xbps-pkgdb: add alternatives check

Closes #66

bin/xbps-pkgdb/Makefile

@@ -3,7 +3,7 @@ TOPDIR = ../..
 
 BIN =	xbps-pkgdb
 OBJS =	main.o check.o check_pkg_files.o
-OBJS +=	check_pkg_rundeps.o
+OBJS +=	check_pkg_alternatives.o check_pkg_rundeps.o
 OBJS +=	check_pkg_symlinks.o check_pkg_unneeded.o
 
 include $(TOPDIR)/mk/prog.mk

bin/xbps-pkgdb/check.c

@@ -72,7 +72,7 @@ check_pkg_integrity(struct xbps_handle *xhp,
 		    xbps_dictionary_t pkgd,
 		    const char *pkgname)
 {
-	xbps_dictionary_t opkgd, filesd = NULL;
+	xbps_dictionary_t opkgd, filesd;
 	const char *sha256;
 	char *buf;
 	int rv = 0, errors = 0;
@@ -128,6 +128,7 @@ do {								\
 	RUN_PKG_CHECK(xhp, symlinks, filesd);
 	RUN_PKG_CHECK(xhp, rundeps, opkgd);
 	RUN_PKG_CHECK(xhp, unneeded, opkgd);
+	RUN_PKG_CHECK(xhp, alternatives, opkgd);
 
 	if (filesd)
 		xbps_object_release(filesd);

bin/xbps-pkgdb/check_pkg_alternatives.c

@@ -0,0 +1,197 @@
+/*-
+ * Copyright (c) 2015 Juan Romero Pardines.
+ * Copyright (c) 2019 Duncan Overbruck <mail@duncano.de>.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <unistd.h>
+#include <libgen.h>
+#include <sys/param.h>
+
+#include <xbps.h>
+#include "defs.h"
+
+/*
+ * Checks package integrity of an installed package.
+ * The following task is accomplished in this file:
+ *
+ * 	o Check alternative symlinks for set alternative groups.
+ *
+ * returns 0 if test ran successfully, 1 otherwise and -1 on error.
+ */
+
+static const char *
+normpath(char *path)
+{
+	char *seg, *p;
+
+	for (p = path, seg = NULL; *p; p++) {
+		if (strncmp(p, "/../", 4) == 0 || strncmp(p, "/..", 4) == 0) {
+			memmove(seg ? seg : p, p+3, strlen(p+3) + 1);
+			return normpath(path);
+		} else if (strncmp(p, "/./", 3) == 0 || strncmp(p, "/.", 3) == 0) {
+			memmove(p, p+2, strlen(p+2) + 1);
+		} else if (strncmp(p, "//", 2) == 0 || strncmp(p, "/", 2) == 0) {
+			memmove(p, p+1, strlen(p+1) + 1);
+		}
+		if (*p == '/')
+			seg = p;
+	}
+	return path;
+}
+
+static char *
+relpath(char *from, char *to)
+{
+	int up;
+	char *p = to, *rel;
+
+	assert(from[0] == '/');
+	assert(to[0] == '/');
+	normpath(from);
+	normpath(to);
+
+	for (; *from == *to && *to; from++, to++) {
+		if (*to == '/')
+			p = to;
+	}
+
+	for (up = -1, from--; from && *from; from = strchr(from + 1, '/'), up++);
+
+	rel = calloc(3 * up + strlen(p), sizeof(char));
+
+	while (up--)
+		strcat(rel, "../");
+	if (*p)
+		strcat(rel, p+1);
+	return rel;
+}
+
+static int
+check_symlinks(struct xbps_handle *xhp, const char *pkgname, xbps_array_t a,
+	const char *grname)
+{
+	int rv = 0;
+	ssize_t l;
+	unsigned int i, n;
+	char *alternative, *tok1, *tok2, *linkpath, *target, *dir, *p;
+	char path[PATH_MAX];
+
+	n = xbps_array_count(a);
+
+	for (i = 0; i < n; i++) {
+		alternative = xbps_string_cstring(xbps_array_get(a, i));
+
+		if (!(tok1 = strtok(alternative, ":")) ||
+		    !(tok2 = strtok(NULL, ":"))) {
+			free(alternative);
+			return -1;
+		}
+
+		target = strdup(tok2);
+		dir = dirname(tok2);
+
+		/* add target dir to relative links */
+		if (tok1[0] != '/')
+			linkpath = xbps_xasprintf("%s/%s/%s", xhp->rootdir, dir, tok1);
+		else
+			linkpath = xbps_xasprintf("%s/%s", xhp->rootdir, tok1);
+
+		if (target[0] == '/') {
+			p = relpath(linkpath + strlen(xhp->rootdir), target);
+			free(target);
+			target = p;
+		}
+
+		if (strncmp(linkpath, "//", 2) == 0) {
+			p = linkpath+1;
+		} else {
+			p = linkpath;
+		}
+		if ((l = readlink(linkpath, path, sizeof path)) == -1) {
+			xbps_error_printf(
+			    "%s: alternatives group %s symlink %s: %s\n",
+			    pkgname, grname, p, strerror(errno));
+			rv = 1;
+		} else if (strncmp(path, target, l) != 0) {
+			xbps_error_printf("%s: alternatives group %s symlink %s has wrong target.\n",
+			    pkgname, grname, p);
+			rv = 1;
+		}
+		free(alternative);
+		free(target);
+		free(linkpath);
+	}
+
+	return rv;
+}
+
+int
+check_pkg_alternatives(struct xbps_handle *xhp, const char *pkgname, void *arg)
+{
+	xbps_array_t allkeys, array;
+	xbps_dictionary_t pkg_propsd = arg;
+	xbps_dictionary_t alternatives, pkg_alternatives;
+	int rv = 0;
+
+	pkg_alternatives = arg;
+
+	alternatives = xbps_dictionary_get(xhp->pkgdb, "_XBPS_ALTERNATIVES_");
+	if (alternatives == NULL)
+		return 0;
+
+	pkg_alternatives = xbps_dictionary_get(pkg_propsd, "alternatives");
+	if (!xbps_dictionary_count(pkg_alternatives))
+		return 0;
+
+	allkeys = xbps_dictionary_all_keys(pkg_alternatives);
+	for (unsigned int i = 0; i < xbps_array_count(allkeys); i++) {
+		xbps_object_t keysym;
+		const char *first= NULL, *group;
+
+		keysym = xbps_array_get(allkeys, i);
+		group = xbps_dictionary_keysym_cstring_nocopy(keysym);
+
+		array = xbps_dictionary_get(alternatives, group);
+		if (array == NULL)
+			continue;
+
+		/* if pkgname is the first entry its set as alternative */
+		xbps_array_get_cstring_nocopy(array, 0, &first);
+		if (strcmp(pkgname, first) != 0)
+			continue;
+
+		array = xbps_dictionary_get(pkg_alternatives, group);
+		if (check_symlinks(xhp, pkgname, array, group) != 0)
+			rv = 1;
+	}
+	xbps_object_release(allkeys);
+
+	return rv;
+}

bin/xbps-pkgdb/defs.h

@@ -40,6 +40,7 @@ CHECK_PKG_DECL(unneeded);
 CHECK_PKG_DECL(files);
 CHECK_PKG_DECL(rundeps);
 CHECK_PKG_DECL(symlinks);
+CHECK_PKG_DECL(alternatives);
 
 /* from convert.c */
 void	convert_pkgdb_format(struct xbps_handle *);

bin/xbps-pkgdb/xbps-pkgdb.1

@@ -12,8 +12,8 @@ The
 .Nm
 utility can check/fix issues and modify the package database (pkgdb).
 It's able to check for missing dependencies, modified files and symlinks,
-and more errors that have been fixed in newer versions of xbps. A mode to update
-the format to the latest version is also available.
+alternatives and more errors that have been fixed in newer versions of xbps.
+A mode to update the format to the latest version is also available.
 This is the list of things that
 .Nm
 currently does:
@@ -29,6 +29,8 @@ compared and checked if they differ.
 For symbolic links the target file is checked that it has not been modified.
 .It Sy DEPENDENCIES CHECK
 Checks that all required dependencies for a package are resolved.
+.It Sy ALTERNATIVES CHECK
+Checks that all alternatives symlinks for set alternatives groups are correct.
 .It Sy OBSOLETE METADATA CHECK
 Checks that the package database does not contain obsolete data from previous
 XBPS versions and removes them if found.