Release libbsd 0.6.0

Try to give a helpful message in case the program is not initializing
the setproctitle() machinery.

.gitignore

@@ -5,6 +5,8 @@ ChangeLog
 *.o
 *.so*
 *.a
+*.log
+*.trs
 .deps/
 .libs/
 Makefile

COPYING

@@ -66,7 +66,7 @@ for man/arc4random.3, man/tree.3 and man/getprogname.3.
 The rest of the licenses apply to code and/or man pages.
 
 
-    Copyright © 2004-2006, 2008-2012 Guillem Jover <guillem@hadrons.org>
+    Copyright © 2004-2006, 2008-2013 Guillem Jover <guillem@hadrons.org>
     Copyright © 2005 Hector Garcia Alvarez
     Copyright © 2005 Aurelien Jarno
     Copyright © 2006 Robert Millan

configure.ac

@@ -11,6 +11,13 @@ AM_INIT_AUTOMAKE([1.8 foreign nostdinc no-dist-gzip dist-xz])
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])],
                             [AC_SUBST([AM_DEFAULT_VERBOSITY], [1])])
 
+LIBBSD_ABI_MAJOR=0
+LIBBSD_ABI_MINOR=6
+LIBBSD_ABI_PATCH=0
+
+LIBBSD_ABI="$LIBBSD_ABI_MAJOR:$LIBBSD_ABI_MINOR:$LIBBSD_ABI_PATCH"
+AC_SUBST([LIBBSD_ABI])
+
 # Check and store if we got user supplied variables
 user_CFLAGS=${CFLAGS-unset}
 
@@ -53,6 +60,51 @@ AC_CHECK_DECL([F_CLOSEM],
               [#include <limits.h>
                #include <fcntl.h>])
 
+AC_CACHE_CHECK(
+	[for GNU .init_array section support],
+	[libbsd_cv_gnu_init_array_support],
+	[AC_RUN_IFELSE(
+		[AC_LANG_SOURCE(
+[[
+static int rc = 1;
+static void init(int argc) { if (argc == 1) rc = 0; }
+void (*init_func)(int argc) __attribute__((section(".init_array"))) = init;
+int main() { return rc; }
+]]
+		)],
+		[libbsd_cv_gnu_init_array_support=yes],
+		[libbsd_cv_gnu_init_array_support=no],
+		[AC_PREPROC_IFELSE(
+			[AC_LANG_SOURCE(
+[[
+/* Look for a known libc that supports .init_array with the GNU extension
+ * to pass main() arguments to the init functions. */
+#include <stdlib.h>
+#if defined __GLIBC_PREREQ
+#  if __GLIBC_PREREQ(2, 4)
+/* glibc supports GNU .init_array since 2.4. */
+#  else
+#    error glibc does not support GNU .init_array
+#  endif
+#else
+/*
+ * Basic SysV ABI .init_array support, init functions do not get arguments:
+ * - Bionic since its inception.
+ * - uClibc since 0.9.29.
+ */
+#  error unknown whether libc supports GNU .init_array
+#endif
+]]
+			)],
+			[libbsd_cv_gnu_init_array_support=yes],
+			[libbsd_cv_gnu_init_array_support=no])
+		]
+	)]
+)
+if test "$libbsd_cv_gnu_init_array_support" = no; then
+	AC_MSG_ERROR([missing required GNU .init_array section support])
+fi
+
 # Checks for library functions.
 AC_MSG_CHECKING([for program_invocation_short_name])
 AC_LINK_IFELSE(
@@ -80,6 +132,7 @@ AC_CONFIG_FILES([
 	man/Makefile
 	src/Makefile
 	src/libbsd.pc
+	src/libbsd-ctor.pc
 	src/libbsd-overlay.pc
 	test/Makefile
 ])

include/bsd/unistd.h

@@ -56,6 +56,10 @@ void *setmode(const char *mode_str);
 
 void closefrom(int lowfd);
 
+/* Compatibility with sendmail implementations. */
+#define initsetproctitle(c, a, e) setproctitle_init((c), (a), (e))
+
+void setproctitle_init(int argc, char *argv[], char *envp[]);
 void setproctitle(const char *fmt, ...);
 
 int getpeereid(int s, uid_t *euid, gid_t *egid);

man/setproctitle.3

@@ -33,6 +33,8 @@
 .In sys/types.h
 .In bsd/unistd.h
 .Ft void
+.Fn setproctitle_init "int argc" "char *argv[]" "char *envp[]"
+.Ft void
 .Fn setproctitle "const char *fmt" "..."
 .Sh DESCRIPTION
 The
@@ -41,6 +43,15 @@ library routine sets the process title that appears on the
 .Xr ps 1
 command.
 .Pp
+The
+.Fn setproctitle_init
+library routine only needs to be called (before any call to
+.Fn setproctitle
+and with
+.Fn main
+arguments), if the automatic constructor support has not
+been linked in through the libbsd-ctor pkg-config file.
+.Pp
 The title is set from the executable's name, followed by the
 result of a
 .Xr printf 3
@@ -101,6 +112,11 @@ first appeared in
 .Fx 2.2 .
 Other operating systems have
 similar functions.
+.Pp
+The
+.Fn setproctitle_init
+function is a libbsd extension not present on the BSDs, avoid using it
+in portable code.
 .Sh AUTHORS
 .An -nosplit
 .An Peter Wemm Aq peter@FreeBSD.org

src/Makefile.am

@@ -10,6 +10,7 @@ AM_CPPFLAGS = \
 EXTRA_DIST = \
 	libbsd.map \
 	libbsd.pc.in \
+	libbsd-ctor.pc.in \
 	libbsd-overlay.pc.in \
 	hash/helper.c \
 	$(nil)
@@ -21,10 +22,12 @@ CLEANFILES = \
 pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = \
 	libbsd.pc \
+	libbsd-ctor.pc \
 	libbsd-overlay.pc \
 	$(nil)
 
 lib_LTLIBRARIES = libbsd.la
+lib_LIBRARIES = libbsd-ctor.a
 
 hash/md5hl.c: $(srcdir)/hash/helper.c
 	$(AM_V_at) $(MKDIR_P) hash
@@ -34,7 +37,7 @@ libbsd_la_DEPENDENCIES = \
 	libbsd.map
 libbsd_la_LDFLAGS = \
 	-Wl,--version-script=$(srcdir)/libbsd.map \
-	-version-number 0:5:0
+	-version-number $(LIBBSD_ABI)
 libbsd_la_SOURCES = \
 	arc4random.c \
 	bsd_getopt.c \
@@ -75,6 +78,10 @@ libbsd_la_SOURCES = \
 	wcslcpy.c \
 	$(nil)
 
+libbsd_ctor_a_SOURCES = \
+	setproctitle_ctor.c \
+	$(nil)
+
 runtimelibdir = $(libdir)
 
 install-exec-hook:

src/libbsd-ctor.pc.in

@@ -0,0 +1,12 @@
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: libbsd-ctor
+Description: Automatic constructor functions for libbsd
+Version: @VERSION@
+URL: http://libbsd.freedesktop.org/
+Cflags: -I${includedir}
+Libs: -L${libdir} -Wl,-z,nodlopen -Wl,-u,libbsd_init_func -lbsd-ctor
+Requires: libbsd

src/libbsd.map

@@ -105,3 +105,8 @@ LIBBSD_0.5 {
     wcslcat;
     wcslcpy;
 } LIBBSD_0.4;
+
+LIBBSD_0.6 {
+    /* Exported to cope with the constructor+dlopen+threads mess. */
+    setproctitle_init;
+} LIBBSD_0.5;

src/setproctitle.c

@@ -1,6 +1,6 @@
 /*
  * Copyright © 2010 William Ahern
- * Copyright © 2012 Guillem Jover <guillem@hadrons.org>
+ * Copyright © 2012-2013 Guillem Jover <guillem@hadrons.org>
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the
@@ -28,6 +28,7 @@
 #include <stdbool.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <err.h>
 #include <unistd.h>
 #include <string.h>
 
@@ -41,6 +42,7 @@ static struct {
 	 /* Pointer to original nul character within base. */
 	char *nul;
 
+	bool warned;
 	bool reset;
 	int error;
 } SPT;
@@ -76,36 +78,60 @@ spt_clearenv(void)
 }
 
 static int
-spt_copyenv(char *oldenv[])
+spt_copyenv(int envc, char *envp[])
 {
+	char **envcopy;
 	char *eq;
+	int envsize;
 	int i, error;
 
-	if (environ != oldenv)
+	if (environ != envp)
 		return 0;
 
+	/* Make a copy of the old environ array of pointers, in case
+	 * clearenv() or setenv() is implemented to free the internal
+	 * environ array, because we will need to access the old environ
+	 * contents to make the new copy. */
+	envsize = (envc + 1) * sizeof(char *);
+	envcopy = malloc(envsize);
+	if (envcopy == NULL)
+		return errno;
+	memcpy(envcopy, envp, envsize);
+
 	error = spt_clearenv();
 	if (error) {
-		environ = oldenv;
+		environ = envp;
+		free(envcopy);
 		return error;
 	}
 
-	for (i = 0; oldenv[i]; i++) {
+	for (i = 0; envcopy[i]; i++) {
-		eq = strchr(oldenv[i], '=');
+		eq = strchr(envcopy[i], '=');
 		if (eq == NULL)
 			continue;
 
 		*eq = '\0';
-		if (setenv(oldenv[i], eq + 1, 1) < 0)
+		if (setenv(envcopy[i], eq + 1, 1) < 0)
 			error = errno;
 		*eq = '=';
 
 		if (error) {
-			environ = oldenv;
+#ifdef HAVE_CLEARENV
+			/* Because the old environ might not be available
+			 * anymore we will make do with the shallow copy. */
+			environ = envcopy;
+#else
+			environ = envp;
+			free(envcopy);
+#endif
 			return error;
 		}
 	}
 
+	/* Dispose of the shallow copy, now that we've finished transfering
+	 * the old environment. */
+	free(envcopy);
+
 	return 0;
 }
 
@@ -129,11 +155,15 @@ spt_copyargs(int argc, char *argv[])
 	return 0;
 }
 
-static void __attribute__((constructor))
+void
-spt_init(int argc, char *argv[], char *envp[])
+setproctitle_init(int argc, char *argv[], char *envp[])
 {
 	char *base, *end, *nul, *tmp;
-	int i, error;
+	int i, envc, error;
+
+	/* Try to make sure we got called with main() arguments. */
+	if (argc < 0)
+		return;
 
 	base = argv[0];
 	if (base == NULL)
@@ -155,6 +185,7 @@ spt_init(int argc, char *argv[], char *envp[])
 
 		end = envp[i] + strlen(envp[i]) + 1;
 	}
+	envc = i;
 
 	SPT.arg0 = strdup(argv[0]);
 	if (SPT.arg0 == NULL) {
@@ -169,7 +200,7 @@ spt_init(int argc, char *argv[], char *envp[])
 	}
 	setprogname(tmp);
 
-	error = spt_copyenv(envp);
+	error = spt_copyenv(envc, envp);
 	if (error) {
 		SPT.error = error;
 		return;
@@ -199,8 +230,14 @@ setproctitle_impl(const char *fmt, ...)
 	char *nul;
 	int len;
 
-	if (SPT.base == NULL)
+	if (SPT.base == NULL) {
+		if (!SPT.warned) {
+			warnx("setproctitle not initialized, please either call "
+			      "setproctitle_init() or link against libbsd-ctor.");
+			SPT.warned = true;
+		}
 		return;
+	}
 
 	if (fmt) {
 		if (fmt[0] == '-') {
@@ -245,11 +282,14 @@ setproctitle_impl(const char *fmt, ...)
 }
 __asm__(".symver setproctitle_impl,setproctitle@@LIBBSD_0.5");
 
-#ifdef HAVE_TYPEOF
 /* The original function introduced in 0.2 was a stub, it only got implemented
  * in 0.5, make the implementation available in the old version as an alias
  * for code linking against that version, and change the default to use the
  * new version, so that new code depends on the implemented version. */
+#ifdef HAVE_TYPEOF
 extern typeof(setproctitle_impl) setproctitle_stub __attribute__((alias("setproctitle_impl")));
-__asm__(".symver setproctitle_stub,setproctitle@LIBBSD_0.2");
+#else
+void setproctitle_stub(const char *fmt, ...)
+	__attribute__((alias("setproctitle_impl")));
 #endif
+__asm__(".symver setproctitle_stub,setproctitle@LIBBSD_0.2");

src/setproctitle_ctor.c

@@ -0,0 +1,52 @@
+/*
+ * Copyright © 2013 Guillem Jover <guillem@hadrons.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
+ * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <unistd.h>
+
+/*
+ * The automatic initialization cannot be part of the main shared library,
+ * because there is no thread-safe way to change the environ global
+ * variable. This is not a problem if the initializaion happens just at
+ * program load time, but becomes one if the shared library is directly or
+ * indirectly dlopen()ed during the execution of the program, which could
+ * have either kept references to the old environ or could change it in
+ * some other thread. This has been observed for example on systems using
+ * Samba NSS modules.
+ *
+ * To avoid any other possible fallout, the constructor is split into a
+ * new static library that needs to be linked explicitly into programs
+ * using setproctitle(). As an additional safety measure the pkg-config
+ * linker flags will mark the program as not allowing to be dlopen()ed
+ * so that we make sure to avoid the problem described above.
+ */
+
+/*
+ * Force setproctitle_init() function into the .init_array section instead of
+ * expecting either the compiler to place constructors there or the linker to
+ * move them from .ctors to .init_array.
+ */
+void (*libbsd_init_func)(int argc, char *argv[], char *envp[])
+	__attribute__((section(".init_array"))) = setproctitle_init;

test/Makefile.am

@@ -18,6 +18,10 @@ check_PROGRAMS = \
 
 humanize_LDFLAGS = $(top_builddir)/src/libbsd.la
 fgetln_LDFLAGS = $(top_builddir)/src/libbsd.la
-proctitle_LDFLAGS = $(top_builddir)/src/libbsd.la
+proctitle_LDFLAGS = \
+	-Wl,-u,libbsd_init_func \
+	$(top_builddir)/src/libbsd-ctor.a \
+	$(top_builddir)/src/libbsd.la \
+	$(nil)
 
 TESTS = $(check_PROGRAMS)

test/humanize.c

@@ -58,7 +58,7 @@ main(int argc, char **argv)
 	assert(val == 20971520);
 
 	assert(dehumanize_number("-3G", &val) == 0);
-	assert(val == -3221225472);
+	assert(val == -3221225472LL);
 
 	return 0;
 }

test/proctitle.c

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2012 Guillem Jover <guillem@hadrons.org>
+ * Copyright © 2012-2013 Guillem Jover <guillem@hadrons.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -35,6 +35,7 @@ main(int argc, char **argv)
 {
 	const char newtitle_base[] = "test arg1 arg2";
 	char *newtitle_full;
+	char *envvar;
 
 	setproctitle("-test %s arg2", "arg1");
 	assert(strcmp(argv[0], newtitle_base) == 0);
@@ -44,5 +45,10 @@ main(int argc, char **argv)
 	assert(strcmp(argv[0], newtitle_full) == 0);
 	free(newtitle_full);
 
+	assert(setenv("LIBBSD_TEST", "test value", 1) == 0);
+	envvar = getenv("LIBBSD_TEST");
+	assert(envvar != NULL);
+	assert(strcmp(envvar, "test value") == 0);
+
 	return 0;
 }