getty-generator: properly escape instance names

[elogind.git] / src / getty-generator / getty-generator.c

diff --git a/src/getty-generator/getty-generator.c b/src/getty-generator/getty-generator.c
index f352a29f99ede35eaefe26a9953efc1caf0411a5..7d4b546f72751af2508832c445f091387ddedf8b 100644 (file)
--- a/src/getty-generator/getty-generator.c
+++ b/src/getty-generator/getty-generator.c
@@ -22,6 +22,7 @@
 #include <string.h>
 #include <errno.h>
 #include <unistd.h>
+#include <fcntl.h>
 
 #include "log.h"
 #include "util.h"
@@ -34,19 +35,14 @@
 static const char *arg_dest = "/tmp";
 
 static int add_symlink(const char *fservice, const char *tservice) {
-        _cleanup_free_ char *from = NULL, *to = NULL;
+        char *from, *to;
         int r;
 
         assert(fservice);
         assert(tservice);
 
-        from = strappend(SYSTEM_DATA_UNIT_PATH "/", fservice);
-        if (!from)
-                return log_oom();
-
-        to = strjoin(arg_dest,"/getty.target.wants/", tservice, NULL);
-        if (!to)
-                return log_oom();
+        from = strappenda(SYSTEM_DATA_UNIT_PATH "/", fservice);
+        to = strappenda3(arg_dest, "/getty.target.wants/", tservice);
 
         mkdir_parents_label(to, 0755);
 
@@ -71,7 +67,7 @@ static int add_serial_getty(const char *tty) {
 
         log_debug("Automatically adding serial getty for /dev/%s.", tty);
 
-        n = unit_name_replace_instance("serial-getty@.service", tty);
+        n = unit_name_from_path_instance("serial-getty", tty, ".service");
         if (!n)
                 return log_oom();
 
@@ -85,13 +81,37 @@ static int add_container_getty(const char *tty) {
 
         log_debug("Automatically adding container getty for /dev/pts/%s.", tty);
 
-        n = unit_name_replace_instance("container-getty@.service", tty);
+        n = unit_name_from_path_instance("container-getty", tty, ".service");
         if (!n)
                 return log_oom();
 
         return add_symlink("container-getty@.service", n);
 }
 
+static int verify_tty(const char *name) {
+        _cleanup_close_ int fd = -1;
+        const char *p;
+
+        /* Some TTYs are weird and have been enumerated but don't work
+         * when you try to use them, such as classic ttyS0 and
+         * friends. Let's check that and open the device and run
+         * isatty() on it. */
+
+        p = strappenda("/dev/", name);
+
+        /* O_NONBLOCK is essential here, to make sure we don't wait
+         * for DCD */
+        fd = open(p, O_RDWR|O_NONBLOCK|O_NOCTTY|O_CLOEXEC|O_NOFOLLOW);
+        if (fd < 0)
+                return -errno;
+
+        errno = 0;
+        if (isatty(fd) <= 0)
+                return errno ? -errno : -EIO;
+
+        return 0;
+}
+
 int main(int argc, char *argv[]) {
 
         static const char virtualization_consoles[] =
@@ -99,7 +119,8 @@ int main(int argc, char *argv[]) {
                 "xvc0\0"
                 "hvsi0\0"
                 "sclp_line0\0"
-                "ttysclp0\0";
+                "ttysclp0\0"
+                "3270!tty1\0";
 
         _cleanup_free_ char *active = NULL;
         const char *j;
@@ -180,6 +201,9 @@ int main(int argc, char *argv[]) {
                         if (isempty(tty) || tty_is_vc(tty))
                                 continue;
 
+                        if (verify_tty(tty) < 0)
+                                continue;
+
                         /* We assume that gettys on virtual terminals are
                          * started via manual configuration and do this magic
                          * only for non-VC terminals. */
@@ -192,14 +216,9 @@ int main(int argc, char *argv[]) {
         /* Automatically add in a serial getty on the first
          * virtualizer console */
         NULSTR_FOREACH(j, virtualization_consoles) {
-                _cleanup_free_ char *p = NULL;
-
-                p = strappend("/sys/class/tty/", j);
-                if (!p) {
-                        log_oom();
-                        return EXIT_FAILURE;
-                }
+                char *p;
 
+                p = strappenda("/sys/class/tty/", j);
                 if (access(p, F_OK) < 0)
                         continue;