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 <sha1.h>
23 #include <zlib.h>
24 #include <time.h>
25 
26 #include "got_error.h"
27 #include "got_object.h"
28 #include "got_path.h"
29 
30 #include "got_lib_deflate.h"
31 
32 #ifndef MIN
33 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
34 #endif
35 
36 const struct got_error *
37 got_deflate_init(struct got_deflate_buf *zb, uint8_t *outbuf, size_t bufsize)
38 {
39 	const struct got_error *err = NULL;
40 	int zerr;
41 
42 	memset(&zb->z, 0, sizeof(zb->z));
43 
44 	zb->z.zalloc = Z_NULL;
45 	zb->z.zfree = Z_NULL;
46 	zerr = deflateInit(&zb->z, Z_DEFAULT_COMPRESSION);
47 	if (zerr != Z_OK) {
48 		if  (zerr == Z_ERRNO)
49 			return got_error_from_errno("deflateInit");
50 		if  (zerr == Z_MEM_ERROR) {
51 			errno = ENOMEM;
52 			return got_error_from_errno("deflateInit");
53 		}
54 		return got_error(GOT_ERR_COMPRESSION);
55 	}
56 
57 	zb->inlen = zb->outlen = bufsize;
58 
59 	zb->inbuf = calloc(1, zb->inlen);
60 	if (zb->inbuf == NULL) {
61 		err = got_error_from_errno("calloc");
62 		goto done;
63 	}
64 
65 	zb->flags = 0;
66 	if (outbuf == NULL) {
67 		zb->outbuf = calloc(1, zb->outlen);
68 		if (zb->outbuf == NULL) {
69 			err = got_error_from_errno("calloc");
70 			goto done;
71 		}
72 		zb->flags |= GOT_DEFLATE_F_OWN_OUTBUF;
73 	} else
74 		zb->outbuf = outbuf;
75 done:
76 	if (err)
77 		got_deflate_end(zb);
78 	return err;
79 }
80 
81 static void
82 csum_output(struct got_deflate_checksum *csum, const char *buf, size_t len)
83 {
84 	if (csum->output_crc)
85 		*csum->output_crc = crc32(*csum->output_crc, buf, len);
86 
87 	if (csum->output_sha1)
88 		SHA1Update(csum->output_sha1, buf, len);
89 }
90 
91 const struct got_error *
92 got_deflate_read(struct got_deflate_buf *zb, FILE *f, size_t *outlenp)
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 	do {
103 		if (z->avail_in == 0) {
104 			size_t n = fread(zb->inbuf, 1, zb->inlen, f);
105 			if (n == 0) {
106 				if (ferror(f))
107 					return got_ferror(f, GOT_ERR_IO);
108 				/* EOF */
109 				ret = deflate(z, Z_FINISH);
110 				break;
111 			}
112 			z->next_in = zb->inbuf;
113 			z->avail_in = n;
114 		}
115 		ret = deflate(z, Z_NO_FLUSH);
116 	} while (ret == Z_OK && z->avail_out > 0);
117 
118 	if (ret == Z_OK) {
119 		zb->flags |= GOT_DEFLATE_F_HAVE_MORE;
120 	} else {
121 		if (ret != Z_STREAM_END)
122 			return got_error(GOT_ERR_COMPRESSION);
123 		zb->flags &= ~GOT_DEFLATE_F_HAVE_MORE;
124 	}
125 
126 	*outlenp = z->total_out - last_total_out;
127 	return NULL;
128 }
129 
130 void
131 got_deflate_end(struct got_deflate_buf *zb)
132 {
133 	free(zb->inbuf);
134 	if (zb->flags & GOT_DEFLATE_F_OWN_OUTBUF)
135 		free(zb->outbuf);
136 	deflateEnd(&zb->z);
137 }
138 
139 const struct got_error *
140 got_deflate_to_file(size_t *outlen, FILE *infile, FILE *outfile,
141     struct got_deflate_checksum *csum)
142 {
143 	const struct got_error *err;
144 	size_t avail;
145 	struct got_deflate_buf zb;
146 
147 	err = got_deflate_init(&zb, NULL, GOT_DEFLATE_BUFSIZE);
148 	if (err)
149 		goto done;
150 
151 	*outlen = 0;
152 
153 	do {
154 		err = got_deflate_read(&zb, infile, &avail);
155 		if (err)
156 			goto done;
157 		if (avail > 0) {
158 			size_t n;
159 			n = fwrite(zb.outbuf, avail, 1, outfile);
160 			if (n != 1) {
161 				err = got_ferror(outfile, GOT_ERR_IO);
162 				goto done;
163 			}
164 			if (csum)
165 				csum_output(csum, zb.outbuf, avail);
166 			*outlen += avail;
167 		}
168 	} while (zb.flags & GOT_DEFLATE_F_HAVE_MORE);
169 
170 done:
171 	got_deflate_end(&zb);
172 	return err;
173 }