InfoMagic Source Code 1993 July/THE_SOURCE_CODE_CD_ROM.iso/bsd_srcs/usr.sbin/sendmail/src/savemail.c

C/C++ Source or Header | 1991-04-20 | 12.9 KB | 542 lines

/*
 * Copyright (c) 1983 Eric P. Allman
 * Copyright (c) 1988 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    This product includes software developed by the University of
 *    California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static char sccsid[] = "@(#)savemail.c    5.14 (Berkeley) 8/29/90";
#endif /* not lint */

# include <sys/types.h>
# include <pwd.h>
# include "sendmail.h"

/*
**  SAVEMAIL -- Save mail on error
**
**    If mailing back errors, mail it back to the originator
**    together with an error message; otherwise, just put it in
**    dead.letter in the user's home directory (if he exists on
**    this machine).
**
**    Parameters:
**        e -- the envelope containing the message in error.
**
**    Returns:
**        none
**
**    Side Effects:
**        Saves the letter, by writing or mailing it back to the
**        sender, or by putting it in dead.letter in her home
**        directory.
*/

/* defines for state machine */
# define ESM_REPORT    0    /* report to sender's terminal */
# define ESM_MAIL    1    /* mail back to sender */
# define ESM_QUIET    2    /* messages have already been returned */
# define ESM_DEADLETTER    3    /* save in ~/dead.letter */
# define ESM_POSTMASTER    4    /* return to postmaster */
# define ESM_USRTMP    5    /* save in /usr/tmp/dead.letter */
# define ESM_PANIC    6    /* leave the locked queue/transcript files */
# define ESM_DONE    7    /* the message is successfully delivered */


savemail(e)
    register ENVELOPE *e;
{
    register struct passwd *pw;
    register FILE *fp;
    int state;
    auto ADDRESS *q;
    char buf[MAXLINE+1];
    extern struct passwd *getpwnam();
    register char *p;
    extern char *ttypath();
    typedef int (*fnptr)();

    if (tTd(6, 1))
        printf("\nsavemail, ErrorMode = %c\n", ErrorMode);

    if (bitset(EF_RESPONSE, e->e_flags))
        return;
    if (e->e_class < 0)
    {
        message(Arpa_Info, "Dumping junk mail");
        return;
    }
    ForceMail = TRUE;
    e->e_flags &= ~EF_FATALERRS;

    /*
    **  In the unhappy event we don't know who to return the mail
    **  to, make someone up.
    */

    if (e->e_from.q_paddr == NULL)
    {
        if (parseaddr("root", &e->e_from, 0, '\0') == NULL)
        {
            syserr("Cannot parse root!");
            ExitStat = EX_SOFTWARE;
            finis();
        }
    }
    e->e_to = NULL;

    /*
    **  Basic state machine.
    **
    **    This machine runs through the following states:
    **
    **    ESM_QUIET    Errors have already been printed iff the
    **            sender is local.
    **    ESM_REPORT    Report directly to the sender's terminal.
    **    ESM_MAIL    Mail response to the sender.
    **    ESM_DEADLETTER    Save response in ~/dead.letter.
    **    ESM_POSTMASTER    Mail response to the postmaster.
    **    ESM_PANIC    Save response anywhere possible.
    */

    /* determine starting state */
    switch (ErrorMode)
    {
      case EM_WRITE:
        state = ESM_REPORT;
        break;

      case EM_BERKNET:
        /* mail back, but return o.k. exit status */
        ExitStat = EX_OK;

        /* fall through.... */

      case EM_MAIL:
        state = ESM_MAIL;
        break;

      case EM_PRINT:
      case '\0':
        state = ESM_QUIET;
        break;

      case EM_QUIET:
        /* no need to return anything at all */
        return;

      default:
        syserr("savemail: ErrorMode x%x\n");
        state = ESM_MAIL;
        break;
    }

    while (state != ESM_DONE)
    {
        if (tTd(6, 5))
            printf("  state %d\n", state);

        switch (state)
        {
          case ESM_QUIET:
            if (e->e_from.q_mailer == LocalMailer)
                state = ESM_DEADLETTER;
            else
                state = ESM_MAIL;
            break;

          case ESM_REPORT:

            /*
            **  If the user is still logged in on the same terminal,
            **  then write the error messages back to hir (sic).
            */

            p = ttypath();
            if (p == NULL || freopen(p, "w", stdout) == NULL)
            {
                state = ESM_MAIL;
                break;
            }

            expand("\001n", buf, &buf[sizeof buf - 1], e);
            printf("\r\nMessage from %s...\r\n", buf);
            printf("Errors occurred while sending mail.\r\n");
            if (e->e_xfp != NULL)
            {
                (void) fflush(e->e_xfp);
                fp = fopen(queuename(e, 'x'), "r");
            }
            else
                fp = NULL;
            if (fp == NULL)
            {
                syserr("Cannot open %s", queuename(e, 'x'));
                printf("Transcript of session is unavailable.\r\n");
            }
            else
            {
                printf("Transcript follows:\r\n");
                while (fgets(buf, sizeof buf, fp) != NULL &&
                       !ferror(stdout))
                    fputs(buf, stdout);
                (void) fclose(fp);
            }
            printf("Original message will be saved in dead.letter.\r\n");
            state = ESM_DEADLETTER;
            break;

          case ESM_MAIL:
          case ESM_POSTMASTER:
            /*
            **  If mailing back, do it.
            **    Throw away all further output.  Don't alias,
            **    since this could cause loops, e.g., if joe
            **    mails to joe@x, and for some reason the network
            **    for @x is down, then the response gets sent to
            **    joe@x, which gives a response, etc.  Also force
            **    the mail to be delivered even if a version of
            **    it has already been sent to the sender.
            */

            if (state == ESM_MAIL)
            {
                if (e->e_errorqueue == NULL)
                    sendtolist(e->e_from.q_paddr,
                        (ADDRESS *) NULL,
                        &e->e_errorqueue);

                /* deliver a cc: to the postmaster if desired */
                if (PostMasterCopy != NULL)
                    sendtolist(PostMasterCopy,
                        (ADDRESS *) NULL,
                        &e->e_errorqueue);
                q = e->e_errorqueue;
            }
            else
            {
                if (parseaddr("postmaster", q, 0, '\0') == NULL)
                {
                    syserr("cannot parse postmaster!");
                    ExitStat = EX_SOFTWARE;
                    state = ESM_USRTMP;
                    break;
                }
            }
            if (returntosender(e->e_message != NULL ? e->e_message :
                       "Unable to deliver mail",
                       q, TRUE) == 0)
            {
                state = ESM_DONE;
                break;
            }

            state = state == ESM_MAIL ? ESM_POSTMASTER : ESM_USRTMP;
            break;

          case ESM_DEADLETTER:
            /*
            **  Save the message in dead.letter.
            **    If we weren't mailing back, and the user is
            **    local, we should save the message in
            **    ~/dead.letter so that the poor person doesn't
            **    have to type it over again -- and we all know
            **    what poor typists UNIX users are.
            */

            p = NULL;
            if (e->e_from.q_mailer == LocalMailer)
            {
                if (e->e_from.q_home != NULL)
                    p = e->e_from.q_home;
                else if ((pw = getpwnam(e->e_from.q_user)) != NULL)
                    p = pw->pw_dir;
            }
            if (p == NULL)
            {
                syserr("Can't return mail to %s", e->e_from.q_paddr);
                state = ESM_MAIL;
                break;
            }
            if (e->e_dfp != NULL)
            {
                auto ADDRESS *q;
                bool oldverb = Verbose;

                /* we have a home directory; open dead.letter */
                define('z', p, e);
                expand("\001z/dead.letter", buf, &buf[sizeof buf - 1], e);
                Verbose = TRUE;
                message(Arpa_Info, "Saving message in %s", buf);
                Verbose = oldverb;
                e->e_to = buf;
                q = NULL;
                sendtolist(buf, (ADDRESS *) NULL, &q);
                if (deliver(e, q) == 0)
                    state = ESM_DONE;
                else
                    state = ESM_MAIL;
            }
            else
            {
                /* no data file -- try mailing back */
                state = ESM_MAIL;
            }
            break;

          case ESM_USRTMP:
            /*
            **  Log the mail in /usr/tmp/dead.letter.
            */

            fp = dfopen("/usr/tmp/dead.letter", "a");
            if (fp == NULL)
            {
                state = ESM_PANIC;
                break;
            }

            putfromline(fp, ProgMailer);
            (*e->e_puthdr)(fp, ProgMailer, e);
            putline("\n", fp, ProgMailer);
            (*e->e_putbody)(fp, ProgMailer, e);
            putline("\n", fp, ProgMailer);
            (void) fflush(fp);
            state = ferror(fp) ? ESM_PANIC : ESM_DONE;
            (void) fclose(fp);
            break;

          default:
            syserr("savemail: unknown state %d", state);

            /* fall through ... */

          case ESM_PANIC:
            syserr("savemail: HELP!!!!");
# ifdef LOG
            if (LogLevel >= 1)
                syslog(LOG_ALERT, "savemail: HELP!!!!");
# endif LOG

            /* leave the locked queue & transcript files around */
            exit(EX_SOFTWARE);
        }
    }
}
/*
**  RETURNTOSENDER -- return a message to the sender with an error.
**
**    Parameters:
**        msg -- the explanatory message.
**        returnq -- the queue of people to send the message to.
**        sendbody -- if TRUE, also send back the body of the
**            message; otherwise just send the header.
**
**    Returns:
**        zero -- if everything went ok.
**        else -- some error.
**
**    Side Effects:
**        Returns the current message to the sender via
**        mail.
*/

static bool    SendBody;

#define MAXRETURNS    6    /* max depth of returning messages */

returntosender(msg, returnq, sendbody)
    char *msg;
    ADDRESS *returnq;
    bool sendbody;
{
    char buf[MAXNAME];
    extern putheader(), errbody();
    register ENVELOPE *ee;
    extern ENVELOPE *newenvelope();
    ENVELOPE errenvelope;
    static int returndepth;
    register ADDRESS *q;

    if (tTd(6, 1))
    {
        printf("Return To Sender: msg=\"%s\", depth=%d, CurEnv=%x,\n",
               msg, returndepth, CurEnv);
        printf("\treturnq=");
        printaddr(returnq, TRUE);
    }

    if (++returndepth >= MAXRETURNS)
    {
        if (returndepth != MAXRETURNS)
            syserr("returntosender: infinite recursion on %s", returnq->q_paddr);
        /* don't "unrecurse" and fake a clean exit */
        /* returndepth--; */
        return (0);
    }

    SendBody = sendbody;
    define('g', "\001f", CurEnv);
    ee = newenvelope(&errenvelope);
    define('a', "\001b", ee);
    ee->e_puthdr = putheader;
    ee->e_putbody = errbody;
    ee->e_flags |= EF_RESPONSE;
    if (!bitset(EF_OLDSTYLE, CurEnv->e_flags))
        ee->e_flags &= ~EF_OLDSTYLE;
    ee->e_sendqueue = returnq;
    openxscript(ee);
    for (q = returnq; q != NULL; q = q->q_next)
    {
        if (q->q_alias == NULL)
            addheader("to", q->q_paddr, ee);
    }

    (void) sprintf(buf, "Returned mail: %s", msg);
    addheader("subject", buf, ee);

    /* fake up an address header for the from person */
    expand("\001n", buf, &buf[sizeof buf - 1], CurEnv);
    if (parseaddr(buf, &ee->e_from, -1, '\0') == NULL)
    {
        syserr("Can't parse myself!");
        ExitStat = EX_SOFTWARE;
        returndepth--;
        return (-1);
    }
    loweraddr(&ee->e_from);

    /* push state into submessage */
    CurEnv = ee;
    define('f', "\001n", ee);
    define('x', "Mail Delivery Subsystem", ee);
    eatheader(ee);

    /* actually deliver the error message */
    sendall(ee, SM_DEFAULT);

    /* restore state */
    dropenvelope(ee);
    CurEnv = CurEnv->e_parent;
    returndepth--;

    /* should check for delivery errors here */
    return (0);
}
/*
**  ERRBODY -- output the body of an error message.
**
**    Typically this is a copy of the transcript plus a copy of the
**    original offending message.
**
**    Parameters:
**        fp -- the output file.
**        m -- the mailer to output to.
**        e -- the envelope we are working in.
**
**    Returns:
**        none
**
**    Side Effects:
**        Outputs the body of an error message.
*/

errbody(fp, m, e)
    register FILE *fp;
    register struct mailer *m;
    register ENVELOPE *e;
{
    register FILE *xfile;
    char buf[MAXLINE];
    char *p;

    /*
    **  Output transcript of errors
    */

    (void) fflush(stdout);
    p = queuename(e->e_parent, 'x');
    if ((xfile = fopen(p, "r")) == NULL)
    {
        syserr("Cannot open %s", p);
        fprintf(fp, "  ----- Transcript of session is unavailable -----\n");
    }
    else
    {
        fprintf(fp, "   ----- Transcript of session follows -----\n");
        if (e->e_xfp != NULL)
            (void) fflush(e->e_xfp);
        while (fgets(buf, sizeof buf, xfile) != NULL)
            putline(buf, fp, m);
        (void) fclose(xfile);
    }
    errno = 0;

    /*
    **  Output text of original message
    */

    if (NoReturn)
        fprintf(fp, "\n   ----- Return message suppressed -----\n\n");
    else if (e->e_parent->e_dfp != NULL)
    {
        if (SendBody)
        {
            putline("\n", fp, m);
            putline("   ----- Unsent message follows -----\n", fp, m);
            (void) fflush(fp);
            putheader(fp, m, e->e_parent);
            putline("\n", fp, m);
            putbody(fp, m, e->e_parent);
        }
        else
        {
            putline("\n", fp, m);
            putline("  ----- Message header follows -----\n", fp, m);
            (void) fflush(fp);
            putheader(fp, m, e->e_parent);
        }
    }
    else
    {
        putline("\n", fp, m);
        putline("  ----- No message was collected -----\n", fp, m);
        putline("\n", fp, m);
    }

    /*
    **  Cleanup and exit
    */

    if (errno != 0)
        syserr("errbody: I/O error");
}