-/* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
- *
- * Libmemcached library
- *
- * Copyright (C) 2011 Data Differential, http://datadifferential.com/
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- * * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *
- * * The names of its contributors may not be used to endorse or
- * promote products derived from this software without specific prior
- * written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-/* -*- Mode: C; tab-width: 2; c-basic-offset: 2; indent-tabs-mode: nil -*- */
-#include <libmemcachedprotocol/common.h>
-
-#include <stdlib.h>
-#include <sys/types.h>
-#include <errno.h>
-#include <stdbool.h>
-#include <string.h>
-#include <strings.h>
-#include <ctype.h>
-#include <stdio.h>
-
-#include <sys/types.h>
-#include <sys/socket.h>
-
-/*
-** **********************************************************************
-** INTERNAL INTERFACE
-** **********************************************************************
-*/
-
-/**
- * The default function to receive data from the client. This function
- * just wraps the recv function to receive from a socket.
- * See man -s3socket recv for more information.
- *
- * @param cookie cookie indentifying a client, not used
- * @param sock socket to read from
- * @param buf the destination buffer
- * @param nbytes the number of bytes to read
- * @return the number of bytes transferred of -1 upon error
- */
-static ssize_t default_recv(const void *cookie,
- memcached_socket_t sock,
- void *buf,
- size_t nbytes)
-{
- (void)cookie;
- return recv(sock, buf, nbytes, 0);
-}
-
-/**
- * The default function to send data to the server. This function
- * just wraps the send function to send through a socket.
- * See man -s3socket send for more information.
- *
- * @param cookie cookie indentifying a client, not used
- * @param sock socket to send to
- * @param buf the source buffer
- * @param nbytes the number of bytes to send
- * @return the number of bytes transferred of -1 upon error
- */
-static ssize_t default_send(const void *cookie,
- memcached_socket_t fd,
- const void *buf,
- size_t nbytes)
-{
- (void)cookie;
- return send(fd, buf, nbytes, MSG_NOSIGNAL);
-}
-
-/**
- * Try to drain the output buffers without blocking
- *
- * @param client the client to drain
- * @return false if an error occured (connection should be shut down)
- * true otherwise (please note that there may be more data to
- * left in the buffer to send)
- */
-static bool drain_output(struct memcached_protocol_client_st *client)
-{
- if (client->is_verbose)
- {
- fprintf(stderr, "%s:%d %s mute:%d output:%s length:%d\n", __FILE__, __LINE__, __func__, (int)client->mute,
- client->output ? "yes" : "no",
- client->output ? (int)(client->output->nbytes - client->output->offset) : 0);
- }
-
- /* Do we have pending data to send? */
- while (client->output != NULL)
- {
- ssize_t len= client->root->send(client,
- client->sock,
- client->output->data + client->output->offset,
- client->output->nbytes - client->output->offset);
-
- if (len == -1)
- {
- if (get_socket_errno() == EWOULDBLOCK)
- {
- return true;
- }
- else if (get_socket_errno() != EINTR)
- {
- client->error= get_socket_errno();
- return false;
- }
- }
- else
- {
- client->output->offset += (size_t)len;
- if (client->output->offset == client->output->nbytes)
- {
- /* This was the complete buffer */
- struct chunk_st *old= client->output;
- client->output= client->output->next;
- if (client->output == NULL)
- {
- client->output_tail= NULL;
- }
- cache_free(client->root->buffer_cache, old);
- }
- }
- }
-
- return true;
-}
-
-/**
- * Allocate an output buffer and chain it into the output list
- *
- * @param client the client that needs the buffer
- * @return pointer to the new chunk if the allocation succeeds, NULL otherwise
- */
-static struct chunk_st *allocate_output_chunk(struct memcached_protocol_client_st *client)
-{
- struct chunk_st *ret= cache_alloc(client->root->buffer_cache);
-
- if (ret == NULL)
- {
- return NULL;
- }
-
- ret->offset= ret->nbytes= 0;
- ret->next= NULL;
- ret->size= CHUNK_BUFFERSIZE;
- ret->data= (void*)(ret + 1);
- if (client->output == NULL)
- {
- client->output= client->output_tail= ret;
- }
- else
- {
- client->output_tail->next= ret;
- client->output_tail= ret;
- }
-
- return ret;
-}
-
-/**
- * Spool data into the send-buffer for a client.
- *
- * @param client the client to spool the data for
- * @param data the data to spool
- * @param length the number of bytes of data to spool
- * @return PROTOCOL_BINARY_RESPONSE_SUCCESS if success,
- * PROTOCOL_BINARY_RESPONSE_ENOMEM if we failed to allocate memory
- */
-static protocol_binary_response_status spool_output(struct memcached_protocol_client_st *client,
- const void *data,
- size_t length)
-{
- if (client->is_verbose)
- {
- fprintf(stderr, "%s:%d %s mute:%d length:%d\n", __FILE__, __LINE__, __func__, (int)client->mute, (int)length);
- }
-
- if (client->mute)
- {
- return PROTOCOL_BINARY_RESPONSE_SUCCESS;
- }
-
- size_t offset= 0;
-
- struct chunk_st *chunk= client->output;
- while (offset < length)
- {
- if (chunk == NULL || (chunk->size - chunk->nbytes) == 0)
- {
- if ((chunk= allocate_output_chunk(client)) == NULL)
- {
- return PROTOCOL_BINARY_RESPONSE_ENOMEM;
- }
- }
-
- size_t bulk= length - offset;
- if (bulk > chunk->size - chunk->nbytes)
- {
- bulk= chunk->size - chunk->nbytes;
- }
-
- memcpy(chunk->data + chunk->nbytes, data, bulk);
- chunk->nbytes += bulk;
- offset += bulk;
- }
-
- return PROTOCOL_BINARY_RESPONSE_SUCCESS;
-}
-
-/**
- * Try to determine the protocol used on this connection.
- * If the first byte contains the magic byte PROTOCOL_BINARY_REQ we should
- * be using the binary protocol on the connection. I implemented the support
- * for the ASCII protocol by wrapping into the simple interface (aka v1),
- * so the implementors needs to provide an implementation of that interface
- *
- */
-static memcached_protocol_event_t determine_protocol(struct memcached_protocol_client_st *client, ssize_t *length, void **endptr)
-{
- if (*client->root->input_buffer == (uint8_t)PROTOCOL_BINARY_REQ)
- {
- if (client->is_verbose)
- {
- fprintf(stderr, "%s:%d PROTOCOL: memcached_binary_protocol_process_data\n", __FILE__, __LINE__);
- }
- client->work= memcached_binary_protocol_process_data;
- }
- else if (client->root->callback->interface_version == 1)
- {
- if (client->is_verbose)
- {
- fprintf(stderr, "%s:%d PROTOCOL: memcached_ascii_protocol_process_data\n", __FILE__, __LINE__);
- }
-
- /*
- * The ASCII protocol can only be used if the implementors provide
- * an implementation for the version 1 of the interface..
- *
- * @todo I should allow the implementors to provide an implementation
- * for version 0 and 1 at the same time and set the preferred
- * interface to use...
- */
- client->work= memcached_ascii_protocol_process_data;
- }
- else
- {
- if (client->is_verbose)
- {
- fprintf(stderr, "%s:%d PROTOCOL: Unsupported protocol\n", __FILE__, __LINE__);
- }
-
- /* Let's just output a warning the way it is supposed to look like
- * in the ASCII protocol...
- */
- const char *err= "CLIENT_ERROR: Unsupported protocol\r\n";
- client->root->spool(client, err, strlen(err));
- client->root->drain(client);
-
- return MEMCACHED_PROTOCOL_ERROR_EVENT; /* Unsupported protocol */
- }
-
- return client->work(client, length, endptr);
-}
-
-/*
-** **********************************************************************
-** * PUBLIC INTERFACE
-** * See protocol_handler.h for function description
-** **********************************************************************
-*/
-struct memcached_protocol_st *memcached_protocol_create_instance(void)
-{
- struct memcached_protocol_st *ret= calloc(1, sizeof(*ret));
- if (ret != NULL)
- {
- ret->recv= default_recv;
- ret->send= default_send;
- ret->drain= drain_output;
- ret->spool= spool_output;
- ret->input_buffer_size= 1 * 1024 * 1024;
- ret->input_buffer= malloc(ret->input_buffer_size);
- if (ret->input_buffer == NULL)
- {
- free(ret);
- ret= NULL;
-
- return NULL;
- }
-
- ret->buffer_cache= cache_create("protocol_handler",
- CHUNK_BUFFERSIZE + sizeof(struct chunk_st),
- 0, NULL, NULL);
- if (ret->buffer_cache == NULL)
- {
- free(ret->input_buffer);
- free(ret);
- ret= NULL;
- }
- }
-
- return ret;
-}
-
-void memcached_protocol_destroy_instance(struct memcached_protocol_st *instance)
-{
- cache_destroy(instance->buffer_cache);
- free(instance->input_buffer);
- free(instance);
-}
-
-struct memcached_protocol_client_st *memcached_protocol_create_client(struct memcached_protocol_st *instance, memcached_socket_t sock)
-{
- struct memcached_protocol_client_st *ret= calloc(1, sizeof(memcached_protocol_client_st));
- if (ret != NULL)
- {
- ret->root= instance;
- ret->sock= sock;
- ret->work= determine_protocol;
- }
-
- return ret;
-}
-
-void memcached_protocol_client_destroy(struct memcached_protocol_client_st *client)
-{
- free(client);
-}
-
-void memcached_protocol_client_set_verbose(struct memcached_protocol_client_st *client, bool arg)
-{
- if (client)
- {
- client->is_verbose= arg;
- }
-}
-
-memcached_protocol_event_t memcached_protocol_client_work(struct memcached_protocol_client_st *client)
-{
- /* Try to send data and read from the socket */
- bool more_data= true;
- do
- {
- ssize_t len= client->root->recv(client,
- client->sock,
- client->root->input_buffer + client->input_buffer_offset,
- client->root->input_buffer_size - client->input_buffer_offset);
-
- if (len > 0)
- {
- /* Do we have the complete packet? */
- if (client->input_buffer_offset > 0)
- {
- memcpy(client->root->input_buffer, client->input_buffer,
- client->input_buffer_offset);
- len += (ssize_t)client->input_buffer_offset;
-
- /* @todo use buffer-cache! */
- free(client->input_buffer);
- client->input_buffer_offset= 0;
- }
-
- void *endptr;
- memcached_protocol_event_t events= client->work(client, &len, &endptr);
- if (events == MEMCACHED_PROTOCOL_ERROR_EVENT)
- {
- return MEMCACHED_PROTOCOL_ERROR_EVENT;
- }
-
- if (len > 0)
- {
- /* save the data for later on */
- /* @todo use buffer-cache */
- client->input_buffer= malloc((size_t)len);
- if (client->input_buffer == NULL)
- {
- client->error= ENOMEM;
- return MEMCACHED_PROTOCOL_ERROR_EVENT;
- }
- memcpy(client->input_buffer, endptr, (size_t)len);
- client->input_buffer_offset= (size_t)len;
- more_data= false;
- }
- }
- else if (len == 0)
- {
- /* Connection closed */
- drain_output(client);
- return MEMCACHED_PROTOCOL_ERROR_EVENT;
- }
- else
- {
- if (get_socket_errno() != EWOULDBLOCK)
- {
- client->error= get_socket_errno();
- /* mark this client as terminated! */
- return MEMCACHED_PROTOCOL_ERROR_EVENT;
- }
- more_data= false;
- }
- } while (more_data);
-
- if (!drain_output(client))
- {
- return MEMCACHED_PROTOCOL_ERROR_EVENT;
- }
-
- memcached_protocol_event_t ret= MEMCACHED_PROTOCOL_READ_EVENT;
- if (client->output)
- {
- ret|= MEMCACHED_PROTOCOL_READ_EVENT;
- }
-
- return ret;
-}