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