From 3586a899e49fbe9d3e5d88b9f0500040dc622565 Mon Sep 17 00:00:00 2001
From: Mike Gilbert <floppym@gentoo.org>
Date: Thu, 23 May 2024 15:28:39 -0400
Subject: openrc-shutdown: simplify broadcast function
Get rid of the alarm/setjmp/longjmp.
Trust that the kernel will not block with O_NDELAY.
Use write() instead of stdio.
Bug: https://bugs.gentoo.org/923326
Signed-off-by: Mike Gilbert <floppym@gentoo.org>
---
src/openrc-shutdown/broadcast.c | 55 ++++++++---------------------------------
1 file changed, 10 insertions(+), 45 deletions(-)
(limited to 'src/openrc-shutdown')
diff --git a/src/openrc-shutdown/broadcast.c b/src/openrc-shutdown/broadcast.c
index f21ee95c..f506354d 100644
--- a/src/openrc-shutdown/broadcast.c
+++ b/src/openrc-shutdown/broadcast.c
@@ -17,8 +17,6 @@
#include <fcntl.h>
#include <paths.h>
#include <pwd.h>
-#include <signal.h>
-#include <setjmp.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@@ -37,15 +35,6 @@
# define _PATH_DEV "/dev/"
#endif
-static sigjmp_buf jbuf;
-
-/*
- * Alarm handler
- */
-RC_NORETURN static void handler(int arg RC_UNUSED)
-{
- siglongjmp(jbuf, 1);
-}
static void getuidtty(char **userp, char **ttyp)
{
@@ -120,19 +109,13 @@ void broadcast(char *text)
char *user;
struct utsname name;
time_t t;
- char *date;
+ char *date;
char *p;
char *line = NULL;
- struct sigaction sa;
- int flags;
+ int len;
+ int fd;
char *term = NULL;
struct utmpx *utmp;
- /*
- * These are set across the sigsetjmp call, so they can't be stored on
- * the stack, otherwise they might be clobbered.
- */
- static int fd;
- static FILE *tp;
getuidtty(&user, &tty);
@@ -149,8 +132,8 @@ void broadcast(char *text)
if (p)
*p = 0;
- xasprintf(&line, "\007\r\nBroadcast message from %s@%s %s(%s):\r\n\r\n",
- user, name.nodename, tty, date);
+ len = xasprintf(&line, "\007\r\nBroadcast message from %s@%s %s(%s):\r\n\r\n%s",
+ user, name.nodename, tty, date, text);
free(tty);
/*
@@ -159,11 +142,6 @@ void broadcast(char *text)
if (fork() != 0)
return;
- memset(&sa, 0, sizeof(sa));
- sa.sa_handler = handler;
- sigemptyset(&sa.sa_mask);
- sigaction(SIGALRM, &sa, NULL);
-
setutxent();
while ((utmp = getutxent()) != NULL) {
@@ -178,25 +156,12 @@ void broadcast(char *text)
continue;
}
- /*
- * Open it non-delay
- */
- if (sigsetjmp(jbuf, 1) == 0) {
- alarm(2);
- flags = O_WRONLY|O_NDELAY|O_NOCTTY;
- if (file_isatty(term) && (fd = open(term, flags)) >= 0) {
- if (isatty(fd) && (tp = fdopen(fd, "w")) != NULL) {
- fputs(line, tp);
- fputs(text, tp);
- fflush(tp);
- }
- }
- }
- alarm(0);
- if (fd >= 0)
+ /* Open it non-delay */
+ if (file_isatty(term) && (fd = open(term, O_WRONLY|O_NDELAY|O_NOCTTY)) >= 0) {
+ if (isatty(fd))
+ write(fd, line, len);
close(fd);
- if (tp != NULL)
- fclose(tp);
+ }
free(term);
}
endutxent();
--
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