xref: /lighttpd1.4/src/mod_fastcgi.c (revision cd48c280)

#include "first.h"

#include "buffer.h"
#include "server.h"
#include "keyvalue.h"
#include "log.h"

#include "http_chunk.h"
#include "fdevent.h"
#include "connections.h"
#include "response.h"
#include "joblist.h"

#include "plugin.h"

#include "inet_ntop_cache.h"
#include "stat_cache.h"
#include "status_counter.h"

#include <sys/types.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <assert.h>
#include <signal.h>

#ifdef HAVE_FASTCGI_FASTCGI_H
# include <fastcgi/fastcgi.h>
#else
# ifdef HAVE_FASTCGI_H
#  include <fastcgi.h>
# else
#  include "fastcgi.h"
# endif
#endif /* HAVE_FASTCGI_FASTCGI_H */

#include <stdio.h>

#include "sys-socket.h"

#ifdef HAVE_SYS_UIO_H
#include <sys/uio.h>
#endif
#ifdef HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif

/*
 *
 * TODO:
 *
 * - add timeout for a connect to a non-fastcgi process
 *   (use state_timestamp + state)
 *
 */

typedef struct fcgi_proc {
	size_t id; /* id will be between 1 and max_procs */
	buffer *unixsocket; /* config.socket + "-" + id */
	unsigned port;  /* config.port + pno */

	buffer *connection_name; /* either tcp:<host>:<port> or unix:<socket> for debugging purposes */

	pid_t pid;   /* PID of the spawned process (0 if not spawned locally) */


	size_t load; /* number of requests waiting on this process */

	size_t requests;  /* see max_requests */
	struct fcgi_proc *prev, *next; /* see first */

	time_t disabled_until; /* this proc is disabled until, use something else until then */

	int is_local;

	enum {
		PROC_STATE_UNSET,    /* init-phase */
		PROC_STATE_RUNNING,  /* alive */
		PROC_STATE_OVERLOADED, /* listen-queue is full,
					  don't send anything to this proc for the next 2 seconds */
		PROC_STATE_DIED_WAIT_FOR_PID, /* */
		PROC_STATE_DIED,     /* marked as dead, should be restarted */
		PROC_STATE_KILLED    /* was killed as we don't have the load anymore */
	} state;
} fcgi_proc;

typedef struct {
	/* the key that is used to reference this value */
	buffer *id;

	/* list of processes handling this extension
	 * sorted by lowest load
	 *
	 * whenever a job is done move it up in the list
	 * until it is sorted, move it down as soon as the
	 * job is started
	 */
	fcgi_proc *first;
	fcgi_proc *unused_procs;

	/*
	 * spawn at least min_procs, at max_procs.
	 *
	 * as soon as the load of the first entry
	 * is max_load_per_proc we spawn a new one
	 * and add it to the first entry and give it
	 * the load
	 *
	 */

	unsigned short max_procs;
	size_t num_procs;    /* how many procs are started */
	size_t active_procs; /* how many of them are really running, i.e. state = PROC_STATE_RUNNING */

	/*
	 * time after a disabled remote connection is tried to be re-enabled
	 *
	 *
	 */

	unsigned short disable_time;

	/*
	 * some fastcgi processes get a little bit larger
	 * than wanted. max_requests_per_proc kills a
	 * process after a number of handled requests.
	 *
	 */
	size_t max_requests_per_proc;


	/* config */

	/*
	 * host:port
	 *
	 * if host is one of the local IP adresses the
	 * whole connection is local
	 *
	 * if port is not 0, and host is not specified,
	 * "localhost" (INADDR_LOOPBACK) is assumed.
	 *
	 */
	buffer *host;
	unsigned short port;
	sa_family_t family;

	/*
	 * Unix Domain Socket
	 *
	 * instead of TCP/IP we can use Unix Domain Sockets
	 * - more secure (you have fileperms to play with)
	 * - more control (on locally)
	 * - more speed (no extra overhead)
	 */
	buffer *unixsocket;

	/* if socket is local we can start the fastcgi
	 * process ourself
	 *
	 * bin-path is the path to the binary
	 *
	 * check min_procs and max_procs for the number
	 * of process to start up
	 */
	buffer *bin_path;

	/* bin-path is set bin-environment is taken to
	 * create the environement before starting the
	 * FastCGI process
	 *
	 */
	array *bin_env;

	array *bin_env_copy;

	/*
	 * docroot-translation between URL->phys and the
	 * remote host
	 *
	 * reasons:
	 * - different dir-layout if remote
	 * - chroot if local
	 *
	 */
	buffer *docroot;

	/*
	 * check_local tells you if the phys file is stat()ed
	 * or not. FastCGI doesn't care if the service is
	 * remote. If the web-server side doesn't contain
	 * the fastcgi-files we should not stat() for them
	 * and say '404 not found'.
	 */
	unsigned short check_local;

	/*
	 * append PATH_INFO to SCRIPT_FILENAME
	 *
	 * php needs this if cgi.fix_pathinfo is provided
	 *
	 */

	unsigned short break_scriptfilename_for_php;

	/*
	 * workaround for program when prefix="/"
	 *
	 * rule to build PATH_INFO is hardcoded for when check_local is disabled
	 * enable this option to use the workaround
	 *
	 */

	unsigned short fix_root_path_name;

	/*
	 * If the backend includes X-Sendfile in the response
	 * we use the value as filename and ignore the content.
	 *
	 */
	unsigned short xsendfile_allow;
	array *xsendfile_docroot;

	ssize_t load; /* replace by host->load */

	size_t max_id; /* corresponds most of the time to
	num_procs.

	only if a process is killed max_id waits for the process itself
	to die and decrements it afterwards */

	buffer *strip_request_uri;

	unsigned short kill_signal; /* we need a setting for this as libfcgi
				       applications prefer SIGUSR1 while the
				       rest of the world would use SIGTERM
				       *sigh* */

	int listen_backlog;
	int refcount;
} fcgi_extension_host;

/*
 * one extension can have multiple hosts assigned
 * one host can spawn additional processes on the same
 *   socket (if we control it)
 *
 * ext -> host -> procs
 *    1:n     1:n
 *
 * if the fastcgi process is remote that whole goes down
 * to
 *
 * ext -> host -> procs
 *    1:n     1:1
 *
 * in case of PHP and FCGI_CHILDREN we have again a procs
 * but we don't control it directly.
 *
 */

typedef struct {
	buffer *key; /* like .php */

	int note_is_sent;
	int last_used_ndx;

	fcgi_extension_host **hosts;

	size_t used;
	size_t size;
} fcgi_extension;

typedef struct {
	fcgi_extension **exts;

	size_t used;
	size_t size;
} fcgi_exts;


typedef struct {
	fcgi_exts *exts;
	fcgi_exts *exts_auth;
	fcgi_exts *exts_resp;

	array *ext_mapping;

	unsigned int debug;
} plugin_config;

typedef struct {
	char **ptr;

	size_t size;
	size_t used;
} char_array;

/* generic plugin data, shared between all connections */
typedef struct {
	PLUGIN_DATA;

	buffer *fcgi_env;

	buffer *path;

	buffer *statuskey;

	plugin_config **config_storage;

	plugin_config conf; /* this is only used as long as no handler_ctx is setup */
} plugin_data;

/* connection specific data */
typedef enum {
	FCGI_STATE_INIT,
	FCGI_STATE_CONNECT_DELAYED,
	FCGI_STATE_PREPARE_WRITE,
	FCGI_STATE_WRITE,
	FCGI_STATE_READ
} fcgi_connection_state_t;

typedef struct {
	fcgi_proc *proc;
	fcgi_extension_host *host;
	fcgi_extension *ext;
	fcgi_extension *ext_auth; /* (might be used in future to allow multiple authorizers)*/
	unsigned short fcgi_mode; /* FastCGI mode: FCGI_AUTHORIZER or FCGI_RESPONDER */

	fcgi_connection_state_t state;
	time_t   state_timestamp;

	chunkqueue *rb; /* read queue */
	chunkqueue *wb; /* write queue */
	off_t     wb_reqlen;

	buffer   *response_header;

	int       fd;        /* fd to the fastcgi process */
	int       fde_ndx;   /* index into the fd-event buffer */

	pid_t     pid;
	int       got_proc;
	int       reconnects; /* number of reconnect attempts */

	int       request_id;
	int       send_content_body;

	plugin_config conf;

	connection *remote_conn;  /* dumb pointer */
	plugin_data *plugin_data; /* dumb pointer */
} handler_ctx;


/* ok, we need a prototype */
static handler_t fcgi_handle_fdevent(server *srv, void *ctx, int revents);

static void reset_signals(void) {
#ifdef SIGTTOU
	signal(SIGTTOU, SIG_DFL);
#endif
#ifdef SIGTTIN
	signal(SIGTTIN, SIG_DFL);
#endif
#ifdef SIGTSTP
	signal(SIGTSTP, SIG_DFL);
#endif
	signal(SIGHUP, SIG_DFL);
	signal(SIGPIPE, SIG_DFL);
	signal(SIGUSR1, SIG_DFL);
}

static void fastcgi_status_copy_procname(buffer *b, fcgi_extension_host *host, fcgi_proc *proc) {
	buffer_copy_string_len(b, CONST_STR_LEN("fastcgi.backend."));
	buffer_append_string_buffer(b, host->id);
	if (proc) {
		buffer_append_string_len(b, CONST_STR_LEN("."));
		buffer_append_int(b, proc->id);
	}
}

static void fcgi_proc_load_inc(server *srv, handler_ctx *hctx) {
	plugin_data *p = hctx->plugin_data;
	hctx->proc->load++;

	status_counter_inc(srv, CONST_STR_LEN("fastcgi.active-requests"));

	fastcgi_status_copy_procname(p->statuskey, hctx->host, hctx->proc);
	buffer_append_string_len(p->statuskey, CONST_STR_LEN(".load"));

	status_counter_set(srv, CONST_BUF_LEN(p->statuskey), hctx->proc->load);
}

static void fcgi_proc_load_dec(server *srv, handler_ctx *hctx) {
	plugin_data *p = hctx->plugin_data;
	hctx->proc->load--;

	status_counter_dec(srv, CONST_STR_LEN("fastcgi.active-requests"));

	fastcgi_status_copy_procname(p->statuskey, hctx->host, hctx->proc);
	buffer_append_string_len(p->statuskey, CONST_STR_LEN(".load"));

	status_counter_set(srv, CONST_BUF_LEN(p->statuskey), hctx->proc->load);
}

static void fcgi_host_assign(server *srv, handler_ctx *hctx, fcgi_extension_host *host) {
	plugin_data *p = hctx->plugin_data;
	hctx->host = host;
	hctx->host->load++;

	fastcgi_status_copy_procname(p->statuskey, hctx->host, NULL);
	buffer_append_string_len(p->statuskey, CONST_STR_LEN(".load"));

	status_counter_set(srv, CONST_BUF_LEN(p->statuskey), hctx->host->load);
}

static void fcgi_host_reset(server *srv, handler_ctx *hctx) {
	plugin_data *p = hctx->plugin_data;
	hctx->host->load--;

	fastcgi_status_copy_procname(p->statuskey, hctx->host, NULL);
	buffer_append_string_len(p->statuskey, CONST_STR_LEN(".load"));

	status_counter_set(srv, CONST_BUF_LEN(p->statuskey), hctx->host->load);

	hctx->host = NULL;
}

static void fcgi_host_disable(server *srv, handler_ctx *hctx) {
	if (hctx->host->disable_time || hctx->proc->is_local) {
		if (hctx->proc->state == PROC_STATE_RUNNING) hctx->host->active_procs--;
		hctx->proc->disabled_until = srv->cur_ts + hctx->host->disable_time;
		hctx->proc->state = hctx->proc->is_local ? PROC_STATE_DIED_WAIT_FOR_PID : PROC_STATE_DIED;

		if (hctx->conf.debug) {
			log_error_write(srv, __FILE__, __LINE__, "sds",
				"backend disabled for", hctx->host->disable_time, "seconds");
		}
	}
}

static int fastcgi_status_init(server *srv, buffer *b, fcgi_extension_host *host, fcgi_proc *proc) {
#define CLEAN(x) \
	fastcgi_status_copy_procname(b, host, proc); \
	buffer_append_string_len(b, CONST_STR_LEN(x)); \
	status_counter_set(srv, CONST_BUF_LEN(b), 0);

	CLEAN(".disabled");
	CLEAN(".died");
	CLEAN(".overloaded");
	CLEAN(".connected");
	CLEAN(".load");

#undef CLEAN

#define CLEAN(x) \
	fastcgi_status_copy_procname(b, host, NULL); \
	buffer_append_string_len(b, CONST_STR_LEN(x)); \
	status_counter_set(srv, CONST_BUF_LEN(b), 0);

	CLEAN(".load");

#undef CLEAN

	return 0;
}

static handler_ctx * handler_ctx_init(void) {
	handler_ctx * hctx;

	hctx = calloc(1, sizeof(*hctx));
	force_assert(hctx);

	hctx->fde_ndx = -1;

	hctx->response_header = buffer_init();

	hctx->request_id = 0;
	hctx->fcgi_mode = FCGI_RESPONDER;
	hctx->state = FCGI_STATE_INIT;
	hctx->proc = NULL;

	hctx->fd = -1;

	hctx->reconnects = 0;
	hctx->send_content_body = 1;

	hctx->rb = chunkqueue_init();
	hctx->wb = chunkqueue_init();
	hctx->wb_reqlen = 0;

	return hctx;
}

static void handler_ctx_free(handler_ctx *hctx) {
	/* caller MUST have called fcgi_backend_close(srv, hctx) if necessary */
	buffer_free(hctx->response_header);

	chunkqueue_free(hctx->rb);
	chunkqueue_free(hctx->wb);

	free(hctx);
}

static void handler_ctx_clear(handler_ctx *hctx) {
	/* caller MUST have called fcgi_backend_close(srv, hctx) if necessary */

	hctx->proc = NULL;
	hctx->host = NULL;
	hctx->ext  = NULL;
	/*hctx->ext_auth is intentionally preserved to flag prior authorizer*/

	hctx->fcgi_mode = FCGI_RESPONDER;
	hctx->state = FCGI_STATE_INIT;
	/*hctx->state_timestamp = 0;*//*(unused; left as-is)*/

	chunkqueue_reset(hctx->rb);
	chunkqueue_reset(hctx->wb);
	hctx->wb_reqlen = 0;

	buffer_reset(hctx->response_header);

	hctx->fd = -1;
	hctx->fde_ndx = -1;
	/*hctx->pid = -1;*//*(unused; left as-is)*/
	hctx->got_proc = 0;
	hctx->reconnects = 0;
	hctx->request_id = 0;
	hctx->send_content_body = 1;

	/*plugin_config conf;*//*(no need to reset for same request)*/

	/*hctx->remote_conn = NULL;*//*(no need to reset for same request)*/
	/*hctx->plugin_data = NULL;*//*(no need to reset for same request)*/
}

static fcgi_proc *fastcgi_process_init(void) {
	fcgi_proc *f;

	f = calloc(1, sizeof(*f));
	f->unixsocket = buffer_init();
	f->connection_name = buffer_init();

	f->prev = NULL;
	f->next = NULL;

	return f;
}

static void fastcgi_process_free(fcgi_proc *f) {
	if (!f) return;

	fastcgi_process_free(f->next);

	buffer_free(f->unixsocket);
	buffer_free(f->connection_name);

	free(f);
}

static fcgi_extension_host *fastcgi_host_init(void) {
	fcgi_extension_host *f;

	f = calloc(1, sizeof(*f));

	f->id = buffer_init();
	f->host = buffer_init();
	f->unixsocket = buffer_init();
	f->docroot = buffer_init();
	f->bin_path = buffer_init();
	f->bin_env = array_init();
	f->bin_env_copy = array_init();
	f->strip_request_uri = buffer_init();
	f->xsendfile_docroot = array_init();

	return f;
}

static void fastcgi_host_free(fcgi_extension_host *h) {
	if (!h) return;
	if (h->refcount) {
		--h->refcount;
		return;
	}

	buffer_free(h->id);
	buffer_free(h->host);
	buffer_free(h->unixsocket);
	buffer_free(h->docroot);
	buffer_free(h->bin_path);
	buffer_free(h->strip_request_uri);
	array_free(h->bin_env);
	array_free(h->bin_env_copy);
	array_free(h->xsendfile_docroot);

	fastcgi_process_free(h->first);
	fastcgi_process_free(h->unused_procs);

	free(h);

}

static fcgi_exts *fastcgi_extensions_init(void) {
	fcgi_exts *f;

	f = calloc(1, sizeof(*f));

	return f;
}

static void fastcgi_extensions_free(fcgi_exts *f) {
	size_t i;

	if (!f) return;

	for (i = 0; i < f->used; i++) {
		fcgi_extension *fe;
		size_t j;

		fe = f->exts[i];

		for (j = 0; j < fe->used; j++) {
			fcgi_extension_host *h;

			h = fe->hosts[j];

			fastcgi_host_free(h);
		}

		buffer_free(fe->key);
		free(fe->hosts);

		free(fe);
	}

	free(f->exts);

	free(f);
}

static int fastcgi_extension_insert(fcgi_exts *ext, buffer *key, fcgi_extension_host *fh) {
	fcgi_extension *fe;
	size_t i;

	/* there is something */

	for (i = 0; i < ext->used; i++) {
		if (buffer_is_equal(key, ext->exts[i]->key)) {
			break;
		}
	}

	if (i == ext->used) {
		/* filextension is new */
		fe = calloc(1, sizeof(*fe));
		force_assert(fe);
		fe->key = buffer_init();
		fe->last_used_ndx = -1;
		buffer_copy_buffer(fe->key, key);

		/* */

		if (ext->size == 0) {
			ext->size = 8;
			ext->exts = malloc(ext->size * sizeof(*(ext->exts)));
			force_assert(ext->exts);
		} else if (ext->used == ext->size) {
			ext->size += 8;
			ext->exts = realloc(ext->exts, ext->size * sizeof(*(ext->exts)));
			force_assert(ext->exts);
		}
		ext->exts[ext->used++] = fe;
	} else {
		fe = ext->exts[i];
	}

	if (fe->size == 0) {
		fe->size = 4;
		fe->hosts = malloc(fe->size * sizeof(*(fe->hosts)));
		force_assert(fe->hosts);
	} else if (fe->size == fe->used) {
		fe->size += 4;
		fe->hosts = realloc(fe->hosts, fe->size * sizeof(*(fe->hosts)));
		force_assert(fe->hosts);
	}

	fe->hosts[fe->used++] = fh;

	return 0;

}

INIT_FUNC(mod_fastcgi_init) {
	plugin_data *p;

	p = calloc(1, sizeof(*p));

	p->fcgi_env = buffer_init();

	p->path = buffer_init();

	p->statuskey = buffer_init();

	return p;
}


FREE_FUNC(mod_fastcgi_free) {
	plugin_data *p = p_d;

	UNUSED(srv);

	buffer_free(p->fcgi_env);
	buffer_free(p->path);
	buffer_free(p->statuskey);

	if (p->config_storage) {
		size_t i, j, n;
		for (i = 0; i < srv->config_context->used; i++) {
			plugin_config *s = p->config_storage[i];
			fcgi_exts *exts;

			if (NULL == s) continue;

			exts = s->exts;

		      if (exts) {
			for (j = 0; j < exts->used; j++) {
				fcgi_extension *ex;

				ex = exts->exts[j];

				for (n = 0; n < ex->used; n++) {
					fcgi_proc *proc;
					fcgi_extension_host *host;

					host = ex->hosts[n];

					for (proc = host->first; proc; proc = proc->next) {
						if (proc->pid != 0) {
							kill(proc->pid, host->kill_signal);
						}

						if (proc->is_local &&
						    !buffer_string_is_empty(proc->unixsocket)) {
							unlink(proc->unixsocket->ptr);
						}
					}

					for (proc = host->unused_procs; proc; proc = proc->next) {
						if (proc->pid != 0) {
							kill(proc->pid, host->kill_signal);
						}
						if (proc->is_local &&
						    !buffer_string_is_empty(proc->unixsocket)) {
							unlink(proc->unixsocket->ptr);
						}
					}
				}
			}

			fastcgi_extensions_free(s->exts);
			fastcgi_extensions_free(s->exts_auth);
			fastcgi_extensions_free(s->exts_resp);
		      }
			array_free(s->ext_mapping);

			free(s);
		}
		free(p->config_storage);
	}

	free(p);

	return HANDLER_GO_ON;
}

static int env_add(char_array *env, const char *key, size_t key_len, const char *val, size_t val_len) {
	char *dst;
	size_t i;

	if (!key || !val) return -1;

	dst = malloc(key_len + val_len + 3);
	memcpy(dst, key, key_len);
	dst[key_len] = '=';
	memcpy(dst + key_len + 1, val, val_len);
	dst[key_len + 1 + val_len] = '\0';

	for (i = 0; i < env->used; i++) {
		if (0 == strncmp(dst, env->ptr[i], key_len + 1)) {
			/* don't care about free as we are in a forked child which is going to exec(...) */
			/* free(env->ptr[i]); */
			env->ptr[i] = dst;
			return 0;
		}
	}

	if (env->size == 0) {
		env->size = 16;
		env->ptr = malloc(env->size * sizeof(*env->ptr));
	} else if (env->size == env->used + 1) {
		env->size += 16;
		env->ptr = realloc(env->ptr, env->size * sizeof(*env->ptr));
	}

	env->ptr[env->used++] = dst;

	return 0;
}

static int parse_binpath(char_array *env, buffer *b) {
	char *start;
	size_t i;
	/* search for spaces */

	start = b->ptr;
	for (i = 0; i < buffer_string_length(b); i++) {
		switch(b->ptr[i]) {
		case ' ':
		case '\t':
			/* a WS, stop here and copy the argument */

			if (env->size == 0) {
				env->size = 16;
				env->ptr = malloc(env->size * sizeof(*env->ptr));
			} else if (env->size == env->used) {
				env->size += 16;
				env->ptr = realloc(env->ptr, env->size * sizeof(*env->ptr));
			}

			b->ptr[i] = '\0';

			env->ptr[env->used++] = start;

			start = b->ptr + i + 1;
			break;
		default:
			break;
		}
	}

	if (env->size == 0) {
		env->size = 16;
		env->ptr = malloc(env->size * sizeof(*env->ptr));
	} else if (env->size == env->used) { /* we need one extra for the terminating NULL */
		env->size += 16;
		env->ptr = realloc(env->ptr, env->size * sizeof(*env->ptr));
	}

	/* the rest */
	env->ptr[env->used++] = start;

	if (env->size == 0) {
		env->size = 16;
		env->ptr = malloc(env->size * sizeof(*env->ptr));
	} else if (env->size == env->used) { /* we need one extra for the terminating NULL */
		env->size += 16;
		env->ptr = realloc(env->ptr, env->size * sizeof(*env->ptr));
	}

	/* terminate */
	env->ptr[env->used++] = NULL;

	return 0;
}

#if !defined(HAVE_FORK)
static int fcgi_spawn_connection(server *srv,
                                 plugin_data *p,
                                 fcgi_extension_host *host,
                                 fcgi_proc *proc) {
	UNUSED(srv);
	UNUSED(p);
	UNUSED(host);
	UNUSED(proc);
	return -1;
}

#else /* -> defined(HAVE_FORK) */

static int fcgi_spawn_connection(server *srv,
                                 plugin_data *p,
                                 fcgi_extension_host *host,
                                 fcgi_proc *proc) {
	int fcgi_fd;
	int status;
	struct timeval tv = { 0, 100 * 1000 };
#ifdef HAVE_SYS_UN_H
	struct sockaddr_un fcgi_addr_un;
#endif
#if defined(HAVE_IPV6) && defined(HAVE_INET_PTON)
	struct sockaddr_in6 fcgi_addr_in6;
#endif
	struct sockaddr_in fcgi_addr_in;
	struct sockaddr *fcgi_addr;

	socklen_t servlen;

	if (p->conf.debug) {
		log_error_write(srv, __FILE__, __LINE__, "sdb",
				"new proc, socket:", proc->port, proc->unixsocket);
	}

	if (!buffer_string_is_empty(proc->unixsocket)) {
#ifdef HAVE_SYS_UN_H
		memset(&fcgi_addr_un, 0, sizeof(fcgi_addr_un));
		fcgi_addr_un.sun_family = AF_UNIX;
		if (buffer_string_length(proc->unixsocket) + 1 > sizeof(fcgi_addr_un.sun_path)) {
			log_error_write(srv, __FILE__, __LINE__, "sB",
					"ERROR: Unix Domain socket filename too long:",
					proc->unixsocket);
			return -1;
		}
		memcpy(fcgi_addr_un.sun_path, proc->unixsocket->ptr, buffer_string_length(proc->unixsocket) + 1);

#ifdef SUN_LEN
		servlen = SUN_LEN(&fcgi_addr_un);
#else
		/* stevens says: */
		servlen = buffer_string_length(proc->unixsocket) + 1 + sizeof(fcgi_addr_un.sun_family);
#endif
		fcgi_addr = (struct sockaddr *) &fcgi_addr_un;

		buffer_copy_string_len(proc->connection_name, CONST_STR_LEN("unix:"));
		buffer_append_string_buffer(proc->connection_name, proc->unixsocket);

#else
		log_error_write(srv, __FILE__, __LINE__, "s",
				"ERROR: Unix Domain sockets are not supported.");
		return -1;
#endif
#if defined(HAVE_IPV6) && defined(HAVE_INET_PTON)
	} else if (host->family == AF_INET6 && !buffer_string_is_empty(host->host)) {
		memset(&fcgi_addr_in6, 0, sizeof(fcgi_addr_in6));
		fcgi_addr_in6.sin6_family = AF_INET6;
		inet_pton(AF_INET6, host->host->ptr, (char *) &fcgi_addr_in6.sin6_addr);
		fcgi_addr_in6.sin6_port = htons(proc->port);
		servlen = sizeof(fcgi_addr_in6);
		fcgi_addr = (struct sockaddr *) &fcgi_addr_in6;
#endif
	} else {
		memset(&fcgi_addr_in, 0, sizeof(fcgi_addr_in));
		fcgi_addr_in.sin_family = AF_INET;

		if (buffer_string_is_empty(host->host)) {
			fcgi_addr_in.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
		} else {
			struct hostent *he;

			/* set a useful default */
			fcgi_addr_in.sin_addr.s_addr = htonl(INADDR_LOOPBACK);


			if (NULL == (he = gethostbyname(host->host->ptr))) {
				log_error_write(srv, __FILE__, __LINE__,
						"sdb", "gethostbyname failed: ",
						h_errno, host->host);
				return -1;
			}

			if (he->h_addrtype != AF_INET) {
				log_error_write(srv, __FILE__, __LINE__, "sd", "addr-type != AF_INET: ", he->h_addrtype);
				return -1;
			}

			if (he->h_length != sizeof(struct in_addr)) {
				log_error_write(srv, __FILE__, __LINE__, "sd", "addr-length != sizeof(in_addr): ", he->h_length);
				return -1;
			}

			memcpy(&(fcgi_addr_in.sin_addr.s_addr), he->h_addr_list[0], he->h_length);

		}
		fcgi_addr_in.sin_port = htons(proc->port);
		servlen = sizeof(fcgi_addr_in);

		fcgi_addr = (struct sockaddr *) &fcgi_addr_in;
	}

	if (buffer_string_is_empty(proc->unixsocket)) {
		buffer_copy_string_len(proc->connection_name, CONST_STR_LEN("tcp:"));
		if (!buffer_string_is_empty(host->host)) {
			buffer_append_string_buffer(proc->connection_name, host->host);
		} else {
			buffer_append_string_len(proc->connection_name, CONST_STR_LEN("localhost"));
		}
		buffer_append_string_len(proc->connection_name, CONST_STR_LEN(":"));
		buffer_append_int(proc->connection_name, proc->port);
	}

	if (-1 == (fcgi_fd = fdevent_socket_cloexec(fcgi_addr->sa_family, SOCK_STREAM, 0))) {
		log_error_write(srv, __FILE__, __LINE__, "ss",
				"failed:", strerror(errno));
		return -1;
	}

	if (-1 == connect(fcgi_fd, fcgi_addr, servlen)) {
		/* server is not up, spawn it  */
		pid_t child;
		int val;

		if (errno != ENOENT &&
		    !buffer_string_is_empty(proc->unixsocket)) {
			unlink(proc->unixsocket->ptr);
		}

		close(fcgi_fd);

		/* reopen socket */
		if (-1 == (fcgi_fd = fdevent_socket_cloexec(fcgi_addr->sa_family, SOCK_STREAM, 0))) {
			log_error_write(srv, __FILE__, __LINE__, "ss",
				"socket failed:", strerror(errno));
			return -1;
		}

		val = 1;
		if (setsockopt(fcgi_fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)) < 0) {
			log_error_write(srv, __FILE__, __LINE__, "ss",
					"socketsockopt failed:", strerror(errno));
			close(fcgi_fd);
			return -1;
		}

		/* create socket */
		if (-1 == bind(fcgi_fd, fcgi_addr, servlen)) {
			log_error_write(srv, __FILE__, __LINE__, "sbs",
				"bind failed for:",
				proc->connection_name,
				strerror(errno));
			close(fcgi_fd);
			return -1;
		}

		if (-1 == listen(fcgi_fd, host->listen_backlog)) {
			log_error_write(srv, __FILE__, __LINE__, "ss",
				"listen failed:", strerror(errno));
			close(fcgi_fd);
			return -1;
		}

		switch ((child = fork())) {
		case 0: {
			size_t i = 0;
			char *c;
			char_array env;
			char_array arg;

			/* create environment */
			env.ptr = NULL;
			env.size = 0;
			env.used = 0;

			arg.ptr = NULL;
			arg.size = 0;
			arg.used = 0;

			if(fcgi_fd != FCGI_LISTENSOCK_FILENO) {
				dup2(fcgi_fd, FCGI_LISTENSOCK_FILENO);
				close(fcgi_fd);
			}
		      #ifdef SOCK_CLOEXEC
			else
				(void)fcntl(fcgi_fd, F_SETFD, 0); /* clear cloexec */
		      #endif

			/* we don't need the client socket */
			for (i = 3; i < 256; i++) {
				close(i);
			}

			/* build clean environment */
			if (host->bin_env_copy->used) {
				for (i = 0; i < host->bin_env_copy->used; i++) {
					data_string *ds = (data_string *)host->bin_env_copy->data[i];
					char *ge;

					if (NULL != (ge = getenv(ds->value->ptr))) {
						env_add(&env, CONST_BUF_LEN(ds->value), ge, strlen(ge));
					}
				}
			} else {
				char ** const e = environ;
				for (i = 0; e[i]; ++i) {
					char *eq;

					if (NULL != (eq = strchr(e[i], '='))) {
						env_add(&env, e[i], eq - e[i], eq+1, strlen(eq+1));
					}
				}
			}

			/* create environment */
			for (i = 0; i < host->bin_env->used; i++) {
				data_string *ds = (data_string *)host->bin_env->data[i];

				env_add(&env, CONST_BUF_LEN(ds->key), CONST_BUF_LEN(ds->value));
			}

			for (i = 0; i < env.used; i++) {
				/* search for PHP_FCGI_CHILDREN */
				if (0 == strncmp(env.ptr[i], "PHP_FCGI_CHILDREN=", sizeof("PHP_FCGI_CHILDREN=") - 1)) break;
			}

			/* not found, add a default */
			if (i == env.used) {
				env_add(&env, CONST_STR_LEN("PHP_FCGI_CHILDREN"), CONST_STR_LEN("1"));
			}

			env.ptr[env.used] = NULL;

			parse_binpath(&arg, host->bin_path);

			/* chdir into the base of the bin-path,
			 * search for the last / */
			if (NULL != (c = strrchr(arg.ptr[0], '/'))) {
				*c = '\0';

				/* change to the physical directory */
				if (-1 == chdir(arg.ptr[0])) {
					*c = '/';
					log_error_write(srv, __FILE__, __LINE__, "sss", "chdir failed:", strerror(errno), arg.ptr[0]);
				}
				*c = '/';
			}

			reset_signals();

			/* exec the cgi */
			execve(arg.ptr[0], arg.ptr, env.ptr);

			/* log_error_write(srv, __FILE__, __LINE__, "sbs",
					"execve failed for:", host->bin_path, strerror(errno)); */

			_exit(errno);

			break;
		}
		case -1:
			/* error */
			close(fcgi_fd);
			break;
		default:
			/* father */
			close(fcgi_fd);

			/* wait */
			select(0, NULL, NULL, NULL, &tv);

			switch (waitpid(child, &status, WNOHANG)) {
			case 0:
				/* child still running after timeout, good */
				break;
			case -1:
				/* no PID found ? should never happen */
				log_error_write(srv, __FILE__, __LINE__, "ss",
						"pid not found:", strerror(errno));
				return -1;
			default:
				log_error_write(srv, __FILE__, __LINE__, "sbs",
						"the fastcgi-backend", host->bin_path, "failed to start:");
				/* the child should not terminate at all */
				if (WIFEXITED(status)) {
					log_error_write(srv, __FILE__, __LINE__, "sdb",
							"child exited with status",
							WEXITSTATUS(status), host->bin_path);
					log_error_write(srv, __FILE__, __LINE__, "s",
							"If you're trying to run your app as a FastCGI backend, make sure you're using the FastCGI-enabled version.\n"
							"If this is PHP on Gentoo, add 'fastcgi' to the USE flags.");
				} else if (WIFSIGNALED(status)) {
					log_error_write(srv, __FILE__, __LINE__, "sd",
							"terminated by signal:",
							WTERMSIG(status));

					if (WTERMSIG(status) == 11) {
						log_error_write(srv, __FILE__, __LINE__, "s",
								"to be exact: it segfaulted, crashed, died, ... you get the idea." );
						log_error_write(srv, __FILE__, __LINE__, "s",
								"If this is PHP, try removing the bytecode caches for now and try again.");
					}
				} else {
					log_error_write(srv, __FILE__, __LINE__, "sd",
							"child died somehow:",
							status);
				}
				return -1;
			}

			/* register process */
			proc->pid = child;
			proc->is_local = 1;

			break;
		}
	} else {
		close(fcgi_fd);
		proc->is_local = 0;
		proc->pid = 0;

		if (p->conf.debug) {
			log_error_write(srv, __FILE__, __LINE__, "sb",
					"(debug) socket is already used; won't spawn:",
					proc->connection_name);
		}
	}

	proc->state = PROC_STATE_RUNNING;
	host->active_procs++;

	return 0;
}

#endif /* HAVE_FORK */

static fcgi_extension_host * unixsocket_is_dup(plugin_data *p, size_t used, buffer *unixsocket) {
	size_t i, j, n;
	for (i = 0; i < used; ++i) {
		fcgi_exts *exts = p->config_storage[i]->exts;
		if (NULL == exts) continue;
		for (j = 0; j < exts->used; ++j) {
			fcgi_extension *ex = exts->exts[j];
			for (n = 0; n < ex->used; ++n) {
				fcgi_extension_host *host = ex->hosts[n];
				if (!buffer_string_is_empty(host->unixsocket)
				    && buffer_is_equal(host->unixsocket, unixsocket)
				    && !buffer_string_is_empty(host->bin_path))
					return host;
			}
		}
	}

	return NULL;
}

SETDEFAULTS_FUNC(mod_fastcgi_set_defaults) {
	plugin_data *p = p_d;
	data_unset *du;
	size_t i = 0;
	buffer *fcgi_mode = buffer_init();
	fcgi_extension_host *host = NULL;

	config_values_t cv[] = {
		{ "fastcgi.server",              NULL, T_CONFIG_LOCAL, T_CONFIG_SCOPE_CONNECTION },       /* 0 */
		{ "fastcgi.debug",               NULL, T_CONFIG_INT  , T_CONFIG_SCOPE_CONNECTION },       /* 1 */
		{ "fastcgi.map-extensions",      NULL, T_CONFIG_ARRAY, T_CONFIG_SCOPE_CONNECTION },       /* 2 */
		{ NULL,                          NULL, T_CONFIG_UNSET, T_CONFIG_SCOPE_UNSET }
	};

	p->config_storage = calloc(1, srv->config_context->used * sizeof(plugin_config *));

	for (i = 0; i < srv->config_context->used; i++) {
		data_config const* config = (data_config const*)srv->config_context->data[i];
		plugin_config *s;

		s = malloc(sizeof(plugin_config));
		s->exts          = NULL;
		s->exts_auth     = NULL;
		s->exts_resp     = NULL;
		s->debug         = 0;
		s->ext_mapping   = array_init();

		cv[0].destination = s->exts; /* not used; T_CONFIG_LOCAL */
		cv[1].destination = &(s->debug);
		cv[2].destination = s->ext_mapping;

		p->config_storage[i] = s;

		if (0 != config_insert_values_global(srv, config->value, cv, i == 0 ? T_CONFIG_SCOPE_SERVER : T_CONFIG_SCOPE_CONNECTION)) {
			goto error;
		}

		/*
		 * <key> = ( ... )
		 */

		if (NULL != (du = array_get_element(config->value, "fastcgi.server"))) {
			size_t j;
			data_array *da = (data_array *)du;

			if (du->type != TYPE_ARRAY) {
				log_error_write(srv, __FILE__, __LINE__, "sss",
						"unexpected type for key: ", "fastcgi.server", "expected ( \"ext\" => ( \"backend-label\" => ( \"key\" => \"value\" )))");

				goto error;
			}

			s->exts      = fastcgi_extensions_init();
			s->exts_auth = fastcgi_extensions_init();
			s->exts_resp = fastcgi_extensions_init();

			/*
			 * fastcgi.server = ( "<ext>" => ( ... ),
			 *                    "<ext>" => ( ... ) )
			 */

			for (j = 0; j < da->value->used; j++) {
				size_t n;
				data_array *da_ext = (data_array *)da->value->data[j];

				if (da->value->data[j]->type != TYPE_ARRAY) {
					log_error_write(srv, __FILE__, __LINE__, "sssbs",
							"unexpected type for key: ", "fastcgi.server",
							"[", da->value->data[j]->key, "](string); expected ( \"ext\" => ( \"backend-label\" => ( \"key\" => \"value\" )))");

					goto error;
				}

				/*
				 * da_ext->key == name of the extension
				 */

				/*
				 * fastcgi.server = ( "<ext>" =>
				 *                     ( "<host>" => ( ... ),
				 *                       "<host>" => ( ... )
				 *                     ),
				 *                    "<ext>" => ... )
				 */

				for (n = 0; n < da_ext->value->used; n++) {
					data_array *da_host = (data_array *)da_ext->value->data[n];

					config_values_t fcv[] = {
						{ "host",              NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },       /* 0 */
						{ "docroot",           NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },       /* 1 */
						{ "mode",              NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },       /* 2 */
						{ "socket",            NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },       /* 3 */
						{ "bin-path",          NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },       /* 4 */

						{ "check-local",       NULL, T_CONFIG_BOOLEAN, T_CONFIG_SCOPE_CONNECTION },      /* 5 */
						{ "port",              NULL, T_CONFIG_SHORT, T_CONFIG_SCOPE_CONNECTION },        /* 6 */
						{ "max-procs",         NULL, T_CONFIG_SHORT, T_CONFIG_SCOPE_CONNECTION },        /* 7 */
						{ "disable-time",      NULL, T_CONFIG_SHORT, T_CONFIG_SCOPE_CONNECTION },        /* 8 */

						{ "bin-environment",   NULL, T_CONFIG_ARRAY, T_CONFIG_SCOPE_CONNECTION },        /* 9 */
						{ "bin-copy-environment", NULL, T_CONFIG_ARRAY, T_CONFIG_SCOPE_CONNECTION },     /* 10 */

						{ "broken-scriptfilename", NULL, T_CONFIG_BOOLEAN, T_CONFIG_SCOPE_CONNECTION },  /* 11 */
						{ "allow-x-send-file",  NULL, T_CONFIG_BOOLEAN, T_CONFIG_SCOPE_CONNECTION },     /* 12 */
						{ "strip-request-uri",  NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },      /* 13 */
						{ "kill-signal",        NULL, T_CONFIG_SHORT, T_CONFIG_SCOPE_CONNECTION },       /* 14 */
						{ "fix-root-scriptname",   NULL, T_CONFIG_BOOLEAN, T_CONFIG_SCOPE_CONNECTION },  /* 15 */
						{ "listen-backlog",    NULL, T_CONFIG_INT,   T_CONFIG_SCOPE_CONNECTION },        /* 16 */
						{ "x-sendfile",        NULL, T_CONFIG_BOOLEAN, T_CONFIG_SCOPE_CONNECTION },      /* 17 */
						{ "x-sendfile-docroot",NULL, T_CONFIG_ARRAY,  T_CONFIG_SCOPE_CONNECTION },      /* 18 */

						{ NULL,                NULL, T_CONFIG_UNSET, T_CONFIG_SCOPE_UNSET }
					};
					unsigned short host_mode = FCGI_RESPONDER;

					if (da_host->type != TYPE_ARRAY) {
						log_error_write(srv, __FILE__, __LINE__, "ssSBS",
								"unexpected type for key:",
								"fastcgi.server",
								"[", da_host->key, "](string); expected ( \"ext\" => ( \"backend-label\" => ( \"key\" => \"value\" )))");

						goto error;
					}

					host = fastcgi_host_init();
					buffer_reset(fcgi_mode);

					buffer_copy_buffer(host->id, da_host->key);

					host->check_local  = 1;
					host->max_procs    = 4;
					host->disable_time = 1;
					host->break_scriptfilename_for_php = 0;
					host->xsendfile_allow = 0;
					host->kill_signal = SIGTERM;
					host->fix_root_path_name = 0;
					host->listen_backlog = 1024;
					host->refcount = 0;

					fcv[0].destination = host->host;
					fcv[1].destination = host->docroot;
					fcv[2].destination = fcgi_mode;
					fcv[3].destination = host->unixsocket;
					fcv[4].destination = host->bin_path;

					fcv[5].destination = &(host->check_local);
					fcv[6].destination = &(host->port);
					fcv[7].destination = &(host->max_procs);
					fcv[8].destination = &(host->disable_time);

					fcv[9].destination = host->bin_env;
					fcv[10].destination = host->bin_env_copy;
					fcv[11].destination = &(host->break_scriptfilename_for_php);
					fcv[12].destination = &(host->xsendfile_allow);
					fcv[13].destination = host->strip_request_uri;
					fcv[14].destination = &(host->kill_signal);
					fcv[15].destination = &(host->fix_root_path_name);
					fcv[16].destination = &(host->listen_backlog);
					fcv[17].destination = &(host->xsendfile_allow);
					fcv[18].destination = host->xsendfile_docroot;

					if (0 != config_insert_values_internal(srv, da_host->value, fcv, T_CONFIG_SCOPE_CONNECTION)) {
						goto error;
					}

					if ((!buffer_string_is_empty(host->host) || host->port) &&
					    !buffer_string_is_empty(host->unixsocket)) {
						log_error_write(srv, __FILE__, __LINE__, "sbsbsbs",
								"either host/port or socket have to be set in:",
								da->key, "= (",
								da_ext->key, " => (",
								da_host->key, " ( ...");

						goto error;
					}

					if (!buffer_string_is_empty(host->unixsocket)) {
						/* unix domain socket */
						struct sockaddr_un un;

						if (buffer_string_length(host->unixsocket) + 1 > sizeof(un.sun_path) - 2) {
							log_error_write(srv, __FILE__, __LINE__, "sbsbsbs",
									"unixsocket is too long in:",
									da->key, "= (",
									da_ext->key, " => (",
									da_host->key, " ( ...");

							goto error;
						}

						if (!buffer_string_is_empty(host->bin_path)) {
							fcgi_extension_host *duplicate = unixsocket_is_dup(p, i+1, host->unixsocket);
							if (NULL != duplicate) {
								if (!buffer_is_equal(host->bin_path, duplicate->bin_path)) {
									log_error_write(srv, __FILE__, __LINE__, "sb",
										"duplicate unixsocket path:",
										host->unixsocket);
									goto error;
								}
								fastcgi_host_free(host);
								host = duplicate;
								++host->refcount;
							}
						}

						host->family = AF_UNIX;
					} else {
						/* tcp/ip */

						if (buffer_string_is_empty(host->host) &&
						    buffer_string_is_empty(host->bin_path)) {
							log_error_write(srv, __FILE__, __LINE__, "sbsbsbs",
									"host or binpath have to be set in:",
									da->key, "= (",
									da_ext->key, " => (",
									da_host->key, " ( ...");

							goto error;
						} else if (host->port == 0) {
							log_error_write(srv, __FILE__, __LINE__, "sbsbsbs",
									"port has to be set in:",
									da->key, "= (",
									da_ext->key, " => (",
									da_host->key, " ( ...");

							goto error;
						}

						host->family = (!buffer_string_is_empty(host->host) && NULL != strchr(host->host->ptr, ':')) ? AF_INET6 : AF_INET;
					}

					if (host->refcount) {
						/* already init'd; skip spawning */
					} else if (!buffer_string_is_empty(host->bin_path)) {
						/* a local socket + self spawning */
						size_t pno;

						if (s->debug) {
							log_error_write(srv, __FILE__, __LINE__, "ssbsdsbsd",
									"--- fastcgi spawning local",
									"\n\tproc:", host->bin_path,
									"\n\tport:", host->port,
									"\n\tsocket", host->unixsocket,
									"\n\tmax-procs:", host->max_procs);
						}

						for (pno = 0; pno < host->max_procs; pno++) {
							fcgi_proc *proc;

							proc = fastcgi_process_init();
							proc->id = host->num_procs++;
							host->max_id++;

							if (buffer_string_is_empty(host->unixsocket)) {
								proc->port = host->port + pno;
							} else {
								buffer_copy_buffer(proc->unixsocket, host->unixsocket);
								buffer_append_string_len(proc->unixsocket, CONST_STR_LEN("-"));
								buffer_append_int(proc->unixsocket, pno);
							}

							if (s->debug) {
								log_error_write(srv, __FILE__, __LINE__, "ssdsbsdsd",
										"--- fastcgi spawning",
										"\n\tport:", host->port,
										"\n\tsocket", host->unixsocket,
										"\n\tcurrent:", pno, "/", host->max_procs);
							}

							if (!srv->srvconf.preflight_check
							    && fcgi_spawn_connection(srv, p, host, proc)) {
								log_error_write(srv, __FILE__, __LINE__, "s",
										"[ERROR]: spawning fcgi failed.");
								fastcgi_process_free(proc);
								goto error;
							}

							fastcgi_status_init(srv, p->statuskey, host, proc);

							proc->next = host->first;
							if (host->first) host->first->prev = proc;

							host->first = proc;
						}
					} else {
						fcgi_proc *proc;

						proc = fastcgi_process_init();
						proc->id = host->num_procs++;
						host->max_id++;
						host->active_procs++;
						proc->state = PROC_STATE_RUNNING;

						if (buffer_string_is_empty(host->unixsocket)) {
							proc->port = host->port;
						} else {
							buffer_copy_buffer(proc->unixsocket, host->unixsocket);
						}

						fastcgi_status_init(srv, p->statuskey, host, proc);

						host->first = proc;

						host->max_procs = 1;
					}

					if (!buffer_string_is_empty(fcgi_mode)) {
						if (strcmp(fcgi_mode->ptr, "responder") == 0) {
							host_mode = FCGI_RESPONDER;
						} else if (strcmp(fcgi_mode->ptr, "authorizer") == 0) {
							host_mode = FCGI_AUTHORIZER;
						} else {
							log_error_write(srv, __FILE__, __LINE__, "sbs",
									"WARNING: unknown fastcgi mode:",
									fcgi_mode, "(ignored, mode set to responder)");
						}
					}

					if (host->xsendfile_docroot->used) {
						size_t k;
						for (k = 0; k < host->xsendfile_docroot->used; ++k) {
							data_string *ds = (data_string *)host->xsendfile_docroot->data[k];
							if (ds->type != TYPE_STRING) {
								log_error_write(srv, __FILE__, __LINE__, "s",
									"unexpected type for x-sendfile-docroot; expected: \"x-sendfile-docroot\" => ( \"/allowed/path\", ... )");
								goto error;
							}
							if (ds->value->ptr[0] != '/') {
								log_error_write(srv, __FILE__, __LINE__, "SBs",
									"x-sendfile-docroot paths must begin with '/'; invalid: \"", ds->value, "\"");
								goto error;
							}
							buffer_path_simplify(ds->value, ds->value);
							buffer_append_slash(ds->value);
						}
					}

					/* s->exts is list of exts -> hosts
					 * s->exts now used as combined list of authorizer and responder hosts (for backend maintenance)
					 * s->exts_auth is list of exts -> authorizer hosts
					 * s->exts_resp is list of exts -> responder hosts
					 * For each path/extension, there may be an independent FCGI_AUTHORIZER and FCGI_RESPONDER
					 * (The FCGI_AUTHORIZER and FCGI_RESPONDER could be handled by the same host,
					 *  and an admin might want to do that for large uploads, since FCGI_AUTHORIZER
					 *  runs prior to receiving (potentially large) request body from client and can
					 *  authorizer or deny request prior to receiving the full upload)
					 */
					fastcgi_extension_insert(s->exts, da_ext->key, host);

					if (host_mode == FCGI_AUTHORIZER) {
						++host->refcount;
						fastcgi_extension_insert(s->exts_auth, da_ext->key, host);
					} else if (host_mode == FCGI_RESPONDER) {
						++host->refcount;
						fastcgi_extension_insert(s->exts_resp, da_ext->key, host);
					} /*(else should have been rejected above)*/

					host = NULL;
				}
			}
		}
	}

	buffer_free(fcgi_mode);
	return HANDLER_GO_ON;

error:
	if (NULL != host) fastcgi_host_free(host);
	buffer_free(fcgi_mode);
	return HANDLER_ERROR;
}

static int fcgi_set_state(server *srv, handler_ctx *hctx, fcgi_connection_state_t state) {
	hctx->state = state;
	hctx->state_timestamp = srv->cur_ts;

	return 0;
}


static void fcgi_backend_close(server *srv, handler_ctx *hctx) {
	if (hctx->fd != -1) {
		fdevent_event_del(srv->ev, &(hctx->fde_ndx), hctx->fd);
		fdevent_unregister(srv->ev, hctx->fd);
		fdevent_sched_close(srv->ev, hctx->fd, 1);
		hctx->fd = -1;
		hctx->fde_ndx = -1;
	}

	if (hctx->host) {
		if (hctx->proc && hctx->got_proc) {
			/* after the connect the process gets a load */
			fcgi_proc_load_dec(srv, hctx);

			if (hctx->conf.debug) {
				log_error_write(srv, __FILE__, __LINE__, "ssdsbsd",
						"released proc:",
						"pid:", hctx->proc->pid,
						"socket:", hctx->proc->connection_name,
						"load:", hctx->proc->load);
			}
		}

		fcgi_host_reset(srv, hctx);
	}
}

static fcgi_extension_host * fcgi_extension_host_get(server *srv, connection *con, plugin_data *p, fcgi_extension *extension) {
	fcgi_extension_host *host;
	int ndx = extension->last_used_ndx + 1;
	if (ndx >= (int) extension->used || ndx < 0) ndx = 0;
	UNUSED(p);

	/* check if the next server has no load */
	host = extension->hosts[ndx];
	if (host->load > 0 || host->active_procs == 0) {
		/* get backend with the least load */
		size_t k;
		int used = -1;
		for (k = 0, ndx = -1; k < extension->used; k++) {
			host = extension->hosts[k];

			/* we should have at least one proc that can do something */
			if (host->active_procs == 0) continue;

			if (used == -1 || host->load < used) {
				used = host->load;
				ndx = k;
			}
		}
	}

	if (ndx == -1) {
		/* all hosts are down */
		/* sorry, we don't have a server alive for this ext */
		con->http_status = 503; /* Service Unavailable */
		con->mode = DIRECT;

		/* only send the 'no handler' once */
		if (!extension->note_is_sent) {
			extension->note_is_sent = 1;

			log_error_write(srv, __FILE__, __LINE__, "sBSbsbs",
					"all handlers for", con->uri.path, "?", con->uri.query,
					"on", extension->key,
					"are down.");
		}
	}

	/* found a server */
	extension->last_used_ndx = ndx;
	return extension->hosts[ndx];
}

static void fcgi_connection_close(server *srv, handler_ctx *hctx) {
	plugin_data *p;
	connection  *con;

	p    = hctx->plugin_data;
	con  = hctx->remote_conn;

	fcgi_backend_close(srv, hctx);
	handler_ctx_free(hctx);
	con->plugin_ctx[p->id] = NULL;

	/* finish response (if not already con->file_started, con->file_finished) */
	if (con->mode == p->id) {
		http_response_backend_done(srv, con);
	}
}

static handler_t fcgi_reconnect(server *srv, handler_ctx *hctx) {
	fcgi_backend_close(srv, hctx);

	hctx->host = fcgi_extension_host_get(srv, hctx->remote_conn, hctx->plugin_data, hctx->ext);
	if (NULL == hctx->host) return HANDLER_FINISHED;

	fcgi_host_assign(srv, hctx, hctx->host);
	hctx->request_id = 0;
	fcgi_set_state(srv, hctx, FCGI_STATE_INIT);
	return HANDLER_COMEBACK;
}


static handler_t fcgi_connection_reset(server *srv, connection *con, void *p_d) {
	plugin_data *p = p_d;
	handler_ctx *hctx = con->plugin_ctx[p->id];
	if (hctx) fcgi_connection_close(srv, hctx);

	return HANDLER_GO_ON;
}


static int fcgi_env_add(void *venv, const char *key, size_t key_len, const char *val, size_t val_len) {
	buffer *env = venv;
	size_t len;
	char len_enc[8];
	size_t len_enc_len = 0;

	if (!key || !val) return -1;

	len = key_len + val_len;

	len += key_len > 127 ? 4 : 1;
	len += val_len > 127 ? 4 : 1;

	if (buffer_string_length(env) + len >= FCGI_MAX_LENGTH) {
		/**
		 * we can't append more headers, ignore it
		 */
		return -1;
	}

	/**
	 * field length can be 31bit max
	 *
	 * HINT: this can't happen as FCGI_MAX_LENGTH is only 16bit
	 */
	force_assert(key_len < 0x7fffffffu);
	force_assert(val_len < 0x7fffffffu);

	buffer_string_prepare_append(env, len);

	if (key_len > 127) {
		len_enc[len_enc_len++] = ((key_len >> 24) & 0xff) | 0x80;
		len_enc[len_enc_len++] = (key_len >> 16) & 0xff;
		len_enc[len_enc_len++] = (key_len >> 8) & 0xff;
		len_enc[len_enc_len++] = (key_len >> 0) & 0xff;
	} else {
		len_enc[len_enc_len++] = (key_len >> 0) & 0xff;
	}

	if (val_len > 127) {
		len_enc[len_enc_len++] = ((val_len >> 24) & 0xff) | 0x80;
		len_enc[len_enc_len++] = (val_len >> 16) & 0xff;
		len_enc[len_enc_len++] = (val_len >> 8) & 0xff;
		len_enc[len_enc_len++] = (val_len >> 0) & 0xff;
	} else {
		len_enc[len_enc_len++] = (val_len >> 0) & 0xff;
	}

	buffer_append_string_len(env, len_enc, len_enc_len);
	buffer_append_string_len(env, key, key_len);
	buffer_append_string_len(env, val, val_len);

	return 0;
}

static int fcgi_header(FCGI_Header * header, unsigned char type, int request_id, int contentLength, unsigned char paddingLength) {
	force_assert(contentLength <= FCGI_MAX_LENGTH);

	header->version = FCGI_VERSION_1;
	header->type = type;
	header->requestIdB0 = request_id & 0xff;
	header->requestIdB1 = (request_id >> 8) & 0xff;
	header->contentLengthB0 = contentLength & 0xff;
	header->contentLengthB1 = (contentLength >> 8) & 0xff;
	header->paddingLength = paddingLength;
	header->reserved = 0;

	return 0;
}

typedef enum {
	CONNECTION_OK,
	CONNECTION_DELAYED, /* retry after event, take same host */
	CONNECTION_OVERLOADED, /* disable for 1 second, take another backend */
	CONNECTION_DEAD /* disable for 60 seconds, take another backend */
} connection_result_t;

static connection_result_t fcgi_establish_connection(server *srv, handler_ctx *hctx) {
	struct sockaddr *fcgi_addr;
	struct sockaddr_in fcgi_addr_in;
#if defined(HAVE_IPV6) && defined(HAVE_INET_PTON)
	struct sockaddr_in6 fcgi_addr_in6;
#endif
#ifdef HAVE_SYS_UN_H
	struct sockaddr_un fcgi_addr_un;
#endif
	socklen_t servlen;

	fcgi_extension_host *host = hctx->host;
	fcgi_proc *proc   = hctx->proc;
	int fcgi_fd       = hctx->fd;

	if (!buffer_string_is_empty(proc->unixsocket)) {
#ifdef HAVE_SYS_UN_H
		/* use the unix domain socket */
		memset(&fcgi_addr_un, 0, sizeof(fcgi_addr_un));
		fcgi_addr_un.sun_family = AF_UNIX;
		if (buffer_string_length(proc->unixsocket) + 1 > sizeof(fcgi_addr_un.sun_path)) {
			log_error_write(srv, __FILE__, __LINE__, "sB",
					"ERROR: Unix Domain socket filename too long:",
					proc->unixsocket);
			return -1;
		}
		memcpy(fcgi_addr_un.sun_path, proc->unixsocket->ptr, buffer_string_length(proc->unixsocket) + 1);

#ifdef SUN_LEN
		servlen = SUN_LEN(&fcgi_addr_un);
#else
		/* stevens says: */
		servlen = buffer_string_length(proc->unixsocket) + 1 + sizeof(fcgi_addr_un.sun_family);
#endif
		fcgi_addr = (struct sockaddr *) &fcgi_addr_un;

		if (buffer_string_is_empty(proc->connection_name)) {
			/* on remote spawing we have to set the connection-name now */
			buffer_copy_string_len(proc->connection_name, CONST_STR_LEN("unix:"));
			buffer_append_string_buffer(proc->connection_name, proc->unixsocket);
		}
#else
		return CONNECTION_DEAD;
#endif
#if defined(HAVE_IPV6) && defined(HAVE_INET_PTON)
	} else if (host->family == AF_INET6 && !buffer_string_is_empty(host->host)) {
		memset(&fcgi_addr_in6, 0, sizeof(fcgi_addr_in6));
		fcgi_addr_in6.sin6_family = AF_INET6;
		inet_pton(AF_INET6, host->host->ptr, (char *) &fcgi_addr_in6.sin6_addr);
		fcgi_addr_in6.sin6_port = htons(proc->port);
		servlen = sizeof(fcgi_addr_in6);
		fcgi_addr = (struct sockaddr *) &fcgi_addr_in6;
#endif
	} else {
		memset(&fcgi_addr_in, 0, sizeof(fcgi_addr_in));
		fcgi_addr_in.sin_family = AF_INET;
		if (!buffer_string_is_empty(host->host)) {
			if (0 == inet_aton(host->host->ptr, &(fcgi_addr_in.sin_addr))) {
				log_error_write(srv, __FILE__, __LINE__, "sbs",
						"converting IP address failed for", host->host,
						"\nBe sure to specify an IP address here");

				return CONNECTION_DEAD;
			}
		} else {
			fcgi_addr_in.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
		}
		fcgi_addr_in.sin_port = htons(proc->port);
		servlen = sizeof(fcgi_addr_in);

		fcgi_addr = (struct sockaddr *) &fcgi_addr_in;
	}

	if (buffer_string_is_empty(proc->unixsocket)) {
		if (buffer_string_is_empty(proc->connection_name)) {
			/* on remote spawing we have to set the connection-name now */
			buffer_copy_string_len(proc->connection_name, CONST_STR_LEN("tcp:"));
			if (!buffer_string_is_empty(host->host)) {
				buffer_append_string_buffer(proc->connection_name, host->host);
			} else {
				buffer_append_string_len(proc->connection_name, CONST_STR_LEN("localhost"));
			}
			buffer_append_string_len(proc->connection_name, CONST_STR_LEN(":"));
			buffer_append_int(proc->connection_name, proc->port);
		}
	}

	if (-1 == connect(fcgi_fd, fcgi_addr, servlen)) {
		if (errno == EINPROGRESS ||
		    errno == EALREADY ||
		    errno == EINTR) {
			if (hctx->conf.debug > 2) {
				log_error_write(srv, __FILE__, __LINE__, "sb",
					"connect delayed; will continue later:", proc->connection_name);
			}

			return CONNECTION_DELAYED;
		} else if (errno == EAGAIN) {
			if (hctx->conf.debug) {
				log_error_write(srv, __FILE__, __LINE__, "sbsd",
					"This means that you have more incoming requests than your FastCGI backend can handle in parallel."
					"It might help to spawn more FastCGI backends or PHP children; if not, decrease server.max-connections."
					"The load for this FastCGI backend", proc->connection_name, "is", proc->load);
			}

			return CONNECTION_OVERLOADED;
		} else {
			log_error_write(srv, __FILE__, __LINE__, "sssb",
					"connect failed:",
					strerror(errno), "on",
					proc->connection_name);

			return CONNECTION_DEAD;
		}
	}

	hctx->reconnects = 0;
	if (hctx->conf.debug > 1) {
		log_error_write(srv, __FILE__, __LINE__, "sd",
				"connect succeeded: ", fcgi_fd);
	}

	return CONNECTION_OK;
}

static void fcgi_stdin_append(server *srv, connection *con, handler_ctx *hctx, int request_id) {
	FCGI_Header header;
	chunkqueue *req_cq = con->request_content_queue;
	off_t offset, weWant;
	const off_t req_cqlen = req_cq->bytes_in - req_cq->bytes_out;

	/* something to send ? */
	for (offset = 0; offset != req_cqlen; offset += weWant) {
		weWant = req_cqlen - offset > FCGI_MAX_LENGTH ? FCGI_MAX_LENGTH : req_cqlen - offset;

		/* we announce toWrite octets
		 * now take all request_content chunks available
		 * */

		fcgi_header(&(header), FCGI_STDIN, request_id, weWant, 0);
		chunkqueue_append_mem(hctx->wb, (const char *)&header, sizeof(header));
		hctx->wb_reqlen += sizeof(header);

		if (hctx->conf.debug > 10) {
			log_error_write(srv, __FILE__, __LINE__, "soso", "tosend:", offset, "/", req_cqlen);
		}

		chunkqueue_steal(hctx->wb, req_cq, weWant);
		/*(hctx->wb_reqlen already includes content_length)*/
	}

	if (hctx->wb->bytes_in == hctx->wb_reqlen) {
		/* terminate STDIN */
		fcgi_header(&(header), FCGI_STDIN, request_id, 0, 0);
		chunkqueue_append_mem(hctx->wb, (const char *)&header, sizeof(header));
		hctx->wb_reqlen += (int)sizeof(header);
	}
}

static int fcgi_create_env(server *srv, handler_ctx *hctx, int request_id) {
	FCGI_BeginRequestRecord beginRecord;
	FCGI_Header header;

	plugin_data *p    = hctx->plugin_data;
	fcgi_extension_host *host= hctx->host;

	connection *con   = hctx->remote_conn;

	http_cgi_opts opts = {
	  (hctx->fcgi_mode == FCGI_AUTHORIZER),
	  host->break_scriptfilename_for_php,
	  host->docroot,
	  host->strip_request_uri
	};

	/* send FCGI_BEGIN_REQUEST */

	fcgi_header(&(beginRecord.header), FCGI_BEGIN_REQUEST, request_id, sizeof(beginRecord.body), 0);
	beginRecord.body.roleB0 = hctx->fcgi_mode;
	beginRecord.body.roleB1 = 0;
	beginRecord.body.flags = 0;
	memset(beginRecord.body.reserved, 0, sizeof(beginRecord.body.reserved));

	/* send FCGI_PARAMS */
	buffer_string_prepare_copy(p->fcgi_env, 1023);

	if (0 != http_cgi_headers(srv, con, &opts, fcgi_env_add, p->fcgi_env)) {
		con->http_status = 400;
		return -1;
	} else {
		buffer *b = buffer_init();

		buffer_copy_string_len(b, (const char *)&beginRecord, sizeof(beginRecord));

		fcgi_header(&(header), FCGI_PARAMS, request_id, buffer_string_length(p->fcgi_env), 0);
		buffer_append_string_len(b, (const char *)&header, sizeof(header));
		buffer_append_string_buffer(b, p->fcgi_env);

		fcgi_header(&(header), FCGI_PARAMS, request_id, 0, 0);
		buffer_append_string_len(b, (const char *)&header, sizeof(header));

		hctx->wb_reqlen = buffer_string_length(b);
		chunkqueue_append_buffer(hctx->wb, b);
		buffer_free(b);
	}

	hctx->wb_reqlen += con->request.content_length;/* (eventual) (minimal) total request size, not necessarily including all fcgi_headers around content length yet */
	fcgi_stdin_append(srv, con, hctx, request_id);

	return 0;
}

static int fcgi_response_parse(server *srv, connection *con, plugin_data *p, buffer *in) {
	char *s, *ns;

	handler_ctx *hctx = con->plugin_ctx[p->id];
	fcgi_extension_host *host= hctx->host;
	int have_sendfile2 = 0;
	off_t sendfile2_content_length = 0;

	UNUSED(srv);

	/* search for \n */
	for (s = in->ptr; NULL != (ns = strchr(s, '\n')); s = ns + 1) {
		char *key, *value;
		int key_len;

		/* a good day. Someone has read the specs and is sending a \r\n to us */

		if (ns > in->ptr &&
		    *(ns-1) == '\r') {
			*(ns-1) = '\0';
		}

		ns[0] = '\0';

		key = s;
		if (NULL == (value = strchr(s, ':'))) {
			/* we expect: "<key>: <value>\n" */
			continue;
		}

		key_len = value - key;

		value++;
		/* strip WS */
		while (*value == ' ' || *value == '\t') value++;

		if (hctx->fcgi_mode != FCGI_AUTHORIZER ||
		    !(con->http_status == 0 ||
		      con->http_status == 200)) {
			/* authorizers shouldn't affect the response headers sent back to the client */

			/* don't forward Status: */
			if (0 != strncasecmp(key, "Status", key_len)) {
				data_string *ds;
				if (NULL == (ds = (data_string *)array_get_unused_element(con->response.headers, TYPE_STRING))) {
					ds = data_response_init();
				}
				buffer_copy_string_len(ds->key, key, key_len);
				buffer_copy_string(ds->value, value);

				array_insert_unique(con->response.headers, (data_unset *)ds);
			}
		}

		if (hctx->fcgi_mode == FCGI_AUTHORIZER &&
		    key_len > 9 &&
		    0 == strncasecmp(key, CONST_STR_LEN("Variable-"))) {
			data_string *ds;
			if (NULL == (ds = (data_string *)array_get_unused_element(con->environment, TYPE_STRING))) {
				ds = data_response_init();
			}
			buffer_copy_string_len(ds->key, key + 9, key_len - 9);
			buffer_copy_string(ds->value, value);

			array_insert_unique(con->environment, (data_unset *)ds);
		}

		switch(key_len) {
		case 4:
			if (0 == strncasecmp(key, "Date", key_len)) {
				con->parsed_response |= HTTP_DATE;
			}
			break;
		case 6:
			if (0 == strncasecmp(key, "Status", key_len)) {
				int status = strtol(value, NULL, 10);
				if (status >= 100 && status < 1000) {
					con->http_status = status;
					con->parsed_response |= HTTP_STATUS;
				} else {
					con->http_status = 502;
				}
			}
			break;
		case 8:
			if (0 == strncasecmp(key, "Location", key_len)) {
				con->parsed_response |= HTTP_LOCATION;
			}
			break;
		case 10:
			if (0 == strncasecmp(key, "Connection", key_len)) {
				con->response.keep_alive = (0 == strcasecmp(value, "Keep-Alive")) ? 1 : 0;
				con->parsed_response |= HTTP_CONNECTION;
			}
			break;
		case 11:
			if (host->xsendfile_allow && 0 == strncasecmp(key, "X-Sendfile2", key_len) && hctx->send_content_body) {
				char *pos = value;
				have_sendfile2 = 1;

				while (*pos) {
					char *filename, *range;
					stat_cache_entry *sce;
					off_t begin_range, end_range, range_len;

					while (' ' == *pos) pos++;
					if (!*pos) break;

					filename = pos;
					if (NULL == (range = strchr(pos, ' '))) {
						/* missing range */
						if (hctx->conf.debug) {
							log_error_write(srv, __FILE__, __LINE__, "ss", "Couldn't find range after filename:", filename);
						}
						return 502;
					}
					buffer_copy_string_len(srv->tmp_buf, filename, range - filename);

					/* find end of range */
					for (pos = ++range; *pos && *pos != ' ' && *pos != ','; pos++) ;

					buffer_urldecode_path(srv->tmp_buf);
					buffer_path_simplify(srv->tmp_buf, srv->tmp_buf);
					if (con->conf.force_lowercase_filenames) {
						buffer_to_lower(srv->tmp_buf);
					}
					if (host->xsendfile_docroot->used) {
						size_t i, xlen = buffer_string_length(srv->tmp_buf);
						for (i = 0; i < host->xsendfile_docroot->used; ++i) {
							data_string *ds = (data_string *)host->xsendfile_docroot->data[i];
							size_t dlen = buffer_string_length(ds->value);
							if (dlen <= xlen
							    && (!con->conf.force_lowercase_filenames
								? 0 == memcmp(srv->tmp_buf->ptr, ds->value->ptr, dlen)
								: 0 == strncasecmp(srv->tmp_buf->ptr, ds->value->ptr, dlen))) {
								break;
							}
						}
						if (i == host->xsendfile_docroot->used) {
							log_error_write(srv, __FILE__, __LINE__, "SBs",
									"X-Sendfile2 (", srv->tmp_buf,
									") not under configured x-sendfile-docroot(s)");
							return 403;
						}
					}

					if (HANDLER_ERROR == stat_cache_get_entry(srv, con, srv->tmp_buf, &sce)) {
						if (hctx->conf.debug) {
							log_error_write(srv, __FILE__, __LINE__, "sb",
								"send-file error: couldn't get stat_cache entry for X-Sendfile2:",
								srv->tmp_buf);
						}
						return 404;
					} else if (!S_ISREG(sce->st.st_mode)) {
						if (hctx->conf.debug) {
							log_error_write(srv, __FILE__, __LINE__, "sb",
								"send-file error: wrong filetype for X-Sendfile2:",
								srv->tmp_buf);
						}
						return 502;
					}
					/* found the file */

					/* parse range */
					end_range = sce->st.st_size - 1;
					{
						char *rpos = NULL;
						errno = 0;
						begin_range = strtoll(range, &rpos, 10);
						if (errno != 0 || begin_range < 0 || rpos == range) goto range_failed;
						if ('-' != *rpos++) goto range_failed;
						if (rpos != pos) {
							range = rpos;
							end_range = strtoll(range, &rpos, 10);
							if (errno != 0 || end_range < 0 || rpos == range) goto range_failed;
						}
						if (rpos != pos) goto range_failed;

						goto range_success;

range_failed:
						if (hctx->conf.debug) {
							log_error_write(srv, __FILE__, __LINE__, "ss", "Couldn't decode range after filename:", filename);
						}
						return 502;

range_success: ;
					}

					/* no parameters accepted */

					while (*pos == ' ') pos++;
					if (*pos != '\0' && *pos != ',') return 502;

					range_len = end_range - begin_range + 1;
					if (range_len < 0) return 502;
					if (range_len != 0) {
						if (0 != http_chunk_append_file_range(srv, con, srv->tmp_buf, begin_range, range_len)) {
							return 502;
						}
					}
					sendfile2_content_length += range_len;

					if (*pos == ',') pos++;
				}
			}
			break;
		case 14:
			if (0 == strncasecmp(key, "Content-Length", key_len)) {
				con->response.content_length = strtoul(value, NULL, 10);
				con->parsed_response |= HTTP_CONTENT_LENGTH;

				if (con->response.content_length < 0) con->response.content_length = 0;
			}
			break;
		default:
			break;
		}
	}

	if (have_sendfile2) {
		data_string *dcls;

		/* fix content-length */
		if (NULL == (dcls = (data_string *)array_get_unused_element(con->response.headers, TYPE_STRING))) {
			dcls = data_response_init();
		}

		buffer_copy_string_len(dcls->key, "Content-Length", sizeof("Content-Length")-1);
		buffer_copy_int(dcls->value, sendfile2_content_length);
		array_replace(con->response.headers, (data_unset *)dcls);

		con->parsed_response |= HTTP_CONTENT_LENGTH;
		con->response.content_length = sendfile2_content_length;
		return 200;
	}

	/* CGI/1.1 rev 03 - 7.2.1.2 */
	if ((con->parsed_response & HTTP_LOCATION) &&
	    !(con->parsed_response & HTTP_STATUS)) {
		con->http_status = 302;
	}

	return 0;
}

typedef struct {
	buffer  *b;
	unsigned int len;
	int      type;
	int      padding;
	int      request_id;
} fastcgi_response_packet;

static int fastcgi_get_packet(server *srv, handler_ctx *hctx, fastcgi_response_packet *packet) {
	chunk *c;
	size_t offset;
	size_t toread;
	FCGI_Header *header;

	if (!hctx->rb->first) return -1;

	packet->b = buffer_init();
	packet->len = 0;
	packet->type = 0;
	packet->padding = 0;
	packet->request_id = 0;

	offset = 0; toread = 8;
	/* get at least the FastCGI header */
	for (c = hctx->rb->first; c; c = c->next) {
		size_t weHave = buffer_string_length(c->mem) - c->offset;

		if (weHave > toread) weHave = toread;

		buffer_append_string_len(packet->b, c->mem->ptr + c->offset, weHave);
		toread -= weHave;
		offset = weHave; /* skip offset bytes in chunk for "real" data */

		if (0 == toread) break;
	}

	if (buffer_string_length(packet->b) < sizeof(FCGI_Header)) {
		/* no header */
		if (hctx->conf.debug) {
			log_error_write(srv, __FILE__, __LINE__, "sdsds", "FastCGI: header too small:", buffer_string_length(packet->b), "bytes <", sizeof(FCGI_Header), "bytes, waiting for more data");
		}

		buffer_free(packet->b);

		return -1;
	}

	/* we have at least a header, now check how much me have to fetch */
	header = (FCGI_Header *)(packet->b->ptr);

	packet->len = (header->contentLengthB0 | (header->contentLengthB1 << 8)) + header->paddingLength;
	packet->request_id = (header->requestIdB0 | (header->requestIdB1 << 8));
	packet->type = header->type;
	packet->padding = header->paddingLength;

	/* ->b should only be the content */
	buffer_string_set_length(packet->b, 0);

	if (packet->len) {
		/* copy the content */
		for (; c && (buffer_string_length(packet->b) < packet->len); c = c->next) {
			size_t weWant = packet->len - buffer_string_length(packet->b);
			size_t weHave = buffer_string_length(c->mem) - c->offset - offset;

			if (weHave > weWant) weHave = weWant;

			buffer_append_string_len(packet->b, c->mem->ptr + c->offset + offset, weHave);

			/* we only skipped the first bytes as they belonged to the fcgi header */
			offset = 0;
		}

		if (buffer_string_length(packet->b) < packet->len) {
			/* we didn't get the full packet */

			buffer_free(packet->b);
			return -1;
		}

		buffer_string_set_length(packet->b, buffer_string_length(packet->b) - packet->padding);
	}

	chunkqueue_mark_written(hctx->rb, packet->len + sizeof(FCGI_Header));

	return 0;
}

static int fcgi_demux_response(server *srv, handler_ctx *hctx) {
	int fin = 0;
	int toread, ret;
	ssize_t r = 0;

	plugin_data *p    = hctx->plugin_data;
	connection *con   = hctx->remote_conn;
	int fcgi_fd       = hctx->fd;
	fcgi_extension_host *host= hctx->host;
	fcgi_proc *proc   = hctx->proc;

	/*
	 * check how much we have to read
	 */
      #if !defined(_WIN32) && !defined(__CYGWIN__)
	if (ioctl(hctx->fd, FIONREAD, &toread)) {
		if (errno == EAGAIN) {
			fdevent_event_add(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_IN);
			return 0;
		}
		log_error_write(srv, __FILE__, __LINE__, "sd",
				"unexpected end-of-file (perhaps the fastcgi process died):",
				fcgi_fd);
		return -1;
	}
      #else
	toread = 4096;
      #endif

	if (toread > 0) {
		char *mem;
		size_t mem_len;

		if ((con->conf.stream_response_body & FDEVENT_STREAM_RESPONSE_BUFMIN)) {
			off_t cqlen = chunkqueue_length(hctx->rb);
			if (cqlen + toread > 65536 + (int)sizeof(FCGI_Header)) { /*(max size of FastCGI packet + 1)*/
				if (cqlen < 65536 + (int)sizeof(FCGI_Header)) {
					toread = 65536 + (int)sizeof(FCGI_Header) - cqlen;
				} else { /* should not happen */
					toread = toread < 1024 ? toread : 1024;
				}
			}
		}

		chunkqueue_get_memory(hctx->rb, &mem, &mem_len, 0, toread);
		r = read(hctx->fd, mem, mem_len);
		chunkqueue_use_memory(hctx->rb, r > 0 ? r : 0);

		if (-1 == r) {
			if (errno == EAGAIN) {
				fdevent_event_add(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_IN);
				return 0;
			}
			log_error_write(srv, __FILE__, __LINE__, "sds",
					"unexpected end-of-file (perhaps the fastcgi process died):",
					fcgi_fd, strerror(errno));
			return -1;
		}
	}
	if (0 == r) {
		log_error_write(srv, __FILE__, __LINE__, "ssdsb",
				"unexpected end-of-file (perhaps the fastcgi process died):",
				"pid:", proc->pid,
				"socket:", proc->connection_name);

		return -1;
	}

	/*
	 * parse the fastcgi packets and forward the content to the write-queue
	 *
	 */
	while (fin == 0) {
		fastcgi_response_packet packet;

		/* check if we have at least one packet */
		if (0 != fastcgi_get_packet(srv, hctx, &packet)) {
			/* no full packet */
			break;
		}

		switch(packet.type) {
		case FCGI_STDOUT:
			if (packet.len == 0) break;

			/* is the header already finished */
			if (0 == con->file_started) {
				char *c;
				data_string *ds;

				/* search for header terminator
				 *
				 * if we start with \r\n check if last packet terminated with \r\n
				 * if we start with \n check if last packet terminated with \n
				 * search for \r\n\r\n
				 * search for \n\n
				 */

				buffer_append_string_buffer(hctx->response_header, packet.b);

				if (NULL != (c = buffer_search_string_len(hctx->response_header, CONST_STR_LEN("\r\n\r\n")))) {
					char *hend = c + 4; /* header end == body start */
					size_t hlen = hend - hctx->response_header->ptr;
					buffer_copy_string_len(packet.b, hend, buffer_string_length(hctx->response_header) - hlen);
					buffer_string_set_length(hctx->response_header, hlen);
				} else if (NULL != (c = buffer_search_string_len(hctx->response_header, CONST_STR_LEN("\n\n")))) {
					char *hend = c + 2; /* header end == body start */
					size_t hlen = hend - hctx->response_header->ptr;
					buffer_copy_string_len(packet.b, hend, buffer_string_length(hctx->response_header) - hlen);
					buffer_string_set_length(hctx->response_header, hlen);
				} else {
					/* no luck, no header found */
					/*(reuse MAX_HTTP_REQUEST_HEADER as max size for response headers from backends)*/
					if (buffer_string_length(hctx->response_header) > MAX_HTTP_REQUEST_HEADER) {
						log_error_write(srv, __FILE__, __LINE__, "sb", "response headers too large for", con->uri.path);
						con->http_status = 502; /* Bad Gateway */
						con->mode = DIRECT;
						fin = 1;
					}
					break;
				}

				/* parse the response header */
				if ((ret = fcgi_response_parse(srv, con, p, hctx->response_header))) {
					if (200 != ret) { /*(200 returned for X-Sendfile2 handled)*/
						con->http_status = ret;
						con->mode = DIRECT;
					}
					con->file_started = 1;
					hctx->send_content_body = 0;
					fin = 1;
					break;
				}

				con->file_started = 1;

				if (hctx->fcgi_mode == FCGI_AUTHORIZER &&
				    (con->http_status == 0 ||
				     con->http_status == 200)) {
					/* a authorizer with approved the static request, ignore the content here */
					hctx->send_content_body = 0;
				}

				if (host->xsendfile_allow && hctx->send_content_body &&
				    (NULL != (ds = (data_string *) array_get_element(con->response.headers, "X-LIGHTTPD-send-file"))
					  || NULL != (ds = (data_string *) array_get_element(con->response.headers, "X-Sendfile")))) {
					http_response_xsendfile(srv, con, ds->value, host->xsendfile_docroot);
					if (con->mode == DIRECT) {
						fin = 1;
					}

					hctx->send_content_body = 0; /* ignore the content */
					break;
				}
			}

			if (hctx->send_content_body && !buffer_string_is_empty(packet.b)) {
				if (0 != http_chunk_append_buffer(srv, con, packet.b)) {
					/* error writing to tempfile;
					 * truncate response or send 500 if nothing sent yet */
					fin = 1;
					break;
				}
				if ((con->conf.stream_response_body & FDEVENT_STREAM_RESPONSE_BUFMIN)
				    && chunkqueue_length(con->write_queue) > 65536 - 4096) {
					if (!con->is_writable) {
						/*(defer removal of FDEVENT_IN interest since
						 * connection_state_machine() might be able to send data
						 * immediately, unless !con->is_writable, where
						 * connection_state_machine() might not loop back to call
						 * mod_fastcgi_handle_subrequest())*/
						fdevent_event_clr(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_IN);
					}
				}
			}
			break;
		case FCGI_STDERR:
			if (packet.len == 0) break;

			log_error_write_multiline_buffer(srv, __FILE__, __LINE__, packet.b, "s",
					"FastCGI-stderr:");

			break;
		case FCGI_END_REQUEST:
			fin = 1;
			break;
		default:
			log_error_write(srv, __FILE__, __LINE__, "sd",
					"FastCGI: header.type not handled: ", packet.type);
			break;
		}
		buffer_free(packet.b);
	}

	return fin;
}

static int fcgi_restart_dead_procs(server *srv, plugin_data *p, fcgi_extension_host *host) {
	fcgi_proc *proc;

	for (proc = host->first; proc; proc = proc->next) {
		int status;

		if (p->conf.debug > 2) {
			log_error_write(srv, __FILE__, __LINE__,  "sbdddd",
					"proc:",
					proc->connection_name,
					proc->state,
					proc->is_local,
					proc->load,
					proc->pid);
		}

		/*
		 * if the remote side is overloaded, we check back after <n> seconds
		 *
		 */
		switch (proc->state) {
		case PROC_STATE_KILLED:
		case PROC_STATE_UNSET:
			/* this should never happen as long as adaptive spawing is disabled */
			force_assert(0);

			break;
		case PROC_STATE_RUNNING:
			break;
		case PROC_STATE_OVERLOADED:
			if (srv->cur_ts <= proc->disabled_until) break;

			proc->state = PROC_STATE_RUNNING;
			host->active_procs++;

			log_error_write(srv, __FILE__, __LINE__,  "sbdb",
					"fcgi-server re-enabled:",
					host->host, host->port,
					host->unixsocket);
			break;
		case PROC_STATE_DIED_WAIT_FOR_PID:
			/* non-local procs don't have PIDs to wait for */
			if (!proc->is_local) {
				proc->state = PROC_STATE_DIED;
			} else {
				/* the child should not terminate at all */

				for ( ;; ) {
					switch(waitpid(proc->pid, &status, WNOHANG)) {
					case 0:
						/* child is still alive */
						if (srv->cur_ts <= proc->disabled_until) break;

						proc->state = PROC_STATE_RUNNING;
						host->active_procs++;

						log_error_write(srv, __FILE__, __LINE__,  "sbdb",
							"fcgi-server re-enabled:",
							host->host, host->port,
							host->unixsocket);
						break;
					case -1:
						if (errno == EINTR) continue;

						log_error_write(srv, __FILE__, __LINE__, "sd",
							"child died somehow, waitpid failed:",
							errno);
						proc->state = PROC_STATE_DIED;
						break;
					default:
						if (WIFEXITED(status)) {
#if 0
							log_error_write(srv, __FILE__, __LINE__, "sdsd",
								"child exited, pid:", proc->pid,
								"status:", WEXITSTATUS(status));
#endif
						} else if (WIFSIGNALED(status)) {
							log_error_write(srv, __FILE__, __LINE__, "sd",
								"child signaled:",
								WTERMSIG(status));
						} else {
							log_error_write(srv, __FILE__, __LINE__, "sd",
								"child died somehow:",
								status);
						}

						proc->state = PROC_STATE_DIED;
						break;
					}
					break;
				}
			}

			/* fall through if we have a dead proc now */
			if (proc->state != PROC_STATE_DIED) break;

		case PROC_STATE_DIED:
			/* local procs get restarted by us,
			 * remote ones hopefully by the admin */

			if (!buffer_string_is_empty(host->bin_path)) {
				/* we still have connections bound to this proc,
				 * let them terminate first */
				if (proc->load != 0) break;

				/* restart the child */

				if (p->conf.debug) {
					log_error_write(srv, __FILE__, __LINE__, "ssbsdsd",
							"--- fastcgi spawning",
							"\n\tsocket", proc->connection_name,
							"\n\tcurrent:", 1, "/", host->max_procs);
				}

				if (fcgi_spawn_connection(srv, p, host, proc)) {
					log_error_write(srv, __FILE__, __LINE__, "s",
							"ERROR: spawning fcgi failed.");
					return HANDLER_ERROR;
				}
			} else {
				if (srv->cur_ts <= proc->disabled_until) break;

				proc->state = PROC_STATE_RUNNING;
				host->active_procs++;

				log_error_write(srv, __FILE__, __LINE__,  "sb",
						"fcgi-server re-enabled:",
						proc->connection_name);
			}
			break;
		}
	}

	return 0;
}

static handler_t fcgi_write_request(server *srv, handler_ctx *hctx) {
	plugin_data *p    = hctx->plugin_data;
	fcgi_extension_host *host= hctx->host;
	connection *con   = hctx->remote_conn;
	fcgi_proc  *proc;

	int ret;

	/* we can't handle this in the switch as we have to fall through in it */
	if (hctx->state == FCGI_STATE_CONNECT_DELAYED) {
		int socket_error;
		socklen_t socket_error_len = sizeof(socket_error);

		/* try to finish the connect() */
		if (0 != getsockopt(hctx->fd, SOL_SOCKET, SO_ERROR, &socket_error, &socket_error_len)) {
			log_error_write(srv, __FILE__, __LINE__, "ss",
					"getsockopt failed:", strerror(errno));

			fcgi_host_disable(srv, hctx);

			return HANDLER_ERROR;
		}
		if (socket_error != 0) {
			if (!hctx->proc->is_local || hctx->conf.debug) {
				/* local procs get restarted */

				log_error_write(srv, __FILE__, __LINE__, "sssb",
						"establishing connection failed:", strerror(socket_error),
						"socket:", hctx->proc->connection_name);
			}

			fcgi_host_disable(srv, hctx);
			log_error_write(srv, __FILE__, __LINE__, "sdssdsd",
				"backend is overloaded; we'll disable it for", hctx->host->disable_time, "seconds and send the request to another backend instead:",
				"reconnects:", hctx->reconnects,
				"load:", host->load);

			fastcgi_status_copy_procname(p->statuskey, hctx->host, hctx->proc);
			buffer_append_string_len(p->statuskey, CONST_STR_LEN(".died"));

			status_counter_inc(srv, CONST_BUF_LEN(p->statuskey));

			return HANDLER_ERROR;
		}
		/* go on with preparing the request */
		hctx->state = FCGI_STATE_PREPARE_WRITE;
	}


	switch(hctx->state) {
	case FCGI_STATE_CONNECT_DELAYED:
		/* should never happen */
		return HANDLER_WAIT_FOR_EVENT;
	case FCGI_STATE_INIT:
		/* do we have a running process for this host (max-procs) ? */
		hctx->proc = NULL;

		for (proc = hctx->host->first;
		     proc && proc->state != PROC_STATE_RUNNING;
		     proc = proc->next);

		/* all children are dead */
		if (proc == NULL) {
			hctx->fde_ndx = -1;

			return HANDLER_ERROR;
		}

		hctx->proc = proc;

		/* check the other procs if they have a lower load */
		for (proc = proc->next; proc; proc = proc->next) {
			if (proc->state != PROC_STATE_RUNNING) continue;
			if (proc->load < hctx->proc->load) hctx->proc = proc;
		}

		if (-1 == (hctx->fd = fdevent_socket_nb_cloexec(host->family, SOCK_STREAM, 0))) {
			if (errno == EMFILE ||
			    errno == EINTR) {
				log_error_write(srv, __FILE__, __LINE__, "sd",
						"wait for fd at connection:", con->fd);

				return HANDLER_WAIT_FOR_FD;
			}

			log_error_write(srv, __FILE__, __LINE__, "ssdd",
					"socket failed:", strerror(errno), srv->cur_fds, srv->max_fds);
			return HANDLER_ERROR;
		}
		hctx->fde_ndx = -1;

		srv->cur_fds++;

		fdevent_register(srv->ev, hctx->fd, fcgi_handle_fdevent, hctx);

		if (-1 == fdevent_fcntl_set(srv->ev, hctx->fd)) {
			log_error_write(srv, __FILE__, __LINE__, "ss",
					"fcntl failed:", strerror(errno));

			return HANDLER_ERROR;
		}

		if (hctx->proc->is_local) {
			hctx->pid = hctx->proc->pid;
		}

		switch (fcgi_establish_connection(srv, hctx)) {
		case CONNECTION_DELAYED:
			/* connection is in progress, wait for an event and call getsockopt() below */

			fdevent_event_set(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_OUT);

			fcgi_set_state(srv, hctx, FCGI_STATE_CONNECT_DELAYED);
			return HANDLER_WAIT_FOR_EVENT;
		case CONNECTION_OVERLOADED:
			/* cool down the backend, it is overloaded
			 * -> EAGAIN */

			if (hctx->host->disable_time) {
				log_error_write(srv, __FILE__, __LINE__, "sdssdsd",
					"backend is overloaded; we'll disable it for", hctx->host->disable_time, "seconds and send the request to another backend instead:",
					"reconnects:", hctx->reconnects,
					"load:", host->load);

				hctx->proc->disabled_until = srv->cur_ts + hctx->host->disable_time;
				if (hctx->proc->state == PROC_STATE_RUNNING) hctx->host->active_procs--;
				hctx->proc->state = PROC_STATE_OVERLOADED;
			}

			fastcgi_status_copy_procname(p->statuskey, hctx->host, hctx->proc);
			buffer_append_string_len(p->statuskey, CONST_STR_LEN(".overloaded"));

			status_counter_inc(srv, CONST_BUF_LEN(p->statuskey));

			return HANDLER_ERROR;
		case CONNECTION_DEAD:
			/* we got a hard error from the backend like
			 * - ECONNREFUSED for tcp-ip sockets
			 * - ENOENT for unix-domain-sockets
			 *
			 * for check if the host is back in hctx->host->disable_time seconds
			 *  */

			fcgi_host_disable(srv, hctx);

			log_error_write(srv, __FILE__, __LINE__, "sdssdsd",
				"backend died; we'll disable it for", hctx->host->disable_time, "seconds and send the request to another backend instead:",
				"reconnects:", hctx->reconnects,
				"load:", host->load);

			fastcgi_status_copy_procname(p->statuskey, hctx->host, hctx->proc);
			buffer_append_string_len(p->statuskey, CONST_STR_LEN(".died"));

			status_counter_inc(srv, CONST_BUF_LEN(p->statuskey));

			return HANDLER_ERROR;
		case CONNECTION_OK:
			/* everything is ok, go on */

			fcgi_set_state(srv, hctx, FCGI_STATE_PREPARE_WRITE);

			break;
		}
		/* fallthrough */
	case FCGI_STATE_PREPARE_WRITE:
		/* ok, we have the connection */

		fcgi_proc_load_inc(srv, hctx);
		hctx->got_proc = 1;

		status_counter_inc(srv, CONST_STR_LEN("fastcgi.requests"));

		fastcgi_status_copy_procname(p->statuskey, hctx->host, hctx->proc);
		buffer_append_string_len(p->statuskey, CONST_STR_LEN(".connected"));

		status_counter_inc(srv, CONST_BUF_LEN(p->statuskey));

		if (hctx->conf.debug) {
			log_error_write(srv, __FILE__, __LINE__, "ssdsbsd",
				"got proc:",
				"pid:", hctx->proc->pid,
				"socket:", hctx->proc->connection_name,
				"load:", hctx->proc->load);
		}

		/* move the proc-list entry down the list */
		if (hctx->request_id == 0) {
			hctx->request_id = 1; /* always use id 1 as we don't use multiplexing */
		} else {
			log_error_write(srv, __FILE__, __LINE__, "sd",
					"fcgi-request is already in use:", hctx->request_id);
		}

		if (-1 == fcgi_create_env(srv, hctx, hctx->request_id)) return HANDLER_ERROR;

		fdevent_event_add(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_IN);
		fcgi_set_state(srv, hctx, FCGI_STATE_WRITE);
		/* fall through */
	case FCGI_STATE_WRITE:
		ret = srv->network_backend_write(srv, con, hctx->fd, hctx->wb, MAX_WRITE_LIMIT);

		chunkqueue_remove_finished_chunks(hctx->wb);

		if (ret < 0) {
			switch(errno) {
			case EPIPE:
			case ENOTCONN:
			case ECONNRESET:
				/* the connection got dropped after accept()
				 * we don't care about that - if you accept() it, you have to handle it.
				 */

				log_error_write(srv, __FILE__, __LINE__, "ssosb",
							"connection was dropped after accept() (perhaps the fastcgi process died),",
						"write-offset:", hctx->wb->bytes_out,
						"socket:", hctx->proc->connection_name);

				return HANDLER_ERROR;
			default:
				log_error_write(srv, __FILE__, __LINE__, "ssd",
						"write failed:", strerror(errno), errno);

				return HANDLER_ERROR;
			}
		}

		if (hctx->wb->bytes_out == hctx->wb_reqlen) {
			fdevent_event_clr(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_OUT);
			fcgi_set_state(srv, hctx, FCGI_STATE_READ);
		} else {
			off_t wblen = hctx->wb->bytes_in - hctx->wb->bytes_out;
			if (hctx->wb->bytes_in < hctx->wb_reqlen && wblen < 65536 - 16384) {
				/*(con->conf.stream_request_body & FDEVENT_STREAM_REQUEST)*/
				if (!(con->conf.stream_request_body & FDEVENT_STREAM_REQUEST_POLLIN)) {
					con->conf.stream_request_body |= FDEVENT_STREAM_REQUEST_POLLIN;
					con->is_readable = 1; /* trigger optimistic read from client */
				}
			}
			if (0 == wblen) {
				fdevent_event_clr(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_OUT);
			} else {
				fdevent_event_add(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_OUT);
			}
		}

		return HANDLER_WAIT_FOR_EVENT;
	case FCGI_STATE_READ:
		/* waiting for a response */
		return HANDLER_WAIT_FOR_EVENT;
	default:
		log_error_write(srv, __FILE__, __LINE__, "s", "(debug) unknown state");
		return HANDLER_ERROR;
	}
}


/* might be called on fdevent after a connect() is delay too
 * */
static handler_t fcgi_send_request(server *srv, handler_ctx *hctx) {
	/* ok, create the request */
	fcgi_extension_host *host = hctx->host;
	handler_t rc = fcgi_write_request(srv, hctx);
	if (HANDLER_ERROR != rc) {
		return rc;
	} else {
		plugin_data *p  = hctx->plugin_data;
		connection *con = hctx->remote_conn;

		if (hctx->state == FCGI_STATE_INIT ||
		    hctx->state == FCGI_STATE_CONNECT_DELAYED) {
			fcgi_restart_dead_procs(srv, p, host);

			/* cleanup this request and let the request handler start this request again */
			if (hctx->reconnects++ < 5) {
				return fcgi_reconnect(srv, hctx);
			} else {
				fcgi_connection_close(srv, hctx);
				con->http_status = 503;

				return HANDLER_FINISHED;
			}
		} else {
			int status = con->http_status;
			fcgi_connection_close(srv, hctx);
			con->http_status = (status == 400) ? 400 : 503;

			return HANDLER_FINISHED;
		}
	}
}


static handler_t fcgi_recv_response(server *srv, handler_ctx *hctx);


SUBREQUEST_FUNC(mod_fastcgi_handle_subrequest) {
	plugin_data *p = p_d;

	handler_ctx *hctx = con->plugin_ctx[p->id];

	if (NULL == hctx) return HANDLER_GO_ON;

	/* not my job */
	if (con->mode != p->id) return HANDLER_GO_ON;

	if ((con->conf.stream_response_body & FDEVENT_STREAM_RESPONSE_BUFMIN)
	    && con->file_started) {
		if (chunkqueue_length(con->write_queue) > 65536 - 4096) {
			fdevent_event_clr(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_IN);
		} else if (!(fdevent_event_get_interest(srv->ev, hctx->fd) & FDEVENT_IN)) {
			/* optimistic read from backend, which might re-enable FDEVENT_IN */
			handler_t rc = fcgi_recv_response(srv, hctx); /*(might invalidate hctx)*/
			if (rc != HANDLER_GO_ON) return rc;           /*(unless HANDLER_GO_ON)*/
		}
	}

	/* (do not receive request body before FCGI_AUTHORIZER has run or else
	 *  the request body is discarded with handler_ctx_clear() after running
	 *  the FastCGI Authorizer) */

	if (hctx->fcgi_mode != FCGI_AUTHORIZER
	    && (0 == hctx->wb->bytes_in
	        ? con->state == CON_STATE_READ_POST
	        : hctx->wb->bytes_in < hctx->wb_reqlen)) {
		/*(64k - 4k to attempt to avoid temporary files
		 * in conjunction with FDEVENT_STREAM_REQUEST_BUFMIN)*/
		if (hctx->wb->bytes_in - hctx->wb->bytes_out > 65536 - 4096
		    && (con->conf.stream_request_body & FDEVENT_STREAM_REQUEST_BUFMIN)){
			con->conf.stream_request_body &= ~FDEVENT_STREAM_REQUEST_POLLIN;
			if (0 != hctx->wb->bytes_in) return HANDLER_WAIT_FOR_EVENT;
		} else {
			handler_t r = connection_handle_read_post_state(srv, con);
			chunkqueue *req_cq = con->request_content_queue;
			if (0 != hctx->wb->bytes_in && !chunkqueue_is_empty(req_cq)) {
				fcgi_stdin_append(srv, con, hctx, hctx->request_id);
				if (fdevent_event_get_interest(srv->ev, hctx->fd) & FDEVENT_OUT) {
					return (r == HANDLER_GO_ON) ? HANDLER_WAIT_FOR_EVENT : r;
				}
			}
			if (r != HANDLER_GO_ON) return r;
		}
	}

	return ((0 == hctx->wb->bytes_in || !chunkqueue_is_empty(hctx->wb))
		&& hctx->state != FCGI_STATE_CONNECT_DELAYED)
	  ? fcgi_send_request(srv, hctx)
	  : HANDLER_WAIT_FOR_EVENT;
}


static handler_t fcgi_recv_response(server *srv, handler_ctx *hctx) {
	connection  *con  = hctx->remote_conn;
	plugin_data *p    = hctx->plugin_data;

	fcgi_proc *proc   = hctx->proc;
	fcgi_extension_host *host= hctx->host;

		switch (fcgi_demux_response(srv, hctx)) {
		case 0:
			break;
		case 1:

			if (hctx->fcgi_mode == FCGI_AUTHORIZER &&
		   	    (con->http_status == 200 ||
			     con->http_status == 0)) {
				/*
				 * If we are here in AUTHORIZER mode then a request for authorizer
				 * was processed already, and status 200 has been returned. We need
				 * now to handle authorized request.
				 */
				buffer *physpath = NULL;

				if (!buffer_string_is_empty(host->docroot)) {
					buffer_copy_buffer(con->physical.doc_root, host->docroot);
					buffer_copy_buffer(con->physical.basedir, host->docroot);

					buffer_copy_buffer(con->physical.path, host->docroot);
					buffer_append_string_buffer(con->physical.path, con->uri.path);
					physpath = con->physical.path;
				}

				fcgi_backend_close(srv, hctx);
				handler_ctx_clear(hctx);

				/* don't do more than 6 loops here, that normally shouldn't happen */
				if (++con->loops_per_request > 5) {
					log_error_write(srv, __FILE__, __LINE__, "sb", "too many loops while processing request:", con->request.orig_uri);
					con->http_status = 500; /* Internal Server Error */
					con->mode = DIRECT;
					return HANDLER_FINISHED;
				}

				/* restart the request so other handlers can process it */

				if (physpath) con->physical.path = NULL;
				connection_response_reset(srv, con); /*(includes con->http_status = 0)*/
				if (physpath) con->physical.path = physpath; /* preserve con->physical.path with modified docroot */

				/*(FYI: if multiple FastCGI authorizers were to be supported,
				 * next one could be started here instead of restarting request)*/

				con->mode = DIRECT;
				return HANDLER_COMEBACK;
			} else {
				/* we are done */
				fcgi_connection_close(srv, hctx);
			}

			return HANDLER_FINISHED;
		case -1:
			if (proc->pid && proc->state != PROC_STATE_DIED) {
				int status;

				/* only fetch the zombie if it is not already done */

				switch(waitpid(proc->pid, &status, WNOHANG)) {
				case 0:
					/* child is still alive */
					break;
				case -1:
					break;
				default:
					/* the child should not terminate at all */
					if (WIFEXITED(status)) {
						log_error_write(srv, __FILE__, __LINE__, "sdsd",
								"child exited, pid:", proc->pid,
								"status:", WEXITSTATUS(status));
					} else if (WIFSIGNALED(status)) {
						log_error_write(srv, __FILE__, __LINE__, "sd",
								"child signaled:",
								WTERMSIG(status));
					} else {
						log_error_write(srv, __FILE__, __LINE__, "sd",
								"child died somehow:",
								status);
					}

					if (hctx->conf.debug) {
						log_error_write(srv, __FILE__, __LINE__, "ssbsdsd",
								"--- fastcgi spawning",
								"\n\tsocket", proc->connection_name,
								"\n\tcurrent:", 1, "/", host->max_procs);
					}

					if (fcgi_spawn_connection(srv, p, host, proc)) {
						/* respawning failed, retry later */
						proc->state = PROC_STATE_DIED;

						log_error_write(srv, __FILE__, __LINE__, "s",
								"respawning failed, will retry later");
					}

					break;
				}
			}

			if (con->file_started == 0) {
				/* nothing has been sent out yet, try to use another child */

				if (hctx->wb->bytes_out == 0 &&
				    hctx->reconnects++ < 5) {

					log_error_write(srv, __FILE__, __LINE__, "ssbsBSBs",
						"response not received, request not sent",
						"on socket:", proc->connection_name,
						"for", con->uri.path, "?", con->uri.query, ", reconnecting");

					return fcgi_reconnect(srv, hctx);
				}

				log_error_write(srv, __FILE__, __LINE__, "sosbsBSBs",
						"response not received, request sent:", hctx->wb->bytes_out,
						"on socket:", proc->connection_name,
						"for", con->uri.path, "?", con->uri.query, ", closing connection");
			} else {
				log_error_write(srv, __FILE__, __LINE__, "ssbsBSBs",
						"response already sent out, but backend returned error",
						"on socket:", proc->connection_name,
						"for", con->uri.path, "?", con->uri.query, ", terminating connection");
			}

			http_response_backend_error(srv, con);
			fcgi_connection_close(srv, hctx);
			return HANDLER_FINISHED;
		}

		return HANDLER_GO_ON;
}


static handler_t fcgi_handle_fdevent(server *srv, void *ctx, int revents) {
	handler_ctx *hctx = ctx;
	connection  *con  = hctx->remote_conn;

	joblist_append(srv, con);

	if (revents & FDEVENT_IN) {
		handler_t rc = fcgi_recv_response(srv, hctx);/*(might invalidate hctx)*/
		if (rc != HANDLER_GO_ON) return rc;          /*(unless HANDLER_GO_ON)*/
	}

	if (revents & FDEVENT_OUT) {
		return fcgi_send_request(srv, hctx); /*(might invalidate hctx)*/
	}

	/* perhaps this issue is already handled */
	if (revents & FDEVENT_HUP) {
		if (hctx->state == FCGI_STATE_CONNECT_DELAYED) {
			/* getoptsock will catch this one (right ?)
			 *
			 * if we are in connect we might get an EINPROGRESS
			 * in the first call and an FDEVENT_HUP in the
			 * second round
			 *
			 * FIXME: as it is a bit ugly.
			 *
			 */
			fcgi_send_request(srv, hctx);
		} else if (con->file_started) {
			/* drain any remaining data from kernel pipe buffers
			 * even if (con->conf.stream_response_body
			 *          & FDEVENT_STREAM_RESPONSE_BUFMIN)
			 * since event loop will spin on fd FDEVENT_HUP event
			 * until unregistered. */
			handler_t rc;
			do {
				rc = fcgi_recv_response(srv,hctx);/*(might invalidate hctx)*/
			} while (rc == HANDLER_GO_ON);            /*(unless HANDLER_GO_ON)*/
			return rc; /* HANDLER_FINISHED or HANDLER_ERROR */
		} else {
			fcgi_proc *proc = hctx->proc;
			log_error_write(srv, __FILE__, __LINE__, "sBSbsbsd",
					"error: unexpected close of fastcgi connection for",
					con->uri.path, "?", con->uri.query,
					"(no fastcgi process on socket:", proc->connection_name, "?)",
					hctx->state);

			fcgi_connection_close(srv, hctx);
		}
	} else if (revents & FDEVENT_ERR) {
		log_error_write(srv, __FILE__, __LINE__, "s",
				"fcgi: got a FDEVENT_ERR. Don't know why.");

		http_response_backend_error(srv, con);
		fcgi_connection_close(srv, hctx);
	}

	return HANDLER_FINISHED;
}

#define PATCH(x) \
	p->conf.x = s->x;
static int fcgi_patch_connection(server *srv, connection *con, plugin_data *p) {
	size_t i, j;
	plugin_config *s = p->config_storage[0];

	PATCH(exts);
	PATCH(exts_auth);
	PATCH(exts_resp);
	PATCH(debug);
	PATCH(ext_mapping);

	/* skip the first, the global context */
	for (i = 1; i < srv->config_context->used; i++) {
		data_config *dc = (data_config *)srv->config_context->data[i];
		s = p->config_storage[i];

		/* condition didn't match */
		if (!config_check_cond(srv, con, dc)) continue;

		/* merge config */
		for (j = 0; j < dc->value->used; j++) {
			data_unset *du = dc->value->data[j];

			if (buffer_is_equal_string(du->key, CONST_STR_LEN("fastcgi.server"))) {
				PATCH(exts);
				PATCH(exts_auth);
				PATCH(exts_resp);
			} else if (buffer_is_equal_string(du->key, CONST_STR_LEN("fastcgi.debug"))) {
				PATCH(debug);
			} else if (buffer_is_equal_string(du->key, CONST_STR_LEN("fastcgi.map-extensions"))) {
				PATCH(ext_mapping);
			}
		}
	}

	return 0;
}
#undef PATCH


static handler_t fcgi_check_extension(server *srv, connection *con, void *p_d, int uri_path_handler) {
	plugin_data *p = p_d;
	size_t s_len;
	size_t k;
	buffer *fn;
	fcgi_extension *extension = NULL;
	fcgi_extension_host *host = NULL;
	handler_ctx *hctx;
	unsigned short fcgi_mode;

	if (con->mode != DIRECT) return HANDLER_GO_ON;

	fn = uri_path_handler ? con->uri.path : con->physical.path;

	if (buffer_string_is_empty(fn)) return HANDLER_GO_ON;

	s_len = buffer_string_length(fn);

	fcgi_patch_connection(srv, con, p);
	if (NULL == p->conf.exts) return HANDLER_GO_ON;

	/* check p->conf.exts_auth list and then p->conf.ext_resp list
	 * (skip p->conf.exts_auth if array is empty or if FCGI_AUTHORIZER already ran in this request */
	hctx = con->plugin_ctx[p->id]; /*(not NULL if FCGI_AUTHORIZER ran; hctx->ext-auth check is redundant)*/
	fcgi_mode = (NULL == hctx || NULL == hctx->ext_auth)
	  ? 0                /* FCGI_AUTHORIZER p->conf.exts_auth will be searched next */
	  : FCGI_AUTHORIZER; /* FCGI_RESPONDER p->conf.exts_resp will be searched next */

      do {

	fcgi_exts *exts;
	if (0 == fcgi_mode) {
		fcgi_mode = FCGI_AUTHORIZER;
		exts = p->conf.exts_auth;
	} else {
		fcgi_mode = FCGI_RESPONDER;
		exts = p->conf.exts_resp;
	}

	if (0 == exts->used) continue;

	/* fastcgi.map-extensions maps extensions to existing fastcgi.server entries
	 *
	 * fastcgi.map-extensions = ( ".php3" => ".php" )
	 *
	 * fastcgi.server = ( ".php" => ... )
	 *
	 * */

	/* check if extension-mapping matches */
	for (k = 0; k < p->conf.ext_mapping->used; k++) {
		data_string *ds = (data_string *)p->conf.ext_mapping->data[k];
		size_t ct_len; /* length of the config entry */

		if (buffer_is_empty(ds->key)) continue;

		ct_len = buffer_string_length(ds->key);

		if (s_len < ct_len) continue;

		/* found a mapping */
		if (0 == strncmp(fn->ptr + s_len - ct_len, ds->key->ptr, ct_len)) {
			/* check if we know the extension */

			/* we can reuse k here */
			for (k = 0; k < exts->used; k++) {
				extension = exts->exts[k];

				if (buffer_is_equal(ds->value, extension->key)) {
					break;
				}
			}

			if (k == exts->used) {
				/* found nothing */
				extension = NULL;
			}
			break;
		}
	}

	if (extension == NULL) {
		size_t uri_path_len = buffer_string_length(con->uri.path);

		/* check if extension matches */
		for (k = 0; k < exts->used; k++) {
			size_t ct_len; /* length of the config entry */
			fcgi_extension *ext = exts->exts[k];

			if (buffer_is_empty(ext->key)) continue;

			ct_len = buffer_string_length(ext->key);

			/* check _url_ in the form "/fcgi_pattern" */
			if (ext->key->ptr[0] == '/') {
				if ((ct_len <= uri_path_len) &&
				    (strncmp(con->uri.path->ptr, ext->key->ptr, ct_len) == 0)) {
					extension = ext;
					break;
				}
			} else if ((ct_len <= s_len) && (0 == strncmp(fn->ptr + s_len - ct_len, ext->key->ptr, ct_len))) {
				/* check extension in the form ".fcg" */
				extension = ext;
				break;
			}
		}
	}

      } while (NULL == extension && fcgi_mode != FCGI_RESPONDER);

	/* extension doesn't match */
	if (NULL == extension) {
		return HANDLER_GO_ON;
	}

	/* check if we have at least one server for this extension up and running */
	host = fcgi_extension_host_get(srv, con, p, extension);
	if (NULL == host) {
		return HANDLER_FINISHED;
	}

	/* a note about no handler is not sent yet */
	extension->note_is_sent = 0;

	/*
	 * if check-local is disabled, use the uri.path handler
	 *
	 */

	/* init handler-context */
	if (uri_path_handler) {
		if (host->check_local != 0) {
			return HANDLER_GO_ON;
		} else {
			/* do not split path info for authorizer */
			if (fcgi_mode != FCGI_AUTHORIZER) {
				/* the prefix is the SCRIPT_NAME,
				* everything from start to the next slash
				* this is important for check-local = "disable"
				*
				* if prefix = /admin.fcgi
				*
				* /admin.fcgi/foo/bar
				*
				* SCRIPT_NAME = /admin.fcgi
				* PATH_INFO   = /foo/bar
				*
				* if prefix = /fcgi-bin/
				*
				* /fcgi-bin/foo/bar
				*
				* SCRIPT_NAME = /fcgi-bin/foo
				* PATH_INFO   = /bar
				*
				* if prefix = /, and fix-root-path-name is enable
				*
				* /fcgi-bin/foo/bar
				*
				* SCRIPT_NAME = /fcgi-bin/foo
				* PATH_INFO   = /bar
				*
				*/
				char *pathinfo;

				/* the rewrite is only done for /prefix/? matches */
				if (host->fix_root_path_name && extension->key->ptr[0] == '/' && extension->key->ptr[1] == '\0') {
					buffer_copy_string(con->request.pathinfo, con->uri.path->ptr);
					buffer_string_set_length(con->uri.path, 0);
				} else if (extension->key->ptr[0] == '/' &&
					buffer_string_length(con->uri.path) > buffer_string_length(extension->key) &&
					NULL != (pathinfo = strchr(con->uri.path->ptr + buffer_string_length(extension->key), '/'))) {
					/* rewrite uri.path and pathinfo */

					buffer_copy_string(con->request.pathinfo, pathinfo);
					buffer_string_set_length(con->uri.path, buffer_string_length(con->uri.path) - buffer_string_length(con->request.pathinfo));
				}
			}
		}
	}

	if (!hctx) hctx = handler_ctx_init();

	hctx->remote_conn      = con;
	hctx->plugin_data      = p;
	hctx->proc             = NULL;
	hctx->ext              = extension;
	fcgi_host_assign(srv, hctx, host);

	hctx->fcgi_mode = fcgi_mode;
	if (fcgi_mode == FCGI_AUTHORIZER) {
		hctx->ext_auth = hctx->ext;
	}

	/*hctx->conf.exts        = p->conf.exts;*/
	/*hctx->conf.exts_auth   = p->conf.exts_auth;*/
	/*hctx->conf.exts_resp   = p->conf.exts_resp;*/
	/*hctx->conf.ext_mapping = p->conf.ext_mapping;*/
	hctx->conf.debug       = p->conf.debug;

	con->plugin_ctx[p->id] = hctx;

	con->mode = p->id;

	if (con->conf.log_request_handling) {
		log_error_write(srv, __FILE__, __LINE__, "s", "handling it in mod_fastcgi");
	}

	return HANDLER_GO_ON;
}

/* uri-path handler */
static handler_t fcgi_check_extension_1(server *srv, connection *con, void *p_d) {
	return fcgi_check_extension(srv, con, p_d, 1);
}

/* start request handler */
static handler_t fcgi_check_extension_2(server *srv, connection *con, void *p_d) {
	return fcgi_check_extension(srv, con, p_d, 0);
}


TRIGGER_FUNC(mod_fastcgi_handle_trigger) {
	plugin_data *p = p_d;
	size_t i, j, n;


	/* perhaps we should kill a connect attempt after 10-15 seconds
	 *
	 * currently we wait for the TCP timeout which is 180 seconds on Linux
	 *
	 *
	 *
	 */

	/* check all children if they are still up */

	for (i = 0; i < srv->config_context->used; i++) {
		plugin_config *conf;
		fcgi_exts *exts;

		conf = p->config_storage[i];

		exts = conf->exts;
		if (NULL == exts) continue;

		for (j = 0; j < exts->used; j++) {
			fcgi_extension *ex;

			ex = exts->exts[j];

			for (n = 0; n < ex->used; n++) {

				fcgi_proc *proc;
				fcgi_extension_host *host;

				host = ex->hosts[n];

				fcgi_restart_dead_procs(srv, p, host);

				for (proc = host->unused_procs; proc; proc = proc->next) {
					int status;

					if (proc->pid == 0) continue;

					switch (waitpid(proc->pid, &status, WNOHANG)) {
					case 0:
						/* child still running after timeout, good */
						break;
					case -1:
						if (errno != EINTR) {
							/* no PID found ? should never happen */
							log_error_write(srv, __FILE__, __LINE__, "sddss",
									"pid ", proc->pid, proc->state,
									"not found:", strerror(errno));

#if 0
							if (errno == ECHILD) {
								/* someone else has cleaned up for us */
								proc->pid = 0;
								proc->state = PROC_STATE_UNSET;
							}
#endif
						}
						break;
					default:
						/* the child should not terminate at all */
						if (WIFEXITED(status)) {
							if (proc->state != PROC_STATE_KILLED) {
								log_error_write(srv, __FILE__, __LINE__, "sdb",
										"child exited:",
										WEXITSTATUS(status), proc->connection_name);
							}
						} else if (WIFSIGNALED(status)) {
							if (WTERMSIG(status) != SIGTERM) {
								log_error_write(srv, __FILE__, __LINE__, "sd",
										"child signaled:",
										WTERMSIG(status));
							}
						} else {
							log_error_write(srv, __FILE__, __LINE__, "sd",
									"child died somehow:",
									status);
						}
						proc->pid = 0;
						if (proc->state == PROC_STATE_RUNNING) host->active_procs--;
						proc->state = PROC_STATE_UNSET;
						host->max_id--;
					}
				}
			}
		}
	}

	return HANDLER_GO_ON;
}


int mod_fastcgi_plugin_init(plugin *p);
int mod_fastcgi_plugin_init(plugin *p) {
	p->version      = LIGHTTPD_VERSION_ID;
	p->name         = buffer_init_string("fastcgi");

	p->init         = mod_fastcgi_init;
	p->cleanup      = mod_fastcgi_free;
	p->set_defaults = mod_fastcgi_set_defaults;
	p->connection_reset        = fcgi_connection_reset;
	p->handle_connection_close = fcgi_connection_reset;
	p->handle_uri_clean        = fcgi_check_extension_1;
	p->handle_subrequest_start = fcgi_check_extension_2;
	p->handle_subrequest       = mod_fastcgi_handle_subrequest;
	p->handle_trigger          = mod_fastcgi_handle_trigger;

	p->data         = NULL;

	return 0;
}