X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=command.c;h=b6c2de2788a131f446f48893717a826ea3fd8845;hp=2bd101919eafa22136926ff244d12d13866fabac;hb=2b471378b49c04db7bb84d1e75db981f91ad93db;hpb=ae0e4594c6a0312c5b4b4c0bde86f9c12253d11b;ds=sidebyside diff --git a/command.c b/command.c index 2bd10191..b6c2de27 100644 --- a/command.c +++ b/command.c @@ -1,53 +1,55 @@ /* - * Copyright (C) 1997-2007 Andre Noll + * Copyright (C) 1997-2008 Andre Noll * - * 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. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. + * Licensed under the GPL v2. For licencing details see COPYING. */ -/** \file command.c does client authentication and executes server commands */ +/** \file command.c Client authentication and server commands. */ + +#include +#include +#include +#include +#include -#include /* gettimeofday */ +#include "para.h" +#include "error.h" #include "server.cmdline.h" +#include "string.h" +#include "afh.h" #include "afs.h" #include "server.h" #include "vss.h" +#include "list.h" #include "send.h" #include "rc4.h" -#include -#include "error.h" #include "net.h" #include "daemon.h" -#include "string.h" #include "fd.h" #include "user_list.h" #include "server_command_list.h" +#include "afs_command_list.h" -/** commands including options must be shorter than this */ -#define MAX_COMMAND_LEN 4096 +/** Commands including options must be shorter than this. */ +#define MAX_COMMAND_LEN 32768 static RC4_KEY rc4_recv_key; static RC4_KEY rc4_send_key; static unsigned char rc4_buf[2 * RC4_KEY_LEN]; -extern const char *status_item_list[NUM_STAT_ITEMS]; extern struct misc_meta_data *mmd; -extern struct audio_file_selector selectors[]; extern struct sender senders[]; -static void dummy(__a_unused int s) -{} +static void dummy(int s) +{ + /* + * At least on Solaris, SIGUSR1 is one-shot, i.e. the signal action is + * restored to the default state once the signal handler has been + * called. + */ + if (s == SIGUSR1) + signal(SIGUSR1, dummy); +} static void mmd_dup(struct misc_meta_data *new_mmd) { @@ -100,93 +102,58 @@ static char *vss_get_status_flags(unsigned int flags) return msg; } -/* - * compute status bar string. Never returns NULL - */ -static char *get_sb_string(struct misc_meta_data *nmmd) -{ - char *base, *ret; - long long unsigned secs = 0, rsecs = 0, percent = 0; - - base = para_basename(nmmd->filename); - if (!base) - return para_strdup(""); - if (!base[0]) - return base; - if (nmmd->afi.chunks_total) { - secs = (long long) nmmd->afi.seconds_total * nmmd->chunks_sent - / nmmd->afi.chunks_total; - rsecs = (long long) nmmd->afi.seconds_total * - (nmmd->afi.chunks_total - nmmd->chunks_sent) - / nmmd->afi.chunks_total; - percent = 100 * ((nmmd->chunks_sent + 5) / 10) - / ((nmmd->afi.chunks_total + 5) / 10); - } - ret = make_message("%llu:%02llu [%llu:%02llu] (%llu%%) %s", - secs / 60, secs % 60, - rsecs / 60, rsecs % 60, - percent, - base - ); - free(base); - return ret; -} - static char *get_status(struct misc_meta_data *nmmd) { - char *bar, *ret, mtime[30] = ""; + char *ret, mtime[30] = ""; char *status, *flags; /* vss status info */ char *ut = uptime_str(); long offset = (nmmd->offset + 500) / 1000; struct timeval now; struct tm mtime_tm; - if (nmmd->audio_format >= 0) { - localtime_r(&nmmd->mtime, &mtime_tm); - strftime(mtime, 29, "%a %b %d %Y", &mtime_tm); - } /* report real status */ status = vss_status_tohuman(nmmd->vss_status_flags); flags = vss_get_status_flags(nmmd->vss_status_flags); - bar = para_basename(nmmd->filename); + if (nmmd->size) { /* parent currently has an audio file open */ + localtime_r(&nmmd->mtime, &mtime_tm); + strftime(mtime, 29, "%b %d %Y", &mtime_tm); + } gettimeofday(&now, NULL); ret = make_message( - "%s:%zu\n" "%s:%s\n" "%s:%lu\n" "%s:%u\n" - "%s:%s\n" "%s:%s\n" "%s:%s\n" "%s:%s\n" - "%s:%li\n" "%s:%s\n" "%s" "%s" - "%s:%s\n" "%s:%lu.%lu\n" "%s:%lu.%lu\n", + "%s: %zu\n" /* file size */ + "%s: %s\n" /* mtime */ + "%s: %s\n" /* status */ + "%s: %s\n" /* status flags */ + "%s: %li\n" /* offset */ + "%s: %s\n" /* afs mode */ + "%s: %lu.%lu\n" /* stream start */ + "%s: %lu.%lu\n" /* current server time */ + "%s", /* afs status info */ status_item_list[SI_FILE_SIZE], nmmd->size / 1024, status_item_list[SI_MTIME], mtime, - status_item_list[SI_LENGTH], nmmd->afi.seconds_total, - status_item_list[SI_NUM_PLAYED], nmmd->num_played, - - status_item_list[SI_STATUS_BAR], bar ? bar : "(none)", status_item_list[SI_STATUS], status, status_item_list[SI_STATUS_FLAGS], flags, - status_item_list[SI_SELECTOR], selectors[nmmd->selector_num].name, status_item_list[SI_OFFSET], offset, - status_item_list[SI_FORMAT], audio_format_name(nmmd->audio_format), - nmmd->selector_info, - nmmd->afi.info_string, + status_item_list[SI_AFS_MODE], mmd->afs_mode_string, - status_item_list[SI_UPTIME], ut, status_item_list[SI_STREAM_START], (long unsigned)nmmd->stream_start.tv_sec, (long unsigned)nmmd->stream_start.tv_usec, status_item_list[SI_CURRENT_TIME], (long unsigned)now.tv_sec, - (long unsigned)now.tv_usec + (long unsigned)now.tv_usec, + + nmmd->afd.verbose_ls_output ); - free(bar); free(flags); free(status); free(ut); return ret; } -static int check_sender_args(int argc, char **argv, struct sender_command_data *scd) +static int check_sender_args(int argc, char * const * argv, struct sender_command_data *scd) { int i; /* this has to match sender.h */ @@ -224,7 +191,7 @@ static int check_sender_args(int argc, char **argv, struct sender_command_data * case SENDER_ALLOW: if (argc != 4 && argc != 5) return -E_COMMAND_SYNTAX; - if (!inet_aton(argv[3], &scd->addr)) + if (!inet_pton(AF_INET, argv[3], &scd->addr)) return -E_COMMAND_SYNTAX; scd->netmask = 32; if (argc == 5) { @@ -237,7 +204,7 @@ static int check_sender_args(int argc, char **argv, struct sender_command_data * case SENDER_DELETE: if (argc != 4 && argc != 5) return -E_COMMAND_SYNTAX; - if (!inet_aton(argv[3], &scd->addr)) + if (!inet_pton(AF_INET, argv[3], &scd->addr)) return -E_COMMAND_SYNTAX; scd->port = -1; if (argc == 5) { @@ -252,7 +219,7 @@ static int check_sender_args(int argc, char **argv, struct sender_command_data * return 1; } -int com_sender(int fd, int argc, char **argv) +int com_sender(int fd, int argc, char * const * argv) { int i, ret; struct sender_command_data scd; @@ -275,9 +242,9 @@ int com_sender(int fd, int argc, char **argv) if (scd.sender_num < 0) return ret; msg = senders[scd.sender_num].help(); - send_buffer(fd, msg); + ret = send_buffer(fd, msg); free(msg); - return 1; + return ret; } for (i = 0; i < 10; i++) { mmd_lock(); @@ -294,19 +261,15 @@ int com_sender(int fd, int argc, char **argv) } /* server info */ -int com_si(int fd, int argc, __a_unused char **argv) +int com_si(int fd, int argc, __a_unused char * const * argv) { int i, ret; char *ut; - char *selector_string = NULL, *sender_info = NULL, *sender_list = NULL; + char *sender_info = NULL, *sender_list = NULL; if (argc != 1) return -E_COMMAND_SYNTAX; mmd_lock(); - for (i = 0; selectors[i].name; i++) { - selector_string = para_strcat(selector_string, selectors[i].name); - selector_string = para_strcat(selector_string, " "); - } for (i = 0; senders[i].name; i++) { char *info = senders[i].info(); sender_info = para_strcat(sender_info, info); @@ -319,97 +282,39 @@ int com_si(int fd, int argc, __a_unused char **argv) "pid: %d\n" "connections (active/accepted/total): %u/%u/%u\n" "current loglevel: %i\n" - "supported audio file selectors: %s\n" "supported audio formats: %s\n" "supported senders: %s\n" "%s", ut, mmd->num_played, - getppid(), + (int)getppid(), mmd->active_connections, mmd->num_commands, mmd->num_connects, conf.loglevel_arg, - selector_string, supported_audio_formats(), sender_list, sender_info ); mmd_unlock(); free(ut); - free(selector_string); free(sender_list); free(sender_info); return ret; } /* version */ -int com_version(int fd, int argc, __a_unused char **argv) +int com_version(int fd, int argc, __a_unused char * const * argv) { if (argc != 1) return -E_COMMAND_SYNTAX; return send_buffer(fd, VERSION_TEXT("server") "built: " BUILD_DATE "\n" - SYSTEM ", " CC_VERSION "\n" + UNAME_RS ", " CC_VERSION "\n" ); } -/* sc */ -int com_sc(int fd, int argc, char **argv) -{ - char *name = NULL; - int ret, old = 0, count = -1; /* print af change forever */ - - if (argc > 1) - count = atoi(argv[1]); -repeat: - mmd_lock(); - if (old != mmd->num_played) { - old = mmd->num_played; - name = para_strdup(mmd->filename); - } - mmd_unlock(); - if (name) { - ret = send_va_buffer(fd, "%s\n", name); - free(name); - name = NULL; - if (ret < 0) - return ret; - if (argc > 1 && !--count) - return 1; - } - usleep(500000); - goto repeat; -} - -/* sb */ -int com_sb(int fd, int argc, char **argv) -{ - char *sb; - int ret, nr = -1; /* status bar will be printed that many - * times. Negative value means: print - * forever - */ - if (argc > 1) - nr = atoi(argv[1]); - while (nr) { - mmd_lock(); - sb = get_sb_string(mmd); - mmd_unlock(); - ret = send_va_buffer(fd, "%s\n", sb); - free(sb); - if (ret < 0) - return ret; - if (nr == 1) - return 1; - usleep(500000); - if (nr > 0) - nr--; - } - return 1; -} - /* stat */ -int com_stat(int fd, int argc, char **argv) +int com_stat(int fd, int argc, char * const * argv) { int ret, num = 0;/* status will be printed that many * times. num <= 0 means: print forever @@ -430,7 +335,7 @@ int com_stat(int fd, int argc, char **argv) if (ret < 0) goto out; ret = 1; - if (num == 1) + if (num > 0 && !--num) goto out; sleep(50); if (getppid() == 1) @@ -458,32 +363,29 @@ static int send_list_of_commands(int fd, struct server_command *cmd, return 1; } -/* always returns string that must be freed by the caller in handler */ -static struct server_command *get_cmd_ptr(char *name, char **handler) +/* returns string that must be freed by the caller */ +static struct server_command *get_cmd_ptr(const char *name, char **handler) { struct server_command *cmd; for (cmd = server_cmds; cmd->name; cmd++) if (!strcmp(cmd->name, name)) { if (handler) - *handler = para_strdup("para_server"); /* server commands */ + *handler = para_strdup("server"); /* server commands */ return cmd; } - /* not found, look for commands supported by the current selector */ - mmd_lock(); - if (handler) - *handler = make_message("the %s selector", - selectors[mmd->selector_num].name); - cmd = selectors[mmd->selector_num].cmd_list; - mmd_unlock(); - for (; cmd->name; cmd++) - if (!strcmp(cmd->name, name)) + /* not found, look for commands supported by afs */ + for (cmd = afs_cmds; cmd->name; cmd++) + if (!strcmp(cmd->name, name)) { + if (handler) + *handler = para_strdup("afs"); return cmd; + } return NULL; } /* help */ -int com_help(int fd, int argc, char **argv) +int com_help(int fd, int argc, char * const * argv) { struct server_command *cmd; char *perms, *handler; @@ -493,13 +395,7 @@ int com_help(int fd, int argc, char **argv) /* no argument given, print list of commands */ if ((ret = send_list_of_commands(fd, server_cmds, "server")) < 0) return ret; - mmd_lock(); - handler = para_strdup(selectors[mmd->selector_num].name); - cmd = selectors[mmd->selector_num].cmd_list; - mmd_unlock(); - ret = send_list_of_commands(fd, cmd, handler); - free(handler); - return ret; + return send_list_of_commands(fd, afs_cmds, "afs"); } /* argument given for help */ cmd = get_cmd_ptr(argv[1], &handler); @@ -527,7 +423,7 @@ int com_help(int fd, int argc, char **argv) } /* hup */ -int com_hup(__a_unused int fd, int argc, __a_unused char **argv) +int com_hup(__a_unused int fd, int argc, __a_unused char * const * argv) { if (argc != 1) return -E_COMMAND_SYNTAX; @@ -536,7 +432,7 @@ int com_hup(__a_unused int fd, int argc, __a_unused char **argv) } /* term */ -int com_term(__a_unused int fd, int argc, __a_unused char **argv) +int com_term(__a_unused int fd, int argc, __a_unused char * const * argv) { if (argc != 1) return -E_COMMAND_SYNTAX; @@ -544,7 +440,7 @@ int com_term(__a_unused int fd, int argc, __a_unused char **argv) return 1; } -int com_play(__a_unused int fd, int argc, __a_unused char **argv) +int com_play(__a_unused int fd, int argc, __a_unused char * const * argv) { if (argc != 1) return -E_COMMAND_SYNTAX; @@ -557,7 +453,7 @@ int com_play(__a_unused int fd, int argc, __a_unused char **argv) } /* stop */ -int com_stop(__a_unused int fd, int argc, __a_unused char **argv) +int com_stop(__a_unused int fd, int argc, __a_unused char * const * argv) { if (argc != 1) return -E_COMMAND_SYNTAX; @@ -570,46 +466,22 @@ int com_stop(__a_unused int fd, int argc, __a_unused char **argv) } /* pause */ -int com_pause(__a_unused int fd, int argc, __a_unused char **argv) +int com_pause(__a_unused int fd, int argc, __a_unused char * const * argv) { if (argc != 1) return -E_COMMAND_SYNTAX; mmd_lock(); - if (!vss_paused()) + if (!vss_paused() && !vss_stopped()) { mmd->events++; - mmd->new_vss_status_flags &= ~VSS_PLAYING; - mmd->new_vss_status_flags &= ~VSS_NEXT; + mmd->new_vss_status_flags &= ~VSS_PLAYING; + mmd->new_vss_status_flags &= ~VSS_NEXT; + } mmd_unlock(); return 1; } -int com_chs(int fd, int argc, char **argv) -{ - int i, ret; - - if (argc == 1) { - char *selector; - mmd_lock(); - selector = para_strdup(selectors[mmd->selector_num].name); - mmd_unlock(); - ret = send_va_buffer(fd, "%s\n", selector); - free(selector); - return ret; - } - for (i = 0; selectors[i].name; i++) { - if (strcmp(selectors[i].name, argv[1])) - continue; - mmd_lock(); - mmd->selector_change = i; - mmd->events++; - mmd_unlock(); - return 1; - } - return -E_BAD_SELECTOR; -} - /* next */ -int com_next(__a_unused int fd, int argc, __a_unused char **argv) +int com_next(__a_unused int fd, int argc, __a_unused char * const * argv) { if (argc != 1) return -E_COMMAND_SYNTAX; @@ -621,7 +493,7 @@ int com_next(__a_unused int fd, int argc, __a_unused char **argv) } /* nomore */ -int com_nomore(__a_unused int fd, int argc, __a_unused char **argv) +int com_nomore(__a_unused int fd, int argc, __a_unused char * const * argv) { if (argc != 1) return -E_COMMAND_SYNTAX; @@ -633,7 +505,7 @@ int com_nomore(__a_unused int fd, int argc, __a_unused char **argv) } /* ff */ -int com_ff(__a_unused int fd, int argc, char **argv) +int com_ff(__a_unused int fd, int argc, char * const * argv) { long promille; int ret, backwards = 0; @@ -648,20 +520,20 @@ int com_ff(__a_unused int fd, int argc, char **argv) backwards = 1; /* jmp backwards */ mmd_lock(); ret = -E_NO_AUDIO_FILE; - if (!mmd->afi.chunks_total || !mmd->afi.seconds_total) + if (!mmd->afd.afhi.chunks_total || !mmd->afd.afhi.seconds_total) goto out; - promille = (1000 * mmd->current_chunk) / mmd->afi.chunks_total; + promille = (1000 * mmd->current_chunk) / mmd->afd.afhi.chunks_total; if (backwards) - promille -= 1000 * i / mmd->afi.seconds_total; + promille -= 1000 * i / mmd->afd.afhi.seconds_total; else - promille += 1000 * i / mmd->afi.seconds_total; + promille += 1000 * i / mmd->afd.afhi.seconds_total; if (promille < 0) promille = 0; if (promille > 1000) { mmd->new_vss_status_flags |= VSS_NEXT; goto out; } - mmd->repos_request = (mmd->afi.chunks_total * promille) / 1000; + mmd->repos_request = (mmd->afd.afhi.chunks_total * promille) / 1000; mmd->new_vss_status_flags |= VSS_REPOS; mmd->new_vss_status_flags &= ~VSS_NEXT; mmd->events++; @@ -672,7 +544,7 @@ out: } /* jmp */ -int com_jmp(__a_unused int fd, int argc, char **argv) +int com_jmp(__a_unused int fd, int argc, char * const * argv) { long unsigned int i; int ret; @@ -683,12 +555,12 @@ int com_jmp(__a_unused int fd, int argc, char **argv) return -E_COMMAND_SYNTAX; mmd_lock(); ret = -E_NO_AUDIO_FILE; - if (!mmd->afi.chunks_total) + if (!mmd->afd.afhi.chunks_total) goto out; if (i > 100) i = 100; PARA_INFO_LOG("jumping to %lu%%\n", i); - mmd->repos_request = (mmd->afi.chunks_total * i + 50)/ 100; + mmd->repos_request = (mmd->afd.afhi.chunks_total * i + 50)/ 100; PARA_INFO_LOG("sent: %lu, offset before jmp: %lu\n", mmd->chunks_sent, mmd->offset); mmd->new_vss_status_flags |= VSS_REPOS; @@ -706,7 +578,7 @@ out: */ static int check_perms(unsigned int perms, struct server_command *cmd_ptr) { - PARA_DEBUG_LOG("%s", "checking permissions\n"); + PARA_DEBUG_LOG("checking permissions\n"); return (cmd_ptr->perms & perms) < cmd_ptr->perms ? -E_PERM : 0; } @@ -726,17 +598,12 @@ static struct server_command *parse_cmd(const char *cmdstr) return get_cmd_ptr(buf, NULL); } -static long int para_rand(long unsigned max) -{ - return (long int) ((max + 0.0) * (random() / (RAND_MAX + 1.0))); -} - static void init_rc4_keys(void) { int i; for (i = 0; i < 2 * RC4_KEY_LEN; i++) - rc4_buf[i] = para_rand(256); + rc4_buf[i] = para_random(256); PARA_DEBUG_LOG("rc4 keys initialized (%u:%u)\n", (unsigned char) rc4_buf[0], (unsigned char) rc4_buf[RC4_KEY_LEN]); @@ -793,12 +660,10 @@ out: } /** - * perform user authentication and execute a command + * Perform user authentication and execute a command. * - * \param fd the file descriptor to send output to - * \param addr socket address info of peer - * - * \return EXIT_SUCCESS or EXIT_FAILURE + * \param fd The file descriptor to send output to. + * \param peername Identifies the connecting peer. * * Whenever para_server accepts an incoming tcp connection on * the port it listens on, it forks and the resulting child @@ -810,12 +675,10 @@ out: * encrypted with its RSA public key. From this point on, * all transfers are crypted with this session key. * - * Next it is checked if the peer supplied a valid server - * command or a command for the audio file selector currently - * in use. If yes, and if the user has sufficient - * permissions to execute that command, the function calls - * the corresponding command handler which does argument - * checking and further processing. + * Next it is checked if the peer supplied a valid server command or a command + * for the audio file selector. If yes, and if the user has sufficient + * permissions to execute that command, the function calls the corresponding + * command handler which does argument checking and further processing. * * In order to cope with a DOS attacks, a timeout is set up * which terminates the function if the connection was not @@ -823,7 +686,7 @@ out: * * \sa alarm(2), rc4(3), crypt.c, crypt.h */ -int handle_connect(int fd, struct sockaddr_in *addr) +__noreturn void handle_connect(int fd, const char *peername) { int ret, argc, use_rc4 = 0; char buf[4096]; @@ -839,8 +702,11 @@ int handle_connect(int fd, struct sockaddr_in *addr) signal(SIGINT, SIG_DFL); signal(SIGTERM, SIG_DFL); signal(SIGHUP, SIG_DFL); - signal(SIGUSR1, SIG_IGN); + /* we need a blocking fd here as recv() might return EAGAIN otherwise. */ + ret = mark_fd_blocking(fd); + if (ret < 0) + goto err_out; challenge_nr = random(); /* send Welcome message */ ret = send_va_buffer(fd, "This is para_server, version " @@ -876,19 +742,19 @@ int handle_connect(int fd, struct sockaddr_in *addr) if (ret <= 0) goto err_out; numbytes = ret; - PARA_DEBUG_LOG("sending %d byte challenge\n", numbytes); + PARA_DEBUG_LOG("sending %zu byte challenge\n", numbytes); /* We can't use send_buffer here since buf may contain null bytes */ ret = send_bin_buffer(fd,(char *) crypt_buf, numbytes); if (ret < 0) - goto err_out; + goto net_err; /* recv decrypted number */ ret = recv_buffer(fd, buf, sizeof(buf)); if (ret < 0) - goto err_out; + goto net_err; numbytes = ret; ret = -E_AUTH; if (!numbytes) - goto err_out; + goto net_err; if (sscanf(buf, CHALLENGE_RESPONSE_MSG "%lu", &chall_response) < 1 || chall_response != challenge_nr) goto err_out; @@ -906,12 +772,14 @@ int handle_connect(int fd, struct sockaddr_in *addr) numbytes = strlen(buf); ret = send_bin_buffer(fd, buf, numbytes); if (ret < 0) - goto err_out; + goto net_err; if (use_rc4) enable_crypt(fd, rc4_recv, rc4_send, NULL); ret = read_command(fd, &command); - if (ret < 0) + if (ret == -E_COMMAND_SYNTAX) goto err_out; + if (ret < 0) + goto net_err; ret = -E_BAD_CMD; cmd = parse_cmd(command); if (!cmd) @@ -927,17 +795,14 @@ int handle_connect(int fd, struct sockaddr_in *addr) mmd->num_commands++; mmd_unlock(); PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", cmd->name, u->name, - inet_ntoa(addr->sin_addr)); + peername); ret = cmd->handler(fd, argc, argv); - if (ret >= 0) { - ret = EXIT_SUCCESS; + if (ret >= 0) goto out; - } err_out: - PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-ret)); - if (ret != -E_SEND && ret != -E_RECV) - send_va_buffer(fd, "%s\n", PARA_STRERROR(-ret)); - ret = EXIT_FAILURE; + send_va_buffer(fd, "%s\n", para_strerror(-ret)); +net_err: + PARA_NOTICE_LOG("%s\n", para_strerror(-ret)); out: free(command); free(argv); @@ -946,5 +811,5 @@ out: mmd->events++; mmd->active_connections--; mmd_unlock(); - return ret; + exit(ret < 0? EXIT_FAILURE : EXIT_SUCCESS); }