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Diffstat (limited to 'src/postqueue/postqueue.c')
| -rw-r--r-- | src/postqueue/postqueue.c | 721 |
1 files changed, 721 insertions, 0 deletions
diff --git a/src/postqueue/postqueue.c b/src/postqueue/postqueue.c new file mode 100644 index 0000000..7efc01f --- /dev/null +++ b/src/postqueue/postqueue.c @@ -0,0 +1,721 @@ +/*++ +/* NAME +/* postqueue 1 +/* SUMMARY +/* Postfix queue control +/* SYNOPSIS +/* .ti -4 +/* \fBTo flush the mail queue\fR: +/* +/* \fBpostqueue\fR [\fB-v\fR] [\fB-c \fIconfig_dir\fR] \fB-f\fR +/* +/* \fBpostqueue\fR [\fB-v\fR] [\fB-c \fIconfig_dir\fR] \fB-i \fIqueue_id\fR +/* +/* \fBpostqueue\fR [\fB-v\fR] [\fB-c \fIconfig_dir\fR] \fB-s \fIsite\fR +/* +/* .ti -4 +/* \fBTo list the mail queue\fR: +/* +/* \fBpostqueue\fR [\fB-v\fR] [\fB-c \fIconfig_dir\fR] \fB-j\fR +/* +/* \fBpostqueue\fR [\fB-v\fR] [\fB-c \fIconfig_dir\fR] \fB-p\fR +/* DESCRIPTION +/* The \fBpostqueue\fR(1) command implements the Postfix user interface +/* for queue management. It implements operations that are +/* traditionally available via the \fBsendmail\fR(1) command. +/* See the \fBpostsuper\fR(1) command for queue operations +/* that require super-user privileges such as deleting a message +/* from the queue or changing the status of a message. +/* +/* The following options are recognized: +/* .IP "\fB-c \fIconfig_dir\fR" +/* The \fBmain.cf\fR configuration file is in the named directory +/* instead of the default configuration directory. See also the +/* MAIL_CONFIG environment setting below. +/* .IP \fB-f\fR +/* Flush the queue: attempt to deliver all queued mail. +/* +/* This option implements the traditional "\fBsendmail -q\fR" command, +/* by contacting the Postfix \fBqmgr\fR(8) daemon. +/* +/* Warning: flushing undeliverable mail frequently will result in +/* poor delivery performance of all other mail. +/* .IP "\fB-i \fIqueue_id\fR" +/* Schedule immediate delivery of deferred mail with the +/* specified queue ID. +/* +/* This option implements the traditional \fBsendmail -qI\fR +/* command, by contacting the \fBflush\fR(8) server. +/* +/* This feature is available with Postfix version 2.4 and later. +/* .IP "\fB-j\fR" +/* Produce a queue listing in JSON format, based on output +/* from the showq(8) daemon. The result is a stream of zero +/* or more JSON objects, one per queue file. Each object is +/* followed by a newline character to support simple streaming +/* parsers. See "\fBJSON OBJECT FORMAT\fR" below for details. +/* +/* This feature is available in Postfix 3.1 and later. +/* .IP \fB-p\fR +/* Produce a traditional sendmail-style queue listing. +/* This option implements the traditional \fBmailq\fR command, +/* by contacting the Postfix \fBshowq\fR(8) daemon. +/* +/* Each queue entry shows the queue file ID, message +/* size, arrival time, sender, and the recipients that still need to +/* be delivered. If mail could not be delivered upon the last attempt, +/* the reason for failure is shown. The queue ID string +/* is followed by an optional status character: +/* .RS +/* .IP \fB*\fR +/* The message is in the \fBactive\fR queue, i.e. the message is +/* selected for delivery. +/* .IP \fB!\fR +/* The message is in the \fBhold\fR queue, i.e. no further delivery +/* attempt will be made until the mail is taken off hold. +/* .IP \fB#\fR +/* The message is forced to expire. See the \fBpostsuper\fR(1) +/* options \fB-e\fR or \fB-f\fR. +/* .sp +/* This feature is available in Postfix 3.5 and later. +/* .RE +/* .IP "\fB-s \fIsite\fR" +/* Schedule immediate delivery of all mail that is queued for the named +/* \fIsite\fR. A numerical site must be specified as a valid RFC 5321 +/* address literal enclosed in [], just like in email addresses. +/* The site must be eligible for the "fast flush" service. +/* See \fBflush\fR(8) for more information about the "fast flush" +/* service. +/* +/* This option implements the traditional "\fBsendmail -qR\fIsite\fR" +/* command, by contacting the Postfix \fBflush\fR(8) daemon. +/* .IP \fB-v\fR +/* Enable verbose logging for debugging purposes. Multiple \fB-v\fR +/* options make the software increasingly verbose. As of Postfix 2.3, +/* this option is available for the super-user only. +/* JSON OBJECT FORMAT +/* .ad +/* .fi +/* Each JSON object represents one queue file; it is emitted +/* as a single text line followed by a newline character. +/* +/* Object members have string values unless indicated otherwise. +/* Programs should ignore object members that are not listed +/* here; the list of members is expected to grow over time. +/* .IP \fBqueue_name\fR +/* The name of the queue where the message was found. Note +/* that the contents of the mail queue may change while it is +/* being listed; some messages may appear more than once, and +/* some messages may be missed. +/* .IP \fBqueue_id\fR +/* The queue file name. The queue_id may be reused within a +/* Postfix instance unless "enable_long_queue_ids = true" and +/* time is monotonic. Even then, the queue_id is not expected +/* to be unique between different Postfix instances. Management +/* tools that require a unique name should combine the queue_id +/* with the myhostname setting of the Postfix instance. +/* .IP \fBarrival_time\fR +/* The number of seconds since the start of the UNIX epoch. +/* .IP \fBmessage_size\fR +/* The number of bytes in the message header and body. This +/* number does not include message envelope information. It +/* is approximately equal to the number of bytes that would +/* be transmitted via SMTP including the <CR><LF> line endings. +/* .IP \fBforced_expire\fR +/* The message is forced to expire (\fBtrue\fR or \fBfalse\fR). +/* See the \fBpostsuper\fR(1) options \fB-e\fR or \fB-f\fR. +/* .sp +/* This feature is available in Postfix 3.5 and later. +/* .IP \fBsender\fR +/* The envelope sender address. +/* .IP \fBrecipients\fR +/* An array containing zero or more objects with members: +/* .RS +/* .IP \fBaddress\fR +/* One recipient address. +/* .IP \fBdelay_reason\fR +/* If present, the reason for delayed delivery. Delayed +/* recipients may have no delay reason, for example, while +/* delivery is in progress, or after the system was stopped +/* before it could record the reason. +/* .RE +/* SECURITY +/* .ad +/* .fi +/* This program is designed to run with set-group ID privileges, so +/* that it can connect to Postfix daemon processes. +/* STANDARDS +/* RFC 7159 (JSON notation) +/* DIAGNOSTICS +/* Problems are logged to \fBsyslogd\fR(8) or \fBpostlogd\fR(8), +/* and to the standard error stream. +/* ENVIRONMENT +/* .ad +/* .fi +/* .IP MAIL_CONFIG +/* Directory with the \fBmain.cf\fR file. In order to avoid exploitation +/* of set-group ID privileges, a non-standard directory is allowed only +/* if: +/* .RS +/* .IP \(bu +/* The name is listed in the standard \fBmain.cf\fR file with the +/* \fBalternate_config_directories\fR configuration parameter. +/* .IP \(bu +/* The command is invoked by the super-user. +/* .RE +/* CONFIGURATION PARAMETERS +/* .ad +/* .fi +/* The following \fBmain.cf\fR parameters are especially relevant to +/* this program. +/* The text below provides only a parameter summary. See +/* \fBpostconf\fR(5) for more details including examples. +/* .IP "\fBalternate_config_directories (empty)\fR" +/* A list of non-default Postfix configuration directories that may +/* be specified with "-c config_directory" on the command line (in the +/* case of \fBsendmail\fR(1), with the "-C" option), or via the MAIL_CONFIG +/* environment parameter. +/* .IP "\fBconfig_directory (see 'postconf -d' output)\fR" +/* The default location of the Postfix main.cf and master.cf +/* configuration files. +/* .IP "\fBcommand_directory (see 'postconf -d' output)\fR" +/* The location of all postfix administrative commands. +/* .IP "\fBfast_flush_domains ($relay_domains)\fR" +/* Optional list of destinations that are eligible for per-destination +/* logfiles with mail that is queued to those destinations. +/* .IP "\fBimport_environment (see 'postconf -d' output)\fR" +/* The list of environment parameters that a privileged Postfix +/* process will import from a non-Postfix parent process, or name=value +/* environment overrides. +/* .IP "\fBqueue_directory (see 'postconf -d' output)\fR" +/* The location of the Postfix top-level queue directory. +/* .IP "\fBsyslog_facility (mail)\fR" +/* The syslog facility of Postfix logging. +/* .IP "\fBsyslog_name (see 'postconf -d' output)\fR" +/* A prefix that is prepended to the process name in syslog +/* records, so that, for example, "smtpd" becomes "prefix/smtpd". +/* .IP "\fBtrigger_timeout (10s)\fR" +/* The time limit for sending a trigger to a Postfix daemon (for +/* example, the \fBpickup\fR(8) or \fBqmgr\fR(8) daemon). +/* .PP +/* Available in Postfix version 2.2 and later: +/* .IP "\fBauthorized_flush_users (static:anyone)\fR" +/* List of users who are authorized to flush the queue. +/* .IP "\fBauthorized_mailq_users (static:anyone)\fR" +/* List of users who are authorized to view the queue. +/* FILES +/* /var/spool/postfix, mail queue +/* SEE ALSO +/* qmgr(8), queue manager +/* showq(8), list mail queue +/* flush(8), fast flush service +/* sendmail(1), Sendmail-compatible user interface +/* postsuper(1), privileged queue operations +/* postlogd(8), Postfix logging +/* syslogd(8), system logging +/* README FILES +/* .ad +/* .fi +/* Use "\fBpostconf readme_directory\fR" or +/* "\fBpostconf html_directory\fR" to locate this information. +/* .na +/* .nf +/* ETRN_README, Postfix ETRN howto +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* HISTORY +/* .ad +/* .fi +/* The postqueue command was introduced with Postfix version 1.1. +/* AUTHOR(S) +/* Wietse Venema +/* IBM T.J. Watson Research +/* P.O. Box 704 +/* Yorktown Heights, NY 10598, USA +/* +/* Wietse Venema +/* Google, Inc. +/* 111 8th Avenue +/* New York, NY 10011, USA +/*--*/ + +/* System library. */ + +#include <sys_defs.h> +#include <sys/stat.h> +#include <unistd.h> +#include <string.h> +#include <stdlib.h> +#include <signal.h> +#include <sysexits.h> +#include <errno.h> + +/* Utility library. */ + +#include <msg.h> +#include <mymalloc.h> +#include <clean_env.h> +#include <vstream.h> +#include <msg_vstream.h> +#include <argv.h> +#include <safe.h> +#include <connect.h> +#include <valid_hostname.h> +#include <warn_stat.h> +#include <events.h> +#include <stringops.h> + +/* Global library. */ + +#include <mail_proto.h> +#include <mail_params.h> +#include <mail_version.h> +#include <mail_conf.h> +#include <mail_task.h> +#include <mail_run.h> +#include <mail_flush.h> +#include <mail_queue.h> +#include <flush_clnt.h> +#include <smtp_stream.h> +#include <user_acl.h> +#include <valid_mailhost_addr.h> +#include <mail_dict.h> +#include <mail_parm_split.h> +#include <maillog_client.h> + +/* Application-specific. */ + +#include <postqueue.h> + + /* + * WARNING WARNING WARNING + * + * This software is designed to run set-gid. In order to avoid exploitation of + * privilege, this software should not run any external commands, nor should + * it take any information from the user, unless that information can be + * properly sanitized. To get an idea of how much information a process can + * inherit from a potentially hostile user, examine all the members of the + * process structure (typically, in /usr/include/sys/proc.h): the current + * directory, open files, timers, signals, environment, command line, umask, + * and so on. + */ + + /* + * Modes of operation. + * + * XXX To support flush by recipient domain, or for destinations that have no + * mapping to logfile, the server has to defend against resource exhaustion + * attacks. A malicious user could fork off a postqueue client that starts + * an expensive requests and then kills the client immediately; this way she + * could create a high Postfix load on the system without ever exceeding her + * own per-user process limit. To prevent this, either the server needs to + * establish frequent proof of client liveliness with challenge/response, or + * the client needs to restrict expensive requests to privileged users only. + * + * We don't have this problem with queue listings. The showq server detects an + * EPIPE error after reporting a few queue entries. + */ +#define PQ_MODE_DEFAULT 0 /* noop */ +#define PQ_MODE_MAILQ_LIST 1 /* list mail queue */ +#define PQ_MODE_FLUSH_QUEUE 2 /* flush queue */ +#define PQ_MODE_FLUSH_SITE 3 /* flush site */ +#define PQ_MODE_FLUSH_FILE 4 /* flush message */ +#define PQ_MODE_JSON_LIST 5 /* JSON-format queue listing */ + + /* + * Silly little macros (SLMs). + */ +#define STR vstring_str + + /* + * Queue manipulation access lists. + */ +char *var_flush_acl; +char *var_showq_acl; + +static const CONFIG_STR_TABLE str_table[] = { + VAR_FLUSH_ACL, DEF_FLUSH_ACL, &var_flush_acl, 0, 0, + VAR_SHOWQ_ACL, DEF_SHOWQ_ACL, &var_showq_acl, 0, 0, + 0, +}; + +/* show_queue - show queue status */ + +static void show_queue(int mode) +{ + const char *errstr; + VSTREAM *showq; + int n; + uid_t uid = getuid(); + + if (uid != 0 && uid != var_owner_uid + && (errstr = check_user_acl_byuid(VAR_SHOWQ_ACL, var_showq_acl, + uid)) != 0) + msg_fatal_status(EX_NOPERM, + "User %s(%ld) is not allowed to view the mail queue", + errstr, (long) uid); + + /* + * Connect to the show queue service. + */ + if ((showq = mail_connect(MAIL_CLASS_PUBLIC, var_showq_service, BLOCKING)) != 0) { + switch (mode) { + case PQ_MODE_MAILQ_LIST: + showq_compat(showq); + break; + case PQ_MODE_JSON_LIST: + showq_json(showq); + break; + default: + msg_panic("show_queue: unknown mode %d", mode); + } + if (vstream_fclose(showq)) + msg_warn("close: %m"); + } + + /* + * Don't assume that the mail system is down when the user has + * insufficient permission to access the showq socket. + */ + else if (errno == EACCES) { + msg_fatal_status(EX_SOFTWARE, + "Connect to the %s %s service: %m", + var_mail_name, var_showq_service); + } + + /* + * When the mail system is down, the superuser can still access the queue + * directly. Just run the showq program in stand-alone mode. + */ + else if (geteuid() == 0) { + char *showq_path; + ARGV *argv; + int stat; + + msg_warn("Mail system is down -- accessing queue directly"); + showq_path = concatenate(var_daemon_dir, "/", var_showq_service, + (char *) 0); + argv = argv_alloc(6); + argv_add(argv, showq_path, "-u", "-S", (char *) 0); + for (n = 0; n < msg_verbose; n++) + argv_add(argv, "-v", (char *) 0); + argv_terminate(argv); + if ((showq = vstream_popen(O_RDONLY, + CA_VSTREAM_POPEN_ARGV(argv->argv), + CA_VSTREAM_POPEN_END)) == 0) { + stat = -1; + } else { + switch (mode) { + case PQ_MODE_MAILQ_LIST: + showq_compat(showq); + break; + case PQ_MODE_JSON_LIST: + showq_json(showq); + break; + default: + msg_panic("show_queue: unknown mode %d", mode); + } + stat = vstream_pclose(showq); + } + argv_free(argv); + if (stat != 0) + msg_fatal_status(stat < 0 ? EX_OSERR : EX_SOFTWARE, + "Error running %s", showq_path); + myfree(showq_path); + } + + /* + * When the mail system is down, unprivileged users are stuck, because by + * design the mail system contains no set_uid programs. The only way for + * an unprivileged user to cross protection boundaries is to talk to the + * showq daemon. + */ + else { + msg_fatal_status(EX_UNAVAILABLE, + "Queue report unavailable - mail system is down"); + } +} + +/* flush_queue - force delivery */ + +static void flush_queue(void) +{ + const char *errstr; + uid_t uid = getuid(); + + if (uid != 0 && uid != var_owner_uid + && (errstr = check_user_acl_byuid(VAR_FLUSH_ACL, var_flush_acl, + uid)) != 0) + msg_fatal_status(EX_NOPERM, + "User %s(%ld) is not allowed to flush the mail queue", + errstr, (long) uid); + + /* + * Trigger the flush queue service. + */ + if (mail_flush_deferred() < 0) + msg_fatal_status(EX_UNAVAILABLE, + "Cannot flush mail queue - mail system is down"); + if (mail_flush_maildrop() < 0) + msg_fatal_status(EX_UNAVAILABLE, + "Cannot flush mail queue - mail system is down"); + event_drain(2); +} + +/* flush_site - flush mail for site */ + +static void flush_site(const char *site) +{ + int status; + const char *errstr; + uid_t uid = getuid(); + + if (uid != 0 && uid != var_owner_uid + && (errstr = check_user_acl_byuid(VAR_FLUSH_ACL, var_flush_acl, + uid)) != 0) + msg_fatal_status(EX_NOPERM, + "User %s(%ld) is not allowed to flush the mail queue", + errstr, (long) uid); + + flush_init(); + + switch (status = flush_send_site(site)) { + case FLUSH_STAT_OK: + exit(0); + case FLUSH_STAT_BAD: + msg_fatal_status(EX_USAGE, "Invalid request: \"%s\"", site); + case FLUSH_STAT_FAIL: + msg_fatal_status(EX_UNAVAILABLE, + "Cannot flush mail queue - mail system is down"); + case FLUSH_STAT_DENY: + msg_fatal_status(EX_UNAVAILABLE, + "Flush service is not configured for destination \"%s\"", + site); + default: + msg_fatal_status(EX_SOFTWARE, + "Unknown flush server reply status %d", status); + } +} + +/* flush_file - flush mail with specific queue ID */ + +static void flush_file(const char *queue_id) +{ + int status; + const char *errstr; + uid_t uid = getuid(); + + if (uid != 0 && uid != var_owner_uid + && (errstr = check_user_acl_byuid(VAR_FLUSH_ACL, var_flush_acl, + uid)) != 0) + msg_fatal_status(EX_NOPERM, + "User %s(%ld) is not allowed to flush the mail queue", + errstr, (long) uid); + + switch (status = flush_send_file(queue_id)) { + case FLUSH_STAT_OK: + exit(0); + case FLUSH_STAT_BAD: + msg_fatal_status(EX_USAGE, "Invalid request: \"%s\"", queue_id); + case FLUSH_STAT_FAIL: + msg_fatal_status(EX_UNAVAILABLE, + "Cannot flush mail queue - mail system is down"); + default: + msg_fatal_status(EX_SOFTWARE, + "Unexpected flush server reply status %d", status); + } +} + +/* unavailable - sanitize exit status from library run-time errors */ + +static void unavailable(void) +{ + exit(EX_UNAVAILABLE); +} + +/* usage - scream and die */ + +static NORETURN usage(void) +{ + msg_fatal_status(EX_USAGE, "usage: postqueue -f | postqueue -i queueid | postqueue -j | postqueue -p | postqueue -s site"); +} + +MAIL_VERSION_STAMP_DECLARE; + +/* main - the main program */ + +int main(int argc, char **argv) +{ + struct stat st; + int c; + int fd; + int mode = PQ_MODE_DEFAULT; + char *site_to_flush = 0; + char *id_to_flush = 0; + ARGV *import_env; + int bad_site; + + /* + * Fingerprint executables and core dumps. + */ + MAIL_VERSION_STAMP_ALLOCATE; + + /* + * Be consistent with file permissions. + */ + umask(022); + + /* + * To minimize confusion, make sure that the standard file descriptors + * are open before opening anything else. XXX Work around for 44BSD where + * fstat can return EBADF on an open file descriptor. + */ + for (fd = 0; fd < 3; fd++) + if (fstat(fd, &st) == -1 + && (close(fd), open("/dev/null", O_RDWR, 0)) != fd) + msg_fatal_status(EX_UNAVAILABLE, "open /dev/null: %m"); + + /* + * Initialize. Set up logging. Read the global configuration file after + * parsing command-line arguments. Censor the process name: it is + * provided by the user. + */ + argv[0] = "postqueue"; + msg_vstream_init(argv[0], VSTREAM_ERR); + msg_cleanup(unavailable); + maillog_client_init(mail_task("postqueue"), MAILLOG_CLIENT_FLAG_NONE); + set_mail_conf_str(VAR_PROCNAME, var_procname = mystrdup(argv[0])); + + /* + * Check the Postfix library version as soon as we enable logging. + */ + MAIL_VERSION_CHECK; + + /* + * Parse JCL. This program is set-gid and must sanitize all command-line + * parameters. The configuration directory argument is validated by the + * mail configuration read routine. Don't do complex things until we have + * completed initializations. + */ + while ((c = GETOPT(argc, argv, "c:fi:jps:v")) > 0) { + switch (c) { + case 'c': /* non-default configuration */ + if (setenv(CONF_ENV_PATH, optarg, 1) < 0) + msg_fatal_status(EX_UNAVAILABLE, "out of memory"); + break; + case 'f': /* flush queue */ + if (mode != PQ_MODE_DEFAULT) + usage(); + mode = PQ_MODE_FLUSH_QUEUE; + break; + case 'i': /* flush queue file */ + if (mode != PQ_MODE_DEFAULT) + usage(); + mode = PQ_MODE_FLUSH_FILE; + id_to_flush = optarg; + break; + case 'j': + if (mode != PQ_MODE_DEFAULT) + usage(); + mode = PQ_MODE_JSON_LIST; + break; + case 'p': /* traditional mailq */ + if (mode != PQ_MODE_DEFAULT) + usage(); + mode = PQ_MODE_MAILQ_LIST; + break; + case 's': /* flush site */ + if (mode != PQ_MODE_DEFAULT) + usage(); + mode = PQ_MODE_FLUSH_SITE; + site_to_flush = optarg; + break; + case 'v': + if (geteuid() == 0) + msg_verbose++; + break; + default: + usage(); + } + } + if (argc > optind) + usage(); + + /* + * Further initialization... + */ + mail_conf_read(); + /* Re-evaluate mail_task() after reading main.cf. */ + maillog_client_init(mail_task("postqueue"), MAILLOG_CLIENT_FLAG_NONE); + mail_dict_init(); /* proxy, sql, ldap */ + get_mail_conf_str_table(str_table); + + /* + * This program is designed to be set-gid, which makes it a potential + * target for attack. Strip and optionally override the process + * environment so that we don't have to trust the C library. + */ + import_env = mail_parm_split(VAR_IMPORT_ENVIRON, var_import_environ); + clean_env(import_env->argv); + argv_free(import_env); + + if (chdir(var_queue_dir)) + msg_fatal_status(EX_UNAVAILABLE, "chdir %s: %m", var_queue_dir); + + signal(SIGPIPE, SIG_IGN); + + /* End of initializations. */ + + /* + * Further input validation. + */ + if (site_to_flush != 0) { + bad_site = 0; + if (*site_to_flush == '[') { + bad_site = !valid_mailhost_literal(site_to_flush, DONT_GRIPE); + } else { + bad_site = !valid_hostname(site_to_flush, DONT_GRIPE); + } + if (bad_site) + msg_fatal_status(EX_USAGE, + "Cannot flush mail queue - invalid destination: \"%.100s%s\"", + site_to_flush, strlen(site_to_flush) > 100 ? "..." : ""); + } + if (id_to_flush != 0) { + if (!mail_queue_id_ok(id_to_flush)) + msg_fatal_status(EX_USAGE, + "Cannot flush queue ID - invalid name: \"%.100s%s\"", + id_to_flush, strlen(id_to_flush) > 100 ? "..." : ""); + } + + /* + * Start processing. + */ + switch (mode) { + default: + msg_panic("unknown operation mode: %d", mode); + /* NOTREACHED */ + case PQ_MODE_MAILQ_LIST: + case PQ_MODE_JSON_LIST: + show_queue(mode); + exit(0); + break; + case PQ_MODE_FLUSH_SITE: + flush_site(site_to_flush); + exit(0); + break; + case PQ_MODE_FLUSH_FILE: + flush_file(id_to_flush); + exit(0); + break; + case PQ_MODE_FLUSH_QUEUE: + flush_queue(); + exit(0); + break; + case PQ_MODE_DEFAULT: + usage(); + /* NOTREACHED */ + } +} |