xref: /freebsd/lib/libnetgraph/msg.c (revision 3193579b66fd7067f898dbc54bdea81a0e6f9bd0)
1 /*
2  * msg.c
3  *
4  * Copyright (c) 1996-1999 Whistle Communications, Inc.
5  * All rights reserved.
6  *
7  * Subject to the following obligations and disclaimer of warranty, use and
8  * redistribution of this software, in source or object code forms, with or
9  * without modifications are expressly permitted by Whistle Communications;
10  * provided, however, that:
11  * 1. Any and all reproductions of the source or object code must include the
12  *    copyright notice above and the following disclaimer of warranties; and
13  * 2. No rights are granted, in any manner or form, to use Whistle
14  *    Communications, Inc. trademarks, including the mark "WHISTLE
15  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
16  *    such appears in the above copyright notice or in the software.
17  *
18  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
19  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
20  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
21  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
22  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
23  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
24  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
25  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
26  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
27  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
28  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
29  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
30  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
31  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
34  * OF SUCH DAMAGE.
35  *
36  * Author: Archie Cobbs <archie@whistle.com>
37  *
38  * $Whistle: msg.c,v 1.9 1999/01/20 00:57:23 archie Exp $
39  */
40 
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43 
44 #include <sys/types.h>
45 #include <stdarg.h>
46 #include <netgraph/ng_message.h>
47 #include <netgraph/ng_socket.h>
48 
49 #include "netgraph.h"
50 #include "internal.h"
51 
52 /* Next message token value */
53 static int	gMsgId;
54 
55 /* For delivering both messages and replies */
56 static int	NgDeliverMsg(int cs, const char *path,
57 		  const struct ng_mesg *hdr, const void *args, size_t arglen);
58 
59 /*
60  * Send a message to a node using control socket node "cs".
61  * Returns -1 if error and sets errno appropriately.
62  * If successful, returns the message ID (token) used.
63  */
64 int
65 NgSendMsg(int cs, const char *path,
66 	  int cookie, int cmd, const void *args, size_t arglen)
67 {
68 	struct ng_mesg msg;
69 
70 	/* Prepare message header */
71 	memset(&msg, 0, sizeof(msg));
72 	msg.header.version = NG_VERSION;
73 	msg.header.typecookie = cookie;
74 	if (++gMsgId < 0)
75 		gMsgId = 1;
76 	msg.header.token = gMsgId;
77 	msg.header.flags = NGF_ORIG;
78 	msg.header.cmd = cmd;
79 	snprintf(msg.header.cmdstr, NG_CMDSTRSIZ, "cmd%d", cmd);
80 
81 	/* Deliver message */
82 	if (NgDeliverMsg(cs, path, &msg, args, arglen) < 0)
83 		return (-1);
84 	return (msg.header.token);
85 }
86 
87 /*
88  * Send a message given in ASCII format. We first ask the node to translate
89  * the command into binary, and then we send the binary.
90  */
91 int
92 NgSendAsciiMsg(int cs, const char *path, const char *fmt, ...)
93 {
94 	const int bufSize = 1024;
95 	char replybuf[2 * sizeof(struct ng_mesg) + bufSize];
96 	struct ng_mesg *const reply = (struct ng_mesg *)replybuf;
97 	struct ng_mesg *const binary = (struct ng_mesg *)reply->data;
98 	struct ng_mesg *ascii;
99 	char *buf, *cmd, *args;
100 	va_list fmtargs;
101 
102 	/* Parse out command and arguments */
103 	va_start(fmtargs, fmt);
104 	vasprintf(&buf, fmt, fmtargs);
105 	va_end(fmtargs);
106 	if (buf == NULL)
107 		return (-1);
108 
109 	/* Parse out command, arguments */
110 	for (cmd = buf; isspace(*cmd); cmd++)
111 		;
112 	for (args = cmd; *args != '\0' && !isspace(*args); args++)
113 		;
114 	if (*args != '\0') {
115 		while (isspace(*args))
116 			*args++ = '\0';
117 	}
118 
119 	/* Get a bigger buffer to hold inner message header plus arg string */
120 	if ((ascii = malloc(sizeof(struct ng_mesg)
121 	    + strlen(args) + 1)) == NULL) {
122 		free(buf);
123 		return (-1);
124 	}
125 	memset(ascii, 0, sizeof(*ascii));
126 
127 	/* Build inner header (only need cmdstr, arglen, and data fields) */
128 	strncpy(ascii->header.cmdstr, cmd, sizeof(ascii->header.cmdstr) - 1);
129 	strcpy(ascii->data, args);
130 	ascii->header.arglen = strlen(ascii->data) + 1;
131 	free(buf);
132 
133 	/* Send node a request to convert ASCII to binary */
134 	if (NgSendMsg(cs, path, NGM_GENERIC_COOKIE, NGM_ASCII2BINARY,
135 	    (u_char *)ascii, sizeof(*ascii) + ascii->header.arglen) < 0)
136 		return (-1);
137 
138 	/* Get reply */
139 	if (NgRecvMsg(cs, reply, sizeof(replybuf), NULL) < 0)
140 		return (-1);
141 
142 	/* Now send binary version */
143 	if (++gMsgId < 0)
144 		gMsgId = 1;
145 	binary->header.token = gMsgId;
146 	if (NgDeliverMsg(cs,
147 	    path, binary, binary->data, binary->header.arglen) < 0)
148 		return (-1);
149 	return (binary->header.token);
150 }
151 
152 /*
153  * Send a message that is a reply to a previously received message.
154  * Returns -1 and sets errno on error, otherwise returns zero.
155  */
156 int
157 NgSendReplyMsg(int cs, const char *path,
158 	const struct ng_mesg *msg, const void *args, size_t arglen)
159 {
160 	struct ng_mesg rep;
161 
162 	/* Prepare message header */
163 	rep = *msg;
164 	rep.header.flags = NGF_RESP;
165 
166 	/* Deliver message */
167 	return (NgDeliverMsg(cs, path, &rep, args, arglen));
168 }
169 
170 /*
171  * Send a message to a node using control socket node "cs".
172  * Returns -1 if error and sets errno appropriately, otherwise zero.
173  */
174 static int
175 NgDeliverMsg(int cs, const char *path,
176 	const struct ng_mesg *hdr, const void *args, size_t arglen)
177 {
178 	u_char sgbuf[NG_PATHSIZ + NGSA_OVERHEAD];
179 	struct sockaddr_ng *const sg = (struct sockaddr_ng *) sgbuf;
180 	u_char *buf = NULL;
181 	struct ng_mesg *msg;
182 	int errnosv = 0;
183 	int rtn = 0;
184 
185 	/* Sanity check */
186 	if (args == NULL)
187 		arglen = 0;
188 
189 	/* Get buffer */
190 	if ((buf = malloc(sizeof(*msg) + arglen)) == NULL) {
191 		errnosv = errno;
192 		if (_gNgDebugLevel >= 1)
193 			NGLOG("malloc");
194 		rtn = -1;
195 		goto done;
196 	}
197 	msg = (struct ng_mesg *) buf;
198 
199 	/* Finalize message */
200 	*msg = *hdr;
201 	msg->header.arglen = arglen;
202 	memcpy(msg->data, args, arglen);
203 
204 	/* Prepare socket address */
205 	sg->sg_family = AF_NETGRAPH;
206 	/* XXX handle overflow */
207 	strlcpy(sg->sg_data, path, NG_PATHSIZ);
208 	sg->sg_len = strlen(sg->sg_data) + 1 + NGSA_OVERHEAD;
209 
210 	/* Debugging */
211 	if (_gNgDebugLevel >= 2) {
212 		NGLOGX("SENDING %s:",
213 		    (msg->header.flags & NGF_RESP) ? "RESPONSE" : "MESSAGE");
214 		_NgDebugSockaddr(sg);
215 		_NgDebugMsg(msg, sg->sg_data);
216 	}
217 
218 	/* Send it */
219 	if (sendto(cs, msg, sizeof(*msg) + arglen,
220 		   0, (struct sockaddr *) sg, sg->sg_len) < 0) {
221 		errnosv = errno;
222 		if (_gNgDebugLevel >= 1)
223 			NGLOG("sendto(%s)", sg->sg_data);
224 		rtn = -1;
225 		goto done;
226 	}
227 
228 done:
229 	/* Done */
230 	free(buf);		/* OK if buf is NULL */
231 	errno = errnosv;
232 	return (rtn);
233 }
234 
235 /*
236  * Receive a control message.
237  *
238  * On error, this returns -1 and sets errno.
239  * Otherwise, it returns the length of the received reply.
240  */
241 int
242 NgRecvMsg(int cs, struct ng_mesg *rep, size_t replen, char *path)
243 {
244 	u_char sgbuf[NG_PATHSIZ + NGSA_OVERHEAD];
245 	struct sockaddr_ng *const sg = (struct sockaddr_ng *) sgbuf;
246 	int len, sglen = sizeof(sgbuf);
247 	int errnosv;
248 
249 	/* Read reply */
250 	len = recvfrom(cs, rep, replen, 0, (struct sockaddr *) sg, &sglen);
251 	if (len < 0) {
252 		errnosv = errno;
253 		if (_gNgDebugLevel >= 1)
254 			NGLOG("recvfrom");
255 		goto errout;
256 	}
257 	if (path != NULL)
258 		strlcpy(path, sg->sg_data, NG_PATHSIZ);
259 
260 	/* Debugging */
261 	if (_gNgDebugLevel >= 2) {
262 		NGLOGX("RECEIVED %s:",
263 		    (rep->header.flags & NGF_RESP) ? "RESPONSE" : "MESSAGE");
264 		_NgDebugSockaddr(sg);
265 		_NgDebugMsg(rep, sg->sg_data);
266 	}
267 
268 	/* Done */
269 	return (len);
270 
271 errout:
272 	errno = errnosv;
273 	return (-1);
274 }
275 
276 /*
277  * Receive a control message and convert the arguments to ASCII
278  */
279 int
280 NgRecvAsciiMsg(int cs, struct ng_mesg *reply, size_t replen, char *path)
281 {
282 	struct ng_mesg *msg, *ascii;
283 	int bufSize, errnosv;
284 	u_char *buf;
285 
286 	/* Allocate buffer */
287 	bufSize = 2 * sizeof(*reply) + replen;
288 	if ((buf = malloc(bufSize)) == NULL)
289 		return (-1);
290 	msg = (struct ng_mesg *)buf;
291 	ascii = (struct ng_mesg *)msg->data;
292 
293 	/* Get binary message */
294 	if (NgRecvMsg(cs, msg, bufSize, path) < 0)
295 		goto fail;
296 	memcpy(reply, msg, sizeof(*msg));
297 
298 	/* Ask originating node to convert the arguments to ASCII */
299 	if (NgSendMsg(cs, path, NGM_GENERIC_COOKIE,
300 	    NGM_BINARY2ASCII, msg, sizeof(*msg) + msg->header.arglen) < 0)
301 		goto fail;
302 	if (NgRecvMsg(cs, msg, bufSize, NULL) < 0)
303 		goto fail;
304 
305 	/* Copy result to client buffer */
306 	if (sizeof(*ascii) + ascii->header.arglen > replen) {
307 		errno = ERANGE;
308 fail:
309 		errnosv = errno;
310 		free(buf);
311 		errno = errnosv;
312 		return (-1);
313 	}
314 	strncpy(reply->data, ascii->data, ascii->header.arglen);
315 
316 	/* Done */
317 	free(buf);
318 	return (0);
319 }
320 
321