[ashd.git] / src / patplex.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 <string.h>
#include <unistd.h>
#include <signal.h>
#include <errno.h>
#include <ctype.h>
#include <regex.h>
#include <sys/wait.h>

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

#define PAT_REST 0
#define PAT_URL 1
#define PAT_METHOD 2
#define PAT_HEADER 3
#define PAT_ALL 4
#define PAT_DEFAULT 5

#define PATFL_MSS 1
#define PATFL_UNQ 2

struct config {
    struct child *children;
    struct pattern *patterns;
};

struct rule {
    int type;
    int fl;
    char *header;
    regex_t *pattern;
};

struct headmod {
    struct headmod *next;
    char *name, *value;
};

struct pattern {
    struct pattern *next;
    struct headmod *headers;
    char *childnm;
    struct rule **rules;
    char *restpat;
};

static struct config *gconfig, *lconfig;
static volatile int reload = 0;

static void freepattern(struct pattern *pat)
{
    struct rule **rule;
    struct headmod *head;
    
    for(rule = pat->rules; *rule; rule++) {
	if((*rule)->header != NULL)
	    free((*rule)->header);
	if((*rule)->pattern != NULL) {
	    regfree((*rule)->pattern);
	    free((*rule)->pattern);
	}
	free(*rule);
    }
    while((head = pat->headers) != NULL) {
	pat->headers = head->next;
	free(head->name);
	free(head->value);
	free(head);
    }
    if(pat->childnm != NULL)
	free(pat->childnm);
    free(pat);
}

static void freeconfig(struct config *cf)
{
    struct child *ch, *nch;
    struct pattern *pat, *npat;
    
    for(ch = cf->children; ch != NULL; ch = nch) {
	nch = ch->next;
	freechild(ch);
    }
    for(pat = cf->patterns; pat != NULL; pat = npat) {
	npat = pat->next;
	freepattern(pat);
    }
    free(cf);
}

static struct child *getchild(struct config *cf, char *name)
{
    struct child *ch;
    
    for(ch = cf->children; ch; ch = ch->next) {
	if(!strcmp(ch->name, name))
	    break;
    }
    return(ch);
}

static struct rule *newrule(struct pattern *pat)
{
    int i;
    struct rule *rule;
    
    for(i = 0; pat->rules[i]; i++);
    pat->rules = srealloc(pat->rules, sizeof(*pat->rules) * (i + 2));
    rule = pat->rules[i] = szmalloc(sizeof(*rule));
    pat->rules[i + 1] = NULL;
    return(rule);
}

static struct pattern *newpattern(void)
{
    struct pattern *pat;
    
    omalloc(pat);
    pat->rules = szmalloc(sizeof(*pat->rules));
    return(pat);
}

static regex_t *regalloc(char *regex, int flags)
{
    regex_t *ret;
    int res;
    char errbuf[256];
    
    omalloc(ret);
    if((res = regcomp(ret, regex, flags | REG_EXTENDED)) != 0) {
	regerror(res, ret, errbuf, sizeof(errbuf));
	flog(LOG_WARNING, "%s: %s", regex, errbuf);
	free(ret);
	return(NULL);
    }
    return(ret);
}

static struct pattern *parsepattern(struct cfstate *s)
{
    struct pattern *pat;
    int sl;
    struct rule *rule;
    struct headmod *head;
    regex_t *regex;
    int rxfl;
    
    if(!strcmp(s->argv[0], "match")) {
	s->expstart = 1;
	pat = newpattern();
    } else {
	return(NULL);
    }
    
    sl = s->lno;
    while(1) {
	getcfline(s);
	if(!strcmp(s->argv[0], "point") ||
	   !strcmp(s->argv[0], "url") ||
	   !strcmp(s->argv[0], "method")) {
	    if(s->argc < 2) {
		flog(LOG_WARNING, "%s:%i: missing pattern for `%s' match", s->file, s->lno, s->argv[0]);
		continue;
	    }
	    rxfl = 0;
	    if(s->argc >= 3) {
		if(strchr(s->argv[2], 'i'))
		    rxfl |= REG_ICASE;
	    }
	    if((regex = regalloc(s->argv[1], rxfl)) == NULL) {
		flog(LOG_WARNING, "%s:%i: invalid regex for `%s' match", s->file, s->lno, s->argv[0]);
		continue;
	    }
	    rule = newrule(pat);
	    if(!strcmp(s->argv[0], "point"))
		rule->type = PAT_REST;
	    else if(!strcmp(s->argv[0], "url"))
		rule->type = PAT_URL;
	    else if(!strcmp(s->argv[0], "method"))
		rule->type = PAT_METHOD;
	    rule->pattern = regex;
	    if(s->argc >= 3) {
		if(strchr(s->argv[2], 's'))
		    rule->fl |= PATFL_MSS;
		if(strchr(s->argv[2], 'q'))
		    rule->fl |= PATFL_UNQ;
	    }
	} else if(!strcmp(s->argv[0], "header")) {
	    if(s->argc < 3) {
		flog(LOG_WARNING, "%s:%i: missing header name or pattern for `header' match", s->file, s->lno);
		continue;
	    }
	    rxfl = 0;
	    if(s->argc >= 4) {
		if(strchr(s->argv[3], 'i'))
		    rxfl |= REG_ICASE;
	    }
	    if((regex = regalloc(s->argv[2], rxfl)) == NULL) {
		flog(LOG_WARNING, "%s:%i: invalid regex for `header' match", s->file, s->lno);
		continue;
	    }
	    rule = newrule(pat);
	    rule->type = PAT_HEADER;
	    rule->header = sstrdup(s->argv[1]);
	    rule->pattern = regex;
	    if(s->argc >= 4) {
		if(strchr(s->argv[3], 's'))
		    rule->fl |= PATFL_MSS;
	    }
	} else if(!strcmp(s->argv[0], "all")) {
	    newrule(pat)->type = PAT_ALL;
	} else if(!strcmp(s->argv[0], "default")) {
	    newrule(pat)->type = PAT_DEFAULT;
	} else if(!strcmp(s->argv[0], "handler")) {
	    if(s->argc < 2) {
		flog(LOG_WARNING, "%s:%i: missing child name for `handler' directive", s->file, s->lno);
		continue;
	    }
	    if(pat->childnm != NULL)
		free(pat->childnm);
	    pat->childnm = sstrdup(s->argv[1]);
	} else if(!strcmp(s->argv[0], "restpat")) {
	    if(s->argc < 2) {
		flog(LOG_WARNING, "%s:%i: missing pattern for `restpat' directive", s->file, s->lno);
		continue;
	    }
	    if(pat->restpat != NULL)
		free(pat->restpat);
	    pat->restpat = sstrdup(s->argv[1]);
	} else if(!strcmp(s->argv[0], "set") || !strcmp(s->argv[0], "xset")) {
	    if(s->argc < 3) {
		flog(LOG_WARNING, "%s:%i: missing header name or pattern for `%s' directive", s->file, s->lno, s->argv[0]);
		continue;
	    }
	    omalloc(head);
	    if(!strcmp(s->argv[0], "xset"))
		head->name = sprintf2("X-Ash-%s", s->argv[1]);
	    else
		head->name = sstrdup(s->argv[1]);
	    head->value = sstrdup(s->argv[2]);
	    head->next = pat->headers;
	    pat->headers = head;
	} else if(!strcmp(s->argv[0], "end") || !strcmp(s->argv[0], "eof")) {
	    break;
	} else {
	    flog(LOG_WARNING, "%s:%i: unknown directive `%s' in pattern declaration", s->file, s->lno, s->argv[0]);
	}
    }
    
    if(pat->rules[0] == NULL) {
	flog(LOG_WARNING, "%s:%i: missing rules in match declaration", s->file, sl);
	freepattern(pat);
	return(NULL);
    }
    if(pat->childnm == NULL) {
	flog(LOG_WARNING, "%s:%i: missing handler in match declaration", s->file, sl);
	freepattern(pat);
	return(NULL);
    }
    return(pat);
}

static struct config *readconfig(char *filename)
{
    struct cfstate *s;
    struct config *cf;
    struct child *ch;
    struct pattern *pat;
    FILE *in;
    
    if((in = fopen(filename, "r")) == NULL) {
	flog(LOG_WARNING, "%s: %s", filename, strerror(errno));
	return(NULL);
    }
    s = mkcfparser(in, filename);
    omalloc(cf);
    
    while(1) {
	getcfline(s);
	if((ch = parsechild(s)) != NULL) {
	    ch->next = cf->children;
	    cf->children = ch;
	} else if((pat = parsepattern(s)) != NULL) {
	    pat->next = cf->patterns;
	    cf->patterns = pat;
	} else if(!strcmp(s->argv[0], "eof")) {
	    break;
	} else {
	    flog(LOG_WARNING, "%s:%i: unknown directive `%s'", s->file, s->lno, s->argv[0]);
	}
    }
    
    freecfparser(s);
    fclose(in);
    return(cf);
}

static void exprestpat(struct hthead *req, struct pattern *pat, char **mstr)
{
    char *p, *p2, *hdr;
    int mc;
    struct charbuf buf;
    
    if(mstr == NULL)
	mc = 0;
    else
	for(mc = 0; mstr[mc]; mc++);
    bufinit(buf);
    for(p = pat->restpat; *p; ) {
	if(*p == '$') {
	    p++;
	    if((*p >= '0') && (*p <= '9')) {
		if(*p - '0' < mc)
		    bufcatstr(buf, mstr[*p - '0']);
		p++;
	    } else if(*p == '_') {
		bufcatstr(buf, req->rest);
		p++;
	    } else if(*p == '$') {
		bufadd(buf, '$');
		p++;
	    } else if(*p == '{') {
		if((p2 = strchr(p, '}')) == NULL) {
		    p++;
		} else {
		    hdr = getheader(req, sprintf3("%.*s", p2 - p - 1, p + 1));
		    if(hdr)
			bufcatstr(buf, hdr);
		}
	    } else if(!*p) {
	    }
	} else {
	    bufadd(buf, *(p++));
	}
    }
    bufadd(buf, 0);
    replrest(req, buf.b);
    buffree(buf);
}

static void qoffsets(char *buf, int *obuf, char *pstr, int unquote)
{
    int i, o, d1, d2;
    
    if(unquote) {
	i = o = 0;
	while(pstr[i]) {
	    obuf[o] = i;
	    if((pstr[i] == '%') && ((d1 = hexdigit(pstr[i + 1])) >= 0) && ((d2 = hexdigit(pstr[i + 2])) >= 0)) {
		buf[o] = (d1 << 4) | d2;
		i += 3;
	    } else {
		buf[o] = pstr[i];
		i++;
	    }
	    o++;
	}
	buf[o] = 0;
    } else {
	for(i = 0; pstr[i]; i++) {
	    buf[i] = pstr[i];
	    obuf[i] = i;
	}
	buf[i] = 0;
    }
}

static struct pattern *findmatch(struct config *cf, struct hthead *req, int trydefault)
{
    int i, o;
    struct pattern *pat;
    struct rule *rule;
    int rmo;
    regex_t *rx;
    char *pstr;
    char **mstr;
    regmatch_t gr[10];
    
    mstr = NULL;
    for(pat = cf->patterns; pat != NULL; pat = pat->next) {
	rmo = -1;
	for(i = 0; (rule = pat->rules[i]) != NULL; i++) {
	    rx = NULL;
	    if(rule->type == PAT_REST) {
		rx = rule->pattern;
		pstr = req->rest;
	    } else if(rule->type == PAT_URL) {
		rx = rule->pattern;
		pstr = req->url;
	    } else if(rule->type == PAT_METHOD) {
		rx = rule->pattern;
		pstr = req->method;
	    } else if(rule->type == PAT_HEADER) {
		rx = rule->pattern;
		if(!(pstr = getheader(req, rule->header)))
		    break;
	    }
	    if(rx != NULL) {
		char pbuf[strlen(pstr) + 1];
		int  obuf[strlen(pstr) + 1];
		qoffsets(pbuf, obuf, pstr, !!(rule->fl & PATFL_UNQ));
		if(regexec(rx, pbuf, 10, gr, 0))
		    break;
		else if(rule->type == PAT_REST)
		    rmo = obuf[gr[0].rm_eo];
		if(rule->fl & PATFL_MSS) {
		    if(mstr) {
			flog(LOG_WARNING, "two pattern rules marked with `s' flag found (for handler %s)", pat->childnm);
			freeca(mstr);
		    }
		    for(o = 0; o < 10; o++) {
			if(gr[o].rm_so < 0)
			    break;
		    }
		    mstr = szmalloc((o + 1) * sizeof(*mstr));
		    for(o = 0; o < 10; o++) {
			if(gr[o].rm_so < 0)
			    break;
			mstr[o] = smalloc(obuf[gr[o].rm_eo] - obuf[gr[o].rm_so] + 1);
			memcpy(mstr[o], pstr + obuf[gr[o].rm_so], obuf[gr[o].rm_eo] - obuf[gr[o].rm_so]);
			mstr[o][obuf[gr[o].rm_eo] - obuf[gr[o].rm_so]] = 0;
		    }
		}
	    } else if(rule->type == PAT_ALL) {
	    } else if(rule->type == PAT_DEFAULT) {
		if(!trydefault)
		    break;
	    }
	}
	if(!rule) {
	    if(pat->restpat) {
		exprestpat(req, pat, mstr);
	    } else if(rmo != -1) {
		replrest(req, req->rest + rmo);
	    }
	    if(mstr)
		freeca(mstr);
	    return(pat);
	}
	if(mstr) {
	    freeca(mstr);
	    mstr = NULL;
	}
    }
    return(NULL);
}

static void childerror(struct hthead *req, int fd)
{
    if(errno == EAGAIN)
	simpleerror(fd, 500, "Server Error", "The request handler is overloaded.");
    else
	simpleerror(fd, 500, "Server Error", "The request handler crashed.");
}

static void serve(struct hthead *req, int fd)
{
    struct pattern *pat;
    struct headmod *head;
    struct child *ch;
    
    pat = NULL;
    if(pat == NULL)
	pat = findmatch(lconfig, req, 0);
    if(pat == NULL)
	pat = findmatch(lconfig, req, 1);
    if(gconfig != NULL) {
	if(pat == NULL)
	    pat = findmatch(gconfig, req, 0);
	if(pat == NULL)
	    pat = findmatch(gconfig, req, 1);
    }
    if(pat == NULL) {
	simpleerror(fd, 404, "Not Found", "The requested resource could not be found on this server.");
	return;
    }
    ch = NULL;
    if(ch == NULL)
	ch = getchild(lconfig, pat->childnm);
    if(gconfig != NULL) {
	if(ch == NULL)
	    ch = getchild(gconfig, pat->childnm);
    }
    if(ch == NULL) {
	flog(LOG_ERR, "child %s requested, but was not declared", pat->childnm);
	simpleerror(fd, 500, "Configuration Error", "The server is erroneously configured. Handler %s was requested, but not declared.", pat->childnm);
	return;
    }
    
    for(head = pat->headers; head != NULL; head = head->next) {
	headrmheader(req, head->name);
	headappheader(req, head->name, head->value);
    }
    if(childhandle(ch, req, fd, NULL, NULL))
	childerror(req, fd);
}

static void reloadconf(char *nm)
{
    struct config *cf;
    
    if((cf = readconfig(nm)) == NULL) {
	flog(LOG_WARNING, "could not reload configuration file `%s'", nm);
	return;
    }
    mergechildren(cf->children, lconfig->children);
    freeconfig(lconfig);
    lconfig = cf;
}

static void chldhandler(int sig)
{
    pid_t pid;
    int st;
    
    while((pid = waitpid(-1, &st, WNOHANG)) > 0) {
	if(WCOREDUMP(st))
	    flog(LOG_WARNING, "child process %i dumped core", pid);
    }
}

static void sighandler(int sig)
{
    if(sig == SIGHUP)
	reload = 1;
}

static void usage(FILE *out)
{
    fprintf(out, "usage: patplex [-hN] CONFIGFILE\n");
}

int main(int argc, char **argv)
{
    int c;
    int nodef;
    char *gcf, *lcf;
    struct hthead *req;
    int fd;
    
    nodef = 0;
    while((c = getopt(argc, argv, "hN")) >= 0) {
	switch(c) {
	case 'h':
	    usage(stdout);
	    exit(0);
	case 'N':
	    nodef = 1;
	    break;
	default:
	    usage(stderr);
	    exit(1);
	}
    }
    if(argc - optind < 1) {
	usage(stderr);
	exit(1);
    }
    if(!nodef) {
	if((gcf = findstdconf("ashd/patplex.rc")) != NULL) {
	    gconfig = readconfig(gcf);
	    free(gcf);
	}
    }
    if((strchr(lcf = argv[optind], '/')) == NULL) {
	if((lcf = findstdconf(sprintf3("ashd/%s", lcf))) == NULL) {
	    flog(LOG_ERR, "could not find requested configuration file `%s'", argv[optind]);
	    exit(1);
	}
    }
    if((lconfig = readconfig(lcf)) == NULL) {
	flog(LOG_ERR, "could not read `%s'", lcf);
	exit(1);
    }
    signal(SIGCHLD, chldhandler);
    signal(SIGHUP, sighandler);
    signal(SIGPIPE, sighandler);
    while(1) {
	if(reload) {
	    reloadconf(lcf);
	    reload = 0;
	}
	if((fd = recvreq(0, &req)) < 0) {
	    if(errno == EINTR)
		continue;
	    if(errno != 0)
		flog(LOG_ERR, "recvreq: %s", strerror(errno));
	    break;
	}
	serve(req, fd);
	freehthead(req);
	close(fd);
    }
    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 <string.h>
	22	#include <unistd.h>
	23	#include <signal.h>
	24	#include <errno.h>
	25	#include <ctype.h>
	26	#include <regex.h>
	27	#include <sys/wait.h>
	28
	29	#ifdef HAVE_CONFIG_H
	30	#include <config.h>
	31	#endif
	32	#include <utils.h>
	33	#include <log.h>
	34	#include <req.h>
	35	#include <proc.h>
	36	#include <resp.h>
	37	#include <cf.h>
	38
	39	#define PAT_REST 0
	40	#define PAT_URL 1
	41	#define PAT_METHOD 2
	42	#define PAT_HEADER 3
	43	#define PAT_ALL 4
	44	#define PAT_DEFAULT 5
	45
	46	#define PATFL_MSS 1
	47	#define PATFL_UNQ 2
	48
	49	struct config {
	50	struct child *children;
	51	struct pattern *patterns;
	52	};
	53
	54	struct rule {
	55	int type;
	56	int fl;
	57	char *header;
	58	regex_t *pattern;
	59	};
	60
	61	struct headmod {
	62	struct headmod *next;
	63	char name, value;
	64	};
	65
	66	struct pattern {
	67	struct pattern *next;
	68	struct headmod *headers;
	69	char *childnm;
	70	struct rule **rules;
	71	char *restpat;
	72	};
	73
	74	static struct config gconfig, lconfig;
	75	static volatile int reload = 0;
	76
	77	static void freepattern(struct pattern *pat)
	78	{
	79	struct rule **rule;
	80	struct headmod *head;
	81
	82	for(rule = pat->rules; *rule; rule++) {
	83	if((*rule)->header != NULL)
	84	free((*rule)->header);
	85	if((*rule)->pattern != NULL) {
	86	regfree((*rule)->pattern);
	87	free((*rule)->pattern);
	88	}
	89	free(*rule);
	90	}
	91	while((head = pat->headers) != NULL) {
	92	pat->headers = head->next;
	93	free(head->name);
	94	free(head->value);
	95	free(head);
	96	}
	97	if(pat->childnm != NULL)
	98	free(pat->childnm);
	99	free(pat);
	100	}
	101
	102	static void freeconfig(struct config *cf)
	103	{
	104	struct child ch, nch;
	105	struct pattern pat, npat;
	106
	107	for(ch = cf->children; ch != NULL; ch = nch) {
	108	nch = ch->next;
	109	freechild(ch);
	110	}
	111	for(pat = cf->patterns; pat != NULL; pat = npat) {
	112	npat = pat->next;
	113	freepattern(pat);
	114	}
	115	free(cf);
	116	}
	117
	118	static struct child getchild(struct config cf, char *name)
	119	{
	120	struct child *ch;
	121
	122	for(ch = cf->children; ch; ch = ch->next) {
	123	if(!strcmp(ch->name, name))
	124	break;
	125	}
	126	return(ch);
	127	}
	128
	129	static struct rule newrule(struct pattern pat)
	130	{
	131	int i;
	132	struct rule *rule;
	133
	134	for(i = 0; pat->rules[i]; i++);
	135	pat->rules = srealloc(pat->rules, sizeof(pat->rules) (i + 2));
	136	rule = pat->rules[i] = szmalloc(sizeof(*rule));
	137	pat->rules[i + 1] = NULL;
	138	return(rule);
	139	}
	140
	141	static struct pattern *newpattern(void)
	142	{
	143	struct pattern *pat;
	144
	145	omalloc(pat);
	146	pat->rules = szmalloc(sizeof(*pat->rules));
	147	return(pat);
	148	}
	149
	150	static regex_t regalloc(char regex, int flags)
	151	{
	152	regex_t *ret;
	153	int res;
	154	char errbuf[256];
	155
	156	omalloc(ret);
	157	if((res = regcomp(ret, regex, flags \| REG_EXTENDED)) != 0) {
	158	regerror(res, ret, errbuf, sizeof(errbuf));
	159	flog(LOG_WARNING, "%s: %s", regex, errbuf);
	160	free(ret);
	161	return(NULL);
	162	}
	163	return(ret);
	164	}
	165
	166	static struct pattern parsepattern(struct cfstate s)
	167	{
	168	struct pattern *pat;
	169	int sl;
	170	struct rule *rule;
	171	struct headmod *head;
	172	regex_t *regex;
	173	int rxfl;
	174
	175	if(!strcmp(s->argv[0], "match")) {
	176	s->expstart = 1;
	177	pat = newpattern();
	178	} else {
	179	return(NULL);
	180	}
	181
	182	sl = s->lno;
	183	while(1) {
	184	getcfline(s);
	185	if(!strcmp(s->argv[0], "point") \|\|
	186	!strcmp(s->argv[0], "url") \|\|
	187	!strcmp(s->argv[0], "method")) {
	188	if(s->argc < 2) {
	189	flog(LOG_WARNING, "%s:%i: missing pattern for `%s' match", s->file, s->lno, s->argv[0]);
	190	continue;
	191	}
	192	rxfl = 0;
	193	if(s->argc >= 3) {
	194	if(strchr(s->argv[2], 'i'))
	195	rxfl \|= REG_ICASE;
	196	}
	197	if((regex = regalloc(s->argv[1], rxfl)) == NULL) {
	198	flog(LOG_WARNING, "%s:%i: invalid regex for `%s' match", s->file, s->lno, s->argv[0]);
	199	continue;
	200	}
	201	rule = newrule(pat);
	202	if(!strcmp(s->argv[0], "point"))
	203	rule->type = PAT_REST;
	204	else if(!strcmp(s->argv[0], "url"))
	205	rule->type = PAT_URL;
	206	else if(!strcmp(s->argv[0], "method"))
	207	rule->type = PAT_METHOD;
	208	rule->pattern = regex;
	209	if(s->argc >= 3) {
	210	if(strchr(s->argv[2], 's'))
	211	rule->fl \|= PATFL_MSS;
	212	if(strchr(s->argv[2], 'q'))
	213	rule->fl \|= PATFL_UNQ;
	214	}
	215	} else if(!strcmp(s->argv[0], "header")) {
	216	if(s->argc < 3) {
	217	flog(LOG_WARNING, "%s:%i: missing header name or pattern for `header' match", s->file, s->lno);
	218	continue;
	219	}
	220	rxfl = 0;
	221	if(s->argc >= 4) {
	222	if(strchr(s->argv[3], 'i'))
	223	rxfl \|= REG_ICASE;
	224	}
	225	if((regex = regalloc(s->argv[2], rxfl)) == NULL) {
	226	flog(LOG_WARNING, "%s:%i: invalid regex for `header' match", s->file, s->lno);
	227	continue;
	228	}
	229	rule = newrule(pat);
	230	rule->type = PAT_HEADER;
	231	rule->header = sstrdup(s->argv[1]);
	232	rule->pattern = regex;
	233	if(s->argc >= 4) {
	234	if(strchr(s->argv[3], 's'))
	235	rule->fl \|= PATFL_MSS;
	236	}
	237	} else if(!strcmp(s->argv[0], "all")) {
	238	newrule(pat)->type = PAT_ALL;
	239	} else if(!strcmp(s->argv[0], "default")) {
	240	newrule(pat)->type = PAT_DEFAULT;
	241	} else if(!strcmp(s->argv[0], "handler")) {
	242	if(s->argc < 2) {
	243	flog(LOG_WARNING, "%s:%i: missing child name for `handler' directive", s->file, s->lno);
	244	continue;
	245	}
	246	if(pat->childnm != NULL)
	247	free(pat->childnm);
	248	pat->childnm = sstrdup(s->argv[1]);
	249	} else if(!strcmp(s->argv[0], "restpat")) {
	250	if(s->argc < 2) {
	251	flog(LOG_WARNING, "%s:%i: missing pattern for `restpat' directive", s->file, s->lno);
	252	continue;
	253	}
	254	if(pat->restpat != NULL)
	255	free(pat->restpat);
	256	pat->restpat = sstrdup(s->argv[1]);
	257	} else if(!strcmp(s->argv[0], "set") \|\| !strcmp(s->argv[0], "xset")) {
	258	if(s->argc < 3) {
	259	flog(LOG_WARNING, "%s:%i: missing header name or pattern for `%s' directive", s->file, s->lno, s->argv[0]);
	260	continue;
	261	}
	262	omalloc(head);
	263	if(!strcmp(s->argv[0], "xset"))
	264	head->name = sprintf2("X-Ash-%s", s->argv[1]);
	265	else
	266	head->name = sstrdup(s->argv[1]);
	267	head->value = sstrdup(s->argv[2]);
	268	head->next = pat->headers;
	269	pat->headers = head;
	270	} else if(!strcmp(s->argv[0], "end") \|\| !strcmp(s->argv[0], "eof")) {
	271	break;
	272	} else {
	273	flog(LOG_WARNING, "%s:%i: unknown directive `%s' in pattern declaration", s->file, s->lno, s->argv[0]);
	274	}
	275	}
	276
	277	if(pat->rules[0] == NULL) {
	278	flog(LOG_WARNING, "%s:%i: missing rules in match declaration", s->file, sl);
	279	freepattern(pat);
	280	return(NULL);
	281	}
	282	if(pat->childnm == NULL) {
	283	flog(LOG_WARNING, "%s:%i: missing handler in match declaration", s->file, sl);
	284	freepattern(pat);
	285	return(NULL);
	286	}
	287	return(pat);
	288	}
	289
	290	static struct config readconfig(char filename)
	291	{
	292	struct cfstate *s;
	293	struct config *cf;
	294	struct child *ch;
	295	struct pattern *pat;
	296	FILE *in;
	297
	298	if((in = fopen(filename, "r")) == NULL) {
	299	flog(LOG_WARNING, "%s: %s", filename, strerror(errno));
	300	return(NULL);
	301	}
	302	s = mkcfparser(in, filename);
	303	omalloc(cf);
	304
	305	while(1) {
	306	getcfline(s);
	307	if((ch = parsechild(s)) != NULL) {
	308	ch->next = cf->children;
	309	cf->children = ch;
	310	} else if((pat = parsepattern(s)) != NULL) {
	311	pat->next = cf->patterns;
	312	cf->patterns = pat;
	313	} else if(!strcmp(s->argv[0], "eof")) {
	314	break;
	315	} else {
	316	flog(LOG_WARNING, "%s:%i: unknown directive `%s'", s->file, s->lno, s->argv[0]);
	317	}
	318	}
	319
	320	freecfparser(s);
	321	fclose(in);
	322	return(cf);
	323	}
	324
	325	static void exprestpat(struct hthead req, struct pattern pat, char **mstr)
	326	{
	327	char p, p2, *hdr;
	328	int mc;
	329	struct charbuf buf;
	330
	331	if(mstr == NULL)
	332	mc = 0;
	333	else
	334	for(mc = 0; mstr[mc]; mc++);
	335	bufinit(buf);
	336	for(p = pat->restpat; *p; ) {
	337	if(*p == '$') {
	338	p++;
	339	if((p >= '0') && (p <= '9')) {
	340	if(*p - '0' < mc)
	341	bufcatstr(buf, mstr[*p - '0']);
	342	p++;
	343	} else if(*p == '_') {
	344	bufcatstr(buf, req->rest);
	345	p++;
	346	} else if(*p == '$') {
	347	bufadd(buf, '$');
	348	p++;
	349	} else if(*p == '{') {
	350	if((p2 = strchr(p, '}')) == NULL) {
	351	p++;
	352	} else {
	353	hdr = getheader(req, sprintf3("%.*s", p2 - p - 1, p + 1));
	354	if(hdr)
	355	bufcatstr(buf, hdr);
	356	}
	357	} else if(!*p) {
	358	}
	359	} else {
	360	bufadd(buf, *(p++));
	361	}
	362	}
	363	bufadd(buf, 0);
	364	replrest(req, buf.b);
	365	buffree(buf);
	366	}
	367
	368	static void qoffsets(char buf, int obuf, char *pstr, int unquote)
	369	{
	370	int i, o, d1, d2;
	371
	372	if(unquote) {
	373	i = o = 0;
	374	while(pstr[i]) {
	375	obuf[o] = i;
	376	if((pstr[i] == '%') && ((d1 = hexdigit(pstr[i + 1])) >= 0) && ((d2 = hexdigit(pstr[i + 2])) >= 0)) {
	377	buf[o] = (d1 << 4) \| d2;
	378	i += 3;
	379	} else {
	380	buf[o] = pstr[i];
	381	i++;
	382	}
	383	o++;
	384	}
	385	buf[o] = 0;
	386	} else {
	387	for(i = 0; pstr[i]; i++) {
	388	buf[i] = pstr[i];
	389	obuf[i] = i;
	390	}
	391	buf[i] = 0;
	392	}
	393	}
	394
	395	static struct pattern findmatch(struct config cf, struct hthead *req, int trydefault)
	396	{
	397	int i, o;
	398	struct pattern *pat;
	399	struct rule *rule;
	400	int rmo;
	401	regex_t *rx;
	402	char *pstr;
	403	char **mstr;
	404	regmatch_t gr[10];
	405
	406	mstr = NULL;
	407	for(pat = cf->patterns; pat != NULL; pat = pat->next) {
	408	rmo = -1;
	409	for(i = 0; (rule = pat->rules[i]) != NULL; i++) {
	410	rx = NULL;
	411	if(rule->type == PAT_REST) {
	412	rx = rule->pattern;
	413	pstr = req->rest;
	414	} else if(rule->type == PAT_URL) {
	415	rx = rule->pattern;
	416	pstr = req->url;
	417	} else if(rule->type == PAT_METHOD) {
	418	rx = rule->pattern;
	419	pstr = req->method;
	420	} else if(rule->type == PAT_HEADER) {
	421	rx = rule->pattern;
	422	if(!(pstr = getheader(req, rule->header)))
	423	break;
	424	}
	425	if(rx != NULL) {
	426	char pbuf[strlen(pstr) + 1];
	427	int obuf[strlen(pstr) + 1];
	428	qoffsets(pbuf, obuf, pstr, !!(rule->fl & PATFL_UNQ));
	429	if(regexec(rx, pbuf, 10, gr, 0))
	430	break;
	431	else if(rule->type == PAT_REST)
	432	rmo = obuf[gr[0].rm_eo];
	433	if(rule->fl & PATFL_MSS) {
	434	if(mstr) {
	435	flog(LOG_WARNING, "two pattern rules marked with `s' flag found (for handler %s)", pat->childnm);
	436	freeca(mstr);
	437	}
	438	for(o = 0; o < 10; o++) {
	439	if(gr[o].rm_so < 0)
	440	break;
	441	}
	442	mstr = szmalloc((o + 1) * sizeof(*mstr));
	443	for(o = 0; o < 10; o++) {
	444	if(gr[o].rm_so < 0)
	445	break;
	446	mstr[o] = smalloc(obuf[gr[o].rm_eo] - obuf[gr[o].rm_so] + 1);
	447	memcpy(mstr[o], pstr + obuf[gr[o].rm_so], obuf[gr[o].rm_eo] - obuf[gr[o].rm_so]);
	448	mstr[o][obuf[gr[o].rm_eo] - obuf[gr[o].rm_so]] = 0;
	449	}
	450	}
	451	} else if(rule->type == PAT_ALL) {
	452	} else if(rule->type == PAT_DEFAULT) {
	453	if(!trydefault)
	454	break;
	455	}
	456	}
	457	if(!rule) {
	458	if(pat->restpat) {
	459	exprestpat(req, pat, mstr);
	460	} else if(rmo != -1) {
	461	replrest(req, req->rest + rmo);
	462	}
	463	if(mstr)
	464	freeca(mstr);
	465	return(pat);
	466	}
	467	if(mstr) {
	468	freeca(mstr);
	469	mstr = NULL;
	470	}
	471	}
	472	return(NULL);
	473	}
	474
	475	static void childerror(struct hthead *req, int fd)
	476	{
	477	if(errno == EAGAIN)
	478	simpleerror(fd, 500, "Server Error", "The request handler is overloaded.");
	479	else
	480	simpleerror(fd, 500, "Server Error", "The request handler crashed.");
	481	}
	482
	483	static void serve(struct hthead *req, int fd)
	484	{
	485	struct pattern *pat;
	486	struct headmod *head;
	487	struct child *ch;
	488
	489	pat = NULL;
	490	if(pat == NULL)
	491	pat = findmatch(lconfig, req, 0);
	492	if(pat == NULL)
	493	pat = findmatch(lconfig, req, 1);
	494	if(gconfig != NULL) {
	495	if(pat == NULL)
	496	pat = findmatch(gconfig, req, 0);
	497	if(pat == NULL)
	498	pat = findmatch(gconfig, req, 1);
	499	}
	500	if(pat == NULL) {
	501	simpleerror(fd, 404, "Not Found", "The requested resource could not be found on this server.");
	502	return;
	503	}
	504	ch = NULL;
	505	if(ch == NULL)
	506	ch = getchild(lconfig, pat->childnm);
	507	if(gconfig != NULL) {
	508	if(ch == NULL)
	509	ch = getchild(gconfig, pat->childnm);
	510	}
	511	if(ch == NULL) {
	512	flog(LOG_ERR, "child %s requested, but was not declared", pat->childnm);
	513	simpleerror(fd, 500, "Configuration Error", "The server is erroneously configured. Handler %s was requested, but not declared.", pat->childnm);
	514	return;
	515	}
	516
	517	for(head = pat->headers; head != NULL; head = head->next) {
	518	headrmheader(req, head->name);
	519	headappheader(req, head->name, head->value);
	520	}
	521	if(childhandle(ch, req, fd, NULL, NULL))
	522	childerror(req, fd);
	523	}
	524
	525	static void reloadconf(char *nm)
	526	{
	527	struct config *cf;
	528
	529	if((cf = readconfig(nm)) == NULL) {
	530	flog(LOG_WARNING, "could not reload configuration file `%s'", nm);
	531	return;
	532	}
	533	mergechildren(cf->children, lconfig->children);
	534	freeconfig(lconfig);
	535	lconfig = cf;
	536	}
	537
	538	static void chldhandler(int sig)
	539	{
	540	pid_t pid;
	541	int st;
	542
	543	while((pid = waitpid(-1, &st, WNOHANG)) > 0) {
	544	if(WCOREDUMP(st))
	545	flog(LOG_WARNING, "child process %i dumped core", pid);
	546	}
	547	}
	548
	549	static void sighandler(int sig)
	550	{
	551	if(sig == SIGHUP)
	552	reload = 1;
	553	}
	554
	555	static void usage(FILE *out)
	556	{
	557	fprintf(out, "usage: patplex [-hN] CONFIGFILE\n");
	558	}
	559
	560	int main(int argc, char **argv)
	561	{
	562	int c;
	563	int nodef;
	564	char gcf, lcf;
	565	struct hthead *req;
	566	int fd;
	567
	568	nodef = 0;
	569	while((c = getopt(argc, argv, "hN")) >= 0) {
	570	switch(c) {
	571	case 'h':
	572	usage(stdout);
	573	exit(0);
	574	case 'N':
	575	nodef = 1;
	576	break;
	577	default:
	578	usage(stderr);
	579	exit(1);
	580	}
	581	}
	582	if(argc - optind < 1) {
	583	usage(stderr);
	584	exit(1);
	585	}
	586	if(!nodef) {
	587	if((gcf = findstdconf("ashd/patplex.rc")) != NULL) {
	588	gconfig = readconfig(gcf);
	589	free(gcf);
	590	}
	591	}
	592	if((strchr(lcf = argv[optind], '/')) == NULL) {
	593	if((lcf = findstdconf(sprintf3("ashd/%s", lcf))) == NULL) {
	594	flog(LOG_ERR, "could not find requested configuration file `%s'", argv[optind]);
	595	exit(1);
	596	}
	597	}
	598	if((lconfig = readconfig(lcf)) == NULL) {
	599	flog(LOG_ERR, "could not read `%s'", lcf);
	600	exit(1);
	601	}
	602	signal(SIGCHLD, chldhandler);
	603	signal(SIGHUP, sighandler);
	604	signal(SIGPIPE, sighandler);
	605	while(1) {
	606	if(reload) {
	607	reloadconf(lcf);
	608	reload = 0;
	609	}
	610	if((fd = recvreq(0, &req)) < 0) {
	611	if(errno == EINTR)
	612	continue;
	613	if(errno != 0)
	614	flog(LOG_ERR, "recvreq: %s", strerror(errno));
	615	break;
	616	}
	617	serve(req, fd);
	618	freehthead(req);
	619	close(fd);
	620	}
	621	return(0);
	622	}