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[unix-history] / usr / src / usr.sbin / sendmail / src / srvrsmtp.c
# include <errno.h>
# include "sendmail.h"
# ifndef SMTP
SCCSID(@(#)srvrsmtp.c 3.47 %G% (no SMTP));
# else SMTP
SCCSID(@(#)srvrsmtp.c 3.47 %G%);
/*
** SMTP -- run the SMTP protocol.
**
** Parameters:
** none.
**
** Returns:
** never.
**
** Side Effects:
** Reads commands from the input channel and processes
** them.
*/
struct cmd
{
char *cmdname; /* command name */
int cmdcode; /* internal code, see below */
};
/* values for cmdcode */
# define CMDERROR 0 /* bad command */
# define CMDMAIL 1 /* mail -- designate sender */
# define CMDRCPT 2 /* rcpt -- designate recipient */
# define CMDDATA 3 /* data -- send message text */
# define CMDHOPS 4 /* hops -- specify hop count */
# define CMDRSET 4 /* rset -- reset state */
# define CMDVRFY 5 /* vrfy -- verify address */
# define CMDHELP 6 /* help -- give usage info */
# define CMDNOOP 7 /* noop -- do nothing */
# define CMDQUIT 8 /* quit -- close connection and die */
# define CMDHELO 9 /* helo -- be polite */
# define CMDDBGQSHOW 10 /* showq -- show send queue (DEBUG) */
# define CMDDBGDEBUG 11 /* debug -- set debug mode */
# define CMDVERB 12 /* verb -- go into verbose mode */
# define CMDDBGKILL 13 /* kill -- kill sendmail */
# define CMDDBGWIZ 14 /* wiz -- become a wizard */
# define CMDONEX 15 /* onex -- sending one transaction only */
# define CMDDBGSHELL 16 /* shell -- give us a shell */
static struct cmd CmdTab[] =
{
"mail", CMDMAIL,
"rcpt", CMDRCPT,
"data", CMDDATA,
"rset", CMDRSET,
"vrfy", CMDVRFY,
"expn", CMDVRFY,
"expn", CMDVRFY,
"help", CMDHELP,
"noop", CMDNOOP,
"quit", CMDQUIT,
"helo", CMDHELO,
"verb", CMDVERB,
"onex", CMDONEX,
"hops", CMDHOPS,
# ifdef DEBUG
"showq", CMDDBGQSHOW,
"debug", CMDDBGDEBUG,
"kill", CMDDBGKILL,
"wiz", CMDDBGWIZ,
"shell", CMDDBGSHELL,
# endif DEBUG
NULL, CMDERROR,
};
# ifdef DEBUG
bool IsWiz = FALSE; /* set if we are a wizard */
char *WizWord = NULL; /* the wizard word to compare against */
# endif DEBUG
bool InChild = FALSE; /* true if running in a subprocess */
bool OneXact = FALSE; /* one xaction only this run */
char *RealHostName = NULL; /* verified hostname, set in daemon.c */
#define EX_QUIT 22 /* special code for QUIT command */
smtp()
{
register char *p;
register struct cmd *c;
char *cmd;
extern char *skipword();
extern bool sameword();
bool hasmail; /* mail command received */
int rcps; /* number of recipients */
extern ADDRESS *sendto();
ADDRESS *a;
hasmail = FALSE;
rcps = 0;
if (OutChannel != stdout)
{
/* arrange for debugging output to go to remote host */
(void) close(1);
(void) dup(fileno(OutChannel));
}
expand("$e", inp, &inp[sizeof inp], CurEnv);
message("220", inp);
(void) setjmp(TopFrame);
QuickAbort = FALSE;
HoldErrs = FALSE;
for (;;)
{
/* setup for the read */
CurEnv->e_to = NULL;
Errors = 0;
(void) fflush(stdout);
/* read the input line */
p = sfgets(inp, sizeof inp, InChannel);
/* handle errors */
if (p == NULL)
{
/* end of file, just die */
message("421", "%s Lost input channel", HostName);
finis();
}
/* clean up end of line */
fixcrlf(inp, TRUE);
/* echo command to transcript */
if (CurEnv->e_xfp != NULL)
fprintf(CurEnv->e_xfp, "<<< %s\n", inp);
/* break off command */
for (p = inp; isspace(*p); p++)
continue;
cmd = p;
while (*++p != '\0' && !isspace(*p))
continue;
if (*p != '\0')
*p++ = '\0';
/* decode command */
for (c = CmdTab; c->cmdname != NULL; c++)
{
if (sameword(c->cmdname, cmd))
break;
}
/* process command */
switch (c->cmdcode)
{
case CMDHELO: /* hello -- introduce yourself */
if (RealHostName != NULL && !sameword(p, RealHostName))
{
char buf[MAXNAME];
(void) sprintf(buf, "%s (%s)", p, RealHostName);
define('s', newstr(buf), CurEnv);
}
else
define('s', newstr(p), CurEnv);
message("250", "%s Hello %s, pleased to meet you", HostName, p);
break;
case CMDMAIL: /* mail -- designate sender */
/* force a sending host even if no HELO given */
if (RealHostName != NULL && macvalue('s', CurEnv) == NULL)
define('s', RealHostName, CurEnv);
/* check for validity of this command */
if (hasmail)
{
message("503", "Sender already specified");
break;
}
if (InChild)
{
syserr("Nested MAIL command");
exit(0);
}
/* fork a subprocess to process this command */
if (runinchild("SMTP-MAIL") > 0)
break;
initsys();
/* child -- go do the processing */
p = skipword(p, "from");
if (p == NULL)
break;
setsender(p);
if (Errors == 0)
{
message("250", "Sender ok");
hasmail = TRUE;
}
else if (InChild)
finis();
break;
case CMDRCPT: /* rcpt -- designate recipient */
p = skipword(p, "to");
if (p == NULL)
break;
a = sendto(p, 1, (ADDRESS *) NULL, 0);
# ifdef DEBUG
if (Debug > 1)
printaddr(a, TRUE);
# endif DEBUG
if (Errors == 0)
{
message("250", "%s... Recipient ok", p);
rcps++;
}
break;
case CMDDATA: /* data -- text of mail */
if (!hasmail)
{
message("503", "Need MAIL command");
break;
}
else if (rcps <= 0)
{
message("503", "Need RCPT (recipient)");
break;
}
/* collect the text of the message */
collect(TRUE);
if (Errors != 0)
break;
/*
** Arrange to send to everyone.
** If sending to multiple people, mail back
** errors rather than reporting directly.
** In any case, don't mail back errors for
** anything that has happened up to
** now (the other end will do this).
** Truncate our transcript -- the mail has gotten
** to us successfully, and if we have
** to mail this back, it will be easier
** on the reader.
** Then send to everyone.
** Finally give a reply code. If an error has
** already been given, don't mail a
** message back.
** We goose error returns by clearing error bit.
*/
if (rcps != 1)
{
HoldErrs = TRUE;
ErrorMode == EM_MAIL;
}
CurEnv->e_flags &= ~EF_FATALERRS;
CurEnv->e_xfp = freopen(queuename(CurEnv, 'x'), "w", CurEnv->e_xfp);
/* send to all recipients */
sendall(CurEnv, SendMode);
CurEnv->e_to = NULL;
/* issue success if appropriate and reset */
if (Errors == 0 || HoldErrs)
message("250", "Ok");
else
CurEnv->e_flags &= ~EF_FATALERRS;
/* if in a child, pop back to our parent */
if (InChild)
finis();
break;
case CMDRSET: /* rset -- reset state */
message("250", "Reset state");
if (InChild)
finis();
break;
case CMDVRFY: /* vrfy -- verify address */
if (runinchild("SMTP-VRFY") > 0)
break;
paddrtree(a);
break;
case CMDHELP: /* help -- give user info */
if (*p == '\0')
p = "SMTP";
help(p);
break;
case CMDNOOP: /* noop -- do nothing */
message("200", "OK");
break;
case CMDQUIT: /* quit -- leave mail */
message("221", "%s closing connection", HostName);
if (InChild)
ExitStat = EX_QUIT;
finis();
case CMDVERB: /* set verbose mode */
Verbose = TRUE;
message("200", "Verbose mode");
break;
case CMDONEX: /* doing one transaction only */
OneXact = TRUE;
message("200", "Only one transaction");
break;
# ifdef DEBUG
case CMDDBGQSHOW: /* show queues */
printf("Send Queue=");
printaddr(CurEnv->e_sendqueue, TRUE);
break;
case CMDDBGDEBUG: /* set debug mode */
tTsetup(tTdvect, sizeof tTdvect, "0-99.1");
tTflag(p);
message("200", "Debug set");
break;
case CMDDBGKILL: /* kill the parent */
if (!iswiz())
break;
if (kill(MotherPid, SIGTERM) >= 0)
message("200", "Mother is dead");
else
message("500", "Can't kill Mom");
break;
case CMDDBGSHELL: /* give us an interactive shell */
if (!iswiz())
break;
if (fileno(InChannel) != 0)
{
(void) close(0);
(void) dup(fileno(InChannel));
if (fileno(InChannel) != fileno(OutChannel))
(void) fclose(InChannel);
InChannel = stdin;
}
if (fileno(OutChannel) != 1)
{
(void) close(1);
(void) dup(fileno(OutChannel));
(void) fclose(OutChannel);
OutChannel = stdout;
}
(void) close(2);
(void) dup(1);
execl("/bin/csh", "sendmail", 0);
execl("/bin/sh", "sendmail", 0);
message("500", "Can't");
exit(EX_UNAVAILABLE);
case CMDDBGWIZ: /* become a wizard */
if (WizWord != NULL)
{
char seed[3];
extern char *crypt();
strncpy(seed, WizWord, 2);
if (strcmp(WizWord, crypt(p, seed)) != 0)
{
message("500", "You are no wizard!");
break;
}
}
IsWiz = TRUE;
message("200", "Please pass, oh mighty wizard");
break;
# endif DEBUG
case CMDERROR: /* unknown command */
message("500", "Command unrecognized");
break;
default:
syserr("smtp: unknown code %d", c->cmdcode);
break;
}
}
}
\f/*
** SKIPWORD -- skip a fixed word.
**
** Parameters:
** p -- place to start looking.
** w -- word to skip.
**
** Returns:
** p following w.
** NULL on error.
**
** Side Effects:
** clobbers the p data area.
*/
static char *
skipword(p, w)
register char *p;
char *w;
{
register char *q;
extern bool sameword();
/* find beginning of word */
while (isspace(*p))
p++;
q = p;
/* find end of word */
while (*p != '\0' && *p != ':' && !isspace(*p))
p++;
while (isspace(*p))
*p++ = '\0';
if (*p != ':')
{
syntax:
message("501", "Syntax error");
Errors++;
return (NULL);
}
*p++ = '\0';
while (isspace(*p))
p++;
/* see if the input word matches desired word */
if (!sameword(q, w))
goto syntax;
return (p);
}
\f/*
** HELP -- implement the HELP command.
**
** Parameters:
** topic -- the topic we want help for.
**
** Returns:
** none.
**
** Side Effects:
** outputs the help file to message output.
*/
help(topic)
char *topic;
{
register FILE *hf;
int len;
char buf[MAXLINE];
bool noinfo;
if (HelpFile == NULL || (hf = fopen(HelpFile, "r")) == NULL)
{
/* no help */
message("502", "HELP not implemented");
return;
}
len = strlen(topic);
makelower(topic);
noinfo = TRUE;
while (fgets(buf, sizeof buf, hf) != NULL)
{
if (strncmp(buf, topic, len) == 0)
{
register char *p;
p = index(buf, '\t');
if (p == NULL)
p = buf;
else
p++;
fixcrlf(p, TRUE);
message("214-", p);
noinfo = FALSE;
}
}
if (noinfo)
message("504", "HELP topic unknown");
else
message("214", "End of HELP info");
(void) fclose(hf);
}
\f/*
** ISWIZ -- tell us if we are a wizard
**
** If not, print a nasty message.
**
** Parameters:
** none.
**
** Returns:
** TRUE if we are a wizard.
** FALSE if we are not a wizard.
**
** Side Effects:
** Prints a 500 exit stat if we are not a wizard.
*/
bool
iswiz()
{
if (!IsWiz)
message("500", "Mere mortals musn't mutter that mantra");
return (IsWiz);
}
\f/*
** RUNINCHILD -- return twice -- once in the child, then in the parent again
**
** Parameters:
** label -- a string used in error messages
**
** Returns:
** zero in the child
** one in the parent
**
** Side Effects:
** none.
*/
runinchild(label)
char *label;
{
int childpid;
if (OneXact)
return (0);
childpid = dofork();
if (childpid < 0)
{
syserr("%s: cannot fork", label);
return (1);
}
if (childpid > 0)
{
auto int st;
/* parent -- wait for child to complete */
st = waitfor(childpid);
if (st == -1)
syserr("%s: lost child", label);
/* if we exited on a QUIT command, complete the process */
if (st == (EX_QUIT << 8))
finis();
return (1);
}
else
{
/* child */
InChild = TRUE;
clearenvelope(CurEnv);
return (0);
}
}
\f/*
** PADDRTREE -- print address tree
**
** Used by VRFY and EXPD to dump the tree of addresses produced.
**
** Parameters:
** a -- address of root.
**
** Returns:
** none.
**
** Side Effects:
** prints the tree in a nice order.
*/
paddrtree(a)
register ADDRESS *a;
{
static ADDRESS *prev;
static int lev;
if (a == NULL)
return;
lev++;
if (!bitset(QDONTSEND, a->q_flags))
{
if (prev != NULL)
{
if (prev->q_fullname != NULL)
message("250-", "%s <%s>", prev->q_fullname, prev->q_paddr);
else
message("250-", "<%s>", prev->q_paddr);
}
prev = a;
}
paddrtree(a->q_child);
paddrtree(a->q_sibling);
if (--lev <= 0)
{
if (prev != NULL)
{
/* last one */
if (prev->q_fullname != NULL)
message("250", "%s <%s>", prev->q_fullname, prev->q_paddr);
else
message("250", "<%s>", prev->q_paddr);
prev = NULL;
}
else
message("550", "User unknown");
}
}
# endif SMTP
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.