xref: /freebsd/lib/libnetgraph/msg.c (revision 35a04710d7286aa9538917fd7f8e417dbee95b82)
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 <sys/socket.h>
46 #include <stdarg.h>
47 #include <netgraph/ng_message.h>
48 #include <netgraph/ng_socket.h>
49 
50 #include "netgraph.h"
51 #include "internal.h"
52 
53 /* Next message token value */
54 static int	gMsgId;
55 
56 /* For delivering both messages and replies */
57 static int	NgDeliverMsg(int cs, const char *path,
58 		  const struct ng_mesg *hdr, const void *args, size_t arglen);
59 
60 /*
61  * Send a message to a node using control socket node "cs".
62  * Returns -1 if error and sets errno appropriately.
63  * If successful, returns the message ID (token) used.
64  */
65 int
66 NgSendMsg(int cs, const char *path,
67 	  int cookie, int cmd, const void *args, size_t arglen)
68 {
69 	struct ng_mesg msg;
70 
71 	/* Prepare message header */
72 	memset(&msg, 0, sizeof(msg));
73 	msg.header.version = NG_VERSION;
74 	msg.header.typecookie = cookie;
75 	if (++gMsgId < 0)
76 		gMsgId = 1;
77 	msg.header.token = gMsgId;
78 	msg.header.flags = NGF_ORIG;
79 	msg.header.cmd = cmd;
80 	snprintf((char *)msg.header.cmdstr, NG_CMDSTRSIZ, "cmd%d", cmd);
81 
82 	/* Deliver message */
83 	if (NgDeliverMsg(cs, path, &msg, args, arglen) < 0)
84 		return (-1);
85 	return (msg.header.token);
86 }
87 
88 /*
89  * Send a message given in ASCII format. We first ask the node to translate
90  * the command into binary, and then we send the binary.
91  */
92 int
93 NgSendAsciiMsg(int cs, const char *path, const char *fmt, ...)
94 {
95 	struct ng_mesg *reply, *binary, *ascii;
96 	char *buf, *cmd, *args;
97 	va_list fmtargs;
98 	int token;
99 
100 	/* Parse out command and arguments */
101 	va_start(fmtargs, fmt);
102 	vasprintf(&buf, fmt, fmtargs);
103 	va_end(fmtargs);
104 	if (buf == NULL)
105 		return (-1);
106 
107 	/* Parse out command, arguments */
108 	for (cmd = buf; isspace(*cmd); cmd++)
109 		;
110 	for (args = cmd; *args != '\0' && !isspace(*args); args++)
111 		;
112 	if (*args != '\0') {
113 		while (isspace(*args))
114 			*args++ = '\0';
115 	}
116 
117 	/* Get a bigger buffer to hold inner message header plus arg string */
118 	if ((ascii = malloc(sizeof(struct ng_mesg)
119 	    + strlen(args) + 1)) == NULL) {
120 		free(buf);
121 		return (-1);
122 	}
123 	memset(ascii, 0, sizeof(*ascii));
124 
125 	/* Build inner header (only need cmdstr, arglen, and data fields) */
126 	strncpy((char *)ascii->header.cmdstr, cmd,
127 	    sizeof(ascii->header.cmdstr) - 1);
128 	strcpy(ascii->data, args);
129 	ascii->header.arglen = strlen(ascii->data) + 1;
130 	free(buf);
131 
132 	/* Send node a request to convert ASCII to binary */
133 	if (NgSendMsg(cs, path, NGM_GENERIC_COOKIE, NGM_ASCII2BINARY,
134 	    (u_char *)ascii, sizeof(*ascii) + ascii->header.arglen) < 0) {
135 		free(ascii);
136 		return (-1);
137 	}
138 	free(ascii);
139 
140 	/* Get reply */
141 	if (NgAllocRecvMsg(cs, &reply, NULL) < 0)
142 		return (-1);
143 
144 	/* Now send binary version */
145 	binary = (struct ng_mesg *)reply->data;
146 	if (++gMsgId < 0)
147 		gMsgId = 1;
148 	binary->header.token = gMsgId;
149 	binary->header.version = NG_VERSION;
150 	if (NgDeliverMsg(cs,
151 	    path, binary, binary->data, binary->header.arglen) < 0) {
152 		free(reply);
153 		return (-1);
154 	}
155 	token = binary->header.token;
156 	free(reply);
157 	return (token);
158 }
159 
160 /*
161  * Send a message that is a reply to a previously received message.
162  * Returns -1 and sets errno on error, otherwise returns zero.
163  */
164 int
165 NgSendReplyMsg(int cs, const char *path,
166 	const struct ng_mesg *msg, const void *args, size_t arglen)
167 {
168 	struct ng_mesg rep;
169 
170 	/* Prepare message header */
171 	rep = *msg;
172 	rep.header.flags = NGF_RESP;
173 
174 	/* Deliver message */
175 	return (NgDeliverMsg(cs, path, &rep, args, arglen));
176 }
177 
178 /*
179  * Send a message to a node using control socket node "cs".
180  * Returns -1 if error and sets errno appropriately, otherwise zero.
181  */
182 static int
183 NgDeliverMsg(int cs, const char *path,
184 	const struct ng_mesg *hdr, const void *args, size_t arglen)
185 {
186 	u_char sgbuf[NG_PATHSIZ + NGSA_OVERHEAD];
187 	struct sockaddr_ng *const sg = (struct sockaddr_ng *) sgbuf;
188 	u_char *buf = NULL;
189 	struct ng_mesg *msg;
190 	int errnosv = 0;
191 	int rtn = 0;
192 
193 	/* Sanity check */
194 	if (args == NULL)
195 		arglen = 0;
196 
197 	/* Get buffer */
198 	if ((buf = malloc(sizeof(*msg) + arglen)) == NULL) {
199 		errnosv = errno;
200 		if (_gNgDebugLevel >= 1)
201 			NGLOG("malloc");
202 		rtn = -1;
203 		goto done;
204 	}
205 	msg = (struct ng_mesg *) buf;
206 
207 	/* Finalize message */
208 	*msg = *hdr;
209 	msg->header.arglen = arglen;
210 	memcpy(msg->data, args, arglen);
211 
212 	/* Prepare socket address */
213 	sg->sg_family = AF_NETGRAPH;
214 	/* XXX handle overflow */
215 	strlcpy(sg->sg_data, path, NG_PATHSIZ);
216 	sg->sg_len = strlen(sg->sg_data) + 1 + NGSA_OVERHEAD;
217 
218 	/* Debugging */
219 	if (_gNgDebugLevel >= 2) {
220 		NGLOGX("SENDING %s:",
221 		    (msg->header.flags & NGF_RESP) ? "RESPONSE" : "MESSAGE");
222 		_NgDebugSockaddr(sg);
223 		_NgDebugMsg(msg, sg->sg_data);
224 	}
225 
226 	/* Send it */
227 	if (sendto(cs, msg, sizeof(*msg) + arglen,
228 		   0, (struct sockaddr *) sg, sg->sg_len) < 0) {
229 		errnosv = errno;
230 		if (_gNgDebugLevel >= 1)
231 			NGLOG("sendto(%s)", sg->sg_data);
232 		rtn = -1;
233 		goto done;
234 	}
235 
236 	/* Wait for reply if there should be one. */
237 	if (msg->header.cmd & NGM_HASREPLY) {
238 		struct pollfd rfds;
239 		int n;
240 
241 		rfds.fd = cs;
242 		rfds.events = POLLIN;
243 		rfds.revents = 0;
244 		n = poll(&rfds, 1, INFTIM);
245 		if (n == -1) {
246 			errnosv = errno;
247 			if (_gNgDebugLevel >= 1)
248 				NGLOG("poll");
249 			rtn = -1;
250 		}
251 	}
252 
253 done:
254 	/* Done */
255 	free(buf);		/* OK if buf is NULL */
256 	errno = errnosv;
257 	return (rtn);
258 }
259 
260 /*
261  * Receive a control message.
262  *
263  * On error, this returns -1 and sets errno.
264  * Otherwise, it returns the length of the received reply.
265  */
266 int
267 NgRecvMsg(int cs, struct ng_mesg *rep, size_t replen, char *path)
268 {
269 	u_char sgbuf[NG_PATHSIZ + NGSA_OVERHEAD];
270 	struct sockaddr_ng *const sg = (struct sockaddr_ng *) sgbuf;
271 	socklen_t sglen = sizeof(sgbuf);
272 	int len, errnosv;
273 
274 	/* Read reply */
275 	len = recvfrom(cs, rep, replen, 0, (struct sockaddr *) sg, &sglen);
276 	if (len < 0) {
277 		errnosv = errno;
278 		if (_gNgDebugLevel >= 1)
279 			NGLOG("recvfrom");
280 		goto errout;
281 	}
282 	if (path != NULL)
283 		strlcpy(path, sg->sg_data, NG_PATHSIZ);
284 
285 	/* Debugging */
286 	if (_gNgDebugLevel >= 2) {
287 		NGLOGX("RECEIVED %s:",
288 		    (rep->header.flags & NGF_RESP) ? "RESPONSE" : "MESSAGE");
289 		_NgDebugSockaddr(sg);
290 		_NgDebugMsg(rep, sg->sg_data);
291 	}
292 
293 	/* Done */
294 	return (len);
295 
296 errout:
297 	errno = errnosv;
298 	return (-1);
299 }
300 
301 /*
302  * Identical to NgRecvMsg() except buffer is dynamically allocated.
303  */
304 int
305 NgAllocRecvMsg(int cs, struct ng_mesg **rep, char *path)
306 {
307 	int len;
308 	socklen_t optlen;
309 
310 	optlen = sizeof(len);
311 	if (getsockopt(cs, SOL_SOCKET, SO_RCVBUF, &len, &optlen) == -1 ||
312 	    (*rep = malloc(len)) == NULL)
313 		return (-1);
314 	if ((len = NgRecvMsg(cs, *rep, len, path)) < 0)
315 		free(*rep);
316 	return (len);
317 }
318 
319 /*
320  * Receive a control message and convert the arguments to ASCII
321  */
322 int
323 NgRecvAsciiMsg(int cs, struct ng_mesg *reply, size_t replen, char *path)
324 {
325 	struct ng_mesg *msg, *ascii;
326 	int bufSize, errnosv;
327 	u_char *buf;
328 
329 	/* Allocate buffer */
330 	bufSize = 2 * sizeof(*reply) + replen;
331 	if ((buf = malloc(bufSize)) == NULL)
332 		return (-1);
333 	msg = (struct ng_mesg *)buf;
334 	ascii = (struct ng_mesg *)msg->data;
335 
336 	/* Get binary message */
337 	if (NgRecvMsg(cs, msg, bufSize, path) < 0)
338 		goto fail;
339 	memcpy(reply, msg, sizeof(*msg));
340 
341 	/* Ask originating node to convert the arguments to ASCII */
342 	if (NgSendMsg(cs, path, NGM_GENERIC_COOKIE,
343 	    NGM_BINARY2ASCII, msg, sizeof(*msg) + msg->header.arglen) < 0)
344 		goto fail;
345 	if (NgRecvMsg(cs, msg, bufSize, NULL) < 0)
346 		goto fail;
347 
348 	/* Copy result to client buffer */
349 	if (sizeof(*ascii) + ascii->header.arglen > replen) {
350 		errno = ERANGE;
351 fail:
352 		errnosv = errno;
353 		free(buf);
354 		errno = errnosv;
355 		return (-1);
356 	}
357 	strncpy(reply->data, ascii->data, ascii->header.arglen);
358 
359 	/* Done */
360 	free(buf);
361 	return (0);
362 }
363 
364 /*
365  * Identical to NgRecvAsciiMsg() except buffer is dynamically allocated.
366  */
367 int
368 NgAllocRecvAsciiMsg(int cs, struct ng_mesg **reply, char *path)
369 {
370 	int len;
371 	socklen_t optlen;
372 
373 	optlen = sizeof(len);
374 	if (getsockopt(cs, SOL_SOCKET, SO_RCVBUF, &len, &optlen) == -1 ||
375 	    (*reply = malloc(len)) == NULL)
376 		return (-1);
377 	if ((len = NgRecvAsciiMsg(cs, *reply, len, path)) < 0)
378 		free(*reply);
379 	return (len);
380 }
381