Ultrix-3.1/src/ucb/sendmail/aux/4.1a_daemon.c
/**********************************************************************
* Copyright (c) Digital Equipment Corporation 1984, 1985, 1986. *
* All Rights Reserved. *
* Reference "/usr/src/COPYRIGHT" for applicable restrictions. *
**********************************************************************/
# include <errno.h>
# include "sendmail.h"
#ifndef DAEMON
SCCSID(@(#)4.1a_daemon.c 3.35+ 12/5/82 (w/o daemon mode));
#else
# include <sys/socket.h>
# include <net/in.h>
# include <wait.h>
SCCSID(@(#)4.1a_daemon.c 3.35+ 12/5/82 (with daemon mode));
/*
** DAEMON.C -- routines to use when running as a daemon.
**
** 4.1a BSD version -- this version is not well supported.
**
** This entire file is highly dependent on the 4.1a 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.
*/
/*
** 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.
*/
getrequests()
{
union wait status;
for (;;)
{
register int pid;
register int port;
/*
** Wait for a connection.
*/
while ((port = getconnection()) < 0)
{
# ifdef LOG
if (LogLevel > 0)
syslog(LOG_SALERT, "cannot get connection");
# endif LOG
finis();
}
/*
** Create a subprocess to process the mail.
*/
# ifdef DEBUG
if (tTd(15, 2))
printf("getrequests: forking (port = %d)\n", port);
# endif DEBUG
pid = fork();
if (pid < 0)
{
syserr("daemon: cannot fork");
sleep(10);
(void) close(port);
continue;
}
if (pid == 0)
{
/*
** CHILD -- return to caller.
** Verify calling user id if possible here.
*/
InChannel = fdopen(port, "r");
OutChannel = fdopen(port, "w");
# ifdef DEBUG
if (tTd(15, 2))
printf("getreq: returning\n");
# endif DEBUG
# ifdef LOG
if (LogLevel > 11)
syslog(LOG_DEBUG, "connected, pid=%d", getpid());
# endif LOG
return;
}
/*
** PARENT -- wait for child to terminate.
** Perhaps we should allow concurrent processing?
*/
# ifdef DEBUG
if (tTd(15, 2))
{
sleep(2);
printf("getreq: parent waiting\n");
}
# endif DEBUG
/* close the port so that others will hang (for a while) */
(void) close(port);
/* pick up old zombies; implement load limiting */
while (wait3(&status, WNOHANG, 0) > 0)
continue;
}
}
/*
** 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 (;; sleep(15))
{
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 */
do
{
errno = 0;
#ifdef NVMUNIX
lotherend = sizeof otherend;
t = accept(s, &otherend, &lotherend, 0);
if (t >= 0)
return (t);
#else NVMUNIX
if (accept(s, &otherend) >= 0)
return (s);
#endif NVMUNIX
} while (errno == EINTR);
syserr("getconnection: accept");
sleep(5);
(void) close(s);
}
}
/*
** 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);
}
/*
** MYHOSTNAME -- return the name of this host.
**
** Parameters:
** hostbuf -- a place to return the name of this host.
** size -- the size of hostbuf.
**
** Returns:
** A list of aliases for this host.
** NULL if it can't find an alias list.
**
** Side Effects:
** none.
*/
char **
myhostname(hostbuf, size)
char hostbuf[];
int size;
{
register char *p;
gethostname(hostbuf, size);
for (p = hostbuf; *p != '\0'; p++)
if (islower(*p))
*p -= 'a' - 'A';
/* now where would we find an alias list? */
return (NULL);
}
# else DAEMON
/*
** MYHOSTNAME -- stub version for case of no daemon code.
**
** Can't convert to upper case here because might be a UUCP name.
*/
char **
myhostname(hostbuf, size)
char hostbuf[];
int size;
{
register FILE *f;
hostbuf[0] = '\0';
f = fopen("/usr/include/whoami", "r");
if (f != NULL)
{
(void) fgets(hostbuf, size, f);
fixcrlf(hostbuf, TRUE);
(void) fclose(f);
}
return (NULL);
}
#endif DAEMON