nfc: constify several pointers to u8, char and sk_buff

Several functions receive pointers to u8, char or sk_buff but do not
modify the contents so make them const.  This allows doing the same for
local variables and in total makes the code a little bit safer.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 25 insertions, 21 deletions

diff --git a/net/nfc/llcp_commands.c b/net/nfc/llcp_commands.c
index 475061c79c44..3c4172a5aeb5 100644
--- a/net/nfc/llcp_commands.c
+++ b/net/nfc/llcp_commands.c
@@ -15,7 +15,7 @@
 #include "nfc.h"
 #include "llcp.h"
 
-static u8 llcp_tlv_length[LLCP_TLV_MAX] = {
+static const u8 llcp_tlv_length[LLCP_TLV_MAX] = {
 	0,
 	1, /* VERSION */
 	2, /* MIUX */
@@ -29,7 +29,7 @@ static u8 llcp_tlv_length[LLCP_TLV_MAX] = {
 
 };
 
-static u8 llcp_tlv8(u8 *tlv, u8 type)
+static u8 llcp_tlv8(const u8 *tlv, u8 type)
 {
 	if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
 		return 0;
@@ -37,7 +37,7 @@ static u8 llcp_tlv8(u8 *tlv, u8 type)
 	return tlv[2];
 }
 
-static u16 llcp_tlv16(u8 *tlv, u8 type)
+static u16 llcp_tlv16(const u8 *tlv, u8 type)
 {
 	if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
 		return 0;
@@ -46,37 +46,37 @@ static u16 llcp_tlv16(u8 *tlv, u8 type)
 }
 
 
-static u8 llcp_tlv_version(u8 *tlv)
+static u8 llcp_tlv_version(const u8 *tlv)
 {
 	return llcp_tlv8(tlv, LLCP_TLV_VERSION);
 }
 
-static u16 llcp_tlv_miux(u8 *tlv)
+static u16 llcp_tlv_miux(const u8 *tlv)
 {
 	return llcp_tlv16(tlv, LLCP_TLV_MIUX) & 0x7ff;
 }
 
-static u16 llcp_tlv_wks(u8 *tlv)
+static u16 llcp_tlv_wks(const u8 *tlv)
 {
 	return llcp_tlv16(tlv, LLCP_TLV_WKS);
 }
 
-static u16 llcp_tlv_lto(u8 *tlv)
+static u16 llcp_tlv_lto(const u8 *tlv)
 {
 	return llcp_tlv8(tlv, LLCP_TLV_LTO);
 }
 
-static u8 llcp_tlv_opt(u8 *tlv)
+static u8 llcp_tlv_opt(const u8 *tlv)
 {
 	return llcp_tlv8(tlv, LLCP_TLV_OPT);
 }
 
-static u8 llcp_tlv_rw(u8 *tlv)
+static u8 llcp_tlv_rw(const u8 *tlv)
 {
 	return llcp_tlv8(tlv, LLCP_TLV_RW) & 0xf;
 }
 
-u8 *nfc_llcp_build_tlv(u8 type, u8 *value, u8 value_length, u8 *tlv_length)
+u8 *nfc_llcp_build_tlv(u8 type, const u8 *value, u8 value_length, u8 *tlv_length)
 {
 	u8 *tlv, length;
 
@@ -130,7 +130,7 @@ struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdres_tlv(u8 tid, u8 sap)
 	return sdres;
 }
 
-struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdreq_tlv(u8 tid, char *uri,
+struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdreq_tlv(u8 tid, const char *uri,
 						  size_t uri_len)
 {
 	struct nfc_llcp_sdp_tlv *sdreq;
@@ -190,9 +190,10 @@ void nfc_llcp_free_sdp_tlv_list(struct hlist_head *head)
 }
 
 int nfc_llcp_parse_gb_tlv(struct nfc_llcp_local *local,
-			  u8 *tlv_array, u16 tlv_array_len)
+			  const u8 *tlv_array, u16 tlv_array_len)
 {
-	u8 *tlv = tlv_array, type, length, offset = 0;
+	const u8 *tlv = tlv_array;
+	u8 type, length, offset = 0;
 
 	pr_debug("TLV array length %d\n", tlv_array_len);
 
@@ -239,9 +240,10 @@ int nfc_llcp_parse_gb_tlv(struct nfc_llcp_local *local,
 }
 
 int nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock *sock,
-				  u8 *tlv_array, u16 tlv_array_len)
+				  const u8 *tlv_array, u16 tlv_array_len)
 {
-	u8 *tlv = tlv_array, type, length, offset = 0;
+	const u8 *tlv = tlv_array;
+	u8 type, length, offset = 0;
 
 	pr_debug("TLV array length %d\n", tlv_array_len);
 
@@ -295,7 +297,7 @@ static struct sk_buff *llcp_add_header(struct sk_buff *pdu,
 	return pdu;
 }
 
-static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, u8 *tlv,
+static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, const u8 *tlv,
 				    u8 tlv_length)
 {
 	/* XXX Add an skb length check */
@@ -389,9 +391,10 @@ int nfc_llcp_send_connect(struct nfc_llcp_sock *sock)
 {
 	struct nfc_llcp_local *local;
 	struct sk_buff *skb;
-	u8 *service_name_tlv = NULL, service_name_tlv_length;
-	u8 *miux_tlv = NULL, miux_tlv_length;
-	u8 *rw_tlv = NULL, rw_tlv_length, rw;
+	const u8 *service_name_tlv = NULL;
+	const u8 *miux_tlv = NULL;
+	const u8 *rw_tlv = NULL;
+	u8 service_name_tlv_length, miux_tlv_length,  rw_tlv_length, rw;
 	int err;
 	u16 size = 0;
 	__be16 miux;
@@ -465,8 +468,9 @@ int nfc_llcp_send_cc(struct nfc_llcp_sock *sock)
 {
 	struct nfc_llcp_local *local;
 	struct sk_buff *skb;
-	u8 *miux_tlv = NULL, miux_tlv_length;
-	u8 *rw_tlv = NULL, rw_tlv_length, rw;
+	const u8 *miux_tlv = NULL;
+	const u8 *rw_tlv = NULL;
+	u8 miux_tlv_length, rw_tlv_length, rw;
 	int err;
 	u16 size = 0;
 	__be16 miux;