6 * Written by Keith Marshall <keithmarshall@users.sourceforge.net>
7 * Copyright (C) 2011, MinGW Project
10 * Implementation of the primary package removal methods.
13 * This is free software. Permission is granted to copy, modify and
14 * redistribute this software, under the provisions of the GNU General
15 * Public License, Version 3, (or, at your option, any later version),
16 * as published by the Free Software Foundation; see the file COPYING
17 * for licensing details.
19 * Note, in particular, that this software is provided "as is", in the
20 * hope that it may prove useful, but WITHOUT WARRANTY OF ANY KIND; not
21 * even an implied WARRANTY OF MERCHANTABILITY, nor of FITNESS FOR ANY
22 * PARTICULAR PURPOSE. Under no circumstances will the author, or the
23 * MinGW Project, accept liability for any damages, however caused,
24 * arising from the use of this software.
41 #define PKGERR_INVALID_MANIFEST( REASON ) \
42 PKGMSG_INVALID_MANIFEST, tarname, REASON
44 #define PKGMSG_INVALID_MANIFEST "%s: invalid manifest; %s\n"
45 #define PKGMSG_NO_RELEASE_KEY "no release key assigned"
46 #define PKGMSG_RELEASE_KEY_MISMATCH "release key mismatch"
48 static const char *request_key = "request";
50 static __inline__ __attribute__((__always_inline__))
51 pkgXmlNode *sysroot_lookup( pkgXmlNode *pkg, const char *tarname )
53 /* A local helper function, to identify the sysroot association
54 * for any package which is to be uninstalled.
56 pkgSpecs lookup( tarname );
57 return pkg->GetSysRoot( lookup.GetSubSystemName() );
60 static __inline__ __attribute__((__always_inline__))
61 const char *id_lookup( pkgXmlNode *reftag, const char *fallback )
63 /* A local convenience function, to retrieve the value of
64 * the "id" attribute associated with any pkgXmlNode element.
66 return reftag->GetPropVal( id_key, fallback );
69 static __inline__ __attribute__((__always_inline__))
70 const char *pathname_lookup( pkgXmlNode *reftag, const char *fallback )
72 /* A local convenience function, to retrieve the value of
73 * the "id" attribute associated with any pkgXmlNode element.
75 return reftag->GetPropVal( pathname_key, fallback );
78 int pkgActionItem::SetAuthorities( pkgActionItem *current )
80 /* Helper method to either grant or revoke authority for removal of
81 * any package, either permanently when the user requests that it be
82 * removed, or temporarily in preparation for replacement be a newer
83 * version, when scheduled for upgrade.
85 * This is a multiple pass method, iterating over the entire list
86 * of scheduled actions within each pass, until the entire schedule
87 * of authorities has been established.
89 if( (flags & ACTION_PREFLIGHT) == 0 )
91 /* This applies exclusively in the first pass, which is effectively
92 * a "preflight" checking pass only.
94 while( current != NULL )
96 /* Each scheduled action is inspected in turn...
99 if( ((current->flags & ACTION_REMOVE) != 0)
100 && ((ref = current->Selection( to_remove )) != NULL) )
102 /* ...and, when it specifies a "remove" action relating to a
103 * package which has been identified as "installed"...
105 const char *tarname = ref->GetPropVal( tarname_key, value_unknown );
106 DEBUG_INVOKE_IF( DEBUGLEVEL && DEBUG_TRACE_INIT,
107 dmh_printf( "%s: selected for %s\n",
108 (tarname = ref->GetPropVal( tarname_key, value_unknown )),
109 (current->flags & ACTION_INSTALL) ? "upgrade" : "removal"
112 /* ...we identify its associated entry in the installed
113 * package manifest...
115 if( (ref = ref->GetInstallationRecord( tarname )) != NULL )
117 /* ...and then, having confirmed its validity...
119 DEBUG_INVOKE_IF( DEBUGLEVEL && DEBUG_TRACE_INIT,
120 dmh_printf( "%s: marked for %s\n",
121 ref->GetPropVal( tarname_key, value_unknown ),
122 (current->flags & ACTION_INSTALL) ? "upgrade" : "removal"
125 /* ...we mark it as a candidate for removal...
127 ref->SetAttribute( request_key, action_name( ACTION_REMOVE ) );
129 /* ...and assign a provisional grant of authority
130 * to proceed with the removal...
132 current->flags |= ACTION_PREFLIGHT;
135 /* ...then, we move on to perform the same "preflight" check
136 * for the next scheduled action, if any.
138 current = current->next;
140 /* When we get to here, we have completed the "preflight" checks
141 * for all scheduled actions. The "current" pointer has advanced,
142 * but the "this" pointer still refers to the head of the actions
143 * list; terminate this "preflight" pass, marking the associated
144 * entry to confirm that it has been completed.
146 return flags |= ACTION_PREFLIGHT;
149 /* We will get to here only in second and subsequent passes, after
150 * the initial "preflight" checks have been completed. For actions
151 * which schedule a package removal, (whether explicitly, or as an
152 * implicit prerequisite in preparation for upgrade), the initial
153 * pass will have provisionally authorised removal; in subsequent
154 * passes, we either ratify that authority, or we revoke it in the
155 * event that it would break a dependency of another package.
157 * FIXME: we need to develop the code to perform the dependency
158 * analysis; for the time being, we simply return zero, ratifying
159 * authority for all removal requests.
164 pkgXmlNode *pkgManifest::GetSysRootReference( const char *key )
166 /* Method to verify that a package manifest includes
167 * a reference to any sysroot which claims it, returning
168 * a pointer to the first such reference found.
170 if( (this != NULL) && (manifest != NULL) && (key != NULL) )
172 /* We appear to have a valid manifest, and a valid sysroot
173 * key to match; locate this manifest's first, (and nominally
174 * its only), references section.
176 pkgXmlNode *grp = manifest->GetRoot()->FindFirstAssociate( reference_key );
179 /* Having identified a references section, locate the
180 * first sysroot reference contained therein...
182 pkgXmlNode *ref = grp->FindFirstAssociate( sysroot_key );
185 /* ...then retrieve the sysroot ID key value,
186 * for comparison with the requested key...
189 if( ((chk = ref->GetPropVal( id_key, NULL )) != NULL)
190 && (strcmp( chk, key ) == 0) )
192 * ...returning immediately, if a match is found...
196 /* ...otherwise, repeat check for any further sysroot
197 * references which may be present...
199 ref = ref->FindNextAssociate( sysroot_key );
201 /* ...ultimately extending the search into any further
202 * (unlikely) references sections which might be present.
204 grp = grp->FindNextAssociate( reference_key );
207 /* If we fell through the preceding loop, then the expected reference
208 * was not present; return NULL, to report this unexpected result.
213 void pkgManifest::DetachSysRoot( const char *sysroot )
215 /* Method to remove all references to a specified sysroot
216 * from a package manifest; (note that it would be unusual
217 * for a manifest to refer to a given sysroot more than once,
218 * but we repeat the request until we are sure no more such
219 * references exist...
222 while( (ref = GetSysRootReference( sysroot )) != NULL )
224 * ...deleting each one we do find, as we go.
226 ref->GetParent()->DeleteChild( ref );
229 /* Format string used to construct absolute path names from the
230 * "sysroot" relative "pathname" maintained in package manifests;
231 * (shared by "pkg_rmdir()" and "pkg_unlink()" functions).
233 static const char *pkg_path_format = "%s/%s";
235 static __inline__ __attribute__((__always_inline__))
236 int pkg_rmdir( const char *sysroot, const char *pathname )
238 /* Local helper, used to remove directories which become empty
239 * during scheduled package removal; "pathname" is specified from
240 * the package manifest, and is relative to "sysroot", (thus both
241 * must be specified and non-NULL). Return value is non-zero
242 * when the specified directory is successfully removed, or
246 if( (sysroot != NULL) && (pathname != NULL) )
248 /* "sysroot" and "pathname" are both specified. Construct
249 * the absolute path name, and attempt to "rmdir" it, setting
250 * return value as appropriate; silently ignore failure.
252 char fullpath[ 1 + snprintf( NULL, 0, pkg_path_format, sysroot, pathname ) ];
253 snprintf( fullpath, sizeof( fullpath ), pkg_path_format, sysroot, pathname );
255 DEBUG_INVOKE_IF( DEBUGLEVEL && DEBUG_TRACE_TRANSACTIONS,
256 dmh_printf( " %s: rmdir\n", fullpath )
259 retval = rmdir( fullpath ) == 0;
264 static __inline__ __attribute__((__always_inline__))
265 int pkg_unlink( const char *sysroot, const char *pathname )
267 /* Local helper, used to delete files during scheduled package
268 * removal; "pathname" is specified within the package manifest,
269 * and is relative to "sysroot", (thus both must be specified and
270 * non-NULL). Return value is non-zero when the specified file
271 * is successfully deleted, or zero otherwise.
274 if( (sysroot != NULL) && (pathname != NULL) )
276 char filepath[ 1 + snprintf( NULL, 0, pkg_path_format, sysroot, pathname ) ];
277 snprintf( filepath, sizeof( filepath ), pkg_path_format, sysroot, pathname );
279 DEBUG_INVOKE_IF( DEBUGLEVEL && DEBUG_TRACE_TRANSACTIONS,
280 dmh_printf( " %s: unlink file\n", filepath )
283 if( ((retval = unlink( filepath )) != 0) && (errno != ENOENT) )
284 dmh_notify( DMH_WARNING, "%s:unlink failed; %s\n", filepath, strerror( errno ) );
289 EXTERN_C void pkgRemove( pkgActionItem *current )
291 /* Common handler for all package removal tasks...
294 if( (pkg = current->Selection( to_remove )) != NULL )
296 /* We've identified a candidate package for removal;
297 * first, identify the canonical tarname for the package,
298 * and the sysroot with which it is associated.
300 const char *tarname = pkg->GetPropVal( tarname_key, value_unknown );
301 pkgXmlNode *sysroot = sysroot_lookup( pkg, tarname );
303 dmh_printf( " removing %s %s\n", pkg->GetName(), tarname );
305 /* Removal of virtual (meta) packages is comparitively simple;
306 * identified by having an associated archive name of "none", they
307 * have no associated archive file, no installed footprint on disk,
308 * and no associated content manifest to process; thus...
310 if( ! match_if_explicit( pkg->ArchiveName(), value_none ) )
312 /* ...only in the case of packages identified as "real", (which
313 * we expect to be in a substantial majority), do we need to refer
314 * to any installation manifest, to identify actual disk files to
318 pkgManifest inventory( package_key, tarname );
319 pkgXmlNode *ref, *manifest = inventory.GetRoot();
321 /* Perform some sanity checks on the retrieved manifest...
323 if( ((ref = manifest) == NULL)
324 || ((ref = ref->FindFirstAssociate( release_key )) == NULL) )
326 * Mostly "belt-and-braces": this should never happen, because
327 * the manifest constructor should never return a manifest which
328 * lacks a "release" element. If we see this, there is something
329 * seriously wrong; hopefully we will get a bug report.
331 dmh_notify( DMH_ERROR, PKGERR_INVALID_MANIFEST( PKGMSG_NO_RELEASE_KEY ) );
333 else if( ((refname = ref->GetPropVal( tarname_key, NULL )) == NULL)
334 || (strcmp( tarname, refname ) != 0) )
336 /* Another "belt-and-braces" case: once again, it should never
337 * happen, because the manifest constructor should never return
338 * a manifest with a "tarname" attribute in the "release" element
339 * which doesn't match the "tarname" requested.
341 dmh_control( DMH_BEGIN_DIGEST );
342 dmh_notify( DMH_ERROR, PKGERR_INVALID_MANIFEST( PKGMSG_RELEASE_KEY_MISMATCH ) );
343 if( refname != NULL )
344 dmh_notify( DMH_ERROR, "%s: found %s instead\n", tarname, refname );
345 dmh_control( DMH_END_DIGEST );
348 else if( ref->FindNextAssociate( release_key ) != NULL )
350 * Yet another "belt-and-braces" case: the constructor should
351 * never create a manifest which does not have exactly one, and
352 * no more than one, "release" element.
354 dmh_notify( DMH_ERROR, PKGERR_INVALID_MANIFEST( "too many release keys" ) );
356 else if( ((ref = manifest->FindFirstAssociate( reference_key )) == NULL)
357 || (ref->FindFirstAssociate( sysroot_key ) == NULL) )
358 dmh_notify( DMH_ERROR, PKGERR_INVALID_MANIFEST( "no references" ) );
361 { /* We have a manifest which we may likely be able to process;
362 * before proceeding, perform a few sanity checks, and report
363 * any anomalies which may be recoverable.
365 const char *sysname = id_lookup( sysroot, NULL );
366 if( inventory.GetSysRootReference( sysname ) == NULL )
368 /* This indicates that the manifest file itself is lacking
369 * a reference to the sysroot. The sysroot record indicates
370 * that such a reference should be present; diagnose the
371 * anomaly, and proceed anyway.
373 * FIXME: we should probably make this an error condition,
374 * which will suppress processing unless it is overridden by
375 * a user specified option.
377 dmh_notify( DMH_WARNING,
378 "%s: unreferenced in %s\n", sysname, id_lookup( manifest, value_unknown )
381 /* Now, we've validated the manifest, and confirmed that it
382 * correctly records its association with the current sysroot,
383 * (or we've reported the inconsistency; we may proceed with
384 * removal of the associated files.
386 if( (manifest = manifest->FindFirstAssociate( manifest_key )) != NULL )
388 /* The manifest records file pathnames relative to sysroot;
389 * thus, first identify the pathname prefix which identifies
390 * the absolute locations of the files and directories which
393 const char *syspath = pathname_lookup( sysroot, value_unknown );
395 /* Read the package manifest...
400 /* ...selecting records identifying installed files...
402 pkgXmlNode *files = ref->FindFirstAssociate( filename_key );
403 while( files != NULL )
405 /* ...and delete each in turn...
407 pkg_unlink( syspath, pathname_lookup( files, NULL ) );
409 * ...before moving on to the next in the list.
411 files = files->FindNextAssociate( filename_key );
413 /* It should not be, but allow for the possibility that
414 * the manifest is subdivided into multiple sections.
416 ref = ref->FindNextAssociate( manifest_key );
419 /* Having deleted all files associated with the package,
420 * we attempt to prune any directories, which may have been
421 * created during the installation of this package, from the
422 * file system tree. We note that we may remove only those
423 * directories which no longer contain any files or other
424 * subdirectories, (i.e. those which are leaf directories
425 * within the file system). We also note that many of the
426 * directories associated with the package being removed
427 * may also contain files belonging to other packages; thus
428 * we do not consider it to be an error if we are unable to
429 * remove any directory specified in the package manifest.
431 * Removal of any leaf directory may expose its own parent
432 * as a new leaf, which may then itself become a candidate
433 * for removal; thus we adopt an iterative removal procedure,
434 * restarting with a further iteration after any pass through
435 * the manifest in which any directory is removed.
439 /* Process the entire manifest on each iteration;
440 * initially assume that no restart will be required.
442 ref = manifest; restart = false;
445 /* Select manifest records which specify directories...
447 pkgXmlNode *dir = ref->FindFirstAssociate( dirname_key );
450 /* ...attempting to remove each in turn; request a
451 * restart when at least one such attempt succeeds...
453 restart |= pkg_rmdir( syspath, pathname_lookup( dir, NULL ) );
455 * ...then move on to the next record, if any.
457 dir = dir->FindNextAssociate( dirname_key );
459 /* As in the case of file removal, allow for the
460 * possibility of a multisectional manifest.
462 ref = ref->FindNextAssociate( manifest_key );
464 /* Restart the directory removal process, with a new
465 * iteration through the entire manifest, until no more
466 * listed directories can be removed.
470 /* Finally, disassociate the package manifest from the active sysroot;
471 * this will automatically delete the manifest itself, unless it has a
472 * further association with any other sysroot, (e.g. in an alternative
475 inventory.DetachSysRoot( sysname );
479 /* In the case of both real and virtual packages, the final phase of removal
480 * is to expunge the installation record from the associated sysroot element
481 * within the system map; (that is, any record of type "installed" contained
482 * within the sysroot element referenced by the "sysroot" pointer identified
483 * above, with a tarname attribute which matches "tarname").
485 pkgXmlNode *expunge, *instrec = sysroot->FindFirstAssociate( installed_key );
486 while( (expunge = instrec) != NULL )
488 /* Consider each installation record in turn, as a possible candidate for
489 * deletion; in any case, always locate the NEXT candidate, BEFORE deleting
490 * a matched record, so we don't destroy our point of reference, whence we
491 * must continue the search.
493 instrec = instrec->FindNextAssociate( installed_key );
494 if( strcmp( tarname, expunge->GetPropVal( tarname_key, value_unknown )) == 0 )
496 /* The CURRENT candidate matches the "tarname" criterion for deletion;
497 * we may delete it, also marking the sysroot record as "modified", so
498 * that the change will be committed to disk.
500 sysroot->DeleteChild( expunge );
501 sysroot->SetAttribute( modified_key, value_yes );
507 /* $RCSfile$: end of file */