a cleanup of the receive_smb() usage, adding timeouts in some places

also added paranoid code in the main process() loop of smbd to detect
when smbd is looping uselessly. This should stop the "smbd is chewing
lots of cpu" reports
(This used to be commit 8e9dce34d50d673cb50531f0c4c7672ce2522cef)

7 files changed, 43 insertions, 24 deletions

diff --git a/source3/include/smb.h b/source3/include/smb.h
index 5fd2e0846b..b9dd13a802 100644
--- a/source3/include/smb.h
+++ b/source3/include/smb.h
@@ -99,6 +99,9 @@ typedef unsigned int uint32;
 #define DEFAULT_PIPE_TIMEOUT 10000000 /* Ten seconds */
 #endif
 
+/* how long to wait for secondary SMB packets (seconds) */
+#define SMB_SECONDARY_WAIT 30
+
 /* debugging code */
 #ifndef SYSLOG
 #define DEBUG(level,body) ((DEBUGLEVEL>=(level))?(Debug1 body):0)
diff --git a/source3/lib/util.c b/source3/lib/util.c
index fc47313b57..ee4fca3ed3 100644
--- a/source3/lib/util.c
+++ b/source3/lib/util.c
@@ -2079,7 +2079,7 @@ int read_smb_length(int fd,char *inbuf,int timeout)
 
       if (msg_type == 0x85) 
 	{
-	  DEBUG(5,( "Got keepalive packet\n"));
+	  DEBUG(5,("Got keepalive packet\n"));
 	  ok = False;
 	}
     }
@@ -2097,8 +2097,7 @@ The timeout is in milli seconds
 ****************************************************************************/
 BOOL receive_smb(int fd,char *buffer,int timeout)
 {
-  int len;
-  BOOL ok;
+  int len,ret;
 
   bzero(buffer,smb_size + 100);
 
@@ -2107,18 +2106,16 @@ BOOL receive_smb(int fd,char *buffer,int timeout)
     return(False);
 
   if (len > BUFFER_SIZE) {
-    DEBUG(0,("Invalid packet length! (%d bytes)\n",len));
+    DEBUG(0,("Invalid packet length! (%d bytes).\n",len));
     if (len > BUFFER_SIZE + (SAFETY_MARGIN/2))
       exit(1);
   }
 
-  ok = (read_data(fd,buffer+4,len) == len);
-
-  if (!ok)
-    {
-      close_sockets();
-      exit(1);
-    }
+  ret = read_data(fd,buffer+4,len);
+  if (ret != len) {
+    DEBUG(0,("ERROR: Invalid SMB length. Expected %d got %d\n",len,ret));
+    return False;
+  }
 
   return(True);
 }
diff --git a/source3/smbd/ipc.c b/source3/smbd/ipc.c
index 594e067ddd..415c939bf3 100644
--- a/source3/smbd/ipc.c
+++ b/source3/smbd/ipc.c
@@ -2790,12 +2790,9 @@ int reply_trans(char *inbuf,char *outbuf)
   while (pscnt < tpscnt || dscnt < tdscnt)
     {
       int pcnt,poff,dcnt,doff,pdisp,ddisp;
-
-      receive_smb(Client,inbuf, 0);
-      show_msg(inbuf);
-	  
-      /* Ensure this is still a trans packet (sanity check) */
-      if(CVAL(inbuf, smb_com) != SMBtrans)
+      
+      if (!receive_smb(Client,inbuf, SMB_SECONDARY_WAIT*1000) ||
+	  CVAL(inbuf, smb_com) != SMBtrans)
 	{
 	  DEBUG(2,("Invalid secondary trans2 packet\n"));
 	  if (params) free(params);
@@ -2803,6 +2800,8 @@ int reply_trans(char *inbuf,char *outbuf)
 	  if (setup) free(setup);
 	  return(ERROR(ERRSRV,ERRerror));
 	}
+
+      show_msg(inbuf);
       
       tpscnt = SVAL(inbuf,smb_vwv0);
       tdscnt = SVAL(inbuf,smb_vwv1);
diff --git a/source3/smbd/password.c b/source3/smbd/password.c
index ae548b8266..a5f597682f 100644
--- a/source3/smbd/password.c
+++ b/source3/smbd/password.c
@@ -1318,9 +1318,10 @@ BOOL server_cryptkey(char *buf)
   CVAL(outbuf,0) = 0x81;
 
   send_smb(password_client,outbuf);
-  receive_smb(password_client,inbuf,5000);
+  
  
-  if (CVAL(inbuf,0) != 0x82) {
+  if (!receive_smb(password_client,inbuf,5000) ||
+      CVAL(inbuf,0) != 0x82) {
     DEBUG(1,("%s rejected the session\n",pserver));
     close(password_client); password_client = -1;
     return(False);
diff --git a/source3/smbd/reply.c b/source3/smbd/reply.c
index 43703982ec..4cfa001ec2 100644
--- a/source3/smbd/reply.c
+++ b/source3/smbd/reply.c
@@ -1590,7 +1590,7 @@ int reply_writebraw(char *inbuf,char *outbuf)
   send_smb(Client,outbuf);
   
   /* Now read the raw data into the buffer and write it */
-  if(read_smb_length(Client,inbuf,0) == -1) {
+  if (read_smb_length(Client,inbuf,SMB_SECONDARY_WAIT) == -1) {
     exit_server("secondary writebraw failed");
   }
   
diff --git a/source3/smbd/server.c b/source3/smbd/server.c
index ecc8e4ce9c..3ececed393 100644
--- a/source3/smbd/server.c
+++ b/source3/smbd/server.c
@@ -3445,6 +3445,27 @@ static void process(void)
 
 	  t = time(NULL);
 
+	  {
+	    /* the following bit of code was added to combat smbd
+               looping chewing lots of CPU time. It should never
+               actually be needed, but it seems that some systems
+               don't set error correctly, which is used to distinguish
+               a select() timeout from a read error 
+	       
+	       we exit if receive_smb() returns false 3 times in one second. 
+	       */
+	    static int error_count=0;
+	    static time_t error_time=0;
+	    if (error_count==0) {
+	      error_time = t;
+	    } else if (error_time != t) {
+	      error_count = 0;
+	    } else if (error_count++ > 2) {
+	      exit_server("looping in process()\n");
+	    }
+	  }
+
+
 	  /* become root again if waiting */
 	  unbecome_user();
 
diff --git a/source3/smbd/trans2.c b/source3/smbd/trans2.c
index 0b113a2ed0..321dabc72c 100644
--- a/source3/smbd/trans2.c
+++ b/source3/smbd/trans2.c
@@ -1554,10 +1554,8 @@ int reply_trans2(char *inbuf,char *outbuf,int length,int bufsize)
 
       while( num_data_sofar < total_data || num_params_sofar < total_params)
 	{
-	  receive_smb(Client,inbuf, 0);
-	  
-	  /* Ensure this is still a trans2 packet (sanity check) */
-	  if(CVAL(inbuf, smb_com) != SMBtranss2)
+	  if(!receive_smb(Client,inbuf, SMB_SECONDARY_WAIT*1000) ||
+	     CVAL(inbuf, smb_com) != SMBtranss2)
 	    {
 	      outsize = set_message(outbuf,0,0,True);
 	      DEBUG(2,("Invalid secondary trans2 packet\n"));