diff options
| -rw-r--r-- | src/vlibmemory/socket_api.c | 128 |
1 files changed, 80 insertions, 48 deletions
diff --git a/src/vlibmemory/socket_api.c b/src/vlibmemory/socket_api.c index c423c526625..edc0f28ff34 100644 --- a/src/vlibmemory/socket_api.c +++ b/src/vlibmemory/socket_api.c @@ -203,43 +203,68 @@ vl_socket_process_api_msg (clib_file_t * uf, vl_api_registration_t * rp, socket_main.current_rp = 0; } +/* + * Read function for API socket. + * + * Read data from socket, invoke SOCKET_READ_EVENT + * for each fully read API message, return 0. + * Store incomplete data for next invocation to continue. + * + * On severe read error, the file is closed. + * + * As reading is single threaded, + * socket_main.input_buffer is used temporarily. + * Even its length is modified, but always restored before return. + * + * Incomplete data is copied into a vector, + * pointer saved in registration's unprocessed_input. + */ clib_error_t * vl_socket_read_ready (clib_file_t * uf) { clib_file_main_t *fm = &file_main; vlib_main_t *vm = vlib_get_main (); vl_api_registration_t *rp; + /* n is the size of data read to input_buffer */ int n; + /* msg_buffer vector can point to input_buffer or unprocessed_input */ i8 *msg_buffer = 0; + /* data_for_process is a vector containing one full message, incl msgbuf_t */ u8 *data_for_process; - u32 msg_len; + /* msgbuf_len is the size of one message, including sizeof (msgbuf_t) */ + u32 msgbuf_len; u32 save_input_buffer_length = vec_len (socket_main.input_buffer); vl_socket_args_for_process_t *a; - msgbuf_t *mbp; - int mbp_set = 0; rp = pool_elt_at_index (socket_main.registration_pool, uf->private_data); + /* Ignore unprocessed_input for now, n describes input_buffer for now. */ n = read (uf->file_descriptor, socket_main.input_buffer, vec_len (socket_main.input_buffer)); - if (n <= 0 && errno != EAGAIN) + if (n <= 0) { - clib_file_del (fm, uf); - - if (!pool_is_free (socket_main.registration_pool, rp)) - { - u32 index = rp - socket_main.registration_pool; - vl_socket_free_registration_index (index); - } - else + if (errno != EAGAIN) { - clib_warning ("client index %d already free?", - rp->vl_api_registration_pool_index); + /* Severe error, close the file. */ + clib_file_del (fm, uf); + + if (!pool_is_free (socket_main.registration_pool, rp)) + { + u32 index = rp - socket_main.registration_pool; + vl_socket_free_registration_index (index); + } + else + { + clib_warning ("client index %d already free?", + rp->vl_api_registration_pool_index); + } } + /* EAGAIN means we do not close the file, but no data to process anyway. */ return 0; } + /* Fake smaller length teporarily, so input_buffer can be used as msg_buffer. */ _vec_len (socket_main.input_buffer) = n; /* @@ -248,37 +273,38 @@ vl_socket_read_ready (clib_file_t * uf) * boundaries. In the case of a long message (>4K bytes) * we have to do (at least) 2 reads, etc. */ + /* Determine msg_buffer. */ + if (vec_len (rp->unprocessed_input)) + { + vec_append (rp->unprocessed_input, socket_main.input_buffer); + msg_buffer = rp->unprocessed_input; + } + else + { + msg_buffer = socket_main.input_buffer; + } + /* Loop to process any full messages. */ + ASSERT (vec_len (msg_buffer) > 0); do { - if (vec_len (rp->unprocessed_input)) - { - vec_append (rp->unprocessed_input, socket_main.input_buffer); - msg_buffer = rp->unprocessed_input; - } - else - { - msg_buffer = socket_main.input_buffer; - mbp_set = 0; - } - - if (mbp_set == 0) - { - /* Any chance that we have a complete message? */ - if (vec_len (msg_buffer) <= sizeof (msgbuf_t)) - goto save_and_split; - - mbp = (msgbuf_t *) msg_buffer; - msg_len = ntohl (mbp->data_len); - mbp_set = 1; - } - - /* We don't have the entire message yet. */ - if (mbp_set == 0 - || (msg_len + sizeof (msgbuf_t)) > vec_len (msg_buffer)) + /* Here, we are not sure how big a chunk of message we have left. */ + /* Do we at least know how big the full message will be? */ + if (vec_len (msg_buffer) <= sizeof (msgbuf_t)) + /* No, so fragment is not a full message. */ + goto save_and_split; + + /* Now we know how big the full message will be. */ + msgbuf_len = + ntohl (((msgbuf_t *) msg_buffer)->data_len) + sizeof (msgbuf_t); + + /* But do we have a full message? */ + if (msgbuf_len > vec_len (msg_buffer)) { save_and_split: - /* if we were using the input buffer save the fragment */ + /* We don't have the entire message yet. */ + /* If msg_buffer is unprocessed_input, nothing needs to be done. */ if (msg_buffer == socket_main.input_buffer) + /* But if we were using the input buffer, save the fragment. */ { ASSERT (vec_len (rp->unprocessed_input) == 0); vec_validate (rp->unprocessed_input, vec_len (msg_buffer) - 1); @@ -286,12 +312,19 @@ vl_socket_read_ready (clib_file_t * uf) vec_len (msg_buffer)); _vec_len (rp->unprocessed_input) = vec_len (msg_buffer); } + /* No more full messages, restore original input_buffer length. */ _vec_len (socket_main.input_buffer) = save_input_buffer_length; return 0; } + /* + * We have at least one full message. + * But msg_buffer can contain more data, so copy one message data + * so we can overwrite its length to what single message has. + */ data_for_process = (u8 *) vec_dup (msg_buffer); - _vec_len (data_for_process) = (msg_len + sizeof (msgbuf_t)); + _vec_len (data_for_process) = msgbuf_len; + /* Everything is ready to signal the SOCKET_READ_EVENT. */ pool_get (socket_main.process_args, a); a->clib_file = uf; a->regp = rp; @@ -300,18 +333,17 @@ vl_socket_read_ready (clib_file_t * uf) vlib_process_signal_event (vm, vl_api_clnt_node.index, SOCKET_READ_EVENT, a - socket_main.process_args); - if (n > (msg_len + sizeof (*mbp))) - vec_delete (msg_buffer, msg_len + sizeof (*mbp), 0); + if (vec_len (msg_buffer) > msgbuf_len) + /* There are some fragments left. Shrink the msg_buffer to simplify logic. */ + vec_delete (msg_buffer, msgbuf_len, 0); else + /* We are done with msg_buffer. */ _vec_len (msg_buffer) = 0; - n -= msg_len + sizeof (msgbuf_t); - msg_len = 0; - mbp_set = 0; } - while (n > 0); + while (vec_len (msg_buffer) > 0); + /* Restore input_buffer, it could have been msg_buffer. */ _vec_len (socket_main.input_buffer) = save_input_buffer_length; - return 0; } |