1 files changed, 268 insertions, 0 deletions
diff --git a/lib/dpkg/db-fsys-override.c b/lib/dpkg/db-fsys-override.c
new file mode 100644
index 0000000..e079c5f
--- /dev/null
+++ b/lib/dpkg/db-fsys-override.c
@@ -0,0 +1,268 @@
+/*
+ * libdpkg - Debian packaging suite library routines
+ * db-fsys-override.c - management of filesystem stat overrides database
+ *
+ * Copyright © 1995 Ian Jackson <ijackson@chiark.greenend.org.uk>
+ * Copyright © 2000, 2001 Wichert Akkerman <wakkerma@debian.org>
+ * Copyright © 2008-2012 Guillem Jover <guillem@debian.org>
+ *
+ * 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 of the License, 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 this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <compat.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <string.h>
+#include <pwd.h>
+#include <grp.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+#include <dpkg/i18n.h>
+#include <dpkg/dpkg.h>
+#include <dpkg/dpkg-db.h>
+#include <dpkg/fdio.h>
+#include <dpkg/debug.h>
+#include <dpkg/db-fsys.h>
+
+static char *statoverridename;
+
+uid_t
+statdb_parse_uid(const char *str)
+{
+	char *endptr;
+	uid_t uid;
+
+	if (str[0] == '#') {
+		long int value;
+
+		errno = 0;
+		value = strtol(str + 1, &endptr, 10);
+		if (str + 1 == endptr || *endptr || value < 0 || errno != 0)
+			ohshit(_("invalid statoverride uid %s"), str);
+		uid = (uid_t)value;
+	} else {
+		struct passwd *pw = getpwnam(str);
+
+		if (pw == NULL)
+			uid = (uid_t)-1;
+		else
+			uid = pw->pw_uid;
+	}
+
+	return uid;
+}
+
+gid_t
+statdb_parse_gid(const char *str)
+{
+	char *endptr;
+	gid_t gid;
+
+	if (str[0] == '#') {
+		long int value;
+
+		errno = 0;
+		value = strtol(str + 1, &endptr, 10);
+		if (str + 1 == endptr || *endptr || value < 0 || errno != 0)
+			ohshit(_("invalid statoverride gid %s"), str);
+		gid = (gid_t)value;
+	} else {
+		struct group *gr = getgrnam(str);
+
+		if (gr == NULL)
+			gid = (gid_t)-1;
+		else
+			gid = gr->gr_gid;
+	}
+
+	return gid;
+}
+
+mode_t
+statdb_parse_mode(const char *str)
+{
+	char *endptr;
+	long int mode;
+
+	mode = strtol(str, &endptr, 8);
+	if (str == endptr || *endptr || mode < 0 || mode > 07777)
+		ohshit(_("invalid statoverride mode %s"), str);
+
+	return (mode_t)mode;
+}
+
+void
+ensure_statoverrides(enum statdb_parse_flags flags)
+{
+	static struct stat sb_prev;
+	struct stat sb_next;
+	static FILE *file_prev;
+	FILE *file;
+	char *loaded_list, *loaded_list_end, *thisline, *nextline, *ptr;
+	struct file_stat *fso;
+	struct fsys_namenode *fnn;
+	struct fsys_hash_iter *iter;
+
+	if (statoverridename == NULL)
+		statoverridename = dpkg_db_get_path(STATOVERRIDEFILE);
+
+	onerr_abort++;
+
+	file = fopen(statoverridename, "r");
+	if (!file) {
+		if (errno != ENOENT)
+			ohshite(_("failed to open statoverride file"));
+	} else {
+		setcloexec(fileno(file), statoverridename);
+
+		if (fstat(fileno(file), &sb_next))
+			ohshite(_("failed to fstat statoverride file"));
+
+		/*
+		 * We need to keep the database file open so that the
+		 * filesystem cannot reuse the inode number (f.ex. during
+		 * multiple dpkg-statoverride invocations in a maintainer
+		 * script), otherwise the following check might turn true,
+		 * and we would skip reloading a modified database.
+		 */
+		if (file_prev &&
+		    sb_prev.st_dev == sb_next.st_dev &&
+		    sb_prev.st_ino == sb_next.st_ino) {
+			fclose(file);
+			onerr_abort--;
+			debug(dbg_general, "%s: same, skipping", __func__);
+			return;
+		}
+		sb_prev = sb_next;
+	}
+	if (file_prev)
+		fclose(file_prev);
+	file_prev = file;
+
+	/* Reset statoverride information. */
+	iter = fsys_hash_iter_new();
+	while ((fnn = fsys_hash_iter_next(iter)))
+		fnn->statoverride = NULL;
+	fsys_hash_iter_free(iter);
+
+	if (!file) {
+		onerr_abort--;
+		debug(dbg_general, "%s: none, resetting", __func__);
+		return;
+	}
+	debug(dbg_general, "%s: new, (re)loading", __func__);
+
+	/* If the statoverride list is empty we don't need to bother
+	 * reading it. */
+	if (!sb_next.st_size) {
+		onerr_abort--;
+		return;
+	}
+
+	loaded_list = m_malloc(sb_next.st_size);
+	loaded_list_end = loaded_list + sb_next.st_size;
+
+	if (fd_read(fileno(file), loaded_list, sb_next.st_size) < 0)
+		ohshite(_("reading statoverride file '%.250s'"), statoverridename);
+
+	thisline = loaded_list;
+	while (thisline < loaded_list_end) {
+		fso = nfmalloc(sizeof(*fso));
+
+		ptr = memchr(thisline, '\n', loaded_list_end - thisline);
+		if (ptr == NULL)
+			ohshit(_("statoverride file is missing final newline"));
+		/* Where to start next time around. */
+		nextline = ptr + 1;
+		if (ptr == thisline)
+			ohshit(_("statoverride file contains empty line"));
+		*ptr = '\0';
+
+		/* Extract the uid. */
+		ptr = memchr(thisline, ' ', nextline - thisline);
+		if (ptr == NULL)
+			ohshit(_("syntax error in statoverride file"));
+		*ptr = '\0';
+
+		fso->uid = statdb_parse_uid(thisline);
+		if (fso->uid == (uid_t)-1)
+			fso->uname = nfstrsave(thisline);
+		else
+			fso->uname = NULL;
+
+		if (fso->uid == (uid_t)-1 && !(flags & STATDB_PARSE_LAX))
+			ohshit(_("unknown system user '%s' in statoverride file; the system user got removed\n"
+			         "before the override, which is most probably a packaging bug, to recover you\n"
+			         "can remove the override manually with %s"), thisline, DPKGSTAT);
+
+		/* Move to the next bit */
+		thisline = ptr + 1;
+		if (thisline >= loaded_list_end)
+			ohshit(_("unexpected end of line in statoverride file"));
+
+		/* Extract the gid */
+		ptr = memchr(thisline, ' ', nextline - thisline);
+		if (ptr == NULL)
+			ohshit(_("syntax error in statoverride file"));
+		*ptr = '\0';
+
+		fso->gid = statdb_parse_gid(thisline);
+		if (fso->gid == (gid_t)-1)
+			fso->gname = nfstrsave(thisline);
+		else
+			fso->gname = NULL;
+
+		if (fso->gid == (gid_t)-1 && !(flags & STATDB_PARSE_LAX))
+			ohshit(_("unknown system group '%s' in statoverride file; the system group got removed\n"
+			         "before the override, which is most probably a packaging bug, to recover you\n"
+			         "can remove the override manually with %s"), thisline, DPKGSTAT);
+
+		/* Move to the next bit */
+		thisline = ptr + 1;
+		if (thisline >= loaded_list_end)
+			ohshit(_("unexpected end of line in statoverride file"));
+
+		/* Extract the mode */
+		ptr = memchr(thisline, ' ', nextline - thisline);
+		if (ptr == NULL)
+			ohshit(_("syntax error in statoverride file"));
+		*ptr = '\0';
+
+		fso->mode = statdb_parse_mode(thisline);
+
+		/* Move to the next bit */
+		thisline = ptr + 1;
+		if (thisline >= loaded_list_end)
+			ohshit(_("unexpected end of line in statoverride file"));
+
+		fnn = fsys_hash_find_node(thisline, 0);
+		if (fnn->statoverride)
+			ohshit(_("multiple statoverrides present for file '%.250s'"),
+			       thisline);
+		fnn->statoverride = fso;
+
+		/* Moving on... */
+		thisline = nextline;
+	}
+
+	free(loaded_list);
+
+	onerr_abort--;
+}