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daemon-bozo.c revision 1.13 
      1 /*	$NetBSD: daemon-bozo.c,v 1.13 2011/03/29 07:22:31 jmmv Exp $	*/
      2 
      3 /*	$eterna: daemon-bozo.c,v 1.22 2010/06/21 06:45:45 mrg Exp $	*/
      4 
      5 /*
      6  * Copyright (c) 1997-2010 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 	while (waitpid(-1, NULL, WNOHANG) > 0) {
     74 	}
     75 }
     76 
     77 /* Signal handler to exit in a controlled manner.  This ensures that
     78  * any atexit(3) handlers are properly executed. */
     79 /* ARGSUSED */
     80 static void
     81 controlled_exit(int signo)
     82 {
     83 
     84 	exit(EXIT_SUCCESS);
     85 }
     86 
     87 static void
     88 remove_pidfile(void)
     89 {
     90 
     91 	if (pidfile_path != NULL && pidfile_pid == getpid()) {
     92 		(void)unlink(pidfile_path);
     93 		pidfile_path = NULL;
     94 	}
     95 }
     96 
     97 static void
     98 create_pidfile(bozohttpd_t *httpd)
     99 {
    100 	FILE *file;
    101 
    102 	assert(pidfile_path == NULL);
    103 
    104 	if (httpd->pidfile == NULL)
    105 		return;
    106 
    107 	if (atexit(remove_pidfile) == -1)
    108 		bozo_err(httpd, 1, "Failed to install pidfile handler");
    109 
    110 	if ((file = fopen(httpd->pidfile, "w")) == NULL)
    111 		bozo_err(httpd, 1, "Failed to create pidfile '%s'",
    112 		    httpd->pidfile);
    113 	(void)fprintf(file, "%d\n", getpid());
    114 	(void)fclose(file);
    115 
    116 	pidfile_path = httpd->pidfile;
    117 	pidfile_pid = getpid();
    118 
    119 	debug((httpd, DEBUG_FAT, "Created pid file '%s' for pid %d",
    120 	    pidfile_path, pidfile_pid));
    121 }
    122 
    123 void
    124 bozo_daemon_init(bozohttpd_t *httpd)
    125 {
    126 	struct addrinfo h, *r, *r0;
    127 	const char	*portnum;
    128 	int e, i, on = 1;
    129 
    130 	if (!httpd->background)
    131 		return;
    132 
    133 	portnum = (httpd->bindport) ? httpd->bindport : "http";
    134 
    135 	memset(&h, 0, sizeof(h));
    136 	h.ai_family = PF_UNSPEC;
    137 	h.ai_socktype = SOCK_STREAM;
    138 	h.ai_flags = AI_PASSIVE;
    139 	e = getaddrinfo(httpd->bindaddress, portnum, &h, &r0);
    140 	if (e)
    141 		bozo_err(httpd, 1, "getaddrinfo([%s]:%s): %s",
    142 		    httpd->bindaddress ? httpd->bindaddress : "*",
    143 		    portnum, gai_strerror(e));
    144 	for (r = r0; r != NULL; r = r->ai_next)
    145 		httpd->nsock++;
    146 	httpd->sock = bozomalloc(httpd, httpd->nsock * sizeof(*httpd->sock));
    147 	httpd->fds = bozomalloc(httpd, httpd->nsock * sizeof(*httpd->fds));
    148 	for (i = 0, r = r0; r != NULL; r = r->ai_next) {
    149 		httpd->sock[i] = socket(r->ai_family, SOCK_STREAM, 0);
    150 		if (httpd->sock[i] == -1)
    151 			continue;
    152 		if (setsockopt(httpd->sock[i], SOL_SOCKET, SO_REUSEADDR, &on,
    153 		    sizeof(on)) == -1)
    154 			bozo_warn(httpd, "setsockopt SO_REUSEADDR: %s",
    155 			    strerror(errno));
    156 		if (bind(httpd->sock[i], r->ai_addr, r->ai_addrlen) == -1)
    157 			continue;
    158 		if (listen(httpd->sock[i], SOMAXCONN) == -1)
    159 			continue;
    160 		httpd->fds[i].events = POLLIN | POLLPRI | POLLRDNORM |
    161 				POLLRDBAND | POLLERR;
    162 		httpd->fds[i].fd = httpd->sock[i];
    163 		i++;
    164 	}
    165 	if (i == 0)
    166 		bozo_err(httpd, 1, "could not find any addresses to bind");
    167 	httpd->nsock = i;
    168 	freeaddrinfo(r0);
    169 
    170 	if (httpd->foreground == 0)
    171 		daemon(1, 0);
    172 
    173 	create_pidfile(httpd);
    174 
    175 	bozo_warn(httpd, "started in daemon mode as `%s' port `%s' root `%s'",
    176 	    httpd->virthostname, portnum, httpd->slashdir);
    177 
    178 	signal(SIGHUP, controlled_exit);
    179 	signal(SIGINT, controlled_exit);
    180 	signal(SIGTERM, controlled_exit);
    181 
    182 	signal(SIGCHLD, sigchild);
    183 }
    184 
    185 void
    186 bozo_daemon_closefds(bozohttpd_t *httpd)
    187 {
    188 	int i;
    189 
    190 	for (i = 0; i < httpd->nsock; i++)
    191 		close(httpd->sock[i]);
    192 }
    193 
    194 static void
    195 daemon_runchild(bozohttpd_t *httpd, int fd)
    196 {
    197 	httpd->request_times++;
    198 
    199 	/* setup stdin/stdout/stderr */
    200 	dup2(fd, 0);
    201 	dup2(fd, 1);
    202 	/*dup2(fd, 2);*/
    203 	close(fd);
    204 }
    205 
    206 static int
    207 daemon_poll_err(bozohttpd_t *httpd, int fd, int idx)
    208 {
    209 	if ((httpd->fds[idx].revents & (POLLNVAL|POLLERR|POLLHUP)) == 0)
    210 		return 0;
    211 
    212 	bozo_warn(httpd, "poll on fd %d pid %d revents %d: %s",
    213 	    httpd->fds[idx].fd, getpid(), httpd->fds[idx].revents,
    214 	    strerror(errno));
    215 	bozo_warn(httpd, "nsock = %d", httpd->nsock);
    216 	close(httpd->sock[idx]);
    217 	httpd->nsock--;
    218 	bozo_warn(httpd, "nsock now = %d", httpd->nsock);
    219 	/* no sockets left */
    220 	if (httpd->nsock == 0)
    221 		exit(0);
    222 	/* last socket closed is the easy case */
    223 	if (httpd->nsock != idx) {
    224 		memmove(&httpd->fds[idx], &httpd->fds[idx+1],
    225 			(httpd->nsock - idx) * sizeof(*httpd->fds));
    226 		memmove(&httpd->sock[idx], &httpd->sock[idx+1],
    227 			(httpd->nsock - idx) * sizeof(*httpd->sock));
    228 	}
    229 
    230 	return 1;
    231 }
    232 
    233 /*
    234  * the parent never returns from this function, only children that
    235  * are ready to run... XXXMRG - still true in fork-lesser bozo?
    236  */
    237 int
    238 bozo_daemon_fork(bozohttpd_t *httpd)
    239 {
    240 	int i;
    241 
    242 	debug((httpd, DEBUG_FAT, "%s: pid %u request_times %d",
    243 		__func__, getpid(),
    244 		httpd->request_times));
    245 	/* if we've handled 5 files, exit and let someone else work */
    246 	if (httpd->request_times > 5 ||
    247 	    (httpd->background == 2 && httpd->request_times > 0))
    248 		_exit(0);
    249 
    250 #if 1
    251 	if (httpd->request_times > 0)
    252 		_exit(0);
    253 #endif
    254 
    255 	while (httpd->background) {
    256 		struct	sockaddr_storage ss;
    257 		socklen_t slen;
    258 		int fd;
    259 
    260 		if (httpd->nsock == 0)
    261 			exit(0);
    262 
    263 		/*
    264 		 * wait for a connection, then fork() and return NULL in
    265 		 * the parent, who will come back here waiting for another
    266 		 * connection.  read the request in in the child, and return
    267 		 * it, for processing.
    268 		 */
    269 again:
    270 		if (poll(httpd->fds, (unsigned)httpd->nsock, INFTIM) == -1) {
    271 			/* fail on programmer errors */
    272 			if (errno == EFAULT ||
    273 			    errno == EINVAL)
    274 				bozo_err(httpd, 1, "poll: %s",
    275 					strerror(errno));
    276 
    277 			/* sleep on some temporary kernel failures */
    278 			if (errno == ENOMEM ||
    279 			    errno == EAGAIN)
    280 				sleep(1);
    281 
    282 			goto again;
    283 		}
    284 
    285 		for (i = 0; i < httpd->nsock; i++) {
    286 			if (daemon_poll_err(httpd, fd, i))
    287 				break;
    288 			if (httpd->fds[i].revents == 0)
    289 				continue;
    290 
    291 			slen = sizeof(ss);
    292 			fd = accept(httpd->fds[i].fd,
    293 					(struct sockaddr *)(void *)&ss, &slen);
    294 			if (fd == -1) {
    295 				if (errno == EFAULT ||
    296 				    errno == EINVAL)
    297 					bozo_err(httpd, 1, "accept: %s",
    298 						strerror(errno));
    299 
    300 				if (errno == ENOMEM ||
    301 				    errno == EAGAIN)
    302 					sleep(1);
    303 
    304 				continue;
    305 			}
    306 
    307 #if 0
    308 			/*
    309 			 * This code doesn't work.  It interacts very poorly
    310 			 * with ~user translation and needs to be fixed.
    311 			 */
    312 			if (httpd->request_times > 0) {
    313 				daemon_runchild(httpd, fd);
    314 				return 0;
    315 			}
    316 #endif
    317 
    318 			switch (fork()) {
    319 			case -1: /* eep, failure */
    320 				bozo_warn(httpd, "fork() failed, sleeping for "
    321 					"10 seconds: %s", strerror(errno));
    322 				close(fd);
    323 				sleep(10);
    324 				break;
    325 
    326 			case 0: /* child */
    327 				daemon_runchild(httpd, fd);
    328 				return 0;
    329 
    330 			default: /* parent */
    331 				close(fd);
    332 				break;
    333 			}
    334 		}
    335 	}
    336 	return 0;
    337 }
    338 
    339 #endif /* NO_DAEMON_MODE */
    340