Description: Use poll(2) instead of select(2) to support more than 1024 file descriptors
Author: Ben Smithurst <ben.smithurst@gradwell.com>
Author: David Duncan Ross Palmer <david.palmer@gradwell.com>
Bug-Debian: https://bugs.debian.org/478193
Bug-Debian: https://bugs.debian.org/770022

diff --git a/src/osdep/unix/os_lnx.c b/src/osdep/unix/os_lnx.c
index 03fd17d..671bbd6 100644
--- a/src/osdep/unix/os_lnx.c
+++ b/src/osdep/unix/os_lnx.c
@@ -41,6 +41,7 @@
 extern int errno;		/* just in case */
 #include <pwd.h>
 #include "misc.h"
+#include <poll.h>
 
 
 #include "fs_unix.c"
diff --git a/src/osdep/unix/os_slx.c b/src/osdep/unix/os_slx.c
index c94d632..f6bf27d 100644
--- a/src/osdep/unix/os_slx.c
+++ b/src/osdep/unix/os_slx.c
@@ -42,6 +42,7 @@ extern int errno;		/* just in case */
 #include <pwd.h>
 #include <shadow.h>
 #include "misc.h"
+#include <poll.h>
 
 
 #include "fs_unix.c"
diff --git a/src/osdep/unix/tcp_unix.c b/src/osdep/unix/tcp_unix.c
index 795fb4f..c69eaec 100644
--- a/src/osdep/unix/tcp_unix.c
+++ b/src/osdep/unix/tcp_unix.c
@@ -235,12 +235,11 @@ TCPSTREAM *tcp_open (char *host,char *service,unsigned long port)
 int tcp_socket_open (int family,void *adr,size_t adrlen,unsigned short port,
 		     char *tmp,int *ctr,char *hst)
 {
-  int i,ti,sock,flgs;
+  int i,ti,sock,flgs,tmo;
+  struct pollfd pfd;
   size_t len;
   time_t now;
   struct protoent *pt = getprotobyname ("tcp");
-  fd_set rfds,wfds,efds;
-  struct timeval tmo;
   struct sockaddr *sadr = ip_sockaddr (family,adr,adrlen,port,&len);
   blocknotify_t bn = (blocknotify_t) mail_parameters (NIL,GET_BLOCKNOTIFY,NIL);
 				/* fetid Solaris */
@@ -252,14 +251,6 @@ int tcp_socket_open (int family,void *adr,size_t adrlen,unsigned short port,
     sprintf (tmp,"Unable to create TCP socket: %s",strerror (errno));
     (*bn) (BLOCK_NONSENSITIVE,data);
   }
-  else if (sock >= FD_SETSIZE) {/* unselectable sockets are useless */
-    sprintf (tmp,"Unable to create selectable TCP socket (%d >= %d)",
-	     sock,FD_SETSIZE);
-    (*bn) (BLOCK_NONSENSITIVE,data);
-    close (sock);
-    sock = -1;
-    errno = EMFILE;
-  }
 
   else {			/* get current socket flags */
     flgs = fcntl (sock,F_GETFL,0);
@@ -284,16 +275,11 @@ int tcp_socket_open (int family,void *adr,size_t adrlen,unsigned short port,
     if ((sock >= 0) && ctr) {	/* want open timeout? */
       now = time (0);		/* open timeout */
       ti = ttmo_open ? now + ttmo_open : 0;
-      tmo.tv_usec = 0;
-      FD_ZERO (&rfds);		/* initialize selection vector */
-      FD_ZERO (&wfds);		/* initialize selection vector */
-      FD_ZERO (&efds);		/* handle errors too */
-      FD_SET (sock,&rfds);	/* block for error or readable or writable */
-      FD_SET (sock,&wfds);
-      FD_SET (sock,&efds);
+      pfd.fd = sock;
+      pfd.events = POLLIN | POLLOUT;
       do {			/* block under timeout */
-	tmo.tv_sec = ti ? ti - now : 0;
-	i = select (sock+1,&rfds,&wfds,&efds,ti ? &tmo : NIL);
+	tmo = ti ? ti - now : 0;
+	i = poll (&pfd, 1, ti ? tmo * 1000 : -1);
 	now = time (0);		/* fake timeout if interrupt & time expired */
 	if ((i < 0) && (errno == EINTR) && ti && (ti <= now)) i = 0;
       } while ((i < 0) && (errno == EINTR));
@@ -302,7 +288,7 @@ int tcp_socket_open (int family,void *adr,size_t adrlen,unsigned short port,
 	fcntl (sock,F_SETFL,flgs);
 	/* This used to be a zero-byte read(), but that crashes Solaris */
 				/* get socket status */
-	if(FD_ISSET(sock, &rfds)) while (((i = *ctr = read (sock,tmp,1)) < 0) && (errno == EINTR));
+	if(pfd.revents & POLLIN) while (((i = *ctr = read (sock,tmp,1)) < 0) && (errno == EINTR));
       }	
       if (i <= 0) {		/* timeout or error? */
 	i = i ? errno : ETIMEDOUT;/* determine error code */
@@ -545,9 +531,8 @@ long tcp_getbuffer (TCPSTREAM *stream,unsigned long size,char *s)
     stream->ictr -=n;
   }
   if (size) {
-    int i;
-    fd_set fds,efds;
-    struct timeval tmo;
+    int i, tmo;
+    struct pollfd pfd;
     time_t t = time (0);
     blocknotify_t bn=(blocknotify_t) mail_parameters (NIL,GET_BLOCKNOTIFY,NIL);
     (*bn) (BLOCK_TCPREAD,NIL);
@@ -556,16 +541,13 @@ long tcp_getbuffer (TCPSTREAM *stream,unsigned long size,char *s)
       time_t now = tl;
       time_t ti = ttmo_read ? now + ttmo_read : 0;
       if (tcpdebug) mm_log ("Reading TCP buffer",TCPDEBUG);
-      tmo.tv_usec = 0;
-      FD_ZERO (&fds);		/* initialize selection vector */
-      FD_ZERO (&efds);		/* handle errors too */
-				/* set bit in selection vectors */
-      FD_SET (stream->tcpsi,&fds);
-      FD_SET (stream->tcpsi,&efds);
+
+      pfd.events = POLLIN;
+      pfd.fd = stream->tcpsi;
       errno = NIL;		/* initially no error */
       do {			/* block under timeout */
-	tmo.tv_sec = ti ? ti - now : 0;
-	i = select (stream->tcpsi+1,&fds,NIL,&efds,ti ? &tmo : NIL);
+	tmo = ti ? ti - now : 0;
+	i = poll (&pfd, 1, ti ? tmo * 1000 : -1);
 	now = time (0);		/* fake timeout if interrupt & time expired */
 	if ((i < 0) && (errno == EINTR) && ti && (ti <= now)) i = 0;
       } while ((i < 0) && (errno == EINTR));
@@ -605,9 +587,8 @@ long tcp_getbuffer (TCPSTREAM *stream,unsigned long size,char *s)
 
 long tcp_getdata (TCPSTREAM *stream)
 {
-  int i;
-  fd_set fds,efds;
-  struct timeval tmo;
+  int i, tmo;
+  struct pollfd pfd;
   time_t t = time (0);
   blocknotify_t bn = (blocknotify_t) mail_parameters (NIL,GET_BLOCKNOTIFY,NIL);
   if (stream->tcpsi < 0) return NIL;
@@ -617,15 +598,12 @@ long tcp_getdata (TCPSTREAM *stream)
     time_t now = tl;
     time_t ti = ttmo_read ? now + ttmo_read : 0;
     if (tcpdebug) mm_log ("Reading TCP data",TCPDEBUG);
-    tmo.tv_usec = 0;
-    FD_ZERO (&fds);		/* initialize selection vector */
-    FD_ZERO (&efds);		/* handle errors too */
-    FD_SET (stream->tcpsi,&fds);/* set bit in selection vectors */
-    FD_SET (stream->tcpsi,&efds);
+    pfd.fd = stream->tcpsi;
+    pfd.events = POLLIN;
     errno = NIL;		/* initially no error */
     do {			/* block under timeout */
-      tmo.tv_sec = ti ? ti - now : 0;
-      i = select (stream->tcpsi+1,&fds,NIL,&efds,ti ? &tmo : NIL);
+      tmo = ti ? ti - now : 0;
+      i = poll (&pfd, 1, ti ? tmo * 1000 : -1);
       now = time (0);		/* fake timeout if interrupt & time expired */
       if ((i < 0) && (errno == EINTR) && ti && (ti <= now)) i = 0;
     } while ((i < 0) && (errno == EINTR));
@@ -677,9 +655,8 @@ long tcp_soutr (TCPSTREAM *stream,char *string)
 
 long tcp_sout (TCPSTREAM *stream,char *string,unsigned long size)
 {
-  int i;
-  fd_set fds,efds;
-  struct timeval tmo;
+  int i, tmo;
+  struct pollfd pfd;
   time_t t = time (0);
   blocknotify_t bn = (blocknotify_t) mail_parameters (NIL,GET_BLOCKNOTIFY,NIL);
   if (stream->tcpso < 0) return NIL;
@@ -689,15 +666,12 @@ long tcp_sout (TCPSTREAM *stream,char *string,unsigned long size)
     time_t now = tl;
     time_t ti = ttmo_write ? now + ttmo_write : 0;
     if (tcpdebug) mm_log ("Writing to TCP",TCPDEBUG);
-    tmo.tv_usec = 0;
-    FD_ZERO (&fds);		/* initialize selection vector */
-    FD_ZERO (&efds);		/* handle errors too */
-    FD_SET (stream->tcpso,&fds);/* set bit in selection vector */
-    FD_SET(stream->tcpso,&efds);/* set bit in error selection vector */
+    pfd.fd = stream->tcpso;
+    pfd.events = POLLOUT;
     errno = NIL;		/* block and write */
     do {			/* block under timeout */
-      tmo.tv_sec = ti ? ti - now : 0;
-      i = select (stream->tcpso+1,NIL,&fds,&efds,ti ? &tmo : NIL);
+      tmo = ti ? ti - now : 0;
+      i = poll (&pfd, 1, ti ? tmo * 1000 : -1);
       now = time (0);		/* fake timeout if interrupt & time expired */
       if ((i < 0) && (errno == EINTR) && ti && (ti <= now)) i = 0;
     } while ((i < 0) && (errno == EINTR));
--- uw-imap.orig/src/osdep/unix/ssl_unix.c	2014-06-04 15:34:16.000000000 +0100
+++ uw-imap/src/osdep/unix/ssl_unix.c	2014-06-04 15:34:21.000000000 +0100
@@ -472,16 +472,14 @@
 
 long ssl_getdata (SSLSTREAM *stream)
 {
-  int i,sock;
-  fd_set fds,efds;
-  struct timeval tmo;
+  int i,sock,tmo;
+  struct pollfd pfd;
   tcptimeout_t tmoh = (tcptimeout_t) mail_parameters (NIL,GET_TIMEOUT,NIL);
   long ttmo_read = (long) mail_parameters (NIL,GET_READTIMEOUT,NIL);
   time_t t = time (0);
   blocknotify_t bn = (blocknotify_t) mail_parameters (NIL,GET_BLOCKNOTIFY,NIL);
   if (!stream->con || ((sock = SSL_get_fd (stream->con)) < 0)) return NIL;
 				/* tcp_unix should have prevented this */
-  if (sock >= FD_SETSIZE) fatal ("unselectable socket in ssl_getdata()");
   (*bn) (BLOCK_TCPREAD,NIL);
   while (stream->ictr < 1) {	/* if nothing in the buffer */
     time_t tl = time (0);	/* start of request */
@@ -490,15 +488,12 @@
     if (SSL_pending (stream->con)) i = 1;
     else {
       if (tcpdebug) mm_log ("Reading SSL data",TCPDEBUG);
-      tmo.tv_usec = 0;
-      FD_ZERO (&fds);		/* initialize selection vector */
-      FD_ZERO (&efds);		/* handle errors too */
-      FD_SET (sock,&fds);	/* set bit in selection vector */
-      FD_SET (sock,&efds);	/* set bit in error selection vector */
+      pfd.fd = sock;
+      pfd.events = POLLIN;
       errno = NIL;		/* block and read */
       do {			/* block under timeout */
-	tmo.tv_sec = ti ? ti - now : 0;
-	i = select (sock+1,&fds,0,&efds,ti ? &tmo : 0);
+	tmo = ti ? ti - now : 0;
+	i = poll (&pfd, 1, ti ? tmo * 1000 : -1);
 	now = time (0);		/* fake timeout if interrupt & time expired */
 	if ((i < 0) && (errno == EINTR) && ti && (ti <= now)) i = 0;
       } while ((i < 0) && (errno == EINTR));