/* $NetBSD: send_to_kdc.c,v 1.7 2017/01/30 00:25:15 christos Exp $ */
/*
* Copyright (c) 1997 - 2002 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Portions Copyright (c) 2010 - 2013 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "krb5_locl.h"
#include "send_to_kdc_plugin.h"
/**
* @section send_to_kdc Locating and sending packets to the KDC
*
* The send to kdc code is responsible to request the list of KDC from
* the locate-kdc subsystem and then send requests to each of them.
*
* - Each second a new hostname is tried.
* - If the hostname have several addresses, the first will be tried
* directly then in turn the other will be tried every 3 seconds
* (host_timeout).
* - UDP requests are tried 3 times, and it tried with a individual timeout of kdc_timeout / 3.
* - TCP and HTTP requests are tried 1 time.
*
* Total wait time shorter then (number of addresses * 3) + kdc_timeout seconds.
*
*/
static int
init_port(const char *s, int fallback)
{
int tmp;
if (s && sscanf(s, "%d", &tmp) == 1)
return htons(tmp);
return fallback;
}
struct send_via_plugin_s {
krb5_const_realm realm;
krb5_krbhst_info *hi;
time_t timeout;
const krb5_data *send_data;
krb5_data *receive;
};
static krb5_error_code KRB5_LIB_CALL
kdccallback(krb5_context context, const void *plug, void *plugctx, void *userctx)
{
const krb5plugin_send_to_kdc_ftable *service = (const krb5plugin_send_to_kdc_ftable *)plug;
struct send_via_plugin_s *ctx = userctx;
if (service->send_to_kdc == NULL)
return KRB5_PLUGIN_NO_HANDLE;
return service->send_to_kdc(context, plugctx, ctx->hi, ctx->timeout,
ctx->send_data, ctx->receive);
}
static krb5_error_code KRB5_LIB_CALL
realmcallback(krb5_context context, const void *plug, void *plugctx, void *userctx)
{
const krb5plugin_send_to_kdc_ftable *service = (const krb5plugin_send_to_kdc_ftable *)plug;
struct send_via_plugin_s *ctx = userctx;
if (service->send_to_realm == NULL)
return KRB5_PLUGIN_NO_HANDLE;
return service->send_to_realm(context, plugctx, ctx->realm, ctx->timeout,
ctx->send_data, ctx->receive);
}
static krb5_error_code
kdc_via_plugin(krb5_context context,
krb5_krbhst_info *hi,
time_t timeout,
const krb5_data *send_data,
krb5_data *receive)
{
struct send_via_plugin_s userctx;
userctx.realm = NULL;
userctx.hi = hi;
userctx.timeout = timeout;
userctx.send_data = send_data;
userctx.receive = receive;
return _krb5_plugin_run_f(context, "krb5", KRB5_PLUGIN_SEND_TO_KDC,
KRB5_PLUGIN_SEND_TO_KDC_VERSION_0, 0,
&userctx, kdccallback);
}
static krb5_error_code
realm_via_plugin(krb5_context context,
krb5_const_realm realm,
time_t timeout,
const krb5_data *send_data,
krb5_data *receive)
{
struct send_via_plugin_s userctx;
userctx.realm = realm;
userctx.hi = NULL;
userctx.timeout = timeout;
userctx.send_data = send_data;
userctx.receive = receive;
return _krb5_plugin_run_f(context, "krb5", KRB5_PLUGIN_SEND_TO_KDC,
KRB5_PLUGIN_SEND_TO_KDC_VERSION_2, 0,
&userctx, realmcallback);
}
struct krb5_sendto_ctx_data {
int flags;
int type;
krb5_sendto_ctx_func func;
void *data;
char *hostname;
krb5_krbhst_handle krbhst;
/* context2 */
const krb5_data *send_data;
krb5_data response;
heim_array_t hosts;
int stateflags;
#define KRBHST_COMPLETED 1
/* prexmit */
krb5_sendto_prexmit prexmit_func;
void *prexmit_ctx;
/* stats */
struct {
struct timeval start_time;
struct timeval name_resolution;
struct timeval krbhst;
unsigned long sent_packets;
unsigned long num_hosts;
} stats;
unsigned int stid;
};
static void
dealloc_sendto_ctx(void *ptr)
{
krb5_sendto_ctx ctx = (krb5_sendto_ctx)ptr;
if (ctx->hostname)
free(ctx->hostname);
heim_release(ctx->hosts);
heim_release(ctx->krbhst);
}
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_sendto_ctx_alloc(krb5_context context, krb5_sendto_ctx *ctx)
{
*ctx = heim_alloc(sizeof(**ctx), "sendto-context", dealloc_sendto_ctx);
if (*ctx == NULL)
return krb5_enomem(context);
(*ctx)->hosts = heim_array_create();
return 0;
}
KRB5_LIB_FUNCTION void KRB5_LIB_CALL
krb5_sendto_ctx_add_flags(krb5_sendto_ctx ctx, int flags)
{
ctx->flags |= flags;
}
KRB5_LIB_FUNCTION int KRB5_LIB_CALL
krb5_sendto_ctx_get_flags(krb5_sendto_ctx ctx)
{
return ctx->flags;
}
KRB5_LIB_FUNCTION void KRB5_LIB_CALL
krb5_sendto_ctx_set_type(krb5_sendto_ctx ctx, int type)
{
ctx->type = type;
}
KRB5_LIB_FUNCTION void KRB5_LIB_CALL
krb5_sendto_ctx_set_func(krb5_sendto_ctx ctx,
krb5_sendto_ctx_func func,
void *data)
{
ctx->func = func;
ctx->data = data;
}
KRB5_LIB_FUNCTION void KRB5_LIB_CALL
_krb5_sendto_ctx_set_prexmit(krb5_sendto_ctx ctx,
krb5_sendto_prexmit prexmit,
void *data)
{
ctx->prexmit_func = prexmit;
ctx->prexmit_ctx = data;
}
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_sendto_set_hostname(krb5_context context,
krb5_sendto_ctx ctx,
const char *hostname)
{
if (ctx->hostname == NULL)
free(ctx->hostname);
ctx->hostname = strdup(hostname);
if (ctx->hostname == NULL) {
krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
return ENOMEM;
}
return 0;
}
KRB5_LIB_FUNCTION void KRB5_LIB_CALL
_krb5_sendto_ctx_set_krb5hst(krb5_context context,
krb5_sendto_ctx ctx,
krb5_krbhst_handle handle)
{
heim_release(ctx->krbhst);
ctx->krbhst = heim_retain(handle);
}
KRB5_LIB_FUNCTION void KRB5_LIB_CALL
krb5_sendto_ctx_free(krb5_context context, krb5_sendto_ctx ctx)
{
heim_release(ctx);
}
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
_krb5_kdc_retry(krb5_context context, krb5_sendto_ctx ctx, void *data,
const krb5_data *reply, int *action)
{
krb5_error_code ret;
KRB_ERROR error;
if(krb5_rd_error(context, reply, &error))
return 0;
ret = krb5_error_from_rd_error(context, &error, NULL);
krb5_free_error_contents(context, &error);
switch(ret) {
case KRB5KRB_ERR_RESPONSE_TOO_BIG: {
if (krb5_sendto_ctx_get_flags(ctx) & KRB5_KRBHST_FLAGS_LARGE_MSG)
break;
krb5_sendto_ctx_add_flags(ctx, KRB5_KRBHST_FLAGS_LARGE_MSG);
*action = KRB5_SENDTO_RESET;
break;
}
case KRB5KDC_ERR_SVC_UNAVAILABLE:
*action = KRB5_SENDTO_CONTINUE;
break;
}
return 0;
}
/*
*
*/
struct host;
struct host_fun {
krb5_error_code (*prepare)(krb5_context, struct host *, const krb5_data *);
krb5_error_code (*send_fn)(krb5_context, struct host *);
krb5_error_code (*recv_fn)(krb5_context, struct host *, krb5_data *);
int ntries;
};
struct host {
enum host_state { CONNECT, CONNECTING, CONNECTED, WAITING_REPLY, DEAD } state;
krb5_krbhst_info *hi;
struct addrinfo *ai;
rk_socket_t fd;
struct host_fun *fun;
unsigned int tries;
time_t timeout;
krb5_data data;
unsigned int tid;
};
static void
debug_host(krb5_context context, int level, struct host *host, const char *fmt, ...)
__attribute__ ((__format__ (__printf__, 4, 5)));
static void
debug_host(krb5_context context, int level, struct host *host, const char *fmt, ...)
{
const char *proto = "unknown";
char name[NI_MAXHOST], port[NI_MAXSERV];
char *text = NULL;
va_list ap;
int ret;
if (!_krb5_have_debug(context, 5))
return;
va_start(ap, fmt);
ret = vasprintf(&text, fmt, ap);
va_end(ap);
if (ret == -1 || text == NULL)
return;
if (host->hi->proto == KRB5_KRBHST_HTTP)
proto = "http";
else if (host->hi->proto == KRB5_KRBHST_TCP)
proto = "tcp";
else if (host->hi->proto == KRB5_KRBHST_UDP)
proto = "udp";
if (getnameinfo(host->ai->ai_addr, host->ai->ai_addrlen,
name, sizeof(name), port, sizeof(port), NI_NUMERICHOST) != 0)
name[0] = '\0';
_krb5_debug(context, level, "%s: %s %s:%s (%s) tid: %08x", text,
proto, name, port, host->hi->hostname, host->tid);
free(text);
}
static void
deallocate_host(void *ptr)
{
struct host *host = ptr;
if (!rk_IS_BAD_SOCKET(host->fd))
rk_closesocket(host->fd);
krb5_data_free(&host->data);
host->ai = NULL;
}
static void
host_dead(krb5_context context, struct host *host, const char *msg)
{
debug_host(context, 5, host, "%s", msg);
rk_closesocket(host->fd);
host->fd = rk_INVALID_SOCKET;
host->state = DEAD;
}
static krb5_error_code
send_stream(krb5_context context, struct host *host)
{
ssize_t len;
len = krb5_net_write(context, &host->fd, host->data.data, host->data.length);
if (len < 0)
return errno;
else if (len < host->data.length) {
host->data.length -= len;
memmove(host->data.data, ((uint8_t *)host->data.data) + len, host->data.length - len);
return -1;
} else {
krb5_data_free(&host->data);
return 0;
}
}
static krb5_error_code
recv_stream(krb5_context context, struct host *host)
{
krb5_error_code ret;
size_t oldlen;
ssize_t sret;
int nbytes;
if (rk_SOCK_IOCTL(host->fd, FIONREAD, &nbytes) != 0 || nbytes <= 0)
return HEIM_NET_CONN_REFUSED;
if (context->max_msg_size - host->data.length < nbytes) {
krb5_set_error_message(context, KRB5KRB_ERR_FIELD_TOOLONG,
N_("TCP message from KDC too large %d", ""),
(int)(host->data.length + nbytes));
return KRB5KRB_ERR_FIELD_TOOLONG;
}
oldlen = host->data.length;
ret = krb5_data_realloc(&host->data, oldlen + nbytes + 1 /* NUL */);
if (ret)
return ret;
sret = krb5_net_read(context, &host->fd, ((uint8_t *)host->data.data) + oldlen, nbytes);
if (sret <= 0) {
ret = errno;
return ret;
}
host->data.length = oldlen + sret;
/* zero terminate for http transport */
((uint8_t *)host->data.data)[host->data.length] = '\0';
return 0;
}
/*
*
*/
static void
host_next_timeout(krb5_context context, struct host *host)
{
host->timeout = context->kdc_timeout / host->fun->ntries;
if (host->timeout == 0)
host->timeout = 1;
host->timeout += time(NULL);
}
/*
* connected host
*/
static void
host_connected(krb5_context context, krb5_sendto_ctx ctx, struct host *host)
{
krb5_error_code ret;
host->state = CONNECTED;
/*
* Now prepare data to send to host
*/
if (ctx->prexmit_func) {
krb5_data data;
krb5_data_zero(&data);
ret = ctx->prexmit_func(context, host->hi->proto,
ctx->prexmit_ctx, host->fd, &data);
if (ret == 0) {
if (data.length == 0) {
host_dead(context, host, "prexmit function didn't send data");
return;
}
ret = host->fun->prepare(context, host, &data);
krb5_data_free(&data);
}
} else {
ret = host->fun->prepare(context, host, ctx->send_data);
}
if (ret)
debug_host(context, 5, host, "failed to prexmit/prepare");
}
/*
* connect host
*/
static void
host_connect(krb5_context context, krb5_sendto_ctx ctx, struct host *host)
{
krb5_krbhst_info *hi = host->hi;
struct addrinfo *ai = host->ai;
debug_host(context, 5, host, "connecting to host");
if (connect(host->fd, ai->ai_addr, ai->ai_addrlen) < 0) {
#ifdef HAVE_WINSOCK
if (WSAGetLastError() == WSAEWOULDBLOCK)
errno = EINPROGRESS;
#endif /* HAVE_WINSOCK */
if (errno == EINPROGRESS && (hi->proto == KRB5_KRBHST_HTTP || hi->proto == KRB5_KRBHST_TCP)) {
debug_host(context, 5, host, "connecting to %d", host->fd);
host->state = CONNECTING;
} else {
host_dead(context, host, "failed to connect");
}
} else {
host_connected(context, ctx, host);
}
host_next_timeout(context, host);
}
/*
* HTTP transport
*/
static krb5_error_code
prepare_http(krb5_context context, struct host *host, const krb5_data *data)
{
char *str = NULL, *request = NULL;
krb5_error_code ret;
int len;
heim_assert(host->data.length == 0, "prepare_http called twice");
len = rk_base64_encode(data->data, data->length, &str);
if(len < 0)
return ENOMEM;
if (context->http_proxy)
ret = asprintf(&request, "GET http://%s/%s HTTP/1.0\r\n\r\n", host->hi->hostname, str);
else
ret = asprintf(&request, "GET /%s HTTP/1.0\r\n\r\n", str);
free(str);
if(ret < 0 || request == NULL)
return ENOMEM;
host->data.data = request;
host->data.length = strlen(request);
return 0;
}
static krb5_error_code
recv_http(krb5_context context, struct host *host, krb5_data *data)
{
krb5_error_code ret;
unsigned long rep_len;
size_t len;
char *p;
/*
* recv_stream returns a NUL terminated stream
*/
ret = recv_stream(context, host);
if (ret)
return ret;
p = strstr(host->data.data, "\r\n\r\n");
if (p == NULL)
return -1;
p += 4;
len = host->data.length - (p - (char *)host->data.data);
if (len < 4)
return -1;
_krb5_get_int(p, &rep_len, 4);
if (len < rep_len)
return -1;
p += 4;
memmove(host->data.data, p, rep_len);
host->data.length = rep_len;
*data = host->data;
krb5_data_zero(&host->data);
return 0;
}
/*
* TCP transport
*/
static krb5_error_code
prepare_tcp(krb5_context context, struct host *host, const krb5_data *data)
{
krb5_error_code ret;
krb5_storage *sp;
heim_assert(host->data.length == 0, "prepare_tcp called twice");
sp = krb5_storage_emem();
if (sp == NULL)
return ENOMEM;
ret = krb5_store_data(sp, *data);
if (ret) {
krb5_storage_free(sp);
return ret;
}
ret = krb5_storage_to_data(sp, &host->data);
krb5_storage_free(sp);
return ret;
}
static krb5_error_code
recv_tcp(krb5_context context, struct host *host, krb5_data *data)
{
krb5_error_code ret;
unsigned long pktlen;
ret = recv_stream(context, host);
if (ret)
return ret;
if (host->data.length < 4)
return -1;
_krb5_get_int(host->data.data, &pktlen, 4);
if (pktlen > host->data.length - 4)
return -1;
memmove(host->data.data, ((uint8_t *)host->data.data) + 4, host->data.length - 4);
host->data.length -= 4;
*data = host->data;
krb5_data_zero(&host->data);
return 0;
}
/*
* UDP transport
*/
static krb5_error_code
prepare_udp(krb5_context context, struct host *host, const krb5_data *data)
{
return krb5_data_copy(&host->data, data->data, data->length);
}
static krb5_error_code
send_udp(krb5_context context, struct host *host)
{
if (send(host->fd, host->data.data, host->data.length, 0) < 0)
return errno;
return 0;
}
static krb5_error_code
recv_udp(krb5_context context, struct host *host, krb5_data *data)
{
krb5_error_code ret;
int nbytes;
if (rk_SOCK_IOCTL(host->fd, FIONREAD, &nbytes) != 0 || nbytes <= 0)
return HEIM_NET_CONN_REFUSED;
if (context->max_msg_size < nbytes) {
krb5_set_error_message(context, KRB5KRB_ERR_FIELD_TOOLONG,
N_("UDP message from KDC too large %d", ""),
(int)nbytes);
return KRB5KRB_ERR_FIELD_TOOLONG;
}
ret = krb5_data_alloc(data, nbytes);
if (ret)
return ret;
ret = recv(host->fd, data->data, data->length, 0);
if (ret < 0) {
ret = errno;
krb5_data_free(data);
return ret;
}
data->length = ret;
return 0;
}
static struct host_fun http_fun = {
prepare_http,
send_stream,
recv_http,
1
};
static struct host_fun tcp_fun = {
prepare_tcp,
send_stream,
recv_tcp,
1
};
static struct host_fun udp_fun = {
prepare_udp,
send_udp,
recv_udp,
3
};
/*
* Host state machine
*/
static int
eval_host_state(krb5_context context,
krb5_sendto_ctx ctx,
struct host *host,
int readable, int writeable)
{
krb5_error_code ret;
if (host->state == CONNECT) {
/* check if its this host time to connect */
if (host->timeout < time(NULL))
host_connect(context, ctx, host);
return 0;
}
if (host->state == CONNECTING && writeable)
host_connected(context, ctx, host);
if (readable) {
debug_host(context, 5, host, "reading packet");
ret = host->fun->recv_fn(context, host, &ctx->response);
if (ret == -1) {
/* not done yet */
} else if (ret == 0) {
/* if recv_foo function returns 0, we have a complete reply */
debug_host(context, 5, host, "host completed");
return 1;
} else {
host_dead(context, host, "host disconnected");
}
}
/* check if there is anything to send, state might DEAD after read */
if (writeable && host->state == CONNECTED) {
ctx->stats.sent_packets++;
debug_host(context, 5, host, "writing packet");
ret = host->fun->send_fn(context, host);
if (ret == -1) {
/* not done yet */
} else if (ret) {
host_dead(context, host, "host dead, write failed");
} else
host->state = WAITING_REPLY;
}
return 0;
}
/*
*
*/
static krb5_error_code
submit_request(krb5_context context, krb5_sendto_ctx ctx, krb5_krbhst_info *hi)
{
unsigned long submitted_host = 0;
krb5_boolean freeai = FALSE;
struct timeval nrstart, nrstop;
krb5_error_code ret;
struct addrinfo *ai = NULL, *a;
struct host *host;
ret = kdc_via_plugin(context, hi, context->kdc_timeout,
ctx->send_data, &ctx->response);
if (ret == 0) {
return 0;
} else if (ret != KRB5_PLUGIN_NO_HANDLE) {
_krb5_debug(context, 5, "send via plugin failed %s: %d",
hi->hostname, ret);
return ret;
}
/*
* If we have a proxy, let use the address of the proxy instead of
* the KDC and let the proxy deal with the resolving of the KDC.
*/
gettimeofday(&nrstart, NULL);
if (hi->proto == KRB5_KRBHST_HTTP && context->http_proxy) {
char *proxy2 = strdup(context->http_proxy);
char *el, *proxy = proxy2;
struct addrinfo hints;
char portstr[NI_MAXSERV];
unsigned short nport;
if (proxy == NULL)
return ENOMEM;
if (strncmp(proxy, "http://", 7) == 0)
proxy += 7;
/* check for url terminating slash */
el = strchr(proxy, '/');
if (el != NULL)
*el = '\0';
/* check for port in hostname, used below as port */
el = strchr(proxy, ':');
if(el != NULL)
*el++ = '\0';
memset(&hints, 0, sizeof(hints));
hints.ai_family = PF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
/* On some systems ntohs(foo(..., htons(...))) causes shadowing */
nport = init_port(el, htons(80));
snprintf(portstr, sizeof(portstr), "%d", ntohs(nport));
ret = getaddrinfo(proxy, portstr, &hints, &ai);
free(proxy2);
if (ret)
return krb5_eai_to_heim_errno(ret, errno);
freeai = TRUE;
} else {
ret = krb5_krbhst_get_addrinfo(context, hi, &ai);
if (ret)
return ret;
}
/* add up times */
gettimeofday(&nrstop, NULL);
timevalsub(&nrstop, &nrstart);
timevaladd(&ctx->stats.name_resolution, &nrstop);
ctx->stats.num_hosts++;
for (a = ai; a != NULL; a = a->ai_next) {
rk_socket_t fd;
fd = socket(a->ai_family, a->ai_socktype | SOCK_CLOEXEC, a->ai_protocol);
if (rk_IS_BAD_SOCKET(fd))
continue;
rk_cloexec(fd);
#ifndef NO_LIMIT_FD_SETSIZE
if (fd >= FD_SETSIZE) {
_krb5_debug(context, 0, "fd too large for select");
rk_closesocket(fd);
continue;
}
#endif
socket_set_nonblocking(fd, 1);
host = heim_alloc(sizeof(*host), "sendto-host", deallocate_host);
if (host == NULL) {
if (freeai)
freeaddrinfo(ai);
rk_closesocket(fd);
return ENOMEM;
}
host->hi = hi;
host->fd = fd;
host->ai = a;
/* next version of stid */
host->tid = ctx->stid = (ctx->stid & 0xffff0000) | ((ctx->stid & 0xffff) + 1);
host->state = CONNECT;
switch (host->hi->proto) {
case KRB5_KRBHST_HTTP :
host->fun = &http_fun;
break;
case KRB5_KRBHST_TCP :
host->fun = &tcp_fun;
break;
case KRB5_KRBHST_UDP :
host->fun = &udp_fun;
break;
default:
heim_abort("undefined http transport protocol: %d", (int)host->hi->proto);
}
host->tries = host->fun->ntries;
/*
* Connect directly next host, wait a host_timeout for each next address
*/
if (submitted_host == 0)
host_connect(context, ctx, host);
else {
debug_host(context, 5, host,
"Queuing host in future (in %ds), its the %lu address on the same name",
(int)(context->host_timeout * submitted_host), submitted_host + 1);
host->timeout = time(NULL) + (submitted_host * context->host_timeout);
}
heim_array_append_value(ctx->hosts, host);
heim_release(host);
submitted_host++;
}
if (freeai)
freeaddrinfo(ai);
if (!submitted_host)
return KRB5_KDC_UNREACH;
return 0;
}
struct wait_ctx {
krb5_context context;
krb5_sendto_ctx ctx;
fd_set rfds;
fd_set wfds;
unsigned max_fd;
int got_reply;
time_t timenow;
};
static void
wait_setup(heim_object_t obj, void *iter_ctx, int *stop)
{
struct wait_ctx *wait_ctx = iter_ctx;
struct host *h = (struct host *)obj;
/* skip dead hosts */
if (h->state == DEAD)
return;
if (h->state == CONNECT) {
if (h->timeout < wait_ctx->timenow)
host_connect(wait_ctx->context, wait_ctx->ctx, h);
return;
}
/* if host timed out, dec tries and (retry or kill host) */
if (h->timeout < wait_ctx->timenow) {
heim_assert(h->tries != 0, "tries should not reach 0");
h->tries--;
if (h->tries == 0) {
host_dead(wait_ctx->context, h, "host timed out");
return;
} else {
debug_host(wait_ctx->context, 5, h, "retrying sending to");
host_next_timeout(wait_ctx->context, h);
host_connected(wait_ctx->context, wait_ctx->ctx, h);
}
}
#ifndef NO_LIMIT_FD_SETSIZE
heim_assert(h->fd < FD_SETSIZE, "fd too large");
#endif
switch (h->state) {
case WAITING_REPLY:
FD_SET(h->fd, &wait_ctx->rfds);
break;
case CONNECTING:
case CONNECTED:
FD_SET(h->fd, &wait_ctx->rfds);
FD_SET(h->fd, &wait_ctx->wfds);
break;
default:
heim_abort("invalid sendto host state");
}
if (h->fd > wait_ctx->max_fd)
wait_ctx->max_fd = h->fd;
}
static int
wait_filter_dead(heim_object_t obj, void *ctx)
{
struct host *h = (struct host *)obj;
return (int)((h->state == DEAD) ? true : false);
}
static void
wait_process(heim_object_t obj, void *ctx, int *stop)
{
struct wait_ctx *wait_ctx = ctx;
struct host *h = (struct host *)obj;
int readable, writeable;
heim_assert(h->state != DEAD, "dead host resurected");
#ifndef NO_LIMIT_FD_SETSIZE
heim_assert(h->fd < FD_SETSIZE, "fd too large");
#endif
readable = FD_ISSET(h->fd, &wait_ctx->rfds);
writeable = FD_ISSET(h->fd, &wait_ctx->wfds);
if (readable || writeable || h->state == CONNECT)
wait_ctx->got_reply |= eval_host_state(wait_ctx->context, wait_ctx->ctx, h, readable, writeable);
/* if there is already a reply, just fall though the array */
if (wait_ctx->got_reply)
*stop = 1;
}
static krb5_error_code
wait_response(krb5_context context, int *action, krb5_sendto_ctx ctx)
{
struct wait_ctx wait_ctx;
struct timeval tv;
int ret;
wait_ctx.context = context;
wait_ctx.ctx = ctx;
FD_ZERO(&wait_ctx.rfds);
FD_ZERO(&wait_ctx.wfds);
wait_ctx.max_fd = 0;
/* oh, we have a reply, it must be a plugin that got it for us */
if (ctx->response.length) {
*action = KRB5_SENDTO_FILTER;
return 0;
}
wait_ctx.timenow = time(NULL);
heim_array_iterate_f(ctx->hosts, &wait_ctx, wait_setup);
heim_array_filter_f(ctx->hosts, &wait_ctx, wait_filter_dead);
if (heim_array_get_length(ctx->hosts) == 0) {
if (ctx->stateflags & KRBHST_COMPLETED) {
_krb5_debug(context, 5, "no more hosts to send/recv packets to/from "
"trying to pulling more hosts");
*action = KRB5_SENDTO_FAILED;
} else {
_krb5_debug(context, 5, "no more hosts to send/recv packets to/from "
"and no more hosts -> failure");
*action = KRB5_SENDTO_TIMEOUT;
}
return 0;
}
tv.tv_sec = 1;
tv.tv_usec = 0;
ret = select(wait_ctx.max_fd + 1, &wait_ctx.rfds, &wait_ctx.wfds, NULL, &tv);
if (ret < 0)
return errno;
if (ret == 0) {
*action = KRB5_SENDTO_TIMEOUT;
return 0;
}
wait_ctx.got_reply = 0;
heim_array_iterate_f(ctx->hosts, &wait_ctx, wait_process);
if (wait_ctx.got_reply)
*action = KRB5_SENDTO_FILTER;
else
*action = KRB5_SENDTO_CONTINUE;
return 0;
}
static void
reset_context(krb5_context context, krb5_sendto_ctx ctx)
{
krb5_data_free(&ctx->response);
heim_release(ctx->hosts);
ctx->hosts = heim_array_create();
ctx->stateflags = 0;
}
/*
*
*/
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_sendto_context(krb5_context context,
krb5_sendto_ctx ctx,
const krb5_data *send_data,
krb5_const_realm realm,
krb5_data *receive)
{
krb5_error_code ret = 0;
krb5_krbhst_handle handle = NULL;
struct timeval nrstart, nrstop, stop_time;
int type, freectx = 0;
int action;
int numreset = 0;
krb5_data_zero(receive);
if (ctx == NULL) {
ret = krb5_sendto_ctx_alloc(context, &ctx);
if (ret)
goto out;
freectx = 1;
}
ctx->stid = (context->num_kdc_requests++) << 16;
memset(&ctx->stats, 0, sizeof(ctx->stats));
gettimeofday(&ctx->stats.start_time, NULL);
type = ctx->type;
if (type == 0) {
if ((ctx->flags & KRB5_KRBHST_FLAGS_MASTER) || context->use_admin_kdc)
type = KRB5_KRBHST_ADMIN;
else
type = KRB5_KRBHST_KDC;
}
ctx->send_data = send_data;
if ((int)send_data->length > context->large_msg_size)
ctx->flags |= KRB5_KRBHST_FLAGS_LARGE_MSG;
/* loop until we get back a appropriate response */
action = KRB5_SENDTO_INITIAL;
while (action != KRB5_SENDTO_DONE && action != KRB5_SENDTO_FAILED) {
krb5_krbhst_info *hi;
switch (action) {
case KRB5_SENDTO_INITIAL:
ret = realm_via_plugin(context, realm, context->kdc_timeout,
send_data, &ctx->response);
if (ret == 0 || ret != KRB5_PLUGIN_NO_HANDLE) {
action = KRB5_SENDTO_DONE;
break;
}
action = KRB5_SENDTO_KRBHST;
/* FALLTHOUGH */
case KRB5_SENDTO_KRBHST:
if (ctx->krbhst == NULL) {
ret = krb5_krbhst_init_flags(context, realm, type,
ctx->flags, &handle);
if (ret)
goto out;
if (ctx->hostname) {
ret = krb5_krbhst_set_hostname(context, handle, ctx->hostname);
if (ret)
goto out;
}
} else {
handle = heim_retain(ctx->krbhst);
}
action = KRB5_SENDTO_TIMEOUT;
/* FALLTHOUGH */
case KRB5_SENDTO_TIMEOUT:
/*
* If we completed, just got to next step
*/
if (ctx->stateflags & KRBHST_COMPLETED) {
action = KRB5_SENDTO_CONTINUE;
break;
}
/*
* Pull out next host, if there is no more, close the
* handle and mark as completed.
*
* Collect time spent in krbhst (dns, plugin, etc)
*/
gettimeofday(&nrstart, NULL);
ret = krb5_krbhst_next(context, handle, &hi);
gettimeofday(&nrstop, NULL);
timevalsub(&nrstop, &nrstart);
timevaladd(&ctx->stats.krbhst, &nrstop);
action = KRB5_SENDTO_CONTINUE;
if (ret == 0) {
_krb5_debug(context, 5, "submissing new requests to new host");
if (submit_request(context, ctx, hi) != 0)
action = KRB5_SENDTO_TIMEOUT;
} else {
_krb5_debug(context, 5, "out of hosts, waiting for replies");
ctx->stateflags |= KRBHST_COMPLETED;
}
break;
case KRB5_SENDTO_CONTINUE:
ret = wait_response(context, &action, ctx);
if (ret)
goto out;
break;
case KRB5_SENDTO_RESET:
/* start over */
_krb5_debug(context, 5,
"krb5_sendto trying over again (reset): %d",
numreset);
reset_context(context, ctx);
if (handle) {
krb5_krbhst_free(context, handle);
handle = NULL;
}
numreset++;
if (numreset >= 3)
action = KRB5_SENDTO_FAILED;
else
action = KRB5_SENDTO_KRBHST;
break;
case KRB5_SENDTO_FILTER:
/* default to next state, the filter function might modify this */
action = KRB5_SENDTO_DONE;
if (ctx->func) {
ret = (*ctx->func)(context, ctx, ctx->data,
&ctx->response, &action);
if (ret)
goto out;
}
break;
case KRB5_SENDTO_FAILED:
ret = KRB5_KDC_UNREACH;
break;
case KRB5_SENDTO_DONE:
ret = 0;
break;
default:
heim_abort("invalid krb5_sendto_context state");
}
}
out:
gettimeofday(&stop_time, NULL);
timevalsub(&stop_time, &ctx->stats.start_time);
if (ret == 0 && ctx->response.length) {
*receive = ctx->response;
krb5_data_zero(&ctx->response);
} else {
krb5_data_free(&ctx->response);
krb5_clear_error_message (context);
ret = KRB5_KDC_UNREACH;
krb5_set_error_message(context, ret,
N_("unable to reach any KDC in realm %s", ""),
realm);
}
_krb5_debug(context, 1,
"%s %s done: %d hosts %lu packets %lu:"
" wc: %jd.%06ld nr: %jd.%06ld kh: %jd.%06ld tid: %08x",
__func__, realm, ret,
ctx->stats.num_hosts, ctx->stats.sent_packets,
(intmax_t)stop_time.tv_sec,
(long)stop_time.tv_usec,
(intmax_t)ctx->stats.name_resolution.tv_sec,
(long)ctx->stats.name_resolution.tv_usec,
(intmax_t)ctx->stats.krbhst.tv_sec,
(long)ctx->stats.krbhst.tv_usec, ctx->stid);
if (freectx)
krb5_sendto_ctx_free(context, ctx);
else
reset_context(context, ctx);
if (handle)
krb5_krbhst_free(context, handle);
return ret;
}