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authorbenno2013-10-20 09:36:29 +0000
committerWynn Wolf Arbor2020-05-24 12:33:55 +0200
commit6d8490608d2f00828fdc16a096ca190f531decd4 (patch)
treeff92e4cb085a42407a04d07946f42befcb60b752
parent1483ec35ca0c0575168c67f6ccfb4244c798b65c (diff)
downloadslowcgi-6d8490608d2f00828fdc16a096ca190f531decd4.tar.gz
reserve file descriptors for incoming connections so we will be able to actually run the cgi for them later on. mirrored on relayd. ok florian@ blambert@
-rw-r--r--slowcgi.c38
1 files changed, 35 insertions, 3 deletions
diff --git a/slowcgi.c b/slowcgi.c
index f3c3f41..96f925c 100644
--- a/slowcgi.c
+++ b/slowcgi.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: slowcgi.c,v 1.18 2013/10/19 14:18:35 florian Exp $ */
+/* $OpenBSD: slowcgi.c,v 1.19 2013/10/20 09:36:29 benno Exp $ */
/*
* Copyright (c) 2013 David Gwynne <dlg@openbsd.org>
* Copyright (c) 2013 Florian Obser <florian@openbsd.org>
@@ -68,6 +68,9 @@
#define FCGI_OVERLOADED 2
#define FCGI_UNKNOWN_ROLE 3
+#define FD_RESERVE 5
+#define FD_NEEDED 6
+volatile int cgi_inflight = 0;
struct listener {
struct event ev, pause;
@@ -128,6 +131,7 @@ struct request {
int stderr_fd_closed;
uint8_t script_flags;
uint8_t request_started;
+ int inflight_fds_accounted;
};
struct requests {
@@ -157,6 +161,8 @@ struct fcgi_end_request_body {
__dead void usage(void);
void slowcgi_listen(char *, gid_t);
void slowcgi_paused(int, short, void *);
+int accept_reserve(int, struct sockaddr *, socklen_t *, int,
+ volatile int *);
void slowcgi_accept(int, short, void *);
void slowcgi_request(int, short, void *);
void slowcgi_response(int, short, void *);
@@ -366,6 +372,25 @@ slowcgi_paused(int fd, short events, void *arg)
event_add(&l->ev, NULL);
}
+int
+accept_reserve(int sockfd, struct sockaddr *addr, socklen_t *addrlen,
+ int reserve, volatile int *counter)
+{
+ int ret;
+ if (getdtablecount() + reserve +
+ (*counter * FD_NEEDED) >= getdtablesize()) {
+ ldebug("inflight fds exceded");
+ errno = EMFILE;
+ return -1;
+ }
+
+ if ((ret = accept(sockfd, addr, addrlen)) > -1) {
+ (*counter)++;
+ ldebug("inflight incremented, now %d", *counter);
+ }
+ return ret;
+}
+
void
slowcgi_accept(int fd, short events, void *arg)
{
@@ -383,8 +408,8 @@ slowcgi_accept(int fd, short events, void *arg)
c = NULL;
len = sizeof(ss);
- s = accept(fd, (struct sockaddr *)&ss, &len);
- if (s == -1) {
+ if ((s = accept_reserve(fd, (struct sockaddr *)&ss,
+ &len, FD_RESERVE, &cgi_inflight)) == -1) {
switch (errno) {
case EINTR:
case EWOULDBLOCK:
@@ -408,12 +433,14 @@ slowcgi_accept(int fd, short events, void *arg)
if (c == NULL) {
lwarn("cannot calloc request");
close(s);
+ cgi_inflight--;
return;
}
requests = calloc(1, sizeof(*requests));
if (requests == NULL) {
lwarn("cannot calloc requests");
close(s);
+ cgi_inflight--;
free(c);
return;
}
@@ -422,6 +449,7 @@ slowcgi_accept(int fd, short events, void *arg)
c->buf_len = 0;
c->request_started = 0;
c->stdin_fd_closed = c->stdout_fd_closed = c->stderr_fd_closed = 0;
+ c->inflight_fds_accounted = 0;
TAILQ_INIT(&c->response_head);
TAILQ_INIT(&c->stdin_head);
@@ -792,6 +820,8 @@ exec_cgi(struct request *c)
lerr(1, "socketpair");
if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, s_err) == -1)
lerr(1, "socketpair");
+ cgi_inflight--;
+ c->inflight_fds_accounted = 1;
ldebug("fork: %s", c->script_name);
switch (pid = fork()) {
@@ -1033,6 +1063,8 @@ cleanup_request(struct request *c)
break;
}
}
+ if (! c->inflight_fds_accounted)
+ cgi_inflight--;
free(c);
}