1 #include <u.h>
2 #include <libc.h>
3 #include <bio.h>
4 #include <flate.h>
5 #include <auth.h>
6 #include <fcall.h>
7 #include <ctype.h>
8 #include "tapefs.h"
9 #include "zip.h"
10 
11 #define FORCE_LOWER	1	/* force filenames to lower case */
12 #define MUNGE_CR	1	/* replace '\r\n' with ' \n' */
13 #define High64 (1LL<<63)
14 
15 /*
16  * File system for zip archives (read-only)
17  */
18 
19 enum {
20 	IS_MSDOS = 0,	/* creator OS (interpretation of external flags) */
21 	IS_RDONLY = 1,	/* file was readonly (external flags) */
22 	IS_TEXT = 1	/* file was text  (internal flags) */
23 };
24 
25 typedef struct Block Block;
26 struct Block{
27 	uchar *pos;
28 	uchar *limit;
29 };
30 
31 static Biobuf *bin;
32 static u32int *crctab;
33 static ulong crc;
34 
35 static int findCDir(Biobuf *);
36 static int header(Biobuf *, ZipHead *);
37 static int cheader(Biobuf *, ZipHead *);
38 /* static void trailer(Biobuf *, ZipHead *); */
39 static char *getname(Biobuf *, int);
40 static int blwrite(void *, void *, int);
41 static ulong get4(Biobuf *);
42 static int get2(Biobuf *);
43 static int get1(Biobuf *);
44 static long msdos2time(int, int);
45 
46 void
47 populate(char *name)
48 {
49 	char *p;
50 	Fileinf f;
51 	ZipHead zh;
52 	int ok, entries;
53 
54 	crctab = mkcrctab(ZCrcPoly);
55 	ok = inflateinit();
56 	if(ok != FlateOk)
57 		sysfatal("inflateinit failed: %s", flateerr(ok));
58 
59 	bin = Bopen(name, OREAD);
60 	if (bin == nil)
61 		error("Can't open argument file");
62 
63 	entries = findCDir(bin);
64 	if(entries < 0)
65 		sysfatal("empty file");
66 
67 	while(entries-- > 0){
68 		memset(&zh, 0, sizeof(zh));
69 		if(!cheader(bin, &zh))
70 			break;
71 		f.addr = zh.off;
72 		if(zh.iattr & IS_TEXT)
73 			f.addr |= High64;
74 		f.mode = (zh.madevers == IS_MSDOS && zh.eattr & IS_RDONLY)? 0444: 0644;
75 		if (zh.meth == 0 && zh.uncsize == 0){
76 			p = strchr(zh.file, '\0');
77 			if(p > zh.file && p[-1] == '/')
78 				f.mode |= (DMDIR | 0111);
79 		}
80 		f.uid = 0;
81 		f.gid = 0;
82 		f.size = zh.uncsize;
83 		f.mdate = msdos2time(zh.modtime, zh.moddate);
84 		f.name = zh.file + ((zh.file[0] == '/')? 1: 0);
85 		poppath(f, 1);
86 		free(zh.file);
87 	}
88 	return ;
89 }
90 
91 void
92 dotrunc(Ram *r)
93 {
94 	USED(r);
95 }
96 
97 void
98 docreate(Ram *r)
99 {
100 	USED(r);
101 }
102 
103 char *
104 doread(Ram *r, vlong off, long cnt)
105 {
106 	int i, err;
107 	Block bs;
108 	ZipHead zh;
109 	static Qid oqid;
110 	static char buf[Maxbuf];
111 	static uchar *cache = nil;
112 
113 	if (cnt > Maxbuf)
114 		sysfatal("file too big (>%d)", Maxbuf);
115 
116 	if (Bseek(bin, r->addr & 0x7FFFFFFFFFFFFFFFLL, 0) < 0)
117 		sysfatal("seek failed");
118 
119 	memset(&zh, 0, sizeof(zh));
120 	if (!header(bin, &zh))
121 		sysfatal("cannot get local header");
122 
123 	switch(zh.meth){
124 	case 0:
125 		if (Bseek(bin, off, 1) < 0)
126 			sysfatal("seek failed");
127 		if (Bread(bin, buf, cnt) != cnt)
128 			sysfatal("read failed");
129 		break;
130 	case 8:
131 		if (r->qid.path != oqid.path){
132 			oqid = r->qid;
133 			if (cache)
134 				free(cache);
135 			cache = emalloc(r->ndata);
136 
137 			bs.pos = cache;
138 			bs.limit = cache+r->ndata;
139 			if ((err = inflate(&bs, blwrite, bin, (int(*)(void*))Bgetc)) != FlateOk)
140 				sysfatal("inflate failed - %s", flateerr(err));
141 
142 			if (blockcrc(crctab, crc, cache, r->ndata) != zh.crc)
143 				fprint(2, "%s - crc failed", r->name);
144 
145 			if ((r->addr & High64) && MUNGE_CR){
146 				for (i = 0; i < r->ndata -1; i++)
147 					if (cache[i] == '\r' && cache[i +1] == '\n')
148 						cache[i] = ' ';
149 			}
150 		}
151 		memcpy(buf, cache+off, cnt);
152 		break;
153 	default:
154 		sysfatal("%d - unsupported compression method", zh.meth);
155 		break;
156 	}
157 
158 	return buf;
159 }
160 
161 void
162 popdir(Ram *r)
163 {
164 	USED(r);
165 }
166 
167 void
168 dowrite(Ram *r, char *buf, long off, long cnt)
169 {
170 	USED(r); USED(buf); USED(off); USED(cnt);
171 }
172 
173 int
174 dopermw(Ram *r)
175 {
176 	USED(r);
177 	return 0;
178 }
179 
180 /*************************************************/
181 
182 static int
183 findCDir(Biobuf *bin)
184 {
185 	vlong ecoff;
186 	long off;
187 	int entries, zclen;
188 
189 	ecoff = Bseek(bin, -ZECHeadSize, 2);
190 	if(ecoff < 0)
191 		sysfatal("can't seek to header");
192 
193 	if(get4(bin) != ZECHeader)
194 		sysfatal("bad magic number on directory");
195 
196 	get2(bin);
197 	get2(bin);
198 	get2(bin);
199 	entries = get2(bin);
200 	get4(bin);
201 	off = get4(bin);
202 	zclen = get2(bin);
203 	while(zclen-- > 0)
204 		get1(bin);
205 
206 	if(Bseek(bin, off, 0) != off)
207 		sysfatal("can't seek to contents");
208 
209 	return entries;
210 }
211 
212 
213 static int
214 header(Biobuf *bin, ZipHead *zh)
215 {
216 	ulong v;
217 	int flen, xlen;
218 
219 	v = get4(bin);
220 	if(v != ZHeader){
221 		if(v == ZCHeader)
222 			return 0;
223 		sysfatal("bad magic on local header");
224 	}
225 	zh->extvers = get1(bin);
226 	zh->extos = get1(bin);
227 	zh->flags = get2(bin);
228 	zh->meth = get2(bin);
229 	zh->modtime = get2(bin);
230 	zh->moddate = get2(bin);
231 	zh->crc = get4(bin);
232 	zh->csize = get4(bin);
233 	zh->uncsize = get4(bin);
234 	flen = get2(bin);
235 	xlen = get2(bin);
236 
237 	zh->file = getname(bin, flen);
238 
239 	while(xlen-- > 0)
240 		get1(bin);
241 	return 1;
242 }
243 
244 static int
245 cheader(Biobuf *bin, ZipHead *zh)
246 {
247 	ulong v;
248 	int flen, xlen, fclen;
249 
250 	v = get4(bin);
251 	if(v != ZCHeader){
252 		if(v == ZECHeader)
253 			return 0;
254 		sysfatal("bad magic number in file");
255 	}
256 	zh->madevers = get1(bin);
257 	zh->madeos = get1(bin);
258 	zh->extvers = get1(bin);
259 	zh->extos = get1(bin);
260 	zh->flags = get2(bin);
261 	zh->meth = get2(bin);
262 	zh->modtime = get2(bin);
263 	zh->moddate = get2(bin);
264 	zh->crc = get4(bin);
265 	zh->csize = get4(bin);
266 	zh->uncsize = get4(bin);
267 	flen = get2(bin);
268 	xlen = get2(bin);
269 	fclen = get2(bin);
270 	get2(bin);		/* disk number start */
271 	zh->iattr = get2(bin);	/* 1 == is-text-file */
272 	zh->eattr = get4(bin);	/* 1 == readonly-file */
273 	zh->off = get4(bin);
274 
275 	zh->file = getname(bin, flen);
276 
277 	while(xlen-- > 0)
278 		get1(bin);
279 
280 	while(fclen-- > 0)
281 		get1(bin);
282 
283 	return 1;
284 }
285 
286 static int
287 blwrite(void *vb, void *buf, int n)
288 {
289 	Block *b = vb;
290 	if(n > b->limit - b->pos)
291 		n = b->limit - b->pos;
292 	memmove(b->pos, buf, n);
293 	b->pos += n;
294 	return n;
295 }
296 
297 /*
298 static void
299 trailer(Biobuf *bin, ZipHead *zh)
300 {
301 	if(zh->flags & ZTrailInfo){
302 		zh->crc = get4(bin);
303 		zh->csize = get4(bin);
304 		zh->uncsize = get4(bin);
305 	}
306 }
307 */
308 
309 static char*
310 getname(Biobuf *bin, int len)
311 {
312 	char *s;
313 	int i, c;
314 
315 	s = emalloc(len + 1);
316 	for(i = 0; i < len; i++){
317 		c = get1(bin);
318 		if(FORCE_LOWER)
319 			c = tolower(c);
320 		s[i] = c;
321 	}
322 	s[i] = '\0';
323 	return s;
324 }
325 
326 
327 static ulong
328 get4(Biobuf *b)
329 {
330 	ulong v;
331 	int i, c;
332 
333 	v = 0;
334 	for(i = 0; i < 4; i++){
335 		c = Bgetc(b);
336 		if(c < 0)
337 			sysfatal("unexpected eof");
338 		v |= c << (i * 8);
339 	}
340 	return v;
341 }
342 
343 static int
344 get2(Biobuf *b)
345 {
346 	int i, c, v;
347 
348 	v = 0;
349 	for(i = 0; i < 2; i++){
350 		c = Bgetc(b);
351 		if(c < 0)
352 			sysfatal("unexpected eof");
353 		v |= c << (i * 8);
354 	}
355 	return v;
356 }
357 
358 static int
359 get1(Biobuf *b)
360 {
361 	int c;
362 
363 	c = Bgetc(b);
364 	if(c < 0)
365 		sysfatal("unexpected eof");
366 	return c;
367 }
368 
369 static long
370 msdos2time(int time, int date)
371 {
372 	Tm tm;
373 
374 	tm.hour = time >> 11;
375 	tm.min = (time >> 5) & 63;
376 	tm.sec = (time & 31) << 1;
377 	tm.year = 80 + (date >> 9);
378 	tm.mon = ((date >> 5) & 15) - 1;
379 	tm.mday = date & 31;
380 	tm.zone[0] = '\0';
381 	tm.yday = 0;
382 
383 	return tm2sec(&tm);
384 }