polkit: temporarily spawn of a polkit agent in terminals for possibly authenticated operations

9 files changed, 299 insertions, 136 deletions

diff --git a/src/login/loginctl.c b/src/login/loginctl.c
index 30e97e352..2633b47e1 100644
--- a/src/login/loginctl.c
+++ b/src/login/loginctl.c
@@ -35,6 +35,7 @@
 #include "strv.h"
 #include "cgroup-show.h"
 #include "sysfs-show.h"
+#include "spawn-polkit-agent.h"
 
 static char **arg_property = NULL;
 static bool arg_all = false;
@@ -46,6 +47,7 @@ static enum transport {
         TRANSPORT_SSH,
         TRANSPORT_POLKIT
 } arg_transport = TRANSPORT_NORMAL;
+static bool arg_ask_password = true;
 static const char *arg_host = NULL;
 
 static bool on_tty(void) {
@@ -68,8 +70,20 @@ static void pager_open_if_enabled(void) {
         /* Cache result before we open the pager */
         on_tty();
 
-        if (!arg_no_pager)
-                pager_open();
+        if (arg_no_pager)
+                return;
+
+        pager_open();
+}
+
+static void polkit_agent_open_if_enabled(void) {
+
+        /* Open the polkit agent as a child process if necessary */
+
+        if (!arg_ask_password)
+                return;
+
+        polkit_agent_open();
 }
 
 static int list_sessions(DBusConnection *bus, char **args, unsigned n) {
@@ -1286,6 +1300,8 @@ static int enable_linger(DBusConnection *bus, char **args, unsigned n) {
 
         dbus_error_init(&error);
 
+        polkit_agent_open_if_enabled();
+
         b = streq(args[0], "enable-linger");
 
         for (i = 1; i < n; i++) {
@@ -1490,6 +1506,8 @@ static int attach(DBusConnection *bus, char **args, unsigned n) {
 
         dbus_error_init(&error);
 
+        polkit_agent_open_if_enabled();
+
         for (i = 2; i < n; i++) {
                 DBusMessage *reply;
 
@@ -1546,6 +1564,8 @@ static int flush_devices(DBusConnection *bus, char **args, unsigned n) {
 
         dbus_error_init(&error);
 
+        polkit_agent_open_if_enabled();
+
         m = dbus_message_new_method_call(
                         "org.freedesktop.login1",
                         "/org/freedesktop/login1",
@@ -1684,7 +1704,8 @@ static int parse_argv(int argc, char *argv[]) {
         enum {
                 ARG_VERSION = 0x100,
                 ARG_NO_PAGER,
-                ARG_KILL_WHO
+                ARG_KILL_WHO,
+                ARG_NO_ASK_PASSWORD
         };
 
         static const struct option options[] = {
@@ -1697,6 +1718,7 @@ static int parse_argv(int argc, char *argv[]) {
                 { "signal",    required_argument, NULL, 's'           },
                 { "host",      required_argument, NULL, 'H'           },
                 { "privileged",no_argument,       NULL, 'P'           },
+                { "no-ask-password", no_argument, NULL, ARG_NO_ASK_PASSWORD },
                 { NULL,        0,                 NULL, 0             }
         };
 
@@ -1744,6 +1766,9 @@ static int parse_argv(int argc, char *argv[]) {
                         arg_no_pager = true;
                         break;
 
+                case ARG_NO_ASK_PASSWORD:
+                        arg_ask_password = false;
+
                 case ARG_KILL_WHO:
                         arg_kill_who = optarg;
                         break;
diff --git a/src/shared/util.c b/src/shared/util.c
index 73e0a290b..7f41fc4f5 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -6035,3 +6035,88 @@ int fd_inc_rcvbuf(int fd, size_t n) {
 
         return 1;
 }
+
+int fork_agent(pid_t *pid, const char *path, ...) {
+        pid_t parent_pid, agent_pid;
+        int fd;
+        bool stdout_is_tty, stderr_is_tty;
+        unsigned n, i;
+        va_list ap;
+        char **l;
+
+        assert(pid);
+        assert(path);
+
+        parent_pid = getpid();
+
+        /* Spawns a temporary TTY agent, making sure it goes away when
+         * we go away */
+
+        agent_pid = fork();
+        if (agent_pid < 0)
+                return -errno;
+
+        if (agent_pid != 0) {
+                *pid = agent_pid;
+                return 0;
+        }
+
+        /* In the child:
+         *
+         * Make sure the agent goes away when the parent dies */
+        if (prctl(PR_SET_PDEATHSIG, SIGTERM) < 0)
+                _exit(EXIT_FAILURE);
+
+        /* Check whether our parent died before we were able
+         * to set the death signal */
+        if (getppid() != parent_pid)
+                _exit(EXIT_SUCCESS);
+
+        /* Don't leak fds to the agent */
+        close_all_fds(NULL, 0);
+
+        stdout_is_tty = isatty(STDOUT_FILENO);
+        stderr_is_tty = isatty(STDERR_FILENO);
+
+        if (!stdout_is_tty || !stderr_is_tty) {
+                /* Detach from stdout/stderr. and reopen
+                 * /dev/tty for them. This is important to
+                 * ensure that when systemctl is started via
+                 * popen() or a similar call that expects to
+                 * read EOF we actually do generate EOF and
+                 * not delay this indefinitely by because we
+                 * keep an unused copy of stdin around. */
+                fd = open("/dev/tty", O_WRONLY);
+                if (fd < 0) {
+                        log_error("Failed to open /dev/tty: %m");
+                        _exit(EXIT_FAILURE);
+                }
+
+                if (!stdout_is_tty)
+                        dup2(fd, STDOUT_FILENO);
+
+                if (!stderr_is_tty)
+                        dup2(fd, STDERR_FILENO);
+
+                if (fd > 2)
+                        close(fd);
+        }
+
+        /* Count arguments */
+        va_start(ap, path);
+        for (n = 0; va_arg(ap, char*); n++)
+                ;
+        va_end(ap);
+
+        /* Allocate strv */
+        l = alloca(sizeof(char *) * (n + 1));
+
+        /* Fill in arguments */
+        va_start(ap, path);
+        for (i = 0; i <= n; i++)
+                l[i] = va_arg(ap, char*);
+        va_end(ap);
+
+        execv(path, l);
+        _exit(EXIT_FAILURE);
+}
diff --git a/src/shared/util.h b/src/shared/util.h
index e0934e59d..5e927df02 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -528,4 +528,7 @@ int is_kernel_thread(pid_t pid);
 
 int fd_inc_sndbuf(int fd, size_t n);
 int fd_inc_rcvbuf(int fd, size_t n);
+
+int fork_agent(pid_t *pid, const char *path, ...);
+
 #endif
diff --git a/src/spawn-agent.c b/src/spawn-agent.c
deleted file mode 100644
index 2de253088..000000000
--- a/src/spawn-agent.c
+++ /dev/null
@@ -1,120 +0,0 @@
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-/***
-  This file is part of systemd.
-
-  Copyright 2011 Lennart Poettering
-
-  systemd is free software; you can redistribute it and/or modify it
-  under the terms of the GNU General Public License as published by
-  the Free Software Foundation; either version 2 of the License, or
-  (at your option) any later version.
-
-  systemd is distributed in the hope that it will be useful, but
-  WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-  General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include <sys/types.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <string.h>
-#include <sys/prctl.h>
-#include <signal.h>
-#include <fcntl.h>
-
-#include "log.h"
-#include "util.h"
-#include "spawn-agent.h"
-
-static pid_t agent_pid = 0;
-
-void agent_open(void) {
-        pid_t parent_pid;
-
-        if (agent_pid > 0)
-                return;
-
-        /* We check STDIN here, not STDOUT, since this is about input,
-         * not output */
-        if (!isatty(STDIN_FILENO))
-                return;
-
-        parent_pid = getpid();
-
-        /* Spawns a temporary TTY agent, making sure it goes away when
-         * we go away */
-
-        agent_pid = fork();
-        if (agent_pid < 0) {
-                log_error("Failed to fork agent: %m");
-                return;
-        }
-
-        if (agent_pid == 0) {
-                /* In the child */
-
-                int fd;
-                bool stdout_is_tty, stderr_is_tty;
-
-                /* Make sure the agent goes away when the parent dies */
-                if (prctl(PR_SET_PDEATHSIG, SIGTERM) < 0)
-                        _exit(EXIT_FAILURE);
-
-                /* Check whether our parent died before we were able
-                 * to set the death signal */
-                if (getppid() != parent_pid)
-                        _exit(EXIT_SUCCESS);
-
-                /* Don't leak fds to the agent */
-                close_all_fds(NULL, 0);
-
-                stdout_is_tty = isatty(STDOUT_FILENO);
-                stderr_is_tty = isatty(STDERR_FILENO);
-
-                if (!stdout_is_tty || !stderr_is_tty) {
-                        /* Detach from stdout/stderr. and reopen
-                         * /dev/tty for them. This is important to
-                         * ensure that when systemctl is started via
-                         * popen() or a similar call that expects to
-                         * read EOF we actually do generate EOF and
-                         * not delay this indefinitely by because we
-                         * keep an unused copy of stdin around. */
-                        fd = open("/dev/tty", O_WRONLY);
-                        if (fd < 0) {
-                                log_error("Failed to open /dev/tty: %m");
-                                _exit(EXIT_FAILURE);
-                        }
-
-                        if (!stdout_is_tty)
-                                dup2(fd, STDOUT_FILENO);
-
-                        if (!stderr_is_tty)
-                                dup2(fd, STDERR_FILENO);
-
-                        if (fd > 2)
-                                close(fd);
-                }
-
-                execl(SYSTEMD_TTY_ASK_PASSWORD_AGENT_BINARY_PATH, SYSTEMD_TTY_ASK_PASSWORD_AGENT_BINARY_PATH, "--watch", NULL);
-
-                log_error("Unable to execute agent: %m");
-                _exit(EXIT_FAILURE);
-        }
-}
-
-void agent_close(void) {
-
-        if (agent_pid <= 0)
-                return;
-
-        /* Inform agent that we are done */
-        kill(agent_pid, SIGTERM);
-        kill(agent_pid, SIGCONT);
-        wait_for_terminate(agent_pid, NULL);
-        agent_pid = 0;
-}
diff --git a/src/spawn-ask-password-agent.c b/src/spawn-ask-password-agent.c
new file mode 100644
index 000000000..82db08c3a
--- /dev/null
+++ b/src/spawn-ask-password-agent.c
@@ -0,0 +1,64 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2011 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/types.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/prctl.h>
+#include <signal.h>
+#include <fcntl.h>
+
+#include "log.h"
+#include "util.h"
+#include "spawn-ask-password-agent.h"
+
+static pid_t agent_pid = 0;
+
+int ask_password_agent_open(void) {
+        int r;
+
+        if (agent_pid > 0)
+                return 0;
+
+        /* We check STDIN here, not STDOUT, since this is about input,
+         * not output */
+        if (!isatty(STDIN_FILENO))
+                return 0;
+
+        r = fork_agent(&agent_pid, SYSTEMD_TTY_ASK_PASSWORD_AGENT_BINARY_PATH, SYSTEMD_TTY_ASK_PASSWORD_AGENT_BINARY_PATH, "--watch", NULL);
+        if (r < 0)
+                log_error("Failed to fork TTY ask password agent: %s", strerror(-r));
+
+        return r;
+}
+
+void ask_password_agent_close(void) {
+
+        if (agent_pid <= 0)
+                return;
+
+        /* Inform agent that we are done */
+        kill(agent_pid, SIGTERM);
+        kill(agent_pid, SIGCONT);
+        wait_for_terminate(agent_pid, NULL);
+        agent_pid = 0;
+}
diff --git a/src/core/spawn-agent.h b/src/spawn-ask-password-agent.h
index fd0a9109b..dae039ad0 100644
--- a/src/core/spawn-agent.h
+++ b/src/spawn-ask-password-agent.h
@@ -1,7 +1,7 @@
 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
 
-#ifndef foospawnagenthfoo
-#define foospawnagenthfoo
+#ifndef foospawnaskpasswordagenthfoo
+#define foospawnaskpasswordagenthfoo
 
 /***
   This file is part of systemd.
@@ -22,7 +22,7 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-void agent_open(void);
-void agent_close(void);
+int ask_password_agent_open(void);
+void ask_password_agent_close(void);
 
 #endif
diff --git a/src/spawn-polkit-agent.c b/src/spawn-polkit-agent.c
new file mode 100644
index 000000000..0da9abb7e
--- /dev/null
+++ b/src/spawn-polkit-agent.c
@@ -0,0 +1,64 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2011 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/types.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/prctl.h>
+#include <signal.h>
+#include <fcntl.h>
+
+#include "log.h"
+#include "util.h"
+#include "spawn-polkit-agent.h"
+
+static pid_t agent_pid = 0;
+
+int polkit_agent_open(void) {
+        int r;
+
+        if (agent_pid > 0)
+                return 0;
+
+        /* We check STDIN here, not STDOUT, since this is about input,
+         * not output */
+        if (!isatty(STDIN_FILENO))
+                return 0;
+
+        r = fork_agent(&agent_pid, POLKIT_AGENT_BINARY_PATH, POLKIT_AGENT_BINARY_PATH, NULL);
+        if (r < 0)
+                log_error("Failed to fork TTY ask password agent: %s", strerror(-r));
+
+        return r;
+}
+
+void polkit_agent_close(void) {
+
+        if (agent_pid <= 0)
+                return;
+
+        /* Inform agent that we are done */
+        kill(agent_pid, SIGTERM);
+        kill(agent_pid, SIGCONT);
+        wait_for_terminate(agent_pid, NULL);
+        agent_pid = 0;
+}
diff --git a/src/spawn-polkit-agent.h b/src/spawn-polkit-agent.h
new file mode 100644
index 000000000..34131f019
--- /dev/null
+++ b/src/spawn-polkit-agent.h
@@ -0,0 +1,28 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#ifndef foospawnpolkitagenthfoo
+#define foospawnpolkitagenthfoo
+
+/***
+  This file is part of systemd.
+
+  Copyright 2012 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+int polkit_agent_open(void);
+void polkit_agent_close(void);
+
+#endif
diff --git a/src/systemctl.c b/src/systemctl.c
index 43a1446a8..7abd92838 100644
--- a/src/systemctl.c
+++ b/src/systemctl.c
@@ -57,7 +57,8 @@
 #include "build.h"
 #include "unit-name.h"
 #include "pager.h"
-#include "spawn-agent.h"
+#include "spawn-ask-password-agent.h"
+#include "spawn-polkit-agent.h"
 #include "install.h"
 #include "logs-show.h"
 
@@ -78,7 +79,7 @@ static bool arg_dry = false;
 static bool arg_quiet = false;
 static bool arg_full = false;
 static int arg_force = 0;
-static bool arg_ask_password = false;
+static bool arg_ask_password = true;
 static bool arg_failed = false;
 static bool arg_runtime = false;
 static char **arg_wall = NULL;
@@ -154,7 +155,7 @@ static void pager_open_if_enabled(void) {
         pager_open();
 }
 
-static void agent_open_if_enabled(void) {
+static void ask_password_agent_open_if_enabled(void) {
 
         /* Open the password agent as a child process if necessary */
 
@@ -164,7 +165,20 @@ static void agent_open_if_enabled(void) {
         if (arg_scope != UNIT_FILE_SYSTEM)
                 return;
 
-        agent_open();
+        ask_password_agent_open();
+}
+
+static void polkit_agent_open_if_enabled(void) {
+
+        /* Open the polkit agent as a child process if necessary */
+
+        if (!arg_ask_password)
+                return;
+
+        if (arg_scope != UNIT_FILE_SYSTEM)
+                return;
+
+        polkit_agent_open();
 }
 
 static const char *ansi_highlight_red(bool b) {
@@ -1601,7 +1615,7 @@ static int start_unit(DBusConnection *bus, char **args) {
 
         assert(bus);
 
-        agent_open_if_enabled();
+        ask_password_agent_open_if_enabled();
 
         if (arg_action == ACTION_SYSTEMCTL) {
                 method =
@@ -1695,6 +1709,8 @@ static int reboot_with_logind(DBusConnection *bus, enum action a) {
 
         dbus_error_init(&error);
 
+        polkit_agent_open_if_enabled();
+
         switch (a) {
 
         case ACTION_REBOOT:
@@ -4290,9 +4306,6 @@ static int systemctl_parse_argv(int argc, char *argv[]) {
         assert(argc >= 0);
         assert(argv);
 
-        /* Only when running as systemctl we ask for passwords */
-        arg_ask_password = true;
-
         while ((c = getopt_long(argc, argv, "ht:p:aqfs:H:Pn:o:", options, NULL)) >= 0) {
 
                 switch (c) {
@@ -5503,7 +5516,8 @@ finish:
         strv_free(arg_property);
 
         pager_close();
-        agent_close();
+        ask_password_agent_close();
+        polkit_agent_close();
 
         return retval;
 }