X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fgetty-generator%2Fgetty-generator.c;h=6a4aa2c1d9a133d793b06d5d1c761ffd44d893b2;hb=590b6b9188e75ba46c42995984a1c2fa06adb6d6;hp=0dc407dd32a70bb82fe97cdbbde599317b8f4fe4;hpb=f85fc8454137a5cfba99b3a24aaa6dc38f6e2768;p=elogind.git

diff --git a/src/getty-generator/getty-generator.c b/src/getty-generator/getty-generator.c
index 0dc407dd3..6a4aa2c1d 100644
--- 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"
@@ -29,6 +30,7 @@
 #include "unit-name.h"
 #include "virt.h"
 #include "fileio.h"
+#include "path-util.h"
 
 static const char *arg_dest = "/tmp";
 
@@ -77,15 +79,57 @@ static int add_serial_getty(const char *tty) {
         return add_symlink("serial-getty@.service", n);
 }
 
+static int add_container_getty(const char *tty) {
+        _cleanup_free_ char *n = NULL;
+
+        assert(tty);
+
+        log_debug("Automatically adding container getty for /dev/pts/%s.", tty);
+
+        n = unit_name_replace_instance("container-getty@.service", tty);
+        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[] =
                 "hvc0\0"
                 "xvc0\0"
-                "hvsi0\0";
+                "hvsi0\0"
+                "sclp_line0\0"
+                "ttysclp0\0"
+                "3270!tty1\0";
 
         _cleanup_free_ char *active = NULL;
         const char *j;
+        int r;
 
         if (argc > 1 && argc != 4) {
                 log_error("This program takes three or no arguments.");
@@ -102,11 +146,44 @@ int main(int argc, char *argv[]) {
         umask(0022);
 
         if (detect_container(NULL) > 0) {
+                _cleanup_free_ char *container_ttys = NULL;
+
                 log_debug("Automatically adding console shell.");
 
                 if (add_symlink("console-getty.service", "console-getty.service") < 0)
                         return EXIT_FAILURE;
 
+                /* When $container_ttys is set for PID 1, spawn
+                 * gettys on all ptys named therein. Note that despite
+                 * the variable name we only support ptys here. */
+
+                r = getenv_for_pid(1, "container_ttys", &container_ttys);
+                if (r > 0) {
+                        char *w, *state;
+                        size_t l;
+
+                        FOREACH_WORD(w, l, container_ttys, state) {
+                                const char *t;
+                                char tty[l + 1];
+
+                                memcpy(tty, w, l);
+                                tty[l] = 0;
+
+                                /* First strip off /dev/ if it is specified */
+                                t = path_startswith(tty, "/dev/");
+                                if (!t)
+                                        t = tty;
+
+                                /* Then, make sure it's actually a pty */
+                                t = path_startswith(t, "pts/");
+                                if (!t)
+                                        continue;
+
+                                if (add_container_getty(t) < 0)
+                                        return EXIT_FAILURE;
+                        }
+                }
+
                 /* Don't add any further magic if we are in a container */
                 return EXIT_SUCCESS;
         }
@@ -129,6 +206,9 @@ 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. */