[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 <sys/stat.h>

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

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

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

static void qputs(char *s, FILE *o)
{
    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", *s);
	} else {
	    fputc(*s, o);
	}
    }
}

static void logitem(struct hthead *req, char o, char *d)
{
    char *h, *p;
    char buf[1024];
    
    switch(o) {
    case '%':
	putc('%', out);
	break;
    case 'h':
	if((h = getheader(req, d)) == NULL) {
	    putc('-', out);
	} else {
	    qputs(h, out);
	}
	break;
    case 'u':
	qputs(req->url, out);
	break;
    case 'U':
	strcpy(buf, req->url);
	if((p = strchr(buf, '?')) != NULL)
	    *p = 0;
	qputs(buf, out);
	break;
    case 'm':
	qputs(req->method, out);
	break;
    case 'r':
	qputs(req->rest, out);
	break;
    case 'v':
	qputs(req->ver, out);
	break;
    case 't':
	if(!*d)
	    d = "%a, %d %b %Y %H:%M:%S %z";
	strftime(buf, sizeof(buf), d, localtime(&now.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(&now.tv_sec));
	qputs(buf, out);
	break;
    case 's':
	fprintf(out, "%06i", (int)now.tv_usec);
	break;
    case 'A':
	logitem(req, 'h', "X-Ash-Address");
	break;
    case 'H':
	logitem(req, 'h', "Host");
	break;
    case 'R':
	logitem(req, 'h', "Referer");
	break;
    case 'G':
	logitem(req, 'h', "User-Agent");
	break;
    }
}

static void logreq(struct hthead *req)
{
    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(req, o, d);
	} else {
	    fputc(*p++, out);
	}
    }
    fputc('\n', out);
    if(flush)
	fflush(out);
}

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

static void sighandler(int sig)
{
    if(sig == SIGHUP)
	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 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, ret;
    struct hthead *req;
    int fd;
    struct pollfd pfd[2];
    char *pidfile;
    FILE *pidout;
    
    pidfile = NULL;
    while((c = getopt(argc, argv, "+hFaLf:p:P:")) >= 0) {
	switch(c) {
	case 'h':
	    usage(stdout);
	    exit(0);
	case 'F':
	    flush = 0;
	    break;
	case 'L':
	    locklog = 0;
	    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\" - - \"%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);
    }
    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)
		    break;
		flog(LOG_ERR, "accesslog: error in recvreq: %s", strerror(errno));
		exit(1);
	    }
	    serve(req, fd);
	    freehthead(req);
	    close(fd);
	}
	if(pfd[1].revents & POLLHUP)
	    break;
    }
    if(pidfile != NULL)
	unlink(pidfile);
    return(0);
}
Commit	Line	Data
	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>
	27	#include <signal.h>
	28	#include <fcntl.h>
	29	#include <sys/stat.h>
	30
	31	#ifdef HAVE_CONFIG_H
	32	#include <config.h>
	33	#endif
	34	#include <utils.h>
	35	#include <log.h>
	36	#include <req.h>
	37	#include <proc.h>
	38
	39	#define DEFFORMAT "%{%Y-%m-%d %H:%M:%S}t %m %u %A \"%G\""
	40
	41	static int ch;
	42	static char *outname = NULL;
	43	static FILE *out;
	44	static int flush = 1, locklog = 1;
	45	static char *format;
	46	static struct timeval now;
	47	static volatile int reopen = 0;
	48
	49	static void qputs(char s, FILE o)
	50	{
	51	for(; *s; s++) {
	52	if(*s == '\"') {
	53	fputs("\\\"", o);
	54	} else if(*s == '\\') {
	55	fputs("\\\\", o);
	56	} else if(*s == '\n') {
	57	fputs("\\n", o);
	58	} else if(*s == '\t') {
	59	fputs("\\t", o);
	60	} else if((s < 32) \|\| (s >= 128)) {
	61	fprintf(o, "\\x%02x", *s);
	62	} else {
	63	fputc(*s, o);
	64	}
	65	}
	66	}
	67
	68	static void logitem(struct hthead req, char o, char d)
	69	{
	70	char h, p;
	71	char buf[1024];
	72
	73	switch(o) {
	74	case '%':
	75	putc('%', out);
	76	break;
	77	case 'h':
	78	if((h = getheader(req, d)) == NULL) {
	79	putc('-', out);
	80	} else {
	81	qputs(h, out);
	82	}
	83	break;
	84	case 'u':
	85	qputs(req->url, out);
	86	break;
	87	case 'U':
	88	strcpy(buf, req->url);
	89	if((p = strchr(buf, '?')) != NULL)
	90	*p = 0;
	91	qputs(buf, out);
	92	break;
	93	case 'm':
	94	qputs(req->method, out);
	95	break;
	96	case 'r':
	97	qputs(req->rest, out);
	98	break;
	99	case 'v':
	100	qputs(req->ver, out);
	101	break;
	102	case 't':
	103	if(!*d)
	104	d = "%a, %d %b %Y %H:%M:%S %z";
	105	strftime(buf, sizeof(buf), d, localtime(&now.tv_sec));
	106	qputs(buf, out);
	107	break;
	108	case 'T':
	109	if(!*d)
	110	d = "%a, %d %b %Y %H:%M:%S %z";
	111	strftime(buf, sizeof(buf), d, gmtime(&now.tv_sec));
	112	qputs(buf, out);
	113	break;
	114	case 's':
	115	fprintf(out, "%06i", (int)now.tv_usec);
	116	break;
	117	case 'A':
	118	logitem(req, 'h', "X-Ash-Address");
	119	break;
	120	case 'H':
	121	logitem(req, 'h', "Host");
	122	break;
	123	case 'R':
	124	logitem(req, 'h', "Referer");
	125	break;
	126	case 'G':
	127	logitem(req, 'h', "User-Agent");
	128	break;
	129	}
	130	}
	131
	132	static void logreq(struct hthead *req)
	133	{
	134	char p, p2;
	135	char d[strlen(format)];
	136	char o;
	137
	138	p = format;
	139	while(*p) {
	140	if(*p == '%') {
	141	p++;
	142	if(*p == '{') {
	143	p++;
	144	if((p2 = strchr(p, '}')) == NULL)
	145	continue;
	146	memcpy(d, p, p2 - p);
	147	d[p2 - p] = 0;
	148	p = p2 + 1;
	149	} else {
	150	d[0] = 0;
	151	}
	152	o = *p++;
	153	if(o == 0)
	154	break;
	155	logitem(req, o, d);
	156	} else {
	157	fputc(*p++, out);
	158	}
	159	}
	160	fputc('\n', out);
	161	if(flush)
	162	fflush(out);
	163	}
	164
	165	static void serve(struct hthead *req, int fd)
	166	{
	167	gettimeofday(&now, NULL);
	168	if(sendreq(ch, req, fd)) {
	169	flog(LOG_ERR, "accesslog: could not pass request to child: %s", strerror(errno));
	170	exit(1);
	171	}
	172	logreq(req);
	173	}
	174
	175	static void sighandler(int sig)
	176	{
	177	if(sig == SIGHUP)
	178	reopen = 1;
	179	}
	180
	181	static int lockfile(FILE *file)
	182	{
	183	struct flock ld;
	184
	185	memset(&ld, 0, sizeof(ld));
	186	ld.l_type = F_WRLCK;
	187	ld.l_whence = SEEK_SET;
	188	ld.l_start = 0;
	189	ld.l_len = 0;
	190	return(fcntl(fileno(file), F_SETLK, &ld));
	191	}
	192
	193	static void fetchpid(char *filename)
	194	{
	195	int fd, ret;
	196	struct flock ld;
	197
	198	if((fd = open(filename, O_WRONLY)) < 0) {
	199	fprintf(stderr, "accesslog: %s: %s\n", filename, strerror(errno));
	200	exit(1);
	201	}
	202	memset(&ld, 0, sizeof(ld));
	203	ld.l_type = F_WRLCK;
	204	ld.l_whence = SEEK_SET;
	205	ld.l_start = 0;
	206	ld.l_len = 0;
	207	ret = fcntl(fd, F_GETLK, &ld);
	208	close(fd);
	209	if(ret) {
	210	fprintf(stderr, "accesslog: %s: %s\n", filename, strerror(errno));
	211	exit(1);
	212	}
	213	if(ld.l_type == F_UNLCK) {
	214	fprintf(stderr, "accesslog: %s: not locked\n", filename);
	215	exit(1);
	216	}
	217	printf("%i\n", (int)ld.l_pid);
	218	}
	219
	220	static void reopenlog(void)
	221	{
	222	FILE *new;
	223	struct stat olds, news;
	224
	225	if(outname == NULL) {
	226	flog(LOG_WARNING, "accesslog: received SIGHUP but logging to stdout, so ignoring");
	227	return;
	228	}
	229	if(locklog) {
	230	if(fstat(fileno(out), &olds)) {
	231	flog(LOG_ERR, "accesslog: could not stat current logfile(?!): %s", strerror(errno));
	232	return;
	233	}
	234	if(!stat(outname, &news)) {
	235	if((olds.st_dev == news.st_dev) && (olds.st_ino == news.st_ino)) {
	236	/*
	237	* This needs to be ignored, because if the same logfile
	238	* is opened and then closed, the lock is lost. To quote
	239	* the Linux fcntl(2) manpage: "This is bad." No kidding.
	240	*
	241	* Technically, there is a race condition here when the
	242	* file has been stat'ed but not yet opened, where the old
	243	* log file, having been previously renamed, changes name
	244	* back to the name accesslog knows and is thus reopened
	245	* regardlessly, but I think that might fit under the
	246	* idiom "pathological case". It should, at least, not be
	247	* a security problem.
	248	*/
	249	flog(LOG_INFO, "accesslog: received SIGHUP, but logfile has not changed, so ignoring");
	250	return;
	251	}
	252	}
	253	}
	254	if((new = fopen(outname, "a")) == NULL) {
	255	flog(LOG_WARNING, "accesslog: could not reopen log file `%s' on SIGHUP: %s", outname, strerror(errno));
	256	return;
	257	}
	258	fcntl(fileno(new), F_SETFD, FD_CLOEXEC);
	259	if(locklog) {
	260	if(lockfile(new)) {
	261	if((errno == EAGAIN) \|\| (errno == EACCES)) {
	262	flog(LOG_ERR, "accesslog: logfile is already locked; reverting to current log", strerror(errno));
	263	fclose(new);
	264	return;
	265	} else {
	266	flog(LOG_WARNING, "accesslog: could not lock logfile, so no lock will be held: %s", strerror(errno));
	267	}
	268	}
	269	}
	270	fclose(out);
	271	out = new;
	272	}
	273
	274	static void usage(FILE *out)
	275	{
	276	fprintf(out, "usage: accesslog [-hFaL] [-f FORMAT] [-p PIDFILE] OUTFILE CHILD [ARGS...]\n");
	277	fprintf(out, " accesslog -P LOGFILE\n");
	278	}
	279
	280	int main(int argc, char **argv)
	281	{
	282	int c, ret;
	283	struct hthead *req;
	284	int fd;
	285	struct pollfd pfd[2];
	286	char *pidfile;
	287	FILE *pidout;
	288
	289	pidfile = NULL;
	290	while((c = getopt(argc, argv, "+hFaLf:p:P:")) >= 0) {
	291	switch(c) {
	292	case 'h':
	293	usage(stdout);
	294	exit(0);
	295	case 'F':
	296	flush = 0;
	297	break;
	298	case 'L':
	299	locklog = 0;
	300	break;
	301	case 'f':
	302	format = optarg;
	303	break;
	304	case 'P':
	305	fetchpid(optarg);
	306	exit(0);
	307	case 'p':
	308	pidfile = optarg;
	309	break;
	310	case 'a':
	311	format = "%A - - [%{%d/%b/%Y:%H:%M:%S %z}t] \"%m %u %v\" - - \"%R\" \"%G\"";
	312	break;
	313	default:
	314	usage(stderr);
	315	exit(1);
	316	}
	317	}
	318	if(argc - optind < 2) {
	319	usage(stderr);
	320	exit(1);
	321	}
	322	if(format == NULL)
	323	format = DEFFORMAT;
	324	if(!strcmp(argv[optind], "-"))
	325	outname = NULL;
	326	else
	327	outname = argv[optind];
	328	if(outname == NULL) {
	329	out = stdout;
	330	locklog = 0;
	331	} else {
	332	if((out = fopen(argv[optind], "a")) == NULL) {
	333	flog(LOG_ERR, "accesslog: could not open %s for logging: %s", argv[optind], strerror(errno));
	334	exit(1);
	335	}
	336	fcntl(fileno(out), F_SETFD, FD_CLOEXEC);
	337	}
	338	if(locklog) {
	339	if(lockfile(out)) {
	340	if((errno == EAGAIN) \|\| (errno == EACCES)) {
	341	flog(LOG_ERR, "accesslog: logfile is already locked", strerror(errno));
	342	exit(1);
	343	} else {
	344	flog(LOG_WARNING, "accesslog: could not lock logfile: %s", strerror(errno));
	345	}
	346	}
	347	}
	348	if((ch = stdmkchild(argv + optind + 1, NULL, NULL)) < 0) {
	349	flog(LOG_ERR, "accesslog: could not fork child: %s", strerror(errno));
	350	exit(1);
	351	}
	352	signal(SIGHUP, sighandler);
	353	if(pidfile) {
	354	if(!strcmp(pidfile, "-")) {
	355	if(!outname) {
	356	flog(LOG_ERR, "accesslog: cannot derive PID file name without an output file");
	357	exit(1);
	358	}
	359	pidfile = sprintf2("%s.pid", outname);
	360	}
	361	if((pidout = fopen(pidfile, "w")) == NULL) {
	362	flog(LOG_ERR, "accesslog: could not open PID file %s for writing: %s", pidfile);
	363	exit(1);
	364	}
	365	fprintf(pidout, "%i\n", (int)getpid());
	366	fclose(pidout);
	367	}
	368	while(1) {
	369	if(reopen) {
	370	reopenlog();
	371	reopen = 0;
	372	}
	373	memset(pfd, 0, sizeof(pfd));
	374	pfd[0].fd = 0;
	375	pfd[0].events = POLLIN;
	376	pfd[1].fd = ch;
	377	pfd[1].events = POLLHUP;
	378	if((ret = poll(pfd, 2, -1)) < 0) {
	379	if(errno != EINTR) {
	380	flog(LOG_ERR, "accesslog: error in poll: %s", strerror(errno));
	381	exit(1);
	382	}
	383	}
	384	if(pfd[0].revents) {
	385	if((fd = recvreq(0, &req)) < 0) {
	386	if(errno == 0)
	387	break;
	388	flog(LOG_ERR, "accesslog: error in recvreq: %s", strerror(errno));
	389	exit(1);
	390	}
	391	serve(req, fd);
	392	freehthead(req);
	393	close(fd);
	394	}
	395	if(pfd[1].revents & POLLHUP)
	396	break;
	397	}
	398	if(pidfile != NULL)
	399	unlink(pidfile);
	400	return(0);
	401	}