X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=command.c;h=6b9f91de7a9b2acf76dd1e719fa6c88af96310ea;hp=5802d37ab7a7353c545bc5dbc9c998f297a2f576;hb=8f69a1302a52163c61142531c4a6944510c3ec12;hpb=6811b2f8ea8b7a8c77046285c9432aee6327da80 diff --git a/command.c b/command.c index 5802d37a..6b9f91de 100644 --- a/command.c +++ b/command.c @@ -1,8 +1,4 @@ -/* - * Copyright (C) 1997 Andre Noll - * - * Licensed under the GPL v2. For licencing details see COPYING. - */ +/* Copyright (C) 1997 Andre Noll , see file COPYING. */ /** \file command.c Client authentication and server commands. */ @@ -52,11 +48,15 @@ static const char * const server_command_perms_txt[] = {LSG_SERVER_CMD_AUX_INFOS extern int mmd_mutex; extern struct misc_meta_data *mmd; -extern struct sender senders[]; int send_afs_status(struct command_context *cc, int parser_friendly); +static bool subcmd_should_die; -static void dummy(__a_unused int s) +static void command_handler_sighandler(int s) { + if (s != SIGTERM) + return; + PARA_EMERG_LOG("terminating on signal %d\n", SIGTERM); + subcmd_should_die = true; } /* @@ -111,14 +111,14 @@ static unsigned get_status(struct misc_meta_data *nmmd, bool parser_friendly, * clang is not smart enough to prove this and complains nevertheless. * Casting the return value to void silences clang. */ - (void)WRITE_STATUS_ITEM(&b, SI_STATUS, "%s\n", status); - (void)WRITE_STATUS_ITEM(&b, SI_STATUS_FLAGS, "%s\n", flags); - (void)WRITE_STATUS_ITEM(&b, SI_OFFSET, "%li\n", offset); - (void)WRITE_STATUS_ITEM(&b, SI_AFS_MODE, "%s\n", mmd->afs_mode_string); - (void)WRITE_STATUS_ITEM(&b, SI_STREAM_START, "%lu.%lu\n", + (void)WRITE_STATUS_ITEM(&b, SI_status, "%s\n", status); + (void)WRITE_STATUS_ITEM(&b, SI_status_flags, "%s\n", flags); + (void)WRITE_STATUS_ITEM(&b, SI_offset, "%li\n", offset); + (void)WRITE_STATUS_ITEM(&b, SI_afs_mode, "%s\n", mmd->afs_mode_string); + (void)WRITE_STATUS_ITEM(&b, SI_stream_start, "%lu.%lu\n", (long unsigned)nmmd->stream_start.tv_sec, (long unsigned)nmmd->stream_start.tv_usec); - (void)WRITE_STATUS_ITEM(&b, SI_CURRENT_TIME, "%lu.%lu\n", + (void)WRITE_STATUS_ITEM(&b, SI_current_time, "%lu.%lu\n", (long unsigned)current_time.tv_sec, (long unsigned)current_time.tv_usec); free(flags); @@ -227,7 +227,7 @@ static int check_sender_args(struct command_context *cc, struct lls_parse_result *lpr, struct sender_command_data *scd) { int i, ret; - const char *subcmds[] = {SENDER_SUBCOMMANDS}; + const char * const subcmds[] = {SENDER_SUBCOMMANDS}; const char *arg; char *errctx; unsigned num_inputs = lls_num_inputs(lpr); @@ -239,20 +239,20 @@ static int check_sender_args(struct command_context *cc, return ret; } arg = lls_input(0, lpr); - for (i = 0; senders[i].name; i++) - if (!strcmp(senders[i].name, arg)) + FOR_EACH_SENDER(i) + if (strcmp(senders[i]->name, arg) == 0) break; - if (!senders[i].name) + if (!senders[i]) return -E_COMMAND_SYNTAX; scd->sender_num = i; arg = lls_input(1, lpr); - for (i = 0; subcmds[i]; i++) + for (i = 0; i < NUM_SENDER_CMDS; i++) if (!strcmp(subcmds[i], arg)) break; - if (!subcmds[i]) + if (i == NUM_SENDER_CMDS) return -E_COMMAND_SYNTAX; scd->cmd_num = i; - if (!senders[scd->sender_num].client_cmds[scd->cmd_num]) + if (!senders[scd->sender_num]->client_cmds[scd->cmd_num]) return -E_SENDER_CMD; switch (scd->cmd_num) { case SENDER_on: @@ -334,10 +334,10 @@ static int com_sender(struct command_context *cc, struct lls_parse_result *lpr) struct sender_command_data scd; if (lls_num_inputs(lpr) == 0) { - for (i = 0; senders[i].name; i++) { + FOR_EACH_SENDER(i) { char *tmp; ret = xasprintf(&tmp, "%s%s\n", msg? msg : "", - senders[i].name); + senders[i]->name); free(msg); msg = tmp; } @@ -348,17 +348,17 @@ static int com_sender(struct command_context *cc, struct lls_parse_result *lpr) if (scd.sender_num < 0) return ret; if (strcmp(lls_input(1, lpr), "status") == 0) - msg = senders[scd.sender_num].status(); + msg = senders[scd.sender_num]->status(); else - msg = senders[scd.sender_num].help(); + msg = senders[scd.sender_num]->help(); return send_sb(&cc->scc, msg, strlen(msg), SBD_OUTPUT, false); } switch (scd.cmd_num) { case SENDER_add: case SENDER_delete: - assert(senders[scd.sender_num].resolve_target); - ret = senders[scd.sender_num].resolve_target(lls_input(2, lpr), + assert(senders[scd.sender_num]->resolve_target); + ret = senders[scd.sender_num]->resolve_target(lls_input(2, lpr), &scd); if (ret < 0) return ret; @@ -398,7 +398,7 @@ static int com_si(struct command_context *cc, "supported audio formats: %s\n", ut, mmd->num_played, (int)getppid(), - (int)mmd->afs_pid, + (int)afs_pid, mmd->active_connections, mmd->num_commands, mmd->num_connects, @@ -426,41 +426,40 @@ EXPORT_SERVER_CMD_HANDLER(version); /** These status items are cleared if no audio file is currently open. */ #define EMPTY_STATUS_ITEMS \ - ITEM(PATH) \ - ITEM(DIRECTORY) \ - ITEM(BASENAME) \ - ITEM(SCORE) \ - ITEM(ATTRIBUTES_BITMAP) \ - ITEM(ATTRIBUTES_TXT) \ - ITEM(HASH) \ - ITEM(IMAGE_ID) \ - ITEM(IMAGE_NAME) \ - ITEM(LYRICS_ID) \ - ITEM(LYRICS_NAME) \ - ITEM(BITRATE) \ - ITEM(FORMAT) \ - ITEM(FREQUENCY) \ - ITEM(CHANNELS) \ - ITEM(DURATION) \ - ITEM(SECONDS_TOTAL) \ - ITEM(NUM_PLAYED) \ - ITEM(LAST_PLAYED) \ - ITEM(TECHINFO) \ - ITEM(ARTIST) \ - ITEM(TITLE) \ - ITEM(YEAR) \ - ITEM(ALBUM) \ - ITEM(COMMENT) \ - ITEM(MTIME) \ - ITEM(FILE_SIZE) \ - ITEM(CHUNK_TIME) \ - ITEM(NUM_CHUNKS) \ - ITEM(AMPLIFICATION) \ + ITEM(path) \ + ITEM(directory) \ + ITEM(basename) \ + ITEM(score) \ + ITEM(attributes_bitmap) \ + ITEM(attributes_txt) \ + ITEM(hash) \ + ITEM(image_id) \ + ITEM(image_name) \ + ITEM(lyrics_id) \ + ITEM(lyrics_name) \ + ITEM(bitrate) \ + ITEM(format) \ + ITEM(frequency) \ + ITEM(channels) \ + ITEM(duration) \ + ITEM(seconds_total) \ + ITEM(num_played) \ + ITEM(last_played) \ + ITEM(techinfo) \ + ITEM(artist) \ + ITEM(title) \ + ITEM(year) \ + ITEM(album) \ + ITEM(comment) \ + ITEM(mtime) \ + ITEM(file_size) \ + ITEM(chunk_time) \ + ITEM(num_chunks) \ + ITEM(amplification) \ -/** - * Write a list of audio-file related status items with empty values. - * - * This is used by vss when currently no audio file is open. +/* + * Create a set of audio-file related status items with empty values. These are + * written to stat clients when no audio file is open. */ static unsigned empty_status_items(bool parser_friendly, char **result) { @@ -498,9 +497,21 @@ static int com_stat(struct command_context *cc, struct lls_parse_result *lpr) bool parser_friendly = SERVER_CMD_OPT_GIVEN(STAT, PARSER_FRIENDLY, lpr) > 0; uint32_t num = SERVER_CMD_UINT32_VAL(STAT, NUM, lpr); + const struct timespec ts = {.tv_sec = 50, .tv_nsec = 0}; - para_sigaction(SIGUSR1, dummy); + para_sigaction(SIGINT, SIG_IGN); + para_sigaction(SIGUSR1, command_handler_sighandler); + para_sigaction(SIGTERM, command_handler_sighandler); + /* + * Simply checking subcmd_should_die is racy because a signal may + * arrive after the check but before the subsequent call to sleep(3). + * If this happens, sleep(3) would not be interrupted by the signal. + * To avoid this we block SIGTERM here and allow it to arrive only + * while we sleep. + */ + para_block_signal(SIGTERM); for (;;) { + sigset_t set; /* * Copy the mmd structure to minimize the time we hold the mmd * lock. @@ -523,7 +534,15 @@ static int com_stat(struct command_context *cc, struct lls_parse_result *lpr) ret = 1; if (num > 0 && !--num) goto out; - sleep(50); + sigemptyset(&set); /* empty set means: unblock all signals */ + /* + * pselect(2) allows to atomically unblock signals, then go to + * sleep. Calling sigprocmask(2) followed by sleep(3) would + * open a race window similar to the one described above. + */ + pselect(1, NULL, NULL, NULL, &ts, &set); + if (subcmd_should_die) + goto out; ret = -E_SERVER_CRASH; if (getppid() == 1) goto out; @@ -745,12 +764,11 @@ out: } EXPORT_SERVER_CMD_HANDLER(jmp); -static int com_tasks(struct command_context *cc, +/* deprecated, does nothing */ +static int com_tasks(__a_unused struct command_context *cc, __a_unused struct lls_parse_result *lpr) { - char *tl = server_get_tasks(); - assert(tl); - return send_sb(&cc->scc, tl, strlen(tl), SBD_OUTPUT, false); + return 1; } EXPORT_SERVER_CMD_HANDLER(tasks); @@ -766,7 +784,7 @@ struct connection_features { int dummy; /* none at the moment */ }; -static int parse_auth_request(char *buf, int len, struct user **u, +static int parse_auth_request(char *buf, int len, const struct user **u, struct connection_features *cf) { int ret; @@ -800,7 +818,7 @@ static int parse_auth_request(char *buf, int len, struct user **u, } } PARA_DEBUG_LOG("received auth request for user %s\n", username); - *u = lookup_user(username); + *u = user_list_lookup(username); ret = 1; out: free_argv(features); @@ -809,8 +827,7 @@ out: #define HANDSHAKE_BUFSIZE 4096 -static int run_command(struct command_context *cc, struct iovec *iov, - const char *peername) +static int run_command(struct command_context *cc, struct iovec *iov) { int ret, i, argc; char *p, *end, **argv; @@ -843,8 +860,8 @@ static int run_command(struct command_context *cc, struct iovec *iov, p += strlen(p) + 1; } argv[argc] = NULL; - PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", lls_command_name(lcmd), - cc->u->name, peername); + PARA_NOTICE_LOG("calling com_%s() for user %s\n", + lls_command_name(lcmd), cc->u->name); ret = lls(lls_parse(argc, argv, lcmd, &lpr, &errctx)); if (ret >= 0) { const struct server_cmd_user_data *ud = lls_user_data(lcmd); @@ -865,7 +882,6 @@ static int run_command(struct command_context *cc, struct iovec *iov, * Perform user authentication and execute a command. * * \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 calls this function. @@ -880,20 +896,22 @@ static int run_command(struct command_context *cc, struct iovec *iov, * 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 + * In order to cope with DOS attacks, a timeout is set up which terminates * the function if the connection was not authenticated when the timeout * expires. * + * \return Standard. + * * \sa alarm(2), \ref crypt.c, \ref crypt.h. */ -__noreturn void handle_connect(int fd, const char *peername) +int handle_connect(int fd) { int ret; unsigned char rand_buf[CHALLENGE_SIZE + 2 * SESSION_KEY_LEN]; unsigned char challenge_hash[HASH_SIZE]; char *command = NULL, *buf = para_malloc(HANDSHAKE_BUFSIZE) /* must be on the heap */; size_t numbytes; - struct command_context cc_struct = {.peer = peername}, *cc = &cc_struct; + struct command_context cc_struct = {.u = NULL}, *cc = &cc_struct; struct iovec iov; struct connection_features cf; @@ -972,7 +990,7 @@ __noreturn void handle_connect(int fd, const char *peername) ret = recv_sb(&cc->scc, SBD_COMMAND, MAX_COMMAND_LEN, &iov); if (ret < 0) goto net_err; - ret = run_command(cc, &iov, peername); + ret = run_command(cc, &iov); free(iov.iov_base); if (ret < 0) goto err_out; @@ -996,5 +1014,5 @@ out: } sc_free(cc->scc.recv); sc_free(cc->scc.send); - exit(ret < 0? EXIT_FAILURE : EXIT_SUCCESS); + return ret; }