/**************************************************************************** * net/local/local_fifo.c * * Copyright (C) 2015 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. 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. * 3. Neither the name NuttX nor the names of its contributors may 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. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #if defined(CONFIG_NET) && defined(CONFIG_NET_LOCAL) #include #include #include #include #include #include #include #include #include #include "local/local.h" /**************************************************************************** * Private Functions ****************************************************************************/ #define LOCAL_CS_SUFFIX "CS" /* Name of the client-to-server FIFO */ #define LOCAL_SC_SUFFIX "SC" /* Name of the server-to-client FIFO */ #define LOCAL_HD_SUFFIX "HD" /* Name of the half duplex datagram FIFO */ #define LOCAL_SUFFIX_LEN 2 #define LOCAL_FULLPATH_LEN (UNIX_PATH_MAX + LOCAL_SUFFIX_LEN) /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: local_cs_name * * Description: * Create the name of the client-to-server FIFO. * ****************************************************************************/ #ifdef CONFIG_NET_LOCAL_STREAM static inline void local_cs_name(FAR struct local_conn_s *conn, FAR char *path) { if (conn->lc_instance_id < 0) { (void)snprintf(path, LOCAL_FULLPATH_LEN-1, "%s" LOCAL_CS_SUFFIX, conn->lc_path); } else { (void)snprintf(path, LOCAL_FULLPATH_LEN-1, "%s" LOCAL_CS_SUFFIX "%x", conn->lc_path, conn->lc_instance_id); } path[LOCAL_FULLPATH_LEN-1] = '\0'; } #endif /* CONFIG_NET_LOCAL_STREAM */ /**************************************************************************** * Name: local_sc_name * * Description: * Create the name of the server-to-client FIFO. * ****************************************************************************/ #ifdef CONFIG_NET_LOCAL_STREAM static inline void local_sc_name(FAR struct local_conn_s *conn, FAR char *path) { if (conn->lc_instance_id < 0) { (void)snprintf(path, LOCAL_FULLPATH_LEN-1, "%s" LOCAL_SC_SUFFIX, conn->lc_path); } else { (void)snprintf(path, LOCAL_FULLPATH_LEN-1, "%s" LOCAL_SC_SUFFIX "%x", conn->lc_path, conn->lc_instance_id); } path[LOCAL_FULLPATH_LEN-1] = '\0'; } #endif /* CONFIG_NET_LOCAL_STREAM */ /**************************************************************************** * Name: local_hd_name * * Description: * Create the name of the half duplex, datagram FIFO. * ****************************************************************************/ #ifdef CONFIG_NET_LOCAL_DGRAM static inline void local_hd_name(FAR const char *inpath, FAR char *outpath) { (void)snprintf(outpath, LOCAL_FULLPATH_LEN-1, "%s" LOCAL_HD_SUFFIX, inpath); outpath[LOCAL_FULLPATH_LEN-1] = '\0'; } #endif /* CONFIG_NET_LOCAL_DGRAM */ /**************************************************************************** * Name: local_fifo_exists * * Description: * Check if a FIFO exists. * ****************************************************************************/ static bool local_fifo_exists(FAR const char *path) { struct stat buf; int ret; /* Create the client-to-server FIFO */ ret = stat(path, &buf); if (ret < 0) { return false; } /* FIFOs are character devices in NuttX. Return true if what we found * is a FIFO. What if it is something else? In that case, we will * return false and mkfifo() will fail. */ return (bool)S_ISCHR(buf.st_mode); } /**************************************************************************** * Name: local_create_fifo * * Description: * Create the one FIFO. * ****************************************************************************/ static int local_create_fifo(FAR const char *path) { int ret; /* Create the client-to-server FIFO if it does not already exist. */ if (!local_fifo_exists(path)) { ret = mkfifo(path, 0644); if (ret < 0) { int errcode = get_errno(); DEBUGASSERT(errcode > 0); nerr("ERROR: Failed to create FIFO %s: %d\n", path, errcode); return -errcode; } } /* The FIFO (or some character driver) exists at PATH or we successfully * created the FIFO at that location. */ return OK; } /**************************************************************************** * Name: local_release_fifo * * Description: * Release a reference from one of the FIFOs used in a connection. * ****************************************************************************/ #ifdef CONFIG_NET_LOCAL_STREAM /* Currently not used by datagram code */ static int local_release_fifo(FAR const char *path) { int ret; /* Unlink the client-to-server FIFO if it exists. */ if (local_fifo_exists(path)) { /* Un-linking the FIFO removes the FIFO from the namespace. It will * also mark the FIFO device "unlinked". When all of the open * references to the FIFO device are closed, the resources consumed * by the device instance will also be freed. */ ret = unlink(path); if (ret < 0) { int errcode = get_errno(); DEBUGASSERT(errcode > 0); nerr("ERROR: Failed to unlink FIFO %s: %d\n", path, errcode); return -errcode; } } /* The FIFO does not exist or we successfully unlinked it. */ return OK; } #endif /**************************************************************************** * Name: local_rx_open * * Description: * Open a FIFO for read-only access. * ****************************************************************************/ static int local_rx_open(FAR struct local_conn_s *conn, FAR const char *path, bool nonblock) { int oflags = nonblock ? O_RDONLY | O_NONBLOCK : O_RDONLY; conn->lc_infd = open(path, oflags); if (conn->lc_infd < 0) { int errcode = get_errno(); DEBUGASSERT(errcode > 0); nerr("ERROR: Failed on open %s for reading: %d\n", path, errcode); /* Map the errcode to something consistent with the return * error codes from connect(): * * If errcode is ENOENT, meaning that the FIFO does exist, * return EFAULT meaning that the socket structure address is * outside the user's address space. */ return errcode == ENOENT ? -EFAULT : -errcode; } return OK; } /**************************************************************************** * Name: local_tx_open * * Description: * Open a FIFO for write-only access. * ****************************************************************************/ static int local_tx_open(FAR struct local_conn_s *conn, FAR const char *path, bool nonblock) { int oflags = nonblock ? O_WRONLY | O_NONBLOCK : O_WRONLY; conn->lc_outfd = open(path, oflags); if (conn->lc_outfd < 0) { int errcode = get_errno(); DEBUGASSERT(errcode > 0); nerr("ERROR: Failed on open %s for writing: %d\n", path, errcode); /* Map the errcode to something consistent with the return * error codes from connect(): * * If errcode is ENOENT, meaning that the FIFO does exist, * return EFAULT meaning that the socket structure address is * outside the user's address space. */ return errcode == ENOENT ? -EFAULT : -errcode; } return OK; } /**************************************************************************** * Name: local_set_policy * * Description: * Set the FIFO buffer policy: * * 0=Free FIFO resources when the last reference is closed * 1=Free FIFO resources when the buffer is empty. * ****************************************************************************/ static int local_set_policy(int fd, unsigned long policy) { int ret; /* Set the buffer policy */ ret = ioctl(fd, PIPEIOC_POLICY, policy); if (ret < 0) { int errcode = get_errno(); DEBUGASSERT(errcode > 0); nerr("ERROR: Failed to set FIFO buffer policty: %d\n", errcode); return -errcode; } return OK; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: local_create_fifos * * Description: * Create the FIFO pair needed for a SOCK_STREAM connection. * ****************************************************************************/ #ifdef CONFIG_NET_LOCAL_STREAM int local_create_fifos(FAR struct local_conn_s *conn) { char path[LOCAL_FULLPATH_LEN]; int ret; /* Create the client-to-server FIFO if it does not already exist. */ local_cs_name(conn, path); ret = local_create_fifo(path); if (ret >= 0) { /* Create the server-to-client FIFO if it does not already exist. */ local_sc_name(conn, path); ret = local_create_fifo(path); } return ret; } #endif /* CONFIG_NET_LOCAL_STREAM */ /**************************************************************************** * Name: local_create_halfduplex * * Description: * Create the half-duplex FIFO needed for SOCK_DGRAM communication. * ****************************************************************************/ #ifdef CONFIG_NET_LOCAL_DGRAM int local_create_halfduplex(FAR struct local_conn_s *conn, FAR const char *path) { char fullpath[LOCAL_FULLPATH_LEN]; /* Create the half duplex FIFO if it does not already exist. */ local_hd_name(path, fullpath); return local_create_fifo(fullpath); } #endif /* CONFIG_NET_LOCAL_DGRAM */ /**************************************************************************** * Name: local_release_fifos * * Description: * Release references to the FIFO pair used for a SOCK_STREAM connection. * ****************************************************************************/ #ifdef CONFIG_NET_LOCAL_STREAM int local_release_fifos(FAR struct local_conn_s *conn) { char path[LOCAL_FULLPATH_LEN]; int ret1; int ret2; /* Destroy the client-to-server FIFO if it exists. */ local_sc_name(conn, path); ret1 = local_release_fifo(path); /* Destroy the server-to-client FIFO if it exists. */ local_cs_name(conn, path); ret2 = local_release_fifo(path); /* Return a failure if one occurred. */ return ret1 < 0 ? ret1 : ret2; } #endif /* CONFIG_NET_LOCAL_STREAM */ /**************************************************************************** * Name: local_release_halfduplex * * Description: * Release a reference to the FIFO used for SOCK_DGRAM communication * ****************************************************************************/ #ifdef CONFIG_NET_LOCAL_DGRAM int local_release_halfduplex(FAR struct local_conn_s *conn) { #if 1 /* REVIST: We need to think about this carefully. Unlike the connection- * oriented Unix domain socket, we don't really know the best time to * release the FIFO resource. It would be extremely inefficient to create * and destroy the FIFO on each packet. But, on the other hand, failing * to destory the FIFO will leave the FIFO resources in place after the * communications have completed. * * I am thinking that there should be something like a timer. The timer * would be started at the completion of each transfer and cancelled at * the beginning of each transfer. If the timer expires, then the FIFO * would be destroyed. */ # warning Missing logic return OK; #else char path[LOCAL_FULLPATH_LEN]; /* Destroy the half duplex FIFO if it exists. */ local_hd_name(conn->lc_path, path); return local_release_fifo(path); #endif } #endif /* CONFIG_NET_LOCAL_DGRAM */ /**************************************************************************** * Name: local_open_client_rx * * Description: * Open the client-side of the server-to-client FIFO. * ****************************************************************************/ #ifdef CONFIG_NET_LOCAL_STREAM int local_open_client_rx(FAR struct local_conn_s *client, bool nonblock) { char path[LOCAL_FULLPATH_LEN]; int ret; /* Get the server-to-client path name */ local_sc_name(client, path); /* Then open the file for read-only access */ ret = local_rx_open(client, path, nonblock); if (ret == OK) { /* Policy: Free FIFO resources when the last reference is closed */ ret = local_set_policy(client->lc_infd, 0); } return ret; } #endif /* CONFIG_NET_LOCAL_STREAM */ /**************************************************************************** * Name: local_open_client_tx * * Description: * Open the client-side of the client-to-server FIFO. * ****************************************************************************/ #ifdef CONFIG_NET_LOCAL_STREAM int local_open_client_tx(FAR struct local_conn_s *client, bool nonblock) { char path[LOCAL_FULLPATH_LEN]; int ret; /* Get the client-to-server path name */ local_cs_name(client, path); /* Then open the file for write-only access */ ret = local_tx_open(client, path, nonblock); if (ret == OK) { /* Policy: Free FIFO resources when the last reference is closed */ ret = local_set_policy(client->lc_outfd, 0); } return ret; } #endif /* CONFIG_NET_LOCAL_STREAM */ /**************************************************************************** * Name: local_open_server_rx * * Description: * Open the server-side of the client-to-server FIFO. * ****************************************************************************/ #ifdef CONFIG_NET_LOCAL_STREAM int local_open_server_rx(FAR struct local_conn_s *server, bool nonblock) { char path[LOCAL_FULLPATH_LEN]; int ret; /* Get the client-to-server path name */ local_cs_name(server, path); /* Then open the file for write-only access */ ret = local_rx_open(server, path, nonblock); if (ret == OK) { /* Policy: Free FIFO resources when the last reference is closed */ ret = local_set_policy(server->lc_infd, 0); } return ret; } #endif /* CONFIG_NET_LOCAL_STREAM */ /**************************************************************************** * Name: local_open_server_tx * * Description: * Only the server-side of the server-to-client FIFO. * ****************************************************************************/ #ifdef CONFIG_NET_LOCAL_STREAM int local_open_server_tx(FAR struct local_conn_s *server, bool nonblock) { char path[LOCAL_FULLPATH_LEN]; int ret; /* Get the server-to-client path name */ local_sc_name(server, path); /* Then open the file for read-only access */ ret = local_tx_open(server, path, nonblock); if (ret == OK) { /* Policy: Free FIFO resources when the last reference is closed */ ret = local_set_policy(server->lc_outfd, 0); } return ret; } #endif /* CONFIG_NET_LOCAL_STREAM */ /**************************************************************************** * Name: local_open_receiver * * Description: * Only the receiving side of the half duplex FIFO. * ****************************************************************************/ #ifdef CONFIG_NET_LOCAL_DGRAM int local_open_receiver(FAR struct local_conn_s *conn, bool nonblock) { char path[LOCAL_FULLPATH_LEN]; int ret; /* Get the server-to-client path name */ local_hd_name(conn->lc_path, path); /* Then open the file for read-only access */ ret = local_rx_open(conn, path, nonblock); if (ret == OK) { /* Policy: Free FIFO resources when the buffer is empty. */ ret = local_set_policy(conn->lc_infd, 1); } return ret; } #endif /* CONFIG_NET_LOCAL_DGRAM */ /**************************************************************************** * Name: local_open_sender * * Description: * Only the sending side of the half duplex FIFO. * ****************************************************************************/ #ifdef CONFIG_NET_LOCAL_DGRAM int local_open_sender(FAR struct local_conn_s *conn, FAR const char *path, bool nonblock) { char fullpath[LOCAL_FULLPATH_LEN]; int ret; /* Get the server-to-client path name */ local_hd_name(path, fullpath); /* Then open the file for read-only access */ ret = local_tx_open(conn, fullpath, nonblock); if (ret == OK) { /* Policy: Free FIFO resources when the buffer is empty. */ ret = local_set_policy(conn->lc_outfd, 1); } return ret; } #endif /* CONFIG_NET_LOCAL_DGRAM */ #endif /* CONFIG_NET && CONFIG_NET_LOCAL */