git: c4c522788720 - stable/13 - LinuxKPI: string.h implement memcpy_and_pad()

From: Bjoern A. Zeeb <bz_at_FreeBSD.org>
Date: Mon, 28 Nov 2022 17:27:02 UTC
The branch stable/13 has been updated by bz:

URL: https://cgit.FreeBSD.org/src/commit/?id=c4c5227887205f4a0d17b8f560f856ea79eb18ab

commit c4c5227887205f4a0d17b8f560f856ea79eb18ab
Author:     Bjoern A. Zeeb <bz@FreeBSD.org>
AuthorDate: 2022-10-31 22:17:00 +0000
Commit:     Bjoern A. Zeeb <bz@FreeBSD.org>
CommitDate: 2022-11-28 16:30:57 +0000

    LinuxKPI: string.h implement memcpy_and_pad()
    
    Add a memcpy variant which takes length of source and destination
    buffers and a padding character in case there is free space in the
    destination.  This is used by a wireless driver.
    
    Reviewed by:    emaste
    Differential Revision: https://reviews.freebsd.org/D37226
    
    (cherry picked from commit 6a647ae51409cd56cc4a78d0a64ba3ff3aa3aac0)
---
 sys/compat/linuxkpi/common/include/linux/string.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/sys/compat/linuxkpi/common/include/linux/string.h b/sys/compat/linuxkpi/common/include/linux/string.h
index 7a118bb17c48..c721ea6bab9d 100644
--- a/sys/compat/linuxkpi/common/include/linux/string.h
+++ b/sys/compat/linuxkpi/common/include/linux/string.h
@@ -227,4 +227,17 @@ memset_p(void **p, void *v, size_t n)
 		return (memset64((uint64_t *)p, (uintptr_t)v, n));
 }
 
+static inline void
+memcpy_and_pad(void *dst, size_t dstlen, const void *src, size_t len, int ch)
+{
+
+	if (len >= dstlen) {
+		memcpy(dst, src, dstlen);
+	} else {
+		memcpy(dst, src, len);
+		/* Pad with given padding character. */
+		memset((char *)dst + len, ch, dstlen - len);
+	}
+}
+
 #endif	/* _LINUXKPI_LINUX_STRING_H_ */