mount.cifs: Use systemd's mechanism for getting password, if present.

If systemd is running and /bin/systemd-ask-password if available,
then use that else fallback on getpass(..).

And add a --enable-systemd configure option, which defaults to yes.

Signed-off-by: Ankit Jain <jankit@suse.com>

diff --git a/configure.ac b/configure.ac
index 10c2f67ad30d0d4cfac66244d3f9b7a53585ba34..599401fa99075c7571c58fc21119c9161fb3a996 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -46,6 +46,12 @@ AC_ARG_ENABLE(cifsacl,
        enable_cifsacl=$enableval,
        enable_cifsacl="maybe")
 
+AC_ARG_ENABLE(systemd,
+       [AC_HELP_STRING([--enable-systemd],
+                       [Enable systemd specific behavior for mount.cifs @<:@default=yes@:>@])],
+       enable_systemd=$enableval,
+       enable_systemd="maybe")
+
 # check for ROOTSBINDIR environment var
 if test -z $ROOTSBINDIR; then
        ROOTSBINDIR="/sbin"
@@ -210,6 +216,10 @@ if test $enable_cifsupcall != "no"; then
        AC_CHECK_FUNCS([krb5_auth_con_setaddrs krb5_auth_con_set_req_cksumtype])
 fi
 
+if test $enable_systemd != "no"; then
+       AC_DEFINE(ENABLE_SYSTEMD, 1, [Enable systemd specific behavior for mount.cifs])
+fi
+
 # MIT krb5 < 1.7 does not have this declaration but does have the symbol
 AC_CHECK_DECLS(krb5_auth_con_set_req_cksumtype, [], [], [#include <krb5.h>])
 

diff --git a/mount.cifs.c b/mount.cifs.c
index 6f3f3823a01e41cd35e663eafbda6d9d4cf7c263..a15ba9e50ba0a7a2026304322034abaf3b59de1e 100644 (file)
--- a/mount.cifs.c
+++ b/mount.cifs.c
@@ -1687,6 +1687,66 @@ drop_child_privs(void)
        return 0;
 }
 
+/*
+ * If systemd is running and /bin/systemd-ask-password --
+ * is available, then use that else fallback on getpass(..)
+ *
+ * Returns: @input or NULL on error
+ */
+static char*
+get_password(const char *prompt, char *input, int capacity)
+{
+#ifdef ENABLE_SYSTEMD
+       int is_systemd_running;
+       struct stat a, b;
+
+       /* We simply test whether the systemd cgroup hierarchy is
+        * mounted */
+       is_systemd_running = (lstat("/sys/fs/cgroup", &a) == 0)
+               && (lstat("/sys/fs/cgroup/systemd", &b) == 0)
+               && (a.st_dev != b.st_dev);
+
+       if (is_systemd_running) {
+               char *cmd, *ret;
+               FILE *ask_pass_fp = NULL;
+
+               cmd = ret = NULL;
+               if (asprintf(&cmd, "/bin/systemd-ask-password \"%s\"", prompt) >= 0) {
+                       ask_pass_fp = popen (cmd, "re");
+                       free (cmd);
+               }
+
+               if (ask_pass_fp) {
+                       ret = fgets(input, capacity, ask_pass_fp);
+                       pclose(ask_pass_fp);
+               }
+
+               if (ret) {
+                       int len = strlen(input);
+                       if (input[len - 1] == '\n')
+                               input[len - 1] = '\0';
+                       return input;
+               }
+       }
+#endif
+
+       /*
+        * Falling back to getpass(..)
+        * getpass is obsolete, but there's apparently nothing that replaces it
+        */
+       char *tmp_pass = getpass(prompt);
+       if (!tmp_pass)
+               return NULL;
+
+       strncpy(input, tmp_pass, capacity - 1);
+       input[capacity - 1] = '\0';
+
+       /* zero-out the static buffer */
+       memset(tmp_pass, 0, strlen(tmp_pass));
+
+       return input;
+}
+
 static int
 assemble_mountinfo(struct parsed_mount_info *parsed_info,
                   const char *thisprogram, const char *mountpoint,
@@ -1768,14 +1828,20 @@ assemble_mountinfo(struct parsed_mount_info *parsed_info,
        }
 
        if (!parsed_info->got_password) {
-               /* getpass is obsolete, but there's apparently nothing that replaces it */
-               char *tmp_pass = getpass("Password: ");
-               if (!tmp_pass) {
+               char tmp_pass[MOUNT_PASSWD_SIZE + 1];
+               char *prompt = NULL;
+
+               if(asprintf(&prompt, "Password for %s@%s: ", parsed_info->username, orig_dev) < 0)
+                       prompt = NULL;
+
+               if (get_password(prompt ? prompt : "Password: ", tmp_pass, MOUNT_PASSWD_SIZE + 1)) {
+                       rc = set_password(parsed_info, tmp_pass);
+               } else {
                        fprintf(stderr, "Error reading password, exiting\n");
                        rc = EX_SYSERR;
-                       goto assemble_exit;
                }
-               rc = set_password(parsed_info, tmp_pass);
+
+               free(prompt);
                if (rc)
                        goto assemble_exit;
        }