iio: proximity: isl29501: Fix return type of isl29501_register_writegrafted

isl29501_register_write() was returning a u32 instead of an int.
Since the function returns negative error codes (such as -ERANGE or
return values from i2c_smbus_write_byte_data()), returning an unsigned
integer type prevents callers from correctly checking for negative error
conditions.

Fix this by changing the function return type from u32 to int.

This was found through manual code review.

Fixes: 1c28799257bc ("iio: light: isl29501: Add support for the ISL29501 ToF sensor.")
Signed-off-by: Salah Triki <salah.triki@gmail.com>
Reviewed-by: Joshua Crofts <joshua.crofts1@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>

1 files changed, 185 insertions, 0 deletions

diff --git a/include/net/ip6_tunnel.h b/include/net/ip6_tunnel.h
new file mode 100644
index 000000000..b99805ee2
--- /dev/null
+++ b/include/net/ip6_tunnel.h
@@ -0,0 +1,185 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _NET_IP6_TUNNEL_H
+#define _NET_IP6_TUNNEL_H
+
+#include <linux/ipv6.h>
+#include <linux/netdevice.h>
+#include <linux/if_tunnel.h>
+#include <linux/ip6_tunnel.h>
+#include <net/ip_tunnels.h>
+#include <net/dst_cache.h>
+
+#define IP6TUNNEL_ERR_TIMEO (30*HZ)
+
+/* capable of sending packets */
+#define IP6_TNL_F_CAP_XMIT 0x10000
+/* capable of receiving packets */
+#define IP6_TNL_F_CAP_RCV 0x20000
+/* determine capability on a per-packet basis */
+#define IP6_TNL_F_CAP_PER_PACKET 0x40000
+
+struct __ip6_tnl_parm {
+	char name[IFNAMSIZ];	/* name of tunnel device */
+	int link;		/* ifindex of underlying L2 interface */
+	__u8 proto;		/* tunnel protocol */
+	__u8 encap_limit;	/* encapsulation limit for tunnel */
+	__u8 hop_limit;		/* hop limit for tunnel */
+	bool collect_md;
+	__be32 flowinfo;	/* traffic class and flowlabel for tunnel */
+	__u32 flags;		/* tunnel flags */
+	struct in6_addr laddr;	/* local tunnel end-point address */
+	struct in6_addr raddr;	/* remote tunnel end-point address */
+
+	IP_TUNNEL_DECLARE_FLAGS(i_flags);
+	IP_TUNNEL_DECLARE_FLAGS(o_flags);
+	__be32			i_key;
+	__be32			o_key;
+
+	__u32			fwmark;
+	__u32			index;	/* ERSPAN type II index */
+	__u8			erspan_ver;	/* ERSPAN version */
+	__u8			dir;	/* direction */
+	__u16			hwid;	/* hwid */
+};
+
+/* IPv6 tunnel */
+struct ip6_tnl {
+	struct ip6_tnl __rcu *next;	/* next tunnel in list */
+	struct net_device *dev;	/* virtual device associated with tunnel */
+	netdevice_tracker dev_tracker;
+	struct net *net;	/* netns for packet i/o */
+	struct __ip6_tnl_parm parms;	/* tunnel configuration parameters */
+	struct flowi fl;	/* flowi template for xmit */
+	struct dst_cache dst_cache;	/* cached dst */
+	struct gro_cells gro_cells;
+
+	int err_count;
+	unsigned long err_time;
+
+	/* These fields used only by GRE */
+	__u32 i_seqno;	/* The last seen seqno	*/
+	atomic_t o_seqno;	/* The last output seqno */
+	int hlen;       /* tun_hlen + encap_hlen */
+	int tun_hlen;	/* Precalculated header length */
+	int encap_hlen; /* Encap header length (FOU,GUE) */
+	struct ip_tunnel_encap encap;
+	int mlink;
+};
+
+struct ip6_tnl_encap_ops {
+	size_t (*encap_hlen)(struct ip_tunnel_encap *e);
+	int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
+			    u8 *protocol, struct flowi6 *fl6);
+	int (*err_handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
+			   u8 type, u8 code, int offset, __be32 info);
+};
+
+#ifdef CONFIG_INET
+
+extern const struct ip6_tnl_encap_ops __rcu *
+		ip6tun_encaps[MAX_IPTUN_ENCAP_OPS];
+
+int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
+			  unsigned int num);
+int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
+			  unsigned int num);
+int ip6_tnl_encap_setup(struct ip6_tnl *t,
+			struct ip_tunnel_encap *ipencap);
+
+static inline int ip6_encap_hlen(struct ip_tunnel_encap *e)
+{
+	const struct ip6_tnl_encap_ops *ops;
+	int hlen = -EINVAL;
+
+	if (e->type == TUNNEL_ENCAP_NONE)
+		return 0;
+
+	if (e->type >= MAX_IPTUN_ENCAP_OPS)
+		return -EINVAL;
+
+	rcu_read_lock();
+	ops = rcu_dereference(ip6tun_encaps[e->type]);
+	if (likely(ops && ops->encap_hlen))
+		hlen = ops->encap_hlen(e);
+	rcu_read_unlock();
+
+	return hlen;
+}
+
+static inline int ip6_tnl_encap(struct sk_buff *skb, struct ip6_tnl *t,
+				u8 *protocol, struct flowi6 *fl6)
+{
+	const struct ip6_tnl_encap_ops *ops;
+	int ret = -EINVAL;
+
+	if (t->encap.type == TUNNEL_ENCAP_NONE)
+		return 0;
+
+	if (t->encap.type >= MAX_IPTUN_ENCAP_OPS)
+		return -EINVAL;
+
+	rcu_read_lock();
+	ops = rcu_dereference(ip6tun_encaps[t->encap.type]);
+	if (likely(ops && ops->build_header))
+		ret = ops->build_header(skb, &t->encap, protocol, fl6);
+	rcu_read_unlock();
+
+	return ret;
+}
+
+/* Tunnel encapsulation limit destination sub-option */
+
+struct ipv6_tlv_tnl_enc_lim {
+	__u8 type;		/* type-code for option         */
+	__u8 length;		/* option length                */
+	__u8 encap_limit;	/* tunnel encapsulation limit   */
+} __packed;
+
+int ip6_tnl_rcv_ctl(struct ip6_tnl *t, const struct in6_addr *laddr,
+		const struct in6_addr *raddr);
+int ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
+		const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
+		bool log_ecn_error);
+int ip6_tnl_xmit_ctl(struct ip6_tnl *t, const struct in6_addr *laddr,
+		     const struct in6_addr *raddr);
+int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
+		 struct flowi6 *fl6, int encap_limit, __u32 *pmtu, __u8 proto);
+__u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw);
+__u32 ip6_tnl_get_cap(struct ip6_tnl *t, const struct in6_addr *laddr,
+			     const struct in6_addr *raddr);
+struct net *ip6_tnl_get_link_net(const struct net_device *dev);
+int ip6_tnl_get_iflink(const struct net_device *dev);
+int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu);
+
+static inline void ip6tunnel_xmit(struct sock *sk, struct sk_buff *skb,
+				  struct net_device *dev, u16 ip6cb_flags)
+{
+	int pkt_len, err;
+
+	if (unlikely(dev_recursion_level() > IP_TUNNEL_RECURSION_LIMIT)) {
+		if (dev) {
+			net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
+					     dev->name);
+			DEV_STATS_INC(dev, tx_errors);
+		}
+		kfree_skb_reason(skb, SKB_DROP_REASON_RECURSION_LIMIT);
+		return;
+	}
+
+	dev_xmit_recursion_inc();
+
+	memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
+	IP6CB(skb)->flags = ip6cb_flags;
+	pkt_len = skb->len - skb_inner_network_offset(skb);
+	err = ip6_local_out(skb_dst_dev_net(skb), sk, skb);
+
+	if (dev) {
+		if (unlikely(net_xmit_eval(err)))
+			pkt_len = -1;
+		iptunnel_xmit_stats(dev, pkt_len);
+	}
+
+	dev_xmit_recursion_dec();
+}
+#endif
+#endif