usr/src/usr.sbin/sendmail/src/daemon.c

# include <errno.h>
# include "sendmail.h"
# include <sys/mx.h>

#ifndef DAEMON
SCCSID(@(#)daemon.c     3.35            %G%     (w/o daemon mode));
#else

# include <sys/socket.h>
# include <net/in.h>
# include <wait.h>

SCCSID(@(#)daemon.c     3.35            %G%     (with daemon mode));

/*
**  DAEMON.C -- routines to use when running as a daemon.
**
**      This entire file is highly dependent on the 4.2 BSD
**      interprocess communication primitives.  No attempt has
**      been made to make this file portable to Version 7,
**      Version 6, MPX files, etc.  If you should try such a
**      thing yourself, I recommend chucking the entire file
**      and starting from scratch.  Basic semantics are:
**
**      getrequests()
**              Opens a port and initiates a connection.
**              Returns in a child.  Must set InChannel and
**              OutChannel appropriately.
**      makeconnection(host, port, outfile, infile)
**              Make a connection to the named host on the given
**              port.  Set *outfile and *infile to the files
**              appropriate for communication.  Returns zero on
**              success, else an exit status describing the
**              error.
**
**      The semantics of both of these should be clean.
*/

static FILE     *MailPort;      /* port that mail comes in on */
\f/*
**  GETREQUESTS -- open mail IPC port and get requests.
**
**      Parameters:
**              none.
**
**      Returns:
**              none.
**
**      Side Effects:
**              Waits until some interesting activity occurs.  When
**              it does, a child is created to process it, and the
**              parent waits for completion.  Return from this
**              routine is always in the child.
*/

# define MAXCONNS       4       /* maximum simultaneous sendmails */

getrequests()
{
        union wait status;
        int numconnections = 0;

        struct wh wbuf;

        wbuf.index = index;
        wbuf.count = 0;
        wbuf.ccount = cnt;
        wbuf.data = buf;
        write(MailPort, &wbuf, sizeof wbuf);
}
\f/*
**  GETCONNECTION -- make a connection with the outside world
**
**      This routine is horribly contorted to try to get around a bunch
**      of 4.1a IPC bugs.  There appears to be nothing we can do to make
**      it "right" -- the code to interrupt accepts just doesn't work
**      right.  However, this is an attempt to minimize the probablity
**      of problems.
**
**      Parameters:
**              none.
**
**      Returns:
**              The port for mail traffic.
**
**      Side Effects:
**              Waits for a connection.
*/

#define IPPORT_PLAYPORT 3055            /* random number */

struct sockaddr_in SendmailAddress = { AF_INET, IPPORT_SMTP };

getconnection()
{
        int s;
#ifdef NVMUNIX
        int t;
#endif NVMUNIX
        struct sockaddr otherend;

        /*
        **  Set up the address for the mailer.
        */

        SendmailAddress.sin_addr.s_addr = 0;
        SendmailAddress.sin_port = IPPORT_SMTP;
# ifdef DEBUG
        if (tTd(15, 15))
                SendmailAddress.sin_port = IPPORT_PLAYPORT;
# endif DEBUG
        SendmailAddress.sin_port = htons(SendmailAddress.sin_port);

        /*
        **  Try to actually open the connection.
        */

# ifdef DEBUG
        if (tTd(15, 1))
                printf("getconnection\n");
# endif DEBUG

        for (;;)
        {
                int i;

                /* get a socket for the SMTP connection */
#ifdef NVMUNIX
                s = socket(AF_INET, SOCK_STREAM, 0, 0);
                bind(s, &SendmailAddress, sizeof SendmailAddress, 0);
                listen(s, 10);
#else NVMUNIX
                /* do loop is to avoid 4.1b kernel bug (?) */
                i = 60;
                do
                {
                        s = socket(SOCK_STREAM, 0, &SendmailAddress, SO_ACCEPTCONN);
                        if (s < 0)
                                sleep(10);
                } while (--i > 0 && s < 0);
#endif NVMUNIX
                if (s < 0)
                {
                        /* probably another daemon already */
                        syserr("getconnection: can't create socket");
                        return (-1);
                }

# ifdef DEBUG
                if (tTd(15, 1))
                        printf("getconnection: %d\n", s);
# endif DEBUG

                /* wait for a connection */
                /* contorted code is due to a 4.1a kernel bug */
                errno = 0;
                if (accept(s, &otherend) >= 0)
                        return (s);
                if (errno != EINTR)
                        syserr("getconnection: accept");
                sleep(5);
                (void) close(s);
        }
}
\f/*
**  MAKECONNECTION -- make a connection to an SMTP socket on another machine.
**
**      Parameters:
**              host -- the name of the host.
**              port -- the port number to connect to.
**              outfile -- a pointer to a place to put the outfile
**                      descriptor.
**              infile -- ditto for infile.
**
**      Returns:
**              An exit code telling whether the connection could be
**                      made and if not why not.
**
**      Side Effects:
**              none.
*/

makeconnection(host, port, outfile, infile)
        char *host;
        u_short port;
        FILE **outfile;
        FILE **infile;
{
        register int s;

        /*
        **  Set up the address for the mailer.
        **      Accept "[a.b.c.d]" syntax for host name.
        */

        if (host[0] == '[')
        {
                long hid = 0;
                int i, j;
                register char *p = host;

                for (i = 3; i >= 0 && *p != ']' && *p != '\0'; i--)
                {
                        j = 0;
                        while (isdigit(*++p))
                                j = j * 10 + (*p - '0');
                        if (*p != (i == 0 ? ']' : '.') || j > 255 || j < 0)
                                break;
                        hid |= j << ((3 - i) * 8);
                }
                if (i >= 0 || *p != ']' || *++p != '\0')
                {
                        usrerr("Invalid numeric domain spec \"%s\"", host);
                        return (EX_NOHOST);
                }
                SendmailAddress.sin_addr.s_addr = hid;
        }
        else if ((SendmailAddress.sin_addr.s_addr = rhost(&host)) == -1)
                return (EX_NOHOST);
        if (port == 0)
                port = IPPORT_SMTP;
        SendmailAddress.sin_port = htons(port);

        /*
        **  Try to actually open the connection.
        */

# ifdef DEBUG
        if (tTd(16, 1))
                printf("makeconnection (%s)\n", host);
# endif DEBUG

#ifdef NVMUNIX
        s = socket(AF_INET, SOCK_STREAM, 0, 0);
#else NVMUNIX
        s = socket(SOCK_STREAM, 0, (struct sockaddr_in *) 0, 0);
#endif NVMUNIX
        if (s < 0)
        {
                syserr("makeconnection: no socket");
                goto failure;
        }

# ifdef DEBUG
        if (tTd(16, 1))
                printf("makeconnection: %d\n", s);
# endif DEBUG
        (void) fflush(CurEnv->e_xfp);                   /* for debugging */
#ifdef NVMUNIX
        bind(s, &SendmailAddress, sizeof SendmailAddress, 0);
        if (connect(s, &SendmailAddress, sizeof SendmailAddress, 0) < 0)
#else NVMUNIX
        if (connect(s, &SendmailAddress) < 0)
#endif NVMUNIX
        {
                /* failure, decide if temporary or not */
        failure:
                switch (errno)
                {
                  case EISCONN:
                  case ETIMEDOUT:
                  case EINPROGRESS:
                  case EALREADY:
                  case EADDRINUSE:
                  case ENETDOWN:
                  case ENETRESET:
                  case ENOBUFS:
                  case ECONNREFUSED:
                        /* there are others, I'm sure..... */
                        return (EX_TEMPFAIL);

                  default:
                        return (EX_UNAVAILABLE);
                }
        }

        /* connection ok, put it into canonical form */
        *outfile = fdopen(s, "w");
        *infile = fdopen(s, "r");

        return (0);
}

#endif DAEMON