From 848189f10a98768b372186de8b9fe013ad49d4e5 Mon Sep 17 00:00:00 2001
From: Omar Polo <op@omarpolo.com>
Date: Thu, 6 Jun 2024 13:43:12 +0000
Subject: [PATCH] attempt to deal with the portability fiasco of strnvis(3)

---
 configure             |  9 +++++++++
 ge.c                  |  2 +-
 gmid.c                |  2 +-
 gmid.h                |  1 +
 have/broken-strnvis.c | 15 +++++++++++++++
 utils.c               | 17 +++++++++++++++++
 6 files changed, 44 insertions(+), 2 deletions(-)
 create mode 100644 have/broken-strnvis.c

diff --git a/configure b/configure
index d44a5f6..f58b605 100755
--- a/configure
+++ b/configure
@@ -275,6 +275,7 @@ fi
 HAVE_ENDIAN_H=0
 HAVE_SYS_ENDIAN_H=0
 HAVE_MACHINE_ENDIAN=0
+HAVE_BROKEN_STRNVIS=0
 
 runtest endian_h	ENDIAN_H	|| \
 runtest sys_endian_h	SYS_ENDIAN_H	|| \
@@ -317,6 +318,12 @@ runtest tree_h		TREE_H		|| true
 runtest vasprintf	VASPRINTF	-D_GNU_SOURCE || true
 runtest vis		VIS		-DLIBBSD_OPENBSD_VIS	|| true
 
+if [ ${HAVE_VIS} -eq 1 ]; then
+	if singletest broken-strnvis BROKEN_STRNVIS "-Wall -Werror"; then
+		HAVE_BROKEN_STRNVIS=1
+	fi
+fi
+
 if [ ${HAVE_ARC4RANDOM} -eq 1 -a ${HAVE_ARC4RANDOM_BUF} -eq 0 ]; then
 	COMPATS="compat/arc4random.c ${COMPATS}"
 fi
@@ -648,6 +655,8 @@ cat <<__HEREDOC__
 #  define HOST_NAME_MAX 255
 # endif
 #endif
+
+#define HAVE_BROKEN_STRNVIS ${HAVE_BROKEN_STRNVIS}
 __HEREDOC__
 
 echo "file config.h: written" 1>&2
diff --git a/ge.c b/ge.c
index 2bd3991..0296dba 100644
--- a/ge.c
+++ b/ge.c
@@ -83,7 +83,7 @@ log_request(struct client *c, int code, const char *meta)
 			strlcpy(cntmp, subj + 4, sizeof(cntmp));
 			if ((n = strchr(cntmp, '/')) != NULL)
 				*n = '\0';
-			strnvis(cn, cntmp, sizeof(cn), VIS_WHITE|VIS_DQ);
+			gmid_strnvis(cn, cntmp, sizeof(cn), VIS_WHITE|VIS_DQ);
 		}
 	}
 
diff --git a/gmid.c b/gmid.c
index 408b184..f050193 100644
--- a/gmid.c
+++ b/gmid.c
@@ -140,7 +140,7 @@ log_request(struct client *c, int code, const char *meta)
 			strlcpy(cntmp, subj + 4, sizeof(cntmp));
 			if ((n = strchr(cntmp, '/')) != NULL)
 				*n = '\0';
-			strnvis(cn, cntmp, sizeof(cn), VIS_WHITE|VIS_DQ);
+			gmid_strnvis(cn, cntmp, sizeof(cn), VIS_WHITE|VIS_DQ);
 		}
 	}
 
diff --git a/gmid.h b/gmid.h
index 21d793c..4546e3a 100644
--- a/gmid.h
+++ b/gmid.h
@@ -469,5 +469,6 @@ EVP_PKEY	*ssl_load_pkey(const uint8_t *, size_t);
 struct vhost	*new_vhost(void);
 struct location	*new_location(void);
 struct proxy	*new_proxy(void);
+int		 gmid_strnvis(char *, const char *, size_t, int);
 
 #endif
diff --git a/have/broken-strnvis.c b/have/broken-strnvis.c
new file mode 100644
index 0000000..f2a9a59
--- /dev/null
+++ b/have/broken-strnvis.c
@@ -0,0 +1,15 @@
+/*
+ * public domain
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <vis.h>
+
+int
+main(void)
+{
+	char buf[128];
+
+	return strnvis(buf, sizeof(buf), "Hello, world!\n", 0);
+}
diff --git a/utils.c b/utils.c
index 7ceea2e..bbb6b11 100644
--- a/utils.c
+++ b/utils.c
@@ -22,6 +22,7 @@
 
 #include <errno.h>
 #include <string.h>
+#include <vis.h>	/* for gmid_strnvis() */
 
 #include <openssl/ec.h>
 #include <openssl/err.h>
@@ -496,3 +497,19 @@ new_proxy(void)
 	p->protocols = TLS_PROTOCOLS_DEFAULT;
 	return p;
 }
+
+/*
+ * I can't rant enough about this situation.  As far as I've understood,
+ * OpenBSD introduced strnvis(3) with a signature, then NetBSD did it but
+ * with a incompatible signature.  FreeBSD followed NetBSD.  libbsd followed
+ * OpenBSD but now is thinking to switch.  WTF?
+ */
+int
+gmid_strnvis(char *dst, const char *src, size_t destsize, int flag)
+{
+#if HAVE_BROKEN_STRNVIS
+	return strnvis(dst, destsize, src, flag);
+#else
+	return strnvis(dst, src, destsize, flag);
+#endif
+}