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     struct got_deflate_checksum *csum)
40 {
41 	const struct got_error *err = NULL;
42 	int zerr;
43 
44 	memset(&zb->z, 0, sizeof(zb->z));
45 
46 	zb->z.zalloc = Z_NULL;
47 	zb->z.zfree = Z_NULL;
48 	zerr = deflateInit(&zb->z, Z_DEFAULT_COMPRESSION);
49 	if (zerr != Z_OK) {
50 		if  (zerr == Z_ERRNO)
51 			return got_error_from_errno("deflateInit");
52 		if  (zerr == Z_MEM_ERROR) {
53 			errno = ENOMEM;
54 			return got_error_from_errno("deflateInit");
55 		}
56 		return got_error(GOT_ERR_COMPRESSION);
57 	}
58 
59 	zb->inlen = zb->outlen = bufsize;
60 
61 	zb->inbuf = calloc(1, zb->inlen);
62 	if (zb->inbuf == NULL) {
63 		err = got_error_from_errno("calloc");
64 		goto done;
65 	}
66 
67 	zb->flags = 0;
68 	if (outbuf == NULL) {
69 		zb->outbuf = calloc(1, zb->outlen);
70 		if (zb->outbuf == NULL) {
71 			err = got_error_from_errno("calloc");
72 			goto done;
73 		}
74 		zb->flags |= GOT_DEFLATE_F_OWN_OUTBUF;
75 	} else
76 		zb->outbuf = outbuf;
77 
78 	zb->csum = csum;
79 done:
80 	if (err)
81 		got_deflate_end(zb);
82 	return err;
83 }
84 
85 static void
86 csum_output(struct got_deflate_checksum *csum, const char *buf, size_t len)
87 {
88 	if (csum->output_crc)
89 		*csum->output_crc = crc32(*csum->output_crc, buf, len);
90 
91 	if (csum->output_sha1)
92 		SHA1Update(csum->output_sha1, buf, len);
93 }
94 
95 const struct got_error *
96 got_deflate_read(struct got_deflate_buf *zb, FILE *f, size_t *outlenp)
97 {
98 	size_t last_total_out = zb->z.total_out;
99 	z_stream *z = &zb->z;
100 	int ret = Z_ERRNO;
101 
102 	z->next_out = zb->outbuf;
103 	z->avail_out = zb->outlen;
104 
105 	*outlenp = 0;
106 	do {
107 		char *csum_out = NULL;
108 		size_t csum_avail = 0;
109 
110 		if (z->avail_in == 0) {
111 			size_t n = fread(zb->inbuf, 1, zb->inlen, f);
112 			if (n == 0) {
113 				if (ferror(f))
114 					return got_ferror(f, GOT_ERR_IO);
115 				/* EOF */
116 				ret = deflate(z, Z_FINISH);
117 				break;
118 			}
119 			z->next_in = zb->inbuf;
120 			z->avail_in = n;
121 		}
122 		if (zb->csum) {
123 			csum_out = z->next_out;
124 			csum_avail = z->avail_out;
125 		}
126 		ret = deflate(z, Z_NO_FLUSH);
127 		if (zb->csum) {
128 			csum_output(zb->csum, csum_out,
129 			   csum_avail - z->avail_out);
130 		}
131 	} while (ret == Z_OK && z->avail_out > 0);
132 
133 	if (ret == Z_OK) {
134 		zb->flags |= GOT_DEFLATE_F_HAVE_MORE;
135 	} else {
136 		if (ret != Z_STREAM_END)
137 			return got_error(GOT_ERR_COMPRESSION);
138 		zb->flags &= ~GOT_DEFLATE_F_HAVE_MORE;
139 	}
140 
141 	*outlenp = z->total_out - last_total_out;
142 	return NULL;
143 }
144 
145 void
146 got_deflate_end(struct got_deflate_buf *zb)
147 {
148 	free(zb->inbuf);
149 	if (zb->flags & GOT_DEFLATE_F_OWN_OUTBUF)
150 		free(zb->outbuf);
151 	deflateEnd(&zb->z);
152 }
153 
154 const struct got_error *
155 got_deflate_to_file(size_t *outlen, FILE *infile, FILE *outfile,
156     struct got_deflate_checksum *csum)
157 {
158 	const struct got_error *err;
159 	size_t avail;
160 	struct got_deflate_buf zb;
161 
162 	err = got_deflate_init(&zb, NULL, GOT_DEFLATE_BUFSIZE, csum);
163 	if (err)
164 		goto done;
165 
166 	*outlen = 0;
167 
168 	do {
169 		err = got_deflate_read(&zb, infile, &avail);
170 		if (err)
171 			goto done;
172 		if (avail > 0) {
173 			size_t n;
174 			n = fwrite(zb.outbuf, avail, 1, outfile);
175 			if (n != 1) {
176 				err = got_ferror(outfile, GOT_ERR_IO);
177 				goto done;
178 			}
179 			*outlen += avail;
180 		}
181 	} while (zb.flags & GOT_DEFLATE_F_HAVE_MORE);
182 
183 done:
184 	got_deflate_end(&zb);
185 	return err;
186 }