + data = &guehdr[1]; + + doffset += GUE_PLEN_REMCSUM; + } + } + + skb_gro_pull(skb, hdrlen); + + list_for_each_entry(p, head, list) { + const struct guehdr *guehdr2; + + if (!NAPI_GRO_CB(p)->same_flow) + continue; + + guehdr2 = (struct guehdr *)(p->data + off); + + /* Compare base GUE header to be equal (covers + * hlen, version, proto_ctype, and flags. + */ + if (guehdr->word != guehdr2->word) { + NAPI_GRO_CB(p)->same_flow = 0; + continue; + } + + /* Compare optional fields are the same. */ + if (guehdr->hlen && memcmp(&guehdr[1], &guehdr2[1], + guehdr->hlen << 2)) { + NAPI_GRO_CB(p)->same_flow = 0; + continue; + } + } + + proto = guehdr->proto_ctype; + +next_proto: + + /* We can clear the encap_mark for GUE as we are essentially doing + * one of two possible things. We are either adding an L4 tunnel + * header to the outer L3 tunnel header, or we are simply + * treating the GRE tunnel header as though it is a UDP protocol + * specific header such as VXLAN or GENEVE. + */ + NAPI_GRO_CB(skb)->encap_mark = 0; + + /* Flag this frame as already having an outer encap header */ + NAPI_GRO_CB(skb)->is_fou = 1; + + offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads; + ops = rcu_dereference(offloads[proto]); + if (WARN_ON_ONCE(!ops || !ops->callbacks.gro_receive)) + goto out; + + pp = call_gro_receive(ops->callbacks.gro_receive, head, skb); + flush = 0; + +out: + skb_gro_flush_final_remcsum(skb, pp, flush, &grc); + + return pp; +} + +static int gue_gro_complete(struct sock *sk, struct sk_buff *skb, int nhoff) +{ + struct guehdr *guehdr = (struct guehdr *)(skb->data + nhoff); + const struct net_offload __rcu **offloads; + const struct net_offload *ops; + unsigned int guehlen = 0; + u8 proto; + int err = -ENOENT; + + switch (guehdr->version) { + case 0: + proto = guehdr->proto_ctype; + guehlen = sizeof(*guehdr) + (guehdr->hlen << 2); + break; + case 1: + switch (((struct iphdr *)guehdr)->version) { + case 4: + proto = IPPROTO_IPIP; + break; + case 6: + proto = IPPROTO_IPV6; + break; + default: + return err; + } + break; + default: + return err; + } + + offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads; + ops = rcu_dereference(offloads[proto]); + if (WARN_ON(!ops || !ops->callbacks.gro_complete)) + goto out; + + err = ops->callbacks.gro_complete(skb, nhoff + guehlen); + + skb_set_inner_mac_header(skb, nhoff + guehlen); + +out: + return err; +} + +static bool fou_cfg_cmp(struct fou *fou, struct fou_cfg *cfg) +{ + struct sock *sk = fou->sock->sk; + struct udp_port_cfg *udp_cfg = &cfg->udp_config; + + if (fou->family != udp_cfg->family || + fou->port != udp_cfg->local_udp_port || + sk->sk_dport != udp_cfg->peer_udp_port || + sk->sk_bound_dev_if != udp_cfg->bind_ifindex) + return false; + + if (fou->family == AF_INET) { + if (sk->sk_rcv_saddr != udp_cfg->local_ip.s_addr || + sk->sk_daddr != udp_cfg->peer_ip.s_addr) + return false; + else + return true; +#if IS_ENABLED(CONFIG_IPV6) + } else { + if (ipv6_addr_cmp(&sk->sk_v6_rcv_saddr, &udp_cfg->local_ip6) || + ipv6_addr_cmp(&sk->sk_v6_daddr, &udp_cfg->peer_ip6)) + return false; + else + return true; +#endif + } + + return false; +} + +static int fou_add_to_port_list(struct net *net, struct fou *fou, + struct fou_cfg *cfg) +{ + struct fou_net *fn = net_generic(net, fou_net_id); + struct fou *fout; + + mutex_lock(&fn->fou_lock); + list_for_each_entry(fout, &fn->fou_list, list) { + if (fou_cfg_cmp(fout, cfg)) { + mutex_unlock(&fn->fou_lock); + return -EALREADY; + } + } + + list_add(&fou->list, &fn->fou_list); + mutex_unlock(&fn->fou_lock); + + return 0; +} + +static void fou_release(struct fou *fou) +{ + struct socket *sock = fou->sock; + + list_del(&fou->list); + udp_tunnel_sock_release(sock); + + kfree_rcu(fou, rcu); +} + +static int fou_create(struct net *net, struct fou_cfg *cfg, + struct socket **sockp) +{ + struct socket *sock = NULL; + struct fou *fou = NULL; + struct sock *sk; + struct udp_tunnel_sock_cfg tunnel_cfg; + int err; + + /* Open UDP socket */ + err = udp_sock_create(net, &cfg->udp_config, &sock); + if (err < 0) + goto error; + + /* Allocate FOU port structure */ + fou = kzalloc(sizeof(*fou), GFP_KERNEL); + if (!fou) { + err = -ENOMEM; + goto error; + } + + sk = sock->sk; + + fou->port = cfg->udp_config.local_udp_port; + fou->family = cfg->udp_config.family; + fou->flags = cfg->flags; + fou->type = cfg->type; + fou->sock = sock; + + memset(&tunnel_cfg, 0, sizeof(tunnel_cfg)); + tunnel_cfg.encap_type = 1; + tunnel_cfg.sk_user_data = fou; + tunnel_cfg.encap_destroy = NULL; + + /* Initial for fou type */ + switch (cfg->type) { + case FOU_ENCAP_DIRECT: + tunnel_cfg.encap_rcv = fou_udp_recv; + tunnel_cfg.gro_receive = fou_gro_receive; + tunnel_cfg.gro_complete = fou_gro_complete; + fou->protocol = cfg->protocol; + break; + case FOU_ENCAP_GUE: + tunnel_cfg.encap_rcv = gue_udp_recv; + tunnel_cfg.gro_receive = gue_gro_receive; + tunnel_cfg.gro_complete = gue_gro_complete; + break; + default: + err = -EINVAL; + goto error; + } + + setup_udp_tunnel_sock(net, sock, &tunnel_cfg); + + sk->sk_allocation = GFP_ATOMIC; + + err = fou_add_to_port_list(net, fou, cfg); + if (err) + goto error; + + if (sockp) + *sockp = sock; + + return 0; + +error: + kfree(fou); + if (sock) + udp_tunnel_sock_release(sock); + + return err; +} + +static int fou_destroy(struct net *net, struct fou_cfg *cfg) +{ + struct fou_net *fn = net_generic(net, fou_net_id); + int err = -EINVAL; + struct fou *fou; + + mutex_lock(&fn->fou_lock); + list_for_each_entry(fou, &fn->fou_list, list) { + if (fou_cfg_cmp(fou, cfg)) { + fou_release(fou); + err = 0; + break; + } + } + mutex_unlock(&fn->fou_lock); + + return err; +} + +static struct genl_family fou_nl_family; + +static const struct nla_policy fou_nl_policy[FOU_ATTR_MAX + 1] = { + [FOU_ATTR_PORT] = { .type = NLA_U16, }, + [FOU_ATTR_AF] = { .type = NLA_U8, }, + [FOU_ATTR_IPPROTO] = { .type = NLA_U8, }, + [FOU_ATTR_TYPE] = { .type = NLA_U8, }, + [FOU_ATTR_REMCSUM_NOPARTIAL] = { .type = NLA_FLAG, }, + [FOU_ATTR_LOCAL_V4] = { .type = NLA_U32, }, + [FOU_ATTR_PEER_V4] = { .type = NLA_U32, }, + [FOU_ATTR_LOCAL_V6] = { .len = sizeof(struct in6_addr), }, + [FOU_ATTR_PEER_V6] = { .len = sizeof(struct in6_addr), }, + [FOU_ATTR_PEER_PORT] = { .type = NLA_U16, }, + [FOU_ATTR_IFINDEX] = { .type = NLA_S32, }, +}; + +static int parse_nl_config(struct genl_info *info, + struct fou_cfg *cfg) +{ + bool has_local = false, has_peer = false; + struct nlattr *attr; + int ifindex; + __be16 port; + + memset(cfg, 0, sizeof(*cfg)); + + cfg->udp_config.family = AF_INET; + + if (info->attrs[FOU_ATTR_AF]) { + u8 family = nla_get_u8(info->attrs[FOU_ATTR_AF]); + + switch (family) { + case AF_INET: + break; + case AF_INET6: + cfg->udp_config.ipv6_v6only = 1; + break; + default: + return -EAFNOSUPPORT; + } + + cfg->udp_config.family = family; + } + + if (info->attrs[FOU_ATTR_PORT]) { + port = nla_get_be16(info->attrs[FOU_ATTR_PORT]); + cfg->udp_config.local_udp_port = port; + } + + if (info->attrs[FOU_ATTR_IPPROTO]) + cfg->protocol = nla_get_u8(info->attrs[FOU_ATTR_IPPROTO]); + + if (info->attrs[FOU_ATTR_TYPE]) + cfg->type = nla_get_u8(info->attrs[FOU_ATTR_TYPE]); + + if (info->attrs[FOU_ATTR_REMCSUM_NOPARTIAL]) + cfg->flags |= FOU_F_REMCSUM_NOPARTIAL; + + if (cfg->udp_config.family == AF_INET) { + if (info->attrs[FOU_ATTR_LOCAL_V4]) { + attr = info->attrs[FOU_ATTR_LOCAL_V4]; + cfg->udp_config.local_ip.s_addr = nla_get_in_addr(attr); + has_local = true; + } + + if (info->attrs[FOU_ATTR_PEER_V4]) { + attr = info->attrs[FOU_ATTR_PEER_V4]; + cfg->udp_config.peer_ip.s_addr = nla_get_in_addr(attr); + has_peer = true; + } +#if IS_ENABLED(CONFIG_IPV6) + } else { + if (info->attrs[FOU_ATTR_LOCAL_V6]) { + attr = info->attrs[FOU_ATTR_LOCAL_V6]; + cfg->udp_config.local_ip6 = nla_get_in6_addr(attr); + has_local = true; + } + + if (info->attrs[FOU_ATTR_PEER_V6]) { + attr = info->attrs[FOU_ATTR_PEER_V6]; + cfg->udp_config.peer_ip6 = nla_get_in6_addr(attr); + has_peer = true; + } +#endif + } + + if (has_peer) { + if (info->attrs[FOU_ATTR_PEER_PORT]) { + port = nla_get_be16(info->attrs[FOU_ATTR_PEER_PORT]); + cfg->udp_config.peer_udp_port = port; + } else { + return -EINVAL; + } + } + + if (info->attrs[FOU_ATTR_IFINDEX]) { + if (!has_local) + return -EINVAL; + + ifindex = nla_get_s32(info->attrs[FOU_ATTR_IFINDEX]); + + cfg->udp_config.bind_ifindex = ifindex; + } + + return 0; +} + +static int fou_nl_cmd_add_port(struct sk_buff *skb, struct genl_info *info) +{ + struct net *net = genl_info_net(info); + struct fou_cfg cfg; + int err; + + err = parse_nl_config(info, &cfg); + if (err) + return err; + + return fou_create(net, &cfg, NULL); +} + +static int fou_nl_cmd_rm_port(struct sk_buff *skb, struct genl_info *info) +{ + struct net *net = genl_info_net(info); + struct fou_cfg cfg; + int err; + + err = parse_nl_config(info, &cfg); + if (err) + return err; + + return fou_destroy(net, &cfg); +} + +static int fou_fill_info(struct fou *fou, struct sk_buff *msg) +{ + struct sock *sk = fou->sock->sk; + + if (nla_put_u8(msg, FOU_ATTR_AF, fou->sock->sk->sk_family) || + nla_put_be16(msg, FOU_ATTR_PORT, fou->port) || + nla_put_be16(msg, FOU_ATTR_PEER_PORT, sk->sk_dport) || + nla_put_u8(msg, FOU_ATTR_IPPROTO, fou->protocol) || + nla_put_u8(msg, FOU_ATTR_TYPE, fou->type) || + nla_put_s32(msg, FOU_ATTR_IFINDEX, sk->sk_bound_dev_if)) + return -1; + + if (fou->flags & FOU_F_REMCSUM_NOPARTIAL) + if (nla_put_flag(msg, FOU_ATTR_REMCSUM_NOPARTIAL)) + return -1; + + if (fou->sock->sk->sk_family == AF_INET) { + if (nla_put_in_addr(msg, FOU_ATTR_LOCAL_V4, sk->sk_rcv_saddr)) + return -1; + + if (nla_put_in_addr(msg, FOU_ATTR_PEER_V4, sk->sk_daddr)) + return -1; +#if IS_ENABLED(CONFIG_IPV6) + } else { + if (nla_put_in6_addr(msg, FOU_ATTR_LOCAL_V6, + &sk->sk_v6_rcv_saddr)) + return -1; + + if (nla_put_in6_addr(msg, FOU_ATTR_PEER_V6, &sk->sk_v6_daddr)) + return -1; +#endif + } + + return 0; +} + +static int fou_dump_info(struct fou *fou, u32 portid, u32 seq, + u32 flags, struct sk_buff *skb, u8 cmd) +{ + void *hdr; + + hdr = genlmsg_put(skb, portid, seq, &fou_nl_family, flags, cmd); + if (!hdr) + return -ENOMEM; + + if (fou_fill_info(fou, skb) < 0) + goto nla_put_failure; + + genlmsg_end(skb, hdr); + return 0; + +nla_put_failure: + genlmsg_cancel(skb, hdr); + return -EMSGSIZE; +} + +static int fou_nl_cmd_get_port(struct sk_buff *skb, struct genl_info *info) +{ + struct net *net = genl_info_net(info); + struct fou_net *fn = net_generic(net, fou_net_id); + struct sk_buff *msg; + struct fou_cfg cfg; + struct fou *fout; + __be16 port; + u8 family; + int ret; + + ret = parse_nl_config(info, &cfg); + if (ret) + return ret; + port = cfg.udp_config.local_udp_port; + if (port == 0) + return -EINVAL; + + family = cfg.udp_config.family; + if (family != AF_INET && family != AF_INET6) + return -EINVAL; + + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (!msg) + return -ENOMEM; + + ret = -ESRCH; + mutex_lock(&fn->fou_lock); + list_for_each_entry(fout, &fn->fou_list, list) { + if (fou_cfg_cmp(fout, &cfg)) { + ret = fou_dump_info(fout, info->snd_portid, + info->snd_seq, 0, msg, + info->genlhdr->cmd); + break; + } + } + mutex_unlock(&fn->fou_lock); + if (ret < 0) + goto out_free; + + return genlmsg_reply(msg, info); + +out_free: + nlmsg_free(msg); + return ret; +} + +static int fou_nl_dump(struct sk_buff *skb, struct netlink_callback *cb) +{ + struct net *net = sock_net(skb->sk); + struct fou_net *fn = net_generic(net, fou_net_id); + struct fou *fout; + int idx = 0, ret; + + mutex_lock(&fn->fou_lock); + list_for_each_entry(fout, &fn->fou_list, list) { + if (idx++ < cb->args[0]) + continue; + ret = fou_dump_info(fout, NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, NLM_F_MULTI, + skb, FOU_CMD_GET); + if (ret) + break; + } + mutex_unlock(&fn->fou_lock); + + cb->args[0] = idx; + return skb->len; +} + +static const struct genl_small_ops fou_nl_ops[] = { + { + .cmd = FOU_CMD_ADD, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .doit = fou_nl_cmd_add_port, + .flags = GENL_ADMIN_PERM, + }, + { + .cmd = FOU_CMD_DEL, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .doit = fou_nl_cmd_rm_port, + .flags = GENL_ADMIN_PERM, + }, + { + .cmd = FOU_CMD_GET, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .doit = fou_nl_cmd_get_port, + .dumpit = fou_nl_dump, + }, +}; + +static struct genl_family fou_nl_family __ro_after_init = { + .hdrsize = 0, + .name = FOU_GENL_NAME, + .version = FOU_GENL_VERSION, + .maxattr = FOU_ATTR_MAX, + .policy = fou_nl_policy, + .netnsok = true, + .module = THIS_MODULE, + .small_ops = fou_nl_ops, + .n_small_ops = ARRAY_SIZE(fou_nl_ops), + .resv_start_op = FOU_CMD_GET + 1, +}; + +size_t fou_encap_hlen(struct ip_tunnel_encap *e) +{ + return sizeof(struct udphdr); +} +EXPORT_SYMBOL(fou_encap_hlen); + +size_t gue_encap_hlen(struct ip_tunnel_encap *e) +{ + size_t len; + bool need_priv = false; + + len = sizeof(struct udphdr) + sizeof(struct guehdr); + + if (e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) { + len += GUE_PLEN_REMCSUM; + need_priv = true; + } + + len += need_priv ? GUE_LEN_PRIV : 0; + + return len; +} +EXPORT_SYMBOL(gue_encap_hlen); + +int __fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e, + u8 *protocol, __be16 *sport, int type) +{ + int err; + + err = iptunnel_handle_offloads(skb, type); + if (err) + return err; + + *sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev), + skb, 0, 0, false); + + return 0; +} +EXPORT_SYMBOL(__fou_build_header); + +int __gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e, + u8 *protocol, __be16 *sport, int type) +{ + struct guehdr *guehdr; + size_t hdrlen, optlen = 0; + void *data; + bool need_priv = false; + int err; + + if ((e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) && + skb->ip_summed == CHECKSUM_PARTIAL) { + optlen += GUE_PLEN_REMCSUM; + type |= SKB_GSO_TUNNEL_REMCSUM; + need_priv = true; + } + + optlen += need_priv ? GUE_LEN_PRIV : 0; + + err = iptunnel_handle_offloads(skb, type); + if (err) + return err; + + /* 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); + + hdrlen = sizeof(struct guehdr) + optlen; + + skb_push(skb, hdrlen); + + 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; + + if (type & SKB_GSO_TUNNEL_REMCSUM) { + u16 csum_start = skb_checksum_start_offset(skb); + __be16 *pd = data; + + if (csum_start < hdrlen) + return -EINVAL; + + csum_start -= hdrlen; + pd[0] = htons(csum_start); + pd[1] = htons(csum_start + skb->csum_offset); + + if (!skb_is_gso(skb)) { + skb->ip_summed = CHECKSUM_NONE; + skb->encapsulation = 0; + } + + *flags |= GUE_PFLAG_REMCSUM; + data += GUE_PLEN_REMCSUM; + } + + } + + return 0; +} +EXPORT_SYMBOL(__gue_build_header); + +#ifdef CONFIG_NET_FOU_IP_TUNNELS + +static void fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e, + struct flowi4 *fl4, u8 *protocol, __be16 sport) +{ + struct udphdr *uh; + + skb_push(skb, sizeof(struct udphdr)); + skb_reset_transport_header(skb); + + uh = udp_hdr(skb); + + uh->dest = e->dport; + uh->source = sport; + uh->len = htons(skb->len); + udp_set_csum(!(e->flags & TUNNEL_ENCAP_FLAG_CSUM), skb, + fl4->saddr, fl4->daddr, skb->len); + + *protocol = IPPROTO_UDP; +} + +static int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e, + u8 *protocol, struct flowi4 *fl4) +{ + int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM ? SKB_GSO_UDP_TUNNEL_CSUM : + SKB_GSO_UDP_TUNNEL; + __be16 sport; + int err; + + err = __fou_build_header(skb, e, protocol, &sport, type); + if (err) + return err; + + fou_build_udp(skb, e, fl4, protocol, sport); + + return 0; +} + +static int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e, + u8 *protocol, struct flowi4 *fl4) +{ + int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM ? SKB_GSO_UDP_TUNNEL_CSUM : + SKB_GSO_UDP_TUNNEL; + __be16 sport; + int err; + + err = __gue_build_header(skb, e, protocol, &sport, type); + if (err) + return err; + + fou_build_udp(skb, e, fl4, protocol, sport); + + return 0; +} + +static int gue_err_proto_handler(int proto, struct sk_buff *skb, u32 info) +{ + const struct net_protocol *ipprot = rcu_dereference(inet_protos[proto]); + + if (ipprot && ipprot->err_handler) { + if (!ipprot->err_handler(skb, info)) + return 0; + } + + return -ENOENT; +} + +static int gue_err(struct sk_buff *skb, u32 info) +{ + int transport_offset = skb_transport_offset(skb); + struct guehdr *guehdr; + size_t len, optlen; + int ret; + + len = sizeof(struct udphdr) + sizeof(struct guehdr); + if (!pskb_may_pull(skb, transport_offset + len)) + return -EINVAL; + + guehdr = (struct guehdr *)&udp_hdr(skb)[1]; + + switch (guehdr->version) { + case 0: /* Full GUE header present */ + break; + case 1: { + /* Direct encapsulation of IPv4 or IPv6 */ + skb_set_transport_header(skb, -(int)sizeof(struct icmphdr)); + + switch (((struct iphdr *)guehdr)->version) { + case 4: + ret = gue_err_proto_handler(IPPROTO_IPIP, skb, info); + goto out; +#if IS_ENABLED(CONFIG_IPV6) + case 6: + ret = gue_err_proto_handler(IPPROTO_IPV6, skb, info); + goto out; +#endif + default: + ret = -EOPNOTSUPP; + goto out; + } + } + default: /* Undefined version */ + return -EOPNOTSUPP; + } + + if (guehdr->control) + return -ENOENT; + + optlen = guehdr->hlen << 2; + + if (!pskb_may_pull(skb, transport_offset + len + optlen)) + return -EINVAL; + + guehdr = (struct guehdr *)&udp_hdr(skb)[1]; + if (validate_gue_flags(guehdr, optlen)) + return -EINVAL; + + /* Handling exceptions for direct UDP encapsulation in GUE would lead to + * recursion. Besides, this kind of encapsulation can't even be + * configured currently. Discard this. + */ + if (guehdr->proto_ctype == IPPROTO_UDP || + guehdr->proto_ctype == IPPROTO_UDPLITE) + return -EOPNOTSUPP; + + skb_set_transport_header(skb, -(int)sizeof(struct icmphdr)); + ret = gue_err_proto_handler(guehdr->proto_ctype, skb, info); + +out: + skb_set_transport_header(skb, transport_offset); + return ret; +} + + +static const struct ip_tunnel_encap_ops fou_iptun_ops = { + .encap_hlen = fou_encap_hlen, + .build_header = fou_build_header, + .err_handler = gue_err, +}; + +static const struct ip_tunnel_encap_ops gue_iptun_ops = { + .encap_hlen = gue_encap_hlen, + .build_header = gue_build_header, + .err_handler = gue_err, +}; + +static int ip_tunnel_encap_add_fou_ops(void) +{ + int ret; + + ret = ip_tunnel_encap_add_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU); + if (ret < 0) { + pr_err("can't add fou ops\n"); + return ret; + } + + ret = ip_tunnel_encap_add_ops(&gue_iptun_ops, TUNNEL_ENCAP_GUE); + if (ret < 0) { + pr_err("can't add gue ops\n"); + ip_tunnel_encap_del_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU); + return ret; + } + + return 0; +} + +static void ip_tunnel_encap_del_fou_ops(void) +{ + ip_tunnel_encap_del_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU); + ip_tunnel_encap_del_ops(&gue_iptun_ops, TUNNEL_ENCAP_GUE); +} + +#else + +static int ip_tunnel_encap_add_fou_ops(void) +{ + return 0; +} + +static void ip_tunnel_encap_del_fou_ops(void) +{ +} + +#endif + +static __net_init int fou_init_net(struct net *net) +{ + struct fou_net *fn = net_generic(net, fou_net_id); + + INIT_LIST_HEAD(&fn->fou_list); + mutex_init(&fn->fou_lock); + return 0; +} + +static __net_exit void fou_exit_net(struct net *net) +{ + struct fou_net *fn = net_generic(net, fou_net_id); + struct fou *fou, *next; + + /* Close all the FOU sockets */ + mutex_lock(&fn->fou_lock); + list_for_each_entry_safe(fou, next, &fn->fou_list, list) + fou_release(fou); + mutex_unlock(&fn->fou_lock); +} + +static struct pernet_operations fou_net_ops = { + .init = fou_init_net, + .exit = fou_exit_net, + .id = &fou_net_id, + .size = sizeof(struct fou_net), +}; + +static int __init fou_init(void) +{ + int ret; + + ret = register_pernet_device(&fou_net_ops); + if (ret) + goto exit; + + ret = genl_register_family(&fou_nl_family); + if (ret < 0) + goto unregister; + + ret = ip_tunnel_encap_add_fou_ops(); + if (ret == 0) + return 0; + + genl_unregister_family(&fou_nl_family); +unregister: + unregister_pernet_device(&fou_net_ops); +exit: + return ret; +} + +static void __exit fou_fini(void) +{ + ip_tunnel_encap_del_fou_ops(); + genl_unregister_family(&fou_nl_family); + unregister_pernet_device(&fou_net_ops); +} + +module_init(fou_init); +module_exit(fou_fini); +MODULE_AUTHOR("Tom Herbert <therbert@google.com>"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Foo over UDP"); |