/**************************************************************************** * net/tcp/tcp_getsockopt.c * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. The * ASF licenses this file to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance with the * License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include #include "socket/socket.h" #include "utils/utils.h" #include "tcp/tcp.h" #ifdef CONFIG_NET_TCPPROTO_OPTIONS /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: tcp_getsockopt * * Description: * tcp_getsockopt() retrieves the value for the option specified by the * 'option' argument for the socket specified by the 'psock' argument. If * the size of the option value is greater than 'value_len', the value * stored in the object pointed to by the 'value' argument will be silently * truncated. Otherwise, the length pointed to by the 'value_len' argument * will be modified to indicate the actual length of the 'value'. * * The 'level' argument specifies the protocol level of the option. To * retrieve options at the socket level, specify the level argument as * SOL_SOCKET; to retrieve options at the TCP-protocol level, the level * argument is SOL_TCP. * * See a complete list of values for the socket-level * 'option' argument. Protocol-specific options are are protocol specific * header files (such as netinet/tcp.h for the case of the TCP protocol). * * Input Parameters: * psock Socket structure of the socket to query * level Protocol level to set the option * option identifies the option to get * value Points to the argument value * value_len The length of the argument value * * Returned Value: * Returns zero (OK) on success. On failure, it returns a negated errno * value to indicate the nature of the error. See psock_getsockopt() for * the complete list of appropriate return error codes. * ****************************************************************************/ int tcp_getsockopt(FAR struct socket *psock, int option, FAR void *value, FAR socklen_t *value_len) { #ifdef CONFIG_NET_TCP_KEEPALIVE /* Keep alive options are the only TCP protocol socket option currently * supported. */ FAR struct tcp_conn_s *conn; int ret; DEBUGASSERT(psock != NULL && value != NULL && value_len != NULL && psock->s_conn != NULL); conn = (FAR struct tcp_conn_s *)psock->s_conn; /* All of the TCP protocol options apply only TCP sockets. The sockets * do not have to be connected.. that might occur later with the KeepAlive * already configured. */ if (psock->s_type != SOCK_STREAM) { nerr("ERROR: Not a TCP socket\n"); return -ENOTCONN; } /* Handle the Keep-Alive option */ switch (option) { /* Handle the SO_KEEPALIVE socket-level option. * * NOTE: SO_KEEPALIVE is not really a socket-level option; it is a * protocol-level option. A given TCP connection may service multiple * sockets (via dup'ing of the socket). There is, however, still only * one connection to be monitored and that is a global attribute across * all of the clones that may use the underlying connection. */ case SO_KEEPALIVE: /* Verifies TCP connections active by enabling the * periodic transmission of probes */ if (*value_len < sizeof(int)) { /* REVISIT: POSIX says that we should truncate the value if it * is larger than value_len. That just doesn't make sense * to me in this case. */ ret = -EINVAL; } else { FAR int *keepalive = (FAR int *)value; *keepalive = conn->keepalive; *value_len = sizeof(int); ret = OK; } break; case TCP_NODELAY: /* Avoid coalescing of small segments. */ if (*value_len < sizeof(int)) { ret = -EINVAL; } else { FAR int *nodelay = (FAR int *)value; /* Always true here since we do not support Nagle. */ *nodelay = 1; *value_len = sizeof(int); ret = OK; } break; case TCP_KEEPIDLE: /* Start keepalives after this IDLE period */ case TCP_KEEPINTVL: /* Interval between keepalives */ { int dsecs; if (option == TCP_KEEPIDLE) { dsecs = conn->keepidle; } else { dsecs = conn->keepintvl; } if (value == NULL) { ret = -EINVAL; } else if (*value_len == sizeof(struct timeval)) { FAR struct timeval *tv = (FAR struct timeval *)value; /* Convert the KeepIdle time from deciseconds to struct * timeval. */ net_dsec2timeval(dsecs, tv); *value_len = sizeof(struct timeval); ret = OK; } else if (*value_len == sizeof(int)) { FAR int *pdsecs = (FAR int *)value; *pdsecs = dsecs; ret = OK; } else { /* REVISIT: POSIX says that we should truncate the value if it * is larger than value_len. That just doesn't make sense * to me in this case. */ ret = -EINVAL; } } break; case TCP_KEEPCNT: /* Number of keepalives before death */ if (*value_len < sizeof(int)) { /* REVISIT: POSIX says that we should truncate the value if it * is larger than value_len. That just doesn't make sense * to me in this case. */ ret = -EINVAL; } else { FAR int *keepcnt = (FAR int *)value; *keepcnt = conn->keepcnt; *value_len = sizeof(int); ret = OK; } break; default: nerr("ERROR: Unrecognized TCP option: %d\n", option); ret = -ENOPROTOOPT; break; } return ret; #else return -ENOPROTOOPT; #endif /* CONFIG_NET_TCP_KEEPALIVE */ } #endif /* CONFIG_NET_TCPPROTO_OPTIONS */