From 8ac6c7a54ed1b98d142dce24b11c6de6a1e239a5 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 22 Oct 2024 10:36:11 +0000
Subject: [PATCH] 修改4g拨号为QMI,需要在系统里后台执行quectel-CM

---
 kernel/net/ipv6/ip6_gre.c |  203 ++++++++++++++++++++++++++------------------------
 1 files changed, 104 insertions(+), 99 deletions(-)

diff --git a/kernel/net/ipv6/ip6_gre.c b/kernel/net/ipv6/ip6_gre.c
index 043e57d..2df1036 100644
--- a/kernel/net/ipv6/ip6_gre.c
+++ b/kernel/net/ipv6/ip6_gre.c
@@ -1,13 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *	GRE over IPv6 protocol decoder.
  *
  *	Authors: Dmitry Kozlov (xeb@mail.ru)
- *
- *	This program is free software; you can redistribute it and/or
- *	modify it under the terms of the GNU General Public License
- *	as published by the Free Software Foundation; either version
- *	2 of the License, or (at your option) any later version.
- *
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -425,59 +420,42 @@
 }
 
 
-static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
+static int ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 		       u8 type, u8 code, int offset, __be32 info)
 {
 	struct net *net = dev_net(skb->dev);
-	const struct gre_base_hdr *greh;
 	const struct ipv6hdr *ipv6h;
-	int grehlen = sizeof(*greh);
+	struct tnl_ptk_info tpi;
 	struct ip6_tnl *t;
-	int key_off = 0;
-	__be16 flags;
-	__be32 key;
 
-	if (!pskb_may_pull(skb, offset + grehlen))
-		return;
-	greh = (const struct gre_base_hdr *)(skb->data + offset);
-	flags = greh->flags;
-	if (flags & (GRE_VERSION | GRE_ROUTING))
-		return;
-	if (flags & GRE_CSUM)
-		grehlen += 4;
-	if (flags & GRE_KEY) {
-		key_off = grehlen + offset;
-		grehlen += 4;
-	}
+	if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IPV6),
+			     offset) < 0)
+		return -EINVAL;
 
-	if (!pskb_may_pull(skb, offset + grehlen))
-		return;
 	ipv6h = (const struct ipv6hdr *)skb->data;
-	greh = (const struct gre_base_hdr *)(skb->data + offset);
-	key = key_off ? *(__be32 *)(skb->data + key_off) : 0;
-
 	t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
-				 key, greh->protocol);
+				 tpi.key, tpi.proto);
 	if (!t)
-		return;
+		return -ENOENT;
 
 	switch (type) {
-		struct ipv6_tlv_tnl_enc_lim *tel;
-		__u32 teli;
 	case ICMPV6_DEST_UNREACH:
 		net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
 				    t->parms.name);
 		if (code != ICMPV6_PORT_UNREACH)
 			break;
-		return;
+		return 0;
 	case ICMPV6_TIME_EXCEED:
 		if (code == ICMPV6_EXC_HOPLIMIT) {
 			net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 					    t->parms.name);
 			break;
 		}
-		return;
-	case ICMPV6_PARAMPROB:
+		return 0;
+	case ICMPV6_PARAMPROB: {
+		struct ipv6_tlv_tnl_enc_lim *tel;
+		__u32 teli;
+
 		teli = 0;
 		if (code == ICMPV6_HDR_FIELD)
 			teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
@@ -492,14 +470,15 @@
 			net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 					    t->parms.name);
 		}
-		return;
+		return 0;
+	}
 	case ICMPV6_PKT_TOOBIG:
 		ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
-		return;
+		return 0;
 	case NDISC_REDIRECT:
 		ip6_redirect(skb, net, skb->dev->ifindex, 0,
 			     sock_net_uid(net, NULL));
-		return;
+		return 0;
 	}
 
 	if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
@@ -507,6 +486,8 @@
 	else
 		t->err_count = 1;
 	t->err_time = jiffies;
+
+	return 0;
 }
 
 static int ip6gre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
@@ -542,7 +523,8 @@
 	return PACKET_REJECT;
 }
 
-static int ip6erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
+static int ip6erspan_rcv(struct sk_buff *skb,
+			 struct tnl_ptk_info *tpi,
 			 int gre_hdr_len)
 {
 	struct erspan_base_hdr *ershdr;
@@ -695,8 +677,8 @@
 
 		tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
 		if (tel->encap_limit == 0) {
-			icmpv6_send(skb, ICMPV6_PARAMPROB,
-				    ICMPV6_HDR_FIELD, offset + 2);
+			icmpv6_ndo_send(skb, ICMPV6_PARAMPROB,
+					ICMPV6_HDR_FIELD, offset + 2);
 			return -1;
 		}
 		*encap_limit = tel->encap_limit - 1;
@@ -724,6 +706,17 @@
 	return 0;
 }
 
+static struct ip_tunnel_info *skb_tunnel_info_txcheck(struct sk_buff *skb)
+{
+	struct ip_tunnel_info *tun_info;
+
+	tun_info = skb_tunnel_info(skb);
+	if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX)))
+		return ERR_PTR(-EINVAL);
+
+	return tun_info;
+}
+
 static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
 			       struct net_device *dev, __u8 dsfield,
 			       struct flowi6 *fl6, int encap_limit,
@@ -731,6 +724,7 @@
 {
 	struct ip6_tnl *tunnel = netdev_priv(dev);
 	__be16 protocol;
+	__be16 flags;
 
 	if (dev->type == ARPHRD_ETHER)
 		IPCB(skb)->flags = 0;
@@ -740,21 +734,17 @@
 	else
 		fl6->daddr = tunnel->parms.raddr;
 
-	if (skb_cow_head(skb, dev->needed_headroom ?: tunnel->hlen))
-		return -ENOMEM;
-
 	/* Push GRE header. */
 	protocol = (dev->type == ARPHRD_ETHER) ? htons(ETH_P_TEB) : proto;
 
 	if (tunnel->parms.collect_md) {
 		struct ip_tunnel_info *tun_info;
 		const struct ip_tunnel_key *key;
-		__be16 flags;
+		int tun_hlen;
 
-		tun_info = skb_tunnel_info(skb);
-		if (unlikely(!tun_info ||
-			     !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
-			     ip_tunnel_info_af(tun_info) != AF_INET6))
+		tun_info = skb_tunnel_info_txcheck(skb);
+		if (IS_ERR(tun_info) ||
+		    unlikely(ip_tunnel_info_af(tun_info) != AF_INET6))
 			return -EINVAL;
 
 		key = &tun_info->key;
@@ -763,25 +753,32 @@
 		fl6->daddr = key->u.ipv6.dst;
 		fl6->flowlabel = key->label;
 		fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
+		fl6->fl6_gre_key = tunnel_id_to_key32(key->tun_id);
 
 		dsfield = key->tos;
 		flags = key->tun_flags &
 			(TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ);
-		tunnel->tun_hlen = gre_calc_hlen(flags);
+		tun_hlen = gre_calc_hlen(flags);
 
-		gre_build_header(skb, tunnel->tun_hlen,
+		if (skb_cow_head(skb, dev->needed_headroom ?: tun_hlen + tunnel->encap_hlen))
+			return -ENOMEM;
+
+		gre_build_header(skb, tun_hlen,
 				 flags, protocol,
 				 tunnel_id_to_key32(tun_info->key.tun_id),
-				 (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++)
+				 (flags & TUNNEL_SEQ) ? htonl(atomic_fetch_inc(&tunnel->o_seqno))
 						      : 0);
 
 	} else {
-		if (tunnel->parms.o_flags & TUNNEL_SEQ)
-			tunnel->o_seqno++;
+		if (skb_cow_head(skb, dev->needed_headroom ?: tunnel->hlen))
+			return -ENOMEM;
 
-		gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
+		flags = tunnel->parms.o_flags;
+
+		gre_build_header(skb, tunnel->tun_hlen, flags,
 				 protocol, tunnel->parms.o_key,
-				 htonl(tunnel->o_seqno));
+				 (flags & TUNNEL_SEQ) ? htonl(atomic_fetch_inc(&tunnel->o_seqno))
+						      : 0);
 	}
 
 	return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
@@ -812,8 +809,8 @@
 	if (err != 0) {
 		/* XXX: send ICMP error even if DF is not set. */
 		if (err == -EMSGSIZE)
-			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
-				  htonl(mtu));
+			icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
+				      htonl(mtu));
 		return -1;
 	}
 
@@ -844,7 +841,7 @@
 			  &mtu, skb->protocol);
 	if (err != 0) {
 		if (err == -EMSGSIZE)
-			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+			icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 		return -1;
 	}
 
@@ -925,7 +922,8 @@
 	return NETDEV_TX_OK;
 
 tx_err:
-	stats->tx_errors++;
+	if (!t->parms.collect_md || !IS_ERR(skb_tunnel_info_txcheck(skb)))
+		stats->tx_errors++;
 	stats->tx_dropped++;
 	kfree_skb(skb);
 	return NETDEV_TX_OK;
@@ -934,6 +932,7 @@
 static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
 					 struct net_device *dev)
 {
+	struct ip_tunnel_info *tun_info = NULL;
 	struct ip6_tnl *t = netdev_priv(dev);
 	struct dst_entry *dst = skb_dst(skb);
 	struct net_device_stats *stats;
@@ -945,7 +944,6 @@
 	__be16 proto;
 	__u32 mtu;
 	int nhoff;
-	int thoff;
 
 	if (!pskb_inet_may_pull(skb))
 		goto tx_err;
@@ -957,19 +955,26 @@
 		goto tx_err;
 
 	if (skb->len > dev->mtu + dev->hard_header_len) {
-		pskb_trim(skb, dev->mtu + dev->hard_header_len);
+		if (pskb_trim(skb, dev->mtu + dev->hard_header_len))
+			goto tx_err;
 		truncate = true;
 	}
 
-	nhoff = skb_network_header(skb) - skb_mac_header(skb);
+	nhoff = skb_network_offset(skb);
 	if (skb->protocol == htons(ETH_P_IP) &&
 	    (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
 		truncate = true;
 
-	thoff = skb_transport_header(skb) - skb_mac_header(skb);
-	if (skb->protocol == htons(ETH_P_IPV6) &&
-	    (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff))
-		truncate = true;
+	if (skb->protocol == htons(ETH_P_IPV6)) {
+		int thoff;
+
+		if (skb_transport_header_was_set(skb))
+			thoff = skb_transport_offset(skb);
+		else
+			thoff = nhoff + sizeof(struct ipv6hdr);
+		if (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff)
+			truncate = true;
+	}
 
 	if (skb_cow_head(skb, dev->needed_headroom ?: t->hlen))
 		goto tx_err;
@@ -981,15 +986,13 @@
 	 * for native mode, call prepare_ip6gre_xmit_{ipv4,ipv6}.
 	 */
 	if (t->parms.collect_md) {
-		struct ip_tunnel_info *tun_info;
 		const struct ip_tunnel_key *key;
 		struct erspan_metadata *md;
 		__be32 tun_id;
 
-		tun_info = skb_tunnel_info(skb);
-		if (unlikely(!tun_info ||
-			     !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
-			     ip_tunnel_info_af(tun_info) != AF_INET6))
+		tun_info = skb_tunnel_info_txcheck(skb);
+		if (IS_ERR(tun_info) ||
+		    unlikely(ip_tunnel_info_af(tun_info) != AF_INET6))
 			goto tx_err;
 
 		key = &tun_info->key;
@@ -998,6 +1001,7 @@
 		fl6.daddr = key->u.ipv6.dst;
 		fl6.flowlabel = key->label;
 		fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
+		fl6.fl6_gre_key = tunnel_id_to_key32(key->tun_id);
 
 		dsfield = key->tos;
 		if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
@@ -1012,12 +1016,14 @@
 					    ntohl(tun_id),
 					    ntohl(md->u.index), truncate,
 					    false);
+			proto = htons(ETH_P_ERSPAN);
 		} else if (md->version == 2) {
 			erspan_build_header_v2(skb,
 					       ntohl(tun_id),
 					       md->u.md2.dir,
 					       get_hwid(&md->u.md2),
 					       truncate, false);
+			proto = htons(ETH_P_ERSPAN2);
 		} else {
 			goto tx_err;
 		}
@@ -1040,25 +1046,26 @@
 			break;
 		}
 
-		if (t->parms.erspan_ver == 1)
+		if (t->parms.erspan_ver == 1) {
 			erspan_build_header(skb, ntohl(t->parms.o_key),
 					    t->parms.index,
 					    truncate, false);
-		else if (t->parms.erspan_ver == 2)
+			proto = htons(ETH_P_ERSPAN);
+		} else if (t->parms.erspan_ver == 2) {
 			erspan_build_header_v2(skb, ntohl(t->parms.o_key),
 					       t->parms.dir,
 					       t->parms.hwid,
 					       truncate, false);
-		else
+			proto = htons(ETH_P_ERSPAN2);
+		} else {
 			goto tx_err;
+		}
 
 		fl6.daddr = t->parms.raddr;
 	}
 
 	/* Push GRE header. */
-	proto = (t->parms.erspan_ver == 1) ? htons(ETH_P_ERSPAN)
-					   : htons(ETH_P_ERSPAN2);
-	gre_build_header(skb, 8, TUNNEL_SEQ, proto, 0, htonl(t->o_seqno++));
+	gre_build_header(skb, 8, TUNNEL_SEQ, proto, 0, htonl(atomic_fetch_inc(&t->o_seqno)));
 
 	/* TooBig packet may have updated dst->dev's mtu */
 	if (!t->parms.collect_md && dst && dst_mtu(dst) > dst->dev->mtu)
@@ -1070,10 +1077,10 @@
 		/* XXX: send ICMP error even if DF is not set. */
 		if (err == -EMSGSIZE) {
 			if (skb->protocol == htons(ETH_P_IP))
-				icmp_send(skb, ICMP_DEST_UNREACH,
-					  ICMP_FRAG_NEEDED, htonl(mtu));
+				icmp_ndo_send(skb, ICMP_DEST_UNREACH,
+					      ICMP_FRAG_NEEDED, htonl(mtu));
 			else
-				icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+				icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 		}
 
 		goto tx_err;
@@ -1082,7 +1089,8 @@
 
 tx_err:
 	stats = &t->dev->stats;
-	stats->tx_errors++;
+	if (!IS_ERR(tun_info))
+		stats->tx_errors++;
 	stats->tx_dropped++;
 	kfree_skb(skb);
 	return NETDEV_TX_OK;
@@ -1105,6 +1113,7 @@
 	fl6->flowi6_oif = p->link;
 	fl6->flowlabel = 0;
 	fl6->flowi6_proto = IPPROTO_GRE;
+	fl6->fl6_gre_key = t->parms.o_key;
 
 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
@@ -1148,14 +1157,16 @@
 				dev->needed_headroom = dst_len;
 
 			if (set_mtu) {
-				dev->mtu = rt->dst.dev->mtu - t_hlen;
-				if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
-					dev->mtu -= 8;
-				if (dev->type == ARPHRD_ETHER)
-					dev->mtu -= ETH_HLEN;
+				int mtu = rt->dst.dev->mtu - t_hlen;
 
-				if (dev->mtu < IPV6_MIN_MTU)
-					dev->mtu = IPV6_MIN_MTU;
+				if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
+					mtu -= 8;
+				if (dev->type == ARPHRD_ETHER)
+					mtu -= ETH_HLEN;
+
+				if (mtu < IPV6_MIN_MTU)
+					mtu = IPV6_MIN_MTU;
+				WRITE_ONCE(dev->mtu, mtu);
 			}
 		}
 		ip6_rt_put(rt);
@@ -1550,7 +1561,7 @@
 static struct inet6_protocol ip6gre_protocol __read_mostly = {
 	.handler     = gre_rcv,
 	.err_handler = ip6gre_err,
-	.flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
+	.flags       = INET6_PROTO_FINAL,
 };
 
 static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
@@ -1931,12 +1942,6 @@
 	netif_keep_dst(dev);
 }
 
-bool is_ip6gretap_dev(const struct net_device *dev)
-{
-	return dev->netdev_ops == &ip6gre_tap_netdev_ops;
-}
-EXPORT_SYMBOL_GPL(is_ip6gretap_dev);
-
 static bool ip6gre_netlink_encap_parms(struct nlattr *data[],
 				       struct ip_tunnel_encap *ipencap)
 {
@@ -2205,8 +2210,8 @@
 	[IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
 	[IFLA_GRE_IKEY]        = { .type = NLA_U32 },
 	[IFLA_GRE_OKEY]        = { .type = NLA_U32 },
-	[IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
-	[IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
+	[IFLA_GRE_LOCAL]       = { .len = sizeof_field(struct ipv6hdr, saddr) },
+	[IFLA_GRE_REMOTE]      = { .len = sizeof_field(struct ipv6hdr, daddr) },
 	[IFLA_GRE_TTL]         = { .type = NLA_U8 },
 	[IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
 	[IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },

--
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