Commit e5cf5107 authored by Lee Trager's avatar Lee Trager Committed by Jakub Kicinski
Browse files

eth: fbnic: Update fbnic_tlv_attr_get_string() to work like nla_strscpy() 



Allow fbnic_tlv_attr_get_string() to return an error code. In the event the
source mailbox attribute is missing return -EINVAL. Like nla_strscpy() return
-E2BIG when the source string is larger than the destination string. In this
case the amount of data copied is equal to dstsize.

Signed-off-by: default avatarLee Trager <lee@trager.us>
Link: https://patch.msgid.link/20250228191935.3953712-3-lee@trager.us


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 56bcc6ec

drivers/net/ethernet/meta/fbnic/fbnic_tlv.c

+30 −9
Original line number Diff line number Diff line
@@ -233,19 +233,40 @@ s64 fbnic_tlv_attr_get_signed(struct fbnic_tlv_msg *attr) 
/**

 * fbnic_tlv_attr_get_string - Retrieve string value from result

 * @attr: Attribute to retrieve data from

 * @str: Pointer to an allocated string to store the data

 * @max_size: The maximum size which can be in str

 * @dst: Pointer to an allocated string to store the data

 * @dstsize: The maximum size which can be in dst

 *

 * Return: the size of the string read from firmware

 * Return: the size of the string read from firmware or negative error.

 **/

size_t fbnic_tlv_attr_get_string(struct fbnic_tlv_msg *attr, char *str,

				 size_t max_size)

ssize_t fbnic_tlv_attr_get_string(struct fbnic_tlv_msg *attr, char *dst,

				  size_t dstsize)

{

	max_size = min_t(size_t, max_size,

			 (le16_to_cpu(attr->hdr.len) * 4) - sizeof(*attr));

	memcpy(str, &attr->value, max_size);

	size_t srclen, len;

	ssize_t ret;



	return max_size;

	if (!attr)

		return -EINVAL;



	if (dstsize == 0)

		return -E2BIG;



	srclen = le16_to_cpu(attr->hdr.len) - sizeof(*attr);

	if (srclen > 0 && attr->value[srclen - 1] == '\0')

		srclen--;



	if (srclen >= dstsize) {

		len = dstsize - 1;

		ret = -E2BIG;

	} else {

		len = srclen;

		ret = len;

	}



	memcpy(dst, &attr->value, len);

	/* Zero pad end of dst. */

	memset(dst + len, 0, dstsize - len);



	return ret;

}



/**

drivers/net/ethernet/meta/fbnic/fbnic_tlv.h

+2 −2
Original line number Diff line number Diff line
@@ -116,8 +116,8 @@ static inline bool fbnic_tlv_attr_get_bool(struct fbnic_tlv_msg *attr) 


u64 fbnic_tlv_attr_get_unsigned(struct fbnic_tlv_msg *attr);

s64 fbnic_tlv_attr_get_signed(struct fbnic_tlv_msg *attr);

size_t fbnic_tlv_attr_get_string(struct fbnic_tlv_msg *attr, char *str,

				 size_t max_size);

ssize_t fbnic_tlv_attr_get_string(struct fbnic_tlv_msg *attr, char *dst,

				  size_t dstsize);



#define get_unsigned_result(id, location) \

do { \