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 #include <sys/queue.h>
18 
19 #include <errno.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <sha1.h>
24 #include <zlib.h>
25 #include <time.h>
26 
27 #include "got_error.h"
28 #include "got_object.h"
29 #include "got_path.h"
30 
31 #include "got_lib_deflate.h"
32 
33 #ifndef MIN
34 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
35 #endif
36 
37 const struct got_error *
38 got_deflate_init(struct got_deflate_buf *zb, uint8_t *outbuf, size_t bufsize)
39 {
40 	const struct got_error *err = NULL;
41 	int zerr;
42 
43 	memset(&zb->z, 0, sizeof(zb->z));
44 
45 	zb->z.zalloc = Z_NULL;
46 	zb->z.zfree = Z_NULL;
47 	zerr = deflateInit(&zb->z, Z_DEFAULT_COMPRESSION);
48 	if (zerr != Z_OK) {
49 		if  (zerr == Z_ERRNO)
50 			return got_error_from_errno("deflateInit");
51 		if  (zerr == Z_MEM_ERROR) {
52 			errno = ENOMEM;
53 			return got_error_from_errno("deflateInit");
54 		}
55 		return got_error(GOT_ERR_COMPRESSION);
56 	}
57 
58 	zb->inlen = zb->outlen = bufsize;
59 
60 	zb->inbuf = calloc(1, zb->inlen);
61 	if (zb->inbuf == NULL) {
62 		err = got_error_from_errno("calloc");
63 		goto done;
64 	}
65 
66 	zb->flags = 0;
67 	if (outbuf == NULL) {
68 		zb->outbuf = calloc(1, zb->outlen);
69 		if (zb->outbuf == NULL) {
70 			err = got_error_from_errno("calloc");
71 			goto done;
72 		}
73 		zb->flags |= GOT_DEFLATE_F_OWN_OUTBUF;
74 	} else
75 		zb->outbuf = outbuf;
76 done:
77 	if (err)
78 		got_deflate_end(zb);
79 	return err;
80 }
81 
82 static void
83 csum_output(struct got_deflate_checksum *csum, const char *buf, size_t len)
84 {
85 	if (csum->output_crc)
86 		*csum->output_crc = crc32(*csum->output_crc, buf, len);
87 
88 	if (csum->output_sha1)
89 		SHA1Update(csum->output_sha1, buf, len);
90 }
91 
92 const struct got_error *
93 got_deflate_read(struct got_deflate_buf *zb, FILE *f, size_t *outlenp)
94 {
95 	size_t last_total_out = zb->z.total_out;
96 	z_stream *z = &zb->z;
97 	int ret = Z_ERRNO;
98 
99 	z->next_out = zb->outbuf;
100 	z->avail_out = zb->outlen;
101 
102 	*outlenp = 0;
103 	do {
104 		if (z->avail_in == 0) {
105 			size_t n = fread(zb->inbuf, 1, zb->inlen, f);
106 			if (n == 0) {
107 				if (ferror(f))
108 					return got_ferror(f, GOT_ERR_IO);
109 				/* EOF */
110 				ret = deflate(z, Z_FINISH);
111 				break;
112 			}
113 			z->next_in = zb->inbuf;
114 			z->avail_in = n;
115 		}
116 		ret = deflate(z, Z_NO_FLUSH);
117 	} while (ret == Z_OK && z->avail_out > 0);
118 
119 	if (ret == Z_OK) {
120 		zb->flags |= GOT_DEFLATE_F_HAVE_MORE;
121 	} else {
122 		if (ret != Z_STREAM_END)
123 			return got_error(GOT_ERR_COMPRESSION);
124 		zb->flags &= ~GOT_DEFLATE_F_HAVE_MORE;
125 	}
126 
127 	*outlenp = z->total_out - last_total_out;
128 	return NULL;
129 }
130 
131 void
132 got_deflate_end(struct got_deflate_buf *zb)
133 {
134 	free(zb->inbuf);
135 	if (zb->flags & GOT_DEFLATE_F_OWN_OUTBUF)
136 		free(zb->outbuf);
137 	deflateEnd(&zb->z);
138 }
139 
140 const struct got_error *
141 got_deflate_to_file(size_t *outlen, FILE *infile, FILE *outfile,
142     struct got_deflate_checksum *csum)
143 {
144 	const struct got_error *err;
145 	size_t avail;
146 	struct got_deflate_buf zb;
147 
148 	err = got_deflate_init(&zb, NULL, GOT_DEFLATE_BUFSIZE);
149 	if (err)
150 		goto done;
151 
152 	*outlen = 0;
153 
154 	do {
155 		err = got_deflate_read(&zb, infile, &avail);
156 		if (err)
157 			goto done;
158 		if (avail > 0) {
159 			size_t n;
160 			n = fwrite(zb.outbuf, avail, 1, outfile);
161 			if (n != 1) {
162 				err = got_ferror(outfile, GOT_ERR_IO);
163 				goto done;
164 			}
165 			if (csum)
166 				csum_output(csum, zb.outbuf, avail);
167 			*outlen += avail;
168 		}
169 	} while (zb.flags & GOT_DEFLATE_F_HAVE_MORE);
170 
171 done:
172 	got_deflate_end(&zb);
173 	return err;
174 }