[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)) &&
	   (url[strlen(url) - strlen(rest) - 1] == '/')) {
	    name = sprintf2("%.*s", (int)(strlen(url) - strlen(rest) - 1), 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 [-p PROGRAM] METHOD URL REST");
}

int main(int argc, char **argv, char **envp)
{
    int c;
    char *file, *prog;
    int inpath;
    int infd, outfd;
    FILE *in, *out;
    char **headers;
    
    environ = envp;
    signal(SIGPIPE, SIG_IGN);
    
    prog = NULL;
    inpath = 0;
    while((c = getopt(argc, argv, "p:")) >= 0) {
	switch(c) {
	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(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));
85059e82 FT	93	putenv(sprintf2("PATH_INFO=/%s", rest));
	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. */
	97	if(*rest && (strlen(url) > strlen(rest)) &&
	98	!strcmp(rest, url + strlen(url) - strlen(rest)) &&
	99	(url[strlen(url) - strlen(rest) - 1] == '/')) {
	100	name = sprintf2("%.*s", (int)(strlen(url) - strlen(rest) - 1), url);
	101	}
	102	putenv(sprintf2("SCRIPT_NAME=%s", name));
8cc51634 FT	103	putenv(sprintf2("QUERY_STRING=%s", qp?qp:""));
	104	if(getenv("REQ_HOST"))
	105	putenv(sprintf2("SERVER_NAME=%s", getenv("REQ_HOST")));
8626e489 FT	106	if(getenv("REQ_X_ASH_SERVER_PORT"))
	107	putenv(sprintf2("SERVER_PORT=%s", getenv("REQ_X_ASH_SERVER_PORT")));
	108	if(getenv("REQ_X_ASH_PROTOCOL") && !strcmp(getenv("REQ_X_ASH_PROTOCOL"), "https"))
	109	putenv("HTTPS=ON");
8cc51634 FT	110	if(getenv("REQ_X_ASH_ADDRESS"))
	111	putenv(sprintf2("REMOTE_ADDR=%s", getenv("REQ_X_ASH_ADDRESS")));
	112	if(getenv("REQ_CONTENT_TYPE"))
	113	putenv(sprintf2("CONTENT_TYPE=%s", getenv("REQ_CONTENT_TYPE")));
	114	if(getenv("REQ_CONTENT_LENGTH"))
	115	putenv(sprintf2("CONTENT_LENGTH=%s", getenv("REQ_CONTENT_LENGTH")));
	116	for(env = environ; *env; env++) {
	117	if(!strncmp(*env, "REQ_", 4))
	118	putenv(sprintf2("HTTP_%s", (*env) + 4));
	119	}
	120	/*
	121	* This is (understandably) missing from the CGI
	122	* specification, but PHP seems to require it.
	123	*/
bac8c1f9	124	putenv(sprintf2("SCRIPT_FILENAME=%s", absolutify(file)));
341b3f0b FT	125	if(inpath)
	126	execlp(prog, prog, file, NULL);
	127	else
	128	execl(prog, prog, file, NULL);
8cc51634 FT	129	exit(127);
	130	}
	131	close(inp[0]);
	132	close(outp[1]);
	133	*infd = inp[1];
	134	*outfd = outp[0];
	135	}
	136
	137	static void trim(struct charbuf *buf)
	138	{
	139	char *p;
	140
	141	for(p = buf->b; (p - buf->b < buf->d) && isspace(*p); p++);
	142	memmove(buf->b, p, buf->d -= (p - buf->b));
	143	for(p = buf->b + buf->d - 1; (p > buf->b) && isspace(*p); p--, buf->d--);
	144	}
	145
	146	static char *parseheaders(FILE s)
	147	{
	148	int c, state;
	149	struct charvbuf hbuf;
	150	struct charbuf buf;
	151
	152	bufinit(hbuf);
	153	bufinit(buf);
	154	state = 0;
	155	while(1) {
	156	c = fgetc(s);
	157	again:
	158	if(state == 0) {
	159	if(c == '\r') {
	160	} else if(c == '\n') {
	161	break;
	162	} else if(c == EOF) {
	163	goto fail;
	164	} else {
	165	state = 1;
	166	goto again;
	167	}
	168	} else if(state == 1) {
	169	if(c == ':') {
	170	trim(&buf);
	171	bufadd(buf, 0);
	172	bufadd(hbuf, buf.b);
	173	bufinit(buf);
	174	state = 2;
	175	} else if(c == '\r') {
	176	} else if(c == '\n') {
	177	goto fail;
	178	} else if(c == EOF) {
	179	goto fail;
	180	} else {
	181	bufadd(buf, c);
	182	}
	183	} else if(state == 2) {
	184	if(c == '\r') {
	185	} else if(c == '\n') {
	186	trim(&buf);
	187	bufadd(buf, 0);
	188	bufadd(hbuf, buf.b);
	189	bufinit(buf);
	190	state = 0;
	191	} else if(c == EOF) {
	192	goto fail;
193	} else {
194	bufadd(buf, c);
195	}
196	}
197	}
198	bufadd(hbuf, NULL);
199	return(hbuf.b);
200
201	fail:
202	buffree(hbuf);
203	buffree(buf);
204	return(NULL);
205	}
206
2e535ab0 FT	207	static char *defstatus(int code)
	208	{
	209	if(code == 200)
	210	return("OK");
	211	else if(code == 201)
	212	return("Created");
	213	else if(code == 202)
	214	return("Accepted");
	215	else if(code == 204)
	216	return("No Content");
	217	else if(code == 300)
	218	return("Multiple Choices");
	219	else if(code == 301)
	220	return("Moved Permanently");
	221	else if(code == 302)
	222	return("Found");
	223	else if(code == 303)
	224	return("See Other");
	225	else if(code == 304)
	226	return("Not Modified");
	227	else if(code == 307)
	228	return("Moved Temporarily");
	229	else if(code == 400)
	230	return("Bad Request");
	231	else if(code == 401)
	232	return("Unauthorized");
	233	else if(code == 403)
	234	return("Forbidden");
	235	else if(code == 404)
	236	return("Not Found");
	237	else if(code == 500)
	238	return("Internal Server Error");
	239	else if(code == 501)
	240	return("Not Implemented");
	241	else if(code == 503)
	242	return("Service Unavailable");
	243	else
	244	return("Unknown status");
	245	}
	246
8cc51634 FT	247	static void sendstatus(char *headers, FILE out)
	248	{
	249	char **hp;
	250	char status, location;
	251
	252	hp = headers;
	253	status = location = NULL;
	254	while(*hp) {
	255	if(!strcasecmp(hp[0], "status")) {
	256	status = hp[1];
	257	/* Clear this header, so that it is not transmitted by sendheaders. */
	258	**hp = 0;
	259	} else if(!strcasecmp(hp[0], "location")) {
	260	location = hp[1];
f9255ddd	261	hp += 2;
8cc51634 FT	262	} else {
	263	hp += 2;
	264	}
	265	}
	266	if(status) {
2e535ab0	267	if(strchr(status, ' '))
81cfca6c	268	fprintf(out, "HTTP/1.1 %s\n", status);
2e535ab0	269	else
81cfca6c	270	fprintf(out, "HTTP/1.1 %i %s\n", atoi(status), defstatus(atoi(status)));
8cc51634	271	} else if(location) {
81cfca6c	272	fprintf(out, "HTTP/1.1 303 See Other\n");
8cc51634	273	} else {
81cfca6c	274	fprintf(out, "HTTP/1.1 200 OK\n");
8cc51634 FT	275	}
	276	}
	277
	278	static void sendheaders(char *headers, FILE out)
	279	{
	280	while(*headers) {
	281	if(**headers)
81cfca6c	282	fprintf(out, "%s: %s\n", headers[0], headers[1]);
8cc51634 FT	283	headers += 2;
	284	}
	285	}
	286
341b3f0b FT	287	static void usage(void)
	288	{
	289	flog(LOG_ERR, "usage: callcgi [-p PROGRAM] METHOD URL REST");
	290	}
	291
8cc51634 FT	292	int main(int argc, char argv, char envp)
8cc51634 FT	293	{
341b3f0b FT	294	int c;
	295	char file, prog;
	296	int inpath;
	297	int infd, outfd;
	298	FILE in, out;
8cc51634 FT	299	char **headers;
	300
	301	environ = envp;
	302	signal(SIGPIPE, SIG_IGN);
341b3f0b FT	303
	304	prog = NULL;
	305	inpath = 0;
	306	while((c = getopt(argc, argv, "p:")) >= 0) {
	307	switch(c) {
	308	case 'p':
	309	prog = optarg;
	310	inpath = 1;
	311	break;
	312	default:
	313	usage();
	314	exit(1);
	315	}
	316	}
	317
	318	if(argc - optind < 3) {
	319	usage();
8cc51634 FT	320	exit(1);
	321	}
	322	if((file = getenv("REQ_X_ASH_FILE")) == NULL) {
	323	flog(LOG_ERR, "callcgi: needs to be called with the X-Ash-File header");
	324	exit(1);
	325	}
341b3f0b FT	326	if(prog == NULL)
	327	prog = file;
	328	forkchild(inpath, prog, file, argv[optind], argv[optind + 1], argv[optind + 2], &infd, &outfd);
	329	in = fdopen(infd, "w");
	330	passdata(stdin, in);
	331	fclose(in);
	332	out = fdopen(outfd, "r");
	333	if((headers = parseheaders(out)) == NULL) {
8cc51634 FT	334	flog(LOG_WARNING, "CGI handler returned invalid headers");
	335	exit(1);
	336	}
	337	sendstatus(headers, stdout);
	338	sendheaders(headers, stdout);
81cfca6c	339	printf("\n");
341b3f0b	340	passdata(out, stdout);
8cc51634 FT	341	return(0);
8cc51634 FT	342	}