[PATCH 14/19] mwrap_httpd: do not abort on fork if out-of-resources

[Eric Wong <e@80x24.org>]

Instead, we'll leak memory if the pthread_atfork handlers can't
stop httpd at fork due to resource limitations.
---
 mwrap_httpd.h | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/mwrap_httpd.h b/mwrap_httpd.h
index f484bdd..fc096c0 100644
--- a/mwrap_httpd.h
+++ b/mwrap_httpd.h
@@ -1094,6 +1094,12 @@ static int h1d_init(struct mw_h1d *h1d, const char *menv)
 	memcpy(h1d->pid_str, p, h1d->pid_len);
 	if (unlink(sa.un.sun_path) < 0 && errno != ENOENT)
 		return fprintf(stderr, "unlink(%s): %m\n", sa.un.sun_path);
+	/*
+	 * lfd may be >=0 if h1d_stop_join failed in parent and we're now
+	 * running in a forked child
+	 */
+	if (h1d->lfd >= 0)
+		(void)close(h1d->lfd);
 	h1d->lfd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
 	if (h1d->lfd < 0)
 		return fprintf(stderr, "socket: %m\n");
@@ -1204,25 +1210,28 @@ static void h1d_stop_join(struct mw_h1d *h1d)
 	socklen_t len = (socklen_t)sizeof(sa);
 	int e, sfd;
 	void *ret;
+#define ERR ": %m (can't stop mwrap-httpd before fork)\n"
 
 	mwrap_assert(uatomic_read(&h1d->alive) == 0);
 	if (getsockname(h1d->lfd, &sa.any, &len) < 0) {
-		fprintf(stderr, "getsockname: %m\n");
-		abort(); /* TODO: graceful fallback (ENOBUFS) */
+		fprintf(stderr, "getsockname"ERR);
+		return;
 	}
 	sfd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0);
 	if (sfd < 0) {
-		fprintf(stderr, "socket: %m\n");
-		abort(); /* TODO: graceful fallback (ENOMEM, EMFILE, ...) */
+		fprintf(stderr, "socket"ERR);
+		return;
 	}
 	if (connect(sfd, &sa.any, len) < 0) {
-		fprintf(stderr, "connect: %m\n");
-		/* TODO: graceful fallback (EAGAIN, ...) */
+		fprintf(stderr, "connect"ERR);
+		close(sfd);
+		return;
 	}
+#undef ERR
 	(void)close(sfd);
 	e = pthread_join(h1d->tid, &ret);
 	if (e) {
-		fprintf(stderr, "pthread_join: %s\n", strerror(e));
+		fprintf(stderr, "BUG? pthread_join: %s\n", strerror(e));
 		abort();
 	}
 	(void)close(h1d->lfd);