From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001 From: hc <hc@nodka.com> Date: Tue, 20 Feb 2024 01:20:52 +0000 Subject: [PATCH] add new system file --- kernel/net/ipv6/fou6.c | 89 ++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 89 insertions(+), 0 deletions(-) diff --git a/kernel/net/ipv6/fou6.c b/kernel/net/ipv6/fou6.c index 6de3c04..430518a 100644 --- a/kernel/net/ipv6/fou6.c +++ b/kernel/net/ipv6/fou6.c @@ -1,9 +1,11 @@ +// 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/udp.h> +#include <linux/icmpv6.h> #include <linux/types.h> #include <linux/kernel.h> #include <net/fou.h> @@ -69,14 +71,100 @@ return 0; } +static int gue6_err_proto_handler(int proto, struct sk_buff *skb, + struct inet6_skb_parm *opt, + u8 type, u8 code, int offset, __be32 info) +{ + const struct inet6_protocol *ipprot; + + ipprot = rcu_dereference(inet6_protos[proto]); + if (ipprot && ipprot->err_handler) { + if (!ipprot->err_handler(skb, opt, type, code, offset, info)) + return 0; + } + + return -ENOENT; +} + +static int gue6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, + u8 type, u8 code, int offset, __be32 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 encasulation of IPv4 or IPv6 */ + skb_set_transport_header(skb, -(int)sizeof(struct icmp6hdr)); + + switch (((struct iphdr *)guehdr)->version) { + case 4: + ret = gue6_err_proto_handler(IPPROTO_IPIP, skb, opt, + type, code, offset, info); + goto out; + case 6: + ret = gue6_err_proto_handler(IPPROTO_IPV6, skb, opt, + type, code, offset, info); + goto out; + 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 icmp6hdr)); + ret = gue6_err_proto_handler(guehdr->proto_ctype, skb, + opt, type, code, offset, info); + +out: + skb_set_transport_header(skb, transport_offset); + return ret; +} + + static const struct ip6_tnl_encap_ops fou_ip6tun_ops = { .encap_hlen = fou_encap_hlen, .build_header = fou6_build_header, + .err_handler = gue6_err, }; static const struct ip6_tnl_encap_ops gue_ip6tun_ops = { .encap_hlen = gue_encap_hlen, .build_header = gue6_build_header, + .err_handler = gue6_err, }; static int ip6_tnl_encap_add_fou_ops(void) @@ -136,3 +224,4 @@ module_exit(fou6_fini); MODULE_AUTHOR("Tom Herbert <therbert@google.com>"); MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Foo over UDP (IPv6)"); -- Gitblit v1.6.2