path: root/main/doas/configuration-directory.patch

From 7de1d454bda06d68a04f4f2e48099398a7711ae9 Mon Sep 17 00:00:00 2001
From: Ariadne Conill <ariadne@dereferenced.org>
Date: Wed, 4 Aug 2021 04:47:04 -0600
Subject: [PATCH 1/8] add --with-confdir feature

This adds support for an /etc/doas.d configuration directory as discussed in #61. It is disabled by default.
---
 README.md |  9 +++++++
 configure |  8 +++++++
 doas.c    | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 parse.y   |  3 ++-
 4 files changed, 91 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index f15610c..f967eca 100644
--- a/README.md
+++ b/README.md
@@ -61,3 +61,12 @@ similar to sudo.
 
 See the comment block in `timestamp.c` for an in-depth description on how
 timestamps are created and checked to be as safe as possible.
+
+### `--with-doas-confdir`
+
+An optional feature can be enabled which will result in `doas` reading configuration
+snippets from `/etc/doas.d`.  These configuration snippets have the same requirements
+as `/etc/doas.conf` (owned by root, not world-writable).
+
+If this feature is enabled, only the `/etc/doas.d` directory is read, and the historical
+`/etc/doas.conf` file is ignored.
\ No newline at end of file
diff --git a/configure b/configure
index 1f92f01..a3078dc 100755
--- a/configure
+++ b/configure
@@ -27,6 +27,7 @@ usage: configure [options]
   --without-shadow       disable shadow support
 
   --with-timestamp       enable timestamp support
+  --with-doas-confdir    enable configuration directory support
 
   --uid-max=NUM          set UID_MAX (default 65535)
   --gid-max=NUM          set GID_MAX (default 65535)
@@ -38,6 +39,7 @@ EOF
 
 # defaults
 WITHOUT_TIMESTAMP=yes
+WITHOUT_CONFDIR=yes
 UID_MAX=65535
 GID_MAX=65535
 
@@ -56,6 +58,8 @@ for x; do
 	--target) TARGET=$var ;;
 	--enable-debug) DEBUG=yes ;;
 	--enable-static) BUILD_STATIC=yes ;;
+	--with-doas-confdir) WITHOUT_CONFDIR= ;;
+	--without-doas-confdir) WITHOUT_CONFDIR=yes ;;
 	--with-pam) WITHOUT_PAM=; WITHOUT_SHADOW=yes ;;
 	--with-shadow) WITHOUT_SHADOW=; WITHOUT_PAM=yes ;;
 	--without-pam) WITHOUT_PAM=yes ;;
@@ -558,4 +562,8 @@ fi
 
 printf '#define DOAS_CONF "%s/doas.conf"\n' "${SYSCONFDIR}" >>$CONFIG_H
 
+if [ -z "$WITHOUT_CONFDIR" ]; then
+	printf '#define DOAS_CONFDIR "%s/doas.d"\n' "${SYSCONFDIR}" >>$CONFIG_H
+fi
+
 printf '\n#endif /* CONFIG_H */\n' >>$CONFIG_H
diff --git a/doas.c b/doas.c
index ac3a42a..58701b7 100644
--- a/doas.c
+++ b/doas.c
@@ -35,6 +35,7 @@
 #include <syslog.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <dirent.h>
 
 #include "openbsd.h"
 #include "doas.h"
@@ -155,6 +156,7 @@ permit(uid_t uid, gid_t *groups, int ngroups, const struct rule **lastr,
 static void
 parseconfig(const char *filename, int checkperms)
 {
+	extern const char *yyfn;
 	extern FILE *yyfp;
 	extern int yyparse(void);
 	struct stat sb;
@@ -164,6 +166,8 @@ parseconfig(const char *filename, int checkperms)
 		err(1, checkperms ? "doas is not enabled, %s" :
 		    "could not open config file %s", filename);
 
+	yyfn = filename;
+
 	if (checkperms) {
 		if (fstat(fileno(yyfp), &sb) != 0)
 			err(1, "fstat(\"%s\")", filename);
@@ -174,11 +178,67 @@ parseconfig(const char *filename, int checkperms)
 	}
 
 	yyparse();
+	yyfn = NULL;
+
 	fclose(yyfp);
 	if (parse_errors)
 		exit(1);
 }
 
+#ifdef DOAS_CONFDIR
+static int
+isconfdir(const char *dirpath)
+{
+	struct stat sb;
+
+	if (lstat(dirpath, &sb) != 0)
+		err(1, "lstat(\"%s\")", dirpath);
+
+	if ((sb.st_mode & (S_IFMT)) == S_IFDIR)
+		return 1;
+
+	errno = ENOTDIR;
+	return 0;
+}
+
+static void
+parseconfdir(const char *dirpath, int checkperms)
+{
+	struct dirent **dirent_table;
+	size_t i, dirent_count;
+	char pathbuf[PATH_MAX];
+
+	if (!isconfdir(dirpath))
+		err(1, checkperms ? "doas is not enabled, %s" :
+		    "could not open config directory %s", dirpath);
+
+	dirent_count = scandir(dirpath, &dirent_table, NULL, alphasort);
+
+	for (i = 0; i < dirent_count; i++)
+	{
+		struct stat sb;
+		size_t pathlen;
+
+		pathlen = snprintf(pathbuf, sizeof pathbuf, "%s/%s", dirpath, dirent_table[i]->d_name);
+		free(dirent_table[i]);
+
+		/* make sure path ends in .conf */
+		if (strcmp(pathbuf + (pathlen - 5), ".conf"))
+			continue;
+
+		if (stat(pathbuf, &sb) != 0)
+			err(1, "stat(\"%s\")", pathbuf);
+
+		if ((sb.st_mode & (S_IFMT)) != S_IFREG)
+			continue;
+
+		parseconfig(pathbuf, checkperms);
+	}
+
+	free(dirent_table);
+}
+#endif
+
 static void __dead
 checkconfig(const char *confpath, int argc, char **argv,
     uid_t uid, gid_t *groups, int ngroups, uid_t target)
@@ -188,7 +248,13 @@ checkconfig(const char *confpath, int argc, char **argv,
 	if (setresuid(uid, uid, uid) != 0)
 		err(1, "setresuid");
 
+#ifdef DOAS_CONFDIR
+	if (isconfdir(confpath))
+		parseconfdir(confpath, 0);
+	else
+#else
 	parseconfig(confpath, 0);
+#endif
 	if (!argc)
 		exit(0);
 
@@ -330,7 +396,13 @@ main(int argc, char **argv)
 	if (geteuid())
 		errx(1, "not installed setuid");
 
+#ifdef DOAS_CONFDIR
+	if (isconfdir(DOAS_CONFDIR))
+		parseconfdir(DOAS_CONFDIR, 1);
+	else
+#else
 	parseconfig(DOAS_CONF, 1);
+#endif
 
 	/* cmdline is used only for logging, no need to abort on truncate */
 	(void)strlcpy(cmdline, argv[0], sizeof(cmdline));
diff --git a/parse.y b/parse.y
index 388c2a5..c6d7ebf 100644
--- a/parse.y
+++ b/parse.y
@@ -49,6 +49,7 @@ typedef struct {
 } yystype;
 #define YYSTYPE yystype
 
+const char *yyfn;
 FILE *yyfp;
 
 struct rule **rules;
@@ -203,7 +204,7 @@ yyerror(const char *fmt, ...)
 	va_start(va, fmt);
 	vfprintf(stderr, fmt, va);
 	va_end(va);
-	fprintf(stderr, " at line %d\n", yylval.lineno + 1);
+	fprintf(stderr, " at %s, line %d\n", yyfn, yylval.lineno + 1);
 	parse_errors++;
 }
 

From 046ff34408ea8bf2cafc079bd71a126aa009b005 Mon Sep 17 00:00:00 2001
From: Ariadne Conill <ariadne@dereferenced.org>
Date: Wed, 4 Aug 2021 09:20:35 -0600
Subject: [PATCH 2/8] gracefully handle ENOENT in isconfdir()

---
 doas.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/doas.c b/doas.c
index 58701b7..4c0cafe 100644
--- a/doas.c
+++ b/doas.c
@@ -191,8 +191,13 @@ isconfdir(const char *dirpath)
 {
 	struct stat sb;
 
-	if (lstat(dirpath, &sb) != 0)
-		err(1, "lstat(\"%s\")", dirpath);
+	if (lstat(dirpath, &sb) != 0) {
+		if (errno != ENOENT)
+			err(1, "lstat(\"%s\")", dirpath);
+
+		errno = ENOTDIR;
+		return 0;
+	}
 
 	if ((sb.st_mode & (S_IFMT)) == S_IFDIR)
 		return 1;

From 6e76fb04ac637a1001ba201559f28279e3abe738 Mon Sep 17 00:00:00 2001
From: Ariadne Conill <ariadne@dereferenced.org>
Date: Wed, 4 Aug 2021 09:31:49 -0600
Subject: [PATCH 3/8] ensure pathlen - 5 is always non-zero

---
 doas.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/doas.c b/doas.c
index 4c0cafe..f827fcd 100644
--- a/doas.c
+++ b/doas.c
@@ -228,6 +228,9 @@ parseconfdir(const char *dirpath, int checkperms)
 		free(dirent_table[i]);
 
 		/* make sure path ends in .conf */
+		if (pathlen < 6)
+			continue;
+
 		if (strcmp(pathbuf + (pathlen - 5), ".conf"))
 			continue;
 

From cac56ea61e16d0ccb91100164a61e9f7215604e5 Mon Sep 17 00:00:00 2001
From: Ariadne Conill <ariadne@dereferenced.org>
Date: Wed, 4 Aug 2021 10:17:35 -0600
Subject: [PATCH 4/8] bail if dirent_count < 0

---
 doas.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/doas.c b/doas.c
index f827fcd..6e308c8 100644
--- a/doas.c
+++ b/doas.c
@@ -210,7 +210,7 @@ static void
 parseconfdir(const char *dirpath, int checkperms)
 {
 	struct dirent **dirent_table;
-	size_t i, dirent_count;
+	int i, dirent_count;
 	char pathbuf[PATH_MAX];
 
 	if (!isconfdir(dirpath))
@@ -218,6 +218,9 @@ parseconfdir(const char *dirpath, int checkperms)
 		    "could not open config directory %s", dirpath);
 
 	dirent_count = scandir(dirpath, &dirent_table, NULL, alphasort);
+	if (dirent_count < 0)
+		err(1, checkperms ? "doas is not enabled, %s" :
+		    "could not open config directory %s", dirpath);
 
 	for (i = 0; i < dirent_count; i++)
 	{

From 8d224060adbdb1dececeb02660df8693f7c54a40 Mon Sep 17 00:00:00 2001
From: Ariadne Conill <ariadne@dereferenced.org>
Date: Wed, 4 Aug 2021 10:20:33 -0600
Subject: [PATCH 5/8] error out if no matching configuration files are found in
 the configuration directory

---
 doas.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/doas.c b/doas.c
index 6e308c8..cdfa3ea 100644
--- a/doas.c
+++ b/doas.c
@@ -210,7 +210,7 @@ static void
 parseconfdir(const char *dirpath, int checkperms)
 {
 	struct dirent **dirent_table;
-	int i, dirent_count;
+	int i, m, dirent_count;
 	char pathbuf[PATH_MAX];
 
 	if (!isconfdir(dirpath))
@@ -222,7 +222,7 @@ parseconfdir(const char *dirpath, int checkperms)
 		err(1, checkperms ? "doas is not enabled, %s" :
 		    "could not open config directory %s", dirpath);
 
-	for (i = 0; i < dirent_count; i++)
+	for (i = 0, m = 0; i < dirent_count; i++)
 	{
 		struct stat sb;
 		size_t pathlen;
@@ -244,9 +244,16 @@ parseconfdir(const char *dirpath, int checkperms)
 			continue;
 
 		parseconfig(pathbuf, checkperms);
+		m++;
 	}
 
 	free(dirent_table);
+
+	if (!m) {
+		fprintf(stderr, "doas is not enabled, %s: no matching configuration files found\n",
+			dirpath);
+		exit(1);
+	}
 }
 #endif
 

From 35c3e69fa52157683b8ae6fe040367390aa63bb6 Mon Sep 17 00:00:00 2001
From: Ariadne Conill <ariadne@dereferenced.org>
Date: Wed, 4 Aug 2021 10:34:28 -0600
Subject: [PATCH 6/8] use errx instead of fprintf(stderr)

---
 doas.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/doas.c b/doas.c
index cdfa3ea..b50138a 100644
--- a/doas.c
+++ b/doas.c
@@ -249,11 +249,8 @@ parseconfdir(const char *dirpath, int checkperms)
 
 	free(dirent_table);
 
-	if (!m) {
-		fprintf(stderr, "doas is not enabled, %s: no matching configuration files found\n",
-			dirpath);
-		exit(1);
-	}
+	if (!m)
+		errx(1, "doas is not enabled, %s: no matching configuration files found\n", dirpath);
 }
 #endif
 

From c9ff0fcdc0253679a0348995c36f89edc8d73a5b Mon Sep 17 00:00:00 2001
From: Ariadne Conill <ariadne@dereferenced.org>
Date: Wed, 4 Aug 2021 16:50:58 -0600
Subject: [PATCH 7/8] fix up the ifndef DOAS_CONFDIR branch

---
 doas.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/doas.c b/doas.c
index b50138a..d77186b 100644
--- a/doas.c
+++ b/doas.c
@@ -267,9 +267,8 @@ checkconfig(const char *confpath, int argc, char **argv,
 	if (isconfdir(confpath))
 		parseconfdir(confpath, 0);
 	else
-#else
-	parseconfig(confpath, 0);
 #endif
+	parseconfig(confpath, 0);
 	if (!argc)
 		exit(0);
 
@@ -415,9 +414,8 @@ main(int argc, char **argv)
 	if (isconfdir(DOAS_CONFDIR))
 		parseconfdir(DOAS_CONFDIR, 1);
 	else
-#else
-	parseconfig(DOAS_CONF, 1);
 #endif
+	parseconfig(DOAS_CONF, 1);
 
 	/* cmdline is used only for logging, no need to abort on truncate */
 	(void)strlcpy(cmdline, argv[0], sizeof(cmdline));

From 9fe4df5f004435fa0b092dc15a3c5ab09090f45d Mon Sep 17 00:00:00 2001
From: Ariadne Conill <ariadne@dereferenced.org>
Date: Fri, 3 Sep 2021 11:59:12 -0600
Subject: [PATCH 8/8] add manpage for doas.d(5)

---
 GNUmakefile |  1 +
 doas.conf.5 |  1 +
 doas.d.5    | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 52 insertions(+)
 create mode 100644 doas.d.5

diff --git a/GNUmakefile b/GNUmakefile
index 2eef88e..423731c 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -24,6 +24,7 @@ install: ${PROG} ${MAN}
 	chmod ${BINMODE} ${DESTDIR}${BINDIR}/${PROG}
 	cp -f doas.1 ${DESTDIR}${MANDIR}/man1
 	cp -f doas.conf.5 ${DESTDIR}${MANDIR}/man5
+	cp -f doas.d.5 ${DESTDIR}${MANDIR}/man5
 
 uninstall:
 	rm -f ${DESTDIR}${BINDIR}/${PROG}
diff --git a/doas.conf.5 b/doas.conf.5
index e98bfbe..e90d512 100644
--- a/doas.conf.5
+++ b/doas.conf.5
@@ -143,6 +143,7 @@ permit nopass keepenv setenv { PATH } root as root
 .Ed
 .Sh SEE ALSO
 .Xr doas 1 ,
+.Xr doas.d 5 ,
 .Xr syslogd 8
 .Sh HISTORY
 The
diff --git a/doas.d.5 b/doas.d.5
new file mode 100644
index 0000000..8f5f96a
--- /dev/null
+++ b/doas.d.5
@@ -0,0 +1,50 @@
+.\"Copyright (c) 2021 Ariadne Conill <ariadne@dereferenced.org>
+.\"
+.\"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.
+.Dd $Mdocdate: October 9 2020 $
+.Dt DOAS.CONF 5
+.Os
+.Sh NAME
+.Nm doas.conf
+.Nd doas configuration file
+.Sh DESCRIPTION
+The
+.Xr doas 1
+utility executes commands as other users according to the rules
+configured in either the configuration file or, optionally, the
+configuration directory.  The preference to use the configuration
+file or configuration directory is determined at compile time,
+.Xr doas 1
+will only consult one or the other.
+.Pp
+Configuration snippets stored in the configuration directory
+follow the same rules as the classic
+.Xr doas 1
+configuration file, documented in
+.Xr doas.conf 5 .
+They must end with the .conf extension, or they will be ignored.
+.Pp
+These snippets are read in alphabetical order and thus can be
+ordered in the same way as other configuration directories.
+.Sh FILES
+.Bl -tag -width /etc/doas.d -compact
+.It Pa /etc/doas.d
+.Xr doas 1
+configuration directory.
+.Sh SEE ALSO
+.Xr doas 1 ,
+.Xr doas.conf 5
+.Sh HISTORY
+The
+.Nm
+configuration directory first appeared in OpenDoas.