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/*
* Copyright (c) 1989 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/
#include <errno.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
#include "popper.h"
#ifdef KERBEROS
#ifdef KRB4
#ifdef KRB5
#error you can only use one of KRB4, KRB5
#endif
#include <krb.h>
AUTH_DAT kdata;
#endif /* KRB4 */
#ifdef KRB5
#include "krb5.h"
#include "com_err.h"
#include <ctype.h>
krb5_principal ext_client;
krb5_context pop_context;
char *client_name;
#endif /* KRB5 */
#endif /* KERBEROS */
/*
* init: Start a Post Office Protocol session
*/
pop_init(p,argcount,argmessage)
POP * p;
int argcount;
char ** argmessage;
{
struct sockaddr_in cs; /* Communication parameters */
struct hostent * ch; /* Client host information */
int errflag = 0;
int c;
int len;
extern char * optarg;
int options = 0;
int sp = 0; /* Socket pointer */
char * trace_file_name;
int standalone = 0;
/* Initialize the POP parameter block */
memset ((char *)p, 0, (int)sizeof(POP));
/* Save my name in a global variable */
p->myname = argmessage[0];
/* Get the name of our host */
(void)gethostname(p->myhost,MAXHOSTNAMELEN);
/* Open the log file */
#ifdef SYSLOG42
(void)openlog(p->myname,0);
#else
(void)openlog(p->myname,POP_LOGOPTS,POP_FACILITY);
#endif
/* Process command line arguments */
while ((c = getopt(argcount,argmessage,"dt:s")) != EOF)
switch (c) {
/* Debugging requested */
case 'd':
p->debug++;
options |= SO_DEBUG;
break;
/* Debugging trace file specified */
case 't':
p->debug++;
if ((p->trace = fopen(optarg,"a+")) == NULL) {
pop_log(p,POP_PRIORITY,
"Unable to open trace file \"%s\", err = %d",
optarg,errno);
exit(-1);
}
trace_file_name = optarg;
break;
/* Standalone operation */
case 's':
standalone++;
break;
/* Unknown option received */
default:
errflag++;
}
/* Exit if bad options specified */
if (errflag) {
(void)fprintf(stderr,"Usage: %s [-d]\n",argmessage[0]);
exit(-1);
}
if (standalone) {
int acc, sock;
struct sockaddr_in sin;
struct servent *spr;
if ((sock = socket(PF_INET, SOCK_STREAM, 0)) < 0) {
syslog(LOG_ERR, "socket: %m");
exit(3);
}
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = 0;
#ifdef KERBEROS
#ifndef KPOP_SERVICE
#define KPOP_SERVICE "kpop"
#endif
if (!(spr = getservbyname(KPOP_SERVICE, "tcp"))) {
syslog(LOG_ERR, "%s/tcp: unknown service", KPOP_SERVICE);
exit(3);
}
#else
if (!(spr = getservbyname("pop", "tcp"))) {
syslog(LOG_ERR, "pop/tcp: unknown service");
exit(3);
}
#endif
sin.sin_port = spr->s_port;
if (bind(sock, (struct sockaddr *)&sin, sizeof(sin))) {
syslog(LOG_ERR, "bind: %m");
exit(3);
}
if (listen(sock, 1) == -1) {
syslog(LOG_ERR, "listen: %m");
exit(3);
}
len = sizeof(cs);
if ((acc = accept(sock, (struct sockaddr *)&cs, &len)) == -1) {
syslog(LOG_ERR, "accept: %m");
exit(3);
}
dup2(acc, sp);
close(sock);
close(acc);
}
/* Get the address and socket of the client to whom I am speaking */
len = sizeof(cs);
if (getpeername(sp,(struct sockaddr *)&cs,&len) < 0){
pop_log(p,POP_PRIORITY,
"Unable to obtain socket and address of client, err = %d",errno);
exit(-1);
}
/* Save the dotted decimal form of the client's IP address
in the POP parameter block */
p->ipaddr = inet_ntoa(cs.sin_addr);
/* Save the client's port */
p->ipport = ntohs(cs.sin_port);
/* Get the canonical name of the host to whom I am speaking */
ch = gethostbyaddr((char *) &cs.sin_addr, sizeof(cs.sin_addr), AF_INET);
if (ch == NULL){
pop_log(p,POP_PRIORITY,
"Unable to get canonical name of client, err = %d",errno);
p->client = p->ipaddr;
}
/* Save the cannonical name of the client host in
the POP parameter block */
else {
#ifndef BIND43
p->client = (char *) ch->h_name;
#else
# include <arpa/nameser.h>
# include <resolv.h>
/* Distrust distant nameservers */
#if (__RES < 19931104)
extern struct state _res;
#endif
struct hostent * ch_again;
char * * addrp;
/* We already have a fully-qualified name */
_res.options &= ~RES_DEFNAMES;
/* See if the name obtained for the client's IP
address returns an address */
if ((ch_again = gethostbyname(ch->h_name)) == NULL) {
pop_log(p,POP_PRIORITY,
"Client at \"%s\" resolves to an unknown host name \"%s\"",
p->ipaddr,ch->h_name);
p->client = p->ipaddr;
}
else {
/* Save the host name (the previous value was
destroyed by gethostbyname) */
p->client = ch_again->h_name;
/* Look for the client's IP address in the list returned
for its name */
for (addrp=ch_again->h_addr_list; *addrp; ++addrp)
if (memcmp(*addrp,&(cs.sin_addr),sizeof(cs.sin_addr)) == 0) break;
if (!*addrp) {
pop_log (p,POP_PRIORITY,
"Client address \"%s\" not listed for its host name \"%s\"",
p->ipaddr,ch->h_name);
p->client = p->ipaddr;
}
}
#endif
}
/* Create input file stream for TCP/IP communication */
if ((p->input = fdopen(sp,"r")) == NULL){
pop_log(p,POP_PRIORITY,
"Unable to open communication stream for input, err = %d",errno);
exit (-1);
}
/* Create output file stream for TCP/IP communication */
if ((p->output = fdopen(sp,"w")) == NULL){
pop_log(p,POP_PRIORITY,
"Unable to open communication stream for output, err = %d",errno);
exit (-1);
}
pop_log(p,POP_PRIORITY,
"(v%s) Servicing request from \"%s\" at %s\n",
VERSION,p->client,p->ipaddr);
#ifdef DEBUG
if (p->trace)
pop_log(p,POP_PRIORITY,
"Tracing session and debugging information in file \"%s\"",
trace_file_name);
else if (p->debug)
pop_log(p,POP_PRIORITY,"Debugging turned on");
#endif
return(authenticate(p, &cs));
}
authenticate(p, addr)
POP *p;
struct sockaddr_in *addr;
{
#ifdef KERBEROS
#ifdef KRB4
Key_schedule schedule;
KTEXT_ST ticket;
char instance[INST_SZ];
char version[9];
int auth;
strcpy(instance, "*");
auth = krb_recvauth(0L, 0, &ticket, "pop", instance,
addr, (struct sockaddr_in *) NULL,
&kdata, "", schedule, version);
if (auth != KSUCCESS) {
pop_msg(p, POP_FAILURE, "Kerberos authentication failure: %s",
krb_err_txt[auth]);
pop_log(p, POP_WARNING, "%s: (%s.%s@%s) %s", p->client,
kdata.pname, kdata.pinst, kdata.prealm, krb_err_txt[auth]);
exit(-1);
}
#ifdef DEBUG
pop_log(p, POP_DEBUG, "%s.%s@%s (%s): ok", kdata.pname,
kdata.pinst, kdata.prealm, inet_ntoa(addr->sin_addr));
#endif /* DEBUG */
strcpy(p->user, kdata.pname);
#endif
#ifdef KRB5
krb5_auth_context * auth_context = NULL;
krb5_error_code retval;
krb5_principal server;
int sock = 0;
krb5_init_context(&pop_context);
krb5_init_ets(pop_context);
if (retval = krb5_sname_to_principal(pop_context, p->myhost, "pop",
KRB5_NT_SRV_HST, &server)) {
pop_msg(p, POP_FAILURE,
"server '%s' mis-configured, can't get principal--%s",
p->myhost, error_message(retval));
pop_log(p, POP_WARNING, "%s: mis-configured, can't get principal--%s",
p->client, error_message(retval));
exit(-1);
}
if (retval = krb5_recvauth(pop_context, &auth_context, (krb5_pointer)&sock,
"KPOPV1.0", server,
0, /* no flags */
NULL, /* default keytab */
NULL /* don't care about ticket */
)) {
pop_msg(p, POP_FAILURE, "recvauth failed--%s", error_message(retval));
pop_log(p, POP_WARNING, "%s: recvauth failed--%s",
p->client, error_message(retval));
exit(-1);
}
krb5_free_principal(pop_context, server);
krb5_auth_con_free(pop_context, auth_context);
if (retval = krb5_unparse_name(pop_context, ext_client, &client_name)) {
pop_msg(p, POP_FAILURE, "name not parsable--%s",
error_message(retval));
pop_log(p, POP_DEBUG, "name not parsable (%s)",
inet_ntoa(addr->sin_addr));
exit(-1);
}
#ifdef DEBUG
pop_log(p, POP_DEBUG, "%s (%s): ok", client_name, inet_ntoa(addr->sin_addr));
#endif /* DEBUG */
if (retval= krb5_aname_to_localname(pop_context, ext_client,
sizeof(p->user), p->user)) {
pop_msg(p, POP_FAILURE, "unable to convert aname(%s) to localname --%s",
client_name,
error_message(retval));
pop_log(p, POP_DEBUG, "unable to convert aname to localname (%s)",
client_name);
exit(-1);
}
#endif /* KRB5 */
#endif /* KERBEROS */
return(POP_SUCCESS);
}
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