diff options
Diffstat (limited to 'usr.bin/bsdiff/bspatch/bspatch.c')
| -rw-r--r-- | usr.bin/bsdiff/bspatch/bspatch.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/usr.bin/bsdiff/bspatch/bspatch.c b/usr.bin/bsdiff/bspatch/bspatch.c new file mode 100644 index 000000000000..ea43d78b12a1 --- /dev/null +++ b/usr.bin/bsdiff/bspatch/bspatch.c @@ -0,0 +1,302 @@ +/*- + * 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 <sys/cdefs.h> +#ifndef WITHOUT_CAPSICUM +#include <sys/capsicum.h> +#endif + +#include <bzlib.h> +#include <err.h> +#include <fcntl.h> +#include <libgen.h> +#include <limits.h> +#include <stdckdint.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <sys/mman.h> + +#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); +} |