telnetd: fix problem with zombies (by Paul Fox <pgf@brightstareng.com>)
syslogd: strip trailing NULs
diff --git a/archival/unzip.c b/archival/unzip.c
index 8462822..001f2e1 100644
--- a/archival/unzip.c
+++ b/archival/unzip.c
@@ -57,7 +57,7 @@
uint16_t filename_len; /* 22-23 */
uint16_t extra_len; /* 24-25 */
} formatted ATTRIBUTE_PACKED;
-} zip_header_t;
+} zip_header_t ATTRIBUTE_PACKED;
/* Check the offset of the last element, not the length. This leniency
* allows for poor packing, whereby the overall struct may be too long,
diff --git a/networking/telnetd.c b/networking/telnetd.c
index cccf03d..108bbf4 100644
--- a/networking/telnetd.c
+++ b/networking/telnetd.c
@@ -279,6 +279,10 @@
/* make new session and process group */
setsid();
+ /* Restore default signal handling */
+ signal(SIGCHLD, SIG_DFL);
+ signal(SIGPIPE, SIG_DFL);
+
/* open the child's side of the tty. */
/* NB: setsid() disconnects from any previous ctty's. Therefore
* we must open child's side of the tty AFTER setsid! */
@@ -302,14 +306,18 @@
/* Uses FILE-based I/O to stdout, but does fflush(stdout),
* so should be safe with vfork.
* I fear, though, that some users will have ridiculously big
- * issue files, and they may block writing to fd 1. */
+ * issue files, and they may block writing to fd 1,
+ * (parent is supposed to read it, but parent waits
+ * for vforked child to exec!) */
print_login_issue(issuefile, NULL);
/* Exec shell / login / whatever */
login_argv[0] = loginpath;
login_argv[1] = NULL;
- execvp(loginpath, (char **)login_argv);
- /* Safer with vfork, and we shouldn't send message
+ /* exec busybox applet (if PREFER_APPLETS=y), if that fails,
+ * exec external program */
+ BB_EXECVP(loginpath, (char **)login_argv);
+ /* _exit is safer with vfork, and we shouldn't send message
* to remote clients anyway */
_exit(1); /*bb_perror_msg_and_die("execv %s", loginpath);*/
}
@@ -374,7 +382,7 @@
#else /* !FEATURE_TELNETD_STANDALONE */
-/* Used in main() only, thus exits. */
+/* Used in main() only, thus "return 0" actually is exit(0). */
#define free_session(ts) return 0
#endif
@@ -384,20 +392,22 @@
pid_t pid;
struct tsession *ts;
- pid = waitpid(-1, &sig, WNOHANG);
- if (pid > 0) {
+ /* Looping: more than one child may have exited */
+ while (1) {
+ pid = waitpid(-1, NULL, WNOHANG);
+ if (pid <= 0)
+ break;
ts = sessions;
while (ts) {
if (ts->shell_pid == pid) {
ts->shell_pid = -1;
- return;
+ break;
}
ts = ts->next;
}
}
}
-
int telnetd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int telnetd_main(int argc, char **argv)
{
@@ -430,7 +440,7 @@
if (!(opt & OPT_FOREGROUND)) {
/* DAEMON_CHDIR_ROOT was giving inconsistent
* behavior with/without -F, -i */
- bb_daemonize_or_rexec(0 /*DAEMON_CHDIR_ROOT*/, argv);
+ bb_daemonize_or_rexec(0 /*was DAEMON_CHDIR_ROOT*/, argv);
}
}
/* Redirect log to syslog early, if needed */
@@ -466,6 +476,8 @@
if (opt & OPT_WATCHCHILD)
signal(SIGCHLD, handle_sigchld);
+ else /* prevent dead children from becoming zombies */
+ signal(SIGCHLD, SIG_IGN);
/*
This is how the buffers are used. The arrows indicate the movement
@@ -497,7 +509,7 @@
while (ts) {
struct tsession *next = ts->next; /* in case we free ts. */
if (ts->shell_pid == -1) {
- /* Child died ad we detected that */
+ /* Child died and we detected that */
free_session(ts);
} else {
if (ts->size1 > 0) /* can write to pty */
@@ -514,7 +526,7 @@
if (!IS_INETD) {
FD_SET(master_fd, &rdfdset);
/* This is needed because free_session() does not
- * take into account master_fd when it finds new
+ * take master_fd into account when it finds new
* maxfd among remaining fd's */
if (master_fd > maxfd)
maxfd = master_fd;
diff --git a/sysklogd/syslogd.c b/sysklogd/syslogd.c
index ba46792..2bf5b5c 100644
--- a/sysklogd/syslogd.c
+++ b/sysklogd/syslogd.c
@@ -381,8 +381,8 @@
}
/* len parameter is used only for "is there a timestamp?" check.
- * NB: some callers cheat and supply 0 when they know
- * that there is no timestamp, short-cutting the test. */
+ * NB: some callers cheat and supply len==0 when they know
+ * that there is no timestamp, short-circuiting the test. */
static void timestamp_and_log(int pri, char *msg, int len)
{
char *timestamp;
@@ -427,10 +427,10 @@
if (*p == '<') {
/* Parse the magic priority number */
pri = bb_strtou(p + 1, &p, 10);
- if (*p == '>') p++;
- if (pri & ~(LOG_FACMASK | LOG_PRIMASK)) {
+ if (*p == '>')
+ p++;
+ if (pri & ~(LOG_FACMASK | LOG_PRIMASK))
pri = (LOG_USER | LOG_NOTICE);
- }
}
while ((c = *p++)) {
@@ -526,14 +526,22 @@
for (;;) {
size_t sz;
-
+ read_again:
sz = safe_read(sock_fd, G.recvbuf, MAX_READ - 1);
- if (sz <= 0) {
- //if (sz == 0)
- // continue; /* EOF from unix socket??? */
+ if (sz < 0) {
bb_perror_msg_and_die("read from /dev/log");
}
+ /* Drop trailing NULs (typically there is one NUL) */
+ while (1) {
+ if (sz == 0)
+ goto read_again;
+ if (G.recvbuf[sz-1])
+ break;
+ sz--;
+ }
+ G.recvbuf[sz] = '\0'; /* make sure it *is* NUL terminated */
+
/* TODO: maybe suppress duplicates? */
#if ENABLE_FEATURE_REMOTE_LOG
/* We are not modifying log messages in any way before send */
@@ -549,7 +557,6 @@
}
}
#endif
- G.recvbuf[sz] = '\0';
split_escape_and_log(G.recvbuf, sz);
} /* for */
}