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 #include <config.h>
35
36 #include <string.h> /* for strlen(), ... */
37 #include <stdlib.h> /* for malloc(), free(), ... */
38 #include <stdarg.h> /* for functions with variable number of arguments */
39 #include <errno.h> /* for the errno variable */
40 #include "sockutils.h"
41 #include "rpcap-protocol.h"
42 #include <pcap/pcap.h>
43
44 #include "portability.h"
45
46 /*
47 * This file contains functions used both by the rpcap client and the
48 * rpcap daemon.
49 */
50
51 /*
52 * This function sends a RPCAP error to our peer.
53 *
54 * It has to be called when the main program detects an error.
55 * It will send to our peer the 'buffer' specified by the user.
56 * This function *does not* request a RPCAP CLOSE connection. A CLOSE
57 * command must be sent explicitly by the program, since we do not know
58 * whether the error can be recovered in some way or if it is a
59 * non-recoverable one.
60 *
61 * \param sock: the socket we are currently using.
62 *
63 * \param ssl: if compiled with openssl, the optional ssl handler to use with the above socket.
64 *
65 * \param ver: the protocol version we want to put in the reply.
66 *
67 * \param errcode: a integer which tells the other party the type of error
68 * we had.
69 *
70 * \param error: an user-allocated (and '0' terminated) buffer that contains
71 * the error description that has to be transmitted to our peer. The
72 * error message cannot be longer than PCAP_ERRBUF_SIZE.
73 *
74 * \param errbuf: a pointer to a user-allocated buffer (of size
75 * PCAP_ERRBUF_SIZE) that will contain the error message (in case there
76 * is one). It could be network problem.
77 *
78 * \return '0' if everything is fine, '-1' if some errors occurred. The
79 * error message is returned in the 'errbuf' variable.
80 */
81 int
rpcap_senderror(PCAP_SOCKET sock,SSL * ssl,uint8 ver,unsigned short errcode,const char * error,char * errbuf)82 rpcap_senderror(PCAP_SOCKET sock, SSL *ssl, uint8 ver, unsigned short errcode, const char *error, char *errbuf)
83 {
84 char sendbuf[RPCAP_NETBUF_SIZE]; /* temporary buffer in which data to be sent is buffered */
85 int sendbufidx = 0; /* index which keeps the number of bytes currently buffered */
86 uint16 length;
87
88 length = (uint16)strlen(error);
89
90 if (length > PCAP_ERRBUF_SIZE)
91 length = PCAP_ERRBUF_SIZE;
92
93 rpcap_createhdr((struct rpcap_header *) sendbuf, ver, RPCAP_MSG_ERROR, errcode, length);
94
95 if (sock_bufferize(NULL, sizeof(struct rpcap_header), NULL, &sendbufidx,
96 RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, errbuf, PCAP_ERRBUF_SIZE))
97 return -1;
98
99 if (sock_bufferize(error, length, sendbuf, &sendbufidx,
100 RPCAP_NETBUF_SIZE, SOCKBUF_BUFFERIZE, errbuf, PCAP_ERRBUF_SIZE))
101 return -1;
102
103 if (sock_send(sock, ssl, sendbuf, sendbufidx, errbuf, PCAP_ERRBUF_SIZE) < 0)
104 return -1;
105
106 return 0;
107 }
108
109 /*
110 * This function fills in a structure of type rpcap_header.
111 *
112 * It is provided just because the creation of an rpcap header is a common
113 * task. It accepts all the values that appears into an rpcap_header, and
114 * it puts them in place using the proper hton() calls.
115 *
116 * \param header: a pointer to a user-allocated buffer which will contain
117 * the serialized header, ready to be sent on the network.
118 *
119 * \param ver: a value (in the host byte order) which will be placed into the
120 * header.ver field and that represents the protocol version number of the
121 * current message.
122 *
123 * \param type: a value (in the host byte order) which will be placed into the
124 * header.type field and that represents the type of the current message.
125 *
126 * \param value: a value (in the host byte order) which will be placed into
127 * the header.value field and that has a message-dependent meaning.
128 *
129 * \param length: a value (in the host by order) which will be placed into
130 * the header.length field, representing the payload length of the message.
131 *
132 * \return Nothing. The serialized header is returned into the 'header'
133 * variable.
134 */
135 void
rpcap_createhdr(struct rpcap_header * header,uint8 ver,uint8 type,uint16 value,uint32 length)136 rpcap_createhdr(struct rpcap_header *header, uint8 ver, uint8 type, uint16 value, uint32 length)
137 {
138 memset(header, 0, sizeof(struct rpcap_header));
139
140 header->ver = ver;
141 header->type = type;
142 header->value = htons(value);
143 header->plen = htonl(length);
144 }
145
146 /*
147 * Convert a message type to a string containing the type name.
148 */
149 static const char *requests[] =
150 {
151 NULL, /* not a valid message type */
152 "RPCAP_MSG_ERROR",
153 "RPCAP_MSG_FINDALLIF_REQ",
154 "RPCAP_MSG_OPEN_REQ",
155 "RPCAP_MSG_STARTCAP_REQ",
156 "RPCAP_MSG_UPDATEFILTER_REQ",
157 "RPCAP_MSG_CLOSE",
158 "RPCAP_MSG_PACKET",
159 "RPCAP_MSG_AUTH_REQ",
160 "RPCAP_MSG_STATS_REQ",
161 "RPCAP_MSG_ENDCAP_REQ",
162 "RPCAP_MSG_SETSAMPLING_REQ",
163 };
164 #define NUM_REQ_TYPES (sizeof requests / sizeof requests[0])
165
166 static const char *replies[] =
167 {
168 NULL,
169 NULL, /* this would be a reply to RPCAP_MSG_ERROR */
170 "RPCAP_MSG_FINDALLIF_REPLY",
171 "RPCAP_MSG_OPEN_REPLY",
172 "RPCAP_MSG_STARTCAP_REPLY",
173 "RPCAP_MSG_UPDATEFILTER_REPLY",
174 NULL, /* this would be a reply to RPCAP_MSG_CLOSE */
175 NULL, /* this would be a reply to RPCAP_MSG_PACKET */
176 "RPCAP_MSG_AUTH_REPLY",
177 "RPCAP_MSG_STATS_REPLY",
178 "RPCAP_MSG_ENDCAP_REPLY",
179 "RPCAP_MSG_SETSAMPLING_REPLY",
180 };
181 #define NUM_REPLY_TYPES (sizeof replies / sizeof replies[0])
182
183 const char *
rpcap_msg_type_string(uint8 type)184 rpcap_msg_type_string(uint8 type)
185 {
186 if (type & RPCAP_MSG_IS_REPLY) {
187 type &= ~RPCAP_MSG_IS_REPLY;
188 if (type >= NUM_REPLY_TYPES)
189 return NULL;
190 return replies[type];
191 } else {
192 if (type >= NUM_REQ_TYPES)
193 return NULL;
194 return requests[type];
195 }
196 }
197