Attachment 116907 Details for Bug 82004 – Enable tty-ask-password-agent to ask on all devices of the system console

Enable tty-ask-password-agent to ask on all devices of the system console

0001-Enable-tty-ask-password-agent-to-ask-on-all-devices-.patch (text/plain), 8.51 KB, created by Werner Fink on 2015-07-03 10:33:22 UTC

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Creator: Werner Fink

Created: 2015-07-03 10:33:22 UTC

Size: 8.51 KB

patch

obsolete

>From 5f7eb5bebe2f3e027688028fea0c9e4b35c5279d Mon Sep 17 00:00:00 2001
>From: Werner Fink <werner@suse.de>
>Date: Fri, 3 Jul 2015 12:29:24 +0200
>Subject: [PATCH] Enable tty-ask-password-agent to ask on all devices of the
> system console
>
>Signed-off-by: Werner Fink <werner@suse.de>
>---
> .../tty-ask-password-agent.c                       | 180 ++++++++++++++++++++-
> 1 file changed, 175 insertions(+), 5 deletions(-)
>
>diff --git a/src/tty-ask-password-agent/tty-ask-password-agent.c b/src/tty-ask-password-agent/tty-ask-password-agent.c
>index 73b19d8..0b040da 100644
>--- a/src/tty-ask-password-agent/tty-ask-password-agent.c
>+++ b/src/tty-ask-password-agent/tty-ask-password-agent.c
>@@ -31,6 +31,10 @@
> #include <getopt.h>
> #include <sys/signalfd.h>
> #include <fcntl.h>
>+#include <sys/prctl.h>
>+#include <signal.h>
>+#include <sys/wait.h>
>+#include <sys/mman.h>
> 
> #include "util.h"
> #include "mkdir.h"
>@@ -45,6 +49,8 @@
> #include "process-util.h"
> #include "terminal-util.h"
> #include "signal-util.h"
>+#include "fileio.h"
>+#include "macro.h"
> 
> static enum {
>         ACTION_LIST,
>@@ -53,6 +59,20 @@ static enum {
>         ACTION_WALL
> } arg_action = ACTION_QUERY;
> 
>+struct console {
>+        char *tty;
>+        pid_t pid;
>+        int id;
>+};
>+
>+static volatile unsigned long *usemask;
>+static volatile sig_atomic_t sigchild;
>+static void chld_handler(int sig)
>+{
>+        (void)sig;
>+        ++sigchild;
>+}
>+
> static bool arg_plymouth = false;
> static bool arg_console = false;
> 
>@@ -211,6 +231,60 @@ static int ask_password_plymouth(
>         return 0;
> }
> 
>+static const char *current_dev = "/dev/console";
>+static struct console* collect_consoles(int * num) {
>+        _cleanup_free_ char *active = NULL;
>+        const char *word, *state;
>+        struct console *con = NULL;
>+        size_t con_len;
>+        size_t len;
>+        int ret, id = 0;
>+
>+        ret = read_one_line_file("/sys/class/tty/console/active", &active);
>+        if (ret < 0)
>+                return con;
>+        FOREACH_WORD(word, len, active, state) {
>+                _cleanup_free_ char *tty = NULL;
>+
>+                if (strneq(word, "tty0", len) &&
>+                    read_one_line_file("/sys/class/tty/tty0/active", &tty) >= 0) {
>+                        word = tty;
>+                        len = strlen(tty);
>+                }
>+                con = greedy_realloc((void**)&con, &con_len, ++id, sizeof(struct console) + 5 + len + 1);
>+                if (con == NULL) {
>+                        log_oom();
>+                        return con;
>+                }
>+                con->tty = ((char*)con)+sizeof(struct console);
>+                sprintf(con->tty, "/dev/%.*s", (int)len, word);
>+                con->id = id;
>+        }
>+        if (con == NULL) {
>+                con = greedy_realloc((void**)&con, &con_len, 1, sizeof(struct console));
>+                if (con == NULL) {
>+                        log_oom();
>+                        return con;
>+                }
>+                con->tty = (char*)current_dev;
>+                con->id = id = 1;
>+        }
>+
>+        if (num)
>+                *num = id;
>+        return con;
>+}
>+
>+static void free_consoles(struct console *con, int num) {
>+        int n;
>+
>+        if (!con)
>+                return;
>+        for (n = 0; n < num; n++)
>+                free(&con[n]);
>+        free(con);
>+}
>+
> static int parse_password(const char *filename, char **wall) {
>         _cleanup_free_ char *socket_name = NULL, *message = NULL, *packet = NULL;
>         uint64_t not_after = 0;
>@@ -311,7 +385,7 @@ static int parse_password(const char *filename, char **wall) {
>                         _cleanup_free_ char *password = NULL;
> 
>                         if (arg_console) {
>-                                tty_fd = acquire_terminal("/dev/console", false, false, false, USEC_INFINITY);
>+                                tty_fd = acquire_terminal(current_dev, false, false, false, USEC_INFINITY);
>                                 if (tty_fd < 0)
>                                         return tty_fd;
>                         }
>@@ -615,8 +689,87 @@ static int parse_argv(int argc, char *argv[]) {
>         return 1;
> }
> 
>+static int wait_for_answer(void)
>+{
>+        struct console *consoles;
>+        struct sigaction sig = {
>+                .sa_handler = chld_handler,
>+                .sa_flags = SA_NOCLDSTOP | SA_RESTART,
>+        };
>+        struct sigaction oldsig;
>+        sigset_t set, oldset;
>+        int status = 0, num = 0, n, ret;
>+        pid_t job;
>+
>+        consoles = collect_consoles(&num);
>+        if (!consoles) {
>+                log_error("Failed to query password: %m");
>+                exit(EXIT_FAILURE);
>+        }
>+        if (num == 1) {
>+                n = 1;
>+                goto nofork;
>+        }
>+
>+        assert_se(sigemptyset(&set) == 0);
>+        assert_se(sigaddset(&set, SIGHUP) == 0);
>+        assert_se(sigaddset(&set, SIGCHLD) == 0);
>+        assert_se(sigemptyset(&sig.sa_mask) == 0);
>+        assert_se(sigprocmask(SIG_UNBLOCK, &set, &oldset) == 0);
>+        assert_se(sigaction(SIGCHLD, &sig, &oldsig) == 0);
>+        sig.sa_handler = SIG_DFL;
>+        assert_se(sigaction(SIGHUP, &sig, NULL) == 0);
>+
>+        for (n = 0; n < num; n++) {
>+                consoles[n].pid = fork();
>+
>+                if (consoles[n].pid < 0) {
>+                        log_error("Failed to query password: %m");
>+                        exit(EXIT_FAILURE);
>+                }
>+
>+                if (consoles[n].pid == 0) {
>+                        if (prctl(PR_SET_PDEATHSIG, SIGHUP) < 0)
>+                                _exit(EXIT_FAILURE);
>+                        zero(sig);
>+                        assert_se(sigprocmask(SIG_UNBLOCK, &oldset, NULL) == 0);
>+                        assert_se(sigaction(SIGCHLD, &oldsig, NULL) == 0);
>+                nofork:
>+                        setsid();
>+                        release_terminal();
>+                        *usemask |= 1 << consoles[n].id;
>+                        current_dev = consoles[n].tty;
>+                        return consoles[n].id; /* child */
>+                }
>+        }
>+
>+        ret = 0;
>+        while ((job = wait(&status)) != 0) {
>+                if (job < 0) {
>+                        if (errno != EINTR)
>+                                break;
>+                        continue;
>+                }
>+                for (n = 0; n < num; n++) {
>+                        if (consoles[n].pid == job || kill(consoles[n].pid, 0) < 0) {
>+                                *usemask &= ~(1 << consoles[n].id);
>+                                continue;
>+                        }
>+                        if (*usemask & (1 << consoles[n].id))
>+                                continue;
>+                        kill(consoles[n].pid, SIGHUP);
>+                        usleep(50000);
>+                        kill(consoles[n].pid, SIGKILL);
>+                }
>+                if (WIFEXITED(status) && ret == 0)
>+                        ret = WEXITSTATUS(status);
>+        }
>+        free_consoles(consoles, num);
>+        exit(ret != 0 ? EXIT_FAILURE : EXIT_SUCCESS); /* parent */
>+}
>+
> int main(int argc, char *argv[]) {
>-        int r;
>+        int r, id = 0;
> 
>         log_set_target(LOG_TARGET_AUTO);
>         log_parse_environment();
>@@ -628,11 +781,27 @@ int main(int argc, char *argv[]) {
>         if (r <= 0)
>                 goto finish;
> 
>+        /*
>+         * Use this shared memory area to be able to synchronize the
>+         * workers asking for password with the main process.
>+         * This allows to continue if one of the consoles had been
>+         * used as afterwards the remaining asking processes will
>+         * be terminated.  The wait_for_terminate() does not help
>+         * for this use case.
>+         */
>+        usemask = mmap(NULL, sizeof(*usemask), PROT_READ | PROT_WRITE,
>+                       MAP_ANONYMOUS | MAP_SHARED, -1, 0);
>+        assert_se(usemask != NULL);
>+
>         if (arg_console) {
>-                setsid();
>-                release_terminal();
>+                if (!arg_plymouth && arg_action != ACTION_WALL &&
>+                    arg_action != ACTION_LIST) {
>+                        id = wait_for_answer();
>+                } else {
>+                        setsid();
>+                        release_terminal();
>+                }
>         }
>-
>         if (IN_SET(arg_action, ACTION_WATCH, ACTION_WALL))
>                 r = watch_passwords();
>         else
>@@ -641,6 +810,7 @@ int main(int argc, char *argv[]) {
>         if (r < 0)
>                 log_error_errno(r, "Error: %m");
> 
>+        *usemask &= ~(1 << id);
> finish:
>         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
> }
>-- 
>2.2.0
>

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Attachments on bug 82004: 103806 | 116907

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