1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2012 The FreeBSD Foundation
5 *
6 * This software was developed by Edward Tomasz Napierala under sponsorship
7 * from the FreeBSD Foundation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 */
31
32#include <sys/types.h>
33#include <sys/time.h>
34#include <sys/ioctl.h>
35#include <sys/param.h>
36#include <sys/linker.h>
37#include <sys/socket.h>
38#include <sys/sysctl.h>
39#include <sys/capsicum.h>
40#include <sys/wait.h>
41#include <netinet/in.h>
42#include <netinet/tcp.h>
43#include <assert.h>
44#include <capsicum_helpers.h>
45#include <errno.h>
46#include <fcntl.h>
47#include <libutil.h>
48#include <netdb.h>
49#include <signal.h>
50#include <stdbool.h>
51#include <stdint.h>
52#include <stdio.h>
53#include <stdlib.h>
54#include <string.h>
55#include <unistd.h>
56
57#include "iscsid.h"
58
59static bool	timed_out(void);
60#ifdef ICL_KERNEL_PROXY
61static void	pdu_receive_proxy(struct pdu *pdu);
62static void	pdu_send_proxy(struct pdu *pdu);
63#endif /* ICL_KERNEL_PROXY */
64
65static volatile bool sigalrm_received = false;
66
67static int nchildren = 0;
68
69static struct connection_ops conn_ops = {
70	.timed_out = timed_out,
71#ifdef ICL_KERNEL_PROXY
72	.pdu_receive_proxy = pdu_receive_proxy,
73	.pdu_send_proxy = pdu_send_proxy,
74#endif
75	.fail = fail,
76};
77
78static void
79usage(void)
80{
81
82	fprintf(stderr, "usage: iscsid [-P pidfile][-d][-m maxproc][-t timeout]\n");
83	exit(1);
84}
85
86#ifdef ICL_KERNEL_PROXY
87
88static void
89pdu_receive_proxy(struct pdu *pdu)
90{
91	struct iscsid_connection *conn;
92	struct iscsi_daemon_receive idr;
93	size_t len;
94	int error;
95
96	conn = (struct iscsid_connection *)pdu->pdu_connection;
97	assert(conn->conn_conf.isc_iser != 0);
98
99	pdu->pdu_data = malloc(conn->conn.conn_max_recv_data_segment_length);
100	if (pdu->pdu_data == NULL)
101		log_err(1, "malloc");
102
103	memset(&idr, 0, sizeof(idr));
104	idr.idr_session_id = conn->conn_session_id;
105	idr.idr_bhs = pdu->pdu_bhs;
106	idr.idr_data_segment_len = conn->conn.conn_max_recv_data_segment_length;
107	idr.idr_data_segment = pdu->pdu_data;
108
109	error = ioctl(conn->conn_iscsi_fd, ISCSIDRECEIVE, &idr);
110	if (error != 0)
111		log_err(1, "ISCSIDRECEIVE");
112
113	len = pdu_ahs_length(pdu);
114	if (len > 0)
115		log_errx(1, "protocol error: non-empty AHS");
116
117	len = pdu_data_segment_length(pdu);
118	assert(len <= (size_t)conn->conn.conn_max_recv_data_segment_length);
119	pdu->pdu_data_len = len;
120}
121
122static void
123pdu_send_proxy(struct pdu *pdu)
124{
125	struct iscsid_connection *conn;
126	struct iscsi_daemon_send ids;
127	int error;
128
129	conn = (struct iscsid_connection *)pdu->pdu_connection;
130	assert(conn->conn_conf.isc_iser != 0);
131
132	pdu_set_data_segment_length(pdu, pdu->pdu_data_len);
133
134	memset(&ids, 0, sizeof(ids));
135	ids.ids_session_id = conn->conn_session_id;
136	ids.ids_bhs = pdu->pdu_bhs;
137	ids.ids_data_segment_len = pdu->pdu_data_len;
138	ids.ids_data_segment = pdu->pdu_data;
139
140	error = ioctl(conn->conn_iscsi_fd, ISCSIDSEND, &ids);
141	if (error != 0)
142		log_err(1, "ISCSIDSEND");
143}
144
145#endif /* ICL_KERNEL_PROXY */
146
147static void
148resolve_addr(const struct connection *conn, const char *address,
149    struct addrinfo **ai, bool initiator_side)
150{
151	struct addrinfo hints;
152	char *arg, *addr, *ch, *tofree;
153	const char *port;
154	int error, colons = 0;
155
156	tofree = arg = checked_strdup(address);
157
158	if (arg[0] == '\0') {
159		fail(conn, "empty address");
160		log_errx(1, "empty address");
161	}
162	if (arg[0] == '[') {
163		/*
164		 * IPv6 address in square brackets, perhaps with port.
165		 */
166		arg++;
167		addr = strsep(&arg, "]");
168		if (arg == NULL) {
169			fail(conn, "malformed address");
170			log_errx(1, "malformed address %s", address);
171		}
172		if (arg[0] == '\0') {
173			port = NULL;
174		} else if (arg[0] == ':') {
175			port = arg + 1;
176		} else {
177			fail(conn, "malformed address");
178			log_errx(1, "malformed address %s", address);
179		}
180	} else {
181		/*
182		 * Either IPv6 address without brackets - and without
183		 * a port - or IPv4 address.  Just count the colons.
184		 */
185		for (ch = arg; *ch != '\0'; ch++) {
186			if (*ch == ':')
187				colons++;
188		}
189		if (colons > 1) {
190			addr = arg;
191			port = NULL;
192		} else {
193			addr = strsep(&arg, ":");
194			if (arg == NULL)
195				port = NULL;
196			else
197				port = arg;
198		}
199	}
200
201	if (port == NULL && !initiator_side)
202		port = "3260";
203
204	memset(&hints, 0, sizeof(hints));
205	hints.ai_family = PF_UNSPEC;
206	hints.ai_socktype = SOCK_STREAM;
207	hints.ai_flags = AI_ADDRCONFIG | AI_NUMERICSERV;
208	if (initiator_side)
209		hints.ai_flags |= AI_PASSIVE;
210
211	error = getaddrinfo(addr, port, &hints, ai);
212	if (error != 0) {
213		fail(conn, gai_strerror(error));
214		log_errx(1, "getaddrinfo for %s failed: %s",
215		    address, gai_strerror(error));
216	}
217
218	free(tofree);
219}
220
221static struct iscsid_connection *
222connection_new(int iscsi_fd, const struct iscsi_daemon_request *request)
223{
224	struct iscsid_connection *conn;
225	struct addrinfo *from_ai, *to_ai;
226	const char *from_addr, *to_addr;
227#ifdef ICL_KERNEL_PROXY
228	struct iscsi_daemon_connect idc;
229#endif
230	int error, optval;
231
232	conn = calloc(1, sizeof(*conn));
233	if (conn == NULL)
234		log_err(1, "calloc");
235
236	connection_init(&conn->conn, &conn_ops,
237	    request->idr_conf.isc_iser != 0);
238	conn->conn_protocol_level = 0;
239	conn->conn_initial_r2t = true;
240	conn->conn_iscsi_fd = iscsi_fd;
241
242	conn->conn_session_id = request->idr_session_id;
243	memcpy(&conn->conn_conf, &request->idr_conf, sizeof(conn->conn_conf));
244	memcpy(&conn->conn.conn_isid, &request->idr_isid,
245	    sizeof(conn->conn.conn_isid));
246	conn->conn.conn_tsih = request->idr_tsih;
247
248	from_addr = conn->conn_conf.isc_initiator_addr;
249	to_addr = conn->conn_conf.isc_target_addr;
250
251	if (from_addr[0] != '\0')
252		resolve_addr(&conn->conn, from_addr, &from_ai, true);
253	else
254		from_ai = NULL;
255
256	resolve_addr(&conn->conn, to_addr, &to_ai, false);
257
258#ifdef ICL_KERNEL_PROXY
259	if (conn->conn_conf.isc_iser) {
260		memset(&idc, 0, sizeof(idc));
261		idc.idc_session_id = conn->conn_session_id;
262		if (conn->conn_conf.isc_iser)
263			idc.idc_iser = 1;
264		idc.idc_domain = to_ai->ai_family;
265		idc.idc_socktype = to_ai->ai_socktype;
266		idc.idc_protocol = to_ai->ai_protocol;
267		if (from_ai != NULL) {
268			idc.idc_from_addr = from_ai->ai_addr;
269			idc.idc_from_addrlen = from_ai->ai_addrlen;
270		}
271		idc.idc_to_addr = to_ai->ai_addr;
272		idc.idc_to_addrlen = to_ai->ai_addrlen;
273
274		log_debugx("connecting to %s using ICL kernel proxy", to_addr);
275		error = ioctl(iscsi_fd, ISCSIDCONNECT, &idc);
276		if (error != 0) {
277			fail(&conn->conn, strerror(errno));
278			log_err(1, "failed to connect to %s "
279			    "using ICL kernel proxy: ISCSIDCONNECT", to_addr);
280		}
281
282		if (from_ai != NULL)
283			freeaddrinfo(from_ai);
284		freeaddrinfo(to_ai);
285
286		return (conn);
287	}
288#endif /* ICL_KERNEL_PROXY */
289
290	if (conn->conn_conf.isc_iser) {
291		fail(&conn->conn, "iSER not supported");
292		log_errx(1, "iscsid(8) compiled without ICL_KERNEL_PROXY "
293		    "does not support iSER");
294	}
295
296	conn->conn.conn_socket = socket(to_ai->ai_family, to_ai->ai_socktype,
297	    to_ai->ai_protocol);
298	if (conn->conn.conn_socket < 0) {
299		fail(&conn->conn, strerror(errno));
300		log_err(1, "failed to create socket for %s", from_addr);
301	}
302	optval = SOCKBUF_SIZE;
303	if (setsockopt(conn->conn.conn_socket, SOL_SOCKET, SO_RCVBUF,
304	    &optval, sizeof(optval)) == -1)
305		log_warn("setsockopt(SO_RCVBUF) failed");
306	optval = SOCKBUF_SIZE;
307	if (setsockopt(conn->conn.conn_socket, SOL_SOCKET, SO_SNDBUF,
308	    &optval, sizeof(optval)) == -1)
309		log_warn("setsockopt(SO_SNDBUF) failed");
310	optval = 1;
311	if (setsockopt(conn->conn.conn_socket, SOL_SOCKET, SO_NO_DDP,
312	    &optval, sizeof(optval)) == -1)
313		log_warn("setsockopt(SO_NO_DDP) failed");
314	if (conn->conn_conf.isc_dscp != -1) {
315		int tos = conn->conn_conf.isc_dscp << 2;
316		if (to_ai->ai_family == AF_INET) {
317			if (setsockopt(conn->conn.conn_socket,
318			    IPPROTO_IP, IP_TOS,
319			    &tos, sizeof(tos)) == -1)
320				log_warn("setsockopt(IP_TOS) "
321				    "failed for %s",
322				    from_addr);
323		} else
324		if (to_ai->ai_family == AF_INET6) {
325			if (setsockopt(conn->conn.conn_socket,
326			    IPPROTO_IPV6, IPV6_TCLASS,
327			    &tos, sizeof(tos)) == -1)
328				log_warn("setsockopt(IPV6_TCLASS) "
329				    "failed for %s",
330				    from_addr);
331		}
332	}
333	if (conn->conn_conf.isc_pcp != -1) {
334		int pcp = conn->conn_conf.isc_pcp;
335		if (to_ai->ai_family == AF_INET) {
336			if (setsockopt(conn->conn.conn_socket,
337			    IPPROTO_IP, IP_VLAN_PCP,
338			    &pcp, sizeof(pcp)) == -1)
339				log_warn("setsockopt(IP_VLAN_PCP) "
340				    "failed for %s",
341				    from_addr);
342		} else
343		if (to_ai->ai_family == AF_INET6) {
344			if (setsockopt(conn->conn.conn_socket,
345			    IPPROTO_IPV6, IPV6_VLAN_PCP,
346			    &pcp, sizeof(pcp)) == -1)
347				log_warn("setsockopt(IPV6_VLAN_PCP) "
348				    "failed for %s",
349				    from_addr);
350		}
351	}
352	/*
353	 * Reduce TCP SYN_SENT timeout while
354	 * no connectivity exists, to allow
355	 * rapid reuse of the available slots.
356	 */
357	int keepinit = 0;
358	if (conn->conn_conf.isc_login_timeout > 0) {
359		keepinit = conn->conn_conf.isc_login_timeout;
360		log_debugx("session specific LoginTimeout at %d sec",
361			keepinit);
362	}
363	if (conn->conn_conf.isc_login_timeout == -1) {
364		int value;
365		size_t size = sizeof(value);
366		if (sysctlbyname("kern.iscsi.login_timeout",
367		    &value, &size, NULL, 0) == 0) {
368			keepinit = value;
369			log_debugx("global login_timeout at %d sec",
370				keepinit);
371		}
372	}
373	if (keepinit > 0) {
374		if (setsockopt(conn->conn.conn_socket,
375		    IPPROTO_TCP, TCP_KEEPINIT,
376		    &keepinit, sizeof(keepinit)) == -1)
377			log_warnx("setsockopt(TCP_KEEPINIT) "
378			    "failed for %s", to_addr);
379	}
380	if (from_ai != NULL) {
381		error = bind(conn->conn.conn_socket, from_ai->ai_addr,
382		    from_ai->ai_addrlen);
383		if (error != 0) {
384			fail(&conn->conn, strerror(errno));
385			log_err(1, "failed to bind to %s", from_addr);
386		}
387	}
388	log_debugx("connecting to %s", to_addr);
389	error = connect(conn->conn.conn_socket, to_ai->ai_addr,
390	    to_ai->ai_addrlen);
391	if (error != 0) {
392		fail(&conn->conn, strerror(errno));
393		log_err(1, "failed to connect to %s", to_addr);
394	}
395
396	if (from_ai != NULL)
397		freeaddrinfo(from_ai);
398	freeaddrinfo(to_ai);
399
400	return (conn);
401}
402
403static void
404limits(struct iscsid_connection *conn)
405{
406	struct iscsi_daemon_limits idl;
407	struct iscsi_session_limits *isl;
408	int error;
409
410	log_debugx("fetching limits from the kernel");
411
412	memset(&idl, 0, sizeof(idl));
413	idl.idl_session_id = conn->conn_session_id;
414	idl.idl_socket = conn->conn.conn_socket;
415
416	error = ioctl(conn->conn_iscsi_fd, ISCSIDLIMITS, &idl);
417	if (error != 0)
418		log_err(1, "ISCSIDLIMITS");
419
420	/*
421	 * Read the driver limits and provide reasonable defaults for the ones
422	 * the driver doesn't care about.  If a max_snd_dsl is not explicitly
423	 * provided by the driver then we'll make sure both conn->max_snd_dsl
424	 * and isl->max_snd_dsl are set to the rcv_dsl.  This preserves historic
425	 * behavior.
426	 */
427	isl = &conn->conn_limits;
428	memcpy(isl, &idl.idl_limits, sizeof(*isl));
429	if (isl->isl_max_recv_data_segment_length == 0)
430		isl->isl_max_recv_data_segment_length = (1 << 24) - 1;
431	if (isl->isl_max_send_data_segment_length == 0)
432		isl->isl_max_send_data_segment_length =
433		    isl->isl_max_recv_data_segment_length;
434	if (isl->isl_max_burst_length == 0)
435		isl->isl_max_burst_length = (1 << 24) - 1;
436	if (isl->isl_first_burst_length == 0)
437		isl->isl_first_burst_length = (1 << 24) - 1;
438	if (isl->isl_first_burst_length > isl->isl_max_burst_length)
439		isl->isl_first_burst_length = isl->isl_max_burst_length;
440
441	/*
442	 * Limit default send length in case it won't be negotiated.
443	 * We can't do it for other limits, since they may affect both
444	 * sender and receiver operation, and we must obey defaults.
445	 */
446	if (conn->conn.conn_max_send_data_segment_length >
447	    isl->isl_max_send_data_segment_length) {
448		conn->conn.conn_max_send_data_segment_length =
449		    isl->isl_max_send_data_segment_length;
450	}
451}
452
453static void
454handoff(struct iscsid_connection *conn)
455{
456	struct iscsi_daemon_handoff idh;
457	int error;
458
459	log_debugx("handing off connection to the kernel");
460
461	memset(&idh, 0, sizeof(idh));
462	idh.idh_session_id = conn->conn_session_id;
463	idh.idh_socket = conn->conn.conn_socket;
464	strlcpy(idh.idh_target_alias, conn->conn_target_alias,
465	    sizeof(idh.idh_target_alias));
466	idh.idh_tsih = conn->conn.conn_tsih;
467	idh.idh_statsn = conn->conn.conn_statsn;
468	idh.idh_protocol_level = conn->conn_protocol_level;
469	idh.idh_header_digest = conn->conn.conn_header_digest;
470	idh.idh_data_digest = conn->conn.conn_data_digest;
471	idh.idh_initial_r2t = conn->conn_initial_r2t;
472	idh.idh_immediate_data = conn->conn.conn_immediate_data;
473	idh.idh_max_recv_data_segment_length =
474	    conn->conn.conn_max_recv_data_segment_length;
475	idh.idh_max_send_data_segment_length =
476	    conn->conn.conn_max_send_data_segment_length;
477	idh.idh_max_burst_length = conn->conn.conn_max_burst_length;
478	idh.idh_first_burst_length = conn->conn.conn_first_burst_length;
479
480	error = ioctl(conn->conn_iscsi_fd, ISCSIDHANDOFF, &idh);
481	if (error != 0)
482		log_err(1, "ISCSIDHANDOFF");
483}
484
485void
486fail(const struct connection *base_conn, const char *reason)
487{
488	const struct iscsid_connection *conn;
489	struct iscsi_daemon_fail idf;
490	int error, saved_errno;
491
492	conn = (const struct iscsid_connection *)base_conn;
493	saved_errno = errno;
494
495	memset(&idf, 0, sizeof(idf));
496	idf.idf_session_id = conn->conn_session_id;
497	strlcpy(idf.idf_reason, reason, sizeof(idf.idf_reason));
498
499	error = ioctl(conn->conn_iscsi_fd, ISCSIDFAIL, &idf);
500	if (error != 0)
501		log_err(1, "ISCSIDFAIL");
502
503	errno = saved_errno;
504}
505
506/*
507 * XXX: I CANT INTO LATIN
508 */
509static void
510capsicate(struct iscsid_connection *conn)
511{
512	cap_rights_t rights;
513	const unsigned long cmds[] = {
514#ifdef ICL_KERNEL_PROXY
515		ISCSIDCONNECT,
516		ISCSIDSEND,
517		ISCSIDRECEIVE,
518#endif
519		ISCSIDLIMITS,
520		ISCSIDHANDOFF,
521		ISCSIDFAIL,
522		ISCSISADD,
523		ISCSISREMOVE,
524		ISCSISMODIFY
525	};
526
527	cap_rights_init(&rights, CAP_IOCTL);
528	if (caph_rights_limit(conn->conn_iscsi_fd, &rights) < 0)
529		log_err(1, "cap_rights_limit");
530
531	if (caph_ioctls_limit(conn->conn_iscsi_fd, cmds, nitems(cmds)) < 0)
532		log_err(1, "cap_ioctls_limit");
533
534	if (caph_enter() != 0)
535		log_err(1, "cap_enter");
536
537	if (cap_sandboxed())
538		log_debugx("Capsicum capability mode enabled");
539	else
540		log_warnx("Capsicum capability mode not supported");
541}
542
543static bool
544timed_out(void)
545{
546
547	return (sigalrm_received);
548}
549
550static void
551sigalrm_handler(int dummy __unused)
552{
553	/*
554	 * It would be easiest to just log an error and exit.  We can't
555	 * do this, though, because log_errx() is not signal safe, since
556	 * it calls syslog(3).  Instead, set a flag checked by pdu_send()
557	 * and pdu_receive(), to call log_errx() there.  Should they fail
558	 * to notice, we'll exit here one second later.
559	 */
560	if (sigalrm_received) {
561		/*
562		 * Oh well.  Just give up and quit.
563		 */
564		_exit(2);
565	}
566
567	sigalrm_received = true;
568}
569
570static void
571set_timeout(int timeout)
572{
573	struct sigaction sa;
574	struct itimerval itv;
575	int error;
576
577	if (timeout <= 0) {
578		log_debugx("session timeout disabled");
579		return;
580	}
581
582	bzero(&sa, sizeof(sa));
583	sa.sa_handler = sigalrm_handler;
584	sigfillset(&sa.sa_mask);
585	error = sigaction(SIGALRM, &sa, NULL);
586	if (error != 0)
587		log_err(1, "sigaction");
588
589	/*
590	 * First SIGALRM will arive after conf_timeout seconds.
591	 * If we do nothing, another one will arrive a second later.
592	 */
593	bzero(&itv, sizeof(itv));
594	itv.it_interval.tv_sec = 1;
595	itv.it_value.tv_sec = timeout;
596
597	log_debugx("setting session timeout to %d seconds",
598	    timeout);
599	error = setitimer(ITIMER_REAL, &itv, NULL);
600	if (error != 0)
601		log_err(1, "setitimer");
602}
603
604static void
605sigchld_handler(int dummy __unused)
606{
607
608	/*
609	 * The only purpose of this handler is to make SIGCHLD
610	 * interrupt the ISCSIDWAIT ioctl(2), so we can call
611	 * wait_for_children().
612	 */
613}
614
615static void
616register_sigchld(void)
617{
618	struct sigaction sa;
619	int error;
620
621	bzero(&sa, sizeof(sa));
622	sa.sa_handler = sigchld_handler;
623	sigfillset(&sa.sa_mask);
624	error = sigaction(SIGCHLD, &sa, NULL);
625	if (error != 0)
626		log_err(1, "sigaction");
627
628}
629
630static void
631handle_request(int iscsi_fd, const struct iscsi_daemon_request *request, int timeout)
632{
633	struct iscsid_connection *conn;
634
635	log_set_peer_addr(request->idr_conf.isc_target_addr);
636	if (request->idr_conf.isc_target[0] != '\0') {
637		log_set_peer_name(request->idr_conf.isc_target);
638		setproctitle("%s (%s)", request->idr_conf.isc_target_addr, request->idr_conf.isc_target);
639	} else {
640		setproctitle("%s", request->idr_conf.isc_target_addr);
641	}
642
643	conn = connection_new(iscsi_fd, request);
644	capsicate(conn);
645	limits(conn);
646	set_timeout(timeout);
647	login(conn);
648	if (conn->conn_conf.isc_discovery != 0)
649		discovery(conn);
650	else
651		handoff(conn);
652
653	log_debugx("nothing more to do; exiting");
654	exit (0);
655}
656
657static int
658wait_for_children(bool block)
659{
660	pid_t pid;
661	int status;
662	int num = 0;
663
664	for (;;) {
665		/*
666		 * If "block" is true, wait for at least one process.
667		 */
668		if (block && num == 0)
669			pid = wait4(-1, &status, 0, NULL);
670		else
671			pid = wait4(-1, &status, WNOHANG, NULL);
672		if (pid <= 0)
673			break;
674		if (WIFSIGNALED(status)) {
675			log_warnx("child process %d terminated with signal %d",
676			    pid, WTERMSIG(status));
677		} else if (WEXITSTATUS(status) != 0) {
678			log_warnx("child process %d terminated with exit status %d",
679			    pid, WEXITSTATUS(status));
680		} else {
681			log_debugx("child process %d terminated gracefully", pid);
682		}
683		num++;
684	}
685
686	return (num);
687}
688
689int
690main(int argc, char **argv)
691{
692	int ch, debug = 0, error, iscsi_fd, maxproc = 30, retval, saved_errno,
693	    timeout = 60;
694	bool dont_daemonize = false;
695	struct pidfh *pidfh;
696	pid_t pid, otherpid;
697	const char *pidfile_path = DEFAULT_PIDFILE;
698	struct iscsi_daemon_request request;
699
700	while ((ch = getopt(argc, argv, "P:dl:m:t:")) != -1) {
701		switch (ch) {
702		case 'P':
703			pidfile_path = optarg;
704			break;
705		case 'd':
706			dont_daemonize = true;
707			debug++;
708			break;
709		case 'l':
710			debug = atoi(optarg);
711			break;
712		case 'm':
713			maxproc = atoi(optarg);
714			break;
715		case 't':
716			timeout = atoi(optarg);
717			break;
718		case '?':
719		default:
720			usage();
721		}
722	}
723	argc -= optind;
724	if (argc != 0)
725		usage();
726
727	log_init(debug);
728
729	pidfh = pidfile_open(pidfile_path, 0600, &otherpid);
730	if (pidfh == NULL) {
731		if (errno == EEXIST)
732			log_errx(1, "daemon already running, pid: %jd.",
733			    (intmax_t)otherpid);
734		log_err(1, "cannot open or create pidfile \"%s\"",
735		    pidfile_path);
736	}
737
738	iscsi_fd = open(ISCSI_PATH, O_RDWR);
739	if (iscsi_fd < 0 && errno == ENOENT) {
740		saved_errno = errno;
741		retval = kldload("iscsi");
742		if (retval != -1)
743			iscsi_fd = open(ISCSI_PATH, O_RDWR);
744		else
745			errno = saved_errno;
746	}
747	if (iscsi_fd < 0)
748		log_err(1, "failed to open %s", ISCSI_PATH);
749
750	if (dont_daemonize == false) {
751		if (daemon(0, 0) == -1) {
752			log_warn("cannot daemonize");
753			pidfile_remove(pidfh);
754			exit(1);
755		}
756	}
757
758	pidfile_write(pidfh);
759
760	register_sigchld();
761
762	for (;;) {
763		log_debugx("waiting for request from the kernel");
764
765		memset(&request, 0, sizeof(request));
766		error = ioctl(iscsi_fd, ISCSIDWAIT, &request);
767		if (error != 0) {
768			if (errno == EINTR) {
769				nchildren -= wait_for_children(false);
770				assert(nchildren >= 0);
771				continue;
772			}
773
774			log_err(1, "ISCSIDWAIT");
775		}
776
777		if (dont_daemonize) {
778			log_debugx("not forking due to -d flag; "
779			    "will exit after servicing a single request");
780		} else {
781			nchildren -= wait_for_children(false);
782			assert(nchildren >= 0);
783
784			while (maxproc > 0 && nchildren >= maxproc) {
785				log_debugx("maxproc limit of %d child processes hit; "
786				    "waiting for child process to exit", maxproc);
787				nchildren -= wait_for_children(true);
788				assert(nchildren >= 0);
789			}
790			log_debugx("incoming connection; forking child process #%d",
791			    nchildren);
792			nchildren++;
793
794			pid = fork();
795			if (pid < 0)
796				log_err(1, "fork");
797			if (pid > 0)
798				continue;
799		}
800
801		pidfile_close(pidfh);
802		handle_request(iscsi_fd, &request, timeout);
803	}
804
805	return (0);
806}
807