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[netbsd-mini2440.git] / external / ibm-public / postfix / dist / src / postqueue / postqueue.c

/*      $NetBSD$        */

/*++
/* NAME
/*      postqueue 1
/* SUMMARY
/*      Postfix queue control
/* SYNOPSIS
/*      \fBpostqueue\fR [\fB-v\fR] [\fB-c \fIconfig_dir\fR] \fB-f\fR
/* .br
/*      \fBpostqueue\fR [\fB-v\fR] [\fB-c \fIconfig_dir\fR] \fB-i \fIqueue_id\fR
/* .br
/*      \fBpostqueue\fR [\fB-v\fR] [\fB-c \fIconfig_dir\fR] \fB-p\fR
/* .br
/*      \fBpostqueue\fR [\fB-v\fR] [\fB-c \fIconfig_dir\fR] \fB-s \fIsite\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-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. This mode of operation is implemented
/*      by executing the \fBpostqueue\fR(1) command. 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.
/* .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 2821
/*      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.
/* SECURITY
/* .ad
/* .fi
/*      This program is designed to run with set-group ID privileges, so
/*      that it can connect to Postfix daemon processes.
/* DIAGNOSTICS
/*      Problems are logged to \fBsyslogd\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, 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 Postfix process will
/*      import from a non-Postfix parent process.
/* .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"
/*      The mail system name that is prepended to the process name in syslog
/*      records, so that "smtpd" becomes, for example, "postfix/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
/* 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
/*--*/

/* 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 <msg_syslog.h>
#include <argv.h>
#include <safe.h>
#include <connect.h>
#include <valid_hostname.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>

/* Application-specific. */

 /*
  * 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 */

 /*
  * 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(void)
{
    const char *errstr;
    char    buf[VSTREAM_BUFSIZE];
    VSTREAM *showq;
    int     n;
    uid_t   uid = getuid();

    if (uid != 0 && uid != var_owner_uid
        && (errstr = check_user_acl_byuid(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. Terminate silently when piping into
     * a program that terminates early.
     */
    if ((showq = mail_connect(MAIL_CLASS_PUBLIC, var_showq_service, BLOCKING)) != 0) {
        while ((n = vstream_fread(showq, buf, sizeof(buf))) > 0) {
            if (vstream_fwrite(VSTREAM_OUT, buf, n) != n
                || vstream_fflush(VSTREAM_OUT) != 0) {
                if (errno == EPIPE)
                    break;
                msg_fatal("write error: %m");
            }
        }
        if (vstream_fclose(showq) && errno != EPIPE)
            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) {
        ARGV   *argv;
        int     stat;

        msg_warn("Mail system is down -- accessing queue directly");
        argv = argv_alloc(6);
        argv_add(argv, var_showq_service, "-u", "-S", (char *) 0);
        for (n = 0; n < msg_verbose; n++)
            argv_add(argv, "-v", (char *) 0);
        argv_terminate(argv);
        stat = mail_run_foreground(var_daemon_dir, argv->argv);
        argv_free(argv);
    }

    /*
     * 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, 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");
}

/* 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, 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, 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 -p | postqueue -s site");
}

MAIL_VERSION_STAMP_DECLARE;

/* main - the main program */

int     main(int argc, char **argv)
{
    struct stat st;
    char   *slash;
    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 and
     * extract configuration information. Set up signal handlers so that we
     * can clean up incomplete output.
     */
    if ((slash = strrchr(argv[0], '/')) != 0 && slash[1])
        argv[0] = slash + 1;
    msg_vstream_init(argv[0], VSTREAM_ERR);
    msg_cleanup(unavailable);
    msg_syslog_init(mail_task("postqueue"), LOG_PID, LOG_FACILITY);
    set_mail_conf_str(VAR_PROCNAME, var_procname = mystrdup(argv[0]));

    /*
     * 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:ps: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 '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();
    if (strcmp(var_syslog_name, DEF_SYSLOG_NAME) != 0)
        msg_syslog_init(mail_task("postqueue"), LOG_PID, LOG_FACILITY);
    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. If not running as root, strip the environment so we
     * don't have to trust the C library. If running as root, don't strip the
     * environment so that showq can receive non-default configuration
     * directory info when the mail system is down.
     */
    if (geteuid() != 0) {
        import_env = argv_split(var_import_environ, ", \t\r\n");
        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:
        show_queue();
        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 */
    }
}