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b2e465d6 AL |
1 | // -*- mode: cpp; mode: fold -*- |
2 | // Description /*{{{*/ | |
7db98ffc | 3 | // $Id: extracttar.cc,v 1.8.2.1 2004/01/16 18:58:50 mdz Exp $ |
b2e465d6 AL |
4 | /* ###################################################################### |
5 | ||
6 | Extract a Tar - Tar Extractor | |
7 | ||
8 | Some performance measurements showed that zlib performed quite poorly | |
1e3f4083 | 9 | in comparison to a forked gzip process. This tar extractor makes use |
b2e465d6 AL |
10 | of the fact that dup'd file descriptors have the same seek pointer |
11 | and that gzip will not read past the end of a compressed stream, | |
12 | even if there is more data. We use the dup property to track extraction | |
13 | progress and the gzip feature to just feed gzip a fd in the middle | |
14 | of an AR file. | |
15 | ||
16 | ##################################################################### */ | |
17 | /*}}}*/ | |
18 | // Include Files /*{{{*/ | |
ea542140 | 19 | #include<config.h> |
b2e465d6 | 20 | |
472ff00e | 21 | #include <apt-pkg/dirstream.h> |
ea542140 | 22 | #include <apt-pkg/extracttar.h> |
b2e465d6 AL |
23 | #include <apt-pkg/error.h> |
24 | #include <apt-pkg/strutl.h> | |
25 | #include <apt-pkg/configuration.h> | |
453b82a3 | 26 | #include <apt-pkg/fileutl.h> |
b2e465d6 | 27 | |
453b82a3 DK |
28 | #include <string.h> |
29 | #include <algorithm> | |
30 | #include <string> | |
b2e465d6 AL |
31 | #include <unistd.h> |
32 | #include <signal.h> | |
33 | #include <fcntl.h> | |
90f057fd | 34 | #include <iostream> |
ea542140 | 35 | |
d77559ac | 36 | #include <apti18n.h> |
b2e465d6 | 37 | /*}}}*/ |
d77559ac | 38 | |
584e4558 | 39 | using namespace std; |
4520bfdf | 40 | |
b2e465d6 AL |
41 | // The on disk header for a tar file. |
42 | struct ExtractTar::TarHeader | |
43 | { | |
44 | char Name[100]; | |
45 | char Mode[8]; | |
46 | char UserID[8]; | |
47 | char GroupID[8]; | |
48 | char Size[12]; | |
49 | char MTime[12]; | |
50 | char Checksum[8]; | |
51 | char LinkFlag; | |
52 | char LinkName[100]; | |
53 | char MagicNumber[8]; | |
54 | char UserName[32]; | |
55 | char GroupName[32]; | |
56 | char Major[8]; | |
57 | char Minor[8]; | |
58 | }; | |
59 | ||
60 | // ExtractTar::ExtractTar - Constructor /*{{{*/ | |
61 | // --------------------------------------------------------------------- | |
62 | /* */ | |
3621b1c7 GJ |
63 | ExtractTar::ExtractTar(FileFd &Fd,unsigned long long Max,string DecompressionProgram) |
64 | : File(Fd), MaxInSize(Max), DecompressProg(DecompressionProgram) | |
b2e465d6 AL |
65 | { |
66 | GZPid = -1; | |
b2e465d6 AL |
67 | Eof = false; |
68 | } | |
69 | /*}}}*/ | |
70 | // ExtractTar::ExtractTar - Destructor /*{{{*/ | |
71 | // --------------------------------------------------------------------- | |
72 | /* */ | |
73 | ExtractTar::~ExtractTar() | |
74 | { | |
4520bfdf AL |
75 | // Error close |
76 | Done(true); | |
b2e465d6 AL |
77 | } |
78 | /*}}}*/ | |
79 | // ExtractTar::Done - Reap the gzip sub process /*{{{*/ | |
80 | // --------------------------------------------------------------------- | |
81 | /* If the force flag is given then error messages are suppressed - this | |
82 | means we hit the end of the tar file but there was still gzip data. */ | |
83 | bool ExtractTar::Done(bool Force) | |
84 | { | |
85 | InFd.Close(); | |
86 | if (GZPid <= 0) | |
87 | return true; | |
88 | ||
89 | /* If there is a pending error then we are cleaning up gzip and are | |
90 | not interested in it's failures */ | |
91 | if (_error->PendingError() == true) | |
92 | Force = true; | |
93 | ||
94 | // Make sure we clean it up! | |
95 | kill(GZPid,SIGINT); | |
b21c0438 MZ |
96 | string confvar = string("dir::bin::") + DecompressProg; |
97 | if (ExecWait(GZPid,_config->Find(confvar.c_str(),DecompressProg.c_str()).c_str(), | |
b2e465d6 AL |
98 | Force) == false) |
99 | { | |
100 | GZPid = -1; | |
101 | return Force; | |
102 | } | |
103 | ||
104 | GZPid = -1; | |
105 | return true; | |
106 | } | |
107 | /*}}}*/ | |
108 | // ExtractTar::StartGzip - Startup gzip /*{{{*/ | |
109 | // --------------------------------------------------------------------- | |
110 | /* This creates a gzip sub process that has its input as the file itself. | |
111 | If this tar file is embedded into something like an ar file then | |
112 | gzip will efficiently ignore the extra bits. */ | |
113 | bool ExtractTar::StartGzip() | |
114 | { | |
3255db2d GJ |
115 | if (DecompressProg.empty()) |
116 | { | |
117 | InFd.OpenDescriptor(File.Fd(), FileFd::ReadOnly, FileFd::None, false); | |
118 | return true; | |
119 | } | |
120 | ||
b2e465d6 AL |
121 | int Pipes[2]; |
122 | if (pipe(Pipes) != 0) | |
05eb7df0 | 123 | return _error->Errno("pipe",_("Failed to create pipes")); |
cf4ff3b7 | 124 | |
b2e465d6 AL |
125 | // Fork off the process |
126 | GZPid = ExecFork(); | |
127 | ||
128 | // Spawn the subprocess | |
129 | if (GZPid == 0) | |
130 | { | |
131 | // Setup the FDs | |
132 | dup2(Pipes[1],STDOUT_FILENO); | |
133 | dup2(File.Fd(),STDIN_FILENO); | |
134 | int Fd = open("/dev/null",O_RDWR); | |
135 | if (Fd == -1) | |
136 | _exit(101); | |
137 | dup2(Fd,STDERR_FILENO); | |
138 | close(Fd); | |
139 | SetCloseExec(STDOUT_FILENO,false); | |
cf4ff3b7 | 140 | SetCloseExec(STDIN_FILENO,false); |
b2e465d6 | 141 | SetCloseExec(STDERR_FILENO,false); |
cf4ff3b7 | 142 | |
b2e465d6 | 143 | const char *Args[3]; |
b21c0438 | 144 | string confvar = string("dir::bin::") + DecompressProg; |
a9be43ff MV |
145 | string argv0 = _config->Find(confvar.c_str(),DecompressProg.c_str()); |
146 | Args[0] = argv0.c_str(); | |
b2e465d6 AL |
147 | Args[1] = "-d"; |
148 | Args[2] = 0; | |
b21c0438 | 149 | execvp(Args[0],(char **)Args); |
05eb7df0 | 150 | cerr << _("Failed to exec gzip ") << Args[0] << endl; |
b2e465d6 AL |
151 | _exit(100); |
152 | } | |
153 | ||
154 | // Fix up our FDs | |
2448a064 | 155 | InFd.OpenDescriptor(Pipes[0], FileFd::ReadOnly, FileFd::None, true); |
b2e465d6 AL |
156 | close(Pipes[1]); |
157 | return true; | |
158 | } | |
159 | /*}}}*/ | |
160 | // ExtractTar::Go - Perform extraction /*{{{*/ | |
161 | // --------------------------------------------------------------------- | |
162 | /* This reads each 512 byte block from the archive and extracts the header | |
163 | information into the Item structure. Then it resolves the UID/GID and | |
164 | invokes the correct processing function. */ | |
165 | bool ExtractTar::Go(pkgDirStream &Stream) | |
166 | { | |
167 | if (StartGzip() == false) | |
168 | return false; | |
169 | ||
170 | // Loop over all blocks | |
a07b81e8 OS |
171 | string LastLongLink, ItemLink; |
172 | string LastLongName, ItemName; | |
b2e465d6 AL |
173 | while (1) |
174 | { | |
175 | bool BadRecord = false; | |
176 | unsigned char Block[512]; | |
177 | if (InFd.Read(Block,sizeof(Block),true) == false) | |
178 | return false; | |
179 | ||
180 | if (InFd.Eof() == true) | |
181 | break; | |
182 | ||
183 | // Get the checksum | |
184 | TarHeader *Tar = (TarHeader *)Block; | |
185 | unsigned long CheckSum; | |
186 | if (StrToNum(Tar->Checksum,CheckSum,sizeof(Tar->Checksum),8) == false) | |
05eb7df0 | 187 | return _error->Error(_("Corrupted archive")); |
b2e465d6 AL |
188 | |
189 | /* Compute the checksum field. The actual checksum is blanked out | |
190 | with spaces so it is not included in the computation */ | |
191 | unsigned long NewSum = 0; | |
192 | memset(Tar->Checksum,' ',sizeof(Tar->Checksum)); | |
193 | for (int I = 0; I != sizeof(Block); I++) | |
194 | NewSum += Block[I]; | |
195 | ||
196 | /* Check for a block of nulls - in this case we kill gzip, GNU tar | |
197 | does this.. */ | |
198 | if (NewSum == ' '*sizeof(Tar->Checksum)) | |
199 | return Done(true); | |
200 | ||
201 | if (NewSum != CheckSum) | |
db0db9fe | 202 | return _error->Error(_("Tar checksum failed, archive corrupted")); |
b2e465d6 AL |
203 | |
204 | // Decode all of the fields | |
205 | pkgDirStream::Item Itm; | |
b2e465d6 | 206 | if (StrToNum(Tar->Mode,Itm.Mode,sizeof(Tar->Mode),8) == false || |
54f2f0a3 NH |
207 | (Base256ToNum(Tar->UserID,Itm.UID,8) == false && |
208 | StrToNum(Tar->UserID,Itm.UID,sizeof(Tar->UserID),8) == false) || | |
209 | (Base256ToNum(Tar->GroupID,Itm.GID,8) == false && | |
210 | StrToNum(Tar->GroupID,Itm.GID,sizeof(Tar->GroupID),8) == false) || | |
211 | (Base256ToNum(Tar->Size,Itm.Size,12) == false && | |
212 | StrToNum(Tar->Size,Itm.Size,sizeof(Tar->Size),8) == false) || | |
213 | (Base256ToNum(Tar->MTime,Itm.MTime,12) == false && | |
214 | StrToNum(Tar->MTime,Itm.MTime,sizeof(Tar->MTime),8) == false) || | |
b2e465d6 AL |
215 | StrToNum(Tar->Major,Itm.Major,sizeof(Tar->Major),8) == false || |
216 | StrToNum(Tar->Minor,Itm.Minor,sizeof(Tar->Minor),8) == false) | |
05eb7df0 | 217 | return _error->Error(_("Corrupted archive")); |
a07b81e8 OS |
218 | |
219 | // Grab the filename and link target: use last long name if one was | |
220 | // set, otherwise use the header value as-is, but remember that it may | |
221 | // fill the entire 100-byte block and needs to be zero-terminated. | |
222 | // See Debian Bug #689582. | |
b2e465d6 AL |
223 | if (LastLongName.empty() == false) |
224 | Itm.Name = (char *)LastLongName.c_str(); | |
225 | else | |
a07b81e8 | 226 | Itm.Name = (char *)ItemName.assign(Tar->Name, sizeof(Tar->Name)).c_str(); |
b2e465d6 AL |
227 | if (Itm.Name[0] == '.' && Itm.Name[1] == '/' && Itm.Name[2] != 0) |
228 | Itm.Name += 2; | |
b2e465d6 AL |
229 | |
230 | if (LastLongLink.empty() == false) | |
231 | Itm.LinkTarget = (char *)LastLongLink.c_str(); | |
a07b81e8 OS |
232 | else |
233 | Itm.LinkTarget = (char *)ItemLink.assign(Tar->LinkName, sizeof(Tar->LinkName)).c_str(); | |
234 | ||
b2e465d6 AL |
235 | // Convert the type over |
236 | switch (Tar->LinkFlag) | |
237 | { | |
238 | case NormalFile0: | |
239 | case NormalFile: | |
240 | Itm.Type = pkgDirStream::Item::File; | |
241 | break; | |
242 | ||
243 | case HardLink: | |
244 | Itm.Type = pkgDirStream::Item::HardLink; | |
245 | break; | |
246 | ||
247 | case SymbolicLink: | |
248 | Itm.Type = pkgDirStream::Item::SymbolicLink; | |
249 | break; | |
250 | ||
251 | case CharacterDevice: | |
252 | Itm.Type = pkgDirStream::Item::CharDevice; | |
253 | break; | |
254 | ||
255 | case BlockDevice: | |
256 | Itm.Type = pkgDirStream::Item::BlockDevice; | |
257 | break; | |
258 | ||
259 | case Directory: | |
260 | Itm.Type = pkgDirStream::Item::Directory; | |
261 | break; | |
262 | ||
263 | case FIFO: | |
264 | Itm.Type = pkgDirStream::Item::FIFO; | |
265 | break; | |
266 | ||
267 | case GNU_LongLink: | |
268 | { | |
3621b1c7 | 269 | unsigned long long Length = Itm.Size; |
b2e465d6 AL |
270 | unsigned char Block[512]; |
271 | while (Length > 0) | |
272 | { | |
273 | if (InFd.Read(Block,sizeof(Block),true) == false) | |
274 | return false; | |
275 | if (Length <= sizeof(Block)) | |
276 | { | |
277 | LastLongLink.append(Block,Block+sizeof(Block)); | |
278 | break; | |
279 | } | |
280 | LastLongLink.append(Block,Block+sizeof(Block)); | |
281 | Length -= sizeof(Block); | |
282 | } | |
283 | continue; | |
284 | } | |
285 | ||
286 | case GNU_LongName: | |
287 | { | |
3621b1c7 | 288 | unsigned long long Length = Itm.Size; |
b2e465d6 AL |
289 | unsigned char Block[512]; |
290 | while (Length > 0) | |
291 | { | |
292 | if (InFd.Read(Block,sizeof(Block),true) == false) | |
293 | return false; | |
294 | if (Length < sizeof(Block)) | |
295 | { | |
296 | LastLongName.append(Block,Block+sizeof(Block)); | |
297 | break; | |
298 | } | |
299 | LastLongName.append(Block,Block+sizeof(Block)); | |
300 | Length -= sizeof(Block); | |
301 | } | |
302 | continue; | |
303 | } | |
304 | ||
305 | default: | |
306 | BadRecord = true; | |
4c6a9fad | 307 | _error->Warning(_("Unknown TAR header type %u, member %s"),(unsigned)Tar->LinkFlag,Tar->Name); |
b2e465d6 AL |
308 | break; |
309 | } | |
310 | ||
311 | int Fd = -1; | |
312 | if (BadRecord == false) | |
313 | if (Stream.DoItem(Itm,Fd) == false) | |
314 | return false; | |
315 | ||
316 | // Copy the file over the FD | |
3621b1c7 | 317 | unsigned long long Size = Itm.Size; |
b2e465d6 AL |
318 | while (Size != 0) |
319 | { | |
320 | unsigned char Junk[32*1024]; | |
3621b1c7 | 321 | unsigned long Read = min(Size, (unsigned long long)sizeof(Junk)); |
b2e465d6 AL |
322 | if (InFd.Read(Junk,((Read+511)/512)*512) == false) |
323 | return false; | |
324 | ||
325 | if (BadRecord == false) | |
326 | { | |
327 | if (Fd > 0) | |
328 | { | |
329 | if (write(Fd,Junk,Read) != (signed)Read) | |
330 | return Stream.Fail(Itm,Fd); | |
331 | } | |
332 | else | |
333 | { | |
334 | /* An Fd of -2 means to send to a special processing | |
335 | function */ | |
336 | if (Fd == -2) | |
337 | if (Stream.Process(Itm,Junk,Read,Itm.Size - Size) == false) | |
338 | return Stream.Fail(Itm,Fd); | |
339 | } | |
340 | } | |
341 | ||
342 | Size -= Read; | |
343 | } | |
344 | ||
345 | // And finish up | |
59152cdb | 346 | if (BadRecord == false) |
b2e465d6 AL |
347 | if (Stream.FinishedFile(Itm,Fd) == false) |
348 | return false; | |
349 | ||
350 | LastLongName.erase(); | |
351 | LastLongLink.erase(); | |
352 | } | |
353 | ||
354 | return Done(false); | |
355 | } | |
356 | /*}}}*/ |