/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include <u.h>#include <libc.h>#include <bio.h>#include "httpd.h"#include "httpsrv.h" Hio *HO;int diffb; enum{ DAY = 24*60*60 }; voidlastbefore(ulong t, char *f, char *b){	Tm *tm;	Dir *dir;	int try;	ulong t0, mtime; 	t0 = t;	for(try=0; try<10; try++) {		tm = localtime(t);		t -= DAY;		sprint(b,"%.4d/%.2d%.2d/netlib/pub/%s",tm->year+1900,tm->mon+1,tm->mday,f);		dir = dirstat(b);		if(dir == nil)			continue;		mtime = dir->mtime;		free(dir);		if(mtime > t0)			continue;		return;	}	strcpy(b, "filenotfound");} // create explicit file for diff, which otherwise would create a// mode 0600 file that it couldn't read (because running as none)voidgunzip(char *f, char *tmp){	int fd = open(tmp, OWRITE); 	if(fd < 0)  // can't happen		return;	switch(fork()){	case 0:		dup(fd, 1);		close(fd);		close(0);		execl("/bin/gunzip", "gunzip", "-c", f, nil);		hprint(HO, "can't exec gunzip: %r\n");		break;	case -1:		hprint(HO, "fork failed: %r\n");	default:		while(waitpid() != -1)			;		break;	}	close(fd);} voidnetlibhistory(char *file){	char buf[500], pair[2][500], tmpf[2][30], *f;	int toggle = 0, started = 0, limit;	Dir *dir;	ulong otime, dt;	int i, fd, tmpcnt; 	if(strncmp(file, "../", 3) == 0 || strstr(file, "/../") ||		strlen(file) >= sizeof(buf) - strlen("1997/0204/netlib/pub/0"))		return;	limit = 50;	if(diffb){		limit = 10;		// create two tmp files for gunzip		for(i = 0, tmpcnt = 0; i < 2 && tmpcnt < 20; tmpcnt++){			snprint(tmpf[i], sizeof(tmpf[0]), "/tmp/d%x", tmpcnt);			if(access(buf, AEXIST) == 0)				continue;			fd = create(tmpf[i], OWRITE, 0666);			if(fd < 0)				goto done;			close(fd);			i++;		}	}	otime = time(0);	hprint(HO,"<UL>\n");	while(limit--){		lastbefore(otime, file, buf);		dir = dirstat(buf);		if(dir == nil)			goto done;		dt = DAY/2;		while(otime <= dir->mtime){			lastbefore(otime-dt, file, buf);			free(dir);			dir = dirstat(buf);			if(dir == nil)				goto done;			dt += DAY/2;		}		f = pair[toggle];		strcpy(f, buf);		if(diffb && strcmp(f+strlen(f)-3, ".gz") == 0){			gunzip(f, tmpf[toggle]);			strcpy(f, tmpf[toggle]);		}		if(diffb && started){			hprint(HO, "<PRE>\n");			hflush(HO);			switch(fork()){			case 0:				execl("/bin/diff", "diff", "-nb",					pair[1-toggle], pair[toggle], nil);				hprint(HO, "can't exec diff: %r\n");				break;			case -1:				hprint(HO, "fork failed: %r\n");				break;			default:				while(waitpid() != -1)					;				break;			}			hprint(HO, "</PRE>\n");		}		hprint(HO,"<LI><A HREF=\"/historic/%s\">%s</A> %lld bytes\n",			buf, 4+asctime(gmtime(dir->mtime)), dir->length);		if(diffb)			hprint(HO," <FONT SIZE=-1>(%s)</FONT>\n", pair[toggle]);		toggle = 1-toggle;		started = 1;		otime = dir->mtime;		free(dir);	}	hprint(HO,"<LI>...\n");done:	hprint(HO,"</UL>\n");	if(diffb){		remove(tmpf[0]);		remove(tmpf[1]);	}} intsend(HConnect *c){	char *file, *s;	HSPairs *q; 	if(strcmp(c->req.meth, "GET") != 0 && strcmp(c->req.meth, "HEAD") != 0)		return hunallowed(c, "GET, HEAD");	if(c->head.expectother || c->head.expectcont)		return hfail(c, HExpectFail, nil);	if(c->req.search == nil || !*c->req.search)		return hfail(c, HNoData, "netlib_history");	s = c->req.search;	while((s = strchr(s, '+')) != nil)		*s++ = ' ';	file = nil;	for(q = hparsequery(c, hstrdup(c, c->req.search)); q; q = q->next){		if(strcmp(q->s, "file") == 0)			file = q->t;		else if(strcmp(q->s, "diff") == 0)			diffb = 1;	}	if(file == nil)		return hfail(c, HNoData, "netlib_history missing file field");	logit(c, "netlib_hist %s%s", file, diffb?" DIFF":""); 	if(c->req.vermaj){		hokheaders(c);		hprint(HO, "Content-type: text/html\r\n");		hprint(HO, "\r\n");	}	if(strcmp(c->req.meth, "HEAD") == 0){		writelog(c, "Reply: 200 netlib_history 0\n");		hflush(HO);		exits(nil);	} 	hprint(HO, "<HEAD><TITLE>%s history</TITLE></HEAD>\n<BODY>\n",file);	hprint(HO, "<H2>%s history</H2>\n",file);	hprint(HO, "<I>Netlib's copy of %s was changed\n", file);	hprint(HO, "on the dates shown.  <BR>Click on the date link\n");	hprint(HO, "to retrieve the corresponding version.</I>\n");	if(diffb){		hprint(HO, "<BR><I>Lines beginning with &lt; are for the\n");		hprint(HO, "newer of the two versions.</I>\n");	} 	if(chdir("/usr/web/historic") < 0)		hprint(HO, "chdir failed: %r\n");	netlibhistory(file); 	hprint(HO, "<BR><A HREF=\"http://cm.bell-labs.com/who/ehg\">Eric Grosse</A>\n");	hprint(HO, "</BODY></HTML>\n");	hflush(HO);	writelog(c, "Reply: 200 netlib_history %ld %ld\n", HO->seek, HO->seek);	return 1;} voidmain(int argc, char **argv){	HConnect *c; 	c = init(argc, argv);	HO = &c->hout;	if(hparseheaders(c, HSTIMEOUT) >= 0)		send(c);	exits(nil);}