Add option to follow symlinks to check_file()

6 files changed, 35 insertions, 7 deletions

diff --git a/src/monitor/monitor.c b/src/monitor/monitor.c
index 2d54748e..18b5b34c 100644
--- a/src/monitor/monitor.c
+++ b/src/monitor/monitor.c
@@ -2473,7 +2473,7 @@ int main(int argc, const char *argv[])
     }
 
     /* Warn if nscd seems to be running */
-    ret = check_file(NSCD_SOCKET_PATH, -1, -1, -1, CHECK_SOCK, NULL);
+    ret = check_file(NSCD_SOCKET_PATH, -1, -1, -1, CHECK_SOCK, NULL, false);
     if (ret == EOK) {
         sss_log(SSS_LOG_NOTICE,
                 "nscd socket was detected.  Nscd caching capabilities "
diff --git a/src/sbus/sbus_client.c b/src/sbus/sbus_client.c
index 1c5c1b24..5b15ef3e 100644
--- a/src/sbus/sbus_client.c
+++ b/src/sbus/sbus_client.c
@@ -46,7 +46,7 @@ int sbus_client_init(TALLOC_CTX *mem_ctx,
         return EIO;
     }
 
-    ret = check_file(filename, 0, 0, 0600, CHECK_SOCK, NULL);
+    ret = check_file(filename, 0, 0, 0600, CHECK_SOCK, NULL, false);
     if (ret != EOK) {
         DEBUG(1, ("check_file failed for [%s].\n", filename));
         return EIO;
diff --git a/src/sbus/sssd_dbus_server.c b/src/sbus/sssd_dbus_server.c
index 1bb58d49..fdcbc4ff 100644
--- a/src/sbus/sssd_dbus_server.c
+++ b/src/sbus/sssd_dbus_server.c
@@ -120,7 +120,7 @@ int sbus_new_server(TALLOC_CTX *mem_ctx,
         return EIO;
     }
 
-    ret = check_file(filename, 0, 0, -1, CHECK_SOCK, &stat_buf);
+    ret = check_file(filename, 0, 0, -1, CHECK_SOCK, &stat_buf, false);
     if (ret != EOK) {
         DEBUG(1, ("check_file failed for [%s].\n", filename));
         return EIO;
diff --git a/src/tests/check_and_open-tests.c b/src/tests/check_and_open-tests.c
index 59879cc9..8e1bc988 100644
--- a/src/tests/check_and_open-tests.c
+++ b/src/tests/check_and_open-tests.c
@@ -100,7 +100,7 @@ START_TEST(test_symlink)
     ret = symlink(filename, newpath);
     fail_unless(ret == 0, "symlink failed [%d][%s]", ret, strerror(errno));
 
-    ret = check_file(newpath, uid, gid, mode, CHECK_REG, NULL);
+    ret = check_file(newpath, uid, gid, mode, CHECK_REG, NULL, false);
     unlink(newpath);
 
     fail_unless(ret == EINVAL,
@@ -108,6 +108,32 @@ START_TEST(test_symlink)
 }
 END_TEST
 
+START_TEST(test_follow_symlink)
+{
+    int ret;
+    char *newpath;
+    size_t newpath_length;
+
+    newpath_length = strlen(filename) + strlen(SUFFIX) + 1;
+    newpath = malloc((newpath_length) * sizeof(char));
+    fail_unless(newpath != NULL, "malloc failed");
+
+    ret = snprintf(newpath, newpath_length, "%s%s", filename, SUFFIX);
+    fail_unless(ret == newpath_length - 1,
+                "snprintf failed: expected [%d] got [%d]", newpath_length -1,
+                                                           ret);
+
+    ret = symlink(filename, newpath);
+    fail_unless(ret == 0, "symlink failed [%d][%s]", ret, strerror(errno));
+
+    ret = check_file(newpath, uid, gid, mode, CHECK_REG, NULL, true);
+    unlink(newpath);
+
+    fail_unless(ret == EOK,
+                "check_and_open_readonly failed on symlink with follow=true");
+}
+END_TEST
+
 START_TEST(test_not_regular_file)
 {
     int ret;
@@ -196,6 +222,7 @@ Suite *check_and_open_suite (void)
     tcase_add_test (tc_check_and_open_readonly, test_wrong_filename);
     tcase_add_test (tc_check_and_open_readonly, test_not_regular_file);
     tcase_add_test (tc_check_and_open_readonly, test_symlink);
+    tcase_add_test (tc_check_and_open_readonly, test_follow_symlink);
     tcase_add_test (tc_check_and_open_readonly, test_wrong_uid);
     tcase_add_test (tc_check_and_open_readonly, test_wrong_gid);
     tcase_add_test (tc_check_and_open_readonly, test_wrong_permission);
diff --git a/src/util/check_and_open.c b/src/util/check_and_open.c
index db926f10..27ef1c88 100644
--- a/src/util/check_and_open.c
+++ b/src/util/check_and_open.c
@@ -35,7 +35,7 @@ static errno_t perform_checks(struct stat *stat_buf,
 
 errno_t check_file(const char *filename, const int uid, const int gid,
                    const int mode, enum check_file_type type,
-                   struct stat *caller_stat_buf)
+                   struct stat *caller_stat_buf, bool follow_symlink)
 {
     int ret;
     struct stat local_stat_buf;
@@ -47,7 +47,8 @@ errno_t check_file(const char *filename, const int uid, const int gid,
         stat_buf = caller_stat_buf;
     }
 
-    ret = lstat(filename, stat_buf);
+    ret = follow_symlink ? stat(filename, stat_buf) : \
+                           lstat(filename, stat_buf);
     if (ret == -1) {
         DEBUG(1, ("lstat for [%s] failed: [%d][%s].\n", filename, errno,
                                                         strerror(errno)));
diff --git a/src/util/util.h b/src/util/util.h
index 6cc8a546..9a006471 100644
--- a/src/util/util.h
+++ b/src/util/util.h
@@ -429,7 +429,7 @@ enum check_file_type {
  */
 errno_t check_file(const char *filename, const int uid, const int gid,
                    const int mode, enum check_file_type type,
-                   struct stat *caller_stat_buf);
+                   struct stat *caller_stat_buf, bool follow_symlink);
 
 /* check_fd()
  * Verify that an open file descriptor has certain permissions and/or