1 /*
2  * Copyright (c) 2019 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 
18 #include <errno.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <zlib.h>
23 #include <time.h>
24 
25 #include "got_error.h"
26 #include "got_object.h"
27 #include "got_path.h"
28 
29 #include "got_lib_deflate.h"
30 
31 #ifndef MIN
32 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
33 #endif
34 
35 const struct got_error *
36 got_deflate_init(struct got_deflate_buf *zb, uint8_t *outbuf, size_t bufsize)
37 {
38 	const struct got_error *err = NULL;
39 	int zerr;
40 
41 	memset(&zb->z, 0, sizeof(zb->z));
42 
43 	zb->z.zalloc = Z_NULL;
44 	zb->z.zfree = Z_NULL;
45 	zerr = deflateInit(&zb->z, Z_DEFAULT_COMPRESSION);
46 	if (zerr != Z_OK) {
47 		if  (zerr == Z_ERRNO)
48 			return got_error_from_errno("deflateInit");
49 		if  (zerr == Z_MEM_ERROR) {
50 			errno = ENOMEM;
51 			return got_error_from_errno("deflateInit");
52 		}
53 		return got_error(GOT_ERR_COMPRESSION);
54 	}
55 
56 	zb->inlen = zb->outlen = bufsize;
57 
58 	zb->inbuf = calloc(1, zb->inlen);
59 	if (zb->inbuf == NULL) {
60 		err = got_error_from_errno("calloc");
61 		goto done;
62 	}
63 
64 	zb->flags = 0;
65 	if (outbuf == NULL) {
66 		zb->outbuf = calloc(1, zb->outlen);
67 		if (zb->outbuf == NULL) {
68 			err = got_error_from_errno("calloc");
69 			goto done;
70 		}
71 		zb->flags |= GOT_DEFLATE_F_OWN_OUTBUF;
72 	} else
73 		zb->outbuf = outbuf;
74 done:
75 	if (err)
76 		got_deflate_end(zb);
77 	return err;
78 }
79 
80 static void
81 csum_output(struct got_deflate_checksum *csum, const uint8_t *buf, size_t len)
82 {
83 	if (csum->output_crc)
84 		*csum->output_crc = crc32(*csum->output_crc, buf, len);
85 
86 	if (csum->output_sha1)
87 		SHA1Update(csum->output_sha1, buf, len);
88 }
89 
90 const struct got_error *
91 got_deflate_read(struct got_deflate_buf *zb, FILE *f, off_t len,
92     size_t *outlenp, off_t *consumed)
93 {
94 	size_t last_total_out = zb->z.total_out;
95 	z_stream *z = &zb->z;
96 	int ret = Z_ERRNO;
97 
98 	z->next_out = zb->outbuf;
99 	z->avail_out = zb->outlen;
100 
101 	*outlenp = 0;
102 	*consumed = 0;
103 	do {
104 		size_t last_total_in = z->total_in;
105 		if (z->avail_in == 0) {
106 			size_t n = 0;
107 			if (*consumed < len) {
108 				n = fread(zb->inbuf, 1,
109 				    MIN(zb->inlen, len - *consumed), f);
110 			}
111 			if (n == 0) {
112 				if (ferror(f))
113 					return got_ferror(f, GOT_ERR_IO);
114 				/* EOF */
115 				ret = deflate(z, Z_FINISH);
116 				break;
117 			}
118 			z->next_in = zb->inbuf;
119 			z->avail_in = n;
120 		}
121 		ret = deflate(z, Z_NO_FLUSH);
122 		*consumed += z->total_in - last_total_in;
123 	} while (ret == Z_OK && z->avail_out > 0);
124 
125 	if (ret == Z_OK) {
126 		zb->flags |= GOT_DEFLATE_F_HAVE_MORE;
127 	} else {
128 		if (ret != Z_STREAM_END)
129 			return got_error(GOT_ERR_COMPRESSION);
130 		zb->flags &= ~GOT_DEFLATE_F_HAVE_MORE;
131 	}
132 
133 	*outlenp = z->total_out - last_total_out;
134 	return NULL;
135 }
136 
137 const struct got_error *
138 got_deflate_read_mmap(struct got_deflate_buf *zb, uint8_t *map, size_t offset,
139     size_t len, size_t *outlenp, size_t *consumed)
140 {
141 	z_stream *z = &zb->z;
142 	size_t last_total_out = z->total_out;
143 	int ret = Z_ERRNO;
144 
145 	z->next_out = zb->outbuf;
146 	z->avail_out = zb->outlen;
147 
148 	*outlenp = 0;
149 	*consumed = 0;
150 	do {
151 		size_t last_total_in = z->total_in;
152 		if (z->avail_in == 0) {
153 			z->next_in = map + offset + *consumed;
154 			if (len - *consumed > UINT_MAX)
155 				z->avail_in = UINT_MAX;
156 			else
157 				z->avail_in = len - *consumed;
158 			if (z->avail_in == 0) {
159 				/* EOF */
160 				ret = deflate(z, Z_FINISH);
161 				break;
162 			}
163 		}
164 		ret = deflate(z, Z_NO_FLUSH);
165 		*consumed += z->total_in - last_total_in;
166 	} while (ret == Z_OK && z->avail_out > 0);
167 
168 	if (ret == Z_OK) {
169 		zb->flags |= GOT_DEFLATE_F_HAVE_MORE;
170 	} else {
171 		if (ret != Z_STREAM_END)
172 			return got_error(GOT_ERR_COMPRESSION);
173 		zb->flags &= ~GOT_DEFLATE_F_HAVE_MORE;
174 	}
175 
176 	*outlenp = z->total_out - last_total_out;
177 	return NULL;
178 }
179 
180 void
181 got_deflate_end(struct got_deflate_buf *zb)
182 {
183 	free(zb->inbuf);
184 	if (zb->flags & GOT_DEFLATE_F_OWN_OUTBUF)
185 		free(zb->outbuf);
186 	deflateEnd(&zb->z);
187 }
188 
189 const struct got_error *
190 got_deflate_to_file(off_t *outlen, FILE *infile, off_t len,
191     FILE *outfile, struct got_deflate_checksum *csum)
192 {
193 	const struct got_error *err;
194 	size_t avail;
195 	off_t consumed;
196 	struct got_deflate_buf zb;
197 
198 	err = got_deflate_init(&zb, NULL, GOT_DEFLATE_BUFSIZE);
199 	if (err)
200 		goto done;
201 
202 	*outlen = 0;
203 
204 	do {
205 		err = got_deflate_read(&zb, infile, len, &avail, &consumed);
206 		if (err)
207 			goto done;
208 		len -= consumed;
209 		if (avail > 0) {
210 			size_t n;
211 			n = fwrite(zb.outbuf, avail, 1, outfile);
212 			if (n != 1) {
213 				err = got_ferror(outfile, GOT_ERR_IO);
214 				goto done;
215 			}
216 			if (csum)
217 				csum_output(csum, zb.outbuf, avail);
218 			*outlen += avail;
219 		}
220 	} while (zb.flags & GOT_DEFLATE_F_HAVE_MORE);
221 
222 done:
223 	got_deflate_end(&zb);
224 	return err;
225 }
226 
227 const struct got_error *
228 got_deflate_to_file_mmap(off_t *outlen, uint8_t *map, size_t offset,
229     size_t len, FILE *outfile, struct got_deflate_checksum *csum)
230 {
231 	const struct got_error *err;
232 	size_t avail, consumed;
233 	struct got_deflate_buf zb;
234 
235 	err = got_deflate_init(&zb, NULL, GOT_DEFLATE_BUFSIZE);
236 	if (err)
237 		goto done;
238 
239 	*outlen = 0;
240 	do {
241 		err = got_deflate_read_mmap(&zb, map, offset, len, &avail,
242 		    &consumed);
243 		if (err)
244 			goto done;
245 		offset += consumed;
246 		len -= consumed;
247 		if (avail > 0) {
248 			size_t n;
249 			n = fwrite(zb.outbuf, avail, 1, outfile);
250 			if (n != 1) {
251 				err = got_ferror(outfile, GOT_ERR_IO);
252 				goto done;
253 			}
254 			if (csum)
255 				csum_output(csum, zb.outbuf, avail);
256 			*outlen += avail;
257 		}
258 	} while (zb.flags & GOT_DEFLATE_F_HAVE_MORE);
259 
260 done:
261 	got_deflate_end(&zb);
262 	return err;
263 }