xref: /netbsd-src/external/bsd/libpcap/dist/rpcap-protocol.c (revision c9055873d0546e63388f027d3d7f85381cde0545)
1 /*
2  * Copyright (c) 2002 - 2005 NetGroup, Politecnico di Torino (Italy)
3  * Copyright (c) 2005 - 2008 CACE Technologies, Davis (California)
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  * notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  * notice, this list of conditions and the following disclaimer in the
14  * documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the Politecnico di Torino, CACE Technologies
16  * nor the names of its contributors may be used to endorse or promote
17  * products derived from this software without specific prior written
18  * permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
24  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
25  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
26  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
30  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  *
32  */
33 
34 #ifdef HAVE_CONFIG_H
35 #include <config.h>
36 #endif
37 
38 #include <string.h>		/* for strlen(), ... */
39 #include <stdlib.h>		/* for malloc(), free(), ... */
40 #include <stdarg.h>		/* for functions with variable number of arguments */
41 #include <errno.h>		/* for the errno variable */
42 #include "sockutils.h"
43 #include "rpcap-protocol.h"
44 #include <pcap/pcap.h>
45 
46 #include "portability.h"
47 
48 /*
49  * This file contains functions used both by the rpcap client and the
50  * rpcap daemon.
51  */
52 
53 /*
54  * This function sends a RPCAP error to our peer.
55  *
56  * It has to be called when the main program detects an error.
57  * It will send to our peer the 'buffer' specified by the user.
58  * This function *does not* request a RPCAP CLOSE connection. A CLOSE
59  * command must be sent explicitly by the program, since we do not know
60  * whether the error can be recovered in some way or if it is a
61  * non-recoverable one.
62  *
63  * \param sock: the socket we are currently using.
64  *
65  * \param ssl: if compiled with openssl, the optional ssl handler to use with the above socket.
66  *
67  * \param ver: the protocol version we want to put in the reply.
68  *
69  * \param errcode: a integer which tells the other party the type of error
70  * we had.
71  *
72  * \param error: an user-allocated (and '0' terminated) buffer that contains
73  * the error description that has to be transmitted to our peer. The
74  * error message cannot be longer than PCAP_ERRBUF_SIZE.
75  *
76  * \param errbuf: a pointer to a user-allocated buffer (of size
77  * PCAP_ERRBUF_SIZE) that will contain the error message (in case there
78  * is one). It could be network problem.
79  *
80  * \return '0' if everything is fine, '-1' if some errors occurred. The
81  * error message is returned in the 'errbuf' variable.
82  */
83 int
84 rpcap_senderror(SOCKET sock, SSL *ssl, uint8 ver, unsigned short errcode, const char *error, char *errbuf)
85 {
86 	char sendbuf[RPCAP_NETBUF_SIZE];	/* temporary buffer in which data to be sent is buffered */
87 	int sendbufidx = 0;			/* index which keeps the number of bytes currently buffered */
88 	uint16 length;
89 
90 	length = (uint16)strlen(error);
91 
92 	if (length > PCAP_ERRBUF_SIZE)
93 		length = PCAP_ERRBUF_SIZE;
94 
95 	rpcap_createhdr((struct rpcap_header *) sendbuf, ver, RPCAP_MSG_ERROR, errcode, length);
96 
97 	if (sock_bufferize(NULL, sizeof(struct rpcap_header), NULL, &sendbufidx,
98 		RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, errbuf, PCAP_ERRBUF_SIZE))
99 		return -1;
100 
101 	if (sock_bufferize(error, length, sendbuf, &sendbufidx,
102 		RPCAP_NETBUF_SIZE, SOCKBUF_BUFFERIZE, errbuf, PCAP_ERRBUF_SIZE))
103 		return -1;
104 
105 	if (sock_send(sock, ssl, sendbuf, sendbufidx, errbuf, PCAP_ERRBUF_SIZE) < 0)
106 		return -1;
107 
108 	return 0;
109 }
110 
111 /*
112  * This function fills in a structure of type rpcap_header.
113  *
114  * It is provided just because the creation of an rpcap header is a common
115  * task. It accepts all the values that appears into an rpcap_header, and
116  * it puts them in place using the proper hton() calls.
117  *
118  * \param header: a pointer to a user-allocated buffer which will contain
119  * the serialized header, ready to be sent on the network.
120  *
121  * \param ver: a value (in the host byte order) which will be placed into the
122  * header.ver field and that represents the protocol version number of the
123  * current message.
124  *
125  * \param type: a value (in the host byte order) which will be placed into the
126  * header.type field and that represents the type of the current message.
127  *
128  * \param value: a value (in the host byte order) which will be placed into
129  * the header.value field and that has a message-dependent meaning.
130  *
131  * \param length: a value (in the host by order) which will be placed into
132  * the header.length field, representing the payload length of the message.
133  *
134  * \return Nothing. The serialized header is returned into the 'header'
135  * variable.
136  */
137 void
138 rpcap_createhdr(struct rpcap_header *header, uint8 ver, uint8 type, uint16 value, uint32 length)
139 {
140 	memset(header, 0, sizeof(struct rpcap_header));
141 
142 	header->ver = ver;
143 	header->type = type;
144 	header->value = htons(value);
145 	header->plen = htonl(length);
146 }
147 
148 /*
149  * Convert a message type to a string containing the type name.
150  */
151 static const char *requests[] =
152 {
153 	NULL,				/* not a valid message type */
154 	"RPCAP_MSG_ERROR",
155 	"RPCAP_MSG_FINDALLIF_REQ",
156 	"RPCAP_MSG_OPEN_REQ",
157 	"RPCAP_MSG_STARTCAP_REQ",
158 	"RPCAP_MSG_UPDATEFILTER_REQ",
159 	"RPCAP_MSG_CLOSE",
160 	"RPCAP_MSG_PACKET",
161 	"RPCAP_MSG_AUTH_REQ",
162 	"RPCAP_MSG_STATS_REQ",
163 	"RPCAP_MSG_ENDCAP_REQ",
164 	"RPCAP_MSG_SETSAMPLING_REQ",
165 };
166 #define NUM_REQ_TYPES	(sizeof requests / sizeof requests[0])
167 
168 static const char *replies[] =
169 {
170 	NULL,
171 	NULL,			/* this would be a reply to RPCAP_MSG_ERROR */
172 	"RPCAP_MSG_FINDALLIF_REPLY",
173 	"RPCAP_MSG_OPEN_REPLY",
174 	"RPCAP_MSG_STARTCAP_REPLY",
175 	"RPCAP_MSG_UPDATEFILTER_REPLY",
176 	NULL,			/* this would be a reply to RPCAP_MSG_CLOSE */
177 	NULL,			/* this would be a reply to RPCAP_MSG_PACKET */
178 	"RPCAP_MSG_AUTH_REPLY",
179 	"RPCAP_MSG_STATS_REPLY",
180 	"RPCAP_MSG_ENDCAP_REPLY",
181 	"RPCAP_MSG_SETSAMPLING_REPLY",
182 };
183 #define NUM_REPLY_TYPES	(sizeof replies / sizeof replies[0])
184 
185 const char *
186 rpcap_msg_type_string(uint8 type)
187 {
188 	if (type & RPCAP_MSG_IS_REPLY) {
189 		type &= ~RPCAP_MSG_IS_REPLY;
190 		if (type >= NUM_REPLY_TYPES)
191 			return NULL;
192 		return replies[type];
193 	} else {
194 		if (type >= NUM_REQ_TYPES)
195 			return NULL;
196 		return requests[type];
197 	}
198 }
199