xref: /freebsd/lib/libnetgraph/msg.c (revision 77a0943ded95b9e6438f7db70c4a28e4d93946d4)
1 
2 /*
3  * msg.c
4  *
5  * Copyright (c) 1996-1999 Whistle Communications, Inc.
6  * All rights reserved.
7  *
8  * Subject to the following obligations and disclaimer of warranty, use and
9  * redistribution of this software, in source or object code forms, with or
10  * without modifications are expressly permitted by Whistle Communications;
11  * provided, however, that:
12  * 1. Any and all reproductions of the source or object code must include the
13  *    copyright notice above and the following disclaimer of warranties; and
14  * 2. No rights are granted, in any manner or form, to use Whistle
15  *    Communications, Inc. trademarks, including the mark "WHISTLE
16  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
17  *    such appears in the above copyright notice or in the software.
18  *
19  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
20  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
21  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
22  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
23  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
24  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
25  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
26  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
27  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
28  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
29  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
30  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
31  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
35  * OF SUCH DAMAGE.
36  *
37  * Author: Archie Cobbs <archie@whistle.com>
38  *
39  * $FreeBSD$
40  * $Whistle: msg.c,v 1.9 1999/01/20 00:57:23 archie Exp $
41  */
42 
43 #include <sys/types.h>
44 #include <stdarg.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 */
52 static int	gMsgId;
53 
54 /* For delivering both messages and replies */
55 static 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  */
63 int
64 NgSendMsg(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 	if (++gMsgId < 0)
74 		gMsgId = 1;
75 	msg.header.token = gMsgId;
76 	msg.header.flags = NGF_ORIG;
77 	msg.header.cmd = cmd;
78 	snprintf(msg.header.cmdstr, NG_CMDSTRLEN + 1, "cmd%d", cmd);
79 
80 	/* Deliver message */
81 	if (NgDeliverMsg(cs, path, &msg, args, arglen) < 0)
82 		return (-1);
83 	return (gMsgId);
84 }
85 
86 /*
87  * Send a message given in ASCII format. We first ask the node to translate
88  * the command into binary, and then we send the binary.
89  */
90 int
91 NgSendAsciiMsg(int cs, const char *path, const char *fmt, ...)
92 {
93 	const int bufSize = 1024;
94 	char replybuf[2 * sizeof(struct ng_mesg) + bufSize];
95 	struct ng_mesg *const reply = (struct ng_mesg *)replybuf;
96 	struct ng_mesg *const binary = (struct ng_mesg *)reply->data;
97 	struct ng_mesg *ascii;
98 	char *buf, *cmd, *args;
99 	va_list fmtargs;
100 
101 	/* Parse out command and arguments */
102 	va_start(fmtargs, fmt);
103 	vasprintf(&buf, fmt, fmtargs);
104 	va_end(fmtargs);
105 	if (buf == NULL)
106 		return (-1);
107 
108 	/* Parse out command, arguments */
109 	for (cmd = buf; isspace(*cmd); cmd++)
110 		;
111 	for (args = cmd; *args != '\0' && !isspace(*args); args++)
112 		;
113 	if (*args != '\0') {
114 		while (isspace(*args))
115 			*args++ = '\0';
116 	}
117 
118 	/* Get a bigger buffer to hold inner message header plus arg string */
119 	if ((ascii = malloc(sizeof(struct ng_mesg)
120 	    + strlen(args) + 1)) == NULL) {
121 		free(buf);
122 		return (-1);
123 	}
124 	memset(ascii, 0, sizeof(*ascii));
125 
126 	/* Build inner header (only need cmdstr, arglen, and data fields) */
127 	strncpy(ascii->header.cmdstr, cmd, 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 		return (-1);
136 
137 	/* Get reply */
138 	if (NgRecvMsg(cs, reply, sizeof(replybuf), NULL) < 0)
139 		return (-1);
140 
141 	/* Now send binary version */
142 	if (++gMsgId < 0)
143 		gMsgId = 1;
144 	binary->header.token = gMsgId;
145 	if (NgDeliverMsg(cs,
146 	    path, binary, binary->data, binary->header.arglen) < 0)
147 		return (-1);
148 	return (gMsgId);
149 }
150 
151 /*
152  * Send a message that is a reply to a previously received message.
153  * Returns -1 and sets errno on error, otherwise returns zero.
154  */
155 int
156 NgSendReplyMsg(int cs, const char *path,
157 	const struct ng_mesg *msg, const void *args, size_t arglen)
158 {
159 	struct ng_mesg rep;
160 
161 	/* Prepare message header */
162 	rep = *msg;
163 	rep.header.flags = NGF_RESP;
164 
165 	/* Deliver message */
166 	return (NgDeliverMsg(cs, path, &rep, args, arglen));
167 }
168 
169 /*
170  * Send a message to a node using control socket node "cs".
171  * Returns -1 if error and sets errno appropriately, otherwise zero.
172  */
173 static int
174 NgDeliverMsg(int cs, const char *path,
175 	const struct ng_mesg *hdr, const void *args, size_t arglen)
176 {
177 	u_char sgbuf[NG_PATHLEN + 3];
178 	struct sockaddr_ng *const sg = (struct sockaddr_ng *) sgbuf;
179 	u_char *buf = NULL;
180 	struct ng_mesg *msg;
181 	int errnosv = 0;
182 	int rtn = 0;
183 
184 	/* Sanity check */
185 	if (args == NULL)
186 		arglen = 0;
187 
188 	/* Get buffer */
189 	if ((buf = malloc(sizeof(*msg) + arglen)) == NULL) {
190 		errnosv = errno;
191 		if (_gNgDebugLevel >= 1)
192 			NGLOG("malloc");
193 		rtn = -1;
194 		goto done;
195 	}
196 	msg = (struct ng_mesg *) buf;
197 
198 	/* Finalize message */
199 	*msg = *hdr;
200 	msg->header.arglen = arglen;
201 	memcpy(msg->data, args, arglen);
202 
203 	/* Prepare socket address */
204 	sg->sg_family = AF_NETGRAPH;
205 	snprintf(sg->sg_data, NG_PATHLEN + 1, "%s", path);
206 	sg->sg_len = strlen(sg->sg_data) + 3;
207 
208 	/* Debugging */
209 	if (_gNgDebugLevel >= 2) {
210 		NGLOGX("SENDING %s:",
211 		    (msg->header.flags & NGF_RESP) ? "RESPONSE" : "MESSAGE");
212 		_NgDebugSockaddr(sg);
213 		_NgDebugMsg(msg, sg->sg_data);
214 	}
215 
216 	/* Send it */
217 	if (sendto(cs, msg, sizeof(*msg) + arglen,
218 		   0, (struct sockaddr *) sg, sg->sg_len) < 0) {
219 		errnosv = errno;
220 		if (_gNgDebugLevel >= 1)
221 			NGLOG("sendto(%s)", sg->sg_data);
222 		rtn = -1;
223 		goto done;
224 	}
225 
226 done:
227 	/* Done */
228 	free(buf);		/* OK if buf is NULL */
229 	errno = errnosv;
230 	return (rtn);
231 }
232 
233 /*
234  * Receive a control message.
235  *
236  * On error, this returns -1 and sets errno.
237  * Otherwise, it returns the length of the received reply.
238  */
239 int
240 NgRecvMsg(int cs, struct ng_mesg *rep, size_t replen, char *path)
241 {
242 	u_char sgbuf[NG_PATHLEN + sizeof(struct sockaddr_ng)];
243 	struct sockaddr_ng *const sg = (struct sockaddr_ng *) sgbuf;
244 	int len, sglen = sizeof(sgbuf);
245 	int errnosv;
246 
247 	/* Read reply */
248 	len = recvfrom(cs, rep, replen, 0, (struct sockaddr *) sg, &sglen);
249 	if (len < 0) {
250 		errnosv = errno;
251 		if (_gNgDebugLevel >= 1)
252 			NGLOG("recvfrom");
253 		goto errout;
254 	}
255 	if (path != NULL)
256 		snprintf(path, NG_PATHLEN + 1, "%s", sg->sg_data);
257 
258 	/* Debugging */
259 	if (_gNgDebugLevel >= 2) {
260 		NGLOGX("RECEIVED %s:",
261 		    (rep->header.flags & NGF_RESP) ? "RESPONSE" : "MESSAGE");
262 		_NgDebugSockaddr(sg);
263 		_NgDebugMsg(rep, sg->sg_data);
264 	}
265 
266 	/* Done */
267 	return (len);
268 
269 errout:
270 	errno = errnosv;
271 	return (-1);
272 }
273 
274 /*
275  * Receive a control message and convert the arguments to ASCII
276  */
277 int
278 NgRecvAsciiMsg(int cs, struct ng_mesg *reply, size_t replen, char *path)
279 {
280 	struct ng_mesg *msg, *ascii;
281 	int bufSize, errnosv;
282 	u_char *buf;
283 
284 	/* Allocate buffer */
285 	bufSize = 2 * sizeof(*reply) + replen;
286 	if ((buf = malloc(bufSize)) == NULL)
287 		return (-1);
288 	msg = (struct ng_mesg *)buf;
289 	ascii = (struct ng_mesg *)msg->data;
290 
291 	/* Get binary message */
292 	if (NgRecvMsg(cs, msg, bufSize, path) < 0)
293 		goto fail;
294 	memcpy(reply, msg, sizeof(*msg));
295 
296 	/* Ask originating node to convert the arguments to ASCII */
297 	if (NgSendMsg(cs, path, NGM_GENERIC_COOKIE,
298 	    NGM_BINARY2ASCII, msg, sizeof(*msg) + msg->header.arglen) < 0)
299 		goto fail;
300 	if (NgRecvMsg(cs, msg, bufSize, NULL) < 0)
301 		goto fail;
302 
303 	/* Copy result to client buffer */
304 	if (sizeof(*ascii) + ascii->header.arglen > replen) {
305 		errno = ERANGE;
306 fail:
307 		errnosv = errno;
308 		free(buf);
309 		errno = errnosv;
310 		return (-1);
311 	}
312 	strncpy(reply->data, ascii->data, ascii->header.arglen);
313 
314 	/* Done */
315 	free(buf);
316 	return (0);
317 }
318 
319