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daemon-bozo.c revision 1.19 
      1 /*	$NetBSD: daemon-bozo.c,v 1.19 2018/11/22 08:54:08 mrg Exp $	*/
      2 
      3 /*	$eterna: daemon-bozo.c,v 1.24 2011/11/18 09:21:15 mrg Exp $	*/
      4 
      5 /*
      6  * Copyright (c) 1997-2018 Matthew R. Green
      7  * All rights reserved.
      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 and
     16  *    dedication in the documentation and/or other materials provided
     17  *    with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     24  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     26  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     27  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  *
     31  */
     32 
     33 /* this code implements daemon mode for bozohttpd */
     34 
     35 #ifndef NO_DAEMON_MODE
     36 
     37 #include <sys/param.h>
     38 #include <sys/socket.h>
     39 #include <sys/wait.h>
     40 
     41 #include <netinet/in.h>
     42 
     43 #include <assert.h>
     44 #include <errno.h>
     45 #include <netdb.h>
     46 #include <poll.h>
     47 #include <stdio.h>
     48 #include <stdlib.h>
     49 #include <string.h>
     50 #include <unistd.h>
     51 
     52 #include "bozohttpd.h"
     53 
     54 static	void	sigchild(int);	/* SIGCHLD handler */
     55 
     56 #ifndef POLLRDNORM
     57 #define POLLRDNORM 0
     58 #endif
     59 #ifndef POLLRDBAND
     60 #define POLLRDBAND 0
     61 #endif
     62 #ifndef INFTIM
     63 #define INFTIM -1
     64 #endif
     65 
     66 static const char* pidfile_path = NULL;
     67 static pid_t pidfile_pid = 0;
     68 
     69 /* ARGSUSED */
     70 static void
     71 sigchild(int signo)
     72 {
     73 
     74 	while (waitpid(-1, NULL, WNOHANG) > 0)
     75 		/* nothing */;
     76 }
     77 
     78 /* Signal handler to exit in a controlled manner.  This ensures that
     79  * any atexit(3) handlers are properly executed. */
     80 /* ARGSUSED */
     81 BOZO_DEAD static void
     82 controlled_exit(int signo)
     83 {
     84 
     85 	exit(EXIT_SUCCESS);
     86 }
     87 
     88 static void
     89 remove_pidfile(void)
     90 {
     91 
     92 	if (pidfile_path != NULL && pidfile_pid == getpid()) {
     93 		(void)unlink(pidfile_path);
     94 		pidfile_path = NULL;
     95 	}
     96 }
     97 
     98 static void
     99 create_pidfile(bozohttpd_t *httpd)
    100 {
    101 	FILE *file;
    102 
    103 	assert(pidfile_path == NULL);
    104 
    105 	if (httpd->pidfile == NULL)
    106 		return;
    107 
    108 	if (atexit(remove_pidfile) == -1)
    109 		bozoerr(httpd, 1, "Failed to install pidfile handler");
    110 
    111 	if ((file = fopen(httpd->pidfile, "w")) == NULL)
    112 		bozoerr(httpd, 1, "Failed to create pidfile '%s'",
    113 		    httpd->pidfile);
    114 	(void)fprintf(file, "%d\n", getpid());
    115 	(void)fclose(file);
    116 
    117 	pidfile_path = httpd->pidfile;
    118 	pidfile_pid = getpid();
    119 
    120 	debug((httpd, DEBUG_FAT, "Created pid file '%s' for pid %d",
    121 	    pidfile_path, pidfile_pid));
    122 }
    123 
    124 void
    125 bozo_daemon_init(bozohttpd_t *httpd)
    126 {
    127 	struct addrinfo h, *r, *r0;
    128 	const char	*portnum;
    129 	int e, i, on = 1;
    130 
    131 	if (!httpd->background)
    132 		return;
    133 
    134 	portnum = (httpd->bindport) ? httpd->bindport : "http";
    135 
    136 	memset(&h, 0, sizeof(h));
    137 	h.ai_family = PF_UNSPEC;
    138 	h.ai_socktype = SOCK_STREAM;
    139 	h.ai_flags = AI_PASSIVE;
    140 	e = getaddrinfo(httpd->bindaddress, portnum, &h, &r0);
    141 	if (e)
    142 		bozoerr(httpd, 1, "getaddrinfo([%s]:%s): %s",
    143 		    httpd->bindaddress ? httpd->bindaddress : "*",
    144 		    portnum, gai_strerror(e));
    145 	for (r = r0; r != NULL; r = r->ai_next)
    146 		httpd->nsock++;
    147 	httpd->sock = bozomalloc(httpd, httpd->nsock * sizeof(*httpd->sock));
    148 	httpd->fds = bozomalloc(httpd, httpd->nsock * sizeof(*httpd->fds));
    149 	for (i = 0, r = r0; r != NULL; r = r->ai_next) {
    150 		httpd->sock[i] = socket(r->ai_family, SOCK_STREAM, 0);
    151 		if (httpd->sock[i] == -1)
    152 			continue;
    153 		if (setsockopt(httpd->sock[i], SOL_SOCKET, SO_REUSEADDR, &on,
    154 		    sizeof(on)) == -1)
    155 			bozowarn(httpd, "setsockopt SO_REUSEADDR: %s",
    156 			    strerror(errno));
    157 		if (bind(httpd->sock[i], r->ai_addr, r->ai_addrlen) == -1)
    158 			continue;
    159 		if (listen(httpd->sock[i], SOMAXCONN) == -1)
    160 			continue;
    161 		httpd->fds[i].events = POLLIN | POLLPRI | POLLRDNORM |
    162 				POLLRDBAND | POLLERR;
    163 		httpd->fds[i].fd = httpd->sock[i];
    164 		i++;
    165 	}
    166 	if (i == 0)
    167 		bozoerr(httpd, 1, "could not find any addresses to bind");
    168 	httpd->nsock = i;
    169 	freeaddrinfo(r0);
    170 
    171 	if (httpd->foreground == 0)
    172 		daemon(1, 0);
    173 
    174 	create_pidfile(httpd);
    175 
    176 	bozowarn(httpd, "started in daemon mode as `%s' port `%s' root `%s'",
    177 	    httpd->virthostname, portnum, httpd->slashdir);
    178 
    179 	signal(SIGHUP, controlled_exit);
    180 	signal(SIGINT, controlled_exit);
    181 	signal(SIGTERM, controlled_exit);
    182 
    183 	signal(SIGCHLD, sigchild);
    184 }
    185 
    186 void
    187 bozo_daemon_closefds(bozohttpd_t *httpd)
    188 {
    189 	int i;
    190 
    191 	for (i = 0; i < httpd->nsock; i++)
    192 		close(httpd->sock[i]);
    193 }
    194 
    195 static void
    196 daemon_runchild(bozohttpd_t *httpd, int fd)
    197 {
    198 	httpd->request_times++;
    199 
    200 	/* setup stdin/stdout/stderr */
    201 	dup2(fd, 0);
    202 	dup2(fd, 1);
    203 	/*dup2(fd, 2);*/
    204 	close(fd);
    205 }
    206 
    207 static int
    208 daemon_poll_err(bozohttpd_t *httpd, int fd, int idx)
    209 {
    210 	if ((httpd->fds[idx].revents & (POLLNVAL|POLLERR|POLLHUP)) == 0)
    211 		return 0;
    212 
    213 	bozowarn(httpd, "poll on fd %d pid %d revents %d: %s",
    214 	    httpd->fds[idx].fd, getpid(), httpd->fds[idx].revents,
    215 	    strerror(errno));
    216 	bozowarn(httpd, "nsock = %d", httpd->nsock);
    217 	close(httpd->sock[idx]);
    218 	httpd->nsock--;
    219 	bozowarn(httpd, "nsock now = %d", httpd->nsock);
    220 	/* no sockets left */
    221 	if (httpd->nsock == 0)
    222 		exit(0);
    223 	/* last socket closed is the easy case */
    224 	if (httpd->nsock != idx) {
    225 		memmove(&httpd->fds[idx], &httpd->fds[idx+1],
    226 			(httpd->nsock - idx) * sizeof(*httpd->fds));
    227 		memmove(&httpd->sock[idx], &httpd->sock[idx+1],
    228 			(httpd->nsock - idx) * sizeof(*httpd->sock));
    229 	}
    230 
    231 	return 1;
    232 }
    233 
    234 /*
    235  * the parent never returns from this function, only children that
    236  * are ready to run... XXXMRG - still true in fork-lesser bozo?
    237  */
    238 int
    239 bozo_daemon_fork(bozohttpd_t *httpd)
    240 {
    241 	int i;
    242 
    243 	debug((httpd, DEBUG_FAT, "%s: pid %u request_times %d",
    244 		__func__, getpid(),
    245 		httpd->request_times));
    246 	/* if we've handled 5 files, exit and let someone else work */
    247 	if (httpd->request_times > 5 ||
    248 	    (httpd->background == 2 && httpd->request_times > 0))
    249 		_exit(0);
    250 
    251 #if 1
    252 	if (httpd->request_times > 0)
    253 		_exit(0);
    254 #endif
    255 
    256 	while (httpd->background) {
    257 		struct	sockaddr_storage ss;
    258 		socklen_t slen;
    259 		int fd;
    260 
    261 		if (httpd->nsock == 0)
    262 			exit(0);
    263 
    264 		/*
    265 		 * wait for a connection, then fork() and return NULL in
    266 		 * the parent, who will come back here waiting for another
    267 		 * connection.  read the request in in the child, and return
    268 		 * it, for processing.
    269 		 */
    270 again:
    271 		if (poll(httpd->fds, (unsigned)httpd->nsock, INFTIM) == -1) {
    272 			/* fail on programmer errors */
    273 			if (errno == EFAULT ||
    274 			    errno == EINVAL)
    275 				bozoerr(httpd, 1, "poll: %s",
    276 					strerror(errno));
    277 
    278 			/* sleep on some temporary kernel failures */
    279 			if (errno == ENOMEM ||
    280 			    errno == EAGAIN)
    281 				sleep(1);
    282 
    283 			goto again;
    284 		}
    285 
    286 		for (i = 0; i < httpd->nsock; i++) {
    287 			if (daemon_poll_err(httpd, fd, i))
    288 				break;
    289 			if (httpd->fds[i].revents == 0)
    290 				continue;
    291 
    292 			slen = sizeof(ss);
    293 			fd = accept(httpd->fds[i].fd,
    294 					(struct sockaddr *)(void *)&ss, &slen);
    295 			if (fd == -1) {
    296 				if (errno == EFAULT ||
    297 				    errno == EINVAL)
    298 					bozoerr(httpd, 1, "accept: %s",
    299 						strerror(errno));
    300 
    301 				if (errno == ENOMEM ||
    302 				    errno == EAGAIN)
    303 					sleep(1);
    304 
    305 				continue;
    306 			}
    307 
    308 #if 0
    309 			/*
    310 			 * This code doesn't work.  It interacts very poorly
    311 			 * with ~user translation and needs to be fixed.
    312 			 */
    313 			if (httpd->request_times > 0) {
    314 				daemon_runchild(httpd, fd);
    315 				return 0;
    316 			}
    317 #endif
    318 
    319 			switch (fork()) {
    320 			case -1: /* eep, failure */
    321 				bozowarn(httpd, "fork() failed, sleeping for "
    322 					"10 seconds: %s", strerror(errno));
    323 				close(fd);
    324 				sleep(10);
    325 				break;
    326 
    327 			case 0: /* child */
    328 				daemon_runchild(httpd, fd);
    329 				return 0;
    330 
    331 			default: /* parent */
    332 				close(fd);
    333 				break;
    334 			}
    335 		}
    336 	}
    337 	return 0;
    338 }
    339 
    340 #endif /* NO_DAEMON_MODE */
    341