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 #if defined(__FreeBSD__)
33 #include <sys/param.h>
34 #if __FreeBSD_version >= 1001511
35 #include <sys/capsicum.h>
55 #define HEADER_SIZE 32
58 static int dirfd = -1;
64 if (dirfd != -1 && newfile != NULL)
65 if (unlinkat(dirfd, newfile, 0))
69 static off_t offtin(u_char *buf)
74 y = y * 256; y += buf[6];
75 y = y * 256; y += buf[5];
76 y = y * 256; y += buf[4];
77 y = y * 256; y += buf[3];
78 y = y * 256; y += buf[2];
79 y = y * 256; y += buf[1];
80 y = y * 256; y += buf[0];
92 fprintf(stderr, "usage: bspatch oldfile newfile patchfile\n");
96 int main(int argc, char *argv[])
98 FILE *f, *cpf, *dpf, *epf;
99 BZFILE *cpfbz2, *dpfbz2, *epfbz2;
100 char *directory, *namebuf;
101 int cbz2err, dbz2err, ebz2err;
103 off_t oldsize, newsize;
104 off_t bzctrllen, bzdatalen;
105 u_char header[HEADER_SIZE], buf[8];
107 off_t oldpos, newpos;
109 off_t i, lenread, offset;
111 cap_rights_t rights_dir, rights_ro, rights_wr;
117 /* Open patch file */
118 if ((f = fopen(argv[3], "rb")) == NULL)
119 err(1, "fopen(%s)", argv[3]);
120 /* Open patch file for control block */
121 if ((cpf = fopen(argv[3], "rb")) == NULL)
122 err(1, "fopen(%s)", argv[3]);
123 /* open patch file for diff block */
124 if ((dpf = fopen(argv[3], "rb")) == NULL)
125 err(1, "fopen(%s)", argv[3]);
126 /* open patch file for extra block */
127 if ((epf = fopen(argv[3], "rb")) == NULL)
128 err(1, "fopen(%s)", argv[3]);
130 if ((oldfd = open(argv[1], O_RDONLY | O_BINARY, 0)) < 0)
131 err(1, "open(%s)", argv[1]);
132 /* open directory where we'll write newfile */
133 if ((namebuf = strdup(argv[2])) == NULL ||
134 (directory = dirname(namebuf)) == NULL ||
135 (dirfd = open(directory, O_DIRECTORY)) < 0)
136 err(1, "open %s", argv[2]);
138 if ((newfile = basename(argv[2])) == NULL)
141 if ((newfd = openat(dirfd, newfile,
142 O_CREAT | O_TRUNC | O_WRONLY | O_BINARY, 0666)) < 0)
143 err(1, "open(%s)", argv[2]);
144 atexit(exit_cleanup);
147 if (cap_enter() < 0) {
148 /* Failed to sandbox, fatal if CAPABILITY_MODE enabled */
150 err(1, "failed to enter security sandbox");
152 /* Capsicum Available */
153 cap_rights_init(&rights_ro, CAP_READ, CAP_FSTAT, CAP_SEEK);
154 cap_rights_init(&rights_wr, CAP_WRITE);
155 cap_rights_init(&rights_dir, CAP_UNLINKAT);
157 if (cap_rights_limit(fileno(f), &rights_ro) < 0 ||
158 cap_rights_limit(fileno(cpf), &rights_ro) < 0 ||
159 cap_rights_limit(fileno(dpf), &rights_ro) < 0 ||
160 cap_rights_limit(fileno(epf), &rights_ro) < 0 ||
161 cap_rights_limit(oldfd, &rights_ro) < 0 ||
162 cap_rights_limit(newfd, &rights_wr) < 0 ||
163 cap_rights_limit(dirfd, &rights_dir) < 0)
164 err(1, "cap_rights_limit() failed, could not restrict"
175 32 X bzip2(control block)
176 32+X Y bzip2(diff block)
177 32+X+Y ??? bzip2(extra block)
178 with control block a set of triples (x,y,z) meaning "add x bytes
179 from oldfile to x bytes from the diff block; copy y bytes from the
180 extra block; seek forwards in oldfile by z bytes".
184 if (fread(header, 1, HEADER_SIZE, f) < HEADER_SIZE) {
186 errx(1, "Corrupt patch");
187 err(1, "fread(%s)", argv[3]);
190 /* Check for appropriate magic */
191 if (memcmp(header, "BSDIFF40", 8) != 0)
192 errx(1, "Corrupt patch");
194 /* Read lengths from header */
195 bzctrllen = offtin(header + 8);
196 bzdatalen = offtin(header + 16);
197 newsize = offtin(header + 24);
198 if (bzctrllen < 0 || bzctrllen > OFF_MAX - HEADER_SIZE ||
199 bzdatalen < 0 || bzctrllen + HEADER_SIZE > OFF_MAX - bzdatalen ||
200 newsize < 0 || newsize > SSIZE_MAX)
201 errx(1, "Corrupt patch");
203 /* Close patch file and re-open it via libbzip2 at the right places */
205 err(1, "fclose(%s)", argv[3]);
206 offset = HEADER_SIZE;
207 if (fseeko(cpf, offset, SEEK_SET))
208 err(1, "fseeko(%s, %jd)", argv[3], (intmax_t)offset);
209 if ((cpfbz2 = BZ2_bzReadOpen(&cbz2err, cpf, 0, 0, NULL, 0)) == NULL)
210 errx(1, "BZ2_bzReadOpen, bz2err = %d", cbz2err);
212 if (fseeko(dpf, offset, SEEK_SET))
213 err(1, "fseeko(%s, %jd)", argv[3], (intmax_t)offset);
214 if ((dpfbz2 = BZ2_bzReadOpen(&dbz2err, dpf, 0, 0, NULL, 0)) == NULL)
215 errx(1, "BZ2_bzReadOpen, bz2err = %d", dbz2err);
217 if (fseeko(epf, offset, SEEK_SET))
218 err(1, "fseeko(%s, %jd)", argv[3], (intmax_t)offset);
219 if ((epfbz2 = BZ2_bzReadOpen(&ebz2err, epf, 0, 0, NULL, 0)) == NULL)
220 errx(1, "BZ2_bzReadOpen, bz2err = %d", ebz2err);
222 if ((oldsize = lseek(oldfd, 0, SEEK_END)) == -1 ||
223 oldsize > SSIZE_MAX ||
224 (old = malloc(oldsize)) == NULL ||
225 lseek(oldfd, 0, SEEK_SET) != 0 ||
226 read(oldfd, old, oldsize) != oldsize ||
228 err(1, "%s", argv[1]);
229 if ((new = malloc(newsize)) == NULL)
234 while (newpos < newsize) {
235 /* Read control data */
236 for (i = 0; i <= 2; i++) {
237 lenread = BZ2_bzRead(&cbz2err, cpfbz2, buf, 8);
238 if ((lenread < 8) || ((cbz2err != BZ_OK) &&
239 (cbz2err != BZ_STREAM_END)))
240 errx(1, "Corrupt patch");
241 ctrl[i] = offtin(buf);
245 if (ctrl[0] < 0 || ctrl[0] > INT_MAX ||
246 ctrl[1] < 0 || ctrl[1] > INT_MAX)
247 errx(1, "Corrupt patch");
250 if (newpos + ctrl[0] > newsize)
251 errx(1, "Corrupt patch");
253 /* Read diff string */
254 lenread = BZ2_bzRead(&dbz2err, dpfbz2, new + newpos, ctrl[0]);
255 if ((lenread < ctrl[0]) ||
256 ((dbz2err != BZ_OK) && (dbz2err != BZ_STREAM_END)))
257 errx(1, "Corrupt patch");
259 /* Add old data to diff string */
260 for (i = 0; i < ctrl[0]; i++)
261 if ((oldpos + i >= 0) && (oldpos + i < oldsize))
262 new[newpos + i] += old[oldpos + i];
264 /* Adjust pointers */
269 if (newpos + ctrl[1] > newsize)
270 errx(1, "Corrupt patch");
272 /* Read extra string */
273 lenread = BZ2_bzRead(&ebz2err, epfbz2, new + newpos, ctrl[1]);
274 if ((lenread < ctrl[1]) ||
275 ((ebz2err != BZ_OK) && (ebz2err != BZ_STREAM_END)))
276 errx(1, "Corrupt patch");
278 /* Adjust pointers */
283 /* Clean up the bzip2 reads */
284 BZ2_bzReadClose(&cbz2err, cpfbz2);
285 BZ2_bzReadClose(&dbz2err, dpfbz2);
286 BZ2_bzReadClose(&ebz2err, epfbz2);
287 if (fclose(cpf) || fclose(dpf) || fclose(epf))
288 err(1, "fclose(%s)", argv[3]);
290 /* Write the new file */
291 if (write(newfd, new, newsize) != newsize || close(newfd) == -1)
292 err(1, "%s", argv[2]);
293 /* Disable atexit cleanup */