From 23fa18eaa71266feff7ba8d83022d9e1cc83c65a Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 10 May 2024 07:42:03 +0000
Subject: [PATCH] disable pwm7
---
kernel/net/core/lwt_bpf.c | 310 +++++++++++++++++++++++++++++++++++++++++++++++----
1 files changed, 284 insertions(+), 26 deletions(-)
diff --git a/kernel/net/core/lwt_bpf.c b/kernel/net/core/lwt_bpf.c
index 4a5f4fb..f6c327c 100644
--- a/kernel/net/core/lwt_bpf.c
+++ b/kernel/net/core/lwt_bpf.c
@@ -1,13 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2016 Thomas Graf <tgraf@tgraf.ch>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
*/
#include <linux/kernel.h>
@@ -16,6 +8,9 @@
#include <linux/types.h>
#include <linux/bpf.h>
#include <net/lwtunnel.h>
+#include <net/gre.h>
+#include <net/ip6_route.h>
+#include <net/ipv6_stubs.h>
struct bpf_lwt_prog {
struct bpf_prog *prog;
@@ -44,16 +39,17 @@
{
int ret;
- /* Preempt disable and BH disable are needed to protect per-cpu
+ /* Migration disable and BH disable are needed to protect per-cpu
* redirect_info between BPF prog and skb_do_redirect().
*/
- preempt_disable();
+ migrate_disable();
local_bh_disable();
bpf_compute_data_pointers(skb);
ret = bpf_prog_run_save_cb(lwt->prog, skb);
switch (ret) {
case BPF_OK:
+ case BPF_LWT_REROUTE:
break;
case BPF_REDIRECT:
@@ -63,9 +59,8 @@
ret = BPF_OK;
} else {
skb_reset_mac_header(skb);
- ret = skb_do_redirect(skb);
- if (ret == 0)
- ret = BPF_REDIRECT;
+ skb_do_redirect(skb);
+ ret = BPF_REDIRECT;
}
break;
@@ -82,9 +77,38 @@
}
local_bh_enable();
- preempt_enable();
+ migrate_enable();
return ret;
+}
+
+static int bpf_lwt_input_reroute(struct sk_buff *skb)
+{
+ int err = -EINVAL;
+
+ if (skb->protocol == htons(ETH_P_IP)) {
+ struct net_device *dev = skb_dst(skb)->dev;
+ struct iphdr *iph = ip_hdr(skb);
+
+ dev_hold(dev);
+ skb_dst_drop(skb);
+ err = ip_route_input_noref(skb, iph->daddr, iph->saddr,
+ iph->tos, dev);
+ dev_put(dev);
+ } else if (skb->protocol == htons(ETH_P_IPV6)) {
+ skb_dst_drop(skb);
+ err = ipv6_stub->ipv6_route_input(skb);
+ } else {
+ err = -EAFNOSUPPORT;
+ }
+
+ if (err)
+ goto err;
+ return dst_input(skb);
+
+err:
+ kfree_skb(skb);
+ return err;
}
static int bpf_input(struct sk_buff *skb)
@@ -98,11 +122,11 @@
ret = run_lwt_bpf(skb, &bpf->in, dst, NO_REDIRECT);
if (ret < 0)
return ret;
+ if (ret == BPF_LWT_REROUTE)
+ return bpf_lwt_input_reroute(skb);
}
if (unlikely(!dst->lwtstate->orig_input)) {
- pr_warn_once("orig_input not set on dst for prog %s\n",
- bpf->out.name);
kfree_skb(skb);
return -EINVAL;
}
@@ -133,10 +157,8 @@
return dst->lwtstate->orig_output(net, sk, skb);
}
-static int xmit_check_hhlen(struct sk_buff *skb)
+static int xmit_check_hhlen(struct sk_buff *skb, int hh_len)
{
- int hh_len = skb_dst(skb)->dev->hard_header_len;
-
if (skb_headroom(skb) < hh_len) {
int nhead = HH_DATA_ALIGN(hh_len - skb_headroom(skb));
@@ -147,6 +169,100 @@
return 0;
}
+static int bpf_lwt_xmit_reroute(struct sk_buff *skb)
+{
+ struct net_device *l3mdev = l3mdev_master_dev_rcu(skb_dst(skb)->dev);
+ int oif = l3mdev ? l3mdev->ifindex : 0;
+ struct dst_entry *dst = NULL;
+ int err = -EAFNOSUPPORT;
+ struct sock *sk;
+ struct net *net;
+ bool ipv4;
+
+ if (skb->protocol == htons(ETH_P_IP))
+ ipv4 = true;
+ else if (skb->protocol == htons(ETH_P_IPV6))
+ ipv4 = false;
+ else
+ goto err;
+
+ sk = sk_to_full_sk(skb->sk);
+ if (sk) {
+ if (sk->sk_bound_dev_if)
+ oif = sk->sk_bound_dev_if;
+ net = sock_net(sk);
+ } else {
+ net = dev_net(skb_dst(skb)->dev);
+ }
+
+ if (ipv4) {
+ struct iphdr *iph = ip_hdr(skb);
+ struct flowi4 fl4 = {};
+ struct rtable *rt;
+
+ fl4.flowi4_oif = oif;
+ fl4.flowi4_mark = skb->mark;
+ fl4.flowi4_uid = sock_net_uid(net, sk);
+ fl4.flowi4_tos = RT_TOS(iph->tos);
+ fl4.flowi4_flags = FLOWI_FLAG_ANYSRC;
+ fl4.flowi4_proto = iph->protocol;
+ fl4.daddr = iph->daddr;
+ fl4.saddr = iph->saddr;
+
+ rt = ip_route_output_key(net, &fl4);
+ if (IS_ERR(rt)) {
+ err = PTR_ERR(rt);
+ goto err;
+ }
+ dst = &rt->dst;
+ } else {
+ struct ipv6hdr *iph6 = ipv6_hdr(skb);
+ struct flowi6 fl6 = {};
+
+ fl6.flowi6_oif = oif;
+ fl6.flowi6_mark = skb->mark;
+ fl6.flowi6_uid = sock_net_uid(net, sk);
+ fl6.flowlabel = ip6_flowinfo(iph6);
+ fl6.flowi6_proto = iph6->nexthdr;
+ fl6.daddr = iph6->daddr;
+ fl6.saddr = iph6->saddr;
+
+ dst = ipv6_stub->ipv6_dst_lookup_flow(net, skb->sk, &fl6, NULL);
+ if (IS_ERR(dst)) {
+ err = PTR_ERR(dst);
+ goto err;
+ }
+ }
+ if (unlikely(dst->error)) {
+ err = dst->error;
+ dst_release(dst);
+ goto err;
+ }
+
+ /* Although skb header was reserved in bpf_lwt_push_ip_encap(), it
+ * was done for the previous dst, so we are doing it here again, in
+ * case the new dst needs much more space. The call below is a noop
+ * if there is enough header space in skb.
+ */
+ err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev));
+ if (unlikely(err))
+ goto err;
+
+ skb_dst_drop(skb);
+ skb_dst_set(skb, dst);
+
+ err = dst_output(dev_net(skb_dst(skb)->dev), skb->sk, skb);
+ if (unlikely(err))
+ return net_xmit_errno(err);
+
+ /* ip[6]_finish_output2 understand LWTUNNEL_XMIT_DONE */
+ return LWTUNNEL_XMIT_DONE;
+
+err:
+ kfree_skb(skb);
+ return err;
+}
+
static int bpf_xmit(struct sk_buff *skb)
{
struct dst_entry *dst = skb_dst(skb);
@@ -154,21 +270,33 @@
bpf = bpf_lwt_lwtunnel(dst->lwtstate);
if (bpf->xmit.prog) {
+ int hh_len = dst->dev->hard_header_len;
+ __be16 proto = skb->protocol;
int ret;
ret = run_lwt_bpf(skb, &bpf->xmit, dst, CAN_REDIRECT);
switch (ret) {
case BPF_OK:
+ /* If the header changed, e.g. via bpf_lwt_push_encap,
+ * BPF_LWT_REROUTE below should have been used if the
+ * protocol was also changed.
+ */
+ if (skb->protocol != proto) {
+ kfree_skb(skb);
+ return -EINVAL;
+ }
/* If the header was expanded, headroom might be too
* small for L2 header to come, expand as needed.
*/
- ret = xmit_check_hhlen(skb);
+ ret = xmit_check_hhlen(skb, hh_len);
if (unlikely(ret))
return ret;
return LWTUNNEL_XMIT_CONTINUE;
case BPF_REDIRECT:
return LWTUNNEL_XMIT_DONE;
+ case BPF_LWT_REROUTE:
+ return bpf_lwt_xmit_reroute(skb);
default:
return ret;
}
@@ -208,8 +336,8 @@
int ret;
u32 fd;
- ret = nla_parse_nested(tb, LWT_BPF_PROG_MAX, attr, bpf_prog_policy,
- NULL);
+ ret = nla_parse_nested_deprecated(tb, LWT_BPF_PROG_MAX, attr,
+ bpf_prog_policy, NULL);
if (ret < 0)
return ret;
@@ -237,7 +365,7 @@
[LWT_BPF_XMIT_HEADROOM] = { .type = NLA_U32 },
};
-static int bpf_build_state(struct nlattr *nla,
+static int bpf_build_state(struct net *net, struct nlattr *nla,
unsigned int family, const void *cfg,
struct lwtunnel_state **ts,
struct netlink_ext_ack *extack)
@@ -250,7 +378,8 @@
if (family != AF_INET && family != AF_INET6)
return -EAFNOSUPPORT;
- ret = nla_parse_nested(tb, LWT_BPF_MAX, nla, bpf_nl_policy, extack);
+ ret = nla_parse_nested_deprecated(tb, LWT_BPF_MAX, nla, bpf_nl_policy,
+ extack);
if (ret < 0)
return ret;
@@ -318,7 +447,7 @@
if (!prog->prog)
return 0;
- nest = nla_nest_start(skb, attr);
+ nest = nla_nest_start_noflag(skb, attr);
if (!nest)
return -EMSGSIZE;
@@ -390,6 +519,135 @@
.owner = THIS_MODULE,
};
+static int handle_gso_type(struct sk_buff *skb, unsigned int gso_type,
+ int encap_len)
+{
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+
+ gso_type |= SKB_GSO_DODGY;
+ shinfo->gso_type |= gso_type;
+ skb_decrease_gso_size(shinfo, encap_len);
+ shinfo->gso_segs = 0;
+ return 0;
+}
+
+static int handle_gso_encap(struct sk_buff *skb, bool ipv4, int encap_len)
+{
+ int next_hdr_offset;
+ void *next_hdr;
+ __u8 protocol;
+
+ /* SCTP and UDP_L4 gso need more nuanced handling than what
+ * handle_gso_type() does above: skb_decrease_gso_size() is not enough.
+ * So at the moment only TCP GSO packets are let through.
+ */
+ if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))
+ return -ENOTSUPP;
+
+ if (ipv4) {
+ protocol = ip_hdr(skb)->protocol;
+ next_hdr_offset = sizeof(struct iphdr);
+ next_hdr = skb_network_header(skb) + next_hdr_offset;
+ } else {
+ protocol = ipv6_hdr(skb)->nexthdr;
+ next_hdr_offset = sizeof(struct ipv6hdr);
+ next_hdr = skb_network_header(skb) + next_hdr_offset;
+ }
+
+ switch (protocol) {
+ case IPPROTO_GRE:
+ next_hdr_offset += sizeof(struct gre_base_hdr);
+ if (next_hdr_offset > encap_len)
+ return -EINVAL;
+
+ if (((struct gre_base_hdr *)next_hdr)->flags & GRE_CSUM)
+ return handle_gso_type(skb, SKB_GSO_GRE_CSUM,
+ encap_len);
+ return handle_gso_type(skb, SKB_GSO_GRE, encap_len);
+
+ case IPPROTO_UDP:
+ next_hdr_offset += sizeof(struct udphdr);
+ if (next_hdr_offset > encap_len)
+ return -EINVAL;
+
+ if (((struct udphdr *)next_hdr)->check)
+ return handle_gso_type(skb, SKB_GSO_UDP_TUNNEL_CSUM,
+ encap_len);
+ return handle_gso_type(skb, SKB_GSO_UDP_TUNNEL, encap_len);
+
+ case IPPROTO_IP:
+ case IPPROTO_IPV6:
+ if (ipv4)
+ return handle_gso_type(skb, SKB_GSO_IPXIP4, encap_len);
+ else
+ return handle_gso_type(skb, SKB_GSO_IPXIP6, encap_len);
+
+ default:
+ return -EPROTONOSUPPORT;
+ }
+}
+
+int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len, bool ingress)
+{
+ struct iphdr *iph;
+ bool ipv4;
+ int err;
+
+ if (unlikely(len < sizeof(struct iphdr) || len > LWT_BPF_MAX_HEADROOM))
+ return -EINVAL;
+
+ /* validate protocol and length */
+ iph = (struct iphdr *)hdr;
+ if (iph->version == 4) {
+ ipv4 = true;
+ if (unlikely(len < iph->ihl * 4))
+ return -EINVAL;
+ } else if (iph->version == 6) {
+ ipv4 = false;
+ if (unlikely(len < sizeof(struct ipv6hdr)))
+ return -EINVAL;
+ } else {
+ return -EINVAL;
+ }
+
+ if (ingress)
+ err = skb_cow_head(skb, len + skb->mac_len);
+ else
+ err = skb_cow_head(skb,
+ len + LL_RESERVED_SPACE(skb_dst(skb)->dev));
+ if (unlikely(err))
+ return err;
+
+ /* push the encap headers and fix pointers */
+ skb_reset_inner_headers(skb);
+ skb_reset_inner_mac_header(skb); /* mac header is not yet set */
+ skb_set_inner_protocol(skb, skb->protocol);
+ skb->encapsulation = 1;
+ skb_push(skb, len);
+ if (ingress)
+ skb_postpush_rcsum(skb, iph, len);
+ skb_reset_network_header(skb);
+ memcpy(skb_network_header(skb), hdr, len);
+ bpf_compute_data_pointers(skb);
+ skb_clear_hash(skb);
+
+ if (ipv4) {
+ skb->protocol = htons(ETH_P_IP);
+ iph = ip_hdr(skb);
+
+ if (!iph->check)
+ iph->check = ip_fast_csum((unsigned char *)iph,
+ iph->ihl);
+ } else {
+ skb->protocol = htons(ETH_P_IPV6);
+ }
+
+ if (skb_is_gso(skb))
+ return handle_gso_encap(skb, ipv4, len);
+
+ return 0;
+}
+
static int __init bpf_lwt_init(void)
{
return lwtunnel_encap_add_ops(&bpf_encap_ops, LWTUNNEL_ENCAP_BPF);
--
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