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: stable/11/lib/libnetgraph/msg.c 353445 2019-10-11 18:05:06Z eugen $");
43
44#include <sys/types.h>
45#include <sys/socket.h>
46#include <stdarg.h>
47#include <stdatomic.h>
48#include <netgraph/ng_message.h>
49#include <netgraph/ng_socket.h>
50
51#include "netgraph.h"
52#include "internal.h"
53
54/* Next message token value */
55static _Atomic(unsigned int) gMsgId;
56
57/* For delivering both messages and replies */
58static int	NgDeliverMsg(int cs, const char *path,
59		  const struct ng_mesg *hdr, const void *args, size_t arglen);
60
61/*
62 * Send a message to a node using control socket node "cs".
63 * Returns -1 if error and sets errno appropriately.
64 * If successful, returns the message ID (token) used.
65 */
66int
67NgSendMsg(int cs, const char *path,
68	  int cookie, int cmd, const void *args, size_t arglen)
69{
70	struct ng_mesg msg;
71
72	/* Prepare message header */
73	memset(&msg, 0, sizeof(msg));
74	msg.header.version = NG_VERSION;
75	msg.header.typecookie = cookie;
76	msg.header.token = atomic_fetch_add(&gMsgId, 1) & INT_MAX;
77	msg.header.flags = NGF_ORIG;
78	msg.header.cmd = cmd;
79	snprintf((char *)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 */
91int
92NgSendAsciiMsg(int cs, const char *path, const char *fmt, ...)
93{
94	struct ng_mesg *reply, *binary, *ascii;
95	char *buf, *cmd, *args;
96	va_list fmtargs;
97	int token;
98
99	/* Parse out command and arguments */
100	va_start(fmtargs, fmt);
101	vasprintf(&buf, fmt, fmtargs);
102	va_end(fmtargs);
103	if (buf == NULL)
104		return (-1);
105
106	/* Parse out command, arguments */
107	for (cmd = buf; isspace(*cmd); cmd++)
108		;
109	for (args = cmd; *args != '\0' && !isspace(*args); args++)
110		;
111	if (*args != '\0') {
112		while (isspace(*args))
113			*args++ = '\0';
114	}
115
116	/* Get a bigger buffer to hold inner message header plus arg string */
117	if ((ascii = malloc(sizeof(struct ng_mesg)
118	    + strlen(args) + 1)) == NULL) {
119		free(buf);
120		return (-1);
121	}
122	memset(ascii, 0, sizeof(*ascii));
123
124	/* Build inner header (only need cmdstr, arglen, and data fields) */
125	strncpy((char *)ascii->header.cmdstr, cmd,
126	    sizeof(ascii->header.cmdstr) - 1);
127	strcpy(ascii->data, args);
128	ascii->header.arglen = strlen(ascii->data) + 1;
129	free(buf);
130
131	/* Send node a request to convert ASCII to binary */
132	if (NgSendMsg(cs, path, NGM_GENERIC_COOKIE, NGM_ASCII2BINARY,
133	    (u_char *)ascii, sizeof(*ascii) + ascii->header.arglen) < 0) {
134		free(ascii);
135		return (-1);
136	}
137	free(ascii);
138
139	/* Get reply */
140	if (NgAllocRecvMsg(cs, &reply, NULL) < 0)
141		return (-1);
142
143	/* Now send binary version */
144	binary = (struct ng_mesg *)reply->data;
145	binary->header.token = atomic_fetch_add(&gMsgId, 1) & INT_MAX;
146	binary->header.version = NG_VERSION;
147	if (NgDeliverMsg(cs,
148	    path, binary, binary->data, binary->header.arglen) < 0) {
149		free(reply);
150		return (-1);
151	}
152	token = binary->header.token;
153	free(reply);
154	return (token);
155}
156
157/*
158 * Send a message that is a reply to a previously received message.
159 * Returns -1 and sets errno on error, otherwise returns zero.
160 */
161int
162NgSendReplyMsg(int cs, const char *path,
163	const struct ng_mesg *msg, const void *args, size_t arglen)
164{
165	struct ng_mesg rep;
166
167	/* Prepare message header */
168	rep = *msg;
169	rep.header.flags = NGF_RESP;
170
171	/* Deliver message */
172	return (NgDeliverMsg(cs, path, &rep, args, arglen));
173}
174
175/*
176 * Send a message to a node using control socket node "cs".
177 * Returns -1 if error and sets errno appropriately, otherwise zero.
178 */
179static int
180NgDeliverMsg(int cs, const char *path,
181	const struct ng_mesg *hdr, const void *args, size_t arglen)
182{
183	u_char sgbuf[NG_PATHSIZ + NGSA_OVERHEAD];
184	struct sockaddr_ng *const sg = (struct sockaddr_ng *) sgbuf;
185	u_char *buf = NULL;
186	struct ng_mesg *msg;
187	int errnosv = 0;
188	int rtn = 0;
189
190	/* Sanity check */
191	if (args == NULL)
192		arglen = 0;
193
194	/* Get buffer */
195	if ((buf = malloc(sizeof(*msg) + arglen)) == NULL) {
196		errnosv = errno;
197		if (_gNgDebugLevel >= 1)
198			NGLOG("malloc");
199		rtn = -1;
200		goto done;
201	}
202	msg = (struct ng_mesg *) buf;
203
204	/* Finalize message */
205	*msg = *hdr;
206	msg->header.arglen = arglen;
207	memcpy(msg->data, args, arglen);
208
209	/* Prepare socket address */
210	sg->sg_family = AF_NETGRAPH;
211	/* XXX handle overflow */
212	strlcpy(sg->sg_data, path, NG_PATHSIZ);
213	sg->sg_len = strlen(sg->sg_data) + 1 + NGSA_OVERHEAD;
214
215	/* Debugging */
216	if (_gNgDebugLevel >= 2) {
217		NGLOGX("SENDING %s:",
218		    (msg->header.flags & NGF_RESP) ? "RESPONSE" : "MESSAGE");
219		_NgDebugSockaddr(sg);
220		_NgDebugMsg(msg, sg->sg_data);
221	}
222
223	/* Send it */
224	if (sendto(cs, msg, sizeof(*msg) + arglen,
225		   0, (struct sockaddr *) sg, sg->sg_len) < 0) {
226		errnosv = errno;
227		if (_gNgDebugLevel >= 1)
228			NGLOG("sendto(%s)", sg->sg_data);
229		rtn = -1;
230		goto done;
231	}
232
233	/* Wait for reply if there should be one. */
234	if (msg->header.cmd & NGM_HASREPLY && !(msg->header.flags & NGF_RESP)) {
235		struct pollfd rfds;
236		int n;
237
238		rfds.fd = cs;
239		rfds.events = POLLIN;
240		rfds.revents = 0;
241		n = poll(&rfds, 1, INFTIM);
242		if (n == -1) {
243			errnosv = errno;
244			if (_gNgDebugLevel >= 1)
245				NGLOG("poll");
246			rtn = -1;
247		}
248	}
249
250done:
251	/* Done */
252	free(buf);		/* OK if buf is NULL */
253	errno = errnosv;
254	return (rtn);
255}
256
257/*
258 * Receive a control message.
259 *
260 * On error, this returns -1 and sets errno.
261 * Otherwise, it returns the length of the received reply.
262 */
263int
264NgRecvMsg(int cs, struct ng_mesg *rep, size_t replen, char *path)
265{
266	u_char sgbuf[NG_PATHSIZ + NGSA_OVERHEAD];
267	struct sockaddr_ng *const sg = (struct sockaddr_ng *) sgbuf;
268	socklen_t sglen = sizeof(sgbuf);
269	int len, errnosv;
270
271	/* Read reply */
272	len = recvfrom(cs, rep, replen, 0, (struct sockaddr *) sg, &sglen);
273	if (len < 0) {
274		errnosv = errno;
275		if (_gNgDebugLevel >= 1)
276			NGLOG("recvfrom");
277		goto errout;
278	}
279	if (path != NULL)
280		strlcpy(path, sg->sg_data, NG_PATHSIZ);
281
282	/* Debugging */
283	if (_gNgDebugLevel >= 2) {
284		NGLOGX("RECEIVED %s:",
285		    (rep->header.flags & NGF_RESP) ? "RESPONSE" : "MESSAGE");
286		_NgDebugSockaddr(sg);
287		_NgDebugMsg(rep, sg->sg_data);
288	}
289
290	/* Done */
291	return (len);
292
293errout:
294	errno = errnosv;
295	return (-1);
296}
297
298/*
299 * Identical to NgRecvMsg() except buffer is dynamically allocated.
300 */
301int
302NgAllocRecvMsg(int cs, struct ng_mesg **rep, char *path)
303{
304	int len;
305	socklen_t optlen;
306
307	optlen = sizeof(len);
308	if (getsockopt(cs, SOL_SOCKET, SO_RCVBUF, &len, &optlen) == -1 ||
309	    (*rep = malloc(len)) == NULL)
310		return (-1);
311	if ((len = NgRecvMsg(cs, *rep, len, path)) < 0)
312		free(*rep);
313	return (len);
314}
315
316/*
317 * Receive a control message and convert the arguments to ASCII
318 */
319int
320NgRecvAsciiMsg(int cs, struct ng_mesg *reply, size_t replen, char *path)
321{
322	struct ng_mesg *msg, *ascii;
323	int bufSize, errnosv;
324	u_char *buf;
325
326	/* Allocate buffer */
327	bufSize = 2 * sizeof(*reply) + replen;
328	if ((buf = malloc(bufSize)) == NULL)
329		return (-1);
330	msg = (struct ng_mesg *)buf;
331	ascii = (struct ng_mesg *)msg->data;
332
333	/* Get binary message */
334	if (NgRecvMsg(cs, msg, bufSize, path) < 0)
335		goto fail;
336	memcpy(reply, msg, sizeof(*msg));
337
338	/* Ask originating node to convert the arguments to ASCII */
339	if (NgSendMsg(cs, path, NGM_GENERIC_COOKIE,
340	    NGM_BINARY2ASCII, msg, sizeof(*msg) + msg->header.arglen) < 0)
341		goto fail;
342	if (NgRecvMsg(cs, msg, bufSize, NULL) < 0)
343		goto fail;
344
345	/* Copy result to client buffer */
346	if (sizeof(*ascii) + ascii->header.arglen > replen) {
347		errno = ERANGE;
348fail:
349		errnosv = errno;
350		free(buf);
351		errno = errnosv;
352		return (-1);
353	}
354	strncpy(reply->data, ascii->data, ascii->header.arglen);
355
356	/* Done */
357	free(buf);
358	return (0);
359}
360
361/*
362 * Identical to NgRecvAsciiMsg() except buffer is dynamically allocated.
363 */
364int
365NgAllocRecvAsciiMsg(int cs, struct ng_mesg **reply, char *path)
366{
367	int len;
368	socklen_t optlen;
369
370	optlen = sizeof(len);
371	if (getsockopt(cs, SOL_SOCKET, SO_RCVBUF, &len, &optlen) == -1 ||
372	    (*reply = malloc(len)) == NULL)
373		return (-1);
374	if ((len = NgRecvAsciiMsg(cs, *reply, len, path)) < 0)
375		free(*reply);
376	return (len);
377}
378