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 char *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 void
130 got_deflate_end(struct got_deflate_buf *zb)
131 {
132 	free(zb->inbuf);
133 	if (zb->flags & GOT_DEFLATE_F_OWN_OUTBUF)
134 		free(zb->outbuf);
135 	deflateEnd(&zb->z);
136 }
137 
138 const struct got_error *
139 got_deflate_to_file(size_t *outlen, FILE *infile, FILE *outfile,
140     struct got_deflate_checksum *csum)
141 {
142 	const struct got_error *err;
143 	size_t avail;
144 	struct got_deflate_buf zb;
145 
146 	err = got_deflate_init(&zb, NULL, GOT_DEFLATE_BUFSIZE);
147 	if (err)
148 		goto done;
149 
150 	*outlen = 0;
151 
152 	do {
153 		err = got_deflate_read(&zb, infile, &avail);
154 		if (err)
155 			goto done;
156 		if (avail > 0) {
157 			size_t n;
158 			n = fwrite(zb.outbuf, avail, 1, outfile);
159 			if (n != 1) {
160 				err = got_ferror(outfile, GOT_ERR_IO);
161 				goto done;
162 			}
163 			if (csum)
164 				csum_output(csum, zb.outbuf, avail);
165 			*outlen += avail;
166 		}
167 	} while (zb.flags & GOT_DEFLATE_F_HAVE_MORE);
168 
169 done:
170 	got_deflate_end(&zb);
171 	return err;
172 }