usr/src/usr.sbin/sendmail/src/savemail.c

# include <pwd.h>
# include "sendmail.h"

SCCSID(@(#)savemail.c   3.42            %G%);

/*
**  SAVEMAIL -- Save mail on error
**
**      If the MailBack flag is set, 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:
**              none
**
**      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.
*/

savemail()
{
        register struct passwd *pw;
        register FILE *xfile;
        char buf[MAXLINE+1];
        extern struct passwd *getpwnam();
        register char *p;
        extern char *ttypath();
        static int exclusive;
        typedef int (*fnptr)();

# ifdef DEBUG
        if (tTd(6, 1))
                printf("\nsavemail: exclusive %d\n", exclusive);
# endif DEBUG

        if (exclusive++)
                return;
        if (CurEnv->e_class <= PRI_JUNK)
        {
                message(Arpa_Info, "Dumping junk mail");
                return;
        }
        ForceMail = TRUE;
        FatalErrors = FALSE;

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

        if (CurEnv->e_returnto == NULL)
        {
                CurEnv->e_returnto = parse("root", (ADDRESS *) NULL, 0);
                if (CurEnv->e_returnto == NULL)
                {
                        syserr("Cannot parse root!");
                        ExitStat = EX_SOFTWARE;
                        finis();
                }
        }
        CurEnv->e_to = NULL;

        /*
        **  If called from Eric Schmidt's network, do special mailback.
        **      Fundamentally, this is the mailback case except that
        **      it returns an OK exit status (assuming the return
        **      worked).
        **  Also, if the from address is not local, mail it back.
        */

        if (BerkNet)
        {
                ExitStat = EX_OK;
                MailBack = TRUE;
        }
        if (!bitset(M_LOCAL, CurEnv->e_returnto->q_mailer->m_flags))
                MailBack = TRUE;

        /*
        **  If writing back, do it.
        **      If the user is still logged in on the same terminal,
        **      then write the error messages back to hir (sic).
        **      If not, set the MailBack flag so that it will get
        **      mailed back instead.
        */

        if (WriteBack)
        {
                p = ttypath();
                if (p == NULL || freopen(p, "w", stdout) == NULL)
                {
                        MailBack = TRUE;
                        errno = 0;
                }
                else
                {
                        (void) fflush(Xscript);
                        xfile = fopen(Transcript, "r");
                        if (xfile == NULL)
                                syserr("Cannot open %s", Transcript);
                        expand("$n", buf, &buf[sizeof buf - 1], CurEnv);
                        printf("\r\nMessage from %s...\r\n", buf);
                        printf("Errors occurred while sending mail; transcript follows:\r\n");
                        while (fgets(buf, sizeof buf, xfile) != NULL && !ferror(stdout))
                                fputs(buf, stdout);
                        if (ferror(stdout))
                                (void) syserr("savemail: stdout: write err");
                        (void) fclose(xfile);
                }
        }

        /*
        **  If mailing back, do it.
        **      Throw away all further output.  Don't do aliases, since
        **      this could cause loops, e.g., if joe mails to x:joe,
        **      and for some reason the network for x: is down, then
        **      the response gets sent to x:joe, 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 (MailBack)
        {
                if (CurEnv->e_errorqueue == NULL)
                if (returntosender("Unable to deliver mail", CurEnv->e_returnto, TRUE) == 0)
                        return;
        }

        /*
        **  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 programmers are.
        **      However, if we are running a "smart" protocol, we don't
        **      bother to return the message, since the other end is
        **      expected to handle that.
        */

        if (ArpaMode)
                return;
        p = NULL;
        if (CurEnv->e_returnto->q_mailer == LocalMailer)
        {
                if (CurEnv->e_returnto->q_home != NULL)
                        p = CurEnv->e_returnto->q_home;
                else if ((pw = getpwnam(CurEnv->e_returnto->q_user)) != NULL)
                        p = pw->pw_dir;
        }
        if (p == NULL)
        {
                syserr("Can't return mail to %s", CurEnv->e_returnto->q_paddr);
# ifdef DEBUG
                p = "/usr/tmp";
# endif
        }
        if (p != NULL && TempFile != NULL)
        {
                auto ADDRESS *q;
                bool oldverb = Verbose;

                /* we have a home directory; open dead.letter */
                Verbose = TRUE;
                message(Arpa_Info, "Saving message in dead.letter");
                Verbose = oldverb;
                define('z', p);
                expand("$z/dead.letter", buf, &buf[sizeof buf - 1], CurEnv);
                CurEnv->e_to = buf;
                q = NULL;
                sendto(buf, (ADDRESS *) NULL, &q);
                (void) deliver(q);
        }

        /* add terminator to writeback message */
        if (WriteBack)
                printf("-----\r\n");
}
\f/*
**  RETURNTOSENDER -- return a message to the sender with an error.
**
**      Parameters:
**              msg -- the explanatory message.
**              returnto -- 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, returnto, sendbody)
        char *msg;
        ADDRESS *returnto;
        bool sendbody;
{
        char buf[MAXNAME];
        extern putheader(), errbody();
        register ENVELOPE *ee;
        extern ENVELOPE *newenvelope();
        ENVELOPE errenvelope;
        static int returndepth;

# ifdef DEBUG
        if (tTd(6, 1))
        {
                printf("Return To Sender: msg=\"%s\", depth=%d, CurEnv=%x,\n",
                       msg, returndepth, CurEnv);
                printf("\treturnto=");
                printaddr(returnto, FALSE);
        }
# endif DEBUG

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

        NoAlias = TRUE;
        SendBody = sendbody;
        ee = newenvelope(&errenvelope);
        ee->e_puthdr = putheader;
        ee->e_putbody = errbody;
        addheader("date", "$b", ee);
        addheader("from", "$g (Mail Delivery Subsystem)", ee);
        addheader("to", returnto->q_paddr, ee);
        addheader("subject", msg, ee);

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

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

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

        /* do any closing error processing */
        checkerrors(ee);

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

        /* should check for delivery errors here */
        return (0);
}
\f/*
**  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:
**              xfile -- the transcript file.
**              fp -- the output file.
**              xdot -- if set, use the SMTP hidden dot algorithm.
**
**      Returns:
**              none
**
**      Side Effects:
**              Outputs the body of an error message.
*/

errbody(fp, m, xdot)
        register FILE *fp;
        register struct mailer *m;
        bool xdot;
{
        register FILE *xfile;
        char buf[MAXLINE];
        bool fullsmtp = bitset(M_FULLSMTP, m->m_flags);

        (void) fflush(stdout);
        if ((xfile = fopen(Transcript, "r")) == NULL)
                syserr("Cannot open %s", Transcript);
        errno = 0;

        /*
        **  Output transcript of errors
        */

        fprintf(fp, "   ----- Transcript of session follows -----\n");
        (void) fflush(Xscript);
        while (fgets(buf, sizeof buf, xfile) != NULL)
                putline(buf, fp, fullsmtp);

        /*
        **  Output text of original message
        */

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

        /*
        **  Cleanup and exit
        */

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