From e9fa36007348c6d0622f3a5d3b52ca2468c843b4 Mon Sep 17 00:00:00 2001 From: Enji Cooper Date: Fri, 5 Jun 2026 18:29:35 -0700 Subject: [PATCH 1/2] Import strlcat(3) implementation from DragonFlyBSD This will be leveraged in the next commit, resolving complaints from compilers about the pathological case where strncat(3) is used in net.c . Obtained from: (DragonFlyBSD.org: lib/libc/string/strlcpy.c @ 667231f1) Signed-off-by: Enji Cooper --- bsd/dma/Makefile | 2 +- dfcompat.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 57 insertions(+), 1 deletion(-) diff --git a/bsd/dma/Makefile b/bsd/dma/Makefile index d49d3a0..5015374 100644 --- a/bsd/dma/Makefile +++ b/bsd/dma/Makefile @@ -6,7 +6,7 @@ DMA_SRCTOP= ${.CURDIR:H:H} .include "../version.mk" CFLAGS+= -I${.CURDIR}/../.. -CFLAGS+= -DHAVE_REALLOCF -DHAVE_STRLCPY -DHAVE_GETPROGNAME +CFLAGS+= -DHAVE_GETPROGNAME -DHAVE_REALLOCF -DHAVE_STRLCAT -DHAVE_STRLCPY CFLAGS+= -DLIBEXEC_PATH='"${LIBEXEC}"' -DDMA_VERSION='"${version}"' CFLAGS+= -DCONF_PATH='"${CONFDIR}"' diff --git a/dfcompat.c b/dfcompat.c index b9e87cc..1ba2307 100644 --- a/dfcompat.c +++ b/dfcompat.c @@ -1,3 +1,59 @@ +#ifndef HAVE_STRLCAT +/* $OpenBSD: strlcpy.c,v 1.11 2006/05/05 15:27:38 millert Exp $ */ + +/* + * Copyright (c) 1998 Todd C. Miller + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + * + * $FreeBSD: head/lib/libc/string/strlcpy.c 189133 2009-02-28 05:15:02Z das $ + */ + +#include +#include + +/* + * Copy src to string dst of size siz. At most siz-1 characters + * will be copied. Always NUL terminates (unless siz == 0). + * Returns strlen(src); if retval >= siz, truncation occurred. + */ +size_t +strlcpy(char * __restrict dst, const char * __restrict src, size_t siz) +{ + char *d = dst; + const char *s = src; + size_t n = siz; + + /* Copy as many bytes as will fit */ + if (n != 0) { + while (--n != 0) { + if ((*d++ = *s++) == '\0') + break; + } + } + + /* Not enough room in dst, add NUL and traverse rest of src */ + if (n == 0) { + if (siz != 0) + *d = '\0'; /* NUL-terminate dst */ + while (*s++) + ; + } + + return(s - src - 1); /* count does not include NUL */ +} +#endif + #ifndef HAVE_STRLCPY /* * SPDX-License-Identifier: BSD-2-Clause AND ISC From 52837663314dcfd4a101b2bba181648a0b4c46fd Mon Sep 17 00:00:00 2001 From: Enji Cooper Date: Fri, 5 Jun 2026 18:32:53 -0700 Subject: [PATCH 2/2] net.c: switch strncat(3) use to strlcat(3) strlcat(3), unlike its predecessor (strncat(3)), NUL terminates buffers when the buffer length meets or exceeds the provided `dstsize`. Leveraging strlcat(3) instead of strncat(3) squashes compiler warnings, and ensures the buffer is properly NUL terminated in the pathological case. Signed-off-by: Enji Cooper --- net.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net.c b/net.c index e8a0192..cee6961 100644 --- a/net.c +++ b/net.c @@ -180,7 +180,7 @@ read_remote(int fd, int extbufsize, char *extbuf) copysize = sizeof(neterr) - strlen(neterr) - 1; if (copysize > len) copysize = len; - strncat(neterr, buff, copysize); + strlcat(neterr, buff, copysize); } /* * If there is an external buffer with a size bigger than zero