[ashd.git] / src / callscgi.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/>.
*/

/*
 * XXX: All the various ways to start a child process makes this
 * program quite ugly at the moment. It is unclear whether it is
 * meaningfully possible to unify them better than they currently are.
 */

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <ctype.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <netinet/in.h>
#include <netdb.h>
#include <sys/signal.h>
#include <errno.h>

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

static char **progspec;
static char *sockid, *unspec, *inspec;
static int nolisten;
static struct sockaddr *curaddr;
static size_t caddrlen;
static int cafamily, isanon;
static pid_t child;

static struct addrinfo *resolv(int flags)
{
    int ret;
    struct addrinfo *ai, h;
    char *name, *srv, *p;
    
    if((p = strchr(inspec, ':')) != NULL) {
	name = smalloc(p - inspec + 1);
	memcpy(name, inspec, p - inspec);
	name[p - inspec] = 0;
	srv = p + 1;
    } else {
	name = sstrdup("localhost");
	srv = inspec;
    }
    memset(&h, 0, sizeof(h));
    h.ai_family = AF_UNSPEC;
    h.ai_socktype = SOCK_STREAM;
    h.ai_flags = flags;
    ret = getaddrinfo(name, srv, &h, &ai);
    free(name);
    if(ret != 0) {
	flog(LOG_ERR, "could not resolve TCP specification `%s': %s", inspec, gai_strerror(ret));
	exit(1);
    }
    return(ai);
}

static char *mksockid(char *sockid)
{
    char *home;
    
    home = getenv("HOME");
    if(home && !access(sprintf3("%s/.ashd/sockets/", home), X_OK))
	return(sprintf3("%s/.ashd/sockets/scgi-p-%s", home, sockid));
    return(sprintf3("/tmp/scgi-%i-%s", getuid(), sockid));
}

static char *mkanonid(void)
{
    char *home;
    char *tmpl;
    int fd;
    
    home = getenv("HOME");
    if(home && !access(sprintf3("%s/.ashd/sockets/", home), X_OK))
	tmpl = sprintf2("%s/.ashd/sockets/scgi-a-XXXXXX");
    else
	tmpl = sprintf2("/tmp/scgi-a-%i-XXXXXX", getuid());
    if((fd = mkstemp(tmpl)) < 0) {
	flog(LOG_ERR, "could not create anonymous socket `%s': %s", tmpl, strerror(errno));
	exit(1);
    }
    unlink(tmpl);
    return(tmpl);
}

static void startlisten(void)
{
    int i, fd;
    struct addrinfo *ai, *cai;
    char *unpath;
    struct sockaddr_un unm;
    char *aname;
    
    isanon = 0;
    if(inspec != NULL) {
	fd = -1;
	for(cai = ai = resolv(AI_PASSIVE); cai != NULL; cai = cai->ai_next) {
	    if((fd = socket(cai->ai_family, cai->ai_socktype, cai->ai_protocol)) < 0)
		continue;
	    if(bind(fd, cai->ai_addr, cai->ai_addrlen)) {
		close(fd);
		fd = -1;
		continue;
	    }
	    if(listen(fd, 128)) {
		close(fd);
		fd = -1;
		continue;
	    }
	    break;
	}
	freeaddrinfo(ai);
	if(fd < 0) {
	    flog(LOG_ERR, "could not bind to specified TCP address: %s", strerror(errno));
	    exit(1);
	}
    } else if((unspec != NULL) || (sockid != NULL)) {
	if((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
	    flog(LOG_ERR, "could not create Unix socket: %s", strerror(errno));
	    exit(1);
	}
	if(unspec != NULL)
	    unpath = unspec;
	else
	    unpath = mksockid(sockid);
	unlink(unpath);
	unm.sun_family = AF_UNIX;
	strcpy(unm.sun_path, unpath);
	if(bind(fd, (struct sockaddr *)&unm, sizeof(unm))) {
	    flog(LOG_ERR, "could not bind Unix socket to `%s': %s", unspec, strerror(errno));
	    exit(1);
	}
	if(listen(fd, 128)) {
	    flog(LOG_ERR, "listen: %s", strerror(errno));
	    exit(1);
	}
    } else {
	if((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
	    flog(LOG_ERR, "could not create Unix socket: %s", strerror(errno));
	    exit(1);
	}
	memset(&unm, 0, sizeof(unm));
	aname = mkanonid();
	unm.sun_family = AF_UNIX;
	strcpy(unm.sun_path, aname);
	free(aname);
	if(bind(fd, (struct sockaddr *)&unm, sizeof(unm))) {
	    flog(LOG_ERR, "could not bind Unix socket to `%s': %s", unspec, strerror(errno));
	    exit(1);
	}
	if(listen(fd, 128)) {
	    flog(LOG_ERR, "listen: %s", strerror(errno));
	    exit(1);
	}
	
	curaddr = smalloc(caddrlen = sizeof(unm));
	memcpy(curaddr, &unm, sizeof(unm));
	cafamily = AF_UNIX;
	isanon = 1;
    }
    if((child = fork()) < 0) {
	flog(LOG_ERR, "could not fork: %s", strerror(errno));
	exit(1);
    }
    if(child == 0) {
	dup2(fd, 0);
	for(i = 3; i < FD_SETSIZE; i++)
	    close(i);
	execvp(*progspec, progspec);
	exit(127);
    }
    close(fd);
}

static void startnolisten(void)
{
    int i;
    
    if((child = fork()) < 0) {
	flog(LOG_ERR, "could not fork: %s", strerror(errno));
	exit(1);
    }
    if(child == 0) {
	for(i = 3; i < FD_SETSIZE; i++)
	    close(i);
	execvp(*progspec, progspec);
	exit(127);
    }
}

static int sconnect(void)
{
    int fd;
    int err;
    socklen_t errlen;

    fd = socket(cafamily, SOCK_STREAM, 0);
    fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_NONBLOCK);
    while(1) {
	if(connect(fd, curaddr, caddrlen)) {
	    if(errno == EINPROGRESS) {
		block(fd, EV_WRITE, 30);
		errlen = sizeof(err);
		if(getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &errlen) || ((errno = err) != 0)) {
		    close(fd);
		    return(-1);
		}
		return(fd);
	    }
	    close(fd);
	    return(-1);
	}
	return(fd);
    }
}

static int econnect(void)
{
    int fd;
    struct addrinfo *ai, *cai;
    int tries;
    char *unpath;
    struct sockaddr_un unm;
    
    tries = 0;
retry:
    if(inspec != NULL) {
	fd = -1;
	for(cai = ai = resolv(0); cai != NULL; cai = cai->ai_next) {
	    if((fd = socket(cai->ai_family, cai->ai_socktype, cai->ai_protocol)) < 0)
		continue;
	    if(connect(fd, cai->ai_addr, cai->ai_addrlen)) {
		close(fd);
		fd = -1;
		continue;
	    }
	    break;
	}
	if(tries++ < nolisten) {
	    sleep(1);
	    goto retry;
	}
	if(fd < 0) {
	    flog(LOG_ERR, "could not connect to specified TCP address: %s", strerror(errno));
	    exit(1);
	}
	curaddr = smalloc(caddrlen = cai->ai_addrlen);
	memcpy(curaddr, cai->ai_addr, caddrlen);
	cafamily = cai->ai_family;
	isanon = 0;
	freeaddrinfo(ai);
	return(fd);
    } else if((unspec != NULL) || (sockid != NULL)) {
	if((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
	    flog(LOG_ERR, "could not create Unix socket: %s", strerror(errno));
	    exit(1);
	}
	if(unspec != NULL)
	    unpath = unspec;
	else
	    unpath = mksockid(sockid);
	unlink(unpath);
	unm.sun_family = AF_UNIX;
	strcpy(unm.sun_path, unpath);
	if(connect(fd, (struct sockaddr *)&unm, sizeof(unm))) {
	    close(fd);
	    if(tries++ < nolisten) {
		sleep(1);
		goto retry;
	    }
	    flog(LOG_ERR, "could not connect to Unix socket `%s': %s", unspec, strerror(errno));
	    exit(1);
	}
	curaddr = smalloc(caddrlen = sizeof(unm));
	memcpy(curaddr, &unm, sizeof(unm));
	cafamily = AF_UNIX;
	isanon = 0;
	return(fd);
    } else {
	flog(LOG_ERR, "servescgi: cannot use an anonymous socket without a program to start");
	exit(1);
    }
}

static int startconn(void)
{
    if(*progspec) {
	if(nolisten == 0)
	    startlisten();
	else
	    startnolisten();
    }
    if(curaddr != NULL)
	return(sconnect());
    return(econnect());
}

static void killcuraddr(void)
{
    if(curaddr == NULL)
	return;
    if(isanon) {
	unlink(((struct sockaddr_un *)curaddr)->sun_path);
	if(child > 0)
	    kill(child, SIGTERM);
    }
    free(curaddr);
    curaddr = NULL;
}

static int reconn(void)
{
    int fd;
    
    if(curaddr != NULL) {
	if((fd = sconnect()) >= 0)
	    return(fd);
	killcuraddr();
    }
    return(startconn());
}

static off_t passdata(FILE *in, FILE *out)
{
    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;
    }
    return(total);
}

static void bufaddenv(struct charbuf *dst, char *name, char *fmt, ...)
{
    va_list args;
    
    bufcatstr2(*dst, name);
    va_start(args, fmt);
    bvprintf(dst, fmt, args);
    va_end(args);
    bufadd(*dst, 0);
}

static char *absolutify(char *file)
{
    static int inited = 0;
    static char cwd[1024];
    
    if(*file != '/') {
	if(!inited) {
	    getcwd(cwd, sizeof(cwd));
	    inited = 1;
	}
	return(sprintf2("%s/%s", cwd, file));
    }
    return(sstrdup(file));
}

/* Mostly copied from callcgi. */
static void mkcgienv(struct hthead *req, struct charbuf *dst)
{
    int i;
    char *url, *qp, *h, *p;
    
    bufaddenv(dst, "SERVER_SOFTWARE", "ashd/%s", VERSION);
    bufaddenv(dst, "GATEWAY_INTERFACE", "CGI/1.1");
    bufaddenv(dst, "SCGI", "1");
    bufaddenv(dst, "SERVER_PROTOCOL", "%s", req->ver);
    bufaddenv(dst, "REQUEST_METHOD", "%s", req->method);
    bufaddenv(dst, "REQUEST_URI", "%s", req->url);
    if(*req->rest)
	bufaddenv(dst, "PATH_INFO", "/%s", req->rest);
    else
	bufaddenv(dst, "PATH_INFO", "");
    url = sstrdup(req->url);
    if((qp = strchr(url, '?')) != NULL)
	*(qp++) = 0;
    /* XXX: This is an ugly hack (I think), but though I can think of
     * several alternatives, none seem to be better. */
    if(*req->rest && (strlen(url) > strlen(req->rest)) &&
       !strcmp(req->rest, url + strlen(url) - strlen(req->rest)) &&
       (url[strlen(url) - strlen(req->rest) - 1] == '/')) {
	bufaddenv(dst, "SCRIPT_NAME", "%.*s", (int)(strlen(url) - strlen(req->rest) - 1), url);
    } else {
	bufaddenv(dst, "SCRIPT_NAME", "%s", url);
    }
    bufaddenv(dst, "QUERY_STRING", "%s", qp?qp:"");
    if((h = getheader(req, "Host")) != NULL)
	bufaddenv(dst, "SERVER_NAME", "%s", h);
    if((h = getheader(req, "X-Ash-Server-Port")) != NULL)
	bufaddenv(dst, "SERVER_PORT", "%s", h);
    if(((h = getheader(req, "X-Ash-Server-Protocol")) != NULL) && !strcmp(h, "https"))
	bufaddenv(dst, "HTTPS", "on");
    if((h = getheader(req, "X-Ash-Address")) != NULL)
	bufaddenv(dst, "REMOTE_ADDR", "%s", h);
    if((h = getheader(req, "Content-Type")) != NULL)
	bufaddenv(dst, "CONTENT_TYPE", "%s", h);
    if((h = getheader(req, "Content-Length")) != NULL)
	bufaddenv(dst, "CONTENT_LENGTH", "%s", h);
    else
	bufaddenv(dst, "CONTENT_LENGTH", "0");
    if((h = getheader(req, "X-Ash-File")) != NULL)
	bufaddenv(dst, "SCRIPT_FILENAME", "%s", absolutify(h));
    for(i = 0; i < req->noheaders; i++) {
	h = sstrdup(req->headers[i][0]);
	for(p = h; *p; p++) {
	    if(isalnum(*p))
		*p = toupper(*p);
	    else
		*p = '_';
	}
	bufcatstr2(*dst, h);
	free(h);
	bufcatstr2(*dst, req->headers[i][1]);
    }
}

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 struct hthead *parseresp(FILE *in)
{
    struct hthead *resp;
    char *st, *p;
    
    omalloc(resp);
    resp->ver = sstrdup("HTTP/1.1");
    if(parseheaders(resp, in)) {
	freehthead(resp);
	return(NULL);
    }
    if((st = getheader(resp, "Status")) != NULL) {
	if((p = strchr(st, ' ')) != NULL) {
	    *(p++) = 0;
	    resp->code = atoi(st);
	    resp->msg = sstrdup(p);
	} else {
	    resp->code = atoi(st);
	    resp->msg = sstrdup(defstatus(resp->code));
	}
	headrmheader(resp, "Status");
    } else if(getheader(resp, "Location")) {
	resp->code = 303;
	resp->msg = sstrdup("See Other");
    } else {
	resp->code = 200;
	resp->msg = sstrdup("OK");
    }
    return(resp);
}

static void serve(struct muth *muth, va_list args)
{
    vavar(struct hthead *, req);
    vavar(int, fd);
    vavar(int, sfd);
    FILE *is, *os;
    struct charbuf head;
    struct hthead *resp;
    
    sfd = reconn();
    is = mtstdopen(fd, 1, 60, "r+");
    os = mtstdopen(sfd, 1, 600, "r+");
    
    bufinit(head);
    mkcgienv(req, &head);
    fprintf(os, "%zi:", head.d);
    fwrite(head.b, head.d, 1, os);
    fputc(',', os);
    buffree(head);
    if(passdata(is, os) < 0)
	goto out;
    
    if((resp = parseresp(os)) == NULL)
	goto out;
    writeresp(is, resp);
    freehthead(resp);
    fputc('\n', is);
    if(passdata(os, is) < 0)
	goto out;
    
out:
    freehthead(req);
    fclose(is);
    fclose(os);
}

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

static void usage(FILE *out)
{
    fprintf(out, "usage: servescgi [-h] [-N RETRIES] [-i ID] [-u UNIX-PATH] [-t [HOST:]TCP-PORT] [PROGRAM [ARGS...]]\n");
}

int main(int argc, char **argv)
{
    int c;
    
    while((c = getopt(argc, argv, "+hN:i:u:t:")) >= 0) {
	switch(c) {
	case 'h':
	    usage(stdout);
	    exit(0);
	case 'N':
	    nolisten = atoi(optarg);
	    break;
	case 'i':
	    sockid = optarg;
	    break;
	case 'u':
	    unspec = optarg;
	    break;
	case 't':
	    inspec = optarg;
	    break;
	default:
	    usage(stderr);
	    exit(1);
	}
    }
    progspec = argv + optind;
    if(((sockid != NULL) + (unspec != NULL) + (inspec != NULL)) > 1) {
	flog(LOG_ERR, "servescgi: at most one of -i, -u or -t may be given");
	exit(1);
    }
    signal(SIGCHLD, SIG_IGN);
    mustart(listenloop, 0);
    atexit(killcuraddr);
    ioloop();
    return(0);
}
Commit	Line	Data
f89ce57a 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	/*
	20	* XXX: All the various ways to start a child process makes this
	21	* program quite ugly at the moment. It is unclear whether it is
	22	* meaningfully possible to unify them better than they currently are.
	23	*/
	24
	25	#include <stdlib.h>
	26	#include <stdio.h>
	27	#include <unistd.h>
	28	#include <string.h>
	29	#include <fcntl.h>
	30	#include <ctype.h>
	31	#include <sys/socket.h>
	32	#include <sys/un.h>
	33	#include <netinet/in.h>
	34	#include <netdb.h>
	35	#include <sys/signal.h>
	36	#include <errno.h>
	37
	38	#ifdef HAVE_CONFIG_H
	39	#include <config.h>
	40	#endif
	41	#include <utils.h>
	42	#include <req.h>
	43	#include <log.h>
	44	#include <mt.h>
	45	#include <mtio.h>
	46
	47	static char **progspec;
	48	static char sockid, unspec, *inspec;
	49	static int nolisten;
	50	static struct sockaddr *curaddr;
	51	static size_t caddrlen;
	52	static int cafamily, isanon;
	53	static pid_t child;
	54
	55	static struct addrinfo *resolv(int flags)
	56	{
	57	int ret;
	58	struct addrinfo *ai, h;
	59	char name, srv, *p;
	60
	61	if((p = strchr(inspec, ':')) != NULL) {
	62	name = smalloc(p - inspec + 1);
	63	memcpy(name, inspec, p - inspec);
	64	name[p - inspec] = 0;
65	srv = p + 1;
66	} else {
67	name = sstrdup("localhost");
68	srv = inspec;
69	}
70	memset(&h, 0, sizeof(h));
71	h.ai_family = AF_UNSPEC;
72	h.ai_socktype = SOCK_STREAM;
73	h.ai_flags = flags;
74	ret = getaddrinfo(name, srv, &h, &ai);
75	free(name);
76	if(ret != 0) {
77	flog(LOG_ERR, "could not resolve TCP specification `%s': %s", inspec, gai_strerror(ret));
78	exit(1);
79	}
80	return(ai);
81	}
82
83	static char mksockid(char sockid)
84	{
85	char *home;
86
87	home = getenv("HOME");
88	if(home && !access(sprintf3("%s/.ashd/sockets/", home), X_OK))
89	return(sprintf3("%s/.ashd/sockets/scgi-p-%s", home, sockid));
90	return(sprintf3("/tmp/scgi-%i-%s", getuid(), sockid));
91	}
92
93	static char *mkanonid(void)
94	{
95	char *home;
96	char *tmpl;
97	int fd;
98
99	home = getenv("HOME");
100	if(home && !access(sprintf3("%s/.ashd/sockets/", home), X_OK))
101	tmpl = sprintf2("%s/.ashd/sockets/scgi-a-XXXXXX");
102	else
103	tmpl = sprintf2("/tmp/scgi-a-%i-XXXXXX", getuid());
104	if((fd = mkstemp(tmpl)) < 0) {
105	flog(LOG_ERR, "could not create anonymous socket `%s': %s", tmpl, strerror(errno));
106	exit(1);
107	}
108	unlink(tmpl);
109	return(tmpl);
110	}
111
112	static void startlisten(void)
113	{
114	int i, fd;
115	struct addrinfo ai, cai;
116	char *unpath;
117	struct sockaddr_un unm;
118	char *aname;
119
120	isanon = 0;
121	if(inspec != NULL) {
122	fd = -1;
123	for(cai = ai = resolv(AI_PASSIVE); cai != NULL; cai = cai->ai_next) {
124	if((fd = socket(cai->ai_family, cai->ai_socktype, cai->ai_protocol)) < 0)
125	continue;
126	if(bind(fd, cai->ai_addr, cai->ai_addrlen)) {
127	close(fd);
128	fd = -1;
129	continue;
130	}
131	if(listen(fd, 128)) {
132	close(fd);
133	fd = -1;
134	continue;
135	}
136	break;
137	}
138	freeaddrinfo(ai);
139	if(fd < 0) {
140	flog(LOG_ERR, "could not bind to specified TCP address: %s", strerror(errno));
141	exit(1);
142	}
143	} else if((unspec != NULL) \|\| (sockid != NULL)) {
144	if((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
145	flog(LOG_ERR, "could not create Unix socket: %s", strerror(errno));
146	exit(1);
147	}
148	if(unspec != NULL)
149	unpath = unspec;
150	else
151	unpath = mksockid(sockid);
152	unlink(unpath);
153	unm.sun_family = AF_UNIX;
154	strcpy(unm.sun_path, unpath);
155	if(bind(fd, (struct sockaddr *)&unm, sizeof(unm))) {
156	flog(LOG_ERR, "could not bind Unix socket to `%s': %s", unspec, strerror(errno));
157	exit(1);
158	}
159	if(listen(fd, 128)) {
160	flog(LOG_ERR, "listen: %s", strerror(errno));
161	exit(1);
162	}
163	} else {
164	if((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
165	flog(LOG_ERR, "could not create Unix socket: %s", strerror(errno));
166	exit(1);
167	}
168	memset(&unm, 0, sizeof(unm));
169	aname = mkanonid();
170	unm.sun_family = AF_UNIX;
171	strcpy(unm.sun_path, aname);
172	free(aname);
173	if(bind(fd, (struct sockaddr *)&unm, sizeof(unm))) {
174	flog(LOG_ERR, "could not bind Unix socket to `%s': %s", unspec, strerror(errno));
175	exit(1);
176	}
177	if(listen(fd, 128)) {
178	flog(LOG_ERR, "listen: %s", strerror(errno));
179	exit(1);
180	}
181
182	curaddr = smalloc(caddrlen = sizeof(unm));
183	memcpy(curaddr, &unm, sizeof(unm));
184	cafamily = AF_UNIX;
185	isanon = 1;
186	}
187	if((child = fork()) < 0) {
188	flog(LOG_ERR, "could not fork: %s", strerror(errno));
189	exit(1);
190	}
191	if(child == 0) {
192	dup2(fd, 0);
193	for(i = 3; i < FD_SETSIZE; i++)
194	close(i);
195	execvp(*progspec, progspec);
196	exit(127);
197	}
198	close(fd);
199	}
200
201	static void startnolisten(void)
202	{
203	int i;
204
205	if((child = fork()) < 0) {
206	flog(LOG_ERR, "could not fork: %s", strerror(errno));
207	exit(1);
208	}
209	if(child == 0) {
210	for(i = 3; i < FD_SETSIZE; i++)
211	close(i);
212	execvp(*progspec, progspec);
213	exit(127);
214	}
215	}
216
217	static int sconnect(void)
218	{
219	int fd;
220	int err;
221	socklen_t errlen;
222
223	fd = socket(cafamily, SOCK_STREAM, 0);
224	fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) \| O_NONBLOCK);
225	while(1) {
226	if(connect(fd, curaddr, caddrlen)) {
227	if(errno == EINPROGRESS) {
228	block(fd, EV_WRITE, 30);
229	errlen = sizeof(err);
230	if(getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &errlen) \|\| ((errno = err) != 0)) {
231	close(fd);
232	return(-1);
233	}
234	return(fd);
235	}
236	close(fd);
237	return(-1);
238	}
239	return(fd);
240	}
241	}
242
243	static int econnect(void)
244	{
245	int fd;
246	struct addrinfo ai, cai;
247	int tries;
248	char *unpath;
249	struct sockaddr_un unm;
250
251	tries = 0;
252	retry:
253	if(inspec != NULL) {
254	fd = -1;
255	for(cai = ai = resolv(0); cai != NULL; cai = cai->ai_next) {
256	if((fd = socket(cai->ai_family, cai->ai_socktype, cai->ai_protocol)) < 0)
257	continue;
258	if(connect(fd, cai->ai_addr, cai->ai_addrlen)) {
259	close(fd);
260	fd = -1;
261	continue;
262	}
263	break;
264	}
265	if(tries++ < nolisten) {
266	sleep(1);
267	goto retry;
268	}
269	if(fd < 0) {
270	flog(LOG_ERR, "could not connect to specified TCP address: %s", strerror(errno));
271	exit(1);
272	}
273	curaddr = smalloc(caddrlen = cai->ai_addrlen);
274	memcpy(curaddr, cai->ai_addr, caddrlen);
275	cafamily = cai->ai_family;
276	isanon = 0;
277	freeaddrinfo(ai);
278	return(fd);
279	} else if((unspec != NULL) \|\| (sockid != NULL)) {
280	if((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
281	flog(LOG_ERR, "could not create Unix socket: %s", strerror(errno));
282	exit(1);
283	}
284	if(unspec != NULL)
285	unpath = unspec;
286	else
287	unpath = mksockid(sockid);
288	unlink(unpath);
289	unm.sun_family = AF_UNIX;
290	strcpy(unm.sun_path, unpath);
291	if(connect(fd, (struct sockaddr *)&unm, sizeof(unm))) {
292	close(fd);
293	if(tries++ < nolisten) {
294	sleep(1);
295	goto retry;
296	}
297	flog(LOG_ERR, "could not connect to Unix socket `%s': %s", unspec, strerror(errno));
298	exit(1);
299	}
300	curaddr = smalloc(caddrlen = sizeof(unm));
301	memcpy(curaddr, &unm, sizeof(unm));
302	cafamily = AF_UNIX;
303	isanon = 0;
304	return(fd);
305	} else {
306	flog(LOG_ERR, "servescgi: cannot use an anonymous socket without a program to start");
307	exit(1);
308	}
309	}
310
311	static int startconn(void)
312	{
313	if(*progspec) {
314	if(nolisten == 0)
315	startlisten();
316	else
317	startnolisten();
318	}
319	if(curaddr != NULL)
320	return(sconnect());
321	return(econnect());
322	}
323
324	static void killcuraddr(void)
325	{
326	if(curaddr == NULL)
327	return;
328	if(isanon) {
329	unlink(((struct sockaddr_un *)curaddr)->sun_path);
330	if(child > 0)
331	kill(child, SIGTERM);
332	}
333	free(curaddr);
334	curaddr = NULL;
335	}
336
337	static int reconn(void)
338	{
339	int fd;
340
341	if(curaddr != NULL) {
342	if((fd = sconnect()) >= 0)
343	return(fd);
344	killcuraddr();
345	}
346	return(startconn());
347	}
348
349	static off_t passdata(FILE in, FILE out)
350	{
351	size_t read;
352	off_t total;
353	char buf[8192];
354
355	total = 0;
356	while(!feof(in)) {
357	read = fread(buf, 1, sizeof(buf), in);
358	if(ferror(in))
359	return(-1);
360	if(fwrite(buf, 1, read, out) != read)
361	return(-1);
362	total += read;
363	}
364	return(total);
365	}
366
367	static void bufaddenv(struct charbuf dst, char name, char *fmt, ...)
368	{
369	va_list args;
370
371	bufcatstr2(*dst, name);
372	va_start(args, fmt);
373	bvprintf(dst, fmt, args);
374	va_end(args);
375	bufadd(*dst, 0);
376	}
377
378	static char absolutify(char file)
379	{
380	static int inited = 0;
381	static char cwd[1024];
382
383	if(*file != '/') {
384	if(!inited) {
385	getcwd(cwd, sizeof(cwd));
386	inited = 1;
387	}
388	return(sprintf2("%s/%s", cwd, file));
389	}
390	return(sstrdup(file));
391	}
392
393	/* Mostly copied from callcgi. */
394	static void mkcgienv(struct hthead req, struct charbuf dst)
395	{
396	int i;
397	char url, qp, h, p;
398
399	bufaddenv(dst, "SERVER_SOFTWARE", "ashd/%s", VERSION);
400	bufaddenv(dst, "GATEWAY_INTERFACE", "CGI/1.1");
401	bufaddenv(dst, "SCGI", "1");
402	bufaddenv(dst, "SERVER_PROTOCOL", "%s", req->ver);
403	bufaddenv(dst, "REQUEST_METHOD", "%s", req->method);
404	bufaddenv(dst, "REQUEST_URI", "%s", req->url);
405	if(*req->rest)
406	bufaddenv(dst, "PATH_INFO", "/%s", req->rest);
407	else
408	bufaddenv(dst, "PATH_INFO", "");
409	url = sstrdup(req->url);
410	if((qp = strchr(url, '?')) != NULL)
411	*(qp++) = 0;
412	/* XXX: This is an ugly hack (I think), but though I can think of
413	* several alternatives, none seem to be better. */
414	if(*req->rest && (strlen(url) > strlen(req->rest)) &&
415	!strcmp(req->rest, url + strlen(url) - strlen(req->rest)) &&
416	(url[strlen(url) - strlen(req->rest) - 1] == '/')) {
417	bufaddenv(dst, "SCRIPT_NAME", "%.*s", (int)(strlen(url) - strlen(req->rest) - 1), url);
418	} else {
419	bufaddenv(dst, "SCRIPT_NAME", "%s", url);
420	}
421	bufaddenv(dst, "QUERY_STRING", "%s", qp?qp:"");
422	if((h = getheader(req, "Host")) != NULL)
423	bufaddenv(dst, "SERVER_NAME", "%s", h);
424	if((h = getheader(req, "X-Ash-Server-Port")) != NULL)
425	bufaddenv(dst, "SERVER_PORT", "%s", h);
426	if(((h = getheader(req, "X-Ash-Server-Protocol")) != NULL) && !strcmp(h, "https"))
427	bufaddenv(dst, "HTTPS", "on");
428	if((h = getheader(req, "X-Ash-Address")) != NULL)
429	bufaddenv(dst, "REMOTE_ADDR", "%s", h);
430	if((h = getheader(req, "Content-Type")) != NULL)
431	bufaddenv(dst, "CONTENT_TYPE", "%s", h);
432	if((h = getheader(req, "Content-Length")) != NULL)
433	bufaddenv(dst, "CONTENT_LENGTH", "%s", h);
434	else
435	bufaddenv(dst, "CONTENT_LENGTH", "0");
436	if((h = getheader(req, "X-Ash-File")) != NULL)
437	bufaddenv(dst, "SCRIPT_FILENAME", "%s", absolutify(h));
438	for(i = 0; i < req->noheaders; i++) {
439	h = sstrdup(req->headers[i][0]);
440	for(p = h; *p; p++) {
441	if(isalnum(*p))
442	p = toupper(p);
443	else
444	*p = '_';
445	}
446	bufcatstr2(*dst, h);
447	free(h);
448	bufcatstr2(*dst, req->headers[i][1]);
449	}
450	}
451
452	static char *defstatus(int code)
453	{
454	if(code == 200)
455	return("OK");
456	else if(code == 201)
457	return("Created");
458	else if(code == 202)
459	return("Accepted");
460	else if(code == 204)
461	return("No Content");
462	else if(code == 300)
463	return("Multiple Choices");
464	else if(code == 301)
465	return("Moved Permanently");
466	else if(code == 302)
467	return("Found");
468	else if(code == 303)
469	return("See Other");
470	else if(code == 304)
471	return("Not Modified");
472	else if(code == 307)
473	return("Moved Temporarily");
474	else if(code == 400)
475	return("Bad Request");
476	else if(code == 401)
477	return("Unauthorized");
478	else if(code == 403)
479	return("Forbidden");
480	else if(code == 404)
481	return("Not Found");
482	else if(code == 500)
483	return("Internal Server Error");
484	else if(code == 501)
485	return("Not Implemented");
486	else if(code == 503)
487	return("Service Unavailable");
488	else
489	return("Unknown status");
490	}
491
492	static struct hthead parseresp(FILE in)
493	{
494	struct hthead *resp;
495	char st, p;
496
497	omalloc(resp);
498	resp->ver = sstrdup("HTTP/1.1");
499	if(parseheaders(resp, in)) {
500	freehthead(resp);
501	return(NULL);
502	}
503	if((st = getheader(resp, "Status")) != NULL) {
504	if((p = strchr(st, ' ')) != NULL) {
505	*(p++) = 0;
506	resp->code = atoi(st);
507	resp->msg = sstrdup(p);
508	} else {
509	resp->code = atoi(st);
510	resp->msg = sstrdup(defstatus(resp->code));
511	}
512	headrmheader(resp, "Status");
513	} else if(getheader(resp, "Location")) {
514	resp->code = 303;
515	resp->msg = sstrdup("See Other");
516	} else {
517	resp->code = 200;
518	resp->msg = sstrdup("OK");
519	}
520	return(resp);
521	}
522
523	static void serve(struct muth *muth, va_list args)
524	{
525	vavar(struct hthead *, req);
526	vavar(int, fd);
527	vavar(int, sfd);
528	FILE is, os;
529	struct charbuf head;
530	struct hthead *resp;
531
532	sfd = reconn();
533	is = mtstdopen(fd, 1, 60, "r+");
534	os = mtstdopen(sfd, 1, 600, "r+");
535
536	bufinit(head);
537	mkcgienv(req, &head);
538	fprintf(os, "%zi:", head.d);
539	fwrite(head.b, head.d, 1, os);
540	fputc(',', os);
541	buffree(head);
542	if(passdata(is, os) < 0)
543	goto out;
544
545	if((resp = parseresp(os)) == NULL)
546	goto out;
547	writeresp(is, resp);
548	freehthead(resp);
549	fputc('\n', is);
550	if(passdata(os, is) < 0)
551	goto out;
552
553	out:
554	freehthead(req);
555	fclose(is);
556	fclose(os);
557	}
558
559	static void listenloop(struct muth *muth, va_list args)
560	{
561	vavar(int, lfd);
562	int fd;
563	struct hthead *req;
564
565	while(1) {
566	block(0, EV_READ, 0);
567	if((fd = recvreq(lfd, &req)) < 0) {
568	if(errno != 0)
569	flog(LOG_ERR, "recvreq: %s", strerror(errno));
570	break;
571	}
572	mustart(serve, req, fd);
573	}
574	}
575
576	static void usage(FILE *out)
577	{
578	fprintf(out, "usage: servescgi [-h] [-N RETRIES] [-i ID] [-u UNIX-PATH] [-t [HOST:]TCP-PORT] [PROGRAM [ARGS...]]\n");
579	}
580
581	int main(int argc, char **argv)
582	{
583	int c;
584
585	while((c = getopt(argc, argv, "+hN:i:u:t:")) >= 0) {
586	switch(c) {
587	case 'h':
588	usage(stdout);
589	exit(0);
590	case 'N':
591	nolisten = atoi(optarg);
592	break;
593	case 'i':
594	sockid = optarg;
595	break;
596	case 'u':
597	unspec = optarg;
598	break;
599	case 't':
600	inspec = optarg;
601	break;
602	default:
603	usage(stderr);
604	exit(1);
605	}
606	}
607	progspec = argv + optind;
608	if(((sockid != NULL) + (unspec != NULL) + (inspec != NULL)) > 1) {
609	flog(LOG_ERR, "servescgi: at most one of -i, -u or -t may be given");
610	exit(1);
611	}
612	signal(SIGCHLD, SIG_IGN);
613	mustart(listenloop, 0);
614	atexit(killcuraddr);
615	ioloop();
616	return(0);
617	}