Fix the code for establishing a controlling terminal.

 -Erik


git-svn-id: svn://busybox.net/trunk/busybox@2901 69ca8d6d-28ef-0310-b511-8ec308f3f277

1 files changed, 42 insertions, 28 deletions

diff --git a/shell/hush.c b/shell/hush.c
index fa01d9135..b0637f806 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -251,7 +251,7 @@ static const char *cwd;
 static struct pipe *job_list;
 static unsigned int last_bg_pid;
 static unsigned int last_jobid;
-static unsigned int ctty;
+static unsigned int shell_terminal;
 static char *PS1;
 static char *PS2;
 struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
@@ -570,11 +570,9 @@ static int builtin_fg_bg(struct child_prog *child)
 
         if (*child->argv[0] == 'f') {
                 /* Make this job the foreground job */
-                signal(SIGTTOU, SIG_IGN);
                 /* suppress messages when run from /linuxrc mag@sysgo.de */
-                if (tcsetpgrp(ctty, pi->pgrp) && errno != ENOTTY)
+                if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
                         perror_msg("tcsetpgrp-1"); 
-                signal(SIGTTOU, SIG_DFL);
         }
 
         /* Restart the processes in the job */
@@ -1263,7 +1261,7 @@ static int checkjobs(struct pipe* fg_pipe)
                 perror_msg("waitpid");
 
         /* move the shell to the foreground */
-        if (interactive && tcsetpgrp(ctty, getpgid(0)))
+        if (interactive && tcsetpgrp(shell_terminal, getpgid(0)))
                 perror_msg("tcsetpgrp-2");
         return -1;
 }
@@ -1271,24 +1269,24 @@ static int checkjobs(struct pipe* fg_pipe)
 /* Figure out our controlling tty, checking in order stderr,
  * stdin, and stdout.  If check_pgrp is set, also check that
  * we belong to the foreground process group associated with
- * that tty.  The value of ctty is needed in order to call
- * tcsetpgrp(ctty, ...); */
+ * that tty.  The value of shell_terminal is needed in order to call
+ * tcsetpgrp(shell_terminal, ...); */
 void controlling_tty(int check_pgrp)
 {
         pid_t curpgrp;
 
-        if ((curpgrp = tcgetpgrp(ctty = 2)) < 0
-                        && (curpgrp = tcgetpgrp(ctty = 0)) < 0
-                        && (curpgrp = tcgetpgrp(ctty = 1)) < 0)
-                goto ctty_error;
+        if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
+                        && (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
+                        && (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
+                goto shell_terminal_error;
 
         if (check_pgrp && curpgrp != getpgid(0))
-                goto ctty_error;
+                goto shell_terminal_error;
 
         return;
 
-ctty_error:
-                ctty = -1;
+shell_terminal_error:
+                shell_terminal = -1;
                 return;
 }
 
@@ -1402,7 +1400,13 @@ static int run_pipe_real(struct pipe *pi)
 
                 /* XXX test for failed fork()? */
                 if (!(child->pid = fork())) {
+                        /* Set the handling for job control signals back to the default.  */
+                        signal(SIGINT, SIG_DFL);
+                        signal(SIGQUIT, SIG_DFL);
+                        signal(SIGTSTP, SIG_DFL);
+                        signal(SIGTTIN, SIG_DFL);
                         signal(SIGTTOU, SIG_DFL);
+                        signal(SIGCHLD, SIG_DFL);
                         
                         close_all();
 
@@ -1429,9 +1433,7 @@ static int run_pipe_real(struct pipe *pi)
                                         pi->pgrp = getpid();
                                 }
                                 if (setpgid(0, pi->pgrp) == 0) {
-                                        signal(SIGTTOU, SIG_IGN);
                                         tcsetpgrp(2, pi->pgrp);
-                                        signal(SIGTTOU, SIG_DFL);
                                 }
                         }
 
@@ -1489,11 +1491,11 @@ static int run_list_real(struct pipe *pi)
                 } else {
                         if (interactive) {
                                 /* move the new process group into the foreground */
-                                if (tcsetpgrp(ctty, pi->pgrp) && errno != ENOTTY)
+                                if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
                                         perror_msg("tcsetpgrp-3");
                                 rcode = checkjobs(pi);
                                 /* move the shell to the foreground */
-                                if (tcsetpgrp(ctty, getpgid(0)) && errno != ENOTTY)
+                                if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
                                         perror_msg("tcsetpgrp-4");
                         } else {
                                 rcode = checkjobs(pi);
@@ -2534,21 +2536,33 @@ static void sigchld_handler(int sig)
         signal(SIGCHLD, sigchld_handler);
 }
 
+/* Make sure we have a controlling tty.  If we get started under a job
+ * aware app (like bash for example), make sure we are now in charge so
+ * we don't fight over who gets the foreground */
 static void setup_job_control()
 {
-        /* If we get started under a job aware app (like bash 
-         * for example), make sure we are now in charge so we 
-         * don't fight over who gets the foreground */
-        /* don't pay any attention to this signal; it just confuses 
-           things and isn't really meant for shells anyway */
-        setpgrp();
-        controlling_tty(0);
+        static pid_t shell_pgrp;
+        /* Loop until we are in the foreground.  */
+        while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
+                kill (- shell_pgrp, SIGTTIN);
+
+        /* Ignore interactive and job-control signals.  */
+        signal(SIGINT, SIG_IGN);
+        signal(SIGQUIT, SIG_IGN);
+        signal(SIGTSTP, SIG_IGN);
+        signal(SIGTTIN, SIG_IGN);
         signal(SIGTTOU, SIG_IGN);
-        setpgid(0, getpid());
-        tcsetpgrp(ctty, getpid());
         signal(SIGCHLD, sigchld_handler);
-}
 
+        /* Put ourselves in our own process group.  */
+        shell_pgrp = getpid ();
+        if (setpgid (shell_pgrp, shell_pgrp) < 0) {
+                perror_msg_and_die("Couldn't put the shell in its own process group");
+        }
+
+        /* Grab control of the terminal.  */
+        tcsetpgrp(shell_terminal, shell_pgrp);
+}
 
 int shell_main(int argc, char **argv)
 {