[ashd.git] / src / accesslog.c

/*
    ashd - A Sane HTTP Daemon
    Copyright (C) 2008  Fredrik Tolf <fredrik@dolda2000.com>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <sys/poll.h>
#include <time.h>
#include <sys/time.h>
#include <signal.h>
#include <fcntl.h>
#include <stdint.h>
#include <sys/stat.h>
#include <sys/socket.h>

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <utils.h>
#include <log.h>
#include <req.h>
#include <proc.h>
#include <mt.h>
#include <mtio.h>

#define DEFFORMAT "%{%Y-%m-%d %H:%M:%S}t %m %u %A \"%G\""

static struct logdata {
    struct hthead *req, *resp;
    struct timeval start, end;
    off_t bytesin, bytesout;
} defdata = {
    .bytesin = -1,
    .bytesout = -1,
};

static int ch, filter;
static char *outname = NULL;
static FILE *out;
static int flush = 1, locklog = 1;
static char *format;
static volatile int reopen = 0;

static void qputs(char *sp, FILE *o)
{
    unsigned char *s = (unsigned char *)sp;
    
    for(; *s; s++) {
	if(*s == '\"') {
	    fputs("\\\"", o);
	} else if(*s == '\\') {
	    fputs("\\\\", o);
	} else if(*s == '\n') {
	    fputs("\\n", o);
	} else if(*s == '\t') {
	    fputs("\\t", o);
	} else if((*s < 32) || (*s >= 128)) {
	    fprintf(o, "\\x%02x", (int)*s);
	} else {
	    fputc(*s, o);
	}
    }
}

static void logitem(struct logdata *data, char o, char *d)
{
    char *h, *p;
    char buf[1024];
    
    switch(o) {
    case '%':
	putc('%', out);
	break;
    case 'h':
	if((h = getheader(data->req, d)) == NULL) {
	    putc('-', out);
	} else {
	    qputs(h, out);
	}
	break;
    case 'u':
	qputs(data->req->url, out);
	break;
    case 'U':
	strncpy(buf, data->req->url, sizeof(buf));
	buf[sizeof(buf) - 1] = 0;
	if((p = strchr(buf, '?')) != NULL)
	    *p = 0;
	qputs(buf, out);
	break;
    case 'm':
	qputs(data->req->method, out);
	break;
    case 'r':
	qputs(data->req->rest, out);
	break;
    case 'v':
	qputs(data->req->ver, out);
	break;
    case 't':
	if(!*d)
	    d = "%a, %d %b %Y %H:%M:%S %z";
	strftime(buf, sizeof(buf), d, localtime(&data->start.tv_sec));
	qputs(buf, out);
	break;
    case 'T':
	if(!*d)
	    d = "%a, %d %b %Y %H:%M:%S %z";
	strftime(buf, sizeof(buf), d, gmtime(&data->start.tv_sec));
	qputs(buf, out);
	break;
    case 's':
	fprintf(out, "%06i", (int)data->start.tv_usec);
	break;
    case 'c':
	if(!data->resp)
	    putc('-', out);
	else
	    fprintf(out, "%i", data->resp->code);
	break;
    case 'i':
	if(data->bytesin < 0)
	    putc('-', out);
	else
	    fprintf(out, "%ji", (intmax_t)data->bytesin);
	break;
    case 'o':
	if(data->bytesout < 0)
	    putc('-', out);
	else
	    fprintf(out, "%ji", (intmax_t)data->bytesout);
	break;
    case 'd':
	if((data->end.tv_sec == 0) && (data->end.tv_usec == 0))
	    fputc('-', out);
	else
	    fprintf(out, "%.6f", (data->end.tv_sec - data->start.tv_sec) + ((data->end.tv_usec - data->start.tv_usec) / 1000000.0));
	break;
    case 'A':
	logitem(data, 'h', "X-Ash-Address");
	break;
    case 'H':
	logitem(data, 'h', "Host");
	break;
    case 'R':
	logitem(data, 'h', "Referer");
	break;
    case 'G':
	logitem(data, 'h', "User-Agent");
	break;
    }
}

static void logreq(struct logdata *data)
{
    char *p, *p2;
    char d[strlen(format)];
    char o;
    
    p = format;
    while(*p) {
	if(*p == '%') {
	    p++;
	    if(*p == '{') {
		p++;
		if((p2 = strchr(p, '}')) == NULL)
		    continue;
		memcpy(d, p, p2 - p);
		d[p2 - p] = 0;
		p = p2 + 1;
	    } else {
		d[0] = 0;
	    }
	    o = *p++;
	    if(o == 0)
		break;
	    logitem(data, o, d);
	} else {
	    fputc(*p++, out);
	}
    }
    fputc('\n', out);
    if(flush)
	fflush(out);
}

static void serve(struct hthead *req, int fd)
{
    struct logdata data;
    
    data = defdata;
    data.req = req;
    gettimeofday(&data.start, NULL);
    if(sendreq(ch, req, fd)) {
	flog(LOG_ERR, "accesslog: could not pass request to child: %s", strerror(errno));
	exit(1);
    }
    logreq(&data);
}

static int passdata(FILE *in, FILE *out, off_t *passed)
{
    size_t read;
    off_t total;
    char buf[8192];
    
    total = 0;
    while(!feof(in)) {
	read = fread(buf, 1, sizeof(buf), in);
	if(ferror(in))
	    return(-1);
	if(fwrite(buf, 1, read, out) != read)
	    return(-1);
	total += read;
    }
    if(passed)
	*passed = total;
    return(0);
}

static void filterreq(struct muth *mt, va_list args)
{
    vavar(struct hthead *, req);
    vavar(int, fd);
    int pfds[2];
    struct hthead *resp;
    FILE *cl, *hd;
    struct logdata data;
    
    hd = NULL;
    resp = NULL;
    data = defdata;
    data.req = req;
    gettimeofday(&data.start, NULL);
    cl = mtstdopen(fd, 1, 600, "r+");
    if(socketpair(PF_UNIX, SOCK_STREAM, 0, pfds))
	goto out;
    hd = mtstdopen(pfds[1], 1, 600, "r+");
    if(sendreq(ch, req, pfds[0])) {
	close(pfds[0]);
	goto out;
    }
    close(pfds[0]);
    
    if(passdata(cl, hd, &data.bytesin))
	goto out;
    shutdown(pfds[1], SHUT_WR);
    if((resp = parseresponse(hd)) == NULL)
	goto out;
    data.resp = resp;
    writeresp(cl, resp);
    fprintf(cl, "\r\n");
    if(passdata(hd, cl, &data.bytesout))
	goto out;
    gettimeofday(&data.end, NULL);
    
out:
    logreq(&data);
    
    freehthead(req);
    if(resp != NULL)
	freehthead(resp);
    fclose(cl);
    if(hd != NULL)
	fclose(hd);
}

static void sighandler(int sig)
{
    if(sig == SIGHUP) {
	if(filter)
	    exitioloop(2);
	else
	    reopen = 1;
    }
}

static int lockfile(FILE *file)
{
    struct flock ld;
    
    memset(&ld, 0, sizeof(ld));
    ld.l_type = F_WRLCK;
    ld.l_whence = SEEK_SET;
    ld.l_start = 0;
    ld.l_len = 0;
    return(fcntl(fileno(file), F_SETLK, &ld));
}

static void fetchpid(char *filename)
{
    int fd, ret;
    struct flock ld;
    
    if((fd = open(filename, O_WRONLY)) < 0) {
	fprintf(stderr, "accesslog: %s: %s\n", filename, strerror(errno));
	exit(1);
    }
    memset(&ld, 0, sizeof(ld));
    ld.l_type = F_WRLCK;
    ld.l_whence = SEEK_SET;
    ld.l_start = 0;
    ld.l_len = 0;
    ret = fcntl(fd, F_GETLK, &ld);
    close(fd);
    if(ret) {
	fprintf(stderr, "accesslog: %s: %s\n", filename, strerror(errno));
	exit(1);
    }
    if(ld.l_type == F_UNLCK) {
	fprintf(stderr, "accesslog: %s: not locked\n", filename);
	exit(1);
    }
    printf("%i\n", (int)ld.l_pid);
}

static void reopenlog(void)
{
    FILE *new;
    struct stat olds, news;
    
    if(outname == NULL) {
	flog(LOG_WARNING, "accesslog: received SIGHUP but logging to stdout, so ignoring");
	return;
    }
    if(locklog) {
	if(fstat(fileno(out), &olds)) {
	    flog(LOG_ERR, "accesslog: could not stat current logfile(?!): %s", strerror(errno));
	    return;
	}
	if(!stat(outname, &news)) {
	    if((olds.st_dev == news.st_dev) && (olds.st_ino == news.st_ino)) {
		/*
		 * This needs to be ignored, because if the same logfile
		 * is opened and then closed, the lock is lost. To quote
		 * the Linux fcntl(2) manpage: "This is bad." No kidding.
		 *
		 * Technically, there is a race condition here when the
		 * file has been stat'ed but not yet opened, where the old
		 * log file, having been previously renamed, changes name
		 * back to the name accesslog knows and is thus reopened
		 * regardlessly, but I think that might fit under the
		 * idiom "pathological case". It should, at least, not be
		 * a security problem.
		 */
		flog(LOG_INFO, "accesslog: received SIGHUP, but logfile has not changed, so ignoring");
		return;
	    }
	}
    }
    if((new = fopen(outname, "a")) == NULL) {
	flog(LOG_WARNING, "accesslog: could not reopen log file `%s' on SIGHUP: %s", outname, strerror(errno));
	return;
    }
    fcntl(fileno(new), F_SETFD, FD_CLOEXEC);
    if(locklog) {
	if(lockfile(new)) {
	    if((errno == EAGAIN) || (errno == EACCES)) {
		flog(LOG_ERR, "accesslog: logfile is already locked; reverting to current log", strerror(errno));
		fclose(new);
		return;
	    } else {
		flog(LOG_WARNING, "accesslog: could not lock logfile, so no lock will be held: %s", strerror(errno));
	    }
	}
    }
    fclose(out);
    out = new;
}

static void listenloop(struct muth *mt, va_list args)
{
    vavar(int, lfd);
    int fd;
    struct hthead *req;
    
    while(1) {
	block(lfd, EV_READ, 0);
	if((fd = recvreq(lfd, &req)) < 0) {
	    if(errno != 0)
		flog(LOG_ERR, "accesslog: error in recvreq: %s", strerror(errno));
	    exit(1);
	}
	mustart(filterreq, req, fd);
    }
}

static void chwatch(struct muth *mt, va_list args)
{
    vavar(int, cfd);
    
    block(cfd, EV_READ, 0);
    exitioloop(1);
}

static void floop(void)
{
    mustart(listenloop, 0);
    mustart(chwatch, ch);
    while(1) {
	switch(ioloop()) {
	case 0:
	case 1:
	    return;
	case 2:
	    reopenlog();
	    break;
	}
    }
}

static void sloop(void)
{
    int fd, ret;
    struct hthead *req;
    struct pollfd pfd[2];
    
    while(1) {
	if(reopen) {
	    reopenlog();
	    reopen = 0;
	}
	memset(pfd, 0, sizeof(pfd));
	pfd[0].fd = 0;
	pfd[0].events = POLLIN;
	pfd[1].fd = ch;
	pfd[1].events = POLLHUP;
	if((ret = poll(pfd, 2, -1)) < 0) {
	    if(errno != EINTR) {
		flog(LOG_ERR, "accesslog: error in poll: %s", strerror(errno));
		exit(1);
	    }
	}
	if(pfd[0].revents) {
	    if((fd = recvreq(0, &req)) < 0) {
		if(errno == 0)
		    return;
		flog(LOG_ERR, "accesslog: error in recvreq: %s", strerror(errno));
		exit(1);
	    }
	    serve(req, fd);
	    freehthead(req);
	    close(fd);
	}
	if(pfd[1].revents & POLLHUP)
	    return;
    }
}

static void usage(FILE *out)
{
    fprintf(out, "usage: accesslog [-hFaL] [-f FORMAT] [-p PIDFILE] OUTFILE CHILD [ARGS...]\n");
    fprintf(out, "       accesslog -P LOGFILE\n");
}

int main(int argc, char **argv)
{
    int c;
    char *pidfile;
    FILE *pidout;
    
    pidfile = NULL;
    while((c = getopt(argc, argv, "+hFaeLf:p:P:")) >= 0) {
	switch(c) {
	case 'h':
	    usage(stdout);
	    exit(0);
	case 'F':
	    flush = 0;
	    break;
	case 'L':
	    locklog = 0;
	    break;
	case 'e':
	    filter = 1;
	    break;
	case 'f':
	    format = optarg;
	    break;
	case 'P':
	    fetchpid(optarg);
	    exit(0);
	case 'p':
	    pidfile = optarg;
	    break;
	case 'a':
	    format = "%A - - [%{%d/%b/%Y:%H:%M:%S %z}t] \"%m %u %v\" %c %o \"%R\" \"%G\"";
	    break;
	default:
	    usage(stderr);
	    exit(1);
	}
    }
    if(argc - optind < 2) {
	usage(stderr);
	exit(1);
    }
    if(format == NULL)
	format = DEFFORMAT;
    if(!strcmp(argv[optind], "-"))
	outname = NULL;
    else
	outname = argv[optind];
    if(outname == NULL) {
	out = stdout;
	locklog = 0;
    } else {
	if((out = fopen(argv[optind], "a")) == NULL) {
	    flog(LOG_ERR, "accesslog: could not open %s for logging: %s", argv[optind], strerror(errno));
	    exit(1);
	}
	fcntl(fileno(out), F_SETFD, FD_CLOEXEC);
    }
    if(locklog) {
	if(lockfile(out)) {
	    if((errno == EAGAIN) || (errno == EACCES)) {
		flog(LOG_ERR, "accesslog: logfile is already locked", strerror(errno));
		exit(1);
	    } else {
		flog(LOG_WARNING, "accesslog: could not lock logfile: %s", strerror(errno));
	    }
	}
    }
    if((ch = stdmkchild(argv + optind + 1, NULL, NULL)) < 0) {
	flog(LOG_ERR, "accesslog: could not fork child: %s", strerror(errno));
	exit(1);
    }
    signal(SIGHUP, sighandler);
    if(pidfile) {
	if(!strcmp(pidfile, "-")) {
	    if(!outname) {
		flog(LOG_ERR, "accesslog: cannot derive PID file name without an output file");
		exit(1);
	    }
	    pidfile = sprintf2("%s.pid", outname);
	}
	if((pidout = fopen(pidfile, "w")) == NULL) {
	    flog(LOG_ERR, "accesslog: could not open PID file %s for writing: %s", pidfile);
	    exit(1);
	}
	fprintf(pidout, "%i\n", (int)getpid());
	fclose(pidout);
    }
    if(filter)
	floop();
    else
	sloop();
    fclose(out);
    if(pidfile != NULL)
	unlink(pidfile);
    return(0);
}
Commit	Line	Data
048ac115 FT	1	/*
	2	ashd - A Sane HTTP Daemon
	3	Copyright (C) 2008 Fredrik Tolf <fredrik@dolda2000.com>
	4
	5	This program is free software: you can redistribute it and/or modify
	6	it under the terms of the GNU General Public License as published by
	7	the Free Software Foundation, either version 3 of the License, or
	8	(at your option) any later version.
	9
	10	This program is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	GNU General Public License for more details.
	14
	15	You should have received a copy of the GNU General Public License
	16	along with this program. If not, see <http://www.gnu.org/licenses/>.
	17	*/
	18
	19	#include <stdlib.h>
	20	#include <stdio.h>
	21	#include <unistd.h>
	22	#include <string.h>
	23	#include <errno.h>
	24	#include <sys/poll.h>
	25	#include <time.h>
	26	#include <sys/time.h>
f99bcc64	27	#include <signal.h>
472abd3c	28	#include <fcntl.h>
5c805444	29	#include <stdint.h>
ca170d77	30	#include <sys/stat.h>
5c805444	31	#include <sys/socket.h>
048ac115 FT	32
	33	#ifdef HAVE_CONFIG_H
	34	#include <config.h>
	35	#endif
	36	#include <utils.h>
	37	#include <log.h>
	38	#include <req.h>
	39	#include <proc.h>
5c805444 FT	40	#include <mt.h>
5c805444 FT	41	#include <mtio.h>
048ac115 FT	42
	43	#define DEFFORMAT "%{%Y-%m-%d %H:%M:%S}t %m %u %A \"%G\""
	44
5c805444 FT	45	static struct logdata {
	46	struct hthead req, resp;
	47	struct timeval start, end;
	48	off_t bytesin, bytesout;
	49	} defdata = {
	50	.bytesin = -1,
	51	.bytesout = -1,
	52	};
	53
	54	static int ch, filter;
f99bcc64	55	static char *outname = NULL;
048ac115	56	static FILE *out;
ca170d77	57	static int flush = 1, locklog = 1;
048ac115	58	static char *format;
f99bcc64	59	static volatile int reopen = 0;
048ac115	60
39522714	61	static void qputs(char sp, FILE o)
048ac115	62	{
39522714 FT	63	unsigned char s = (unsigned char )sp;
39522714 FT	64
048ac115 FT	65	for(; *s; s++) {
	66	if(*s == '\"') {
	67	fputs("\\\"", o);
	68	} else if(*s == '\\') {
	69	fputs("\\\\", o);
	70	} else if(*s == '\n') {
	71	fputs("\\n", o);
	72	} else if(*s == '\t') {
	73	fputs("\\t", o);
	74	} else if((s < 32) \|\| (s >= 128)) {
39522714	75	fprintf(o, "\\x%02x", (int)*s);
048ac115 FT	76	} else {
	77	fputc(*s, o);
	78	}
	79	}
	80	}
	81
5c805444	82	static void logitem(struct logdata data, char o, char d)
048ac115 FT	83	{
	84	char h, p;
	85	char buf[1024];
048ac115 FT	86
	87	switch(o) {
	88	case '%':
	89	putc('%', out);
	90	break;
	91	case 'h':
5c805444	92	if((h = getheader(data->req, d)) == NULL) {
048ac115 FT	93	putc('-', out);
	94	} else {
	95	qputs(h, out);
	96	}
	97	break;
	98	case 'u':
5c805444	99	qputs(data->req->url, out);
048ac115 FT	100	break;
048ac115 FT	101	case 'U':
5c805444 FT	102	strncpy(buf, data->req->url, sizeof(buf));
5c805444 FT	103	buf[sizeof(buf) - 1] = 0;
048ac115 FT	104	if((p = strchr(buf, '?')) != NULL)
	105	*p = 0;
	106	qputs(buf, out);
	107	break;
	108	case 'm':
5c805444	109	qputs(data->req->method, out);
048ac115 FT	110	break;
048ac115 FT	111	case 'r':
5c805444	112	qputs(data->req->rest, out);
048ac115 FT	113	break;
048ac115 FT	114	case 'v':
5c805444	115	qputs(data->req->ver, out);
048ac115 FT	116	break;
	117	case 't':
	118	if(!*d)
	119	d = "%a, %d %b %Y %H:%M:%S %z";
5c805444	120	strftime(buf, sizeof(buf), d, localtime(&data->start.tv_sec));
048ac115 FT	121	qputs(buf, out);
	122	break;
	123	case 'T':
	124	if(!*d)
	125	d = "%a, %d %b %Y %H:%M:%S %z";
5c805444	126	strftime(buf, sizeof(buf), d, gmtime(&data->start.tv_sec));
048ac115 FT	127	qputs(buf, out);
	128	break;
	129	case 's':
5c805444 FT	130	fprintf(out, "%06i", (int)data->start.tv_usec);
	131	break;
	132	case 'c':
	133	if(!data->resp)
	134	putc('-', out);
	135	else
	136	fprintf(out, "%i", data->resp->code);
	137	break;
	138	case 'i':
	139	if(data->bytesin < 0)
	140	putc('-', out);
	141	else
	142	fprintf(out, "%ji", (intmax_t)data->bytesin);
	143	break;
	144	case 'o':
	145	if(data->bytesout < 0)
	146	putc('-', out);
	147	else
	148	fprintf(out, "%ji", (intmax_t)data->bytesout);
	149	break;
	150	case 'd':
	151	if((data->end.tv_sec == 0) && (data->end.tv_usec == 0))
	152	fputc('-', out);
	153	else
	154	fprintf(out, "%.6f", (data->end.tv_sec - data->start.tv_sec) + ((data->end.tv_usec - data->start.tv_usec) / 1000000.0));
048ac115 FT	155	break;
048ac115 FT	156	case 'A':
5c805444	157	logitem(data, 'h', "X-Ash-Address");
048ac115 FT	158	break;
048ac115 FT	159	case 'H':
5c805444	160	logitem(data, 'h', "Host");
048ac115 FT	161	break;
048ac115 FT	162	case 'R':
5c805444	163	logitem(data, 'h', "Referer");
048ac115 FT	164	break;
048ac115 FT	165	case 'G':
5c805444	166	logitem(data, 'h', "User-Agent");
048ac115 FT	167	break;
	168	}
	169	}
	170
5c805444	171	static void logreq(struct logdata *data)
048ac115 FT	172	{
	173	char p, p2;
	174	char d[strlen(format)];
	175	char o;
	176
	177	p = format;
	178	while(*p) {
	179	if(*p == '%') {
	180	p++;
	181	if(*p == '{') {
	182	p++;
	183	if((p2 = strchr(p, '}')) == NULL)
	184	continue;
	185	memcpy(d, p, p2 - p);
	186	d[p2 - p] = 0;
	187	p = p2 + 1;
	188	} else {
	189	d[0] = 0;
	190	}
	191	o = *p++;
	192	if(o == 0)
	193	break;
5c805444	194	logitem(data, o, d);
048ac115 FT	195	} else {
	196	fputc(*p++, out);
	197	}
	198	}
	199	fputc('\n', out);
	200	if(flush)
	201	fflush(out);
	202	}
	203
	204	static void serve(struct hthead *req, int fd)
	205	{
5c805444 FT	206	struct logdata data;
	207
	208	data = defdata;
	209	data.req = req;
	210	gettimeofday(&data.start, NULL);
048ac115 FT	211	if(sendreq(ch, req, fd)) {
	212	flog(LOG_ERR, "accesslog: could not pass request to child: %s", strerror(errno));
	213	exit(1);
	214	}
5c805444 FT	215	logreq(&data);
	216	}
	217
	218	static int passdata(FILE in, FILE out, off_t *passed)
	219	{
	220	size_t read;
	221	off_t total;
	222	char buf[8192];
	223
	224	total = 0;
	225	while(!feof(in)) {
	226	read = fread(buf, 1, sizeof(buf), in);
	227	if(ferror(in))
	228	return(-1);
	229	if(fwrite(buf, 1, read, out) != read)
	230	return(-1);
	231	total += read;
	232	}
	233	if(passed)
	234	*passed = total;
	235	return(0);
	236	}
	237
	238	static void filterreq(struct muth *mt, va_list args)
	239	{
	240	vavar(struct hthead *, req);
	241	vavar(int, fd);
	242	int pfds[2];
	243	struct hthead *resp;
	244	FILE cl, hd;
	245	struct logdata data;
	246
	247	hd = NULL;
	248	resp = NULL;
	249	data = defdata;
	250	data.req = req;
	251	gettimeofday(&data.start, NULL);
	252	cl = mtstdopen(fd, 1, 600, "r+");
	253	if(socketpair(PF_UNIX, SOCK_STREAM, 0, pfds))
	254	goto out;
	255	hd = mtstdopen(pfds[1], 1, 600, "r+");
	256	if(sendreq(ch, req, pfds[0])) {
	257	close(pfds[0]);
	258	goto out;
	259	}
	260	close(pfds[0]);
	261
	262	if(passdata(cl, hd, &data.bytesin))
	263	goto out;
	264	shutdown(pfds[1], SHUT_WR);
	265	if((resp = parseresponse(hd)) == NULL)
	266	goto out;
	267	data.resp = resp;
	268	writeresp(cl, resp);
	269	fprintf(cl, "\r\n");
	270	if(passdata(hd, cl, &data.bytesout))
	271	goto out;
	272	gettimeofday(&data.end, NULL);
	273
	274	out:
	275	logreq(&data);
	276
	277	freehthead(req);
	278	if(resp != NULL)
279	freehthead(resp);
280	fclose(cl);
281	if(hd != NULL)
282	fclose(hd);
048ac115 FT	283	}
048ac115 FT	284
f99bcc64 FT	285	static void sighandler(int sig)
f99bcc64 FT	286	{
5c805444 FT	287	if(sig == SIGHUP) {
	288	if(filter)
	289	exitioloop(2);
	290	else
	291	reopen = 1;
	292	}
f99bcc64 FT	293	}
f99bcc64 FT	294
ca170d77 FT	295	static int lockfile(FILE *file)
	296	{
	297	struct flock ld;
	298
	299	memset(&ld, 0, sizeof(ld));
	300	ld.l_type = F_WRLCK;
	301	ld.l_whence = SEEK_SET;
	302	ld.l_start = 0;
	303	ld.l_len = 0;
	304	return(fcntl(fileno(file), F_SETLK, &ld));
	305	}
	306
	307	static void fetchpid(char *filename)
	308	{
	309	int fd, ret;
	310	struct flock ld;
	311
	312	if((fd = open(filename, O_WRONLY)) < 0) {
	313	fprintf(stderr, "accesslog: %s: %s\n", filename, strerror(errno));
	314	exit(1);
	315	}
	316	memset(&ld, 0, sizeof(ld));
	317	ld.l_type = F_WRLCK;
	318	ld.l_whence = SEEK_SET;
	319	ld.l_start = 0;
	320	ld.l_len = 0;
	321	ret = fcntl(fd, F_GETLK, &ld);
	322	close(fd);
	323	if(ret) {
	324	fprintf(stderr, "accesslog: %s: %s\n", filename, strerror(errno));
	325	exit(1);
	326	}
	327	if(ld.l_type == F_UNLCK) {
	328	fprintf(stderr, "accesslog: %s: not locked\n", filename);
	329	exit(1);
	330	}
	331	printf("%i\n", (int)ld.l_pid);
	332	}
	333
f99bcc64 FT	334	static void reopenlog(void)
	335	{
	336	FILE *new;
ca170d77	337	struct stat olds, news;
f99bcc64 FT	338
	339	if(outname == NULL) {
	340	flog(LOG_WARNING, "accesslog: received SIGHUP but logging to stdout, so ignoring");
	341	return;
	342	}
ca170d77 FT	343	if(locklog) {
	344	if(fstat(fileno(out), &olds)) {
	345	flog(LOG_ERR, "accesslog: could not stat current logfile(?!): %s", strerror(errno));
	346	return;
	347	}
	348	if(!stat(outname, &news)) {
	349	if((olds.st_dev == news.st_dev) && (olds.st_ino == news.st_ino)) {
	350	/*
	351	* This needs to be ignored, because if the same logfile
	352	* is opened and then closed, the lock is lost. To quote
	353	* the Linux fcntl(2) manpage: "This is bad." No kidding.
	354	*
	355	* Technically, there is a race condition here when the
	356	* file has been stat'ed but not yet opened, where the old
	357	* log file, having been previously renamed, changes name
	358	* back to the name accesslog knows and is thus reopened
	359	* regardlessly, but I think that might fit under the
	360	* idiom "pathological case". It should, at least, not be
	361	* a security problem.
	362	*/
	363	flog(LOG_INFO, "accesslog: received SIGHUP, but logfile has not changed, so ignoring");
	364	return;
	365	}
	366	}
	367	}
f99bcc64 FT	368	if((new = fopen(outname, "a")) == NULL) {
	369	flog(LOG_WARNING, "accesslog: could not reopen log file `%s' on SIGHUP: %s", outname, strerror(errno));
	370	return;
	371	}
e09f3227	372	fcntl(fileno(new), F_SETFD, FD_CLOEXEC);
ca170d77 FT	373	if(locklog) {
	374	if(lockfile(new)) {
	375	if((errno == EAGAIN) \|\| (errno == EACCES)) {
	376	flog(LOG_ERR, "accesslog: logfile is already locked; reverting to current log", strerror(errno));
	377	fclose(new);
	378	return;
	379	} else {
	380	flog(LOG_WARNING, "accesslog: could not lock logfile, so no lock will be held: %s", strerror(errno));
	381	}
	382	}
	383	}
f99bcc64 FT	384	fclose(out);
	385	out = new;
	386	}
	387
5c805444 FT	388	static void listenloop(struct muth *mt, va_list args)
	389	{
	390	vavar(int, lfd);
	391	int fd;
	392	struct hthead *req;
	393
	394	while(1) {
	395	block(lfd, EV_READ, 0);
	396	if((fd = recvreq(lfd, &req)) < 0) {
	397	if(errno != 0)
	398	flog(LOG_ERR, "accesslog: error in recvreq: %s", strerror(errno));
	399	exit(1);
	400	}
	401	mustart(filterreq, req, fd);
	402	}
	403	}
	404
	405	static void chwatch(struct muth *mt, va_list args)
	406	{
	407	vavar(int, cfd);
	408
	409	block(cfd, EV_READ, 0);
	410	exitioloop(1);
	411	}
	412
	413	static void floop(void)
	414	{
	415	mustart(listenloop, 0);
	416	mustart(chwatch, ch);
	417	while(1) {
	418	switch(ioloop()) {
	419	case 0:
	420	case 1:
	421	return;
	422	case 2:
	423	reopenlog();
	424	break;
	425	}
	426	}
	427	}
	428
	429	static void sloop(void)
	430	{
	431	int fd, ret;
	432	struct hthead *req;
	433	struct pollfd pfd[2];
	434
	435	while(1) {
	436	if(reopen) {
	437	reopenlog();
	438	reopen = 0;
	439	}
	440	memset(pfd, 0, sizeof(pfd));
	441	pfd[0].fd = 0;
	442	pfd[0].events = POLLIN;
	443	pfd[1].fd = ch;
	444	pfd[1].events = POLLHUP;
	445	if((ret = poll(pfd, 2, -1)) < 0) {
	446	if(errno != EINTR) {
	447	flog(LOG_ERR, "accesslog: error in poll: %s", strerror(errno));
	448	exit(1);
	449	}
	450	}
	451	if(pfd[0].revents) {
452	if((fd = recvreq(0, &req)) < 0) {
453	if(errno == 0)
454	return;
455	flog(LOG_ERR, "accesslog: error in recvreq: %s", strerror(errno));
456	exit(1);
457	}
458	serve(req, fd);
459	freehthead(req);
460	close(fd);
461	}
462	if(pfd[1].revents & POLLHUP)
463	return;
464	}
465	}
466
048ac115 FT	467	static void usage(FILE *out)
048ac115 FT	468	{
ca170d77	469	fprintf(out, "usage: accesslog [-hFaL] [-f FORMAT] [-p PIDFILE] OUTFILE CHILD [ARGS...]\n");
e51483a1	470	fprintf(out, " accesslog -P LOGFILE\n");
048ac115 FT	471	}
	472
	473	int main(int argc, char **argv)
	474	{
5c805444	475	int c;
472abd3c FT	476	char *pidfile;
472abd3c FT	477	FILE *pidout;
048ac115	478
472abd3c	479	pidfile = NULL;
5c805444	480	while((c = getopt(argc, argv, "+hFaeLf:p:P:")) >= 0) {
048ac115 FT	481	switch(c) {
	482	case 'h':
	483	usage(stdout);
	484	exit(0);
048ac115 FT	485	case 'F':
	486	flush = 0;
	487	break;
ca170d77 FT	488	case 'L':
	489	locklog = 0;
	490	break;
5c805444 FT	491	case 'e':
	492	filter = 1;
	493	break;
048ac115 FT	494	case 'f':
	495	format = optarg;
	496	break;
ca170d77 FT	497	case 'P':
	498	fetchpid(optarg);
	499	exit(0);
472abd3c FT	500	case 'p':
	501	pidfile = optarg;
	502	break;
048ac115	503	case 'a':
5c805444	504	format = "%A - - [%{%d/%b/%Y:%H:%M:%S %z}t] \"%m %u %v\" %c %o \"%R\" \"%G\"";
048ac115 FT	505	break;
	506	default:
	507	usage(stderr);
	508	exit(1);
	509	}
	510	}
9701afc5	511	if(argc - optind < 2) {
048ac115 FT	512	usage(stderr);
	513	exit(1);
	514	}
	515	if(format == NULL)
	516	format = DEFFORMAT;
f99bcc64 FT	517	if(!strcmp(argv[optind], "-"))
	518	outname = NULL;
	519	else
	520	outname = argv[optind];
	521	if(outname == NULL) {
9701afc5	522	out = stdout;
e09f3227	523	locklog = 0;
9701afc5 FT	524	} else {
	525	if((out = fopen(argv[optind], "a")) == NULL) {
	526	flog(LOG_ERR, "accesslog: could not open %s for logging: %s", argv[optind], strerror(errno));
048ac115 FT	527	exit(1);
048ac115 FT	528	}
e09f3227	529	fcntl(fileno(out), F_SETFD, FD_CLOEXEC);
048ac115	530	}
ca170d77 FT	531	if(locklog) {
	532	if(lockfile(out)) {
	533	if((errno == EAGAIN) \|\| (errno == EACCES)) {
	534	flog(LOG_ERR, "accesslog: logfile is already locked", strerror(errno));
	535	exit(1);
	536	} else {
	537	flog(LOG_WARNING, "accesslog: could not lock logfile: %s", strerror(errno));
	538	}
	539	}
	540	}
9701afc5	541	if((ch = stdmkchild(argv + optind + 1, NULL, NULL)) < 0) {
e3f12675	542	flog(LOG_ERR, "accesslog: could not fork child: %s", strerror(errno));
048ac115 FT	543	exit(1);
048ac115 FT	544	}
f99bcc64	545	signal(SIGHUP, sighandler);
472abd3c FT	546	if(pidfile) {
	547	if(!strcmp(pidfile, "-")) {
	548	if(!outname) {
	549	flog(LOG_ERR, "accesslog: cannot derive PID file name without an output file");
	550	exit(1);
	551	}
	552	pidfile = sprintf2("%s.pid", outname);
	553	}
	554	if((pidout = fopen(pidfile, "w")) == NULL) {
	555	flog(LOG_ERR, "accesslog: could not open PID file %s for writing: %s", pidfile);
	556	exit(1);
	557	}
	558	fprintf(pidout, "%i\n", (int)getpid());
	559	fclose(pidout);
	560	}
5c805444 FT	561	if(filter)
	562	floop();
	563	else
	564	sloop();
f95bc205	565	fclose(out);
472abd3c FT	566	if(pidfile != NULL)
472abd3c FT	567	unlink(pidfile);
048ac115 FT	568	return(0);
048ac115 FT	569	}