- Fix buffer head/tail code.

- Correctly handle no more data and remote disconnect.

diff --git a/omapip/buffer.c b/omapip/buffer.c
index a3bb2f2a429a278adf8fd410b24f2313d5fdcd42..37cfc2cb6341fa417f25b6d1d0b9369b526240cd 100644 (file)
--- a/omapip/buffer.c
+++ b/omapip/buffer.c
@@ -51,7 +51,7 @@ isc_result_t omapi_connection_reader (omapi_object_t *h)
                for (buffer = c -> inbufs; buffer -> next;
                     buffer = buffer -> next)
                        ;
-               if (!BUFFER_BYTES_AVAIL (buffer)) {
+               if (!BUFFER_BYTES_FREE (buffer)) {
                        status = omapi_buffer_new (&buffer -> next,
                                                   "omapi_private_read");
                        if (status != ISC_R_SUCCESS)
@@ -66,19 +66,19 @@ isc_result_t omapi_connection_reader (omapi_object_t *h)
                buffer = c -> inbufs;
        }
 
-       bytes_to_read = BUFFER_BYTES_AVAIL (buffer);
+       bytes_to_read = BUFFER_BYTES_FREE (buffer);
 
        while (bytes_to_read) {
-               if (buffer -> tail >= buffer -> head)
-                       read_len = sizeof (buffer -> buf) - buffer -> tail - 1;
+               if (buffer -> tail > buffer -> head)
+                       read_len = sizeof (buffer -> buf) - buffer -> tail;
                else
-                       read_len = buffer -> tail - buffer -> head - 1;
+                       read_len = buffer -> head - buffer -> tail;
 
                read_status = read (c -> socket,
                                    &buffer -> buf [buffer -> tail], read_len);
                if (read_status < 0) {
                        if (errno == EWOULDBLOCK)
-                               return ISC_R_NOMORE;
+                               break;
                        else if (errno == EIO)
                                return ISC_R_IOERROR;
                        else if (errno == EINVAL)
@@ -89,6 +89,8 @@ isc_result_t omapi_connection_reader (omapi_object_t *h)
                        } else
                                return ISC_R_UNEXPECTED;
                }
+               /* If we got a zero-length read, as opposed to EWOULDBLOCK,
+                  the remote end closed the connection. */
                if (read_status == 0) {
                        omapi_disconnect (h, 0);
                        return ISC_R_SHUTTINGDOWN;
@@ -142,7 +144,7 @@ isc_result_t omapi_connection_copyin (omapi_object_t *h,
        while (bytes_copied < len) {
                /* If there is no space available in this buffer,
                    allocate a new one. */
-               if (!BUFFER_BYTES_AVAIL (buffer)) {
+               if (!BUFFER_BYTES_FREE (buffer)) {
                        status = (omapi_buffer_new
                                  (&buffer -> next,
                                   "omapi_private_buffer_copyin"));
@@ -151,10 +153,11 @@ isc_result_t omapi_connection_copyin (omapi_object_t *h,
                        buffer = buffer -> next;
                }
 
-               if (buffer -> tail < buffer -> head)
-                       copy_len = buffer -> tail - buffer -> head - 1;
+               if (buffer -> tail > buffer -> head)
+                       copy_len = sizeof (buffer -> buf) - buffer -> tail;
                else
-                       copy_len = sizeof (buffer -> buf) - buffer -> tail - 1;
+                       copy_len = buffer -> head - buffer -> tail;
+
                if (copy_len > (len - bytes_copied))
                        copy_len = len - bytes_copied;
 
@@ -178,6 +181,7 @@ isc_result_t omapi_connection_copyout (unsigned char *buf,
 {
        unsigned bytes_remaining;
        unsigned bytes_this_copy;
+       unsigned first_byte;
        omapi_buffer_t *buffer;
        unsigned char *bufp;
        omapi_connection_object_t *c;
@@ -195,36 +199,39 @@ isc_result_t omapi_connection_copyout (unsigned char *buf,
        while (bytes_remaining) {
                if (!buffer)
                        return ISC_R_UNEXPECTED;
-               if (buffer -> head != buffer -> tail) {
-                       if (buffer -> head > buffer -> tail) {
+               if (BYTES_IN_BUFFER (buffer)) {
+                       if (buffer -> head == (sizeof buffer -> buf) - 1)
+                               first_byte = 0;
+                       else
+                               first_byte = buffer -> head + 1;
+
+                       if (first_byte > buffer -> tail) {
                                bytes_this_copy = (sizeof buffer -> buf -
-                                                  buffer -> head);
+                                                  first_byte);
                        } else {
                                bytes_this_copy =
-                                       buffer -> tail - buffer -> head;
+                                       buffer -> tail - first_byte;
                        }
                        if (bytes_this_copy > bytes_remaining)
                                bytes_this_copy = bytes_remaining;
                        if (bufp) {
-                               memcpy (bufp, &buffer -> buf [buffer -> head],
+                               memcpy (bufp, &buffer -> buf [first_byte],
                                        bytes_this_copy);
                                bufp += bytes_this_copy;
                        }
                        bytes_remaining -= bytes_this_copy;
-                       buffer -> head += bytes_this_copy;
-                       if (buffer -> head == sizeof buffer -> buf)
-                               buffer -> head = 0;
+                       buffer -> head = first_byte + bytes_this_copy - 1;
                        c -> in_bytes -= bytes_this_copy;
                }
                        
-               if (buffer -> head == buffer -> tail)
+               if (!BYTES_IN_BUFFER (buffer))
                        buffer = buffer -> next;
        }
 
        /* Get rid of any input buffers that we emptied. */
        buffer = (omapi_buffer_t *)0;
        while (c -> inbufs &&
-              c -> inbufs -> head == c -> inbufs -> tail) {
+              !BYTES_IN_BUFFER (c -> inbufs)) {
                if (c -> inbufs -> next) {
                        omapi_buffer_reference
                                (&buffer,
@@ -236,11 +243,13 @@ isc_result_t omapi_connection_copyout (unsigned char *buf,
                }
                omapi_buffer_dereference (&c -> inbufs,
                                          "omapi_private_buffer_copyout");
-               omapi_buffer_reference (&c -> inbufs,
-                                       buffer,
-                                       "omapi_private_buffer_copyout");
-               omapi_buffer_dereference (&buffer,
-                                         "omapi_private_buffer_copyout");
+               if (buffer) {
+                       omapi_buffer_reference
+                               (&c -> inbufs, buffer,
+                                "omapi_private_buffer_copyout");
+                       omapi_buffer_dereference
+                               (&buffer, "omapi_private_buffer_copyout");
+               }
        }
        return ISC_R_SUCCESS;
 }
@@ -249,6 +258,7 @@ isc_result_t omapi_connection_writer (omapi_object_t *h)
 {
        unsigned bytes_this_write;
        unsigned bytes_written;
+       unsigned first_byte;
        omapi_buffer_t *buffer;
        unsigned char *bufp;
        omapi_connection_object_t *c;
@@ -266,16 +276,21 @@ isc_result_t omapi_connection_writer (omapi_object_t *h)
        while (c -> out_bytes) {
                if (!buffer)
                        return ISC_R_UNEXPECTED;
-               if (buffer -> head != buffer -> tail) {
-                       if (buffer -> head > buffer -> tail) {
+               if (BYTES_IN_BUFFER (buffer)) {
+                       if (buffer -> head == (sizeof buffer -> buf) - 1)
+                               first_byte = 0;
+                       else
+                               first_byte = buffer -> head + 1;
+
+                       if (first_byte > buffer -> tail) {
                                bytes_this_write = (sizeof buffer -> buf -
-                                                  buffer -> head);
+                                                  first_byte);
                        } else {
                                bytes_this_write =
-                                       (buffer -> tail - buffer -> head);
+                                       buffer -> tail - first_byte;
                        }
                        bytes_written = write (c -> socket,
-                                              &buffer -> buf [buffer -> head],
+                                              &buffer -> buf [first_byte],
                                               bytes_this_write);
                        /* If the write failed with EWOULDBLOCK or we wrote
                           zero bytes, a further write would block, so we have
@@ -302,9 +317,7 @@ isc_result_t omapi_connection_writer (omapi_object_t *h)
                        if (bytes_written == 0)
                                return ISC_R_SUCCESS;
 
-                       buffer -> head += bytes_written;
-                       if (buffer -> head == sizeof buffer -> buf)
-                               buffer -> head = 0;
+                       buffer -> head = first_byte + bytes_written - 1;
                        c -> out_bytes -= bytes_written;
 
                        /* If we didn't finish out the write, we filled the
@@ -314,14 +327,14 @@ isc_result_t omapi_connection_writer (omapi_object_t *h)
                                return ISC_R_SUCCESS;
                }
                        
-               if (buffer -> head == buffer -> tail)
+               if (!BYTES_IN_BUFFER (buffer))
                        buffer = buffer -> next;
        }
                
        /* Get rid of any output buffers we emptied. */
        buffer = (omapi_buffer_t *)0;
        while (c -> outbufs &&
-              c -> outbufs -> head == c -> outbufs -> tail) {
+              !BYTES_IN_BUFFER (c -> outbufs)) {
                if (c -> outbufs -> next) {
                        omapi_buffer_reference
                                (&buffer, c -> outbufs -> next,