From 6270eb96ce1247ad55d832288114b4016e3e5468 Mon Sep 17 00:00:00 2001
From: "Todd C. Miller" <Todd.Miller@courtesan.com>
Date: Wed, 9 Jun 2010 16:20:04 -0400
Subject: [PATCH] Implement background mode.  If I/O logging we use pipes
 instead of a pty.

--HG--
branch : 1.7
---
 exec.c     | 24 ++++++++++++++++++++----
 exec_pty.c |  9 +++++----
 sudo.c     | 17 ++---------------
 sudo.h     |  2 +-
 4 files changed, 28 insertions(+), 24 deletions(-)

diff --git a/exec.c b/exec.c
index 4cb521892..d075d48fa 100644
--- a/exec.c
+++ b/exec.c
@@ -136,27 +136,43 @@ static int fork_cmnd(path, argv, envp, sv, rbac_enabled)
  * we fact that we have two different controlling terminals to deal with.
  */
 int
-sudo_execve(path, argv, envp, uid, cstat, dowait)
+sudo_execve(path, argv, envp, uid, cstat, dowait, bgmode)
     const char *path;
     char *argv[];
     char *envp[];
     uid_t uid;
     struct command_status *cstat;
     int dowait;
+    int bgmode;
 {
     sigaction_t sa;
     fd_set *fdsr, *fdsw;
     int maxfd, n, nready, status, sv[2];
     int rbac_enabled = 0;
-    int log_io = 0;
+    int log_io;
     pid_t child;
 
-    cstat->type = CMD_INVALID;
+    /* If running in background mode, fork and exit. */
+    if (bgmode) {
+	switch (fork()) {
+	    case -1:
+		cstat->type = CMD_ERRNO;
+		cstat->val = errno;
+		return -1;
+	    case 0:
+		/* child continues */   
+		break;
+	    default:
+		/* parent exits */
+		exit(0);
+	}
+    }
 
 #ifdef _PATH_SUDO_IO_LOGDIR
     log_io = def_log_output || def_log_input || def_use_pty;
     if (log_io) {
-	pty_setup(uid);
+	if (!bgmode)
+	    pty_setup(uid);
 	io_log_open();
 	dowait = TRUE;
     }
diff --git a/exec_pty.c b/exec_pty.c
index ccea5dc3f..06c83c389 100644
--- a/exec_pty.c
+++ b/exec_pty.c
@@ -195,7 +195,8 @@ suspend_parent(signo)
 	/* Suspend self and continue child when we resume. */
 	sa.sa_handler = SIG_DFL;
 	sigaction(signo, &sa, &osa);
-	killpg(ppgrp, signo);
+	if (killpg(ppgrp, signo) != 0)
+	    warning("killpg(%d, %d)", ppgrp, signo);
 
 	/* Check foreground/background status on resume. */
 	check_foreground();
@@ -388,7 +389,7 @@ fork_pty(path, argv, envp, sv, rbac_enabled, maxfd)
      * to interpose ourselves instead of duping the pty fd.
      */
     memset(io_pipe, 0, sizeof(io_pipe));
-    if (!isatty(STDIN_FILENO)) {
+    if (io_fds[SFD_STDIN] == -1 || !isatty(STDIN_FILENO)) {
 	pipeline = TRUE;
 	if (pipe(io_pipe[STDIN_FILENO]) != 0)
 	    error(1, "unable to create pipe");
@@ -396,7 +397,7 @@ fork_pty(path, argv, envp, sv, rbac_enabled, maxfd)
 	    log_stdin, iobufs);
 	io_fds[SFD_STDIN] = io_pipe[STDIN_FILENO][0];
     }
-    if (!isatty(STDOUT_FILENO)) {
+    if (io_fds[SFD_STDOUT] == -1 || !isatty(STDOUT_FILENO)) {
 	pipeline = TRUE;
 	if (pipe(io_pipe[STDOUT_FILENO]) != 0)
 	    error(1, "unable to create pipe");
@@ -404,7 +405,7 @@ fork_pty(path, argv, envp, sv, rbac_enabled, maxfd)
 	    log_stdout, iobufs);
 	io_fds[SFD_STDOUT] = io_pipe[STDOUT_FILENO][1];
     }
-    if (!isatty(STDERR_FILENO)) {
+    if (io_fds[SFD_STDERR] == -1 || !isatty(STDERR_FILENO)) {
 	if (pipe(io_pipe[STDERR_FILENO]) != 0)
 	    error(1, "unable to create pipe");
 	iobufs = io_buf_new(io_pipe[STDERR_FILENO][0], STDERR_FILENO,
diff --git a/sudo.c b/sudo.c
index c9b1d9acf..158485211 100644
--- a/sudo.c
+++ b/sudo.c
@@ -864,20 +864,6 @@ exec_setup(flags, rbac_enabled, ttyname, ttyfd)
 	    goto done;
     }
 
-    if (ISSET(sudo_mode, MODE_BACKGROUND)) {
-	switch (fork()) {
-	    case -1:
-		warning("fork");
-		goto done;
-	    case 0:
-		/* child continues */
-		break;
-	    default:
-		/* parent exists */
-		exit(0);
-	}
-    }
-
     rval = TRUE;
 
 done:
@@ -905,7 +891,8 @@ run_command(path, argv, envp, uid, dowait)
     cstat.type = CMD_INVALID;
     cstat.val = 0;
 
-    sudo_execve(path, argv, envp, uid, &cstat, dowait);
+    sudo_execve(path, argv, envp, uid, &cstat, dowait,
+	ISSET(sudo_mode, MODE_BACKGROUND));
 
     switch (cstat.type) {
     case CMD_ERRNO:
diff --git a/sudo.h b/sudo.h
index 059dcd438..015537235 100644
--- a/sudo.h
+++ b/sudo.h
@@ -232,7 +232,7 @@ void validate_env_vars	__P((struct list_member *));
 
 /* exec.c */
 int sudo_execve __P((const char *path, char *argv[], char *envp[], uid_t uid,
-    struct command_status *cstat, int dowait));
+    struct command_status *cstat, int dowait, int bgmode));
 int my_execve __P((const char *path, char *argv[], char *envp[]));
 
 /* exec_pty.c */
-- 
2.40.0