1 /* 2 * ng_ether_echo.c 3 */ 4 5 /*- 6 * Copyright (c) 1996-1999 Whistle Communications, Inc. 7 * All rights reserved. 8 * 9 * Subject to the following obligations and disclaimer of warranty, use and 10 * redistribution of this software, in source or object code forms, with or 11 * without modifications are expressly permitted by Whistle Communications; 12 * provided, however, that: 13 * 1. Any and all reproductions of the source or object code must include the 14 * copyright notice above and the following disclaimer of warranties; and 15 * 2. No rights are granted, in any manner or form, to use Whistle 16 * Communications, Inc. trademarks, including the mark "WHISTLE 17 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as 18 * such appears in the above copyright notice or in the software. 19 * 20 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND 21 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO 22 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, 23 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF 24 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. 25 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY 26 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS 27 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE. 28 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES 29 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING 30 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 31 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR 32 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 35 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY 36 * OF SUCH DAMAGE. 37 * 38 * Author: Julian Elisher <julian@freebsd.org> 39 * $Whistle: ng_echo.c,v 1.13 1999/11/01 09:24:51 julian Exp $ 40 */ 41 42 /* 43 * Netgraph "ether_echo" node 44 * 45 * This node simply bounces data and messages back to whence they came. 46 * However it swaps the source and destination ether fields. 47 * No testing is done! 48 */ 49 50 #include <sys/param.h> 51 #include <sys/systm.h> 52 #include <sys/kernel.h> 53 #include <sys/malloc.h> 54 #include <sys/mbuf.h> 55 #include <netgraph/ng_message.h> 56 #include <netgraph/netgraph.h> 57 #include <netgraph/ng_ether_echo.h> 58 59 #include <net/ethernet.h> 60 61 /* Netgraph methods */ 62 static ng_constructor_t ngee_cons; 63 static ng_rcvmsg_t ngee_rcvmsg; 64 static ng_rcvdata_t ngee_rcvdata; 65 static ng_disconnect_t ngee_disconnect; 66 67 /* Netgraph type */ 68 static struct ng_type typestruct = { 69 .version = NG_ABI_VERSION, 70 .name = NG_ETHER_ECHO_NODE_TYPE, 71 .constructor = ngee_cons, 72 .rcvmsg = ngee_rcvmsg, 73 .rcvdata = ngee_rcvdata, 74 .disconnect = ngee_disconnect, 75 }; 76 NETGRAPH_INIT(ether_echo, &typestruct); 77 78 static int 79 ngee_cons(node_p node) 80 { 81 return (0); 82 } 83 84 /* 85 * Receive control message. We just bounce it back as a reply. 86 */ 87 static int 88 ngee_rcvmsg(node_p node, item_p item, hook_p lasthook) 89 { 90 struct ng_mesg *msg; 91 int error = 0; 92 93 NGI_GET_MSG(item, msg); 94 msg->header.flags |= NGF_RESP; 95 NG_RESPOND_MSG(error, node, item, msg); 96 return (error); 97 } 98 99 /* 100 * Receive data 101 */ 102 static int 103 ngee_rcvdata(hook_p hook, item_p item) 104 { 105 int error; 106 struct mbuf *m; 107 108 struct ether_header *eh; 109 struct ether_addr tmpaddr; 110 111 /* Make sure we have an entire header */ 112 NGI_GET_M(item, m); 113 if (m->m_len < sizeof(*eh) ) { 114 m = m_pullup(m, sizeof(*eh)); 115 if (m == NULL) { 116 NG_FREE_ITEM(item); 117 return(EINVAL); 118 } 119 } 120 eh = mtod(m, struct ether_header *); 121 122 /* swap the source and destination fields */ 123 bcopy(eh->ether_dhost, &tmpaddr, ETHER_ADDR_LEN); 124 bcopy(eh->ether_shost, eh->ether_dhost, ETHER_ADDR_LEN); 125 bcopy(&tmpaddr, eh->ether_shost, ETHER_ADDR_LEN); 126 127 NG_FWD_NEW_DATA(error, item, hook, m); 128 return (error); 129 } 130 131 /* 132 * Removal of the last link destroys the nodeo 133 */ 134 static int 135 ngee_disconnect(hook_p hook) 136 { 137 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) 138 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) { 139 ng_rmnode_self(NG_HOOK_NODE(hook)); 140 } 141 return (0); 142 } 143