2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright 2003-2005 Colin Percival
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted providing that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
20 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
24 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
25 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #ifndef WITHOUT_CAPSICUM
33 #include <sys/capsicum.h>
50 #define HEADER_SIZE 32
53 static int dirfd = -1;
59 if (dirfd != -1 && newfile != NULL)
60 if (unlinkat(dirfd, newfile, 0))
64 static off_t offtin(u_char *buf)
69 y = y * 256; y += buf[6];
70 y = y * 256; y += buf[5];
71 y = y * 256; y += buf[4];
72 y = y * 256; y += buf[3];
73 y = y * 256; y += buf[2];
74 y = y * 256; y += buf[1];
75 y = y * 256; y += buf[0];
87 fprintf(stderr, "usage: bspatch oldfile newfile patchfile\n");
91 int main(int argc, char *argv[])
93 FILE *f, *cpf, *dpf, *epf;
94 BZFILE *cpfbz2, *dpfbz2, *epfbz2;
95 char *directory, *namebuf;
96 int cbz2err, dbz2err, ebz2err;
98 off_t oldsize, newsize;
99 off_t bzctrllen, bzdatalen;
100 u_char header[HEADER_SIZE], buf[8];
102 off_t oldpos, newpos;
104 off_t i, lenread, offset;
105 #ifndef WITHOUT_CAPSICUM
106 cap_rights_t rights_dir, rights_ro, rights_wr;
112 /* Open patch file */
113 if ((f = fopen(argv[3], "rb")) == NULL)
114 err(1, "fopen(%s)", argv[3]);
115 /* Open patch file for control block */
116 if ((cpf = fopen(argv[3], "rb")) == NULL)
117 err(1, "fopen(%s)", argv[3]);
118 /* open patch file for diff block */
119 if ((dpf = fopen(argv[3], "rb")) == NULL)
120 err(1, "fopen(%s)", argv[3]);
121 /* open patch file for extra block */
122 if ((epf = fopen(argv[3], "rb")) == NULL)
123 err(1, "fopen(%s)", argv[3]);
125 if ((oldfd = open(argv[1], O_RDONLY | O_BINARY, 0)) < 0)
126 err(1, "open(%s)", argv[1]);
127 /* open directory where we'll write newfile */
128 if ((namebuf = strdup(argv[2])) == NULL ||
129 (directory = dirname(namebuf)) == NULL ||
130 (dirfd = open(directory, O_DIRECTORY)) < 0)
131 err(1, "open %s", argv[2]);
133 if ((newfile = basename(argv[2])) == NULL)
136 if ((newfd = openat(dirfd, newfile,
137 O_CREAT | O_TRUNC | O_WRONLY | O_BINARY, 0666)) < 0)
138 err(1, "open(%s)", argv[2]);
139 atexit(exit_cleanup);
141 #ifndef WITHOUT_CAPSICUM
143 err(1, "failed to enter security sandbox");
145 cap_rights_init(&rights_ro, CAP_READ, CAP_FSTAT, CAP_SEEK);
146 cap_rights_init(&rights_wr, CAP_WRITE);
147 cap_rights_init(&rights_dir, CAP_UNLINKAT);
149 if (cap_rights_limit(fileno(f), &rights_ro) < 0 ||
150 cap_rights_limit(fileno(cpf), &rights_ro) < 0 ||
151 cap_rights_limit(fileno(dpf), &rights_ro) < 0 ||
152 cap_rights_limit(fileno(epf), &rights_ro) < 0 ||
153 cap_rights_limit(oldfd, &rights_ro) < 0 ||
154 cap_rights_limit(newfd, &rights_wr) < 0 ||
155 cap_rights_limit(dirfd, &rights_dir) < 0)
156 err(1, "cap_rights_limit() failed, could not restrict"
166 32 X bzip2(control block)
167 32+X Y bzip2(diff block)
168 32+X+Y ??? bzip2(extra block)
169 with control block a set of triples (x,y,z) meaning "add x bytes
170 from oldfile to x bytes from the diff block; copy y bytes from the
171 extra block; seek forwards in oldfile by z bytes".
175 if (fread(header, 1, HEADER_SIZE, f) < HEADER_SIZE) {
177 errx(1, "Corrupt patch");
178 err(1, "fread(%s)", argv[3]);
181 /* Check for appropriate magic */
182 if (memcmp(header, "BSDIFF40", 8) != 0)
183 errx(1, "Corrupt patch");
185 /* Read lengths from header */
186 bzctrllen = offtin(header + 8);
187 bzdatalen = offtin(header + 16);
188 newsize = offtin(header + 24);
189 if (bzctrllen < 0 || bzctrllen > OFF_MAX - HEADER_SIZE ||
190 bzdatalen < 0 || bzctrllen + HEADER_SIZE > OFF_MAX - bzdatalen ||
191 newsize < 0 || newsize > SSIZE_MAX)
192 errx(1, "Corrupt patch");
194 /* Close patch file and re-open it via libbzip2 at the right places */
196 err(1, "fclose(%s)", argv[3]);
197 offset = HEADER_SIZE;
198 if (fseeko(cpf, offset, SEEK_SET))
199 err(1, "fseeko(%s, %jd)", argv[3], (intmax_t)offset);
200 if ((cpfbz2 = BZ2_bzReadOpen(&cbz2err, cpf, 0, 0, NULL, 0)) == NULL)
201 errx(1, "BZ2_bzReadOpen, bz2err = %d", cbz2err);
203 if (fseeko(dpf, offset, SEEK_SET))
204 err(1, "fseeko(%s, %jd)", argv[3], (intmax_t)offset);
205 if ((dpfbz2 = BZ2_bzReadOpen(&dbz2err, dpf, 0, 0, NULL, 0)) == NULL)
206 errx(1, "BZ2_bzReadOpen, bz2err = %d", dbz2err);
208 if (fseeko(epf, offset, SEEK_SET))
209 err(1, "fseeko(%s, %jd)", argv[3], (intmax_t)offset);
210 if ((epfbz2 = BZ2_bzReadOpen(&ebz2err, epf, 0, 0, NULL, 0)) == NULL)
211 errx(1, "BZ2_bzReadOpen, bz2err = %d", ebz2err);
213 if ((oldsize = lseek(oldfd, 0, SEEK_END)) == -1 ||
214 oldsize > SSIZE_MAX ||
215 (old = malloc(oldsize)) == NULL ||
216 lseek(oldfd, 0, SEEK_SET) != 0 ||
217 read(oldfd, old, oldsize) != oldsize ||
219 err(1, "%s", argv[1]);
220 if ((new = malloc(newsize)) == NULL)
225 while (newpos < newsize) {
226 /* Read control data */
227 for (i = 0; i <= 2; i++) {
228 lenread = BZ2_bzRead(&cbz2err, cpfbz2, buf, 8);
229 if ((lenread < 8) || ((cbz2err != BZ_OK) &&
230 (cbz2err != BZ_STREAM_END)))
231 errx(1, "Corrupt patch");
232 ctrl[i] = offtin(buf);
236 if (ctrl[0] < 0 || ctrl[0] > INT_MAX ||
237 ctrl[1] < 0 || ctrl[1] > INT_MAX)
238 errx(1, "Corrupt patch");
241 if (newpos + ctrl[0] > newsize)
242 errx(1, "Corrupt patch");
244 /* Read diff string */
245 lenread = BZ2_bzRead(&dbz2err, dpfbz2, new + newpos, ctrl[0]);
246 if ((lenread < ctrl[0]) ||
247 ((dbz2err != BZ_OK) && (dbz2err != BZ_STREAM_END)))
248 errx(1, "Corrupt patch");
250 /* Add old data to diff string */
251 for (i = 0; i < ctrl[0]; i++)
252 if ((oldpos + i >= 0) && (oldpos + i < oldsize))
253 new[newpos + i] += old[oldpos + i];
255 /* Adjust pointers */
260 if (newpos + ctrl[1] > newsize)
261 errx(1, "Corrupt patch");
263 /* Read extra string */
264 lenread = BZ2_bzRead(&ebz2err, epfbz2, new + newpos, ctrl[1]);
265 if ((lenread < ctrl[1]) ||
266 ((ebz2err != BZ_OK) && (ebz2err != BZ_STREAM_END)))
267 errx(1, "Corrupt patch");
269 /* Adjust pointers */
274 /* Clean up the bzip2 reads */
275 BZ2_bzReadClose(&cbz2err, cpfbz2);
276 BZ2_bzReadClose(&dbz2err, dpfbz2);
277 BZ2_bzReadClose(&ebz2err, epfbz2);
278 if (fclose(cpf) || fclose(dpf) || fclose(epf))
279 err(1, "fclose(%s)", argv[3]);
281 /* Write the new file */
282 if (write(newfd, new, newsize) != newsize || close(newfd) == -1)
283 err(1, "%s", argv[2]);
284 /* Disable atexit cleanup */