1 /*-
2 * Copyright 2003-2005 Colin Percival
3 * All rights reserved
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted providing that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
16 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
18 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
22 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
23 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
24 * POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #if 0
28 __FBSDID("$FreeBSD: src/usr.bin/bsdiff/bspatch/bspatch.c,v 1.1 2005/08/06 01:59:06 cperciva Exp $");
29 #endif
30
31 #include <bzlib.h>
32 #include <stdlib.h>
33 #include <stdio.h>
34 #include <string.h>
35 #include <err.h>
36 #include <unistd.h>
37 #include <fcntl.h>
38 #include <sys/types.h> // android
39
offtin(u_char * buf)40 static off_t offtin(u_char *buf)
41 {
42 off_t y;
43
44 y=buf[7]&0x7F;
45 y=y*256;y+=buf[6];
46 y=y*256;y+=buf[5];
47 y=y*256;y+=buf[4];
48 y=y*256;y+=buf[3];
49 y=y*256;y+=buf[2];
50 y=y*256;y+=buf[1];
51 y=y*256;y+=buf[0];
52
53 if(buf[7]&0x80) y=-y;
54
55 return y;
56 }
57
main(int argc,char * argv[])58 int main(int argc,char * argv[])
59 {
60 FILE * f, * cpf, * dpf, * epf;
61 BZFILE * cpfbz2, * dpfbz2, * epfbz2;
62 int cbz2err, dbz2err, ebz2err;
63 int fd;
64 ssize_t oldsize,newsize;
65 ssize_t bzctrllen,bzdatalen;
66 u_char header[32],buf[8];
67 u_char *old, *new;
68 off_t oldpos,newpos;
69 off_t ctrl[3];
70 off_t lenread;
71 off_t i;
72
73 if(argc!=4) errx(1,"usage: %s oldfile newfile patchfile\n",argv[0]);
74
75 /* Open patch file */
76 if ((f = fopen(argv[3], "r")) == NULL)
77 err(1, "fopen(%s)", argv[3]);
78
79 /*
80 File format:
81 0 8 "BSDIFF40"
82 8 8 X
83 16 8 Y
84 24 8 sizeof(newfile)
85 32 X bzip2(control block)
86 32+X Y bzip2(diff block)
87 32+X+Y ??? bzip2(extra block)
88 with control block a set of triples (x,y,z) meaning "add x bytes
89 from oldfile to x bytes from the diff block; copy y bytes from the
90 extra block; seek forwards in oldfile by z bytes".
91 */
92
93 /* Read header */
94 if (fread(header, 1, 32, f) < 32) {
95 if (feof(f))
96 errx(1, "Corrupt patch\n");
97 err(1, "fread(%s)", argv[3]);
98 }
99
100 /* Check for appropriate magic */
101 if (memcmp(header, "BSDIFF40", 8) != 0)
102 errx(1, "Corrupt patch\n");
103
104 /* Read lengths from header */
105 bzctrllen=offtin(header+8);
106 bzdatalen=offtin(header+16);
107 newsize=offtin(header+24);
108 if((bzctrllen<0) || (bzdatalen<0) || (newsize<0))
109 errx(1,"Corrupt patch\n");
110
111 /* Close patch file and re-open it via libbzip2 at the right places */
112 if (fclose(f))
113 err(1, "fclose(%s)", argv[3]);
114 if ((cpf = fopen(argv[3], "r")) == NULL)
115 err(1, "fopen(%s)", argv[3]);
116 if (fseeko(cpf, 32, SEEK_SET))
117 err(1, "fseeko(%s, %lld)", argv[3],
118 (long long)32);
119 if ((cpfbz2 = BZ2_bzReadOpen(&cbz2err, cpf, 0, 0, NULL, 0)) == NULL)
120 errx(1, "BZ2_bzReadOpen, bz2err = %d", cbz2err);
121 if ((dpf = fopen(argv[3], "r")) == NULL)
122 err(1, "fopen(%s)", argv[3]);
123 if (fseeko(dpf, 32 + bzctrllen, SEEK_SET))
124 err(1, "fseeko(%s, %lld)", argv[3],
125 (long long)(32 + bzctrllen));
126 if ((dpfbz2 = BZ2_bzReadOpen(&dbz2err, dpf, 0, 0, NULL, 0)) == NULL)
127 errx(1, "BZ2_bzReadOpen, bz2err = %d", dbz2err);
128 if ((epf = fopen(argv[3], "r")) == NULL)
129 err(1, "fopen(%s)", argv[3]);
130 if (fseeko(epf, 32 + bzctrllen + bzdatalen, SEEK_SET))
131 err(1, "fseeko(%s, %lld)", argv[3],
132 (long long)(32 + bzctrllen + bzdatalen));
133 if ((epfbz2 = BZ2_bzReadOpen(&ebz2err, epf, 0, 0, NULL, 0)) == NULL)
134 errx(1, "BZ2_bzReadOpen, bz2err = %d", ebz2err);
135
136 if(((fd=open(argv[1],O_RDONLY,0))<0) ||
137 ((oldsize=lseek(fd,0,SEEK_END))==-1) ||
138 ((old=malloc(oldsize+1))==NULL) ||
139 (lseek(fd,0,SEEK_SET)!=0) ||
140 (read(fd,old,oldsize)!=oldsize) ||
141 (close(fd)==-1)) err(1,"%s",argv[1]);
142 if((new=malloc(newsize+1))==NULL) err(1,NULL);
143
144 oldpos=0;newpos=0;
145 while(newpos<newsize) {
146 /* Read control data */
147 for(i=0;i<=2;i++) {
148 lenread = BZ2_bzRead(&cbz2err, cpfbz2, buf, 8);
149 if ((lenread < 8) || ((cbz2err != BZ_OK) &&
150 (cbz2err != BZ_STREAM_END)))
151 errx(1, "Corrupt patch\n");
152 ctrl[i]=offtin(buf);
153 };
154
155 /* Sanity-check */
156 if(newpos+ctrl[0]>newsize)
157 errx(1,"Corrupt patch\n");
158
159 /* Read diff string */
160 lenread = BZ2_bzRead(&dbz2err, dpfbz2, new + newpos, ctrl[0]);
161 if ((lenread < ctrl[0]) ||
162 ((dbz2err != BZ_OK) && (dbz2err != BZ_STREAM_END)))
163 errx(1, "Corrupt patch\n");
164
165 /* Add old data to diff string */
166 for(i=0;i<ctrl[0];i++)
167 if((oldpos+i>=0) && (oldpos+i<oldsize))
168 new[newpos+i]+=old[oldpos+i];
169
170 /* Adjust pointers */
171 newpos+=ctrl[0];
172 oldpos+=ctrl[0];
173
174 /* Sanity-check */
175 if(newpos+ctrl[1]>newsize)
176 errx(1,"Corrupt patch\n");
177
178 /* Read extra string */
179 lenread = BZ2_bzRead(&ebz2err, epfbz2, new + newpos, ctrl[1]);
180 if ((lenread < ctrl[1]) ||
181 ((ebz2err != BZ_OK) && (ebz2err != BZ_STREAM_END)))
182 errx(1, "Corrupt patch\n");
183
184 /* Adjust pointers */
185 newpos+=ctrl[1];
186 oldpos+=ctrl[2];
187 };
188
189 /* Clean up the bzip2 reads */
190 BZ2_bzReadClose(&cbz2err, cpfbz2);
191 BZ2_bzReadClose(&dbz2err, dpfbz2);
192 BZ2_bzReadClose(&ebz2err, epfbz2);
193 if (fclose(cpf) || fclose(dpf) || fclose(epf))
194 err(1, "fclose(%s)", argv[3]);
195
196 /* Write the new file */
197 if(((fd=open(argv[2],O_CREAT|O_TRUNC|O_WRONLY,0666))<0) ||
198 (write(fd,new,newsize)!=newsize) || (close(fd)==-1))
199 err(1,"%s",argv[2]);
200
201 free(new);
202 free(old);
203
204 return 0;
205 }
206