xref: /f-stack/tools/libnetgraph/msg.c (revision e7145e36)
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 <[email protected]>
37  *
38  * $Whistle: msg.c,v 1.9 1999/01/20 00:57:23 archie Exp $
39  */
40 
41 #ifdef FSTACK
42 #define _GNU_SOURCE
43 #include <stdio.h>
44 #endif
45 
46 #include <sys/cdefs.h>
47 __FBSDID("$FreeBSD$");
48 
49 #include <sys/types.h>
50 #include <sys/socket.h>
51 #include <stdarg.h>
52 #include <netgraph/ng_message.h>
53 #include <netgraph/ng_socket.h>
54 
55 #include "netgraph.h"
56 #include "internal.h"
57 
58 /* Next message token value */
59 static int	gMsgId;
60 
61 /* For delivering both messages and replies */
62 static int	NgDeliverMsg(int cs, const char *path,
63 		  const struct ng_mesg *hdr, const void *args, size_t arglen);
64 
65 /*
66  * Send a message to a node using control socket node "cs".
67  * Returns -1 if error and sets errno appropriately.
68  * If successful, returns the message ID (token) used.
69  */
70 int
71 NgSendMsg(int cs, const char *path,
72 	  int cookie, int cmd, const void *args, size_t arglen)
73 {
74 	struct ng_mesg msg;
75 
76 	/* Prepare message header */
77 	memset(&msg, 0, sizeof(msg));
78 	msg.header.version = NG_VERSION;
79 	msg.header.typecookie = cookie;
80 	if (++gMsgId < 0)
81 		gMsgId = 1;
82 	msg.header.token = gMsgId;
83 	msg.header.flags = NGF_ORIG;
84 	msg.header.cmd = cmd;
85 	snprintf((char *)msg.header.cmdstr, NG_CMDSTRSIZ, "cmd%d", cmd);
86 
87 	/* Deliver message */
88 	if (NgDeliverMsg(cs, path, &msg, args, arglen) < 0)
89 		return (-1);
90 	return (msg.header.token);
91 }
92 
93 /*
94  * Send a message given in ASCII format. We first ask the node to translate
95  * the command into binary, and then we send the binary.
96  */
97 int
98 NgSendAsciiMsg(int cs, const char *path, const char *fmt, ...)
99 {
100 	struct ng_mesg *reply, *binary, *ascii;
101 	char *buf, *cmd, *args;
102 	va_list fmtargs;
103 	int token;
104 
105 	/* Parse out command and arguments */
106 	va_start(fmtargs, fmt);
107 	vasprintf(&buf, fmt, fmtargs);
108 	va_end(fmtargs);
109 	if (buf == NULL)
110 		return (-1);
111 
112 	/* Parse out command, arguments */
113 	for (cmd = buf; isspace(*cmd); cmd++)
114 		;
115 	for (args = cmd; *args != '\0' && !isspace(*args); args++)
116 		;
117 	if (*args != '\0') {
118 		while (isspace(*args))
119 			*args++ = '\0';
120 	}
121 
122 	/* Get a bigger buffer to hold inner message header plus arg string */
123 	if ((ascii = malloc(sizeof(struct ng_mesg)
124 	    + strlen(args) + 1)) == NULL) {
125 		free(buf);
126 		return (-1);
127 	}
128 	memset(ascii, 0, sizeof(*ascii));
129 
130 	/* Build inner header (only need cmdstr, arglen, and data fields) */
131 	strncpy((char *)ascii->header.cmdstr, cmd,
132 	    sizeof(ascii->header.cmdstr) - 1);
133 	strcpy(ascii->data, args);
134 	ascii->header.arglen = strlen(ascii->data) + 1;
135 	free(buf);
136 
137 	/* Send node a request to convert ASCII to binary */
138 	if (NgSendMsg(cs, path, NGM_GENERIC_COOKIE, NGM_ASCII2BINARY,
139 	    (u_char *)ascii, sizeof(*ascii) + ascii->header.arglen) < 0) {
140 		free(ascii);
141 		return (-1);
142 	}
143 	free(ascii);
144 
145 	/* Get reply */
146 	if (NgAllocRecvMsg(cs, &reply, NULL) < 0)
147 		return (-1);
148 
149 	/* Now send binary version */
150 	binary = (struct ng_mesg *)reply->data;
151 	if (++gMsgId < 0)
152 		gMsgId = 1;
153 	binary->header.token = gMsgId;
154 	binary->header.version = NG_VERSION;
155 	if (NgDeliverMsg(cs,
156 	    path, binary, binary->data, binary->header.arglen) < 0) {
157 		free(reply);
158 		return (-1);
159 	}
160 	token = binary->header.token;
161 	free(reply);
162 	return (token);
163 }
164 
165 /*
166  * Send a message that is a reply to a previously received message.
167  * Returns -1 and sets errno on error, otherwise returns zero.
168  */
169 int
170 NgSendReplyMsg(int cs, const char *path,
171 	const struct ng_mesg *msg, const void *args, size_t arglen)
172 {
173 	struct ng_mesg rep;
174 
175 	/* Prepare message header */
176 	rep = *msg;
177 	rep.header.flags = NGF_RESP;
178 
179 	/* Deliver message */
180 	return (NgDeliverMsg(cs, path, &rep, args, arglen));
181 }
182 
183 /*
184  * Send a message to a node using control socket node "cs".
185  * Returns -1 if error and sets errno appropriately, otherwise zero.
186  */
187 static int
188 NgDeliverMsg(int cs, const char *path,
189 	const struct ng_mesg *hdr, const void *args, size_t arglen)
190 {
191 	u_char sgbuf[NG_PATHSIZ + NGSA_OVERHEAD];
192 	struct sockaddr_ng *const sg = (struct sockaddr_ng *) sgbuf;
193 	u_char *buf = NULL;
194 	struct ng_mesg *msg;
195 	int errnosv = 0;
196 	int rtn = 0;
197 
198 	/* Sanity check */
199 	if (args == NULL)
200 		arglen = 0;
201 
202 	/* Get buffer */
203 	if ((buf = malloc(sizeof(*msg) + arglen)) == NULL) {
204 		errnosv = errno;
205 		if (_gNgDebugLevel >= 1)
206 			NGLOG("malloc");
207 		rtn = -1;
208 		goto done;
209 	}
210 	msg = (struct ng_mesg *) buf;
211 
212 	/* Finalize message */
213 	*msg = *hdr;
214 	msg->header.arglen = arglen;
215 	memcpy(msg->data, args, arglen);
216 
217 	/* Prepare socket address */
218 	sg->sg_family = AF_NETGRAPH;
219 	/* XXX handle overflow */
220 	strlcpy(sg->sg_data, path, NG_PATHSIZ);
221 	sg->sg_len = strlen(sg->sg_data) + 1 + NGSA_OVERHEAD;
222 
223 	/* Debugging */
224 	if (_gNgDebugLevel >= 2) {
225 		NGLOGX("SENDING %s:",
226 		    (msg->header.flags & NGF_RESP) ? "RESPONSE" : "MESSAGE");
227 		_NgDebugSockaddr(sg);
228 		_NgDebugMsg(msg, sg->sg_data);
229 	}
230 
231 	/* Send it */
232 	if (sendto(cs, msg, sizeof(*msg) + arglen,
233 		   0, (struct sockaddr *) sg, sg->sg_len) < 0) {
234 		errnosv = errno;
235 		if (_gNgDebugLevel >= 1)
236 			NGLOG("sendto(%s)", sg->sg_data);
237 		rtn = -1;
238 		goto done;
239 	}
240 
241 #ifndef FSTACK
242 	/* Wait for reply if there should be one. */
243 	if (msg->header.cmd & NGM_HASREPLY && !(msg->header.flags & NGF_RESP)) {
244 		struct pollfd rfds;
245 		int n;
246 
247 		rfds.fd = cs;
248 		rfds.events = POLLIN;
249 		rfds.revents = 0;
250 		n = poll(&rfds, 1, INFTIM);
251 		if (n == -1) {
252 			errnosv = errno;
253 			if (_gNgDebugLevel >= 1)
254 				NGLOG("poll");
255 			rtn = -1;
256 		}
257 	}
258 #endif
259 
260 done:
261 	/* Done */
262 	free(buf);		/* OK if buf is NULL */
263 	errno = errnosv;
264 	return (rtn);
265 }
266 
267 /*
268  * Receive a control message.
269  *
270  * On error, this returns -1 and sets errno.
271  * Otherwise, it returns the length of the received reply.
272  */
273 int
274 NgRecvMsg(int cs, struct ng_mesg *rep, size_t replen, char *path)
275 {
276 	u_char sgbuf[NG_PATHSIZ + NGSA_OVERHEAD];
277 	struct sockaddr_ng *const sg = (struct sockaddr_ng *) sgbuf;
278 	socklen_t sglen = sizeof(sgbuf);
279 	int len, errnosv;
280 
281 	/* Read reply */
282 	len = recvfrom(cs, rep, replen, 0, (struct sockaddr *) sg, &sglen);
283 	if (len < 0) {
284 		errnosv = errno;
285 		if (_gNgDebugLevel >= 1)
286 			NGLOG("recvfrom");
287 		goto errout;
288 	}
289 	if (path != NULL)
290 		strlcpy(path, sg->sg_data, NG_PATHSIZ);
291 
292 	/* Debugging */
293 	if (_gNgDebugLevel >= 2) {
294 		NGLOGX("RECEIVED %s:",
295 		    (rep->header.flags & NGF_RESP) ? "RESPONSE" : "MESSAGE");
296 		_NgDebugSockaddr(sg);
297 		_NgDebugMsg(rep, sg->sg_data);
298 	}
299 
300 	/* Done */
301 	return (len);
302 
303 errout:
304 	errno = errnosv;
305 	return (-1);
306 }
307 
308 /*
309  * Identical to NgRecvMsg() except buffer is dynamically allocated.
310  */
311 int
312 NgAllocRecvMsg(int cs, struct ng_mesg **rep, char *path)
313 {
314 	int len;
315 #ifndef FSTACK
316 	socklen_t optlen;
317 
318 	optlen = sizeof(len);
319 	if (getsockopt(cs, SOL_SOCKET, SO_RCVBUF, &len, &optlen) == -1 ||
320 #else
321 	len = NGCTL_DEFAULT_RCVBUF;
322 	if (
323 #endif
324 	    (*rep = malloc(len)) == NULL)
325 		return (-1);
326 	if ((len = NgRecvMsg(cs, *rep, len, path)) < 0)
327 		free(*rep);
328 	return (len);
329 }
330 
331 /*
332  * Receive a control message and convert the arguments to ASCII
333  */
334 int
335 NgRecvAsciiMsg(int cs, struct ng_mesg *reply, size_t replen, char *path)
336 {
337 	struct ng_mesg *msg, *ascii;
338 	int bufSize, errnosv;
339 	u_char *buf;
340 
341 	/* Allocate buffer */
342 	bufSize = 2 * sizeof(*reply) + replen;
343 	if ((buf = malloc(bufSize)) == NULL)
344 		return (-1);
345 	msg = (struct ng_mesg *)buf;
346 	ascii = (struct ng_mesg *)msg->data;
347 
348 	/* Get binary message */
349 	if (NgRecvMsg(cs, msg, bufSize, path) < 0)
350 		goto fail;
351 	memcpy(reply, msg, sizeof(*msg));
352 
353 	/* Ask originating node to convert the arguments to ASCII */
354 	if (NgSendMsg(cs, path, NGM_GENERIC_COOKIE,
355 	    NGM_BINARY2ASCII, msg, sizeof(*msg) + msg->header.arglen) < 0)
356 		goto fail;
357 	if (NgRecvMsg(cs, msg, bufSize, NULL) < 0)
358 		goto fail;
359 
360 	/* Copy result to client buffer */
361 	if (sizeof(*ascii) + ascii->header.arglen > replen) {
362 		errno = ERANGE;
363 fail:
364 		errnosv = errno;
365 		free(buf);
366 		errno = errnosv;
367 		return (-1);
368 	}
369 	strncpy(reply->data, ascii->data, ascii->header.arglen);
370 
371 	/* Done */
372 	free(buf);
373 	return (0);
374 }
375 
376 /*
377  * Identical to NgRecvAsciiMsg() except buffer is dynamically allocated.
378  */
379 int
380 NgAllocRecvAsciiMsg(int cs, struct ng_mesg **reply, char *path)
381 {
382 	int len;
383 #ifndef FSTACK
384 	socklen_t optlen;
385 
386 	optlen = sizeof(len);
387 	if (getsockopt(cs, SOL_SOCKET, SO_RCVBUF, &len, &optlen) == -1 ||
388 #else
389 	len = NGCTL_DEFAULT_RCVBUF;
390 	if (
391 #endif
392 	    (*reply = malloc(len)) == NULL)
393 		return (-1);
394 	if ((len = NgRecvAsciiMsg(cs, *reply, len, path)) < 0)
395 		free(*reply);
396 	return (len);
397 }
398