[ashd.git] / src / callcgi.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 <string.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <ctype.h>
#include <signal.h>

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

static char **environ;

static void passdata(FILE *in, FILE *out)
{
    int ret;
    char *buf;
    
    buf = smalloc(65536);
    while(!feof(in)) {
	ret = fread(buf, 1, 65536, in);
	if(ferror(in)) {
	    flog(LOG_ERR, "sendfile: could not read input: %s", strerror(errno));
	    break;
	}
	if(fwrite(buf, 1, ret, out) != ret) {
	    flog(LOG_ERR, "sendfile: could not write output: %s", strerror(errno));
	    break;
	}
    }
    free(buf);
}

static char *absolutify(char *file)
{
    char cwd[1024];
    
    if(*file != '/') {
	getcwd(cwd, sizeof(cwd));
	return(sprintf2("%s/%s", cwd, file));
    }
    return(sstrdup(file));
}

static void forkchild(int inpath, char *prog, char *file, char *method, char *url, char *rest, int *infd, int *outfd)
{
    int i;
    char *qp, **env, *name;
    int inp[2], outp[2];
    pid_t pid;

    pipe(inp);
    pipe(outp);
    if((pid = fork()) < 0) {
	flog(LOG_ERR, "callcgi: could not fork");
	exit(1);
    }
    if(pid == 0) {
	close(inp[1]);
	close(outp[0]);
	dup2(inp[0], 0);
	dup2(outp[1], 1);
	for(i = 3; i < FD_SETSIZE; i++)
	    close(i);
	if((qp = strchr(url, '?')) != NULL)
	    *(qp++) = 0;
	putenv(sprintf2("SERVER_SOFTWARE=ashd/%s", VERSION));
	putenv("GATEWAY_INTERFACE=CGI/1.1");
	if(getenv("HTTP_VERSION"))
	    putenv(sprintf2("SERVER_PROTOCOL=%s", getenv("HTTP_VERSION")));
	putenv(sprintf2("REQUEST_METHOD=%s", method));
	putenv(sprintf2("PATH_INFO=%s", rest));
	name = url;
	/* XXX: This is an ugly hack (I think), but though I can think
	 * of several alternatives, none seem to be better. */
	if(*rest && (strlen(url) >= strlen(rest)) &&
	   !strcmp(rest, url + strlen(url) - strlen(rest))) {
	    name = sprintf2("%.*s", (int)(strlen(url) - strlen(rest)), url);
	}
	putenv(sprintf2("SCRIPT_NAME=%s", name));
	putenv(sprintf2("QUERY_STRING=%s", qp?qp:""));
	if(getenv("REQ_HOST"))
	    putenv(sprintf2("SERVER_NAME=%s", getenv("REQ_HOST")));
	if(getenv("REQ_X_ASH_SERVER_PORT"))
	    putenv(sprintf2("SERVER_PORT=%s", getenv("REQ_X_ASH_SERVER_PORT")));
	if(getenv("REQ_X_ASH_PROTOCOL") && !strcmp(getenv("REQ_X_ASH_PROTOCOL"), "https"))
	    putenv("HTTPS=on");
	if(getenv("REQ_X_ASH_ADDRESS"))
	    putenv(sprintf2("REMOTE_ADDR=%s", getenv("REQ_X_ASH_ADDRESS")));
	if(getenv("REQ_CONTENT_TYPE"))
	    putenv(sprintf2("CONTENT_TYPE=%s", getenv("REQ_CONTENT_TYPE")));
	if(getenv("REQ_CONTENT_LENGTH"))
	    putenv(sprintf2("CONTENT_LENGTH=%s", getenv("REQ_CONTENT_LENGTH")));
	for(env = environ; *env; env++) {
	    if(!strncmp(*env, "REQ_", 4))
		putenv(sprintf2("HTTP_%s", (*env) + 4));
	}
	/*
	 * This is (understandably) missing from the CGI
	 * specification, but PHP seems to require it.
	 */
	putenv(sprintf2("SCRIPT_FILENAME=%s", absolutify(file)));
	if(inpath)
	    execlp(prog, prog, file, NULL);
	else
	    execl(prog, prog, file, NULL);
	exit(127);
    }
    close(inp[0]);
    close(outp[1]);
    *infd = inp[1];
    *outfd = outp[0];
}

static void trim(struct charbuf *buf)
{
    char *p;
    
    for(p = buf->b; (p - buf->b < buf->d) && isspace(*p); p++);
    memmove(buf->b, p, buf->d -= (p - buf->b));
    for(p = buf->b + buf->d - 1; (p > buf->b) && isspace(*p); p--, buf->d--);
}

static char **parseheaders(FILE *s)
{
    int c, state;
    struct charvbuf hbuf;
    struct charbuf buf;
    
    bufinit(hbuf);
    bufinit(buf);
    state = 0;
    while(1) {
	c = fgetc(s);
    again:
	if(state == 0) {
	    if(c == '\r') {
	    } else if(c == '\n') {
		break;
	    } else if(c == EOF) {
		goto fail;
	    } else {
		state = 1;
		goto again;
	    }
	} else if(state == 1) {
	    if(c == ':') {
		trim(&buf);
		bufadd(buf, 0);
		bufadd(hbuf, buf.b);
		bufinit(buf);
		state = 2;
	    } else if(c == '\r') {
	    } else if(c == '\n') {
		goto fail;
	    } else if(c == EOF) {
		goto fail;
	    } else {
		bufadd(buf, c);
	    }
	} else if(state == 2) {
	    if(c == '\r') {
	    } else if(c == '\n') {
		trim(&buf);
		bufadd(buf, 0);
		bufadd(hbuf, buf.b);
		bufinit(buf);
		state = 0;
	    } else if(c == EOF) {
		goto fail;
	    } else {
		bufadd(buf, c);
	    }
	}
    }
    bufadd(hbuf, NULL);
    return(hbuf.b);
    
fail:
    buffree(hbuf);
    buffree(buf);
    return(NULL);
}

static char *defstatus(int code)
{
    if(code == 200)
	return("OK");
    else if(code == 201)
	return("Created");
    else if(code == 202)
	return("Accepted");
    else if(code == 204)
	return("No Content");
    else if(code == 300)
	return("Multiple Choices");
    else if(code == 301)
	return("Moved Permanently");
    else if(code == 302)
	return("Found");
    else if(code == 303)
	return("See Other");
    else if(code == 304)
	return("Not Modified");
    else if(code == 307)
	return("Moved Temporarily");
    else if(code == 400)
	return("Bad Request");
    else if(code == 401)
	return("Unauthorized");
    else if(code == 403)
	return("Forbidden");
    else if(code == 404)
	return("Not Found");
    else if(code == 500)
	return("Internal Server Error");
    else if(code == 501)
	return("Not Implemented");
    else if(code == 503)
	return("Service Unavailable");
    else
	return("Unknown status");
}

static void sendstatus(char **headers, FILE *out)
{
    char **hp;
    char *status, *location;
    
    hp = headers;
    status = location = NULL;
    while(*hp) {
	if(!strcasecmp(hp[0], "status")) {
	    status = hp[1];
	    /* Clear this header, so that it is not transmitted by sendheaders. */
	    **hp = 0;
	} else if(!strcasecmp(hp[0], "location")) {
	    location = hp[1];
	    hp += 2;
	} else {
	    hp += 2;
	}
    }
    if(status) {
	if(strchr(status, ' '))
	    fprintf(out, "HTTP/1.1 %s\n", status);
	else
	    fprintf(out, "HTTP/1.1 %i %s\n", atoi(status), defstatus(atoi(status)));
    } else if(location) {
	fprintf(out, "HTTP/1.1 303 See Other\n");
    } else {
	fprintf(out, "HTTP/1.1 200 OK\n");
    }
}

static void sendheaders(char **headers, FILE *out)
{
    while(*headers) {
	if(**headers)
	    fprintf(out, "%s: %s\n", headers[0], headers[1]);
	headers += 2;
    }
}

static void usage(void)
{
    flog(LOG_ERR, "usage: callcgi [-c] [-p PROGRAM] METHOD URL REST");
}

int main(int argc, char **argv, char **envp)
{
    int c;
    char *file, *prog, *sp;
    int inpath, cd;
    int infd, outfd;
    FILE *in, *out;
    char **headers;
    
    environ = envp;
    signal(SIGPIPE, SIG_IGN);
    
    prog = NULL;
    inpath = 0;
    cd = 0;
    while((c = getopt(argc, argv, "cp:")) >= 0) {
	switch(c) {
	case 'c':
	    cd = 1;
	    break;
	case 'p':
	    prog = optarg;
	    inpath = 1;
	    break;
	default:
	    usage();
	    exit(1);
	}
    }
    
    if(argc - optind < 3) {
	usage();
	exit(1);
    }
    if((file = getenv("REQ_X_ASH_FILE")) == NULL) {
	flog(LOG_ERR, "callcgi: needs to be called with the X-Ash-File header");
	exit(1);
    }
    
    if(cd) {
	/* This behavior is encouraged by the CGI specification (RFC 3875, 7.2),
	 * but not strictly required, and I get the feeling it might break some
	 * relative paths here or there, so it's not the default for now. */
	if((sp = strrchr(file, '/')) != NULL) {
	    *sp = 0;
	    if(chdir(file)) {
		*sp = '/';
	    } else {
		file = sp + 1;
	    }
	}
    }
    
    if(prog == NULL)
	prog = file;
    forkchild(inpath, prog, file, argv[optind], argv[optind + 1], argv[optind + 2], &infd, &outfd);
    in = fdopen(infd, "w");
    passdata(stdin, in);
    fclose(in);
    out = fdopen(outfd, "r");
    if((headers = parseheaders(out)) == NULL) {
	flog(LOG_WARNING, "CGI handler returned invalid headers");
	exit(1);
    }
    sendstatus(headers, stdout);
    sendheaders(headers, stdout);
    printf("\n");
    passdata(out, stdout);
    return(0);
}
Commit	Line	Data
8cc51634 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 <string.h>
	21	#include <stdio.h>
	22	#include <unistd.h>
	23	#include <errno.h>
	24	#include <ctype.h>
	25	#include <signal.h>
	26
	27	#ifdef HAVE_CONFIG_H
	28	#include <config.h>
	29	#endif
	30	#include <utils.h>
	31	#include <log.h>
	32
	33	static char **environ;
	34
	35	static void passdata(FILE in, FILE out)
	36	{
	37	int ret;
	38	char *buf;
	39
	40	buf = smalloc(65536);
	41	while(!feof(in)) {
	42	ret = fread(buf, 1, 65536, in);
	43	if(ferror(in)) {
	44	flog(LOG_ERR, "sendfile: could not read input: %s", strerror(errno));
	45	break;
	46	}
	47	if(fwrite(buf, 1, ret, out) != ret) {
	48	flog(LOG_ERR, "sendfile: could not write output: %s", strerror(errno));
	49	break;
	50	}
	51	}
	52	free(buf);
	53	}
	54
bac8c1f9 FT	55	static char absolutify(char file)
	56	{
	57	char cwd[1024];
	58
	59	if(*file != '/') {
	60	getcwd(cwd, sizeof(cwd));
	61	return(sprintf2("%s/%s", cwd, file));
	62	}
	63	return(sstrdup(file));
	64	}
	65
341b3f0b	66	static void forkchild(int inpath, char prog, char file, char method, char url, char rest, int infd, int *outfd)
8cc51634 FT	67	{
8cc51634 FT	68	int i;
85059e82	69	char qp, env, name;
8cc51634 FT	70	int inp[2], outp[2];
	71	pid_t pid;
	72
	73	pipe(inp);
	74	pipe(outp);
	75	if((pid = fork()) < 0) {
	76	flog(LOG_ERR, "callcgi: could not fork");
	77	exit(1);
	78	}
	79	if(pid == 0) {
	80	close(inp[1]);
	81	close(outp[0]);
	82	dup2(inp[0], 0);
	83	dup2(outp[1], 1);
	84	for(i = 3; i < FD_SETSIZE; i++)
	85	close(i);
	86	if((qp = strchr(url, '?')) != NULL)
	87	*(qp++) = 0;
8cc51634 FT	88	putenv(sprintf2("SERVER_SOFTWARE=ashd/%s", VERSION));
	89	putenv("GATEWAY_INTERFACE=CGI/1.1");
	90	if(getenv("HTTP_VERSION"))
147c2b51	91	putenv(sprintf2("SERVER_PROTOCOL=%s", getenv("HTTP_VERSION")));
8cc51634	92	putenv(sprintf2("REQUEST_METHOD=%s", method));
2d65add0	93	putenv(sprintf2("PATH_INFO=%s", rest));
85059e82 FT	94	name = url;
	95	/* XXX: This is an ugly hack (I think), but though I can think
	96	* of several alternatives, none seem to be better. */
2d65add0 FT	97	if(*rest && (strlen(url) >= strlen(rest)) &&
	98	!strcmp(rest, url + strlen(url) - strlen(rest))) {
	99	name = sprintf2("%.*s", (int)(strlen(url) - strlen(rest)), url);
85059e82 FT	100	}
85059e82 FT	101	putenv(sprintf2("SCRIPT_NAME=%s", name));
8cc51634 FT	102	putenv(sprintf2("QUERY_STRING=%s", qp?qp:""));
	103	if(getenv("REQ_HOST"))
	104	putenv(sprintf2("SERVER_NAME=%s", getenv("REQ_HOST")));
8626e489 FT	105	if(getenv("REQ_X_ASH_SERVER_PORT"))
	106	putenv(sprintf2("SERVER_PORT=%s", getenv("REQ_X_ASH_SERVER_PORT")));
	107	if(getenv("REQ_X_ASH_PROTOCOL") && !strcmp(getenv("REQ_X_ASH_PROTOCOL"), "https"))
f0a758cc	108	putenv("HTTPS=on");
8cc51634 FT	109	if(getenv("REQ_X_ASH_ADDRESS"))
	110	putenv(sprintf2("REMOTE_ADDR=%s", getenv("REQ_X_ASH_ADDRESS")));
	111	if(getenv("REQ_CONTENT_TYPE"))
	112	putenv(sprintf2("CONTENT_TYPE=%s", getenv("REQ_CONTENT_TYPE")));
	113	if(getenv("REQ_CONTENT_LENGTH"))
	114	putenv(sprintf2("CONTENT_LENGTH=%s", getenv("REQ_CONTENT_LENGTH")));
	115	for(env = environ; *env; env++) {
	116	if(!strncmp(*env, "REQ_", 4))
	117	putenv(sprintf2("HTTP_%s", (*env) + 4));
	118	}
	119	/*
	120	* This is (understandably) missing from the CGI
	121	* specification, but PHP seems to require it.
	122	*/
bac8c1f9	123	putenv(sprintf2("SCRIPT_FILENAME=%s", absolutify(file)));
341b3f0b FT	124	if(inpath)
	125	execlp(prog, prog, file, NULL);
	126	else
	127	execl(prog, prog, file, NULL);
8cc51634 FT	128	exit(127);
	129	}
	130	close(inp[0]);
	131	close(outp[1]);
	132	*infd = inp[1];
	133	*outfd = outp[0];
	134	}
	135
	136	static void trim(struct charbuf *buf)
	137	{
	138	char *p;
	139
	140	for(p = buf->b; (p - buf->b < buf->d) && isspace(*p); p++);
	141	memmove(buf->b, p, buf->d -= (p - buf->b));
	142	for(p = buf->b + buf->d - 1; (p > buf->b) && isspace(*p); p--, buf->d--);
	143	}
	144
	145	static char *parseheaders(FILE s)
	146	{
	147	int c, state;
	148	struct charvbuf hbuf;
	149	struct charbuf buf;
	150
	151	bufinit(hbuf);
	152	bufinit(buf);
	153	state = 0;
	154	while(1) {
	155	c = fgetc(s);
	156	again:
	157	if(state == 0) {
	158	if(c == '\r') {
	159	} else if(c == '\n') {
	160	break;
	161	} else if(c == EOF) {
	162	goto fail;
	163	} else {
	164	state = 1;
	165	goto again;
	166	}
	167	} else if(state == 1) {
	168	if(c == ':') {
	169	trim(&buf);
	170	bufadd(buf, 0);
	171	bufadd(hbuf, buf.b);
	172	bufinit(buf);
	173	state = 2;
	174	} else if(c == '\r') {
	175	} else if(c == '\n') {
	176	goto fail;
	177	} else if(c == EOF) {
	178	goto fail;
	179	} else {
	180	bufadd(buf, c);
	181	}
	182	} else if(state == 2) {
	183	if(c == '\r') {
	184	} else if(c == '\n') {
	185	trim(&buf);
	186	bufadd(buf, 0);
	187	bufadd(hbuf, buf.b);
	188	bufinit(buf);
	189	state = 0;
	190	} else if(c == EOF) {
	191	goto fail;
192	} else {
193	bufadd(buf, c);
194	}
195	}
196	}
197	bufadd(hbuf, NULL);
198	return(hbuf.b);
199
200	fail:
201	buffree(hbuf);
202	buffree(buf);
203	return(NULL);
204	}
205
2e535ab0 FT	206	static char *defstatus(int code)
	207	{
	208	if(code == 200)
	209	return("OK");
	210	else if(code == 201)
	211	return("Created");
	212	else if(code == 202)
	213	return("Accepted");
	214	else if(code == 204)
	215	return("No Content");
	216	else if(code == 300)
	217	return("Multiple Choices");
	218	else if(code == 301)
	219	return("Moved Permanently");
	220	else if(code == 302)
	221	return("Found");
	222	else if(code == 303)
	223	return("See Other");
	224	else if(code == 304)
	225	return("Not Modified");
	226	else if(code == 307)
	227	return("Moved Temporarily");
	228	else if(code == 400)
	229	return("Bad Request");
	230	else if(code == 401)
	231	return("Unauthorized");
	232	else if(code == 403)
	233	return("Forbidden");
	234	else if(code == 404)
	235	return("Not Found");
	236	else if(code == 500)
	237	return("Internal Server Error");
	238	else if(code == 501)
	239	return("Not Implemented");
	240	else if(code == 503)
	241	return("Service Unavailable");
	242	else
	243	return("Unknown status");
	244	}
	245
8cc51634 FT	246	static void sendstatus(char *headers, FILE out)
	247	{
	248	char **hp;
	249	char status, location;
	250
	251	hp = headers;
	252	status = location = NULL;
	253	while(*hp) {
	254	if(!strcasecmp(hp[0], "status")) {
	255	status = hp[1];
	256	/* Clear this header, so that it is not transmitted by sendheaders. */
	257	**hp = 0;
	258	} else if(!strcasecmp(hp[0], "location")) {
	259	location = hp[1];
f9255ddd	260	hp += 2;
8cc51634 FT	261	} else {
	262	hp += 2;
	263	}
	264	}
	265	if(status) {
2e535ab0	266	if(strchr(status, ' '))
81cfca6c	267	fprintf(out, "HTTP/1.1 %s\n", status);
2e535ab0	268	else
81cfca6c	269	fprintf(out, "HTTP/1.1 %i %s\n", atoi(status), defstatus(atoi(status)));
8cc51634	270	} else if(location) {
81cfca6c	271	fprintf(out, "HTTP/1.1 303 See Other\n");
8cc51634	272	} else {
81cfca6c	273	fprintf(out, "HTTP/1.1 200 OK\n");
8cc51634 FT	274	}
	275	}
	276
	277	static void sendheaders(char *headers, FILE out)
	278	{
	279	while(*headers) {
	280	if(**headers)
81cfca6c	281	fprintf(out, "%s: %s\n", headers[0], headers[1]);
8cc51634 FT	282	headers += 2;
	283	}
	284	}
	285
341b3f0b FT	286	static void usage(void)
341b3f0b FT	287	{
5e74f3f1	288	flog(LOG_ERR, "usage: callcgi [-c] [-p PROGRAM] METHOD URL REST");
341b3f0b FT	289	}
341b3f0b FT	290
8cc51634 FT	291	int main(int argc, char argv, char envp)
8cc51634 FT	292	{
341b3f0b	293	int c;
5e74f3f1 FT	294	char file, prog, *sp;
5e74f3f1 FT	295	int inpath, cd;
341b3f0b FT	296	int infd, outfd;
341b3f0b FT	297	FILE in, out;
8cc51634 FT	298	char **headers;
	299
	300	environ = envp;
	301	signal(SIGPIPE, SIG_IGN);
341b3f0b FT	302
	303	prog = NULL;
	304	inpath = 0;
5e74f3f1 FT	305	cd = 0;
5e74f3f1 FT	306	while((c = getopt(argc, argv, "cp:")) >= 0) {
341b3f0b	307	switch(c) {
5e74f3f1 FT	308	case 'c':
	309	cd = 1;
	310	break;
341b3f0b FT	311	case 'p':
	312	prog = optarg;
	313	inpath = 1;
	314	break;
	315	default:
	316	usage();
	317	exit(1);
	318	}
	319	}
	320
	321	if(argc - optind < 3) {
	322	usage();
8cc51634 FT	323	exit(1);
	324	}
	325	if((file = getenv("REQ_X_ASH_FILE")) == NULL) {
	326	flog(LOG_ERR, "callcgi: needs to be called with the X-Ash-File header");
	327	exit(1);
	328	}
5e74f3f1 FT	329
	330	if(cd) {
	331	/* This behavior is encouraged by the CGI specification (RFC 3875, 7.2),
	332	* but not strictly required, and I get the feeling it might break some
	333	* relative paths here or there, so it's not the default for now. */
	334	if((sp = strrchr(file, '/')) != NULL) {
	335	*sp = 0;
	336	if(chdir(file)) {
	337	*sp = '/';
	338	} else {
	339	file = sp + 1;
	340	}
	341	}
	342	}
	343
341b3f0b FT	344	if(prog == NULL)
	345	prog = file;
	346	forkchild(inpath, prog, file, argv[optind], argv[optind + 1], argv[optind + 2], &infd, &outfd);
	347	in = fdopen(infd, "w");
	348	passdata(stdin, in);
	349	fclose(in);
	350	out = fdopen(outfd, "r");
	351	if((headers = parseheaders(out)) == NULL) {
8cc51634 FT	352	flog(LOG_WARNING, "CGI handler returned invalid headers");
	353	exit(1);
	354	}
	355	sendstatus(headers, stdout);
	356	sendheaders(headers, stdout);
81cfca6c	357	printf("\n");
341b3f0b	358	passdata(out, stdout);
8cc51634 FT	359	return(0);
8cc51634 FT	360	}