From: Denis Vlasenko <vda.linux@googlemail.com>
Date: Sun, 14 Jan 2007 12:07:25 +0000 (-0000)
Subject: fakeidentd: fix daemon mode (was thinking that it is in
X-Git-Tag: 1_4_0~36
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=19250813a83cb4e1691810d1887658e60e2942d8;p=oweals%2Fbusybox.git

fakeidentd: fix daemon mode (was thinking that it is in
inetd-wait mode and dying after timeout). Minor fixes,
comments are improved in places.
---

diff --git a/networking/isrv.c b/networking/isrv.c
index 02ca1d787..5193f30f3 100644
--- a/networking/isrv.c
+++ b/networking/isrv.c
@@ -21,6 +21,8 @@
 
 /* Helpers */
 
+/* Even if _POSIX_MONOTONIC_CLOCK is defined, this
+ * may require librt */
 #if 0 /*def _POSIX_MONOTONIC_CLOCK*/
 static time_t monotonic_time(void)
 {
@@ -194,7 +196,8 @@ static void handle_accept(isrv_state_t *state, int fd)
 	if (newfd < 0) {
 		if (errno == EAGAIN) return;
 		/* Most probably someone gave us wrong fd type
-		 * (for example, non-socket) */
+		 * (for example, non-socket). Don't want
+		 * to loop forever. */
 		bb_perror_msg_and_die("accept");
 	}
 
@@ -210,6 +213,7 @@ static void handle_fd_set(isrv_state_t *state, fd_set *fds, int (*h)(int, void *
 	enum { LONG_CNT = sizeof(fd_set) / sizeof(long) };
 	int fds_pos;
 	int fd, peer;
+	/* need to know value at _the beginning_ of this routine */
 	int fd_cnt = FD_COUNT;
 
 	if (LONG_CNT * sizeof(long) != sizeof(fd_set))
@@ -235,10 +239,15 @@ static void handle_fd_set(isrv_state_t *state, fd_set *fds, int (*h)(int, void *
 		}
 		break; /* all words are zero */
  found_fd:
-		if (fd >= fd_cnt) /* paranoia */
+		if (fd >= fd_cnt) { /* paranoia */
+			DPRINTF("handle_fd_set: fd > fd_cnt?? (%d > %d)",
+					fd, fd_cnt);
 			break;
+		}
 		DPRINTF("handle_fd_set: fd %d is active", fd);
 		peer = FD2PEER[fd];
+		if (peer < 0)
+			continue; /* peer is already gone */
 		if (peer == 0) {
 			handle_accept(state, fd);
 			continue;
@@ -259,9 +268,9 @@ static void handle_timeout(isrv_state_t *state, int (*do_timeout)(void **))
 	peer = PEER_COUNT-1;
 	/* peer 0 is not checked */
 	while (peer > 0) {
-		DPRINTF("peer %d: time diff %d", peer, (int)(CURTIME - TIMEO_TBL[peer]));
-
-		if ((CURTIME - TIMEO_TBL[peer]) > TIMEOUT) {
+		DPRINTF("peer %d: time diff %d", peer,
+				(int)(CURTIME - TIMEO_TBL[peer]));
+		if ((CURTIME - TIMEO_TBL[peer]) >= TIMEOUT) {
 			DPRINTF("peer %d: do_timeout()", peer);
 			n = do_timeout(&PARAM_TBL[peer]);
 			if (n)
@@ -279,7 +288,7 @@ void isrv_run(
 	int (*do_wr)(int fd, void **),
 	int (*do_timeout)(void **),
 	int timeout,
-	int exit_if_no_clients)
+	int linger_timeout)
 {
 	isrv_state_t *state = xzalloc(sizeof(*state));
 	state->new_peer = new_peer;
@@ -300,6 +309,8 @@ void isrv_run(
 		int n;
 
 		tv.tv_sec = timeout;
+		if (PEER_COUNT <= 1)
+			tv.tv_sec = linger_timeout;
 		tv.tv_usec = 0;
 		rd = state->rd;
 		if (WR_COUNT) {
@@ -307,8 +318,9 @@ void isrv_run(
 			wrp = &wr;
 		}
 
-		DPRINTF("run: select(FD_COUNT:%d,timeout:%d)...", FD_COUNT, timeout);
-		n = select(FD_COUNT, &rd, wrp, NULL, timeout ? &tv : NULL);
+		DPRINTF("run: select(FD_COUNT:%d,timeout:%d)...",
+				FD_COUNT, (int)tv.tv_sec);
+		n = select(FD_COUNT, &rd, wrp, NULL, tv.tv_sec ? &tv : NULL);
 		DPRINTF("run: ...select:%d", n);
 
 		if (n < 0) {
@@ -317,7 +329,7 @@ void isrv_run(
 			continue;
 		}
 
-		if (exit_if_no_clients && n == 0 && PEER_COUNT <= 1)
+		if (n == 0 && linger_timeout && PEER_COUNT <= 1)
 			break;
 
 		if (timeout) {
@@ -334,4 +346,5 @@ void isrv_run(
 		}
 	}
 	DPRINTF("run: bailout");
+	/* NB: accept socket is not closed. Caller is to decide what to do */
 }
diff --git a/networking/isrv_identd.c b/networking/isrv_identd.c
index b9481f8d3..30f9a7a26 100644
--- a/networking/isrv_identd.c
+++ b/networking/isrv_identd.c
@@ -13,14 +13,6 @@
 
 enum { TIMEOUT = 20 };
 
-/* Why use alarm(TIMEOUT-1)?
- * isrv's internal select() will run with timeout=TIMEOUT.
- * If nothing happens during TIMEOUT-1 seconds (no accept/read),
- * then ALL sessions timed out by now. Instead of closing them one-by-one
- * (isrv calls do_timeout for each 'stale' session),
- * SIGALRM triggered by alarm(TIMEOUT-1) will kill us, terminating them all.
- */
-
 typedef struct identd_buf_t {
 	int pos;
 	int fd_flag;
@@ -34,8 +26,6 @@ static int new_peer(isrv_state_t *state, int fd)
 	int peer;
 	identd_buf_t *buf = xzalloc(sizeof(*buf));
 
-	alarm(TIMEOUT - 1);
-
 	peer = isrv_register_peer(state, buf);
 	if (peer < 0)
 		return 0; /* failure */
@@ -53,11 +43,9 @@ static int do_rd(int fd, void **paramp)
 	char *cur, *p;
 	int sz;
 
-	alarm(TIMEOUT - 1);
-
 	cur = buf->buf + buf->pos;
 
-	fcntl(fd, F_SETFL, buf->fd_flag | O_NONBLOCK);
+	fcntl(fd, F_SETFL, buf->fd_flag);
 	sz = safe_read(fd, cur, sizeof(buf->buf) - buf->pos);
 
 	if (sz < 0) {
@@ -95,6 +83,8 @@ static void inetd_mode(void)
 	identd_buf_t *buf = xzalloc(sizeof(*buf));
 	/* We do NOT want nonblocking I/O here! */
 	buf->fd_flag = fcntl(0, F_GETFL, 0);
+	do
+		alarm(TIMEOUT);
 	while (do_rd(0, (void*)&buf) == 0) /* repeat */;
 }
 
@@ -139,6 +129,7 @@ int fakeidentd_main(int argc, char **argv)
 		xlisten(fd, 5);
 	}
 
-	isrv_run(fd, new_peer, do_rd, NULL, do_timeout, TIMEOUT, 1);
+	isrv_run(fd, new_peer, do_rd, /*do_wr:*/ NULL, do_timeout,
+			TIMEOUT, (opt & OPT_inetdwait) ? TIMEOUT : 0);
 	return 0;
 }