text: /*
   * msg.c
   *
   * Copyright (c) 1996-1999 Whistle Communications, Inc.
   * All rights reserved.
   * 
   * Subject to the following obligations and disclaimer of warranty, use and
   * redistribution of this software, in source or object code forms, with or
   * without modifications are expressly permitted by Whistle Communications;
   * provided, however, that:
   * 1. Any and all reproductions of the source or object code must include the
   *    copyright notice above and the following disclaimer of warranties; and
   * 2. No rights are granted, in any manner or form, to use Whistle
   *    Communications, Inc. trademarks, including the mark "WHISTLE
   *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
   *    such appears in the above copyright notice or in the software.
   * 
   * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
   * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
   * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
   * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
   * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
   * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
   * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
   * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
   * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
   * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
   * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
   * OF SUCH DAMAGE.
   *
   * Author: Archie Cobbs <archie@whistle.com>
   *
   * $Whistle: msg.c,v 1.9 1999/01/20 00:57:23 archie Exp $
   */
  
  #include <sys/cdefs.h>
  __FBSDID("$FreeBSD$");
  
  #include <sys/types.h>
  #include <sys/socket.h>
  #include <stdarg.h>
  #include <stdatomic.h>
  #include <netgraph/ng_message.h>
  #include <netgraph/ng_socket.h>
  
  #include "netgraph.h"
  #include "internal.h"
  
  /* Next message token value */
  static _Atomic(unsigned int) gMsgId;
  
  /* For delivering both messages and replies */
  static int	NgDeliverMsg(int cs, const char *path,
  		  const struct ng_mesg *hdr, const void *args, size_t arglen);
  
  /*
   * Send a message to a node using control socket node "cs".
   * Returns -1 if error and sets errno appropriately.
   * If successful, returns the message ID (token) used.
   */
  int
  NgSendMsg(int cs, const char *path,
  	  int cookie, int cmd, const void *args, size_t arglen)
  {
  	struct ng_mesg msg;
  
  	/* Prepare message header */
  	memset(&msg, 0, sizeof(msg));
  	msg.header.version = NG_VERSION;
  	msg.header.typecookie = cookie;
  	msg.header.token = atomic_fetch_add(&gMsgId, 1) & INT_MAX;
  	msg.header.flags = NGF_ORIG;
  	msg.header.cmd = cmd;
  	snprintf((char *)msg.header.cmdstr, NG_CMDSTRSIZ, "cmd%d", cmd);
  
  	/* Deliver message */
  	if (NgDeliverMsg(cs, path, &msg, args, arglen) < 0)
  		return (-1);
  	return (msg.header.token);
  }
  
  /*
   * Send a message given in ASCII format. We first ask the node to translate
   * the command into binary, and then we send the binary.
   */
  int
  NgSendAsciiMsg(int cs, const char *path, const char *fmt, ...)
  {
  	struct ng_mesg *reply, *binary, *ascii;
  	char *buf, *cmd, *args;
  	va_list fmtargs;
  	int token;
  
  	/* Parse out command and arguments */
  	va_start(fmtargs, fmt);
  	vasprintf(&buf, fmt, fmtargs);
  	va_end(fmtargs);
  	if (buf == NULL)
  		return (-1);
  
  	/* Parse out command, arguments */
  	for (cmd = buf; isspace(*cmd); cmd++)
  		;
  	for (args = cmd; *args != '\0' && !isspace(*args); args++)
  		;
  	if (*args != '\0') {
  		while (isspace(*args))
  			*args++ = '\0';
  	}
  
  	/* Get a bigger buffer to hold inner message header plus arg string */
  	if ((ascii = malloc(sizeof(struct ng_mesg)
  	    + strlen(args) + 1)) == NULL) {
  		free(buf);
  		return (-1);
  	}
  	memset(ascii, 0, sizeof(*ascii));
  
  	/* Build inner header (only need cmdstr, arglen, and data fields) */
  	strncpy((char *)ascii->header.cmdstr, cmd,
  	    sizeof(ascii->header.cmdstr) - 1);
  	strcpy(ascii->data, args);
  	ascii->header.arglen = strlen(ascii->data) + 1;
  	free(buf);
  
  	/* Send node a request to convert ASCII to binary */
  	if (NgSendMsg(cs, path, NGM_GENERIC_COOKIE, NGM_ASCII2BINARY,
  	    (u_char *)ascii, sizeof(*ascii) + ascii->header.arglen) < 0) {
  		free(ascii);
  		return (-1);
  	}
  	free(ascii);
  
  	/* Get reply */
  	if (NgAllocRecvMsg(cs, &reply, NULL) < 0)
  		return (-1);
  
  	/* Now send binary version */
  	binary = (struct ng_mesg *)reply->data;
  	binary->header.token = atomic_fetch_add(&gMsgId, 1) & INT_MAX;
  	binary->header.version = NG_VERSION;
  	if (NgDeliverMsg(cs,
  	    path, binary, binary->data, binary->header.arglen) < 0) {
  		free(reply);
  		return (-1);
  	}
  	token = binary->header.token;
  	free(reply);
  	return (token);
  }
  
  /*
   * Send a message that is a reply to a previously received message.
   * Returns -1 and sets errno on error, otherwise returns zero.
   */
  int
  NgSendReplyMsg(int cs, const char *path,
  	const struct ng_mesg *msg, const void *args, size_t arglen)
  {
  	struct ng_mesg rep;
  
  	/* Prepare message header */
  	rep = *msg;
  	rep.header.flags = NGF_RESP;
  
  	/* Deliver message */
  	return (NgDeliverMsg(cs, path, &rep, args, arglen));
  }
  
  /*
   * Send a message to a node using control socket node "cs".
   * Returns -1 if error and sets errno appropriately, otherwise zero.
   */
  static int
  NgDeliverMsg(int cs, const char *path,
  	const struct ng_mesg *hdr, const void *args, size_t arglen)
  {
  	u_char sgbuf[NG_PATHSIZ + NGSA_OVERHEAD];
  	struct sockaddr_ng *const sg = (struct sockaddr_ng *) sgbuf;
  	u_char *buf = NULL;
  	struct ng_mesg *msg;
  	int errnosv = 0;
  	int rtn = 0;
  
  	/* Sanity check */
  	if (args == NULL)
  		arglen = 0;
  
  	/* Get buffer */
  	if ((buf = malloc(sizeof(*msg) + arglen)) == NULL) {
  		errnosv = errno;
  		if (_gNgDebugLevel >= 1)
  			NGLOG("malloc");
  		rtn = -1;
  		goto done;
  	}
  	msg = (struct ng_mesg *) buf;
  
  	/* Finalize message */
  	*msg = *hdr;
  	msg->header.arglen = arglen;
  	memcpy(msg->data, args, arglen);
  
  	/* Prepare socket address */
  	sg->sg_family = AF_NETGRAPH;
  	/* XXX handle overflow */
  	strlcpy(sg->sg_data, path, NG_PATHSIZ);
  	sg->sg_len = strlen(sg->sg_data) + 1 + NGSA_OVERHEAD;
  
  	/* Debugging */
  	if (_gNgDebugLevel >= 2) {
  		NGLOGX("SENDING %s:",
  		    (msg->header.flags & NGF_RESP) ? "RESPONSE" : "MESSAGE");
  		_NgDebugSockaddr(sg);
  		_NgDebugMsg(msg, sg->sg_data);
  	}
  
  	/* Send it */
  	if (sendto(cs, msg, sizeof(*msg) + arglen,
  		   0, (struct sockaddr *) sg, sg->sg_len) < 0) {
  		errnosv = errno;
  		if (_gNgDebugLevel >= 1)
  			NGLOG("sendto(%s)", sg->sg_data);
  		rtn = -1;
  		goto done;
  	}
  
  	/* Wait for reply if there should be one. */
  	if (msg->header.cmd & NGM_HASREPLY && !(msg->header.flags & NGF_RESP)) {
  		struct pollfd rfds;
  		int n;
  
  		rfds.fd = cs;
  		rfds.events = POLLIN;
  		rfds.revents = 0;
  		n = poll(&rfds, 1, INFTIM);
  		if (n == -1) {
  			errnosv = errno;
  			if (_gNgDebugLevel >= 1)
  				NGLOG("poll");
  			rtn = -1;
  		}
  	}
  
  done:
  	/* Done */
  	free(buf);		/* OK if buf is NULL */
  	errno = errnosv;
  	return (rtn);
  }
  
  /*
   * Receive a control message.
   *
   * On error, this returns -1 and sets errno.
   * Otherwise, it returns the length of the received reply.
   */
  int
  NgRecvMsg(int cs, struct ng_mesg *rep, size_t replen, char *path)
  {
  	u_char sgbuf[NG_PATHSIZ + NGSA_OVERHEAD];
  	struct sockaddr_ng *const sg = (struct sockaddr_ng *) sgbuf;
  	socklen_t sglen = sizeof(sgbuf);
  	int len, errnosv;
  
  	/* Read reply */
  	len = recvfrom(cs, rep, replen, 0, (struct sockaddr *) sg, &sglen);
  	if (len < 0) {
  		errnosv = errno;
  		if (_gNgDebugLevel >= 1)
  			NGLOG("recvfrom");
  		goto errout;
  	}
  	if (path != NULL)
  		strlcpy(path, sg->sg_data, NG_PATHSIZ);
  
  	/* Debugging */
  	if (_gNgDebugLevel >= 2) {
  		NGLOGX("RECEIVED %s:",
  		    (rep->header.flags & NGF_RESP) ? "RESPONSE" : "MESSAGE");
  		_NgDebugSockaddr(sg);
  		_NgDebugMsg(rep, sg->sg_data);
  	}
  
  	/* Done */
  	return (len);
  
  errout:
  	errno = errnosv;
  	return (-1);
  }
  
  /*
   * Identical to NgRecvMsg() except buffer is dynamically allocated.
   */
  int
  NgAllocRecvMsg(int cs, struct ng_mesg **rep, char *path)
  {
  	int len;
  	socklen_t optlen;
  
  	optlen = sizeof(len);
  	if (getsockopt(cs, SOL_SOCKET, SO_RCVBUF, &len, &optlen) == -1 ||
  	    (*rep = malloc(len)) == NULL)
  		return (-1);
  	if ((len = NgRecvMsg(cs, *rep, len, path)) < 0)
  		free(*rep);
  	return (len);
  }
  
  /*
   * Receive a control message and convert the arguments to ASCII
   */
  int
  NgRecvAsciiMsg(int cs, struct ng_mesg *reply, size_t replen, char *path)
  {
  	struct ng_mesg *msg, *ascii;
  	int bufSize, errnosv;
  	u_char *buf;
  
  	/* Allocate buffer */
  	bufSize = 2 * sizeof(*reply) + replen;
  	if ((buf = malloc(bufSize)) == NULL)
  		return (-1);
  	msg = (struct ng_mesg *)buf;
  	ascii = (struct ng_mesg *)msg->data;
  
  	/* Get binary message */
  	if (NgRecvMsg(cs, msg, bufSize, path) < 0)
  		goto fail;
  	memcpy(reply, msg, sizeof(*msg));
  
  	/* Ask originating node to convert the arguments to ASCII */
  	if (NgSendMsg(cs, path, NGM_GENERIC_COOKIE,
  	    NGM_BINARY2ASCII, msg, sizeof(*msg) + msg->header.arglen) < 0)
  		goto fail;
  	if (NgRecvMsg(cs, msg, bufSize, NULL) < 0)
  		goto fail;
  
  	/* Copy result to client buffer */
  	if (sizeof(*ascii) + ascii->header.arglen > replen) {
  		errno = ERANGE;
  fail:
  		errnosv = errno;
  		free(buf);
  		errno = errnosv;
  		return (-1);
  	}
  	strncpy(reply->data, ascii->data, ascii->header.arglen);
  
  	/* Done */
  	free(buf);
  	return (0);
  }
  
  /*
   * Identical to NgRecvAsciiMsg() except buffer is dynamically allocated.
   */
  int
  NgAllocRecvAsciiMsg(int cs, struct ng_mesg **reply, char *path)
  {
  	int len;
  	socklen_t optlen;
  
  	optlen = sizeof(len);
  	if (getsockopt(cs, SOL_SOCKET, SO_RCVBUF, &len, &optlen) == -1 ||
  	    (*reply = malloc(len)) == NULL)
  		return (-1);
  	if ((len = NgRecvAsciiMsg(cs, *reply, len, path)) < 0)
  		free(*reply);
  	return (len);
  }
  