Pulled from SVN, then munged to apply to 1.9.  Modifies cm.h so that a

struct select_state has an alternate layout when USE_POLL is defined,

and if we detect <poll.h> at configure-time, have sendto_kdc.c define

USE_POLL to force its use.  Adapts sendto_kdc.c to handle both cases,

so that the previous behavior is preserved when <poll.h> is not found.

RT#6905

Index: src/include/cm.h

===================================================================

--- src/include/cm.h	(revision 24907)

+++ src/include/cm.h	(revision 24908)

@@ -24,11 +24,20 @@

  * or implied warranty.

  */

-/* Since fd_set is large on some platforms (8K on AIX 5.2), this

-   probably shouldn't be allocated in automatic storage.  */

+/*

+ * Since fd_set is large on some platforms (8K on AIX 5.2), this probably

+ * shouldn't be allocated in automatic storage.  Define USE_POLL and

+ * MAX_POLLFDS in the consumer of this header file to use poll state instead of

+ * select state.

+ */

 struct select_state {

-    int max, nfds;

+#ifdef USE_POLL

+    struct pollfd fds[MAX_POLLFDS];

+#else

+    int max;

     fd_set rfds, wfds, xfds;

+#endif

+    int nfds;

     struct timeval end_time;    /* magic: tv_sec==0 => never time out */

 };

Index: src/configure.in

===================================================================

--- src/configure.in	(revision 24907)

+++ src/configure.in	(revision 24908)

@@ -67,7 +67,7 @@

 ])

 AC_SUBST(LIBUTIL)

 # for kdc

-AC_CHECK_HEADERS(syslog.h stdarg.h sys/select.h sys/sockio.h ifaddrs.h unistd.h)

+AC_CHECK_HEADERS(syslog.h stdarg.h sys/sockio.h ifaddrs.h unistd.h)

 AC_CHECK_FUNCS(openlog syslog closelog strftime vsprintf vasprintf vsnprintf)

 AC_CHECK_FUNCS(strlcpy)

 EXTRA_SUPPORT_SYMS=

@@ -472,7 +472,7 @@

   AC_DEFINE(POSIX_TERMIOS,1,[Define if termios.h exists and tcsetattr exists]))])

 KRB5_SIGTYPE

-AC_CHECK_HEADERS(stdlib.h string.h stddef.h sys/types.h sys/file.h sys/param.h sys/stat.h sys/time.h netinet/in.h sys/uio.h sys/filio.h sys/select.h time.h paths.h errno.h)

+AC_CHECK_HEADERS(poll.h stdlib.h string.h stddef.h sys/types.h sys/file.h sys/param.h sys/stat.h sys/time.h netinet/in.h sys/uio.h sys/filio.h sys/select.h time.h paths.h errno.h)

 AC_HEADER_STDARG

 KRB5_AC_INET6

Index: src/lib/krb5/os/cm.c

===================================================================

--- src/lib/krb5/os/cm.c	(revision 0)

+++ src/lib/krb5/os/cm.c	(revision 24908)

@@ -0,0 +1,97 @@

+/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */

+/* lib/krb5/os/cm.c - Connection manager functions */

+/*

+ * Copyright (C) 2011 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.

+ */

+

+/*

+ * This file include krb5int_cm_call_select, which is used by

+ * lib/apputils/net-server.c and sometimes by sendto_kdc.c.

+ */

+

+#include "k5-int.h"

+#ifdef HAVE_SYS_SELECT_H

+#include <sys/select.h>

+#endif

+#ifdef _WIN32

+#include <sys/timeb.h>

+#endif

+#include "cm.h"

+

+int

+k5_getcurtime(struct timeval *tvp)

+{

+#ifdef _WIN32

+    struct _timeb tb;

+    _ftime(&tb);

+    tvp->tv_sec = tb.time;

+    tvp->tv_usec = tb.millitm * 1000;

+    /* Can _ftime fail?  */

+    return 0;

+#else

+    if (gettimeofday(tvp, 0))

+        return errno;

+    return 0;

+#endif

+}

+

+/*

+ * Call select and return results.

+ * Input: interesting file descriptors and absolute timeout

+ * Output: select return value (-1 or num fds ready) and fd_sets

+ * Return: 0 (for i/o available or timeout) or error code.

+ */

+krb5_error_code

+krb5int_cm_call_select (const struct select_state *in,

+                        struct select_state *out, int *sret)

+{

+    struct timeval now, *timo;

+    krb5_error_code e;

+

+    *out = *in;

+    e = k5_getcurtime(&now;;

+    if (e)

+        return e;

+    if (out->end_time.tv_sec == 0)

+        timo = 0;

+    else {

+        timo = &out->end_time;

+        out->end_time.tv_sec -= now.tv_sec;

+        out->end_time.tv_usec -= now.tv_usec;

+        if (out->end_time.tv_usec < 0) {

+            out->end_time.tv_usec += 1000000;

+            out->end_time.tv_sec--;

+        }

+        if (out->end_time.tv_sec < 0) {

+            *sret = 0;

+            return 0;

+        }

+    }

+

+    *sret = select(out->max, &out->rfds, &out->wfds, &out->xfds, timo);

+    e = SOCKET_ERRNO;

+

+    if (*sret < 0)

+        return e;

+    return 0;

+}

Index: src/lib/krb5/os/Makefile.in

===================================================================

--- src/lib/krb5/os/Makefile.in	(revision 24907)

+++ src/lib/krb5/os/Makefile.in	(revision 24908)

@@ -18,6 +18,7 @@

 	def_realm.o	\

 	ccdefname.o	\

 	changepw.o	\

+	cm.o		\

 	dnsglue.o	\

 	dnssrv.o	\

 	free_krbhs.o	\

@@ -62,6 +63,7 @@

 	$(OUTPRE)def_realm.$(OBJEXT)	\

 	$(OUTPRE)ccdefname.$(OBJEXT)	\

 	$(OUTPRE)changepw.$(OBJEXT)	\

+	$(OUTPRE)cm.$(OBJEXT)		\

 	$(OUTPRE)dnsglue.$(OBJEXT)	\

 	$(OUTPRE)dnssrv.$(OBJEXT)	\

 	$(OUTPRE)free_krbhs.$(OBJEXT)	\

@@ -106,6 +108,7 @@

 	$(srcdir)/def_realm.c	\

 	$(srcdir)/ccdefname.c	\

 	$(srcdir)/changepw.c	\

+	$(srcdir)/cm.c		\

 	$(srcdir)/dnsglue.c	\

 	$(srcdir)/dnssrv.c	\

 	$(srcdir)/free_krbhs.c	\

Index: src/lib/krb5/os/os-proto.h

===================================================================

--- src/lib/krb5/os/os-proto.h	(revision 24907)

+++ src/lib/krb5/os/os-proto.h	(revision 24908)

@@ -32,6 +32,10 @@

 #ifndef KRB5_LIBOS_INT_PROTO__

 #define KRB5_LIBOS_INT_PROTO__

+#ifdef HAVE_SYS_TIME_H

+#include <sys/time.h>

+#endif

+

 struct addrlist;

 krb5_error_code krb5_locate_kdc(krb5_context, const krb5_data *,

                                 struct addrlist *, int, int, int);

@@ -101,6 +105,8 @@

 /* The io vector is *not* const here, unlike writev()!  */

 int krb5int_net_writev (krb5_context, int, sg_buf *, int);

+int k5_getcurtime(struct timeval *tvp);

+

 #include "k5-thread.h"

 extern k5_mutex_t krb5int_us_time_mutex;

Index: src/lib/krb5/os/sendto_kdc.c

===================================================================

--- src/lib/krb5/os/sendto_kdc.c	(revision 24907)

+++ src/lib/krb5/os/sendto_kdc.c	(revision 24908)

@@ -30,17 +30,16 @@

 #include "fake-addrinfo.h"

 #include "k5-int.h"

-#ifdef HAVE_SYS_TIME_H

-#include <sys/time.h>

-#else

-#include <time.h>

-#endif

 #include "os-proto.h"

 #ifdef _WIN32

 #include <sys/timeb.h>

 #endif

-#ifdef _AIX

+#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

@@ -168,29 +167,6 @@

                 p = strerror(err);

             putstr(p);

             break;

-        case 'F':

-            /* %F => fd_set *, fd_set *, fd_set *, int */

-            rfds = va_arg(args, fd_set *);

-            wfds = va_arg(args, fd_set *);

-            xfds = va_arg(args, fd_set *);

-            maxfd = va_arg(args, int);

-

-            for (i = 0; i < maxfd; i++) {

-                int r = FD_ISSET(i, rfds);

-                int w = wfds && FD_ISSET(i, wfds);

-                int x = xfds && FD_ISSET(i, xfds);

-                if (r || w || x) {

-                    putf(" %d", i);

-                    if (r)

-                        putstr("r");

-                    if (w)

-                        putstr("w");

-                    if (x)

-                        putstr("x");

-                }

-            }

-            putstr(" ");

-            break;

         case 's':

             /* %s => char * */

             p = va_arg(args, const char *);

@@ -437,75 +413,154 @@

 #include "cm.h"

-static int

-getcurtime (struct timeval *tvp)

+/*

+ * 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)

 {

-#ifdef _WIN32

-    struct _timeb tb;

-    _ftime(&tb);

-    tvp->tv_sec = tb.time;

-    tvp->tv_usec = tb.millitm * 1000;

-    /* Can _ftime fail?  */

-    return 0;

+    selstate->nfds = 0;

+    selstate->end_time.tv_sec = selstate->end_time.tv_usec = 0;

+#ifndef USE_POLL

+    selstate->max = 0;

+    selstate->nfds = 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

-    if (gettimeofday(tvp, 0)) {

-        dperror("gettimeofday");

-        return errno;

+#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);

     }

-    return 0;

 #endif

+    selstate->nfds--;

 }

-/*

- * Call select and return results.

- * Input: interesting file descriptors and absolute timeout

- * Output: select return value (-1 or num fds ready) and fd_sets

- * Return: 0 (for i/o available or timeout) or error code.

- */

-krb5_error_code

-krb5int_cm_call_select (const struct select_state *in,

-                        struct select_state *out, int *sret)

+static void

+cm_unset_write(struct select_state *selstate, int fd)

 {

-    struct timeval now, *timo;

-    krb5_error_code e;

+#ifdef USE_POLL

+    int i;

-    *out = *in;

-    e = getcurtime(&now;;

-    if (e)

-        return e;

-    if (out->end_time.tv_sec == 0)

-        timo = 0;

+    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 {

-        timo = &out->end_time;

-        out->end_time.tv_sec -= now.tv_sec;

-        out->end_time.tv_usec -= now.tv_usec;

-        if (out->end_time.tv_usec < 0) {

-            out->end_time.tv_usec += 1000000;

-            out->end_time.tv_sec--;

-        }

-        if (out->end_time.tv_sec < 0) {

-            *sret = 0;

-            return 0;

-        }

+        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;

     }

-    dprint("selecting on max=%d sockets [%F] timeout %t\n",

-           out->max,

-           &out->rfds, &out->wfds, &out->xfds, out->max,

-           timo);

-    *sret = select(out->max, &out->rfds, &out->wfds, &out->xfds, timo);

+    /* 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

+}

-    dprint("select returns %d", *sret);

-    if (*sret < 0)

-        dprint(", error = %E\n", e);

-    else if (*sret == 0)

-        dprint(" (timeout)\n");

-    else

-        dprint(":%F\n", &out->rfds, &out->wfds, &out->xfds, out->max);

+static unsigned int

+cm_get_ssflags(struct select_state *selstate, int fd)

+{

+    unsigned int ssflags = 0;

+#ifdef USE_POLL

+    int i;

-    if (*sret < 0)

-        return e;

-    return 0;

+    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,

@@ -702,6 +757,7 @@

                  krb5_data *callback_buffer)

 {

     int fd, e;

+    unsigned int ssflags;

     struct addrinfo *ai = state->addr;

     dprint("start_connection(@%p)\ngetting %s socket in family %d...", state,

@@ -711,14 +767,6 @@

         dprint("socket: %m creating with af %d\n", state->err, ai->ai_family);

         return -1;              /* try other hosts */

     }

-#ifndef _WIN32 /* On Windows FD_SETSIZE is a count, not a max value.  */

-    if (fd >= FD_SETSIZE) {

-        closesocket(fd);

-        state->err = EMFILE;

-        dprint("socket: fd %d too high\n", fd);

-        return -1;

-    }

-#endif

     set_cloexec_fd(fd);

     /* Make it non-blocking.  */

     if (ai->ai_socktype == SOCK_STREAM) {

@@ -801,17 +849,16 @@

         }

     }

 #endif

-    FD_SET(state->fd, &selstate->rfds);

+    ssflags = SSF_READ | SSF_EXCEPTION;

     if (state->state == CONNECTING || state->state == WRITING)

-        FD_SET(state->fd, &selstate->wfds);

-    FD_SET(state->fd, &selstate->xfds);

-    if (selstate->max <= state->fd)

-        selstate->max = state->fd + 1;

-    selstate->nfds++;

+        ssflags |= SSF_WRITE;

+    if (!cm_add_fd(selstate, state->fd, ssflags)) {

+        (void) closesocket(state->fd);

+        state->fd = INVALID_SOCKET;

+        state->state = FAILED;

+        return -1;

+    }

-    dprint("new select vectors: %F\n",

-           &selstate->rfds, &selstate->wfds, &selstate->xfds, selstate->max);

-

     return 0;

 }

@@ -868,22 +915,11 @@

 kill_conn(struct conn_state *conn, struct select_state *selstate, int err)

 {

     conn->state = FAILED;

+    conn->err = err;

     shutdown(conn->fd, SHUTDOWN_BOTH);

-    FD_CLR(conn->fd, &selstate->rfds);

-    FD_CLR(conn->fd, &selstate->wfds);

-    FD_CLR(conn->fd, &selstate->xfds);

-    conn->err = err;

+    cm_remove_fd(selstate, conn->fd);

     dprint("abandoning connection %d: %m\n", conn->fd, err);

     /* Fix up max fd for next select call.  */

-    if (selstate->max == 1 + conn->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);

-    }

-    selstate->nfds--;

 }

 /* Check socket for error.  */

@@ -1005,7 +1041,7 @@

             /* Done writing, switch to reading.  */

             /* Don't call shutdown at this point because

              * some implementations cannot deal with half-closed connections.*/

-            FD_CLR(conn->fd, &selstate->wfds);

+            cm_unset_write(selstate, conn->fd);

             /* Q: How do we detect failures to send the remaining data

                to the remote side, since we're in non-blocking mode?

                Will we always get errors on the reading side?  */

@@ -1125,7 +1161,8 @@

     while (selstate->nfds > 0) {

         unsigned int i;

-        e = krb5int_cm_call_select(selstate, seltemp, &selret);

+        selret = 0;

+        e = cm_select_or_poll(selstate, seltemp, &selret);

         if (e == EINTR)

             continue;

         if (e != 0)

@@ -1149,18 +1149,12 @@ service_fds (krb5_context context,

             return 0;

         /* Got something on a socket, process it.  */

-        for (i = 0; i <= (unsigned int)selstate->max && selret > 0 && i < n_conns; i++) {

+        for (i = 0; i < n_conns; i++) {

             int ssflags;

             if (conns[i].fd == INVALID_SOCKET)

                 continue;

-            ssflags = 0;

-            if (FD_ISSET(conns[i].fd, &seltemp->rfds))

-                ssflags |= SSF_READ, selret--;

-            if (FD_ISSET(conns[i].fd, &seltemp->wfds))

-                ssflags |= SSF_WRITE, selret--;

-            if (FD_ISSET(conns[i].fd, &seltemp->xfds))

-                ssflags |= SSF_EXCEPTION, selret--;

+            ssflags = cm_get_ssflags(seltemp, conns[i].fd);

             if (!ssflags)

                 continue;

@@ -1229,12 +1259,7 @@

         retval = ENOMEM;

         goto egress;

     }

-    sel_state->max = 0;

-    sel_state->nfds = 0;

-    sel_state->end_time.tv_sec = sel_state->end_time.tv_usec = 0;

-    FD_ZERO(&sel_state->rfds);

-    FD_ZERO(&sel_state->wfds);

-    FD_ZERO(&sel_state->xfds);

+    cm_init_selstate(sel_state);

     /* Set up connections.  */

@@ -1295,7 +1295,7 @@ krb5int_sendto (krb5_context context, co

                            (callback_info ? &callback_data[host] : NULL)))

                 continue;

-            retval = getcurtime(&now;;

+            retval = k5_getcurtime(&now;;

             if (retval)

                 goto egress;

             sel_state->end_time = now;

@@ -1314,7 +1314,7 @@ krb5int_sendto (krb5_context context, co

         }

         if (e)

             break;

-        retval = getcurtime(&now;;

+        retval = k5_getcurtime(&now;;

         if (retval)

             goto egress;

         /* Possible optimization: Find a way to integrate this select