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 			z->avail_in = len - *consumed;
155 			if (z->avail_in == 0) {
156 				/* EOF */
157 				ret = deflate(z, Z_FINISH);
158 				break;
159 			}
160 		}
161 		ret = deflate(z, Z_NO_FLUSH);
162 		*consumed += z->total_in - last_total_in;
163 	} while (ret == Z_OK && z->avail_out > 0);
164 
165 	if (ret == Z_OK) {
166 		zb->flags |= GOT_DEFLATE_F_HAVE_MORE;
167 	} else {
168 		if (ret != Z_STREAM_END)
169 			return got_error(GOT_ERR_COMPRESSION);
170 		zb->flags &= ~GOT_DEFLATE_F_HAVE_MORE;
171 	}
172 
173 	*outlenp = z->total_out - last_total_out;
174 	return NULL;
175 }
176 
177 void
178 got_deflate_end(struct got_deflate_buf *zb)
179 {
180 	free(zb->inbuf);
181 	if (zb->flags & GOT_DEFLATE_F_OWN_OUTBUF)
182 		free(zb->outbuf);
183 	deflateEnd(&zb->z);
184 }
185 
186 const struct got_error *
187 got_deflate_to_file(off_t *outlen, FILE *infile, off_t len,
188     FILE *outfile, struct got_deflate_checksum *csum)
189 {
190 	const struct got_error *err;
191 	size_t avail;
192 	off_t consumed;
193 	struct got_deflate_buf zb;
194 
195 	err = got_deflate_init(&zb, NULL, GOT_DEFLATE_BUFSIZE);
196 	if (err)
197 		goto done;
198 
199 	*outlen = 0;
200 
201 	do {
202 		err = got_deflate_read(&zb, infile, len, &avail, &consumed);
203 		if (err)
204 			goto done;
205 		len -= consumed;
206 		if (avail > 0) {
207 			size_t n;
208 			n = fwrite(zb.outbuf, avail, 1, outfile);
209 			if (n != 1) {
210 				err = got_ferror(outfile, GOT_ERR_IO);
211 				goto done;
212 			}
213 			if (csum)
214 				csum_output(csum, zb.outbuf, avail);
215 			*outlen += avail;
216 		}
217 	} while (zb.flags & GOT_DEFLATE_F_HAVE_MORE);
218 
219 done:
220 	got_deflate_end(&zb);
221 	return err;
222 }
223 
224 const struct got_error *
225 got_deflate_to_file_mmap(off_t *outlen, uint8_t *map, size_t offset,
226     size_t len, FILE *outfile, struct got_deflate_checksum *csum)
227 {
228 	const struct got_error *err;
229 	size_t avail, consumed;
230 	struct got_deflate_buf zb;
231 
232 	err = got_deflate_init(&zb, NULL, GOT_DEFLATE_BUFSIZE);
233 	if (err)
234 		goto done;
235 
236 	*outlen = 0;
237 	do {
238 		err = got_deflate_read_mmap(&zb, map, offset, len, &avail,
239 		    &consumed);
240 		if (err)
241 			goto done;
242 		offset += consumed;
243 		len -= consumed;
244 		if (avail > 0) {
245 			size_t n;
246 			n = fwrite(zb.outbuf, avail, 1, outfile);
247 			if (n != 1) {
248 				err = got_ferror(outfile, GOT_ERR_IO);
249 				goto done;
250 			}
251 			if (csum)
252 				csum_output(csum, zb.outbuf, avail);
253 			*outlen += avail;
254 		}
255 	} while (zb.flags & GOT_DEFLATE_F_HAVE_MORE);
256 
257 done:
258 	got_deflate_end(&zb);
259 	return err;
260 }