示例#1
0
unsigned int shbufsz(enum msgchannels_t chnid)
{
	unsigned int defvalue = 0, result = 0;
	char *v = NULL;

	if (chnid != C_LAST) {
		switch (chnid) {
		  case C_STATUS: v = getenv("MAXMSG_STATUS"); defvalue = 256; break;
		  case C_CLIENT: v = getenv("MAXMSG_CLIENT"); defvalue = 512; break;
		  case C_CLICHG: v = getenv("MAXMSG_CLICHG"); defvalue = shbufsz(C_CLIENT); break;
		  case C_DATA:   v = getenv("MAXMSG_DATA");   defvalue = 256; break;
		  case C_NOTES:  v = getenv("MAXMSG_NOTES");  defvalue = 256; break;
		  case C_STACHG: v = getenv("MAXMSG_STACHG"); defvalue = shbufsz(C_STATUS); break;
		  case C_PAGE:   v = getenv("MAXMSG_PAGE");   defvalue = shbufsz(C_STATUS); break;
		  case C_ENADIS: v = getenv("MAXMSG_ENADIS"); defvalue =  32; break;
		  case C_USER:   v = getenv("MAXMSG_USER");   defvalue = 128; break;
		  default: break;
		}

		if (v) {
			result = atoi(v);
			/* See if it is an old setting in bytes */
			if (result > 32*1024) result = (result / 1024);
		}

		if (result < 32) result = defvalue;
	}
	else {
		enum msgchannels_t i;
		unsigned int isz;

		result = 0;

		for (i=C_STATUS; (i < C_LAST); i++) {
			isz = shbufsz(i);
			if (isz > result) result = isz;
		}
	}

	return result;
}
示例#2
0
unsigned char *get_xymond_message(enum msgchannels_t chnid, char *id, int *seq, struct timespec *timeout)
{
	static unsigned int seqnum = 0;
	static char *idlemsg = NULL;
	static char *buf = NULL;
	static size_t bufsz = 0;
	static size_t maxmsgsize = 0;
	static int ioerror = 0;

	static char *startpos;	/* Where our unused data starts */
	static char *endpos;	/* Where the first message ends */
	static char *fillpos;	/* Where our unused data ends (the \0 byte) */

	int truncated = 0;
	struct timespec cutoff;
	int maymove, needmoredata;
	char *endsrch;		/* Where in the buffer do we start looking for the end-message marker */
	char *result;

	/*
	 * The way this works is to read data from stdin into a
	 * buffer. Each read fetches as much data as possible,
	 * i.e. all that is available up to the amount of 
	 * buffer space we have.
	 *
	 * When the buffer contains a complete message,
	 * we return a pointer to the message.
	 *
	 * Since a read into the buffer can potentially
	 * fetch multiple messages, we need to keep track of
	 * the start/end positions of the next message, and
	 * where in the buffer new data should be read in.
	 * As long as there is a complete message available
	 * in the buffer, we just return that message - only
	 * when there is no complete message do we read data
	 * from stdin.
	 *
	 * A message is normally NOT copied, we just return
	 * a pointer to our input buffer. The only time we 
	 * need to shuffle data around is if the buffer
	 * does not have room left to hold a complete message.
	 */

	if (buf == NULL) {
		/*
		 * Initial setup of the buffers.
		 * We allocate a buffer large enough for the largest message
		 * that can arrive on this channel, and add 4KB extra room.
		 * The EXTRABUFSPACE is to allow the memmove() that will be
		 * needed occasionally some room to work optimally.
		 */
		maxmsgsize = 1024*shbufsz(chnid);
		bufsz = maxmsgsize + EXTRABUFSPACE;
		buf = (char *)malloc(bufsz+1);
		*buf = '\0';
		startpos = fillpos = buf;
		endpos = NULL;

		/* idlemsg is used to return the idle message in case of timeouts. */
		idlemsg = strdup("@@idle\n");

		/* We dont want to block when reading data. */
		fcntl(inputfd, F_SETFL, O_NONBLOCK);
	}

	/*
	 * If the start of the next message doesn't begin with "@" then 
	 * there's something rotten.
	 */
	if (*startpos && (*startpos != '@')) {
		errprintf("Bad data in channel, skipping it\n");
		startpos = strstr(startpos, "\n@@");
		endpos = (startpos ? strstr(startpos, "\n@@\n") : NULL);
		if (startpos && (startpos == endpos)) {
			startpos = endpos + 4;
			endpos = strstr(startpos, "\n@@\n");
		}

		if (!startpos) {
			/* We're lost - flush the buffer and try to recover */
			errprintf("Buffer sync lost, flushing data\n");
			*buf = '\0';
			startpos = fillpos = buf;
			endpos = NULL;
		}

		seqnum = 0; /* After skipping, we dont know what to expect */
	}

startagain:
	if (ioerror) {
		errprintf("get_xymond_message: Returning NULL due to previous i/o error\n");
		return NULL;
	}

	if (timeout) {
		/* Calculate when the read should timeout. */
		getntimer(&cutoff);
		cutoff.tv_sec += timeout->tv_sec;
		cutoff.tv_nsec += timeout->tv_nsec;
		if (cutoff.tv_nsec > 1000000000) {
			cutoff.tv_sec += 1;
			cutoff.tv_nsec -= 1000000000;
		}
	}

	/*
	 * Start looking for the end-of-message marker at the beginning of
	 * the message. The next scans will only look at the new data we've
	 * got when reading data in.
	 */
	endsrch = startpos;

	/*
	 * See if the current available buffer space is enough to hold a full message.
	 * If not, then flag that we may do a memmove() of the buffer data.
	 */
	maymove = ((startpos + maxmsgsize) >= (buf + bufsz));

	/* We only need to read data, if we do not have an end-of-message marker */
	needmoredata = (endpos == NULL);
	while (needmoredata) {
		/* Fill buffer with more data until we get an end-of-message marker */
		struct timespec now;
		struct timeval selecttmo;
		fd_set fdread;
		int res;
		size_t bufleft = bufsz - (fillpos - buf);
		size_t usedbytes = (fillpos - startpos);

		dbgprintf("Want msg %d, startpos %ld, fillpos %ld, endpos %ld, usedbytes=%ld, bufleft=%ld\n",
			  (seqnum+1), (startpos-buf), (fillpos-buf), (endpos ? (endpos-buf) : -1), usedbytes, bufleft);

		if (usedbytes >= maxmsgsize) {
			/* Over-size message. Truncate it. */
			errprintf("Got over-size message, truncating at %d bytes (max: %d)\n", usedbytes, maxmsgsize);
			endpos = startpos + usedbytes - 5;
			memcpy(endpos, "\n@@\n", 4);	/* Simulate end-of-message and flush data */
			needmoredata = 0;
			truncated = 1;
		}

		if (needmoredata) {
			if (maymove && (bufleft < EXTRABUFSPACE)) {
				/* Buffer is almost full - move data to accomodate a large message. */
				dbgprintf("Moving %d bytes to start of buffer\n", usedbytes);
				memmove(buf, startpos, usedbytes);
				startpos = buf;
				fillpos = startpos + usedbytes;
				*fillpos = '\0';
				endsrch = (usedbytes >= 4) ? (fillpos - 4) : startpos;
				maymove = 0;
				bufleft = bufsz - (fillpos - buf);
			}

			if (timeout) {
				/* How long time until the timeout ? */

				getntimer(&now);
				selecttmo.tv_sec = cutoff.tv_sec - now.tv_sec;
				selecttmo.tv_usec = (cutoff.tv_nsec - now.tv_nsec) / 1000;
				if (selecttmo.tv_usec < 0) {
					selecttmo.tv_sec--;
					selecttmo.tv_usec += 1000000;
				}
			}

			FD_ZERO(&fdread);
			FD_SET(inputfd, &fdread);

			res = select(inputfd+1, &fdread, NULL, NULL, (timeout ? &selecttmo : NULL));

			if (res < 0) {
				if (errno == EAGAIN) continue;

				if (errno == EINTR) {
					dbgprintf("get_xymond_message: Interrupted\n");
					*seq = 0;
					return idlemsg;
				}

				/* Some error happened */
				ioerror = 1;
				dbgprintf("get_xymond_message: Returning NULL due to select error %s\n",
						strerror(errno));
				return NULL;
			}
			else if (res == 0) {
				/* 
				 * Timeout - return the "idle" message.
				 * NB: If select() was not passed a timeout parameter, this cannot trigger
				 */
				*seq = 0;
				return idlemsg;
			}
			else if (FD_ISSET(inputfd, &fdread)) {
				res = read(inputfd, fillpos, bufleft);
				if (res < 0) {
					if ((errno == EAGAIN) || (errno == EINTR)) continue;

					ioerror = 1;
					dbgprintf("get_xymond_message: Returning NULL due to read error %s\n",
							strerror(errno));
					return NULL;
				}
				else if (res == 0) {
					/* read() returns 0 --> End-of-file */
					ioerror = 1;
					dbgprintf("get_xymond_message: Returning NULL due to EOF\n");
					return NULL;
				}
				else {
					/* 
					 * Got data - null-terminate it, and update fillpos
					 */
					dbgprintf("Got %d bytes\n", res);

					*(fillpos+res) = '\0';
					fillpos += res;

					/* Did we get an end-of-message marker ? Then we're done. */
					endpos = strstr(endsrch, "\n@@\n");
					needmoredata = (endpos == NULL);

					/*
					 * If not done, update endsrch. We need to look at the
					 * last 3 bytes of input we got - they could be "\n@@" so
					 * all that is missing is the final "\n".
					 */
					if (needmoredata && (res >= 3)) endsrch = fillpos-3;
				}
			}
		}
	}

	/* We have a complete message between startpos and endpos */
	result = startpos;
	*endpos = '\0';
	if (truncated) {
		startpos = fillpos = buf;
		endpos = NULL;
	}
	else {
		startpos = endpos+4; /* +4 because we skip the "\n@@\n" end-marker from the previous message */
		endpos = strstr(startpos, "\n@@\n");	/* To see if we already have a full message loaded */
		/* fillpos stays where it is */
	}

	/* Check that it really is a message, and not just some garbled data */
	if (strncmp(result, "@@", 2) != 0) {
		errprintf("Dropping (more) garbled data\n");
		goto startagain;
	}

	{
		/* 
		 * Get and check the message sequence number.
		 * We dont do this for network based workers, since the
		 * sequence number is globally generated (by xymond)
		 * but a network-based worker may only see some of the
		 * messages (those that are not handled by other network-based
		 * worker modules).
		 */
		char *p = result + strcspn(result, "#/|\n");
		if (*p == '#') {
			*seq = atoi(p+1);

			if (debug) {
				p = strchr(result, '\n'); if (p) *p = '\0';
				dbgprintf("%s: Got message %u %s\n", id, *seq, result);
				if (p) *p = '\n';
			}

			if ((seqnum == 0) || (*seq == (seqnum + 1))) {
				/* First message, or the correct sequence # */
				seqnum = *seq;
			}
			else if (*seq == seqnum) {
				/* Duplicate message - drop it */
				errprintf("%s: Duplicate message %d dropped\n", id, *seq);
				goto startagain;
			}
			else {
				/* Out-of-sequence message. Cant do much except accept it */
				if (!locatorid) errprintf("%s: Got message %u, expected %u\n", id, *seq, seqnum+1);
				seqnum = *seq;
			}

			if (seqnum == 999999) seqnum = 0;
		}
	}

	/* Verify checksum - except for truncated messages, where it won't match since we overwrite bytes with the end-marker */
	if (result && !truncated) {
		static struct digestctx_t *ctx = NULL;
		char *hashstr;

		if (!ctx) {
			ctx = (digestctx_t *) malloc(sizeof(digestctx_t));
			ctx->digestname = strdup("md5");
			ctx->digesttype = D_MD5;
			ctx->mdctx = (void *)malloc(myMD5_Size());
		}

		hashstr = result + strcspn(result, ":#/|\n");

		if (*hashstr == ':') {
			unsigned char md_value[16];
			char md_string[2*16+1];
			int i;
			char *p;

			myMD5_Init(ctx->mdctx);
			myMD5_Update(ctx->mdctx, result, (hashstr - result));
			myMD5_Update(ctx->mdctx, hashstr + 33, strlen(hashstr + 33));
			myMD5_Update(ctx->mdctx, "\n@@\n", 4);	/* Stripped earlier */
			myMD5_Final(md_value, ctx->mdctx);
			for(i = 0, p = md_string; (i < sizeof(md_value)); i++)
				p += sprintf(p, "%02x", md_value[i]);
			*p = '\0';
			if (memcmp(hashstr+1, md_string, 32) != 0) {
				p = strchr(result, '\n'); if (p) *(p+1) = '\0';
				errprintf("get_xymond_message: Invalid checksum, skipping message '%s'\n", result);
				result = NULL;
				goto startagain;
			}
		}
	}

	dbgprintf("startpos %ld, fillpos %ld, endpos %ld\n",
		  (startpos-buf), (fillpos-buf), (endpos ? (endpos-buf) : -1));

	return result;
}
示例#3
0
hobbitd_channel_t *setup_channel(enum msgchannels_t chnid, int role)
{
	key_t key;
	struct stat st;
	struct sembuf s;
	hobbitd_channel_t *newch;
	unsigned int bufsz;
	int flags = ((role == CHAN_MASTER) ? (IPC_CREAT | 0600) : 0);
	char *bbh = xgetenv("BBHOME");

	if ( (bbh == NULL) || (stat(bbh, &st) == -1) ) {
		errprintf("BBHOME not defined, or points to invalid directory - cannot continue.\n");
		return NULL;
	}

	bufsz = 1024*shbufsz(chnid);
	dbgprintf("Setting up %s channel (id=%d)\n", channelnames[chnid], chnid);

	dbgprintf("calling ftok('%s',%d)\n", bbh, chnid);
	key = ftok(bbh, chnid);
	if (key == -1) {
		errprintf("Could not generate shmem key based on %s: %s\n", bbh, strerror(errno));
		return NULL;
	}
	dbgprintf("ftok() returns: 0x%X\n", key);

	newch = (hobbitd_channel_t *)malloc(sizeof(hobbitd_channel_t));
	newch->seq = 0;
	newch->channelid = chnid;
	newch->msgcount = 0;
	newch->shmid = shmget(key, bufsz, flags);
	if (newch->shmid == -1) {
		errprintf("Could not get shm of size %d: %s\n", bufsz, strerror(errno));
		xfree(newch);
		return NULL;
	}
	dbgprintf("shmget() returns: 0x%X\n", newch->shmid);

	newch->channelbuf = (char *) shmat(newch->shmid, NULL, 0);
	if (newch->channelbuf == (char *)-1) {
		errprintf("Could not attach shm %s\n", strerror(errno));
		if (role == CHAN_MASTER) shmctl(newch->shmid, IPC_RMID, NULL);
		xfree(newch);
		return NULL;
	}

	newch->semid = semget(key, 3, flags);
	if (newch->semid == -1) {
		errprintf("Could not get sem: %s\n", strerror(errno));
		shmdt(newch->channelbuf);
		if (role == CHAN_MASTER) shmctl(newch->shmid, IPC_RMID, NULL);
		xfree(newch);
		return NULL;
	}

	if (role == CHAN_CLIENT) {
		/*
		 * Clients must register their presence.
		 * We use SEM_UNDO; so if the client crashes, it wont leave a stale count.
		 */
		s.sem_num = CLIENTCOUNT; s.sem_op = +1; s.sem_flg = SEM_UNDO;
		if (semop(newch->semid, &s, 1) == -1) {
			errprintf("Could not register presence: %s\n", strerror(errno));
			shmdt(newch->channelbuf);
			xfree(newch);
			return NULL;
		}
	}
	else if (role == CHAN_MASTER) {
		int n;

		n = semctl(newch->semid, CLIENTCOUNT, GETVAL);
		if (n > 0) {
			errprintf("FATAL: hobbitd sees clientcount %d, should be 0\nCheck for hanging hobbitd_channel processes or stale semaphores\n", n);
			shmdt(newch->channelbuf);
			shmctl(newch->shmid, IPC_RMID, NULL);
			semctl(newch->semid, 0, IPC_RMID);
			xfree(newch);
			return NULL;
		}
	}

#ifdef MEMORY_DEBUG
	add_to_memlist(newch->channelbuf, bufsz);
#endif
	return newch;
}