2.9BSD/usr/src/ucb/sendmail/src/daemon4.2.c
# include <errno.h>
# include "sendmail.h"
#ifndef DAEMON
SCCSID(@(#)daemon.c 4.4 8/28/83 (w/o daemon mode));
#else
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <sys/wait.h>
SCCSID(@(#)daemon.c 4.4 8/28/83 (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.
** clrdaemon()
** Close any open files associated with getting
** the connection; this is used when running the queue,
** etc., to avoid having extra file descriptors during
** the queue run and to avoid confusing the network
** code (if it cares).
** 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. The file pointers
** "InChannel" and "OutChannel" should be set to point
** to the communication channel.
*/
struct sockaddr_in SendmailAddress;/* internet address of sendmail */
int DaemonSocket = -1; /* fd describing socket */
getrequests()
{
int t;
union wait status;
register struct servent *sp;
/*
** Set up the address for the mailer.
*/
sp = getservbyname("smtp", "tcp");
if (sp == NULL)
{
syserr("server \"smtp\" unknown");
goto severe;
}
SendmailAddress.sin_family = AF_INET;
SendmailAddress.sin_addr.s_addr = INADDR_ANY;
SendmailAddress.sin_port = sp->s_port;
/*
** Try to actually open the connection.
*/
# ifdef DEBUG
if (tTd(15, 1))
printf("getrequests: port 0x%x\n", SendmailAddress.sin_port);
# endif DEBUG
/* get a socket for the SMTP connection */
DaemonSocket = socket(AF_INET, SOCK_STREAM, 0, 0);
if (DaemonSocket < 0)
{
/* probably another daemon already */
syserr("getrequests: can't create socket");
severe:
# ifdef LOG
if (LogLevel > 0)
syslog(LOG_SALERT, "cannot get connection");
# endif LOG
finis();
}
#ifdef DEBUG
/* turn on network debugging? */
if (tTd(15, 15))
(void) setsockopt(DaemonSocket, SOL_SOCKET, SO_DEBUG, 0, 0);
#endif DEBUG
if (bind(DaemonSocket, &SendmailAddress, sizeof SendmailAddress, 0) < 0)
{
syserr("getrequests: cannot bind");
(void) close(DaemonSocket);
goto severe;
}
listen(DaemonSocket, 10);
# ifdef DEBUG
if (tTd(15, 1))
printf("getrequests: %d\n", DaemonSocket);
# endif DEBUG
for (;;)
{
register int pid;
auto int lotherend;
struct sockaddr_in otherend;
extern int RefuseLA;
/* see if we are rejecting connections */
while (getla() > RefuseLA)
sleep(5);
/* wait for a connection */
do
{
errno = 0;
lotherend = sizeof otherend;
t = accept(DaemonSocket, &otherend, &lotherend, 0);
} while (t < 0 && errno == EINTR);
if (t < 0)
{
syserr("getrequests: accept");
sleep(5);
continue;
}
/*
** Create a subprocess to process the mail.
*/
# ifdef DEBUG
if (tTd(15, 2))
printf("getrequests: forking (fd = %d)\n", t);
# endif DEBUG
pid = fork();
if (pid < 0)
{
syserr("daemon: cannot fork");
sleep(10);
(void) close(t);
continue;
}
if (pid == 0)
{
extern struct hostent *gethostbyaddr();
register struct hostent *hp;
extern char *RealHostName; /* srvrsmtp.c */
char buf[MAXNAME];
/*
** CHILD -- return to caller.
** Collect verified idea of sending host.
** Verify calling user id if possible here.
*/
/* determine host name */
hp = gethostbyaddr(&otherend.sin_addr, sizeof otherend.sin_addr, AF_INET);
if (hp != NULL)
(void) sprintf(buf, "%s.ARPA", hp->h_name);
else
/* this should produce a dotted quad */
(void) sprintf(buf, "%lx", otherend.sin_addr.s_addr);
RealHostName = newstr(buf);
(void) close(DaemonSocket);
InChannel = fdopen(t, "r");
OutChannel = fdopen(t, "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(t);
/* pick up old zombies */
while (wait3(&status, WNOHANG, 0) > 0)
continue;
}
/*NOTREACHED*/
}
/*
** CLRDAEMON -- reset the daemon connection
**
** Parameters:
** none.
**
** Returns:
** none.
**
** Side Effects:
** releases any resources used by the passive daemon.
*/
clrdaemon()
{
if (DaemonSocket >= 0)
(void) close(DaemonSocket);
DaemonSocket = -1;
}
/*
** 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;
register char *p = index(host, ']');
if (p != NULL)
{
*p = '\0';
hid = inet_addr(&host[1]);
*p = ']';
}
if (p == NULL || hid == -1)
{
usrerr("Invalid numeric domain spec \"%s\"", host);
return (EX_NOHOST);
}
SendmailAddress.sin_addr.s_addr = hid;
}
else
{
register struct hostent *hp = gethostbyname(host);
if (hp == NULL)
return (EX_NOHOST);
bmove(hp->h_addr, (char *) &SendmailAddress.sin_addr, hp->h_length);
}
/*
** Determine the port number.
*/
if (port != 0)
SendmailAddress.sin_port = htons(port);
else
{
register struct servent *sp = getservbyname("smtp", "tcp");
if (sp == NULL)
{
syserr("makeconnection: server \"smtp\" unknown");
return (EX_OSFILE);
}
SendmailAddress.sin_port = sp->s_port;
}
/*
** Try to actually open the connection.
*/
# ifdef DEBUG
if (tTd(16, 1))
printf("makeconnection (%s)\n", host);
# endif DEBUG
s = socket(AF_INET, SOCK_STREAM, 0, 0);
if (s < 0)
{
syserr("makeconnection: no socket");
goto failure;
}
# ifdef DEBUG
if (tTd(16, 1))
printf("makeconnection: %d\n", s);
/* turn on network debugging? */
if (tTd(16, 14))
(void) setsockopt(s, SOL_SOCKET, SO_DEBUG, 0, 0);
# endif DEBUG
(void) fflush(CurEnv->e_xfp); /* for debugging */
errno = 0; /* for debugging */
SendmailAddress.sin_family = AF_INET;
if (connect(s, &SendmailAddress, sizeof SendmailAddress, 0) < 0)
{
/* failure, decide if temporary or not */
failure:
switch (errno)
{
case EISCONN:
case ETIMEDOUT:
case EINPROGRESS:
case EALREADY:
case EADDRINUSE:
case EHOSTDOWN:
case ENETDOWN:
case ENETRESET:
case ENOBUFS:
case ECONNREFUSED:
case ECONNRESET:
case EHOSTUNREACH:
case ENETUNREACH:
/* there are others, I'm sure..... */
return (EX_TEMPFAIL);
case EPERM:
/* why is this happening? */
syserr("makeconnection: funny failure, addr=%lx, port=%x",
SendmailAddress.sin_addr.s_addr, SendmailAddress.sin_port);
return (EX_TEMPFAIL);
default:
return (EX_UNAVAILABLE);
}
}
/* connection ok, put it into canonical form */
*outfile = fdopen(s, "w");
*infile = fdopen(s, "r");
return (EX_OK);
}
/*
** 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.
**
** Side Effects:
** none.
*/
char **
myhostname(hostbuf, size)
char hostbuf[];
int size;
{
extern struct hostent *gethostbyname();
struct hostent *hp;
auto int i = size;
gethostname(hostbuf, &i);
hp = gethostbyname(hostbuf);
if (hp != NULL)
return (hp->h_aliases);
else
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.
**
** Mark, you can change this to be anything you want......
*/
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