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sendto_kdc.c
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sendto_kdc.c
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/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* lib/krb5/os/sendto_kdc.c */
/*
* Copyright 1990,1991,2001,2002,2004,2005,2007,2008 by the Massachusetts Institute of Technology.
* All Rights Reserved.
*
* Export of this software from the United States of America may
* require a specific license from the United States Government.
* It is the responsibility of any person or organization contemplating
* export to obtain such a license before exporting.
*
* WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
* distribute this software and its documentation for any purpose and
* without fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright notice and
* this permission notice appear in supporting documentation, and that
* the name of M.I.T. not be used in advertising or publicity pertaining
* to distribution of the software without specific, written prior
* permission. Furthermore if you modify this software you must label
* your software as modified software and not distribute it in such a
* fashion that it might be confused with the original M.I.T. software.
* M.I.T. makes no representations about the suitability of
* this software for any purpose. It is provided "as is" without express
* or implied warranty.
*/
/* Send packet to KDC for realm; wait for response, retransmitting
* as necessary. */
#include "fake-addrinfo.h"
#include "k5-int.h"
#include "os-proto.h"
#ifdef _WIN32
#include <sys/timeb.h>
#endif
#if defined(HAVE_POLL_H)
#include <poll.h>
#define USE_POLL
#define MAX_POLLFDS 1024
#elif defined(HAVE_SYS_SELECT_H)
#include <sys/select.h>
#endif
#ifndef _WIN32
/* For FIONBIO. */
#include <sys/ioctl.h>
#ifdef HAVE_SYS_FILIO_H
#include <sys/filio.h>
#endif
#endif
#ifdef KRB5_KRBLDAP
#include <lber.h>
#include <ldap.h>
#endif
#define MAX_PASS 3
#define DEFAULT_UDP_PREF_LIMIT 1465
#define HARD_UDP_LIMIT 32700 /* could probably do 64K-epsilon ? */
#undef DEBUG
#ifdef DEBUG
int krb5int_debug_sendto_kdc = 0;
#define debug krb5int_debug_sendto_kdc
static void
default_debug_handler (const void *data, size_t len)
{
#if 0
static FILE *logfile;
if (logfile == NULL) {
logfile = fopen("/tmp/sendto_kdc.log", "a");
if (logfile == NULL)
return;
setbuf(logfile, NULL);
}
fwrite(data, 1, len, logfile);
#else
fwrite(data, 1, len, stderr);
/* stderr is unbuffered */
#endif
}
void (*krb5int_sendtokdc_debug_handler) (const void *, size_t) = default_debug_handler;
static void
put(const void *ptr, size_t len)
{
(*krb5int_sendtokdc_debug_handler)(ptr, len);
}
static void
putstr(const char *str)
{
put(str, strlen(str));
}
#else
void (*krb5int_sendtokdc_debug_handler) (const void *, size_t) = 0;
#endif
#define dprint krb5int_debug_fprint
void
krb5int_debug_fprint (const char *fmt, ...)
{
#ifdef DEBUG
va_list args;
/* Temporaries for variable arguments, etc. */
krb5_error_code kerr;
int err;
fd_set *rfds, *wfds, *xfds;
int i;
int maxfd;
struct timeval *tv;
struct addrinfo *ai;
const krb5_data *d;
char addrbuf[NI_MAXHOST], portbuf[NI_MAXSERV];
const char *p;
#ifndef max
#define max(a,b) ((a) > (b) ? (a) : (b))
#endif
char tmpbuf[max(NI_MAXHOST + NI_MAXSERV + 30, 200)];
struct k5buf buf;
if (!krb5int_debug_sendto_kdc)
return;
va_start(args, fmt);
#define putf(FMT,X) (snprintf(tmpbuf,sizeof(tmpbuf),FMT,X),putstr(tmpbuf))
for (; *fmt; fmt++) {
if (*fmt != '%') {
const char *fmt2;
size_t len;
for (fmt2 = fmt+1; *fmt2; fmt2++)
if (*fmt2 == '%')
break;
len = fmt2 - fmt;
put(fmt, len);
fmt += len - 1; /* then fmt++ in loop header */
continue;
}
/* After this, always processing a '%' sequence. */
fmt++;
switch (*fmt) {
case 0:
default:
abort();
case 'E':
/* %E => krb5_error_code */
kerr = va_arg(args, krb5_error_code);
snprintf(tmpbuf, sizeof(tmpbuf), "%lu/", (unsigned long) kerr);
putstr(tmpbuf);
p = error_message(kerr);
putstr(p);
break;
case 'm':
/* %m => errno value (int) */
/* Like syslog's %m except the errno value is passed in
rather than the current value. */
err = va_arg(args, int);
putf("%d/", err);
p = NULL;
#ifdef HAVE_STRERROR_R
if (strerror_r(err, tmpbuf, sizeof(tmpbuf)) == 0)
p = tmpbuf;
#endif
if (p == NULL)
p = strerror(err);
putstr(p);
break;
case 's':
/* %s => char * */
p = va_arg(args, const char *);
putstr(p);
break;
case 't':
/* %t => struct timeval * */
tv = va_arg(args, struct timeval *);
if (tv) {
snprintf(tmpbuf, sizeof(tmpbuf), "%ld.%06ld",
(long) tv->tv_sec, (long) tv->tv_usec);
putstr(tmpbuf);
} else
putstr("never");
break;
case 'd':
/* %d => int */
putf("%d", va_arg(args, int));
break;
case 'p':
/* %p => pointer */
putf("%p", va_arg(args, void*));
break;
case 'A':
/* %A => addrinfo */
ai = va_arg(args, struct addrinfo *);
krb5int_buf_init_dynamic(&buf);
if (ai->ai_socktype == SOCK_DGRAM)
krb5int_buf_add(&buf, "dgram");
else if (ai->ai_socktype == SOCK_STREAM)
krb5int_buf_add(&buf, "stream");
else
krb5int_buf_add_fmt(&buf, "socktype%d", ai->ai_socktype);
if (0 != getnameinfo (ai->ai_addr, ai->ai_addrlen,
addrbuf, sizeof (addrbuf),
portbuf, sizeof (portbuf),
NI_NUMERICHOST | NI_NUMERICSERV)) {
if (ai->ai_addr->sa_family == AF_UNSPEC)
krb5int_buf_add(&buf, " AF_UNSPEC");
else
krb5int_buf_add_fmt(&buf, " af%d", ai->ai_addr->sa_family);
} else
krb5int_buf_add_fmt(&buf, " %s.%s", addrbuf, portbuf);
if (krb5int_buf_data(&buf))
putstr(krb5int_buf_data(&buf));
krb5int_free_buf(&buf);
break;
case 'D':
/* %D => krb5_data * */
d = va_arg(args, krb5_data *);
/* may not be nul-terminated */
put(d->data, d->length);
break;
}
}
va_end(args);
#endif
}
static int
in_addrlist(struct server_entry *entry, struct serverlist *list)
{
size_t i;
struct server_entry *le;
for (i = 0; i < list->nservers; i++) {
le = &list->servers[i];
if (entry->hostname != NULL && le->hostname != NULL &&
strcmp(entry->hostname, le->hostname) == 0)
return 1;
if (entry->hostname == NULL && le->hostname == NULL &&
entry->addrlen == le->addrlen &&
memcmp(&entry->addr, &le->addr, entry->addrlen) == 0)
return 1;
}
return 0;
}
static int
check_for_svc_unavailable (krb5_context context,
const krb5_data *reply,
void *msg_handler_data)
{
krb5_error_code *retval = (krb5_error_code *)msg_handler_data;
*retval = 0;
if (krb5_is_krb_error(reply)) {
krb5_error *err_reply;
if (decode_krb5_error(reply, &err_reply) == 0) {
*retval = err_reply->error;
krb5_free_error(context, err_reply);
/* Returning 0 means continue to next KDC */
return (*retval != KDC_ERR_SVC_UNAVAILABLE);
}
}
return 1;
}
/*
* send the formatted request 'message' to a KDC for realm 'realm' and
* return the response (if any) in 'reply'.
*
* If the message is sent and a response is received, 0 is returned,
* otherwise an error code is returned.
*
* The storage for 'reply' is allocated and should be freed by the caller
* when finished.
*/
krb5_error_code
krb5_sendto_kdc(krb5_context context, const krb5_data *message,
const krb5_data *realm, krb5_data *reply, int *use_master,
int tcp_only)
{
krb5_error_code retval, err;
struct serverlist servers;
int socktype1 = 0, socktype2 = 0, server_used;
/*
* find KDC location(s) for realm
*/
/*
* BUG: This code won't return "interesting" errors (e.g., out of mem,
* bad config file) from locate_kdc. KRB5_REALM_CANT_RESOLVE can be
* ignored from one query of two, but if only one query is done, or
* both return that error, it should be returned to the caller. Also,
* "interesting" errors (not KRB5_KDC_UNREACH) from sendto_{udp,tcp}
* should probably be returned as well.
*/
dprint("krb5_sendto_kdc(%d@%p, \"%D\", use_master=%d, tcp_only=%d)\n",
message->length, message->data, realm, *use_master, tcp_only);
TRACE_SENDTO_KDC(context, message->length, realm, *use_master, tcp_only);
if (!tcp_only && context->udp_pref_limit < 0) {
int tmp;
retval = profile_get_integer(context->profile,
KRB5_CONF_LIBDEFAULTS, KRB5_CONF_UDP_PREFERENCE_LIMIT, 0,
DEFAULT_UDP_PREF_LIMIT, &tmp);
if (retval)
return retval;
if (tmp < 0)
tmp = DEFAULT_UDP_PREF_LIMIT;
else if (tmp > HARD_UDP_LIMIT)
/* In the unlikely case that a *really* big value is
given, let 'em use as big as we think we can
support. */
tmp = HARD_UDP_LIMIT;
context->udp_pref_limit = tmp;
}
if (tcp_only)
socktype1 = SOCK_STREAM, socktype2 = 0;
else if (message->length <= (unsigned int) context->udp_pref_limit)
socktype1 = SOCK_DGRAM, socktype2 = SOCK_STREAM;
else
socktype1 = SOCK_STREAM, socktype2 = SOCK_DGRAM;
retval = k5_locate_kdc(context, realm, &servers, *use_master,
tcp_only ? SOCK_STREAM : 0);
if (retval)
return retval;
#ifdef KRB5_KRBLDAP
dprint("using krbldap protocol to send kerberos message.");
retval = krbldap_sendto(context, message, &servers, socktype1, socktype2,
NULL, reply, NULL, NULL, &server_used,
check_for_svc_unavailable, &err);
#else
dprint("using kerberos v5 protocol to send kerberos message.");
retval = k5_sendto(context, message, &servers, socktype1, socktype2,
NULL, reply, NULL, NULL, &server_used,
check_for_svc_unavailable, &err);
#endif
if (retval == KRB5_KDC_UNREACH) {
if (err == KDC_ERR_SVC_UNAVAILABLE) {
retval = KRB5KDC_ERR_SVC_UNAVAILABLE;
} else {
krb5_set_error_message(context, retval,
_("Cannot contact any KDC for realm "
"'%.*s'"), realm->length, realm->data);
}
}
if (retval)
goto cleanup;
/* Set use_master to 1 if we ended up talking to a master when we didn't
* explicitly request to. */
if (*use_master == 0) {
struct serverlist mservers;
struct server_entry *entry = &servers.servers[server_used];
retval = k5_locate_kdc(context, realm, &mservers, TRUE,
entry->socktype);
if (retval == 0) {
if (in_addrlist(entry, &mservers))
*use_master = 1;
k5_free_serverlist(&mservers);
}
TRACE_SENDTO_KDC_MASTER(context, *use_master);
retval = 0;
}
cleanup:
k5_free_serverlist(&servers);
return retval;
}
#ifdef DEBUG
#ifdef _WIN32
#define dperror(MSG) \
dprint("%s: an error occurred ... " \
"\tline=%d errno=%m socketerrno=%m\n", \
(MSG), __LINE__, errno, SOCKET_ERRNO)
#else
#define dperror(MSG) dprint("%s: %m\n", MSG, errno)
#endif
#define dfprintf(ARGLIST) (debug ? fprintf ARGLIST : 0)
#else /* ! DEBUG */
#define dperror(MSG) ((void)(MSG))
#define dfprintf(ARGLIST) ((void)0)
#endif
/*
* Notes:
*
* Getting "connection refused" on a connected UDP socket causes
* select to indicate write capability on UNIX, but only shows up
* as an exception on Windows. (I don't think any UNIX system flags
* the error as an exception.) So we check for both, or make it
* system-specific.
*
* Always watch for responses from *any* of the servers. Eventually
* fix the UDP code to do the same.
*
* To do:
* - TCP NOPUSH/CORK socket options?
* - error codes that don't suck
* - getsockopt(SO_ERROR) to check connect status
* - handle error RESPONSE_TOO_BIG from UDP server and use TCP
* connections already in progress
*/
#include "cm.h"
/*
* Currently only sendto_kdc.c knows how to use poll(); the other candidate
* user, lib/apputils/net-server.c, is stuck using select() for the moment
* since it is entangled with the RPC library. The following cm_* functions
* are not fully generic, are O(n^2) in the poll case, and are limited to
* handling 1024 connections (in order to maintain a constant-sized selstate).
* More rearchitecting would be appropriate before extending this support to
* the KDC and kadmind.
*/
static void
cm_init_selstate(struct select_state *selstate)
{
selstate->nfds = 0;
selstate->end_time.tv_sec = selstate->end_time.tv_usec = 0;
#ifndef USE_POLL
selstate->max = 0;
FD_ZERO(&selstate->rfds);
FD_ZERO(&selstate->wfds);
FD_ZERO(&selstate->xfds);
#endif
}
static krb5_boolean
cm_add_fd(struct select_state *selstate, int fd, unsigned int ssflags)
{
#ifdef USE_POLL
if (selstate->nfds >= MAX_POLLFDS)
return FALSE;
selstate->fds[selstate->nfds].fd = fd;
selstate->fds[selstate->nfds].events = 0;
if (ssflags & SSF_READ)
selstate->fds[selstate->nfds].events |= POLLIN;
if (ssflags & SSF_WRITE)
selstate->fds[selstate->nfds].events |= POLLOUT;
#else
#ifndef _WIN32 /* On Windows FD_SETSIZE is a count, not a max value. */
if (fd >= FD_SETSIZE)
return FALSE;
#endif
if (ssflags & SSF_READ)
FD_SET(fd, &selstate->rfds);
if (ssflags & SSF_WRITE)
FD_SET(fd, &selstate->wfds);
if (ssflags & SSF_EXCEPTION)
FD_SET(fd, &selstate->xfds);
if (selstate->max <= fd)
selstate->max = fd + 1;
#endif
selstate->nfds++;
return TRUE;
}
static void
cm_remove_fd(struct select_state *selstate, int fd)
{
#ifdef USE_POLL
int i;
/* Find the FD in the array and move the last entry to its place. */
assert(selstate->nfds > 0);
for (i = 0; i < selstate->nfds && selstate->fds[i].fd != fd; i++);
assert(i < selstate->nfds);
selstate->fds[i] = selstate->fds[selstate->nfds - 1];
#else
FD_CLR(fd, &selstate->rfds);
FD_CLR(fd, &selstate->wfds);
FD_CLR(fd, &selstate->xfds);
if (selstate->max == 1 + fd) {
while (selstate->max > 0
&& ! FD_ISSET(selstate->max-1, &selstate->rfds)
&& ! FD_ISSET(selstate->max-1, &selstate->wfds)
&& ! FD_ISSET(selstate->max-1, &selstate->xfds))
selstate->max--;
dprint("new max_fd + 1 is %d\n", selstate->max);
}
#endif
selstate->nfds--;
}
static void
cm_unset_write(struct select_state *selstate, int fd)
{
#ifdef USE_POLL
int i;
for (i = 0; i < selstate->nfds && selstate->fds[i].fd != fd; i++);
assert(i < selstate->nfds);
selstate->fds[i].events &= ~POLLOUT;
#else
FD_CLR(fd, &selstate->wfds);
#endif
}
static krb5_error_code
cm_select_or_poll(const struct select_state *in, struct select_state *out,
int *sret)
{
#ifdef USE_POLL
struct timeval now;
int e, timeout;
if (in->end_time.tv_sec == 0)
timeout = -1;
else {
e = k5_getcurtime(&now);
if (e)
return e;
timeout = (in->end_time.tv_sec - now.tv_sec) * 1000 +
(in->end_time.tv_usec - now.tv_usec) / 1000;
}
/* We don't need a separate copy of the selstate for poll, but use one
* anyone for consistency with the select wrapper. */
*out = *in;
*sret = poll(out->fds, out->nfds, timeout);
e = SOCKET_ERRNO;
return (*sret < 0) ? e : 0;
#else
/* Use the select wrapper from cm.c. */
return krb5int_cm_call_select(in, out, sret);
#endif
}
static unsigned int
cm_get_ssflags(struct select_state *selstate, int fd)
{
unsigned int ssflags = 0;
#ifdef USE_POLL
int i;
for (i = 0; i < selstate->nfds && selstate->fds[i].fd != fd; i++);
assert(i < selstate->nfds);
if (selstate->fds[i].revents & POLLIN)
ssflags |= SSF_READ;
if (selstate->fds[i].revents & POLLOUT)
ssflags |= SSF_WRITE;
if (selstate->fds[i].revents & POLLERR)
ssflags |= SSF_EXCEPTION;
#else
if (FD_ISSET(fd, &selstate->rfds))
ssflags |= SSF_READ;
if (FD_ISSET(fd, &selstate->wfds))
ssflags |= SSF_WRITE;
if (FD_ISSET(fd, &selstate->xfds))
ssflags |= SSF_EXCEPTION;
#endif
return ssflags;
}
static int service_tcp_fd(krb5_context context, struct conn_state *conn,
struct select_state *selstate, int ssflags);
static int service_udp_fd(krb5_context context, struct conn_state *conn,
struct select_state *selstate, int ssflags);
static void
set_conn_state_msg_length (struct conn_state *state, const krb5_data *message)
{
if (!message || message->length == 0)
return;
if (!state->is_udp) {
store_32_be(message->length, state->x.out.msg_len_buf);
SG_SET(&state->x.out.sgbuf[0], state->x.out.msg_len_buf, 4);
SG_SET(&state->x.out.sgbuf[1], message->data, message->length);
state->x.out.sg_count = 2;
} else {
SG_SET(&state->x.out.sgbuf[0], message->data, message->length);
SG_SET(&state->x.out.sgbuf[1], 0, 0);
state->x.out.sg_count = 1;
}
}
static krb5_error_code
add_connection(struct conn_state **conns, struct addrinfo *ai,
size_t server_index, const krb5_data *message, char **udpbufp)
{
struct conn_state *state, **tailptr;
state = calloc(1, sizeof(*state));
if (state == NULL)
return ENOMEM;
state->state = INITIALIZING;
state->err = 0;
state->x.out.sgp = state->x.out.sgbuf;
state->socktype = ai->ai_socktype;
state->family = ai->ai_family;
state->addrlen = ai->ai_addrlen;
memcpy(&state->addr, ai->ai_addr, ai->ai_addrlen);
state->fd = INVALID_SOCKET;
state->server_index = server_index;
SG_SET(&state->x.out.sgbuf[1], 0, 0);
if (ai->ai_socktype == SOCK_STREAM) {
/*
SG_SET(&state->x.out.sgbuf[0], message_len_buf, 4);
SG_SET(&state->x.out.sgbuf[1], message->data, message->length);
state->x.out.sg_count = 2;
*/
state->is_udp = 0;
state->service = service_tcp_fd;
set_conn_state_msg_length (state, message);
} else {
/*
SG_SET(&state->x.out.sgbuf[0], message->data, message->length);
SG_SET(&state->x.out.sgbuf[1], 0, 0);
state->x.out.sg_count = 1;
*/
state->is_udp = 1;
state->service = service_udp_fd;
set_conn_state_msg_length (state, message);
if (*udpbufp == NULL) {
*udpbufp = malloc(krb5_max_dgram_size);
if (*udpbufp == 0)
return ENOMEM;
}
state->x.in.buf = *udpbufp;
state->x.in.bufsize = krb5_max_dgram_size;
}
/* Chain the new state onto the tail of the list. */
for (tailptr = conns; *tailptr != NULL; tailptr = &(*tailptr)->next);
*tailptr = state;
return 0;
}
static int
translate_ai_error (int err)
{
switch (err) {
case 0:
return 0;
case EAI_BADFLAGS:
case EAI_FAMILY:
case EAI_SOCKTYPE:
case EAI_SERVICE:
/* All of these indicate bad inputs to getaddrinfo. */
return EINVAL;
case EAI_AGAIN:
/* Translate to standard errno code. */
return EAGAIN;
case EAI_MEMORY:
/* Translate to standard errno code. */
return ENOMEM;
#ifdef EAI_ADDRFAMILY
case EAI_ADDRFAMILY:
#endif
#if defined(EAI_NODATA) && EAI_NODATA != EAI_NONAME
case EAI_NODATA:
#endif
case EAI_NONAME:
/* Name not known or no address data, but no error. Do
nothing more. */
return 0;
#ifdef EAI_OVERFLOW
case EAI_OVERFLOW:
/* An argument buffer overflowed. */
return EINVAL; /* XXX */
#endif
#ifdef EAI_SYSTEM
case EAI_SYSTEM:
/* System error, obviously. */
return errno;
#endif
default:
/* An error code we haven't handled? */
return EINVAL;
}
}
/*
* Resolve the entry in servers with index ind, adding connections to the list
* *conns. Connections are added for each of socktype1 and (if not zero)
* socktype2. message and udpbufp are used to initialize the connections; see
* add_connection above. If no addresses are available for an entry but no
* internal name resolution failure occurs, return 0 without adding any new
* connections.
*/
static krb5_error_code
resolve_server(krb5_context context, const struct serverlist *servers,
size_t ind, int socktype1, int socktype2,
const krb5_data *message, char **udpbufp,
struct conn_state **conns)
{
krb5_error_code retval;
struct server_entry *entry = &servers->servers[ind];
struct addrinfo *addrs, *a, hint, ai;
int err, result;
char portbuf[64];
/* Skip any stray entries of socktypes we don't want. */
if (entry->socktype != 0 && entry->socktype != socktype1 &&
entry->socktype != socktype2)
return 0;
if (entry->hostname == NULL) {
ai.ai_socktype = entry->socktype;
ai.ai_family = entry->family;
ai.ai_addrlen = entry->addrlen;
ai.ai_addr = (struct sockaddr *)&entry->addr;
return add_connection(conns, &ai, ind, message, udpbufp);
}
memset(&hint, 0, sizeof(hint));
hint.ai_family = entry->family;
hint.ai_socktype = (entry->socktype != 0) ? entry->socktype : socktype1;
hint.ai_flags = AI_ADDRCONFIG;
#ifdef AI_NUMERICSERV
hint.ai_flags |= AI_NUMERICSERV;
#endif
result = snprintf(portbuf, sizeof(portbuf), "%d", ntohs(entry->port));
if (SNPRINTF_OVERFLOW(result, sizeof(portbuf)))
return EINVAL;
TRACE_SENDTO_KDC_RESOLVING(context, entry->hostname);
err = getaddrinfo(entry->hostname, portbuf, &hint, &addrs);
if (err)
return translate_ai_error(err);
/* Add each address with the preferred socktype. */
retval = 0;
for (a = addrs; a != 0 && retval == 0; a = a->ai_next)
retval = add_connection(conns, a, ind, message, udpbufp);
if (retval == 0 && entry->socktype == 0 && socktype2 != 0) {
/* Add each address again with the non-preferred socktype. */
for (a = addrs; a != 0 && retval == 0; a = a->ai_next) {
a->ai_socktype = socktype2;
retval = add_connection(conns, a, ind, message, udpbufp);
}
}
freeaddrinfo(addrs);
return retval;
}
static int
start_connection(krb5_context context, struct conn_state *state,
struct select_state *selstate,
struct sendto_callback_info *callback_info)
{
int fd, e;
unsigned int ssflags;
static const int one = 1;
static const struct linger lopt = { 0, 0 };
dprint("start_connection(@%p)\ngetting %s socket in family %d...", state,
state->socktype == SOCK_STREAM ? "stream" : "dgram", state->family);
fd = socket(state->family, state->socktype, 0);
if (fd == INVALID_SOCKET) {
state->err = SOCKET_ERRNO;
dprint("socket: %m creating with af %d\n", state->err, state->family);
return -1; /* try other hosts */
}
set_cloexec_fd(fd);
/* Make it non-blocking. */
if (ioctlsocket(fd, FIONBIO, (const void *) &one))
dperror("sendto_kdc: ioctl(FIONBIO)");
if (state->socktype == SOCK_STREAM) {
if (setsockopt(fd, SOL_SOCKET, SO_LINGER, &lopt, sizeof(lopt)))
dperror("sendto_kdc: setsockopt(SO_LINGER)");
TRACE_SENDTO_KDC_TCP_CONNECT(context, state);
}
/* Start connecting to KDC. */
e = connect(fd, (struct sockaddr *)&state->addr, state->addrlen);
if (e != 0) {
/*
* This is the path that should be followed for non-blocking
* connections.
*/
if (SOCKET_ERRNO == EINPROGRESS || SOCKET_ERRNO == EWOULDBLOCK) {
state->state = CONNECTING;
state->fd = fd;
} else {
dprint("connect failed: %m\n", SOCKET_ERRNO);
(void) closesocket(fd);
state->err = SOCKET_ERRNO;
state->state = FAILED;
return -2;
}
} else {
/*
* Connect returned zero even though we made it non-blocking. This
* happens normally for UDP sockets, and can perhaps also happen for
* TCP sockets connecting to localhost.
*/
state->state = WRITING;
state->fd = fd;
}
dprint("new state = %s\n", state_strings[state->state]);
/*
* Here's where KPASSWD callback gets the socket information it needs for
* a kpasswd request
*/
if (callback_info) {
e = callback_info->pfn_callback(state, callback_info->context,
&state->callback_buffer);
if (e != 0) {
dprint("callback failed: %m\n", e);
(void) closesocket(fd);
state->err = e;
state->fd = INVALID_SOCKET;
state->state = FAILED;
return -3;
}
set_conn_state_msg_length(state, &state->callback_buffer);
}
if (state->socktype == SOCK_DGRAM) {
/* Send it now. */
ssize_t ret;
sg_buf *sg = &state->x.out.sgbuf[0];
TRACE_SENDTO_KDC_UDP_SEND_INITIAL(context, state);
dprint("sending %d bytes on fd %d\n", SG_LEN(sg), state->fd);
ret = send(state->fd, SG_BUF(sg), SG_LEN(sg), 0);
if (ret < 0 || (size_t) ret != SG_LEN(sg)) {
TRACE_SENDTO_KDC_UDP_ERROR_SEND_INITIAL(context, state,
SOCKET_ERRNO);
dperror("sendto");
(void) closesocket(state->fd);
state->fd = INVALID_SOCKET;
state->state = FAILED;
return -4;
} else {
state->state = READING;
}
}
ssflags = SSF_READ | SSF_EXCEPTION;
if (state->state == CONNECTING || state->state == WRITING)
ssflags |= SSF_WRITE;
if (!cm_add_fd(selstate, state->fd, ssflags)) {
(void) closesocket(state->fd);
state->fd = INVALID_SOCKET;
state->state = FAILED;
return -1;
}
return 0;
}
/* Return 0 if we sent something, non-0 otherwise.
If 0 is returned, the caller should delay waiting for a response.
Otherwise, the caller should immediately move on to process the
next connection. */
static int
maybe_send(krb5_context context, struct conn_state *conn,
struct select_state *selstate,
struct sendto_callback_info *callback_info)
{
sg_buf *sg;
ssize_t ret;
dprint("maybe_send(@%p) state=%s type=%s\n", conn,
state_strings[conn->state],
conn->is_udp ? "udp" : "tcp");
if (conn->state == INITIALIZING)
return start_connection(context, conn, selstate, callback_info);
/* Did we already shut down this channel? */
if (conn->state == FAILED) {
dprint("connection already closed\n");
return -1;
}
if (conn->socktype == SOCK_STREAM) {
dprint("skipping stream socket\n");
/* The select callback will handle flushing any data we
haven't written yet, and we only write it once. */
return -1;
}
/* UDP - retransmit after a previous attempt timed out. */
sg = &conn->x.out.sgbuf[0];
TRACE_SENDTO_KDC_UDP_SEND_RETRY(context, conn);
dprint("sending %d bytes on fd %d\n", SG_LEN(sg), conn->fd);
ret = send(conn->fd, SG_BUF(sg), SG_LEN(sg), 0);
if (ret < 0 || (size_t) ret != SG_LEN(sg)) {
TRACE_SENDTO_KDC_UDP_ERROR_SEND_RETRY(context, conn, SOCKET_ERRNO);
dperror("send");
/* Keep connection alive, we'll try again next pass.
Is this likely to catch any errors we didn't get from the
select callbacks? */
return -1;
}
/* Yay, it worked. */
return 0;
}
static void
kill_conn(struct conn_state *conn, struct select_state *selstate, int err)
{
dprint("abandoning connection %d: %m\n", conn->fd, err);
cm_remove_fd(selstate, conn->fd);
closesocket(conn->fd);
conn->fd = INVALID_SOCKET;
conn->state = FAILED;
conn->err = err;
}
/* Check socket for error. */
static int
get_so_error(int fd)
{
int e, sockerr;
socklen_t sockerrlen;
sockerr = 0;
sockerrlen = sizeof(sockerr);
e = getsockopt(fd, SOL_SOCKET, SO_ERROR, &sockerr, &sockerrlen);
if (e != 0) {
/* What to do now? */
e = SOCKET_ERRNO;
dprint("getsockopt(SO_ERROR) on fd failed: %m\n", e);
return e;
}
return sockerr;
}
/* Return nonzero only if we're finished and the caller should exit
its loop. This happens in two cases: We have a complete message,
or the socket has closed and no others are open. */
static int
service_tcp_fd(krb5_context context, struct conn_state *conn,
struct select_state *selstate, int ssflags)
{
int e = 0;
ssize_t nwritten, nread;
if (!(ssflags & (SSF_READ|SSF_WRITE|SSF_EXCEPTION)))
abort();
switch (conn->state) {
SOCKET_WRITEV_TEMP tmp;
case CONNECTING:
if (ssflags & SSF_READ) {
/* Bad -- the KDC shouldn't be sending to us first. */
e = EINVAL /* ?? */;
kill_conn:
TRACE_SENDTO_KDC_TCP_DISCONNECT(context, conn);
kill_conn(conn, selstate, e);
if (e == EINVAL) {
closesocket(conn->fd);
conn->fd = INVALID_SOCKET;
}
return e == 0;
}
if (ssflags & SSF_EXCEPTION) {
handle_exception:
e = get_so_error(conn->fd);
if (e)
dprint("socket error on exception fd: %m", e);
else
dprint("no socket error info available on exception fd");
goto kill_conn;
}
/*
* Connect finished -- but did it succeed or fail?
* UNIX sets can_write if failed.
* Call getsockopt to see if error pending.
*
* (For most UNIX systems it works to just try writing the
* first time and detect an error. But Bill Dodd at IBM