1 files changed, 124 insertions, 50 deletions

diff --git a/lib/libpam/openpam_dynamic.c b/lib/libpam/openpam_dynamic.c
index 1dfc1ac43eb8..27cd4e6776da 100644
--- a/lib/libpam/openpam_dynamic.c
+++ b/lib/libpam/openpam_dynamic.c
@@ -32,16 +32,18 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: openpam_dynamic.c 607 2012-04-20 11:09:37Z des $
+ * $Id: openpam_dynamic.c 683 2013-04-14 14:49:59Z des $
  */
 
 #ifdef HAVE_CONFIG_H
 # include "config.h"
 #endif
 
+#include <sys/param.h>
+
 #include <dlfcn.h>
-#include <fcntl.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -50,6 +52,9 @@
 #include <security/pam_appl.h>
 
 #include "openpam_impl.h"
+#include "openpam_asprintf.h"
+#include "openpam_ctype.h"
+#include "openpam_dlfunc.h"
 
 #ifndef RTLD_NOW
 #define RTLD_NOW RTLD_LAZY
@@ -68,8 +73,12 @@ try_dlopen(const char *modfn)
 	void *dlh;
 	int fd;
 
-	if ((fd = open(modfn, O_RDONLY)) < 0)
+	openpam_log(PAM_LOG_LIBDEBUG, "dlopen(%s)", modfn);
+	if ((fd = open(modfn, O_RDONLY)) < 0) {
+		if (errno != ENOENT)
+			openpam_log(PAM_LOG_ERROR, "%s: %m", modfn);
 		return (NULL);
+	}
 	if (OPENPAM_FEATURE(VERIFY_MODULE_FILE) &&
 	    openpam_check_desc_owner_perms(modfn, fd) != 0) {
 		close(fd);
@@ -91,6 +100,7 @@ try_dlopen(const char *modfn)
 	int check_module_file;
 	void *dlh;
 
+	openpam_log(PAM_LOG_LIBDEBUG, "dlopen(%s)", modfn);
 	openpam_get_feature(OPENPAM_VERIFY_MODULE_FILE,
 	    &check_module_file);
 	if (check_module_file &&
@@ -106,83 +116,147 @@ try_dlopen(const char *modfn)
 #endif
 
 /*
- * OpenPAM internal
- *
- * Locate a dynamically linked module
+ * Try to load a module from the suggested location.
  */
-
-pam_module_t *
-openpam_dynamic(const char *path)
+static pam_module_t *
+try_module(const char *modpath)
 {
 	const pam_module_t *dlmodule;
 	pam_module_t *module;
-	const char *prefix;
-	char *vpath;
-	void *dlh;
 	int i, serrno;
 
-	dlh = NULL;
-
-	/* Prepend the standard prefix if not an absolute pathname. */
-	if (path[0] != '/')
-		prefix = OPENPAM_MODULES_DIR;
-	else
-		prefix = "";
-
-	/* try versioned module first, then unversioned module */
-	if (asprintf(&vpath, "%s%s.%d", prefix, path, LIB_MAJ) < 0)
+	if ((module = calloc(1, sizeof *module)) == NULL ||
+	    (module->path = strdup(modpath)) == NULL ||
+	    (module->dlh = try_dlopen(modpath)) == NULL)
 		goto err;
-	if ((dlh = try_dlopen(vpath)) == NULL && errno == ENOENT) {
-		*strrchr(vpath, '.') = '\0';
-		dlh = try_dlopen(vpath);
-	}
-	if (dlh == NULL)
-		goto err;
-	if ((module = calloc(1, sizeof *module)) == NULL)
-		goto buf_err;
-	if ((module->path = strdup(path)) == NULL)
-		goto buf_err;
-	module->dlh = dlh;
-	dlmodule = dlsym(dlh, "_pam_module");
+	dlmodule = dlsym(module->dlh, "_pam_module");
 	for (i = 0; i < PAM_NUM_PRIMITIVES; ++i) {
 		if (dlmodule) {
 			module->func[i] = dlmodule->func[i];
 		} else {
-			module->func[i] =
-			    (pam_func_t)dlsym(dlh, pam_sm_func_name[i]);
+			module->func[i] = (pam_func_t)dlfunc(module->dlh,
+			    pam_sm_func_name[i]);
 			/*
 			 * This openpam_log() call is a major source of
 			 * log spam, and the cases that matter are caught
 			 * and logged in openpam_dispatch().  This would
 			 * be less problematic if dlerror() returned an
 			 * error code so we could log an error only when
-			 * dlsym() failed for a reason other than "no such
-			 * symbol".
+			 * dlfunc() failed for a reason other than "no
+			 * such symbol".
 			 */
 #if 0
 			if (module->func[i] == NULL)
-				openpam_log(PAM_LOG_DEBUG, "%s: %s(): %s",
-				    path, pam_sm_func_name[i], dlerror());
+				openpam_log(PAM_LOG_LIBDEBUG, "%s: %s(): %s",
+				    modpath, pam_sm_func_name[i], dlerror());
 #endif
 		}
 	}
-	FREE(vpath);
 	return (module);
-buf_err:
-	serrno = errno;
-	if (dlh != NULL)
-		dlclose(dlh);
-	FREE(module);
-	errno = serrno;
 err:
 	serrno = errno;
-	if (errno != 0)
-		openpam_log(PAM_LOG_ERROR, "%s: %m", vpath);
-	FREE(vpath);
+	if (module != NULL) {
+		if (module->dlh != NULL)
+			dlclose(module->dlh);
+		if (module->path != NULL)
+			FREE(module->path);
+		FREE(module);
+	}
+	errno = serrno;
+	if (serrno != 0 && serrno != ENOENT)
+		openpam_log(PAM_LOG_ERROR, "%s: %m", modpath);
 	errno = serrno;
 	return (NULL);
 }
 
 /*
+ * OpenPAM internal
+ *
+ * Locate a dynamically linked module
+ */
+
+pam_module_t *
+openpam_dynamic(const char *modname)
+{
+	pam_module_t *module;
+	char modpath[PATH_MAX];
+	const char **path, *p;
+	int has_so, has_ver;
+	int dot, len;
+
+	/*
+	 * Simple case: module name contains path separator(s)
+	 */
+	if (strchr(modname, '/') != NULL) {
+		/*
+		 * Absolute paths are not allowed if RESTRICT_MODULE_NAME
+		 * is in effect (default off).  Relative paths are never
+		 * allowed.
+		 */
+		if (OPENPAM_FEATURE(RESTRICT_MODULE_NAME) ||
+		    modname[0] != '/') {
+			openpam_log(PAM_LOG_ERROR,
+			    "invalid module name: %s", modname);
+			return (NULL);
+		}
+		return (try_module(modname));
+	}
+
+	/*
+	 * Check for .so and version sufixes
+	 */
+	p = strchr(modname, '\0');
+	has_ver = has_so = 0;
+	while (is_digit(*p))
+		--p;
+	if (*p == '.' && *++p != '\0') {
+		/* found a numeric suffix */
+		has_ver = 1;
+		/* assume that .so is either present or unneeded */
+		has_so = 1;
+	} else if (*p == '\0' && p >= modname + sizeof PAM_SOEXT &&
+	    strcmp(p - sizeof PAM_SOEXT + 1, PAM_SOEXT) == 0) {
+		/* found .so suffix */
+		has_so = 1;
+	}
+
+	/*
+	 * Complicated case: search for the module in the usual places.
+	 */
+	for (path = openpam_module_path; *path != NULL; ++path) {
+		/*
+		 * Assemble the full path, including the version suffix.  Take
+		 * note of where the suffix begins so we can cut it off later.
+		 */
+		if (has_ver)
+			len = snprintf(modpath, sizeof modpath, "%s/%s%n",
+			    *path, modname, &dot);
+		else if (has_so)
+			len = snprintf(modpath, sizeof modpath, "%s/%s%n.%d",
+			    *path, modname, &dot, LIB_MAJ);
+		else
+			len = snprintf(modpath, sizeof modpath, "%s/%s%s%n.%d",
+			    *path, modname, PAM_SOEXT, &dot, LIB_MAJ);
+		/* check for overflow */
+		if (len < 0 || (unsigned int)len >= sizeof modpath) {
+			errno = ENOENT;
+			continue;
+		}
+		/* try the versioned path */
+		if ((module = try_module(modpath)) != NULL)
+			return (module);
+		if (errno == ENOENT && modpath[dot] != '\0') {
+			/* no luck, try the unversioned path */
+			modpath[dot] = '\0';
+			if ((module = try_module(modpath)) != NULL)
+				return (module);
+		}
+	}
+
+	/* :( */
+	return (NULL);
+}
+
+/*
  * NOPARSE
  */