/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright 2003-2005 Colin Percival * All rights reserved * * Redistribution and use in source and binary forms, with or without * modification, are permitted providing that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include #ifndef WITHOUT_CAPSICUM #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #ifndef O_BINARY #define O_BINARY 0 #endif #define HEADER_SIZE 32 static char *newfile; static int dirfd = -1; static void exit_cleanup(void) { if (dirfd != -1 && newfile != NULL) if (unlinkat(dirfd, newfile, 0)) warn("unlinkat"); } static inline off_t add_off_t(off_t a, off_t b) { off_t result; if (ckd_add(&result, a, b)) errx(1, "Corrupt patch"); return result; } static off_t offtin(u_char *buf) { off_t y; y = buf[7] & 0x7F; y = y * 256; y += buf[6]; y = y * 256; y += buf[5]; y = y * 256; y += buf[4]; y = y * 256; y += buf[3]; y = y * 256; y += buf[2]; y = y * 256; y += buf[1]; y = y * 256; y += buf[0]; if (buf[7] & 0x80) y = -y; return (y); } static void usage(void) { fprintf(stderr, "usage: bspatch oldfile newfile patchfile\n"); exit(1); } int main(int argc, char *argv[]) { FILE *f, *cpf, *dpf, *epf; BZFILE *cpfbz2, *dpfbz2, *epfbz2; char *directory, *namebuf; int cbz2err, dbz2err, ebz2err; int newfd, oldfd; off_t oldsize, newsize; off_t bzctrllen, bzdatalen; u_char header[HEADER_SIZE], buf[8]; u_char *old, *new; off_t oldpos, newpos; off_t ctrl[3]; off_t i, lenread, offset; #ifndef WITHOUT_CAPSICUM cap_rights_t rights_dir, rights_ro, rights_wr; #endif if (argc != 4) usage(); /* Open patch file */ if ((f = fopen(argv[3], "rb")) == NULL) err(1, "fopen(%s)", argv[3]); /* Open patch file for control block */ if ((cpf = fopen(argv[3], "rb")) == NULL) err(1, "fopen(%s)", argv[3]); /* open patch file for diff block */ if ((dpf = fopen(argv[3], "rb")) == NULL) err(1, "fopen(%s)", argv[3]); /* open patch file for extra block */ if ((epf = fopen(argv[3], "rb")) == NULL) err(1, "fopen(%s)", argv[3]); /* open oldfile */ if ((oldfd = open(argv[1], O_RDONLY | O_BINARY, 0)) < 0) err(1, "open(%s)", argv[1]); /* open directory where we'll write newfile */ if ((namebuf = strdup(argv[2])) == NULL || (directory = dirname(namebuf)) == NULL || (dirfd = open(directory, O_DIRECTORY)) < 0) err(1, "open %s", argv[2]); free(namebuf); if ((newfile = basename(argv[2])) == NULL) err(1, "basename"); /* open newfile */ if ((newfd = openat(dirfd, newfile, O_CREAT | O_TRUNC | O_WRONLY | O_BINARY, 0666)) < 0) err(1, "open(%s)", argv[2]); atexit(exit_cleanup); #ifndef WITHOUT_CAPSICUM if (cap_enter() < 0) err(1, "failed to enter security sandbox"); cap_rights_init(&rights_ro, CAP_READ, CAP_FSTAT, CAP_SEEK, CAP_MMAP_R); cap_rights_init(&rights_wr, CAP_WRITE); cap_rights_init(&rights_dir, CAP_UNLINKAT); if (cap_rights_limit(fileno(f), &rights_ro) < 0 || cap_rights_limit(fileno(cpf), &rights_ro) < 0 || cap_rights_limit(fileno(dpf), &rights_ro) < 0 || cap_rights_limit(fileno(epf), &rights_ro) < 0 || cap_rights_limit(oldfd, &rights_ro) < 0 || cap_rights_limit(newfd, &rights_wr) < 0 || cap_rights_limit(dirfd, &rights_dir) < 0) err(1, "cap_rights_limit() failed, could not restrict" " capabilities"); #endif /* File format: 0 8 "BSDIFF40" 8 8 X 16 8 Y 24 8 sizeof(newfile) 32 X bzip2(control block) 32+X Y bzip2(diff block) 32+X+Y ??? bzip2(extra block) with control block a set of triples (x,y,z) meaning "add x bytes from oldfile to x bytes from the diff block; copy y bytes from the extra block; seek forwards in oldfile by z bytes". */ /* Read header */ if (fread(header, 1, HEADER_SIZE, f) < HEADER_SIZE) { if (feof(f)) errx(1, "Corrupt patch"); err(1, "fread(%s)", argv[3]); } /* Check for appropriate magic */ if (memcmp(header, "BSDIFF40", 8) != 0) errx(1, "Corrupt patch"); /* Read lengths from header */ bzctrllen = offtin(header + 8); bzdatalen = offtin(header + 16); newsize = offtin(header + 24); if (bzctrllen < 0 || bzctrllen > OFF_MAX - HEADER_SIZE || bzdatalen < 0 || bzctrllen + HEADER_SIZE > OFF_MAX - bzdatalen || newsize < 0 || newsize > SSIZE_MAX) errx(1, "Corrupt patch"); /* Close patch file and re-open it via libbzip2 at the right places */ if (fclose(f)) err(1, "fclose(%s)", argv[3]); offset = HEADER_SIZE; if (fseeko(cpf, offset, SEEK_SET)) err(1, "fseeko(%s, %jd)", argv[3], (intmax_t)offset); if ((cpfbz2 = BZ2_bzReadOpen(&cbz2err, cpf, 0, 0, NULL, 0)) == NULL) errx(1, "BZ2_bzReadOpen, bz2err = %d", cbz2err); offset = add_off_t(offset, bzctrllen); if (fseeko(dpf, offset, SEEK_SET)) err(1, "fseeko(%s, %jd)", argv[3], (intmax_t)offset); if ((dpfbz2 = BZ2_bzReadOpen(&dbz2err, dpf, 0, 0, NULL, 0)) == NULL) errx(1, "BZ2_bzReadOpen, bz2err = %d", dbz2err); offset = add_off_t(offset, bzdatalen); if (fseeko(epf, offset, SEEK_SET)) err(1, "fseeko(%s, %jd)", argv[3], (intmax_t)offset); if ((epfbz2 = BZ2_bzReadOpen(&ebz2err, epf, 0, 0, NULL, 0)) == NULL) errx(1, "BZ2_bzReadOpen, bz2err = %d", ebz2err); if ((oldsize = lseek(oldfd, 0, SEEK_END)) == -1 || oldsize > SSIZE_MAX) err(1, "%s", argv[1]); old = mmap(NULL, oldsize+1, PROT_READ, MAP_SHARED, oldfd, 0); if (old == MAP_FAILED || close(oldfd) != 0) err(1, "%s", argv[1]); if ((new = malloc(newsize)) == NULL) err(1, NULL); oldpos = 0; newpos = 0; while (newpos < newsize) { /* Read control data */ for (i = 0; i <= 2; i++) { lenread = BZ2_bzRead(&cbz2err, cpfbz2, buf, 8); if ((lenread < 8) || ((cbz2err != BZ_OK) && (cbz2err != BZ_STREAM_END))) errx(1, "Corrupt patch"); ctrl[i] = offtin(buf); } /* Sanity-check */ if (ctrl[0] < 0 || ctrl[0] > INT_MAX || ctrl[1] < 0 || ctrl[1] > INT_MAX) errx(1, "Corrupt patch"); /* Sanity-check */ if (add_off_t(newpos, ctrl[0]) > newsize) errx(1, "Corrupt patch"); /* Read diff string */ lenread = BZ2_bzRead(&dbz2err, dpfbz2, new + newpos, ctrl[0]); if ((lenread < ctrl[0]) || ((dbz2err != BZ_OK) && (dbz2err != BZ_STREAM_END))) errx(1, "Corrupt patch"); /* Add old data to diff string */ for (i = 0; i < ctrl[0]; i++) if (add_off_t(oldpos, i) < oldsize) new[newpos + i] += old[oldpos + i]; /* Adjust pointers */ newpos = add_off_t(newpos, ctrl[0]); oldpos = add_off_t(oldpos, ctrl[0]); /* Sanity-check */ if (add_off_t(newpos, ctrl[1]) > newsize) errx(1, "Corrupt patch"); /* Read extra string */ lenread = BZ2_bzRead(&ebz2err, epfbz2, new + newpos, ctrl[1]); if ((lenread < ctrl[1]) || ((ebz2err != BZ_OK) && (ebz2err != BZ_STREAM_END))) errx(1, "Corrupt patch"); /* Adjust pointers */ newpos = add_off_t(newpos, ctrl[1]); oldpos = add_off_t(oldpos, ctrl[2]); } /* Clean up the bzip2 reads */ BZ2_bzReadClose(&cbz2err, cpfbz2); BZ2_bzReadClose(&dbz2err, dpfbz2); BZ2_bzReadClose(&ebz2err, epfbz2); if (fclose(cpf) || fclose(dpf) || fclose(epf)) err(1, "fclose(%s)", argv[3]); /* Write the new file */ if (write(newfd, new, newsize) != newsize || close(newfd) == -1) err(1, "%s", argv[2]); /* Disable atexit cleanup */ newfile = NULL; free(new); munmap(old, oldsize+1); return (0); }