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, size_t *outlenp)
92 {
93 	size_t last_total_out = zb->z.total_out;
94 	z_stream *z = &zb->z;
95 	int ret = Z_ERRNO;
96 
97 	z->next_out = zb->outbuf;
98 	z->avail_out = zb->outlen;
99 
100 	*outlenp = 0;
101 	do {
102 		if (z->avail_in == 0) {
103 			size_t n = fread(zb->inbuf, 1, zb->inlen, f);
104 			if (n == 0) {
105 				if (ferror(f))
106 					return got_ferror(f, GOT_ERR_IO);
107 				/* EOF */
108 				ret = deflate(z, Z_FINISH);
109 				break;
110 			}
111 			z->next_in = zb->inbuf;
112 			z->avail_in = n;
113 		}
114 		ret = deflate(z, Z_NO_FLUSH);
115 	} while (ret == Z_OK && z->avail_out > 0);
116 
117 	if (ret == Z_OK) {
118 		zb->flags |= GOT_DEFLATE_F_HAVE_MORE;
119 	} else {
120 		if (ret != Z_STREAM_END)
121 			return got_error(GOT_ERR_COMPRESSION);
122 		zb->flags &= ~GOT_DEFLATE_F_HAVE_MORE;
123 	}
124 
125 	*outlenp = z->total_out - last_total_out;
126 	return NULL;
127 }
128 
129 const struct got_error *
130 got_deflate_read_mmap(struct got_deflate_buf *zb, uint8_t *map, size_t offset,
131     size_t len, size_t *outlenp, size_t *consumed)
132 {
133 	z_stream *z = &zb->z;
134 	size_t last_total_out = z->total_out;
135 	int ret = Z_ERRNO;
136 
137 	z->next_out = zb->outbuf;
138 	z->avail_out = zb->outlen;
139 
140 	*outlenp = 0;
141 	*consumed = 0;
142 	do {
143 		size_t last_total_in = z->total_in;
144 		if (z->avail_in == 0) {
145 			z->next_in = map + offset + *consumed;
146 			z->avail_in = len - *consumed;
147 			if (z->avail_in == 0) {
148 				/* EOF */
149 				ret = deflate(z, Z_FINISH);
150 				break;
151 			}
152 		}
153 		ret = deflate(z, Z_NO_FLUSH);
154 		*consumed += z->total_in - last_total_in;
155 	} while (ret == Z_OK && z->avail_out > 0);
156 
157 	if (ret == Z_OK) {
158 		zb->flags |= GOT_DEFLATE_F_HAVE_MORE;
159 	} else {
160 		if (ret != Z_STREAM_END)
161 			return got_error(GOT_ERR_COMPRESSION);
162 		zb->flags &= ~GOT_DEFLATE_F_HAVE_MORE;
163 	}
164 
165 	*outlenp = z->total_out - last_total_out;
166 	return NULL;
167 }
168 
169 void
170 got_deflate_end(struct got_deflate_buf *zb)
171 {
172 	free(zb->inbuf);
173 	if (zb->flags & GOT_DEFLATE_F_OWN_OUTBUF)
174 		free(zb->outbuf);
175 	deflateEnd(&zb->z);
176 }
177 
178 const struct got_error *
179 got_deflate_to_file(size_t *outlen, FILE *infile, FILE *outfile,
180     struct got_deflate_checksum *csum)
181 {
182 	const struct got_error *err;
183 	size_t avail;
184 	struct got_deflate_buf zb;
185 
186 	err = got_deflate_init(&zb, NULL, GOT_DEFLATE_BUFSIZE);
187 	if (err)
188 		goto done;
189 
190 	*outlen = 0;
191 
192 	do {
193 		err = got_deflate_read(&zb, infile, &avail);
194 		if (err)
195 			goto done;
196 		if (avail > 0) {
197 			size_t n;
198 			n = fwrite(zb.outbuf, avail, 1, outfile);
199 			if (n != 1) {
200 				err = got_ferror(outfile, GOT_ERR_IO);
201 				goto done;
202 			}
203 			if (csum)
204 				csum_output(csum, zb.outbuf, avail);
205 			*outlen += avail;
206 		}
207 	} while (zb.flags & GOT_DEFLATE_F_HAVE_MORE);
208 
209 done:
210 	got_deflate_end(&zb);
211 	return err;
212 }
213 
214 const struct got_error *
215 got_deflate_to_file_mmap(size_t *outlen, uint8_t *map, size_t offset,
216     size_t len, FILE *outfile, struct got_deflate_checksum *csum)
217 {
218 	const struct got_error *err;
219 	size_t avail, consumed;
220 	struct got_deflate_buf zb;
221 
222 	err = got_deflate_init(&zb, NULL, GOT_DEFLATE_BUFSIZE);
223 	if (err)
224 		goto done;
225 
226 	*outlen = 0;
227 	do {
228 		err = got_deflate_read_mmap(&zb, map, offset, len, &avail,
229 		    &consumed);
230 		if (err)
231 			goto done;
232 		offset += consumed;
233 		len -= consumed;
234 		if (avail > 0) {
235 			size_t n;
236 			n = fwrite(zb.outbuf, avail, 1, outfile);
237 			if (n != 1) {
238 				err = got_ferror(outfile, GOT_ERR_IO);
239 				goto done;
240 			}
241 			if (csum)
242 				csum_output(csum, zb.outbuf, avail);
243 			*outlen += avail;
244 		}
245 	} while (zb.flags & GOT_DEFLATE_F_HAVE_MORE);
246 
247 done:
248 	got_deflate_end(&zb);
249 	return err;
250 }