apcups branch: Some debug messages and such.

collectd dies when the port is forwarded using ssh and then the server exits.
Apparently ssh doesn't anser with a connection refused right away which may
result in problems..
This revision adds some debug messages and handles `EOF' correctly (when
reading).

diff --git a/src/apcups.c b/src/apcups.c
index 977b793..e2ad70c 100644 (file)
--- a/src/apcups.c
+++ b/src/apcups.c
@@ -153,16 +153,25 @@ static int read_nbytes (int *fd, char *ptr, int nbytes)
        {
                nread = read (*fd, ptr, nleft);
 
-               if (nread == -1 && (errno == EINTR || errno == EAGAIN))
+               if ((nread < 0) && (errno == EINTR || errno == EAGAIN))
                        continue;
 
-               if (nread == -1)
+               if (nread < 0)
                {
                        *fd = -1;
-                       syslog (LOG_ERR, "apcups plugin: write failed: %s", strerror (errno));
+                       DBG ("Reading from socket failed failed: %s; *fd = -1;", strerror (errno));
+                       syslog (LOG_ERR, "apcups plugin: Reading from socket failed failed: %s", strerror (errno));
                        return (-1);
                }
 
+               if (nread == 0)
+               {
+                       DBG ("Received EOF. Closing socket %i.", *fd);
+                       close (*fd);
+                       *fd = -1;
+                       return (nbytes - nleft);
+               }
+
                nleft -= nread;
                ptr += nread;
        }
@@ -190,13 +199,14 @@ static int write_nbytes (int *fd, void *buf, int buflen)
        {
                nwritten = write (*fd, ptr, nleft);
 
-               if ((nwritten == -1) && ((errno == EAGAIN) || (errno == EINTR)))
+               if ((nwritten < 0) && ((errno == EAGAIN) || (errno == EINTR)))
                        continue;
 
-               if (nwritten == -1)
+               if (nwritten < 0)
                {
-                       syslog (LOG_ERR, "Writing to socket failed: %s", strerror (errno));
                        *fd = -1;
+                       DBG ("Writing to socket failed: %s; *fd = -1;", strerror (errno));
+                       syslog (LOG_ERR, "apcups plugin: Writing to socket failed: %s", strerror (errno));
                        return (-1);
                }
 
@@ -215,6 +225,8 @@ static void net_close (int *fd)
 
        assert (*fd >= 0);
 
+       DBG ("Gracefully shutting down socket %i.", *fd);
+
        /* send EOF sentinel */
        write_nbytes (fd, &pktsiz, sizeof (short));
 
@@ -222,7 +234,6 @@ static void net_close (int *fd)
        *fd = -1;
 }
 
-
 /*     
  * Open a TCP connection to the UPS network server
  * Returns -1 on error
@@ -282,7 +293,7 @@ static int net_open (char *host, char *service, int port)
                return (-1);
        }
 
-       DBG ("Done opening a socket: %i", sd);
+       DBG ("Done opening a socket %i", sd);
 
        return (sd);
 } /* int net_open (char *host, char *service, int port) */
@@ -341,6 +352,7 @@ static int net_send (int *sockfd, char *buff, int len)
        short packet_size;
 
        assert (len > 0);
+       assert (*sockfd >= 0);
 
        /* send short containing size of data packet */
        packet_size = htons ((short) len);
@@ -419,7 +431,6 @@ static int apc_query_server (char *host, int port,
                        value = atof (tokptr);
 
                        PRINT_VALUE (key, value);
-                       DBG ("key = %s; value = %f;", key, value);
 
                        if (strcmp ("LINEV", key) == 0)
                                apcups_detail->linev = value;
@@ -446,9 +457,11 @@ static int apc_query_server (char *host, int port,
        {
                syslog (LOG_WARNING, "apcups plugin: Error reading from socket");
                return (-1);
-       } else {
+       }
+       else
+       {
                /* close the opened socket */
-               net_close(&sockfd);
+               net_close (&sockfd);
        }
 
        return (0);