main-menu/main-menu.c

/*
 * Debian Installer main menu program.
 *
 * Copyright 2000,2004  Joey Hess <joeyh@debian.org>
 * 
 * This program 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 program 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.
 */

#include "main-menu.h"
#include <cdebconf/debconfclient.h>
#include <stdarg.h>
#include <stdlib.h>
#include <search.h>
#include <stdio.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <sys/types.h>
#include <unistd.h>
#include <dirent.h>
#include <errno.h>

const int RAISE = 1;
const int LOWER = 0;

di_hash_table *seen_items;
di_hash_table *notinstallables;
int last_successful_item = -1;

/* Save default priority, to be able to return to it when we have to lower it */
int default_priority = 1;

/* Save priority set by main-menu to detect priority changes from the user */
int local_priority = -1;

/* Force display of the menu at the current priority */
int display_menu = 0;

static struct debconfclient *debconf;

static int di_config_package(di_system_package *p,
			     int (*virtfunc)(di_system_package *));

static void modify_debconf_priority (int raise_or_lower);

static char *debconf_priorities[] =
  {
    "low",
    "medium",
    "high",
    "critical"
  };

#define ARRAY_SIZE(a) (sizeof(a)/sizeof(a[0]))
static int debconf_to_pri (char *priority) {
	int i;

	if (priority)
		for (i = 0; (size_t)i < ARRAY_SIZE(debconf_priorities); ++i)
			if (0 == strcmp(priority, debconf_priorities[i]))
				return i;

	return -1;
}

static char *xasprintf (const char *format, ...)
{
	va_list args;
	char *result;

	va_start(args, format);
	if (vasprintf(&result, format, args) < 0) {
		if (errno == ENOMEM) {
			fputs("Out of memory!\n", stderr);
			abort();
		}
		return NULL;
	}

	return result;
}

/*
 * qsort comparison function (sort by menu item values, fall back to
 * lexical sort to resolve ties deterministically).
 */
int package_array_compare (const void *v1, const void *v2) {
	di_system_package *p1, *p2;

	p1 = *(di_system_package **)v1;
	p2 = *(di_system_package **)v2;

	int r = p1->installer_menu_item - p2->installer_menu_item;
	//di_log(DI_LOG_LEVEL_DEBUG, "menu compare: %s (%i) vs %s (%i): %i", 
	//		p1->p.package, p1->installer_menu_item,
	//		p2->p.package, p2->installer_menu_item, r);
	if (r) return r;
	return strcmp(p1->p.package, p2->p.package);
}

static void seen_items_key_destroy (void *key)
{
	di_rstring *s = key;
	di_free(s->string);
	di_free(s);
}

static void notinstallables_key_destroy (void *key)
{
	di_rstring *s = key;
	di_free(s->string);
	di_free(s);
}

int isdefault(di_system_package *p) {
	int check;

	check = di_system_dpkg_package_control_file_exec(&p->p, "menutest", 0, NULL);
	if (check <= 0 || p->p.status == di_package_status_unpacked || p->p.status == di_package_status_half_configured)
		return true;
	return false;
}

/*
 * Menu items with a number equal to 99999 are intended only to be shown
 * during package selection in anna, but not in the main menu, so mark
 * them uninstallable.
 * For other packages, run the isinstallable maintainer script and check
 * its return code.
 */
bool isinstallable(di_system_package *p) {
	int check;

	if (p->installer_menu_item == 99999)
		return false;

	check = di_system_dpkg_package_control_file_exec(&p->p, "isinstallable", 0, NULL);
	if (check <= 0)
		return true;

	/* Add to table listing not installable packages */
	di_rstring *p_name = di_new0(di_rstring, 1);
	p_name->string = di_stradup(p->p.key.string, p->p.key.size);
	p_name->size = p->p.key.size;
	di_hash_table_insert(notinstallables, p_name, p_name);

	return false;
}

/* Return nonzero if all of the virtual packages that P provides are
   provided by installed packages.  */
int provides_installed_virtual_packages(di_package *p) {
	di_slist_node *node1, *node2;
	int provides = 0;

	for (node1 = p->depends.head; node1; node1 = node1->next) {
		di_package_dependency *d = node1->data;

		if (d->type == di_package_dependency_type_provides) {
			int installed = 0;

			provides = 1;

			for (node2 = d->ptr->depends.head; node2; node2 = node2->next) {
				d = node2->data;

				if (d->type == di_package_dependency_type_reverse_provides
				    && d->ptr->status == di_package_status_installed) {
					installed = 1;
					break;
				}
			}

			if (!installed)
				return 0;
		}
	}

	return provides;
}

/* Expects a topologically ordered linked list of packages. */
static di_system_package *
get_default_menu_item(di_slist *list)
{
	di_system_package *p;
	di_slist_node *node;

	/* Create table listing not installable packages from scratch as
	 * the isinstallable status can change at any time
	 */
	di_hash_table_destroy(notinstallables);
	notinstallables = di_hash_table_new_full(di_rstring_hash, di_rstring_equal,
						 notinstallables_key_destroy, NULL);

	/* Traverse the list, return the first menu item that isn't installed */
	for (node = list->head; node != NULL; node = node->next) {
		p = node->data;
		//di_log(DI_LOG_LEVEL_DEBUG, "find default; on: %s", p->p.package);
		if (!p->installer_menu_item ||
		    p->p.status == di_package_status_installed ||
		    !isinstallable(p)) {
			//di_log(DI_LOG_LEVEL_DEBUG, "not a menu item, not installed or not installable");
			continue;
		}
		if (p->installer_menu_item >= NEVERDEFAULT) {
			//di_log(DI_LOG_LEVEL_DEBUG, "not in range to be default");
			continue;
		}
		if (p->installer_menu_item < last_successful_item &&
		    di_hash_table_lookup(seen_items, &p->p.key)) {
			//di_log(DI_LOG_LEVEL_DEBUG, "menu item (%d) is before last_successful_item (%d), and is not new", p->installer_menu_item, last_successful_item);
			continue;
		}
		/* If menutest says this item should be default, make it so */
		if (!isdefault(p)) {
			//di_log(DI_LOG_LEVEL_DEBUG, "isdefault says no");
			continue;
		}
		/* If all of the virtual packages provided by a
		   package have already been satisfied, do not default
		   to it.  */
		if (!provides_installed_virtual_packages(&p->p)) {
			//di_log(DI_LOG_LEVEL_DEBUG, "success on this one");
			return p;
		}

		//di_log(DI_LOG_LEVEL_DEBUG, "not default");
	}
	/* Severely broken, there are no menu items in the sorted list */
	return NULL;
}

#define menu_entry_maxlen 256

/* Returns a the text of the menu entry for PACKAGE (in a buffer
 * that will persist until the next call of the function) */
const char *menu_entry(struct debconfclient *debconf, di_system_package *package)
{
	char question[menu_entry_maxlen];
	static char buf[menu_entry_maxlen];

	snprintf(question, sizeof(question), "debian-installer/%s/title", package->p.package);
	if (!debconf_metaget(debconf, question, "Description")) {
		strncpy(buf, debconf->value, menu_entry_maxlen);
		return buf;
	}

	/* The following fallback case can go away once all packages
	   have transitioned to the new form.  */
	di_log(DI_LOG_LEVEL_INFO, "Falling back to the package description for %s", package->p.package);
	if (package->p.short_description)
		strncpy(buf, package->p.short_description, menu_entry_maxlen);
	else
		buf[0]='\0';
	return buf;
}

/* Escapes a string so it can be added to a Choices list. */
const char *choices_escape(const char *string) {
	static char buf[menu_entry_maxlen * 2];
	const char *s;
	char *p;

	s = strchr(string, ',');
	if (s == NULL)
		return string;

	/* This is not the cheapest way to do it, but a comma in a
	 * choice is very rare. */
	s=string;
	p=buf;
	while (s[0] != '\0') {
		if (s[0] == ',') {
			p[0] = '\\';
			p++;
		}

		p[0]=s[0];

		p++;
		s++;
	}
	p[0] = '\0';
	return buf;
}

/* Priority at which the menu should be displayed */
static int menu_priority() {
	static int default_menu_priority = -1;
	int menu_prio = -1;

	if (default_menu_priority == -1)
		default_menu_priority = debconf_to_pri(MENU_PRIORITY);

	if (display_menu)
		menu_prio = local_priority;

	if (menu_prio < 0 ||
	    (size_t)menu_prio >= ARRAY_SIZE(debconf_priorities))
		menu_prio = default_menu_priority;

	//di_log(DI_LOG_LEVEL_INFO, "default: %i; debconf: %i; menu: %i",
	//	default_menu_priority, local_priority, menu_prio);

	return menu_prio;
}

/* Displays the main menu via debconf and returns the selected menu item. */
di_system_package *show_main_menu(di_packages *packages, di_packages_allocator *allocator) {
	di_system_package **package_array, *p;
	di_slist *list;
	di_slist_node *node;
	di_system_package *menudefault = NULL, *ret = NULL;
	int i = 0, num = 0;
	char *menu, *s;
	const char *buf;
	int menu_prio, menu_size, menu_used, size;

	for (node = packages->list.head; node; node = node->next) {
		p = node->data;
		if (((di_system_package *)p)->installer_menu_item)
			num++;
	}
	package_array = di_new (di_system_package *, num + 1);
	package_array[num] = NULL;
	for (node = packages->list.head; node; node = node->next) {
		p = node->data;
		if (p->installer_menu_item)
			package_array[i++] = node->data;
	}
	
	/* Sort by menu number. */
	qsort(package_array, num, sizeof (di_system_package *), package_array_compare);

	/* Order menu so depended-upon packages come first. */
	/* The menu number is really only used to break ties. */
	list = di_system_packages_resolve_dependencies_array_permissive (packages, (di_package **) package_array, allocator);

	/*
	 * Generate list of menu choices for debconf.
	 */
	menu_size = 1024;
	menu = di_malloc(menu_size);
	menu[0] = '\0';
	menu_used = 1;
	for (node = list->head; node != NULL; node = node->next) {
		p = node->data;
		if (!p->installer_menu_item ||
		    !isinstallable(p))
			continue;
		buf = choices_escape(menu_entry(debconf, p));
		size = strlen(buf);
		if (menu_used + size + 2 > menu_size)
		{
			menu_size += 1024;
			menu = di_realloc(menu, menu_size);
		}
		if (*menu)
			strcat(menu, ", ");
		strcat(menu, buf);
		menu_used += size + 2;
	}
	menudefault = get_default_menu_item(list);
	di_slist_free(list);

	/* Make debconf show the menu and get the user's choice. */
	debconf_settitle(debconf, "debian-installer/main-menu-title");
	debconf_capb(debconf);
	debconf_subst(debconf, MAIN_MENU, "MENU", menu);
	if (menudefault) {
		buf=menu_entry(debconf, menudefault);
		debconf_set(debconf, MAIN_MENU, buf);
	}
	else {
		di_log(DI_LOG_LEVEL_INFO, "no default menu item"); 
		modify_debconf_priority(LOWER);
	}
	menu_prio = menu_priority();
	debconf_input(debconf, debconf_priorities[menu_prio], MAIN_MENU);
	debconf_go(debconf);
	debconf_get(debconf, MAIN_MENU);
	s = strdup(debconf->value);
	
	/* Figure out which menu item was selected. */
	for (i = 0; i < num; i++) {
		p = package_array[i];
		buf = menu_entry(debconf, p);
		if (strcmp(buf, s) == 0) {
			ret = p;
			break;
		}
	}

	if (! ret) {
		/* This could happen because of a debconf protocol problem
		 * (for example, leading whitespace in menu items can
		 * be stripped and confuse the comparisons), or other
		 * problem. */
		di_log(DI_LOG_LEVEL_WARNING, "Internal error! Cannot find \"%s\" in menu.", s);
	}

	free(s);
	free(menu);
	free(package_array);

	return ret;
}

/*
 * Satisfy the dependencies of a virtual package. Its dependencies
 * that actually provide the package are presented in a debconf select
 * question for the user to pick and choose. Other dependencies are
 * just fed recursively through di_config_package.
 */
static int satisfy_virtual(di_system_package *p) {
	di_slist_node *node;
	di_system_package *dep, *defpkg = NULL;
	char *menu, *s = NULL;
	const char *buf;
	size_t menu_size, menu_used, size;
	int is_menu_item = 0;

	menu = di_malloc(1024);
	menu[0] = '\0';
	menu_size = 1024;
	menu_used = 1;
	/* Compile a list of providing package. The default choice will be the
	 * package with highest priority. If we have ties, menu items are
	 * preferred. If we still have ties, the default choice is arbitrary */
	for (node = p->p.depends.head; node; node = node->next) {
		di_package_dependency *d = node->data;
		dep = (di_system_package *)d->ptr;
		if (d->type == di_package_dependency_type_depends) {
			/* Non-providing dependency */
			di_log(DI_LOG_LEVEL_DEBUG, "non-providing dependency from %s to %s", p->p.package, dep->p.package);
			if (dep->p.status != di_package_status_installed) {
				switch (di_config_package(dep, satisfy_virtual)) {
					case -1:
						di_free(menu);
						return -1;
					case EXIT_BACKUP:
						di_free(menu);
						return EXIT_BACKUP;
				}
			}
			continue;
		}
		if (d->type != di_package_dependency_type_reverse_provides)
			continue;
		if (dep->p.status == di_package_status_installed) {
			/* This means that a providing package is already
			 * configure. So we short-circuit. */
			menu_used = 0;
			break;
		}
		if (defpkg == NULL || dep->p.priority > defpkg->p.priority ||
				(dep->p.priority == defpkg->p.priority &&
				 dep->installer_menu_item < defpkg->installer_menu_item))
			defpkg = dep;
		/* This only makes sense if one of the dependencies
		 * is a menu item */
		if (dep->installer_menu_item)
			is_menu_item = 1;

		buf = choices_escape(menu_entry(debconf, dep));
		size = strlen(buf);
		if (menu_used + size + 2 > menu_size)
		{
			menu_size += 1024;
			menu = di_realloc(menu, menu_size);
		}

		if (dep == defpkg) {
			/* We want the default to be the first item */
			char *temp;
			temp = di_malloc (menu_size);
			strcpy(temp, menu);
			strcpy(menu, buf);
			if (strlen(temp)) {
				strcat(menu, ", ");
				strcat(menu, temp);
			}
			di_free(temp);
		} else {
			if (strlen(menu)) {
				strcat(menu, ", ");
			}
			strcat(menu, buf);
		}
		menu_used += size + 2;
	}
	if (menu_used >= 2)
		menu[menu_used-2] = '\0';
	if (menu_used > 1) {
		if (is_menu_item) {
			char *priority = "medium";
			/* Only let the user choose if one of them is a menu item */
			if (defpkg != NULL) {
				buf = menu_entry(debconf, defpkg);
				debconf_set(debconf, MISSING_PROVIDE, buf);
			} else {
				/* TODO: How to figure out a default? */
				priority = "critical";
			}
			debconf_capb(debconf, "backup");
			debconf_subst(debconf, MISSING_PROVIDE, "CHOICES", menu);
			debconf_input(debconf, priority, MISSING_PROVIDE);
			if (debconf_go(debconf) != 0) {
				di_free(menu);
				return 0;
			}
			debconf_capb(debconf);
			debconf_get(debconf, MISSING_PROVIDE);
			s = strdup(debconf->value);
		}
		/* Go through the dependencies again */
		for (node = p->p.depends.head; node; node = node->next) {
			di_package_dependency *d = node->data;
			dep = (di_system_package *)d->ptr;
			buf = menu_entry(debconf, dep);
			if (!is_menu_item || strcmp(s, buf) == 0) {
				/* Ick. If we have a menu item it has to match the
				 * debconf choice, otherwise we configure all of
				 * the providing packages */
				switch (di_config_package(dep, satisfy_virtual)) {
					case -1:
						di_free(menu);
						free(s);
						return -1;
					case EXIT_BACKUP:
						di_free(menu);
						free(s);
						return EXIT_BACKUP;
				}
				if (is_menu_item)
					break;
			}
		}
	}
	di_free(menu);
	free(s);
	/* It doesn't make sense to configure virtual packages,
	 * since they are, well, virtual. */
	p->p.status = di_package_status_installed;
	return 1;
}

static void set_package_title(di_system_package *p) {
	char *title;

	if (!p->installer_menu_item)
		return;
	title = xasprintf("debian-installer/%s/title", p->p.package);
	if (debconf_settitle(debconf, title))
		di_log(DI_LOG_LEVEL_WARNING, "Unable to set title for %s.", p->p.package);
	free(title);
}

static int do_menu_item(di_system_package *p) {
	di_log(DI_LOG_LEVEL_INFO, "Menu item '%s' selected", p->p.package);

	return di_config_package(p, satisfy_virtual);
}

static void modify_debconf_priority (int raise_or_lower) {
	int pri;
	const char *template = "debconf/priority";
	debconf_get(debconf, template);
	
	pri = debconf_to_pri(debconf->value);
	if ( pri == -1 )
		pri = 1;

	if (raise_or_lower == LOWER) {
		--pri;
		/* Make sure the menu is always displayed after an error */
		display_menu = 1;
	}
	else if (raise_or_lower == RAISE)
		++pri;
	if (0 > pri)
		pri = 0;
	if (pri > default_priority)
		pri = default_priority;
	if (local_priority != pri) {
		if (local_priority > -1)
			di_log(DI_LOG_LEVEL_INFO, "Modifying debconf priority limit from '%s' to '%s'",
				debconf->value ? debconf->value : "(null)",
				debconf_priorities[pri] ? debconf_priorities[pri] : "(null)");
		local_priority = pri;
	    
		debconf_set(debconf, template, debconf_priorities[pri]);
	}
}
	
static void adjust_default_priority (void) {
	int pri;
	const char *template = "debconf/priority";
	debconf_get(debconf, template);

	pri = debconf_to_pri(debconf->value);
	
	if (pri > -1 && pri != local_priority) {
		if (local_priority > -1)
			di_log(DI_LOG_LEVEL_INFO, "Priority changed externally, setting main-menu default to '%s' (%s)",
				debconf_priorities[pri] ? debconf_priorities[pri] : "(null)", debconf->value);
		local_priority = pri;
		default_priority = pri;
	}
}

static void restore_default_priority (void) {
	const char *template = "debconf/priority";

	if (local_priority != default_priority) {
		di_log(DI_LOG_LEVEL_INFO, "Restoring default debconf priority '%s'",
			debconf_priorities[default_priority] ? debconf_priorities[default_priority] : "(null)");
		debconf_set(debconf, template, debconf_priorities[default_priority]);
		local_priority = default_priority;
	}
}

void notify_user_of_failure (di_system_package *p) {
	const char *buf;