From 04dd17822334871b23ea2862f7798fb0e0007777 Mon Sep 17 00:00:00 2001 From: hc <hc@nodka.com> Date: Sat, 11 May 2024 08:53:19 +0000 Subject: [PATCH] change otg to host mode --- kernel/net/ipv4/fou.c | 244 +++++++++++++++++++++++++++++++++++++++++++----- 1 files changed, 216 insertions(+), 28 deletions(-) diff --git a/kernel/net/ipv4/fou.c b/kernel/net/ipv4/fou.c index 854ff1e..e5f69b0 100644 --- a/kernel/net/ipv4/fou.c +++ b/kernel/net/ipv4/fou.c @@ -1,8 +1,10 @@ +// 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> @@ -136,7 +138,7 @@ break; case 1: { - /* Direct encasulation of IPv4 or IPv6 */ + /* Direct encapsulation of IPv4 or IPv6 */ int prot; @@ -170,9 +172,7 @@ /* guehdr may change after pull */ guehdr = (struct guehdr *)&udp_hdr(skb)[1]; - hdrlen = sizeof(struct guehdr) + optlen; - - if (guehdr->version != 0 || validate_gue_flags(guehdr, optlen)) + if (validate_gue_flags(guehdr, optlen)) goto drop; hdrlen = sizeof(struct guehdr) + optlen; @@ -237,7 +237,7 @@ /* 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 are simply + * 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. */ @@ -429,7 +429,7 @@ /* 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 are simply + * 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. */ @@ -500,15 +500,45 @@ return err; } -static int fou_add_to_port_list(struct net *net, struct fou *fou) +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->port == fout->port && - fou->family == fout->family) { + if (fou_cfg_cmp(fout, cfg)) { mutex_unlock(&fn->fou_lock); return -EALREADY; } @@ -586,7 +616,7 @@ sk->sk_allocation = GFP_ATOMIC; - err = fou_add_to_port_list(net, fou); + err = fou_add_to_port_list(net, fou, cfg); if (err) goto error; @@ -606,14 +636,12 @@ static int fou_destroy(struct net *net, struct fou_cfg *cfg) { struct fou_net *fn = net_generic(net, fou_net_id); - __be16 port = cfg->udp_config.local_udp_port; - u8 family = cfg->udp_config.family; int err = -EINVAL; struct fou *fou; mutex_lock(&fn->fou_lock); list_for_each_entry(fou, &fn->fou_list, list) { - if (fou->port == port && fou->family == family) { + if (fou_cfg_cmp(fou, cfg)) { fou_release(fou); err = 0; break; @@ -627,16 +655,27 @@ 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_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; @@ -658,8 +697,7 @@ } if (info->attrs[FOU_ATTR_PORT]) { - __be16 port = nla_get_be16(info->attrs[FOU_ATTR_PORT]); - + port = nla_get_be16(info->attrs[FOU_ATTR_PORT]); cfg->udp_config.local_udp_port = port; } @@ -671,6 +709,52 @@ 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; } @@ -703,15 +787,37 @@ 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_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; } @@ -764,7 +870,7 @@ ret = -ESRCH; mutex_lock(&fn->fou_lock); list_for_each_entry(fout, &fn->fou_list, list) { - if (port == fout->port && family == fout->family) { + if (fou_cfg_cmp(fout, &cfg)) { ret = fou_dump_info(fout, info->snd_portid, info->snd_seq, 0, msg, info->genlhdr->cmd); @@ -805,24 +911,24 @@ return skb->len; } -static const struct genl_ops fou_nl_ops[] = { +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, - .policy = fou_nl_policy, .flags = GENL_ADMIN_PERM, }, { .cmd = FOU_CMD_DEL, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, .doit = fou_nl_cmd_rm_port, - .policy = fou_nl_policy, .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, - .policy = fou_nl_policy, }, }; @@ -831,10 +937,11 @@ .name = FOU_GENL_NAME, .version = FOU_GENL_VERSION, .maxattr = FOU_ATTR_MAX, + .policy = fou_nl_policy, .netnsok = true, .module = THIS_MODULE, - .ops = fou_nl_ops, - .n_ops = ARRAY_SIZE(fou_nl_ops), + .small_ops = fou_nl_ops, + .n_small_ops = ARRAY_SIZE(fou_nl_ops), }; size_t fou_encap_hlen(struct ip_tunnel_encap *e) @@ -1005,15 +1112,95 @@ 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) @@ -1117,3 +1304,4 @@ module_exit(fou_fini); MODULE_AUTHOR("Tom Herbert <therbert@google.com>"); MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Foo over UDP"); -- Gitblit v1.6.2