[dm-devel] [PATCH 6/8] libmultipath: improve checks for set_str

[Benjamin Marzinski]

multipath always requires absolute pathnames, so make sure all file and
directory names start with a slash.  Also check that the directories
exist.  Finally, some strings, like the alias, will be used in paths.
These must not contain the slash character '/', since it is a forbidden
character in file/directory names. This patch adds seperate handlers for
these three cases. If a config line is invalid, these handlers retain
the existing config string, if any.

Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>
---
 libmultipath/dict.c | 88 +++++++++++++++++++++++++++++++++++++++------
 1 file changed, 78 insertions(+), 10 deletions(-)

diff --git a/libmultipath/dict.c b/libmultipath/dict.c
index 1758bd26..91333068 100644
--- a/libmultipath/dict.c
+++ b/libmultipath/dict.c
@@ -5,6 +5,8 @@
  * Copyright (c) 2005 Kiyoshi Ueda, NEC
  */
 #include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
 #include <pwd.h>
 #include <string.h>
 #include "checkers.h"
@@ -111,6 +113,72 @@ set_str(vector strvec, void *ptr, const char *file, int line_nr)
 	return 0;
 }
 
+static int
+set_dir(vector strvec, void *ptr, const char *file, int line_nr)
+{
+	char **str_ptr = (char **)ptr;
+	char *old_str = *str_ptr;
+	struct stat sb;
+
+	*str_ptr = set_value(strvec);
+	if (!*str_ptr) {
+		free(old_str);
+		return 1;
+	}
+	if ((*str_ptr)[0] != '/'){
+		condlog(1, "%s line %d, %s is not an absolute directory path. Ignoring", file, line_nr, *str_ptr);
+		*str_ptr = old_str;
+	} else {
+		if (stat(*str_ptr, &sb) == 0 && S_ISDIR(sb.st_mode))
+			free(old_str);
+		else {
+			condlog(1, "%s line %d, %s is not an existing directory. Ignoring", file, line_nr, *str_ptr);
+			*str_ptr = old_str;
+		}
+	}
+	return 0;
+}
+
+static int
+set_path(vector strvec, void *ptr, const char *file, int line_nr)
+{
+	char **str_ptr = (char **)ptr;
+	char *old_str = *str_ptr;
+
+	*str_ptr = set_value(strvec);
+	if (!*str_ptr) {
+		free(old_str);
+		return 1;
+	}
+	if ((*str_ptr)[0] != '/'){
+		condlog(1, "%s line %d, %s is not an absolute path. Ignoring",
+			file, line_nr, *str_ptr);
+		*str_ptr = old_str;
+	} else
+		free(old_str);
+	return 0;
+}
+
+static int
+set_str_noslash(vector strvec, void *ptr, const char *file, int line_nr)
+{
+	char **str_ptr = (char **)ptr;
+	char *old_str = *str_ptr;
+
+	*str_ptr = set_value(strvec);
+	if (!*str_ptr) {
+		free(old_str);
+		return 1;
+	}
+	if (strchr(*str_ptr, '/')) {
+		condlog(1, "%s line %d, %s cannot contain a slash. Ignoring",
+			file, line_nr, *str_ptr);
+		*str_ptr = old_str;
+	} else
+		free(old_str);
+	return 0;
+}
+
 static int
 set_yes_no(vector strvec, void *ptr, const char *file, int line_nr)
 {
@@ -353,13 +421,13 @@ declare_def_snprint(verbosity, print_int)
 declare_def_handler(reassign_maps, set_yes_no)
 declare_def_snprint(reassign_maps, print_yes_no)
 
-declare_def_handler(multipath_dir, set_str)
+declare_def_handler(multipath_dir, set_dir)
 declare_def_snprint(multipath_dir, print_str)
 
 static int def_partition_delim_handler(struct config *conf, vector strvec,
 				       const char *file, int line_nr)
 {
-	int rc = set_str(strvec, &conf->partition_delim, file, line_nr);
+	int rc = set_str_noslash(strvec, &conf->partition_delim, file, line_nr);
 
 	if (rc != 0)
 		return rc;
@@ -490,11 +558,11 @@ declare_hw_snprint(prio_name, print_str)
 declare_mp_handler(prio_name, set_str)
 declare_mp_snprint(prio_name, print_str)
 
-declare_def_handler(alias_prefix, set_str)
+declare_def_handler(alias_prefix, set_str_noslash)
 declare_def_snprint_defstr(alias_prefix, print_str, DEFAULT_ALIAS_PREFIX)
-declare_ovr_handler(alias_prefix, set_str)
+declare_ovr_handler(alias_prefix, set_str_noslash)
 declare_ovr_snprint(alias_prefix, print_str)
-declare_hw_handler(alias_prefix, set_str)
+declare_hw_handler(alias_prefix, set_str_noslash)
 declare_hw_snprint(alias_prefix, print_str)
 
 declare_def_handler(prio_args, set_str)
@@ -586,13 +654,13 @@ declare_hw_snprint(user_friendly_names, print_yes_no_undef)
 declare_mp_handler(user_friendly_names, set_yes_no_undef)
 declare_mp_snprint(user_friendly_names, print_yes_no_undef)
 
-declare_def_handler(bindings_file, set_str)
+declare_def_handler(bindings_file, set_path)
 declare_def_snprint(bindings_file, print_str)
 
-declare_def_handler(wwids_file, set_str)
+declare_def_handler(wwids_file, set_path)
 declare_def_snprint(wwids_file, print_str)
 
-declare_def_handler(prkeys_file, set_str)
+declare_def_handler(prkeys_file, set_path)
 declare_def_snprint(prkeys_file, print_str)
 
 declare_def_handler(retain_hwhandler, set_yes_no_undef)
@@ -692,7 +760,7 @@ def_config_dir_handler(struct config *conf, vector strvec, const char *file,
 	/* this is only valid in the main config file */
 	if (conf->processed_main_config)
 		return 0;
-	return set_str(strvec, &conf->config_dir, file, line_nr);
+	return set_path(strvec, &conf->config_dir, file, line_nr);
 }
 declare_def_snprint(config_dir, print_str)
 
@@ -1732,7 +1800,7 @@ multipath_handler(struct config *conf, vector strvec, const char *file,
 declare_mp_handler(wwid, set_str)
 declare_mp_snprint(wwid, print_str)
 
-declare_mp_handler(alias, set_str)
+declare_mp_handler(alias, set_str_noslash)
 declare_mp_snprint(alias, print_str)
 
 /*
-- 
2.17.2