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-rw-r--r--lib/dbmodify.c256
1 files changed, 256 insertions, 0 deletions
diff --git a/lib/dbmodify.c b/lib/dbmodify.c
new file mode 100644
index 000000000..9fdd646d3
--- /dev/null
+++ b/lib/dbmodify.c
@@ -0,0 +1,256 @@
+/*
+ * dpkg - main program for package management
+ * dbmodify.c - routines for managing dpkg database updates
+ *
+ * Copyright (C) 1994,1995 Ian Jackson <iwj10@cus.cam.ac.uk>
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2,
+ * or (at your option) any later version.
+ *
+ * This is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with dpkg; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <errno.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <limits.h>
+#include <ctype.h>
+#include <assert.h>
+
+#include "config.h"
+#include "dpkg.h"
+#include "dpkg-db.h"
+
+char *statusfile=0, *availablefile=0;
+
+static enum modstatdb_rw cstatus=-1, cflags=0;
+static char *importanttmpfile=0;
+static FILE *importanttmp;
+static int nextupdate;
+static int updateslength;
+static char *updatefnbuf, *updatefnrest;
+static const char *admindir;
+static struct varbuf uvb;
+
+static int ulist_select(const struct dirent *de) {
+ const char *p;
+ int l;
+ for (p= de->d_name, l=0; *p; p++, l++)
+ if (!isdigit(*p)) return 0;
+ if (l > IMPORTANTMAXLEN)
+ ohshit("updates directory contains file `%.250s' whose name is too long "
+ "(length=%d, max=%d)", de->d_name, l, IMPORTANTMAXLEN);
+ if (updateslength == -1) updateslength= l;
+ else if (l != updateslength)
+ ohshit("updates directory contains files with different length names "
+ "(both %d and %d)", l, updateslength);
+ return 1;
+}
+
+static void cleanupdates(void) {
+ struct dirent **cdlist;
+ int cdn, i;
+
+ parsedb(statusfile, pdb_weakclassification, 0,0,0);
+
+ *updatefnrest= 0;
+ updateslength= -1;
+ cdn= scandir(updatefnbuf, &cdlist, &ulist_select, alphasort);
+ if (cdn == -1) ohshite("cannot scan updates directory `%.255s'",updatefnbuf);
+
+ if (cdn) {
+
+ for (i=0; i<cdn; i++) {
+ strcpy(updatefnrest, cdlist[i]->d_name);
+ parsedb(updatefnbuf, pdb_weakclassification, 0,0,0);
+ if (cstatus < msdbrw_write) free(cdlist[i]);
+ }
+
+ if (cstatus >= msdbrw_write) {
+ writedb(statusfile,0,1);
+
+ for (i=0; i<cdn; i++) {
+ strcpy(updatefnrest, cdlist[i]->d_name);
+ if (unlink(updatefnbuf))
+ ohshite("failed to remove incorporated update file %.255s",updatefnbuf);
+ free(cdlist[i]);
+ }
+ }
+
+ }
+ free(cdlist);
+
+ nextupdate= 0;
+}
+
+static void createimptmp(void) {
+ int i;
+
+ onerr_abort++;
+
+ importanttmp= fopen(importanttmpfile,"w");
+ if (!importanttmp) ohshite("unable to create %.250s",importanttmpfile);
+ for (i=0; i<512; i++) fputs("#padding\n",importanttmp);
+ if (ferror(importanttmp))
+ ohshite("unable to fill %.250s with padding",importanttmpfile);
+ if (fflush(importanttmp))
+ ohshite("unable flush %.250s after padding",importanttmpfile);
+ if (fseek(importanttmp,0,SEEK_SET))
+ ohshite("unable seek to start of %.250s after padding",importanttmpfile);
+
+ onerr_abort--;
+}
+
+enum modstatdb_rw modstatdb_init(const char *adir, enum modstatdb_rw readwritereq) {
+ static const struct fni { const char *suffix; char **store; } fnis[]= {
+ { STATUSFILE, &statusfile },
+ { AVAILFILE, &availablefile },
+ { UPDATESDIR IMPORTANTTMP, &importanttmpfile },
+ { 0 }
+ }, *fnip;
+
+ admindir= adir;
+
+ for (fnip=fnis; fnip->suffix; fnip++) {
+ free(*fnip->store);
+ *fnip->store= m_malloc(strlen(adir)+strlen(fnip->suffix)+2);
+ sprintf(*fnip->store, "%s/%s", adir, fnip->suffix);
+ }
+
+ cflags= readwritereq & msdbrw_flagsmask;
+ readwritereq &= ~msdbrw_flagsmask;
+
+ switch (readwritereq) {
+ case msdbrw_needsuperuser:
+ case msdbrw_needsuperuserlockonly:
+ if (getuid() || geteuid())
+ ohshit("requested operation requires superuser privilege");
+ /* fall through */
+ case msdbrw_write: case msdbrw_writeifposs:
+ if (access(adir,W_OK)) {
+ if (errno != EACCES)
+ ohshite("unable to access dpkg status area");
+ else if (readwritereq == msdbrw_write)
+ ohshit("operation requires read/write access to dpkg status area");
+ cstatus= msdbrw_readonly;
+ } else {
+ lockdatabase(adir);
+ cstatus= (readwritereq == msdbrw_needsuperuserlockonly ?
+ msdbrw_needsuperuserlockonly :
+ msdbrw_write);
+ }
+ break;
+ case msdbrw_readonly:
+ cstatus= msdbrw_readonly; break;
+ default:
+ internerr("unknown readwritereq");
+ }
+
+ updatefnbuf= m_malloc(strlen(adir)+sizeof(UPDATESDIR)+IMPORTANTMAXLEN+5);
+ strcpy(updatefnbuf,adir);
+ strcat(updatefnbuf,"/" UPDATESDIR);
+ updatefnrest= updatefnbuf+strlen(updatefnbuf);
+
+ cleanupdates();
+
+ if (cstatus >= msdbrw_write) {
+ createimptmp();
+ uvb.used= 0;
+ uvb.size= 10240;
+ uvb.buf= m_malloc(uvb.size);
+ }
+
+ if (cstatus != msdbrw_needsuperuserlockonly) {
+ parsedb(statusfile, pdb_weakclassification, 0,0,0);
+ parsedb(statusfile, pdb_recordavailable, 0,0,0);
+ parsedb(availablefile,
+ pdb_recordavailable|pdb_rejectstatus|
+ (cflags & msdbrw_availablepreferversion ? pdb_preferversion : 0),
+ 0,0,0);
+ }
+
+ return cstatus;
+}
+
+static void checkpoint(void) {
+ int i;
+
+ assert(cstatus >= msdbrw_write);
+ writedb(statusfile,0,1);
+
+ for (i=0; i<nextupdate; i++) {
+ sprintf(updatefnrest, IMPORTANTFMT, i);
+ assert(strlen(updatefnrest)<=IMPORTANTMAXLEN); /* or we've made a real mess */
+ if (unlink(updatefnbuf))
+ ohshite("failed to remove my own update file %.255s",updatefnbuf);
+ }
+ nextupdate= 0;
+}
+
+void modstatdb_shutdown(void) {
+ switch (cstatus) {
+ case msdbrw_write:
+ checkpoint();
+ if (!(cflags & msdbrw_availablepreferversion))
+ writedb(availablefile,1,0);
+
+ /* tidy up a bit, but don't worry too much about failure */
+ fclose(importanttmp);
+ strcpy(updatefnrest, IMPORTANTTMP); unlink(updatefnbuf);
+ varbuffree(&uvb);
+ /* fall through */
+ case msdbrw_needsuperuserlockonly:
+ unlockdatabase(admindir);
+ default:
+ break;
+ }
+
+ free(updatefnbuf);
+}
+
+void modstatdb_note(struct pkginfo *pkg) {
+ assert(cstatus >= msdbrw_write);
+
+ onerr_abort++;
+
+ varbufreset(&uvb);
+ varbufrecord(&uvb, pkg, &pkg->installed);
+ if (fwrite(uvb.buf, 1, uvb.used, importanttmp) != uvb.used)
+ ohshite("unable to write updated status of `%.250s'", pkg->name);
+ if (fflush(importanttmp))
+ ohshite("unable to flush updated status of `%.250s'", pkg->name);
+ if (ftruncate(fileno(importanttmp), uvb.used))
+ ohshite("unable to truncate for updated status of `%.250s'", pkg->name);
+ if (fsync(fileno(importanttmp)))
+ ohshite("unable to fsync updated status of `%.250s'", pkg->name);
+ if (fclose(importanttmp))
+ ohshite("unable to close updated status of `%.250s'", pkg->name);
+ sprintf(updatefnrest, IMPORTANTFMT, nextupdate);
+ if (rename(importanttmpfile, updatefnbuf))
+ ohshite("unable to install updated status of `%.250s'", pkg->name);
+ assert(strlen(updatefnrest)<=IMPORTANTMAXLEN); /* or we've made a real mess */
+
+ nextupdate++;
+
+ if (nextupdate > MAXUPDATES) checkpoint();
+
+ createimptmp();
+
+ onerr_abort--;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2025-07-13 11:49:13 +0000