dpkg.c

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		}
		free(array);
	}
}

/* This function lists information on the installed packages. It loops through
 * the status_hashtable to retrieve the info. This results in smaller code than
 * scanning the status file. The resulting list, however, is unsorted. 
 */
void list_packages(void)
{
        int i;

	printf("    Name           Version\n");
	printf("+++-==============-==============\n");
	
	/* go through status hash, dereference package hash and finally strings */
	for (i=0; i<STATUS_HASH_PRIME+1; i++) {

	        if (status_hashtable[i]) {
		        const char *stat_str;  /* status string */
			const char *name_str;  /* package name */
			const char *vers_str;  /* version */
			char  s1, s2;          /* status abbreviations */
			int   spccnt;          /* space count */      
			int   j;
			
			stat_str = name_hashtable[status_hashtable[i]->status];
			name_str = name_hashtable[package_hashtable[status_hashtable[i]->package]->name];
			vers_str = name_hashtable[package_hashtable[status_hashtable[i]->package]->version];
			
			/* get abbreviation for status field 1 */
			s1 = stat_str[0] == 'i' ? 'i' : 'r';
			
			/* get abbreviation for status field 2 */
			for (j=0, spccnt=0; stat_str[j] && spccnt<2; j++) {
			        if (stat_str[j] == ' ') spccnt++;
			}
			s2 = stat_str[j];
			
			/* print out the line formatted like Debian dpkg */
			printf("%c%c  %-14s %s\n", s1, s2, name_str, vers_str);
		}
    }
}

void remove_package(const unsigned int package_num)
{
	const char *package_name = name_hashtable[package_hashtable[package_num]->name];
	const unsigned int status_num = search_status_hashtable(package_name);
	const int package_name_length = strlen(package_name);
	char **remove_files;
	char **exclude_files;
	char list_name[package_name_length + 25];
	char conffile_name[package_name_length + 30];
	int return_value;

	printf("Removing %s ...\n", package_name);

	/* run prerm script */
	return_value = run_package_script(package_name, "prerm");
	if (return_value == -1) {
		error_msg_and_die("script failed, prerm failure");
	}

	/* Create a list of files to remove, and a seperate list of those to keep */
	sprintf(list_name, "/var/lib/dpkg/info/%s.list", package_name);
	remove_files = create_list(list_name);

	sprintf(conffile_name, "/var/lib/dpkg/info/%s.conffiles", package_name);
	exclude_files = create_list(conffile_name);

	/* Some directories cant be removed straight away, so do multiple passes */
	while (remove_file_array(remove_files, exclude_files));
	free_array(exclude_files);
	free_array(remove_files);

	/* Create a list of files in /var/lib/dpkg/info/<package>.* to keep  */
	exclude_files = xmalloc(sizeof(char*) * 3);
	exclude_files[0] = xstrdup(conffile_name);
	exclude_files[1] = xmalloc(package_name_length + 27);
	sprintf(exclude_files[1], "/var/lib/dpkg/info/%s.postrm", package_name);
	exclude_files[2] = NULL;

	/* Create a list of all /var/lib/dpkg/info/<package> files */
	remove_files = all_control_list(package_name);

	remove_file_array(remove_files, exclude_files);
	free_array(remove_files);
	free_array(exclude_files);

	/* rename <package>.conffile to <package>.list */
	rename(conffile_name, list_name);

	/* Change package status */
	set_status(status_num, "deinstall", 1);
	set_status(status_num, "config-files", 3);
}

void purge_package(const unsigned int package_num)
{
	const char *package_name = name_hashtable[package_hashtable[package_num]->name];
	const unsigned int status_num = search_status_hashtable(package_name);
	char **remove_files;
	char **exclude_files;
	char list_name[strlen(package_name) + 25];

	/* run prerm script */
	if (run_package_script(package_name, "prerm") != 0) {
		error_msg_and_die("script failed, prerm failure");
	}

	/* Create a list of files to remove */
	sprintf(list_name, "/var/lib/dpkg/info/%s.list", package_name);
	remove_files = create_list(list_name);

	exclude_files = xmalloc(sizeof(char*));
	exclude_files[0] = NULL;

	/* Some directories cant be removed straight away, so do multiple passes */
	while (remove_file_array(remove_files, exclude_files));
	free_array(remove_files);

	/* Create a list of all /var/lib/dpkg/info/<package> files */
	remove_files = all_control_list(package_name);
	remove_file_array(remove_files, exclude_files);
	free_array(remove_files);
	free(exclude_files);

	/* run postrm script */
	if (run_package_script(package_name, "postrm") == -1) {
		error_msg_and_die("postrm fialure.. set status to what?");
	}

	/* Change package status */
	set_status(status_num, "purge", 1);
	set_status(status_num, "not-installed", 3);
}

void unpack_package(deb_file_t *deb_file)
{
	const char *package_name = name_hashtable[package_hashtable[deb_file->package]->name];
	const unsigned int status_num = search_status_hashtable(package_name);
	const unsigned int status_package_num = status_hashtable[status_num]->package;

	FILE *out_stream;
	char *info_prefix;

	/* If existing version, remove it first */
	if (strcmp(name_hashtable[get_status(status_num, 3)], "installed") == 0) {
		/* Package is already installed, remove old version first */
		printf("Preparing to replace %s %s (using %s) ...\n", package_name,
			name_hashtable[package_hashtable[status_package_num]->version],
			deb_file->filename);
		remove_package(status_package_num);
	} else {
		printf("Unpacking %s (from %s) ...\n", package_name, deb_file->filename);
	}

	/* Extract control.tar.gz to /var/lib/dpkg/info/<package>.filename */
	info_prefix = (char *) xmalloc(strlen(package_name) + 20 + 4 + 2);
	sprintf(info_prefix, "/var/lib/dpkg/info/%s.", package_name);
	deb_extract(deb_file->filename, stdout, (extract_quiet | extract_control_tar_gz | extract_all_to_fs | extract_unconditional), info_prefix, NULL);

	/* Run the preinst prior to extracting */
	if (run_package_script(package_name, "preinst") != 0) {
		/* when preinst returns exit code != 0 then quit installation process */
		error_msg_and_die("subprocess pre-installation script returned error.");
	}	

	/* Extract data.tar.gz to the root directory */
	deb_extract(deb_file->filename, stdout, (extract_quiet | extract_data_tar_gz | extract_all_to_fs | extract_unconditional), "/", NULL);

	/* Create the list file */
	strcat(info_prefix, "list");
	out_stream = xfopen(info_prefix, "w");			
	deb_extract(deb_file->filename, out_stream, (extract_quiet | extract_data_tar_gz | extract_list), "/", NULL);
	fclose(out_stream);

	/* change status */
	set_status(status_num, "install", 1);
	set_status(status_num, "unpacked", 3);

	free(info_prefix);
}

void configure_package(deb_file_t *deb_file)
{
	const char *package_name = name_hashtable[package_hashtable[deb_file->package]->name];
	const char *package_version = name_hashtable[package_hashtable[deb_file->package]->version];
	const int status_num = search_status_hashtable(package_name);

	printf("Setting up %s (%s)\n", package_name, package_version);

	/* Run the postinst script */
	if (run_package_script(package_name, "postinst") != 0) {
		/* TODO: handle failure gracefully */
		error_msg_and_die("postrm failure.. set status to what?");
	}
	/* Change status to reflect success */
	set_status(status_num, "install", 1);
	set_status(status_num, "installed", 3);
}

int dpkg_main(int argc, char **argv)
{
	deb_file_t **deb_file = NULL;
	status_node_t *status_node;
	int opt;
	int package_num;
	int dpkg_opt = 0;
	int deb_count = 0;
	int state_status;
	int status_num;
	int i;

	while ((opt = getopt(argc, argv, "CF:ilPru")) != -1) {
		switch (opt) {
			case 'C': // equivalent to --configure in official dpkg
				dpkg_opt |= dpkg_opt_configure;
				dpkg_opt |= dpkg_opt_package_name;
				break;
			case 'F': // equivalent to --force in official dpkg
				if (strcmp(optarg, "depends") == 0) {
					dpkg_opt |= dpkg_opt_force_ignore_depends;
				}				
			case 'i':
				dpkg_opt |= dpkg_opt_install;
				dpkg_opt |= dpkg_opt_filename;
				break;
			case 'l':
				dpkg_opt |= dpkg_opt_list_installed;
				break;
			case 'P':
				dpkg_opt |= dpkg_opt_purge;
				dpkg_opt |= dpkg_opt_package_name;
				break;
			case 'r':
				dpkg_opt |= dpkg_opt_remove;
				dpkg_opt |= dpkg_opt_package_name;
				break;
			case 'u':	/* Equivalent to --unpack in official dpkg */
				dpkg_opt |= dpkg_opt_unpack;
				dpkg_opt |= dpkg_opt_filename;
				break;
			default:
				show_usage();
		}
	}
	/* check for non-otion argument if expected  */
	if ((dpkg_opt == 0) || ((argc == optind) && !(dpkg_opt && dpkg_opt_list_installed))) {
		show_usage();
	}

/*	puts("(Reading database ... xxxxx files and directories installed.)"); */
	index_status_file("/var/lib/dpkg/status");

	/* if the list action was given print the installed packages and exit */
	if (dpkg_opt & dpkg_opt_list_installed) {
		list_packages();
		return(EXIT_SUCCESS);
	}
	
	/* Read arguments and store relevant info in structs */
	while (optind < argc) {
		/* deb_count = nb_elem - 1 and we need nb_elem + 1 to allocate terminal node [NULL pointer] */
		deb_file = xrealloc(deb_file, sizeof(deb_file_t *) * (deb_count + 2));
		deb_file[deb_count] = (deb_file_t *) xmalloc(sizeof(deb_file_t));
		if (dpkg_opt & dpkg_opt_filename) {
			deb_file[deb_count]->filename = xstrdup(argv[optind]);
			deb_file[deb_count]->control_file = deb_extract(argv[optind], stdout, (extract_control_tar_gz | extract_one_to_buffer), NULL, "./control");
			if (deb_file[deb_count]->control_file == NULL) {
				error_msg_and_die("Couldnt extract control file");
			}
			package_num = fill_package_struct(deb_file[deb_count]->control_file);

			if (package_num == -1) {
				error_msg("Invalid control file in %s", argv[optind]);
				continue;
			}
			deb_file[deb_count]->package = (unsigned int) package_num;
			/* Add the package to the status hashtable */
			if ((dpkg_opt & dpkg_opt_unpack) || (dpkg_opt & dpkg_opt_install)) {
				status_node = (status_node_t *) xmalloc(sizeof(status_node_t));
				status_node->package = deb_file[deb_count]->package;
				/* Try and find a currently installed version of this package */
				status_num = search_status_hashtable(name_hashtable[package_hashtable[deb_file[deb_count]->package]->name]);
				/* If no previous entry was found initialise a new entry */
				if ((status_hashtable[status_num] == NULL) ||
					(status_hashtable[status_num]->status == 0)) {
					/* reinstreq isnt changed to "ok" until the package control info
					 * is written to the status file*/
					status_node->status = search_name_hashtable("want-install reinstreq not-installed");
					status_hashtable[status_num] = status_node;
				} else {
					status_hashtable[status_num]->status = search_name_hashtable("want-install reinstreq not-installed");
				}
			}
		}
		else if (dpkg_opt & dpkg_opt_package_name) {
			deb_file[deb_count]->filename = NULL;
			deb_file[deb_count]->control_file = NULL;
			deb_file[deb_count]->package = search_package_hashtable(
				search_name_hashtable(argv[optind]),
				search_name_hashtable("ANY"), VER_ANY);
			if (package_hashtable[deb_file[deb_count]->package] == NULL) {
				error_msg_and_die("Package %s is uninstalled or unknown\n", argv[optind]);
			}
			state_status = get_status(search_status_hashtable(name_hashtable[package_hashtable[deb_file[deb_count]->package]->name]), 3);

			/* check package status is "installed" */
			if (dpkg_opt & dpkg_opt_remove) {
				if ((strcmp(name_hashtable[state_status], "not-installed") == 0) ||
					(strcmp(name_hashtable[state_status], "config-files") == 0)) {
					error_msg_and_die("%s is already removed.", name_hashtable[package_hashtable[deb_file[deb_count]->package]->name]);
				}
			}
			else if (dpkg_opt & dpkg_opt_purge) {
				/* if package status is "conf-files" then its ok */
				if (strcmp(name_hashtable[state_status], "not-installed") == 0) {
					error_msg_and_die("%s is already purged.", name_hashtable[package_hashtable[deb_file[deb_count]->package]->name]);
				}
			}
		}
		deb_count++;
		optind++;
	}
	deb_file[deb_count] = NULL;

	/* Check that the deb file arguments are installable */
	/* TODO: check dependencies before removing */
	if ((dpkg_opt & dpkg_opt_force_ignore_depends) != dpkg_opt_force_ignore_depends) {
		if (!check_deps(deb_file, 0, deb_count)) {
			error_msg_and_die("Dependency check failed");
		}
	}

	for (i = 0; i < deb_count; i++) {
		/* Remove or purge packages */
		if (dpkg_opt & dpkg_opt_remove) {
			remove_package(deb_file[i]->package);
		}
		else if (dpkg_opt & dpkg_opt_purge) {
			purge_package(deb_file[i]->package);
		}
		else if (dpkg_opt & dpkg_opt_unpack) {
			unpack_package(deb_file[i]);
		}
		else if (dpkg_opt & dpkg_opt_install) {
			unpack_package(deb_file[i]);
			configure_package(deb_file[i]);
		}
		else if (dpkg_opt & dpkg_opt_configure) {
			configure_package(deb_file[i]);
		}
	}

	write_status_file(deb_file);

	for (i = 0; i < deb_count; i++) {
		free(deb_file[i]->control_file);
		free(deb_file[i]->filename);
		free(deb_file[i]);
	}

	free(deb_file);

	for (i = 0; i < NAME_HASH_PRIME; i++) {
		if (name_hashtable[i] != NULL) {
			free(name_hashtable[i]);
		}
	}

	for (i = 0; i < PACKAGE_HASH_PRIME; i++) {
		if (package_hashtable[i] != NULL) {
			free_package(package_hashtable[i]);
		}
	}

	for (i = 0; i < STATUS_HASH_PRIME; i++) {
		if (status_hashtable[i] != NULL) {
			free(status_hashtable[i]);
		}
	}

	return(EXIT_SUCCESS);
}