]>
Commit | Line | Data |
---|---|---|
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 | /* */ | |
b21c0438 MZ |
63 | ExtractTar::ExtractTar(FileFd &Fd,unsigned long Max,string DecompressionProgram) : File(Fd), |
64 | MaxInSize(Max), DecompressProg(DecompressionProgram) | |
b2e465d6 AL |
65 | |
66 | { | |
67 | GZPid = -1; | |
b2e465d6 AL |
68 | Eof = false; |
69 | } | |
70 | /*}}}*/ | |
71 | // ExtractTar::ExtractTar - Destructor /*{{{*/ | |
72 | // --------------------------------------------------------------------- | |
73 | /* */ | |
74 | ExtractTar::~ExtractTar() | |
75 | { | |
4520bfdf AL |
76 | // Error close |
77 | Done(true); | |
b2e465d6 AL |
78 | } |
79 | /*}}}*/ | |
80 | // ExtractTar::Done - Reap the gzip sub process /*{{{*/ | |
81 | // --------------------------------------------------------------------- | |
82 | /* If the force flag is given then error messages are suppressed - this | |
83 | means we hit the end of the tar file but there was still gzip data. */ | |
84 | bool ExtractTar::Done(bool Force) | |
85 | { | |
86 | InFd.Close(); | |
87 | if (GZPid <= 0) | |
88 | return true; | |
89 | ||
90 | /* If there is a pending error then we are cleaning up gzip and are | |
91 | not interested in it's failures */ | |
92 | if (_error->PendingError() == true) | |
93 | Force = true; | |
94 | ||
95 | // Make sure we clean it up! | |
96 | kill(GZPid,SIGINT); | |
b21c0438 MZ |
97 | string confvar = string("dir::bin::") + DecompressProg; |
98 | if (ExecWait(GZPid,_config->Find(confvar.c_str(),DecompressProg.c_str()).c_str(), | |
b2e465d6 AL |
99 | Force) == false) |
100 | { | |
101 | GZPid = -1; | |
102 | return Force; | |
103 | } | |
104 | ||
105 | GZPid = -1; | |
106 | return true; | |
107 | } | |
108 | /*}}}*/ | |
109 | // ExtractTar::StartGzip - Startup gzip /*{{{*/ | |
110 | // --------------------------------------------------------------------- | |
111 | /* This creates a gzip sub process that has its input as the file itself. | |
112 | If this tar file is embedded into something like an ar file then | |
113 | gzip will efficiently ignore the extra bits. */ | |
114 | bool ExtractTar::StartGzip() | |
115 | { | |
3255db2d GJ |
116 | if (DecompressProg.empty()) |
117 | { | |
118 | InFd.OpenDescriptor(File.Fd(), FileFd::ReadOnly, FileFd::None, false); | |
119 | return true; | |
120 | } | |
121 | ||
b2e465d6 AL |
122 | int Pipes[2]; |
123 | if (pipe(Pipes) != 0) | |
05eb7df0 | 124 | return _error->Errno("pipe",_("Failed to create pipes")); |
cf4ff3b7 | 125 | |
b2e465d6 AL |
126 | // Fork off the process |
127 | GZPid = ExecFork(); | |
128 | ||
129 | // Spawn the subprocess | |
130 | if (GZPid == 0) | |
131 | { | |
132 | // Setup the FDs | |
133 | dup2(Pipes[1],STDOUT_FILENO); | |
134 | dup2(File.Fd(),STDIN_FILENO); | |
135 | int Fd = open("/dev/null",O_RDWR); | |
136 | if (Fd == -1) | |
137 | _exit(101); | |
138 | dup2(Fd,STDERR_FILENO); | |
139 | close(Fd); | |
140 | SetCloseExec(STDOUT_FILENO,false); | |
cf4ff3b7 | 141 | SetCloseExec(STDIN_FILENO,false); |
b2e465d6 | 142 | SetCloseExec(STDERR_FILENO,false); |
cf4ff3b7 | 143 | |
b2e465d6 | 144 | const char *Args[3]; |
b21c0438 | 145 | string confvar = string("dir::bin::") + DecompressProg; |
a9be43ff MV |
146 | string argv0 = _config->Find(confvar.c_str(),DecompressProg.c_str()); |
147 | Args[0] = argv0.c_str(); | |
b2e465d6 AL |
148 | Args[1] = "-d"; |
149 | Args[2] = 0; | |
b21c0438 | 150 | execvp(Args[0],(char **)Args); |
05eb7df0 | 151 | cerr << _("Failed to exec gzip ") << Args[0] << endl; |
b2e465d6 AL |
152 | _exit(100); |
153 | } | |
154 | ||
155 | // Fix up our FDs | |
2448a064 | 156 | InFd.OpenDescriptor(Pipes[0], FileFd::ReadOnly, FileFd::None, true); |
b2e465d6 AL |
157 | close(Pipes[1]); |
158 | return true; | |
159 | } | |
160 | /*}}}*/ | |
161 | // ExtractTar::Go - Perform extraction /*{{{*/ | |
162 | // --------------------------------------------------------------------- | |
163 | /* This reads each 512 byte block from the archive and extracts the header | |
164 | information into the Item structure. Then it resolves the UID/GID and | |
165 | invokes the correct processing function. */ | |
166 | bool ExtractTar::Go(pkgDirStream &Stream) | |
167 | { | |
168 | if (StartGzip() == false) | |
169 | return false; | |
170 | ||
171 | // Loop over all blocks | |
a07b81e8 OS |
172 | string LastLongLink, ItemLink; |
173 | string LastLongName, ItemName; | |
b2e465d6 AL |
174 | while (1) |
175 | { | |
176 | bool BadRecord = false; | |
177 | unsigned char Block[512]; | |
178 | if (InFd.Read(Block,sizeof(Block),true) == false) | |
179 | return false; | |
180 | ||
181 | if (InFd.Eof() == true) | |
182 | break; | |
183 | ||
184 | // Get the checksum | |
185 | TarHeader *Tar = (TarHeader *)Block; | |
186 | unsigned long CheckSum; | |
187 | if (StrToNum(Tar->Checksum,CheckSum,sizeof(Tar->Checksum),8) == false) | |
05eb7df0 | 188 | return _error->Error(_("Corrupted archive")); |
b2e465d6 AL |
189 | |
190 | /* Compute the checksum field. The actual checksum is blanked out | |
191 | with spaces so it is not included in the computation */ | |
192 | unsigned long NewSum = 0; | |
193 | memset(Tar->Checksum,' ',sizeof(Tar->Checksum)); | |
194 | for (int I = 0; I != sizeof(Block); I++) | |
195 | NewSum += Block[I]; | |
196 | ||
197 | /* Check for a block of nulls - in this case we kill gzip, GNU tar | |
198 | does this.. */ | |
199 | if (NewSum == ' '*sizeof(Tar->Checksum)) | |
200 | return Done(true); | |
201 | ||
202 | if (NewSum != CheckSum) | |
db0db9fe | 203 | return _error->Error(_("Tar checksum failed, archive corrupted")); |
b2e465d6 AL |
204 | |
205 | // Decode all of the fields | |
206 | pkgDirStream::Item Itm; | |
b2e465d6 | 207 | if (StrToNum(Tar->Mode,Itm.Mode,sizeof(Tar->Mode),8) == false || |
54f2f0a3 NH |
208 | (Base256ToNum(Tar->UserID,Itm.UID,8) == false && |
209 | StrToNum(Tar->UserID,Itm.UID,sizeof(Tar->UserID),8) == false) || | |
210 | (Base256ToNum(Tar->GroupID,Itm.GID,8) == false && | |
211 | StrToNum(Tar->GroupID,Itm.GID,sizeof(Tar->GroupID),8) == false) || | |
212 | (Base256ToNum(Tar->Size,Itm.Size,12) == false && | |
213 | StrToNum(Tar->Size,Itm.Size,sizeof(Tar->Size),8) == false) || | |
214 | (Base256ToNum(Tar->MTime,Itm.MTime,12) == false && | |
215 | StrToNum(Tar->MTime,Itm.MTime,sizeof(Tar->MTime),8) == false) || | |
b2e465d6 AL |
216 | StrToNum(Tar->Major,Itm.Major,sizeof(Tar->Major),8) == false || |
217 | StrToNum(Tar->Minor,Itm.Minor,sizeof(Tar->Minor),8) == false) | |
05eb7df0 | 218 | return _error->Error(_("Corrupted archive")); |
a07b81e8 OS |
219 | |
220 | // Grab the filename and link target: use last long name if one was | |
221 | // set, otherwise use the header value as-is, but remember that it may | |
222 | // fill the entire 100-byte block and needs to be zero-terminated. | |
223 | // See Debian Bug #689582. | |
b2e465d6 AL |
224 | if (LastLongName.empty() == false) |
225 | Itm.Name = (char *)LastLongName.c_str(); | |
226 | else | |
a07b81e8 | 227 | Itm.Name = (char *)ItemName.assign(Tar->Name, sizeof(Tar->Name)).c_str(); |
b2e465d6 AL |
228 | if (Itm.Name[0] == '.' && Itm.Name[1] == '/' && Itm.Name[2] != 0) |
229 | Itm.Name += 2; | |
b2e465d6 AL |
230 | |
231 | if (LastLongLink.empty() == false) | |
232 | Itm.LinkTarget = (char *)LastLongLink.c_str(); | |
a07b81e8 OS |
233 | else |
234 | Itm.LinkTarget = (char *)ItemLink.assign(Tar->LinkName, sizeof(Tar->LinkName)).c_str(); | |
235 | ||
b2e465d6 AL |
236 | // Convert the type over |
237 | switch (Tar->LinkFlag) | |
238 | { | |
239 | case NormalFile0: | |
240 | case NormalFile: | |
241 | Itm.Type = pkgDirStream::Item::File; | |
242 | break; | |
243 | ||
244 | case HardLink: | |
245 | Itm.Type = pkgDirStream::Item::HardLink; | |
246 | break; | |
247 | ||
248 | case SymbolicLink: | |
249 | Itm.Type = pkgDirStream::Item::SymbolicLink; | |
250 | break; | |
251 | ||
252 | case CharacterDevice: | |
253 | Itm.Type = pkgDirStream::Item::CharDevice; | |
254 | break; | |
255 | ||
256 | case BlockDevice: | |
257 | Itm.Type = pkgDirStream::Item::BlockDevice; | |
258 | break; | |
259 | ||
260 | case Directory: | |
261 | Itm.Type = pkgDirStream::Item::Directory; | |
262 | break; | |
263 | ||
264 | case FIFO: | |
265 | Itm.Type = pkgDirStream::Item::FIFO; | |
266 | break; | |
267 | ||
268 | case GNU_LongLink: | |
269 | { | |
270 | unsigned long Length = Itm.Size; | |
271 | unsigned char Block[512]; | |
272 | while (Length > 0) | |
273 | { | |
274 | if (InFd.Read(Block,sizeof(Block),true) == false) | |
275 | return false; | |
276 | if (Length <= sizeof(Block)) | |
277 | { | |
278 | LastLongLink.append(Block,Block+sizeof(Block)); | |
279 | break; | |
280 | } | |
281 | LastLongLink.append(Block,Block+sizeof(Block)); | |
282 | Length -= sizeof(Block); | |
283 | } | |
284 | continue; | |
285 | } | |
286 | ||
287 | case GNU_LongName: | |
288 | { | |
289 | unsigned long Length = Itm.Size; | |
290 | unsigned char Block[512]; | |
291 | while (Length > 0) | |
292 | { | |
293 | if (InFd.Read(Block,sizeof(Block),true) == false) | |
294 | return false; | |
295 | if (Length < sizeof(Block)) | |
296 | { | |
297 | LastLongName.append(Block,Block+sizeof(Block)); | |
298 | break; | |
299 | } | |
300 | LastLongName.append(Block,Block+sizeof(Block)); | |
301 | Length -= sizeof(Block); | |
302 | } | |
303 | continue; | |
304 | } | |
305 | ||
306 | default: | |
307 | BadRecord = true; | |
4c6a9fad | 308 | _error->Warning(_("Unknown TAR header type %u, member %s"),(unsigned)Tar->LinkFlag,Tar->Name); |
b2e465d6 AL |
309 | break; |
310 | } | |
311 | ||
312 | int Fd = -1; | |
313 | if (BadRecord == false) | |
314 | if (Stream.DoItem(Itm,Fd) == false) | |
315 | return false; | |
316 | ||
317 | // Copy the file over the FD | |
318 | unsigned long Size = Itm.Size; | |
319 | while (Size != 0) | |
320 | { | |
321 | unsigned char Junk[32*1024]; | |
42ab8223 | 322 | unsigned long Read = min(Size,(unsigned long)sizeof(Junk)); |
b2e465d6 AL |
323 | if (InFd.Read(Junk,((Read+511)/512)*512) == false) |
324 | return false; | |
325 | ||
326 | if (BadRecord == false) | |
327 | { | |
328 | if (Fd > 0) | |
329 | { | |
330 | if (write(Fd,Junk,Read) != (signed)Read) | |
331 | return Stream.Fail(Itm,Fd); | |
332 | } | |
333 | else | |
334 | { | |
335 | /* An Fd of -2 means to send to a special processing | |
336 | function */ | |
337 | if (Fd == -2) | |
338 | if (Stream.Process(Itm,Junk,Read,Itm.Size - Size) == false) | |
339 | return Stream.Fail(Itm,Fd); | |
340 | } | |
341 | } | |
342 | ||
343 | Size -= Read; | |
344 | } | |
345 | ||
346 | // And finish up | |
59152cdb | 347 | if (BadRecord == false) |
b2e465d6 AL |
348 | if (Stream.FinishedFile(Itm,Fd) == false) |
349 | return false; | |
350 | ||
351 | LastLongName.erase(); | |
352 | LastLongLink.erase(); | |
353 | } | |
354 | ||
355 | return Done(false); | |
356 | } | |
357 | /*}}}*/ |